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121.
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During the past decade, Mexico has experienced both large-scale emigration directly, mostly to the US, and the mass immigration of Central American refugees. The implementation of the US Immigration and Control Act of 1986 and the possible escalation of armed conflicts in Central America may result in expanded inflows either of returning citizens or of new refugee waves. To develop appropriate policy responses, Mexico needs reliable information on international migration flows. This research note reviews available sources of that information--arrival and departure statistics, population censuses, refugee censuses, and survey data--and concludes that most of them are relatively weak. Currently, the published data on entries and departures provide little information on the demographic impact of legal migration, although they suggest that the inflow of foreigners is small. The census corroborates such findings, but it yields inadequate demographic detail. The movement of Mexican nationals, on the other hand, is poorly reflected by both sources. The void they leave has been palliated somewhat by surveys, but the only nationally representative survey on emigration was carried out in the late 1970s and might be a less than ideal basis for current policy formulation. It is hoped that as the relevance of international migration becomes more evident, steps towards the improvement of existing statistical systems may be undertaken. In the absence of such measures, policy-makers and researchers will have to continue relying on ad hoc surveys to answer the most pressing questions on the subject.  相似文献   
123.
This paper analyzes the migration phenomenon within a framework that treats migration movements as continuous loops, from the country of origin to the destination and back. Significant social-psychological factors at each step of the loop process contribute to the development of migration streams along a predictable pattern. The general model of the loop process shows that the migration stream is 1st sparked when labor is recruited from less developed countries for work in developed industrialized countries. Once the social process of migration has begun, it tends to acquire a self-feeding character. Social and economic change in sending and receiving societies brought about by migration make further migration more likely. The case of the Mexico-US-Mexico loop process is analyzed. This case illustrates the effects of socioeconomic stratification that occurs in communities where the migration loop process reaches a certain level of maturity. The majority of a town's population may become committed to migration as a way of life. Eventually, wealth becomes concentrated in the hands of those that are most able to migrate. Thus, migrants may become a new elite segment of rural populations that were once relatively homogenous societies. Further research of the migration loop process should be conducted. At least in the case of Mexico, the socioeconomic stratification in the villages and towns acting as sources of migration loops with destinations in the US have significant internal economic, social, and political implications.  相似文献   
124.
Logistic models with a random intercept are prevalent in medical and social research where clustered and longitudinal data are often collected. Traditionally, the random intercept in these models is assumed to follow some parametric distribution such as the normal distribution. However, such an assumption inevitably raises concerns about model misspecification and misleading inference conclusions, especially when there is dependence between the random intercept and model covariates. To protect against such issues, we use a semiparametric approach to develop a computationally simple and consistent estimator where the random intercept is distribution‐free. The estimator is revealed to be optimal and achieve the efficiency bound without the need to postulate or estimate any latent variable distributions. We further characterize other general mixed models where such an optimal estimator exists.  相似文献   
125.
This study sought to examine the family environments of a sample of Hispanic women who reported childhood sexual abuse. Eighteen women, taken from a larger college sample, were individually interviewed and administered the Family Environment Scale (FES; Moos & Moos, 1994). Cultural values and the relationship of family characteristics to the individual's experience of sexual abuse were explored. The abused women obtained significantly higher scores on the Achievement-Orientation subscale of the FES than the normative group. Qualitative data revealed some patterns in these families regarding sexual discussions and poor conflict resolution skills. Implications for treatment of Hispanic victims are discussed.  相似文献   
126.
One of the principal uses of simulation in business and industry is to compare alternative policies or decision rules for the operation and control of complex systems. The immediate objective of such simulation studies is usually quite simple: to discover the best of the several policies under consideration. The measure of effectiveness used is also usually straightforward, often dollars of cost or profit. The basic experimental design that will produce the best comparison of alternatives is generally agreed upon: all policies should be compared under, to the extent possible, identical experimental conditions, i.e., when randomness is involved, all alternatives in a simulation experiment should be simulated using a common sequence of randomly-generated events.  相似文献   
127.
It is becoming increasingly common to hear life scientists say that high quality life science research relies upon high quality laboratory animal care. However, the idea that animal care is a crucial part of scientific knowledge production is at odds with previous social science and historical scholarship regarding laboratory animals. How are we to understand this discrepancy? To begin to address this question, this paper seeks to disentangle the values of scientists in identifying animal care as important to the production of high quality scientific research. To do this, we conducted a survey of scientists working in the United Kingdom who use animals in their research. The survey found that being British is associated with thinking that animal care is a crucial part of conducting high quality science. To understand this finding, we draw upon the concept of ‘civic epistemologies’ (Jasanoff 2005; Prainsack 2006) and argue that ‘animals’ and ‘care’ in Britain may converge in taken‐for‐granted assumptions about what constitutes good scientific knowledge. These ideas travel through things like state regulations or the editorial policies of science journals, but do not necessarily carry the embodied civic epistemology of ‘animals’ and ‘science’ from which such modes of regulating laboratory animal welfare comes.  相似文献   
128.
Considering the goal of Ergonomic Work Analysis to establish, from the point of view of workers, safe, healthy, comfortable and efficient environments, this study propose to analyze the work situation of machine operators at five joineries from Florianópolis-SC. For this, it was applied the LEST Method to evaluate the task made by the operators, considering the physical, cognitive and organizational work environment. As results, it was identified the main ergonomics problems of these workstations, presenting an ergonomic diagnosis and their implications on health and safety of workers. As result, it was concluded that the main ergonomics problems at joineries are related with noise, with constant load of weight and with the postures taken. Besides these problems, others were diagnosed, for example, the pressure for workers to comply strictly the task stipulated and also the poor training and capacity of workers.  相似文献   
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130.
Decisions regarding research and development (R&D) activities of an organization greatly affect the fiscal and market outcomes of technologically oriented firms. Yet, the resource allocation choices between these two activities are tied strongly to an organization's technology knowledge. Technological knowledge is itself a resource that the firm can manage to achieve strategic and competitive advantage. In this paper, the authors present a system dynamics view of the decomposition of R&D efforts into explorative and exploitive activities and the resultant knowledge‐specific and performance outcomes from the decision to focus on one type of activity or another. Four factors are shown to affect the relative value of innovative knowledge to the organization: resource availability, exogenous competition, aging of knowledge bases, and adaptive capacity, a firm's ability to adapt to its environment. A variety of long‐ and short‐term strategic issues are discussed in relation to these forces.  相似文献   
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