磺酸自硬砂引起球铁件表层异常组织的研究

通过实验研究,用甲苯磺酸作催化剂的呋喃树脂自硬砂与稀土镁作催化剂生产的球铁件,通常在其铸件表层出现异常组织。提出导致异常组织产生的原因,同时又降低了试件的冲击值,并且采用反应型或屏蔽型涂料将可防止球铁件表层异常组织缺陷,为生产性能良好的球铁件提供技术依据。     

Studies of community structure and seasonal dynamics of planktonic copepods in saline-alkaline ponds

Abstracts Species abundance and seasonal succession of copepods in saline-alkaline ponds were studied in Zhaodian Fish Farm, Gaoqing County, Shandong Province, from 5 April 1997 to 1 September 1998. The results indicated that in the conditions of salinity ranging from 1.36 to 20 g/L, total alkalinity changing from 2.4 to 7.2 mmol/L and pH 8-9, zooplankton in saline-alkaline ponds was composed of freshwater salt-tolerated species or halophile species, some of which are halobiont species and usually occurs in freshwater. In our study, copepods were predominant in many fish-culture ponds and all control ponds without fishes in spring, late autumn and early winter. Dominant species of copepods were Sinocalanus tenellus, Cyclops vicinus, Thermocyclops taihokuensis. The biomass of copepods in the control ponds without fishes was higher than that of the fish-culture ponds.     

A tangential wind profile for simulating strong tropical cyclones with MM5

A new tangential wind profile for simulating strong tropical cyclones is put forward and planted into the NCARAFWA tropical cyclone bogussing scheme in MM5. The scheme for the new profile can make full use of the information from routine typhoon reports, including not only the maximum wind, but also the additional information of the wind speeds of 25.7 and 15.4 ms^-1 and their corresponding radii, which are usually provided for strong cyclones. Thus, the new profile can be used to describe the outer structure of cyclones more accurately than by using the earlier scheme of MM5 in which only the maximum wind speed is considered. Numerical experimental forecasts of two strong tropical cyclones are performed to examine the new profile. Results show that by using the new profile the prediction of both cyclones‘ intensity can be obviously improved, but the effects on the track prediction of the two cyclones are different. It seems that the new profile might be more suitable for strong cyclones with shifted tracks. However, the conclusion is drawn from only two typhoon cases, so more cases are needed to evaluate the new profile.     

Development of experimental apparatus about reverse circulation bit

A set of experimental apparatus on reverse circulation bit are developed, in order to lucubrate the mechanism of the new type reverse circulation bits, and the structure of the bits influencing the ability of taking core and carrying powder.Both the major structure of the equipment and the procession of experiment are described.     

基于卫星观测的两例青藏高原低涡结构的初步分析

应用风云2C卫星云图和配有云顶亮温的MTSAT卫星红外云图,描述了两例青藏高原低涡形成、发展及消亡过程,云图清晰显示了高原低涡具有涡眼和暖心结构的特征,并利用水汽图分析揭示了缺乏水汽供应是导致这类低涡不能进一步发展并移出高原的重要原因.最后用1°×1°NCEP分析资料对高原低涡形成眼结构时的基本物理场进行了诊断计算.结果表明:低涡整体为上升气流,而涡眼区在近地层为下沉气流,上层为相对涡区较弱的上升气流;低层辐合,高层辐散.进而印证了动力学研究工作得出的高原低涡具有与热带气旋类低涡(TCLV, tropical cyclone-like vortices)类似的涡眼和暖心结构特征的结论.     

日照市岚山区土地利用现状分析

分析了岚山区耕地、园地、林地、居民点及独立工矿用地、交通用地、水利设施用地和未利用地的数量结构,总结出土地利用空间分布3个片区的特点,在分析土地利用现状的基础上,找出土地利用中存在的问题,并提出合理利用土地的建议。     

湖北随州 ML4.7地震序列基础资料分析

依据随州三里岗ML4.7地震序列的地震监测和宏观调查所获得的基础资料,对此次地震序列的时空强特征及地震成因机理进行了分析。为使地震资料准确可靠,对混淆在序列中的爆破波形与地震波形进行了鉴别和剔除。结合这些基础资料和震源机制解结果。分析认为随州地震序列在成因上与该地区存在的北东和北西向两组断裂构造有关,但主发震构造是北西向断裂。     

论中国西部的经济开发

本文多方面系统地分析了中国西部地区的经济态势,从生产总值、产业结构(第一产业、工业、矿产、能源,第三产业等)以及生态环境等,论述西部的经济开发。     

Industrial structural changes in Hong Kong, China under one country, two systems framework

Hong Kong has undergone substantial economic transformations and developed into a sophisticated business and financial center in the Asia-Pacific region,since the return of sovereignty to China as a Special Administrative Region under the One Country Two Systems (OCTS) in 1997.This paper discusses and analyzes the industrial structural changes of Hong Kong in recent decades as well as its future challenges and opportunities.The data and finding reveal that even though Hong Kong will face fierce competition from the Mainland’s cities as the rise of China,the important role as a bridge between China and the rest of the world will brace Hong Kong itself under the OCTS for developing into a service hub for business and trade in the Asia-Pacific region.     

Changing spatial and structural patterns of non-agricultural activities in outward-moving Beijing urban fringe

As responses to metropolitan suburbanization and rural urbanization,the formation and evolution of urban fringes should be understood against the background of overall economic development and spatial reconstruction of entire metropolises.At the same time,however,endogenous interactions between industrial structure and spatial patterns of non-agricultural activities are also worthy of scholarly attention.Since the 1980s,studies on urban fringes in China have been restricted by the lack of micro-level data.This paper investigates the spatial expansion and structural evolution of the urban fringe by taking the case of Beijing and uses systematic firm-level data in 1996 and 2001 from the National Census of Basic Units.The diversity of distribution patterns across industrial sectors brings about two interrelated results.On the one hand,structural adjustment of non-agricultural industries promotes the expansion and spatial evolution of the urban fringe.On the other hand,the stability and dynamics of industrial structure coexist in the moving urban fringe.This study also reveals that the outward-moving urban fringe is the optimal location for manufacturing,especially heavy manufacturing,as well as traditional producer and consumer services.However,industries with spatial stickiness such as tourism and sports have not moved with the fringe.Most advanced services remain concentrated in the city center.The authors argue that it is essential for understanding and managing urban fringes to take into account spatial evolution and industrial structural adjustment together with their interaction with each other.