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201.
Input‐output analysis is frequently used in studies of large‐scale weather‐related (e.g., Hurricanes and flooding) disruption of a regional economy. The economy after a sudden catastrophe shows a multitude of imbalances with respect to demand and production and may take months or years to recover. However, there is no consensus about how the economy recovers. This article presents a theoretical route map for imbalanced economic recovery called dynamic inequalities. Subsequently, it is applied to a hypothetical postdisaster economic scenario of flooding in London around the year 2020 to assess the influence of future shocks to a regional economy and suggest adaptation measures. Economic projections are produced by a macro econometric model and used as baseline conditions. The results suggest that London's economy would recover over approximately 70 months by applying a proportional rationing scheme under the assumption of initial 50% labor loss (with full recovery in six months), 40% initial loss to service sectors, and 10–30% initial loss to other sectors. The results also suggest that imbalance will be the norm during the postdisaster period of economic recovery even though balance may occur temporarily. Model sensitivity analysis suggests that a proportional rationing scheme may be an effective strategy to apply during postdisaster economic reconstruction, and that policies in transportation recovery and in health care are essential for effective postdisaster economic recovery. 相似文献
202.
Christopher D. Ives Grant C. Hose David A. Nipperess Mark Patrick Taylor 《Urban Ecosystems》2011,14(1):1-16
Protecting riparian corridors is a commonly applied environmental policy in urban landscapes. However, empirical data demonstrating
their efficacy for biodiversity conservation outcomes is scarce. In this study we investigated whether riparian corridor width
influences the diversity and community structure of ant (Hymenoptera: Formicidae) and vascular plant assemblages therein.
Eighteen corridors of differing widths were selected from within the Ku-ring-gai Local Government Area, Sydney Australia.
Ants were sampled using pitfall traps positioned within rectangular vegetation transects (30 × 10 m). Both ant and plant species
richness, when standardised for sampling effort, were unrelated to riparian corridor width. However, significant compositional
differences between sites were evident with increased width up to ~50 m. Narrow corridors contained greater abundances of
opportunistic ant species and higher proportions of exotic plants. We interpret this to be the result of the greater disturbance/edge
influence derived from adjacent upland urban environments. Site beta diversity did not increase with corridor width, suggesting
that the exclusion of novel upslope habitats in narrow riparian corridors is not a significant cause of community assemblage
modification at these sites. To minimise the impact of deleterious edge effects on ant fauna, environmental managers should
seek to retain riparian corridors wider than ~50 m. However, we observed substantial between-site variability of biotic assemblages,
irrespective of corridor width. Therefore we recommend that environmental management practice needs to take a catchment-wide
approach and consider other parameters that may contribute to riparian health so as to optimise the protection of riparian
biodiversity. 相似文献
203.
Markéta Bačáková 《Intercultural Education》2011,22(2):163-175
All children in the Czech Republic have the legal right to primary education, regardless of nationality and legal status. This article is based on a study of refugee children and their educational situation. The study reveals that refugee students in the Czech Republic are not benefiting fully from this fundamental right and that their educational future is in jeopardy. The study identified six major barriers to full participation and educational benefits. Finally, a plan of action to overcome barriers is put forward. Key ingredients are effective information transfer among state agencies, non‐governmental organizations, parents, children and schools. 相似文献
204.
Neural correlates of anticipatory and reactive saccades were studied in 4‐month‐old infants by recording high‐density event‐related potentials. Infants were presented with a fixed sequence of stimulus presentation to which they rapidly showed anticipatory saccades, as well as continuing with some reactive (stimulus‐driven) saccades. As in a previous study, no clear evidence was found for adultlike, saccade‐related potentials, although some presaccadic differences between reactive and anticipatory saccades were observed. Infants also showed different stimulus offset‐related effects preceding the 2 types of trials with a right‐frontal positivity when an anticipatory look follows, but only left‐frontal positivity when a reactive saccade follows. 相似文献
205.
206.
Assume independent random samples are drawn from two populations which are exponentially distributed with unknown location parameters and a common known scale parameter. We want to estimate the maximum and the minimum of the unknowo location paremeters. In this paper several estimators are proposed which are better than the natural estimations in terms of absolute bias and /or meaqn squared error. 相似文献
207.
Yonatan Reshef Mark Kizilos Gerald E. Ledford Susan G. Cohen 《Journal of Labor Research》1999,20(4):557-569
We test the mediated effects of participation in employee involvement (EI) programs on employee desires for union involvement
in the future development and diffusion of EI and the perceived durability of an EI program as a possible moderator of these
effects. Results indicate that participants developed more positive attitudes toward the EI program than nonparticipants and,
in turn, these attitudes were related to higher desires for union involvement in EI. Additionally, volunteers developed more
positive attitudes toward the EI program than nonvolunteers and, in turn, these attitudes were related to higher desires for
union involvement in EI. However, the relationship between attitudes toward EI and desires for union involvement in EI was
significantly less positive for participants who viewed the EI program as durable. 相似文献
208.
209.
210.
Model-based clustering for social networks 总被引:5,自引:0,他引:5
Mark S. Handcock Adrian E. Raftery Jeremy M. Tantrum 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2007,170(2):301-354
Summary. Network models are widely used to represent relations between interacting units or actors. Network data often exhibit transitivity, meaning that two actors that have ties to a third actor are more likely to be tied than actors that do not, homophily by attributes of the actors or dyads, and clustering. Interest often focuses on finding clusters of actors or ties, and the number of groups in the data is typically unknown. We propose a new model, the latent position cluster model , under which the probability of a tie between two actors depends on the distance between them in an unobserved Euclidean 'social space', and the actors' locations in the latent social space arise from a mixture of distributions, each corresponding to a cluster. We propose two estimation methods: a two-stage maximum likelihood method and a fully Bayesian method that uses Markov chain Monte Carlo sampling. The former is quicker and simpler, but the latter performs better. We also propose a Bayesian way of determining the number of clusters that are present by using approximate conditional Bayes factors. Our model represents transitivity, homophily by attributes and clustering simultaneously and does not require the number of clusters to be known. The model makes it easy to simulate realistic networks with clustering, which are potentially useful as inputs to models of more complex systems of which the network is part, such as epidemic models of infectious disease. We apply the model to two networks of social relations. A free software package in the R statistical language, latentnet, is available to analyse data by using the model. 相似文献