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181.
为提高短时强降水的监测和预警技术在山区等复杂地形中的应用,本文选取相关的探空资料分析天气背景,划分降水类型,与自动站订正技术相结合,采用Z-I分型最优化技术估测降水,利用交叉相关法对雷达反射率因子进行外推,并预测30min后的累积降水量。根据近3年的观测资料,制定出适合岳阳地区雷达反射率因子以及雷达估测降水对应的降水量级。通过与自动站雨量对比,Z-I分型最优化技术估测降水的相对误差较小;与Z-I经验公式估测降水对比分析,雷达估测降水的准确率有一定提高。经过岳阳示范区一年的实际应用表明:该方法对短时强降水的估测和预警均取得良好的效果,对强降水引起的山体滑坡等灾害具有一定的防范作用。  相似文献   
182.
Concentrations of total Hg (T-Hg) were measured in mine waste, stream water, soil and moss samples collected from the Tongren area, Guizhou, China to identify potential Hg contamination to local environments, which has resulted from artisanal Hg mining. Mine waste contained high T-Hg concentrations, ranging from 1.8 to 900 mg/kg. High concentrations of Hg were also found in the leachates of mine waste, confirming that mine waste contains significant water-soluble Hg compounds. Total Hg distribution patterns in soil profiles showed that top soil is contaminated with Hg, which has been derived from atmospheric deposition. Data suggest that organic matter plays an important role in the binding and transport of Hg in soil. Elevated T-Hg concentrations (5.9–44 mg/kg) in moss samples suggest that atmospheric deposition is the dominant source of Hg to local terrestrial ecosystems. Concentrations of T-Hg were highly elevated in stream water samples, varying from 92 to 2300 ng/L. Particulate Hg in water constituted a large proportion of the T-Hg and played a major role in Hg transport. Methyl–Hg (Me–Hg) concentrations in the water samples was as high as 7.9 ng/L. Data indicate that Hg contamination is dominantly from artisanal Hg mining in the study area, but the extent of Hg contamination is dependent on the mining history and the scale of artisanal Hg mining.  相似文献   
183.
The Variscan Hauzenberg pluton consists of granite and granodiorite that intruded late- to postkinematically into HT-metamorphic rocks of the Moldanubian unit at the southwestern margin of the Bohemian Massif (Passauer Wald). U–Pb dating of zircon single-grains and monazite fractions, separated from medium- to coarse-grained biotite-muscovite granite (Hauzenberg granite II), yielded concordant ages of 320 ± 3 and 329 ± 7 Ma, interpreted as emplacement age. Zircons extracted from the younger Hauzenberg granodiorite yielded a 207Pb–206Pb mean age of 318.6 ± 4.1 Ma. The Hauzenberg granite I has not been dated. The pressure during solidification of the Hauzenberg granite II was estimated at 4.6 ± 0.6 kbar using phengite barometry on magmatic muscovite, corresponding to an emplacement depth of 16-18 km. The new data are compatible with pre-existing cooling ages of biotite and muscovite which indicate the Hauzenberg pluton to have cooled below T = 250–400 °C in Upper Carboniferous times. A compilation of age data from magmatic and metamorphic rocks of the western margin of the Bohemian Massif suggests a west- to northwestward shift of magmatism and HT/LP metamorphism with time. Both processes started at > 325 Ma within the South Bohemian Pluton and magmatism ceased at ca. 310 Ma in the Bavarian Oberpfalz. The slight different timing of HT metamorphism in northern Austria and the Bavarian Forest is interpreted as being the result of partial delamination of mantle lithosphere or removal of the thermal boundary layer.  相似文献   
184.
关于岩土工程类比法的研究   总被引:19,自引:3,他引:19  
为了提高岩土工程类比法的应用水平, 有必要对工程类比法的理论依据、应用条件、可比性和可比度进行深入研究。本文还提出了可比度的概念和以影响因素分析为基础的可比度确定方法。在若干边坡工程的实际应用说明该方法可行。  相似文献   
185.
黄河上游水电工程对局地气候的影响   总被引:4,自引:0,他引:4  
本文阐述了黄河上游段水电工程概况,并以刘家峡和龙羊峡水库为主对库周各站建加前后各5年或10年的气象资料进行了对比分析,揭示了水库对周围地区各气候因子影响程度。  相似文献   
186.
已发现的金矿物有60余种。本文将其分为七类。在附表中列有20种较常见的金矿物及其鉴定特征。金在自然界中有三种赋存状态:可见独立矿物形式;呈次显微状于载体矿物中;或以原子状态混入其他矿物。金的工业矿物以第一种赋存状态为主,它们常与黄铁矿、毒砂、黄铜矿、磁黄铁矿、闪锌矿、方铅矿、黝铜矿和石英等连生,或以其作为载体矿物。呈次显微状的金,是以粒径小于0.2um的球粒形质点,呈机械混入物状态于黄铁矿等硫化物中。  相似文献   
187.
南水北调(中线)安阳主干渠段施工过程中开挖出大量成熟度低且受近源构造影响较大的河湖相沉积岩。对现场采集的上第三系岩石样品开展了化学成分、 岩石骨架成分测试。利用Dickinson法和化学指标法, 研究得到安阳主干渠段西部物源区属于被动陆缘, 在上新世晚期向活动陆缘变化的认识。同期构造活动强烈的克什米尔N—J引水隧洞段的沉积岩, 属于岛弧和活动陆缘的大地构造背景。本文结果丰富了构造稳定和活跃区新近纪沉积构造背景认识, 可为喜马拉雅运动以来不同构造活动背景下的岩石组分和化学指标特征提供参考。  相似文献   
188.
Thermally carbonization biochar produced from a traditional Chinese herbal medicine waste (Astragalus mongholicus residue) was investigated for its performance in ciprofloxacin adsorption. Batch sorption experiments were conducted, and scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller surface area analyses were employed to characterize the biochar. The results demonstrated that thermal activation process improves the adsorbent characteristics. Biochar produced at 800 °C had the best adsorption capacity, a better pore structure and the largest surface areas. The adsorption process fit well to a pseudo-second-order kinetics model. The adsorption isothermal model results revealed that the adsorption process of ciprofloxacin is described better by the Freundlich isotherm and the type of adsorption is a chemical process. The maximum adsorption of ciprofloxacin occurred at pH 7. The present research demonstrated that A. mongholicus biochar might be an attractive and cost-effective adsorbent with good adsorption performance for removing ciprofloxacin from water solution.  相似文献   
189.
新疆巴里坤矿区唯一含煤地层为下侏罗统八道湾组(J1b),根据煤层赋存状态可分为西区、中区与东区,通过对矿区大量钻孔数据和生产矿井实测资料的综合分析,基本查明矿区煤层气赋存状态为水平方向上从西到东呈阶梯状增长、垂直方向上随煤层埋深呈线性增长的赋存规律。矿区煤层气赋存受多种控气地质因素共同作用:稳定的沉积环境有利于成煤聚煤,为煤层气的生成提供了原始条件;后期的构造运动导致西部矿区煤层抬升露头,中东部矿区逆冲、压扭性断层发育,断层面的封闭性与构造煤的透气性共同导致煤层气在近断层处的应力集中带聚集形成气顶;地下水对游离态煤层气形成有效封堵,且随着煤层埋深煤层含气量有显著增大的趋势。上述控气地质因素共同造成巴里坤矿区煤层气赋存呈现西部逸散、中东部富集形成水力封堵-断层型煤层气藏。  相似文献   
190.
Experiments on the partitioning of Cu between different granitic silicate melts and the respective coexisting aqueous fluids have been performed under conditions of 850 °C, 100 MPa and oxygen fugacity(f O2) buffered at approaching Ni–Ni O(NNO). Partition coefficients of Cu(DCu= cfluid/cmelt) were varied with different alumina/alkali mole ratios [Al2O3/(Na2O·K2O), abbreviated as Al/Alk], Na/K mole ratios, and Si O2 mole contents. The DCu increased from 1.28 ± 0.01 to 22.18 ± 0.22 with the increase of Al/Alk mole ratios(ranging from 0.64 to 1.20)and Na/K mole ratios(ranging from 0.58 to 2.56). The experimental results also showed that DCuwas positively correlated with the HCl concentration of the starting fluid.The DCuwas independent of the Si O2 mole content in the range of Si O2 content considered. No DCuvalue was less than 1 in our experiments at 850 °C and 100 MPa, indicating that Cu preferred to enter the fluid phase rather than the coexisting melt phase under most conditions in the melt-fluid system, and thus a significant amount of Cu could be transported in the fluid phase in the magmatichydrothermal environment. The results indicated that Cu favored partitioning into the aqueous fluid rather than themelt phase if there was a high Na/K ratio, Na-rich, peraluminous granitic melt coexisting with the high Cl-fluid.  相似文献   
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