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91.
线性地质统计学的发展与地质工作逐渐由定性向定量、由人工劳动逐渐被计算机取代的过程密切相关的。对样品品位赋予一定的权值进行滑动加权平均,来估计中心块段平均品位的方法,使地质问题的计算能在计算机上实现开辟了新的途径。 相似文献
92.
Xiaodong Wu Lin Zhao Tonghua Wu Ji Chen Qiangqiang Pang Erji Du Hongbing Fang Zhiwei Wang Yonghua Zhao Yongjian Ding 《Environmental Earth Sciences》2013,68(3):865-870
A large volume of underground gas in the permafrost region of the Qinghai-Tibetan Plateau has been identified. Although many studies were performed to investigate the soil organic carbon dynamics and Earth degassing in volcanic areas, this is the first report of a large amount of non-volcanic CO2 contained in permafrost. The gas was mostly CO2 (81.76 vol. %) and nitrogen (14.59 vol. %). The gas composition and the evidence from carbon stable isotope values (?23.9 ‰, PDB) suggested that the gases possibly had a deep origin. The gas emissions may be triggered by permafrost degradation, which means mitigation of the barrier effect of permafrost for the gas. In addition, plate tectonic processes may also lead to gas emissions, as the tectonic activity is strong in the area. Therefore, particular attention should be paid to the underground gases in the study of global change and permafrost degradation. 相似文献
93.
This study presents a laboratory study of the following two aspects: (1) the influence of sea laver treatment acid on the
geoenvironmental properties of Ariake Sea tidal mud, and (2) the natural remediation effect on the sea laver treatment acid
contaminated Ariake Sea tidal mud caused by the upward seepage of pore water liquid in the mud. Firstly, the mechanisms of
the transport of sea laver treatment acid in the Ariake Sea tidal mud and the generation mechanisms of the upward seepage
flow in the Ariake Sea tidal mud are discussed. Secondly, a series of one-dimensional laboratory infiltration tests were carried
out to investigate the deterioration of the Ariake Sea tidal mud caused by the sea laver acid treatment practice. Test results
reveal that the acid treatment practice caused considerable change in the geochemical properties of the mud in terms of increase
in sulfide content and decrease in pH value. After the treatment by the sea laver treatment acid, the sulfide content of the
mud even exceeded the safe limit value for the benthos, which represents undesirable living condition for benthos. Thirdly,
series of laboratory fresh seawater infiltration tests for the deteriorated Iida site mud were conducted to illustrate this
natural remediation efficiency. It is found that with the infiltration of the fresh seawater, the sulfide content of the Iida
site mud was considerably reduced and pH value increased to an acceptable range for benthos living in the tidal flat mud.
With the increase in the infiltration time and the hydraulic gradient, the remediation efficiency could be increased. 相似文献
94.
Du Jianguo 《中国地球化学学报》1992,11(3):237-243
Heat flow and the origin of helium in natural gases from fault basins of the continental rift-valley in eastern China are
discussed in terms of helium isotope geochemistry.3He/4He ratios in natural gases from the rift-valley range from 2.23 × 10−7 to 7.21 × 10−6, which are directly proportional to the concentration of helium and ΣNHC/ΣHC ratio in natural gases. Geological and isotope
geochemical data suggest that helium in natural gases consists predominantly of crustal radio-genic and upper mantle-derived
helium. In a simple mixing pattern between crustal He and mantle-derived He, mantle-derived helium in natural gases would
account for 10–60%. Calculated values for heat flow (Q) range from 59.7 to 82.4mWm−2, of which about 60 percent in the rift-valley is derived from the upper mantle. Natural helium reservoirs would be found
in the areas where the upper mantle uplifted greatly and heat flow is large in the continental rift-valley.
The project is financially supported by the National Natural Science Foundation of China. 相似文献
95.
使用粉末压片法制样,X射线荧光光谱法测定地质样品中氯,探讨了样片背衬、样片接受X光照射时间对测量结果的影响。Cl的精密度(RSD,n=12)小于10%。Cl的方法检出限为12μg/g,采用国家一级标准物质分析验证方法,其结果与标准值相符。 相似文献
96.
Ling-zhi Huang Guang-ming Zeng Dan-lian Huang Li-feng Li Chun-yan Du Ling Zhang 《Environmental Earth Sciences》2010,60(8):1683-1691
Biosorption is an effective method to remove heavy metals from wastewater. In this work, the biosorption of Cd(II) onto Hydrilla verticillata was examined in aqueous solution with parameters of initial pH, adsorbent dosage, contact time, initial Cd(II) concentration,
temperature, and co-existing ion. Linear Langmuir and Freundlich models were applied to describe the equilibrium isotherms,
and both of the two models were fitted well. The monolayer adsorption capacity of Cd(II) was found to be 50 mg/g at pH 6 and
20°C. Dubinin–Radushkevich isotherm model was also applied to the equilibrium data. The mean free energy of adsorption (11.18 kJ/mol)
indicated that the adsorption of Cd(II) onto H. verticillata might be carried out via chemical ion-exchange mechanism. Thermodynamic parameters, including free energy (∆G
0), enthalpy (∆H
0), and entropy (∆S
0) of adsorption, were also calculated. These results showed that the biosorption of Cd(II) onto H. verticillata was a feasible, spontaneous, and exothermic process in nature. Desorption experiments indicated that 0.01 mol/L EDTA and
HNO3 were efficient desorbents for the recovery of Cd(II) from biomass. IR spectrum analysis suggested that amido, hydroxyl, C=O
and C–O could combine strongly with Cd(II). EDX spectrum analysis suggested that an ion exchange mechanism might be involved. 相似文献
97.
NewEvidenceforEastwardExtensionofLateHercynian-EarlyIndosinianQinlingSeaDuYuansheng;FengQinglai;YinHongfu(FacultyofEarthScien... 相似文献
98.
下扬子区二叠系层序地层的地球化学特征 总被引:4,自引:1,他引:4
本文以安徽巢县平顶山、鬼门关剖面为例,阐述了二叠系沉岩的主要岩石类型,即灰岩、硅质岩和泥质岩的岩石学特征及稀土元素组成特点;划分出七种沉积相类型,即局限台地相、开阔台地相、斜坡相、盆地相、三角洲相、汪 相和陆缘泻湖相;识别出七个Ⅲ级层序,其中四个为Ⅰ型层,三个为Ⅱ型层序。对栖霞组灰岩的地球化学测试数据进行了统计分析,总结了海侵体系域,高水位体系域的氧碳同位素、稀土元素和微量元素组成的差异,并认为造 相似文献
99.
结构双层多重调谐质量阻尼器(DMTMD)控制策略的鲁棒性评价 总被引:1,自引:0,他引:1
基于定义的二类优化目标函数,评价双层多重调谐质量阻尼器(DMTMD)控制策略对漂移频率系数(DFR)摄动的鲁棒性。数值研究表明,使用第二类优化准则设计的DMTMD、双重调谐质量阻尼器(DTMD)和多重调谐质量阻尼器(MTMD)比使用第一类优化准则设计的DMTMD、DTMD和MTMD具有更高的对DFR摄动的鲁棒性。而且,使用第二类优化准则设计的总数为4的DMTMD、DTMD和总数为11的MTMD具有近似相同的对DFR摄动的鲁棒性。 相似文献
100.
Following an earlier climatological study of North Pacific Polar Lows by employing dynamical downscaling of NCEP1 reanalysis in the regional climate model COSMO-CLM, the characteristics of Polar Low genesis over the North Pacific under different global warming scenarios are investigated. Simulations based on three scenarios from the Special Report on Emissions Scenarios were conducted using a global climate model (ECHAM5) and used to examine systematic changes in the occurrence of Polar Lows over the twenty first century. The results show that with more greenhouse gas emissions, global air temperature would rise, and the frequency of Polar Lows would decrease. With sea ice melting, the distribution of Polar Low genesis shows a northward shift. In the scenarios with stronger warming there is a larger reduction in the number of Polar Lows. 相似文献