考虑湿度影响的城市气溶胶夜晚温度效应   总被引：10，自引：0，他引：10  

李子华  涂晓萍 《大气科学》1996,20(3):359-366

本文利用一维非定常模式，研究了城市上空干、湿气溶胶粒子对夜间边界层温度的影响。结果表明，湿气溶胶粒子对低层大气有明显的升温作用，而对中上层大气则起降温作用，同时改变了贴地逆温层结构和边界层稳定度。  相似文献   

地震空间分维Dq及b值的临震变化特征及其非线性机制分析     

吴小平  黄雍 《地震研究》1996,19(1):42-49

对云南省几个不同地区的强震孕震阶段及临震时的地震空间分维Ｄｑ（ｑ＝０，１，２，）及ｂ值进行了计算和研究，发现虽然在孕震阶段各地区的Ｄｑ及ｂ值均有着共同的下降主趋势，但临震时不同区域的Ｄｑ及ｂ的变化形态却存在着差异，大地震可能发生在Ｄｑ及ｂ值均降至最低时，也可能发生在Ｄｑ及ｂ值下降后又回升之时，还可能发生在Ｄｑ回升而ｂ值仍保持最低时。本着重对Ｄｑ及ｂ值的临震变化特征及其个体差异从非线性的角度作了物  相似文献   

地震序列自仿射分形及自相似分形的计算与比较     

何玉梅  吴小平 《地震研究》1996,19(4):363-370

本用标准偏差法和标度变换法，计算了云南省五个地震区带上１９６５－１９９５年间地震序列的自仿射分形的分维值Ｄ△ｔ（地震时间间隔序列自仿射分形）ＤＭ－ｔ（地震震级一时间序列自仿射分形）及自相似分形的分维值Ｄ０（地震时间分布自相似分形）得到了相应的时间变化曲线，ＤＭ－ｔ～ｔ，Ｄ△ｔ～ｔ和Ｄ０～ｔ。通过相互比较发现，其中ＤＭ－ｔ的随时间变化在中强地震前的反应最为敏感。  相似文献   

RSM－16H动测仪在面波法岩土体检测中的应用   总被引：1，自引：0，他引：1  

黄嘉正  张学强  关小平 《岩土力学》1995,(2)

对在岩土体检测中推广应用的新技术──瑞雷面波法作了简述，介绍了ＲＳＭ－１６Ｈ型动测仪对稳态和瞬态面波资料的处理实例，并提出了对该仪器在面波测量中的软件改进建议。  相似文献   

工程地质类比分析的扩展及实现方法   总被引：5，自引：0，他引：5  

吕小平 《地质论评》1993,39(5):412-417

本文借助于计算机技术,将传统的工程地质类比方法作了扩展,称之为工程地质类比系统。根据地质体复杂多样的特点,提出了不追求概括出一般知识和它的应用,而是从每个个体的特征类比入手,把成功的经验、失利的教训应用到研究对象中去的模型及实现方法,它的应用能避免其它评价方法对条件的过于简化而产生的偏差,还能有助于发掘出隐含在地质体内还不被认识的有用信息,并加以利用。初步应用表明,该方法具有良好的适用性和发展前景。  相似文献   

隧道围岩分类的层次类比系统方法   总被引：1，自引：0，他引：1  

吕小平 《水文地质工程地质》1993,20(4):10-13

在本文中,把围岩分类的因素分为3种。第一种为大的地质环境,它主要包括地层、构造、地形等;第二种为围岩的小环境,它包括岩体结构、结构面的发育情况、地下水的分布等;第三种为围岩的物理、力学、水理以及埋深等具体参数。这3种因素从大到小形成一个层次递阶关系,下层元素是上层元素的具体表现,上层元素对下层元素产生影响。把用这种层次关系表征的典型工点集合,作为一个工程地质评价模型的基础。按典型工点的稳定性进行排序或进行聚类分析,再把新工点的稳定性权重与典型工点的稳定性权重序列或相似序列比较,找出新工点在典型工点序列中的相当位置,这样就可根据与新工点相近的典型工点围岩类别以及施工、支护等成功的设计参数或经验教训作为新工点的设计参数。  相似文献   

The status of the ecological environment and a proposed protection strategy in Sanya Bay,Hainan Island,China   总被引：8，自引：0，他引：8  

Huang L  Tan Y  Song X  Huang X  Wang H  Zhang S  Dong J  Chen R 《Marine pollution bulletin》2003,47(1-6):180-186

Sanya Bay encompasses a high diversity of natural habitats, ranging from coral reefs, rocky and sandy shores and mudflats to mangroves. Seasonal physicochemical and biological investigations were conducted from 1998 to 1999 and again in April 2000. Water-related environmental quality in Sanya Bay is in good condition. The levels of dissolved oxygen, nitrogen, phosphorus and heavy metals are within the first class of National Seawater Quality Standards for China. Annual mean values of chlorophyll a of 0.93 mg m(-3) and phytoplankton primary productivity of 440.8 mgC m(-2)d(-1), respectively, were found in the waters, both of which show a significant correlation with inorganic nitrogen. A mean new productivity of 144.6 mgC m(-2) d(-1) was recorded in summer. Sanya Bay is rich in natural resources and biodiversity with 235 species of phytoplankton and 129 species of zooplankton identified in the survey. The annual mean abundance of phytoplankton and zooplankton were 1564 x 10 cells m(-3) and 121 individuals m(-3), respectively, with an annual mean zooplankton biomass of 129 mg m(-3). A total of 243 species of fish were sampled in the survey including many of high economic value. Three hundred and eighty-four species of benthos in 121 families were found by mud sampling and trawling. The average biomass of benthic organisms was 11.55 gm(-2), with a density of 31 individuals m(-2). Molluscs were the dominant group, followed by crustaceans; coelenterates exhibited the lowest biomass. One hundred and twenty-six species from 48 families of intertidal organisms were collected by frame sampling, with a mean annual biomass of 644.7 gm(-2) and average density of 816 individuals m(-2). The highest biomass of 1673.5 gm(-2) was collected in a coral reef region, while the highest density of 1219 individuals m(-2) occurred in a mangrove region. The coastline is characterized by coral reefs that accounts for 30% of the total coastline length in the bay, so coral reefs are a key ecosystem that are important for maintaining the regional marine resources and biodiversity. We need to pay much more attention to such diverse marine resources to maintain the integrity and function of these coastal ecosystems.  相似文献   

Basic characteristics of active tectonics of China   总被引：84，自引：8，他引：76  

邓起东  张培震  冉勇康  杨晓平  闵伟  楚全芝 《中国科学D辑(英文版)》2003,46(4):356-372

Active tectonics is inferred to all the structures which have been active since the late Pleisto-cene, 100—120 ka B.P., are still active recently, and will be active in a certain time period in the future, such as active faults, active folds, active basi…  相似文献   

全球化、跨国公司投资与地区发展关系研究进展   总被引：5，自引：1，他引：4  

张晓平  刘卫东 《地理科学进展》2003,22(6):627-638

近年来,全球化力量成为影响区域经济发展及其空间格局演变的主要因素之一。在未来相当长一个时期内,全球化因素影响的深度与广度都将进一步扩展。随着经济活动全球化的发展,学术界有相当多的研究关注全球化、跨国公司投资及其社会经济影响。本文分别从国家、区域和企业三个不同的层面及全球化与区域发展互动的角度对现有的关于全球化、跨国公司投资与地区发展的相关研究进行总结和评述。  相似文献   

Experimental investigation of drag coefficients of gobi surfaces     

董治宝  屈建军  刘小平  张伟民  王训明 《中国科学D辑(英文版)》2002,45(7):609-615

The response of gobi surfaces to the near-surface air flow can be characterized quantitatively by drag coefficients. By using wind tunnel tests, an attempt is made to define the relationship between the drag coefficients of gobi surfaces and gravel size and coverage. It is concluded that the drag coefficients of gobi surfaces tend to be constants when gravel coverage is over 40%-50%. Consequently, we think that the gobi deflation planes expanding vastly in the arid Northwestern China are aerodynamically stable, at least not the supplying sources of current dust storms, and therefore the emphasis on dust storm control should be paid on the so-called "earth gobi" that has low gravel coverage. The prediction model for drag coefficients of gobi surfaces has been developed by regressing drag coefficients on gravel size and coverage, the predicted results are in reasonably good agreement with wind tunnel results (R 2 = 0.94). The change of drag coefficients with gravel friction Reynolds number implies that the development extent of drag effect increases with gravel size and coverage.  相似文献