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Taking into Account of Functional Constraints in Optimization of Modes of Power Systems by Genetic Algorithms 预览
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作者 Gayibov Tulkin Shernazarovich Latipov Sherkhon Shuxratovich 《工程(英文)(1947-3931)》 2019年第4期240-246,共7页
The development of the capabilities of computational tools has created up new possibilities for the effective use of a number of classical mathematical methods and algorithms for solving many important problems in the... The development of the capabilities of computational tools has created up new possibilities for the effective use of a number of classical mathematical methods and algorithms for solving many important problems in the power engineering. In particular, a set of algorithms are developed to optimize the modes of electric power systems based on genetic algorithms. At the same time, the issues of taking into account functional constraints in solving such problems by genetic algorithms need to be improved. In accordance with it in this article the problems of taking into account of different constraints in optimization of modes of power systems using genetic algorithms are considered. The algorithm of optimization by genetic algorithm taking into account of functional constraints in forms of equality and inequality by penalty functions is proposed. The results of research of proposed algorithm’s efficiency in example of optimization of mode of power system with 8 buses, 4 thermal power plants and 3 transmission lines with controlled power flow are presented. 展开更多
关键词 OPTIMIZATION POWER System POWER Plant Objective Function CONSTRAINT
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突发网络环境下风险控制机制的研究 预览
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作者 李栋 蔡昱 《长春师范大学学报》 2019年第10期45-48,共4页
针对数据中心网络业务突发特性引发的业务风险,探讨了一种在突发环境下的风险控制算法。算法依托软件定义网络布局中的控制域具有全局侦听的优势,对具有重度风险的突发业务开展测评,计算出风险业务对象范畴。同时通过控制域实施风险化... 针对数据中心网络业务突发特性引发的业务风险,探讨了一种在突发环境下的风险控制算法。算法依托软件定义网络布局中的控制域具有全局侦听的优势,对具有重度风险的突发业务开展测评,计算出风险业务对象范畴。同时通过控制域实施风险化解策略的制定。将算法部署在控制域中对复杂数据中心网络的突发风险业务开展风险调度。所设计的算法经平台测试,验证了其部署在突发环境中具有良好的适应性,与传统算法对比,表现出了显著的差异性。 展开更多
关键词 突发 风险 控制域 约束 计算
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一种改进的回溯试探组卷算法 预览
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作者 李川 杨俊清 +1 位作者 王奕豪 张少茹 《火力与指挥控制》 CSCD 北大核心 2019年第9期144-148,共5页
组卷是在线测评系统中一个重点、难点问题,常见组卷算法随机抽取法、遗传算法、回溯试探等各有优缺点,只能适应一些特定的情况。针对回溯试探法平均组卷时间长、重复率高的问题,进行了两次改进,分别是一次回溯试探搜索的多个解和修正重... 组卷是在线测评系统中一个重点、难点问题,常见组卷算法随机抽取法、遗传算法、回溯试探等各有优缺点,只能适应一些特定的情况。针对回溯试探法平均组卷时间长、重复率高的问题,进行了两次改进,分别是一次回溯试探搜索的多个解和修正重复率降低重复率。通过试验,得出的结论是改进回溯试探法的平均组卷时间和重复率都有明显降低且比较稳定,可适用于各种规模的题库。 展开更多
关键词 组卷 回溯 约束 效率 重复率
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Estimation of J—R Curves for Small-Sized COEC Specimens and Its Application Considering Crack-Tip Cons tr aints
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作者 G.W.He C.Bao +1 位作者 L.X.Cai Y.J.Wu 《固体力学学报:英文版》 SCIE EI CSCD 2019年第3期261-276,共16页
The normalization method has been employed to estimate the J-resistance (J—R) curves for C-shaped outside edge-notched compression (COEC) specimens of SA-508 steel. The COEC specimens present the lowest J—R curves i... The normalization method has been employed to estimate the J-resistance (J—R) curves for C-shaped outside edge-notched compression (COEC) specimens of SA-508 steel. The COEC specimens present the lowest J—R curves in comparison with other three types of specimens. Based on the J—Q—M met hod, the constraint parame ter Q determined at the mid-plane in the through-thickness direction of the specimen is used to approximately quantify the threedimensional crack-tip constraint for COEC specimens. Combining with the previous experiments on J—R curves, the constraint-coirected J—R curves for SA-508 steel specimens are given, which may be used to predict the fracture toughness of actual cracked components in structural integrity assessment. 展开更多
关键词 Ductile fracture toughness COEC specimen DIMENSIONLESS load separation principle NORMALIZATION METHOD CRACK-TIP constraint J-Q-M METHOD
Modified Independent Component Regression Method Without Prewhitening 预览
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作者 Rong Guo Jimin Ye 《哈尔滨工业大学学报:英文版》 EI CAS 2019年第4期50-57,共8页
Independent component analysis(ICA) can reveal the essential underlying structure of data, and independent component regression(ICR) methods usually obtain better performance than other regression methods such as prin... Independent component analysis(ICA) can reveal the essential underlying structure of data, and independent component regression(ICR) methods usually obtain better performance than other regression methods such as principal component regression. However, when existing ICR methods separate or extract independent components using prewhitened data, the backward propagation of inevitable prewhitened errors deteriorates the final linear prediction accuracy. To overcome this weakness, first, we proposed using weighted orthogonal constraint condition to replace the prewhitening of the data in ICA. Next, the statistical independence of ICs and the close relationship between ICs and quality variables are considered at the same time. Then, by combining the merits of improved ICR and ensemble ICR algorithm which solved the problem of selecting an appropriate nonquadratic function in ICA iteration procedure, a modified independent component regression(MICR) method that directly used the measured process data was proposed. Finally, three experimental results were used to validate excellent performance of modified algorithm. 展开更多
关键词 INDEPENDENT COMPONENT analysis WEIGHTED ORTHOGONAL CONSTRAINT INDEPENDENT COMPONENT regression prewhitened data
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Unit Test Data Generation for C Using Rule-Directed Symbolic Execution
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作者 Ming-Zhe Zhang Yun-Zhan Gong +1 位作者 Ya-Wen Wang Da-Hai Jin 《计算机科学技术学报:英文版》 SCIE EI CSCD 2019年第3期670-689,共20页
Unit testing is widely used in software development. One important activity in unit testing is automatic test data generation. Constraint-based test data generation is a technique for automatic generation of test data... Unit testing is widely used in software development. One important activity in unit testing is automatic test data generation. Constraint-based test data generation is a technique for automatic generation of test data, which uses symbolic execution to generate constraints. Unit testing only tests functions instead of the whole program, where individual functions typically have preconditions imposed on their inputs. Conventional symbolic execution cannot detect these preconditions, let alone converting these preconditions into constraints. To overcome these limitations, we propose a novel unit test data generation approach using rule-directed symbolic execution for dealing with functions with missing input preconditions. Rule-directed symbolic execution uses predefined rules to detect preconditions in the individual function, and generates constraints for inputs based on preconditions. We introduce implicit constraints to represent preconditions, and unify implicit constraints and program constraints into integrated constraints. Test data generated based on integrated constraints can explore previously unreachable code and help developers find more functional faults and logical faults. We have implemented our approach in a tool called CTS-IC, and applied it to real-world projects. The experimental results show that rule-directed symbolic execution can find preconditions (implicit constraints) automatically from an individual function. Moreover, the unit test data generated by our approach achieves higher coverage than similar tools and efficiently mitigates missing input preconditions problems in unit testing for individual functions. 展开更多
关键词 AUTOMATED UNIT testing program CONSTRAINT SYMBOLIC EXECUTION static analysis
Predictive analysis for race detection in software-defined networks
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作者 Gongzheng LU Lei XU +1 位作者 Yibiao YANG Baowen XU 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第6期34-53,共20页
Race condition remains one kind of the most common concurrency bugs in software-defined networks(SDNs). The race conditions can be exploited to lead to security and reliability risks. However,the race conditions are n... Race condition remains one kind of the most common concurrency bugs in software-defined networks(SDNs). The race conditions can be exploited to lead to security and reliability risks. However,the race conditions are notoriously difficult to detect. The existing race detectors for SDNs have limited detection capability. They can only detect the races in the original traces(observed traces) and cause false negatives. In this study, we present a predictive analysis framework called SDN-predict for race detection in SDNs. By encoding the order between the specified network events in SDNs as constraint, we formulate race detection as a constraint solving problem. In addition to detecting the races in the original trace, our framework can also detect the races in the feasible traces got from reordering the events in the original trace while satisfying the consistency requirements of trace. Moreover, we formally prove that our predictive analysis framework is sound and can achieve the maximal possible detection capability for any sound dynamic race detector with respect to the same trace. We evaluate our framework on a set of traces collected from three SDN controllers(POX, Floodlight, ONOS), running 5 representative applications including reactive and proactive applications in large networks, on three different network topologies. These experiments show that our framework has higher race detection capability than exisiting SDN race detector-SDNRacer, and detects more 1173 races. These 1173 races were previously undetected and confirmed by checking the race graphs. 展开更多
关键词 CONSTRAINT SOLVING PREDICTIVE analysis RACE detection software-defined NETWORKS
P92钢高温断裂韧性的试验 预览 被引量:1
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作者 荆洪阳 李世波 +1 位作者 徐连勇 赵雷 《焊接学报》 EI CAS CSCD 北大核心 2019年第2期8-12,72,161共7页
文中以P92耐热钢为研究对象,研究了不同尺寸的开侧槽和不开侧槽的紧凑拉伸试样在630°C下的断裂韧性,得到了相应的的阻力曲线及断裂韧度JQ. P92钢在高温下为典型的韧性断裂机制.基于三维有限元计算对侧槽的拘束效应进行表征,结果表... 文中以P92耐热钢为研究对象,研究了不同尺寸的开侧槽和不开侧槽的紧凑拉伸试样在630°C下的断裂韧性,得到了相应的的阻力曲线及断裂韧度JQ. P92钢在高温下为典型的韧性断裂机制.基于三维有限元计算对侧槽的拘束效应进行表征,结果表明,侧槽可明显提高试样的拘束水平,试样尺寸越小,J阻力曲线差异越明显.随载荷增大,非侧槽试样的拘束变化更明显,开侧槽将导致试样阻力曲线不同.试样尺寸及结构的改变,对韧性材料的阻力曲线影响较大,而对断裂韧度值影响较小.试样开侧槽之后裂纹扩展更平齐,可优化断裂韧性试验过程. 展开更多
关键词 P92钢 高温断裂韧性 紧凑拉伸试样 侧槽 拘束
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进一步加强基层站段安全管理工作的思考 预览
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作者 李广渊 张武 《中国铁路》 2019年第10期25-28,共4页
基层站段是铁路运输安全工作的主要执行者,其安全管理能力的强弱是决定铁路运输安全能否持续稳定的关键因素。通过分析当前基层站段安全管理工作现状及制约因素,从站段管理能力、责任落实能力、决策执行能力等8个方面提出进一步提升基... 基层站段是铁路运输安全工作的主要执行者,其安全管理能力的强弱是决定铁路运输安全能否持续稳定的关键因素。通过分析当前基层站段安全管理工作现状及制约因素,从站段管理能力、责任落实能力、决策执行能力等8个方面提出进一步提升基层站段安全管理能力的对策建议,为夯实基层安全管理基础提供借鉴。 展开更多
关键词 铁路 站段 安全管理 制约因素 对策
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某“华龙一号”核电站核岛基础大体积混凝土施工裂缝控制
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作者 张海明 潘乐 +1 位作者 荣华 徐海翔 《工业建筑》 CSCD 北大核心 2019年第2期27-30,共4页
华龙一号”是中国自主创新研发的第三代核电技术。核岛基础底板是核电站反应堆主要的支承结构,对抗裂要求极高。基础底板常采取分层整体浇筑,因水泥水化热的释放,温度场、应力场互相影响,施工难度大,裂缝控制困难。对混凝土温度和应力... 华龙一号”是中国自主创新研发的第三代核电技术。核岛基础底板是核电站反应堆主要的支承结构,对抗裂要求极高。基础底板常采取分层整体浇筑,因水泥水化热的释放,温度场、应力场互相影响,施工难度大,裂缝控制困难。对混凝土温度和应力准确推算、分析、模拟,是有效控制裂缝的前提。结合国内某“华龙一号”核电站基础底板大体积混凝土施工实例,研究了混凝土的应力状态、温度收缩机制,并很好地控制了裂缝的发生。 展开更多
关键词 温度应力 收缩应力 约束 有限元分析 裂缝
改进的POTTS模型及其数据多分类直推学习算法 预览
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作者 赵方丽 潘振宽 +1 位作者 徐止磊 郑世秀 《计算机仿真》 北大核心 2019年第5期310-315,359共7页
借助于图上离散非局部算子,计算机视觉领域图像分割的Potts模型可直接应用于数据多分类直推学习,但为受多种约束的能量泛函极值问题。采用传统的惩罚函数方法将受约束优化问题转化为无约束优化问题的求解涉及多个难以设定的惩罚参数。... 借助于图上离散非局部算子,计算机视觉领域图像分割的Potts模型可直接应用于数据多分类直推学习,但为受多种约束的能量泛函极值问题。采用传统的惩罚函数方法将受约束优化问题转化为无约束优化问题的求解涉及多个难以设定的惩罚参数。通过用较少的标记函数设计每类数据的特征函数自然满足原有的Simplex约束避免了对这类约束的惩罚。通过直接投影方法保证了直推学习中预设标记点精确约束进一步减少了能量泛函中惩罚项及惩罚参数的数量。对平衡分类约束和变量分裂引起的约束通过设计ADMM(Alternating Direction Method of Multipliers)方法降低了对惩罚参数的过分依赖。通过对多个标准数据集进行数值实验验证了所提出模型和算法的有效性。 展开更多
关键词 离散非局部算子 数据多分类 算法约束
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The Belt and Road Initiative and Financing Constraint for Chinese Enterprises 预览
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作者 徐思 何晓怡 钟凯 《中国经济学人:英文版》 2019年第6期109-124,共16页
In the context of China’s proactive implementation of the Belt and Road Initiative(BRI),unraveling the BRI’s effect on corporate behavior is of vital importance to China’s policymaking on overseas investment.With t... In the context of China’s proactive implementation of the Belt and Road Initiative(BRI),unraveling the BRI’s effect on corporate behavior is of vital importance to China’s policymaking on overseas investment.With the BRI’s enactment as a quasi-natural experiment,this paper employs the difference in differences(DID)method to investigate the BRI’s effect on the financing constraint for Chinese enterprises.Our study finds that the BRI’s implementation has significantly reduced financing constraints for BRI enterprises,and the effect is more significant for emerging advantageous industries and export-oriented node cities. 展开更多
关键词 the BELT and ROAD Initiative(BRI) FINANCING CONSTRAINT government support FINANCING cost quasi-natural experiment
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虚拟手交互中约束类物体操作研究 预览
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作者 邹俞 晁建刚 林万洪 《计算机工程与应用》 CSCD 北大核心 2019年第9期168-177,共10页
虚拟手技术是虚拟现实技术中的一种交互方式,是指通过手势识别技术将人的真实手映射到虚拟环境中并与虚拟物体进行交互操作的人机交互方式。主要应用于虚拟训练、虚拟手术和虚拟装配等领域。对虚拟手交互的约束类对象进行了研究,提出了... 虚拟手技术是虚拟现实技术中的一种交互方式,是指通过手势识别技术将人的真实手映射到虚拟环境中并与虚拟物体进行交互操作的人机交互方式。主要应用于虚拟训练、虚拟手术和虚拟装配等领域。对虚拟手交互的约束类对象进行了研究,提出了基于运动学的约束类物体操作方法,解决了阀门类有约束物体交互中虚拟手姿态不真实、操作不可控的问题。设计实验验证了基于运动学的方法能以符合实际操作的效果完成虚拟现实系统中的操作任务,可以应用到虚拟训练、虚拟装配等仿真平台。 展开更多
关键词 虚拟手 运动学 约束 阀门 旋转
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Analysis of the relation between ocean internal wave parameters and ocean surface fluctuation
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作者 Yufei ZHANG Bing DENG Ming ZHANG 《地球科学前沿:英文版》 SCIE CAS CSCD 2019年第2期336-350,共15页
The relation between ocean internal waves (IWs) and surface fluctuation is studied using a quasiincompressible two-dimensional linear ocean wave model.The main conclusions are as follows: the IW parameters can be obta... The relation between ocean internal waves (IWs) and surface fluctuation is studied using a quasiincompressible two-dimensional linear ocean wave model.The main conclusions are as follows: the IW parameters can be obtained by solving the boundary value problem of ordinary differential equations with the frequency,wave number,and amplitude of the surface fluctuation.When the ocean surface fluctuation state is given,the ocean IW presents a different structure,i.e.,the uncertainty of the solution,which reflects the characteristics of the inverse problem.To obtain a definite solution,this study proposes constraint conditions for the inverse problem,namely,the relationship among background flow,buoyancy frequency,sea surface height,and geostrophic parameters.The necessary and sufficient conditions for the existence of IWs and external waves (surface wave) can be obtained according to the different constraint conditions.The amplitude of the surface fluctuation is positively correlated with IWs,and they share the same frequency and wave number.We also examined the relationship between the vertical structure,the maximum amplitude,and the constraint conditions.For a certain wave number,when the ocean environment is defined,the natural frequency (characteristic frequency) of IWs can be obtained.If the frequency of the surface fluctuation is similar or equal to the natural frequency,the resonance phenomenon will occur and can result in very strong IWs.The presented theory can serve as a basis for the analytical estimation of IWs. 展开更多
关键词 CONSTRAINT CONDITION surface FLUCTUATION INTERNAL wave INVERSE problem
高校校园戏剧文化育人功能的探索与实践——以安庆师范大学校园戏剧发展为例 预览 被引量:2
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作者 方瑞 左方霞 《内江师范学院学报》 2019年第3期90-94,共5页
高校校园戏剧作为大学生美育实践的重要载体,为大学生提供了语言艺术创作和个人能力展示的平台,推动了大学生文化素质教育和高校校园文化建设。校园文化活动的实用性、业余性、娱乐性对校园戏剧的文化育人功能产生了较大的影响。安庆师... 高校校园戏剧作为大学生美育实践的重要载体,为大学生提供了语言艺术创作和个人能力展示的平台,推动了大学生文化素质教育和高校校园文化建设。校园文化活动的实用性、业余性、娱乐性对校园戏剧的文化育人功能产生了较大的影响。安庆师范大学立足地域文化特色,重视校园戏剧的发展,营造良好的校园文化氛围,通过多种途径不断扩大校园戏剧文化对学生群体的影响力。 展开更多
关键词 校园戏剧 大学生 文化育人 制约 途径
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环境承载力容量约束模型下景区型森林文化价值评估实证研究 预览
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作者 修新田 陈秋华 黄小玲 《林业资源管理》 北大核心 2019年第5期76-83,共8页
用森林文化币的尺度来衡量森林文化价值;在吸收、借鉴森林文化币已有研究理论和研究成果的基础上,构建基于森林文化资源环境承载力容量约束下,以森林文化币为衡量尺度的景区型森林文化价值评估模型。运用评估模型对乌金山国家级森林公... 用森林文化币的尺度来衡量森林文化价值;在吸收、借鉴森林文化币已有研究理论和研究成果的基础上,构建基于森林文化资源环境承载力容量约束下,以森林文化币为衡量尺度的景区型森林文化价值评估模型。运用评估模型对乌金山国家级森林公园的森林文化价值进行实证分析,得到乌金山国家森林公园的森林文化价值量为154.45(万森林文化币)。同时,研究从森林文化资源价值的利用、森林文化资源生态容量的扩展、森林公园森林文化力的建设等方面提出乌金山国家森林公园森林文化价值的提升、利用建议。 展开更多
关键词 环境承载力容量 约束 森林文化价值 景区 评估
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Optimal harvesting for a single-species population governed by Gompertz law:Influence of environmental fluctuation and limited harvesting capacity
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作者 P.D.N.Srinivasu Simon D.Zawka 《生物数学学报:英文版》 2019年第2期115-142,共28页
This work presents an optimal harvesting problem associated with a single-species population governed by Gompertz law in a seasonally fluctuating environment.The influence of environmental fluctuation is accommodated ... This work presents an optimal harvesting problem associated with a single-species population governed by Gompertz law in a seasonally fluctuating environment.The influence of environmental fluctuation is accommodated by choosing the coefficients in the differential equation to be periodic functions with the same period and restriction on the harvesting effort is accommodated by considering binding constraints on the control variable.Hence,a linear optimal control problem has been considered where the state dynamics is governed by Gompertz equation and the control variable is subject to the binding constraints.With the help of maximum principle and the concept of blocked intervals,an optimal periodic solution has been obtained which is followed by the construe tion of optimal solution using the theory of most rapid approach.Important results of the study are demonstrated through numerical simulations. 展开更多
关键词 Optimal HARVESTING GOMPERTZ equation SEASONALITY binding CONSTRAINT blocked INTERVALS
管道结构与不同实验室试样间裂尖拘束度的匹配 预览
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作者 杨杰 刘玉嫚 《机械工程材料》 CAS CSCD 北大核心 2019年第9期43-47,共5页
选用统一拘束参数Ap,采用有限元模拟方法分别对不同初始裂纹尺寸下管道结构和实验室单边缺口弯曲(SENB)试样、紧凑拉伸(CT)试样、单边裂纹拉伸(SENT)试样和中心裂纹拉伸(CCT)试样的裂尖拘束度进行了表征,并构建了管道结构与实验室试样... 选用统一拘束参数Ap,采用有限元模拟方法分别对不同初始裂纹尺寸下管道结构和实验室单边缺口弯曲(SENB)试样、紧凑拉伸(CT)试样、单边裂纹拉伸(SENT)试样和中心裂纹拉伸(CCT)试样的裂尖拘束度进行了表征,并构建了管道结构与实验室试样间裂尖拘束度的匹配。结果表明:管道结构的裂尖拘束度与SENB试样和CCT试样的裂尖拘束度匹配性较差;初始裂纹尺寸a/c=0.2,a/t=0.5(a为裂纹深度,c为1/2裂纹长度,t为管壁厚度)条件下管道结构的裂尖拘束度与含有深裂纹(a/W=0.7,W为试样宽度)CT试样的裂尖拘束度相接近,初始裂纹尺寸a/c=0.8,a/t=0.5,0.8条件下管道结构的裂尖拘束度与含有深裂纹(a/W=0.5,0.6,0.7)CT试样的裂尖拘束度相匹配;管道结构的裂尖拘束度与SENT试样的裂尖拘束度相近,二者具有较好的匹配性;在对实际结构进行完整性评定时,可选择与实际结构裂尖拘束度相近的实验室试样进行断裂力学试验,以其测定的断裂力学性能对该实际结构进行评定,从而增加评定的准确性。 展开更多
关键词 管道结构 实验室试样 拘束 匹配 结构完整性评定
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Nuclear Mechanotransduction under Geometric Constraint
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作者 Yuan Hong Yuhui Li +2 位作者 Shaobao Liu Genin MGuy Feng Xu 《医用生物力学》 CAS CSCD 北大核心 2019年第A01期133-134,共2页
Cells in vivo reside within a complex microenvironment that is rich in biological,chemical and mechanical cues,playing critical roles in regulating cellular activities(e.g.,proliferation,migration,differentiation)both... Cells in vivo reside within a complex microenvironment that is rich in biological,chemical and mechanical cues,playing critical roles in regulating cellular activities(e.g.,proliferation,migration,differentiation)both spatially and temporally.Although it is well accepted that biochemical cues can significantly influence cell functions,accumulating evidence has also shown that mechanical feedback from the cell microenvironment(e.g.,stiffness of ECM,morphology,and tension force)also plays an important role in controlling cell fate.Disequilibrium of the mechanical microenvironment is associated with a series of diseases,such as cancer migration and tissue fibrosis.Thus,there is a pressing need to understand how cells transduce these mechanobiological cues.The cell cytoskeleton is linked to both the nuclear lamina via LINC complexes and to focal adhesions.This enables the intriguing possibility that forces directly transduced by the nucleus might in fact affect gene expression.Can force transmitted to nucleus and associated alterations to the special organization of genome inside the nucleus modulate gene expression programmes and change cell behaviors? This kind of putative mechanotransduction dominated by the nucleus is termed as nuclear mechanotransduction.Evidence shows that isolated nuclei regulate their stiffness to in response to force applied on nesprin with integrated nuclear lamina and emerin required.Another example is that the force applied on integrins in focal adhesions can be transmitted through actin filaments to the LINC complex and then stretch the chromatin directly through lamina-chromatin interactions.However,the mechanism of nuclear mechanotransduction is still unclear.Three hypotheses have been proposed.The first proposed mechanism is that the proteins on the nuclear lamina are phosphorylated induced by force and their special organization is changed to regulate downstream signal transduction.Transcription factors like YAP and calcium ions would enter the nucleus in the context of force stretch 展开更多
关键词 NUCLEAR MECHANOTRANSDUCTION GEOMETRIC CONSTRAINT
多种约束下大型矩形纺丝箱的热-固耦合分析 预览
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作者 王垒智 董金善 孙存旭 《轻工学报》 CAS 2019年第2期95-101,共7页
针对大型矩形纺丝箱体的热应力对支座处产生影响的问题,以某公司12位联苯气相加热大型纺丝箱体作为研究对象,对矩形纺丝箱整体结构进行 ANSYS 有限元分析,研究设置支架对纺丝箱支座处温度变化的影响规律,采用间接法考察其支座在不同种... 针对大型矩形纺丝箱体的热应力对支座处产生影响的问题,以某公司12位联苯气相加热大型纺丝箱体作为研究对象,对矩形纺丝箱整体结构进行 ANSYS 有限元分析,研究设置支架对纺丝箱支座处温度变化的影响规律,采用间接法考察其支座在不同种类约束下热-固耦合的热应力变化规律.结果表明:支座通过支架散热更快,支座区域存在较大的温度梯度;纺丝箱最大热应力出现在箱体支座的螺栓孔处,组件圈的温度梯度较小;在全约束下支座的热应力最大,当温度梯度小于10℃时,支座的热应力大小不受约束变化的影响.进行工程设计时,可选用隔热性能优良的保温材料,适当调节纺丝箱不同支座处的螺栓松紧性,有效降低热应力,保障设备安全运行. 展开更多
关键词 矩形纺丝箱 热-固耦合 热应力 约束
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