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1.
安徽石台大山地区分布着较为广泛的下寒武统荷塘组石煤层,而石煤出露地区即是富硒区也是放射性水平含量较高区。根据本次调查在下寒武统荷塘组含煤岩系分布区的地方,其天然γ射线水平较高,不适宜人类在此居住。而调查区内的居民村庄大多远离含煤岩系分布区的地方,对当地的居民接收天然γ辐射照射人均年有效剂量估算,该地区居民居住的村庄和学校的人年均天然贯穿辐射有效剂量当量为0.32~0.43 m Sv。因此,可以确定认为该地区居民居住γ射线辐射水平对人居环境影响不大,天然γ射线辐射环境对当地居民健康是安全的。  相似文献   

2.
介绍了皖南地区区域地震台网20个测震台站的基本情况。对20个台站的背景噪声数字化记录进行了计算和分析,得其背景噪声均方根RMS值、有效测量动态范围,分析了噪声水平并按照地噪声水平的规定对各台进行了台基噪声分类。结果表明,20个测震台站中有9个I类台址、9个Ⅱ类台址、2个Ⅲ类台址。同时,分析了皖南地区区域台网的最小监测能力,结果表明,皖南地区区域台网最小监测能力为M_L≥-0.1—0.6,台站监测能力基本满足皖南地区监测需求。  相似文献   

3.
高安市建山镇牌楼村早稻富硒种植试验,是通过在富硒土壤中施用生石灰、有机肥、火土灰等方法,研究促进和提高早稻米吸收土壤中的硒元素,探索最简便、最经济和最适合普通农户操作的富硒稻米实用生产技术。本次种植试验采用对比试验,共设置3个不同处理试验区和一个对照区,每种处理设置2次重复小区。通过对比不同处理,早稻富硒种植试验结果,发现处理试验1(即亩施67kg生石灰,常规施肥和管理)是目前试验中提高早稻米硒元素含量最有效的一种技术方法。  相似文献   

4.
富硒土壤资源日益引起重视,但如何界定富硒土壤没有统一标准.本文选取安徽琴溪地区作为研究对象,利用安徽省富硒土壤分级标准,系统研究琴溪地区农业可耕地土壤及其植物中硒含量,这为琴溪地区富硒产品开发的定位提供了一定的理论依据,并对当地富硒产品的开发提出可行性建议.  相似文献   

5.
本文阐述了江西富硒土壤资源应用性生态地球化学评价的基本工作方法,列举了评价标准及依据,介绍了富硒土壤资源综合评价模型、富硒农产品质量综合评价模型和富硒农作物适宜性评估模型,展示了江西高安市灰埠—相城地区的富硒土壤资源的评价效果.结果表明,江西富硒土壤资源生态地球化学评价的工作方法具有可实际操作性,评价结果直观,成果具良好的应用性.  相似文献   

6.
在皖南地区,作者近年来从事过多项重大建设工程场地的历史地震调查工作,本文以皖南地区为例,根据历史地震资料,对一些历史地震提出有待商榷的论点,希望能对该地区的历史地震研究有所裨益,其目的在于促进历史地震调查更好地服务于工程建设.  相似文献   

7.
赣南和赣北-皖南是华南两个最重要的钨成矿带,其中赣南发育有"崇-余-犹"矿集区、于都矿集区、"三南"矿集区等,产有西华山、漂塘、盘古山和大吉山等重要钨矿床.近年来,赣北-皖南地区钨矿找矿工作取得重大突破,新发现了一系列与晚中生代岩浆活动有关的中型、大型甚至超大型的钨-铜(钼)矿床(如大湖塘、朱溪、东源、百丈岩等),使该区成为了华南又一个重要的钨矿带.本文旨在将这一新的钨矿带与赣南钨矿带中的含钨花岗岩的时空分布、岩石地球化学特征、物质起源及其含矿性差异等方面进行对比研究,以利于对华南含钨花岗岩及其成矿作用机制有更深入的理解.结果表明:(1)赣南钨矿的成岩成矿时代主要集中在晚侏罗世(165~150Ma),赣北-皖南地区钨-铜(钼)矿的成岩成矿时代则分为两期:晚侏罗世-早白垩世(150~140Ma)和早白垩世(135~120Ma);(2)赣北-皖南和赣南含钨花岗岩都属于高度演化的岩石,赣南花岗岩可能经历了更高程度的分异和更为强烈的流体-熔体相互作用;(3)赣北-皖南地区含钨花岗岩的源岩可能来自于新元古代双桥山群中一套砂质-泥质岩夹变火山岩岩系,赣南含钨花岗岩则起源于中元古代富粘土质泥岩的重熔.本文认为,赣北-皖南地区钨-铜(钼)矿和赣南钨矿不同的成矿作用特征主要是受花岗岩岩浆的源区物质控制以及演化分异程度的影响.  相似文献   

8.
皖南谭山岩体的锆石定年及地质意义   总被引:1,自引:0,他引:1  
皖南地区广泛分布燕山期岩浆岩,但其年代学方面的工作较为薄弱。为厘定该地区燕山期岩浆岩年代学格架,本文利用LA-ICP-MS锆石U-Pb定年方法对皖南谭山岩体的正长花岗岩进行了锆石U-Pb年代学研究,两个样品的206Pb/238U加权平均年龄分别为128.5±1.7Ma和128.3±1.5Ma,基本一致,为早白垩世岩浆活动的产物。结合本地区高精度年代学数据,皖南地区中生代岩浆岩可划分为三个峰期:第一峰期为142~139Ma;第二峰期为133~130Ma;第三峰期为128~125Ma。  相似文献   

9.
王清晨 《地球》2020,(9):36-40
<正>朋友发来微信,问我要不要补硒。补硒?为什么要补硒?硒到底是什么?我刚好在读一本书,里面讲到美国怀俄明州有一种紫菀花,当地的牛和羊吃了以后会得一种叫"蹒跚盲"的病,走起路来摇摇晃晃的,像喝醉了酒。后来发现,是因为紫菀花里含有硒,牛羊吃进去以后,浓集起来的硒会破坏从大脑向肌肉传递信息的一种酶。那么,人吃了以后,会不会受到影响?俗话说,病从口入。把东西放进自己嘴里之前,千万要弄明白它是什么。  相似文献   

10.
《地球》2016,(9)
正近日,青海省第五地质矿产勘查院《青海省都兰县绿洲农业生态地球化学评价》项目组表示,继该院在青海东部地区发现大面积富硒土壤后,首次在柴达木盆地诺木洪地区发现大面积连片富硒土壤。项目负责人介绍,2015~2016年,项目组通过对土壤、水体、名特优农产品等5000余件样品进行高精度测试,获得了大量数据,在柴达木盆地发现富硒土壤共计417平方千米,富硒区内每千克土壤硒平均含量达0.47  相似文献   

11.
The problem of detecting discontinuities which interrupt coal seams is of great importance to the coal mining industry. One possible method of detecting such discontinuities is that of in-seam seismology where both source and detectors are placed under- ground on the coal face. In this paper the propagation of SH waves from a line source in the seam is investigated. There exists a particular set of waves–channel waves–, confined to the coal seam. These waves are dispersive and have an associated Airy phase whose geometrical attenuation is least. However, if absorption of energy within the coal is included then the Airy phase is the dominant wavegroup only for distances less than a certain maximum. If a detection criterion proposed by Dresen and Freystätter applies, then there is a lower limit to the frequency that should be used for exploration. This requirement may be in conflict with attenuation considerations.  相似文献   

12.
天目湖流域丘陵山区典型土地利用类型氮流失特征   总被引:4,自引:2,他引:2  
天目湖丘陵山区农业综合开发持续推进,大量林地转变为茶园,迫切需要认识茶园扩张对流域氮流失的影响.本研究选取茶园、次生马尾松林和毛竹林开展自然降雨条件下的径流小区实验,分析天目湖丘陵山区典型用地类型径流氮流失规律,为评估丘陵山区综合开发的水环境影响提供实测参数.研究表明:茶园、次生马尾松林和毛竹林地表径流TN浓度分别为11.25、2.83和3.60 mg/L,均以溶解态为主;壤中流TN浓度分别为27.16、3.59和1.06 mg/L,茶园和次生马尾松林均以溶解性无机氮(尤其是硝态氮)为主,毛竹林以溶解性有机氮为主;茶园、次生马尾松林和毛竹林的小区尺度地表径流系数均不到0.03,壤中流是丘陵山区径流的主要来源;茶园开发加剧了丘陵山区的氮素流失,茶园径流TN流失强度高达103.08 kg/(hm2·a),分别是次生马尾松林和毛竹林的7.6和23.2倍,壤中流贡献了流失总量的86.7%~99.7%.防治茶园径流氮流失需重点关注壤中流输出,在减量施肥的基础上,采取坡脚构建毛竹林生态缓冲带/在小流域出口布设塘坝等原位拦截措施,实现流域氮流失综合防控.  相似文献   

13.
Numerous green polished stone axes have been excavated from the Sannai-Maruyama site, one of Japan's largest archeological sites in the Jomon period (5.9–4.2 cal kyr BP). The axes are composed of weakly metamorphosed fine-grained volcaniclastic rock having a peculiar texture that includes numerous acicular actinolites growing in random directions within a quartz and albite matrix. Cobbles of Aotora stone found along the Nukabira River, Biratori town, southern Hokkaido, are the most likely raw material for these stone axes. Aotora stones have alternate bands of a soft dark-green picritic layer and a hard SiO2-rich pale-green layer. The pale-green layer has a texture similar to the stone axes. Basaltic and picritic volcanic rocks of the Sorachi-Yezo Belt occupy the area along the Shidoni River, a tributary of the Nukabira River. Volcaniclastic rocks similar in texture, mineralogy, and bulk rock compositions to the Aotora stone are exposed in the area. These rocks underwent metamorphism under the actinolite-pumpellyite facies conditions. Their protolith is submarine hyaloclastic rocks that are intercalated with laminated picrite detritus. The stone axes, pale-green layers of Aotora stone, and those of the volcaniclastic rocks of the Shidoni River area all have high SiO2 (~ 55 wt%), Cr (~ 840 μg/g), and Ni (~ 370 μg/g). The rare earth element patterns with abundant light rare earth elements and depleted heavy rare earth elements of stone axes were also consistent with the pale-green layers of the outcrop. These pale-green layers, interleaved with dark-green layers of picritic detritus, were the likely source rock of the stone axes. The high SiO2 content in the pale-green layer caused the crystallization of quartz and albite in the matrix, which resulted in high-quality raw material for making stone axes.  相似文献   

14.
依据密度测井资料评估煤层的含气量   总被引:1,自引:0,他引:1  
煤层甲烷长期以来认为是对采煤工作的危害,只是近十多年来才被认为是一种潜在的能源。煤层不仅是甲烷的储层,而且是甲烷的源岩。煤的物理结构是一种双重孔隙结构,即煤层中含有由基质孔隙和裂缝孔隙组成的孔隙系统。煤层中的气(甲烷)主要吸附在基质孔隙的内表面,是吸附气,而不是存在于骨架粒间的孔隙空间内,因而传统的评价天然气储层含气量的方法虽然不能适合于评估煤层的气含量。本文利用密度测井资料和煤样煤质化验资料确定  相似文献   

15.
0.9 m薄煤层SH型槽波频散特征及波形模式   总被引:3,自引:2,他引:1       下载免费PDF全文
在0.9 m薄煤层中使用放炮方法做微震震源的条件,通过对所采集到的薄煤层槽波信号进行分析,发现薄煤层槽波在频域中存在高频和低频两个独立并且不连续的波段.其中高频区大约以2000 Hz为中心,低频域的中心频率约为490 Hz,并且高频域和低频域的能量差异不显著.通过时频分析,可以清晰地看到高、低两个频域几乎在同一时刻触发,并且其小波相关系数在这两个域中的分布规律表现出一定的相似性.通过对0.9 m薄煤层槽波频散曲线的理论分析可知,现场观测到的Airy震相的频率及速度和其理论值较为接近.震源置于煤层中心,且炸药能量对顶底板的扰动,对第二阶对称波形模式下槽波高频部分的形成起着关键作用.在这一对称高阶波形模式下槽波的波速基本上和煤层顶底板中S波的波速一致.由于这两个触发的波形模式在时间域中具有相似的特征,建议在高频域和低频域同时发育较好的薄煤层槽波勘探中,可以采用在同一时间域中高低频相结合的方法提高利用槽波勘探分析的效果.  相似文献   

16.
利用煤体破裂电磁信号进行局部震源定位方法研究   总被引:1,自引:0,他引:1       下载免费PDF全文
准确预测煤岩破裂震源方位,确定采掘工作面重点灾害区域,可以使煤岩动力灾害防治措施更为有效.根据煤岩变形破裂电磁效应规律和电磁波基础理论,提出了一种利用电磁信号能量来确定局部震源方位的方法,并通过实验室定向接收实验和平煤十矿现场测试验证该方法的有效性.结果表明,电磁信号强度随着煤岩体应力状态变化而变化;两个正交天线接收的电磁信号能量分别与各自接收夹角余弦值的平方成正比,利用此比例关系可以确定震源的方位;电磁信号定位方法与静态指标法预测局部区域危险性具有较好的检验一致性.研究成果为煤岩动力灾害重点灾害区域的判定提供依据.  相似文献   

17.
Thermocatalytic low temperature conversion (LTC) is a new method for the disposal of sewage sludge. Using this method, sludge is converted into a residual solid (coal) along with reaction water, oil, and non‐condensable gases. The oil can be used as an energy source and the coal as a substitute for charcoal. To this end, it is important to determine whether there are any easily available contaminants present in the coal generated by the process. Contaminants that can be strongly sorbed by sewage sludge solids are, e. g., pharmaceuticals and disinfectants. As an example the fate of the persistent and strong adsorbing disinfectant benzalkonium chloride (BAC) has been investigated within the LTC process. The sewage sludge was spiked with BAC and then subjected to the LTC process. The resulting coal was extracted and analyzed using LC‐LC/ESI‐MS/MS (ion trap). BAC could not be detected in the LTC coal, although it could be extracted from the spiked sludge before the LTC treatment. It can thus be concluded that the investigated compound is not easily available in the coal, and hence that its use does not present a risk.  相似文献   

18.
The common practice of freezing sediment cores for later chemical investigation was shown to be inappropriate for samples containing selenium. Pore waters from frozen estuarine sediment cores contained up to eighty times the selenium content of those extracted from chilled but unfrozen cores. Experiments suggested that the increase in selenium concentrations resulted from rupturing the cells of selenium-accumulating bacteria present in the samples.  相似文献   

19.
The efficacy of radio-wave imaging (RIM) in extended geological strata which are planar and regular, such as coal seams, continues to be questioned, because the electromagnetic wave excitation and propagation mechanisms remain unclear. To eradicate the doubts, a full-wave finite element simulation of a ‘realistic’ coal seam boundary value problem has been constructed and is described and analysed in this paper. The model is used to examine electromagnetic waves (near-fields) in the vicinity of the magnetic source and resonant modal patterns distant from it, for a range of electrical parameters for the coal medium and for a variety of possible boundary conditions. These studies suggest that only for very low loss seams can RIM be effective, and consequently a new guided electromagnetic wave (GEM) system has been proposed to circumvent the acknowledged deficiencies inherent in RIM.  相似文献   

20.
At present, as the easily mining resources are being increasingly depleted, the exploitation of coal under buildings, water-bodies and railways is imminent for the sustainable production. Probability in-tegral method is a general method for mining subsidence in the coal system. Because of poor under-standing of mining subsidence for other sections, the authors suggest probability integral method for the study of coal mining under buildings, water-bodies and railways. Moreover, the calculation result of probability integral method should be corrected by numerical simulation method. Based on practical projects, the impact has been evaluated on the security of Xifeihe left embankment under coal mining. Combining with the results of probability integral method, we propose that the 600 m far from em-bankment is a good rationality. This article provides the basis for the rational exploitation of coal re-source which is a major practical problem under the premise of Water Infrastructure Security. Fur-thermore, it also can be served as a reference for the similar projects, such as mining Xiaolangdi res-ervoir area, mining Yuecheng reservoir and mining the major channels of Middle Route South to North Water Transfer.  相似文献   

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