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981.
A resource selection function is one that yields values proportional to the probability of use of a resource unit. This quantity is influenced by the heterogeneity of landscape structures, which occurs over multiple spatial scales. To provide input into wildlife management strategies, we investigated the scale dependency and functional responses of Japanese macaques using multiple scale analysis. The multiple buffers with radii of 100, 500, 1000, 1500, 2000, and 2500 m were defined as the spatial scale. Crop damage was predicted at the within-home range scale, using the Random Forests algorithm with environmental variables linked to resource selection of Japanese macaques. Sixteen environmental variables were defined, covering aspects of landscape configuration, human disturbance, topography, and adopted countermeasures. Crop damage was most accurately predicted within a buffer zone of 1000 m, although radii exceeding 1000 m were also highly accurate. Although the importance of variables differed among spatial extents, the functional responses for each environmental variable were independent of spatial extent. These results suggest that the limiting factors of crop damage depend on spatial extent, while functional responses in resource selection remain constant across spatial extents. We also compared a multi-scale gradient map with a typical binary map to demonstrate the uncertainty in damage predictions at different spatial scales. Our results may aid wildlife management planning, for which differences in resource selection across different spatial scales are critically important.  相似文献   
982.
The geography of violence in Mexico has changed in recent years because of an explosive increase in regional homicide rates since 2006. This study relies on spatial statistical data analysis to address the issue of convergence in homicide victim rates across Mexican municipalities from 2001 to 2010. Based on the results of spatial panel modeling, we conclude that despite strong regional disparities in murders, municipal-level homicide growth rates display a pattern of convergence with spatial interaction features. This convergent pattern is gender-specific; the homicide growth rates for females show stronger convergence than those for males when local and regional factors are not considered. We postulate that homicide growth dynamics among females more closely follow the predictions of the “modernization hypothesis” than do the dynamics among males. This finding suggests that violence (specifically, homicides) against women in Mexico is driven by underlying factors other than short-term factors, such as drug cartel dynamics, and regional factors, such as local institutions and governments. The data might support the long-established feminist hypothesis that contends that violence against women follows specific dynamics that are different from the dynamics of violence against men.  相似文献   
983.
This work seeks to understand the variability of warm and cool events during summer in Turkey. Daily maximum air temperature data from 97 weather stations were analyzed to determine percentile threshold values (99th, 95th, 90th, 1st, 5th, and 10th) at each station. Trends in the percentile values were determined using the Mann–Kendall trend test. The analysis demonstrates an increase in frequency of warm, hot, and extremely hot days, whereas cool, cold, and extremely cold days show a decreasing trend. Increasing trends are statistically significant at the 0.05 and 0.01 levels for 13 and 46% of the stations, respectively. Significant decreasing trends have been detected at 0.05 and 0.01 levels for 19 and 15% of 97 stations, respectively. Analysis of the observations shows that the number of warm and hot event started to increase in the 1970s. Warm events are comparatively more numerous than cold events in western and southern parts of the country.  相似文献   
984.
Abstract

Many spatial analysis algorithms for cellular representations and data structures are based on an ordering of cells or objects to transform a two-dimensional problem to a one-dimensional one. Several orderings are available and their differing properties influence the performance of the data structures and algorithms. The relative merits of five orderings (row, row prime, Hilbert, Morton and Gray code) are assessed empirically for four paradigmatic geographical data-processing tasks in spatial analysis and data management. It is concluded that the Hilbert ordering deserves further investigation.  相似文献   
985.
While some geographic phenomena hold uniform properties, such as land‐use zones, many geographic phenomena are distributed such that their properties vary across an extended area. While such distributed phenomena are best represented as continuous surfaces, individual objects (or features) often emerge among clusters of high or low values in a field. For example, areas of relatively high elevation may be viewed as hills, while flat low‐lying areas are perceived as plains in a terrain. A comprehensive spatial analysis of distributed phenomena should examine both the spatial variance of its attribute surfaces and the characteristics of individual objects embedded in the field. An immediate research challenge to meet such spatial analysis needs is that these emerging features often have vague boundaries that vary according to the use and the user. The nature, and even existence, of these objects depend upon the range of values, or thresholds, used to define them. We propose a representation framework that takes a dual raster‐vector approach to capture both field‐ and object‐like characteristics of distributed phenomena and maintain multiple representations of embedded features delineated by boundaries that are likely to be relevant for the expected uses of the data. We demonstrate how boundaries influence the analysis and understanding of spatiotemporal characteristics of distributed phenomena. Using precipitation as a proof of concept, we show how the proposed framework enhances semantic flexibility in spatiotemporal query and analysis of distributed phenomena in geographic information systems.  相似文献   
986.
Constraint‐based models and models constructing accessibility measures mainly focus on single agents having only one available transport mode. However, numerous cases exist where multiple agents or groups of individuals with different available transport modes want to participate in a joint activity at a certain location. The aim of this paper is to provide new insights into representing and reasoning about feasible space–time opportunities for multiple agents. Relying on concepts of time geography, we propose a conceptual framework in order to determine interaction spaces for groups of individuals. Besides availability of means of transport and the locations of each individual, minimum activity duration and opening hours of opportunities are taken into account. The reasoning about space and time is visualized in three dimensions using a hybrid (CAD/GIS) system.  相似文献   
987.
Today, the opportunity for potential human activity has gone beyond physical space to virtual space. Based on a proposed conceptual framework that models the relationships between physical and virtual spaces, this paper presents an attempt to adjust the space–time prism concept of Hägerstrand's time geography to identify potential activity opportunities in virtual space, focusing on the virtual space access channels available in physical space. A three‐dimensional (3D) spatio‐temporal Geographic Information System (GIS) design has been developed in this research to accommodate the adjusted space–time prism concept to support the representation, visualization, and analysis of potential human activities and interactions in physical and virtual spaces using the prism representation. Following the design, a prototype system has been successfully implemented in a 3D GIS environment. Such a system can provide powerful analytical tools for studies related to potential human activities and applications such as location‐based services (LBS) and accessibility analysis in the information age.  相似文献   
988.
In classical time geography, an individual travel path is composed of a chain of visits, with each visit being a flexible activity between two fixed activities at two known stations. In reality, individuals tend to carry out trips with much variation and complexity, with multipurpose trips being a prominent and pervasive phenomenon. There is limited research to date on multipurpose trips in time-geographic analysis by geographic information system (GIS) scientists, or more specifically, multiple flexible activities between two fixed stations. To fill this gap, this article proposes four models for identifying the choice set with multiple flexible activities under space–time constraints. The models are derived through set-theoretic formalism based on the concept of trip chaining. The structure of the four models establishes a theoretical framework for conceptualizing trip-chaining behaviour with respect to the fixity of activities and the number of fixed stations as destinations or origins. They provide fundamental and rigorous apparatus for studying complex individual activity–travel patterns in many applied contexts when multipurpose trips are involved. This article also describes implementation of the models with a real transportation network as a way of validation.  相似文献   
989.
Attesting to the powerful capabilities and in technology trends, many scholars envisioned the consolidation of geographic information systems (GIS) into vital tools for disseminating spatial information. GIS are presently used to inform, advise and instruct users in several contexts and to further engage citizens in decision-making processes that can impact and sustain policy development. Interaction with these applications incorporates risk and uncertainty, which have been repeatedly identified as preconditions in nurturing trust perceptions and which instigate a user's decision to rely on a system and act on the provided information. Research studies consistently demonstrated that a trust-oriented interface design can facilitate the development of more trustworthy, mainly e-commerce, systems. Trust in the Web GIS context, despite its significance, has only relatively recently received some attention. A set of human–computer interaction (HCI) user-based studies revealed some Web GIS trustee attributes that influence non-experts' trust beliefs and found that when these are problematic or absent from interface design, users form irrational trust perceptions, which amplifies the risk and may impose dangers to the user. These Web GIS trustee attributes that influence non-experts' trust perceptions are formulated here into a set of trust guidelines. These are then evaluated using the PE-Nuclear tool, a Web GIS application, to inform the public about the site selection of a nuclear waste repository in the United Kingdom. Our preliminary results indicate that the proposed trust guidelines not only support the development of rational trust perceptions that protect non-experts from inappropriate use of Web GIS technology but also contribute towards improving interaction with such applications of public interest issue.  相似文献   
990.
This paper presents an original methodology for the construction of a harmonized database for urban areas in the United States from 1790 to 2010 (a period with a census every 10 years, amounting to 23 dates). Upstream, this method is based on a theoretical choice, the use of a spatio-temporal reference frame to construct urban areas over the long term, defined by a maximum range of one hour’s travel for each period. We used an automatic aggregation from a Reilly model. Urban measures (growth, concentration) derived from this harmonized database are then presented, providing a unified picture of urbanization in the United States over more than two centuries. They are compared with results derived from more classical databases established using the official figures from the Census Bureau, or from other constructions differing from the present system. The results diverge considerably in some instances, which confirms the impact of the method of delineation of geographical areas in measures of growth.  相似文献   
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