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Search Results: 1 - 10 of 42232 matches for " Chuan Dong Xue "
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Magnetic Method Surveying and Its Application for the Concealed Ore-Bodies Prospecting of Laba Porphyry Molybdenum Ore Field in Shangri-La, Northwestern Yunnan Province, China  [PDF]
Nguyen Ba Dai, Chuan Dong Xue, Kun Xiang, Kun Xiang, Tran Trong Lap, Qureshi Javed Akhter, Shi Lei Li
Journal of Geoscience and Environment Protection (GEP) , 2014, DOI: 10.4236/gep.2014.23006
Abstract:

Recently, a number of large molybdenum (-copper) deposits have been discovered successively in the Laba area, Shangri-La county, northwestern Yunnan province. The investigation confirmed that there is a superlarge porphyry-skarn hydrothermal vein type molybdenum-polymetallic- metallogenic system with the total prediction reservoir of more than 150 mt molybdenum. The porphyry intrusions contributed to the mineralization closely, the superficial little vein molybdenum (-copper, lead, silver) ore-bodies are usually located in faults and fractures, and the deep porphyry type ore-bodies occurred in the granodiorite porphyries, the skarn type ore-bodies occurred in the contact zone intrused into Triassic limestone or Permian basalts. Laba ore block is a new exploration area with great prospecting potential. In order to reduce the target area and guide the further exploration work, the magnetic method measurement about 3.3 square kilometres was carried out in the ore field. This paper presents an application of analyzing the horizontal and vertical derivative, using Fast Fourier Transform (FFT) filter (FFT high-pass, low-pass, cosine roll-off, suscepbility), calculated spectra frequency energy to predict the depth and intensity of the apparent remanence magnetization of source (Hilbert). The calculated results and magnetic anomalous show that the remanence anomaly is caused by the intrusions into the Triassic limestone and Permian basalts with small anomalies, and the depth of located source is not great. We have identified a number of positions to the three drilled well, the drilled result specify interpretation with very high accuracy. The magnetic method is helpful to identify porphyry mineralization, and judge the shape and depth of the concealed ore-bearing intrusive bodies under the similar geological condition.

A Study on the Spatial Process for the Evolution of Urban Agglomerations and Optimal Land Use
城市群演化的空间过程及土地利用优化配置

XUE Dong qian,WANG Chuan sheng,
薛东前
,王传胜

地理科学进展 , 2002,
Abstract: The evolution of urban agglomerations includes many contents, such as population, industry, type of cities, function of cities and so on. The most comprehensive and direct expression that urban agglomerations evolve is spatial process. Urban agglomerations can be divided into three layers, namely, primacy urban belt, growth belt of urban group, and hinterland belt of urban agglomerations. The evolution of the structure follows the laws of urban growth and regional economic development. The spatial dispersion of urbanization is the beginning of spatial spreading about urban agglomerations. The spreading of urban agglomerations has four phrases, namely, the expanding phrase of multi-central cities, the directional sprawl phrase of urban space, the centripetal and centrifugal phrase between cities, and the complex expanding phrase in urban agglomerations. Concentration of industries and evolvement of industrial structures are immediacy powers of spatial expansion of urban agglomeration. There has a close connection between urban development and land exploiture. Economic development brings about land exploiture, suburbanization and the growth of urban agglomerations promote land exploiture, and construction of developing region brings land exploiture. At the same time, urban spatial growth promotes land increment. This paper analyzes the spatial process for the evolution of urban agglomerations, studies its dynamic mechanism, and describes its basic features and regulars from the structure of urban agglomerations, space of urban agglomerations and land-use of cities. At last, the paper reveals the connections between the evolution of urban agglomerations and the changes of land use as well as its development trends. That are growth axis and expanding diversity (including type, speed and direction).
URBAN LAND EXPANSION IN WUXI CITY: SPACE-TIME FEATURES AND NEW TRENDS
无锡城市用地扩展的时空特征与趋势分析

XUE Dong qian,WANG Chuan sheng,
薛东前、王传胜

资源科学 , 2003,
Abstract: By calculating concentration index of land expansion and intensity, the space time features of land expansion of Wuxi city are described in this paper. It indicates that the built up area has increased by 50 percent since 1990s. From 1990 to 1998, construction land have a net increase of 20 2 km 2, among them 38 52 percent are industrial land, which means industrial land increased at the speed of 4 82 percent each year. It also indicates that expansion is mostly occurred in city proper of Wuxi city since the middle of 1990s. Taking city proper as an example, built up area has increased from 65 4 km 2 to 97 8 km 2 from 1990 to 1999, having a net increase of 32 4 km 2 in 9 years. Analyzed in terms of time, expansion rate in each year is comparatively balanced. While with respect to city proper of Wuxi, land expansion fluctuates since the middle of 1980s, which has two heights, namely, in 1985 and in 1990, when the elastic coefficient of land expansion is over 3 3. Thus it is argued that the land expansion of Wuxi is a highly increased type. In terms of allomertry, this type can be called a positive allomertric type, that is, the expansion rate of built up areas is much bigger than that of non agricultural population in city proper. Therefore, the main time space features of land expansion in Wuxi city are explored and its developmental trend is estimated. Finally, it is suggested the south be the feasible direction for land expansion in Wuxi city, based upon the comprehensive research within this region.
The causes and alleviating countermeasures of the problems of wa ter resources utilization in areas along Yellow River in Inner Mongolia
内蒙古沿黄地区水资源利用矛盾的主要动因与缓解对策

WANG Chuan-sheng,YOU Fei,XUE Dong-qian,
王传胜
,尤飞,薛东前

自然资源学报 , 2002,
Abstract: Due to the changing regime of the main stream runoff of the Yellow River and the in creasingly deteriorated ecological environment,the contradictions among water resources,eco-logical environment and economic development get quite acute in the areas along the Yellow River in Inner Mongolia,which are the main irrigated areas along the upstream s of the Yellow River and the greatest water consumed areas besides the others.This paper emphatically discuss-es the main causes that result in the problems of water utilization in the areas.The conclusions are that the main natural cause of the problems is the great reduction of the passing water of the Yellow River,and the anthropogenic factors are summed up into the following aspects:the irra-tional water use,se rious pollution of water environment,low efficiency of local economy,and single urban function.The authors propose two groups of countermeasures to alleviate the con-tradictions among water resources,ecological environment and economic development.One be-longs to short-term measures,such as the change of irrigative model,adjustment of water price,and the treatment of water environment al pollution.The other is the long-term strategies,includ-ing the constitutional innovation,the key technological breakthrough,the effect of urban driving,and the environmen tal construction.
Wave equation finite-element modeling including rugged topography and complicated medium
起伏地表复杂介质波动方程有限元数值模拟方法

XUE Dong-chuan,WANG Shang-xu,JIAO Shu-jing,
薛东川
,王尚旭,焦淑静

地球物理学进展 , 2007,
Abstract: Wave equation modeling is a effective means of research the wave propagate phenomena.Because of simpleness and high-accuracy,finite-difference modeling has been applied wildly.As a result of difficult to deal with complex geometry interface,finite-difference has low-accuracy when encountering rugged topography or complicated structure.In order to accurately modeling wave field including complicated geology,this paper presents finite-element method solving 2-D acoustic wave equation.Triangular elements were adopted for approximating free surface and velocity interfaces.Both field and velocity were regarded as linear functions in elements to adapt to complex medium.Absorbing boundary conditions were employed for eliminating reflection from truncation boundaries.In order to improving computation efficiency,lumped mass matrix and lumped damp matrix were adopted for reason of enable avoid matrix inversion.The modeling results of examples proved the method's validity.
On the laws of territorial differentiation of socio-economic development in western China
中国西部经济社会地域分异规律研究

DONG Suo-cheng,WANG Chuan-sheng,YOU Fei,XUE Dong-qian,
董锁成
,王传胜,尤飞,薛东前

地理研究 , 2002,
Abstract: By integrating quantitative with qualitative approaches, as well as GIS technology along with 12 major selected indicators which can well reflect the regional development of western China, this article makes a comprehensive assessment on the socio-economic development of the 106 cities at prefectural level. Also, the characteristics and the laws of socio-economic disparities in western China are probed. Factors that mainly influence the socio-economic territorial differentiations are identified as follows: (1) physical disparities essentially influence the socio-economic disparities; (2) regional integration of agricultural resources shapes the territorial differentiation of agriculture in western China; (3) regional combination of energy and mineral resources constitutes the key factors determining the mineral cities' formation and distribution; (4) large cities and developed regions are located along major rivers and traffic lines, taking on point-axis diffusion form; (5) the interactions of location, resources, labour forces, technology, market, and policy determine the properties and patterns of economic regions;and (6) the high correlativity between each indicator selected in this article results in the strong conflicts between socio-economic development and ecological environment, which constitutes the main constraints to the development of western China. In conclusion, the laws of the socio-economic territorial differentiation of western China reflects the immense physical restrictions to the socio-economic development, which requires reconsideration of the ecological carrying capacity and resources' restriction in the course of developing western China. Moreover, blind migration into western China and reclamation should by no means be advocated
The Protective Antibodies Induced by a Novel Epitope of Human TNF-α Could Suppress the Development of Collagen-Induced Arthritis
Jie Dong,Yaping Gao,Yu Liu,Jinxia Shi,Jiannan Feng,Zhanguo Li,Heping Pan,Yanning Xue,Chuan Liu,Beifen Shen,Ningsheng Shao,Guang Yang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0008920
Abstract: Tumor necrosis factor alpha (TNF-α) is a major inflammatory mediator that exhibits actions leading to tissue destruction and hampering recovery from damage. At present, two antibodies against human TNF-α (hTNF-α) are available, which are widely used for the clinic treatment of certain inflammatory diseases. This work was undertaken to identify a novel functional epitope of hTNF-α. We performed screening peptide library against anti-hTNF-α antibodies, ELISA and competitive ELISA to obtain the epitope of hTNF-α. The key residues of the epitope were identified by means of combinatorial alanine scanning and site-specific mutagenesis. The N terminus (80–91 aa) of hTNF-α proved to be a novel epitope (YG1). The two amino acids of YG1, proline and valine, were identified as the key residues, which were important for hTNF-α biological function. Furthermore, the function of the epitope was addressed on an animal model of collagen-induced arthritis (CIA). CIA could be suppressed in an animal model by prevaccination with the derivative peptides of YG1. The antibodies of YG1 could also inhibit the cytotoxicity of hTNF-α. These results demonstrate that YG1 is a novel epitope associated with the biological function of hTNF-α and the antibodies against YG1 can inhibit the development of CIA in animal model, so it would be a potential target of new therapeutic antibodies.
Urbanization base of city-land use expansion in the Zhujiang River Delta
珠江三角洲城镇用地扩展的城市化背景研究

ZHANG Wen-zhong,WANG Chuan-sheng,XUE Dong-qian,
张文忠
,王传胜,薛东前

自然资源学报 , 2003,
Abstract: City-land use change(CLUC)in confusion during speedup urbanization is a common problem in many countries and also one of the best concerns of researchers.Correlative studies on it have signality in understanding mechanisms of CLUC and instituting policies of city-land use regulation.The author selected the Zhujiang River Delta in Guangdong,China,one of the regions with the highest level and the most rapid urbanization process as a case.Relations be-tween CLUC and urbanization of its courses,current status and special structure were discussed in this paper.And CLUC characters and trends under different levels,status and special struc-tures of urbanization also were analyzed.The paper first abstracted city-land use information from RS data of1990and2000in Zhujiang River Delta,and then revealed expansion characters and spatial disparities of city-land use.Also,by calculating synthesized index of CLUC(Ulc),28counties in investigated area were divided into3classes of CLUC:high expansion,low expan-sion and comparative stabilization.Meanwhile,the coupling relationship between CLUC and ur-banization was studied by comparing with relative urbanization levels of development.And cou-pling relationship in spatial structure between CLUC and urbanization was further dealt with.The main conclusions show the coupling relationship between CLUC and urbanization is quite good in Zhujiang River Delta from1990-2000.High expansion regions are centralized in the triangle with Guangzhou-Shenzhen-Zhuhai as its vertexes and in both sides along the main traffic lines.The trends of diminishing intension of CLUC are also showed from the cores centered around Guangzhou,Shenzhen and Zhuhai to the marginal areas.
Synchronization of Chaotic Systems and Its Applications in Secure Communication
混沌同步及其在保密通信中的应用*

WANG Xue-bing,ZHANG Lin-hua,LI Chuan-dong,
汪学兵
,张林华,李传东

计算机应用研究 , 2007,
Abstract: Based on detailed introduction to the purposes and methods of chaotic synchronization,a typical lag-synchronization encryption approach applied to the chaotic secure communication was proposed and the effectiveness of the proposed scheme was shown by computer simulation.Finally three security analyzing methods were given and applied in the scheme.
Particle swarm optimization algorithm for nonuniform linear arrays with multiple constraints
多约束非均匀线阵天线的粒子群布阵优化算法

ZHANG Xue-dong,ZHAO Chuan-xin,JI Yi-mu,
张雪东
,赵传信,季一木

计算机应用研究 , 2009,
Abstract: 为了有效解决孔径约束的非均匀线阵天线优化问题,提出一种动态边界计算的粒子群算法,并在优化过程中利用多种群协作提高优化稳定性。实验仿真显示,该算法可以快速得到满意解,有效地解决非线性优化中的约束问题,提高算法收敛速度和解的质量。
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