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991.
中国西部地区生态环境十分脆弱,又是大江大河的河源地,如果发生不利的开发行为,西部大开发可能导致环境的大污染,生态的大破坏和不可再生资源的全面枯竭,最终威胁到西部人的生存和发展。因此,制定正确的开发战略至关重要。利用地理学原理,客观地分析西部经济发展的限制因素和比较优势,依据非均衡的增长极开发理论,探讨如何推进西部小城镇建设,培育具有西部比较优势的特色农业支柱产业,以信息化带动工业化,实现西部资源的综合利用,使城市增长极和产业增长极成为动广大中西部地区经济增长的不竭动力。 相似文献
992.
在多煤层发育地区,各煤层组之间发育低渗透岩层,使得上下煤组之间形成独立的多层叠置含煤层气系统。根据相对独立含气系统理论对西山煤田南部赤峪地区的多煤层进行了含气系统的划分,并对储层压力、临界解吸压力等参数进行了分析,在此基础上采用COMET3数值模拟软件进行了单层排采、合层排采和递进排采分析。模拟结果显示:单层排采产量低,经济可采时间短,且成本较高;合层排采比单层排采产量高,经济可采时间长,但各含气系统之间由于相互干扰,贡献不一,使资源浪费;递进排采产气量和稳产时间均优于前两者。可根据产气压力来确定多层叠置含煤层气系统排采次序,首先排采产气压力最高的含气系统,当压力降至压力低的系统时再合排。 相似文献
993.
R. R. Liu Q. Tian Ph.D. B. Yang Ph.D. J. H. Chen Ph.D. 《International Journal of Environmental Science and Technology》2010,7(1):111-118
Polyvinyl alcohol-containing desizing wastewater discharged within final textile wastewater has a great impact to the environment due to its poor biodegradability. An improved lab-scale hybrid anaerobic baffled reactor was developed to treat desizing wastewater. The modification was achieved by increasing the height of hybrid anaerobic baffled reactor and application of proper effluent recycle enabled to increase the ability of entrapping microbe-rich small particles in the reactor and prompted the formation of granules. The significant difficulty in hybrid anaerobic baffled reactor operation is the slow start-up procedure, which is crucial to the overall polyvinyl alcohol-containing desizing wastewater treatment. Therefore, the ability of a hybrid anaerobic baffled reactor, treating desizing wastewater, to achieve a prompt start-up was studied at lab-scale. Results showed that inoculated with anaerobic granular sludge and adoption of effluent recycle during start-up, the system demonstrated a good performance of polyvinyl alcohol removal efficiency (above 17.2 %) and satisfactory stability of pH and alkalinity in effluent (range around 7.4–8.0 and 700–920 mg/L, respectively) and the sludge appeared obviously granulation. Thus, the prompt start-up was achieved after 60 days. The start-up strategy used for this process has achieved its goals by creating an active microbial population. The improved lab-scale hybrid anaerobic baffled reactor proved to be an efficient reactor configuration for the treatment of desizing wastewater, which favored the prompt start-up of hybrid anaerobic baffled reactor. The results also provide evidence to modify the design of anaerobic baffled reactor to improve reactor performance. 相似文献
994.
Qiyu Chen Gang Liu Xiaogang Ma Zhong Yao Yiping Tian Hongling Wang 《Earth Science Informatics》2018,11(4):591-603
The construction of a large-scale integrated information system has been a hot issue in the field of geoinformatics. It aims to integrate aboveground and underground spatial information and objects in a unified visual environment. Virtual globe, as the most commonly used technology in the construction of Digital Earth, can provide a platform and framework for the integration and visualization of worldwide spatial objects and models. However, the existing works mainly focused on terrains and aboveground spatial entities, and there is still little research on the integration and visualization of large-scale underground geological models and entities in a virtual globe. In this work, the data organizations of aboveground and underground 3D spatial objects were analyzed in detail according to the technical characteristics of the virtual globe. Improved strategies were proposed to achieve the integrated visualization of aboveground and underground 3D spatial objects in a virtual globe-based spherical coordinate. In this process, the terrain surface based on Triangulated Irregular Network (TIN) was used as an intermediate layer to unify the spatial coordinate system. An improved scene cutting approach was used to overcome the challenge that underground geological structures cannot be integrated and visualized with aboveground spatial entities, terrains and landforms. Finally, we developed a virtual globe-based prototype system using OpenSceneGraph (OSG) and osgEarth as the 3D visualization engine. The aboveground and underground spatial models of Fuzhou, a coastal city of eastern China, were applied in this system to verify the validity of the strategies proposed in this paper. In addition, the efficiency of this system in terms of scheduling and visualizing was tested by using the massive models of Fuzhou. 相似文献
995.
996.
本文介绍了碘酸钾标准物质的研制程序,其中包括溶液的配制、均匀性和稳定性检验、分析方法和数据统计处理方法等。并选择了具有高准确度的精密库仑法和自动电位滴定法分析定值,对制备浓度为0.01mol/dm3碘酸钾标准物质,其定值的相对不确定度可达0.1%,稳定期在一年以上 相似文献
997.
本文以东营凹陷西部沙河街组三段上部白云岩为例,对白云岩产出的层序类型进行了分析,结果表明区内白云岩在不同钻井中产出的层序特征不同,分别与砂砾岩、粉砂岩、泥岩等互层.在上述基础上,运用层序地层学理论对白云岩层进行了层序地层学分析,其为高水位体系域晚期发展阶段的产物,是进积准层序的组成单元。 相似文献
998.
Chunyan Zhu Leicheng Guo Dirk Sebastiaan van Maren Bo Tian Xianye Wang Qing He Zheng Bing Wang 《地球表面变化过程与地形》2019,44(12):2319-2332
The morphology of the Yangtze Estuary has changed substantially at decadal time scales in response to natural processes, local human interference and reduced sediment supply. Due to its high sediment load, the morphodynamic response time of the estuary is short, providing a valuable semi-natural system to evaluate large-scale estuarine morphodynamic responses to interference. Previous studies primarily addressed local morphologic changes within the estuary, but since an overall sediment balance is missing, it remains unclear whether the estuary as a whole has shifted from sedimentation to erosion in response to reduced riverine sediment supply (e.g. resulting from construction of the Three Gorges Dam). In this paper we examine the morphological changes of two large shoals in the mouth zone (i.e. the Hengsha flat and the Jiuduan shoal) using bathymetric data collected between 1953 and 2016 and a series of satellite images. We observe that the two shoals accreted at different rates before 2010 but reverted to erosion thereafter. Human activities such as dredging and dumping contribute to erosion, masking the impacts of sediment source reduction. The effects of local human intervention (such as the construction of a navigation channel) are instantaneous and are likely to have already resulted in new dynamic equilibrium conditions. The morphodynamic response time of the mouth zone to riverine sediment decrease is further suggested to be >30 years (starting from the mid-1980s). Accounting for the different adaptation time scales of various human activities is essential when interpreting morphodynamic changes in large-scale estuaries and deltas. © 2019 John Wiley & Sons, Ltd. 相似文献
999.
1000.
安徽铜陵朝山金矿床稳定同位素、稀土元素地球化学研究 总被引:14,自引:0,他引:14
朝山金矿床位于安徽铜陵狮子山矿田,属于矽卡岩型金矿床,侵入岩体为白芒山辉石二长闪长岩体。成矿过程包括矽卡岩阶段、石英-硫化物阶段和碳酸盐阶段3个主要成矿阶段。文章通过对朝山金矿床的氢、氧、碳、硫、硅同位素组成和稀土元素地球化学特征的研究,探讨成矿溶液中水、碳、硅和硫的来源以及成矿溶液的演化问题。研究表明,成矿热液早期以岩浆热液为主,随着成矿过程的进行,加入的大气降水比重越来越大,到晚期可能主要以大气降水为主。该矿床矿石中方解石的碳、氧同位素组成与矿区大理岩的碳、氧同位素组成明显不同,其δ^13 Cv-PDB、δ^18OV-SMOW值分别为-4.5~-5.3‰、13.9~14.0‰,与岩浆作用形成的CO2的碳、氧同位素组成一致,表明矿石中方解石的碳、氧来源于岩浆作用。硅和硫具深部岩浆或岩浆热液来源的特点。 相似文献