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991.
992.
1 INTRODUCTION Sitting in the central part of the Pearl River Delta, Guangzhou is one of the cities in China that are most polluted by acid rain. Broad attention has been brought to the problem. Since the early 1980s, a series of observation and studies h… 相似文献
993.
The interannual variations of atmospheric heat sources and moisture sinks over the Equatorial Pacific and their relations with the SST anomalies are studied using ECMWF reanalysis data from 1979 to 1993. It is found by singular value decomposition (SVD)… 相似文献
994.
The characteristics of atmospheric heat source associated with the summer monsoon onset in the South China Sea (SCS) are studied using ECMWF reanalysis data from 1979 to 1993. A criterion of the SCS summer monsoon onset is defined by the atmospheric hea… 相似文献
995.
安徽淮河构造变形带及邻近块体现代构造应力场特征 总被引:3,自引:1,他引:3
针对安徽省较特殊的构造环境及历史地震分布特点,利用直达波最大振幅比和系统聚类分析方法,在对安徽淮河中游区1974年以来近百个中小地震震源机制反演、聚类及空间合成的基础上,分析了华北断块南缘的安徽淮河构造变形带及邻近块体震源断层滑动方式、构造应力场分布及块体运动方式、应力场随时间变化等。结果显示:淮河构造变形带及其邻近块体上震源断层总体上以近走滑型或斜滑型破裂为主,但倾滑型破裂也占一定比例;该地区构造应力以水平作用为主,但也存在一定的垂向作用。其中淮北和皖中块体仍可能分别向SWW和NEE方向运动,并在淮河构造变形带上产生左旋剪切作用,呈现一定的继承性活动特征;各块(带)上主压应力P轴走向随时间的变化在总体上较为一致,而各时段之间P轴方位存在一定差异,显示安徽淮河中游区受华北和华南应力场的共同作用,但其地震活动可能主要受控于华北应力场。 相似文献
996.
Global monsoons in the mid-Holocene and oceanic feedback 总被引:10,自引:3,他引:10
The response of the six major summer monsoon systems (the North American monsoon, the northern Africa monsoon, the Asia monsoon, the northern Australasian monsoon, the South America monsoon and the southern Africa monsoon) to mid-Holocene orbital forcing has been investigated using a coupled ocean–atmosphere general circulation model (FOAM), with the focus on the distinct roles of the direct insolation forcing and oceanic feedback. The simulation result is also found to compare well with the NCAR CSM. The direct effects of the change in insolation produce an enhancement of the Northern Hemisphere monsoons and a reduction of the Southern Hemisphere monsoons. Ocean feedbacks produce a further enhancement of the northern Africa monsoon and the North American monsoon. However, ocean feedbacks appear to weaken the Asia monsoon, although the overall effect (direct insolation forcing plus ocean feedback) remains a strengthened monsoon. The impact of ocean feedbacks on the South American and southern African monsoons is relatively small, and therefore these regions, especially the South America, experienced a reduced monsoon regime compared to present. However, there is a strong ocean feedback on the northern Australian monsoon that negates the direct effects of orbital changes and results in a strengthening of austral summer monsoon precipitation in this region. A new synthesis is made for mid-Holocene paleoenvironmental records and is compared with the model simulations. Overall, model simulations produce changes in regional climates that are generally consistent with paleoenvironmental observations. 相似文献
997.
未定名矿物(Bi38CrO60)的矿物学研究 总被引:2,自引:0,他引:2
人工合成立方晶体Bi38CrO60在自然界首次发现于中国陕西省洛南县驾鹿金矿床中,暂称之为未定名矿物.其共生和伴生矿物有黄铁矿、自然金、碲金矿、含氧金矿物等.常呈不规则粒状集合体,偶见立方体微晶(粒径小于0.05 mm),棕黑色,金属光泽;HV=232.78 kg/mm2 ,HM=4.15;D=14.10(3)g/cm3,Dx=14.08(2)g/cm3,n=3.14(3).EPM8100探针分析Bi2O3为98.854%、CrO3为1.111%,合计99.965%,化学式为Bi38.009Cr0.995O60;CAMEBAX-SX51探针分析Bi2O3为98.862%,CrO3为1.112%,合计99.974%,化学式为Bi38.008Cr0.996O60.均可写为Bi38CrO60.X射线粉晶分析主要强度线d(I)(hkl)分别为0.321 5(100),(310);0.272 11(72),(321);0.171 45(40),(530);0.169 6(30),(600);0.165 1(30),(611);0.160 8(30),(620);0.294 11(25),(222);0.359 6(22),(220);0.217 1(20),(332);0.150 3(20),(631),等轴晶系,可能的空间群为Im3m;a=1.018 1(1)nm,c/a=1,晶胞体积v=1.055 29(1)nm3,z=1.1-Kp/Kc=0.019.Cr6 ,Bi3 ,O2-.未定名矿物和人工晶体的化学成分与X射线粉晶数据基本一致. 相似文献
998.
In this study, the relationship between fluorine in drinking water and that in urine of urban residents in China is assessed. Fluorine concentrations in tap water and those in urine show a good correlation with a linear regression coefficient of 0. 9798, indicating that the fluorine concentrations in big cities under investigation are extremely low, and the main source of fluorine is tap water. The weather effect on the intake amount of fluorine is also discussed. When air temperature is above 15℃, people would intake more fluorine through drinking water with the rise of air temperature. When temperature is below 15℃, no remarkable relationship is observed between air temperature and the intake amount of fluorine. This phenomenon indicates that the main source of fluorine in China is tap water instead of foodstuff. 相似文献
999.
Environmental Properties of Minerals and Contaminants Purified by the Mineralogical Method 总被引:2,自引:0,他引:2
The investigation of the environmental properties of minerals, i.e., environmental mineralogy, is a branch of science dealing with interactions between natural minerals and spheres of the Earth surface as well as a reflection of global change, prevention of ecological destruction, participation in biomineralogy, and remediation of environmental pollution. Pollutant treatment by natural minerals is based on the natural law and reflects natural self-purification functions in the inorganic world, similar to that of the organic world - a biological treatment. A series of case studies related to natural self-purification, which were mostly completed by our group, are discussed in this paper. In natural cryptomelane there is a larger pseudotetragonal tunnel than that formed by [MnO6] octahedral double chains, with an aperture of 0.462-0.466 nm2, filled with K cations. Cryptomelane might be a real naturally-occurring mineral of the active octahedral molecular sieve (OMS-2). CrⅥ-bearing wastewater can be treate 相似文献
1000.
1IntroductionThecarbonisotopiccompositionofnaturalgasesisregardedasacontanttracerusedinthegeochemicalresearchofnaturalgases .Basedonthecarbonisotopiccomposition ,thegenetictypesofnaturalgasesarebasicallydividedtodeterminethematurationofnaturalgasesandmakegas sourcecorrelations (Stahl,1 973;StahlandCarey ,1 975;Stahletal.,1 977;James ,1 983;Schoell,1 983,1 988;DaiJinxingetal.,1 992 ;FuJiamoetal.,1 992 ;XuYongchang ,1 994 ) .Theformationofnaturalgasescouldbededucedintermsofcarbonisotopicvar… 相似文献