避免腹部B超检查漏诊的经验交流

总结腹部B超检查经验,探讨避免腹部B超检查漏诊的方法,为临床提供可靠的影像学资料。     

大学科技园发展中的政府“碎片化”治理对策

大学科技园在国家创新型经济社会发展和文化强国过程中起了重要作用。而政府积极为大学科技园发展提供资金支持、政策助推和服务咨询,是实现大学科技园健康发展的有力保障,但其存在的一些"碎片化"管理问题却也成为制约大学科技园发展的硬伤。新形势下,政府要进一步转变职能,克服"碎片化"管理模式,努力创新我国大学科技园的发展策略,为实现大学科技园可持续发展提供机制保障。     

Pizza over the Internet: e-commerce,the fragmentation of activity and the tyranny of the region

This study is aimed at analysing the relationships between local development agencies and various actors from within their environments. The authors explore the applicability of a relationship marketing approach to local development and propose the influence of economic development objectives on the relational orientation of partnerships, as well as the correspondence between the relational orientation, the results obtained and the expectations of continuity. The empirical study focuses on particular cases of Spanish development agencies operating at local and regional level. A structural equations analysis in a sample of 174 relationships of 18 local development agencies evidences that while the relational orientation of internal relationships and lateral relationships with other development agents is hardly influenced by the objectives of economic development, the closeness of vertical relationships (residents, firms, tourists and local entrepreneurs) depends to a large extent on these objectives. Moreover, it has been confirmed the that effect of relational orientation on competitiveness, on efficient management, and on satisfaction, whereas the creation of infrastructures seems not to be a direct result. The authors conclude that managing relationships with suppliers and target groups as alliances, working together, sharing information, resolving conflicts satisfactorily, and sharing common values, will guarantee performance and resources management efficiency, and will ensure the continuity of fruitful relationships.     

Property taxation and rural land values: Their effect on private forestland ownership structure in Texas

The objective of this study was to estimate the effect of property tax and rural land market value on the ownership structure of private forestland in Texas. Using county-level panel data in an Instrumental Variable regression framework, we estimated the effect of property tax rate and rural land value on two measures of ownership fragmentation: the total number of private forest landowners and the average size of private forest holdings. The results indicate that after controlling for the total amount of private forest area in a county, both property tax rates and rural land values increased ownership fragmentation. However, the rate of ownership fragmentation was relatively inelastic in both property tax rate and rural land value. While further restructuring local property tax rates might minimize the negative effect on private ownership dynamics, policy instruments that decrease the disparity between productivity value and market value of rural forestland might be needed to check the ongoing ownership fragmentation in Texas and elsewhere in the United States.     

The effects of political fragmentation on investments: A case study of watermill construction in medieval Ponthieu, France

The link between political fragmentation and economic development has been frequently discussed in the pre-modern growth literature, yet, it has mostly been treated in a general manner. This paper provides a specific and detailed case study of the patterns of watermill construction in the northern French region of Ponthieu, France. The results suggest that political fragmentation in the juridical context of medieval Europe positively affected investments in machinery. I concentrate on the eleventh and twelfth centuries, a period characterized by political fragmentation and weak central authority, and provide original evidence that watermill construction was significantly more intense in areas where authority was fragmented and landholding was divided between numerous landlords. I suggest that the mechanism behind the phenomenon is that in the institutional context of medieval Europe political fragmentation reduced the territorial extent of lords' jurisdiction and therefore, of their monopoly over watermill construction. This, in return, promoted the construction of neighboring watermills, thereby affecting the number of watermills and the level of competition in the milling industry.     

选煤厂破碎及破碎机械的性能分析

本文主要阐述了选煤厂物料进行破碎的作用、破碎的基本形式、破碎效果及破碎机的类型。分析了齿辊式破碎机、额式破碎机、冲击式破碎机和滚筒式破碎机的性能状况。     

Agrobiodiversity,farm profits and land fragmentation: Evidence from Bulgaria

This paper presents an empirical analysis of the role of land fragmentation, crop biodiversity and their interplay with farm profitability. Original primary data are drawn from a survey conducted in the Plodiv region of Bulgaria. The econometric results stress the ambiguous role of land fragmentation on farm profitability. On one hand, land fragmentation reduces farm profitability. On the other hand, land fragmentation fosters crop diversification. We also find that crop biodiversity plays a beneficial role in farm profitability. Policies that aim to increase land consolidation and reduce fragmentation may overlook the positive link between diversity and plot heterogeneity. Policies that encourage land consolidation should, therefore, consider the crucial role that this has on other variables such as farm biodiversity.     

SnO_2透明导电膜的结构性能及光电特性分析

本文采用超声喷雾热解淀积技术将SnO2:F透明导电薄膜均匀制备于小尺寸石英管内,使玻璃圆柱体的内壁依次沉积了一层透明电极,使导电液体和电极形成一个电容,在其两端施加电压可以有效的改变导电液体与介电层之间的界面张力,即改变液体的界面形状,从而实现变焦透镜的功能。通过对SnO2导电薄膜结构性能及光电特性的分析和测试,研究了不同温度和薄膜厚度对薄膜光电性能的影响。     

Assessing the fragmentation of construction land in urban areas: An index method and case study in Shunde, China

The fragmentation of construction land due to decentralised urban development, disorderly mixed land use, and large-scale transportation infrastructure poses a threat to urban integrity. There is a need to quantify the fragmentation level in a consistent way for inclusion in planning-related decisions. In the context of China's urban sprawl, this study develops a quantitative and intuitive index approach that planners can use to analyse multiple fragmentation features of construction land within urban areas. The approach can be used in planning policy reviews for timely land-use assessment and can be integrated into urban planning processes for developing strategic land-use scenarios. The method was applied in Shunde, a typical urban area in southern China, and construction-land fragmentation and its impacts on environmental quality were analysed. The results show that the entire built-up area in Shunde displays a high level of fragmentation. Patches of industrial and rural residence have been identified specifically higher fragmentation level. The shortage of available construction land makes land consolidation within built-up areas very important in planning Shunde's future development. Moreover, the land shortage requires the progressive reduction of construction land fragmentation. The results of the study also indicate that although land fragmentation has been affected by transportation infrastructure and the existence of rivers and hills in this region, decentralised decisions from hierarchical local governance regimes have greatly exacerbated this situation. Shunde provides examples of typical land-use problems associated with quasi-urbanised regions in China; construction-land fragmentation is a greater determinant for the sustainable development of urban and rural areas than construction-land growth.     

国外社保整合对我国碎片化养老保险制度改革的经验和启示

目前,我国养老保险制度碎片化的状况比较严重。文章分析了我国养老保险制度碎片化的现状,发现其造成了公平和效率的严重失衡,并且产生了影响社会的稳定和发展的弊端。文章借鉴英、法、美等西方国家在社保整合方面所采取的管理体制改革和养老金制度改革等整合社会养老保险制度的措施,总结经验和教训,为我国的碎片化养老保险制度改革提供思路,以期促进我国养老保险事业的健康发展和制度的不断完善。