全文获取类型
收费全文 | 11190篇 |
免费 | 623篇 |
专业分类
各国政治 | 494篇 |
工人农民 | 411篇 |
世界政治 | 881篇 |
外交国际关系 | 354篇 |
法律 | 7423篇 |
中国共产党 | 3篇 |
中国政治 | 64篇 |
政治理论 | 2137篇 |
综合类 | 46篇 |
出版年
2023年 | 48篇 |
2021年 | 69篇 |
2020年 | 217篇 |
2019年 | 269篇 |
2018年 | 283篇 |
2017年 | 337篇 |
2016年 | 338篇 |
2015年 | 276篇 |
2014年 | 294篇 |
2013年 | 1105篇 |
2012年 | 271篇 |
2011年 | 333篇 |
2010年 | 319篇 |
2009年 | 326篇 |
2008年 | 307篇 |
2007年 | 287篇 |
2006年 | 303篇 |
2005年 | 285篇 |
2004年 | 268篇 |
2003年 | 256篇 |
2002年 | 255篇 |
2001年 | 472篇 |
2000年 | 423篇 |
1999年 | 294篇 |
1998年 | 185篇 |
1997年 | 149篇 |
1996年 | 126篇 |
1995年 | 121篇 |
1994年 | 150篇 |
1993年 | 138篇 |
1992年 | 199篇 |
1991年 | 219篇 |
1990年 | 210篇 |
1989年 | 215篇 |
1988年 | 206篇 |
1987年 | 195篇 |
1986年 | 231篇 |
1985年 | 209篇 |
1984年 | 163篇 |
1983年 | 174篇 |
1982年 | 114篇 |
1981年 | 121篇 |
1980年 | 86篇 |
1979年 | 133篇 |
1978年 | 75篇 |
1977年 | 74篇 |
1976年 | 70篇 |
1974年 | 73篇 |
1973年 | 66篇 |
1972年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Larry J. Nelson Laura M. Padilla-Walker Sarah Badger Carolyn McNamara Barry Jason S. Carroll Stephanie D. Madsen 《Journal of youth and adolescence》2008,37(5):605-615
Many studies have documented the ways in which shyness can be a barrier to personal well-being and social adjustment throughout
childhood and adolescence; however, less is known regarding shyness in emerging adulthood. Shyness as experienced during emerging
adulthood may continue to be a risk factor for successful development. The purpose of this study was to compare shy emerging
adults with their non-shy peers in (a) internalizing behaviors, (b) externalizing behaviors, and (c) close relationships.
Participants included 813 undergraduate students (500 women, 313 men) from a number of locations across the United States.
Results showed that relatively shy emerging adults, both men and women, had more internalizing problems (e.g., anxious, depressed,
low self-perceptions in multiple domains), engaged in fewer externalizing behaviors (e.g., less frequent drinking), and experienced
poorer relationship quality with parents, best friends, and romantic partners than did their non-shy peers.
Larry J. Nelson is an Associate Professor in the School of Family Life at Brigham Young University. He received his Ph.D. in 2000 from the University of Maryland, College Park. His major research interests are in social and self development during early childhood and emerging adulthood. Laura M. Padilla-Walker is an Assistant Professor in the School of Family Life at Brigham Young University. She received her Ph.D. in 2005 from the University of Nebraska—Lincoln. Her major research interests center on the parent-adolescent relationship as it relates to adolescents’ moral and prosocial behaviors and internalization of values. Sarah Badger received her Ph.D. in 2005 from Brigham Young University. Her major research interests are marriage formation and development as well as emerging adulthood and marriage readiness. Carolyn McNamara Barry is an Assistant Professor of Psychology at Loyola College in Maryland. She received her Ph.D. in 2001 from the University of Maryland, College Park. Her major research interests are in social and self development during adolescence and emerging adulthood. Jason S. Carroll is an Associate Professor in the School of Family Life at Brigham Young University. He received his Ph.D. in 2001 from the University of Minnesota. His major research interests are in marriage formation and development as well as emerging adulthood and marriage readiness. Stephanie D. Madsen is an Associate Professor of Psychology at McDaniel College. She received her Ph.D. in 2001 from the Institute of Child Development, University of Minnesota. She is particularly interested in how relationships with significant others impact child and adolescent development. 相似文献
Larry J. NelsonEmail: |
Larry J. Nelson is an Associate Professor in the School of Family Life at Brigham Young University. He received his Ph.D. in 2000 from the University of Maryland, College Park. His major research interests are in social and self development during early childhood and emerging adulthood. Laura M. Padilla-Walker is an Assistant Professor in the School of Family Life at Brigham Young University. She received her Ph.D. in 2005 from the University of Nebraska—Lincoln. Her major research interests center on the parent-adolescent relationship as it relates to adolescents’ moral and prosocial behaviors and internalization of values. Sarah Badger received her Ph.D. in 2005 from Brigham Young University. Her major research interests are marriage formation and development as well as emerging adulthood and marriage readiness. Carolyn McNamara Barry is an Assistant Professor of Psychology at Loyola College in Maryland. She received her Ph.D. in 2001 from the University of Maryland, College Park. Her major research interests are in social and self development during adolescence and emerging adulthood. Jason S. Carroll is an Associate Professor in the School of Family Life at Brigham Young University. He received his Ph.D. in 2001 from the University of Minnesota. His major research interests are in marriage formation and development as well as emerging adulthood and marriage readiness. Stephanie D. Madsen is an Associate Professor of Psychology at McDaniel College. She received her Ph.D. in 2001 from the Institute of Child Development, University of Minnesota. She is particularly interested in how relationships with significant others impact child and adolescent development. 相似文献
952.
European Journal of Political Research - 相似文献
953.
A simple method was devised to assess dental attrition in terms of its area and number of sites by using dental plaster casts and a computer assisted image analyser. The changes presented on the occlusal surfaces of teeth were investigated for age estimation using these criteria. The area of attrition on each tooth demonstrated a significant positive correlation with age, but a wide individual variation was observed in the values for each tooth. Therefore, this method was unsuitable for accurate age estimation of a single tooth. A strong negative correlation with age was observed in the number of sites of attrition. A multiple stepwise regression analysis using the variables 'attrition area' and 'attrition number' revealed multiple correlation coefficient values of 0.93. The quantitative assessment of both horizontal and vertical factors of dental attrition would be essential to improve the accuracy of this method. 相似文献
954.
V. Auwaerter M. Grosse Perdekamp J. Kempf U. Schmidt W. Weinmann S. Pollak 《Forensic Science International Supplement Series》2007,170(2-3):139
A 23-year-old man was found on a raised hide in lying position, the head wrapped in a plastic bag connected with a helium gas cylinder by a polypropylene tube. The autopsy did not show any specific findings nor did the routine toxicological analysis reveal significant information regarding the cause of death (BAC 0.9 mg/g, diphenhydramine 0.81 μg/ml in heart serum). For the detection of helium in the lungs, gas samples from both lungs were collected by a method ensuring minimal dilution. Gas analyses were performed using a GC–MS with a split–splitless injector and a headspace syringe. As carrier gas the commonly used helium was replaced by nitrogen. Helium was found in clearly elevated concentrations in gas samples from both lungs. Therefore, suffocation by breathing helium enriched, and thus oxygen deficient atmosphere, can strongly be assumed as the cause of death. 相似文献
955.
956.
Abstract: A new screening method for detecting gamma-hydroxybutyric acid (GHB) in drink matrices, using the IonSense, Inc. (Saugus, MA) direct analysis in real time (DART) ion source coupled to a JEOL exact mass time-of-flight mass spectrometer (AccuTOF), was validated and compared with the current screening methodology. The DART ion source allows for analysis of samples under ambient conditions with little to no sample preparation. Fifty drink specimens were spiked at levels of 1, 2, 3, and 4 mg/mL GHB, and analyzed on the AccuTOF-DART. Positive detection of GHB occurred for each of the samples at each concentration level, giving 100% accuracy for the samples tested. Twenty-five of the 50 drink specimens were spiked at 1 mg/mL GHB and tested using a color test known as the GHB Color Test #3. Only two of these 25 specimens tested positive for the presence of GHB, giving only 8% accuracy. Implementation of this new methodology as a screening tool for GHB analysis will quickly eliminate negative specimens allowing the examiner to focus analysis time on those that screened positive. 相似文献
957.
The intradural sagittal diameter at the second cervical vertebra (SD/C2) of 62 SIDS cases was measured myelographically. This SD/C2 proved to be dependent on body size, body weight, and age. A clear, age-dependent difference is to be found in the primarily narrow spinal canal. This parameter (SD/C2), which is more precisely defined in adults on the basis of clinical, radiological, and autopsical findings is assumed to have the value of 0.5 cm in the first 2 months, 0.6 cm in the third month, and 0.65 cm in the fourth month. The resulting potential danger to infants is dependent upon their position. The SD/C2, was significantly decreased in extension as compared to a neutral posture. With consideration of the primarily narrow spinal canal in the infant, there is, according to our measurements, a potential hazard for the infant in any further, significant shortening of the SD/C2. This is independent of the width of the spinal canal under maximal extension. We found individual cases in which the SD/C2 was decreased by almost 50% from the normal value in neutral position. No correlation was found between the primary width of the spinal canal and the degree of luminal reduction upon extension. 相似文献
958.
We consider a system made up of two committees, with overlapping membership but with different rules for passing decisions; the passage of a joint resolution requires separate approval by each committee. We show that it is possible for one voter a to be stronger (have greater voting power) than another voter b in both of the two committees, while in the two-committee system (considered as a single composite entity) b is stronger than a. We argue that this apparently paradoxical phenomenon is inherent in the structure of the decision-making system in question, rather than being an artefact of any particular index used to measure voting power. 相似文献
959.
Derek S. Reveron Author Vitae 《Orbis》2009,53(3):489-505
960.
S D Cohle 《Journal of forensic sciences》1986,31(4):1475-1478
As punishment for lying, the foster mother of a five-year-old white male poured pepper into his throat. He immediately became dyspneic, then apneic, and was pronounced dead about 1 h later. At autopsy, the main stem and several smaller bronchi were occluded with pepper. Mechanisms of asphyxia by pepper include mechanical obstruction of the tracheobronchial tree and mucosal edema caused by the irritant effect of volatile oils in pepper. This rare circumstance represents the second reported fatal case of pepper aspiration and the third reported case overall. 相似文献