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°.     

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.     

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.     

Research advances of un-symmetric constitutive theory of anisotropic viscoelastic liquids and its hydrodynamic behavior

Research advances of un-symmetric constitutive equation of anisotropic fluid,influence of un-symmetric stress tensor on material functions,vibrational shear flow of the fluid with small amplitudes and rheology of anisotropic suspension were reported.A new concept of simple anisotropic fluid was introduced.On the basis of anisotropic principle,the simple fluid stress behaviour was described by velocity gradient tensor F and spin tensor W instead of velocity gradient tensor D in the classic Leslie-Ericksen continuum theory.Two relaxation times analyzing rheological nature of the fluid and using tensor analysis a general form of the constitutive equation of co-rotational type was introduced.More general model LCP-H for the fluid was developed.The unsymmetry of the shear stress was predicted by the present continuum theory for anisotropic viscoelastic fluid-LC polymer liquids.The influence of the relaxation times on material functions was specially studied.It is important to study the unsteady vibrational rotating flow with small amplitudes,as it is a best way to obtain knowledge of elasticity of the LC polymer,i.e.dynamic viscoelasticity.For the shear-unsymmetric stresses,two shear stresses were obtained thus two complex viscosities and two complex shear modulus(i.e.first and second one) were introduced by the constitutive equation which was defined by rotating shear rate introduced by author.For the two stability problems of fluid,such as stability of hydrodynamic flow and orientational motion,were discussed.The results show that the polymer suspension systems exhibit anisotropic character.The PNC systems can exhibit significant shear-thinning effects.For more concentrated polymer nano-suspensions,the first normal stress difference change from positive to negative,which is similar to LC polymer behavior.     

2008年我国房地产业的发展模式与市场把握

在深入市场调查、认真采集数据和科学分析研究的基础上,从我国新一年房地产业发展的"背景和环境"、"预期和责任"、"风险和影响"、"保障和创新"等方面进行阐述和论证.     

窃取商业秘密获得的专利权归商业秘密权利人所有——兼谈商业秘密构成要件和范围

中国加入WTO以后,知识产权的保护意识日益强化,作为知识产权范畴的专利权更是被人们普遍关注和重视.以"错案"为研究对象,运用商业秘密的有关理论以及保护商业秘密和专利权的有关法律制度,特别是从窃取商业秘密获得的专利权归谁所有的角度,对人民法院的判决进行了分析研究,指出了人民法院的判决是错误的,提出了窃取商业秘密获得的专利权归商业秘密权利人所有.这有利于人民法院公正司法,依法审判.     

当前民办高校融资难的成因及对策

针对民办高校所需办学经费无国家财政拨款,全部为自筹资金的现状,分析了形成当前民办高校融资难的原因,既有信贷政策、银行方面的因素,也有民办高校自身的因素.提出民办高校要生存,要发展,光靠举办者投入或捐赠以及每年的学费收入是不够的,还需要积极拓展更多融资渠道解决办校融资难的问题.     

从语气助词的角度浅析日语表达方式的特性

日语中有着十分丰富的语气助词,其虽然不具有实际的意义,然而通过语气助词,却能够流露出说话者的心情和感受,传递出不溢于言表的隐性含义,在日常的表达中扮演着十分重要的角色.从语气助词的角度,分析总结日语在表达上所具有的特性.