VLSI中双层多晶硅结构的剖面研究

本文对VLSI中双层多晶硅结构的剖面及用于结构成形的干法腐蚀技术进行了研究,获得了优化的剖面结构.研究分析表明,多晶硅Ⅰ的侧墙越倾斜,则双层多晶硅结构越佳.改变刻蚀条件可以有效地调节横向对纵向的刻蚀速率比δ,满意地获得多晶硅Ⅰ侧墙倾角α为49°左右;多晶硅Ⅱ采用二步刻蚀工艺.结果既消除了3μm工艺中用各向异性的RIE刻蚀易出现的多晶硅Ⅱ沿多晶硅Ⅰ侧墙的残留造成的相邻字线短路现象,又保证了线宽的精确控制,对下层SiO_2只有轻微的侵蚀.为VLSI制造提供了适用的工艺结构设计和加工技术,成功地研制出了64K DRAM合格样品.     

一种废纸面石膏板处理工艺及其设备

介绍了国内外对废纸面石膏板回收利用的工艺和方法,在此基础上,提出了一种废纸面石膏板处理的新工艺,采取两步法将废石膏板破碎并与纸张彻底分离,分离后的纸张和石膏可以直接应用于纸面石膏板的生产,并对其设备进行了简述。该废纸面石膏板处理系统利用了石膏板生产过程中产生的固体废弃物,可减少土地占用,节约资源,符合建筑材料可循环再生利用的可持续发展要求。     

城市综合管廊线性定位优化

随着城市的飞速发展,以传统直埋方式敷设的地下管线已经不能很好地满足现代化城市的发展需求,综合管廊的建设成为城市发展的必然趋势。为了提高综合管廊的利用效率,节省建设和运营成本,该研究在假设综合管廊是由多条垂直线和水平线组成的连续多段线基础上,以规划区内各需求点至水平线的距离加权之和最小为目标,构建了综合管廊中心线定位优化模型,得出了综合管廊中心线的平面定位。通过实例分析,验证了模型及求解程序的可行性。为综合管廊线路定位的定量研究提供了基础理论依据,并为综合管廊的合理规划提供了新思路。     

基于SIP协议的短波接入系统

传统电信网需要研究将包括短波通信系统在内的现有各种通信系统融合到统一的核心分组网中的方法,以实现向下一代网络(NGN)的演进。论文从系统需求分析出发,提出了一种基于SIP协议的短波接入系统实现方法,给出了系统体系结构和参考设计,可以为下一代网络融合短波通信系统标准的制定提供参考。     

浅议我国农村社会养老保险的法治困境

我国目前没有关于社会保障的基本法,也没有关于农村社会养老保险的单独立法。现有的关于农村养老保险问题的立法层级单一、位阶较低,制约了我国农村养老保险制度的完善及效用的发挥。完善农村社会养老保险制度,需要从完善立法开始。     

STUDY ON THE HYDROLIZATION OF THE Na_2O-CaO-P_2O_5-SiO_2 BIOLOGICAL GLASSES

The bio-glass in the Na_2O-Ca_2O-P_2O_5-SiO_2 system involved in this paper is highly bio-active.The hydrolization of this glass with calcium phosphateand low silica is studied.The structure-compositicon-property relation of the glass is discussed by means ofIR spectrum,DTA and SEM.This study shows that:(a)the structure of the glass is mainly chain-like orlayer-like;(b)the glass is separated into a calciumphosphate-rich phase and a silica-rich phase;(c)thechain-or layer-like structure and the separation hareadvantages with hydrolization.     

Highly Carboxylated,Cellular Structured,and Underwater Superelastic Nanofibrous Aerogels for Efficient Protein Separation

Chromatographic media with synchronously large protein adsorption capacity and high processing flux are highly desired in protein separation; however, the creation of such materials still faces enormous challenges. Herein, a robust strategy to develop highly carboxylated monolithic media by combining nanofibrous aerogels' forming technique and an in situ modification approach is reported. The obtained ion‐exchange nanofibrous aerogels (IENFAs) exhibit a unique cellular structure consisting of flexible ceramic nanofibers and a functional polymer wrapping layer, endowing them with outstanding underwater superelasticity and compressive fatigue resistance (nearly no plastic deformation after 1000 compressive cycles). Benefiting from the interconnected nanofibrous cellular structure, good hydrophilicity, high carboxylation, and excellent mechanical properties, the IENFAs exhibit synchronously promoted static (2.9 × 10³ mg g^?1) and dynamic (1.7 × 10³ mg g^?1) lysozyme adsorption capacities and improved buffer flux (2.17 × 10⁴ L m^?2 h^?1, gravity driven), which are superior to these reported nanofibrous materials and commercial ion‐exchange membranes. The IENFAs also possess outstanding performance stability, easy operation, and excellent regenerability. Moreover, the IENFA‐packed column could directly and continuously separate lysozyme from egg white solely driven by gravity, highlighting their excellent practical application performance. This work may provide a new avenue to design and develop next‐generation high‐performance chromatographic media for bioseparation.     

Growth of 3D branched ZnO nanowire for DC-type piezoelectric nanogenerators

In this paper, we have demonstrated 3D branched ZnO nanotrees (ZNTs) on flexible ITO–PET substrates by a facile two-step hydrothermal approach. The characterization of the as-grown ZNTs was studied by using SEM and XRD. Furthermore, self-powered piezoelectric nanogenerators (NGs) based on these ZNTs were fabricated. It is proved that the ZNT structures could significantly enhance the output current to ~300 nA, much higher than that of the previously reported NWs-based NGs, and their application toward energy harvesting devices is promising for the miniaturization of a power package and wearable devices.     

恒压变频调速给水系统的优化

本文通过改进水泵组合方式和控制方式以降低变频器设计容量的途经,优化出一种实用的给水方案。该方案可大大降低整套设备的成本,改善夜间或日间小流量给水性能,同时延长系统使用寿命,进一步推进了变频调速技术在给水系统中的应用。     

低分子量聚苯乙烯悬浮聚合工艺

以过氧化二苯甲酰为引发剂,聚乙烯醇为悬浮分散剂,叔十二烷基硫醇为链转移剂,通过悬浮聚合的方法制得了具有可控分子量的白色颗粒状聚苯乙烯。考察了引发剂、分散剂、链转移剂的添加量、反应温度、反应时间、搅拌速度、水和单体比例等对聚合产物分子量和收率的影响。研究表明本合成最适宜的反应条件为:反应温度75~80℃,反应时间7小时,V水/V单体=8,m引发剂/m单体=10%,m分散剂/m单体=3.5%,m硫醇/m单体=3%时,得到的产物分子量1.2万左右。