全文获取类型
收费全文 | 530篇 |
免费 | 28篇 |
专业分类
管理学 | 43篇 |
民族学 | 5篇 |
人口学 | 51篇 |
理论方法论 | 51篇 |
综合类 | 5篇 |
社会学 | 264篇 |
统计学 | 139篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 9篇 |
2019年 | 20篇 |
2018年 | 42篇 |
2017年 | 52篇 |
2016年 | 33篇 |
2015年 | 19篇 |
2014年 | 18篇 |
2013年 | 94篇 |
2012年 | 60篇 |
2011年 | 23篇 |
2010年 | 20篇 |
2009年 | 17篇 |
2008年 | 24篇 |
2007年 | 15篇 |
2006年 | 14篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 13篇 |
2001年 | 1篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有558条查询结果,搜索用时 15 毫秒
501.
Carlos Cardoso Narcisa Bandarra Helena Lourenço Cláudia Afonso Maria Nunes 《Risk analysis》2010,30(5):827-840
The intake of methyl‐Hg and EPA + DHA through consumption of seafood in Europe as well as the associated probability of exceeding the provisional tolerable weekly intake (PTWI) and the recommended daily intake (RDI), respectively, were estimated by combining methyl‐Hg and EPA + DHA contents in the five most consumed seafood species with hypothesized consumption distributions for eight European countries, chosen on the basis of size and representative significance. Two estimators were used: plug‐in (PI) and tail estimation (TE). The latter was based on the application of the extreme value theory to the intakes distribution curves. Whereas contents data were collected from own database and published scientific papers, consumption data were obtained from statistical sources of the various countries. Seafood consumption levels varied considerably between countries, from 140 in the United Kingdom to 628.5 g/(person.week) in Iceland. The main consumed species were also different between countries. The probability of exceeding the methyl‐Hg PTWI ranged from 0.04% in the United Kingdom to 9.61% in Iceland. Concerning the probability of exceeding the RDI of EPA + DHA, Iceland was third, after Portugal (66.05%) and Spain (61.05%) and the United Kingdom was the last (0.32%). While TE was most accurate for small probabilities, PI yielded best estimates for larger probabilities. 相似文献
502.
The use of probabilistic approaches in exposure assessments of contaminants migrating from food packages is of increasing interest but the lack of concentration or migration data is often referred as a limitation. Data accounting for the variability and uncertainty that can be expected in migration, for example, due to heterogeneity in the packaging system, variation of the temperature along the distribution chain, and different time of consumption of each individual package, are required for probabilistic analysis. The objective of this work was to characterize quantitatively the uncertainty and variability in estimates of migration. A Monte Carlo simulation was applied to a typical solution of the Fick's law with given variability in the input parameters. The analysis was performed based on experimental data of a model system (migration of Irgafos 168 from polyethylene into isooctane) and illustrates how important sources of variability and uncertainty can be identified in order to refine analyses. For long migration times and controlled conditions of temperature the affinity of the migrant to the food can be the major factor determining the variability in the migration values (more than 70% of variance). In situations where both the time of consumption and temperature can vary, these factors can be responsible, respectively, for more than 60% and 20% of the variance in the migration estimates. The approach presented can be used with databases from consumption surveys to yield a true probabilistic estimate of exposure. 相似文献
503.
Lynn Jamieson Kathryn Backett Milburn Roona Simpson Fran Wasoff 《The Sociological review》2010,58(3):463-485
Attitude survey and interview data are mobilised to address neglect of men's contribution to low fertility and wider social change in families and relationships. Men's attitudes are as relevant as women's to understanding fertility behaviour. However, fertility behaviour can only be understood in the context of a package of changes in gender relations and family life. Data from a random sample of men aged 18–49 surveyed in the Scottish Social Attitudes (SSA) survey 2005/06 are combined with in‐depth interviews conducted in 2007 with 75 men aged 25–44 identified through the Scottish Household Survey as not living in co‐resident partnership arrangements. Both datasets encompass the age span conventionally associated with having children and men who were the potential partners of women delaying a first child until their 30s. They allow consideration of the impact of social contact with parents and children on men's fertility intentions and how the role of provider features in men's views about parenting. The interviews focus on men who have fallen out of, or have not entered, co‐resident partnerships and examine the relationship between partnering and parenting. In combination the data suggest how men act as a complementary or contradictory downward drag on women's fertility and that their role has been underestimated in understanding the package of family change of which low fertility is a part. 相似文献
504.
In an unbalanced and heteroscedastic one-way random effects model of analysis of variance we consider hypotheses concerning the between group variance where in a classical set-up the hypothesis whether this variance component is zero is tested. We consider the still open problem of testing also extended hypotheses concerning this parameter and generalize the prominent Welch test to deal with these hypotheses, too. 相似文献
505.
Low fertility in most developed countries has prompted policy concern in relation to labour market supply, pensions, and expenditure
on health and welfare services as well as policy debate about both the cost of children and the opportunity costs of parenthood.
The extent to which family policy interventions can be effective in slowing or reversing fertility decline is much debated.
This paper, based on a fertility module of the Scottish Social Attitudes Survey 2005, examines the current fertility, and
ideal and expected fertility of a nationally representative sample of 455 parents of reproductive age and focuses on whether
they plan to have another child. It compares the characteristics of those who intend to have another child with those who
do not, and how parents with one child differ from those with more children. It addresses three questions about family size:
(1) fertility ideals, (2) resources and the economic implications of childbearing, and (3) opportunities for childbearing
and the effects of a late start on fertility expectations. It concludes that, despite a sustained period of low fertility
in Scotland, childbearing ideals are robust and explanations of low fertility must derive from difficulties in realising those
ideals. Difficulties in realising fertility aspirations are associated less with resources than with opportunities for childbearing,
especially the timing of first birth. Those who delay their first birth are less likely to realise their ideal family size,
and their lower fertility is associated with the opportunity costs of childbearing in terms of foregone qualifications, careers
and earnings. 相似文献
506.
François Poulin Anne‐Sophie Denault Sara Pedersen 《Journal of research on adolescence》2011,21(4):776-788
The impact of the changes in the gender composition of friendship networks during early adolescence on substance use in late adolescence was examined. The hypothesis was that initial level and increase in the proportion of other‐sex friends in the network would be associated with higher levels of substance use among girls, but not among boys. Girls and boys (n=390) were interviewed annually from ages 12 to 18 (79% retention). For both boys and girls, initial level in the proportion of other‐sex friends predicted alcohol use in late adolescence, whereas it was predictive of drug use in girls only. Moreover, for girls only, a faster increase in the proportion of other‐sex friends in the network predicted later use of alcohol and drugs. 相似文献
507.
This paper investigates the monetary policy reaction functions of the Central Bank of Republic of Turkey (CBRT) over the periods 1987:01–2001:12 and 2002:01–2009:05. We specifically attempt to shed light on question to what extent exchange rate developments still continue to influence monetary policy, even under inflation targeting. This study seeks to investigate how the monetary policy responded to the exchange rate shocks before and after adoption of inflation targeting regime. How large the effect of exchange rate shocks is accounted for in forecast error variances decompositions for monetary policy as compared to other shocks? Using the VAR model, this study shows that there has been strong pass-through during whole period. Moreover, in the postcrisis period, exchange rate has been the main reaction variable for the CBRT. 相似文献
508.
Christopher Leleu Jean Menotti Pascale Meneceur Firas Choukri Annie Sulahian Yves Jean‐François Garin Jean‐Baptiste Denis Francis Derouin 《Risk analysis》2013,33(8):1441-1453
Invasive aspergillosis (IA) is a major cause of mortality in immunocompromized hosts, most often consecutive to the inhalation of spores of Aspergillus. However, the relationship between Aspergillus concentration in the air and probability of IA is not quantitatively known. In this study, this relationship was examined in a murine model of IA. Immunosuppressed Balb/c mice were exposed for 60 minutes at day 0 to an aerosol of A. fumigatus spores (Af293 strain). At day 10, IA was assessed in mice by quantitative culture of the lungs and galactomannan dosage. Fifteen separate nebulizations with varying spore concentrations were performed. Rates of IA ranged from 0% to 100% according to spore concentrations. The dose‐response relationship between probability of infection and spore exposure was approximated using the exponential model and the more flexible beta‐Poisson model. Prior distributions of the parameters of the models were proposed then updated with data in a Bayesian framework. Both models yielded close median dose‐responses of the posterior distributions for the main parameter of the model, but with different dispersions, either when the exposure dose was the concentration in the nebulized suspension or was the estimated quantity of spores inhaled by a mouse during the experiment. The median quantity of inhaled spores that infected 50% of mice was estimated at 1.8 × 104 and 3.2 × 104 viable spores in the exponential and beta‐Poisson models, respectively. This study provides dose‐response parameters for quantitative assessment of the relationship between airborne exposure to the reference A. fumigatus strain and probability of IA in immunocompromized hosts. 相似文献
509.
Johanne Saint-Charles Pierre Mongeau Jean-François Biron 《International Gambling Studies》2013,13(3):233-247
Video Lottery Terminals (VLT) are associated with pathological gambling and with most of the requests for help in combating gambling addiction. Embeddedness of a person in his or her social network is among the communicational factors that may help explain this phenomenon. To verify this, we compared ego networks of VLT gamblers, of gamblers of games with low request for help and of VLT gamblers in treatment (n = 90). The networks of regular VLT gamblers are small and dense and offer little social support. Gamblers in treatment also have small networks, but they are less dense, have more components and offer more social support. Networks of gamblers with low requests for assistance are approximately twice the size as those of VLT gamblers, are sparser and offer more companionship. In conclusion, the VLT gambler is not an isolated individual, but rather an individual ‘shut-in’ a small network of tightly knitted relationships. 相似文献
510.
Sinan Saraçli 《Journal of Statistical Computation and Simulation》2013,83(10):1890-1899
In this study, the performances of linear regression techniques, which are especially used in clinical chemistry in method comparison studies, are compared via the Monte-Carlo simulation. The regression techniques that take the measurement errors of both dependent and independent variables into account are called Type II regression techniques. In this study, we also compare the performances of Type II and Type I (classical regression techniques that do not take the measurement errors of the independent variable into account) regression techniques for different sample sizes and different shape parameters of the Weibull distribution. The mean square error is used as a performance criterion of each technique. MATLAB 7.02 software is used in the simulation study. As a result, in all conditions, the ordinary least-square (OLS)-bisector regression technique, which bisects the OLS(Y | X) and the OLS(X | Y), shows the best performance. 相似文献