全文获取类型
收费全文 | 1930篇 |
免费 | 71篇 |
国内免费 | 46篇 |
专业分类
管理学 | 206篇 |
民族学 | 10篇 |
人才学 | 2篇 |
人口学 | 38篇 |
丛书文集 | 97篇 |
理论方法论 | 69篇 |
综合类 | 912篇 |
社会学 | 139篇 |
统计学 | 574篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 12篇 |
2021年 | 18篇 |
2020年 | 30篇 |
2019年 | 35篇 |
2018年 | 56篇 |
2017年 | 71篇 |
2016年 | 49篇 |
2015年 | 59篇 |
2014年 | 86篇 |
2013年 | 290篇 |
2012年 | 113篇 |
2011年 | 130篇 |
2010年 | 98篇 |
2009年 | 110篇 |
2008年 | 118篇 |
2007年 | 105篇 |
2006年 | 94篇 |
2005年 | 62篇 |
2004年 | 85篇 |
2003年 | 56篇 |
2002年 | 56篇 |
2001年 | 45篇 |
2000年 | 42篇 |
1999年 | 45篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 15篇 |
1995年 | 14篇 |
1994年 | 20篇 |
1993年 | 11篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 6篇 |
1977年 | 1篇 |
排序方式: 共有2047条查询结果,搜索用时 15 毫秒
41.
BackgroundIn the Palestinian community, lifestyle changes, rapid urbanization and socioeconomic development, stress, smoking, and changes in food habits has increased the risk of non-communicable diseases especially diabetes mellitus. Diabetes complications can be prevented if the glycemic status of patients with diabetes is maintained within a nearly normal range. Therefore, patient education is critical in controlling blood glucose levels within the normal range.ObjectiveThis study aimed at measuring the effect of diabetes educational intervention program for patients suffering from type 2 diabetes attending the Diabetes Clinic in Tulkarim Directorate of Health.MethodsA short duration observational study involving pre- and post-test educational intervention program was carried out on a relatively small number of type 2 diabetes patients at the Diabetes Clinic in Tulkarim Directorate of Health. In total, 215 patients attended a group-based 4 h educational intervention session about diabetes. The program included explaining diabetes mellitus-symptoms, risk factors, types, treatment and complications and main aspects of self-care of the disease (foot care, eye care, and blood glucose monitoring), main aspects of dietary management, weight reduction, blood pressure, smoking cessation, periodic investigations, home monitoring and importance of physical activity. Knowledge evaluation questionnaire were evaluated pre- and post-study. Anthropometric measurements such as body weight (WT), body mass index (BMI) and laboratory tests such as fasting blood glucose (FBG), hemoglobin A1C (HbA1c), cholesterol (Chol), and triglycerides (TG) were measured both at the beginning and at the end of the study. Significance of the results was assessed by paired t-test at 95% confidence interval.ResultsThe participant’s mean age was 51.07 that ranged between 31 and 70 years. For a total of 215 participants, 41.4% were males and 58.6% were females. The mean weight before educational intervention was 80.81 ± 14.95 kg (82.6 kg for males and 79.5 kg for females) that decreased to 78.9 ± 14.33 kg (81.1 kg for males and 77.3 kg for females) after educational intervention program. The BMI also decreased significantly after educational intervention. The mean fasting blood sugar was 188.65 ± 71.45 mg/dL before educational intervention that decreased to 177.7 ± 66.11 mg/dL after the educational intervention (p = 0.049). The mean glycosylated hemoglobin was 8.57 ± 1.21 before educational intervention that decreased to 7.95 ± 1.42 after educational intervention. The mean value of cholesterol before educational intervention was 183.27 ± 37.74 mg/dL that decreased to 169.57 ± 34.23 mg/dL after educational intervention. The mean triglycerides value decreased after educational intervention from 209.85 ± 171.04 mg/dL to 183.28 ± 152.4 mg/dL (p = 0.025). The mean score of knowledge questionnaire before educational intervention was 60.6 ± 20.65 that increased to 78.1 ± 13.4 after conducting educational intervention.ConclusionsDiabetes education was found to be effective on BMI, FBG, HbA1c, Chol, TG, and knowledge.RecommendationsDiabetes education is a cornerstone in the management and care of diabetes and should be an integral part of health planning involving patient’s family, diabetes care team, community, and decision makers in the education process. 相似文献
42.
R2是最近十几年迅速发展的一个研究课题,其研究取向从纯粹的计量经济学符号演变为股价同步性特征变量,并与公司特质信息含量联系起来,赋予了全新的内涵.学者们通过跨学科的交叉与融合,从法与金融理论、委托代理理论、信息不对称理论、公司治理理论等视角对R2背后的生成机制、作用渠道和影响后果展开富有成效的研究.本文首先梳理从资产定价模型到R2,再从R2到股价同步性中间的学理关系和因果顺承,接着回顾了关于R2形成机理与经济后果的相关讨论,然后对R2的学术争论进行总结和评述,最后就R2的溯源问题、以及文化与政治潜在影响对未来R2研究提出展望. 相似文献
43.
Power comparison of the Kolmogorov–Smirnov test under ranked set sampling and simple random sampling
Yusuf Can Sevil 《Journal of Statistical Computation and Simulation》2017,87(11):2175-2185
Many studies have been used to compare the power of several goodness-of-fit (GOF) tests under simple random sampling (SRS) and ranked set sampling (RSS). In our study, a different design procedure and ranking process in RSS are thoroughly investigated. A simulation study is conducted to compare the power of the Kolmogorov–Smirnov test under SRS and RSS with different sets and cycle sizes for several distributions. Level-2 sampling design and partially rank-ordered sets are used. Also, we benefited from auxiliary variables in the ranking process. Finally, results are presented with tables and figures. Under these conditions we show that the RSS has better performance against the SRS in finite population. 相似文献
44.
In a special paired sample case, Hotelling’s T2 test based on the differences of the paired random vectors is the likelihood ratio test for testing the hypothesis that the paired random vectors have the same mean; with respect to a special group of affine linear transformations it is the uniformly most powerful invariant test for the general alternative of a difference in mean. We present an elementary straightforward proof of this result. The likelihood ratio test for testing the hypothesis that the covariance structure is of the assumed special form is derived and discussed. Applications to real data are given. 相似文献
45.
Łukasz Smaga 《统计学通讯:模拟与计算》2017,46(10):7654-7667
The nonparametric and parametric bootstrap methods for multivariate hypothesis testing are developed. They are used to approximate the null distribution of the test statistics proposed by Duchesne and Francq (2015), resulting in bootstrap testing procedures. In the problem of testing for the mean vector of a multivariate distribution, the asymptotic validity of the bootstrap methods is proved. The finite sample performance of the new solutions is demonstrated by means of Monte Carlo simulation studies. They indicate that for small-sample size, the bootstrap tests provide a better finite sample properties than the asymptotic tests considered by Duchesne and Francq (2015). 相似文献
46.
分析中国P2P网络借贷信用风险的生成机理,借鉴商业银行典型个人信用风险测量理论基础与方法,构建基于涵盖借款人软信息的P2P网络借贷信用风险评级指标体系。通过向在银行从事信贷工作的专业人员发放调查问卷,确定具体指标,使用AHP(层次分析法)与DEMATEL(决策实验室法)相结合的方法综合确定指标体系权重,最后评级结果以百分制数值给出,并换算成具体的信用等级,有效解决了平台对借款人信用等级测量问题。 相似文献
47.
A powerful and efficient algorithm for breaking the links between aliased effects in asymmetric designs 下载免费PDF全文
A. M. Elsawah 《Australian & New Zealand Journal of Statistics》2017,59(1):17-41
Fractional factorial (FF) designs are no doubt the most widely used designs in experimental investigations due to their efficient use of experimental runs. One price we pay for using FF designs is, clearly, our inability to obtain estimates of some important effects (main effects or second order interactions) that are separate from estimates of other effects (usually higher order interactions). When the estimate of an effect also includes the influence of one or more other effects the effects are said to be aliased. Folding over an FF design is a method for breaking the links between aliased effects in a design. The question is, how do we define the foldover structure for asymmetric FF designs, whether regular or nonregular? How do we choose the optimal foldover plan? How do we use optimal foldover plans to construct combined designs which have better capability of estimating lower order effects? The main objective of the present paper is to provide answers to these questions. Using the new results in this paper as benchmarks, we can implement a powerful and efficient algorithm for finding optimal foldover plans which can be used to break links between aliased effects. 相似文献
48.
Xiaofeng Steven Liu 《统计学通讯:模拟与计算》2013,42(6):1433-1436
This short article shows an unified approach to representing and computing the cumulative distribution function for noncentral t, F, and χ2. Unlike the existing algorithms, which involve different expansion and/or recurrence, the new approach consistently represents all the three noncentral cumulative distribution functions as the integral of the normal cumulative distribution function and χ2 density function. 相似文献
49.
Let T2 i=z′iS?1zi, i==,…k be correlated Hotelling's T2 statistics under normality. where z=(z′i,…,z′k)′ and nS are independently distributed as Nkp((O,ρ?∑) and Wishart distribution Wp(∑, n), respectively. The purpose of this paper is to study the distribution function F(x1,…,xk) of (T2 i,…,T2 k) when n is large. First we derive an asymptotic expansion of the characteristic function of (T2 i,…,T2 k) up to the order n?2. Next we give asymptotic expansions for (T2 i,…,T2 k) in two cases (i)ρ=Ik and (ii) k=2 by inverting the expanded characteristic function up to the orders n?2 and n?1, respectively. Our results can be applied to the distribution function of max (T2 i,…,T2 k) as a special case. 相似文献
50.
刘淑霞 《西南石油大学学报(社会科学版)》2009,33(2):133-136
针对大庆外围油田特低渗透油藏剩余油潜力大、井网加密效益差、水驱采收率低等问题,提出了特低渗透油藏 CO2驱技术。通过细管实验和天然岩芯 CO2 驱油实验,确定了 CO2 与高台子油田原油的最小混相压力,评价了特低渗透砂岩油藏 CO2 驱油效果。实验结果表明,CO2 驱可以应用于高台子油田,并取得较好的驱油效果。当天然岩芯空气渗透率为0.58 mD 时,在水驱基础上,气驱可以进一步提高采收率 8% 以上,特低渗透油藏实施 CO2 驱油技术是可行的。 相似文献