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Outside Class Reading Contributes to English Learning --A Survey of Non-English Major University Students' Opinions on the Relation between Outside Class Reading in English and English Learning 被引量:1
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作者 Xiaoxiang Li 《Sino-US English Teaching》 2005年第9期77-79,共3页
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Landscape Changes from 1974 to 1995 in the Upper Minjiang River Basin, China 被引量:16
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作者 HE Xing-Yuan ZHAO Yong-Hua +2 位作者 HU Yuan-Man CHANG Yu ZHOU Qi-Xing 《Pedosphere》 SCIE CAS CSCD 2006年第3期398-405,共8页
Landscape changes were traced over the 20 years from 1974 to 1995 in the upper Minjiang River basin, one of the most important forest regions in China, based on satellite image interpretation to provide basic data for... Landscape changes were traced over the 20 years from 1974 to 1995 in the upper Minjiang River basin, one of the most important forest regions in China, based on satellite image interpretation to provide basic data for local decision-making as well as sustainable landscape use and management. Results revealed that landscape from 1974 to 1995 changed at the regional scale as the area of forestland decreased, while cropland, shrubland, economic forest, grassland, and built-up land increased. Landscape changes mainly occurred in forestland, shrubland, grassland, economic forest, and built-up land. Moreover, the changes among forestland, shrubland, and grassland were the largest, influencing the whole characteristics of the changes in the basin. Analysis of the changes between 1974 and 1995 in the study area indicated that landscape heterogeneity and fragmentation increased, whereas landscape connectivity decreased. There were multiple reasons for landscape changes. A principal component analysis (PCA) was used to quantitatively study driving forces of landscape changes. The PCA results showed that economic and population factors were the principal driving forces of landscape changes from 1974 to 1995 in the upper Minjiang River basin, and that PCA was a suitable method for investigating driving forces of landscape changes. 展开更多
关键词 卫星图象 量化 生态系统 空间尺寸 环境问题
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Division of diagenesis reservoir facies and its control——Case study of Chang-3 reservoir in Yangchang formation of Fuxian exploration area in northern Shaanxi 被引量:6
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作者 FU Guo-min QIN Xiao-li +2 位作者 MIAO Qing ZHANG Tian-jin YANG Jian-peng 《Mining Science and Technology》 EI CAS 2009年第4期537-543,共7页
By dividing the diagenetic reservoir facies and studying its distribution,we can effectively evaluate reservoirs.Using an analytical method for mutual relationships among diagenesis of reservoirs,structural characteri... By dividing the diagenetic reservoir facies and studying its distribution,we can effectively evaluate reservoirs.Using an analytical method for mutual relationships among diagenesis of reservoirs,structural characteristics and the origin of types of sand,we classified the diagenetic reservoir of the Yanchang formation Chang-3 oil layer into different types and analyzed the factors controlling this high quality reservoir.The results show that:1) the catagenesis of the Chang-3 oil layer in the Fuxian region is complex and variable;2) mechanical compaction,pressure solutions and cementation of all kinds of authogenous minerals decreases porosity by 28.13% and 3) corrosion increases porosity by 3.39%.Cementation and corrosion of laumontite is a kind of catagenesis which makes this region different from other exploratory regions.The original amount and rate of corrosion of laumontite are the main factors for the increase in laumontite porosity.The Chang-3 oil layer developed four kinds of diagenetic reservoir facies,of which the weak compaction facies,i.e.,laumontite corrosion and overgrowth,of the original pore reservoir facies has the most promising diagenesis.Its distribution is controlled by a sedimentary facies zone and is widely developed in the original truncated tributary channel facies belt of the delta plain.The development of this high quality reservoir is controlled by the distribution of sedimentary sand bodies and secondarily-eroded porosity of laumontite in the Chang-3 oil layer of the Fuxian exploratory region. 展开更多
关键词 陕北富县探区 成岩作用 储层 控制
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Oxygen and hydrogen isotope exchange of geopressured thermal water in the central Guanzhong basin 被引量:6
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作者 YU Juan MA Zhi-yuan +2 位作者 WANG Zhao-wei LI Wei-liang SU Yan 《Mining Science and Technology》 EI CAS 2009年第1期115-119,共5页
Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with dat... Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that 18O exchange of geothermal water at the perimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geopressured thermal water in the central basin, in cities such as Xi'an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilib-rium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi'an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of dissolute solids and temperatures of geothermal waters, the oxygen exchange accelerates. 展开更多
关键词 广州煤田矿井 氧氢同位素交换 地质热液 矿水学
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GEOCHEMICAL CHARACTERISTICS OF PLATINUM GROUP ELEMENTS IN JINCHUAN SUPER-LARGE SULFIDE COPPER-NICKEL DEPOSIT, JINCHANG CITY, GANSU PROVINCE, CHINA
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作者 WANG Ruiting MAO Jingwen +2 位作者 HE Ying WANG Dongsheng TANG Zhongli 《Geotectonica et Metallogenia》 2005年第2期152-163,共12页
The platinum-group element geochemistry of rocks and ores from Jinchuan super-large copper-nickel sulfide deposit is systemically studied in this paper. The Cu/Pd mean ratio of Jinchuan intrusion is lower than that of... The platinum-group element geochemistry of rocks and ores from Jinchuan super-large copper-nickel sulfide deposit is systemically studied in this paper. The Cu/Pd mean ratio of Jinchuan intrusion is lower than that of original mantle magma, which indicates that these ultrabasic rocks were crystallized from magma that lost Pd in the form of melting segregation of sulfides. The PGE of the rocks show trend of partial melting, similar to that of mantle peridotite, which shows that magma formation occurs during rock-forming and ore-forming processes. The chondrite normalized PGE patterns of the rocks and ores are well related to each other, which signifies the signatures of multi-episode magmatic intrusion, melting and differentiation in the formation processes of rocks and ores. In addition, analyses about the relation between PGE and S, and study on Re-Os isotopes indicate that few contamination of the crustal substances occurred during the magmatic intrusion and the formation of deposit. However, contamination by crustal substances helps to supply part of the S for the enrichment of PGE. Meanwhile, the hydrothermal process is also advantageous for the enrichment of PGE, especially for Pt and Pd, due to deep melting segregation. The characteristic parameters (such as Pt/(Pt+Pd), (Pt+Pd)/(Ru+Ir+Os), Pd/Ir, Cu/(Ni+Cu), and so on.) for platinum-group elements for Jinchuan sulfide copper-nickel deposit show the same features as those for sulfide copper-nickel deposit related to basic magma, which also illustrates its original magma propertyrepresentative of Mg-high tholeiite. Therefore, it is the mafic (not ultramafic) magma that resulted in the formation of the superlarge sulfide copper-nickel deposit enriched in Cu and PGE. To sum up, the geochemical characteristics of platinum-group elements in rocks and ores from Jinchuan copper-nickel sulfide deposit are constrained by the continental rift tectonic environment, the parent magma features, the enriched mantel magma source, the complex metallogenesis and PGE geochemical signatures, and this would be rather significant for the study about the genetic mechanism of copper-nickel sulfide deposits. 展开更多
关键词 硫化物 沉积物 地质特征 甘肃 白金
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A new edge recognition technology based on the normalized vertical derivative of the total horizontal derivative for potential field data 被引量:84
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作者 Wang Wanyin Pan Yu Qiu Zhiyun 《Applied Geophysics》 SCIE CSCD 2009年第3期226-233,299,共9页
边察觉和改进技术通常在用潜在的域数据认出地质的身体的边被使用。我们在场一种新边识别技术基于有边察觉和改进技术的功能的全部的水平衍生物的规范的垂直衍生物。首先,我们计算潜在地的数据的全部的水平衍生物(THDR ) 然后计算 n 顺... 边察觉和改进技术通常在用潜在的域数据认出地质的身体的边被使用。我们在场一种新边识别技术基于有边察觉和改进技术的功能的全部的水平衍生物的规范的垂直衍生物。首先,我们计算潜在地的数据的全部的水平衍生物(THDR ) 然后计算 n 顺序 THDR 的垂直衍生物(VDRn ) 。为 n 顺序垂直衍生物,全部的水平衍生物(PTHDR ) 的山峰价值用比 0 大的阀值价值被获得。这 PTHDR 能被用于边察觉。第二, PTHDR 价值被全部的水平衍生物划分并且由最大的价值使正常化。最后,我们使用了数字模型的不同类型验证新边识别技术的有效性和可靠性。 展开更多
关键词 水平导数 识别技术 衍生物 垂直 基础 边缘检测 N阶导数 增强技术
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Comparisons of extraction and purification methods of soil microorganism DNA from rhizosphere soil 被引量:7
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作者 JIA Xia HAN Shi-jie +1 位作者 ZHAO Yong-hua ZHOU Yu-mei 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第1期31-34,共4页
从 Pinus koraiensis 和 Pinussylvestriformis 的根围土壤的微生物脱氧核糖核酸被朊酶 K 基于 SDS 方法, CTAB 方法, PVP ( polyvinylpolypyrrolidone )方法,和结冰并且融化的方法提取,从根围土壤的粗略的脱氧核糖核酸被分离方法... 从 Pinus koraiensis 和 Pinussylvestriformis 的根围土壤的微生物脱氧核糖核酸被朊酶 K 基于 SDS 方法, CTAB 方法, PVP ( polyvinylpolypyrrolidone )方法,和结冰并且融化的方法提取,从根围土壤的粗略的脱氧核糖核酸被分离方法净化,银祷告吸收方法,并且挤压 DNAgel 方法。方法的不同提取并且净化的结果被比较并且评估。结果显示为在根围的微生物脱氧核糖核酸的抽取的最好的方法与 1.0% 的高盐集中(w/v ) 基于 SDS 方法玷污 wasproteinse K NaCl,它能有效地消除胡敏酸和其它杂质。因为有效地移开棕色的事和胡敏酸,分离方法对从根围土壤的 purifyDNA 合适,净化的产品被适合到 PCR 扩大。挤压脱氧核糖核酸胶化方法也是有优点的一个好纯化方法在费用便宜、在使用有效。 展开更多
关键词 微生物 土壤 纯化作用 根圈
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Hydrogeochemical characteristics of groundwater depression cones in Yinchuan City, Northwest China 被引量:7
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作者 SUN Yaqiao QIAN Hui WU Xuehua 《Chinese Journal Of Geochemistry》 EI CAS 2007年第4期350-355,共6页
Groundwater in Yinchuan City has been heavily over-exploited, thus leading to the formation of depression cones in confined and phreatic groundwater environments. The depression cones have an important influence on th... Groundwater in Yinchuan City has been heavily over-exploited, thus leading to the formation of depression cones in confined and phreatic groundwater environments. The depression cones have an important influence on the hydrodynamic and hydrochemical fields of groundwaters. The evolution of depression cones was analyzed on the basis of the monitoring data on groundwater level accumulated in the past 14 years. The ratio of rCl-/rCa2+ showed that phreatic water circulation was intensified, and confined groundwater was affected by external factors. Mass balance of Cl- showed confined water mixed with about 11% phreatic water. It is shown that the alternative function of confined water was affected by external factors. At last, the evolution of groundwater hydrochemical field on the basis of groundwater chemical composition showed that phreatic water quality has been improved whereas confined water quality has been deteriorated. Saturation indices of minerals with respect to phreatic and confined waters were calculated by using PHREEQC. 展开更多
关键词 地下水漏斗 水化学测量 地下水循环 饱和指数
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Fossil Association from the Lower Cambrian Yanjiahe Formation in the Yangtze Gorges Area,Hubei,South China 被引量:8
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作者 GUO Junfeng LI Yong +7 位作者 HAN Jian ZHANG Xingliang ZHANG Zhifei OU Qiang LIU Jianni SHU Degan Shigenori MARUYAMA Tsuyoshi KOMIYA 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第6期1124-1132,共9页
Apart from previously reported Small Shelly Fossils (SSFs), a macroscopic fossil assemblage, comprising abundant algae, cone-shaped tubular fossil forms, and probable impressions of a megascopic metazoan, comes from... Apart from previously reported Small Shelly Fossils (SSFs), a macroscopic fossil assemblage, comprising abundant algae, cone-shaped tubular fossil forms, and probable impressions of a megascopic metazoan, comes from the Lower Cambrian Yanjiahe Formation in the Yangtze Gorges area of western Hubei Province, south China. The visible fossils are preserved in thinlaminated siltstone or muddy siltstone intercalated between 8-15 ram-thick carbonate deposits, probably representing sedimentary settings of a constrained local depression in the shallow water carbonate platform during the Early Cambrian Meishucunian Stage. The macroscopic fossil association provides significant fossil evidence about the evolution of life from the late Precambrian to the 'Cambrian explosion' interval. 展开更多
关键词 macrofossil association Yanjiahe Formation Lower Cambrian Yangtze Gorges Area Hubei Province
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Classification of Magmatic Sulphide Deposits in China and Mineralization of Small Intrusions 被引量:6
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作者 TANG Zhongli YAN Haiqing +1 位作者 JIAO Jiangang LI Xiaohu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2006年第3期412-419,共8页
Many important metal resources, such as Ni (Cu, Co), PGE, exist in magmatic sulfide deposits, are a hot spot in geological research. We divide the magmatic sulphide deposits in China into four types according to the... Many important metal resources, such as Ni (Cu, Co), PGE, exist in magmatic sulfide deposits, are a hot spot in geological research. We divide the magmatic sulphide deposits in China into four types according to their tectonic setting, intruding mode, ore deposit mode, main metallogenic elements. The four types are as follows: (1) Small-intrusion deposits in paleo-continent; (2) Smallintrusion deposits in continental flood basalt; (3) Small-intrusion deposits in orogenic belt; and (4) The deposits associated with ophiolites. On the basis of the classification, we put forward that the main magmatic metallogenic type in China is small-intrusion metallogeny, and describe its characteristics from small intrusions related concept, three geologic settings, three volcanic-intrusive assemblages and metallogenic key factors. According to the experiences of prospecting at home and abroad, we point out that there is big potential in prospecting small-intrusion deposits, which need further study. At last, we indicate that small-intrusion metallogeny not only widely distributes in mafic-ultramafic intrusions, but also has an important economic value and scientific significance in intermediate-acid intrusions. 展开更多
关键词 magmatic sulfide deposits CLASSIFICATION small intrusions METALLOGENESIS
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Petroleum System of the Sufyan Depression at the Eastern Margin of a Huge Strike-slip Fault Zone in Central Africa 被引量:5
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作者 ZHANG Yamin GU Qin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第6期1182-1187,共6页
The present paper mainly studies the petroleum system of the Sufyan Depression in the Muglad Basin of central Africa and analyzes its control of hydrocarbon accumulation. On the basis of comprehensive analysis of effe... The present paper mainly studies the petroleum system of the Sufyan Depression in the Muglad Basin of central Africa and analyzes its control of hydrocarbon accumulation. On the basis of comprehensive analysis of effective source rock, reservoir bed types and source-reservoir-seal assemblages, petroleum system theory has been used to classify the petroleum system of the Sufyan Depression. Vertically, the Sufyan Depression consists of two subsystems. One is an Abu Gabra subsystem as a self generating, accumulating and sealing assemblage. The other subsystem is composed of an Abu Gabra source rock, Bentiu channel sandstone reservoir and Darfur group shale seal, which is a prolific assemblage in this area. Laterally, the Sufyan Depression is divided into eastern and western parts with separate hydrocarbon generation centers more than 10 000 m deep. The potential of the petroleum system is tremendous. Recently, there has been a great breakthrough in exploration. The Sufyan C-1 well drilled in the central structural belt obtained high-yielding oil flow exceeding 100 tons per day and controlled geologic reserves of tens of millions of tons. The total resource potential of the Sufyan Depression is considerable. The central structural belt is most favorable as an exploration and development prospect. 展开更多
关键词 effective hydrocarbon source rock petroleum system half-graben (graben) Sufyan Depression Muglad Basin
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Moving Shadow Detection and Removal for Traffic Sequences 被引量:12
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作者 Mei Xiao Chong-Zhao Han Lei Zhang 《International Journal of Automation and computing》 EI 2007年第1期38-46,共9页
Segmentation of moving objects in a video sequence is a basic task for application of computer vision. However, shadows extracted along with the objects can result in large errors in object localization and recognitio... Segmentation of moving objects in a video sequence is a basic task for application of computer vision. However, shadows extracted along with the objects can result in large errors in object localization and recognition. In this paper, we propose a method of moving shadow detection based on edge information, which can effectively detect the cast shadow of a moving vehicle in a traffic scene. Having confirmed shadows existing in a figure, we execute the shadow removal algorithm proposed in this paper to segment the shadow from the foreground. The shadow eliminating algorithm removes the boundary of the cast shadow and preserves object edges firstly; secondly, it reconstructs coarse object shapes based on the edge information of objects; and finally, it extracts the cast shadow by subtracting the moving object from the change detection mask and performs further processing. The proposed method has been further tested on images taken under different shadow orientations, vehicle colors and vehicle sizes, and the results have revealed that shadows can be successfully eliminated and thus good video segmentation can be obtained. 展开更多
关键词 Moving shadow detection moving shadow removal edge information traffic scene.
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Selenium and Sulfur Systematics of Mafic Dykes in Western Fujian Province,Southern China 被引量:4
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作者 FAN Haifeng WEN Hanjie +1 位作者 ZHANG Guishan HU Ruizhong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第4期884-895,共12页
Fifteen samples from three study areas (the Bancun diabase dykes, the Bali hornblende gabbro dykes, the Linzifen gabbro-diabase dykes) were collected and analyzed for selenium (Se), sulfur (S), copper (Cu), ma... Fifteen samples from three study areas (the Bancun diabase dykes, the Bali hornblende gabbro dykes, the Linzifen gabbro-diabase dykes) were collected and analyzed for selenium (Se), sulfur (S), copper (Cu), major and trace elements. In general, Se, S and Cu do positively correlate to each other. The concentration of S and Se and the S/Se ratio are higher than the corresponding value of primitive mantle (PM), and the Cu/S ratio falls in a narrow range (0.04-0.29), which is consistent with that of primitive mantle (0.05-0.20). The Bancun diabase dykes and the Bali hornblende gabbro dykes were located in an intraplate environment during the Late Mesozoic. Oceanic subduction was closely related to magmatic activities. The magmatic activities play an important role in the transportation mechanism of Se and S. Because those two groups were closer to fault zones, which may affect the distribution of S and Se and other elements. In the two groups, no crustal contamination was observed, indicating that all analyzed elements may come from enriched mantle metasomtism associated with slab subduction. However, the Linzifen gabbro-diabase dykes were located in an intraplate rift environment, and its invading age is older than the other two groups, the primitive magma comes from mantle, and there is an anomalous relation between S, Se and Al2O3, (La/Sm)N, and all these factors could result in higher S and Se concentration. 展开更多
关键词 selenium and sulfur systematics mafic dyke MESOZOIC Fujian southern China
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Geochemical modeling of groundwater in southern plain area of Pengyang County,Ningxia,China 被引量:4
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作者 Pei-yue LI Hui QIAN Jian-hua WU Jia DING 《Water Science and Engineering》 EI CAS 2010年第3期282-291,共10页
The purpose of this paper is to examine the evolution mechanisms of a hydrochemical field and to promote its benefits to the living standards of local people and to the local economy in the southern plain area of Peng... The purpose of this paper is to examine the evolution mechanisms of a hydrochemical field and to promote its benefits to the living standards of local people and to the local economy in the southern plain area of Pengyang County, in Ningxia, China. Based on understanding of the hydrogeological conditions in Pengyang County, the chemical evolution characteristics of groundwater in the plain area were analyzed. PHREEQC geochemical modeling software was used to perform hydrochemical modeling of water-rock interaction and to quantitatively analyze the evolution processes and the formation mechanisms of the local groundwater. Geochemical modeling was performed for two groundwater paths. The results showed that, along path 1, Na+ adsorption played the leading role in the precipitation process and its amount was the largest, up to 6.08 mmol/L; cation exchange was significant along path 1, while along simulated path 2, albite accounted for the largest amount of dissolution, reaching 9.06 mmol/L, and the cation exchange was not significant. According to the modeling results, along the groundwater flow path, calcite and dolomite showed oversaturated status with a precipitation trend, while the fluorite and gypsum throughout the simulated path were not saturated and showed a dissolution trend. The total dissolved solids (TDS) increased and water quality worsened along the flow path. The dissolution reactions of albite, CO2, and halite, the exchange adsorption reaction of Na+, and the precipitation of sodium montmorillonite and calcite were the primary hydrogeochemical reactions, resulting in changes of hydrochemical ingredients. 展开更多
关键词 HYDROGEOCHEMISTRY water-rock reaction groundwater modeling Pengyang County
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Analysis of ecological effects of comprehensive treatment in the Tarim River Basin using remote sensing data 被引量:4
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作者 Tan Kelong Wang Xiaofeng Gao Huijun 《Mining Science and Technology》 EI CAS 2011年第4期519-524,共6页
Based on multi-type,multi-temporal remote sensing data,we have monitored recent changes in cultivated land use and vegetation,in sandy areas and salinized desertification in the Green Corridor zone of the main channel... Based on multi-type,multi-temporal remote sensing data,we have monitored recent changes in cultivated land use and vegetation,in sandy areas and salinized desertification in the Green Corridor zone of the main channel of the Tarim River Basin.The results of our investigation show that the ecological environment in the Green Corridor of the main channel of the Tarim River Basin has conspicuously improved from 2002 to 2004.These improvements show up largely in such aspects as an increase in the rate of vegetation cover,a reduction in desertification land areas and a weakening in the intensity of sandy and the salinized land.On the other hand,the cultivated area in the Tarim River Basin significantly increased from 2002 to 2004.The rate of growth in cultivated areas during this period was significantly higher than that from 1999 to 2002.The increase in the use of irrigation resulting from the substantial increase in cultivated areas has a long-term potential restraining effect on the restoration of ecological functions of the Tarim River. 展开更多
关键词 塔里木河流域 遥感数据 流域综合治理 生态效应 盐渍化土地 耕地面积 植被变化 绿色走廊
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Environmental Isotopes Study on Geothermal Water in Guanzhong Basin,Shaanxi Province 被引量:6
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作者 MA Zhi-yuan WU Wen-di FAN Ji-jiao SU Yan 《Journal of China University of Mining and Technology》 EI 2007年第1期45-48,共4页
There exists abundant thermal water recourses in Guanzhong basin, Shaanxi province (northwestern China). With the deepening of exploitation for thermal aquifer nowadays, the information about the origin and movement o... There exists abundant thermal water recourses in Guanzhong basin, Shaanxi province (northwestern China). With the deepening of exploitation for thermal aquifer nowadays, the information about the origin and movement of thermal water is limited by using traditional methods. This paper applies environmental isotope techniques to offer direct constraints on the recharge and movement of thermal water and improve the geological and hydrogeological data- base in Guanzhong Basin. The research on the environmental isotopes shows that the geothermal water of the area is mainly recharged by meteoric water. The temperature of meteoric water which replenishes geothermal water in the study area is -16 ℃. The estimated age of recharging the geothermal water is 13.3-28.2 ka based on the isotope analysis, belonging to the last glacial period in Late Quaternary. The source of replenishment of the geothermal water is thought to have been derived from glacial snow-melt water with an elevation higher than 1 500 m (ASL) in the north side of Qinling Mountain. The isotopic analysis denotes that the geothermal water in the southern Guanzhong basin is the mixture of net thermal water and normal temperature groundwater. Based on calculating the percentage of the mixture, nearly half of cold groundwater had participated the circulating of the geothermal water. However, in the center part of the basin, some artificial factors such as mismanage of pumping are probably the reason for the mixturing. The temperature range of the geothermal reservoirs in the basin is estimated at about 80-121 ℃ based on calculation of both SiO2 geothermometer and thermal water saturation index, which are basically in accordance with the measured temperature of thermal water. Based on the replenishment time and mixture extent with cold water, the thermal water in the studied area can be classified into three parts: mixed thermal water replenished by modern meteoric water; mixed thermal water replenished by both modern and ancient meteoric water, and deep circulating thermal water replenished by ancient meteoric water without mixture. 展开更多
关键词 同位素 水地球化学 关中盆地 陕西 地下热水
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Effects of heat treatment on properties of multi-element low alloy wear-resistant steel 被引量:3
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作者 SONG Xu-ding FU Han-guang 《China Foundry》 SCIE CAS 2007年第1期18-21,共4页
The paper has studied the mechanical properties and heat treatment effects on multi-element low alloy wear-resistant steel (MLAWS) used as a material for the liner of rolling mill torii. The results show that when que... The paper has studied the mechanical properties and heat treatment effects on multi-element low alloy wear-resistant steel (MLAWS) used as a material for the liner of rolling mill torii. The results show that when quenched at 900-920℃ and tempered at 350-370℃, the MLAWS has achieved hardness above 60 HRC, tensile strength greater than 1 600 MPa, impact toughness higher than 18J/cm2 and fracture toughness greater than 37 MPa·m1/2. When the quenching temperature is lower than 900℃, the hardness of the MLAWS increases with the temperature. When the quenching temperature is higher than 900℃, the hardness decreases with the increase of temperature. At a quenching temperature below 920℃, the effect of quenching temperature on the impact toughness is not obvious. In quenching at above 920℃, impact toughness decreases as the temperature increases. When the tempering temperature is exceeding 450℃, the hardness begins to decrease significantly. Tempering at 350℃ has produced the best wear resistance on the MLAWS. 展开更多
关键词 多元素 低合金钢 耐磨钢 热处理 机械性能
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Two-dimensional PSD based automatic docking of self-reconfiguration modular exploration robot system 被引量:3
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作者 Zhang Liping Ma Shugen +2 位作者 Li Bin Zhang Zheng Cao Binggang 《仪器仪表学报》 EI CAS CSCD 北大核心 2007年第7期1198-1204,共7页
Based on the design of a docking mechanism,this paper thoroughly investigates the space automatic doc- king of self-reconfiguration modular exploration robot system(RMERS).The method that leads robot to achieve space ... Based on the design of a docking mechanism,this paper thoroughly investigates the space automatic doc- king of self-reconfiguration modular exploration robot system(RMERS).The method that leads robot to achieve space docking by using two-dimensional PSD is put forward innovatively for the median size robot system.At the same time,in order to enlarge the detecting extension and the precision of PSD and reduce its dependence on light- ing signal,the PSD was remade by increasing the optical device over its light-sensitive surface.The emission board and LED light scheduling were designed according to docking arithmetic,and the operating principle of docking process was analyzed based on these.The simulation experiments were carried out and their results are presented. 展开更多
关键词 位置检测器 机器人 对接机构 自动对接 重新配置 二维相位灵敏调解器
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Application of isotopic and hydro-geochemical methods in identifying sources of mine inrushing water 被引量:3
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作者 Dou Huiping Ma Zhiyuan +3 位作者 Cao Haidong Liu Feng Hu Weiwei Li Ting 《Mining Science and Technology》 EI CAS 2011年第3期319-323,共5页
Isotopic and hydro-geochemical surveys were carried out to identify the source of mine inrushing water at the #73003 face in the Laohutai Mine. Based on the analysis of isotopes and hydro-chemical features of surface ... Isotopic and hydro-geochemical surveys were carried out to identify the source of mine inrushing water at the #73003 face in the Laohutai Mine. Based on the analysis of isotopes and hydro-chemical features of surface water, groundwater from different levels and the inrushing water, a special relationship between water at the #73003 face and cretaceous water has been found. The results show that the isotopic and hydro-chemical features of the inrushing water are completely different from those of other groundwater bodies, except for the cretaceous water. The isotopic and hydrochemical characteristics of cretaceous water are similar to the inrushing water of the #73003 face, which aided with obtaining the evidence for the possible source of the inrushing water at the #73003 face. The isotope calculations show that the inrushing water at the #73003 face is a mixture of cretaceous water and Quaternary water. Water from the cretaceous conglomerate is the main source, accounting for 67% of the inrushing water, while the Quaternary water accounts for 33%. The conclusion is also supported by a study of inrushing-water channels and an active fault near the inrushing-water plot on the #73003 face. 展开更多
关键词 水文地球化学方法 突涌水 同位素 水来源 水化学特征 应用 矿井 地球化学调查
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Responses of soil microorganisms to elevated CO2 in experiment sites of Pinus sylvestriformis and Pinus koraiensis 被引量:2
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作者 JIA Xia HAN Shi-jie ZHOU Yu-mei 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第3期219-222,共4页
土壤的回答到在 Pinus sylvestriformis 和 Pinus koraiensis 幼苗的实验地点的提高的 CO_2 的微生物引起的活动在 2003 在夏天被学习。结果显示细菌的数字显著地减少了(p < 0.05 ) 在为 Pinussylvestriformis 和 Pinus koraiensis ... 土壤的回答到在 Pinus sylvestriformis 和 Pinus koraiensis 幼苗的实验地点的提高的 CO_2 的微生物引起的活动在 2003 在夏天被学习。结果显示细菌的数字显著地减少了(p < 0.05 ) 在为 Pinussylvestriformis 和 Pinus koraiensis 的提高的 CO_2 下面。在土壤的淀粉酶和转化酶活动为 Pinussylvestriformis 增加了并且与那些相比与 CO_2 丰富为 Pinus koraiensis 减少了在周围(350 μ m ol · mol^(-1)) 。微生物引起的生物资源 C 的尺寸也在 700 μ m ol · mol~ 显著地减少了(-1) CO_2。细菌的社区结构在细菌的 16S rDNA 基因碎片的分析从从土壤直接提取的脱氧核糖核酸由 PCR 放大了的提高的 CO_2by DGGE (使中毒的坡度胶化电气泳动) 下面有一些明显的变化。结果建议到提高的 CO_2 的土壤微生物的回答将与暴露于提高的 CO_2 的植物种类有关。 展开更多
关键词 森林 土壤 微生物 CO2 细菌 生物环境
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