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101.
在收集以往自然重砂测量、土壤测量资料的基础上,结合1∶5万土壤地球化学调查,进行苏州西部土壤中汞的分布特征及成因解析。结果表明,研究区土壤中Hg含量变化范围较大,介于0.023~5.012 mg/kg之间,平均值高达0.386 mg/kg,远高于苏州地区表层土壤及太湖水网平原表层土壤Hg含量平均值,土壤汞污染比较严重。区内辰砂矿物与土壤中Hg的空间分布具有较高的耦合性,与区内断裂构造、矿床分布有关,表明区内土壤中的汞、辰砂分布是多金属矿成生作用的产物,人类活动的影响不大。 相似文献
102.
河南水灾变化及典型水灾年大气环流异常特征分析 总被引:4,自引:1,他引:3
利用河南1950-2007年的逐年水灾统计数据,对水灾年的时间特征进行分析,并对典型水灾年大气环流的异常特征进行分析,结果表明:在1950-2007年的58 a中,河南年年都出现水灾,全省水灾受灾面积66.7万hm2的有28年;66.7万hm2的有30年,约2年一遇;受灾面积133.3万hm2的有17年,约4年一遇;333.3万hm2的有4年,约15年一遇。在河南的典型水灾年,中高纬度的长波和南支系统都有很强的稳定性;亚洲中高纬阻塞形势非常明显,在西西伯利亚上空出现了强烈的偏北风分量,因而冷空气暴发南下非常频繁;副热带高压脊线在24°N左右,584 dgpm线呈西南东北走向,将来自孟加拉湾和南海的充沛水汽带到内陆。河南省正处于来自北方的冷空气和南支系统带来的暖湿气流交汇的区域,这是造成河南省出现严重水灾的主要原因。 相似文献
103.
准噶尔盆地陆西地区吐谷鲁群(K_1tg)油气层电阻率一般为5~12Ω·m,与相邻水层电阻率的比值小于2。用其他井区白垩系油层图版(图1)来解释陆西地区的测井资料,误差较大。该低阻油层的粘土矿物组分以伊利石、伊/蒙混层和绿泥石为主,均呈薄膜状分布于砂粒周缘,膜厚2~5μm,最厚可达10μm 左右,油层具亲水性。这种含水粘土膜极大地扩大了储层中导电网络的截面积,它是导致储层 K_1tg 低电阻率的主要原因。由于 K_1tg 储层的孔隙度较该区其他储层高,在含水饱和度相同的情况下,K_1tg 储层的含水率相对较高,这也能使电阻率降低。 相似文献
104.
邻羟基萘基荧光酮-溴化十二烷基二甲基苄铵光度法测定微量锡 总被引:1,自引:0,他引:1
邻羟基萘基荧光酮-溴化十二烷基二甲基苄铵光度法测定微量锡冯泳兰,邝代治衡阳师范高等专科学校化学系421008邻羟基萘基荧光酮(β-HNF)已应用于光度分析测定微量Mo ̄[1]。本文研究了在稀H_2SO_4介质中,溴化十二烷基二甲基苄铵(DDMAB)存... 相似文献
105.
106.
本文根据川东地区天然气勘探开发历史,系统归纳和总结了成组气田整体勘探开发、多高点滚动勘探开发和多产层立体勘探开发三种模式的勘探程序、勘探部署以及开发特点和原则。以供后续天然气勘探开发决策时参考。 相似文献
107.
Cell biotechnology of rhodophytes is important not only in theoretical research but also in cultural practice and for exploitation of genetic resources. In this paper, cell biotechnology ofPorphyra is reviewed. Tissue culture and protoplast studies on other rhodophytes in China are discussed.
相似文献108.
本文报道了一例脊髓纵裂征,并着重讨论了该病X线CT表现,其中脊髓中央的骨嵴是诊断该病的关键,通过X线CT检查对比认为CT是最理想的诊断依据 相似文献
109.
Proceeding from gaining a knowledge of the structural settings in this area, the authors applied remotesensing techniques and selected multi-temporal image processing to extract information of buried structures inthe Beijing plain area. Good results have been achieved. Through an integrated analysis of remote-sensing, geo-logical, seismic and aeromagnetic data, it is pointed out that there exist two sets of buried fractures of differingtrends and orders-the northeast set and the northwest set. forming a rhombic framework in the images. Thetwo sets of fractures have still been active since the Quaternary. which is of practical signifcance for geologicalstudy, earthquake prevention and planning of urban construction in the area. The results demonstrate that theselection of multi-temporal processing of remote sensing images and the integrated analytic method are impor-tant in the study of buried structures. 相似文献
110.
B. Schutz M. Bevis F. Taylor D. Kuang P. Abusali M. Watkins J. Recy B. Perin O. Peyroux 《Journal of Geodesy》1993,67(4):224-240
The Southwest Pacific GPS Project (SWP) is using the Global Positioning System (GPS) to monitor crustal motion across and within a plate boundary complex between the Australian and Pacific plates. GPS field campaigns were conducted in 1988, 1989 and 1990, to observe networks of increasing size and complexity. The 1990 campaign consisted of two periods, or Bursts, and this paper focuses on the analysis of data collected during the nine day Burst 1 in July, 1990, a period in which GPS Selective Availability was activated. During Burst 1, baselines that spanned the Tonga Trench and the Lau Basin were observed, and only one station (Espiritu Santo, Vanuatu) was located west of Fiji in the network. The lengths of the baselines observed fall mainly between 300 km and 1600 km, but some lines are as long as 3500 km. A total of 78 station-days of field site data and approximately 150 station-days of global fiducial data were processed from predominantly codeless receivers. A global fiducial network of 20 sites was used to provide orbit control and accuracy assessment for the 13 available satellites. The daily solutions for 45 baselines between 10 SWP sites have an RMS scatter in the length of 24 mm plus 6 parts per billion. This scatter provides an estimate of baseline precision for the Burst 1 nominal solution. Experiments were conducted to investigate a variety of possible effects on the SWP Network baseline estimates, including the influence of a reduced global fiducial network for the purpose of assessing the quality of results obtained in 1988 and 1989 in which the fiducial network was smaller than in 1990. These experiments produced results that agreed with the nominal solution at the level of the precision estimate. Furthermore, estimates for selected baselines in Australia, the Central Pacific, North America and Europe, also measured by VLBI and SLR, were used for an external accuracy evaluation. The GPS and VLBI or SLR determinations of length agreed at a level consistent with the nominal solution precision estimate. 相似文献