全文获取类型
收费全文 | 93171篇 |
免费 | 1960篇 |
国内免费 | 4篇 |
专业分类
管理学 | 12652篇 |
民族学 | 541篇 |
人才学 | 25篇 |
人口学 | 7271篇 |
丛书文集 | 528篇 |
教育普及 | 2篇 |
理论方法论 | 9515篇 |
现状及发展 | 1篇 |
综合类 | 2182篇 |
社会学 | 43446篇 |
统计学 | 18972篇 |
出版年
2023年 | 510篇 |
2021年 | 569篇 |
2020年 | 1512篇 |
2019年 | 2201篇 |
2018年 | 2119篇 |
2017年 | 3187篇 |
2016年 | 2407篇 |
2015年 | 2059篇 |
2014年 | 2634篇 |
2013年 | 18856篇 |
2012年 | 2444篇 |
2011年 | 2272篇 |
2010年 | 1998篇 |
2009年 | 2197篇 |
2008年 | 2059篇 |
2007年 | 1881篇 |
2006年 | 2132篇 |
2005年 | 2313篇 |
2004年 | 2180篇 |
2003年 | 1920篇 |
2002年 | 2019篇 |
2001年 | 2094篇 |
2000年 | 1887篇 |
1999年 | 1757篇 |
1998年 | 1527篇 |
1997年 | 1398篇 |
1996年 | 1356篇 |
1995年 | 1362篇 |
1994年 | 1335篇 |
1993年 | 1332篇 |
1992年 | 1340篇 |
1991年 | 1273篇 |
1990年 | 1244篇 |
1989年 | 1094篇 |
1988年 | 1185篇 |
1987年 | 1045篇 |
1986年 | 956篇 |
1985年 | 1117篇 |
1984年 | 1179篇 |
1983年 | 1065篇 |
1982年 | 980篇 |
1981年 | 880篇 |
1980年 | 829篇 |
1979年 | 911篇 |
1978年 | 793篇 |
1977年 | 716篇 |
1976年 | 665篇 |
1975年 | 649篇 |
1974年 | 538篇 |
1973年 | 458篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
Children may be more susceptible to toxicity from some environmental chemicals than adults. This susceptibility may occur during narrow age periods (windows), which can last from days to years depending on the toxicant. Breathing rates specific to narrow age periods are useful to assess inhalation dose during suspected windows of susceptibility. Because existing breathing rates used in risk assessment are typically for broad age ranges or are based on data not representative of the population, we derived daily breathing rates for narrow age ranges of children designed to be more representative of the current U.S. children's population. These rates were derived using the metabolic conversion method of Layton (1993) and energy intake data adjusted to represent the U.S. population from a relatively recent dietary survey (CSFII 1994–1996, 1998). We calculated conversion factors more specific to children than those previously used. Both nonnormalized (L/day) and normalized (L/kg-day) breathing rates were derived and found comparable to rates derived using energy estimates that are accurate for the individuals sampled but not representative of the population. Estimates of breathing rate variability within a population can be used with stochastic techniques to characterize the range of risk in the population from inhalation exposures. For each age and age-gender group, we present the mean, standard error of the mean, percentiles (50th, 90th, and 95th), geometric mean, standard deviation, 95th percentile, and best-fit parametric models of the breathing rate distributions. The standard errors characterize uncertainty in the parameter estimate, while the percentiles describe the combined interindividual and intra-individual variability of the sampled population. These breathing rates can be used for risk assessment of subchronic and chronic inhalation exposures of narrow age groups of children. 相似文献
132.
Has the image of Che Guevara lost its power to evoke radical politics in the face of pervasive commodification? The commercialization of this 1960s political icon has called into question the power of the market to shape collective memories. Meanwhile, antisystemic movements of the left continue to erect his image at protest events. In light of this contest over how Che Guevara is remembered, we investigate, using data from a survey of Spanish citizens, who is most likely to recall him. We find qualified support for the theory of generational imprinting—Che is more often recalled by those generations who saw him rise to prominence during their formative years, although prominent as a collective symbol rather than as a living person. Our results also corroborate the claim that historical figures or events are more salient for, and therefore more likely to be remembered by, some subgenerational units than others. Thus, although the younger generations are in general more likely than their elders to recall Che, he is most frequently remembered by the highly educated leftists who espouse postmaterialist and posttraditionalist values and identify more with their local regions than with the nation of Spain. These patterns suggest that, in contrast to the dire predictions of mass culture theorists, the memory of Che Guevara has become increasingly tied to markers of social, ethnic‐regional, and political identity. 相似文献
133.
134.
135.
Summary Referrals from general practitioners to a social services departmentover a period of six months were analyzed with a view to assessingthe quality of communication. It was found that the referrals,predominantly related to ill health and practical problems,frequently lacked important background information, and manywere considered to be innacurate or inadequate. A high proportionof allocated referrals led to no contact, and there were significantdifferences between the various social services workers in thenature and extent of contacts made. General practitioners rarelycontacted the social services department during intervention.Social workers were the most consistent in involving G.P.s incase management, and the doctors, when contacted, were rarelyunhelpful, and frequently helpful. A wide variety of alternativeactions were discussed when contact was made, and there wasgenerally a high degree of agreement. Contact with G.P.s consideredto have a positive view of social services was more extensivethan with other G.P.s, and positive G.P.s were generally consideredmost helpful. 相似文献
136.
Medical fraud and overservicing are estimated to cost the Australian community between $130 and $200 million per annum, a figure far greater than the national cost of burglary and almost the same as the total property loss from all conventional crime. An examination of the social antecedents of medical fraud and overservicing suggests that the predisposition of some doctors to engage in these practices occurs because of the following: (1) medical training and professional socialization that orientate student doctors away from altruistic health issues towards narrower self-interested professional concerns; (2) career expectations of a high pattern of material consumption that are often frustrated by an increasingly competitive medical market place; and (3) professional medical organizations that lobby for national health policies which reflect the mercenary self-interest of doctors rather than the health interest of the nation. 相似文献
137.
The Analysis of Verbal Behavior - 相似文献
138.
Barbara Chaulk Phyllis J. Johnson Richard Bulcroft 《Journal of Family and Economic Issues》2003,24(3):257-279
Family development and prospect theory were used as a framework to predict variability in individuals' subjective financial risk tolerance within distinct family structures. Gender, age, and income were expected to interact with the main effects of family structure (marital status and children). Theory-generated hypotheses were examined in Study 1 (data from university housing respondents, n = 76) and Study 2 (the 1998 Survey of Consumer Finances, n = 4,305). One family structure main effect (child presence) was significant for investment risk tolerance in both studies. Family structure interactions (marital status × age and child × income) were significant for employment risk (Study 1), and child × age was significant for investment risk in Study 2. 相似文献
139.
Lukas D. Tsitsipis 《Journal of Sociolinguistics》2004,8(4):569-594
Through the use of two central Bakhtinian concepts, authoritative and internally persuasive discourse (word), this paper examines the tension between the ideology of linguistic hegemony as a source of power in the Greek public sphere and the condition of language shift faced by the Albanian‐speaking communities of modern Greece. I argue here that a cautious application of these two notions, which are relevant to linguistic ideology, can reveal crucial aspects of two processes: that of subordination to and that of questioning of the dominant linguistic ideology by local Albanian‐speaking communities. Thus, in language shift contexts, it is possible that no simple relations obtain that place social agents in unquestionable and easily predictable positions. Such an approach proves useful for the sociolinguistic study of threatened language communities. 相似文献
140.
For a wide variety of applications, experiments are based on units ordered over time or space. Models for these experiments generally may include one or more of: correlations, systematic trends, carryover effects and interference effects. Since the standard optimal block designs may not be efficient in these situations, orthogonal arrays of type I and type II, which were introduced in 1961 by C.R. Rao [Combinatorial arrangements analogous to orthogonal arrays, Sankhya A 23 (1961) 283–286], have been recently used to construct optimal and efficient designs for many of these experiments. Results in this area are unified and the salient features are outlined. 相似文献