检索结果-南通市图书馆

维普期刊数据库

A hybrid contact approach for modeling soil-structure interaction using the material point method

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1864-1882页

作者： Qinyang Sang Yonglin Xiong Rongyue zheng Xiaohua Bao Guanlin ye feng Zhang Key Laboratory of Impact and Safety Engineering Ministry of EducationSchool of Mechanical Engineering and MechanicsNingbo UniversityNingbo315211China Institute of Geotechnical Engineering Ningbo UniversityNingbo315211China College of Civil and Transportation Engineering Shenzhen UniversityShenzhen518060China Department of Civil Engineering Shanghai Jiao Tong UniversityShanghai200240China Department of Civil Engineering Nagoya Institute of TechnologyShowa-kuGokiso-choNagoya466-8555Japan

The grid-based multi-velocity field technique has become increasingly popular for simulating the Material Point Method(MPM)in contact ***,this traditional technique has some shortcomings,such as(1)early contact and contact penetration can occur when the contact conditions are unsuitable,and(2)the method is not available for contact problems involving rigid-nonrigid materials,which can cause numerical *** study presents a new hybrid contact approach for the MPM to address these limitations to simulate the soil and structure *** approach combines the advantages of point-point and point-segment contacts to implement contact detection,satisfying the impenetrability condition and smoothing the corner contact *** proposed approach is first validated through a disk test on an inclined ***,several typical cases,such as granular collapse,bearing capacity,and deformation of a flexible retaining wall,are simulated to demonstrate the robustness of the proposed approach compared with FEM or analytical ***,the proposed method is used to simulate the impact of sand flow on a deformable *** results show that the proposed contact approach can well describe the phenomenon of soil-structure interaction problems.

关键词： Material point method Soil-structure interaction Numerical simulation Contact algorithm

New formula for predicting the plastic buckling pressure of steel torispherical heads under internal pressure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第8期25卷 618-630页

作者： Sheng ye Keming LI Jinyang zheng Shan SUN Institute of Process Equipment Zhejiang UniversityHangzhou 310027China Engineering Research Center for High Pressure Process Equipment and Safety of Ministry of Education Hangzhou 310027China State Key Laboratory of Fluid Power and Mechatronic Systems Hangzhou 310058China

Thin-walled torispherical heads under internal pressure can fail by plastic buckling because of compressive circumferential stresses in the head ***,existing formulas still have limitations,such as complicated expressions and low accuracy,in determining buckling *** this paper,we propose a new formula for calculating the buckling pressure of torispherical heads based on elastic-plastic analysis and experimental ***,a finite element(FE)method based on the arc-length method is established to calculate the plastic buckling pressure of torispherical heads,considering the effects of material strain hardening and geometrical *** buckling pressure results calculated by the FE method in this paper have good consistency with those of BOSOR5,which is a program for calculating the elastic-plastic bifurcation buckling pressure based on the finite difference energy ***,the effects of geometric parameters,material parameters,and restraint form of head edge on buckling pressure are ***,a new formula for calculating plastic buckling pressure is developed by fitting the curve of FE results and introducing a reduction factor determined from experimental ***,based on the experimental results,we compare the predictions of the new formula with those of existing *** is shown that the new formula has a higher accuracy than the existing ones.

关键词： Torispherical head Plastic buckling Elastic-plastic analysis Prediction formula Finite element method

A Trust Evaluation Mechanism Based on Autoencoder Clustering Algorithm for Edge Device Access of IoT

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 1881-1895页

作者： Xiao feng zheng Yuan Cyber Security Academy Beijing University of Posts and TelecommunicationsBeijing100876China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China State Grid Info-Telecom Great Power Science and Technology Co. Ltd.Beijing102211China

First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism based on the time decay factor is proposed,taking into account the influence of historical interaction *** weight the time attenuation factor to each historical interaction record for updating and got the new historical record *** refer to the beta distribution to enhance the flexibility and adaptability of the direct trust assessment model to better capture time trends in the historical *** we propose an autoencoder-based trust clustering *** perform feature extraction based on *** leibler(KL)divergence is used to calculate the reconstruction *** constructing a convolutional autoencoder,we introduce convolutional neural networks to improve training efficiency and introduce sparse constraints into the hidden layer of the *** sparse penalty term in the loss function measures the difference through the KL *** clustering is performed based on the density based spatial clustering of applications with noise(DBSCAN)clustering *** the clustering process,edge nodes have a variety of trustworthy attribute *** assign different attribute weights according to the relative importance of each attribute in the clustering process,and a larger weight means that the attribute occupies a greater weight in the calculation of ***,we introduced adaptive weights to calculate comprehensive trust *** experiments prove that our trust evaluation mechanism has excellent reliability and accuracy.

关键词： Cross-domain authentication trust evaluation autoencoder

CXCL13 shapes tumor immune microenvironment in ovarian cancer with homologous recombination deficiency

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第5期11卷 48-50页

作者： Yue Ding zheng ye Bo Ding Songwei feng Furong Du Xuejiao Ma Xiaoxuan Wang Yang Shen Department of Obstetrics and Gynaecology Zhongda HospitalSchool of MedicineSoutheast UniversityNanjingJiangsu 210008China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjingJiangsu 210096China State Key Laboratory of Translational Medicine and Innovative Drug Development Jiangsu Simcere Diagnostics Co.Ltd.NanjingJiangsu 210042China

Recently,immune checkpoint inhibitors(ICIs)and poly(ADP-ribose)polymerase inhibitors(PARPi)have played a pivotal role in prolonging the recurrence-free survival of patients with ovarian cancer(OC).1,2 Although PARPi have revolutionized the treatment of OC,the absence of reliable predictive biomarkers limits the broad application of ICIs for patients with homologous recombination(HR)deficiency(HRD).3 CXC-chemokine ligand 13(CXCL13)is a cytokine constitutively secreted in the stromal cells of the B-cell region of secondary lymphoid tissue.4 It exclusively binds to the chemokine receptor CXCR5,which is abundantly expressed in subsets of mature circulating B lymphocytes,follicular helper T cells,and skin-derived dendritic cells,and governs the migration of these cells into secondary lymphoid organs in response to the CXCL13 gradient.5 In this study,we aimed to elucidate the role of CXCL13 in shaping the tumor immune microenvironment(TIME)in HR-deficient OC and to explore its relationship with the cGAS-STING signaling pathway.

关键词： CXCL13 cancer organs

Dimension by Dimension Finite Volume HWENO Method for Hyperbolic Conservation Laws

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第1期6卷 605-624页

作者： feng zheng Jianxian Qiu College of Mathematics and Statistics Fujian Normal UniversityFuzhou350117FujianChina School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling&High-Performance Scientific Computing Xiamen UniversityXiamen361005FujianChina

In this paper,we propose a finite volume Hermite weighted essentially non-oscillatory(HWENO)method based on the dimension by dimension framework to solve hyperbolic conservation *** can maintain the high accuracy in the smooth region and obtain the high resolution solution when the discontinuity appears,and it is compact which will be good for giving the numerical boundary ***,it avoids complicated least square procedure when we implement the genuine two dimensional(2D)finite volume HWENO reconstruction,and it can be regarded as a generalization of the one dimensional(1D)HWENO *** numerical tests are performed to verify the high resolution and high accuracy of the scheme.

关键词： Finite volume Dimension by dimension HWENO Hyperbolic conservation laws

Clinical observation on 90 cases of primary dysmenorrhea treated by buccal acupuncture therapy:a randomized controlled study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2024年第1期44卷 172-181页

作者： YANG Yi ye Huijun zheng Huiling JIN Lihua Department of Obstetrics and Gynecology the Second Affiliated Hospital of Zhejiang Chinese Medical UniversityXinhua Hospital of Zhejiang ProvinceHangzhou 310005China

OBJECTIVE:To explore the short-term and long-term efficacy of buccal acupuncture therapy in the treatment of patients with primary dysmenorrhea(PD).METHODS:A total of 90 patients with PD who were admitted to the Second Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from January 2020 to December 2021 were included in this study and randomly divided into three groups,including the observation group,the control group,and the placebo group,with 30 patients in each *** in the observation group were treated according to the syndrome types of Traditional Chinese Medicine,those in the control group were treated with Saridon,and those in the placebo group received a *** visual analog scale(VAS)scores of these patients were evaluated at different time points(before treatment,5 min after needle retention,30 min after needle retention,1 h after treatment,2 h after treatment,1 d after treatment,and 2 d after treatment).The Cox Menstrual Symptom Scale(CMSS)scores were assessed before the treatment and after three courses of ***,these two scales were also evaluated during ***,the pain score and adverse reactions of these patients were assessed during ***:After treatment,the VAS and CMSS scores in the observation group decreased significantly(P<0.05)5 and 30 min after needle retention and after ***:Buccal acupuncture therapy is verified to have short-term efficacy in the treatment of *** addition,this therapy has an immediate analgesic effect and long-term efficacy in reducing the severity and frequency of PD.

关键词： buccal acupuncture therapy primary dysmenorrhea pain score randomized controlled trial

维普期刊数据库

Stimulating Start-up Investment Through Government-Sponsored Venture Capital: Theory and Chinese Evidence

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第5期37卷 2021-2053页

作者： NI Xuanming zheng Tiantian GAO feng ZHAO Huimin School of Software and Microelectronics Peking University School of Economics and Management Tsinghua University School of Business Sun Yat-sen University

Government-sponsored venture capital(GVC) has been used to support financially constrained start-ups as an important policy tool in China. Typically, to motivate the social capital to invest in start-ups, GVC provides subsidies for them to bridge the funding gap in the early-stage venture capital market. However, the effect and mechanism of GVC affecting social capital investment have not been clearly studied. In this paper, the authors not only develop a game model to analyze this issue in theory, but conduct an empirical study by analyzing the 14741 records matched by propensity score matching(PSM) of Chinese venture capital market data from 2011 to 2021. The proposed findings are as the follows. Firstly, the subsidies offered by GVC will simultaneously increase the returns and risks of investments in start-ups of social capital with more volatile incentive effect of GVC. The incentive effect of GVC is only effective when the returns resulting from the subsidies outweigh the risks they introduce. In the context of the Chinese venture capital market, the incentive effect of GVC is effective. Secondly, the incentive effect of GVC is more pronounced in high-tech industries, which can be attributed to the signaling effect facilitated by GVC. In this context, the subsidy mainly helps social capital to bear the costs associated with screening potential investments. Thirdly, the incentive effect of GVC is more significant in underdeveloped venture capital markets, which can be explained by the “virtuous cycle” effect, in which GVC plays a pioneering role in establishing a more robust early-stage market trading system. By examining these three points, this study contributes to a better understanding of how GVC can effectively guide social capital investment, especially in the Chinese landscape.

关键词： Government-sponsored venture capital fund incentive effect social capital subsidy venture capital

Cholesky GAS models for large time-varying covariance matrices

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Management Science and Engineering 2024年第1期9卷 115-142页

作者： Tingguo zheng Shiqi ye Department of Statistics and Data Science School of EconomicsXiamen UniversityXiamen361005China Wang Yanan Institute for Studies in Economics Xiamen UniversityXiamen361005China Paula and Gregory Chow Institute for Studies in Economics Xiamen UniversityXiamen361005China

This paper develops a new class of multivariate models for large-dimensional time-varying covariance matrices,called Cholesky generalized autoregressive score(GAS)models,which are based on the Cholesky decomposition of the covariance matrix and assume that the parameters are ***,two types of score-driven updates are considered:one is closer to the GARCH family,and the other is inspired by the stochastic volatility *** demonstrate that the models can be estimated equation-wise and are computationally feasible for high-dimensional ***,we design an equationwise dynamic model averaging or selection algorithm which simultaneously extracts model and parameter uncertainties,equipped with dynamically estimated model *** simulation results illustrate the superiority of the proposed ***,using a sizeable daily return dataset that includes 124 sectors in the Chinese stock market,two empirical studies with a small sample and a full sample are conducted to verify the advantages of our *** full sample analysis by a dynamic correlation network documents significant structural changes in the Chinese stock market before and after COVID-19.

关键词： Cholesky decomposition GAS Dynamic conditional correlations Dynamic model averaging

Enhancing blocking temperature using inverse hydrogen bonds for non-radical bridged dimeric Dy(Ⅲ) single-molecule magnets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第10期67卷 3328-3338页

作者： Peng-Bo Jin Qian-Cheng Luo ye-ye Liu Yan-Zhen zheng Frontier Institute of Science and Technology State Key Laboratory of Electrical Insulation and Power EquipmentMOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi'an Key Laboratory of Electronic Devices and Material Chemistry and School of ChemistryXi'an Jiaotong University

Single-molecule magnets（SMMs） are a kind of nanosized magnetic materials that are capable of storing massive bytes of *** coupling the spin centers in a proper manner is a usual approach to promote the working temperature（or blocking temperature） for *** delocalized radicals have been widely employed to accomplish this ***,we show a new manner by using weak but multiple B–Hδ-···Dy3+inverse hydrogen bonding（IHB） interactions to control the magnetic couplings in a series of dimeric dysprosiacaborane *** approach leads to a record high TB100sof 10 K among non-radical bridged dimeric SMMs,which is mainly ascribed to strong ferromagnetic coupling(4.38 cm-1) and the proper alignment of the magnetic principle axes of the adjacent dysprosium（Ⅲ） *** verifying by theoretical calculations,these results demonstrate that IHB interactions can be used to construct strong axial ferromagnetic coupling and enhancing magnetic blocking temperature for SMMs.

关键词： single-molecule magnets carborane dysprosium ferromagnetic coupling inverse hydrogen bond