全文获取类型
收费全文 | 2481758篇 |
免费 | 197278篇 |
国内免费 | 5341篇 |
专业分类
耳鼻咽喉 | 36447篇 |
儿科学 | 80550篇 |
妇产科学 | 64756篇 |
基础医学 | 351781篇 |
口腔科学 | 65915篇 |
临床医学 | 234763篇 |
内科学 | 497171篇 |
皮肤病学 | 58458篇 |
神经病学 | 197901篇 |
特种医学 | 93498篇 |
外国民族医学 | 489篇 |
外科学 | 388337篇 |
综合类 | 47778篇 |
现状与发展 | 84篇 |
一般理论 | 850篇 |
预防医学 | 189228篇 |
眼科学 | 57368篇 |
药学 | 176416篇 |
11篇 | |
中国医学 | 4639篇 |
肿瘤学 | 137937篇 |
出版年
2021年 | 21744篇 |
2019年 | 21521篇 |
2018年 | 33453篇 |
2017年 | 26610篇 |
2016年 | 29766篇 |
2015年 | 32747篇 |
2014年 | 49224篇 |
2013年 | 67362篇 |
2012年 | 79745篇 |
2011年 | 84633篇 |
2010年 | 56055篇 |
2009年 | 56599篇 |
2008年 | 79826篇 |
2007年 | 83312篇 |
2006年 | 86064篇 |
2005年 | 81265篇 |
2004年 | 77152篇 |
2003年 | 73540篇 |
2002年 | 71277篇 |
2001年 | 111986篇 |
2000年 | 114063篇 |
1999年 | 96219篇 |
1998年 | 30001篇 |
1997年 | 26498篇 |
1996年 | 26742篇 |
1995年 | 25343篇 |
1994年 | 22448篇 |
1993年 | 20962篇 |
1992年 | 73137篇 |
1991年 | 71264篇 |
1990年 | 69287篇 |
1989年 | 66627篇 |
1988年 | 61147篇 |
1987年 | 59875篇 |
1986年 | 55982篇 |
1985年 | 53605篇 |
1984年 | 39783篇 |
1983年 | 33837篇 |
1982年 | 20294篇 |
1979年 | 36131篇 |
1978年 | 25936篇 |
1977年 | 21557篇 |
1976年 | 20544篇 |
1975年 | 22052篇 |
1974年 | 26339篇 |
1973年 | 25012篇 |
1972年 | 23466篇 |
1971年 | 22199篇 |
1970年 | 20460篇 |
1969年 | 19381篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
The aim of the study was to explore the relationship between alexithymia and machiavellianism in a group of 201 university students. The subjects filled out the TAS-20 and the MACH-IV forms. The results showed firstly, a significant correlation between the two total scores (r = 0.35, P < 0.05), and secondly between the identification of feelings subscale of the TAS-20 and the opinions about human nature subscale of the Mach-IV (r = 0.44, P < 0.05). The results were discussed in light of the different factors (depression, dependency, psychoticism…) that could explain the relationship between the two concepts. 相似文献
995.
996.
I. Fishtik C.A. Callaghan J.D. Fehribach R. Datta 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》2005,576(1):57-63
The reaction route (RR) graph approach recently developed by us for complex, non-linear kinetic mechanisms is applied to the hydrogen oxidation and evolution reactions. A corresponding RR graph is constructed and translated into an equivalent electrical circuit network by associating each elementary step with a characteristic resistance for the steady-state case and considering the overall reaction as a power source. It is further shown that the steady-state kinetics of the reaction can be investigated employing the conventional methods of the electrical network theory. Using a set of rate constants for the hydrogen evolution reaction (her) in alkaline solutions from the literature, the dominant RRs are identified and simplified mechanisms and kinetics derived. 相似文献
997.
998.
999.
Color Stability of Dry Earth Pigmented Maxillofacial Silicone A-2186 Subjected to Microwave Energy Exposure 总被引:2,自引:0,他引:2
Sudarat Kiat-amnuay DDS MS ; Dennis A. Johnston PhD ; John M. Powers PhD ; Rhonda F. Jacob DDS MS 《Journal of prosthodontics》2005,14(2):91-96
PURPOSE: The purpose of this study was to measure spectrophotometrically the color stability of pigmented A-2186 silicone maxillofacial elastomer with 10% by volume of titanium white dry earth opacifier before and after exposure to microwave energy over a simulated 1.5-year period of microwave sterilization. Materials AND METHODS: A-2186 silicone elastomer opacified with titanium white dry earth pigment, pigmented with 5 cosmetic dry earth pigment colors [no pigment (control) group (Pc), red (Pr), yellow ochre (Py), burnt sienna (Po), and a mixture of Pr + Py + Po color group (P3)], was used in this study. Each of the 5 experimental groups consisted of 5 specimens. All specimens were placed in a 250 ml glass beaker filled with 150 ml of water (replenished for each microwave exposure). An exposure of 6 minutes was used 18 times (simulating 1.5 years of microwave sterilization with one 6 minute exposure monthly). Reflectance values were measured by spectrophotometer. Three- and two-way analyses of variance with repeated measures were performed for the color difference (DeltaE*) with the factors of group/color/months, and group/months, respectively. Means were compared by Tukey Honest Significant Difference (HSD) multiple range test calculated at the 0.05 level of significance using SPSS. RESULTS: The trained human eye can detect color changes (DeltaE*) greater than 1.0. Most DeltaE* values of the red pigment group at all intervals and the mixed pigment group at 15- and 18- month intervals increased significantly greater than 1.0 (p < 0.001) compared with the control group. Yellow and burnt sienna groups remained the most color stable over time with DeltaE* values below 0.35. CONCLUSIONS: Lack of color stability of red dry earth pigmented A-2186 silicone maxillofacial elastomers was clinically significant after 12-month exposure to microwave energy as compared with yellow, burnt sienna, and opacified A-2186 dry earth pigments. 相似文献
1000.
A new approach to the activation of reactants during the condensation of aromatic aldehydes with N-aroylglycines (acting as
CH-acids) is described. The condensation reaction carried out on heating in phosphorus oxychloride leads to a high yield of
4-benzylideneoxazol-5-one derivatives. The hydrolysis of these intermediate products yields the target α-benzoylaminocinnamic
acids.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 7, pp. 41 – 42, July, 2005. 相似文献