FACTORS CONTROLLING DIFFERENTIATION OF SELENIUM ECONVIRONMENT IN THE LOESS PLATEAU

ItisataskofNationaScienceandTechnologyProjectNo.75-62-03-05and06forthe7thFive-YearPlanperiod.InvestigationsinGansuandShanxiwereundertakenbyInstituteofGeography,CAS,whiiethatinShaanxiwascarriedoutbyNortllwestInstitllteofWaterandSoilConservation,CAS.**OthermembersintheGroupofEndemicDiseaseandEnvironment,InstituteofGeograpl1y,CASare:YangLinsheng,ZhaoYuanwei,ZhaoNaiqin,LiDezhu,WangLizhenandTanJianan.I.IntrodIlcti01llthasbeenreported[21thattwoendemics,KeshanandKaschin-Beck,arecl…     

辉碲铋矿单矿物的化学分析

辉碲铋矿物经ＨＮＯ３－ＫＣｌＯ３溶解，用火焰原子吸收法或乙二胺四乙酸二钠事滴定法测定Ｂｉ，火焰原子吸收法测定Ｔｅ、Ｆｅ、Ｃｕ，３，３＇－二氨基联苯胺光度法测定Ｓｅ，硫酸重量法测定Ｓ。其结果与矿物化学成分理论值十分接近，主、次量元素平行测定６次，其ＲＳＤ小于０．８％，痕量元素ＲＳＤ（ｎ＝６）小于１０％。     

地壳岩石的渗透性状及孔隙水对岩石力学性质的影响

本文概述地壳岩石渗透性状和孔隙水对岩石力学性质影响的研究现状及已取得的成果;指出孔隙压的形成及分布,孔隙度、渗透率与孔隙压的关系。孔隙压的有效应力,孔隙压对岩石形变。破裂机制的影响以及从断裂力学观点考察孔隙压的作用等系今后该领域研究的主要课题和发展方向。     

根据波速-压力关系评价岩石岩性、物性的实验研究

本文在实验室里对老爷庙油田馆陶组（Ng）油气贮层砂岩岩芯的孔隙度φ、空气渗透率κ、骨架密度ρ_ma、岩石密度ρ_b和不同有效覆盖压力△P下岩芯的声波时差△t,做了精确测量,用回归分析拟合了φ-K、φ-ρ_b、φ-△t和V-△p（△t-△p）的经验关系式;保持原始孔隙结构不变的前提下,在岩芯饱和各种矿化度的孔隙流体时测定了声波时差△t与孔隙度φ的关系.研究结果表明,当贮层的φ-K、φ-ρ_b和φ-△t相关时,可用声波时差△t或波速V解释贮层的岩性,并可反演求出贮层的φ、K和ρ_b;地层有效覆盖压力对贮层的孔隙度和波速具有明显的影响.根据V-△p曲线的变化规律,可以评价贮层的岩性和埋藏地质体的油、气储集能力.这些结果对油田地震勘探和石油测井资料的解释具有重要的参考价值,并为预测储油有利地区和评价贮层提供了一种新的途径.     

水平电偶源频率测深中全区视电阻率定义的新方法

从电磁场的统一性出发，分析了水平电偶源频率测深中等效电阻率的算法原理和具体定义．分析表明，等效电阻率可明显地改善波区视电阻率在非波区场的畸变，较为形象、直观地反映出地电断面的电性变化．数值计算、三维模型计算和实际数据处理表明，等效电阻率具有良好的特性和应用前景．     

Evaluating assumptions for seismic assessment of existing buildings

This paper evaluates the American FEMA 356 and the Greek GRECO (EC 8 based) procedural assumptions for the assessment of the seismic capacity of existing buildings via pushover analyses. Available experimental results from a four-storeyed building are used to compare the two different sets of assumptions. If the comparison is performed in terms of initial stiffness or plastic deformation capacities, the different partial assumptions of the procedures lead to large discrepancies, while the opposite occurs when the comparison is performed in terms of structural performance levels at target displacements. According to FEMA 356 assumptions, effective yield point rigidities are approximately four times greater than those of EC 8. Both procedures predicted that the structure would behave elastically during low-level excitation and that the structural performance level at target displacement for a high-level excitation would be between the Immediate Occupancy and Life Safety performance levels.     

农业资源高效利用评价指标体系初步研究

本文从农业自然再生产和经济再生产统一体和整体性的角度出发 ,在阐述构建农业资源高效利用评价指标体系宜遵循的基本原则的基础上 ,通过对农业资源的农业生产行为特征及高效利用途径进行系统分析 ,筛选、构建和设计出了农业资源高效利用评价指标体系 ,并对其中的重要指标进行了讨论。     

EFFECTIVE DISCHARGE CALCULATION GUIDE

1 mTRonvcnox: moareS Aun CoxcmSAJluvial rivers have the pOtenhal to adjust their shaPe and dimensions to all flows that tranSPOrtsediment, but Inglis (l94l) suggested that, for rivers that are in regime, a single steady flow could beidenhfied which would Produce the same bankfll dimensions as the natural sequence of events. Hereferrd to this now as the dondnan discharge.Wolman and Mller (l960) idenhfied that the flow doing most bed material transPort over a period ofyears may be taken tO…     

氢化物发生—原子荧光光谱法测定煤样中的硒

采用氢化物发生原子荧光光谱法测定了煤样中的总Se。煤样选用高压闷罐强酸消解的方法进行处理，所得消解液经6mol/L HCl将Se（Ⅵ）还原为Se（Ⅳ），然后进行测定。标准工作曲线的线性范围为0－400μg/L Se，检测限为0.4μg/L Se。用标准参考物质煤飞灰对方法进行了验证，所得总Se含量与标准值相符，对ω为10^-6级Se的4次测定，RSD≤4.5％。     

湖州台的近震监测能力

本文根据湖州地震台DD-1地震仪记录的1980—1990年期间Δ<500km的近震资料和仪器放大倍率,利用理论计算Δ—Mmin曲线,b值检验3种方法,对湖州台的近震监测能力进行了估算和评价,得出了该台对目标监测区域内的有效监测震级。最后对区域地震台站的近震监测能力进行了讨论。