GFPP玻璃钢的SHPB实验及动态性能分析

利用分离式Hopkinson压杆(SHPB)研究了GFPP玻璃钢的在不同应变率下的力学响应,通过其动态的应力应变曲线发现,其属于一种典型的粘弹性材料,具有明显的应变率敏感性。在冲击载荷作用下,GFPP玻璃钢表现出明显的各向异性,分析认为:其各向异性除了与纤维的排列和铺层等有关外,材料中的微裂纹和空洞等损伤的发展演化也会导致各向异性。损伤的发展演化将导致材料的软化和破坏;并且损伤的发展演化除了与应变有关,还与应变率有关。本文还阐明了这种材料在两个相互垂直加载方向上的应变率效应,对这两个方向在不同加载条件下的破坏机制进行了分析。     

临沂市区主要园林植物害虫种类及其危害

通过调查、采集、室内饲养,对临沂市园林植物害虫进行了比较全面系统的调查。研究了园林植物主要害虫的危害性,特别是园林植物害虫对园林景观和城市环境的危害情况,为害虫防治提供了理论依据。共调查了主要园林植物50余种,鉴定出临沂园林植物害虫种类有100多种。并重点调查了部分发生较重的害虫的危害情况．     

论婚内损害赔偿制度的构建

在我国,婚内损害赔偿应该属于侵权责任的范畴．针对婚内夫妻侵权行为,我国的法律更多的是追究行为人的刑事责任或行政责任,婚内侵权行为所引起的民事责任却往往被人们所忽视。2001年《婚姻法》修正案中明确规定了夫妻个人财产的范围,夫妻约定财产的内容、方式和效力等问题,这些规定为婚内损害赔偿提供了可能。我国立法有必要对该制度加以确认,使之与我国婚姻法修正案已确立的离婚损害赔偿制度相结合,形成完整的婚姻损害赔偿责任的完整体系。     

Damage functions in heritage science

Abstract

This contribution critically examines various concepts related to damage functions in current use; it does not represent a comprehensive review, however. In heritage science, damage functions can be defined as functions of unacceptable change, dependent on agents of change. Unlike in other domains of science, the reference to unacceptable change implies that a value-based decision needs to be applied to the analytically determinable change, or dose–response function. Since there are a number of values associated with heritage, there can be a number of damage functions describing one and the same physical or chemical process of change. For practical reasons, it is thus useful to decouple the value function from the dose–response function, as the latter can be independently deduced (empirically or experimentally). While the behaviour of single materials and objects is often modelled deterministically, the probabilistic approach can be used to describe the degradation of complex structures, e.g. buildings, although not commonly in heritage research. There is a case to be made for more in-depth exploration of incremental and stochastic processes of degradation of heritage materials and structures, and the associated values, with a view towards developing more damage functions. Damage functions find use in modelling for predictive maintenance. However, predictions are associated with uncertainty due to the need for extrapolation, and this is also rarely analytically examined. Validation of modelling processes is possible using accurate methodologies of asset monitoring, which would enable an effective appraisal of preservation strategies.     

Perturbation spectrum method for seismic analysis of non-classically damped systems

Fundamental principles from structural dynamics, random theory and perturbation methods are adopted to develop a new response spectrum combination rule for the seismic analysis of non-classically damped systems, such as structure-damper systems. The approach, which is named the perturbation spectrum method, can provide a more accurate evaluation of a non-classically damped system＇s mean peak response in terms of the ground response spectrum. To account for the effect of non-classical damping, all elements are included in the proposed method for seismic analysis of structure, which is usually approximated by ignoring the off-diagonal elements of the modal damping matrix. Moreover, as has been adopted in the traditional Complete Quadratic Combination （CQC） method, the white noise model is also used to simplify the expressions of perturbation correlation coefficients. Finally, numerical work is performed to examine the accuracy of the proposed method by comparing the approximate results with exact ones and to demonstrate the importance of the neglected off-diagonal elements of the modal damping matrix. In the examined cases, the proposed method shows good agreement with direct time-history integration. Also, the perturbation spectrum method leads to a more efficient and economical calculation by avoiding the integral and complex operation.     

再论共同危险行为——以客观关联共同侵权行为理论为视角

现代侵权法的数人侵权行为承担连带责任的理论基础从"主观说"转化为"关联共同说",对共同危险行为的体系定位产生了重大影响.共同危险行为人承担连带责任的基础不再是共同过失,而是客观危险的可责难性.共同危险行为侵权责任构成的因果关系应采"群体危险行为"理论.共同危险行为人应该承担连带责任,并按照客观危险比例进行最终责任分担.证明自己没有实际造成损害的共同危险行为人,应该对其他连带责任人承担补充责任.     

大鼠不同负荷游泳运动后骨骼肌损伤与血浆CK及其同工酶活性水平变化

雄性SD大鼠分别进行25分钟、50分钟和力竭三个负荷的游泳运动,运动后取血样和比目鱼肌检测大鼠运动后血浆CK及其同工酶活性水平变化以及骨骼肌Z线异常率;结果发现,大鼠游泳运动后即刻血浆CK及其同工酶CK-MM%活性水平变化与比目鱼肌Z线异常率之间的线性相关系数分别是r=0.875(P<0.01)和r=0.47(P<0.01);这表明,大鼠游泳运动后骨骼肌的损伤状况与血浆CK及其同工酶CK-MM%的变化表现出明显的线性相关的变化趋势。     

SIEMENS与FANUC数控系统复合循环指令在沟槽加工中的运用

复合循环指令通过指定切削参数、轮廓形状,由系统自动完成相关计算,控制刀具完成切削过程。而各系统厂家提供的复合循环指令各不相同,文章分别应用SIEMENS与FANUC的复合循环指令对沟槽进行加工,阐述了相关指令的应用技巧。     

高层建筑减震与模态分析

为了研究高层建筑隔震结构对高层建筑抗震能力的作用,应用Ansys有限元软件对固定高层建筑和隔震高层建筑进行了模态分析。研究结果显示,结构的固有频率随着阶数的增大而增大;隔震结构的隔震层消耗了大量的隔振能量;通过在建筑物上部结构与基础间设置足够安全可靠的隔震系统,形成柔性底层,使建筑物与基础隔开,以延长整个结构体系的自振周期。减少输出上部结构的地震能量,从而大幅度降低建筑物对地震的影响;隔振节点加速度明显降低;隔震后位移发生微小的减少。由模拟结果可知,地震破坏以水平破坏为主,震烈度决定了建筑物的破坏程度;隔震层吸收了地震中大量的能量,隔震上部结构绝对加速度明显降低,基础隔震体系能够降低结构的水平地震作用。     

The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance

In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad · s -1 and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5 - 7.1 years (mean - s ). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets 2 10 repetitions at 70% body mass load). Strength was reduced for 4 days ( P ? 0.05) but no significant differences ( P > 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6 - 1.1% vs 95.2 - 1.3% of pre-exercise values, P ? 0.05) and drop jump (95.2 - 1.4%, P ? 0.05) performance. Creatine kinase was elevated ( P ? 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.