基于心理感知和行为激发的高层住区环境研究

从高层住区室外环境现状问题出发,在借鉴环境行为理论的基础上,从密度感和邻里感两个方面,探讨了适宜的高层空间优化办法。     

Finite-time stabilization for a class of stochastic nonlinear systems via output feedback

This paper investigates the problem of global finite-time stabilization in probability for a class of stochastic nonlinear systems. The drift and diffusion terms satisfy lower-triangular or upper-triangular homogeneous growth conditions. By adding one power integrator technique, an output feedback controller is first designed for the nominal system without perturbing nonlinearities. Based on homogeneous domination approach and stochastic finite-time stability theorem, it is proved that the solution of the closed-loop system will converge to the origin in finite time and stay at the origin thereafter with probability one. Two simulation examples are presented to illustrate the effectiveness of the proposed design procedure.     

Interaction between rice bran albumin and epigallocatechin gallate and their physicochemical analysis

Epigallocatechin gallate (EGCG) is sensitive to heat thus its application in food industry is limited. In this work, rice bran albumin protein (RAP) was used as a carrier for EGCG. RAP-EGCG complexes (RAPE) were prepared with the binding number n of 0.0505:1 (EGCG: RAP, w/w) and binding constant K of (0.74?±?0.002)?×?10⁴ M^?1, which suggests that hydrogen bond/van der Waals forces played important roles in such binding. FTIR analysis demonstrated that EGCG could induce the secondary structure changes of RAP above the ratio of 1.92:1 (EGCG:RAP, w/w). Dynamic light scattering and scanning electron microscope results showed that EGCG could trigger RAP association. Furthermore, the EGCG stability in RAPE was significantly improved than that of free EGCG in 10–60 °C. The antioxidant ability of EGCG in RAPE was partially retained. These findings prove that RAP is a potential carrier for polyphenols and is beneficial for mechanism investigation between protein and polyphenols.     

特高压冲击电压分压器线性度测量方法比较

线性度为冲击电压分压器的关键技术参数,随着额定电压的不能提高,对于不能在全部电压范围内进行比对校准的冲击分压器,必须进行单独的线性度试验。本文介绍了两种不同的测量高压冲击分压器线性度的方法：测量冲击电压发生器输出电压与充电电压的比值变化;使用球形电压测量仪来测量冲击分压器的线性度。研究充电电压测量准确度、充电时间、充电电压补偿以及充电电压不均匀程度等因素对冲击电压发生器输出电压的影响;球形电场测量仪的输出电压与被测电场成正比,在均匀场与非均匀场中都可以测量冲击电压波形,其线性度≤±1%,可通过改变测量仪的布置位置来扩大测量电压范围;使用上述两种方法测量同一台弱阻尼冲击电压分压器的线性度,测量结果一致性好,因此球形电场测量仪也可用于进行特高压冲击分压器线性度的现场校准。     

基于云模型的电信客户行为关联规则研究

研究如何运用基于云模型改进的关联规则来分析电信客户行为,进行客户行为知识表示.针对传统数量关联规则挖掘存在的问题,提出基于云模型的数值区间划分方法,这种划分摒弃了以前的硬划分,使得到的结果除了保留传统硬划分所具有的优点以外,也更加符合实际的数据分布和人的思维方式,从而得到概括、易理解和有效的关联规则,将其应用于电信服务业,可提高电信服务的质量.     

Densification of alumina components via indirect selective laser sintering combined with isostatic pressing

To improve the final density of ceramic parts via indirect selective laser sintering (SLS), cold/hot isostatic pressing (CIP/HIP) technologies were introduced into the process. The proposed approach in the present study combined spray drying with mechanical mixing by which we prepared a kind of compound powder consisting of polyvinyl alcohol (PVA, 1.5 wt%), epoxy resin E06 (8 wt%), and alumina so as to get a good fluidity for SLS. At the first step, SLS parts reached the highest relative density of about 32 % when the laser energy density was 0.094 J/mm², which facilitated the next operation and improvement of final density. Then, a soft polymer canning was prepared for CIP around the surface of SLS alumina ceramic parts using pre-vulcanized natural rubber latex RTV-2, gelation and film. Following that, we experimented on different CIP maximum pressure which had different effects on densification of SLS alumina parts, the whole process in CIP was divided into three stages of I, II, and III. Based on thermal gravity curve of epoxy resin E06, ignoring the impacts of the only 1.5 wt% PVA on degreasing, green bodies were degreased and furnace-sintered. Finally, the relative density of alumina parts reached 95.94 % after HIP process. Field emission scanning electron microscopy was used to analyze the densification evolvement in each stage of process and the fracture mechanism. The study showed a positive and practical approach to manufacture ceramic matrix and ceramic components with complex shape by indirect SLS technology.     

近二十年中国乡村景观特征体系研究 进展

乡村景观是乡村生态环境及文化的重要承载单元之一,基于乡村景观特征体系开展科学合理的规划,建设生态宜居乡村,是在生态文明思想引领下建设美丽中国的重要内容。对乡村景观特征体系的研究是乡村景观研究及规划的基础,以CNKI数据库为基础,梳理了中国乡村景观研究相关文献。首先归纳了乡村景观研究进展,结合文献可视化分析软件Cite Space绘制知识图谱,分析2000—2020年中国乡村景观特征体系的研究现状和研究热点;系统介绍了现有的景观特征体系理论和应用研究;总结归纳中国乡村景观特征体系的发展趋势及方向为：1)基于应用目标指引建立合理的中国乡村景观特征指标体系;2)乡村景观特征分类及价值评价协同研究;3)乡村景观特征体系应用信息化发展研究。     

水轮发电机定子铁心端部冲片逸出原因分析及预防措施

本文研究了水轮发电机定子铁心端部冲片逸出,割伤线圈主绝缘,导致绕组接地的问题。分析了冲片逸出的原因,总结了一些在结构设计、生产工艺和安装方面预防端部冲片逸出的措施。本文对定子铁心结构设计以及处理冲片逸出具有指导意义。     

溅射膜电极与氧化锌压敏陶瓷的界面机制研究

利用溅射法制备半导体陶瓷表面的电极有着广阔的产业化前景,但关于溅射膜电极与陶瓷表面的界面机制研究尚鲜有报道。本文采用磁控溅射法在ZnO压敏陶瓷表面制备了Cr+Cu电极,通过X射线光电子能谱等技术研究分析了Cr/ZnO的界面反应及界面成分。研究结果表明:常温下Cr膜在氧化锌表面的沉积模式为混态生长模式,在Cr的初始沉积阶段,Cr价层电子与氧化锌表面存在电子转移作用,有氧化态的Cr生成;随着覆盖度的增加,电子转移逐渐减弱,最后Cr完全呈现为金属态的中性吸附。该界面反应生成的化合物对溅射膜电极的欧姆接触,附着力等性能有重要作用,而且能有效阻止电极元素Cu或Ag的纵向扩散。     

关于增加核电厂场外应急撤离时间管理要求的建议

在制定核电厂应急撤离计划和应急决策时,撤离时间估算是一项重要的技术支持手段。本文根据我国场外应急撤离的管理要求现状,借鉴美国撤离时间估算的相关经验,对核电厂场外应急撤离时间问题进行了分析,同时建议我国相关核安全管理规定中增加场外应急撤离时间的要求。