加快结构调整，促进经济发展方式转变

加快结构调整、促进经济发展方式转变是关系国民经济全局紧迫而重大的战略任务。本文以严谨的逻辑和充分的事实依据的基础,对成都市加快结构调整,促进经济发展方式转变的意义,方向和路径等进行了阐述。     

Renewal strategies for old industrial areas in the post-industrial age—Take “Zurich-West” in Switzerland as an example

This paper introduces and analyses the renewal planning of “Zurich-West”, an old industrial area. It points out that systematic and comprehensive target orientation, extensive collaboration in argumentation and decision-making, and the design ideas of coexistence and integration are the key to its success. Considering the status quo of China’s old industrial district remodeling, the paper offers some suggestions. Supported by the National Natural Science Foundation of China (Grant No. 50878045)     

Discrimination for ablative control mechanism in solid-propellant rocket nozzle

The ablation in solid-propellant rocket nozzle is a coupling process resulted by chemistry, heat and mass transfer. Based on the heat and mass transfer theory, the aero-thermo-dynamic, and thermo-chemical kinetics, the thermal-chemical ablation model is established. Simulations are completed on the heat flow field and chemical ablation in the nozzle with different concentrations, frequency factors and activation energy of H2. The calculation results show that the concentration and the activation energy of H...     

色谱顶空法测活度系数及对三元极性体系液液平衡预测

用气相色谱顶空分析法测定 18组部分互溶三元极性体系在完全互溶区的 3个组分活度系数 ,由此拟合出 U NIQU AC过量自由焓模型参数 ,再用 U NIQUAC方程预测液液平衡。这一方法曾很好地用在水-正烷烃 -醇体系。将此法拓展到含醇、酮、酯 ,醚、卤烷烃和水等多种极性组分的三元体系液液平衡的预测 ,其结果与文献的液液平衡数据比较 ,平均均方根误差 1.4 1% ,表明本法对含极性组分的体系仍然可行     

钯－银合金膜分离氢气的研究

采用厚为５０μｍ的Ｐｄ／Ａｇ（２３）合金膜进行了氢气渗透系数的测定和Ｈ＿２／Ｎ＿２混和气分离的研究，得出温度、压力、膜厚、进料气流量、膜的预处理和再活化及膜表面中毒等因素对氢气渗透的影响。分离Ｈ＿２／Ｎ＿２混和气可获得高纯氢气。     

纳米管合成研究进展

当今纳米科学技术飞速发展，其中纳米管已构成了纳米材料的一个非常重要的类别。本文介绍近几年来由化学键结合的纳米管以及由分子间力形成的一些纳米或具有中观尺度的管状结构材料的合成研究进展。     

Optimization of uncertain acoustic metamaterial with Helmholtz resonators based on interval model

Uncertainties existing in the acoustic metamaterial may strongly affect its unusual properties. Aiming at this actuality, the interval model is introduced to treat with uncertainties existing in the acoustic metamaterial with Helmholtz resonators. Frequency intervals in which the sound intensity transmission coefficients are certainly less than the required value and the effective bulk moduli are certainly negative are defined as conservative approximations. Frequency intervals in which the sound intensity transmission coefficients may be less than the required value and the effective bulk moduli may be negative are defined as unsafe approximations. The proportion of the conservative approximation and the unsafe approximation is defined as an approximate precision. Based on the quantification of uncertainties of the sound intensity transmission coefficients and the negative effective bulk moduli, an optimization model for the interval acoustic metamaterial with Helmholtz resonators is constructed. Numerical results showed that even suffering from effects of interval parameters, unusual properties of the optimized acoustic metamaterial (such as the bandgap of the sound transmission and the negative effective bulk modulus) could be improved.     

Aerodynamic performance analysis of trains on slope topography under crosswinds

This work used the computational fluid dynamics method combined with full-scale train tests to analyze the train aerodynamic performance on special slope topography. Results show that with the increment in the slope gradient, the aerodynamic forces and moment increase sharply. Compared with the flat ground condition, the lateral force, lift force, and overturning moment of the train on the first line increase by 153.2%, 53.4% and 124.7%, respectively, under the slope gradient of 20°. However, with the increment of the windward side's depth, the windbreak effect is improved obviously. When the depth is equal to 10 m, compared with the 0 m, the lateral force, lift force and overturning moment of the train on the first line decrease by 70.9%, 77.0% and 70.6%,respectively. Through analyzing the influence of slope parameters on the aerodynamic performance of the train, the relationships among them are established. All these will provide a basic reference for enhancing train aerodynamic performances under different slope conditions and achieve reasonable train speeds for the operation safety in different wind environments.     

层间接触状态和横向力大小对车辙贡献率的影响

车辙贡献率是反映沥青路面各结构层车辙病害程度的一个主要参数,可用于指导沥青路面的设计和施工.利用三维有限元计算软件建立三维有限元模型用于理论分析,将有限元计算结果与理论解进行对比,验证了该三维有限元模型的可靠性.采用实测的轮胎接地压力,考虑不同层间接触状态和横向力大小,结合有限元计算的数据,分析了沥青路面结构层的车辙贡献率.结果表明:在层间完全连续状态下,横向力大小的选取不能简单地选取最大垂直轮胎接地压力的一定比例,而是要根据所研究的具体情况具体分析.在对沥青路面车辙贡献率的研究中,可以忽略层间接触状态,即假定层间完全连续.     

Evaluation research on applicability of rapid iodide migration test

The applicability of the rapid iodide migration test was systematically studied. Comparative experimental tests of different test conditions, including several external voltages, test durations, concrete ages and mixing proportions, were carried out to make clear the transport behaviors of iodide under parallel electric fields. Numerical simulations were also done using the finite element method to found the correlation between chloride and iodide transport behaviors. The test and numerical results show that the chloride transport behaviors of RIM and RCM tests have a good correlation under the several conditions used in the present paper. Moreover, the influence of external conditions （external voltages, test durations） on the test results is small. Thus, it can be concluded that the RIM method is available to determine the chloride penetration resistance of the chloride-eroded structural concrete.