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941.
Madagascar has always held a special place on the bioprospecting map. Designated as one of the world’s “hottest” biodiversity hotspots, scientists believe the extremely high flora and faunal endemism contain unique potential for the commercialisation of natural products. Years of collections by bioprospectors in Madagascar are beginning to pay off, not necessarily from drug discovery, but through the biodata from their botanical collections. In the paper, we highlight the links between labour and value over time to illustrate the historical process of collecting inventories of biodata and calculating biodiversity metrics. As we demonstrate, biodata originally used for the purposes of drug discovery and scientific exploration are now being repurposed in biodiversity offsetting programs for multinational mining operations in Madagascar. This project of “re-mining” biodata has reinforced the power of select research institutions which now service their expertise for biodiversity offsetting initiatives. In sum, botanical agencies are far from apolitical actors in these new iterations of market-conservation but active participants in a new age of green grabbing.  相似文献   
942.
Numerous natural and anthropogenic processes in a watershed produce the geochemical composition of a river, which can be altered over time by snowmelt and rainfall events and by built infrastructure (i.e., dams and diversions). Trace element concentrations coupled with isotopic ratios offer valuable insights to disentangle the effects of these processes on water quality. In this study, we measured a suite of 40+ trace and major elements (including As, Cd, Ce, Cr, Cs, Fe, La, Li, Mo, Pb, Rb, Sb, Se, Sr, Ti, Tl, U, and Zn), Sr isotopes (87Sr/86Sr), and stable isotopes of H and O (δD and δ18O) to investigate natural and anthropogenic processes impacting the Provo River in northern Utah, USA. The river starts as a pristine mountain stream and passes through agricultural and urban areas, with two major reservoirs and several major diversions to and from the river. We sampled the entire 120 km length of the Provo River at 13 locations from the Uinta Mountains to Utah Valley, as well as two important tributaries, across the range of hydrologic conditions from low flow to snowmelt runoff during the 2013 water year. We also sampled the furthest downstream site in the Utah Valley urban area during a major flood event. Trace element concentrations indicate that a variety of factors potentially influence Provo River chemistry, including inputs from weathering of carbonate/siliciclastic rocks (Sr) and black shales (Se and U), geothermal groundwater (As, Cs, Li, and Rb), soil erosion during snowmelt runoff (Ce, Cr, Fe, La, Pb, and Ti), legacy mining operations (Mo, Sb, and Tl), and urban runoff (Cr, Pb, and Zn). Although specific elements overlap between different groups, the combination of different elements together with isotopic measurements and streamflow observations may act as diagnostic tools to identify sources. 87Sr/86Sr ratios indicate a strong influence of siliciclastic bedrock in the headwaters with values exceeding 0.714 and carbonate bedrock in the lower reaches of the river with values approaching 0.709. δD and δ18O changed little throughout the year in the Provo River, suggesting that the river is primarily fed by snowmelt during spring runoff and snowmelt-fed groundwater during baseflow. Based on nonmetric multidimensional scaling (NMS) water chemistry was unique across the upper, middle, and lower portions of the river, with high temporal variability above the first reservoir but minimal temporal variability below the reservoir. Thus, the results show that dams alter water chemistry by allowing for settling of particle-associated elements and also by homogenizing inflows throughout the year to minimize dilution during snowmelt runoff. Taken together, trace element concentrations and isotopic measurements can be used to evaluate the complex geochemical patterns of rivers and their variability in space and time. These measurements are critical for identifying natural and anthropogenic impacts on river systems.  相似文献   
943.
Urban geological hazards involving ground instability can be costly, dangerous, and affect many people, yet there is little information about the extent or distribution of geohazards within Europe’s urban areas. A reason for this is the impracticality of measuring ground instability associated with the many geohazard processes that are often hidden beneath buildings and are imperceptible to conventional geological survey detection techniques. Satellite radar interferometry, or InSAR, offers a remote sensing technique to map mm-scale ground deformation over wide areas given an archive of suitable multi-temporal data. The EC FP7 Space project named PanGeo (2011–2014), used InSAR to map areas of unstable ground in 52 of Europe’s cities, representing ∼15% of the EU population. In partnership with Europe’s national geological surveys, the PanGeo project developed a standardised geohazard-mapping methodology and recorded 1286 instances of 19 types of geohazard covering 18,000 km2. Presented here is an analysis of the results of the PanGeo-project output data, which provides insights into the distribution of European urban geohazards, their frequency and probability of occurrence. Merging PanGeo data with Eurostat’s GeoStat data provides a systematic estimate of population exposures. Satellite radar interferometry is shown to be as a valuable tool for the systematic detection and mapping of urban geohazard phenomena.  相似文献   
944.
This paper presents a new drought assessment method by spatially and temporally integrating temperature vegetation dryness index (TVDI) with regional water stress index (RWSI) based on a synergistic approach. With the aid of LANDSAT TM/ETM data, we were able to retrieve the land-use and land-cover (LULC), vegetation indices (VIs), and land surface temperature (LST), leading to the derivation of three types of modified TVDI, including TVDI_SAVI, TVDI_ANDVI and TVDI_MSAVI, for drought assessment in a fast growing coastal area, Northern China. The categorical classification of four drought impact levels associated with the RWSI values enables us to refine the spatiotemporal relationship between the LST and the VIs. Holistic drought impact assessment between 1987 and 2000 was carried out by linking RWSI with TVDIs group wise. Research findings indicate that: (1) LST and VIs were negatively correlated in most cases of low, medium, and high vegetation cover except the case of high density vegetation cover in 2000 due to the effect of urban heat island (UHI) effect; (2) the shortage of water in 1987 was more salient than that that in 2000 based on all indices of TVDI and RWSI; and (3) TVDIs are more suitable for monitoring mild drought, normal and wet conditions when RWSI is smaller than 0.752; but they are not suitable for monitoring moderate and severe drought conditions.  相似文献   
945.
An effective 3D method incorporating user assistance for modeling complex buildings is described. This method utilizes the connectivity and similar structure information among unit blocks in a multi-component building structure, to enable the user to incrementally construct models of many types of buildings. The system attempts to minimize the complexity and the number of user interactions needed to assist an existing automatic system in this task. Several examples are presented that demonstrate significant improvement and efficiency, compared with other approaches and with purely manual systems.  相似文献   
946.
主要通过教学对象、教材的选择、教学过程的改革以及考核方式的探索来讨论<控制测量学>在高等职业院校的改革.选择适应新时代的教材,并提出基于工作过程的教学模式,采用项目自我检验法检验学生知识掌握能力,培养出满足社会和用人单位需要的可持续发展的高技术人才.  相似文献   
947.
通过年度遥感影像的叠加分析来量测和跟踪城市建设的发展变化,结合GIS技术提取中心城区各类用地变化信息数据,并制作城市变化专题正射影像图,为政府和有关部门科学地进行城市规划与建设、管理和监测提供基础资料和决策依据。  相似文献   
948.
Harold A. Perkins 《Geoforum》2011,42(5):558-566
The US Department of Agriculture Forest Service and the Wisconsin Department of Natural Resources coordinate the distribution of urban forestry grants to nonprofits and citizen groups. These granting agencies increased state funding during a period of neoliberal, fiscal austerity in order to channel ecosystem services provided by urban forests. Increased funding is an instance of rollout neoliberalism whereby the fiscally austere state builds market capacity to harness these services as part of an ecologically modernist agenda. A Gramscian perspective and data gathered from 20 in-depth interviews with foresters are used in this paper to theorize how rollout policy is deployed through urban forestry to extend market hegemony to new geographies. This is anything but a smooth process because the public’s perception of urban trees is highly varied. State bureaucracies must build civil sector capacity to educate people about the ecosystem services trees provide as market commodities. In doing so the state’s market-oriented regulatory legitimacy is consolidated through the apparently benign act of promoting urban forestry. This dialectical process limits participation in urban forestry because markets are inherently selective. Yet it potentially gives rise to an alternative political ecology of praxis beyond market ideology when grant recipients participate in the production of urban ecology and recognize their relationship with nature.  相似文献   
949.
Li Zhang 《Geoforum》2011,42(4):473-483
Informal settlements become an intriguing spatial dimension of urbanization in those countries which experience the systemic shift from socialism to neoliberal regimes. This paper takes chengzhongcun(s) (literally meaning ‘villages encircled by the city’ boundaries) as a case to explore the dynamics of informal settlements in post-socialist China that has certain distinctive features related to the legacy of socialist institutions and restructuring of urban space by various forces. The paper details the political and economic contexts, as well as the ways in which chengzhongcun(s) are transformed into functional but unregulated urban space. It also elucidates the policy approach towards formalizing chengzhongcun(s) and confrontation involving in government-led redevelopment. The analysis illustrates how spatial informality is shaped by the interaction of economic interests and political considerations in a post-socialist economy with retaining the rural-urban dualism of land ownership and the control of urban citizenship.  相似文献   
950.
An investigation of the spatial variability of topsoil contamination level was performed in 49 preschool playgrounds located in Vilnius city and correlated with urban (height and age of the preschools and height of surrounding buildings) and natural (altitude) factors. Composite samples, consisting of 20–30 sub-samples, were collected from 10 cm topsoil layer with a 3–5 m distance from each other. Sieved fraction (< 0.63 mm) was ashed at 400 °C, ground to < 1.0 μm and analysed for the real total concentrations of 22 trace elements (Ag, B, Ba, Co, Cr, Cu, Ga, Li, Mn, Mo, Nb, Ni, Pb, Sc, Sn, Sr, Ti, V, Y, Yb, Zn and Zr) using optical atomic emission spectrophotometry. Information on construction year and height (number of building stories) of preschool and surrounding buildings was acquired from the Centre of Registers of Lithuania. Out of 22 analysed elements, 13 to a greater extent exceeded the background values in several areas and were used to calculate the total contamination index (Zs13). Out of 49 analysed areas, 21 had moderately hazardous to hazardous levels of contamination as indicated by Zs13. The main contaminating elements, exceeding the permissible concentrations were Ag, Cu, Mo, Pb, Sn and Zn, the origins of which coincide with city industry and traffic. Topsoil around the newer preschool buildings, despite their location, contained lower concentrations of contaminants, while areas at higher altitudes were more contaminated than those located at lower altitudes. The latter causality is biased, as the city industry, and hence the highest contamination, is in districts located higher above sea level than the remaining studied sites.  相似文献   
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