全文获取类型
收费全文 | 4442篇 |
免费 | 46篇 |
国内免费 | 1篇 |
专业分类
各国政治 | 178篇 |
工人农民 | 39篇 |
世界政治 | 686篇 |
外交国际关系 | 489篇 |
法律 | 2344篇 |
中国共产党 | 104篇 |
中国政治 | 291篇 |
政治理论 | 252篇 |
综合类 | 106篇 |
出版年
2023年 | 25篇 |
2021年 | 25篇 |
2018年 | 24篇 |
2016年 | 21篇 |
2015年 | 21篇 |
2014年 | 115篇 |
2013年 | 34篇 |
2012年 | 300篇 |
2011年 | 279篇 |
2010年 | 102篇 |
2009年 | 114篇 |
2008年 | 266篇 |
2007年 | 282篇 |
2006年 | 257篇 |
2005年 | 231篇 |
2004年 | 236篇 |
2003年 | 225篇 |
2002年 | 245篇 |
2001年 | 181篇 |
2000年 | 201篇 |
1999年 | 74篇 |
1998年 | 54篇 |
1997年 | 40篇 |
1996年 | 31篇 |
1995年 | 43篇 |
1994年 | 75篇 |
1993年 | 57篇 |
1992年 | 43篇 |
1991年 | 52篇 |
1990年 | 36篇 |
1989年 | 32篇 |
1988年 | 116篇 |
1987年 | 26篇 |
1986年 | 34篇 |
1985年 | 38篇 |
1984年 | 29篇 |
1983年 | 27篇 |
1982年 | 20篇 |
1981年 | 40篇 |
1980年 | 35篇 |
1979年 | 35篇 |
1978年 | 20篇 |
1977年 | 41篇 |
1976年 | 32篇 |
1964年 | 27篇 |
1963年 | 24篇 |
1962年 | 40篇 |
1961年 | 18篇 |
1960年 | 23篇 |
1959年 | 31篇 |
排序方式: 共有4489条查询结果,搜索用时 31 毫秒
141.
设计了6对分别针对鸡传染性支气管炎病毒(IBV)、禽流感病毒(AIV)、鸡毒霉形体(MG)、鸡传染性喉气管炎病毒(ILTV)、新城疫病毒(NDV)和滑液霉形体(MS)的特异性引物,根据反转录聚合酶链反应(RT-PCR)原理和多重PCR原则,优化建立了一次PCR反应同时检测6种禽呼吸道病原的二温式多重PCR.该方法可同时扩增出6条区段大小与设计相符的特异性片段,即IBV 1720 bp、AIV 1050 bp、MG 732 bp、ILTV 647 bp、NDV 310 bp、MS 207 bp,对人工感染鸡临床样品检测结果证明,该方法可用于临床诊断. 相似文献
142.
143.
利用差减抑制杂交(SSH)技术,以旋毛虫5日龄成虫的cDNA为试验方(tester),以肌幼虫+3日龄成虫的cDNA为驱动方(driver),制备5日龄成虫差减cDNA,并与pT-Adv载体相连接,转入大肠埃希氏菌TOP 10F.以试验方的差减cDNA PCR产物+未差减cDNA为试验方探针,以驱动方的差减cDNA PCR产物+未差减cDNA为驱动方探针,对5日龄成虫差减cDNA克隆进行初步筛选,对筛选到的阳性克隆进一步用southern blot进行鉴定,并对其测序,进行序列分析.结果表明,获得1个大小为464 bp的旋毛虫5日龄成虫期特异性cDNA片段,经BLAST软件分析表明,该序列是1个未见报道的旋毛虫基因序列片段,可能编码1种表皮胶原蛋白.这为旋毛虫5日龄成虫期特异性基因全长序列的钓取、分析及鉴定奠定了基础. 相似文献
144.
145.
在19世纪,除了浪漫主义的解释学外,还有历史主义的解释学。它们之间的一个重要的联结点是解释学循环。除此之外,二者的密切关系在其师承和道统方面。布克、德罗伊森和狄尔泰三人的思想代表了西方19世纪下半叶解释学的一个重要的特点,那就是突出与人文科学的联系,这是以历史意识的逐步确立为中介的,但是他们,尤其是德罗伊森和狄尔泰最终都没能摆脱历史的局限。 相似文献
147.
Shulman S Zlotnik A Shachar-Shapira L Connolly J Bohr Y 《Journal of youth and adolescence》2012,41(5):593-606
This study examined the links between parental divorce, quality of maternal parenting, spousal relationships and middle adolescent
romantic competence in 80 mother-adolescent daughter pairs (40 divorced). Mothers were asked to describe their attitudes and
behaviors with regard to their daughters’ romantic behavior. In addition, mothers were interviewed about their own romantic
experiences when they were at the age of their daughters. Adolescent girls (mean age = 16.98 years; range 16–18) were administered
a comprehensive interview about romantic competence. Findings indicated that adolescent girls from divorced families showed
lower levels of romantic competence, which were expressed in their behavior, attitudes toward relationships and skill in handling
those relationships. Divorce was found to have had an adverse effect on girls’ romantic competence, whereas continued adaptive
parenting and spousal relationships alleviated the effect of divorce. Mothers’ coherent representation of their own adolescent
romantic experiences also alleviated the effect of divorce on daughters’ romantic behavior. Results show the important role
of family relationships in fostering romantic competence among adolescent girls. 相似文献
148.
Previous studies have indicated homophily in depressive symptoms among adolescent friends, resulting from both peer selection
and socialization processes. However, developmental differences and the role of school transitions in these processes have
not been elucidated. A sample of 367 (51% female) adolescents was followed from 6th to 11th grade to investigate prospective
relationships between adolescents’ and their friends’ depressive symptoms in middle school and in high school. Results revealed
that students selected friends with similar levels of depressive symptoms after each school transition. Additionally, friends
appeared to socialize adolescents to become more similar in depressive affect in late middle school years. These findings
suggest normative selection effects after school transitions, followed by socialization effects in middle school, but not
high school. 相似文献
149.
Although adolescents often participate in multiple extracurricular activities, little research has examined how the breadth
of activities in which an adolescent is involved relates to school-related affect and academic performance. Relying on a large,
multi-ethnic sample (N = 864; 55.9% female), the current study investigated linear and non-linear relationships of 11th grade activity participation
in four activity domains (academic/leadership groups, arts activities, clubs, and sports) to adolescents’ sense of belonging
at school, academic engagement, and grade point average, contemporarily and in 12th grade. Results of multiple regression
models revealed curvilinear relationships for sense of belonging at school in 11th and 12th grade, grade point average in
11th grade, and academic engagement in 12th grade. Adolescents who were moderately involved (i.e., in two domains) reported
a greater sense of belonging at school in 11th and 12th grade, a higher grade point average in 11th grade, and greater academic
engagement in 12th grade, relative to those who were more or less involved. Furthermore, adolescents’ sense of belonging at
school in 11th grade mediated the relationship of domain participation in 11th grade to academic engagement in 12th grade.
This study suggests that involvement in a moderate number of activity domains promotes positive school-related affect and
greater academic performance. School policy implications and recommendations are discussed. 相似文献
150.
正第三章五年计划下的经济发展与经济政策①第一节苏维埃经济彻底社会主义化的历程起初,国外并没有把五年计划当回事,仅将其当作一种宣传,意在激励人们工作。这种怀疑论走得太远了;当计划的内容在苏维埃俄国大多得以落实时,怀疑让位于震惊,在某些圈子里,及至痴迷。然而,彻底的怀疑与过度的痴迷一样,都是非理性的。但是,怀疑论者有一点是对的:一眼就能看出,计划的巨额投资并没有带来一般生活水准的同步改善。同时,不要忘记,掌控所有资源、以 相似文献