全文获取类型
收费全文 | 110篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
化学 | 73篇 |
数学 | 20篇 |
物理学 | 27篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 10篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 16篇 |
2012年 | 6篇 |
2011年 | 14篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1968年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有120条查询结果,搜索用时 31 毫秒
41.
42.
43.
The effects on the radiation response of Harwell polymethylmethacrylate (PMMA) dosimeters of dose-rate, radiation type, temperature during irradiation and post-irradiation storage, and post-irradiation stability, are of importance to the operators of commercial irradiation facilities.
This paper describes recent studies of the effects of some of these parameters on the radiation response of Harwell Red 4034, Amber 3042, and Gammachrome YR Perspex dosimeters, and provides data on batch to batch variation and shelf-life. 相似文献
44.
Wehbe J Kassem T Rolland V Rolland M Tabcheh M Roumestant ML Martinez J 《Organic & biomolecular chemistry》2003,1(11):1938-1942
A short asymmetric synthesis of optically pure beta-substituted beta-hydroxy aspartates is described. The key step is an aldol reaction between a glycine enolate derived from an oxazinone intermediate used as chiral auxiliary and various alpha-keto esters. Excellent diastereomeric excesses are obtained. 相似文献
45.
The steady laminar natural convection of a fluid having chemical reaction of order n past a semi-infinite vertical plate is considered. The solution of the problem by means of one-parameter group method reduces the number of independent variables by one leading to a system of nonlinear ordinary differential equations. Two different similarity transformations are found. In each case the set of differential equations are solved numerically using Runge–Kutta and the shooting method. For each transformation different Schmidt numbers and chemical reaction orders are tested. 相似文献
46.
Hassanain M. A. Alshrani H. F. A. Ibraheem Awad A. Anwar M. Behairy Kassem O. Mahmoud Zakaria M. M. Darwish Eed M. 《Physics of Atomic Nuclei》2019,82(6):615-622
Physics of Atomic Nuclei - The elastic scattering of 16O+40Ca system at the incident energy 214 MeV has been analyzed within the optical model (OM) potential using the phenomenological Woods-Saxon... 相似文献
47.
Bajracharya GB Koranne PS Nadaf RN Gabr RK Takenaka K Takizawa S Sasai H 《Chemical communications (Cambridge, England)》2010,46(47):9064-9066
The 5-endo-trig-type cyclization has been performed using a Pd-bis(isoxazoline) catalyst. The present cyclization of β,γ-unsaturated carbonyl compounds gave γ-butenolides and 3-pyrrolin-2-ones in good to excellent yields. 相似文献
48.
49.
Marc Rolland Tarek Kassem Valérie Rolland Jean Martinez 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(12):1415-1417
We present the crystal and molecular structures of 2,3,6,7,8,8a-hexahydro-6,8-methano-7,7,8a-trimethyl-3-(1-methyl-2-oxopropylidene)-5H-1,4-benzoxazin-2-one, C16H21NO3, (III), and 2,3,6,7,8,8a-hexahydro-3-(2-hydroxy-1-methylpropyl)-6,8-methano-7,7,8a-trimethyl-5H-1,4-benzoxazin-2-one, C16H25NO3, (V). These compounds are two of the four key intermediates in our synthetic route to (2R,3R,4R)-4-hydroxyisoleucine. The two structures provide a full understanding of the stereochemistry in successive steps. This synthesis was based on a new optically pure chiral oxazinone auxiliary derived from (1R,2R,5R)-2-hydroxypinan-3-one. 相似文献
50.