The lunar surface and its deep layers contain abundant resources and valuable information resources,the exploration and exploitation of which are important for the sustainable development of the human economy and soci...The lunar surface and its deep layers contain abundant resources and valuable information resources,the exploration and exploitation of which are important for the sustainable development of the human economy and society.Technological exploration and research in the field of deep space science,especially lunar-based exploration,is a scientific strategy that has been pursued in China and worldwide.Drilling and sampling are key to accurate exploration of the desirable characteristics of deep lunar resources.In this study,an in-situ condition preserved coring(ICP-Coring)and analysis system,which can be used to test drilling tools and develop effective sampling strategies,was designed.The key features of the system include:(1)capability to replicate the extreme temperature fluctuations of the lunar environment(-185 to 200℃)with intelligent temperature control;(2)ability to maintain a vacuum environment at a scale of 10^(-3) Pa,both under unloaded conditions within Ф580 mm×1000 mm test chamber,and under loaded conditions using Ф400 mm×800 mm lunar rock simulant;(3)application of axial pressures up to 4 MPa and confining pressures up to 3.5 MPa;(4)sample rotation at any angle with a maximum sampling length of 800 mm;and(5)multiple modes of rotary-percussive drilling,controlled by penetration speed and weight on bit(WOB).Experimental studies on the drilling characteristics in the lunar rock simulant-loaded state under different drill bit-percussive-vacuum environment configurations were conducted.The results show that the outgassing rate of the lunar soil simulant is greater than that of the lunar rock simulant and that a low-temperature environment contributes to a reduced vacuum of the lunar-based simulated environment.The rotary-percussive drilling method effectively shortens the sampling time.With increasing sampling depth,the temperature rise of the drilling tools tends to rapidly increase,followed by slow growth or steady fluctuations.The temperature rise energy accumulation of the drill bits under vacuum is more significant than that under atmospheric pressure,approximately 1.47 times higher.The real-time monitored drilling pressure,penetration speed and rotary torque during drilling serve as parameters for discriminating the drilling status.The results of this research can provide a scientific basis for returning samples from lunar rock in extreme lunar-based environments.展开更多
An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis sugges...An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.展开更多
Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation a...Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation and development.In this paper,the off-grid wind power hydrogen production system is considered as the research object,and the operating characteristics of a proton exchange membrane(PEM)electrolysis cell,including underload,overload,variable load,and start-stop are analyzed.On this basis,the characteristic extraction of wind power output data after noise reduction is carried out,and then the self-organizing mapping neural network algorithm is used for clustering to extract typical wind power output scenarios and perform weight distribution based on the statistical probability.The trend and fluctuation components are superimposed to generate the typical operating conditions of an off-grid PEM electrolytic hydrogen production system.The historical output data of an actual wind farm are used for the case study,and the results confirm the feasibility of the method proposed in this study for obtaining the typical conditions of off-grid wind power hydrogen production.The results provide a basis for studying the dynamic operation characteristics of PEM electrolytic hydrogen production systems,and the performance degradation mechanism of PEM electrolysis cells under fluctuating inputs.展开更多
Background The neurophysiological differences in cortical plasticity and cholinergic system function due to ageing and their correlation with cognitive function remain poorly understood.Aims To reveal the differences ...Background The neurophysiological differences in cortical plasticity and cholinergic system function due to ageing and their correlation with cognitive function remain poorly understood.Aims To reveal the differences in long-term potentiation(LTP)-like plasticity and short-latency afferent inhibition(SAl)between older and younger individuals,alongside their correlation with cognitive function using transcranial magnetic stimulation(TMS).Methods The cross-sectional study involved 31 younger adults aged 18-30 and 46 older adults aged 60-80.All participants underwent comprehensive cognitive assessments and a neurophysiological evaluation based on TMS.Cognitive function assessments included evaluations of global cognitive function,language,memory and executive function.The neurophysiological assessment included LTP-like plasticity and SAl.Results The findings of this study revealed a decline in LTP among the older adults compared with the younger adults(wald χ^(2)=3.98,p=0.046).Subgroup analysis further demonstrated a significant reduction in SAl level among individuals aged 70-80 years in comparison to both the younger adults(SAI(N20)):(t=-3.37,p=0.018);SAl(N20+4):(t=-3.13,p=0.038)and those aged 60-70(SAl(N20)):(t=3.26,p=0.025);SAl(N20+4):(t=-3.69,p=0.006).Conversely,there was no notable difference in SAl level between those aged 60-70 years and the younger group.Furthermore,after employing the Bonferroni correction,the correlation analysis revealed that only the positive correlation between LTP-like plasticity and language function(r=0.61,p<0.001)in the younger group remained statistically significant.Conclusions During the normal ageing process,a decline in synaptic plasticity may precede cholinergic system dysfunction.In individuals over 60 years of age,there is a reduction in LTP-like plasticity,while a decline in cholinergic system function is observed in those over 70.Thus,the cholinergic system may play a vital role in preventing cognitive decline during normal ageing.In younger individuals,LTP-like plasticity might represent a potential neurophysiological marker for language function.展开更多
How to trigger strong anti-tumor immune responses has become a focus for tumor therapy.Here,we report the human-induced pluripotent stem cells(iPSs)to deliver MnO2@Ce6 nanoprobes into tumors for simultaneous photodyna...How to trigger strong anti-tumor immune responses has become a focus for tumor therapy.Here,we report the human-induced pluripotent stem cells(iPSs)to deliver MnO2@Ce6 nanoprobes into tumors for simultaneous photodynamic therapy(PDT)and enhanced immunotherapy.Ce6 photosensitizer was attached on manganese dioxide(MnO2)nanoparticles,and resultant MnO2@Ce6 nanoprobes were delivered into mitomycin-treated iPSs to form iPS-MnO2@Ce6 nanoprobes.The iPS-MnO2@Ce6 actively targeted in vivo tumors,the acidic microenvironment triggered interaction between MnO2 and H2O2,released large quantities of oxygen,alleviated hypoxia in tumor.Upon PDT,singlet oxygen formed,broken iPSs released tumor-shared antigens,which evoked an intensive innate and adaptive immune response against the tumor,improving dendritic cells matured,effector T cells,and natural killer cells were activated.Meanwhile,regulatory T cells were reduced,and then the immune response induced by iPS-MnO2@Ce6 was markedly stronger than the immune reaction induced by MnO2@Ce6(P<0.05).The iPS-MnO2@Ce6 markedly inhibited tumor growth and metastasis and reduced mortality in mice models with tumor.Human iPS s loaded with MnO2-based nanoprobes are a promising strategy for simultaneous PDT and enhanced immunotherapy against tumor and own clinical translational prospect.展开更多
Objective To assesse the therapeutic effect of interventional therapy in aged patients with unprotected left main coronary artery （UPLM） lesions. Methods A total of 61 patients who were over 60 years and accepted in...Objective To assesse the therapeutic effect of interventional therapy in aged patients with unprotected left main coronary artery （UPLM） lesions. Methods A total of 61 patients who were over 60 years and accepted interventional therapy of UPLM from January 2012 to November 2013 in our hospital were followed up for average 14.6 months by telephone call or outpatient visits. We analyzed the clinical features data of the interventional therapy and assessed the factors that likely influenced the clinical prognosis. Results The average age of the 61 patients was 73.9 years. The average left ventricular ejection fraction （LVEF） was 47.7%. The median of the estimated glomerular filtration rate （eGFR） was 52 mL/min per 1.73 mmz. The average SYNTAX score was 27.4 and the median of stent length was 36 mm. The cumulative incidence of cardiac death at 30 days and major adverse cardiac events （MACE） after one year was 6.6% and 32.5% estimated by Kaplan-Meier plots respectively. No severe hemorrhagic complications were observed during follow-up period. On multivariate regression analysis with a COX proportional hazards model, LVEF was an independent predictor of cardiac death at 30 days [Hazard ratio （HR）： 0.7, P = 0.01]. As for MACE after one year, LVEF and eGFR were both independent predictors （HR： 0.91, P = 0.06 for LVEF, HR： 0.03, P = 0.097 for eGFR）. Conclusions The interventional therapy for UPLM was effective and safe in aged patients. LVEF was the only predictor of cardiac death at 30 days, while LVEF and eGFR were both independent predictors of MACE after one year.展开更多
Background Rotational atherectomy （RA） could facilitate the percutaneous coronary intervention （PCI） in heavily coronary calcified patients. The effectiveness and safety of this technique needs to be further evalu...Background Rotational atherectomy （RA） could facilitate the percutaneous coronary intervention （PCI） in heavily coronary calcified patients. The effectiveness and safety of this technique needs to be further evaluated. Methods ＆ Results Eighty patients who underwent RA in our center from September 2011 to June 2014 were enrolled. The mean age was 72.4 ± 10.4 years. The left ventricular ejection frac- tion （LVEF） was average 52.3% ± 8.48% and the estimated glomerular filtration rate was 73.2 ± 3.20 mL/min per 1.73 m2. The coronary lesions were complex, with Syntax score 29.5 ± 9.86. The diameter of reference vessel was 3.4 ± 0.45 mm and the average diameter stenosis of target vessels was 80% ~ 10%. All the patients were deployed with drug eluting stents （DES） successfully aiter RA. The patients were followed up for 12-18 months. Kaplan-Meier plots estimated the survival rate was 93.4% and the cumulative incidence of major adverse cardiac and cerebral events （MACCE） was 25.4%. Bleeding and procedural-related complications were quite low. COX proportional hazards model for multivariate analysis demonstrated that diabetes, LVEF and maximum pressure of postdilatation were the predictors of MACCE. Conclusions RA followed by implantation of DES was effective and safe for heavily coronary calcified patients. Diabetes, LVEF and maximum pressure ofpostdilatation were predictive for MACCE.展开更多
Takotsubo cardiomyopathy （TTC） was first described by Japanese in 1990. The cardiomyopathy has got this name because the outline of the left ventricle looks like the octo-pus trap. TTC is usually induced by physical...Takotsubo cardiomyopathy （TTC） was first described by Japanese in 1990. The cardiomyopathy has got this name because the outline of the left ventricle looks like the octo-pus trap. TTC is usually induced by physical triggers, emotional triggers, both of them or neither of them some-times. The patients of TTC usually present the symptoms just like acute myocardial infarction or heart failure. Coronary angiography and left ventriculography are able to make the diagnosis and differential diagnosis. Although we have already good recognition of TTC, it might occur to the patients unexpectedly and sometimes preclude early diagnosis of it.展开更多
In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization...In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization and modification of complexity structure without going back to CAD for reconstruction of geometric models or to finite element analysis（ FEA） for remodeling. Design of experiments（ DOE） and response surface method（ RSM） are applied to approximate the constitutive parameters of a machine gun system based on experimental tests. Further FEA,secondary development technique and genetic algorithm（ GA） are introduced to find all the optimal solutions in one go and the optimal design of the demonstrated machine gun system is obtained. Results of the rigid-flexible coupling dynamic analysis and exterior ballistics calculation validate the proposed methodology,which is relatively time-saving,reliable and has the potential to solve similar problems.展开更多
To deal with the problem that the initial velocity of the bullet is difficult to increase,the research on the super-high initial velocity propulsion in the barrel weapon with an adaptive pressure-maintaining chamber a...To deal with the problem that the initial velocity of the bullet is difficult to increase,the research on the super-high initial velocity propulsion in the barrel weapon with an adaptive pressure-maintaining chamber are conducted.Considering the law of gun-powder burning and the flow characteristics of gun-powder gas in multi-chamber,the scheme of super-high initial velocity propulsion with an adaptive pressure-maintaining chamber is designed,the ballistic model of the barrel weapon with super-high velocity bullet propulsion is established.The research results show that the technical scheme can greatly increase the initial velocity of the bullet with the peak pressure keeping nearly the same as the tradition barrel weapon.The research results can provide a theoretical foundation to significantly increase the initial velocity in barrel weapons using solid propellants,and have an important reference value to comprehensively increase the power of the barrel weapons.展开更多
As a frontier of biology,mechanobiology plays an important role in tissue and biomedical engineering.It is a common sense that mechanical cues under extracellular microenvironment affect a lot in regulating the behavi...As a frontier of biology,mechanobiology plays an important role in tissue and biomedical engineering.It is a common sense that mechanical cues under extracellular microenvironment affect a lot in regulating the behaviors of cells such as proliferation and gene expression,etc.In such an interdisciplinary field,engineering methods like the pneumatic and motor-driven devices have been employed for years.Nevertheless,such techniques usually rely on complex structures,which cost much but not so easy to control.Dielectric elastomer actuators(DEAs)are well known as a kind of soft actuation technology,and their research prospect in biomechanical field is gradually concerned due to their properties just like large deformation(>100%)and fast response(<1 ms).In addition,DEAs are usually optically transparent and can be fabricated into small volume,which make them easy to cooperate with regular microscope to realize real-time dynamic imaging of cells.This paper first reviews the basic components,principle,and evaluation of DEAs and then overview some corresponding applications of DEAs for cellular mechanobiology research.We also provide a comparison between DEA-based bioreactors and current custom-built devices and share some opinions about their potential applications in the future according to widely reported results via other methods.展开更多
Chemical disorder on the surface and lattice strain in GaN implanted by Fe^(10+)ions are investigated.In this study,3-MeV Fe^(10+)ions fluence ranges from 1×10^(13)ions/cm^(2)to 5×10^(15)ions/cm^(2)at room t...Chemical disorder on the surface and lattice strain in GaN implanted by Fe^(10+)ions are investigated.In this study,3-MeV Fe^(10+)ions fluence ranges from 1×10^(13)ions/cm^(2)to 5×10^(15)ions/cm^(2)at room temperature.X-ray photoelectron spectroscopy,high-resolution x-ray diffraction,and high-resolution transmission electron microscopy were used to characterize lattice disorder.The transition of Ga-N bonds to oxynitride bonding is caused by ion sputtering.The change of tensile strain out-of-plane with fluence was measured.Lattice disorder due to the formation of stacking faults prefers to occur on the basal plane.展开更多
In the optical quantum random walk system,phase nuctuation and Deam splitter uuctuation are two unavoldable decoherence factors.These two factors degrade the performance of quantum random walk by destroying coherence,...In the optical quantum random walk system,phase nuctuation and Deam splitter uuctuation are two unavoldable decoherence factors.These two factors degrade the performance of quantum random walk by destroying coherence,and even degrade it into a classical one.We propose a scheme for the simulation of quantum random walk using phase shifters,tunable beam splitters,and photodetectors.This proposed scheme enables us to analyze the effect of phase fluctuation and beam splitter fluctuation on two-photon quantum random walk.Furthermore,it is helpful to guide the control of phase fluctuation and beam snlitter fluctuation in the exneriment.展开更多
The Shanghai advanced proton therapy facility is a proton cancer treatment device designed and built by the Shanghai Institute of applied physics at the Chinese academy of sciences.The accelerator part comprises a pro...The Shanghai advanced proton therapy facility is a proton cancer treatment device designed and built by the Shanghai Institute of applied physics at the Chinese academy of sciences.The accelerator part comprises a proton linear accelerator(linac)injector and a circular synchrotron.An alternating current current transformer(ACCT)is used for non-intercepting beam current measurement at the drift tube linac exit.According to the beam characteristics,the ACCT is required to complete real-time beam current and pulse width measurements at currents of3-30 mA,frequencies of 1-10 Hz,and pulse widths of40-400μs.In this paper,we report the design and development of an ACCT.The designed ACCT was simulated using CST Microwave Studio,and calibrated using an oscilloscope and signal generator.Variations in the output signal of the ACCT were investigated as a function of ceramic gap size,number of coil turns,and resistance.According to the simulation and experimental results,the optimal number of coil turns was found to be 30.In addition,a low-pass filter was adopted to filter the noise introduced during long-distance signal transmission using a coaxial cable with the length of 20 m.The calibration results show that the corresponding rise time of the ACCT is 800 ns with the sensitivity of 8.2 V/A and a droop of less than 1%,meeting the design requirements.展开更多
Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capac...Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capacity fading.Herein,the dual-strategy of Cr,B complex coating and local gradient doping is simultaneously achieved on LLO surface by a one-step wet chemical reaction at room temperature.Density functional theory(DFT)calculations prove that stable B-O and Cr-O bonds through the local gradient doping can significantly reduce the high-energy O 2p states of interfacial lattice O,which is also effective for the near-surface lattice O,thus greatly stabilizing the LLO surface,Besides,differential electrochemical mass spectrometry(DEMS)indicates that the Cr_(x)B complex coating can adequately inhibit oxygen release and prevents the migration or dissolution of transition metal ions,including allowing speedy Li^(+)migration,The voltage and capacity fading of the modified cathode(LLO-C_(r)B)are adequately suppressed,which are benefited from the uniformly dense cathode electrolyte interface(CEI)composed of balanced organic/inorganic composition.Therefore,the specific capacity of LLO-CrB after 200 cycles at 1C is 209.3 mA h g^(-1)(with a retention rate of 95.1%).This dual-strategy through a one-step wet chemical reaction is expected to be applied in the design and development of other anionic redox cathode materials.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52225403,U2013603,52434004,and 52404365)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08G315)+2 种基金the Shenzhen National Science Fund for Distinguished Young Scholars(No.RCJC20210706091948015)the National Key Research and Development Program of China(2023YFF0615404)the Scientific Instrument Developing Project of Shenzhen University。
文摘The lunar surface and its deep layers contain abundant resources and valuable information resources,the exploration and exploitation of which are important for the sustainable development of the human economy and society.Technological exploration and research in the field of deep space science,especially lunar-based exploration,is a scientific strategy that has been pursued in China and worldwide.Drilling and sampling are key to accurate exploration of the desirable characteristics of deep lunar resources.In this study,an in-situ condition preserved coring(ICP-Coring)and analysis system,which can be used to test drilling tools and develop effective sampling strategies,was designed.The key features of the system include:(1)capability to replicate the extreme temperature fluctuations of the lunar environment(-185 to 200℃)with intelligent temperature control;(2)ability to maintain a vacuum environment at a scale of 10^(-3) Pa,both under unloaded conditions within Ф580 mm×1000 mm test chamber,and under loaded conditions using Ф400 mm×800 mm lunar rock simulant;(3)application of axial pressures up to 4 MPa and confining pressures up to 3.5 MPa;(4)sample rotation at any angle with a maximum sampling length of 800 mm;and(5)multiple modes of rotary-percussive drilling,controlled by penetration speed and weight on bit(WOB).Experimental studies on the drilling characteristics in the lunar rock simulant-loaded state under different drill bit-percussive-vacuum environment configurations were conducted.The results show that the outgassing rate of the lunar soil simulant is greater than that of the lunar rock simulant and that a low-temperature environment contributes to a reduced vacuum of the lunar-based simulated environment.The rotary-percussive drilling method effectively shortens the sampling time.With increasing sampling depth,the temperature rise of the drilling tools tends to rapidly increase,followed by slow growth or steady fluctuations.The temperature rise energy accumulation of the drill bits under vacuum is more significant than that under atmospheric pressure,approximately 1.47 times higher.The real-time monitored drilling pressure,penetration speed and rotary torque during drilling serve as parameters for discriminating the drilling status.The results of this research can provide a scientific basis for returning samples from lunar rock in extreme lunar-based environments.
基金supported by the Sino-German Postdoc Scholarship Program of the China Scholarship Council(CSC)the German Academic Exchange Service(DAAD)+4 种基金supported in part by the National Natural Science Foundation of China(Nos.32071541,41971071)the Ministry of Science and Technology of China(Nos.2021FY100200,2021FY100702,2023YFF0805802)the Youth Innovation Promotion Association,CAS(No.2021392)the International Partnership Program,CAS(No.151853KYSB20190027)the“Climate Change Research Initiative of the Bavarian National Parks”funded by the Bavarian State Ministry of the Environment and Consumer Protection.
文摘An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.
基金supported by the National Key Research and Development Program of China(Program Number 2021YFB4000100)the Beijing Postdoctoral Research Foundation(Grant Number 2023-ZZ-63).
文摘Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation and development.In this paper,the off-grid wind power hydrogen production system is considered as the research object,and the operating characteristics of a proton exchange membrane(PEM)electrolysis cell,including underload,overload,variable load,and start-stop are analyzed.On this basis,the characteristic extraction of wind power output data after noise reduction is carried out,and then the self-organizing mapping neural network algorithm is used for clustering to extract typical wind power output scenarios and perform weight distribution based on the statistical probability.The trend and fluctuation components are superimposed to generate the typical operating conditions of an off-grid PEM electrolytic hydrogen production system.The historical output data of an actual wind farm are used for the case study,and the results confirm the feasibility of the method proposed in this study for obtaining the typical conditions of off-grid wind power hydrogen production.The results provide a basis for studying the dynamic operation characteristics of PEM electrolytic hydrogen production systems,and the performance degradation mechanism of PEM electrolysis cells under fluctuating inputs.
基金the National Key Research and Development Program of China(2022YFC2009700)the National Science Foundation of China(82372582)+1 种基金the Medical Applications Basic Research Project of Suzhou Science and Technology Bureau(SKY2023033)the Wujiang District Science,Education,Health and Promotion Project(WWK202021).
文摘Background The neurophysiological differences in cortical plasticity and cholinergic system function due to ageing and their correlation with cognitive function remain poorly understood.Aims To reveal the differences in long-term potentiation(LTP)-like plasticity and short-latency afferent inhibition(SAl)between older and younger individuals,alongside their correlation with cognitive function using transcranial magnetic stimulation(TMS).Methods The cross-sectional study involved 31 younger adults aged 18-30 and 46 older adults aged 60-80.All participants underwent comprehensive cognitive assessments and a neurophysiological evaluation based on TMS.Cognitive function assessments included evaluations of global cognitive function,language,memory and executive function.The neurophysiological assessment included LTP-like plasticity and SAl.Results The findings of this study revealed a decline in LTP among the older adults compared with the younger adults(wald χ^(2)=3.98,p=0.046).Subgroup analysis further demonstrated a significant reduction in SAl level among individuals aged 70-80 years in comparison to both the younger adults(SAI(N20)):(t=-3.37,p=0.018);SAl(N20+4):(t=-3.13,p=0.038)and those aged 60-70(SAl(N20)):(t=3.26,p=0.025);SAl(N20+4):(t=-3.69,p=0.006).Conversely,there was no notable difference in SAl level between those aged 60-70 years and the younger group.Furthermore,after employing the Bonferroni correction,the correlation analysis revealed that only the positive correlation between LTP-like plasticity and language function(r=0.61,p<0.001)in the younger group remained statistically significant.Conclusions During the normal ageing process,a decline in synaptic plasticity may precede cholinergic system dysfunction.In individuals over 60 years of age,there is a reduction in LTP-like plasticity,while a decline in cholinergic system function is observed in those over 70.Thus,the cholinergic system may play a vital role in preventing cognitive decline during normal ageing.In younger individuals,LTP-like plasticity might represent a potential neurophysiological marker for language function.
基金financially supported by National Nature Scientific foundation(81803094,81802979 and 81921002)the National Foundational Basic Research Project of China(2017YFA0205301 and 2015CB931802)+3 种基金Shanghai Municipal Commission of Economy and Information Technology Fund(No.XC-ZXSJ-02-2016-05)the medical engineering cross project of Shanghai Jiao Tong university(YG2017ZD05,YG2016ZD10 and YG2017Z D05)the Project of Thousand Youth Talents from Chinathe National Key Research and Development Program of China(2017YFC1200904 and 2017YFE0124400)。
文摘How to trigger strong anti-tumor immune responses has become a focus for tumor therapy.Here,we report the human-induced pluripotent stem cells(iPSs)to deliver MnO2@Ce6 nanoprobes into tumors for simultaneous photodynamic therapy(PDT)and enhanced immunotherapy.Ce6 photosensitizer was attached on manganese dioxide(MnO2)nanoparticles,and resultant MnO2@Ce6 nanoprobes were delivered into mitomycin-treated iPSs to form iPS-MnO2@Ce6 nanoprobes.The iPS-MnO2@Ce6 actively targeted in vivo tumors,the acidic microenvironment triggered interaction between MnO2 and H2O2,released large quantities of oxygen,alleviated hypoxia in tumor.Upon PDT,singlet oxygen formed,broken iPSs released tumor-shared antigens,which evoked an intensive innate and adaptive immune response against the tumor,improving dendritic cells matured,effector T cells,and natural killer cells were activated.Meanwhile,regulatory T cells were reduced,and then the immune response induced by iPS-MnO2@Ce6 was markedly stronger than the immune reaction induced by MnO2@Ce6(P<0.05).The iPS-MnO2@Ce6 markedly inhibited tumor growth and metastasis and reduced mortality in mice models with tumor.Human iPS s loaded with MnO2-based nanoprobes are a promising strategy for simultaneous PDT and enhanced immunotherapy against tumor and own clinical translational prospect.
文摘Objective To assesse the therapeutic effect of interventional therapy in aged patients with unprotected left main coronary artery （UPLM） lesions. Methods A total of 61 patients who were over 60 years and accepted interventional therapy of UPLM from January 2012 to November 2013 in our hospital were followed up for average 14.6 months by telephone call or outpatient visits. We analyzed the clinical features data of the interventional therapy and assessed the factors that likely influenced the clinical prognosis. Results The average age of the 61 patients was 73.9 years. The average left ventricular ejection fraction （LVEF） was 47.7%. The median of the estimated glomerular filtration rate （eGFR） was 52 mL/min per 1.73 mmz. The average SYNTAX score was 27.4 and the median of stent length was 36 mm. The cumulative incidence of cardiac death at 30 days and major adverse cardiac events （MACE） after one year was 6.6% and 32.5% estimated by Kaplan-Meier plots respectively. No severe hemorrhagic complications were observed during follow-up period. On multivariate regression analysis with a COX proportional hazards model, LVEF was an independent predictor of cardiac death at 30 days [Hazard ratio （HR）： 0.7, P = 0.01]. As for MACE after one year, LVEF and eGFR were both independent predictors （HR： 0.91, P = 0.06 for LVEF, HR： 0.03, P = 0.097 for eGFR）. Conclusions The interventional therapy for UPLM was effective and safe in aged patients. LVEF was the only predictor of cardiac death at 30 days, while LVEF and eGFR were both independent predictors of MACE after one year.
文摘Background Rotational atherectomy （RA） could facilitate the percutaneous coronary intervention （PCI） in heavily coronary calcified patients. The effectiveness and safety of this technique needs to be further evaluated. Methods ＆ Results Eighty patients who underwent RA in our center from September 2011 to June 2014 were enrolled. The mean age was 72.4 ± 10.4 years. The left ventricular ejection frac- tion （LVEF） was average 52.3% ± 8.48% and the estimated glomerular filtration rate was 73.2 ± 3.20 mL/min per 1.73 m2. The coronary lesions were complex, with Syntax score 29.5 ± 9.86. The diameter of reference vessel was 3.4 ± 0.45 mm and the average diameter stenosis of target vessels was 80% ~ 10%. All the patients were deployed with drug eluting stents （DES） successfully aiter RA. The patients were followed up for 12-18 months. Kaplan-Meier plots estimated the survival rate was 93.4% and the cumulative incidence of major adverse cardiac and cerebral events （MACCE） was 25.4%. Bleeding and procedural-related complications were quite low. COX proportional hazards model for multivariate analysis demonstrated that diabetes, LVEF and maximum pressure of postdilatation were the predictors of MACCE. Conclusions RA followed by implantation of DES was effective and safe for heavily coronary calcified patients. Diabetes, LVEF and maximum pressure ofpostdilatation were predictive for MACCE.
文摘Takotsubo cardiomyopathy （TTC） was first described by Japanese in 1990. The cardiomyopathy has got this name because the outline of the left ventricle looks like the octo-pus trap. TTC is usually induced by physical triggers, emotional triggers, both of them or neither of them some-times. The patients of TTC usually present the symptoms just like acute myocardial infarction or heart failure. Coronary angiography and left ventriculography are able to make the diagnosis and differential diagnosis. Although we have already good recognition of TTC, it might occur to the patients unexpectedly and sometimes preclude early diagnosis of it.
基金Supported by the National Natural Science Foundation of China(51376090,51676099)
文摘In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization and modification of complexity structure without going back to CAD for reconstruction of geometric models or to finite element analysis（ FEA） for remodeling. Design of experiments（ DOE） and response surface method（ RSM） are applied to approximate the constitutive parameters of a machine gun system based on experimental tests. Further FEA,secondary development technique and genetic algorithm（ GA） are introduced to find all the optimal solutions in one go and the optimal design of the demonstrated machine gun system is obtained. Results of the rigid-flexible coupling dynamic analysis and exterior ballistics calculation validate the proposed methodology,which is relatively time-saving,reliable and has the potential to solve similar problems.
基金Supported by the National Natural Science Foundation of China(51676099,51376090)the Natural Science Foundation of Jiangsu Province(BK20180473)。
文摘To deal with the problem that the initial velocity of the bullet is difficult to increase,the research on the super-high initial velocity propulsion in the barrel weapon with an adaptive pressure-maintaining chamber are conducted.Considering the law of gun-powder burning and the flow characteristics of gun-powder gas in multi-chamber,the scheme of super-high initial velocity propulsion with an adaptive pressure-maintaining chamber is designed,the ballistic model of the barrel weapon with super-high velocity bullet propulsion is established.The research results show that the technical scheme can greatly increase the initial velocity of the bullet with the peak pressure keeping nearly the same as the tradition barrel weapon.The research results can provide a theoretical foundation to significantly increase the initial velocity in barrel weapons using solid propellants,and have an important reference value to comprehensively increase the power of the barrel weapons.
基金the financial support from the National Natural Science Foundation of China(Grant Nos.81822024,11761141006,and 21605102)the National Key Research and Development Program of China(Grant No.2017YFC1200904).
文摘As a frontier of biology,mechanobiology plays an important role in tissue and biomedical engineering.It is a common sense that mechanical cues under extracellular microenvironment affect a lot in regulating the behaviors of cells such as proliferation and gene expression,etc.In such an interdisciplinary field,engineering methods like the pneumatic and motor-driven devices have been employed for years.Nevertheless,such techniques usually rely on complex structures,which cost much but not so easy to control.Dielectric elastomer actuators(DEAs)are well known as a kind of soft actuation technology,and their research prospect in biomechanical field is gradually concerned due to their properties just like large deformation(>100%)and fast response(<1 ms).In addition,DEAs are usually optically transparent and can be fabricated into small volume,which make them easy to cooperate with regular microscope to realize real-time dynamic imaging of cells.This paper first reviews the basic components,principle,and evaluation of DEAs and then overview some corresponding applications of DEAs for cellular mechanobiology research.We also provide a comparison between DEA-based bioreactors and current custom-built devices and share some opinions about their potential applications in the future according to widely reported results via other methods.
基金Project supported by the National Natural Science Foundation of China(Grant No.12075194)the Fund of Collage Student Innovation and Entrepreneurship Training Program(Grant No.S202010619053)。
文摘Chemical disorder on the surface and lattice strain in GaN implanted by Fe^(10+)ions are investigated.In this study,3-MeV Fe^(10+)ions fluence ranges from 1×10^(13)ions/cm^(2)to 5×10^(15)ions/cm^(2)at room temperature.X-ray photoelectron spectroscopy,high-resolution x-ray diffraction,and high-resolution transmission electron microscopy were used to characterize lattice disorder.The transition of Ga-N bonds to oxynitride bonding is caused by ion sputtering.The change of tensile strain out-of-plane with fluence was measured.Lattice disorder due to the formation of stacking faults prefers to occur on the basal plane.
基金Project supported by the National Natural Science Foundation of China(Grant No.61701139).
文摘In the optical quantum random walk system,phase nuctuation and Deam splitter uuctuation are two unavoldable decoherence factors.These two factors degrade the performance of quantum random walk by destroying coherence,and even degrade it into a classical one.We propose a scheme for the simulation of quantum random walk using phase shifters,tunable beam splitters,and photodetectors.This proposed scheme enables us to analyze the effect of phase fluctuation and beam splitter fluctuation on two-photon quantum random walk.Furthermore,it is helpful to guide the control of phase fluctuation and beam snlitter fluctuation in the exneriment.
基金supported by the Ministry of Education of the People's Republic of China(MOE)(No.021312921002)。
文摘The Shanghai advanced proton therapy facility is a proton cancer treatment device designed and built by the Shanghai Institute of applied physics at the Chinese academy of sciences.The accelerator part comprises a proton linear accelerator(linac)injector and a circular synchrotron.An alternating current current transformer(ACCT)is used for non-intercepting beam current measurement at the drift tube linac exit.According to the beam characteristics,the ACCT is required to complete real-time beam current and pulse width measurements at currents of3-30 mA,frequencies of 1-10 Hz,and pulse widths of40-400μs.In this paper,we report the design and development of an ACCT.The designed ACCT was simulated using CST Microwave Studio,and calibrated using an oscilloscope and signal generator.Variations in the output signal of the ACCT were investigated as a function of ceramic gap size,number of coil turns,and resistance.According to the simulation and experimental results,the optimal number of coil turns was found to be 30.In addition,a low-pass filter was adopted to filter the noise introduced during long-distance signal transmission using a coaxial cable with the length of 20 m.The calibration results show that the corresponding rise time of the ACCT is 800 ns with the sensitivity of 8.2 V/A and a droop of less than 1%,meeting the design requirements.
基金financially supported by the National Natural Science Foundation of China(No.12304077)the Natural Science Foundation of Science and Technology Department of Sichuan Province(No.23NSFSC6224)+3 种基金Sichuan Science and Technology Program(No.2024NSFSC0989)the Key Laboratory of Computational Physics of Sichuan Province(No.YBUJSWL-YB-2022-03)the Material Corrosion and Protection Key Laboratory of Sichuan Province(No.2023CL14 and No.2023CL01)the National Innovation Practice Project(No.202411079005S).
文摘Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capacity fading.Herein,the dual-strategy of Cr,B complex coating and local gradient doping is simultaneously achieved on LLO surface by a one-step wet chemical reaction at room temperature.Density functional theory(DFT)calculations prove that stable B-O and Cr-O bonds through the local gradient doping can significantly reduce the high-energy O 2p states of interfacial lattice O,which is also effective for the near-surface lattice O,thus greatly stabilizing the LLO surface,Besides,differential electrochemical mass spectrometry(DEMS)indicates that the Cr_(x)B complex coating can adequately inhibit oxygen release and prevents the migration or dissolution of transition metal ions,including allowing speedy Li^(+)migration,The voltage and capacity fading of the modified cathode(LLO-C_(r)B)are adequately suppressed,which are benefited from the uniformly dense cathode electrolyte interface(CEI)composed of balanced organic/inorganic composition.Therefore,the specific capacity of LLO-CrB after 200 cycles at 1C is 209.3 mA h g^(-1)(with a retention rate of 95.1%).This dual-strategy through a one-step wet chemical reaction is expected to be applied in the design and development of other anionic redox cathode materials.
