Plastic limit load analysis for pressure pipe with incomplete welding defects based on the extended Net Section Collapse Criteria

With von Mises yield criterion, the loading range of Net Section Collapse （NSC） Criteria is extended from combined tension and bending loadings to combined bending, torsion and internal pressure loadings. A new theoretical analyzing method of plastic limit load for pressure pipe with incomplete welding defects based on the extended NSC Criteria is presented and the correlative formulas are deduced, the influences of pipe curvature, circumferential length and depth of incomplete welding defects on the plastic limit load of pressure pipe are considered as well in this method. Meanwhile, according to the orthogonal experimental design method, the plastic limit loads are calculated by the finite element method and compared with the theoretical values. The results show that the expressions of plastic limit load of pressure pipe with incomplete welding defects under bending, torsion and internal pressure based on extended NSC criteria are reliable. The study provides an important theoretical basis for the establishment of safety assessment measure towards pressure pipe with incomplete welding defects.     

社会经济的发展与竞技体育的相关分析

为了在量上更加明确经济与体育竞赛成绩的关系，分别以我国六大区域（华北、东北、华东、中南、西南、西北）为具体研究对象，采用文献资料调研、数理统计法、逻辑分析法，运用定量与定性相结合的分析手段，以2001年各区域国内生产总值（含第一、二、三产业）、农业人口、非农业人口、农民纯收入、科技投入、文体投入、教育投入、科技人员、教育程度（大学本科人数）、文体人员与九运会成绩为具体研究指标，通过研究和揭示经济以直接、间接等不同形式作用于体育事业，从而影响竞技体育与体育竞赛成绩，明确经济与体育竞赛成绩在量上的相互关系。     

高等师范院校生物类专业的分析化学教学之我见

分析化学课程教学在高等师范院校生物类专业(生物科学、生物技术、生物制药等)本科生的培养过程中具有重要的意义。为了提高本科生的培养质量,使其满足毕业后工作岗位的需求,该文通过对高等师范院校生物类专业的教学环节(包括理论课教学和实验课教学)进行探究和总结,并结合该课程在江苏师范大学的教学资源和条件,归纳了提高高等师范院校生物类专业本科生分析化学教学水平的思路和方法。     

复合营养液对小鼠抗疲劳研究

通过小鼠实验对复合营养液的抗疲劳作用进行了研究.实验结果表明:复合营养液可明显延长小鼠的游泳时间,显著降低小鼠血乳酸及尿素氮的含量,初步证明复合营养液具有抗疲劳作用,对运动机能有促进作用.     

区域竞技体育发展现状与社会人口结构的相关研究

分别以我国六大区域(华北、东北、华东、中南、西南、西北)为研究对象,运用文献资料、数理统计和逻辑分析等方法,对区域竞技体育现状与社会人口结构(职业、城乡、文化、年龄、发展及分布结构)进行相关分析.结果表明:传统型人口产业结构是制约我国竞技体育发展的重要因素,发展型和现代型人口产业结构对竞技体育发展具有积极影响.竞技体育与非农业人口成正向关系,与农业人口成反向关系.竞技体育与高文化程度人群存在显著正相关.年轻型人口社会可为竞技体育发展提供人才储备,成年型人口社会是竞技体育发展的"黄金时期",而老年型人口社会可能制约竞技体育的发展.人口发展结构与竞技体育呈负相关,人口分布结构也可通过一些渠道影响竞技体育.     

试论绘画作品中色彩的语言功能

黑、灰、白是稳定与活跃画面的最基本的要素,面对纷繁的物象,只有通过黑、灰、白的提炼、概括,画面才能既有对抗产生的活跃性,又有和谐产生的稳定性,它可使静止、稳定的画面产生动感。因此,运用艺术概括的手段去认识与研究黑、灰、白的关系,是绘画学习中重要的课题。     

Factors affecting the quality of engineering education in the four largest emerging economies

A huge increase in engineering graduates from the BRIC countries in recent decades potentially threatens the competitiveness of developed countries in producing high value-added products and services, while also holding great promise for substantially increasing the level of global basic and applied innovation. The key question is whether the quality of these new BRIC engineers will be high enough to actualize this potential. The objective of our study is to assess the evolving capacity of BRIC higher education systems to produce qualified engineering graduates. To meet this objective, we compare developments in the quality of undergraduate engineering programs across elite and non-elite higher education tiers within and across each BRIC country. To assess and compare the quality of engineering education across the BRIC countries, we use multiple sources of primary and secondary data gathered from each BRIC country from 2008 to 2011. In combination with this, we utilize a production function approach that focuses on key input-, process- and outcome-based indicators associated with the quality of education programs. Our analysis suggests that in all four countries, a minority of engineering students receives high quality training in elite institutions while the majority of students receive low quality training in non-elite institutions. Our analysis also shows how the BRIC countries vary in their capacity to improve the quality of engineering education.     

我国环境责任保险实施现状及立法改进设想

迄今为止,主要发达国家的环境责任保险制度已进入较为成熟阶段,并成为通过社会化途径解决环境损害赔偿问题的主要方式之一。受经济发展水平、环境保护意识、保险公司的规模与实力等因素的制约,我国尚未建立实质意义上的环境责任保险制度。近年来,国内众多学者分析和阐述了我国环境责任保险的立法模式、承保范围、保险费率等问题,但就我国环境责任保险制度的实施现状来看,改进我国环境责任保险立法、促进环境责任保险事业发展仍有诸多亟待解决的问题。     

Microstructured multi-well plate for three-dimensional packed cell seeding and hepatocyte cell culture

In this article, we present a microstructured multi-well plate for enabling three-dimensional (3D) high density seeding and culture of cells through the use of a standard laboratory centrifuge to promote and maintain 3D tissue-like cellular morphology and cell-specific functionality in vitro without the addition of animal derived or synthetic matrices or coagulants. Each well has microfeatures on the bottom that are comprised of a series of ditches/open microchannels. The dimensions of the microchannels promote and maintain 3D tissue-like cellular morphology and cell-specific functionality in vitro. After cell seeding with a standard pipette, the microstructured multi-well plates were centrifuged to tightly pack cells inside the ditches in order to enhance cell-cell interactions and induce formation of 3D cellular structures during cell culture. Cell-cell interactions were optimized based on cell packing by considering dimensions of the ditches/open microchannels, orientation of the microstructured multi-well plate during centrifugation, cell seeding density, and the centrifugal force and time. With the optimized cell packing conditions, we demonstrated that after 7 days of cell culture, primary human hepatocytes adhered tightly together to form cord-like structures that resembled 3D tissue-like cellular architecture. Importantly, cell membrane polarity was restored without the addition of animal derived or synthetic matrices or coagulants.     

中国马拉松赛事发展的空间分布与自相关特征研究

以2014-2019年全国31省份马拉松赛事举办量为研究数据,采用地理空间计量分析模型对我国各地区马拉松赛事发展的空间分布与自相关特征进行分析。结果显示:①31省份马拉松赛事发展的空间自相关关系总体上呈正相关,其分布具有明显的空间集聚性,且空间依赖性较强,但这种依赖程度和空间集聚性已有下降趋势。②我国马拉松赛事存在一定的空间异质性。东、西部马拉松赛事发展的两极差异明显,马拉松赛事发展的 “马太效应”逐渐增强。③新疆和东部沿海地区的马拉松赛事发展存在显著的空间集聚特征,但大部分地区并未与周边邻接地区形成显著的空间集聚关系,且这种情况多年来并未发生太大改变。在此基础上提出区域间合作办赛、向发展较差地区倾斜、以点带面等建议,旨在促进全国马拉松赛事整体发展。