检索结果-南通市图书馆

An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion

引用

Petroleum Science 2024年第1期21卷 352-365页

作者： kai-Xuan Qiu Jia Li Dong feng Shi-Ming Wei Gang Lei Jiangmen Laboratory of Carbon Science and Technology Jiangmen529100GuangdongChina The Hong Kong University of Science and Technology(Guangzhou) Guangzhou511400GuangdongChina China University of Geosciences(Beijing) Beijing100083China China University of Petroleum(Beijing) Beijing102249China China University of Geosciences(Wuhan) Wuhan430074HubeiChina Shenzhen Research Institute China University of GeosciencesShenzhen518063GuangdongChina

In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture *** has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture *** addition,most of the existing models are solved analytically based on Laplace transform and numerical ***,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix *** simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the ***,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by ***,a relationship between oil rate and production time in real-time space is *** new model is verified against classical analytical *** the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,***,the new model also has an excellent agreement with the numerical *** model is then applied to two actual tight oil wells completed in western Canada sedimentary *** identifying the flow regime,the solution suitably matches the field production data,and the model parameters are *** these output parameters,we can accurately forecast the production and even estimate the petrophysical properties.

关键词： Analytical solution Unconventional reservoir Variable matrix Simultaneous flow

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

Geometric error measuring,modeling,and compensation for CNC machine tools:A review

引用

Chinese Journal of Aeronautics 2024年第2期37卷 163-198页

作者： Zhao ZHANG feng JIANG Ming LUO Baohai WU Dinghua ZHANG kai TANG Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong KongChina

Geometric error,mainly due to imperfect geometry and dimensions of machine components,is one of the major error sources of machine *** that geometric error has significant effects on the machining quality of manufactured parts,it has been a popular topic for academic and industrial research for many years.A great deal of research work has been carried out since the 1970s for solving the problem and improving the machining *** have studied how to measure,detect,model,identify,reduce,and compensate the geometric *** paper presents a thorough review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to geometric *** advances in measuring the geometrical errors of machine tools are summarized,and different kinds of error identification methods of translational axes and rotation axes are illustrated ***,volumetric geometric error modeling,tracing,and compensation techniques for five-axis machine tools are emphatically ***,research challenges in order to improve the volumetric accuracy of machine tools are also highlighted.

关键词： Error compensation Error identification Error measurement Error modeling Geometric error Machine tools

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

Contributors to tidal duration asymmetry with varied coastline configurations on western shelf of Yellow Sea

引用

Water Science and Engineering 2024年第1期17卷 1-12页

作者： Xi feng zheng Li Hui feng Jia-yan Yang Shou-peng Xie Wei-bing feng College of Harbor.Coastal and Offshore Engineering Hohai UniversityNanjing 210098China China Harbour Engineering Co. LtdBeijing 100027China Key Laboratory of Port Waterway and Sedimentation Engineering of the Ministry of CommunicationsNanjing 210029China China South-to-North Water Diversion Corporation Limited Beijing 100036China

Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is the resilience to coastal flooding,which depends on the ability to predict tidal *** duration asymmetry(TDA)is a key parameter in determination of the arrival and duration of flood *** study selected the western inner shelf of the Yellow Sea(WYS)as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level *** responses of TDA to shoreline reconstruction yielded spatial variability locally and *** the nearshore area,the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection,bottom friction,and advection,which controlled the energy transfer from M2 or S2 constituents to their overtides or compound *** sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner *** vulnerability of tidal responses was due to the displacement of the M2 amphidrome of the Kelvin wave on the WYS,which in turn changed tidal energy fluxes over the *** relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation.

关键词： Tidal duration asymmetry Western inner shelf of Yellow Sea Natural restoration Relative sea level rise Tidal amphidrome

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

Learning accurate template matching with differentiable coarseto-fine correspondence refinement

引用

Computational Visual Media 2024年第2期10卷 309-330页

作者： Zhirui Gao Renjiao Yi zheng Qin Yunfan Ye Chenyang Zhu kai Xu College of Computer National University of Defense TechnologyChangsha 410073China

Template matching is a fundamental task in computer vision and has been studied for *** plays an essential role in manufacturing industry for estimating the poses of different parts,facilitating downstream tasks such as robotic *** methods fail when the template and source images have different modalities,cluttered backgrounds,or weak *** also rarely consider geometric transformations via homographies,which commonly exist even for planar industrial *** tackle the challenges,we propose an accurate template matching method based on differentiable coarse-tofine correspondence *** use an edge-aware module to overcome the domain gap between the mask template and the grayscale image,allowing robust *** initial warp is estimated using coarse correspondences based on novel structure-aware information provided by *** initial alignment is passed to a refinement network using references and aligned images to obtain sub-pixel level correspondences which are used to give the final geometric *** evaluation shows that our method to be significantly better than state-of-the-art methods and baselines,providing good generalization ability and visually plausible results even on unseen real data.

关键词： template matching differentiable homography structure-awareness transformers

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

Towards the universal defense for query-based audio adversarial attacks on speech recognition system

引用

Cybersecurity 2024年第1期7卷 53-70页

作者： feng Guo zheng Sun Yuxuan Chen Lei Ju School of Cyber Science and Technology Shandong UniversityQingdaoChina Quancheng Laboratory QCLJinanChina

Recently,studies show that deep learning-based automatic speech recognition(ASR)systems are vulnerable to adversarial examples(AEs),which add a small amount of noise to the original audio *** AE attacks pose new challenges to deep learning security and have raised significant concerns about deploying ASR systems and *** existing defense methods are either limited in application or only defend on results,but not on *** this work,we propose a novel method to infer the adversary intent and discover audio adversarial examples based on the AEs generation *** insight of this method is based on the observation:many existing audio AE attacks utilize query-based methods,which means the adversary must send continuous and similar queries to target ASR models during the audio AE generation *** by this observation,We propose a memory mechanism by adopting audio fingerprint technology to analyze the similarity of the current query with a certain length of memory ***,we can identify when a sequence of queries appears to be suspectable to generate audio *** extensive evaluation on four state-of-the-art audio AE attacks,we demonstrate that on average our defense identify the adversary’s intent with over 90%*** careful regard for robustness evaluations,we also analyze our proposed defense and its strength to withstand two adaptive ***,our scheme is available out-of-the-box and directly compatible with any ensemble of ASR defense models to uncover audio AE attacks effectively without model retraining.

关键词： Adversarial attacks Defense Memory mechanism Query-based

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

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

引用

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

来源：

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

Passive particles driven by self-propelled particle:The wake effect

引用

Chinese Physics B 2024年第4期33卷 500-507页

作者：郑凯选汪静文王世锋聂德明 Institute of Fluid Mechanics China Jiliang UniversityHangzhou 310018China Department of Mechanical Engineering Hangzhou Vocational&Technical CollegeHangzhou 310018China

This work focuses on numerically studying hydrodynamic interaction between a passive particle and a self-propelled particle,termed a squirmer,by using a two-dimensional lattice Boltzmann method(LBM).It is found that the squirmer can capture a passive particle and propel it simultaneously,provided the passive particle is situated within the squirmer's *** research shows that the critical capture distance,which determines whether the particle is captured,primarily depends on the intensity of the squirmer's *** stronger dipolarity of squirmer results in an increased critical capture ***,the Reynolds number is found to have minimal influence on this ***,the passive particle,when driven by the squirmer's wake,contributes to a reduction in the squirmer's *** results in a mutual acceleration for both *** findings can provide valuable perspectives for formulating the principles of reducing the drag of micro-swimmers and help to achieve the goal of using micro-swimmers to transport goods without physical tethers.

关键词： lattice Boltzmann method(LBM) self-propelled particles particle-laden flow

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

Convex-up Style of Deformation within Grabens in Regions of Incomplete Crossing Conjugate Normal Faults: A Numerical Simulation Investigation and Case Study

引用

Journal of Earth Science 2024年第3期35卷 839-849页

作者： zheng Li kai Wang Xiong Xiong Bing Zhou School of Geophysics and Geomatics China University of GeosciencesWuhan 430074China State Key Laboratory of Geodesy and Earth’s Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China Department of Earth Sicences Khalifa UniversityAbu DhabiUnited Arab Emirates

Crossing conjugate normal faults(CCNFs)are extensively developed in many hydrocarbon-producing basins,generally existing in the form of incomplete ***,the effect of the non-conjugate zone of the CCNFs on the conjugate relay zone post late tectonic action has not been previously *** use 3D elastic-plastic modeling to investigate the influence of incomplete(i.e.,partially intersecting)CCNFs on the pattern of deformation of strata in the intersection region.A series of model simulations were performed to examine the effects of horizontal tectonic extension,fault size,and fault depth on the deformation of conjugate relay zones of incomplete *** analyses yielded the following results.(1)The model of incomplete conjugation predicts a convex-up style of deformation in the conjugate graben region superimposed on overall subsidence under applied horizontal tectonic extension.(2)The degree of convex-up deformation of the conjugate graben depends on the influence of the non-conjugate zone on the conjugate relay zone,which varies with the amount of horizontal tectonic extension,fault size,and fault burial depth.(3)Our results indicate that incomplete CCNFs can form convex-up deformation,similar to that in the Nanpu Sag area and provide a sound understanding of hydrocarbon migration and accumulation.

关键词： incomplete conjugate normal fault conjugate graben convex-up deformation hydrocarbons Nanpu Sag tectonics.

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

Molecular regulation of the key specialized metabolism pathways in medicinal plants

引用

Journal of Integrative Plant Biology 2024年第3期66卷 510-531页

作者： Min Shi Siwei Zhang Zizhen zheng Itay Maoz Lei Zhang Guoyin kai Zhejiang Provincial International S&T Cooperation Base for Active Ingredients of Medicinal and Edible Plants and Health Zhejiang Provincial Key TCM Laboratory for Chinese Resource Innovation and TransformationSchool of Pharmaceutical SciencesJinhua AcademyZhejiang Chinese Medical UniversityHangzhou 310053China Department of Postharvest Science Agricultural Research OrganizationVolcani CenterRishonLeZion 7505101Israel Department of Pharmaceutical Botany School of PharmacyNaval Medical UniversityShanghai 200433China

The basis of modern pharmacology is the human ability to exploit the production of specialized metabolites from medical plants,for example,terpenoids,alkaloids,and phenolic ***,in most cases,the availability of these valuable compounds is limited by cellular or organelle barriers or spatio-temporal accumulation patterns within different plant *** factors(TFs)regulate biosynthesis of these specialized metabolites by tightly controlling the expression of biosynthetic ***-edge technologies and/or combining multiple strategies and approaches have been applied to elucidate the role of *** this review,we focus on recent progress in the transcription regulation mechanism of representative high-value products and describe the transcriptional regulatory network,and future perspectives are discussed,which will help develop high-yield plant resources.

关键词： biosynthesis medicinal plants omics secondary metabolism transcription factors

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

Nanomedicine Disrupts Stromal Barriers to Augment Drug Penetration for Improved Cancer Therapy

引用

Chinese Journal of Chemistry 2024年第10期42卷 1175-1189页

作者： Guo-feng Luo Wei-Hai Chen Xian-zheng Zhang state Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei KeyLaboratory of StomatologySchool&Hospital of StomatologyWuhan UniversityWuhanHubei 430079China Key Laboratoryof Biomedical Polymers of Ministry of Education&Departmentof Chemistry Wuhan UniversityWuhanHubei 430072China

Tumor stroma composing diverse extracellular matrixes(ECM)and stromal cells shapes a condensed physical barrier,which severely hampers the efficient accessibility of nanomedicine to tumor cells,especially these deep-seated in the core of *** barrier significantly compromises the antitumor effects of drug-loaded nanomedicine,revealing the remarkable importance of disrupting stromal barrier for improved tumor therapy with deep penetration *** achieve this goal,various nanoparticle-based strategies have been developed,including direct depleting ECM components via delivering anti-fibrotic agents or targeting stromal cells to suppress ECM expression,dynamic regulation of nanoparticles’physicochemical properties(i.e.,size,surface charge,and morphology),mechanical force-driven deep penetration,natural/biomimetic self-driven nanomedicine,and transcytosis-inducing *** these nanostrategies were systemically summarized in this review,and the design principles for obtaining admirable nanomedicine were *** the rapid development of nanotechnology,elaborate design of multifunctional nanomedicine provides new opportunities for overcoming the critical stromal barriers to maximize the therapeutic index of various therapies,such as chemotherapy,photodynamic therapy,and immunotherapy.

关键词： Nanomedicine Tumor stroma Deep penetration Enhanced drug perfusion Cancer therapy Drug carriers Biomaterials Nanotechnology

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：