全文获取类型
收费全文 | 601篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
化学 | 380篇 |
晶体学 | 4篇 |
力学 | 5篇 |
数学 | 71篇 |
物理学 | 148篇 |
出版年
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 23篇 |
2012年 | 18篇 |
2011年 | 24篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 23篇 |
2007年 | 16篇 |
2006年 | 27篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 18篇 |
2001年 | 7篇 |
2000年 | 10篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 14篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 18篇 |
1989年 | 5篇 |
1988年 | 9篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1977年 | 14篇 |
1976年 | 13篇 |
1975年 | 7篇 |
1974年 | 15篇 |
1973年 | 8篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1905年 | 6篇 |
1900年 | 5篇 |
1891年 | 4篇 |
1890年 | 5篇 |
1888年 | 4篇 |
排序方式: 共有608条查询结果,搜索用时 682 毫秒
41.
Ant colony optimization: Introduction and recent trends 总被引:21,自引:0,他引:21
Ant colony optimization is a technique for optimization that was introduced in the early 1990's. The inspiring source of ant colony optimization is the foraging behavior of real ant colonies. This behavior is exploited in artificial ant colonies for the search of approximate solutions to discrete optimization problems, to continuous optimization problems, and to important problems in telecommunications, such as routing and load balancing. First, we deal with the biological inspiration of ant colony optimization algorithms. We show how this biological inspiration can be transfered into an algorithm for discrete optimization. Then, we outline ant colony optimization in more general terms in the context of discrete optimization, and present some of the nowadays best-performing ant colony optimization variants. After summarizing some important theoretical results, we demonstrate how ant colony optimization can be applied to continuous optimization problems. Finally, we provide examples of an interesting recent research direction: The hybridization with more classical techniques from artificial intelligence and operations research. 相似文献
42.
43.
44.
45.
Kubo K Akemoto M Anderson S Aoki T Araki S Bane KL Blum P Corlett J Dobashi K Emma P Frisch J Fukuda M Guo Z Hasegawa K Hayano H Higo T Higurashi A Honda Y Iimura T Imai T Jobe K Kamada S Karataev P Kashiwagi S Kim E Kobuki T Kotseroglou T Kurihara Y Kuriki M Kuroda R Kuroda S Lee T Luo X McCormick DJ McKee B Mimashi T Minty M Muto T Naito T Naumenko G Nelson J Nguyen MN Oide K Okugi T Omori T Oshima T Pei G Potylitsyn A Qin Q Raubenheimer T Ross M Sakai H Sakai I Schmidt F Slaton T Smith H 《Physical review letters》2002,88(19):194801
Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance. 相似文献
46.
The shot noise in the current through a quantum dot is calculated as a function of voltage from the high-voltage Coulomb-blockaded regime to the low-voltage Kondo regime. Using several complementary approaches, it is shown that the zero-frequency shot noise (scaled by the voltage) exhibits a nonmonotonic dependence on voltage, with a peak around the Kondo temperature. Beyond giving a good estimate of the Kondo temperature, it is shown that the shot noise yields additional information on the effects of electronic correlations on the local density of states in the Kondo regime, unaccessible in traditional transport measurements. 相似文献
47.
Regen SL Janout V Stedronsky ER Zhang Lh Blum JS Boyajian AR Butow ME Carbonelli KL Liebentritt S Rouse RK Shay DT Vincent GA Warholic HM Yanagisawa H 《Organic letters》2000,2(14):2157-2160
The use of partially quaternized, chloromethylated polystyrene as a covalent scavenger of cholate ion in aqueous media has been demonstrated. The ability of such polymers to scavenge organic anions by covalent as well as by ionic means has important implications in the areas of medicinal and environmental chemistry, which are briefly discussed. 相似文献
48.
Youval Shvo Yigal Blum Deborah Reshef Marit Menzin 《Journal of organometallic chemistry》1982,226(1):C21-C24
Ru3(CO)12 acts as a homogeneous catalyst precursor for the transformation of αω-diols to polyesters and lactones. 相似文献
49.
Eugen Blum 《Commentarii Mathematici Helvetici》1969,44(1):319-340
Ohne Zusammenfassung 相似文献
50.