检索结果-南通市图书馆

Damage constitutive model of lunar soil simulant geopolymer under impact loading

Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1059-1071页

作者： Hanyan Wang Qinyong ma Qianyun Wu School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan232001China Engineering Research Center of Underground Mine Construction Ministry of EducationAnhui University of Science and TechnologyHuainan232001China

Lunar base construction is a crucial component of the lunar exploration program,and considering the dynamic characteristics of lunar soil is important for moon ***,investigating the dynamic properties of lunar soil by establishing a constitutive relationship is critical for providing a theoretical basis for its damage *** this paper,a split Hopkinson pressure bar(SHPB)device was used to perform three sets of impact tests under different pressures on a lunar soil simulant geopolymer(LSSG)with sodium silicate(Na_(2)SiO_(3))contents of 1%,3%,5%and 7%.The dynamic stressestrain curves,failure modes,and energy variation rules of LSSG under different pressures were *** equation was modified based on the ZWT viscoelastic constitutive model and was combined with the damage *** damage element obeys the Weibull distribution and the constitutive equation that can describe the mechanical properties of LSSG under dynamic loading was *** results demonstrate that the dynamic compressive strength of LSSG has a.ma.ked strain-rate strengthening ***_(2)SiO_(3) has both strengthening and deterioration effects on the dynamic compressive strength of *** Na_(2)SiO_(3) grows,the dynamic compressive strength of LSSG first increases and then *** a fixed air pressure,5%Na_(2)SiO_(3) had the largest dynamic compressive strength,the largest incident energy,the smallest absorbed energy,and the lightest *** ZWT equation was modified according to the stress response properties of LSSG and the range of the SHPB strain rate to obtain the constitutive equation of the LSSG,and the model’s correctness was confirmed.

关键词： Lunar soil simulant geopolymer(LSSG) Split hopkinson pressure bar(SHPB)test Constitutive model Energy analysis Failure mode

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Reassessing the contributions of terrestrial waters to sea level variations in the South China Sea and its response to alternating ENSO events

引用

Science China Earth Sciences 2024年第7期67卷 2253-2267页

作者： Pengfei YANG Hok Sum FOK Zhongtian ma MOE Key Laboratory of Geospace Environment and Geodesy&MNR Key Laboratory of Geophysical Geodesy School of Geodesy and GeomaticsWuhan UniversityWuhan 430079China Hubei Luojia Laboratory Wuhan 730079China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong Kong 999077China

Regional sea level variability is linked to regional terrestrial water and the el Ni?o-Southern Oscillation(ENSO).This study assessed the relationships between the sea level variations in the South China Sea(SCS)and ENSO,the impact of terrestrial water storage(TWS)on non-steric sea level(NSSL),and the contributions of steric sea level(SSL)and NSSL to sea level anomaly(SLA),*** 2003 to 2015,the SLAs exhibited a long-term trend of 6.65±0.78 mm/yr,which was primarily attributed to the ***,during 2003-2015,ENSO events alternating with varying intensities might also be responsible for the unusually high SLA *** to the SSLs,the NSSLs contributed the seasonal signals to the SLAs,while the NSSLs changes were largely explained by the TWS in the Mekong River Basin at the seasonal scale and in the Pearl River Basin and Red River Basin at other time *** contrast to the TWS,the contributions of precipitation and evapotranspiration were relatively minor.A negative correlation between the sea level variations and ENSO was also found,with cross-correlation coefficients between the oceanic Ni?o index and SLAs/SSLs/NSSLs of -0.36/-0.37/-0.62 with lags of 2/3/2 months,*** findings systematically reassessed the contributions of different components to the sea level *** study provided a benchmark for in-depth analysis of the impacts of terrestrial water and other potential causes on sea level rise in the SCS.

关键词： South China Sea Sea level variations Terrestrial water storage ENSO

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

引用

National Science Review 2024年第4期11卷 111-122页

作者： Rui Zhang Qi Meng Zhi-Ming ma Academy of mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional *** to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computing Persistent Homology by Spanning Trees and Critical Simplices

引用

Research 2024年第2期2023卷 519-527页

作者： Dinghua Shi Zhifeng Chen Chuang ma Guanrong Chen Department of mathematics Cllege of ScienceShanghai UniversityShanghaiChina School of Big Data Fuzhou University of International Studies and TradeFuzhouChina Department of Data Science and Big Data Technology School of InternetAnhui UniversityHefeiChina Department of electrical Engineering City University of Hong KongHong KongChina

Topological data analysis can extract effective information from higher-dimensional *** mathematical basis is persistent *** persistent homology can calculate topological features at different spatiotemporal scales of the dataset,that is,establishing the integrated taxonomic relation among points,lines,and ***,the simplicial network composed of all-order simplices in a simplicial complex is *** the sequence of nested simplicial subnetworks can be regarded as a discrete Morse function from the simplicial network to real values,a method based on the concept of critical simplices can be developed by searching all-order spanning *** this new method,not only the Morse function values with the theoretical minimum number of critical simplices can be obtained,but also the Betti numbers and composition of all-order cavities in the simplicial network can be calculated ***,this method is used to analyze some examples and compared with other methods,showing its effectiveness and feasibility.

关键词： Morse establishing topological

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of pla.ma.spraying process on microstructure and mechanical properties of Cr2AlC/410 composite coatings

引用

高速铁路（英文） 2024年第2期2卷 110-115页

作者： Yihu ma Chaosheng ma Guozheng ma Wenbo Yu Center of materials Science and Engineering School of Mechanical and electronic Control Engineering Beijing Jiaotong University Beijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China

To investigate the influences of Cr2AlC mass fraction and supersonic pla.ma.spraying process on the mi-crostructure and mechanical properties of Cr2AlC reinforced 410 stainless steel composite coatings,the coatings containing different mass fractions of Cr2AlC were prepared and *** composite coating exhibited low porosity and high adhesion *** addition of Cr2AlC significantly enhanced the hardness of the composite coatings through particle ***,when the mass fraction of Cr2AlC was 20％,the aggregation of Cr2AlC resulted in a strong decrease in the coating preparation efficiency,as well as a decline in adhesion *** the supersonic pla.ma.spraying process,the Ar flow rate mainly influenced the flight velocity of the particles,while the H2 flow rate and the current mainly affected the temperature of the pla.ma.***,all of them influenced the melting degree of particles and the quality of the *** lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125L/min,the H2 flow rate is 25L/min,and the current is 385 A.

关键词： maX phase Pla.ma.spray Parameter Coating

来源：博看期刊评论

在线全文

博看期刊

学校读者我要写书评

暂无评论

A Bronchopulmonary Onset of Candidemia Revealing a Granulomatosis with Polyangiitis

引用

Case Reports in Clinical Medicine 2024年第5期13卷 147-154页

作者： Cha.ma. Zeroual Mina Moudatir Khadija Echchilali Leila Barakat Hassan el Kabli Department of Internal Medicine Ibn Rochd University Hospital Center Casablanca Morocco

Candidemia is defined as being a yeast infection confirmed by the presence of at least one positive Candida blood culture. It is a life threatening infection causing high mortality. The clinical signs are generally compatible with the causative agent (whether there is a deep venous catheter or not). On the other hand and according to the 2012 Revised Chapel Hill Classification, granulomatosis with polyangiitis GPA is classified as a vasculitis associated with antineutrophil cytoplasmic antibodies ANCA. It is a systemic disease characterized by the anatomopathological aspect of granuloma. We report the case of a patient who presented an atypical and a very rare revealing mode of GPA which was a bronchopulmonary candidiasis complicated by candidemia. Despite its controversy, the combination in the acute phase of antifungal treatment based on intravenous voriconazole and glucocorticoid therapy has made it possible to control candidemia and calm vasculitis.

关键词： Candidemia C. glabrata Pulmonary Candidiasis Vasculitis Immunodepression Granulomatosis with Polyangiitis Cavitary Lesions Antifungal Therapy Immunosuppressants

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Near-infrared non-fused electron acceptors for efficient organic photovoltaics

引用

Chinese Chemical Letters 2024年第4期35卷 436-441页

作者： Wenxiang ma Xinyu He Tianyi Chen De-Li ma Hongzheng Chen Chang-Zhi Li State Key Laboratory of Silicon and Advanced Semiconductor materials Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Developing narrow-bandgap organic semiconductors is important to facilitate the advancement of organic photovoltaics(OPVs). Herein, two near-infrared non-fused ring acceptors(NIR NFRAs), PTBFTT-F and PTBFTT-Cl have been developed with A-π_A-π_D-D-π_D-π_A-A non-fused structures. It is revealed that the introduction of electron deficient π-bridge(π_A) and multiple intramolecular noncovalent interactions effectively retained the structural planarity and intramolecular charge transfer of NFRAs, extending strong NIR photon absorption up to 950 nm. Further, the chlorinated acceptor, with the enlarged π-surface compared to the fluorinated counterpart, promoted not only molecular stacking in solid, but also the desirable photochemical stability in ambient, which are helpful to thereby improve the exciton and charge dynamics for the corresponding OPVs. Overall, this work provides valuable insights into the design of NIR organic semiconductors.

关键词： Organic photovoltaic Near-infrared Non-fused electron acceptor Noncovalent interaction Stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Review on heat-to-power conversion technologies for hypersonic vehicles

引用

Chinese Journal of Aeronautics 2024年第5期37卷 148-179页

作者： Yinke QI Xiaofeng ma Peixue JIANG Yinhai ZHU Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Beijing Key Laboratory of CO_(2)Utilization and Reduction Technology Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

Hypersonic vehicles have enormous military and economic value,while their power and thermal protection demands will increase substantially with the rise in mach number and *** the tremendous high-quality heat on the vehicle surface and engine wall into electrical energy through heat-to-power technologies will not only play a role in thermal protection,but also supply power for the *** paper provides a comprehensive review of heat-to-power conversion technologies on hypersonic vehicles,including the indirect conversion of Brayton and Rankine cycles,direct conversion of thermoelectric materials,and combined *** the open Brayton cycle with hydrocarbon fuel as the working fluid,the Power-to-Weight Ratio(PWR)can achieve the highest,at around 1.8,due to the high PWR of the hydrocarbon fuel turbine and the few components of the ***,its work capacity is limited by the flow rate of the supplied *** closed Brayton cycle can maintain a relatively high PWR,ranging from 0.2 to 0.8,while achieving relatively high output power and conversion *** Rankine cycle has a higher PWR,its range is close to that of the closed Brayton cycle,peaking at about *** thermoelectric materials technology has a small power generation level,making it more suitable for scenarios with low power *** review provides a basis for selecting and developing heat-to-power conversion technologies on hypersonic vehicles.

关键词： Hypersonic vehicles Heat-to-power conversion Brayton cycle Rankine cycle Thermoelectric materials

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Age of Information for Short-Packet Covert Communication with Time Modulated Retrodirective Array

引用

China Communications 2024年第4期21卷 23-37页

作者： ma Yue ma Ruiqian Lin Zhi Yang Weiwei Cai Yueming Miao Chen Wu Wen Key Laboratory of Near-Range RF Sensing ICs&Microsystems(NJUST) Ministry of EducationSchool of Electronic and Optical EngineeringNanjing University of Science and TechnologyNanjing 210094China College of electronic Engineering National University of Defense TechnologyHefei 230037China College of Communications Engineering Army Engineering University of PLANanjing 210007China

In this paper,the covert age of information(CAoI),which characterizes the timeliness and covertness performance of communication,is first investigated in the short-packet covert communication with time modulated retrodirective array(TMRDA).Specifically,the TMRDA is designed to maximize the antenna gain in the target direction while the side lobe is sufficiently *** this basis,the covertness constraint and CAoI are derived in closed *** facilitate the covert transmission design,the transmit power and block-length are jointly optimized to minimize the CAoI,which demonstrates the trade-off between covertness and *** results illustrate that there exists an optimal block-length that yields the minimum CAoI,and the presented optimization results can achieve enhanced performance compared with the fixed block-length ***,we observe that smaller beam pointing error at Bob leads to improvements in CAoI.

关键词： age of information covert communication retrodirective array time modulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fast source mask co-optimization method for high-NA EUV lithography

引用

Opto-electronic Advances 2024年第4期7卷 44-54页

作者： Ziqi Li Lisong Dong Xu ma Yayi Wei EDA Center Institute of Microelectronics of Chinese Academy of SciencesBeijing 100029China Key Laboratory of Photoelectronic Imaging Technology and System of Ministry of Education of China School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China Guangdong Greater Bay Area Applied Research Institute of Integrated Circuit and Systems Guangzhou 510700China

Extreme ultraviolet(EUV)lithography with high numerical aperture(NA)is a future technology to manufacture the integrated circuit in sub-nanometer ***,source mask co-optimization(SMO)is an extensively used approach for advanced lithography process beyond 28 nm technology *** work proposes a novel SMO method to improve the image fidelity of high-NA EUV lithography system.A fast high-NA EUV lithography imaging model is established first,which includes the effects of mask three-dimensional structure and anamorphic ***,this paper develops an efficient SMO method that combines the gradient-based mask optimization algorithm and the compressivesensing-based source optimization algorithm.a.ma.k rule check(MRC)process is further proposed to simplify the optimized mask *** illustrate that the proposed SMO method can significantly reduce the lithography patterning error,and maintain high computational efficiency.

关键词： computational lithography high-NA EUV lithography source-mask co-optimization lithography imaging model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：