中压一体划产品的节能方案

阐述了一体划产品的优点,以具体工程案例分析在实际应用中的优势,方案灵活,经济,节能。

A Comparative Study of Methods for Delineating Sphere of Urban Influence: A Case Study on Central China

A number of urban and regional plans have been developed with the advancement of urbanization and regional integration, among which the delineation of sphere of urban influence and improvement of integration between the city and its hinterland have be- come vital important for guiding practices. In terms of delineating sphere of urban influence, existing studies have been focused on static study by using single year data or single method, resulting in a lack of time-series longitudinal analysis or comprehensive analysis based on multiple methods This study emphasizes on comparing two methods from both the theoretical and empirical perspective. Both gravity model and improwd field model are applied to the selected study area for measurements and comparison, to explore their strengths and weaknesses. A research framework for comprehensive analysis on delineating sphere of urban influence is proposed. In the end, the differences of deli：aeating methods are illustrated and the feasibility of comprehensive analysis is discussed. Recommendations are provided for selecting appropriate methods for delineating sphere of urban influence or developing regional hierarchy system plans and urban spatial structure schemes.

Changing Concepts of City and Urban Planning Practices in Guangzhou(1949–2010): An Approach to Sustainable Urban Development

By focusing on Guangzhou, this paper examines how different concepts of city in terms of urban-rural relationships are shaped in transforming China since 1949, and explores how they influence the way in which urban planning are practiced. In the pre-reform era, the city was defined as a productive space under the system of urban-rural segregation established for securing rapid industrialization. Urban planning was thus only concerned with the development of urban areas. In the 1980 s and 1990 s after the reform, institutional change and economic transformation mobilized the urban-rural linkages. The development of suburban areas was then considered by urban planning, but this consideration was a passive response to urban problems such as population explosion and water resources protection. Since the new millennium, the agenda for sustainable development and problems of uneven urban-rural development have called for the development of urban-rural integration. In this context, the city is conceptualized as a complex of mountain, city, river, farmland and sea, reconstructing the ideology of urban-rural division in defining urban development. Urban planning has therefore sought in an active way to develop a sustainable city embracing rural and natural elements, and to balance economic growth and environmental protection. It is argued that developing the concept of city as a complex of urban and rural elements contributes to the urban planning for sustainable urban development, while this conceptualization relies on the recognition of the integrated urban-rural relationship.

Tripartition of Arbitrary Single-Qubit Information via a Class of Asymmetric Four-Qubit W State

A four-party scheme is put forward for a sender to partition arbitrary single-qubit information among three receivers by utilizing a class of asymmetric four-qubit W state as quantum channels. In the scheme the sender＇s quantum information can be recovered by the three receivers if and only if they collaborate together. Specifically, they collaborate to perform first two different 2-qubit collective unitary operations and then a single-qubit unitary operation. The scheme is symmetric and （3, 3）-threshold with regard to the reconstruction, for any receiver can be assigned to conclusively recover the quantum information with the other two＇s assistances.

典型蒙皮框桁结构产品高效装配工艺研究

为提高某典型蒙皮框桁结构产品端框钻导孔的工作效率,提出去除用样板划桁条轴线、改用在端框钻孔机上钻桁条定位孔的方法,考虑程序可读性和运行时不易出错,选用分开钻铆钉底孔和桁条定位孔的方案。根据实际装配情况对桁条定位孔进行轴向偏差补偿,并设计钻划一体式刀,在钻桁条定位孔时进行划窝,整体效率提升1.3倍。

UPWIND FINITE VOLUME ELEMENT METHODS FOR ONE-DIMENSIONAL SEMICONDUCTOR DEVICE

This work is supported in part-by Shandong Province Natural Science Foundation under Grant No. ZR2010AQ010 and a Project of Shandong Province Higher Educational Science and Technology Program under Grant Nos. JllLA09 and J10LA01.