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1.
应用ＩＣＰ－ＭＳ法测定了岩石中的痕量Ｎｂ、Ｔａ、Ｚｒ、Ｈｆ、Ｔｈ、Ｕ，给出了检出限，并对酸溶和碱熔两种制样方法进行了对比实验。 相似文献
2.
矿产勘查的新思路,新方法,新技术 总被引：4，自引：0，他引：4
本文总结了国外矿产勘查新思路，新方法、新技术、指出矿产勘查工作在由“实物工作量型”向“科学找矿型”转变；普查工作部置上由单一矿床转向整个成矿带，实现了矿产勘查思路从区域到局部的重大转变；同时，发展各种勘查方法及其有机结合是当今找隐伏矿的最重要途径。本文以勘查地球化学方法为例阐述了上述思路和方法。 相似文献
3.
为配合辽宁省钱币学会考古研究工作，本文拟定了一个测定古钱币中铜、锡、铅的分析方法。该方法具有取样量少，操作方便，结果准确的特点。用于３２枚古钱币中铜、锡、铅的测定，分析结果理想。 相似文献
4.
综合利用岩芯,测井,地震资料预测孔隙度 总被引：2，自引：0，他引：2
综合利用岩芯、测井、地震资料预测储层孔隙度，首先是利用分辨率高的测井、岩芯资料建立关系模式，然后利用地震层速度计算孔隙度。在远离钻井的地区，也能确定孔隙度的分布情况。文章还介绍了该方法在三个地区的实际应用。 相似文献
5.
研制了测定岩石、矿物及矿石中０．０１－１００μｇ／ｇ的砷、锑、硒和碲的原子吸收方法，该方法建立在通过从含硫－溴化物溶液中用乙烯－１和甲苯的混和物萃取这些经预富集的元素的基础上。硒和碲作为附加到烯烃双链上的有机金属化合物－亲电子产物被不可逆地萃取。就砷和锑来说，可产生与甲苯络合的分了了溴化物的可逆萃取。 相似文献
6.
卢治平 《华东地质学院学报》1994,17(3):287-293
本文提出了在醋酸－醋酸钠－酒石酸钾钠介质中连续测定天然水中铋、铜、铅、镉、锌、锰的微分阳极溶出伏安法。研究了底液的组成和波峰的性质，试验了共存元素的允许量。方法灵敏度高，不经分离富集，可直接用于测定天然水中上述六种离子。 相似文献
7.
喷,锚,网结构在基坑支护中的应用 总被引：5，自引：1，他引：5
高层建筑地下室基坑开挖时，边坡需要支护。本文就应用喷、锚、网结构进行边坡支护的作用机理、计算方法、施工中应注意的几个问题作了介绍和讨论。 相似文献
8.
本文采用了流动注射分析技术，用氢化物发生原子吸收分光光度法直接连续测定砷、锑、铋。在稀盐酸介质中，试样溶液中以不同氧化态存在的待测元素被硫脲、碘化钾、抗坏血酸混合还原抑制剂溶液在线还原为易生成氢化物的形式，与硼氢化钠反应生成氢化物，经我们自制的带雾化器的气液分离器分离后进入原子化器。方法稳定灵敏，再现性好，一次溶样可直接连续测定地质样品中砷、锑、铋３种元素。用本方法测定地质标样结果吻合很好，其检出限（３σ）分别为８．８４，６．９１，１２．２９×１０￣（－８）ｇ／Ｌ。相对标准偏差小于２％。 相似文献
9.
苏伯苓 《河北地质学院学报》1995,18(2):193-198
还有５年就到２１世纪，是人才竞争更加激烈的时代。如何改革教学，培养大学生的创造能力已迫在眉睫。本文分析了目前大学教育现状与弊端，提出作者大学教学３０余年的经验总结－“以心教学，培养学生创造能力”为核心的教学原则与方法；“以心教学”变革教学思想－改革三个错误教学观点，摆正两个关系，实现教为主导，学为主体的统一；提高教师素质，革新教学内容，教学－科研－生产相结合，促进学生创造能力的培养；改革教学方法， 相似文献
10.
201富铀矿床氢,氧,碳,硫,铅同位素研究 总被引：5，自引：0，他引：5
产于花岗岩中的２０１铀矿床是我国花岗岩型铀矿富矿之一。本文通过氢、氧、碳、硫、铅同位素组成的研究，探讨成矿溶液和成矿物质的来源，推测成矿环境。研究结果表明，该矿床成矿流体是以大气降水为主，主要成矿物质来自前燕山期花岗岩体，可能部分来自下部地壳，成矿作用是在较稳定的物化条件下进行。 相似文献
11.
S. Tung J. K. C. Leung J. J. Jiao J. Wiegand W. Wartenberg 《Environmental Earth Sciences》2013,68(3):679-689
Radon and its progenies have been ranked second of being responsible for lung cancer in humans. Hong Kong has four major groups of uranium-rich plutonic and volcanic rocks and is suffering from radon emanated therefrom. However, there is a lack of radon potential maps in Hong Kong to resolve the spatial distribution of radon-prone areas. A ten-point radon potential system was developed in Germany (2005) to predict radon potential using both the in situ geogenic and geographic parameters under hierarchical ranking. Primarily, the ten-point system requires the desk study of the geological environment of sampling sites, which has an advantage of saving resources and manpower in extensive radon potential mapping over the traditional soil radon concentration sampling method. This paper presents a trial of radon potential mapping in Hong Kong to further verify the system. Despite some slight departures, the system demonstrates an acceptable correlation with soil radon concentrations (R 2 = 0.62–0.66) from 768 samples of mainly intermediate radon potential. Hong Kong has a mean soil radon concentrations of 58.9 kBqm?3, while the radon potential from the ten-point system achieves an average of 4.93 out of 10 over the territory. The vicinity of fault zone showed high soil radon concentrations and potentials, which were conducive to uranium enrichment and rapid soil-gas diffusion near faults. High uranium-238 content in soil was found to cause high soil radon concentration with a large R 2, 0.84. The Jurassic granite and volcanic crystal tuff cover more than 85 % of the whole Hong Kong area, and they show relatively high radon concentrations (Geometric mean 83 and 49 kBqm?3, respectively) which are associated with their high uranium contents (Geometric mean 234 and 197 Bqkg?1, respectively). While indoor radon concentration is an important factor for radon risk assessment, this study has not considered the correlation between indoor radon concentration and radon potential. The reason is that almost all buildings in Hong Kong are high-rise buildings where indoor radon concentrations are governed only by the radium content in the building materials and the ventilation conditions. 相似文献
12.
基于土壤氡气测量识别甘肃北山南缘隐伏断裂 总被引：1，自引：0，他引：1
我国高放废物地质处置库首选预选区位于甘肃北山南缘，区内分布有多条大型非活动断裂构造，这些断裂很可能成为未来放射性核素迁移的主要通道。断裂在向地表延伸过程中，受第四系覆盖等因素影响，造成关键构造部位隐伏地下而难以识别。本文以北山地区新场地段南部红旗山和前红泉断裂为研究对象，采用土壤中氡气测量方法，探讨了大型断裂构造中隐伏段落的识别及其指示的水文地质意义。结果表明：土壤中氡气测量对于识别北山南缘隐伏断裂具有很好的指示意义，是传统地质调查方法的一种重要补充；红旗山和前红泉断裂裂隙系统整体开启性均较差，裂隙系统不发育，影响范围较小，不具备形成较大规模储水空间的可能性。不同断裂带土壤氡浓度背景值差异较大，可根据土壤氡浓度累积频率分布图确定背景值；土壤氡浓度等值线分布图对判断隐伏断裂位置具有一定的指示作用。对于压剪性断裂而言，主断裂多沿氡气高异常与低异常边界分布或表现为氡气中等异常，而两侧的次级断裂表现为氡气高异常。 相似文献
13.
研究了广东省四家温泉宾馆室内温泉水及其使用过程中对氡浓度的影响。利用RAD-7测氡仪和NR667A测氡义连续测量室内外氡浓度和水氡浓度,发现室内氡浓度受地基土壤、建筑物类型、利用方式(是否洗浴、洗浴时间长短等)、通风状况等诸多因素的影响。无人入住时宾馆室内氡浓度的变化说明土壤氡的渗入是底层房间室内氡的重要影响因素。当在浴室内使用温泉水洗浴时,浴室内平均氡浓度比没有用温泉水时高出1～8．3倍,客房内氡浓度比没有用温泉水洗浴时高出1．2～8．3倍。在使用温泉水时,某些宾馆室内氡浓度超标,可能对宾馆工作人员造成潜在的健康危害,应采取管理措施或技术手段降低其暴露水平。 相似文献
14.
From radon hazard to risk prediction-based on geological maps,soil gas and indoor measurements in Germany 总被引：3，自引：0，他引：3
Mapped geological units can be regarded as proxies standing for a complex series of subsoil geochemical and physical properties
including the assigned radon activity concentration in soil gas, which is taken as best estimator of the regional geogenic
radon potential. Areal distribution of measuring sites for soil gas in Germany is adapted to spatial variation of geology.
A grid-based and distance-weighted interpolation procedure is applied, following geologically defined neighbourhood relations
of measuring sites and accounting for isolated outcrops of known geology but without measurements. To investigate the statistical
relationship between indoor radon, house type and building ground specifications, measurements of the indoor radon concentration
have been carried out in more than 10,000 dwellings in different regions of Germany. Multiple regression analyses of variance
reveal that besides region-specific geological properties and building characteristics, various house type and living style
variables significantly contribute to the explained variance for ground floor radon concentrations. These parameters are also
dominant in controlling the radon transfer relation from soil gas to indoor air. Risk prediction maps for radon in houses
indicating the probability to exceed certain indoor threshold values can be useful especially for regions with no or only
a few measurements of indoor radon. 相似文献
15.
Douglas G. Brookins 《Environmental Geology》1991,17(3):209-217
High indoor radon in approximately 30 percent of private dwellings in the Albuquerque, New Mexico area has been reported previously. The present study explains the areas of high indoor radon as a function of different soil and/or bedrock in the area. Soils were sampled during summer and winter periods using alpha track radon detectors. The values range from 40 to 890 pCi/I air at a depth of 38 cm. The gross mean average is 360 pCi/I for the area for summer readings and 200 pCi/I for winter readings; both values are well over the average U.S. soil radon values of approximately 100 pCi/I. Analyses of soil uranium show a range in values of 1–6 ppm, with a mean of 3.1 ppm. Thorium values range from 3.3 to 28.8 ppm, and Th/U ratios range from 2.9 to 4.6.These values for U, Th, and Th/U suggest that soil U and Th are close to the values reported for the Sandia granite, the source of most of the pediment on which Albuquerque is built. Soil infiltration rates range from ~6 × 10–4 to 4.5 × 10–3 cm/sec for the samples, and soil moisture content ranges from 1.4 to 7.2 percent. A fair correlation of summer soil radon with infiltration rate is noted. Correlation of soil radon with moisture content and/or with percent silt, silt + clay, clay size fraction material is not established by this study. Soil radon values do correlate with regions in the Albuquerque area where high indoor radon is common. A better correlation of high indoor radon values with soils developed immediately over bedrock is observed. Furthermore, all values of average soil and indoor radon increase significantly with proximity of the stations to the Sandia Mountains. Soil uranium also shows this trend. The data argue that regions of potentially high radon can thus be identified. 相似文献
16.
Attempts to predict which geographic areas should be associated with a high percentage of homes with unusually high indoor radon levels have been based on estimates of soil radon and soil permeability for geological units. In northern Virginia and southern Maryland, it appears that predictions of indoor radon based on estimates of homesite soil radon and soil permeability are very useful. 相似文献
17.
Douglas G. Brookins 《Environmental Geology》1988,12(3):187-196
Radon buildup in homes is now recognized throughout the world as a potentially major health hazard. The U.S. Nuclear Regulatory
Commission and the U.S. Environmental Protection Agency estimate 8,000–30,000 fatalities per year in the United States due
to indoor radon.
The Albuquerque, New Mexico area was chosen for study because it is representative of metropolitan areas in the southwestern
United States where slightly uraniferous source rocks (Sandia granite) have provided the very immature soil for much of the
area. The granite contains 4.7 ppm U, and limestone capping the granite 5.7 ppm U. Soils in the area average 4.24 ppm U, and
Th/U ratios average 3.2. These data suggest some removal of U from the source rocks, but fixation of the U in the soils (that
is, as opposed to widespread removal of the U by solution), thus providing a ready source for soil radon. A pilot study of
soil radon in the area in winter of 1983–1984 shows high values, 180 pCi/l, relative to the U.S. average (about 100 pCi/l).
In the winter of 1986–1987, 180 dwellings were surveyed for their indoor radon levels, including 20 that had been surveyed
in summer of 1986. Twenty-eight percent of those in the winter study yielded indoor radon above the EPA suggested maximum
permissible level of 4 pCi/l air, well above the EPA estimate of 10–15 dwellings for the U.S. The indoor radon levels show
positive correlation with closeness to the Sandia Mountains, to soil radon, to excess insulation, to homes with solar capacities,
and other factors. Building materials may provide a very minor source of some indoor radon. Summer readings are lower than
winter readings except when the houses possess refrigerated air conditioning. 相似文献
18.
The main purpose of this work is to demonstrate the possibility of using soil gas radon survey as a promising technique for locating the trend of western extension of Damascus fault, where it is hidden under a cover of Pliocene unconsolidated deposits. The normal level of radon background was established in a stationary area away from the tectonic influence of the fault zone. The sites of radon measurements were chosen according to the accessibility and suitability of the area, besides some indicative geologic and tectonic evidences. A total of 81 radon sampling points were analyzed, and the results revealed some reasonable spatial increases, with peak values of 2–3 times higher than the background level, trending in accordance with what is believed to be the general direction of the fault in the bedrock. However, permeability properties rather than geotectonic activities seemed to be the main causes controlling the variations of radon concentration over the concerned fault zone. Yet, the moderate level of the observed radon values could be attributed to the nature of the prevailing rock types, as well as the probable effect of locked tectonic structure due to the action of high regional compressive regime which typically originates such reverse faulting. Further, the accumulation of fill materials due to rock alteration along the plane of such dormant fault, through long geologic time, possibly led to increase in the ratio of clay minerals which may affect soil gas mobility through the medium. 相似文献
19.
采用IED-3000R轻便型测氡仪,对四川阿坝地区土壤、空气中的氡气浓度开展初步调查。结果表明：(1)测区空气中氡气浓度较高,均在平均值185 Bq/m3附近;(2)所测得土壤的氡气浓度范围为2 736～93 486 Bq/m3,平均值为26 021 Bq/m3,远远高于全国城市土壤中氡气浓度7 300 Bq/m3的平均值,同时在156个土壤氡气浓度被测点中共有91个测点氡气浓度值超过20 000 Bq/m3,而按照国家标准,对于民用建筑工程土壤中氡气浓度超过20 000 Bq/m3要进行不同程度的防氡工程;(3)地质环境、土壤松散度、岩土性质、土壤含水率为影响阿坝地区土壤氡气浓度的主要因素。 相似文献
20.
Radon measurements were made in the soil and spring/seepage water in and around an active landslide located along the Pindar river in the Chamoli District of Uttaranchal in Garhwal Lesser Himalaya, to understand the application of radon in geological disasters. The landslide is a compound slide i.e. a slump in the crown portion, and debris slide and fall in the lower part. The bedrock consists of gneisses and schists of the Saryu Formation of the Almora Group of Precambrian age. The presence of several small slump scars and debris slide/fall scars along the length of the slide indicates continuous downward movement. The radon concentrations in the present study are much lower in comparison to values reported from other regions. However, the present radon data show relative variation in the slide zone. The concentration of radon measured in landslide zones varies from 3.1 Bq/l to 18.4 Bq/l in spring water and from 2.3 kBq/m3 to 12.2 kBq/m3 in the soil gas of the debris. Along the section of the slide, the radon values in water and soil are slightly higher in the upper slopes i.e. toward the crown portion of the landslide as compared to the distal portion. The relatively low concentration of radon both in soil gas and water in the toe portion of the landslide may be due to the high porosity of the debris, which does not allow radon to accumulate in the soil and water, whereas, towards the crown portion, the high frequency of fractures increases the surface area due to particle size reduction, and the near absence of debris enhances the radon emanation in soil. 相似文献