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Extended digital image correlation method for micro-region deformation measurement

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Science China(Technological Sciences) 2011年第6期54卷 1355-1361页

作者： CHEN JinLong zhang xiaochuan ZHAN Nan Department of Mechanics Tianjin University Tianjin 300072 China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin 300072 China

Extended digital image correlation(X-DIC) method is one novel test method in experimental *** this paper,the principle of the X-DIC method was introduced in detail.A selection scheme of the initial value of Newton iteration method was proposed when Newton iteration method was applied to solve the partial differential *** scheme could make the X-DIC method suitable for the large deformation measurement and avoid the non-convergence phenomenon *** performance of the X-DIC method was verified by simulated *** the pixel point with the maximum absolute error occurred mainly at the corner or on the interface of the region of interest(ROI,region used for correlation calculation),measured deformation of the core area(area surrounding the center point of the ROI with a smaller size) was taken as the reliable measured *** measurement accuracy of the X-DIC method could be improved greatly by using the core *** with a long-distance microscope,the X-DIC method could be used in the deformation measurement of the *** deformation experiment was done to test the precision of the measurement ***,the X-DIC method was applied to measure the micro-region deformation of the specimen with a *** value was proved to be in accordance with the actual deformation,showing that the X-DIC method is suitable for the research of microscale mechanical behavior of materials.

关键词： extended digital image correlation(X-DIC) initial value core area micro-region deformation

Dual-axial self-attention network for text classification

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Science China(Information Sciences) 2021年第12期64卷 80-90页

作者： xiaochuan zhang Xipeng QIU Jianmin PANG Fudong LIU Xingwei LI State Key Laboratory of Mathematical Engineering and Advanced Computing Shanghai Key Laboratory of Intelligent Information Processing Fudan University School of Computer Science Fudan University

Text classification is an important task in natural language processing and numerous studies aim to improve the accuracy and efficiency of text classification models. In this study, we propose an effective and efficient text classification model which is based on self-attention solely. The recently proposed multidimensional self-attention significantly improved the performance of self-attention. However, existing models suffer from two major limitations:(1) the previous multi-dimensional self-attention models are quite timeconsuming;(2) the dependencies of elements along the feature axis are not taken into account. To overcome these problems, in this paper, a much more computational efficient multi-dimensional self-attention model is proposed, and two parallel self-attention modules, called dual-axial self-attention, are applied to capture rich dependencies along the feature axis as well as the text axis. A text classification model is then *** experimental results on eight representative datasets show that the proposed text classification model can obtain state-of-the-art results and the proposed self-attention outperforms conventional self-attention models.

关键词： text classification dual-axial self-attention feature-axial dependency

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Digital Image Correlation Using Specific Shape Function for Stress Intensity Factor Measurement

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Transactions of Tianjin University 2017年第2期23卷 157-162页

作者： Chunhua Ren Jia Yang xiaochuan zhang Hongwei Ji School of Mechanical Engineering Tianjin University School of Mechanical Engineering Tianjin University of Commerce

The stress intensity factor (SIF) is a critical parameter associated with the fracture behaviour of materials. In this paper, we select the displacement function around a crack tip as the shape function of the digital image correlation (DIC), which makes it possible to directly calculate the SIF by the correlation scheme. Moreover, we use a non-rectangular subset, which can reduce the influence of plastic deformation and crack width on the DIC measurement accuracy. We measured the SIF of a mode I crack in a super-hard aluminium alloy specimen to verify the performance of the proposed method. Our experimental results show that a DIC with a specific shape function can be used to accurately and efficiently calculate the SIF. Furthermore, we also present a practical application of our proposed method for determining the SIF, crack propagation angle and crack tip displacement. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

关键词： Crack propagation Cracks Fracture mechanics Image analysis Strain measurement Stress intensity factors

High-resolution mapping of brain vasculature and its impairment in the hippocampus of Alzheimer's disease mice

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National Science Review 2019年第6期6卷 1223-1238页

作者： xiaochuan zhang Xianzhen Yin Jingjing zhang Anan Li Hui Gong Qingming Luo Haiyan zhang Zhaobing Gao Hualiang Jiang School of Pharmacy East China University of Science and Technology CAS Key Laboratory of Receptor Research Shanghai Institute of Materia MedicaChinese Academy of Sciences Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and Technology MoE Key Laboratory for Biomedical Photonics School of Engineering Sciences Huazhong University of Science and Technology Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and TechnologyShanghai Tech University

Accumulating evidence indicates the critical importance of cerebrovascular dysfunction in the pathogenesis of Alzheimer’s disease(AD). However, systematic comparative studies on the precise brain vasculature of wild-type and AD model mice are still rare. Using an image-optimization method for analysing Micro-Optical Sectioning Tomography(MOST) data, we generated cross-scale whole-brain 3 D atlases that cover the entire vascular system from large vessels down to smallest capillaries at submicron resolution,for both wild-type mice and a transgenic(APP/PS1) mouse model of AD. In addition to distinct vascular patterns in different brain regions, we found that the main vessels of the molecular layer of the hippocampal dentate gyrus(DG-ml) undergo abrupt changes in both diameter and branch angle, spreading a unique comb-like pattern of capillaries. By using a quantitative analysis workflow, we identified in the hippocampus of AD mice an overall reduction of the mean vascular diameter, volume fraction and branch angle, with most significant impairment in the DG-ml. In addition, virtual endoscopy revealed irregular morphological features in the vessel lumen of the AD mice, potentially contributing to the impairment of blood flow. Our results demonstrate the capability of high-resolution cross-scale evaluation of brain vasculature and underscore the importance of studying hippocampal microcirculation for understanding AD pathogenesis.

关键词： Micro-Optical Sectioning Tomography image optimization Alzheimer’s disease impaired hippocampal vasculature virtual vascular endoscopy

Three-in-one to enhance visible-light driven photocatalytic activity of BiOCl: Synergistic effect of mesocrystalline stacking superstructure, porous nanosheet and oxygen vacancy

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Journal of Materiomics 2021年第2期7卷 328-338页

作者： Xianzi Li Shaodong Sun Xin zhang xiaochuan zhang Jie Cui Qing Yang Shuhua Liang Engineering Research Center of Conducting Materials and Composite Technology Ministry of EducationShaanxi Engineering Research Center of MetalBased Heterogeneous Materials and Advanced Manufacturing TechnologyShaanxi Province Key Laboratory for Electrical Materials and Infiltration TechnologySchool of Materials Science and EngineeringXi’an University of TechnologyXi’an710048ShaanxiChina

Simultaneously integrating mesocrystalline stacking superstructures,porous nanosheets and defective oxygen vacancies(OVs)into BiOCl crystals is an available strategy to enhance the visible-light-driven photocatalytic ***,we report a facile etching agent-assisted hydrothermal approach to achieve one-pot fabrication of mesocrystalline BiOCl porous nanosheet stacking superstructures with defective OVs,which show high catalytic activities towards to the visible-light-driven degradation of organic *** formation of stacking superstructure in a mesocrystalline BiOCl is responsibility for increasing the transport of charge *** results and theoretical calculations suggest that the presence of OVs is beneficial to tuning the energy band structure for the improvement of visible light harvesting,prolonging the lifetime and enhancing the oxidation activity of photogenerated charge ***,the porous morphology and thin nanosheet building block could supply abundant active sites for *** research might arouse in-depth investigations on the development of novel precursor-modified strategy for the synthesis of high-active BiOX(X¼Cl,Br and I)-based photocatalysts.

关键词： BiOCl Porous nanosheet Stacking superstructure Oxygen vacancy Photocatalysis

Boosting performance in attack intention recognition by integrating multiple techniques

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Frontiers of Computer Science 2011年第1期5卷 109-118页

作者： Hao Bai (1) david_xiaobai@*** Kunsheng Wang (2) Changzhen Hu (1) Gang zhang (2) xiaochuan Jing (2) Beijing Inst Technol Sch Comp Sci & Technol Beijing 100081 Peoples R China China Aerosp Engn Consultat Ctr Beijing 100048 Peoples R China

Recognizing attack intention is crucial for security analysis. In recent years, a number of methods for attack intention recognition have been proposed. However, most of these techniques mainly focus on the alerts of an intrusion detection system and use algorithms of low efficiency that mine frequent attack patterns without reconstructing attack paths. In this paper, a novel and effective method is proposed, which integrates several techniques to identify attack intentions. Using this method, a Bayesian-based attack scenario is constructed, where frequent attack patterns are identified using an efficient data-mining algorithm based on frequent patterns. Subsequently, attack paths are rebuilt by recorrelating frequent attack patterns mined in the scenario. The experimental results demonstrate the capability of our method in rebuilding attack paths, recognizing attack intentions as well as in saving system resources. Specifically, to the best of our knowledge, the proposed method is the first to correlate complementary intrusion evidence with frequent pattern mining techniques based on the FP-Growth algorithm to rebuild attack paths and to recognize attack intentions.

关键词： attack path attack intention compensatoryintrusion evidence FP-Growth

A Texas Hold’em decision model based on Reinforcement Learning

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A Texas Hold’em decision model based on Reinforcement Learn...

第32届中国控制与决策会议

作者： xiaochuan zhang Yi Li Department of Computer Science of Chongqing University of Technology Chongqing University of Technology

Texas Hold ’em is a typical example of computer incomplete information *** traditional machine learning method has been unable to deal with the huge search state space of Texas Hold ’*** this paper,the value-based reinforcement learning algorithm is adopted,which can deal with the huge amount of data without manual extraction of data features,and can realize the unsupervised training of the ***,the value based reinforcement learning algorithm has the problems of too complex acquisition process and over estimation of DQN ***,this paper introduces DQN-S model,which combines reinforcement learning algorithm with Monte Carlo game search,and integrates Sarsa algorithm to solve the above problems to a certain ***,experimental data show that the over estimation effect of DQN algorithm is weakened to a certain extent after the Sarsa algorithm is *** average return of each game of DQN-S model and model is more than 5 chips,and the average return of each game of DQN-S model is more than 3 chips in the game with its strongest training version.

关键词： Incomplete information machine game Reinforcement learning Texas Hold ’em DQN-S model Monte Carlo search Sarsa algorithm DQN algorithm

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毛泽东对斯大林的评价及其启示

高校理论战线 2009年第1期 47-51页

作者：张小川清华大学人文社会科学学院马克思主义研究中心 100084

斯大林评价是一个关乎社会主义制度和历史的大问题。毛泽东对斯大林的评价,从一开始就坚持了科学分析的方法,在指出他的过错的同时,坚决维护了他作为社会主义制度奠基者之一的地位和形象。苏共二十大对斯大林的全盘否定,对苏联的社会主... 详细信息

斯大林评价是一个关乎社会主义制度和历史的大问题。毛泽东对斯大林的评价,从一开始就坚持了科学分析的方法,在指出他的过错的同时,坚决维护了他作为社会主义制度奠基者之一的地位和形象。苏共二十大对斯大林的全盘否定,对苏联的社会主义制度和国际共产主义运动造成了极大的冲击和破坏。我国对社会主义制度的创立者们采取了稳定的尊重的态度,维护了稳步发展中国特色社会主义的思想基础。

关键词：毛泽东斯大林评价

20世纪60年代美国青年权利意识的觉醒及启示

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中国青年研究 2008年第9期 106-109页

作者：张小川清华大学人文社会科学学院马克思主义研究中心2006级博士研究生

20世纪60年代的美国风起云涌,各种社会力量积极行动,以自身群体权利要求推动着整个社会的发展。青年作为一支独立的社会力量首次登上世界历史舞台,他们逐渐意识到自身的权利并开始提出要求,并以实际行动参与到社会变革中去。尽管所采取... 详细信息

20世纪60年代的美国风起云涌,各种社会力量积极行动,以自身群体权利要求推动着整个社会的发展。青年作为一支独立的社会力量首次登上世界历史舞台,他们逐渐意识到自身的权利并开始提出要求,并以实际行动参与到社会变革中去。尽管所采取的实际行动方式各个不同,但都表现了在美国当时的现代化进程中所凸显出来的青年的权利意识的觉醒和发展。在我国现代化进程发展到一定阶段时,研究美国青年当时的权利意识,对于更科学更有效地开展青年工作是十分有益的。

关键词： 60年代美国青年权利意识