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791.
The Analysis of Verbal Behavior - This study describes procedures and outcomes in a functional analysis of problem behavior of 2 public school students. For a 13-year-old honors student, bizarre...  相似文献   
792.
793.
Abstract Parents shape children's social choices through their social and economic actions. Parental social participation connects children to a civic culture and encourages involvement in civic groups. Parents' ties to farming in farm‐dependent communities further enhance children's civic orientations by providing added opportunities and incentives for social participation. Data from the Iowa Youth and Families Project confirm these hypotheses, showing that the children of farmers and of rural leaders are more likely to participate in civic groups. These results establish parental social involvement as a source of social capital and demonstrate the importance of farm influences for understanding the social involvement of youth in rural society.  相似文献   
794.
795.
In this article, we review the major research advances made during the 1990s in the study of sexuality in marriage and other close relationships. More specifically, we provide a critical review of the empirical findings from the last decade on such sexual phenomena as sexual behavior, sexual satisfaction, and sexual attitudes within the context of marriage, dating, and other committed relationships. After highlighting the major theoretical and methodological advances of the 1990s, we focus on the research literatures of: (1) frequency and correlates of sexual activity in marriage; (2) sexual satisfaction, including its association with general relationship satisfaction; (3) sexuality in gay and lesbian committed relationships; (4) trends in sexual behavior and attitudes in dating relationships; and (5) the role of sexuality in dating relationships. We also incorporate brief reviews of the past decade's research on sexual assault and coercion in marriage and dating and on extramarital sex. We end our decade review with recommendations for the study of sexuality into the next decade.  相似文献   
796.
Over 880 communities have put regulations in place to reduce or eliminate tobacco use in buildings used by the public. This study examines the experience of one such community—Well City, Ohio. The nonsmoker protection efforts in Well City help us identify and discuss eight important considerations affecting policy development and implementation: (1) anticipate community opposition, (2) identify and collaborate with a support network, (3) control the community hearing process, (4) anticipate outside interests, (5) recognize the potential for legal challenges, (6) address life with legal limbo, (7) start strong, and (8) watch the mix of politics and public health. Current clean indoor air efforts seem to focus on establishing coalitions and encouraging employers to voluntarily establish tobacco-free workplaces and restaurants. These efforts certainly need to continue but as a basic part of a comprehensive program which recognizes the importance and fosters the development of strong nonsmoker protection regulations developed at the local level by health boards, county boards of supervisors, and/or city councils.  相似文献   
797.
Headwater streams are in close contact with the landscape and known to mediate disturbances to downstream waterways through important ecological interactions. We studied how elevated chloride from road deicer, a pollutant of rising concern in urban ecosystems, influenced the leaf-microbial matrix in streams, and subsequent processing of C and N. In a multi-factorial laboratory experiment, we determined if elevated chloride interacts with nitrogen loading and invertebrate consumer feeding to alter rates of leaf litter breakdown and N immobilization. Naturally colonized leaf litter, the dominant C source in small streams, was collected from five Piedmont streams (Maryland, USA) and subjected to a gradient of NaCl (0, 1,000, 5,000?mg Cl l?1) and dissolved nitrogen (ambient, elevated), and an invertebrate treatment (presence, absence) in a total of 60 microcosms. Loss rate and C:N content were determined from remaining leaf litter after 16 d of incubation. Chloride loading significantly (P?<?0.05) reduced loss rate regardless of N loading, and C:N content significantly (P?<?0.05) increased with Cl concentration, interacting marginally (P?<?0.10) with N loading. Invertebrate feeding had a marginally-significant (P?<?0.10), negative effect on loss rate, but not C:N content. Overall, elevated chloride significantly influenced organic matter loss rate and N immobilization, despite N loading and the presence of invertebrates. We conclude that there is the potential for chloride loading as road deicer runoff to negatively influence microbial processing of C and N by stream-dwelling microbial communities.  相似文献   
798.
Infants greatly refine their ability to discriminate language sounds by 12 months, yet 14‐month‐olds appear to confuse similar‐sounding novel words. Two explanations could account for this phenomenon: infants initially have incomplete phoneme representations, suggesting developmental discontinuity; or word‐learning demands interfere with use of established phonetic detail. These hypotheses were tested at 14 months by pairing a novel word with an object preexposed to half the infants and novel to the other half. If demands are key, only preexposed infants should efficiently use phonetic detail; there is no need to concurrently learn object details with the word. If representations lack detail, object familiarity should not matter. Only infants preexposed to the object noticed a change in its label, thus challenging the discontinuity position and demonstrating the impact of object familiarity on early word learning.  相似文献   
799.
Supersaturated designs are an increasingly popular tool for screening factors in the presence of effect sparsity. The advantage of this class of designs over resolution III factorial designs or Plackett–Burman designs is that n, the number of runs, can be substantially smaller than the number of factors, m. A limitation associated with most supersaturated designs produced thus far is that the capability of these designs for estimating g active effects has not been discussed. In addition to exploring this capability, we develop a new class of model-robust supersaturated designs that, for a given n and m, maximizes the number g   of active effects that can be estimated simultaneously. The capabilities of model-robust supersaturated designs for model discrimination are assessed using a model-discrimination criterion, the subspace angle. Finally, we introduce the class of partially supersaturated designs, intended for use when we require a specific subset of m1m1 core factors to be estimable, and the sparsity of effects principle applies to the remaining (m-m1m-m1) factors.  相似文献   
800.
A dimension reduction technique is proposed for matrix data, with applications to face recognition from images. In particular, we propose a factored covariance model for the data under study, estimate the parameters using maximum likelihood, and then carry out eigendecompositions of the estimated covariance matrix. We call the resulting method factored principal components analysis. We also develop a method for classification using a likelihood ratio criterion, which has previously been used for evaluating the strength of forensic evidence. The methodology is illustrated with applications in face recognition.  相似文献   
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