前驱体浓度对纳米TiO2薄膜生长及光激发特性的影响

以Ti（SO4）2为原料,无水碳酸钠（Na2CO3）为添加剂,采用水热合成法在钛合金基底上成功制备了锐钛矿相的纳米TiO2薄膜。利用X射线衍射（XRD）、扫描电子显微镜（SEM）等测试手段系统的研究了前驱体浓度对纳米TiO2薄膜生长特性、结晶特性和相组成的影响规律;利用光致激发光谱（PL）研究了所制备TiO2薄膜的光激发特性,并通过微观机制对其影响规律进行了理论解释。     

快速凝固NiAl-Cr（Mo）-Zr合金的显微组织与力学性能

研究了快速凝固NiAl-Cr（Mo）-Zr合金及其均匀化热处理后的显微组织和力学性能。结果表明：快速凝固NiAl-Cr（Mo）-Zr合金的组织由NiAl和Cr（Mo）两相组成,并有少量初生NiAl相,在共晶胞界处存在少量不连续分布的Heusler（Ni2AlZr）相。随着Zr含量的增加,Heusler相的数量增加,Cr（Mo）相的片层间距增大。均匀化热处理后,共晶胞界上不连续分布的Heusler相或大量消失、或全部消失,NiAl和Cr（Mo）层片状组织形貌基本没有变化。NiAl-Cr（Mo）-0.5Zr合金在应变速率为2.78×10-3s-1时,随着测试温度的升高,合金的压缩屈服强度降低。     

Triaxial compression strength for artificial frozen clay with thermal gradient

A series of triaxial compression tests for frozen clay were performed by K0DCGF (freezing with non-uniform temperature under loading after K0 consolidation) method and GFC (freezing with non-uniform temperature without experiencing K0 consolidation) method at various confining pressures and thermal gradients. The experimental results indicate that the triaxial compression strength for frozen clay in K0DCGF test increases with the increase of confining pressure, but it decreases as the confining pressure increases further in GFC test. In other words, the compression strength for frozen clay with identical confining pressure decreases with the increase in thermal gradient both in K0DCGF test and GFC test. The strength of frozen clay in K0DCGF test is dependent of pore ice strength, soil particle strength and interaction between soil skeleton and pore ice. The decrease of water content and distance between soil particles leads to the decrease of pore size and the increase of contact area between particles in K0DCGF test, which further results in a higher compression strength than that in GFC test. The compression strength for frozen clay with thermal gradient can be descried by strength for frozen clay with a uniform temperature identical to the temperature at the height of specimen where the maximum tensile stress appears.     

三层复合PI薄膜厚度比对其介电性能影响

利用微乳化-热液法制备纳米分散液,制备了掺杂层与中间纯聚酰亚胺（PI）层厚度比不同的三层复合薄膜.在相同环境条件下通过透射电镜（TEM）、击穿场强和耐电晕测试分别对三层复合薄膜的微观结构和纳米掺杂层厚度比例的变化与介电性能的影响进行了分析.TEM测试结果表明纳米粒子在有机基体中的分散均匀;介电强度测试和耐电晕测试表明随掺杂层厚度比例的增加,击穿场强逐渐下降,耐电晕性能呈先上升后下降趋势.     

纤维素醚对瓷砖粘结剂主要性能的影响

本文通过正交试验摸索出纤维素醚对瓷砖粘结剂主要性能的影响及规律,通过比对胶粉的掺量、胶砂比对其部分性能的作用效果摸索出纤维素醚能够对其进行优化的主要方面,对于调节瓷砖粘结剂的部分性能具有一定的参考意义．     

Mechanical properties and failure characteristics of fractured sandstone with grouting and anchorage简

Based on uniaxial compression experimental results on fractured sandstone with grouting and anchorage, we studied the strength and deformation properties, the failure model, crack formation and evolution laws of fractured sandstone under different conditions of anchorage. The experimental results show that the strength and elastic modulus of fractured sandstone with different fracture angles are significantly lower than those of intact sandstone. Compared with the fractured samples without anchorage, the peak strength, residual strength, peak and ultimate axial strain of fractured sandstone under different anchorage increase by 64.5–320.0%, 62.8–493.0%, and 31.6–181.4%, respectively. The number of bolts and degree of pre-stress has certain effects on the peak strength and failure model of fractured sandstone. The peak strength of fractured sandstone under different anchorage increases to some extent, and the failure model of fractured sandstone also transforms from tensile failure to tensile–shear mixed failure with the number of bolts. The pre-stress can restrain the formation and evolution process of tensile cracks, delay the failure process of fractured sandstone under anchorage and impel the transformation of failure model from brittle failure to plastic failure.     

A damage-based constitutive model for rock under impacting load

Using the Splitting Hopkinson Pressure Bar (SHPB) experimental system, investigations were made into the dynamic mechanical performances of underground soft rocks. The experiments proved that the measured stress–strain curves display the characteristics of plastic deformation. By making use of a revised overstress constitutive formula for the stress model and by taking into account that the strain rate and strain are a function of 1 − E(t)/E₀, a revised overstress constitutive formula for the stress model was simplified by applying dimensional analysis and consequently, a simplified overstress formula was obtained for the stress model. Then, by taking into consideration the effects of damage under a dynamic load on the dynamic loading strength of the rock, the continuous damage theory and the statistical strength theory were introduced into the development of the simplified overstress constitutive formula for the stress model. Hence, a damage-based constitutive formula for an overstress model, which can be appropriately applied to the analysis of full dynamic stress–strain curves, was developed. By using the simplified damage-based constitutive formula for an overstress model, the actually measured curves are fitted, indicating that the fitting curves and those actually measured are in good agreement.     

改进的BP神经网络模型预测充填体强度

为了准确评价和预测充填体强度,采用改进的BP神经网络算法,利用实验室做的18组充填体单轴抗压强度试验结果,建立了充填体强度与影响因素之间的5-7-1网络模型结构(输入层为5个神经元,隐含层为7个神经元,输出层为1个神经元,输入为胶砂比及各胶凝材料掺量,输出为充填体28 d单轴抗压强度).结果表明,改进的BP神经网络对于充填体的强度具有良好的预测能力,建立的网络模型不仅收敛速度快而且训练精度高,对充填体强度的预测结果与训练数据和测试数据的最大相对误差仅为4.23％.     

考虑发电约束的输电断面最大传输能力

为了打破以往输电能力求解过程中发电机端电压维持不变的假设,提出了考虑发电约束求解最大输电能力(TTC)的新方法.根据大型风电场并网及同步发电机调速器和励磁系统等动态元件的运行限制,建立了计算输电断面最大输电能力的优化模型,并采用信赖域内点法进行序列迭代求解.在信赖域内,将非线性优化问题逼近为线性规划(LP)子问题,以构造的价值函数为依据调整信赖域半径.在New England 39节点算例系统中验证了模型和计算方法的有效性.实验结果表明,考虑发电约束的输电断面最大传输能力计算结果更接近系统的实际运行情况.