全文获取类型
收费全文 | 665篇 |
免费 | 18篇 |
国内免费 | 12篇 |
专业分类
管理学 | 47篇 |
民族学 | 23篇 |
人才学 | 1篇 |
人口学 | 9篇 |
丛书文集 | 42篇 |
理论方法论 | 22篇 |
综合类 | 334篇 |
社会学 | 156篇 |
统计学 | 61篇 |
出版年
2023年 | 6篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 20篇 |
2019年 | 17篇 |
2018年 | 18篇 |
2017年 | 26篇 |
2016年 | 28篇 |
2015年 | 14篇 |
2014年 | 30篇 |
2013年 | 89篇 |
2012年 | 28篇 |
2011年 | 37篇 |
2010年 | 22篇 |
2009年 | 42篇 |
2008年 | 35篇 |
2007年 | 39篇 |
2006年 | 38篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 25篇 |
2002年 | 24篇 |
2001年 | 22篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 16篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有695条查询结果,搜索用时 15 毫秒
1.
将农村中品种、胎次相同的60头怀孕母猪分为三组进行试验。试验结果表明,给产仔前5天的怀孕母猪口服调痢生,按每公斤体重100毫克剂量,每日一次,连用5天,对预防其所产仔猪不患黄、白痢病具有显著效果;而且仔猪增重快,药费成本低,使用方便,经济效益明显。 相似文献
2.
中国近30 年来的农村改革发展历程回顾与展望 总被引:3,自引:0,他引:3
张新光 《中国农业大学学报(社会科学版)》2006,23(4):19-23
文章重点从农村改革的整体性、综合性、协调性和党在农村政策的稳定性、连续性、实效性等方面入手,把我国近30年来的农村改革发展历程划分为三个不同的时期:即从1978年到1988年,是农村改革的起步阶段,出现了第一个“黄金发展期”;从1988年到1998年,是农村改革的停滞阶段,出现了“三农综合症”;从1998年10月至今,是农村改革的快速推进阶段,出现了第二个“黄金发展期”。全面准确地认识和把握我国农村改革的历史进程,对于科学制定农村综合改革的整体方案及相关配套政策措施至关重要。 相似文献
3.
牛心朴子草抗植物病毒组分的生物活性研究 总被引:18,自引:2,他引:16
牛心朴子草地上部分醇浸粗提物(H)对烟草花叶病毒(TMV)有高抑制活性。该草抗植物病毒有效组分是菲并吲哚是西定生物总碱(G),半中枯斑法测定(G)制剂对TMV,马铃薯Y病毒(PVY),和芜菁花叶病毒(TUMV)呈现高活性;用酶联免疫法(Elisa)测定(G)制剂对TUMV的最佳浓度防效,与枯斑法测定结果基本要符。(G)中含量最丰的(1)7-脱甲氧基娃儿藤碱(antofine)是该草活性最高的主组分,它在10^-6g/ml浓度的TMV抑制率达60%。 相似文献
4.
John Richens John Imrie Helen Weiss 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2003,166(2):207-215
Summary. The cumulative number of human immunodeficiency virus (HIV) infections worldwide has reached 60 million in little over 30 years. HIV continues to spread despite a detailed understanding of the manner in which it spreads and measures which can prevent spread. Some governments have been highly successful in containing the spread of HIV through blood products and from mother to child and among injecting drug users. Lack of political will, lack of resources or challenges to widely accepted scientific evidence have held back similar interventions in other countries. It has proved much more difficult to reduce the sexual transmission of HIV in both high and low income countries. A wide range of strategies has been identified but it remains unclear which strategies deserve priority and what methods of promoting them have the greatest effect. There is ample evidence that awareness of HIV and changes in sexual behaviour have occurred widely but the penetration of information remains poor in some vulnerable groups especially adolescents and women in poorer countries. Further obstacles face those who have information about the risk. The subordinate position of women and a desire for large families are important obstacles to condom negotiation and use. Urbanization, poverty, conflict and declining public services all exacerbate unsafe sexual behaviour. We argue that so-called 'structural' interventions directed at these wider contexts of unsafe behaviour merit greater attention. Such approaches have the added benefit of being less susceptible to 'risk compensation' which has the potential to undermine strategies directed at reducing the transmission efficiency of HIV. 相似文献
5.
Peter B. Gilbert 《Journal of the Royal Statistical Society. Series C, Applied statistics》2005,54(1):143-158
Summary. To help to design vaccines for acquired immune deficiency syndrome that protect broadly against many genetic variants of the human immunodeficiency virus, the mutation rates at 118 positions in HIV amino-acid sequences of subtype C versus those of subtype B were compared. The false discovery rate (FDR) multiple-comparisons procedure can be used to determine statistical significance. When the test statistics have discrete distributions, the FDR procedure can be made more powerful by a simple modification. The paper develops a modified FDR procedure for discrete data and applies it to the human immunodeficiency virus data. The new procedure detects 15 positions with significantly different mutation rates compared with 11 that are detected by the original FDR method. Simulations delineate conditions under which the modified FDR procedure confers large gains in power over the original technique. In general FDR adjustment methods can be improved for discrete data by incorporating the modification proposed. 相似文献
6.
张家芯 《吉林工程技术师范学院学报》2005,(10)
一切视觉表象都是由色彩和亮度产生的,那界定形状的轮廓线,是眼睛区分几个在亮度和色彩方面都绝然不同的区域时推导出来的。色彩在服装中的表现力是极强的,是服装款式所不能替代的,特别是色彩的表情作用、象征性、情感表露、意志性的体现,使服装的蕴涵更充实。本文讲述了作为流行色的旋转中轴———黑白色,它没有时段性的流行特征,而是永久的流行色,具有永恒的特征。 相似文献
7.
对微观辨证整体化研究 ,认为目前一是应该对大量的前期研究工作进行总结 ,对异病同证者及同病异证者的宏观症状进行循证医学研究 ;对异病同证者及同病异证者的微观指标进行循证医学研究 ;最终寻求宏观整体指标与微观整体指标的结合 ,从而使微观辨证升华到微观层次上的整体化水平。二是进行基因组学与中医证候相关性研究 ,寻找与中医证候相关的基因组 ,从而实现中医证候研究的基因水平上的整体化。 相似文献
8.
I. Bray & D. E. Wright 《Journal of the Royal Statistical Society. Series C, Applied statistics》1998,47(4):589-602
Data collected before the routine application of prenatal screening are of unique value in estimating the natural live-birth prevalence of Down syndrome. However, much of these data are from births from over 20 years ago and they are of uncertain quality. In particular, they are subject to varying degrees of underascertainment. Published approaches have used ad hoc corrections to deal with this problem or have been restricted to data sets in which ascertainment is assumed to be complete. In this paper we adopt a Bayesian approach to modelling ascertainment and live-birth prevalence. We consider three prior specifications concerning ascertainment and compare predicted maternal-age-specific prevalence under these three different prior specifications. The computations are carried out by using Markov chain Monte Carlo methods in which model parameters and missing data are sampled. 相似文献
9.
This prospective study aimed to investigate the relationship between metabolic syndrome (Met S) and premature ejaculation (PE) among men. The study included 300 consecutive male patients (53.6 y?±?8.7) who attended the urology clinic (December 2013–September 2014), mostly complaining of renal/ureteric calculi. A diagnostic approach was undertaken to include demographics, clinical features and laboratory investigations of the study subjects. Both erectile function and PE were evaluated using the International Index of Erectile Function (abridged form, IIEF-5) and Premature Ejaculation Diagnostic Tool (PEDT) questionnaires, respectively. Results identified 182 (60.7%) men had Met S. Prevalence of PE was significantly higher in the subjects with Met S than the controls (35.2% vs 7.6%, p?< 0.001). Patients with Met S and PE had significantly higher PEDT scores (15.4 vs 6.7), smaller waist circumference (108.3?cm vs 111.5?cm) and higher fasting blood sugar (187?mg% vs 161?mg%) than those with no PE (p?0.001, 0.047 and 0.019, respectively). The other variables including IIEF-5 score, body mass index, serum triglycerides and high-density lipoprotein (14.98 vs 16.8, 30.6 vs 31.5, 192.9?mg% vs 178.1?mg% and 37.4?mg% vs 36.2?mg%, respectively) did not reveal significant differences. Both systolic hypertension and erectile dysfunction (ED) had significant associations (p?=?0.047 and <0.001, respectively) with PE in Met S. In conclusion, PE has a high prevalence in Met S. Patients with Met S should be questioned about PE. Both ED and systolic hypertension may be associated with PE. Prevention of Met S should be considered, and this may be of help to decrease the prevalence of PE. 相似文献
10.