The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickne...The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickness, a new photoelectric control and analysis system has been developed. In the new system, main techniques include a photoelectric system with dual-light path, a dual-lock-phase circuit system and a comprehensive digital processing-control-analysis system.The test results of new system show that the static and dynamic stabilities and the control precision of thin-film thickness are extremely increased. The standard deviation of thin-film thickness, which indicates the duplication of thin-film thickness monitoring, is equal to or less than 0.72%. The display resolution limit on reflectivity is 0.02 %. In the system, the linearity of drift is very high, and the static drift ratio approaches zero.展开更多
Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thi...Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.展开更多
In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method...In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies.展开更多
Neutron-skin thickness is a key parameter for a neutron-rich nucleus;however,it is difficult to determine.In the framework of the Lanzhou Quantum Molecular Dynamics(LQMD)model,a possible probe for the neutron-skin thi...Neutron-skin thickness is a key parameter for a neutron-rich nucleus;however,it is difficult to determine.In the framework of the Lanzhou Quantum Molecular Dynamics(LQMD)model,a possible probe for the neutron-skin thickness(δ_(np))of neutron-rich ^(48)Ca was studied in the 140A MeV ^(48)Ca+^(9)Be projectile fragmentation reaction based on the parallel momentum distribution(p∥)of the residual fragments.A Fermi-type density distribution was employed to initiate the neutron density distributions in the LQMD simulations.A combined Gaussian function with different width parameters for the left side(Γ_(L))and the right side(Γ_(R))in the distribution was used to describe the p∥of the residual fragments.Taking neutron-rich sulfur isotopes as examples,Γ_(L) shows a sensitive correlation withδ_(np) of ^(48)Ca,and is proposed as a probe for determining the neutron skin thickness of the projectile nucleus.展开更多
The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(ever...The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(every third isotopes)+112 Sn for full reduced impact parameters using the isospin-dependent quantum molecular dynamics(IQMD)model.The neutron and proton density distributions and root-mean-square radii of the reaction systems were obtained using the Skyrme-Hartree-Fock model,which was used for the phase space initialization of the projectile and target in IQMD.We defined the unified neutron skin thickness asΔRnp=<r^(2)>^(1∕2) n−<r^(2)>^(1∕2)p,which was negative for neutron-deficient nuclei.The unifiedΔRnp values for nuclei with the same relative neutron excess from different isotopic chains were nearly equal,except for extreme neutron-rich isotopes,which is a type of scaling behavior.The yield ratios of the three isotopic chain-induced reactions,which depended on the reduced impact parameter and unified neutron skin thickness,were studied.The results showed that both R(n/p)and R(^(3)H∕^(3)He)decreased with a reduced impact parameter for extreme neutron-deficient isotopes;however,they increased with reduced impact parameters for extreme neutron-rich isotopes,and increased with theΔRnp of the projectiles for all reduced impact parameters.In addition,a scaling phenomenon was observed betweenΔR np and the yield ratios in peripheral colli-sions from different isotopic chain projectiles(except for extreme neutron-rich isotopes).Thus,R(n/p)and R(^(3)H∕^(3)He)from peripheral collisions were suggested as experimental probes for extracting the neutron or proton skin thicknesses of non-extreme neutron-rich nuclei from different isotopic chains.展开更多
Precise knowledge of the nuclear symmetry energy can be tentatively calibrated using multimessenger constraints.The neutron skin thickness of a heavy nucleus is one of the most sensitive indicators for probing the iso...Precise knowledge of the nuclear symmetry energy can be tentatively calibrated using multimessenger constraints.The neutron skin thickness of a heavy nucleus is one of the most sensitive indicators for probing the isovector components of effective interactions in asymmetric nuclear matter.Recent studies have suggested that the experimental data from the CREX and PREX2 collaborations are not mutually compatible with existing nuclear models.In this study,we review the quantification of the slope parameter of the symmetry energy L from the neutron skin thicknesses of^(48)Ca and^(208)Pb.Skyrme energy density functionals classified by various isoscalar incompressibility coefficients K were employed to evaluate the bulk properties of finite nuclei.The calculated results suggest that the slope parameter L deduced from^(208)Pb is sensitive to the compression modulus of symmetric nuclear matter,but not that from^(48)Ca.The effective parameter sets classified by K=220 MeV can provide an almost overlapping range of L from^(48)Ca and^(208)Pb.展开更多
We derive an effective Hamiltonian for a spin-1/2 particle confined within a curved thin layer with non-uniform thickness using the confining potential approach.Our analysis reveals the presence of a pseudo-magnetic f...We derive an effective Hamiltonian for a spin-1/2 particle confined within a curved thin layer with non-uniform thickness using the confining potential approach.Our analysis reveals the presence of a pseudo-magnetic field and effective spin–orbit interaction(SOI)arising from the curvature,as well as an effective scalar potential resulting from variations in thickness.Importantly,we demonstrate that the physical effect of additional SOI from thickness fluctuations vanishes in low-dimensional systems,thus guaranteeing the robustness of spin interference measurements to thickness imperfection.Furthermore,we establish the applicability of the effective Hamiltonian in both symmetric and asymmetric confinement scenarios,which is crucial for its utilization in one-side etching systems.展开更多
At the first time,the finite element method was used to model and analyze the free vibration and transient response of non-uniform thickness bi-directional functionally graded sandwich porous(BFGSP)skew plates.The who...At the first time,the finite element method was used to model and analyze the free vibration and transient response of non-uniform thickness bi-directional functionally graded sandwich porous(BFGSP)skew plates.The whole BFGSP skew-plates is placed on a variable visco-elastic foundation(VEF)in the hygro-thermal environment and subjected to the blast load.The BFGSP skew-plate thickness is permitted to vary non-linearly over both the length and width of the skew-plate,thereby faithfully representing the real behavior of the structure itself.The analysis is based on a four-node planar quadrilateral element with eight degrees of freedom per node,which is approximated using Lagrange Q_(4)shape function and C^(1)level non-conforming Hermite shape function based on refined higher-order shear deformation plate theory.The forced vibration parameters of the non-uniform thickness BFGSP skew-plate are fully determined using Hamilton's principle and the Newmark-βdirect integration technique.Accuracy of the calculation program is validated by comparing its numerical results with those from reputable sources.Furthermore,a thorough assessment is conducted to determine the impact of various parameters on the free and forced vibration responses of the non-uniform thickness BFGSP skew-plate.The findings of the paper may be used in the development of civil and military structures in situations that are prone to exceptional forces,such as explosions and impacts load.展开更多
This work introduces a novel method for measuring thin film thickness,employing a multi-wavelength method that significantly reduces the need for broad-spectrum data.Unlike traditional techniques that require sev⁃eral...This work introduces a novel method for measuring thin film thickness,employing a multi-wavelength method that significantly reduces the need for broad-spectrum data.Unlike traditional techniques that require sev⁃eral hundred spectral data points,the multi-wavelength method achieves precise thickness measurements with data from only 10 wavelengths.This innovation not only simplifies the process of spectral measurement analysis but also enables accurate real-time thickness measurement on industrial coating production lines.The method effectively reconstructs and fits the visible spectrum(400-800 nm)using a minimal amount of data,while maintaining measurement error within 7.1%.This advancement lays the foundation for more practical and efficient thin film thickness determination techniques in various industrial applications.展开更多
Due to the overlapping of echoes from the inner and outer walls of thin⁃walled tubes,thickness measurement based on ultrasonic time⁃of⁃flight method is difficult to apply.Therefore,the ultrasonic resonance method has ...Due to the overlapping of echoes from the inner and outer walls of thin⁃walled tubes,thickness measurement based on ultrasonic time⁃of⁃flight method is difficult to apply.Therefore,the ultrasonic resonance method has become an effective mean of measuring thin⁃walled tube thickness.The resonance method often demands a perpendicular incidence of ultrasound,but having the ultrasonic probe strictly perpendicular to the measured surface is challenging for installation reasons.The ultrasonic resonance model by considering ultrasonic inclination angles is derived.The model explains that an inclination angle theoretically does not affect the calculation results of measuring thin thickness.However,increasing the inclination angle reduces the reflection coefficient,resulting in a shorter length of the effective reflected wave,thus reducing the calculation accuracy.Additionally,the research evaluated the ultrasonic echo from the tubes of different diameters and found that if ultrasound transmits with an inclined incidence,smaller diameter tubes result in lower normal reflection coefficients,leading to poorer measurement accuracy.The research simulated and tested the tilted⁃incidence resonant method based on the subject of water⁃steel⁃air,and the results prove the correctness of the model.展开更多
Highly oriented（00l）（La_（0.26）Bi_（0.74））_2Ti_4O_（11 ）thin films are deposited on（100） SrTiO_（3 ）substrates using the pulsed laser deposition technique.The grains form a texture of bar-like arrays along S...Highly oriented（00l）（La_（0.26）Bi_（0.74））_2Ti_4O_（11 ）thin films are deposited on（100） SrTiO_（3 ）substrates using the pulsed laser deposition technique.The grains form a texture of bar-like arrays along Sr Ti O_3110directions for the film thickness above 350 nm,in contrast to spherical grains for the reduced film thickness below 220 nm.X-ray diffraction patterns show that the highly ordered bar-like grains are the ensemble of two lattice-matched monoclinic（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components above a critical film thickness.Otherwise,the phase decomposes into the random mixture of Bi_2Ti_2O_（7 ）and Bi_4Ti_3O_（4 ）spherical grains in thinner films.The critical thickness can increase up to 440 nm as the films are deposited on LaNiO_3-buffered SrTiO_（3 ）substrates.The electrical measurements show the dielectric enhancement of the multi-components,and comprehensive charge injection into interfacial traps between（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components occurs under the application of a threshold voltage for the realization of high-charge storage.展开更多
Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lit...Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.展开更多
The practical application of lithium–sulfur(Li–S)batteries is limited by the easy dissolution of polysulfides in the electrolyte,resulting in the lithium polysulfide(LPS)shuttle effect.Several two-dimensional(2D)mat...The practical application of lithium–sulfur(Li–S)batteries is limited by the easy dissolution of polysulfides in the electrolyte,resulting in the lithium polysulfide(LPS)shuttle effect.Several two-dimensional(2D)materials with abundant active binding sites and high surface-to-volume ratios have been developed to prepare functional separators that suppress the diffusion of polysulfides.However,the influence of modified layer thickness on Li+transport has not been considered.Herein,we synthesized individual and multilayered 2D Ti3C2Tx MXene nanosheets and used them to fabricate a series of Ti3C2Tx-PP modified separators.The separators had mass loadings ranging from 0.16 to 0.016 mg cm-2,which is the lowest value reported for 2D materials to the best of our knowledge.The corresponding reductions in thickness ranged from 1.2μm to 100 nm.LPS shuttling was effectively suppressed,even at the lowest mass loading of 0.016 mg cm-2.Suppression was due to the strong interaction between LPS intermediates and Ti atoms and hydroxyl functional groups on the separator surface.The lithium-ion diffusion coefficient increased with the reduction of Ti3C2Tx layers on the separator.Superior cycling stability and rate performance were attained when the separator with a Ti3C2Tx-PP mass loading of 0.016 mg cm-2 was incorporated into a Li–S battery.Carbon nanotubes(CNTs)were introduced into the separators to further improve the electrical and Li+ionic conductivity in the cross-plane direction of the 2D Ti3C2Txlayers.With the ultralightweight Ti3C2Tx/CNTs modified PP separator,the cell maintained a capacity of 640 m Ah g-1after 200cycles at 1C with a capacity decay of only 0.079%per cycle.展开更多
Background Previous studies reported a close relationship between obesity and insulin resistance in the essential hypertensive patients. Objective In this study, we examined the relationship between the skin fold thic...Background Previous studies reported a close relationship between obesity and insulin resistance in the essential hypertensive patients. Objective In this study, we examined the relationship between the skin fold thickness and insulin resistance then developed a formula to estimate the insulin resistance index according to the skin fold thickness in the essential hypertensive patients. Subjects and Methods Medical records of 80 patients (37 males, 43 females) were reviewed and the data were tabulated. Anthropometric indexes (including height, weight, waist circumference, hip circumference, and skins fold thickness at 5 fatty difference points on the Erdheim diagram), fasting plasma glucose and insulin concentration were recorded. The mean age was 57.0 ?9.2 years. The insulin resistance index was calculated following the Homeostasis Model Assessment (HOMA) formula. Results Compared with the group with BMI < 23 kg/m2, the group with BMI≥23 kg/m2 had higher fasting insulin concentration (8.85±4.97 pmol/L vs 15.60±8.70 pmol/L, P<0.001 ) and higher insulin resistance index in ( 2.15±1,24 vs 3.76±2.22, P<0.001). No significant difference in fasting plasma insulin concentration, insulin resistance index between male and female was observed (P > 0.05). There was a positive correlation between skin fold thickness and the fasting insulin concentration and insulin resistance index. The skin fold thickness at point A8 had the best coefficient correlated with fasting plasma insulin(r=0.79, P < 0.001) and insulin resistance index (r= 0.79, P < 0.001). A formula to estimate the insulin resistance index by skin fold thickness at point A8 as: Insulin resistance index = 0.12×[skin fold thickness at A8 point (mm)] - 1. Conclusion: In the essential hypertensive patients, the formula to estimate insulin resistance index as 0.12×[skin fold thickness at A8 point (mm)]-1 may predict accurately the level of insulin resistance. (J Geriatr Cardiol 2005; 2(4):228-232 )展开更多
Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored ...Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.展开更多
Backgroud and Objectives Previous studies have reported that skin fold thickness (SF) strongly correlated with insulin resistance in the metabolic syndrome (MetS). In this study, we developed a MetS definition by SF a...Backgroud and Objectives Previous studies have reported that skin fold thickness (SF) strongly correlated with insulin resistance in the metabolic syndrome (MetS). In this study, we developed a MetS definition by SF at A8 point (SFA8) on Erdheim diagram(MetSSFA8) in essential hypertensive patients. Subjects and Methods Medical records of 268 essential hypertensive patients (126males and 122 females) were analyzed, including 210 non-diabetic patients (NDM group) and 58 patients with diabetes (DM group).The mean age was 61.4 ± 9.9 and 59.0 ± 11.0 years, respectively. The control group consisted of 90 non-diabetic, non-hypertensive patients with a mean age of 58.0 ± 11.3 years. The proposed MetSSFA8 definition included SFA8 specific values ( ≥30 mm in female and ≥27 mm in male) and at least two of the following: raised triglyceride levels ( ≥1.7 mmol/L), or specific treatment for this lipid abnormality; raised blood pressure (SBP≥130 mmHg and/or DBP≥85 mmHg), or treatment of previously diagnosed hypertension;reduced HDL-cholesterol (＜ 1.03 mmol/L in men, ＜1.29 mmol/L in women), or specific treatment for this lipid abnormality; raised fasting plasma glucose (≥5.6 mmol/l), or previously diagnosed DM. Metabolic Syndrome by the National Cholesterol Education Program and International Diabetes Federation definitions were determined with abdominal obesity defined by Asia-Pacific criteria for waist circumference (NCEPA and IDFA). Results The percentage of MetS as defined by NCEPA, IDFA and MetSSFA8 in NDM group was lower than that of NCEPA, IDFA and MetSSFA8 in DM group [OR=7.7 (95%CI, 2.9-20.2) and 2.5 (95%CI, 1.4-4.8) and 2.7(95%CI, 1.3-5.6), respectively] and higher than that of the control group [OR=53.3 (95%CI, 16.7-170.6), 5.8 (95%CI, 2.6-13.2) and18.8 (95%CI, 7.3-48.7), respectively]. The percentage of MetS by NCEPA, IDFA and MetSSFA8 in males in NDM group was lower than the percentage of MetS by NCEPA, IDFA and MetSSFA8 in females in NDM group (50.8% and 77.9%, P＜ 0.001; 15,9% and 67.2%, P＜ 0.001; 60.3% and 73.8%, P ＜0.05, respectively). In subjects with normal WC or both normal WC and BMI, the percentage of MetS by SFAS was higher than that the percentage of MetS by NCEPA (36.9% and 50.8%, P＜ 0.05 and 36.0% and 51.0%, P＜ 0.05).The sensitivity, specificity, false positive rate, positive predictive value, negative predictive value of MetSSFA8 assessed with NCEPA definitions were 0.87, 0.73, 0.27, 0.79 and 0.82, respectively. There was a close agreement between MetSSFA8 and NCEPA (The coefficient of Kapa was 0.60, P＜ 0.001). Conclusions The MetSSFA8 definition was developed which may be useful in order to define and manage MetS in patients with normal WC or normal weight.展开更多
Based on the newest experimentally extracted nuclear density distributions for double-magic nucleus208Pb(Tarbert et al. in Phys Rev Lett 112:242502, 2014),the sensitivity of α-decay half-life to nuclear skin thicknes...Based on the newest experimentally extracted nuclear density distributions for double-magic nucleus208Pb(Tarbert et al. in Phys Rev Lett 112:242502, 2014),the sensitivity of α-decay half-life to nuclear skin thickness is explored in the vicinity of the shell closure region around208 Pb, i.e., isotopes of Z ? 82 and isotones of N ? 126.With the two-parameter Fermi(2PF) density distributions and an analytically derived formula, the α-decay half-life is found to be closely related to the magnitude of nuclear skin thickness. For a decays to the Z ? 82 isotopes, the α-decay half-life is found to decrease with the increasing neutron skin thickness, while the opposite behavior is found for a decays to the N ? 126 isotones. Therefore, it could be a possible way to extract the nuclear skin thickness from measured α-decay half-lives.展开更多
Thin oxidized copper films in various thickness values are deposited onto quartz glass substrates by electron beam evaporation. The ellipsometry parameters and transmittance in a wavelength range of 300 nm-1000 nm are...Thin oxidized copper films in various thickness values are deposited onto quartz glass substrates by electron beam evaporation. The ellipsometry parameters and transmittance in a wavelength range of 300 nm-1000 nm are collected by a spectroscopic ellipsometer and a spectrophotometer respectively. The effective thickness and optical constants, i.e., refractive index n and extinction coefficient k, are accurately determined by using newly developed ellipsometry combined with transmittance iteration method. It is found that the effective thickness determined by this method is close to the physical thickness and has obvious difference from the mass thickness for very thin film due to variable density of film. Furthermore, the thickness dependence of optical constants of thin oxidized Cu films is analyzed.展开更多
The dependence between neutron skin thickness and neutron abrasion cross section （σnabr） for neutron-rich nuclei is investigated within the framework of the statistical abrasion ablation model. Assuming that the de...The dependence between neutron skin thickness and neutron abrasion cross section （σnabr） for neutron-rich nuclei is investigated within the framework of the statistical abrasion ablation model. Assuming that the density distributions for proton and neutron are of Fermi-type, and adjusting the diffuseness parameter of neutron density distribution in the droplet model, we find out the good linear correlation between the neutron skin thickness and the abrasion cross section σnabr for neutron-rich nuclei. The uncertainty of neutron skin thickness determined from σnabr is very small. It is suggested that σnabr can be used as a new experimental observable to extract the neutron skin thickness for neutronrich nucleus. The scaling behaviours between neutron skin thickness and σnabr, separately, for isotopes of ^26-35Na, ^44-56Ar, ^48-60Ca, ^67-78Ni are also investigated.展开更多
Sapwood density and bark thickness of Calophyllum inophyllum L. （a multipurpose durable timber species） were studied in various locations in Northern Australia and in Sri Lanka. Measurements were taken non-destructi...Sapwood density and bark thickness of Calophyllum inophyllum L. （a multipurpose durable timber species） were studied in various locations in Northern Australia and in Sri Lanka. Measurements were taken non-destructively by using core sampling and bark gauge. From each provenance, 4–15 mature trees having girth at breast height over bark （GBHOB） at 100–150 cm were selected on the basis of the population size. Significant （p0.05） hemispheric and provenance variations in bark thickness were found. Variations in the bark thickness are influenced by environmental variables. Variations in sapwood density were less pronounced compared to that of bark thickness. Variations in sapwood density are likely to be governed by genotypic variations.展开更多
基金Sponsored by the Ordnance Industry Scientific Research Fund(ZZ9682-3).
文摘The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickness, a new photoelectric control and analysis system has been developed. In the new system, main techniques include a photoelectric system with dual-light path, a dual-lock-phase circuit system and a comprehensive digital processing-control-analysis system.The test results of new system show that the static and dynamic stabilities and the control precision of thin-film thickness are extremely increased. The standard deviation of thin-film thickness, which indicates the duplication of thin-film thickness monitoring, is equal to or less than 0.72%. The display resolution limit on reflectivity is 0.02 %. In the system, the linearity of drift is very high, and the static drift ratio approaches zero.
基金Project supported by the Natural Science Foundation of Jilin Province of China(Grant Nos.20240402081GH and 20220101012JC)the National Natural Science Foundation of China(Grant No.42074139)the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant No.SKLA202308)。
文摘Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT)(No. 2021R1I1A1A0105621313, No. 2022R1F1A1074441, No. 2022K1A3A1A20014496, and No. 2022R1F1A1074083)supported by the Ministry of Education Funding (No. RIS 2021-004)supported by the Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea (RS-2023-00284318).
文摘In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies.
基金the National Natural Science Foundation of China(Nos.12375123,11975091,and 12305130)the Natural Science Foundation of Henan Province(No.242300421048)+1 种基金China Postdoctoral Science Foundation(No.2023M731016)Henan Postdoctoral Foundation(No.HN2022164).
文摘Neutron-skin thickness is a key parameter for a neutron-rich nucleus;however,it is difficult to determine.In the framework of the Lanzhou Quantum Molecular Dynamics(LQMD)model,a possible probe for the neutron-skin thickness(δ_(np))of neutron-rich ^(48)Ca was studied in the 140A MeV ^(48)Ca+^(9)Be projectile fragmentation reaction based on the parallel momentum distribution(p∥)of the residual fragments.A Fermi-type density distribution was employed to initiate the neutron density distributions in the LQMD simulations.A combined Gaussian function with different width parameters for the left side(Γ_(L))and the right side(Γ_(R))in the distribution was used to describe the p∥of the residual fragments.Taking neutron-rich sulfur isotopes as examples,Γ_(L) shows a sensitive correlation withδ_(np) of ^(48)Ca,and is proposed as a probe for determining the neutron skin thickness of the projectile nucleus.
基金supported by National Natural Science Foundation of China(No.11405025).
文摘The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(every third isotopes)+112 Sn for full reduced impact parameters using the isospin-dependent quantum molecular dynamics(IQMD)model.The neutron and proton density distributions and root-mean-square radii of the reaction systems were obtained using the Skyrme-Hartree-Fock model,which was used for the phase space initialization of the projectile and target in IQMD.We defined the unified neutron skin thickness asΔRnp=<r^(2)>^(1∕2) n−<r^(2)>^(1∕2)p,which was negative for neutron-deficient nuclei.The unifiedΔRnp values for nuclei with the same relative neutron excess from different isotopic chains were nearly equal,except for extreme neutron-rich isotopes,which is a type of scaling behavior.The yield ratios of the three isotopic chain-induced reactions,which depended on the reduced impact parameter and unified neutron skin thickness,were studied.The results showed that both R(n/p)and R(^(3)H∕^(3)He)decreased with a reduced impact parameter for extreme neutron-deficient isotopes;however,they increased with reduced impact parameters for extreme neutron-rich isotopes,and increased with theΔRnp of the projectiles for all reduced impact parameters.In addition,a scaling phenomenon was observed betweenΔR np and the yield ratios in peripheral colli-sions from different isotopic chain projectiles(except for extreme neutron-rich isotopes).Thus,R(n/p)and R(^(3)H∕^(3)He)from peripheral collisions were suggested as experimental probes for extracting the neutron or proton skin thicknesses of non-extreme neutron-rich nuclei from different isotopic chains.
基金supported partly by the National Key R&D Program of China(No.2023YFA1606401)the National Natural Science Foundation of China(Nos.12135004,11635003,11961141004,12047513)+1 种基金the support of the National Natural Science Foundation of China(Nos.12275025 and 11975096)the Fundamental Research Funds for the Central Universities(No.2020NTST06)。
文摘Precise knowledge of the nuclear symmetry energy can be tentatively calibrated using multimessenger constraints.The neutron skin thickness of a heavy nucleus is one of the most sensitive indicators for probing the isovector components of effective interactions in asymmetric nuclear matter.Recent studies have suggested that the experimental data from the CREX and PREX2 collaborations are not mutually compatible with existing nuclear models.In this study,we review the quantification of the slope parameter of the symmetry energy L from the neutron skin thicknesses of^(48)Ca and^(208)Pb.Skyrme energy density functionals classified by various isoscalar incompressibility coefficients K were employed to evaluate the bulk properties of finite nuclei.The calculated results suggest that the slope parameter L deduced from^(208)Pb is sensitive to the compression modulus of symmetric nuclear matter,but not that from^(48)Ca.The effective parameter sets classified by K=220 MeV can provide an almost overlapping range of L from^(48)Ca and^(208)Pb.
基金This work was supported in part by the National Natural Science Foundation of China(Grant No.12104239)National Natural Science Foundation of Jiangsu Province of China(Grant No.BK20210581)+2 种基金Nanjing University of Posts and Telecommunications Science Foundation(Grant Nos.NY221024 and NY221100)the Science and Technology Program of Guangxi,China(Grant No.2018AD19310)the Jiangxi Provincial Natural Science Foundation(Grant No.20224BAB211020).
文摘We derive an effective Hamiltonian for a spin-1/2 particle confined within a curved thin layer with non-uniform thickness using the confining potential approach.Our analysis reveals the presence of a pseudo-magnetic field and effective spin–orbit interaction(SOI)arising from the curvature,as well as an effective scalar potential resulting from variations in thickness.Importantly,we demonstrate that the physical effect of additional SOI from thickness fluctuations vanishes in low-dimensional systems,thus guaranteeing the robustness of spin interference measurements to thickness imperfection.Furthermore,we establish the applicability of the effective Hamiltonian in both symmetric and asymmetric confinement scenarios,which is crucial for its utilization in one-side etching systems.
文摘At the first time,the finite element method was used to model and analyze the free vibration and transient response of non-uniform thickness bi-directional functionally graded sandwich porous(BFGSP)skew plates.The whole BFGSP skew-plates is placed on a variable visco-elastic foundation(VEF)in the hygro-thermal environment and subjected to the blast load.The BFGSP skew-plate thickness is permitted to vary non-linearly over both the length and width of the skew-plate,thereby faithfully representing the real behavior of the structure itself.The analysis is based on a four-node planar quadrilateral element with eight degrees of freedom per node,which is approximated using Lagrange Q_(4)shape function and C^(1)level non-conforming Hermite shape function based on refined higher-order shear deformation plate theory.The forced vibration parameters of the non-uniform thickness BFGSP skew-plate are fully determined using Hamilton's principle and the Newmark-βdirect integration technique.Accuracy of the calculation program is validated by comparing its numerical results with those from reputable sources.Furthermore,a thorough assessment is conducted to determine the impact of various parameters on the free and forced vibration responses of the non-uniform thickness BFGSP skew-plate.The findings of the paper may be used in the development of civil and military structures in situations that are prone to exceptional forces,such as explosions and impacts load.
基金Supported by National Key R&D Program of China(2021YFA0715500)National Natural Science Foundation of China(NSFC)(12227901)+2 种基金Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB0580000)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)Chinese Academy of Sciences President's International Fellowship Initiative(2021PT0007).
文摘This work introduces a novel method for measuring thin film thickness,employing a multi-wavelength method that significantly reduces the need for broad-spectrum data.Unlike traditional techniques that require sev⁃eral hundred spectral data points,the multi-wavelength method achieves precise thickness measurements with data from only 10 wavelengths.This innovation not only simplifies the process of spectral measurement analysis but also enables accurate real-time thickness measurement on industrial coating production lines.The method effectively reconstructs and fits the visible spectrum(400-800 nm)using a minimal amount of data,while maintaining measurement error within 7.1%.This advancement lays the foundation for more practical and efficient thin film thickness determination techniques in various industrial applications.
文摘Due to the overlapping of echoes from the inner and outer walls of thin⁃walled tubes,thickness measurement based on ultrasonic time⁃of⁃flight method is difficult to apply.Therefore,the ultrasonic resonance method has become an effective mean of measuring thin⁃walled tube thickness.The resonance method often demands a perpendicular incidence of ultrasound,but having the ultrasonic probe strictly perpendicular to the measured surface is challenging for installation reasons.The ultrasonic resonance model by considering ultrasonic inclination angles is derived.The model explains that an inclination angle theoretically does not affect the calculation results of measuring thin thickness.However,increasing the inclination angle reduces the reflection coefficient,resulting in a shorter length of the effective reflected wave,thus reducing the calculation accuracy.Additionally,the research evaluated the ultrasonic echo from the tubes of different diameters and found that if ultrasound transmits with an inclined incidence,smaller diameter tubes result in lower normal reflection coefficients,leading to poorer measurement accuracy.The research simulated and tested the tilted⁃incidence resonant method based on the subject of water⁃steel⁃air,and the results prove the correctness of the model.
基金Supported by the Basic Research Project of Shanghai Science and Technology Innovation Action under Grant No 17JC1400300the National Key Basic Research Program of China under Grant No 2014CB921004+1 种基金the National Natural Science Foundation of China under Grant No 61674044the Program of Shanghai Subject Chief Scientist under Grant No 17XD1400800
文摘Highly oriented（00l）（La_（0.26）Bi_（0.74））_2Ti_4O_（11 ）thin films are deposited on（100） SrTiO_（3 ）substrates using the pulsed laser deposition technique.The grains form a texture of bar-like arrays along Sr Ti O_3110directions for the film thickness above 350 nm,in contrast to spherical grains for the reduced film thickness below 220 nm.X-ray diffraction patterns show that the highly ordered bar-like grains are the ensemble of two lattice-matched monoclinic（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components above a critical film thickness.Otherwise,the phase decomposes into the random mixture of Bi_2Ti_2O_（7 ）and Bi_4Ti_3O_（4 ）spherical grains in thinner films.The critical thickness can increase up to 440 nm as the films are deposited on LaNiO_3-buffered SrTiO_（3 ）substrates.The electrical measurements show the dielectric enhancement of the multi-components,and comprehensive charge injection into interfacial traps between（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components occurs under the application of a threshold voltage for the realization of high-charge storage.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFF0712800 and 2019YFA0308700)。
文摘Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.
基金financially supported by the National Natural Science Foundation of China(21706292)support from the Hunan Provincial Science and Technology Plan Project,China(No.2017TP1001).
文摘The practical application of lithium–sulfur(Li–S)batteries is limited by the easy dissolution of polysulfides in the electrolyte,resulting in the lithium polysulfide(LPS)shuttle effect.Several two-dimensional(2D)materials with abundant active binding sites and high surface-to-volume ratios have been developed to prepare functional separators that suppress the diffusion of polysulfides.However,the influence of modified layer thickness on Li+transport has not been considered.Herein,we synthesized individual and multilayered 2D Ti3C2Tx MXene nanosheets and used them to fabricate a series of Ti3C2Tx-PP modified separators.The separators had mass loadings ranging from 0.16 to 0.016 mg cm-2,which is the lowest value reported for 2D materials to the best of our knowledge.The corresponding reductions in thickness ranged from 1.2μm to 100 nm.LPS shuttling was effectively suppressed,even at the lowest mass loading of 0.016 mg cm-2.Suppression was due to the strong interaction between LPS intermediates and Ti atoms and hydroxyl functional groups on the separator surface.The lithium-ion diffusion coefficient increased with the reduction of Ti3C2Tx layers on the separator.Superior cycling stability and rate performance were attained when the separator with a Ti3C2Tx-PP mass loading of 0.016 mg cm-2 was incorporated into a Li–S battery.Carbon nanotubes(CNTs)were introduced into the separators to further improve the electrical and Li+ionic conductivity in the cross-plane direction of the 2D Ti3C2Txlayers.With the ultralightweight Ti3C2Tx/CNTs modified PP separator,the cell maintained a capacity of 640 m Ah g-1after 200cycles at 1C with a capacity decay of only 0.079%per cycle.
文摘Background Previous studies reported a close relationship between obesity and insulin resistance in the essential hypertensive patients. Objective In this study, we examined the relationship between the skin fold thickness and insulin resistance then developed a formula to estimate the insulin resistance index according to the skin fold thickness in the essential hypertensive patients. Subjects and Methods Medical records of 80 patients (37 males, 43 females) were reviewed and the data were tabulated. Anthropometric indexes (including height, weight, waist circumference, hip circumference, and skins fold thickness at 5 fatty difference points on the Erdheim diagram), fasting plasma glucose and insulin concentration were recorded. The mean age was 57.0 ?9.2 years. The insulin resistance index was calculated following the Homeostasis Model Assessment (HOMA) formula. Results Compared with the group with BMI < 23 kg/m2, the group with BMI≥23 kg/m2 had higher fasting insulin concentration (8.85±4.97 pmol/L vs 15.60±8.70 pmol/L, P<0.001 ) and higher insulin resistance index in ( 2.15±1,24 vs 3.76±2.22, P<0.001). No significant difference in fasting plasma insulin concentration, insulin resistance index between male and female was observed (P > 0.05). There was a positive correlation between skin fold thickness and the fasting insulin concentration and insulin resistance index. The skin fold thickness at point A8 had the best coefficient correlated with fasting plasma insulin(r=0.79, P < 0.001) and insulin resistance index (r= 0.79, P < 0.001). A formula to estimate the insulin resistance index by skin fold thickness at point A8 as: Insulin resistance index = 0.12×[skin fold thickness at A8 point (mm)] - 1. Conclusion: In the essential hypertensive patients, the formula to estimate insulin resistance index as 0.12×[skin fold thickness at A8 point (mm)]-1 may predict accurately the level of insulin resistance. (J Geriatr Cardiol 2005; 2(4):228-232 )
基金Project supported by the National Natural Science Foundation of China(Grant No.61705066)the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),China(Grant No.IPOC2018B004)the National Key Research and Development Program,China(Grant No.2016YFA0202401)
文摘Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.
文摘Backgroud and Objectives Previous studies have reported that skin fold thickness (SF) strongly correlated with insulin resistance in the metabolic syndrome (MetS). In this study, we developed a MetS definition by SF at A8 point (SFA8) on Erdheim diagram(MetSSFA8) in essential hypertensive patients. Subjects and Methods Medical records of 268 essential hypertensive patients (126males and 122 females) were analyzed, including 210 non-diabetic patients (NDM group) and 58 patients with diabetes (DM group).The mean age was 61.4 ± 9.9 and 59.0 ± 11.0 years, respectively. The control group consisted of 90 non-diabetic, non-hypertensive patients with a mean age of 58.0 ± 11.3 years. The proposed MetSSFA8 definition included SFA8 specific values ( ≥30 mm in female and ≥27 mm in male) and at least two of the following: raised triglyceride levels ( ≥1.7 mmol/L), or specific treatment for this lipid abnormality; raised blood pressure (SBP≥130 mmHg and/or DBP≥85 mmHg), or treatment of previously diagnosed hypertension;reduced HDL-cholesterol (＜ 1.03 mmol/L in men, ＜1.29 mmol/L in women), or specific treatment for this lipid abnormality; raised fasting plasma glucose (≥5.6 mmol/l), or previously diagnosed DM. Metabolic Syndrome by the National Cholesterol Education Program and International Diabetes Federation definitions were determined with abdominal obesity defined by Asia-Pacific criteria for waist circumference (NCEPA and IDFA). Results The percentage of MetS as defined by NCEPA, IDFA and MetSSFA8 in NDM group was lower than that of NCEPA, IDFA and MetSSFA8 in DM group [OR=7.7 (95%CI, 2.9-20.2) and 2.5 (95%CI, 1.4-4.8) and 2.7(95%CI, 1.3-5.6), respectively] and higher than that of the control group [OR=53.3 (95%CI, 16.7-170.6), 5.8 (95%CI, 2.6-13.2) and18.8 (95%CI, 7.3-48.7), respectively]. The percentage of MetS by NCEPA, IDFA and MetSSFA8 in males in NDM group was lower than the percentage of MetS by NCEPA, IDFA and MetSSFA8 in females in NDM group (50.8% and 77.9%, P＜ 0.001; 15,9% and 67.2%, P＜ 0.001; 60.3% and 73.8%, P ＜0.05, respectively). In subjects with normal WC or both normal WC and BMI, the percentage of MetS by SFAS was higher than that the percentage of MetS by NCEPA (36.9% and 50.8%, P＜ 0.05 and 36.0% and 51.0%, P＜ 0.05).The sensitivity, specificity, false positive rate, positive predictive value, negative predictive value of MetSSFA8 assessed with NCEPA definitions were 0.87, 0.73, 0.27, 0.79 and 0.82, respectively. There was a close agreement between MetSSFA8 and NCEPA (The coefficient of Kapa was 0.60, P＜ 0.001). Conclusions The MetSSFA8 definition was developed which may be useful in order to define and manage MetS in patients with normal WC or normal weight.
基金supported by the National Natural Science Foundation of China(Nos.11175085,11235001,11375086,and 11120101005)the 973 Program of China(No.2013CB834400)+1 种基金the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Open Project Program of the State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,Chinese Academy of Sciences,China(No.Y5KF141CJ1)
文摘Based on the newest experimentally extracted nuclear density distributions for double-magic nucleus208Pb(Tarbert et al. in Phys Rev Lett 112:242502, 2014),the sensitivity of α-decay half-life to nuclear skin thickness is explored in the vicinity of the shell closure region around208 Pb, i.e., isotopes of Z ? 82 and isotones of N ? 126.With the two-parameter Fermi(2PF) density distributions and an analytically derived formula, the α-decay half-life is found to be closely related to the magnitude of nuclear skin thickness. For a decays to the Z ? 82 isotopes, the α-decay half-life is found to decrease with the increasing neutron skin thickness, while the opposite behavior is found for a decays to the N ? 126 isotones. Therefore, it could be a possible way to extract the nuclear skin thickness from measured α-decay half-lives.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11074232,10874160,and 21002097)the National Basic Research Program of China(Grant Nos.2011CB932801 and 2012CB933702)
文摘Thin oxidized copper films in various thickness values are deposited onto quartz glass substrates by electron beam evaporation. The ellipsometry parameters and transmittance in a wavelength range of 300 nm-1000 nm are collected by a spectroscopic ellipsometer and a spectrophotometer respectively. The effective thickness and optical constants, i.e., refractive index n and extinction coefficient k, are accurately determined by using newly developed ellipsometry combined with transmittance iteration method. It is found that the effective thickness determined by this method is close to the physical thickness and has obvious difference from the mass thickness for very thin film due to variable density of film. Furthermore, the thickness dependence of optical constants of thin oxidized Cu films is analyzed.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10775168,10405032,10535010,10405033,10605036 and 10475108)the Shanghai Development Foundation for Science and Technology (Grant Nos 06QA14062,06JC14082 and 05XD14021)+1 种基金the State Key Program of Basic Research of China (Grant No 2007CB815004)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No KJCX3.SYW.N2)
文摘The dependence between neutron skin thickness and neutron abrasion cross section （σnabr） for neutron-rich nuclei is investigated within the framework of the statistical abrasion ablation model. Assuming that the density distributions for proton and neutron are of Fermi-type, and adjusting the diffuseness parameter of neutron density distribution in the droplet model, we find out the good linear correlation between the neutron skin thickness and the abrasion cross section σnabr for neutron-rich nuclei. The uncertainty of neutron skin thickness determined from σnabr is very small. It is suggested that σnabr can be used as a new experimental observable to extract the neutron skin thickness for neutronrich nucleus. The scaling behaviours between neutron skin thickness and σnabr, separately, for isotopes of ^26-35Na, ^44-56Ar, ^48-60Ca, ^67-78Ni are also investigated.
文摘Sapwood density and bark thickness of Calophyllum inophyllum L. （a multipurpose durable timber species） were studied in various locations in Northern Australia and in Sri Lanka. Measurements were taken non-destructively by using core sampling and bark gauge. From each provenance, 4–15 mature trees having girth at breast height over bark （GBHOB） at 100–150 cm were selected on the basis of the population size. Significant （p0.05） hemispheric and provenance variations in bark thickness were found. Variations in the bark thickness are influenced by environmental variables. Variations in sapwood density were less pronounced compared to that of bark thickness. Variations in sapwood density are likely to be governed by genotypic variations.
