钢岔管三维参数化设计方法在ART工程中的应用

以阿尔塔什水利枢纽工程生态电站的3个月牙肋岔管为例,通过规范初步拟定钢岔管体型,用Autodesk Revit和Inventor软件进行三维参数化建模,将建立好的实体模型导入有限元软件进行受力分析,利用此类计算方法提高结构优化效率,确定出合理体型,为钢岔管三维参数化设计提供借鉴思路.     

公开市场操作:国债与央行票据替代性分析

本文认为由于国债安全性高、收益稳定,尤其是短期国债具有期限短、变现性强、市场表现活跃等特点,符合公开市场操作的要求,理应成为央行公开市场操作的主流工具。目前,央行票据作为操作工具的局限性显现,国债具有的优势可弥补其局限。长远看,随着短期国债规模的扩大,央行票据将淡出,国债将成为公开市场操作的主流工具。但当前国情下,国债与央行票据短期内不可能完全替代,二者可能在一定时期内并存。     

Beyond absorptive capacity in open innovation process: the relationships between openness,capacities and firm performance

The literature has shown that open innovation (OI) can be a winning strategy in improving firm performance. However, in order to adopt and implement it, managers need to resolve practical problems, such as understanding the role played by OI capacities and openness on firm performance. In response to these needs, this study aims to investigate the hierarchical relationships between openness, OI capacities and performance using a structural equation model approach. This paper also attempts to compare the levels of openness between firms in different industries to discover similarities and differences in OI phenomena. The analysis of data obtained from a survey of Korean firms shows significant interrelations between openness, OI capacities and firm performance. Our results go further in developing understanding of the building blocks on which successful OI is built and particularly suggest that desorptive capacity which underpins the out-bound OI process, is in turn strongly supported by knowledge management capacity. It is hoped that the results of this study can enrich our understanding of the OI mechanism and provide managerial and policy implications.     

Property price effects of a national wildlife refuge: Great Meadows National Wildlife Refuge in Massachusetts

The amenity value of proximity to a National Wildlife Refuge (NWR) in central Middlesex County, Massachusetts is estimated and compared to the values of proximity to five other open space types, including agricultural land, cemeteries, conservation land, golf courses, and sport/recreation parks. A hedonic model is used to explore the relationships among residential property values and proximity to these distinct types of open space. Open space characteristics in the empirical model include measures of continuous distance from each property to the nearest open space of each type and an index describing the diversity of open space types within neighborhoods of 100 and 1000 meters around a home. Results reveal that a property located 100 meters closer to the NWR than a neighboring property has a price premium of $984. Further, proximity to the NWR is valued more than proximity to agricultural land, cemeteries, and conservation land. No significant differences are found among the values of proximity to the NWR, golf courses, and sport/recreation parks.     

VB.NET结合Inventor iLogic在工程中的应用

利用VB.NET面向对象的强大功能和内嵌的i Logic对Inventor进行二次开发,创建自定义用户界面,使交互起来更方便、更直观,实现自身f(x)参数表不能实现的功能,从而在实际工作中提高效率。     

官商结盟的体制效应——以近代中国民营企业发展为例的分析

开放经济条件下,在一个相对集权的体制中,为规避潜在的风险,民营企业通常会采取"消极适应或积极适应"两种发展形式。"以牺牲企业对外部(技术、市场)变化适应性为代价换取产权安全"的消极适应型发展的直接后果是使得政府提升国家产业竞争力的努力受挫。与消极适应型发展模式不同,一些民营企业会选择积极适应型的发展模式,即通过寻求官方庇护的政治方式来确保创新收益安全,企业发展与滋生腐败之间极易发生联系。"‘腐败’成为企业发展‘润滑剂’"现象的出现,侵蚀了国家政治体制,加剧了政府和社会大众的不满,客观上加大了企业发展面临的潜在风险。体制"怪圈"的形成,既不利于国家竞争力的提升,又极可能引发政府统治的合法性危机。本文分析表明,只有将民营企业从坏体制"始作俑者"的角色中解放出来,才能破解体制怪圈。这需要从根本上改变民营企业"既是被需要的,同时又是被歧视的"尴尬处境。中国近代史上有关民营企业发展的案例为本文假说提供了丰富的实质性内容。     

The effect of external partner heterogeneity on open innovation: the moderating role of the technological regime

There is widespread agreement that open innovation (OI) is strongly influenced by external partner heterogeneity. While previous studies have examined partner heterogeneity using quantitative analysis, the implications of a weighted assignment using an external partner heterogeneity index have received less attention. The purpose of this study is to develop a modified partner heterogeneity model. Specifically, using a questionnaire survey of Chinese firms, we develop a new method to measure partner organisational heterogeneity (POH). Then, the moderating factors of an industry's technological environment, termed the technological regime, are introduced. The empirical analysis shows that the technological regime is positively correlated with POH and OI performance. Hence, an advanced technological regime improves POH and OI performance by incorporating external resources and increasing innovation potential.     

基于资源约束的产业集成系统

随着工业化进程的深入,现有资源已难以承载产业发展的规模和速度。产业系统作为一个开放的复杂巨系统,有必要采取"集成"的方法来突破资源的束缚。在产业协同发展的过程中,如何实现产业内部各组成部分的物质、能量、信息的管理、交流和共享,已成为亟须解决的问题。本文提出采取产业集成化发展战略,遵循系统分析原则,构建多层次的产业集成系统框架,结合可持续发展理论,针对产业集成化的实现提出相应的策略建议。     

院校实验室科学管理思考

增强科学研究能力是当前实验室建设的主要任务。如何完成好这一任务、做好实验室的管理工作,是当前院校值得探讨的问题。从更新教育观念、健全规章制度、优化队伍结构、实行开放管理、营造和谐氛围5个方面,提出了提高院校实验室科学管理水平的对策。     

Ruling out pareto dominated monetary equilibria

It is well known that under nominal money supply rules accomplished through lump sum transfers, non-uniqueness and non-optimality of the resource allocation often obtains in monetary models. We show that uniqueness and optimality of the resource allocation obtains if the monetary authority conducts Friedman's rule through open market operations. Our result necessitates and we provide a clarification of existing irrelevance theorems for open market operations. Our result also provides a partial resolution of the uniqueness-efficiency conflict of nominal money supply rules raised by Woodford (Economic Theory 4 (1994) 345–380).