Mobile Agent系统结构及其关键技术     

董青  吴跃 《成都信息工程学院学报》2004,19(3):359-362

Mobile Agent技术是一门新兴的技术,具有移动性、智能性和异步计算的特点,已成为计算机网络和分布式系统最具活力的发展方向.现对Mobile Agent的概念、系统结构及其关键技术进行了分析和探讨.  相似文献   

西南矿区山体崩塌成因机制分析及防治对策   总被引：1，自引：0，他引：1  

杜蜀宾 《地球科学与环境学报》2004,26(1):89-92

西南地区的矿区具有相似的地理、地质环境,通过四川芙蓉煤矿白岩崩塌的典型实例,对西南矿区山体崩塌的成灾环境进行调查研究,揭示了西南矿区山体崩塌的成因机制,并简要提出了对该煤矿开发与综合治理建议,指出了加强防治工作的紧迫性,强调开展系统工程防灾的重要性,并为该煤矿解决正常采掘接替及工作面的布置问题作出了科学的指导.  相似文献   

西宁盆地泥石流类型及其防治意见     

洪文之  徐旭 《青海国土经略》1997,(1)

概略地叙述了西宁地区的泥石流形成条件和形成机理,并将西宁地区泥石流划分为稀性泥石流类及泥石质泥石流种类。在此基础上提出防治泥石流灾害的意见。  相似文献   

山区公路软基病害研究   总被引：2，自引：0，他引：2  

刘雪岭  苏生瑞  周新民 《地球科学与环境学报》2005,27(1):65-69

随着高等级公路建设规模的扩大，山区公路所面临的路基病害特别是软土路基病害问题也逐渐增多。结合对陕南勉(县)一宁(强)高速公路工程实例分析，对山区软土成因及其特性进行了初步分析，认为山区软土属以坡洪积、湖积和冲积为主的软土，也有少量是由坡残积物堆积而形成。山区软土的特殊性表现在成分的复杂性、分布的不均匀性、隐蔽性和物理力学性质的特殊性。根据其特性以及中国山区公路软基普遍存在的病害问题，总结了山区公路软基的主要病害类型为剪切拉裂破坏、浸水沉陷破坏、剥蚀坍塌破坏、推挤滑动破坏。还提出了相应的软基处理方法及建议。  相似文献   

Simulating methane emission from a Chinese rice field as influenced by fertilizer and water level     

Z. Yu  X. Shangguan  D. Pollard  E. J. Barron 《水文研究》2003,17(17):3485-3501

Natural and agricultural wetlands are considered to be the major sources of global atmospheric methane (CH₄). A one‐dimensional model was developed to simulate methane emission and used to examine the influence of various physical processes on the rate of methane emission. Three processes involved in the methane emission are implemented in the model: production, reoxidation and transport. Three transport pathways were considered: diffusion across water–air or soil–air interfaces, ebullition and diffusion through plants. These pathways are influenced by soil properties, plant growth, water‐table conditions, temperature and external inputs (e.g. fertilizer). The model was used to examine the seasonal variation of the methane emission at a rice field in Hunan, China, which was observed during a field experiment for consecutive (early and late) rice seasons in 1992. The observed seasonal variations of methane emission, and role of plants in transporting methane to the atmosphere, are captured by the model simulation. Further model applications were conducted to simulate effects of fertilizer and water‐level condition on the methane emission. The results indicate that unfermented organic fertilizer produces a higher methane emission rate than mineral fertilizer. The simulations with treatments of a deep‐water covering and constant moisture reduced the methane emission. The rice field study provides a framework for further development of the model towards simulations based on spatially distributed variables (e.g. water table, soil temperature and vegetation) at a regional scale. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

PKI中RA的功能模型及一种实现方式     

张元茂  刘玓 《成都信息工程学院学报》2005,20(1):12-15

网络安全是近年来研究的热点，各种新技术不断涌现，身份认证是安全应用中最重要的一个问题，也是PKI的核心服务之一。PKI作为信息安全的基石经过几年的发展不断走向成熟，在许多领域发挥着重要的作用。针对目前对PKI中的重要部件RA的研究很少的状况，着重对RA的实现模型进行了探讨。  相似文献   

Anthropogenic influence on trace element geochemistry of healing mud (peloid) from Makirina Cove (Croatia)     

S. Miko  G. Koch  S. Mesić  M. Šparica-Miko  M. Šparica  R. Čepelak  A. Bačani  P. Vreča  T. Dolenec  S. Bergant 《Environmental Geology》2008,55(3):517-537

Due to their balneotherapeutic features, the organic-rich sediments in Makirina Cove are an important source of healing mud. An environmental geochemistry approach using normalization techniques was applied to evaluate the anthropogenic contribution of trace metals to sediments used as healing mud. Sediment geochemistry was found to be associated with land-use change and storm events, as well as with proximity of a road with heavy traffic in the summer months. Local valley topography preferentially channels lithogenic and pollutant transport to the cove. Concentrations and distribution of trace metals indicate lithogenic (Ni, Cr, Co) and anthropogenic (Pb, Cu, Zn and Se) contributions to the sediments. The calculation of enrichment factors indicates a moderate (EFs between 2–3.5) input of anthropogenic Cu and Pb in surficial sediments to a depth of 10 cm. Patients using the Makirina Cove sediments as healing mud could be to some extent exposed to enhanced uptake of metals from anthropogenic sources via dermal contact.  相似文献   

Experimental study on the deterioration and natural remediation of the Ariake Sea tidal mud caused by the sea laver treatment acid practice and the upward seepage of pore water liquid     

Yan-Jun Du  Song-Yu Liu  Shigenori Hayashi 《Environmental Geology》2008,55(4):889-900

This study presents a laboratory study of the following two aspects: (1) the influence of sea laver treatment acid on the geoenvironmental properties of Ariake Sea tidal mud, and (2) the natural remediation effect on the sea laver treatment acid contaminated Ariake Sea tidal mud caused by the upward seepage of pore water liquid in the mud. Firstly, the mechanisms of the transport of sea laver treatment acid in the Ariake Sea tidal mud and the generation mechanisms of the upward seepage flow in the Ariake Sea tidal mud are discussed. Secondly, a series of one-dimensional laboratory infiltration tests were carried out to investigate the deterioration of the Ariake Sea tidal mud caused by the sea laver acid treatment practice. Test results reveal that the acid treatment practice caused considerable change in the geochemical properties of the mud in terms of increase in sulfide content and decrease in pH value. After the treatment by the sea laver treatment acid, the sulfide content of the mud even exceeded the safe limit value for the benthos, which represents undesirable living condition for benthos. Thirdly, series of laboratory fresh seawater infiltration tests for the deteriorated Iida site mud were conducted to illustrate this natural remediation efficiency. It is found that with the infiltration of the fresh seawater, the sulfide content of the Iida site mud was considerably reduced and pH value increased to an acceptable range for benthos living in the tidal flat mud. With the increase in the infiltration time and the hydraulic gradient, the remediation efficiency could be increased.  相似文献   

三峡库区生基包滑坡监测及成果分析          下载免费PDF全文

赵重  李长明  李厚芝 《探矿工程》2008,35(7):32-34,37

生基包滑坡监测属于三峡库区奉节县三期地质灾害监测预警项目之一,该滑坡位于长江左岸,临近人口稠密的安坪乡集镇,地理位置重要。三峡水库175 m蓄水后,其变形破坏特征有何表现？对航道安全运营有无潜在威胁？是否会对滑坡体上的重要建筑及村民生产生活构成危害？针对这些问题,首先分析了滑坡的工程地质特征及主要的影响因素;其次,确立以4种监测手段为主、人工巡查为辅的监测方案;通过对大地变形GPS、深部位移、滑坡推力等几种监测方法的运用及对其成果进行分析研究,以实例说明其在滑坡监测中的应用;再次,结合宏观人工巡查进行对照分析,以充分说明大地变形、深部位移和滑坡推力监测在实际运用中的可行性;最后,根据监测结论提出对生基包滑坡防治的建议。  相似文献   

旋流除砂机理研究及自动旋流除砂器的开发          下载免费PDF全文

张学强  鄢泰宁 《探矿工程》2008,35(11):34-36

旋流除砂技术是利用离心力从泥浆中分离固相成分的技术,可广泛应用在地质钻探、有色、冶金工业及石油天然气工业领域。研制开发的自动旋流除砂器弥补了传统除砂器固相成分分离效果不佳、排砂口易堵的缺陷,显著提高泥浆或矿浆的净化质量与除砂效率,且能自动排堵,降低了除砂工作的时间消耗和成本。  相似文献