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911.
912.
Assessing the effects of land use and land cover patterns on thermal conditions using landscape metrics in city of Indianapolis,United States 总被引:6,自引:0,他引:6
Direct applications of remote sensing thermal infrared (TIR) data in landscape ecological research are rare due to limitations
in the sensors, calibration, and difficulty in interpretation. Currently there is a general lack of methodology for examining
the relationship between land surface temperatures (LST) derived from TIR data and landscape patterns extracted from optical
sensors. A separation of landscapes into values directly related to their scale and signature is a key step. In this study,
a Landsat ETM+ image of Indianapolis, Unites States, acquired on June 22, 2000, was spectrally unmixed (using spectral mixture
analysis, SMA) into fraction endmembers of green vegetation, soil, high albedo, and low albedo. Impervious surface was then
computed from the high and low albedo images. A hybrid classification procedure was developed to classify the fraction images
into seven land use and land cover (LULC) classes. Using the fractional images, the landscape composition and pattern were
examined. Next, pixel-based LST measurements were correlated with the landscape fractional components to investigate LULC
based relationships between LST and impervious surface and green vegetation fractions. An examination of the relationship
between the LULC and LST maps with landscape metrics was finally conducted to deepen understanding of their interactions.
Results indicate that SMA-derived fraction images were effective for quantifying the urban morphology and for providing reliable
measurements of biophysical variables. LST was found to be positively correlated with impervious surface fraction but negatively
correlated with green vegetation fraction. Each temperature zone was associated with a dominant LULC category. Further research
should be directed to the theoretical and applied implications of describing such relationships between LULC patterns and
urban thermal conditions.
相似文献
Dengsheng LuEmail: |
913.
Sauer MM 《Journal of lesbian studies》2007,11(3-4):331-345
This article explores the study of lesbians in the Middle Ages and proposes that the unstable construct of lesbian poses a problem for traditional Medieval Studies that can lead to the development in Medieval Studies of more nuanced and productive theorizing. 相似文献
914.
This paper reviews the main bodies of contemporary urban sustainability theory. From this analysis, two underpinning paradigms
of urban sustainability are identified: (1) The ‘Human Exemptionalism Paradigm’ (HEP), which emphasizes the ability of humans
to overcome environmental problems—see Urban Sociology, Urban Ecology, Urban Geography, Urban Psychology and Political Economy;
and (2) The ‘New Ecological Paradigm’ (NEP), which emphasizes the criticality of ecological limits to human progress—see Urban
Metabolism, Energy/Emergy Analysis and Ecological Footprinting. Each of these approaches is critically reviewed, highlighting
their main assumptions, theoretical and practical foci. It is argued in the paper that if the related issues of urban sustainability
and development are to be progressed, there needs to be: (1) a greater maturation of the NEP approaches, which are ‘relative
newcomers’ to the area of urban theory; and (2) greater integration and dialogue between the HEP and NEP approaches to urban
sustainability than has hitherto been the case.
相似文献
Murray G. PattersonEmail: |
915.
Using a spatially extensive urban database constructed from the Maryland Biological Stream Survey (MBSS), we describe the
relationships of nutrients in small-order streams to eight defined categories of percent catchment urbanization, correlations
between chloride and conductivity in urban streams, and relationships between nutrients and chloride with two Maryland-specific
indices of biotic integrity for benthic macroinvertebrates and fish assemblages. Stream nutrients become elevated with increasing
percent catchment urbanization, followed by increases in all four measured nitrogen species and total phosphorus at catchment
urbanization levels greater than 10%. There was a strong collinear relationship (r
2 = 0.90) between chloride and conductivity (trimeans) across all eight urbanization classes, where Cl (mg/L) = −0.397 + 0.188*conductivity
(μS/cm). Critical values for all water quality parameters with the two Maryland biological indices were derived using quantile
regression, with significant regressions developed for 11 of 16 water quality parameters and the two biotic indices. For nitrate
(NO3-N), the critical thresholds between fair and poor stream quality for the two Maryland biological indices were 0.83 mg/L (benthic
macroinvertebrate assemblages) and 0.86 mg/L (fish assemblages). Increasing stream nutrient and chloride levels, associated
with widespread catchment urbanization intensity, now affect many small streams in Maryland, with implications for decreasing
water quality in major tributaries and the Chesapeake Bay. 相似文献
916.
Rupert Hasenzagl 《Gruppendynamik und Organisationsberatung》2007,38(4):351-370
The theoretical basis behind consultancy does not match its importance to the economy. Although theory building research has been advanced since the 1990s, it still remains fragmentary. The impact of these consulting theories on practice has therefore been limited. This paper provides a contribution to this recent field of research. Based on the Social Systems Theory by Luhmann, a model outlining the impact of consultancy is presented. Three empirical cases outline the usefulness of the presented model in practice. 相似文献
917.
Ovarian cancer is the leading cause of gynaecological cancer death. The mortality rate of ovarian cancer could be greatly decreased if there were a screening test which was able to detect the disease at an early stage, resulting in an increased probability of cure. The most promising prospect for the early detection of ovarian cancer comes from the rapidly advancing field of clinical proteomics. An increasing number of reports on the potential clinical application of proteomics research for early detection as well as risk assessment and management of ovarian cancer are being published. Although the research is very promising, major technical challenges are still preventing new discoveries in ovarian cancer proteomics from being translated into clinical practice. 相似文献
918.
919.
Yonatan Reshef 《Journal of Labor Research》2007,28(4):677-696
In the public sector, Canadian governments intervene frequently in labor disputes by suspending collective bargaining and
curtailing legal strikes. Previous research has focused on the contours of government intervention, such as its overall effects
on collective bargaining and strikes. The discussion highlights one actor, a government, restricting the behavior of another
actor, a union, using legislation and policy making. As a result, we know less about more micro-level elements and implications
of the process of government intervention. I address these themes using a detailed case study of the Alberta Teachers’ Association
and the strikes it coordinated in 2002.
相似文献
Yonatan ReshefEmail: |
920.
The Experience-Earnings Profile: Productivity-Augmenting or Purely Contractual? Evidence from the UK
William J. Moore Robert J. Newman Geoffrey K. Turnbull 《Journal of Labor Research》2007,28(3):417-435
We test the human capital interpretation of the experience-earnings profile. Does the upward sloping portion of the experience-earnings
profile reflect on-the-job training which in turn causes the experience-productivity profile to slope upwards, or do purely
contractual factors determine the nature of life-cycle earnings. Herein, we provide additional evidence on the relationship
between productivity and earnings by examining earnings differentials in the UK academic labor market for economists. Using
a test first suggested by Mincer, we find that the empirical results are consistent with human capital theory. We find that,
although the positive relationship between earnings and experience persists when individual productivity measures are included
in the salary equations for lecturers and senior lecturers, the positive relationship becomes statistically insignificant
when the same productivity measures are included in the salary equations for professors. For lecturers and senior lecturers,
the experience-salary profile properly reflects the structure of the national pay scale rather than variations in individual
research productivity. At the professor level, where individual salaries are not determined by a pay scale, the data support
the human capital explanation of the positive experience-earnings profile.
相似文献
Robert J. NewmanEmail: |