全文获取类型
收费全文 | 181篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
教育 | 107篇 |
科学研究 | 50篇 |
各国文化 | 2篇 |
体育 | 1篇 |
文化理论 | 3篇 |
信息传播 | 21篇 |
出版年
2022年 | 5篇 |
2021年 | 6篇 |
2020年 | 1篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 28篇 |
2012年 | 9篇 |
2011年 | 7篇 |
2010年 | 11篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 1篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1984年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有184条查询结果,搜索用时 265 毫秒
1.
2.
3.
In this article we derive the distribution, mean and variance of the number of cycles in a randomly selected permutation of the first n integers. 相似文献
4.
Tertiary Education and Management - External quality audits have been introduced in many parts of the world including Asia Pacific, Asia, Africa, Europe, and the Middle East. While external quality... 相似文献
5.
6.
J. Baxi Kavita Sharma Rajbala Asha Mehta A. K. Pendse P. P. Singh 《Indian journal of clinical biochemistry : IJCB》1994,9(1):47-49
Evaluation of serum SOD and MDA level was done in 21 first episode renal stone formers, 9 recurrent stone formers, 20 patients with obstructive uropathy other than urolithiasis and 12 patients with urinary infection. Twenty-two healthy volunteers were taken as controls. The level of SOD in respective groups was 2.12±0.84, 2.78±0.85, 1.42±0.31, 1.98±0.70 and 2.32±0.62 units/ml and of MDA was 2.61±1.07, 2.69±1.15, 1.65±0.33, 1.33±0.34 and 1.55±0.48 n mol/ml respectively. The results indicate increased peroxidative stressin nephrolithiasis only. Since SOD level was normal in all groups, this increased peroxidative stress in nephrolithiasis should be due to factors other than this one. 相似文献
7.
Lakshmi Lavanya Reddy Swarup A. V. Shah Alpa J. Dherai Chandrashekhar K. Ponde Tester F. Ashavaid 《Indian journal of clinical biochemistry : IJCB》2016,31(1):87-92
Acute coronary syndrome (ACS) is a term for a range of clinical signs and symptoms suggestive of myocardial ischemia. It results in functional and structural changes and ultimately releasing protein from injured cardiomyocytes. These cardiac markers play a major role in diagnosis and prognosis of ACS. This study aims to assess the efficacy of heart type fatty acid binding protein (h-FABP) as a marker for ACS along with the routinely used hs-TropT. In our observational study, plasma h-FABP (cut-off 6.32 ng/ml) and routinely done hs-Trop T (cutoff 0.1 and 0.014 ng/ml) were estimated by immunometric laboratory assays in 88 patients with acute chest pain. Based on the clinical and laboratory test findings the patients were grouped into ACS (n = 41) and non-ACS (n = 47). The diagnostic sensitivity, specificity, NPV, PPV and ROC curve at 95 % CI were determined. Sensitivity of hs-TropT (0.1 ng/ml), hs-TropT (0.014 ng/ml) and h-FABP were 53, 86 and 78 % respectively and specificity for the same were 98, 73 and 70 % respectively. Sensitivity, specificity and NPV calculated for a cut-off combination of hs-TropT 0.014 ng/ml and h-FABP was 100, 51 and 100 % respectively. These results were substantiated by ROC analysis. Measurement of plasma h-FABP and hs-TropT together on admission appears to be more precise predictor of ACS rather than either hs-Trop T or h-FABP. 相似文献
8.
The last few years have seen a growing debate and new initiatives by government and other agencies on the concept of lifelong learning. The objectives of these have been to provide better access to a broad knowledge base and to develop individuals' employability and economic success. But lifelong learning is not a new phenomenon. In the UK and elsewhere many adults have always studied for a variety of reasons and in a variety of ways. Study through part‐time degrees has long been one option for many adult learners. This paper draws on data from a study undertaken for the Department for Education and Employment on the employment of part‐time students and considers whether part‐time study benefits people's careers and whether some people benefit more than others. 相似文献
9.
Carbon encapsulated iron nanoparticles(CEINPs) with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature(AIT) of 800 ℃. The results of high resolution transmission electron microscope(HRTEM), energy dispersive X-ray(EDX) spectroscope, X-ray diffraction(XRD), and X-ray photoelectron spectroscope(XPS) characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5—5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24. 7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization(Ms) and coercivity(Hc) of the product B are 107.4 emu/g and 143 Oe, respectively. The formation of the CEINPs in the product B is discussed briefly. 相似文献
10.