A new approach for suppressing harmonic disturbances in distribution system based on regression analysis

Based on state variable techniques, sensitivity and regression analysis were applied to a distribution system model to study harmonic disturbances. In this research work, a framework for reducing harmonic distortion, in particular the ninth harmonic, is presented. Through measurements, a model based on harmonic distortion representation was developed. The model is represented as a load in the form of an inductor, capacitor, and resistor in parallel with a harmonic current source. With state variable representation of the model, the first- and second-order sensitivity eigenvalues along with Taylor series expansion were employed to study the ninth harmonic. Then a comprehensive analysis was done to reduce the ninth harmonic based on parameters perturbation of the system capacitors. To see the effectiveness of the perturbation analysis and compare it to other methods, the results of a conventional simulation using the Electromagnetic Transients Program (EMTP) are presented. To develop an analytical model representation free of the ninth harmonics, quadratic regression models in multivariables were used.     

地下水大尺度非列线不等距采样网的优化研究

采样的方法决定地质统计学中克立格法的估值精度。以研究区由开采井构成的具有99个地下水位长期观测孔的观测网为例,对地下水大尺度非列线不等距最佳采样网的合理性选择方法进行了研究。以采样点要避免过滤效应、分团效应以及采样数据分布要满足均匀性和随机性的检验准则为原则,选择了具有66个样本点的最佳采样网。     

白僵菌与生物农药混用对亚洲小车蝗的生物活性研究

在室内和田间分别测定了印楝素和阿维菌素与白僵菌(Beauveryia bassiana)混用对亚洲小车蝗(Oedaleus asiaticus)的生物活性。共毒系数测定结果表明,印楝素与白僵菌混用具有协同增效作用,而阿维菌素与白僵菌混用具有拮抗作用。田间小区试验表明,印楝素100 mL/hm2和白僵菌800 mL/hm2的混合液施药后第11 d防效达到88%以上,可以用于防治亚洲小车蝗。     

硝酸铵基绿色洁净固体推进剂的研究进展

介绍了硝酸铵(AN)氧化剂的特点,综述了国内外AN的处理方法以及AN基固体推进剂研究的进展,总结了AN基固体推进剂的特点,认为AN的改性及提高燃烧性能将是研究AN基绿色洁净固体推进剂的重点,对我国开展AN基绿色洁净固体推进剂研究提出了几点建议.     

低温固体推进剂的研究进展

介绍了国外低温固体推进技术（CSP）的研究和发动机试验情况。重点介绍了国外H2O2基低温固体推进剂和ALICE（铝冰）推进剂的研究进展。详细分析了ALICE推进剂应用于固体火箭发动机的可行性,并对我国发展CSP推进剂提出了几点建议。     

硝胺类推进剂用键合剂的研究进展

综述了各类适用于硝胺类推进剂的键合剂的研究情况,认为中性聚合物键合剂（NPBA）提高硝胺类推进剂的力学性能效果较好,需根据具体配方情况合成具有适当溶度积参数的NPBA,并根据NPBA的临界温度确定合适的推进剂制备温度条件。酰胺类和硼化物类键合剂具有成为优良键合剂的潜力,应加强对其合成与应用的研究。通过文献分析,认为键合剂的作用效果是官能团因素和分子结构因素共同作用的结果。对今后用于硝胺类推进剂的键合剂的发展提出了一些建议。     

牧区水草资源持续利用与生态系统阈值研究

本文基于水资源-草地生态-社会经济复合系统耦合机理，综合考虑水资源对地区人口、资源、环境和经济协调发展的支撑能力，应用目标规划法建立区域性“水-草-畜”系统平衡优化决策数学模型，并构建草原生态建设中“水-草-畜”系统平衡理论及调控系统。应用该模型定量化分析研究了毛乌素沙地典型牧区生态建设发展的两个关键阶段(人工种植冷季补饲型阶段和暖季放牧冷季舍饲型阶段)的水草资源承载力和相关技术经济指标，提出了研究区草地生态系统管理的阈值水平。     

Inner Mongolia must “leapfrog” the energy mistakes of the western developed nations

The purpose of the Asian Development Bank Report was to investigate and study the energy infrastructure development of western industrialized nations along with their impact on the environment. Then there could be an analysis of how IMAR could “leapfrog” or jump over the mistakes of the west and create an energy infrastructure for itself and China. The report reflects and summarizes this historical energy infrastructure development over the 20th Century. The five countries were the UK, Germany, S. Africa, USA and Australia.The foreign energy advisors felt that there were two additional elements that needed to be included. First was the fact that the USA as a whole was different than its regions or states, particularly California. So the nation-state of California was added. Secondly, the western nations of Germany and S. Africa in particular, had carefully considered some advanced coal technologies that were “cleaner” than the traditional and conventional approaches to mining. Both nations developed these “clean coal” technologies that are now being used more and more today in other developed nations like the USA. If IMAR was to retain much of its coal production and reduce it over time, then it had to install these technologies now to reduce global warming and reverse the climate change caused by current coal mining.     

热压罐传热分析

热压罐的传热设计是热压罐设计的难点。本文对热压罐保温最差的开门处进行传热分析,对开门处的典型结构进行介绍,利用cosmos软件进行传热分析,提出改善热压罐开门处传热的措施,初步建立适合热压罐传热分析的简单方法,为以后传热设计提供参考和依据。     

基于爆破试验的CFRP固体火箭发动机壳体的可靠性设计

根据GJB 1878-94制备了8个碳纤维缠绕复合材料压力容器，通过试验获得壳体的纤维强度、缠绕角、几何尺寸、爆破压强等随机变量特征值，利用这些实验数据对固体火箭发动机壳体进行可靠性设计，并与传统的安全系数法设计进行比较。结果表明，使用可靠性安全系数法设计可以实现安全性和经济性的统一。分析了材料的力学性能参数及壳体的几何参数等随机变量的变异系数对CFRP固体火箭发动机壳体爆破压强分散程度的影响。纤维应力、壳体纤维层厚度和壳体半径的变异系数的大小直接影响了爆破压强的分散程度；而纤维缠绕角除其变异系数的大小直接影响爆破压强的分散程度外，其参数均值也对爆破压强的分散程度有影响。