期刊文献+
共找到493篇文章
< 1 2 25 >
每页显示 20 50 100
原发性膜性肾病与乙肝病毒相关性膜性肾病的鉴别诊断:一例报告并文献复习
1
作者 孟元 赵文景 +12 位作者 王素霞 张旭 屈磊 张帆 王雨 张红凯 孙雪艳 王梦迪 张康 刘梦超 刘会强 李瑞明 卜雯婧 《中华肾病研究电子杂志》 2024年第5期296-299,共4页
乙肝病毒相关性膜性肾病(hepatitisBvirus-associated membranous nephropathy,HBV-MN)是常见的继发性膜性肾病。以往研究显示,M型磷脂酶A2受体(M-type phospholipase A2 receptor,PLA2R)是参与特发性膜性肾病(idiopathic membranous ne... 乙肝病毒相关性膜性肾病(hepatitisBvirus-associated membranous nephropathy,HBV-MN)是常见的继发性膜性肾病。以往研究显示,M型磷脂酶A2受体(M-type phospholipase A2 receptor,PLA2R)是参与特发性膜性肾病(idiopathic membranous nephropathy,IMN)发病的主要抗原[1];患者肾组织的PLA2R阳性和血清的PLA2R抗体(PLA2R antibody,PLA2Rab)阳性有助于区分IMN和继发性膜性肾病。近年研究显示,肾组织PLA2R以及血清PLA2Rab在HBV-MN患者中也有一定表达。 展开更多
关键词 特发性膜性肾病 原发性膜性肾病 PLA2 主要抗原 肾组织 鉴别诊断
原文传递
习近平法治思想指引下的法律硕士教育创新机制研究
2
作者 徐彰 卢春雪 《山西开放大学学报》 2024年第2期86-90,共5页
我国的法律硕士教育自设立至今取得了丰硕的成果,同时在实践中也存在诸多问题,主要包括思想政治教育与法学专业教育融合不够、忽视实践能力培养、缺乏国际化视野等,制约了法律硕士人才培养目标的实现。在新时代背景下,法律硕士教育应当... 我国的法律硕士教育自设立至今取得了丰硕的成果,同时在实践中也存在诸多问题,主要包括思想政治教育与法学专业教育融合不够、忽视实践能力培养、缺乏国际化视野等,制约了法律硕士人才培养目标的实现。在新时代背景下,法律硕士教育应当坚持以习近平法治思想为指引,通过建立法律硕士教育创新平台,加强法律硕士教育师资队伍建设,完善法律硕士教育质量评价体系及推进法律硕士教育国际化等途径,构建以培养应用型、复合型、国际化法律人才为目标的法律硕士教育创新机制,为我国法治建设提供高层次的人才保障。 展开更多
关键词 习近平法治思想 法律硕士教育 创新机制
下载PDF
Activation of the wnt/β-catenin/CYP1B1 pathway alleviates oxidative stress and protects the blood-brain barrier under cerebral ischemia/reperfusion conditions 被引量:9
3
作者 Xingyong Chen Nannan Yao +4 位作者 Yanguang Mao Dongyun Xiao Yiyi Huang xu zhang Yinzhou Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1541-1547,共7页
Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic strok... Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic stroke remain largely unknown.The present study found that cerebral ischemia leads to oxidative stress and repression of the Wnt/β-catenin pathway.Meanwhile,Wnt/β-catenin pathway activation by the pharmacological inhibito r,TWS119,relieved oxidative stress,increased the levels of cytochrome P4501B1(CYP1B1)and tight junction-associated proteins(zonula occludens-1[ZO-1],occludin and claudin-5),as well as brain microvascular density in cerebral ischemia rats.Moreove r,rat brain microvascular endothelial cells that underwent oxygen glucose deprivation/reoxygenation displayed intense oxidative stress,suppression of the Wnt/β-catenin pathway,aggravated cell apoptosis,downregulated CYP1B1and tight junction protein levels,and inhibited cell prolife ration and migration.Overexpression ofβ-catenin or knockdown ofβ-catenin and CYP1B1 genes in rat brain mic rovascular endothelial cells at least partly ameliorated or exacerbated these effects,respectively.In addition,small interfering RNA-mediatedβ-catenin silencing decreased CYP1B1 expression,whereas CYP1B1 knoc kdown did not change the levels of glycogen synthase kinase 3β,Wnt-3a,andβ-catenin proteins in rat brain microvascular endothelial cells after oxygen glucose deprivatio n/reoxygenation.Thus,the data suggest that CYP1B1 can be regulated by Wnt/β-catenin signaling,and activation of the Wnt/β-catenin/CYP1B1 pathway contributes to alleviation of oxidative stress,increased tight junction levels,and protection of the blood-brain barrier against ischemia/hypoxia-induced injury. 展开更多
关键词 blood-brain barrier CYP1B1 oxidative stress oxygen glucose deprivation/reoxygenation tight junction vascular endothelial cells Wnt/β-catenin pathway β-catenin
下载PDF
Ferroptosis and endoplasmic reticulum stress in ischemic stroke 被引量:6
4
作者 Yina Li Mingyang Li +4 位作者 Shi Feng Qingxue xu xu zhang Xiaoxing Xiong Lijuan Gu 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第3期611-618,共8页
Ferroptosis is a form of non-apoptotic programmed cell death,and its mechanisms mainly involve the accumulation of lipid peroxides,imbalance in the amino acid antioxidant system,and disordered iron metabolism.The prim... Ferroptosis is a form of non-apoptotic programmed cell death,and its mechanisms mainly involve the accumulation of lipid peroxides,imbalance in the amino acid antioxidant system,and disordered iron metabolism.The primary organelle responsible for coordinating external challenges and internal cell demands is the endoplasmic reticulum,and the progression of inflammatory diseases can trigger endoplasmic reticulum stress.Evidence has suggested that ferroptosis may share pathways or interact with endoplasmic reticulum stress in many diseases and plays a role in cell survival.Ferroptosis and endoplasmic reticulum stress may occur after ischemic stroke.However,there are few reports on the interactions of ferroptosis and endoplasmic reticulum stress with ischemic stroke.This review summarized the recent research on the relationships between ferroptosis and endoplasmic reticulum stress and ischemic stroke,aiming to provide a reference for developing treatments for ischemic stroke. 展开更多
关键词 cell death endoplasmic reticulum stress ferroptosis ischemic stroke lipid peroxidation
下载PDF
Vagus nerve stimulation in cerebral stroke:biological mechanisms,therapeutic modalities,clinical applications,and future directions 被引量:3
5
作者 Li Du xuan He +3 位作者 Xiaoxing Xiong xu zhang Zhihong Jian Zhenxing Yang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第8期1707-1717,共11页
Stroke is a major disorder of the central nervous system that poses a serious threat to human life and quality of life.Many stro ke victims are left with long-term neurological dysfunction,which adversely affects the ... Stroke is a major disorder of the central nervous system that poses a serious threat to human life and quality of life.Many stro ke victims are left with long-term neurological dysfunction,which adversely affects the well-being of the individual and the broader socioeconomic impact.Currently,poststroke brain dysfunction is a major and difficult area of treatment.Vagus nerve stimulation is a Food and Drug Administration-approved exploratory treatment option for autis m,refractory depression,epilepsy,and Alzheimer’s disease.It is expected to be a novel therapeutic technique for the treatment of stroke owing to its association with multiple mechanisms such as alte ring neurotransmitters and the plasticity of central neuro ns.In animal models of acute ischemic stroke,vagus nerve stimulation has been shown to reduce infarct size,reduce post-stroke neurological damage,and improve learning and memory capacity in rats with stroke by reducing the inflammatory response,regulating bloodbrain barrier permeability,and promoting angiogenesis and neurogenesis.At present,vagus nerve stimulation includes both invasive and non-invasive vagus nerve stimulation.Clinical studies have found that invasive vagus nerve stimulation combined with rehabilitation therapy is effective in im proving upper limb motor and cognitive abilities in stroke patients.Further clinical studies have shown that non-invasive vagus nerve stimulation,including ear/ce rvical vagus nerve stimulation,can stimulate vagal projections to the central nervous system similarly to invasive vagus nerve stimulation and can have the same effect.In this paper,we first describe the multiple effects of vagus nerve stimulation in stroke,and then discuss in depth its neuroprotective mechanisms in ischemic stroke.We go on to outline the res ults of the current major clinical applications of invasive and non-invasive vagus nerve stimulation.Finally,we provide a more comprehensive evaluation of the advantages and disadvantages of different types of vagus nerve stimulation in the treatment of cerebral ischemia and provide an outlook on the developmental trends.We believe that vagus nerve stimulation,as an effective treatment for stroke,will be widely used in clinical practice to promote the recovery of stroke patients and reduce the incidence of disability. 展开更多
关键词 cerebral stroke NEUROPLASTICITY non-invasive vagus nerve stimulation REHABILITATION vagus nerve stimulation
下载PDF
Spatial transcriptomics reveals that metabolic characteristics define the tumor immunosuppression microenvironment via iCAF transformation in oral squamous cell carcinoma 被引量:2
6
作者 Zheqi Liu Zhen zhang +7 位作者 Yu zhang Wenkai Zhou xu zhang Canbang Peng Tong Ji Xin Zou Zhiyuan zhang Zhenhu Ren 《International Journal of Oral Science》 SCIE CAS CSCD 2024年第1期110-121,共12页
Tumor progression is closely related to tumor tissue metabolism and reshaping of the microenvironment. Oral squamous cell carcinoma (OSCC), a representative hypoxic tumor, has a heterogeneous internal metabolic enviro... Tumor progression is closely related to tumor tissue metabolism and reshaping of the microenvironment. Oral squamous cell carcinoma (OSCC), a representative hypoxic tumor, has a heterogeneous internal metabolic environment. To clarify the relationship between different metabolic regions and the tumor immune microenvironment (TME) in OSCC, Single cell (SC) and spatial transcriptomics (ST) sequencing of OSCC tissues were performed. The proportion of TME in the ST data was obtained through SPOTlight deconvolution using SC and GSE103322 data. The metabolic activity of each spot was calculated using scMetabolism,and k-means clustering was used to classify all spots into hyper-, normal-, or hypometabolic regions. CD4T cell infiltration and TGF-βexpression is higher in the hypermetabolic regions than in the others. Through CellPhoneDB and NicheNet cell-cell communication analysis, it was found that in the hypermetabolic region, fibroblasts can utilize the lactate produced by glycolysis of epithelial cells to transform into inflammatory cancer-associated fibroblasts (iCAFs), and the increased expression of HIF1A in iCAFs promotes the transcriptional expression of CXCL12. The secretion of CXCL12 recruits regulatory T cells (Tregs), leading to Treg infiltration and increased TGF-β secretion in the microenvironment and promotes the formation of a tumor immunosuppressive microenvironment. This study delineates the coordinate work axis of epithelial cells-iCAFs-Tregs in OSCC using SC, ST and TCGA bulk data, and highlights potential targets for therapy. 展开更多
关键词 CXCL12 MICROENVIRONMENT SQUAMOUS
下载PDF
Unsaturated bi-heterometal clusters in metal-vacancy sites of 2D MoS2 for efficient hydrogen evolution 被引量:1
7
作者 Gonglei Shao Jie xu +4 位作者 Shasha Gao zhang zhang Song Liu xu zhang Zhen Zhou 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期264-275,共12页
The valence states and coordination structures of doped heterometal atoms in two-dimensional(2D)nanomaterials lack predictable regulation strategies.Hence,a robust method is proposed to form unsaturated heteroatom clu... The valence states and coordination structures of doped heterometal atoms in two-dimensional(2D)nanomaterials lack predictable regulation strategies.Hence,a robust method is proposed to form unsaturated heteroatom clusters via the metal-vacancy restraint mechanism,which can precisely regulate the bonding and valence state of heterometal atoms doped in 2D molybdenum disulfide.The unsaturated valence state of heterometal Pt and Ru cluster atoms form a spatial coordination structure with Pt–S and Ru–O–S as catalytically active sites.Among them,the strong binding energy of negatively charged suspended S and O sites for H+,as well as the weak adsorption of positively charged unsaturated heterometal atoms for H*,reduces the energy barrier of the hydrogen evolution reaction proved by theoretical calculation.Whereupon,the electrocatalytic hydrogen evolution performance is markedly improved by the ensemble effect of unsaturated heterometal atoms and highlighted with an overpotential of 84 mV and Tafel slope of 68.5 mV dec^(−1).In brief,this metal vacancy-induced valence state regulation of heterometal can manipulate the coordination structure and catalytic activity of heterometal atoms doped in the 2D atomic lattice but not limited to 2D nanomaterials. 展开更多
关键词 CLUSTERS hydrogen evolution reaction metal vacancy MOS2 unsaturated heterometal
下载PDF
审计提升企业合规有效性的作用研究 被引量:1
8
作者 徐彰 童北南 《经济问题》 CSSCI 北大核心 2024年第1期123-128,F0003,共7页
如何建立有效的合规计划是企业合规实践中监管机构和企业面临的核心问题。审计通过主动调查企业经营中留存的文件和凭证,依靠实证分析发现危险信号、考核合规效果,使合规计划从“响应式”的被动合规转向主动合规。同时,我国企业合规改... 如何建立有效的合规计划是企业合规实践中监管机构和企业面临的核心问题。审计通过主动调查企业经营中留存的文件和凭证,依靠实证分析发现危险信号、考核合规效果,使合规计划从“响应式”的被动合规转向主动合规。同时,我国企业合规改革强调通过合规建立现代化企业治理体系,提升产业水平。这意味着合规实践应以提升企业整体治理水平为目标,综合运用各类治理手段。审计作为成熟的经济监督方法,在防范企业风险、提升企业治理水平的目标上与企业合规高度一致,企业和监管机构应当运用包括审计与合规在内的不同治理机制,注重不同机制间的联动和互补,通过发挥体系效应提升企业整体治理水平。 展开更多
关键词 企业合规 有效合规 审计 综合治理
下载PDF
Periodic Variation Studies of the Two Short Period W UMa-type Eclipsing Binaries: LX Lyn and V0853 Aur
9
作者 xu zhang Bin zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期273-284,共12页
In this paper,new light curves(LCs) of contact eclipsing binary(CEB) systems LX Lyn and V0853 Aur are presented and analyzed by using the 2015 version of the Wilson-Devinney(W-D) code.In order to explain their asymmet... In this paper,new light curves(LCs) of contact eclipsing binary(CEB) systems LX Lyn and V0853 Aur are presented and analyzed by using the 2015 version of the Wilson-Devinney(W-D) code.In order to explain their asymmetric LCs,cool starspots on the components were employed.It is suggested that their fill-out degrees are f=12.0%(LX Lyn) and f=26.3%(V0853 Aur).At the same time,we found that LX Lyn is a W-type eclipsing binary(EB) with an orbital inclination of i=84°.88 and a mass ratio of q=2.31.V0853 Aur is also a W-type CEB with a mass ratio of q=2.77 and an orbital inclination of i= 79°.26.Based on all available times of light minimum,their orbital period changes are studied by using the O-C method.The O-C diagram of LX Lyn reveals a cyclic oscillation with a period of about 14.84 yr and an amplitude of 0.0019 days,which can be explained by the light-travel time effect(LTTE) due to the presence of a third body with a minimum mass of0.06M_⊙.For V0853 Aur,it is discovered that the O-C diagram of the system also shows a cyclic oscillation with a period of 9.64 yr and an amplitude of 0.03365 days.The cyclic oscillation of V0853 Aur can be attributed to the LTTE by means of a third body with a mass no less than 3.77M_⊙.The third body may play an important role in the formation and evolution of these systems. 展开更多
关键词 stars:activity (stars:)binaries(including multiple):close (stars:)binaries:eclipsing (stars:)brown dwarfs stars:evolution stars:formation
下载PDF
Removal of rubidium from brine by an integrated film of sulfonated polysulfone/graphene/potassium copper ferricyanide
10
作者 Huanxi xu Peihua Lin +6 位作者 Pei-Jun Liu Hai-Gang Liu Hui-Bin Guo Chao-Xiang Wu Ming Fang xu zhang Guan-Ping Jin 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第5期112-121,共10页
A novel integrated film of sulfonated polysulfone/graphene/potassium copper ferricyanide(KCuFC/SPSG)was used for selectively extracting rubidium ion(Rb^(+))from brine.To form KCuFC/SPSG,the precursor film of sulfonate... A novel integrated film of sulfonated polysulfone/graphene/potassium copper ferricyanide(KCuFC/SPSG)was used for selectively extracting rubidium ion(Rb^(+))from brine.To form KCuFC/SPSG,the precursor film of sulfonated polysulfone/graphene(SPSG)was synthesized by phase conversion process,which was alternately immersed in 0.1 mol·L^(-1)CuSO_(4)/K_(4)[Fe(CN)_(6)]by in-situ adsorption coupled co-precipitation method.Various data such as nuclear magnetic resonance spectrometer,Fourier transform infrared spectroscope,X-ray photoelectron spectroscope,X-ray diffraction,scanning electron microscope,and energy dispersive spectroscopy all verified that abundant KCuFC were uniformly located on the film.The resulting KCuFC/SPSG was used in film separation system.As the solution was fed into the system,the Rb^(+)could be selectively adsorption by KCuFC/SPSG.After the saturation adsorption,0.5 mol·L^(-1)NH_(4)Cl/HCl was fed into the film cell,Rb^(+)could be quickly desorbed by ion-exchange between Rb^(+)and NH_(4)^(+)in the lattice of KCuFC.The purpose of separating and recovering Rb^(+)from the brine can be achieved after the repeated operation.The effects of pH,adsorption time,and interferential ions on the adsorption capacity of Rb^(+)were investigated by batch experiments.The adsorption behavior fits the pseudo-second order kinetic process,while KCuFC has a higher adsorption capacity(Langmuir maximum sorption 165.4 mg·g^(-1)).In addition,KCuFC/SPSG shows excellent selectivity for Rb^(+)even in complex brine systems.KCuFC/SPSG could maintain 93.5%extraction efficiency after five adsorption/desorption cycles. 展开更多
关键词 Rubidium extraction Potassium copper ferricyanide Sulfonated polysulfone Graphene oxide Adsorption
下载PDF
Deep Learning for Financial Time Series Prediction:A State-of-the-Art Review of Standalone and HybridModels
11
作者 Weisi Chen Walayat Hussain +1 位作者 Francesco Cauteruccio xu zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期187-224,共38页
Financial time series prediction,whether for classification or regression,has been a heated research topic over the last decade.While traditional machine learning algorithms have experienced mediocre results,deep lear... Financial time series prediction,whether for classification or regression,has been a heated research topic over the last decade.While traditional machine learning algorithms have experienced mediocre results,deep learning has largely contributed to the elevation of the prediction performance.Currently,the most up-to-date review of advanced machine learning techniques for financial time series prediction is still lacking,making it challenging for finance domain experts and relevant practitioners to determine which model potentially performs better,what techniques and components are involved,and how themodel can be designed and implemented.This review article provides an overview of techniques,components and frameworks for financial time series prediction,with an emphasis on state-of-the-art deep learning models in the literature from2015 to 2023,including standalonemodels like convolutional neural networks(CNN)that are capable of extracting spatial dependencies within data,and long short-term memory(LSTM)that is designed for handling temporal dependencies;and hybrid models integrating CNN,LSTM,attention mechanism(AM)and other techniques.For illustration and comparison purposes,models proposed in recent studies are mapped to relevant elements of a generalized framework comprised of input,output,feature extraction,prediction,and related processes.Among the state-of-the-artmodels,hybrid models like CNNLSTMand CNN-LSTM-AM in general have been reported superior in performance to stand-alone models like the CNN-only model.Some remaining challenges have been discussed,including non-friendliness for finance domain experts,delayed prediction,domain knowledge negligence,lack of standards,and inability of real-time and highfrequency predictions.The principal contributions of this paper are to provide a one-stop guide for both academia and industry to review,compare and summarize technologies and recent advances in this area,to facilitate smooth and informed implementation,and to highlight future research directions. 展开更多
关键词 Financial time series prediction convolutional neural network long short-term memory deep learning attention mechanism FINANCE
下载PDF
Low-Volatile Binder Enables Thermal Shock-Resistant Thin-Film Cathodes for Thermal Batteries
12
作者 Yong Xie Yong Cao +8 位作者 xu zhang Liangping Dong Xiaojiang Liu Yixiu Cui Chao Wang Yanhua Cui xuyong Feng Hongfa Xiang Long Qie 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第4期126-134,共9页
Manufacturing thin-film components is crucial for achieving high-efficiency and high-power thermal batteries(TBs).However,developing binders with low-gas production at the operating temperature range of TBs(400-550... Manufacturing thin-film components is crucial for achieving high-efficiency and high-power thermal batteries(TBs).However,developing binders with low-gas production at the operating temperature range of TBs(400-550°C)has proven to be a significant challenge.Here,we report the use of acrylic acid derivative terpolymer(LA136D)as a low-volatile binder for thin-film cathode fabrication and studied the chain scission and chemical bondbreaking mechanisms in pyrolysis.It is shown LA136D defers to randomchain scission and cross-linking chain scission mechanisms,which gifts it with a low proportion of volatile products(ψ,ψ=39.2 wt%)at even up to 550°C,well below those of the conventional PVDF(77.6 wt%)and SBR(99.2 wt%)binders.Surprisingly,LA136D contributes to constructing a thermal shock-resistant cathode due to the step-by-step bond-breaking process.This is beneficial for the overall performance of TBs.In discharging test,the thin-film cathodes exhibited a remarkable 440%reduction in polarization and 300%enhancement in the utilization efficiency of cathode materials,while with just a slight increase of 0.05 MPa in gas pressure compared with traditional“thick-film”cathode.Our work highlights the potential of LA136D as a low-volatile binder for thin-film cathodes and shows the feasibility of manufacturing high-efficiency and high-power TBs through polymer molecule engineering. 展开更多
关键词 gas production HIGH-POWER low-volatile binder thermal battery thin-film cathode
下载PDF
Prediction of ILI following the COVID-19 pandemic in China by using a partial differential equation
13
作者 xu zhang Yu-Rong Song Ru-Qi Li 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期118-128,共11页
The COVID-19 outbreak has significantly disrupted the lives of individuals worldwide.Following the lifting of COVID-19 interventions,there is a heightened risk of future outbreaks from other circulating respiratory in... The COVID-19 outbreak has significantly disrupted the lives of individuals worldwide.Following the lifting of COVID-19 interventions,there is a heightened risk of future outbreaks from other circulating respiratory infections,such as influenza-like illness(ILI).Accurate prediction models for ILI cases are crucial in enabling governments to implement necessary measures and persuade individuals to adopt personal precautions against the disease.This paper aims to provide a forecasting model for ILI cases with actual cases.We propose a specific model utilizing the partial differential equation(PDE)that will be developed and validated using real-world data obtained from the Chinese National Influenza Center.Our model combines the effects of transboundary spread among regions in China mainland and human activities’impact on ILI transmission dynamics.The simulated results demonstrate that our model achieves excellent predictive performance.Additionally,relevant factors influencing the dissemination are further examined in our analysis.Furthermore,we investigate the effectiveness of travel restrictions on ILI cases.Results can be used to utilize to mitigate the spread of disease. 展开更多
关键词 partial differential equations INFLUENZA SIS model PREDICTION
下载PDF
Micropillar compression using discrete dislocation dynamics and machine learning
14
作者 Jin Tao Dean Wei +3 位作者 Junshi Yu Qianhua Kan Guozheng Kang xu zhang 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第1期39-47,共9页
Discrete dislocation dynamics(DDD)simulations reveal the evolution of dislocation structures and the interaction of dislocations.This study investigated the compression behavior of single-crystal copper micropillars u... Discrete dislocation dynamics(DDD)simulations reveal the evolution of dislocation structures and the interaction of dislocations.This study investigated the compression behavior of single-crystal copper micropillars using fewshot machine learning with data provided by DDD simulations.Two types of features are considered:external features comprising specimen size and loading orientation and internal features involving dislocation source length,Schmid factor,the orientation of the most easily activated dislocations and their distance from the free boundary.The yielding stress and stress-strain curves of single-crystal copper micropillar are predicted well by incorporating both external and internal features of the sample as separate or combined inputs.It is found that the machine learning accuracy predictions for single-crystal micropillar compression can be improved by incorporating easily activated dislocation features with external features.However,the effect of easily activated dislocation on yielding is less important compared to the effects of specimen size and Schmid factor which includes information of orientation but becomes more evident in small-sized micropillars.Overall,incorporating internal features,especially the information of most easily activated dislocations,improves predictive capabilities across diverse sample sizes and orientations. 展开更多
关键词 Discrete dislocation dynamics simulations Machine learning Size effects Orientation effects Microstructural features
下载PDF
A COMPACT EMBEDDING RESULT FOR NONLOCAL SOBOLEV SPACES AND MULTIPLICITY OF SIGN-CHANGING SOLUTIONS FOR NONLOCAL SCHRÖDINGER EQUATIONS
15
作者 xu zhang Hao ZHAI Fukun ZHAO 《Acta Mathematica Scientia》 SCIE CSCD 2024年第5期1853-1876,共24页
For any s∈(0,1),let the nonlocal Sobolev space X^(s)(R^(N))be the linear space of Lebesgue measure functions from R^(N) to R such that any function u in X^(s)(R^(N))belongs to L2(R^(N))and the function(x,y)→(u(x)-u... For any s∈(0,1),let the nonlocal Sobolev space X^(s)(R^(N))be the linear space of Lebesgue measure functions from R^(N) to R such that any function u in X^(s)(R^(N))belongs to L2(R^(N))and the function(x,y)→(u(x)-u(y)√K(x-y)is in L^(2)(R^(N),R^(N)).First,we show,for a coercive function V(x),the subspace E:={u∈X^s(R^N):f_(R)^N}V(x)u^(2)dx<+∞}of X^(s)(R^(N))is embedded compactly into L^(p)(R^(N))for p\in[2,2_(s)^(*)),where 2_(s)^(*)is the fractional Sobolev critical exponent.In terms of applications,the existence of a least energy sign-changing solution and infinitely many sign-changing solutions of the nonlocal Schrödinger equation-L_(k)u+V(x)u=f(x,u),x∈R^N are obtained,where-L_(K)is an integro-differential operator and V is coercive at infinity. 展开更多
关键词 sign-changing solution integro-differential operator least energy variational method
下载PDF
Quantifying the Effects of Near-Surface Viscosity on Seismic Acquisition Geometry: A case study from Chepaizi Exploration Area, Junggar Basin (NW China)
16
作者 Hongqin Ren Tao Liu +2 位作者 xu zhang Jian zhang Renwei Ding 《Applied Geophysics》 SCIE CSCD 2024年第3期433-439,616,共8页
The Chepaizi Exploration Area,Junggar Basin(NW China)holds substantial importance for seismic exploration endeavors,yet it poses notable challenges due to the intricate nature of its subsurface and near-surface condit... The Chepaizi Exploration Area,Junggar Basin(NW China)holds substantial importance for seismic exploration endeavors,yet it poses notable challenges due to the intricate nature of its subsurface and near-surface conditions.To address these challenges,we introduce a novel and comprehensive workflow tailored to evaluate and optimize seismic acquisition geometries while considering the impacts of near-surface viscosity.By integrating geological knowledge,historical seismic data,and subsurface modeling,we conduct simulations employing the visco-acoustic wave equation and reverse-time migration to produce detailed subsurface images.The quality of these images is quantitatively evaluated using a local similarity metric,a pivotal tool for evaluating the accuracy of seismic imaging.The culmination of this workflow results in an automated optimization strategy for acquisition geometries that enhances subsurface exploration.Our proposed methodology underscores the importance of incorporating near-surface viscosity effects in seismic imaging,offering a robust framework for improving the accuracy of subsurface imaging.Herein,we aim to contribute to the advancement of seismic imaging methodologies by providing valuable insights for achieving high-quality seismic exploration outcomes in regions characterized by complex subsurface and near-surface conditions. 展开更多
关键词 seismic acquisition visco-acoustic reverse-time migration local similarity
下载PDF
A High-Accuracy Curve Boundary Recognition Method Based on the Lattice Boltzmann Method and Immersed Moving Boundary Method
17
作者 Jie-Di Weng Yong-Zheng Jiang +2 位作者 Long-Chao Chen xu zhang Guan-Yong zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2533-2557,共25页
Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved bound-aries is vital in aircraft design,ocean,and construction engineering.However,current methods such as Latti... Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved bound-aries is vital in aircraft design,ocean,and construction engineering.However,current methods such as Lattice Boltzmann(LBM)and the immersion boundary method based on solid ratio(IMB)have limitations in identifying custom curved boundaries.Meanwhile,IBM based on velocity correction(IBM-VC)suffers from inaccuracies and numerical instability.Therefore,this study introduces a high-accuracy curve boundary recognition method(IMB-CB),which identifies boundary nodes by moving the search box,and corrects the weighting function in LBM by calculating the solid ratio of the boundary nodes,achieving accurate recognition of custom curve boundaries.In addition,curve boundary image and dot methods are utilized to verify IMB-CB.The findings revealed that IMB-CB can accurately identify the boundary,showing an error of less than 1.8%with 500 lattices.Also,the flow in the custom curve boundary and aerodynamic characteristics of the NACA0012 airfoil are calculated and compared to IBM-VC.Results showed that IMB-CB yields lower lift and drag coefficient errors than IBM-VC,with a 1.45%drag coefficient error.In addition,the characteristic curve of IMB-CB is very stable,whereas that of IBM-VC is not.For the moving boundary problem,LBM-IMB-CB with discrete element method(DEM)is capable of accurately simulating the physical phenomena of multi-moving particle flow in complex curved pipelines.This research proposes a new curve boundary recognition method,which can significantly promote the stability and accuracy of fluid-solid interaction simulations and thus has huge applications in engineering. 展开更多
关键词 Fluid-solid interaction curve boundary recognition method Lattice Boltzmann method immersed moving boundary method
下载PDF
A Novel Anti-Collision Algorithm for Large Scale of UHF RFID Tags Access Systems
18
作者 xu zhang Yi He +9 位作者 Haiwen Yi Yulu zhang Yuan Li Shuai Ma Gui Li Zhiyuan Zhao Yue Liu Junyang Liu Guangjun Wen Jian Li 《Computers, Materials & Continua》 SCIE EI 2024年第7期897-912,共16页
When the radio frequency identification(RFID)system inventories multiple tags,the recognition rate will be seriously affected due to collisions.Based on the existing dynamic frame slotted Aloha(DFSA)algorithm,a sub-fr... When the radio frequency identification(RFID)system inventories multiple tags,the recognition rate will be seriously affected due to collisions.Based on the existing dynamic frame slotted Aloha(DFSA)algorithm,a sub-frame observation and cyclic redundancy check(CRC)grouping combined dynamic framed slotted Aloha(SUBF-CGDFSA)algorithm is proposed.The algorithm combines the precise estimation method of the quantity of large-scale tags,the large-scale tags grouping mechanism based on CRC pseudo-randomcharacteristics,and the Aloha anti-collision optimization mechanism based on sub-frame observation.By grouping tags and sequentially identifying themwithin subframes,it accurately estimates the number of remaining tags and optimizes frame length accordingly to improve efficiency in large-scale RFID systems.Simulation outcomes demonstrate that this proposed algorithmcan effectively break through the system throughput bottleneck of 36.8%,which is up to 30%higher than the existing DFSA standard scheme,and has more significant advantages,which is suitable for application in largescale RFID tags scenarios. 展开更多
关键词 Radio frequency identification ANTI-COLLISION tags grouping dynamic framed slotted Aloha
下载PDF
Values of macular ganglion cell-inner plexiform layer and 10-2 visual field measurements in detecting and evaluating glaucoma
19
作者 Hai-Jian Hu Ping Li +7 位作者 Bin Tong Yu-Lian Pang Hong-Dou Luo Fei-Fei Wang Chan Xiong Yu-Lin Yu Hai He xu zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期852-860,共9页
AIM:To assess the performance of macular ganglion cell-inner plexiform layer thickness(mGCIPLT)and 10-2 visual field(VF)parameters in detecting early glaucoma and evaluating the severity of advanced glaucoma.METHODS:T... AIM:To assess the performance of macular ganglion cell-inner plexiform layer thickness(mGCIPLT)and 10-2 visual field(VF)parameters in detecting early glaucoma and evaluating the severity of advanced glaucoma.METHODS:Totally 127 eyes from 89 participants(36 eyes of 19 healthy participants,45 eyes of 31 early glaucoma patients and 46 eyes of 39 advanced glaucoma patients)were included.The relationships between the optical coherence tomography(OCT)-derived parameters and VF sensitivity were determined.Patients with early glaucoma were divided into eyes with or without central 10°of the VF damages(CVFDs),and the diagnostic performances of OCT-derived parameters were assessed.RESULTS:In early glaucoma,the mGCIPLT was significantly correlated with 10-2 VF pattern standard deviation(PSD;with average mGCIPLT:β=-0.046,95%CI,-0.067 to-0.024,P<0.001).In advanced glaucoma,the mGCIPLT was related to the 24-2 VF mean deviation(MD;with average mGCIPLT:β=0.397,95%CI,0.199 to 0.595,P<0.001),10-2 VF MD(with average mGCIPLT:β=0.762,95%CI,0.485 to 1.038,P<0.001)and 24-2 VF PSD(with average mGCIPLT:β=0.244,95%CI,0.124 to 0.364,P<0.001).Except for the minimum and superotemporal mGCIPLT,the decrease of mGCIPLT in early glaucomatous eyes with CVFDs was more severe than that of early glaucomatous eyes without CVFDs.The area under the curve(AUC)of the average mGCIPLT(AUC=0.949,95%CI,0.868 to 0.982)was greater than that of the average circumpapillary retinal nerve fiber layer thickness(cpRNFLT;AUC=0.827,95%CI,0.674 to 0.918)and rim area(AUC=0.799,95%CI,0.610 to 0.907)in early glaucomatous eyes with CVFDs versus normal eyes.CONCLUSION:The 10-2 VF and mGCIPLT parameters are complementary to 24-2 VF,cpRNFLT and ONH parameters,especially in detecting early glaucoma with CVFDs and evaluating the severity of advanced glaucoma in group level. 展开更多
关键词 10-2 visual field ganglion cell-inner plexiform layer retinal nerve fiber layer thickness GLAUCOMA
下载PDF
上一页 1 2 25 下一页 到第
使用帮助 返回顶部