开关磁阻电机调速系统在煤矿井下的应用

随着开关磁阻电机的调速控制系统日臻完善，因其优越性能使得在各行业得到迅速推广，但在煤矿井下的特定环境中使用该调速系统仍存在着诸多问题有待分析研究。     

吐丝圈径对大规格高碳盘条组织性能的影响

计算与分析了斯太尔摩冷线上盘条的吐丝圈径、搭接密度及"佳灵"装置横向布风曲线之间的关系,研究了吐丝圈径的大小对大规格82B盘条组织和性能的影响,确定了大规格82B盘条最小吐丝圈径应为980mm.     

新型高k栅介质材料研究进展

随着半导体技术的不断发展，MOSFET（metal-oxide-semiconductor field effect transistor）的特征尺寸不断缩小，栅介质等效氧化物厚度已小至nm数量级。这时电子的直接隧穿效应将非常显著，将严重影响器件的稳定性和可靠性。因此需要寻找新型高k介质材料，能够在保持和增大栅极电容的同时，使介质层仍保持足够的物理厚度来限制隧穿效应的影响。本文综述了研究高k栅介质材料的意义；MOS栅介质的要求；主要新型高k栅介质材料的最新研究动态；展望了高k介质材料今后发展的主要趋势和需要解决的问题。     

长江螺山站高水位流量关系和城陵矶（莲花塘）控制水位的研究

螺山站高水位流量关系是确定长江城陵矶（莲花糖）控制水位的基本依据，从基本的河道水力学规律出发，考虑涨落率修正、瞬时比降修正，计算各时段点的代表性比降，和相应糙率，求出均值，根据断面资料，得出高水位的稳定流曲线，并以各日流量转化的稳定流点，进行验证，精度很好，分析了河段区间流量对螺山站稳定流量的影响。阐明了螺山站稳定流量的变化情况和趋势，推求了各次大洪水的超额洪量，计算出莲花糖以上的总入流，根据现今的湖区及槽蓄容积进行洪水演进，计算1954年特大洪水的超额洪量，并分析节三峡水库拦洪后对长江中下游超额水量的影响；对莲花塘不同防洪控制水位进行了技术经济分析和评价，提出了抬高控制水位的具体建议。     

深穿透复合射孔技术在中原油田的应用

深穿透复合射孔是一项把射孔与高能气体压裂两种技术有机地结合在一起的综合改造油气层的新技术。重点对它的技术原理，包括设计原理、枪身内火药燃烧气体对射孔孔眼的冲刷作用原理、火药燃烧气体射流的高能气体压裂作用原理等进行了研究与探讨，同时对它的施工工艺、现场应用等方面进行了阐述，经中原油田189口井现场应用证明，其工艺简便，成本低廉，可实现多层跨隔层使用，处理后增产效果显著，投入产出比高，可代替传统的聚能射孔技术，具有广阔的推广和应用价值。     

双河油田特高含水后期开发阶段注采结构调整的实践与应用

针对双河油田的注采结构的现状及特征,通过近几年来在注采结构调整方面的实践与应用,总结出了油田在特高含水后期开发阶段,实现油田控水稳油目标的途径和方法,注水结构调整主要是结合地质特点,减少欠注层段,减少和控制不合理超注井层段和改善吸水剖面;在采液结构调整上,控制高含水层段的注入,加强中低渗透层段的注入,封堵高渗透、高水淹干扰层段,解放动用较差的中低渗透层段,改善平面上采出不平衡的状况。通过实施注采结构调整,双河油田在特高含水后期实现了高效开发。     

电潜泵中压变频调速系统的改进

电潜泵中压变频器输出端产生高次谐波和脉冲电流 ,对电潜泵电动机的绝缘性能和轴承寿命造成不利影响。为此 ,提出 3项改进对策 :①采用谐振软性开关逆变电路 ,使功率开关器件在零电压条件下导通 ;②在变频器逆变输出端设置电抗滤波器抑制高次谐波电流 ;③改变电动机内部结构 ,如加大定子槽宽 ,增加转子导条尺寸 ,变星接法为星 角接法 ,采用绝缘轴承等。实践证明 ,采取改进对策后 ,不仅提高了电潜泵的产量 ,而且变频器滤波后电动机端的过电压明显减小 ,电潜泵和电缆的寿命延长     

建筑墙体表面传热系数辨识研究

对实验房间南向墙体内表面中心区域的换热过程进行实验，发现当风速在0－5．5m/s之间时，表面传热系数在8－18W（m^2.K）之间波动，而风向对墙体表面传热系数影响不大；用辅助变量法分析墙体表面传热过程，并结合实验推导出墙体表面传热系数。模型的预测结果与实测结果吻合良好。     

Facile modifications of polyimide via chloromethylation: II. Synthesis and characterization of thermocurable transparent polyimide having methylene acrylate side groups

From chloromethylated polyimide, a useful starting material for modification of aromatic polyimides, a thermocurable transparent polyimide having acrylate side groups was prepared. In the presence of 1,8‐diazabicyclo[5,4,0]undec‐7‐ene, chloromethylated polyimide was esterified with acrylic acid to synthesize poly(imide methylene acrylate). The polymer was soluble in organic solvent, which makes it possible to prepare a planar film by spin coating. The polymer film became insoluble after thermal treatment at 230 °C for 30 min. Optical transparency of the film at 400 nm (for 1 µm thickness) was higher than 98 % and not affected by further heating at 230 °C for 250 min. Adhesion properties measured by the ASTM D3359‐B method ranged from 4B to 5B. Preliminary results of planarization testing showed a high degree of planarization (DOP) value (>0.53). These properties demonstrate that poly(imide methylene acrylate) could be utilized as a thermocurable transparent material in fabricating display devices such as TFT‐LCD. Copyright © 2004 Society of Chemical Industry     

High char‐yielding poly[acrylonitrile‐co‐(itaconic acid)‐co‐(methyl acrylate)]: synthesis and properties

Polyacrylonitrile terpolymers of various compositions consisting of acrylonitrile (AN), itaconic acid (IA) and methyl acrylate (MA) were synthesized by solution polymerization in dimethylsulfoxide. Increase in concentration of either IA or MA retarded the overall polymerization rate and the polymer molecular weight. The system consisting of AN + MA and varying IA concentration was more prone to retardation in comparison with the system composed of AN + IA with variable MA concentration. The retardation factors were quantified. Minor quantities of MA boost the reactivity of IA in the terpolymer system. The terpolymer was richer in MA vis‐à‐vis the feed. The thermal characteristics of the terpolymer were examined as a function of its composition. In contrast to the copolymer of AN and IA requiring 1–1.5 mol% IA, the terpolymer required an IA content of approximately 2.5 mol% for optimum thermal stability. The polymer with 90 mol% AN, 2.5 mol% IA and 7.5 mol% MA exhibited reasonably good char‐forming characteristics and thermal stability. The overall crystallinity and crystallite size of the polymers were found to decrease on incorporation of the comonomers. The ‘aromatization index’ of the copolymer increased with the temperature of pyrolysis through re‐organization of the tetrahydropyridine ladder structure. Copyright © 2005 Society of Chemical Industry