Analysis of Heat Transference in Regenerative Exchanger of a Thermal Power Plant

The process of electricity generation in a power plant involves several phases for heat exchange generally between hot fluid (water, fumes of steam) and one of the input fluids (cool water, cook oven gas, fuel, blast furnace gas, etc) The process of exchange evolves in time at the same time as installation itself. This improvement is another step in a deep study of the time-changing conditions of the heat transmission due to ageing, but it will also make possible the introduction of new parameters in the physical formulation whose relation is unknown. Modelling is done using feedforward neural networks after a very extensive pre-processing step.     

图中含有k—因子的判定算法

本文依据图论中已有的一个理论成果（定理１），给出了判定一个图是否含有k-因子的一个算法，同时对算法的复杂性作了分析，又示出了一些简单情况的结果。     

Effect of oxidation on the performance of low-temperature petroleum cokes as anodes in lithium ion batteries

The effect of an oxidative treatment on the electrochemical performance of various low-temperature cokes as anodes in lithium ion batteries was examined in order to optimize their chemical composition and textural properties. Annealing in a stream of dry synthetic air over short time and temperature ranges was found to result in substantially increased cell capacity and improved capacity retention during cycling in coke oxidized at 350 °C for 1 h, which exhibited a capacity as high as 385 mAh g⁻¹ after 20 cycles at C/50. However, raising the oxidation temperature to 500 °C resulted in undesirably increased irreversible capacity and polarization between the charge and discharge branches, the effect being confirmed by the high impedance values obtained after only a few cycles. ⁷Li MAS NMR spectroscopy was used to assess covalency in lithium bonds and its relationship to electrochemical performance in the studied batteries.     

我们需要什么样的毕业生?——我国建筑教育问题谈

本文通过分析大学生毕业在刚刚步入工作岗位时存在的一些通病,指出现今的建筑教育中的弊端是造成这种现象的原 因。并进一步提出对教育体制的改革建议。     

超大规模无线网络规划

就如何对超大GSM无线网络建设改造的前期规划工作提出一些观点和方法,并对整个规划流程分步进行了描述。涉及的主要内容有业务预测的方法和步骤、建设规模确定的方法和步骤、各种网元规划方法及原则等。     

From ELF to Compressibility in Solids

Understanding the electronic nature of materials’ compressibility has always been a major issue behind tabulation and rationalization of bulk moduli. This is especially because this understanding is one of the main approaches to the design and proposal of new materials with a desired (e.g., ultralow) compressibility. It is well recognized that the softest part of the solid will be the one responsible for its compression at the first place. In chemical terms, this means that the valence will suffer the main consequences of pressurization. It is desirable to understand this response to pressure in terms of the valence properties (charge, volume, etc.). One of the possible approaches is to consider models of electronic separability, such as the bond charge model (BCM), which provides insight into the cohesion of covalent crystals in analogy with the classical ionic model. However, this model relies on empirical parametrization of bond and lone pair properties. In this contribution, we have coupled electron localization function (ELF) ab initio data with the bond charge model developed by Parr in order to analyze solid state compressibility from first principles and moreover, to derive general trends and shed light upon superhard behavior.     

Effect of Temperature on Oxidation Behavior of 3‐Dimensional C/SiC Composites Coated by Different Structural SiC and a‐BCx Coatings in Static Wet Oxygen Atmosphere

The effect of temperature on oxidation behavior of 3‐dimensional C/SiC composites coated with SiC and a‐BC_x coatings was investigated. Below 1000°C, C/SiC composites with SiC coating (sample SSS) showed low residual strength, while the composites with a‐BC_x coating (sample BBB) and the composites with a‐BC_x/a‐BC_x/SiC coatings (sample BBS) showed high residual strength. Above 1000°C, samples SSS and BBS showed high residual strength, while sample BBB showed the opposite results. Sample BBS presented better oxidation resistance during 700–1200°C. The oxidation temperature made an effect on self‐sealing mode of sample BBS.     

全尺寸封闭室内燃烧气体速度测量法的比较

1导言火灾释放的热量使周围的气体在膨胀和浮力的作用下产生了运动。结果是火灾流动的速度非常慢,而且它们（火灾感应流动）可能出现在大空间区域的上方,特别是在全尺寸封闭室内燃烧实验中这种情况尤为明显。在封闭室内燃烧中精确量化通风很困难,原因是由于这种量化方法需要在大空间内测量体积较小的气体流速,而且此时室内已经达到了着火的危险条件。     

车辆用户载荷谱试验场关联强化试验方法

研究了某车辆用户用法与试验场强化试验之间的载荷谱关联特性。根据用户损伤与试验场损伤相等的原理,建立车辆在试验场内的耐久性考核试验方法。通过一辆已安装传感器的车辆,采集真实汽车用户和试验场强化路的相关试验数据,应用雨流计数法获得疲劳载荷谱分布矩阵,并计算产生的疲劳伪损伤。利用市场调查统计用户的路面比例和装载质量,结合采集的用户实际使用数据,应用蒙特卡洛方法对汽车用户实际用法载荷谱的疲劳损伤进行仿真计算,确定涵盖90%汽车用户的疲劳载荷谱(雨流循环分级矩阵)。对比用户用法与试验场损伤载荷谱获得试验场强化试验技术参数,制定与试验场强化组合路面、试验里程、试验车速相关的试验方法。实际应用结果表明,该方法可准确预报车辆承载结构的潜在故障,有效缩短试验里程及产品研发周期。