全文获取类型
收费全文 | 13564篇 |
免费 | 41篇 |
国内免费 | 1篇 |
专业分类
教育 | 10215篇 |
科学研究 | 1343篇 |
各国文化 | 53篇 |
体育 | 598篇 |
综合类 | 1篇 |
文化理论 | 395篇 |
信息传播 | 1001篇 |
出版年
2024年 | 4篇 |
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 35篇 |
2020年 | 59篇 |
2019年 | 118篇 |
2018年 | 2279篇 |
2017年 | 2196篇 |
2016年 | 1651篇 |
2015年 | 172篇 |
2014年 | 201篇 |
2013年 | 527篇 |
2012年 | 282篇 |
2011年 | 747篇 |
2010年 | 892篇 |
2009年 | 493篇 |
2008年 | 707篇 |
2007年 | 1206篇 |
2006年 | 118篇 |
2005年 | 438篇 |
2004年 | 483篇 |
2003年 | 399篇 |
2002年 | 160篇 |
2001年 | 35篇 |
2000年 | 41篇 |
1999年 | 23篇 |
1998年 | 34篇 |
1997年 | 33篇 |
1996年 | 13篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 18篇 |
1992年 | 13篇 |
1991年 | 17篇 |
1990年 | 19篇 |
1989年 | 18篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 9篇 |
1983年 | 11篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1977年 | 5篇 |
1974年 | 5篇 |
1968年 | 3篇 |
1948年 | 3篇 |
1852年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
Bharti Jain J. Kumarasamy Chandrakala Gholve Savita Kulkarni M. G. R. Rajan 《Indian journal of clinical biochemistry : IJCB》2017,32(2):193-199
Serum thyroglobulin (Tg) and thyroid stimulating hormone (TSH) measurements have evolved as important analytes for monitoring the prognosis of patients with differentiated thyroid cancer, post-thyroidectomy. Individual analyte immunoassay is the current practice in clinical pathology, but the simultaneous assay for all relevant analytes for a given disease, can reduce assay costs, improve patient compliance and give the clinician more information for an unequivocal diagnosis. Microarray immunoassay (MI) can achieve this goal and, hence, we have developed and validated a immuno-radiometric MI for quantitation of serum TSH and Tg by using highly micro-porous polycarbonate (PC) track-etched membranes (TEM) to immobilize the monoclonal anti-TSH and polyclonal anti-Tg antibodies in ~1 mm diameter spots. Non-competitive immunoassays were performed using mixture of 125I labeled monoclonal anti-TSH and anti-Tg antibodies. Phosphorimager was used to quantify the bound radioactivity. TSH and Tg were detected with detection limit of 0.07 µIU/ml and 0.13 ng/ml respectively, which is lower than the clinically required cut-off level. The assay showed: acceptable intra-assay precision within 20 % and recovery in the range of 76–111.2 %. MI compared well with the established immunoradiometric assay (IRMA) with r = 0.98, p < 0.01 (n = 41). No cross-reactivity was seen between the immobilized antibodies. Although two hormones are addressed in this report, MI using PC TEM and isotopic/non-isotopic tracers has the potential for highly automated multiplexed analysis. 相似文献
86.
87.
Inger Andersen Naoko Ishii Thomas Brooks Cynthia Cummis Gustavo Fonseca Astrid Hillers Nicholas Macfarlane Nebojsa Nakicenovic Kevin Moss Johan Rockstr?m Andrew Steer Dominic Waughray Caroline Zimm 《国家科学评论(英文版)》2021,(7):12-15
The 2015 Paris Agreement to keep global warming well below 2℃above pre-industrial levels and aim towards limiting warming to 1.5℃marked a wa-tershed in planetar... 相似文献
88.
Collaboration in large-scale projects introduces challenges involving both coordination (the ability to collaborate) as well as cooperation (the willingness to do so). Existing research has shown how modular designs can improve coordination by locating interdependencies within rather than between different modules. Based on an in-depth case study of collaboration in a large-scale infrastructure project, our study highlights an effect of modularity on collaboration that previously has been overlooked. Specifically, we show that while modular designs may help overcome coordination challenges by reducing interdependencies between modules, they can in turn hamper collaboration by emphasizing specialization within modules. Therefore, though existing work typically perceives modularity and integration as opposites, we clarify how they can also act as complements. In particular, we show how firms need to complement modular designs with integrating practices that stimulate cooperation. Overall, we contribute to the literature on collaboration and modularity by explaining when and how organizations can combine modularity and integration. 相似文献
89.
90.
Bhupendra Pal Singh Shailendra Dwivedi Urmila Dhakad Ramesh Chandra Murthy Vimal Kumar Choubey Apul Goel Satya Narayan Sankhwar 《Indian journal of clinical biochemistry : IJCB》2016,31(1):50-56
Deficiency or excess of certain trace elements has been considered as risk factor for prostate cancer. This study was aimed to detect differential changes and mutual correlations of selected trace elements in prostate cancer tissue versus benign prostatic hyperplasia tissue. Zinc, copper, iron, calcium and selenium were analysed in histologically proven 15 prostate cancer tissues and 15 benign prostatic hyperplasia tissues using atomic absorption spectrophotometer. Unpaired two tailed t test/Mann–Whitney U test and Pearson correlation coefficient were used to compare the level of trace elements, elemental ratios and their interrelations. As compared to benign prostatic tissue, malignant prostatic tissue had significantly lower selenium (p = 0.038) and zinc (p = 0.043) concentrations, a lower zinc/iron ratio (p = 0.04) and positive correlation of selenium with zinc (r = 0.71, p = 0.02) and iron (r = 0.76, p = 0.009). Considerably divergent interrelationship of elements and elemental ratios in prostate cancer versus benign prostatic hyperplasia was noted. Understanding of differential elemental changes and their interdependence may be useful in defining the complex metabolic alterations in prostate carcinogenesis with potential for development of element based newer diagnostic, preventive and therapeutic strategies. Further studies may be needed to elucidate this complex relationship between trace elements and prostate carcinogenesis. 相似文献