如何做好气象物资装备供应管理     

蒋冬雁  陈平 《气象研究与应用》2019,40(1):115-117

气象事业的发展离不开先进的设备,做好气象物资的供应管理是保障气象发展的前提,是气象业务顺利开展的重要保障。加强气象物资的供应管理才能使各种物资最大限度的发挥作用,让各种物资达到最佳组合,节约资源,降低成本。本着节约、环保、高效的原则,依据《气象技术装备管理办法》,做好物资计划、采购、储备、配送等工作。本文主要简述基于节约、环保、高效原则,如何做好气象装备的储存、保管、供应各环节的工作。  相似文献   

Stress‐dependent hardening and failure surfaces of dry sand     

W. Ehlers  O. Avci 《国际地质力学数值与分析法杂志》2013,37(8):787-809

During several triaxial compression experiments on plastic hardening, softening, and failure properties of dense sand specimens, it was found on various stress paths that the size of the failure surface was not constant. Instead, it changed depending on the current state of hydrostatic pressure. This finding is in contrast to the standard opinion consisting of the fact that the failure surface remains constant, once it has been reached during an experiment or in situ. In general, the behaviour of cohesionless granular‐material‐like sand is somehow characterised in between fluid and solid, where the solid behaviour results from the angle of internal friction and the confining pressure. Although the friction angle is an intrinsic material property, the confining pressure varies with the boundary conditions, thus defining different solid properties like plastic hardening, softening, and also failure. Based on our findings, it was the goal of the present contribution to introduce an improved setting for the plastic strain hardening and softening behaviour including the newly found yield properties at the limit state. For the identification of the material parameters, a complete triaxial experimental analysis of the tested sand is given. The overall elasto‐plasticity concept is validated by numerical computations of several laboratory foundation‐ and slope‐failure experiments. The performance of the proposed approach is compared with the standard concept of a constant failure surface, where the corresponding yield surfaces are understood as contours of equivalent plastic work or plastic strain. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Internal erosion of chemically reinforced granular materials: a mathematical modeling approach     

Tony Khalil  Nadia Saiyouri  Bogdan Muresan  Pierre‐Yves Hicher 《国际地质力学数值与分析法杂志》2013,37(5):491-502

Internal erosion (IE) affects the stability of natural and reinforced materials by causing instability within their granular structure. The dislodgement and transport of eroded particles affect both the particulate concentration of eroding fluid and the pore network of eroded material. In this study, we examined these modifications using a transport model with a finite element code. First, IE tests on chemically reinforced sand columns were performed to obtain information about eroded material loss of mass, particulate concentration of effluent, porosity and permeability modifications, and existing IE stages. Second, based on experimental results, a mathematical one‐dimensional model has been formulated to monitor the evolution and spatial distribution of erodible solids, fluidized particles, porosity, permeability, and seepage stresses. The model consists of a set of coupled nonlinear differential equations solved in sequence. It provides valuable information about the extent and the dynamics of structural changes, which can be used to estimate an IE time for the hydraulic work to reach failure. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Attenuation properties of viscoelastic material     

Mohammad Qausar 《Pure and Applied Geophysics》1989,131(4):703-713

The attenuation properties of eight rheological models have been studied theoretically. The expressions forQ have been obtained by using dissipated and stored energies and/or complex modulus for each model. The dependence ofQ on frequency has been demonstrated. The three-element elastic model appears to be the best one to represent the viscoelastic nature of the earth's material for a finite value ofQ.  相似文献   

胶东金矿成矿系列硫同位素研究   总被引：24，自引：2，他引：24  

黄德业 《矿床地质》1994,13(1):75-87

胶东金矿的早晚两期成矿系列中，岩浆成因或在岩浆期即有天然水和表生矿质加入的矿床，δ＾３４Ｓ值均有自早而晚依次降低的规律。为重熔岩浆分异成矿理论和成矿系列的建立提供了重要证据。焦家式和某些晚期矿床，在形成矿液后有表生硫加入，扰乱了这一规律性。胶东群中的硫同位素没有达到均匀化，副变质岩偏重，而斜长角闪岩偏轻，接近陨石硫值，是近似原始岩浆的产物。  相似文献   

华南湘赣粤地区红层残积红土的工程地质研究     

ZuoQuan  Wang Qing  Tang Daxiong 《吉林大学学报(地球科学版)》1994,(1)

通过对红层残积红土的粒度成分、矿物成分、化学成分、物理化学特性、宏观结构、微观结构特征的全面系统分析，揭示红层残积红土不仅经历了物理风化作用，而且经受过红土化作用，具有红土的一般特点，是一种强度稍高，压缩性中等，含较多游离氧化物的超固结土。最后对红层残积红土的工程地质评价提出建议，认为其特性与母岩有关，砂砾岩、砂岩残积红土接近花岗岩残积红土；粉砂岩、泥岩残积红土接近红粘土，并对地基承载力和变形等问题提出具体的评价意见。  相似文献   

矿物热敏参数测试仪及其在地质找矿中的应用     

赵亨达  王忠荣 《岩石矿物学杂志》1994,13(2):175-186

介绍了国内外第一台矿物热敏参数测试仪研制的原理、应用范围和对一些金属矿物、半导体矿物的测试情况以及仪器在浙江、赣南等地区金矿找矿中的初步应用。  相似文献   

塔克拉玛干沙漠南缘绿洲沙物质粒度特征   总被引：16，自引：4，他引：16  

钱亦兵  张希明 《中国沙漠》1995,15(2):131-135

运用沉积物的粒度分析方法，研究了塔克拉玛干沙漠南缘绿洲不同类型沙样的粒度参数、粒度频率分布、平均粒径对标准差特性图等粒度特征及其空间关系，为查明沙源物质的性质和风力作用状况，分析风沙运动及风沙地貌形成，建立绿洲防护体系提供依据。  相似文献   

硅酸盐氧同位素标样研制   总被引：1，自引：0，他引：1  

刘敬秀 《岩矿测试》1990,9(4):276-282

本文介绍了硅酸盐氧同位素标准物质(SH和H)的研制。均匀性检验证实该标准物质是均匀的。该标准物质采用直接比较测量法标定,即直接与国际标准V-SMOW和SLAP进行比较。 国际标准水样采用CO_2-H_2O平衡法制备CO_2;石英标样采用BrF_5法制备CO_2。将六个定值实验室提供的数据统一处理后,获得SH和H的δ~(18)Ox/v-s_(MOW)值分别为11.11±0.06(‰)和-1.75+0.08(‰)。该标准物质于89年12月被国家技术监督局批准为国家一级标准物质,山阳石英标样(SH)统一编号为GBW04409,浒坑石英标样(H)为GBW04410。  相似文献   

广东化州大坡高岭土矿的物质成分和矿物学特性及其对造纸应用的影响     

周国平 《岩石矿物学杂志》1990,(3)

广东化州大坡高岭土矿属花岗岩风化残积型矿床,矿石矿物成分简单,以高岭石和石英为主,两者在粒级分布上差异明显,很易分选。精选后的高岭土中,高岭石含量可达91%,石英为1%以下。高岭石有序度较高,晶形规则,大多以叠片状和蠕虫状产出,但经机械处理后大部分可剥离成细小的高岭石单晶。矿石化学成分中Fe2O3,TiO2含量低,使高岭土具有较高的自然白度。造纸涂布试验表明高岭土的涂布性能良好,涂布纸具较高的平滑度,但涂料粘度偏高,这些性能和高岭石的矿物学特征有关。  相似文献