变构

The characteristics of creep, rheological constitutive model and the theory of consolidation on soil are also compendiously discussed.

根据软土蠕变和固结的理论，对其耦合效应的研究现状做了综述，其中也简要论述了土的蠕变特性、土体流变本构模型、土的固结理论等方面的内容，最后对于进一步的研究提出了一些基本思路

1H NMR spectroscopic analysis of aromatic protons combined with theoretical analysis of molecular structures proved the existence of two rotational isomers at 300 K, as well as a rapid interconversion equilibrium at 330 K for both compounds Ⅰ and Ⅱ. However, only one conformer exists for compound Ⅲ and puerarin containing 7-phenolic hydroxyl instead of propyl in A-ring as the case of compounds Ⅰ and Ⅱ. Based on UV-Visible absorption data of neutral and basic solutions, and on the density function calculations, the 7-phenolic hydroxyl group in A-ring was found to be more acidic than the 4'-phenolic hydroxyl group in B-ring. The mechanism of derivation reaction and the structure-reactivity relationship of puerarin as an antioxidant were further discussed.

其中7-丙基葛根素Ⅱ属于新型取代衍生物；变温1H NMR和理论计算结果表明，在300 K时，葛根素和4'-丙基葛根素以单一构型存在；而7，4'-二丙基葛根素和7-丙基葛根素则存在两种核磁可分辨的旋转异构体，当温度升至330 K时，两种异构体可以相互转化；通过对比分析葛根素及其衍生物脱质子产物的紫外可见吸收光谱并结合理论计算，确定了A环上7位酚羟基比B环上4'位酚羟基先脱去质子，并由此进一步阐明了葛根素衍生化反应机理以及在抗氧化作用中可能的活性位点和结构活性关系。

A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate, and an Arrhenius relationship with the temperature. The strain hardening coefficient n and deformation activation energy Q are evaluated by linear regression analysis. And the flow stress constitutive equation of the alloy during hot compression is obtained.

应变速率和流变应力之间满足指数关系，温度和流变应力之间满足Arrhenius关系，通过线性回归分析计算出该材料的应变硬化指数n以及变形激活能Q，获得该铝合金高温条件下的流变应力本构方程。

The results indicate that the flow stress of the alloy increases with increasing strain rate and decreasing deformation temperature. The flow stress increases with increasing strain until the stress reaches the peak value, then the flow stress remains constant, which indicates that dynamic recrystallization happens during deformation. The flow behaviors are described by the hyperbolic sine constitutive equation, and the activation energy calculated is 337.75 kJ/mol. The as-forged microstructure consists of refined α2/γ and γ grains, and the grains are much homogeneous than before. The B2 phase distributes uniformly at the grain boundary of α2/γ and γ grains. The B2 phase decreases with increasing deformation temperature.

结果表明：流变应力随着应变速率提高和变形温度降低而增大；在变形过程中，流变应力随着变形量增大而增大，当流变应力达到峰值后趋于平稳，表明合金在变形过程中发生了动态再结晶；热变形过程的流变应力可采用双曲正弦本构关系来描述，平均激活能为337.75 kJ/mol；从合金的组织演化过程中可以看出，合金中不均匀的原始组织得到明显均匀化，变形后的组织是由α2/γ层片晶团和γ晶粒组成的双态组织，在α2/γ层片晶团和γ晶粒的晶界交界处发现分布均匀的B2相，并且随着变形温度升高B2相数量逐渐减少。

In order to analyze rheological property and establish constitutive model of Q_2 loess, a series of uniaxial creep experiments on different water content are done .The creep test curves and stress-strain isochronism curves are drawed with the result of experiments and conclusions are reached from the curves. The creep performance of Q_2 loess is different under the different stress level. In the different time the stress-strain isochronism curve has obvious inflection point namely yield stress and the yield stress reduces along with the increase of water content, which can be described by exponential function.

为了分析黄土的流变特性和建立相应的本构模型，本文首先根据对不同含水量的Q_2黄土进行的一系列单轴应力条件的室内蠕变试验结果，分析总结了Q_2黄土蠕变特征和应力—应变等时曲线特征，得出Q_2黄土在不同的应力水平下蠕变变形表现形式不同；在不同的时刻应力—应变等时曲线存在有较明显的拐点，拐点所对应的应力即为屈服应力，屈服应力随着含水量的增大而呈指数形式降低；Q_2黄土可近似看成一种线性粘弹塑性体。

But it is very difficult to design and implement query optimization because of the distribution and heterogeneity of the computing environment and the autonomy of multiple local data sources.

查询优化是异构数据集成中需要解决的关键问题之一，但环境的分布性、异构性以及局部数据源的自治性使得异构数据集成中的查询优化变得非常困难。

Basing on the exploring of the functions of cohesion force and friction force during rheology course and the assumptin that viscosity lost according viscosic strain, a constitutive model for viscous, elastic and plastic rock is set up,which can simulate the third course of creep.Then the impact of transcient damage to rheology is discussed and corresponding creep model for rock is proposed.

在探导岩石颗粒间粘聚力和颗粒间摩擦力在岩石发生流变过程中的作用基础上假设粘性失效按流变应变统计概率分布，建立了岩石粘弹塑性本构关系，能够描述岩石蠕变加速阶段特征；讨论了瞬时损伤对岩石流变的影响和相应的损伤蠕变模型建模问题。

It can be employed to transmit torque by the shear stress of MR fluids.In this paper,the design method of the disc-shaped magnetorheological fan clutch is investigated theoretically.The expressions of the torque and the output rotational speed within the fan clutch is derived to provide the theoretical foundation in the discal design of the clutch.A Bingham model is used to c...

将磁流变液用于发动机冷却系风扇离合器的设计中，在理论上分析了盘式磁流变液调速风扇离合器的工作机理，应用B ingham模型来描述磁流变液的本构方程，建立了离合器的输出转矩与转速的计算模型，导出了离合器基本几何参数的工程设计计算公式，为盘式磁流变风扇离合器的设计提供了理论依据。

The results are in good agreement with available experimental results. The entropy effect on the Gibbs free energies of 6-thioxanthine base is very small and there is little significance for the tautomeric equilibria of the base.

计算结果同已有实验结果一致。6-硫代黄嘌呤异构化的熵效应小，对互变异构平衡几乎没有显著的影响，而焓变对互变异构产生了主要的影响。

Based on the statistical damage evolution equation considering stress damage threshold and the multiple rheological model of gypsum breccias, the damage rheological constitutional model is established from hypothesis of strain equivalence. The calculated results of the model agree well with creep test results.

在Kachanov提出的一维蠕变损伤演化方程的基础上，建立了同时考虑瞬时损伤和蠕变损伤的流变本构模型，理论值与试验值基本一致，验证了提出的蠕变损伤演化方程是正确的，所建的损伤流变模型能够较好地描述石膏角砾岩的加速蠕变阶段。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！