首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2655篇
  免费   280篇
  国内免费   168篇
  2024年   5篇
  2023年   66篇
  2022年   30篇
  2021年   57篇
  2020年   126篇
  2019年   167篇
  2018年   113篇
  2017年   162篇
  2016年   124篇
  2015年   85篇
  2014年   108篇
  2013年   451篇
  2012年   81篇
  2011年   105篇
  2010年   57篇
  2009年   131篇
  2008年   131篇
  2007年   125篇
  2006年   102篇
  2005年   107篇
  2004年   92篇
  2003年   75篇
  2002年   83篇
  2001年   74篇
  2000年   45篇
  1999年   43篇
  1998年   50篇
  1997年   33篇
  1996年   28篇
  1995年   58篇
  1994年   19篇
  1993年   13篇
  1992年   15篇
  1991年   9篇
  1989年   7篇
  1988年   14篇
  1987年   5篇
  1986年   3篇
  1985年   10篇
  1984年   12篇
  1983年   11篇
  1982年   6篇
  1981年   10篇
  1980年   14篇
  1979年   13篇
  1978年   10篇
  1977年   7篇
  1976年   3篇
  1975年   2篇
  1974年   4篇
排序方式: 共有3103条查询结果,搜索用时 15 毫秒
861.
862.
In the present investigation longitudinal data obtained from recruits undergoing basic military training in the Swiss Armed Forces were used to examine the effects of organizational citizenship behavior (OCB) on a subsequent cadre selection and the willingness to voluntarily pursue a career as militia cadre. Results of the hierarchical logistic regression controlling for demographic variables, cadre recommendation, and allocation to the desired branch of service showed OCB predicted both the selection as cadre and the voluntariness to pursue a career as militia cadre. These effects show to what extent OCB may predict significant additional effort. Results are discussed with regard to further examination of the effects of OCB on career outcomes and selection decisions.  相似文献   
863.
Microstructure of a nanocrystalline soft magnetic Fe85Si2B8P4Cu1 alloy (NANOMET®) was investigated by the state of the art spherical aberration-corrected TEM/STEM. Observation by TEM shows that the microstructure of NANOMET® heat treated at 738 K for 600 s which exhibits the optimum soft magnetic properties has homogeneously distributed bcc-Fe nanocrystallites with the average grain size of 30 nm embedded in an amorphous matrix. Elemental mappings indicate that P is excluded from bcc-Fe grains and enriched outside the grains, which causes to retard the grain growth of bcc-Fe crystallites. The aberration-corrected STEM-EDS analysis with the ultrafine electron probe successfully proved that Cu atoms form nanometre scale clusters inside and/or outside the bcc-Fe nanocrystallites.  相似文献   
864.
In the lead-up to Australia committing military resources and personnel to the coalition opposing the Islamic State in the Levant (ISIL), Prime Minister Tony Abbott consistently categorized the al-Qaeda splinter group as a “death cult.” Examining Abbott's official rhetoric on ISIL and the threat it poses to Australia and the world, this article argues that his use of the term “death cult” reflects patterns in Western political demonology and demonizing enemies, namely, creating adversaries as monsters by highlighting the atrocities they commit in order to garner support for (often lethal) actions against them. In traditional political demonology, establishment representatives often target minority or marginal groups as these pariahs. However, in demonizing ISIL, Abbott deliberately made distinctions between it and its members and the majority of Muslims, including Australian Muslims, and utilized political demonology differently. In so doing, he affirmed this religious minority's status within the parameters of Australian citizenship. This is indeed commendable. However, Abbott rarely mentioned Muslims outside of references to terrorism. Despite the fact that Abbott acknowledges that only a comparative handful of Muslims are indeed violent, he has not yet fully engaged with the broader notions of Australian Muslims’ contributions to Australian society and their citizenship.  相似文献   
865.
Women with attention‐deficit/hyperactivity disorder (ADHD) often struggle with the developmental challenges of adulthood and ADHD‐related problems. The authors provide specific clinical interventions from a narrative‐based group approach to help women with ADHD understand their symptoms, create strength‐based narratives, and apply these narratives to the developmental tasks of early adulthood.  相似文献   
866.
Breast cancer impacts an entire family system. The mothers of breast cancer patients are likely impacted in a variety of ways by their daughters’ diagnoses. To date, few researchers have investigated the experiences and perspectives of this population. In the present study, the authors explored how mothers of breast cancer survivors managed adversities associated with this disease and illness. Using secondary data and narrative analysis, the investigators analyzed data gathered from 30 mothers. Findings indicate that participants relied on their spirituality for the management of stress and hardship related to having a loved one with breast cancer.  相似文献   
867.
Two genetic technologies capable of making heritable changes to the human genome have revived interest in, and in some quarters a very familiar panic concerning, so-called germline interventions. These technologies are: most recently the use of CRISPR/Cas9 to edit genes in non-viable IVF zygotes and Mitochondrial Replacement Therapy (MRT) the use of which was approved in principle in a landmark vote earlier this year by the United Kingdom Parliament. The possibility of using either of these techniques in humans has encountered the most violent hostility and suspicion. However it is important to be aware that much of this hostility dates back to the fears associated with In Vitro Fertilization (IVF) and other reproductive technologies and by cloning; fears which were baseless at the time concerning both IVF and cloning the use of both of which have proved to be highly beneficial to humanity and which have been effectively regulated and controlled. This paper argues that CRISPR should by pursued through researh until it is safe enough for use in humans but there is no reason to suppose at this stage that such use will be unsafe or unethical (Collins 2015).  相似文献   
868.
The published norms for the Depression Anxiety and Stress Scale (DASS) give results for clinical populations that largely fall in the severe to very severe categories. As a result, within this population, the ability to compare the comparative contributions of the underlying emotional components is reduced. The present study presents results from a large general psychiatric outpatient population and provides percentile norms with confidence intervals for both the original DASS and the shorter 21‐item form. It is noted that both forms have high validity but that the correlations between scales are higher than those reported in non‐clinical populations. There was little variation between sexes but some variation of results with age with both younger and older cohorts having lower scores except for the Stress scale where there were higher scores in the older group. There is some evidence of a ceiling effect in the Depression and Stress scales. It was noted that nearly a quarter of patient scores fell within the originally defined normal range suggesting that the DASS would not be a particularly sensitive instrument in its previously reported use as a screening instrument for psychiatric illness.  相似文献   
869.
In this paper, the performance of six types of techniques for comparisons of means is examined. These six emerge from the distinction between the method employed (hypothesis testing, model selection using information criteria, or Bayesian model selection) and the set of hypotheses that is investigated (a classical, exploration‐based set of hypotheses containing equality constraints on the means, or a theory‐based limited set of hypotheses with equality and/or order restrictions). A simulation study is conducted to examine the performance of these techniques. We demonstrate that, if one has specific, a priori specified hypotheses, confirmation (i.e., investigating theory‐based hypotheses) has advantages over exploration (i.e., examining all possible equality‐constrained hypotheses). Furthermore, examining reasonable order‐restricted hypotheses has more power to detect the true effect/non‐null hypothesis than evaluating only equality restrictions. Additionally, when investigating more than one theory‐based hypothesis, model selection is preferred over hypothesis testing. Because of the first two results, we further examine the techniques that are able to evaluate order restrictions in a confirmatory fashion by examining their performance when the homogeneity of variance assumption is violated. Results show that the techniques are robust to heterogeneity when the sample sizes are equal. When the sample sizes are unequal, the performance is affected by heterogeneity. The size and direction of the deviations from the baseline, where there is no heterogeneity, depend on the effect size (of the means) and on the trend in the group variances with respect to the ordering of the group sizes. Importantly, the deviations are less pronounced when the group variances and sizes exhibit the same trend (e.g., are both increasing with group number).  相似文献   
870.
Mexican‐origin families are a large and rapidly increasing subgroup of the U.S. population, but they remain underrepresented in family scholarship. This paper introduces a special section of four papers on Mexican‐origin families designed to contribute to the advancement of research on how cultural, family, and gender socialization processes unfold across key developmental periods and life transitions in this cultural context. Two longitudinal studies of Mexican‐origin families provided the data for these four papers: (a) The Juntos Project, an 8‐year longitudinal study of mothers, fathers, and adolescent sibling pairs in 246 Mexican‐origin families; and (b) The Supporting MAMI Project, a study following 204 adolescent mothers and their mother figures from the third trimester of pregnancy through their young children's 5th birthdays. In this introductory paper, we highlight four themes, including (a) differential acculturation and reciprocal socialization, (b) interdependence in families, (c) the intersection of culture and gender, and (d) methodological issues. We end with suggestions for future research.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号