检索结果-南通市图书馆

Indentation behavior of a semi-infinite piezoelectric semiconductor under a rigid flat-ended cylindrical indenter

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 649-662页

作者： shijing GAO Lele ZHANG Jinxi LIU Guoquan nie Weiqiu CHEN State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China Hebei Key Laboratory for Mechanics of Intelligent Materials and Structures Department of Engineering MechanicsShijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Computer Aided Design and Computer Graphics Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceDepartment of Engineering MechanicsZhejiang UniversityHangzhou 310027China

This paper theoretically studies the axisymmetric frictionless indentation of a transversely isotropic piezoelectric semiconductor(PSC)half-space subject to a rigid flatended cylindrical *** contact area and other surface of the PSC half-space are assumed to be electrically *** the Hankel integral transformation,the problem is reduced to the Fredholm integral equation of the second *** equation is solved numerically to obtain the indentation behaviors of the PSC half-space,mainly including the indentation force-depth relation and the electric potential-depth *** results show that the effect of the semiconductor property on the indentation responses is limited within a certain range of variation of the steady carrier *** dependence of indentation behavior on material properties is also analyzed by two different kinds of *** element simulations are conducted to verify the results calculated by the integral equation technique,and good agreement is demonstrated.

关键词： piezoelectric semiconductor(PSC) insulating indenter electromechanical response singular integral equation finite element simulation

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

Swimming velocity of spherical squirmers in a square tube at finite fluid inertia

引用

Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1481-1498页

作者： Tongxiao jiaNG Deming nie jianzhong LIN Institute of Fluid Mechanics China Jiliang UniversityHangzhou 310008China Key Laboratory of Impact and Safety Engineering(Ningbo University) Ministry of EducationNingbo 315211China Institute of Fluid Engineering Zhejiang UniversityHangzhou 310027China

The three-dimensional lattice Boltzmann method(LBM)is used to simulate the motion of a spherical squirmer in a square tube,and the steady motion velocity of a squirmer with different Reynolds numbers(Re,ranging from 0.1 to 2)and swimming types is investigated and analyzed to better understand the swimming characteristics of microorganisms in different ***,as the Reynolds number increases,the effect of the inertial forces becomes significant,disrupting the squirmer's ability to maintain its theoretical ***,as the Reynolds number increases,the structure of the flow field around the squirmer changes,affecting its velocity of ***,the swimming velocity of the squirmer exhibits a quadratic relationship with the type of swimming and the Reynolds ***,the narrow tube exerts a significant inhibitory effect on the squirmer *** addition,although chirality does not directly affect the swimming velocity of the squirmer,it can indirectly affect the velocity by changing its motion mode.

关键词： spherical squirmer swimming characteristics swimming velocity fow structure

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

Exact satisfiability and phase transition analysis of the regular(k,d)-CNF formula

引用

Frontiers of Computer Science 2024年第1期18卷 263-265页

作者： Guoxia nie Daoyun XU Xi WANG Zaijun ZHANG College of Computer Science and Technology Guizhou UniversityGuiyang 550025China School of Mathematics and Statistics Qiannan Normal University for NationalitiesDuyun 558000China Key Laboratory of Industrial Automation and Machine Vision of Qiannan Duyun 558000China

1Introduction The satisfiability(SAT)problem has been considered the"seed"of other NP-complete *** regular partial exact(k,d)-SAT problem is an important extension of the SAT *** any(k,d)-CNF formula with a variable set V,V'is a proper subset of V,the problem involves determining whether a truth assignment set on V'exists such that only a literal in each clause is *** V'=V,it is a regular exact(k,d)-SAT ***,both experimental verifications and theoretical analyses of k-SAT problem have shown that the ratioα(clause constraint density)of the number of clauses m to the number of variables n is an important parameter affecting the satisfiability of the formula[1].However,the regular(k,d)-SAT problem has the same clause constraint density d/k.

关键词： formula constraint exact

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

Enzyme-driven Nanorobots Walking Along Predesigned Tracks on the DNA Origami for Cargo Transport and Catalysis

引用

Chemical Research in Chinese Universities 2024年第2期40卷 333-342页

作者： nie Cunpeng MA Tianran CHEN Tingting CHU Xia State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha410082P.R.China

In molecular engineering,designing and synthesizing molecular machines with capable of performing complex tasks,remains a formidable *** is an excellent candidate for building molecular robots because it is highly ***,we present an artificial nanorobot,in which a DNA cube serves as the inert‘body’,and nucleic acid catalysts based on an enzymatic nicking reaction act as the‘legs’for *** nanorobot can execute a series of actions,such as‘start’,‘turn’,and‘stop’when it walks along a predefined *** performance could be confirmed and monitored by using an atomic force microscope(AFM)and fluorescence *** by biological machines,we artificially designed a series of specialized tasks that combined walking with control of cargo transport and ***-time fluorescence kinetics curves provide monitoring signals for cargo transport and catalytic *** work can enrich the toolbox of DNA machinery and has great potential for engineering molecular nanofactories.

关键词： DNA origami DNA nanorobot Controlled cargo transport DNAzyme catalysis

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

Resilience effects for household food expenditure and dietary diversity in rural western China

引用

Journal of Integrative Agriculture 2024年第2期23卷 384-396页

作者： Xiao Han Kaiyu Lyu Fengying nie Yuquan Chen Institute of Agricultural Economics and Development Chinese Academy of Agricultural SciencesBeijing 100081China Agricultural Information Institute Chinese Academy of Agricultural SciencesBeijing 100081China Academy of Global Food Economics and Policy China Agricultural UniversityBeijing 100083China

A more resilient livelihood is increasingly recognized as an efficient way to improve vulnerable households’food security and optimize their dietary *** study quantifies rural household resilience in western China,identifies the three pillars(absorptive capacity,adaptive capacity,and transformative capacity)contribution to resilience,and then establishes the estimated Resilience Capacity Index(RCI)linked with food security and dietary diversity supported by the multiple indicator multiple cause(MIMIC)*** show that,despite geographical heterogeneity,the RCI consistently increased from 2015 to *** with a higher RCI inheriting better capacity to deal with risk and shocks are significantly and positively correlated with increasing food expenditure and diversifying food *** can be because resilient households will allocate more money to food expenditure instead of saving for livelihood ***,policymakers can provide more incentives for rural households to adopt more dynamic and effective risk management ***,in turn,could yield positive spillover effects by preventing human capital loss associated with dietary-related chronic diseases and mortality.

关键词： resilience food expenditure dietary diversity China risk management

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

Conductive edge-warping graphite mesas for robust structural superlubricity

引用

Science China(Technological Sciences) 2024年第7期67卷 2040-2049页

作者： FENG Weijia LIU Ying MA Ming PENG DeLi nie JinHui State Key Laboratory of Tribology in Advanced Equipment&Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Center for Nano and Micro Mechanics Tsinghua UniversityBeijing 100084China Institute of Superlubricity Technology Research Institute of Tsinghua University in ShenzhenShenzhen 518057China

Structural superlubricity(SSL) refers to a state of ultralow friction and zero wear when two solid surfaces slide against each other. Recent investigations have identified amorphous carbon at the edge of the graphite mesa as the primary source of friction in such SSL systems. Here, the tensile stress of metal thin film is exploited to engineer vertically conductive edge-warping graphite mesas(EWGM). Through this approach, robust SSL performance is realized, demonstrated by sliding an 8 μm side length square EWGM on an atomically smooth Au substrate for 10000 cycles at a constant voltage of 1 m V. In this SSL system,differential friction coefficients lower than 1.5 × 10^(-4) are achieved, with static contact resistance between EWGM and Au substrate as low as 28Ω and sliding contact resistance as low as 32Ω. Moreover, the EWGM exhibits SSL behavior on polished Si wafer substrates. Furthermore, because of the no-edge contact with the substrate during sliding, friction is independent of the sliding speed of the EWGM. This study presents the first successful fabrication of conductive EWGM. Remarkably, in both EWGM-Au and EWGM-Si SSL systems, the measured frictions are more than one order of magnitude lower than those of ordinary self-retracting graphite mesas with no-edge warping, and no wear is observed during extended current-carrying ***, these findings establish a solid groundwork for the future realization of macroscale conductive SSL systems.

关键词： structural superlubricity graphite mesa contact resistance tensile stress edge warping

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

Selective immobilization of Pb(Ⅱ)by biogenic whewellite and its mechanism

引用

Journal of Environmental Sciences 2024年第3期137卷 664-676页

作者： Xingxing Wang Kaiyan Ren Kairui jiao Wenjun nie Xiaochi An Bin Lian College of Life Sciences College of Marine Science and EngineeringNanjing Normal UniversityNanjing 210023China

The development of bio-adsorbents with highly selective immobilization properties for specific heavy metals is a great challenge,but has important application *** whewellite(BW)with high selectivity for Pb(Ⅱ)was synthesized by mineral microbial *** selective immobilization properties and mechanism of BW for Pb(Ⅱ)were analyzed by combining mineral characterization technology and batch adsorption research *** results indicated that BW can efficiently and selectively immobilize Pb(Ⅱ)in single or composite heavy metal adsorption solutions,and the immobilized Pb(Ⅱ)is difficult to *** undergoes monolayer adsorption on Pb(Ⅱ),Qmax≈1073.17 mg/*** immobilization of Pb(Ⅱ)by BW is a physico-chemical adsorption process with spontaneous heat absorption and an accompanying increase in *** addition,the sequestration of Pb(Ⅱ)by BW remains around 756.99 mg/g even at p H=*** excellent selective immobilization properties of BW for Pb(Ⅱ)are closely related to its smaller Ksp,electrostatic repulsion effect,organic-inorganic composite structure,acid resistance and the formation of Pb(Ⅱ)*** study provides beneficial information about the recycling of lead in acidic lead-containing wastewater and composite heavy metal contaminated water bodies.

关键词： Aspergillus niger Biogenic whewellite Pb(Ⅱ) Selective adsorption Immobilization mechanism

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

Nano friction behaviour between magnetic materials and copper considering the inter-diffusion effect

引用

Friction 2024年第7期12卷 1532-1547页

作者： Zilin LI Lisha DOU shiyu YANG Huajiang OUYANG Qichen ZHU Xiaoyang CHEN Xin jia Shuaiwei DOU Xiaolong CUI Yudong ZHANG Jingjiang QIU Guochen QI Bangbang nie Pan LIU Ronghan WEI School of Mechanics and Safety Engineering Zhengzhou UniversityZhengzhou 450001China Engineering Technology Research Center of Henan Province for MEMS Manufacturing and Application Zhengzhou UniversityZhengzhou 450001China Institute of Intelligent Sensing Zhengzhou UniversityZhengzhou 450001China School of Engineering University of LiverpoolLiverpool L693GHUK School of Cyber Science and Engineering&Hanwei Institute of Internet of Things Zhengzhou UniversityZhengzhou 450001China

Copper,permalloy,cobalt,and silicon are the materials that have been widely utilised in magnetic *** the size of interest is down to the nanoscale,the inter-diffusion between certain materials becomes *** paper studies the nanoscale friction characteristics between frictional pairs with and without inter-diffusion properties through the atomic force *** distinct evolution features of nanoscale friction force when inter-diffusion is involved are discovered experimentally,which is also confirmed through theoretical ***,through the thin film deposition method,four pairs of contact materials(Cu–Ni_(81)Fe_(19),Si–Ni_(81)Fe_(19),Cu–Co,Cu–Si)are designed for friction tests,in which diffusion occurs at the interface of Cu–Ni_(81)Fe_(19)***,the effects of sliding velocity and loading force on the nano friction of each pair are *** is found that regardless of the diffusion phenomenon:(1)the adhesion force values exhibit a notable correlation to the values of the friction force;(2)the friction force in all four material pairs consistently increases with the growth of the normal loading force,although the growth rate may *** terms of the sliding velocity effect,the friction forces of immiscible materials(Si–Ni_(81)Fe_(19),Cu–Co,and Cu–Si)are found to increase with the increasing sliding ***,the friction force of Cu–Ni_(81)Fe_(19),decreases with the increasing sliding ***,a compositive friction model considering both the velocity and the normal force effect was proposed,which shows good agreement with the experimental results and explains the nano friction behaviour of both miscible and immiscible metals.

关键词： atomic force microscope friction force normal load sliding velocity

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

Benchmark experiment on slab^(238)U with D-T neutrons for validation of evaluated nuclear data

引用

Nuclear Science and Techniques 2024年第2期35卷 145-159页

作者： Yan-Yan Ding Yang-Bo nie Yue Zhang Zhi-Jie Hu Qi Zhao Huan-Yu Zhang Kuo-Zhi Xu shi-Yu Zhang Xin-Yi Pan Chang-Lin Lan Jie Ren Xi-Chao Ruan Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 62100China

A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of Atomic *** leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight *** samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 *** leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and *** on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were *** results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.

关键词： Leakage neutron spectra Uranium D-T neutron source Evaluated nuclear data

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

Association of tumor budding with clinicopathological features and prognostic value in stage III-IV colorectal cancer

引用

World Journal of Gastroenterology 2024年第2期30卷 158-169页

作者： Yue-Hao Luo Zhe-Cheng Yan jia-Ying Liu Xin-Yi Li Ming Yang Jun Fan Bo Huang Cheng-Gong Ma Xiao-Na Chang Xiu nie Department of Pathology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina

BACKGROUND Tumor budding(TB)has emerged as a promising independent prognostic biomarker in colorectal cancer(CRC).The prognostic role of TB has been extensively studied and currently affects clinical decision making in patients with stage I and II ***,existing prognostic studies on TB in stage III CRC have been confined to small retrospective cohort ***,this study investigated the correlation among TB categories,clinicopathological features,and prognosis in stage III-IV CRC to further enhance the precision and individualization of treatment through refined prognostic risk *** To analyze the relationship between TB categories and clinicopathological characteristics and assess their prognostic value in stage III-IV CRC to further refine the prognostic risk stratification of stage III-IV *** The clinical data of 547 CRC patients were collected for this retrospective *** at the front edge of the tumor buds was counted according to the 2016 International Tumor Budding Consensus Conference *** Multivariate Cox proportional hazards regression analysis demonstrated that chemotherapy(P=0.004),clinical stage IV(P<0.001),≥4 regional lymph node metastases(P=0.004),left-sided colonic cancer(P=0.040),and Bd 2-3(P=0.002)were independent prognostic factors in patients with stage III-IV ***,the density of tumor infiltrating lymphocytes was higher in Bd 1 than in Bd 2-3,both in the tumor stroma and its invasive *** TB has an independent predictive prognostic value in patients with stage III-IV *** is recommended to complete the TB report of stage III-IV CRC cases in the standardized pathological report to further refine risk stratification.

关键词： Tumor budding Tumor infiltrating lymphocytes Colorectal cancer Survival analysis Prognosis

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

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：