新农村建设与农民的选择行为

中国的新农村建设必须在得到农民群体经济行为上的响应后才能获得预期收效。目前农民群体的具有经济合理性的行为与政府的新农村建设的意愿尚存在逆向选择问题。现有的农地产权是约束农民经济行为,使之难以对新农村建设做出积极响应的根本性制度安排。新农村建设预期效果的获得,最终将取决于现行农地产权制度能否发生变迁。     

Study of Martensitic Phase Transformation in a NiTiCu Thin‐Film Shape‐Memory Alloy Using Photoelectron Emission Microscopy

Thermally induced martensitic phase transformation in a polycrystalline NiTiCu thin‐film shape‐memory alloy is probed using photoelectron emission microscopy (PEEM). In situ PEEM images reveal distinct changes in microstructure and photoemission intensity at the phase‐transition temperatures. In particular, images of the low‐temperature, martensite phase are brighter than that of the high‐temperature, austenite phase, because of the lower work function of the martensite. UV photoelectron spectroscopy shows that the effective work‐function changes by about 0.16 eV during thermal cycling. In situ PEEM images also show that the network of trenches observed on the room‐temperature film disappears suddenly during heating and reappears suddenly during subsequent cooling. These trenches are also characterized using atomic force microscopy at selected temperatures. The implications of these observations with respect to the spatial distribution of phases during thermal cycling in this thin‐film shape‐memory alloy are discussed.     

基于图像处理的车辆通行管理系统设计

随着汽车数量的增多,车辆的通行管理日趋繁重和复杂。本文基于数字图像处理技术设计了一智能车辆通行管理控制系统。将一些先进的数字图像处理技术应用于本系统中,提高了系统的自动化程序和智能性。     

用于相变存储器的W亚微米管加热电极性能

为了降低C-RAM器件的操作电流,利用0.18μm标准CMOS工艺线制备出外径为260nm的W亚微米管加热电极,并对其进行了电学性能的表征.使用W亚微米管加热电极制备出C-RAM器件,并通过疲劳特性测试分析了器件失效的原因.结果表明,W亚微米管具有良好的电学稳定性和疲劳特性,为降低C-RAM器件的操作电流提供了一种非常有效的途径.     

基于组织变革的商业银行营业机构业务流程再造

随着经济和金融体系市场化程度的不断加深，银企问的交易机制必然发生相应变革，降低“交易成本”、提高管理效率，将逐步成为稳定银企长期合作关系的关键因素。这一变化必然引起我国商业银行“再造”自身业务流程，以提高自身的核心竞争能力。在分析我国商业银行营业机构业务流程的传统模式及缺陷的基础上，对商业银行营业机构业务流程再造的方案进行了深入研究；提出了“以客户为导向”，以客户、行业、地区和产品为线索的网状矩阵式组织和经营构架，并据此对其业务流程进行了重新设计。     

基于空间矢量脉宽调制的新型永磁同步电机矢量控制调速系统

针对采用空间矢量脉宽调制的永磁同步电动机的转子磁场定向矢量控制系统,介绍了一种新型的矢量控制策略,对传统的电流环、速度环控制器做了改进。在电流环中引入了一组电流交叉乘积项计算出准确的轴电压控制值,实现控制系统在较宽的速度范围内满足较高的控制精度。速度环采用参数自整定模糊控制器,通过模糊控制规则自动整定控制器参数,改善了系统的性能。仿真结果表明,与常规矢量控制的永磁同步电机调速系统相比,新型矢量控制策略具有良好的动态、稳态性能以及较强的鲁棒性,从而证明了这种设计方法的合理性和优越性。     

广州地区出土脆弱青铜器加固材料筛选研究

广州地区出土青铜器十分脆弱,强度极低。为筛选最佳的加固材料,选取水性丙烯酸乳液、水性丙烯酸树脂、有机硅、丙烯酸清漆、水性聚氨酯分散液、聚乙烯醇缩丁醛树脂、热塑性丙烯酸树脂共7类8种加固材料进行实验,通过对比粘结性、渗透性、颜色变化、耐酸碱、成膜性、耐水性等7项性能,热塑性丙烯酸树脂B48N是目前最适合广州地区出土脆弱青铜器的加固材料。     

相变蓄能材料在建筑节能方面的应用研究进展

相变蓄能材料由于相变时吸收或释放潜热的独特性能,在建筑节能方面得到了广泛的应用和研究。分析了相变材料的分类和性能,综述了国内外对相变蓄能材料基本性能的研究进展,并系统地阐述了相变蓄能材料在蓄冷空调系统以及被动式太阳房中的应用研究。     

Institutional stability and industry renewal: diverging trajectories in the Cognac beverage cluster

Adding to approaches highlighting network dynamics as a basis for regional economic development, increased attention is paid to institutions as contextual factors contributing to explaining how and why economies change. Research has shown that firms tend to react differently to the same institutional configurations, with the main explanatory factors being their sectoral backgrounds and intra-firm characteristics. This study adds to these insights by examining a regional economy in France, that of Cognac, in which 300 firms are operating under homogeneous institutional preconditions. Despite these similarities, we identify different development trajectories from the 1990s onwards. Our observations illustrate how firms’ responses to external change diverge and bring them on different trajectories due to different positions in the industry hierarchy and different experiences and capabilities among individuals within firms. The study contributes to the better understanding of mechanisms of path dependence, which have gained wide recognition in the literature in the recent decades.     

A Dynamically Tunable,Bioinspired Micropatterned Surface Regulates Vascular Endothelial and Smooth Muscle Cells Growth at Vascularization

Regulation of the growth of vascular endothelial cells (ECs) and smooth muscle cells (SMCs) with artificial vascular grafts at vascularization is well‐known to regenerate functional blood vessels for treating cardiovascular disease; however, little research has been published on this subject. Here, a novel polymer vascular graft is presented, whose inner surface contains an assembled circular microgroove pattern decorated with a combination of concentric circular microgrooves and radial, straight microgrooves inspired by the orientation of SMCs and ECs in natural tissues. The surface micropatterns can produce dynamically tunable variations via the thermally switched shape memory. The results from the in vitro EC/SMC co‐cultures reveal that the surface micropatterns have a great capacity to regulate the specific distribution of ECs/SMCs because the ECs grow along the radial, straight microgrooves and the SMCs grow along concentric circular microgrooves. The in vivo vascularization is further analyzed by implanting the vascular graft in the rabbit carotid artery. Both histological analysis and immunofluorescence staining demonstrate that it is capable of highly effectively capturing ECs and SMCs in the blood and subsequent regeneration of new blood vessels. Therefore, this study opens a new possibility for regenerating neovessels to replace and repair damaged vessels for cardiovascular diseases treatment.