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951.
保护生态环境、防治矸石灾害   总被引:2,自引:0,他引:2  
我国是世界上唯一以煤炭为基本能源的大国,在一次能源消费中,煤炭占57%以上。随着经济的发展,煤炭资源的开采日益加强,煤矸石的产量亦日趋增多,然而对煤矸石的随意堆存和缺乏有效管理,不但占用了土地资源,而且对生态和人文环境均造成了一定的危害。本文较详细地论述了对煤矸石的不合理堆放给人类生存环境带来的一些常见危害以及如何充分利用煤矸石,使之变“废”为“宝”。文章最后,作者提出了一些合理化切实可行的防治对策和管理措施。  相似文献   
952.
The world is marching into a new development period when the digital technology, physical technology, and biological technology have achieved an unprecedented development respectively in their own fields, and at the same time their applications are converging greatly. These are the three major technological drivers for the Fourth Industrial Revolution. This paper discusses the specific technology niches of each kind technological driver behind the Fourth Industrial Revolution, and then evaluates impacts of the Fourth Industrial Revolution on global industrial, economic, and social development. At last this paper proposes possible measures and policies for both firms and governments to cope with the changes brought by the Fourth Industrial Revolution.  相似文献   
953.
Sediment samples obtained from the South Mid-Atlantic Ridge were analyzed for the major and trace elements by inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry. Results revealed that the contents of elements (e.g., Fe, Mn, Cu, Zn, V, Co) were high in samples 22V-TVG10 and 26V-TVG05 from the sites near the hydrothermal areas, and low in sample 22V-TVG14, which was collected far from the hydrothermal areas. The contents of Ca, Sr and Ba in the samples showed opposite trends. A positive correlation between the concentrations of metallic elements (Cu, Zn, Co, Ni, Pb, V) and Fe in the samples were observed. These results are consistent with chemical evolution of the dispersing hydrothermal plume.  相似文献   
954.
The three dimensional(3D) geometry of soil macropores largely controls preferential flow, which is a significant infiltrating mechanism for rainfall in forest soils and affects slope stability. However, detailed studies on the 3D geometry of macropore networks in forest soils are rare. The intense rainfall-triggered potentially unstable slopes were threatening the villages at the downstream of Touzhai valley(Yunnan, China). We visualized and quantified the 3D macropore networks in undisturbed soil columns(Histosols) taken from a forest hillslope in Touzhai valley, and compared them with those in agricultural soils(corn and soybean in USA; barley, fodder beet and red fescue in Denmark) and grassland soils in USA. We took two large undisturbed soil columns(250 mm×250 mm×500 mm), and scanned the soil columns at in-situ soil water content conditions using X-ray computed tomography at a voxel resolution of 0.945 × 0.945 × 1.500 mm~3. After reconstruction and visualization, we quantified the characteristics of macropore networks. In the studiedforest soils, the main types of macropores were root channels, inter-aggregate voids, macropores without knowing origin, root-soil interface and stone-soil interface. While macropore networks tend to be more complex, larger, deeper and longer. The forest soils have high macroporosity, total macropore wall area density, node density, and large macropore volume, hydraulic radius, mean macropore length, angle, and low tortuosity. The findings suggest that macropore networks in the forest soils have high interconnectivity, vertical continuity, linearity and less vertically oriented.  相似文献   
955.
Focusing on the peculiarities of urban construction resulting from specific mountain terrains, the purpose of this study is to find out a suitable method based on a Spatial Network Comprehensive Model (SNCM) to reasonably plan and distribute primary schools in low-income mountain cities. The construction principles and advantages of the SNCM method are proposed and the method tested in Wanyuan city of Qinba Mountain area (Southwest China) to verify its feasibility and optimization. Taking account of the mountain terrain and its influence on user behavior, we used the SNCM method to build a comprehensive model which integrates the road slope and the walking speed of pupils into the basic spatial model. The model is used to calculate a reasonable layout of the primary schools and to validate the rationale. The results show that the SNCM method can be effectively applied in low-income mountainous cities. It can not only improve the accessibility and service efficiency of primary schools using as little capital-investment as possible, but also help the city grow in an intensive and efficient way.  相似文献   
956.
Based on the results of regional eco-geochemical survey in Pearl River Delta Economic Zone and the local land use patterns, two conventional risk assessment models are introduced to evaluate the ecological risk of eight heavy metals in the topsoil (0~20 cm) of Pearl River Delta. The spatial distribution characteristics of risk caused by metals in the region were characterized by GIS. Results show that As、Cd、Cu and Hg in the topsoil are the primary heavy metals posing risk to the Pearl River Delta while Cr and Zn are negligible. Meanwhile, 23.89% of soil samples have a hazard index of more than 1 which suggests that it is likely to cause chronic diseases in the region. The soils with high hazard index are mainly distributed in the Quaternary area. 37.22% of soil samples have a negligible chronic risk level, of which the spatial distribution is consistent with granite area. Moreover, the spatial distribution of carcinogenic risk is similar to chronic risk, where 25.68% of samples exceed the cancer risk index (1×10-4) recommended by USEPA. Furthermore, the evaluation results presented at administrative units indicate that there are both higher chronic and cancer risk in Panyu and Nansha district where more attentions should be paid to.  相似文献   
957.
This paper analyzed contents and geochemical fractions of four heavy metals in four Quaternary boreholes from different sedimentary areas in Pearl River Delta. The results revealed that the geochemical features of heavy metals were controlled by geological provenance and sedimentary environment. The contribution rates of geological sources showed differentiation in four sedimentary environments. In delta plain sedimentary environment, geological sources were the most predominant. In the sea land interaction sedimentary environment, the control of the geological source factor was weakened. The effect of land-sea interaction became more important. Due to different chemical properties of heavy metals, they showed distinct sensitivities to sedimentary environment. Cadmium (Cd) was enriched significantly in the study areas. Mobile fraction of Cd possessed the highest proportion. Potential ecological risk of Cadmium was the highest among heavy metals. Asenic, mercury and lead were enriched weakly. Arsenic and Mercury were dominated by residual fraction. Lead was mainly composed of residual and Fe-Mn oxidation fraction. Their potential ecological risks were relatively lower. In different sedimentary environment, physicochemical parameters had various effects on Cadmium geochemical fraction such as pH. The mobile fraction of Cd was mainly correlated with pH and leaching coefficient.  相似文献   
958.
In recent decades, due to the combined effect of human activities and climate change, the ecosystem of our country has been continuously degraded, seriously affecting the sustainable economic and social development. In order to protect and recover the ecosystem, China has invested heavily in launching a series of key ecological programs and projects including North Shelter Forest Program, Grain for Green Project and integrated ecosystem management of rock desertification. How to comprehensively and timely grasp the ecological effects and existing flaws of the implementation of key ecological projects so as to scroll the implementation of ecological projects and ensure the implementation effect of the projects, and promote the follow-up ecological engineering deployment of being scientific and space-oriented is a major imperative for the country. Therefore, the National Key Research and Development Program of China set up the project of “Monitoring and Assessment of Ecological Benefits of Key Ecological Engineering in China”. Through the implementation of this project, we will establish an indicator system for monitoring and evaluating the ecological benefits of key ecological projects, developing various technical systems for monitoring and evaluating the ecological benefits of key ecological projects, quantitatively evaluating the ecological benefits of key ecological projects, and concise the technical approaches to enhancing ecological benefits. We will provide a scientific basis for future planning and management of key ecological projects.  相似文献   
959.
国家数字地震台网产出资料的分析与说明   总被引:1,自引:0,他引:1  
介绍了2001年以来地震台站的资料分析情况和国家数字地震台网分中心的资料产出情况,通过分析表明,由于宽频带数字地震资料具有频带宽、动态范围大等特点,2003年利用数字地震台网资料分析地震的数量比传统的模拟记录提高30%~40%。  相似文献   
960.
Traditional magneto-electric vibration sensors and servo accelerometers have severe shortcomings when used to measure vibration where low frequency components predominate. A low frequency characteristic extension for velocity vibration sensors is presented in this paper. The passive circuit technology, active compensation technology and the closedcycle pole compensation technology are used to extend the measurable range and to improve low frequency characteristics of sensors. Thses three types of low frequency velocity vibration sensors have been developed and widely adopted in China.  相似文献   
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