气象因子对金花梨生长发育的影响     

刘晓天  杨全勇 《河南气象》2006,(4):52-53

通过试验研究,探讨主要气象因子在唐河县的变化规律和对金花梨生长发育的影响,研究金花梨在遭受灾害性天气影响时,采取相应的技术措施,确保金花梨的高产、稳产。  相似文献   

Cohesive Crack Analysis of Toughness Increase Due to Confining Pressure     

Kazushi Sato  Toshiyuki Hashida 《Pure and Applied Geophysics》2006,163(5-6):1059-1072

Apparent fracture toughness in Mode I of microcracking materials such as rocks under confining pressure is analyzed based on a cohesive crack model. In rocks, the apparent fracture toughness for crack propagation varies with the confining pressure. This study provides analytical solutions for the apparent fracture toughness using a cohesive crack model, which is a model for the fracture process zone. The problem analyzed in this study is a fluid-driven fracture of a two-dimensional crack with a cohesive zone under confining pressure. The size of the cohesive zone is assumed to be negligibly small in comparison to the crack length. The analyses are performed for two types of cohesive stress distribution, namely the constant cohesive stress (Dugdale model) and the linearly decreasing cohesive stress. Furthermore, the problem for a more general cohesive stress distribution is analyzed based on the fracture energy concept. The analytical solutions are confirmed by comparing them with the results of numerical computations performed using the body force method. The analytical solution suggests a substantial increase in the apparent fracture toughness due to increased confining pressures, even if the size of the fracture process zone is small.  相似文献   

兰州台FSQ自记水管倾斜仪与CZB-1型竖直摆倾斜仪的对比分析     

余飞龙  龙艳  梅东林 《高原地震》2006,18(2):42-48

将兰州台的FSQ与CZB-1仪的观测资料质量、变化趋势、潮汐响应函数及映震能力进行了对比分析,认为:FSQ的观测资料的质量比CZB-1要好,因CZB-1的资料存在漂移现象;在潮汐因子和相位滞后方面,FSQ比CZB-1反应灵敏;但CZB-1的映震能力比FSQ强。  相似文献   

Study on the nutrient evolution and its controlling factors of Longgan Lake for the last 200 years     

LIU Jian  YANG Xiangdong  WANG Sumin 《中国科学D辑(英文版)》2006,49(Z1)

Based on the total phosphorous (TP) concentration in sediment core, the TP concentration in lake water quantitatively reconstructed from fossil diatoms and diatom-TP transfer function in the Longgan Lake during the last 200 years, the temperature and precipitation data from meteorological observation for the last 50 years, the temperatures and precipitation sequences of climate simulation for the last 200 years, as well as the amount of the agricultural phosphate fertilizer in Longgan area for nearly 50 years, the characteristic and the law of the nutrient status evolution were analyzed, and the influence of the climatic factor, the anthropologic factor and the aquatic biology factor on the nutrient status evolution and its mechanism were discussed for the Longgan Lake during the last 200 years. The results showed that, in the nearly 200 years, the TP concentration in the sediment core of the Longgan Lake gradually increased, its range of variation was situated between 330-580 mg/kg, the mean value was 388 mg/kg, a nearly 30-year vibration adjustment period existed at 1950 around. The TP concentration in lake water changed in a different way. Before 1950, it had a slow increasing tendency in fluctuated background, to 1950 around it reached up to the mean value (52.18μg/L), and vibrated and adjusted around the mean value, then it fast declined, its change range was situated between 37.75-62.33μg/L. The analyses indicated that, in the centennial time scale, the climate change was the main controlling factor, while in the decadal time scale in the recent 50 years, human activities were the leading factors for the nutrient status evolution of the Longgan Lake. 60% of the variability of the TP concentration in the sediments and 57% of that in lake water were due to human activities. The differentiation between phosphorus concentration in the sediment and in the lake water reflected the response processes and the adjustment abilities of the lake aquatic ecosystems to the lake nutrient level, implying the maintenance and the destruction of the balances between the algae and the aquatic plants, as well as the corresponding accumulating characteristics of the phosphorus.  相似文献   

煤矿瓦斯浓度与气象因子相关分析及预报模型   总被引：2，自引：0，他引：2  

韩虹  康中华李胜韩文琦  刘勇明 《气象科技》2006,34(6):796-798

对山西省大同市地方煤矿1979~1997年发生的90起重大典型事故案例进行分析,发现瓦斯事故是发生次数最多,占事故总数的33%,而其造成的灾害也最重。瓦斯浓度的高低与气象因子具有一定的相关性,通过统计计算,得出了旬瓦斯浓度与旬气温、旬气压的相关关系,建立了旬瓦斯浓度预报模型和逐日瓦斯浓度等级预报模型,预报拟合率和试报效果较好。利用该研究成果,结合中短期天气预报,可以提前预报瓦斯浓度的变化趋势,对于搞好煤矿安全生产的管理,及时加大通风,减少事故发生具有重要意义。  相似文献   

柴达木盆地北缘结绿素-红山地区古新统至中新统沉积相   总被引：4，自引：2，他引：4  

金振奎  齐聪伟  薛建勤  王春生 《古地理学报》2006,8(3):377-388

根据柴达木盆地北缘露头剖面、钻井剖面的地层学和岩石学研究所取得的各种定量及定性资料,采用冯增昭教授倡导的单因素分析多因素综合作图法,编制了柴达木盆地北缘结绿素—红山地区古新统—始新统、渐新统和中新统的各种单因素图和沉积相图。这是首次将定量的沉积相研究方法应用于柴达木盆地的古新统至中新统。结绿素—红山地区古新统至中新统发育2种沉积相类型,即冲积扇和辫状河。其中辫状河可划分为砾质辫状河和砂质辫状河。古新世—始新世发育冲积扇—辫状河—湖泊沉积体系,渐新世—中新世发育辫状河—湖泊沉积体系。从古新世到中新世,柴达木盆地北缘经历了由大规模冲积扇沉积到辫状河沉积的演化过程。  相似文献   

塔里木地区寒武纪岩相古地理   总被引：2，自引：5，他引：2  

冯增昭  鲍志东  吴茂炳  金振奎  时晓章 《古地理学报》2006,8(4):427-439

塔里木地区是以当今的塔里木盆地为主体并包括其周边山地的广大地区,北至中天山,南至西昆仑山,西至我国国界,东至阿尔金山,面积逾100万km2。在39个露头剖面和钻井剖面的各种单因素定量及定性资料的基础上,采用单因素分析多因素综合作图法,编制出了塔里木地区寒武系下、中、上统的各种单因素图及相应的寒武纪早、中、晚世的岩相古地理图。这些岩相古地理图最主要的特征是定量,即每个古地理单位的划分和确定都有确切的定量资料与定量的单因素图。这种定量的岩相古地理图在塔里木地区还是首次出现。在早寒武世,塔里木地区是一个碳酸盐岩台地,其中散布着准滩、云坪和膏盐湖。其北侧和东北侧是南天山和塔东硅岩石灰岩泥岩盆地。其南侧是昆仑台地,其中有2个小陆地。其东南侧有阿尔金陆。中寒武世和晚寒武世的岩相古地理格局与早寒武世相似,但陆地面积逐渐缩小,盆地面积逐渐扩大,塔里木碳酸盐岩台地变化不大。从早寒武世到晚寒武世是一个逐渐的海进过程。  相似文献   

大庆油田葡萄花油层组储层非均质性主控因素分析   总被引：6，自引：0，他引：6       下载免费PDF全文

单敬福  纪友亮 《沉积与特提斯地质》2006,26(4):95-100

本文对萨尔图油田中部葡萄花油层组的非均质性进行定量半定量研究,认为葡萄花油层组PⅠ2小层层内非均质性最严重,与沉积微相密切相关;单砂层垂向上渗透率的变化以正韵律和复合式韵律为主,局部发育反韵律模式;层内非均质性强弱依次为PⅠ2a、PⅠ3、PⅠ2b、PⅠ1、PⅠ4;层间非均质性在PⅠ3和PⅠ4间表现得最强,其它相对要弱;各小层平面非均质性相差无几,整体表现为较强的非均质性。  相似文献   

滑坡稳定性分析与安全系数取值研究   总被引：5，自引：0，他引：5  

徐青  陈士军  陈胜宏 《中国地质灾害与防治学报》2006,17(3):58-62

在地质灾害中,滑坡灾害分布最广、发生频率最高、危害最大,是我国地质灾害防治的主要对象。滑坡研究的主要任务之一是稳定性分析。论文针对三板溪水电站进水口滑坡和水布垭水电站大岩淌滑坡,分别采用刚体极限平衡法、块体单元法、有限单元法对稳定安全系数和条间推力分布曲线进行分析和比较,研究各种方法的差异和计算精度,以及各种方法稳定安全系数的取值标准,希望为水利水电工程边坡设计规范有关有限单元法、块体单元法条目的编写和相应的允许安全系数取值标准的制定提供一定的参考。研究结果表明:①块体单元法计算的安全系数与刚体极限平衡法计算的安全系数可以采用相同的取值标准,而有限单元法计算的安全系数取值标准可适当降低;②块体单元法计算的条间水平推力、条间剪切力与刚体极限平衡法(尤其是Sarma法)计算的条间水平推力、条间剪切力非常相近,有限单元法计算的条间水平推力、条间剪切力较小;③分析方法、力学模型与参数取值应与安全系数取值标准相匹配。  相似文献   

采矿引起的边坡倾倒滑移变形机理与变形安全性分析研究—以抚顺西露天矿边坡为例   总被引：1，自引：0，他引：1  

申力  纪玉石  刘大勇  祖国林  刘晶辉 《中国地质灾害与防治学报》2006,17(3):63-68

在矿山开发、水电建设过程中倾倒变形问题日渐突出。倾倒变形边坡一般具有反倾边坡结构,变形的过程和机理比较复杂、涉及的变形岩体范围较大、危害严重。论文以抚顺西露天矿边坡为例,通过岩体位移监测资料的跟踪分析、底面摩擦模拟试验,以岩体力学、松散介质力学原理为理论基础,探讨了采矿影响下边坡倾倒滑移体的变形机理,分析认为采矿引起的倾倒滑移变形问题是在特定的地质构造和采矿工程条件下产生的,并提出了岩体变形安全性分析方法。通过工程实例,验证了方法的实用性,并针对实际问题提出了变形整治对策。  相似文献