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21.
There is growing recognition of urban areas as hosts for innovative ways to conserve and promote biodiversity. Parks, as one specific type of urban green space, constitute particularly important biodiversity hotspots in the cityscape. We reviewed empirical findings on the species richness in urban parks across all species groups that have been studied. The aim was to assess and discuss the overall species richness of urban parks, its community attributes and drivers. Search and subsequent selection process resulted in 62 papers from 25 different countries. For all examined species groups, the findings consistently show that parks are among the most species rich types of urban green spaces, but also that exotics constitute large shares, especially of plant species. Key ecological theories like the gradient approach and the island habitat ecological theory, and fundamental ecological relationships such as the species-area relationship are valid despite the manipulated ‘nature’ of parks and the surrounding urban matrix. Most studies surveyed large number of parks and applied ‘multi-scale’ approaches in tests of confounding variables, providing methodological strength. While matrix effects are consistently found to affect species richness negatively, the diversity of habitats and microhabitat heterogeneity contained in urban parks appears as the most decisive factor for the overall species richness. However, a constraint of research to date is the limitation of individual studies to one or a few species groups, rarely bridging between flora and fauna. Adopting ‘multi-species group’ approaches in future research is needed to further advance the understanding of the overall biodiversity of urban parks, and its drivers.  相似文献   
22.
Empowerment is a keyword in treatment. Users should have the means and possibilities to influence their treatment and become self-managing. Drawing on ethnographic fieldwork in a Danish methadone treatment project, we find that the practices of users and staff are often not carried out in accordance with governmental intentions. We identify a gap between the official notions of treatment and practices. We analyse the notions and practices of empowerment by applying two analytical perspectives. First, we apply a constructionist perspective in which empowerment is analysed as wanting to set users ‘free’ but also as ways to govern. We elaborate the analysis by applying a more practice-oriented focus. Drawing on this perspective, we analyse the ways in which staff and users constantly produce, construct and negotiate institutional practices that differ from the governmental intentions for treatment.  相似文献   
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This study reexamines the engagement of U.S. and French courts with immigration politics, aiming to provide a fuller accounting of how law and immigration politics shape one another. Jurisprudential principles are placed in national and historical context, elucidating the role of rights‐oriented legal networks in formulating these arguments during the 1970s and early 1980s. The analysis traces how these judicial constructions of immigrants subsequently contributed to catalyzing a transformation of immigration politics in both countries. Immigrant rights jurisprudence is shown to be produced by, as well as productive of, broader political values, agendas, and identities.  相似文献   
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Childhood sexual abuse is a severe problem worldwide. Childhood sexual abuse can be detrimental to children and their abilities to cope with and communicate in their subsequent adult intimate relationships. The aim of this review was to generate and summarize knowledge about how childhood sexual abuse manifests in adult intimate relationships so healthcare professionals can incorporate this knowledge into treatment and care. A scoping review methodology was selected because it supports examination of the extent, range, and nature of research activity. A content analysis of the studies included in this review led to three thematic categories of challenges in adult intimate relationships after childhood sexual abuse: (a) relationship satisfaction, (b) sexual satisfaction, and (c) communication and trust.  相似文献   
26.
Twenty-four-hour recall data from the Continuing Survey of Food Intake by Individuals (CSFII) are frequently used to estimate dietary exposure for risk assessment. Food frequency questionnaires are traditional instruments of epidemiological research; however, their application in dietary exposure and risk assessment has been limited. This article presents a probabilistic method of bridging the National Health and Nutrition Examination Survey (NHANES) food frequency and the CSFII data to estimate longitudinal (usual) intake, using a case study of seafood mercury exposures for two population subgroups (females 16 to 49 years and children 1 to 5 years). Two hundred forty-nine CSFII food codes were mapped into 28 NHANES fish/shellfish categories. FDA and state/local seafood mercury data were used. A uniform distribution with minimum and maximum blood-diet ratios of 0.66 to 1.07 was assumed. A probabilistic assessment was conducted to estimate distributions of individual 30-day average daily fish/shellfish intakes, methyl mercury exposure, and blood levels. The upper percentile estimates of fish and shellfish intakes based on the 30-day daily averages were lower than those based on two- and three-day daily averages. These results support previous findings that distributions of "usual" intakes based on a small number of consumption days provide overestimates in the upper percentiles. About 10% of the females (16 to 49 years) and children (1 to 5 years) may be exposed to mercury levels above the EPA's RfD. The predicted 75th and 90th percentile blood mercury levels for the females in the 16-to-49-year group were similar to those reported by NHANES. The predicted 90th percentile blood mercury levels for children in the 1-to-5-year subgroup was similar to NHANES and the 75th percentile estimates were slightly above the NHANES.  相似文献   
27.
Knowledge Management Systems (KMSs) are becoming part of the agenda in many of today's leading firms. Through in-depth case studies of seven multinational companies (MNCs), examined over a period of four years, we identify four distinctive types of KMS - Fragmented, Content-based, Process-based and Capability-based - and their characteristics. These characteristics include both the structure, dimension and flow of the knowledge itself, and the staffing, training and reward systems in place to support the KMS. Relevant organisational factors influencing KMS design and implementation include the level of resource commitment by the headquarters, the structure of the firm, and the distribution of roles between headquarters and subsidiaries. Key external influences include the degree of environmental change and pressures to follow industry norms in technology investment. Our empirical evidence suggests that while some MNCs adopt the same type of KMS for relatively long periods of time, others transit between different KMS types. Moreover, transitions between types may follow either an increased resource commitment and augmented KMS sophistication, or a decreased resource commitment and reduced KMS complexity. Insights from the strategy-structure-process and change management literatures are utilised to examine these transitions between KMS types. Key lessons for MNC managers are provided in relation to both the initial adoption of a KMS and the handling of transitions between different systems.  相似文献   
28.
Product development and market penetration strategy rely on dependable forecasts. Market segmentation is necessary for finding profitable niches. The paper describes macro- forecasts in the maritime sector divided by nine ship types. Balance between supply and demand is calculated with dynamic models. Demand for transportation depends on the development of world trade. Supply of transportation capacity depends on present fleet size, future contracting, scrapping and productivity.  相似文献   
29.
This paper provides a means of accurately simulating explosive autoregressive processes and uses this method to analyze the distribution of the likelihood ratio test statistic for an explosive second-order autoregressive process of a unit root. While the standard Dickey-Fuller distribution is known to apply in this case, simulations of statistics in the explosive region are beset by the magnitude of the numbers involved, which cause numerical inaccuracies. This has previously constituted a bar on supporting asymptotic results by means of simulation, and analyzing the finite sample properties of tests in the explosive region.  相似文献   
30.
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