Intact soft clay’s critical response to dynamic stress paths on different combinations of principal stress orientation

Comprehensive tests on Hangzhou intact soft clay were performed, which were used to obtain the soils’ critical response to undrained dynamic stress paths under different combinations of principal stress orientation. The different combinations included cyclic principal stress rotation (CPSR for short), cyclic shear with abrupt change of principal stress orientation (CAPSO for short) and cyclic shear with fixed principal stress orientation (CFPSO for short). On one side, under all these stress paths, samples have obvious strain inflection points and shear bands, and the excess pore water pressure is far from the level of initial effective confining pressure at failure. Stress paths of major principal stress orientation (α) alternating from negative and positive have quite different influence on soil’s properties with those in which α is kept negative or positive. On the other side, due to the soil’s strongly initial anisotropy, samples under double-amplitudes CPSR and CAPSO (or single-amplitude CPSR and CFPSO) have similar properties on dynamic shear strength and pore water pressure development tendency when α is kept within ±45°, while have quite different properties when α oversteps ±45°.     

直击现代艺术之门——由决澜社的产生及影响谈其先锋性和局限性

20世纪30年代,向现代派艺术学习的从艺者成立了艺术团体决澜社,虽然它并没有如其发起者所预想的那样造成狂澜决堤之势,但终究为当时的画坛打开了一扇放眼世界的窗口,并且提出了"现代中国绘画艺术与现代世界艺术合流"的问题.是他们让人们意识到世界艺术日趋多元化的格局的到来.通过对其先锋性和局限性的思考让我们对于中国艺术的发展道路了解更加深入.     

解读连战先生的民族情

文章试图从两方面解读连战先生深厚的民族情.这种民族情一方面来源于他的家族,连战的先祖到台湾死也不臣服清,曾祖父至父亲三代以各种形式坚持抗日及父母对他言传身教;另一方面与他早年在祖国大陆的生活经历有关,从他对抗战和日本的态度及祖国大陆寻踪等方面体现出来.     

GPS传感器网络助力洪水预警

在美国西南部和墨西哥西北部,雨季的降雨量占全年降雨量的一半以上,这些雨季降雨通常强度大且难以预测.在雨季到来的时候,来自加利福尼亚湾和墨西哥湾等海洋上的湿润气流经常会给太阳炙烤的土地带来暴雨的突袭.这种突发强降雨可能会冲毁道路,在短时间内诱发泥石流等自然灾害,不仅会对农业和生态系统造成重大影响,也严重威胁着人类的生命及财产安全.     

CH3CONH2/ZnCl2低共熔溶剂脱除模拟油中的硫化物

在110℃下,加热搅拌乙酰胺和氯化锌混合物制备了CH₃CONH₂/ZnCl₂低共熔溶剂,对其结构进行 了电喷雾电离质谱分析、红外分析和黏度分析。以CH₃CONH₂/ZnCl₂作为萃取剂和催化剂,H₂O₂作为氧化剂,氧 化脱除模拟油中的噻吩硫化物。对n(ZnCl₂)/n(CH₃CONH₂)、n(H₂O₂)/n(S)、反应温度、剂油体积比和不同硫化 物对脱硫率的影响进行了考察。在模拟油体积5mL、n(ZnCl₂)/n(CH₃CONH₂)=0. 4、n(H₂O₂)/n(S)=8、剂油体 积比1∶3、反应温度70℃、反应时间200min的最佳条件下,二苯并噻吩的脱除率达到87. 12%。经过5次循环之 后,脱硫率略有降低。     

从《劝学篇》看张之洞的立宪思想

一般论者认为,张之洞的<劝学篇>是反"民权"的;其核心创获--"中体西用"论中的"西用",仍停留在"西技西艺,,层面.本文通过分析<劝学篇>中张之洞对西方民权、立法、议院的理解,认为他反对"民权"却不反"立宪",并且对西方立宪制度中的"立法"与"议院"颇为认同,不无效仿之意;张之洞的"立宪"在于"保教",这大大限制了他对"西政"的吸收.尽管如此,<劝学篇>仍不失为张之洞立宪思想的首次表达之作.     

Evaluation of ultimate bearing capacity of Y-shaped vibro-pile

Based on Mindlin stress solution, a numerical computational method was proposed to calculate the stresses in the ground induced by side friction and the resistance of Y-shaped vibro-pile. The improved Terzaghi’s and ЪерезанцевВГ’s methods for ultimate bearing capacity evaluation were proposed by considering the stress strength induced by friction resistance at pile head level of Y-pile. A new method to calculate the ultimate bearing capacity of Y-pile was also proposed based on the assumptions of soil failure mode at the tip of Y-pile and the use of Mohr-Coulomb soil yield criterion and Vesic compressive correction coefficient with the induced stresses in the ground. Based on the comparisons with the field static load test results, it is found that the improved Terzaghi’s method gives higher ultimate capacity, while the other two methods shows good agreement with the field results.     

Adhesion coefficient of automobile tire and road surface

The adhesion coefficient of automobile tire and road surface was analyzed and the formula about it was derived.Some suggestions about highway construction,driving safety of the drivers and the judgment of the traffic accidents were presented.The results show that the adhesion coefficient is a function with the extreme value.If there is atmospheric pressure in the tire,the load of the vehicle and the degree of the coarse on the road surface is not selected properly,it will reach the least and affect the safety of the running automobile.     

Effects of stress conditions on rheological properties of granular soil in large triaxial rheology laboratory tests

In order to study the rheological properties of red stone granular soil,a series of rheological experiments were executed on large tri-axial rheological apparatus.Under 100,200 and 300 kPa confining stress conditions,the rheological tests were carried out.These experiment results showed that the stress conditions,especially the stress level were the critical influencing factors of the rheological deformation properties.Under the low stress level(S=0.1),the granular soil showed the elastic properties,and there was no obvious rheological deformation.Under the middle stress level(0.20.8) creep curves showed the non-linear viscous plastic rheological properties.Especially,under the stress level of S=1.0,the accelerated rheological phase of creep curves occurred at early time with a trend of failure.The stress level had obvious effects on the final rheological deformation of the soil sample,and the final rheological deformation increments nonlinearly increased with stress level.The final rheological deformation increment and step was little under low stress level,while it became large under high stress level,which showed the nonlinearly rheological properties of the granular soil.The confining pressure also had direct effects on final rheological deformation,and the final rheological deformation linearly increased with confining pressure increments.     

一种新型微电脑大流量校准仪

提出了一种专用微电脑大流量校准仪的设计方案,通过测量孔板静压差来求孔口流量计的流量,其中重点考虑到了因测量现场环境大气压、温度等因素的变化所造成的测量误差,并提出了相应的补偿措施,同时设计出了包括对孔板静压差、大气压、温度进行监控的测量电路,采用单片机对信号进行处理计算.该校准仪实现了对大气TSP采样器流量校准测量过程的智能化,能够实时适应大气压强、温度的变化,把环境因素带来的误差降低到最小,并采用大屏幕液晶显示配合人性化的操作界,使仪器的操作更简便直观.     

对董事自相交易忠实义务的研究

自相交易是指董事代表公司的利益与自己或者与自己有利益关系的其他公司或者企业进行的交易,是忠实义务的核心问题。因此,董事的自相交易是董事信义义务所要规制的主要方面。比较了英美法系和大陆法系的交易互相规则;结合自我交易的具体内容,分析了我国公司法关于自相交易的相关规定。     

红土颗粒粒度的分维变化特征

借助分形几何理论,探讨红土在不同处理方法下其颗粒粒度的分维变化特征结果表明：红土的颗粒粒度具有线性分形结构的特点是客观存在的事实,其分维值的大小反映了土中颗粒粒度的分布情况,并与土的物理力学性之间存在一定的关系分维是描述土的颗粒粒度的一个新的特征参数     

齿轮—五杆机构的轨迹特性研究

采用计算机机构动画仿真的方法，对齿轮五杆机构的轨迹特性进行了研究。分析了该机构双曲柄存在的条件，两连杆铰接点Ｃ的轨迹曲线可到达的区域及该轨迹曲线形状随机构结构参数的不同而变化的规律，从而为齿轮五杆机构的轨迹综合提供了重要依据。     

数学优化方法在新安江模型参数率定中的应用分析

以3种数学优化方法及新安江(三水源)模型的理论为依据,介绍了优化方法在新安江三水源模型参数率定中的应用.将率定成果与API模型进行了对比,说明这3种优化方法在大宁河流域参数率定中应用效果良好,具有很好的参考和推广价值.     

物联网演进路线的探究

分析研究物联网的起源及发展路线,并从人和物二个角度探讨网络的技术特征,给出物联网的演进模型。分析结果显示,虚拟世界与物理世界对信息通信的探索将会融合,物联网发展的终极目标是网络的泛在化。据此结论,从公共物联网和系统应用角度对我国物联网的发展与研究提出两点建议。     

扬声器的自滤波特性与D类功放失真的改善

应用动圈式扬声器的电—力—声类比等效线路对动圈式扬声器的频率特性进行了初步的研究,提出了利用扬声器的自滤波性能改善因D类功放移相网络引起信号相位失真的方法。同时,采用比较、反馈的方法对音频信号的谐波加以抑制,使得数字功放的总体失真指数下降。     

离心机转鼓底的最优设计

离心机转鼓底的设计计算是相当复杂的,传统的方法都是基于已有尺寸的前提下进行校核性的强度计算。本文采用最优化方法,通过微机Apple—Ⅱ设计出转鼓底关键部位的最佳尺寸。     

独立学院学风建设的调查与思考

文章在对独立学院进行抽样调查的基础上,分析了影响独立学院学风的种种内部和外部因素,并由此探讨了建设优良学风的措施。     

浅析资产减值会计对利润的操纵

会计制度规定企业定期或者至少于每年年度终了，对各项资产进行全面检查，合理地预计各项资产可能发生的损失，并计提资产减值准备，既不高估资产或收益，也不少计负债或费用，从而避免虚增企业利润。但在实务中，一些企业却利用会计法规准则中的原则性，通过资产减值准备达到操纵会计利润的目的，本文即是从企业滥用资产减值入手，以实例来揭示企业计提秘密准备的意图，以引起业内人士的重视。     

确定盘形凸轮曲率半径的相对加速度法及其应用

提出了一种确定盘形凸轮曲率半径的新方法。该方法基于在世界坐标系中，质点沿空间曲线运动时，其速度，法向(向心)加速度和空间曲线曲率半径之间的关系，利用凸轮与从动件的相对速度和相对加速度来确定凸轮的曲率半径。应用从动件和支承绕凸轮轴线反转的模型，将凸轮与从动件的相对速度和相对加速度转变成绝对速度和绝对加速度，凸轮的曲率半径或理论曲率半径转变为凸轮与从动件接触线或者滚子轴线轨迹的曲率半径；利用复数向量结合从动件坐标系中的分量表达位移，速度和加速度，导出了4种常用凸轮机构的凸轮曲率半径解析表达式。该方法推导凸轮曲率半径解析表达式过程简单，意义明确，适用范围较广。