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Boundary element analysis for elastic and elastoplastic problems of 2D orthotropic media with stress concentration

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Acta Mechanica Sinica 2005年第5期21卷 472-484页

作者： xiushan sun Lixin Huang Yinghua Liu Zhangzhi Cen Department of Engineering Mechanics Tsinghua UniversityBeiiing 100084 China College of Civil Engineering and Architecture Guangxi University Nanning 530004 Guangxi China

Both the orthotropy and the stress concentration are common issues in modem structural engineering. This paper introduces the boundary element method （BEM） into the elastic and elastoplastic analyses for 2D orthotropic media with stress concentration. The discretized boundary element formulations are established, and the stress formulae as well as the fundamental solutions are derived in matrix notations. The numerical procedures are proposed to analyze both elastic and elastoplastic problems of 2D orthotropic me- dia with stress concentration. To obtain more precise stress values with fewer elements, the quadratic isoparametric element formulation is adopted in the boundary discretization and numerical procedures. Numerical examples show that there are significant stress concentrations and different elastoplastic behaviors in some orthotropic media, and some of the computational results are compared with other solutions. Good agreements are also observed, which demonstrates the efficiency and reliability of the present BEM in the stress concentration analysis for orthotropic media.

关键词： Boundary element method (BEM) . Fundamental solution . Orthotropic medium . Stress concentration .Elastic and elastoplastic problems

Combining ability for main quality traits in peanut(Arachis hypogaea L.)

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Oil Crop Science 2021年第4期6卷 175-179页

作者： Chuantang Wang Zhiwei Wang Hongwei Han Jiakai Li Hongjv Li xiushan sun Guosheng Song Shandong Peanut Research Institute Qingdao266100China Shenyang Agricultural University Shenyang110866China Jilin Agricultural University Changchun130118China

High-oleic peanuts has been recognized by processing sectors,seed sellers and consumers for their longer shelf life,longer seed life and mutiple healthe *** oleate is becoming a requisite for varietal releases in many peanut breeding programs at *** select desirable parents for high-oleic peanut breeding,the study was conducted to evaluate the combining ability of 5 high-oleic donors from our research team,based on quality of individual single *** combining ability was significant for oleic,linoleic,stearic and palmitic acid,oil and protein,while specific combining ability was significant for the traits except *** them,oil content was found to be conditioned solely by additive gene actions,and for other quality traits,additive gene effects were more important than non-additive gene ***-oleic CTW and normal-oleic Xiaojingsheng were selected as the best general combiners for peanut oleic acid ***-sense heritability was high for quality traits other than protein,suggesting that there was high potential for genetic improvement in these traits.

关键词： Combining ability High oleate Heritability Groundnut Oil Protein Fatty acid

Geochemistry　of　Thermal－Mineral　Waters　in　Siping＇an　District，　Shanxi　Province，　China

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Journal of Earth Science 1994年第1期13卷 79-87页

作者： Wan Yanxin sun Lianfa (Department of Hydrogeology and Engineering Geology, China University of Geosciences, Wuhan 430074)sun xiushan(Whter Resource Management Committee of Yangquan City, Shanxi Province, Yangquan 045000)Li Chunyan(Whter Resource Managem

The thermal-mineral waters in Siping'an district are hydrogeologically and geochemically unique in *** occurrence is controlled by faulted structures in Precambrian *** physico-chemical properties, hydrochemical thpes ,major and minor elements ,dissolved gases and organic suboances have been characterized to describe the hydrochemical features and therapeutic effect of the thermal-mineral waters. Hydrogen, oxygen, sulfur and helium isotope compositions of the waters were measured tO explain their ages, origlm and related geochemical procee. The thermal-mineral waters have been formed as a result of the deep circulation of meteoric water in fractures and fissures of hard rocks. Miking of the thermal waters from the deep with cold groundwaters in the Quaternary sediments and the Hutuo River water takes place when the thermal waters move upward to the discharge area.

关键词： hydrogeology geochemistry isotope mimeal water Siping'an.

An Inverse Analysis Algorithm of Material Parameters in Two-Dimensional Orthotropic Media

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An Inverse Analysis Algorithm of Material Parameters in Two-...

The Sixth World Congress on Computational Mechanics in Conjunction with the Second Asian-Pacific Congress on Computational Mechanics

作者： Lixin Huang, xiushan sun, Yinghua Liu, Zhangzhi Cen Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China

An inverse analysis algorithm is developed to identify the material parameters in two -dimensional orthotropic media. The inverse analysis problem of the material parameters is formulated as the problem of minimizing the cost function defined as a square sum of differences between the measured displacement and the computed displacement by a boundary element model. Levenberg-Marquardt method is used to solve the minimization problem. The sensitivities of displacements with respect to the material parameters in the minimization of the cost fun ction are computed by the finite difference approximation method and the direct differentiation method respectively. The direct differentiation method is based on the direct differentiation of the discretized algebraic boundary element matrix equations wit h respect to the material parameters, in which the derivatives of fundamental solutions with respect to the material parameters are derived.

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连续梁及网架浮顶的强度与稳定性

清华大学学报（自然科学版） 2006年第11期46卷 1937-1940页

作者：王建滨孙秀山刘应华蔺书田清华大学工程力学系北京100084

浮顶在实际运行中必须具有足够的强度和稳定性能。采用有限元计算并辅以模型试验的方法,对连续梁及网架浮顶在雨载作用下的强度破坏、屈曲失稳、浮顶沉没以及船舱漏水导致浮顶倾覆等强度和稳定性问题进行了分析。针对这种浮顶的结构特... 详细信息

浮顶在实际运行中必须具有足够的强度和稳定性能。采用有限元计算并辅以模型试验的方法,对连续梁及网架浮顶在雨载作用下的强度破坏、屈曲失稳、浮顶沉没以及船舱漏水导致浮顶倾覆等强度和稳定性问题进行了分析。针对这种浮顶的结构特点设计了专门的有限元求解方案和模型试验方案,并在此基础上利用商业软件AN SY S的二次开发功能,研制出了浮顶模拟分析专用程序。对计算结果和试验结果进行了比较和分析,二者吻合较好,并验证了该浮顶具有较好的强度和稳定性能。

关键词：连续梁及网架浮顶强度稳定性有限元方法

二维正交各向异性结构弹塑性问题的边界元分析

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复合材料学报 2005年第3期22卷 156-161页

作者：孙秀山黄立新刘应华岑章志方东平清华大学土木工程系北京100084 广西大学土木建筑工程学院南宁530004 清华大学工程力学系北京100084

给出了二维正交各向异性结构弹塑性问题的边界元分析方法,包括相应边界积分方程、内点应力公式、边界元求解格式以及弹塑性应力计算方法。在弹塑性分析中,引入了HillTsai屈服准则,采用初应力法和切向预测径向返回法确定实际应力状态。... 详细信息

给出了二维正交各向异性结构弹塑性问题的边界元分析方法,包括相应边界积分方程、内点应力公式、边界元求解格式以及弹塑性应力计算方法。在弹塑性分析中,引入了HillTsai屈服准则,采用初应力法和切向预测径向返回法确定实际应力状态。通过具体算例分析了二维正交各向异性结构的弹塑性应力和塑性区分布情况,部分数值结果与已有结果进行了比较,两者基本吻合。结果表明,本文中给出的边界元法可以有效地用于求解二维正交各向异性结构的弹塑性问题。

关键词：二维正交各向异性结构弹塑性问题边界元法

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基于频谱位移模块的环境声音识别方法

电子测量技术 2022年第5期45卷 62-67页

作者：李传坤郭锦铭李剑孙袖山中北大学信息与通信工程学院太原030051 中北大学省部共建动态测试技术国家重点实验室太原030051 中北大学无损检测技术中心太原030051

针对卷积操作只能提取局部频谱信息,不能有效地挖掘频谱之间相关信息的问题,提出了一种基于频谱位移模块的神经网络。该网络采用密集卷积神经网络的架构,并在支路上使用频谱位移模块实现频谱信息之间的交互。利用这种频谱移位取代了频... 详细信息

针对卷积操作只能提取局部频谱信息,不能有效地挖掘频谱之间相关信息的问题,提出了一种基于频谱位移模块的神经网络。该网络采用密集卷积神经网络的架构,并在支路上使用频谱位移模块实现频谱信息之间的交互。利用这种频谱移位取代了频谱间的下采样操作,实现了频谱的全局化特征提取,同时避免了下采样过程中信息的丢失,进一步地提高了频谱特征图质量。并在公开的数据集ESC10和ESC50上验证频谱位移密集模块,在两种数据集的分类准确度分别达到了96.00%和88.75%,与原有的网络相比准确度分别提升了2.1%和2.25%。实验结果表明,和现有的其他卷积神经网络方法相比,所提出的网络能够更好有效地挖掘全局时频信息,具有更高的识别准确率。

关键词：环境声音识别卷积神经网络频谱位移密集神经网络深度学习

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边坡生态防护技术研究

绿色科技 2020年第4期22卷 192-194页

作者：谢潇孙秀山陕西省土地工程建设集团有限责任公司陕西西安710075 陕西地建土地工程技术研究院有限责任公司陕西西安710075 自然资源部退化及未利用土地整治工程重点实验室陕西西安710075 西宁市测绘院青海西宁810000

指出了近年来随着我国公路建设等工程活动的急剧增加,大规模的裸露边坡开始出现,对边坡土体的结构和原有植被产生了破坏,极易造成水土流失、边坡失稳、生态环境破坏等不良影响。边坡的生态防护不仅可以加固边坡土体,还能起到美化生态环... 详细信息

指出了近年来随着我国公路建设等工程活动的急剧增加,大规模的裸露边坡开始出现,对边坡土体的结构和原有植被产生了破坏,极易造成水土流失、边坡失稳、生态环境破坏等不良影响。边坡的生态防护不仅可以加固边坡土体,还能起到美化生态环境的作用。对边坡生态防护的主要方法进行了总结,并从水文效应和力学效应2个方面阐述了其防护机理。在此基础上,探讨了生态护坡技术目前研究中存在问题及发展的趋势。以供参考。

关键词：边坡生态防护技术水文效应力学效应

花生磷利用特性及磷高效管理措施研究进展与展望

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核农学报 2015年第11期29卷 2246-2251页

作者：沈浦孙秀山王才斌石程仁于天一山东省花生研究所山东青岛266100

磷在花生田生态系统的物质循环过程中起重要作用。探究磷在土壤-花生系统供需特性及磷高效管理措施,对缓解资源紧缺与环境污染有重要意义。本文综述了国内外花生对磷素的需求状况、土壤磷素供应特点、植株对磷的吸收机制及磷高效利用途... 详细信息

磷在花生田生态系统的物质循环过程中起重要作用。探究磷在土壤-花生系统供需特性及磷高效管理措施,对缓解资源紧缺与环境污染有重要意义。本文综述了国内外花生对磷素的需求状况、土壤磷素供应特点、植株对磷的吸收机制及磷高效利用途径等方面花生田磷管理的研究现状,提出了今后花生田磷管理的研究重点:根据花生对磷肥的需求和土壤供应特性,强化花生品种选育、开展磷肥长效高效化研究和土壤潜在磷释放研究,以减缓磷资源耗竭、提高磷肥利用效率和降低环境污染。

关键词：花生合理施肥磷高效潜在有效磷养分管理