TOPOLOGY OPTIMIZATION OF TRUSS STRUCTURES WITH SYSTEMATIC RELIABILITY CONSTRAINTS UNDER MULTIPLE LOADING CASES

In this paper, a mathematical model for topology optimization oftruss structures with constraints of displacement and systemreliability under multiple loading cases is constructed. In order toavoid the difficulty of computing the structure's system reliability,a solving approach is presented in which the failure probability ofsystem is divided into the sum of a all bars' failures probability bymeans of reliability distribution. In addition, by drawing into thereliability safety factor and the fundamen- tal relationship instructural mechanics, all probability constraints of displacement andstress are equiv- alently displayed as conventional form and linearfunction of the design variables.

Land Use Structure Optimization Under Systematic Framework

This paper puts forward the concept of land use structure optimization under space_time coupling through analyzing the systematic characteristic of land use structure optimization.It mainly expounds the construction of land use structure optimization model at different levels.Lastly,this paper explains the practicableness of land use structure optimization under systematic framework through the example of Qionghai city.

A three-layer model for the thermal structure in the Huanghai Sea

A one-dimentional three-layer model for the thermal structure in the Huanghai Sea is presented in this study, me model consists of the upper mixed layer caused by heating and wind mixing, the lower mixed layer driven by tidal mixing, and the thermocline with certain thickness. The entrainment velocities of the upper and lower layers are obtained respectively. The results show that the model is capable of describing the development and decline processes of the seasonal thermocline in the Huanghai Sea, simulating successfully the Huanghai Sea Cold Water Mass, the nearshore front and surface cold water off North Jiangsu and explaining reasonably their formation mechanisms as well as the strong thermocline off Qingdao. It is suggested that the tidal mixing plays key role in the formation of the nearshore front off North Jiangsu and the strong thermocline off Qingdao. The wind mixing and the tidal mixing make the lower layer water with high nutrients go up to the upper layer. This physical process may be significant for biological plant production.

Forest Structure Analysis in the Oban Division of Cross River National Park, Nigeria

Information on forest structure is important for forest management decisions. This is inadequate in many situations, especially where timber is not of primary interest. We analyzed the structure of two forest types in the Oban Division of Cross River National Park, Nigeria. Systematic sampling technique was used to establish two transects measuring 2,000 x 2 m, at 600 m interval in the two forest types in four locations. Four 50 m x 50 m plots were located alternately at 500 m intervals along each transect, constituting 32 plots per forest type and 64 plots in all, Diameters at breast height （DBH）, base; middle and top; crown diameter; total height and crown length were measured on all trees with DBH 〉_ 10 cm. There were 159 stems/ha in the close-canopy forest and 132 stems/ha in the secondary forest. The mean DBH were 34.5 cm and 33.62 cm respectively. The mean heights were 24.79 m and 23.97 m, respectively. Basal area/ha were 41.59 m2 ha~ and 27.38 m2 hal for the two forest types. Majority of the trees encountered in the two forest types belonged to the middle stratum which has implication for small mammals＇ populations. Emergent trees which are otherwise scarce in other parts of the country were recorded, which also has implications for density thinning and seed supplies.

Boosted urea electro-oxidation over Ni_(3)N-based nanocomposite via systematic regulation tactic

Exploiting high-efficiency Ni-based materials for electrocatalytic urea oxidation reaction(UOR) is critical for urea-related technologies.The catalytic site density,intrinsic activity,charge transfer,and mass diffusion determine overall electrocatalytic efficiency.Simultaneous modulation over the above four factors promises advanced electrocatalysis,yet challenging.Herein we propose a systematic regulation tactic over composition and geometric structure,constructing a nanocomposite comprising Mn doped Ni_(3)N nanoparticles anchored on reduced graphene oxide(rGO/Mn-Ni_(3)N),achieving elegant integration of four design principles into one,thereby eminently boosting UOR.Particularly,Mn doping in Ni_(3)N can modulate electronic state to induce intrinsic activity regulation.Combining metallic Mn-Ni_(3)N with rGO to engineer hierarchical architecture not only promotes charge transfer,but also enriches active site population.Intriguingly,improved hydrophilicity could impart better electrolyte penetration and gas escape.Consequently,such system-optimized rGO/Mn-Ni_(3)N demonstrates state-of-the-art-level UOR electrocatalysis.This work offers a novel paradigm to create advanced catalysts via systematic and integrated modulation.

Direct-chill semi-continuous casting process of three-layer composite ingot of 4045/3004/4045 aluminum alloys

Three-layer composite ingot of 4045/3004/4045 aluminum alloys was prepared by direct-chill semi-continuous casting process,the temperature field distribution near the composite interface,macro-morphology,microstructure and composition distribution of the composite interface were investigated.The results show that semi-solid layer with a certain thickness forms near the interface due to the effect of cooling plate,which ensures successful implementation of casting the composite ingot.Two different aluminum alloys are well bonded metallurgically.The mechanical properties of composite interface were measured,the tensile and shearing strengths of composite interface are 105 and 88 MPa,respectively,which proves that the composite interface is a kind of metallurgical bonding.

Composition and structure design of three-layered composite phosphors for high color rendering chip-on-board light-emitting diode devices

A three-layered phosphor structure was designed and prepared by the spin coating of BaSi_(2)N_(2)O_(2):Eu(cyan-emitting)and(Sr,Ca)AlSiN_(3):Eu(red-emitting)phosphor films on the yellowemitting Y_(3)Al_(5)O_(12):Ce(YAG:Ce)phosphor ceramic synthesized by the solid-state reaction under vacuum sintering.In order to achieve high color rendering lighting,the influence of the composition and structure of the three-layered phosphors on the optical,thermal,and electrical properties of the chip-on-board(COB)packaged white-light-emitting diodes(WLEDs)was studied systematically.The WLED with the structure of“red+cyan+yellow”(R+C+Y)three-layered phosphor generated neutral white light and had a luminous efficacy of 75 lm/W,the fidelity index(R_(f))of 93,the gamut index(R_(g))of 97,and the correlated color temperature(CCT)of 3852 K.Under the excitation of laser diode(LD),the layer-structured phosphor yielded the white light with a luminous efficacy of 120 lm/W,color rendering index(CRI)of 90,and CCT of 5988 K.The result indicates that the three-layered phosphor structure is a promising candidate to achieve high color rendering and high luminous efficacy lighting.

Characteristics Analysis of Chemical Concentration Sensor Based on Three-layer FBG

The three-layer structure model of the fiber Bragg grating is proposed in this paper. And through experimental study and reasoning calculation to verify the three layer structure of the optical waveguide model, so the sensitivity characteristic of the Bragg wavelength to the refractive index of chemical solution is obtained. And the relationships between the concentration and the shift of Bragg wavelength of sucrose, ethanol, and Nacl solution are achieved. Finally the shifts of the Bragg wavelength with the external concentration are obtained by experiments. A kind of simple structure, small size, good stability, high sensitivity chemical concentration sensor is obtained.

Wave Scattering by a Submerged Sphere in Three-Layer Fluid

Using linear water wave theory,three-dimensional problems concerning the interaction of waves with spherical structures in a fluid which contains a three-layer fluid consisting of a layer of finite depth bounded above by freshwater of finite depth with free surface and below by an infinite layer of water of greater density are considered.In such a situation timeharmonic waves with a given frequency can propagate with three wavenumbers.The sphere is submerged in either of the three layers.Each problem is reduced to an infinite system of linear equations by employing the method of multipoles and the system of equations is solved numerically by standard technique.The hydrodynamic forces(vertical and horizontal forces)are obtained and depicted graphically against the wavenumber.When the density ratio of the upper and middle layer is made to approximately one,curves for vertical and horizontal forces almost coincide with the corresponding curves for the case of a two-layer fluid with a free surface.This means that in the limit,the density ratio of the upper and middle layer goes to approximately one,the solution agrees with the solution for the case of a two-layer fluid with a free surface.

紫花苜蓿CNGC基因家族成员鉴定及分析

环核苷酸门控通道(CNGC)基因家族作为非选择性阳离子通道基因家族之一,在植物信号转导、生长发育和环境胁迫等生理过程中发挥着重要作用。本研究利用生物信息学手段和转录组数据对紫花苜蓿CNGC家族成员的进化关系、基因结构、保守基序、顺式作用元件、染色体定位、共线性关系以及基因表达进行分析。结果表明,紫花苜蓿MsCNGC基因家族成员有16个,在染色体上不均匀分布,存在片段重复,大多数蛋白定位于细胞质膜。系统发育树将MsCNGCs为4个亚家族。基因结构和保守基序分析表明,都含有cNMP/CNBD和ITP功能域。顺式作用元件分析表明,MsCNGCs基因含有许多与非生物或生物胁迫和激素响应元件。MsCNGC4和MsCNGC7.2蛋白之间存在互作。MsCNGC基因具有组织表达特异性。MsCNGC基因对干旱、盐和激素等非生物胁迫均有显著的响应,为进一步研究MsCNGC基因在调控非生物胁迫过程中的潜在功能提供了理论依据。

全过程人民民主制度的体系化建构:一个结构层次视角

全过程人民民主意在解决中国民主的操作性命题,其有效运行离不开制度体系的完善。“健全全过程人民民主制度体系”被视为进一步全面深化改革的重要战略举措。对于全过程人民民主制度的建构问题,当前无论制度优势论、制度生成论、制度完善论还是制度价值论、制度构成论等研究成果均未作出系统回答。基于结构层次视角并借助“根本制度—基本制度—重要制度—具体制度”的四维分析框架探讨全过程人民民主制度的体系化建构问题,研究认为:由党的领导制度和人民代表大会制度构成的全过程人民民主“根本制度”处于其制度体系的宏观层次,致力于解决国家权力的归属问题,扮演“统领者”角色;涉及各领域布局的“基本制度”和“重要制度”处于其制度体系的中观层次,着力解决治国理政各领域的权力分配问题,分别扮演“支撑者”和“支柱者”角色;覆盖于民主各环节的“具体制度”处于其制度体系的微观层次,致力于解决中国民主的操作机制问题,扮演“执行者”角色。理清全过程人民民主制度的内容结构及其层次关系,实现不同层次制度在体系化建构过程的结构互补与功能耦合,形成完备、规范、高效的全过程人民民主制度体系,有助于充分释放人民民主的制度优势与治理效能,为提高其制度化、规范化、程序化水平提供理论参考。

思政课程与课程思政的交叠:新问题还是新开始

思想政治理论课程和课程思政是我国当前思想政治教育中的重要组成部分。两者存在价值上的相似,两者的交叠产生诸多问题,其知识内容重合,在德行教育上造成偏离。在大思政课程体系化建设背景下,应确定两者的范畴,辨明边界,完成价值互通,实现规范联结,注重资源互补。

无意识设计系统方法的类型补充及方法细分

深泽直人提出的无意识设计方法,因其在设计实践中具有文本表意有效性的显著优势,在日本设计界被广泛运用。在《设计的生态学》一书中,深泽直人将无意识设计分为两大基础类型:“客观写生”强调产品系统内两种新符号规约的生成及其意义的传递;“重层性”侧重外部事物与产品之间相互的修辞解释。由于两大基础类型分类方式过于笼统,以使用者与产品间的三类环境所对应的四种符号来源为路径,对无意识设计进行类型的补充及方法的细分,分为三大类型、六种设计方法。无意识设计的典型结构主义特征表现在,文本表意与编写皆围绕四种符号规约展开,四种符号规约覆盖了使用者对产品三种认知方式的全域,且它们在来源上具有“先验”与“既有”的特征,这些保证了文本意义的精准与有效传递。因此,对无意识设计类型补充与方法细分,也是对结构主义产品文本表意有效性的方法总结,使之成为指导设计实践行之有效的系统化工具。

教育法典背景下“教育法律主体”的体系化

教育法典所追求的体系化,应当由体现规范秩序的外部体系与践行价值理念的内部体系共同构成。现有的教育法律主体制度采取的是罗列式结构,这一结构存在缺乏逻辑融贯性、较难覆盖完整、难以彰显法典原则与价值、易使主体定位不清等缺陷,未能达到教育法典体系化的要求。教育法律主体制度应采用层级式结构代替罗列式结构,类型化与概念化思维可以成为建立层级式结构体系的方法论。层级式教育法律主体制度的初步构想为:以受教育者、教育工作参与者、开展教育活动的组织、教育行政机关为抽象主体层级,分别统领包含学生、其他受教育者、未成年受教育者的父母或者其他监护人、教师、其他教育工作者、学校、校外教育培训机构、教育中介组织、公共文化服务机构的具体主体层级。

供应链结构与研发投入:促进还是抑制?

基于供应链管理理论,采用2012—2022年中国体育制造业A股上市公司的数据为研究样本,对企业供应链结构与研发投入之间的关系进行实证分析。研究表明,供应链结构的3个关键维度(供应商集中度、客户集中度以及供应链整体集中度)均对企业的研发投入产生负向影响,主要通过风险承担的路径体现,而非传统的交易成本路径。此外,异质性结果表明,供应链结构对研发投入的作用存在显著的异质性。具体而言,客户集中度对研发投入的影响存在行业竞争程度、市场优势地位以及系统性风险异质性;供应商集中度对研发投入的影响存在行业竞争程度和系统性风险异质性;供应链整体集中度对研发投入的影响存在市场优势地位异质性。这不仅揭示了体育制造业企业研发投入的影响机制,还为促进创新链、产业链、资金链与人才链的深度融合提供了宝贵的启示和建议。

烟台市海洋产业结构分析与优化调整

烟台市海洋经济近年得到较快发展,关于烟台市海洋产业的研究增多,而对海洋产业结构的时间聚类研究较少,研究和探索烟台市海洋产业的发展能够为规划、设计和建设半岛经济区提供一定的参考。基于烟台市海洋产业总产值、产业结构比例和各代表性产业产值与产量发展变化,进行相关分析后利用系统聚类法和K均值聚类法对年份和代表性海洋产业进行聚类,分析海洋产业发展的时间阶段变化特征。结果表明:烟台市海洋产业发展较快,海洋产业产值稳定增长,但存在不稳定因素使得个别产业产值与产量波动幅度较大;产业结构不断优化调整,重心逐渐向二、三产业转移;各产业发展速度不同,近年整体呈放缓趋势。

CITES监管植物习志野叶绿体基因组结构特征及系统发育分析

利用二代测序技术Illumina平台对CITES附录监管物种习志野(Tephrocactus geometricus)进行叶绿体全基因组测序与组装,并对其基因组结构特征及系统进化关系进行分析。结果表明,习志野叶绿体基因组具备典型的环状四分体结构,全长116183 bp,包含72个蛋白编码基因、6个rRNA基因和30个tRNA基因。习志野叶绿体基因组共编码16119个密码子,编码亮氨酸(Leu)的最多;共发现微卫星位点259个,其中最多的是单核苷酸重复序列186个。采用ML法构建系统进化树,习志野与巨人柱属的巨人柱(Carnegiea gigantea)亲缘关系最近。本研究为习志野的分子标记开发、系统发育关系研究、叶绿体转化技术、濒危机制的解析等提供了基础数据参考,同时也丰富了仙人掌科植物的叶绿体基因组遗传信息。

基于多层网络的系统辨证脉学诊断模式探析

中医脉诊能够较为客观、全面地反映人体常变概况,但需要建立一个客观化、逻辑化的诊断模式。将多层网络的概念迁移至脉象与疾病的关系中,通过输入提取25对脉象要素节点构建时空脉象网络,在中医学知识体系指导下对节点建立连边,提取出病因层、体质个性层、心理状态层、功能失调层及结构紊乱层,最终输出对患者一般情况、病因病机及疾病演化过程的认识,从而指导临证辨治,形成以系统辨证脉学脉象要素网络为主导的疾病诊断模式。

一种简单高精度的线结构光传感器标定方法

线结构光三维视觉测量是获取物体表面三维数据的主要方法之一,传统的线结构光标定结果完全依赖提取光条纹特征点的数量,实际操作中无法保证提取足够多的特征点来拟合平面。针对这一问题,设计1种新的线结构光标定方法,将相机中心与结构光光条纹中心的任一特征点连成直线,不需求得光条纹中心线所有点的坐标,只需找到光条纹与棋盘格格边的交点;将其作为光条纹的特征点,控制特征点的数量,基于一次拟合特征点在像素坐标系下的直线方程,再联立直线方程与棋盘格平面方程,得到相机坐标系下的特征点坐标,依次求得3条及以上光条纹的中心坐标;利用多条不重合的直线拟合平面,采用二次拟合的方法提高标定精度。通过实验室搭建的线结构光单目相机对本文方法进行标定实验,结果表明:特征点到光平面的平均距离为0.052 mm,该距离在标定误差范围内,本文方法可有效解决因特征点较少而导致标定误差大的问题。

基于ISM模型的设施布置优化方法

随着社会的发展,设施规划由于能减少运营成本越来越受到重视。考虑到现有设施布置方法相对复杂,在运用系统化设施布置原理和方法的基础上,引入解析结构模型和计算机编程方面的知识,得出一种设施布置的优化方法。该方法能够高效地得到相对合理的设施布置方案。首先运用ISM模型将各个工作单元之间的相互关系梳理清楚,之后通过工作单元之间综合关系密切程度以及面积图法对得到的ISM模型进行调整,最终得出科学合理的设施布置。