中国粮食产量保险费率的订定方法和保险费率区划   总被引：3，自引：0，他引：3  

周玉淑  邓国  齐斌  张敏 《南京气象学院学报》2003,26(6):806-814

在分析切比雪夫大数定律的保险学意义的基础上，对粮食产量资料经过合适的处理，并参照美国、日本、台湾等国家和地区保险费率的计算方法，计算了中国全国范围内保险费率的数值。计算的结果与国内其他同样的保险费率的数值相比较，数量级相同但更加稳定可靠。最后采用动态迭代自组织聚类算法将保险费率在全国分区，给出了全国保险费率的分布情况，这些数值还可根据保险实践适当修改，结果可为防灾减灾和保险公司业务运行提供参考。  相似文献   

潘谢矿区新生界底部沉积物水文地质特征及结构分区     

李垚 《中国煤田地质》2003,15(5):32-33,49

淮南煤田潘谢矿区新生界底部沉积了“下含”、“红层”、“碎石层”、“砂砾岩”等地质沉积物，在分析沉积物的岩性特征、分布规律、水文地质特征的基础上，根据沉积物的含、隔水性特征进行了危险性分区，明确其对矿井回采工作的影响。  相似文献   

松辽东缘羊草沟盆地层序地层划分与地层对比     

张海龙  王敬 《吉林地质》2003,22(4):4-10

羊草沟盆地位于松辽盆地东南缘,其地层可与松辽盆地地层对比。羊草沟盆地层序(三级)地层应与松辽盆地Ⅰ～Ⅹ层序(火石岭组、沙河子组、营城组、登娄库组和泉头组)地层相对应。羊草沟盆地地层应该划分为侏罗系上统火石岭组(J3h);白垩系下统沙河子组(K1sh)、营城组(K1y)、大羊草沟组(K1d)和泉头组(K1q);第四系(Q)。主要可采工业煤层产在大羊草沟组。  相似文献   

Microbial fossilization in carbonate sediments: a result of the bacterial surface involvement in dolomite precipitation   总被引：14，自引：1，他引：14  

Yvonne Van Lith  Rolf Warthmann  Crisogono Vasconcelos  Judith A. McKenzie 《Sedimentology》2003,50(2):237-245

ABSTRACT Recent dolomitic sediment samples from Lagoa Vermelha, Brazil, were examined microscopically to study the process of bacterial fossilization in carbonate sediments. Bacteria‐like bodies were intimately associated with carbonate mineral surfaces, and coatings on the former demonstrate the calcification of single bacterial cells. The bacterial fossilization process in Lagoa Vermelha sediments was simulated in the laboratory by cultivation of mixed and pure cultures of sulphate‐reducing bacteria, which were isolated from the Lagoa Vermelha sediments. These cultures produced carbonate minerals that were studied to provide insight into the initiation of the fossilization process. In mixed culture experiments, bacterial colonies became calcified, whereas in pure culture experiments, single bacterial cells were associated with dolomite surfaces. Dolomite nucleated exclusively in bacterial colonies, intimately associated with extracellular organic matter and bacterial cells. Electrophoretic mobility measurements of the bacterial cells in electrolyte solutions demonstrated the specific adsorption of Ca²⁺ and Mg²⁺ onto the cell surfaces, indicating the role of the bacterial surface in carbonate nucleation and bacterial fossilization. The affinity of the cells for Mg²⁺ was related to the capability of the strains to mediate dolomite formation. Combined with sulphate uptake, which dissociates the [MgSO₄]⁰ ion pair and increases the Mg²⁺ availability, the concentration of Mg²⁺ ions in the microenvironment around the cells, where the conditions are favourable for dolomite precipitation, may be the key to overcome the kinetic barrier to dolomite formation. These results demonstrate that bacterial fossilization is a consequence of the cell surface involvement in carbonate precipitation, implying that fossilized bacterial bodies can be used as a tool to recognize microbially mediated carbonates.  相似文献   

非线性反演方法的新进展   总被引：4，自引：1，他引：4  

贺传松  王椿镛 《地震地磁观测与研究》2002,23(6):9-17

线性方法在许多具体反演问题中遇到困难的情况下，人们提出了非线性方法，同时，计算技术的发展为非线性方法的应用提供了基础。最近几年，人们对非线性方法又进行了改进和发展，例如：Vasco(1993)提出了集合推论的思想；Sambridge(1995)基于Voronoi单元的思想，提出了自然相邻对不规则数据参数化和插值的方法，相邻算法正是基于以上思想和理论，以及其他非线性方法的实践而提出的一种新的非线性反演方法。  相似文献   

对流涡自组织过程的数值研究     

薛具奎  胡隐樵 《高原气象》2002,21(4):354-358

利用一个简化的浅对流模式，从非线性热力学观点出发，分析了热对流涡的自组织过程，揭示了系统熵收支与对流涡的形成及发展过程的关系。结果表明，系统失稳构成了对流涡形成的触发过程；在对流涡的发展过程中，涡的非线性自组织是对流涡组合兼并的动力学原因，而与这一过程相对应的负熵流是引起涡自组织并最终维持对流涡有序结构的非线性热力学原因。  相似文献   

绿山设计软件在三维地震勘探中的应用   总被引：1，自引：2，他引：1  

牛鹏程 《中国煤田地质》2002,14(3):57-59

绿山设计软件是三维地震勘探野外观测系统的设计软件,其依据测区的地质、地球物理参数以及地理条件,可以生成多种符合要求的观测系统。考虑各种参数的相互制约及相互影响因素,根据东欢坨三维地震勘探项目的要求,利用绿山设计软件,求证了各种参数的设计流程及控制方法,布设特殊的观测系统,达到了勘探目的。  相似文献   

阴山东段(冀北及冀晋内蒙古接壤地带)的太古宙地层问题讨论   总被引：3，自引：0，他引：3  

王启超  牛树银  肖文暹  王礼胜  张少卿  王琴廷 《地层学杂志》2002,26(1):55-61,72

在对区内太古宙地层的原岩性质、大的层序、同位素地质测年值的地质意义 (主要是 H2 O、CO2 流体作用在变质作用中能否造成同位素的开放及 TDM值能否反映为变质年龄 )等众多认识分歧进行剖析的基础上 ,将其自下而上划分为桑干岩群、集宁群、单塔子群、红旗营子群 (或称乌拉山群 ) ,其时代依次归属中太古代早期 (330 0—30 0 0 Ma)、晚期 (30 0 0— 2 80 0 Ma)及新太古代早期 (2 80 0— 2 6 5 0 Ma)、中期 (2 6 5 0— 2 5 6 0 Ma)  相似文献   

浙江省仙居县地质灾害调查与区划   总被引：4，自引：0，他引：4  

曹恺  孟高头等 《地球科学》2002,27(2):217-221

结合地质灾害调查与区划项目中“以人为本”的思想,在调查仙居县具体地理情况、地质环境的基础上，分析了对地质灾害起控制作用的因素，建立了敏感因子评估模型，由于地质灾害致灾害因素的复杂性及不确定性，引进了模糊数学综合评判法，对地质灾害进行区划，依据区划结果在仙居县土地规划提出了切实可行的建议。  相似文献   

High-pressure phase transition and behavior of protons in brucite Mg(OH)2: a high-pressure–temperature study using IR synchrotron radiation     

K. Shinoda  M. Yamakata  T. Nanba  H. Kimura  T. Moriwaki  Y. Kondo  T. Kawamoto  N. Niimi  N. Miyoshi  N. Aikawa 《Physics and Chemistry of Minerals》2002,29(6):396-402

 Infrared absorption spectra of brucite Mg (OH)₂ were measured under high pressure and high temperature from 0.1 MPa 25 °C to 16 GPa 360 °C using infrared synchrotron radiation at BL43IR of Spring-8 and a high-temperature diamond-anvil cell. Brucite originally has an absorption peak at 3700 cm⁻¹, which is due to the OH dipole at ambient pressure. Over 3 GPa, brucite shows a pressure-induced absorption peak at 3650 cm⁻¹. The pressure-induced peak can be assigned to a new OH dipole under pressure. The new peak indicates that brucite has a new proton site under pressure and undergoes a high-pressure phase transition. From observations of the pressure-induced peak under various P–T condition, a stable region of the high-pressure phase was determined. The original peak shifts to lower wavenumber at −0.25 cm⁻¹ GPa⁻¹, while the pressure-induced peak shifts at −5.1 cm⁻¹ GPa⁻¹. These negative dependences of original and pressure-induced peak shifts against pressure result from enhanced hydrogen bond by shortened O–H···O distance, and the two dependences must result from the differences of hydrogen bond types of the original and pressure-induced peaks, most likely from trifurcated and bent types, respectively. Under high pressure and high temperature, the pressure-induced peak disappears, but a broad absorption band between 3300 and 3500 cm⁻¹ was observed. The broad absorption band may suggest free proton, and the possibility of proton conduction in brucite under high pressure and temperature. Received: 16 July 2001 / Accepted: 25 December 2001  相似文献