The recently developed magic-intensity trapping technique of neutral atoms efficiently mitigates the detrimental effect of light shifts on atomic qubits and substantially enhances the coherence time. This technique re...The recently developed magic-intensity trapping technique of neutral atoms efficiently mitigates the detrimental effect of light shifts on atomic qubits and substantially enhances the coherence time. This technique relies on applying a bias magnetic field precisely parallel to the wave vector of a circularly polarized trapping laser field. However, due to the presence of the vector light shift experienced by the trapped atoms, it is challenging to precisely define a parallel magnetic field, especially at a low bias magnetic field strength, for the magic-intensity trapping of85Rb qubits. In this work, we present a method to calibrate the angle between the bias magnetic field and the trapping laser field with the compensating magnetic fields in the other two directions orthogonal to the bias magnetic field direction. Experimentally, with a constantdepth trap and a fixed bias magnetic field, we measure the respective resonant frequencies of the atomic qubits in a linearly polarized trap and a circularly polarized one via the conventional microwave Rabi spectra with different compensating magnetic fields and obtain the corresponding total magnetic fields via the respective resonant frequencies using the Breit–Rabi formula. With known total magnetic fields, the angle is a function of the other two compensating magnetic fields.Finally, the projection value of the angle on either of the directions orthogonal to the bias magnetic field direction can be reduced to 0(4)° by applying specific compensating magnetic fields. The measurement error is mainly attributed to the fluctuation of atomic temperature. Moreover, it also demonstrates that, even for a small angle, the effect is strong enough to cause large decoherence of Rabi oscillation in a magic-intensity trap. Although the compensation method demonstrated here is explored for the magic-intensity trapping technique, it can be applied to a variety of similar precision measurements with trapped neutral atoms.展开更多
Previous studies have shown that trans fatty acids(TFA) are associated with several chronic diseases,the gut microbiota is directly influenced by dietary components and linked to chronic diseases.Our research investig...Previous studies have shown that trans fatty acids(TFA) are associated with several chronic diseases,the gut microbiota is directly influenced by dietary components and linked to chronic diseases.Our research investigated the effects of elaidic acid(EA),a typical TFA,on the gut microbiota to understand the underlying mechanisms of TFA-related chronic diseases.16S rDNA gene sequencing on faecal samples from Sprague-Dawley rats were performed to explore the composition change of the gut microbiota by EA gavage for 4 weeks.The results showed that the intake of EA increased the abundance of well-documented harmful bacteria,such as Proteobacteria,Anaerotruncus,Oscillibacter and Desulfovibrionaceae.Plus,EA induced translocation of lipopolysaccharides(LPS) and the above pathogenic bacteria,disrupted the intestinal barrier,led to gut-liver axis derangement and TLR4 pathway activation in the liver.Overall,EA induced intestinal barrier damage and regulated TLR4-MyD88-NF-κB/MAPK pathways in the liver of SD rats,leading to the activation of NLRP3 inflammasome and inflammatory liver damage.展开更多
The thrust coefficients and propulsive efficiency of a two-dimensional flexible fin with heaving and pitching motion were computed using FLUENT. The effect of different locations of the pitching axis on propulsive per...The thrust coefficients and propulsive efficiency of a two-dimensional flexible fin with heaving and pitching motion were computed using FLUENT. The effect of different locations of the pitching axis on propulsive performance was examined using three deflexion modes which are respectively, modified Bose mode, cantilever beam with uniformly distributed load and cantilever beam with non-uniformly distributed load. The results show that maximum thrust can be achieved with the pitching axis at the trailing edge, but the highest propulsive efficiency can be achieved with the pitching axis either 1/3 of the chord length from the leading edge in modified Bose mode, or 2/3 of the chord length from the leading edge in cantilever beam mode. At the same time, the effects of the Strouhal number and maximal attack angle on the hydrodynamics performance of the flexible fin were analyzed. Parameter interval of the maximum thrust coefficient and the highest propulsive efficiency were gained. If the Strouhal number is low, high propulsive efficiency can be achieved at low αmax , and vice versa.展开更多
NC machining path of sculptured surfaces in CAD/CAM system plays an important role on manufacture. This paper describes a new algorithm for 5 axis machining of sculptured surfaces and the algorithm is interference fr...NC machining path of sculptured surfaces in CAD/CAM system plays an important role on manufacture. This paper describes a new algorithm for 5 axis machining of sculptured surfaces and the algorithm is interference free. The approach includes: (1) the tesselation of the parametric surfaces into triangles; (2) building topological relations among triangles;(3) 5 axis tool path generation; (4) interference detection and tool position correction.展开更多
In this paper, hydrodynamic analysis of vertical axis tidal turbine （both fixed pitch ＆ variable pitch） is numerically analyzed. Two-dimensional numerical modeling ＆ simulation of the unsteady flow through the bla...In this paper, hydrodynamic analysis of vertical axis tidal turbine （both fixed pitch ＆ variable pitch） is numerically analyzed. Two-dimensional numerical modeling ＆ simulation of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX, which is based on a Reynolds-Averaged Navier-Stokes （RANS） model. A transient simulation is done for fixed pitch and variable pitch vertical axis tidal turbine using a Shear Stress Transport turbulence （SST） scheme. Main hydrodynamic parameters like torque T, combined moment CM, coefficients of performance Cp and coefficient of torque Cr, etc. are investigated. The modeling and meshing of turbine rotor is performed in ICEM-CFD. Moreover, the difference in meshing schemes between fixed pitch and variable pitch is also mentioned. Mesh motion option is employed for variable pitch turbine. This article is one part of the ongoing research on tm＇bine design and developments. The numerical simulation results are validated with well reputed analytical results performed by Edinburgh Design Ltd. The article concludes with a parametric study of turbine performance, comparison between fixed and variable pitch operation for a four-bladed turbine. It is found that for variable pitch we get maximum Ce and peak power at smaller revolution per minute N and tip sped ratio 2.展开更多
Food-microbiota-host interactions provide an overarching framework for understanding the function of the gut microbiota axis.Diet is a major modulator of gut microbiota.Plant-based foods are rich in phytochemicals;the...Food-microbiota-host interactions provide an overarching framework for understanding the function of the gut microbiota axis.Diet is a major modulator of gut microbiota.Plant-based foods are rich in phytochemicals;therefore,it is essential to assess such foods and elucidate the mechanisms underlying their action.In this review,we summarize the role of gut microbiota in the communication between the gut and the brain,liver,lung,kidney,and joints,as well as the role of the gut microbiota axis in diseases involving these organs.In addition,we assess the effects of phytochemicals from plant-based foods on the gut microbiota axis via different pathways.展开更多
A simple method is applied to calculating the optical path difference （OPD） of a plane parallel uniaxial plate with an arbitrary optical axis direction. Then, the theoretical expressions of the OPD and lateral displ...A simple method is applied to calculating the optical path difference （OPD） of a plane parallel uniaxial plate with an arbitrary optical axis direction. Then, the theoretical expressions of the OPD and lateral displacement （LD） of Savart polariscope under non-ideal conditions are obtained exactly. The variations of OPD and LD are simulated, and some important conclusions are obtained when the optical axis directions have an identical tolerance of ／pm 1^{{／circ}}. An application example is given that the tolerances of optical axis directions are gained according to the spectral resolution tolerances of the stationary polarization interference imaging spectrometer （SPIIS）. Several approximate formulae are obtained for explaining some conclusions above. The work provides a theoretical guidance for the optic design, crystal processing, installation and debugging, data analysis and spectral reconstruction of the SPIIS.展开更多
Periodontitis has been proposed as a novel risk factor of genitourinary cancers:although periodontitis and genitourinary cancers are two totally distinct types of disorders,epidemiological and clinical studies,have es...Periodontitis has been proposed as a novel risk factor of genitourinary cancers:although periodontitis and genitourinary cancers are two totally distinct types of disorders,epidemiological and clinical studies,have established associations between them.Dysbiosis of oral microbiota has already been established as a major factor contributing to periodontitis.Recent emerging epidemiological evidence and the detection of oral microbiota in genitourinary organs indicate the presence of an oral-genitourinary axis and oral microbiota may be involved in the pathogenesis of genitourinary cancers.Therefore,oral microbiota provides the bridge between periodontitis and genitourinary cancers.We have carried out this narrative review which summarizes epidemiological studies exploring the association between periodontitis and genitourinary cancers.We have also highlighted the current evidence demonstrating the capacity of oral microbiota to regulate almost all hallmarks of cancer,and proposed the potential mechanisms of oral microbiota in the development of genitourinary cancers.展开更多
We transform the singular integral equations with solutions simultaneously having singularities of higher order at infinite point and at several finite points on the real axis into ones along a closed contour with sol...We transform the singular integral equations with solutions simultaneously having singularities of higher order at infinite point and at several finite points on the real axis into ones along a closed contour with solutions having singularities of higher order, and for the former obtain the extended Neother theorem of complete equation as well as the solutions and the solvable conditions of characteristic equation from the latter. The conclusions drawn by this article contain special cases discussed before.展开更多
Objective： To investigate the effects of sleep electroencephalogram-modulated repetitive transcranial magnetic stimulation （SEM-rTMS） and conventional rTMS （C-rTMS） on the activity of hypothalamic-pituitary-adren...Objective： To investigate the effects of sleep electroencephalogram-modulated repetitive transcranial magnetic stimulation （SEM-rTMS） and conventional rTMS （C-rTMS） on the activity of hypothalamic-pituitary-adrenal （HPA） axis in patients with depression. Methods： In a double-blind, randomized controlled trial, 164 patients diagnosed with depression were randomized to treatment with SEM-rTMS （n=57）, C-rTMS （n=55） or sham rTMS （n=52） for 30 rain every day for 10 d. Before and after treatment plasma concentrations of adrenocorticotropic hormone （ACTH） and cortisol （CORT） were measured, and the 24-item Hamilton Depression Rating Scale （HAMD-24） was used for assessment. Results： The HAMD-24 scores and plasma ACTH and CORT concentrations of these depressive patients before treatment were significantly different from those of the normal control group （P〈0.05）. The HAMD-24 scores and plasma ACTH and CORT concentrations in the SEM-rTMS group and conventional rTMS group were decreased significantly （P〈0.05）. There was a significant positive correlation between the HAMD-24 scores and plasma ACTH （n=240, r=0.105, P=0.048） and CORT concentrations （n-240, r=0.126, P=0.023） in the patients with depression before and after treatment. Conclusion： The antidepressant effect of rTMS, including SEM-rTMS, may be related to its decreasing HPA axis activity. （This trail was registered. No： ChiCTR-TRC-00000465）展开更多
In VTI media,the conventional inversion methods based on the existing approximation formulas are difficult to accurately estimate the anisotropic parameters of reservoirs,even more so for unconventional reservoirs wit...In VTI media,the conventional inversion methods based on the existing approximation formulas are difficult to accurately estimate the anisotropic parameters of reservoirs,even more so for unconventional reservoirs with strong seismic anisotropy.Theoretically,the above problems can be solved by utilizing the exact reflection coefficients equations.However,their complicated expression increases the difficulty in calculating the Jacobian matrix when applying them to the Bayesian deterministic inversion.Therefore,the new reduced approximation equations starting from the exact equations are derived here by linearizing the slowness expressions.The relatively simple form and satisfactory calculation accuracy make the reduced equations easy to apply for inversion while ensuring the accuracy of the inversion results.In addition,the blockiness constraint,which follows the differentiable Laplace distribution,is added to the prior model to improve contrasts between layers.Then,the concept of GLI and an iterative reweighted least-squares algorithm is combined to solve the objective function.Lastly,we obtain the iterative solution expression of the elastic parameters and anisotropy parameters and achieve nonlinear AVA inversion based on the reduced equations.The test results of synthetic data and field data show that the proposed method can accurately obtain the VTI parameters from prestack AVA seismic data.展开更多
In this study, a vertical axis tidal turbine with flexible blades is investigated. The focus is on analyzing the effect of flexible airfoils types and blade flexibility on turbine net output power. To this end, five d...In this study, a vertical axis tidal turbine with flexible blades is investigated. The focus is on analyzing the effect of flexible airfoils types and blade flexibility on turbine net output power. To this end, five different flexible airfoils （Symmetric and Non-symmetric） are employed. The results show that the use of a thick flexible symmetric airfoil can effectively increase output power compared to that achievable with a conventional rigid blade. Moreover, the use of highly flexible blades, as opposed to less flexible or rigid blades, is not recommended.展开更多
Objective To investigate the effect of XBXT-2 on the activity of hypothalamic-pituitary-adrenal(HPA)axis in chronic mild stress(CMS)model of rats.Methods Using ELISA to test the serum corticosterone,adrenocorticotropi...Objective To investigate the effect of XBXT-2 on the activity of hypothalamic-pituitary-adrenal(HPA)axis in chronic mild stress(CMS)model of rats.Methods Using ELISA to test the serum corticosterone,adrenocorticotropic hormone(ACTH)and corticotropin-releasing hormone(CRH)level in CMS rats;Using western blot to determine hippocampal glucocorticoids receptors(GR)expression in CMS rats.Results Co-administration of XBXT-2(25,50 mg·kg-1,p.o.,28 days,the effective doses for behavioral responses)significantly decreased the serum corticosterone and ACTH level in CMS rats,while the CRH level was not markedly affected by chronic stress or drugs.Moreover,XBXT-2 significantly increased the GR expression in the hippocampus of CMS rats.The same effects were observed in the positive control drug imipramine(10 mg·kg-1,p.o.).Conclusions The decrease of serum corticosterone and ACTH level,as well as the increase of hippocampal GR expression may be the mechanisms underlying the antidepressant action of XBXT-2,which may associate with HPA axis.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12104414,12122412,12104464,and 12104413)the China Postdoctoral Science Foundation(Grant No.2021M702955).
文摘The recently developed magic-intensity trapping technique of neutral atoms efficiently mitigates the detrimental effect of light shifts on atomic qubits and substantially enhances the coherence time. This technique relies on applying a bias magnetic field precisely parallel to the wave vector of a circularly polarized trapping laser field. However, due to the presence of the vector light shift experienced by the trapped atoms, it is challenging to precisely define a parallel magnetic field, especially at a low bias magnetic field strength, for the magic-intensity trapping of85Rb qubits. In this work, we present a method to calibrate the angle between the bias magnetic field and the trapping laser field with the compensating magnetic fields in the other two directions orthogonal to the bias magnetic field direction. Experimentally, with a constantdepth trap and a fixed bias magnetic field, we measure the respective resonant frequencies of the atomic qubits in a linearly polarized trap and a circularly polarized one via the conventional microwave Rabi spectra with different compensating magnetic fields and obtain the corresponding total magnetic fields via the respective resonant frequencies using the Breit–Rabi formula. With known total magnetic fields, the angle is a function of the other two compensating magnetic fields.Finally, the projection value of the angle on either of the directions orthogonal to the bias magnetic field direction can be reduced to 0(4)° by applying specific compensating magnetic fields. The measurement error is mainly attributed to the fluctuation of atomic temperature. Moreover, it also demonstrates that, even for a small angle, the effect is strong enough to cause large decoherence of Rabi oscillation in a magic-intensity trap. Although the compensation method demonstrated here is explored for the magic-intensity trapping technique, it can be applied to a variety of similar precision measurements with trapped neutral atoms.
基金supported by fund from the National Natural Science Foundation of China (32172322)Shandong Provincial Natural Science Foundation (ZR2023QC291)Shandong Traditional Chinese Medicine Technology Project (Q-2023130)。
文摘Previous studies have shown that trans fatty acids(TFA) are associated with several chronic diseases,the gut microbiota is directly influenced by dietary components and linked to chronic diseases.Our research investigated the effects of elaidic acid(EA),a typical TFA,on the gut microbiota to understand the underlying mechanisms of TFA-related chronic diseases.16S rDNA gene sequencing on faecal samples from Sprague-Dawley rats were performed to explore the composition change of the gut microbiota by EA gavage for 4 weeks.The results showed that the intake of EA increased the abundance of well-documented harmful bacteria,such as Proteobacteria,Anaerotruncus,Oscillibacter and Desulfovibrionaceae.Plus,EA induced translocation of lipopolysaccharides(LPS) and the above pathogenic bacteria,disrupted the intestinal barrier,led to gut-liver axis derangement and TLR4 pathway activation in the liver.Overall,EA induced intestinal barrier damage and regulated TLR4-MyD88-NF-κB/MAPK pathways in the liver of SD rats,leading to the activation of NLRP3 inflammasome and inflammatory liver damage.
基金Supported by the National Natural Science Foundation of China under Grant No.50879031
文摘The thrust coefficients and propulsive efficiency of a two-dimensional flexible fin with heaving and pitching motion were computed using FLUENT. The effect of different locations of the pitching axis on propulsive performance was examined using three deflexion modes which are respectively, modified Bose mode, cantilever beam with uniformly distributed load and cantilever beam with non-uniformly distributed load. The results show that maximum thrust can be achieved with the pitching axis at the trailing edge, but the highest propulsive efficiency can be achieved with the pitching axis either 1/3 of the chord length from the leading edge in modified Bose mode, or 2/3 of the chord length from the leading edge in cantilever beam mode. At the same time, the effects of the Strouhal number and maximal attack angle on the hydrodynamics performance of the flexible fin were analyzed. Parameter interval of the maximum thrust coefficient and the highest propulsive efficiency were gained. If the Strouhal number is low, high propulsive efficiency can be achieved at low αmax , and vice versa.
文摘NC machining path of sculptured surfaces in CAD/CAM system plays an important role on manufacture. This paper describes a new algorithm for 5 axis machining of sculptured surfaces and the algorithm is interference free. The approach includes: (1) the tesselation of the parametric surfaces into triangles; (2) building topological relations among triangles;(3) 5 axis tool path generation; (4) interference detection and tool position correction.
基金financially supported by National "863" Program (Grant No.2007AA05Z450, No. 200805040)National S&T Program (No.2008BAA15B04)+2 种基金2010 National Ocean Special Funds(No.ZJME2010GC01, No. ZJME2010CY01, No.GHME2010GC02)supported by the Fundamental Research Funds of the Universities(No.HEUCF130105)supported by "111 project" foundation(No. B07019) from State Administration of Foreign Experts Affairs of China and Ministry of Education of China
文摘In this paper, hydrodynamic analysis of vertical axis tidal turbine （both fixed pitch ＆ variable pitch） is numerically analyzed. Two-dimensional numerical modeling ＆ simulation of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX, which is based on a Reynolds-Averaged Navier-Stokes （RANS） model. A transient simulation is done for fixed pitch and variable pitch vertical axis tidal turbine using a Shear Stress Transport turbulence （SST） scheme. Main hydrodynamic parameters like torque T, combined moment CM, coefficients of performance Cp and coefficient of torque Cr, etc. are investigated. The modeling and meshing of turbine rotor is performed in ICEM-CFD. Moreover, the difference in meshing schemes between fixed pitch and variable pitch is also mentioned. Mesh motion option is employed for variable pitch turbine. This article is one part of the ongoing research on tm＇bine design and developments. The numerical simulation results are validated with well reputed analytical results performed by Edinburgh Design Ltd. The article concludes with a parametric study of turbine performance, comparison between fixed and variable pitch operation for a four-bladed turbine. It is found that for variable pitch we get maximum Ce and peak power at smaller revolution per minute N and tip sped ratio 2.
基金supported by the National Key Research and Development Program(2021YFE0190100)National Natural Science Foundation of China(81760776,81874336)。
文摘Food-microbiota-host interactions provide an overarching framework for understanding the function of the gut microbiota axis.Diet is a major modulator of gut microbiota.Plant-based foods are rich in phytochemicals;therefore,it is essential to assess such foods and elucidate the mechanisms underlying their action.In this review,we summarize the role of gut microbiota in the communication between the gut and the brain,liver,lung,kidney,and joints,as well as the role of the gut microbiota axis in diseases involving these organs.In addition,we assess the effects of phytochemicals from plant-based foods on the gut microbiota axis via different pathways.
基金supported by the State Key Program of National Natural Science Foundation of China (Grant No. 40537031)the National Natural Science Foundation of China (Grant No. 40875013)+1 种基金the National Defense Basic Scientific Research Project, China (Grant No. A1420080187)the National High Technology Research and Development Program of China (Grant No. 2006AA12Z152)
文摘A simple method is applied to calculating the optical path difference （OPD） of a plane parallel uniaxial plate with an arbitrary optical axis direction. Then, the theoretical expressions of the OPD and lateral displacement （LD） of Savart polariscope under non-ideal conditions are obtained exactly. The variations of OPD and LD are simulated, and some important conclusions are obtained when the optical axis directions have an identical tolerance of ／pm 1^{{／circ}}. An application example is given that the tolerances of optical axis directions are gained according to the spectral resolution tolerances of the stationary polarization interference imaging spectrometer （SPIIS）. Several approximate formulae are obtained for explaining some conclusions above. The work provides a theoretical guidance for the optic design, crystal processing, installation and debugging, data analysis and spectral reconstruction of the SPIIS.
基金the Zhongnan Hospital of Wuhan University Science,Technology and Innovation Seed Fund(No.znpy2019011)the Fundamental Research Funds for the Central Universities(No.2042020kf0130)+1 种基金the Nature Science Foundation of Hubei Province(No.2019FFB03902)the Health Commission of Hubei Province Scientific Research Project(No.WJ2019H035).
文摘Periodontitis has been proposed as a novel risk factor of genitourinary cancers:although periodontitis and genitourinary cancers are two totally distinct types of disorders,epidemiological and clinical studies,have established associations between them.Dysbiosis of oral microbiota has already been established as a major factor contributing to periodontitis.Recent emerging epidemiological evidence and the detection of oral microbiota in genitourinary organs indicate the presence of an oral-genitourinary axis and oral microbiota may be involved in the pathogenesis of genitourinary cancers.Therefore,oral microbiota provides the bridge between periodontitis and genitourinary cancers.We have carried out this narrative review which summarizes epidemiological studies exploring the association between periodontitis and genitourinary cancers.We have also highlighted the current evidence demonstrating the capacity of oral microbiota to regulate almost all hallmarks of cancer,and proposed the potential mechanisms of oral microbiota in the development of genitourinary cancers.
基金Supported by the NNSF of China (10471107)RFDP of Higher Education of China (20060486001)
文摘We transform the singular integral equations with solutions simultaneously having singularities of higher order at infinite point and at several finite points on the real axis into ones along a closed contour with solutions having singularities of higher order, and for the former obtain the extended Neother theorem of complete equation as well as the solutions and the solvable conditions of characteristic equation from the latter. The conclusions drawn by this article contain special cases discussed before.
基金Supported by the Social Development Guide Projects of Science and Technology Committee of Jiangsu Province in 2005 (BS2005629)"The Six Major Expert Peaks" Projects of Jiangsu Provincial Government in 2006 [Surentong (2006) 174]
文摘Objective： To investigate the effects of sleep electroencephalogram-modulated repetitive transcranial magnetic stimulation （SEM-rTMS） and conventional rTMS （C-rTMS） on the activity of hypothalamic-pituitary-adrenal （HPA） axis in patients with depression. Methods： In a double-blind, randomized controlled trial, 164 patients diagnosed with depression were randomized to treatment with SEM-rTMS （n=57）, C-rTMS （n=55） or sham rTMS （n=52） for 30 rain every day for 10 d. Before and after treatment plasma concentrations of adrenocorticotropic hormone （ACTH） and cortisol （CORT） were measured, and the 24-item Hamilton Depression Rating Scale （HAMD-24） was used for assessment. Results： The HAMD-24 scores and plasma ACTH and CORT concentrations of these depressive patients before treatment were significantly different from those of the normal control group （P〈0.05）. The HAMD-24 scores and plasma ACTH and CORT concentrations in the SEM-rTMS group and conventional rTMS group were decreased significantly （P〈0.05）. There was a significant positive correlation between the HAMD-24 scores and plasma ACTH （n=240, r=0.105, P=0.048） and CORT concentrations （n-240, r=0.126, P=0.023） in the patients with depression before and after treatment. Conclusion： The antidepressant effect of rTMS, including SEM-rTMS, may be related to its decreasing HPA axis activity. （This trail was registered. No： ChiCTR-TRC-00000465）
文摘In VTI media,the conventional inversion methods based on the existing approximation formulas are difficult to accurately estimate the anisotropic parameters of reservoirs,even more so for unconventional reservoirs with strong seismic anisotropy.Theoretically,the above problems can be solved by utilizing the exact reflection coefficients equations.However,their complicated expression increases the difficulty in calculating the Jacobian matrix when applying them to the Bayesian deterministic inversion.Therefore,the new reduced approximation equations starting from the exact equations are derived here by linearizing the slowness expressions.The relatively simple form and satisfactory calculation accuracy make the reduced equations easy to apply for inversion while ensuring the accuracy of the inversion results.In addition,the blockiness constraint,which follows the differentiable Laplace distribution,is added to the prior model to improve contrasts between layers.Then,the concept of GLI and an iterative reweighted least-squares algorithm is combined to solve the objective function.Lastly,we obtain the iterative solution expression of the elastic parameters and anisotropy parameters and achieve nonlinear AVA inversion based on the reduced equations.The test results of synthetic data and field data show that the proposed method can accurately obtain the VTI parameters from prestack AVA seismic data.
文摘In this study, a vertical axis tidal turbine with flexible blades is investigated. The focus is on analyzing the effect of flexible airfoils types and blade flexibility on turbine net output power. To this end, five different flexible airfoils （Symmetric and Non-symmetric） are employed. The results show that the use of a thick flexible symmetric airfoil can effectively increase output power compared to that achievable with a conventional rigid blade. Moreover, the use of highly flexible blades, as opposed to less flexible or rigid blades, is not recommended.
文摘Objective To investigate the effect of XBXT-2 on the activity of hypothalamic-pituitary-adrenal(HPA)axis in chronic mild stress(CMS)model of rats.Methods Using ELISA to test the serum corticosterone,adrenocorticotropic hormone(ACTH)and corticotropin-releasing hormone(CRH)level in CMS rats;Using western blot to determine hippocampal glucocorticoids receptors(GR)expression in CMS rats.Results Co-administration of XBXT-2(25,50 mg·kg-1,p.o.,28 days,the effective doses for behavioral responses)significantly decreased the serum corticosterone and ACTH level in CMS rats,while the CRH level was not markedly affected by chronic stress or drugs.Moreover,XBXT-2 significantly increased the GR expression in the hippocampus of CMS rats.The same effects were observed in the positive control drug imipramine(10 mg·kg-1,p.o.).Conclusions The decrease of serum corticosterone and ACTH level,as well as the increase of hippocampal GR expression may be the mechanisms underlying the antidepressant action of XBXT-2,which may associate with HPA axis.
