Influence of Microplasticity on the Static and Dynamic Elastic Moduli of Rocks

Using the analysis of experimental data as the base, it is shown that the difference in the values of static and dynamic elastic moduli of rocks is governed by viscoelastic and microplastic mechanisms of deformation, provided the stresses do not exceed the proportionality limit.     

胶凝材料对地质聚合物混凝土的 抗冻融循环性能的影响

地质聚合物混凝土（GPC）能最大限度地减少自然资源的消耗。粉煤灰和矿粉的配合比对于GPC的性能具有较大影响。本研究制备了普通硅酸盐混凝土（OPC）、全粉煤灰配方及部分矿粉代替FA制备的地质聚合物混凝土GPC-0、GPC-10、GPC-20、GPC-30（矿粉：0、10%、20%和30%）,对比不同GPC的冻融后的性能,即重量变化,抗压强度损失,相对动态弹性模量损失。结果表明：矿粉含量最高的GPC-30的质量损失率小和抗压强度高,远优于其他地质聚合物混凝土。利用共振频率测试（RFT）的无损检测方法测定动态弹性模量,表明矿粉基比全粉煤灰CPC具有更好的抗冻融性。粉煤灰的含量越高,矿粉的含量越低,养护制备出的混凝土的力学性能退化就越大,并得出GPC的实用性能以及不同比例配方,这为今后的试验和工程应用提供数据和理论支持。     

Modellrechnungen zur Beanspruchung heterogener elastischer Körper durch allseitigen Druck

Hydraulic comminution is especially suitable if the elastic properties of the components differ significantly. Here, the basic equations of the elasticity theory were drafted for two model shapes. In cylindrical as well as in Cartesian coordinates, the solution to the equation system is obtained through the solution of the bipotential equation via the introduction of a stress function. However, certain boundary conditions have to be fulfilled. In the case of all‐round constant compression, this can be achieved through an approach in integral form for both model shapes.     

一款保湿面贴膜的即时功效初步研究

采用配有水分测试探头CM825、色素测试探头MX18的皮肤弹性测试仪Cutometer MPA580,测定在使用一款保湿面贴膜前后及用后5 h内面部皮肤角质层含水量、黑色素含量及弹性的变化,评估面贴膜使用后改善皮肤水分、肤色及弹性的即时功效。结果表明使用该面贴膜有非常明显的即时功效,主要表现在皮肤水分含量较使用前有非常显著的增加（P〈0.05）,测得皮肤黑色素含量也明显降低（P〈0.05）,但弹性无明显增加。     

A GENERALIZED NEWTON METHOD FOR HIGHER-ORDER FINITE ELEMENT APPROXIMATIONS IN NON-LINEAR ELASTICITY

A generalized Newton method is proposed in conjunction with a higher-order Lagrangian finite element discretization of bodies undergoing finite elastic deformations. The method is based on a gradient-like modification of the Newton method, designed to suppress the sensitivity of higher-order elements during the early iterations, thus allowing for solutions to be obtained using moderately large step-sizes.     

销售侧分行业实行丰枯峰谷分时电价初探

在用户电量电价弹性矩阵的基础上探讨制定与各行业电力用户电价响应情况相一致的分行业丰枯峰谷分时电价的方法。通过建立各用户行业的丰枯季节电价弹性矩阵和峰谷分时电价弹性矩阵,依据各行业电力用户的调查数据建立分行业的丰枯季节电价与峰谷分时电价的电量转移成本函数与获益函数。通过求取两函数的交点,得到各行业电力用户在电量转移成本约束下达到电量转移极限所需的丰枯峰谷分时电价调整比例。最后将所提出的方法应用于云南电力系统,应用结果表明,不同行业电力用户达到电量转移极限所需的电价调整量存在较大差异性,以及针对不同用户行业的用电特性实施不同的丰枯峰谷电价的必要性。     

某天线弹射机构方案设计

通过对某天线弹射机构设计方案选择和设计的论述,说明了在微、小型空间进行往复式弹射机构设计时的一种方法和需要着重考虑的几个问题,可以作为同行进行类似设计时参考。     

Evolution of elastic behavior of alite paste at early hydration stages

Elastic behavior is an important aspect of fresh cement-based materials. In this paper, the elasticity development of fresh pure alite paste within 5 hours was monitored in situ by small amplitude oscillation shear. Isothermal microcalorimetry, X-ray diffraction, scanning electronic microscopy, ¹H nuclear magnetic resonance, zeta potential measurements were used to investigate the underlying mechanisms. It was found that the evolution of storage modulus can be characterized by three different stages. The first stage stems from the compression of electrical double layer and the slight increase of solid volume fraction; the second stage is only controlled by the colloidal interaction; and the third stage is associated to the significant growth of solid volume fraction, the enhancement of short-range attraction and the rigidification of calcium silicate hydrate (CSH) network. Moreover, the relationship between the formation of CSH and the growth of elasticity was also quantified.     

弹性力学极坐标辛体系Hamilton函数的守恒律

用弹性力学直角坐标辛体系中类似的形式,定义了极坐标问题径向和环向辛体系的Hamilton函数,对其守恒性进行了研究,由Hamilton对偶方程推出了Hamilton函数的守恒律,同时给出了守恒条件,指出两种极坐标辛体系中Hamilton函数是否守恒均取决于两侧边的荷载和位移情况。在径向和环向辛体系中都给出了算例,验证了Hamilton函数的守恒律。这一守恒律丰富了弹性力学辛体系的理论内容,不仅对于弹性力学极坐标问题的理论分析有所帮助,也为极坐标问题的数值计算分析提供了一个判断依据。     

平板颤振导数的参数弹性研究

提出了颤振导数的“参数弹性”概念;基于复模态理论,计算了平板颤振导数的平板宽度、质量、质量惯矩、竖弯频率、扭转频率和空气密度6种参数弹性;绘制了8个颤振导数的参数弹性曲线和诺模图,分析了各自特点,获得了无量纲参数对颤振导数参数弹性的影响规律。分析结果表明,新提出的参数弹性具有概念无量纲、简洁、直观、实用特点,为颤振导数参数分析提供了一种新的有效途径。