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41.
Increasing attention is being given to the possible consequences which might follow from the exhaustion of the world's natural resources. Countering the pessimistic conclusions of such institutions as the Club of Rome, economists such as Wilfred Beckerman have emphasized the importance of substitution, pointing to many examples where a shortage of one raw material has led to the discovery or development of alternative materials, e.g. artificial for natural rubber, aluminium for copper.Substitution usually occurs through normal market mechanisms, i.e. changes in relative prices. However in some circumstances the market mechanism may be inhibited by a variety of factors, so that its operation requires to be supplemented by an outside agency. This article explores this possibility in relation to the paper making industry, which provides a particularly interesting example owing to the existence of a well established market in waste paper, the main substitute for the major natural resource, woodpulp.A brief indication is given of the relative importance of waste paper and an outline of the structure of the U.K. market; the conditions under which greater utilization of waste paper might occur are then considered taking a sideways look at the influence of the individual. In the final section the various implications for the role of the state are summarized. 相似文献
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43.
V. Kerry Smith 《决策科学》1974,5(1):115-127
Recent efforts by several authors have resulted in the development of techniques for analytically describing the dynamic properties of linear stochastic difference equation models 1 1 For examples of this work see Chow [1]; Chow and Levitan [2] [3]; Howrey [8] [9]; Howrey and Kelejian [10] and Howrey and Klein [11].
. Since these techniques have not been extensively applied to econometric models and consequently are not generally familiar to economic modelers, the purpose of this paper is to summarize the techniques these researchers have developed and to illustrate them using a simple (and admittedly unrealistic) econometric model. 相似文献
. Since these techniques have not been extensively applied to econometric models and consequently are not generally familiar to economic modelers, the purpose of this paper is to summarize the techniques these researchers have developed and to illustrate them using a simple (and admittedly unrealistic) econometric model. 相似文献
44.
Marketers are often interested in testing whether the mean vectors of multivariate distributions are equal. The test usually applied, one-way MANOVA, assumes the distributions are multinormal. Unfortunately, this assumption is not supported in many studies. As an alternative, a nonparametric multivariate one-way analysis of variance procedure is presented. 相似文献
45.
It is shown that the uncertainty connected with a `random in a broad sense' (not necessarily stochastic) event always has some `statistical regularity' (SR) in the form of a family of finite-additive probability distributions. The specific principle of guaranteed result in decision making is introduced. It is shown that observing this principle of guaranteed result leads to determine the one optimality criterion corresponding to a decision system with a given `statistical regularity'. 相似文献
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47.
Residential preferences and population distribution 总被引:2,自引:1,他引:1
Public opinion research has revealed decided preferences for living in rural areas and small towns, and proponents of population deconcentration have interpreted this as support for their policies. This study, based on a national sample, yielded similar results, but when we introduced the additional possibility of a preference for proximity to a larger city, then the rural areas preferred were found, for most respondents, to be those within the commuting range of a metropolitan central city. Although persons wishing to live near large cities were found to be looking for the same qualities of living sought by those who prefer a more remote location, these findings are not, in general, consistent with the argument that public preferences support strategies of population dispersal into nonmetropolitan areas. Instead they indicate that most of those who wish to live in a different location favor the peripheral metropolitan ring areas that have, in fact, been growing rapidly by in-migration. 相似文献
48.
With increasing demand for low-density recreational services and limited supply of facilities to provide them, congestion is becoming an important management problem. The purpose of this paper is to outline a model of congestion, estimate the effect of it upon individual willingness to pay for wilderness experiences, and illustrate how these results might be used for efficient management. A survey of users of the Spanish Peaks Primitive Area indicates that their revealed willingness to pay is significantly affected by encroachments upon the solitude they experience during their trip. Consequently, congestion effects for such services can be measured and used in the formation of administrative policy. 相似文献
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50.
Hagelin John S. Rainforth Maxwell V. Cavanaugh Kenneth L. C. Alexander Charles N. Shatkin Susan F. Davies John L. Hughes Anne O. Ross Emanuel Orme-Johnson David W. 《Social indicators research》1999,47(2):153-201
This paper reports the results of a prospective experiment in which a group of approximately 4,000 participants in the Transcendental Meditation and TM-Sidhi programs of Maharishi Mahesh Yogi assembled in Washington, D.C., from June 7 to July 30, 1993. It was hypothesized that levels of violent crime in the District of Columbia would fall substantially during the Demonstration Project, as a result of the group's effect of increasing coherence and reducing stress in the collective consciousness of the District. A 27-member Project Review Board comprising independent scientists and leading citizens approved the research protocol and monitored the research process. Weekly crime data was derived from database records provided by the District of Columbia Metropolitan Police Department (DCMPD), which are used in the FBI Uniform Crime Reports. Statistical analysis considered the effect of weather variables, daylight, historical crime trends and annual patterns in the District of Columbia, as well as trends in neighboring cities. Consistent with previous research, levels of homicides, rapes and assaults (HRA crimes) correlated with average weekly temperature. Robberies approximately followed an annually recurring cycle. Time series analysis of 1993 data, controlling for temperature, showed that HRA crimes dropped significantly during the Demonstration Project, corresponding with increases in the size of the group; the maximum decrease was 23.3% (p < 2 × 10–9) [24.6% using a longer baseline, with 1988--1993 data (p < 3 × 10–5)], coincident with the peak number of participants in the group during the final week of the assembly. When the same period in each of the five previous years was examined, no significant decreases in HRA crimes were found. Robberies did not decrease significantly. However, a model that jointly estimated the effect of the Demonstration Project on both HRA crimes and robberies showed a significant reduction in violent crimes overall of 15.6% (p = 0.0008). Further analysis showed that the effect of the coherence-creating group on reducing HRA crimes could not be accounted for by additional police staffing. The time series analysis for HRA crimes gave results that are highly robust to alternative model specifications, and showed that the effect of the group size was cumulative and persisted after the Demonstration Project ended. Also, calculation of the steady state gain based on the time series model predicted that a permanent group of 4,000 coherence-creating experts in the District would have a long-term effect of reducing HRA crimes by 48%. 相似文献