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901.
用转换波检测煤层裂隙的方法探讨 总被引:7,自引:2,他引:7
根据理论模型计算结果对比分析找出的煤层纵波场和转换波场和转换波场与煤层裂隙状态变化间的相关关系,探讨了综合使用纵波和转换波检测煤层裂隙的可行方法,对有效开展转换法地震勘探工作具有指导意义。 相似文献
902.
用改性粘土矿物治理赤潮灾害的前景 总被引:3,自引:0,他引:3
赤潮,这一当今全球性的海洋灾害,正严重干扰着30多个沿海国家的经济发展。近年来,我国已成为一个赤潮灾害多发的国家。我国大陆沿海1972年至1994年记录有256次赤潮灾害,且呈逐年增加趋势。据统计,仅1998年的赤潮所造成的经济损失就已超过10亿人民币。1998年是我国赤潮重灾年:三四月份,赤潮袭击香港,造成约3亿港元的损失。广东省从饶平市、汕尾市到深圳、珠海、阳江沿海相继发生了赤潮,蔓延速度之快,致灾面积之大,实属历史罕见,是广东省近13年来最严重的一次,造成的经济损失超过1亿元。1998年下… 相似文献
903.
Although it has been shown that the potential of tight‐sand gas resources is large, the research into the mechanisms of hydrocarbon charging of tight sandstone reservoirs has been relatively sparse. Researchers have found that there is a force balance during hydrocarbon charging, but discriminant models still have not been established. Based on the force balance conditions observed during gas migration from source rocks to tight sandstone reservoirs, a calculation formula was established. A formula for identifying effective source rocks was developed with the gas expulsion intensity as the discrimination parameter. The critical gas expulsion intensity under conditions of various burial depths, temperatures, and pressures can be obtained using the calculation formula. This method was applied in the Jurassic tight sandstone reservoirs of the eastern Kuqa Depression, Tarim Basin, and it was calculated that the critical expulsion intensity range from 6.05 × 108 m3/km2 to 10.07 × 108 m3/km2. The critical gas charging force first increases with depth and later decreases with greater depths. The distribution range of effective gas source rocks and total expelled gas volume can be determined based on this threshold. This method provides new insight into and method for predicting favourable tight‐sand gas‐bearing regions and estimating their resource potentials. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
904.
Environmental magnetic techniques provide significant potential for characterizing sediments and soils and inferring their sources. This article discusses the application of environmental magnetic techniques in the study of an evolving landscape in the Shangqiu area, China, an archaeologically important region for investigating the origin of Shang civilization. Two magnetic parameters—anhysteretic remanent magnetization (ARM) and low-field magnetic susceptibility (χ)—are employed to discriminate the pre-Neolithic paleosol from the historic alluvium. In order to quantitatively interpret magnetic measurements, ARM versus χ plots are utilized with rigorous statistical analyses including group comparison and discriminant classification. With the ARM/χ classification model defined by the pre-Neolithic paleosol and historic alluvium, the sediment sources of three anthropogenic deposits (A-1, A-2, and A-3 from oldest to youngest) are addressed. Magnetic data clearly show that A-1 and A-3 are closely associated with the pre-Neolithic paleosol and historic alluvium, respectively. Cultural mixing processes might be partially responsible for the formation of A-2. © 1998 John Wiley & Sons, Inc. 相似文献
905.
Feixiang Wu Xinhai Li Zhixing Wang Ling Wu Huajun Guo Xunhui Xiong Xiaoping Zhang Xiaojuan Wang 《International Journal of Mineral Processing》2011,98(1-2):106-112
The hydrolyzed titania residue with mainly precipitated hydrated TiO2 is prepared from mechanically activated Panzhihua ilmenite leached by hydrochloric acid. We use H2O2 as a coordination agent to leach Ti from the hydrolyzed titania residue. The effects of H2O2 to-hydrolyzed titania residue mass ratio, leaching pH value, leaching temperature, leaching time, and H2O2 concentration on leaching of hydrolyzed titania residue by H2O2 are investigated. The recovery of Ti is above 98% under the optimal conditions. XRD shows that the peroxo-titania powder prepared by boiling the aqueous titanium peroxide solution is crystalline anatase phase. A well-crystallized anatase TiO2 and rutile TiO2 can be obtained through calcining at the temperature of 800 and 1000 °C, respectively. EDS shows that the impurities including silicon are enriched in the leaching slag. Little Si is detected as the only impurity in the synthetic TiO2 due to the weak alkaline condition of leaching. 相似文献
906.
以松树头煤矿水文地质勘查为例,介绍了测井曲线在含水层解释中的应用。实例表明,自然伽马、自然电位和视电阻率三种曲线对含水层具有明显的异常反应,在含水层中,前二种曲线表现为负异常,后者表现为正异常;对于隔水层,前二种曲线则表现为正异常,而视电阻率表现为负异常。根据测井解释成果与钻孔消耗量、岩心及抽水试验资料相互印证,解释松树头煤矿ZK5-2钻孔368.30~406.42m段,从上到下依次为含水层、隔水层、含水层、隔水层四段。另外,从实例应用的三种曲线可知,视电阻率曲线对于岩石粒度及含水层具有明显的响应特征,极差高达117Ω.m。 相似文献
907.
Behavior of REE Fractionation during Weathering of Dolomite Regolith Profile in Southwest China 总被引:3,自引:0,他引:3
<正>REE fractionation during the weathering of dolomite has been recognized for decades.A regolith profile on dolomite in southwest Yunnan of China was selected to investigate the behaviors of REE during weathering.The weathering of dolomite is divided into two stages:the pedogenesis stage and soil evolution stage,corresponding to the saprolites and soils respectively in the regolith profile. SiO_2,TiO_2,P_2O_5,Zr,Hf,Nb and Ta were immobile components during the weathering by and large, while Al_2O_3,K_2O and Fe_2O_3 were lost during the soil evolution stage in the physical form(clay minerals probably).REE were fractionated during the whole weathering of dolomite.The field weathering profile and the lab acid-leaching experiments on dolomite indicate that MREE were enriched clearly relative to other REE during the pedogenesis stage in a capillary ascending-adsorption mechanism, but they did not fractionate clearly in the soil evolution stage.REE were lost and accumulated in the weathering front of dolomite during the soil evolution stage in a physical-chemical leaching mechanism. 相似文献
908.
909.
Managing the risks of extreme events such as natural disasters to advance climate change adaptation (CCA) has been a global focus. However, a critical challenge in supporting CCA is to improve its linkage with disaster risk reduction (DRR). Based on discussions on similarities and differences between CCA and DRR concerning their spatial–temporal scales, main focuses, preferred research approaches and methodologies, etc., this paper tentatively put forward an analytical framework of “6W” for linking DRR with CCA. This framework presented preliminary answers to a series of fundamental questions, such as “What is adaptation with respect to disaster risk?” “Why adaptation is needed?” “Who adapt to what?” “How to adapt?” “What are the possible principles to assess the adaptation effect?” To bridge the research gaps between CCA and DRR, it is imperative to associate the adaptation actions with both near-term disaster risk and long-term climate change and formulate adaptation strategies at various spatial–temporal scales by embracing uncertainty in a changing climate. 相似文献
910.
R. R. Giri H. Ozaki X. Guo R. Takanami S. Taniguchi 《International Journal of Environmental Science and Technology》2014,11(5):1277-1284
This article aims to elucidate on usefulness of vacuum ultraviolet (VUV) for photoreductive degradation of perfluorooctanoic acid (PFOA), a representative perfluorinated compound (PFC), in water for the first time. Bench-scale tests were conducted on oxidative and reductive (with aquated electron: e aq ? ) mineralization of PFOA using low-pressure UV (LPUV) lamps and potassium iodide. Unlike with 254 nm wavelength (UVC), the reductive mineralization with VUV was very inefficient compared to the corresponding oxidative mineralization. The inefficiency is attributed to low reactivity of e aq ? with PFOA and its fluorinated products than that of 185 nm photons. Direct VUV photolysis of PFOA and its products in reductive reaction conditions was not apparent due to a very big difference in reactivity of 185 and 254 nm photons with iodide. The results demonstrated that highly energetic VUV photons are not suitable for photoreductive degradations of PFCs involving e aq ? , but they can be best used for oxidative degradations. These findings should serve as an important reference on VUV usage to decompose refractory micropollutants. 相似文献