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1.
澜沧铅锌银铜矿床矿物包裹体及成矿物化条件的研究   总被引:4,自引:0,他引:4  
李虎杰  田煦 《矿产与地质》1995,9(2):107-111
矿物流体包裹体的研究表明,澜沧铅锌银铜矿床成矿流体的温度为160 ̄350℃,压力69000kPa,盐度4.6 ̄17.0NaClwt%,密度0.85 ̄1.0g/cm^3,fs210^-9.3 ̄10^-11.0Pa,fo210^-35 ̄10^-37Pa,Ph值5.1 ̄5.7。成矿元素主要以氯化物络合物的形式迁移、温度降低,fs2和pH值的升高是引起矿物质沉淀的主要因素。  相似文献   

2.
李维华  段玉然 《岩矿测试》1999,18(1):19-20,24
采用光散射技术,促使氢分子产生转动跃迁,得到正氢和仲氢的转动拉曼光谱,其峰位为587.4、1035.1、354.9和814.7cm^-1。通过测定正氢和氢的拉曼峰587.4和354.9cm^-1的强度,得到氢气样品中正-仲氢质量比为(2.94 ̄3.04):1,与理论计算值3:1吻合。  相似文献   

3.
析相萃取光度法测定法质样品中痕量钯   总被引:3,自引:0,他引:3  
研究了表面活动剂加醇析相对钯-硫代米Chi酮络合物的萃取行为,建立了痕量钯的光度测定方法。析相对Pd的萃取回收率为99.5%,富集倍率搂25。络合物的λmax=530nm,形成后至少稳定2h,ε达2.6×10^6L·mol^-1·cm^-1,线性范围1.4 ̄40.0μg/LPd(Ⅱ),检出限是1.4μg/L,对于10μg/LPd测定11次,计算相对标准偏差为4.4%。方法已用岩矿中痕量钯的测定,结  相似文献   

4.
通过对华东地区21个铀矿区内居民居住环境大气中氡与其子体α潜能浓度的调查,居民居室外氡浓度均值范围为6.73~132.Bq/m^3,氡子体α潜能浓度均值范围为11.0~78.8hJ/m^3。居室内的平均氡浓度范围为14.5~185.8Bq/m^3,氡子体α潜能浓度均值范围为13.8~104.2nJ/m^3;对居民饮用水源的取样分析表明,铀的均值范围为0.12~1.68μg/L,钍的均值范围为0.02~0.42μg/L,镭--226的均值范围为0.90~12.1mBq/L,与全国和当地的放射性天然本底水平比较接近,均属正常本底水平。  相似文献   

5.
研究了Al^3+与间硝基偶氮氯膦显色反应。在pH5.3HAc-NaAc缓冲溶液中,Al^3+与间硝基偶氮氯膦形成的络合物最大吸收位于656nm,表观摩尔吸光系数εmax=1.76×10^4L·mol^-1·cm^-1,Al在浓度0 ̄1.0μg/ml范围内遵守比尔定律。本方法已用于沸石分子筛中Al的分析,结果令人满意。  相似文献   

6.
乙基紫光度法测定地质样品中痕量铊   总被引:5,自引:0,他引:5  
试样分解后制成硫酸溶液,在0.5mol/LHBr-0.1mol/LH2SO4混酸介质中,用乙酸异戎酯萃取Tl^3+,测量有机相中铊配合物吸光度,本法准确,灵敏,ε值达1.2*10^5L.mol.cm^-1,相对标准偏差〈8%,适用于多种复杂试样分析。  相似文献   

7.
TritonX—100—5—Br—PADAP光度法测定铜和镍   总被引:2,自引:0,他引:2  
萨木嘎  刘颖 《岩矿测试》1999,18(4):291-294
研究了非离子型表面活性剂TritonX-100存在下,用5-Br-PADAP光度法测定铜镍的方法。结果表明:在PH9.0的硼砂缓冲介质中,5-Br-PADAP与铜和镍生成紫红色络合物,λmax^Cu=575nm,εCu=1.04×10^5L·mol^-1·cm^-1,λmax^Ni=575nm,εNi=1.14×10^5L·mol^-1·nm^-1。铜和镍的质量浓度分别在0 ̄560μg/L和0 ̄5  相似文献   

8.
冯泳兰 《岩矿测试》1999,18(4):311-313
研究了新合成的1-(2-羟基-3,5-二硝基苯基)-3-「4-(苯基偶氮)苯基」-三氮烯(HDNPAPT)试剂与铜的显色反应。在乳化剂OP存在下,PH11.0的Na2B4O7-NaOH介质中,铜与HDNPAPT形成的红色配合物,其组成比为1:2,λmax=540nm,表观摩尔吸光系数ε540=1.73×10^5L·mol^-1·cm^-1,铜的质量浓度在0 ̄360μg/L符合比尔定律。方法应用于大  相似文献   

9.
在PH3.4时,铱能与碘化钾、丁基罗丹明B型成紫色络合物,其组成比Ir4+:I^-:BRhB^+=1:6:2,最大吸收波长为610nm,ε=1.36×10^5L.mol^-1.cm^-1,铱在(0-8)μg/25ml范围时服从比尔定律,采用阳离子交换树脂分离大量基体离子,可对冶金物料中微量铱进行测定。  相似文献   

10.
福建首次发现软玉   总被引:3,自引:0,他引:3  
最近在福建南平地区发现软玉,其质地细腻,白色-浅绿色,RI=1.61 ̄1.62,密度2.979 ̄2.989g/cm^3,硬度6.0 ̄6.1,矿物成分较为简单,为透闪石,局部含少量透辉石包裹体。化学成分接近于透闪石的理论成分,FeO的含量很低,是一种品质较好的玉雕材料。  相似文献   

11.
第四纪时期东亚季风变化的动力机制   总被引:41,自引:8,他引:41       下载免费PDF全文
本文作者主张:古气候演化的动力机制研究应从动力因子和动力过程两个方面人手。通过对比东亚冬季风、夏季风、印度季风及全球冰量变化的时间特征和频率特征,我们得到以下认识:1)大致在过去0.8Ma这个时段,东亚冬、夏季风基本上具同相位、同周期的互为消长演化特征;2)东南季风演化具0.1Ma的主导周期,而印度季风变化则以较短周期为主;3)东亚冬、夏季风与全球冰量变化在时间范畴上可作很好的对比,尤其是这三者均含有主导性的0.1Ma周期。在此基础上,本文提出东亚季风演化的“全球冰量驱动模式”,并初步讨论了东亚季风变化对全球冰量变化响应的动力过程。  相似文献   

12.
利用美国国家大气研究中心(NCAR)的CCSM2.0全球气候系统模式,并结合重建的古地理资料,研究了晚白垩世(80Ma)东亚气候特征以及CO2浓度变化对东亚气候的影响。模拟结果表明: 与现代气候比较,晚白垩纪时期的东亚大陆冬季风和夏季风都偏强,具有同步变化的特点,并且中高纬度年平均地表气温明显增加,而低纬度地区有所下降,年降水变化的区域性特征明显; 就年平均而言,在 30°~40°N 的内陆地区地面净失去水分、变干燥,而在低纬度、大陆东岸以及高纬度地区,地表获得水分、变湿润。晚白垩纪CO2浓度变化对大气辐射和大气热状况的影响是复杂的; 降低CO2浓度可以导致东亚地区气候显著变化,冬季东亚中纬度地区大陆降温比其附近的海洋大,太平洋中高纬度的低压系统加强,因而造成东亚冬季风偏强; 而在夏季,中纬度大陆地区降温幅度大于海洋,西太平洋副热带高压减弱,因而夏季风减弱。对应于较低的CO2浓度,年降水量在东亚及其沿岸的中、低纬度大部分地区显著减少,在东亚高纬度的大陆和海洋上降水的减少幅度不大,而在 30°N 附近亚洲大陆中部和东部的一些地区降水有所增加; 总体上,地表水分收支在东亚大陆的东部都是以负值为主,地面净失去水分、变干燥,其中 30°N 以南的大陆沿岸最显著; 而在东亚大陆的内陆地区,水分收支差异以0~0.5mm/天的正值为主,东亚大陆的东部是以地面净得到水分、变潮湿为主。  相似文献   

13.
Interannual variations of the monsoons have been studied utilising homogeneous rainfall records of 41 years (1951–1991) from Malaysia and upper air data of stations in Asia, Australia and Western Pacific. Sources of upper air data are U.S. Department of Commerce and Kuala Lumpur Northern Winter Monsoon Activity Centre. Extreme wet and dry years have been identified and the influence of ENSO on Malaysian annual rainfall has been discussed. Influence of ENSO on the performance of northern summer and winter monsoons has also been studied from Malaysian rainfall data. Further, regional circulation patterns associated with El Nino and La Nina years have also been identified. No linear trend has been found in the annual rainfall of 16 stations in Malaysia. Most El Nino years are associated with below median and La Nina years with above median rainfall at most stations in Malaysia. ENSO has greater influence over East Malaysia than peninsular Malaysia. Interannual variability of rainfall with reference to ENSO conditions has been discussed in details. Also, circulation features have been identified to foresee El Nino/La Nina events.  相似文献   

14.
In the East Asian monsoon region,eolian deposits widely distributed in the middle-lower reaches of the Yantgze River are among the best materials available for studies on Quaternary climate change in the subtropical zone of Southern China.Typical eolian deposits in this region include upper Xiashu Loess(XL) and underlying Vermiculated Red Soil(VRS) layers.In this paper,chronological and paleoclimatic studies are conducted on an eolian deposit sequence near Jiujiang(JJ) city in northern Jiangxi province.A magnetostratigraphic study,combined with optically stimulated luminescence(OSL) dating,is conducted on the JJ section and provides further evidence that eolian deposits in the middle-lower reaches of the Yangtze River have been formed since the late Early Pleistocene,and that the boundary age between the XL and VRS layers is about 300-400 kaBP.In grain-size records of the JJ section,the median grain-size and content of the 30 μm size fraction increase sharply after 300-400 kaBP,representing an East Asian winter monsoon intensification event.Further pollen analysis reveals differing pollen assemblages before and after 300-400 kaBP:there is an evident increase in plants adapted to grow in a warm humid environment after 300-400 kaBP,implying an increase in precipitation caused by intensification of the East Asian summer monsoon.Global ice volume and uplift of the Tibet Plateau(TP) are regarded as crucial factors influencing variations of the East Asian monsoon on a long-term scale.The deep-sea δ~(18)O record,which reflects variations in global ice volume,shows no obvious change after 300-400 kaBP.Moreover,the influence of global ice volume changes on the East Asian summer and winter monsoons is inverse;the global ice volume increase(decrease) implies a strengthened(weakened) winter monsoon and weakened(strengthened) summer monsoon.We therefore interpret the coupled intensifications of the East Asian summer and winter monsoons at about 300-400 kaBP to the uplift of the TP in the Middle Pleistocene.This climate event is also documented in eolian deposits from the southern margin of the Chinese Loess Plateau(CLP) and from the desert-loess transitional belt.However,it is not recorded in the loess-paleosol sequences from the central part of the CLP,thereby indicating differing climate responses to TP uplift in different regions,which requires further study.  相似文献   

15.
In order to make clear a problem in the human impact on the East Asian monsoons, navigation in the period from the 7th century to the 19th century was studied from the standpoint of historical climatology. 1. are described the periods of winter and summer monsoons over East Asia in relation to the division of the natural season. 2. based on the characteristics of the wind direction and velocity during the monsoons, it is shown that the winter monsoon is extremely unfavorable for navigation in contrast to the favorable summer monsoon. 3. statistical results on the possible frequency of navigation over the East China Sea by small boats are dealt with according to the meteorological records. 4. it is indicated that the navigations of the missions between Japan and China, Korea or Po Hai in the 7th – 9th centuries showed clear relations to the monsoon seasons. Lastly, the navigation mainly in 17th, 18th and 19th centuries around Ryukyu Islands, on the Chinese coast and the Japanese Islands are mentioned in detail. Even in this period the winter monsoon affected strongly on the navigation, that is, sailing and entries kept away the winter monsoon season almost completely.  相似文献   

16.
The MGS2 segment of the Milanggouwan stratigraphical section in China’s Salawusu River Valley records 5.5 sedimentary cycles consisting of dune sands alternating with fluviolacustrine facies or/and palaeosols. The high Rb and Sr contents and low Rb/Sr ratios in the fluviolacustrine facies indicate the presence of a warm and humid climate, and vice versa for a dry and cold climate. Rb and Sr appeared to have 5.5 element cycles that are consistent with the sedimentation changes, and each cycle lasts about 2 ka on average. This study suggests that the observed cycles mainly resulted from variations in the strength of the East Asian winter and summer monsoons, and the MGS2 segment experienced six cold-dry winter monsoons and five warm-humid summer monsoons during the OIS2. In addition, the millennial-scale monsoonal climate fluctuations revealed by the element cycles corresponded well with the Dansgaard–Oeschger cycles recorded in the Greenland ice cores and Heinrich events in the North Atlantic marine sediments. Therefore, the monsoonal climate fluctuations revealed by the Rb and Sr in the MGS2 segment were likely triggered by global climate change.  相似文献   

17.
洛川黄土记录的最近2500ka东亚冬夏季风变化周期   总被引:16,自引:2,他引:14  
鹿化煜  刘洪滨 《地质论评》1998,44(5):553-558
对厚约140m的陕西洛川坡头村黄土剖面进行间距3~10cm的系统采样,测量了全部样品的磁化率和粒度,选择〉30μm颗粒百分含量和磁化率分别作东亚冬,夏季风强度变化的替代性指标,以新建立的时间标尺为基础,分析了最近2500ka以来东亚季风变化的周期特征。结果表明,第四纪东亚冬,夏季风变化时间序列包括含有100ka,41ka和23ka地球运动轨道要素变化的周期,同时包含有约80ka,56ka和30ka  相似文献   

18.
Although recent studies have recognized peatlands as a sink for atmospheric CO2, little is known about the role of Siberian peatlands in the global carbon cycle. We have estimated the Holocene peat and carbon accumulation rate in the peatlands of the southern taiga and subtaiga zones of western Siberia. We explain the accumulation rates by calculating the average peat accumulation rate and the long-term apparent rate of carbon accumulation (LORCA) and by using the model of Clymo (1984, Philosophical Transactions of the Royal Society of London Series B 303, 605-654). At three key areas in the southern taiga and subtaiga zones we studied eight sites, at which the dry bulk density, ash content, and carbon content were measured every 10 cm. Age was established by radiocarbon dating. The average peat accumulation rate at the eight sites varied from 0.35 ± 0.03 to 1.13 ± 0.02 mm yr−1 and the LORCA values of bogs and fens varied from 19.0 ± 1.1 to 69.0 ± 4.4 g C m−2 yr−1. The accumulation rates had different trends especially during the early Holocene, caused by variations in vegetation succession resulting in differences in peat and carbon accumulation rates. The indirect effects of climate change through local hydrology appeared to be more important than direct influences of changes in precipitation and temperature. River valley fens were more drained during wetter periods as a result of deeper river incision, while bogs became wetter. From our dry bulk density results and our age-depth profiles we conclude that compaction is negligible and decay was not a relevant factor for undrained peatlands. These results contribute to our understanding of the influence of peatlands on the global carbon cycle and their potential impact on global change.  相似文献   

19.
四川盆地白垩纪沙漠风向变化规律及其意义   总被引:4,自引:1,他引:3  
本文报道了四川盆地白垩纪沙漠古风向测量结果,总结了风向变化的规律。认为该浙江省早期处于副热高压带地区的西北和东北切变带(divergent latitudes of westerly winds and northeasterly trade winds)。随着气候的波动,该切变带发生了短周期的南北向漂变,造成西风与东北信风交替现象。  相似文献   

20.
本文通过对渭南黄土剖面末次盛冰期地层较高分辨率的蜗牛化石记录研究,发现这一时期特征蜗牛种类峰值的演替反映了古气候的演化过程和温,湿度的组合关系。气候变化显示出百年-千年尺度波动的特征,温度的变化明显地要早于湿度(降水)的变化1000-2000a,表现为变冷-冷湿-冷干-温干-温湿的气候过程,研究认为造成这一气候特点的原因是东亚冬,夏季风共同作用的结果,可喜温湿蜗牛种类的研究,揭示出东亚夏季风在这一时期至少能够持续地影响到黄土高原的东南部地区,这个时期冬季风强化的结果之一是影响了夏季风在这一地区滞留的时间,加大了季节性的差异,分析表明尽管夏季风在这一地区滞留的时间缩短,但维持了它固有的强度,提供了适量的水热条件供喜温湿蜗牛种类在这一寒冷阶段持续地生长和发育。  相似文献   

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