全文获取类型
收费全文 | 1282篇 |
免费 | 21篇 |
国内免费 | 28篇 |
专业分类
化学 | 995篇 |
晶体学 | 11篇 |
力学 | 21篇 |
数学 | 62篇 |
物理学 | 242篇 |
出版年
2022年 | 6篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2016年 | 11篇 |
2015年 | 18篇 |
2014年 | 8篇 |
2013年 | 42篇 |
2012年 | 44篇 |
2011年 | 56篇 |
2010年 | 23篇 |
2009年 | 31篇 |
2008年 | 83篇 |
2007年 | 67篇 |
2006年 | 73篇 |
2005年 | 72篇 |
2004年 | 82篇 |
2003年 | 62篇 |
2002年 | 91篇 |
2001年 | 35篇 |
2000年 | 26篇 |
1999年 | 16篇 |
1998年 | 21篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 17篇 |
1992年 | 17篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1986年 | 15篇 |
1985年 | 28篇 |
1984年 | 30篇 |
1983年 | 8篇 |
1982年 | 34篇 |
1981年 | 22篇 |
1980年 | 26篇 |
1979年 | 23篇 |
1978年 | 19篇 |
1977年 | 17篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1974年 | 13篇 |
1973年 | 7篇 |
1972年 | 10篇 |
1971年 | 5篇 |
1967年 | 6篇 |
排序方式: 共有1331条查询结果,搜索用时 15 毫秒
1.
Cellulose derivative resin (CDR) suspensions containing resin particles of cellulose nitrate (CDR(CN)), cellulose acetate (CDR(CA)), or cellulose triacetate (CDR(CTA)) were prepared as the sorbent for resin suspension injection (RSI) electrothermal atomic absorption spectrometry (ETAAS), in which fine resin particles holding a desired trace element were directly injected into the graphite tube as the suspension. To compare the sorption ability, the distribution ratios of the Mo(VI)-phenylfluorone complex were measured between the aqueous phase and the sorbents, including the CDRs mentioned above and the finely divided anion exchange resin (AR). The results showed that the sorption ability decreases in the following order: CDR(CN) > or = AR > CDR(CA) > or = CDR(CTA). It was concluded that CDR(CN) was able to extract more than 98% of Mo(VI), and was suitable for RSI-ETAAS as well as AR. CDR(CN) was used for the determination of Mo in NIES certified reference materials, No. 10 Rice flour-unpolished; the results showed fairly good agreements between the analytical values and the certified values. 相似文献
2.
方永得 张玉虎 M.Oshima Y.Toh 周小红 M.Koizumi A.Osa A.Kimura Y.Hatsukawa T.Morikawa M.Nakamura M.Sugawara H.Kusakari 《中国物理 C》2006,30(2):99-104
利用在束γ谱学实验技术, 通过173Yb(19F,4nγ)反应
布居了188Au的高自旋态, 并对其准粒子带结构进行了研究. 基于实验测量结果, 对原有的双奇核188Au能级纲图做了较大的修改. 通过系统性比较, 对15+以上的能级结构进行了讨论. 相似文献
3.
4.
An InGaAs/InAlAs five-layer asymmetric coupled quantum well (FACQW) is expected to show very large electrorefractive index change. n in a wideband transparency region. Band structures of the FACQW are analyzed with Luttinger-Kohn Hamiltonian. The electrorefractive characteristics of the FACQW are discussed. 相似文献
5.
13C NMR studies showed that the population of the norcaradiene form of the title systems containing p-CH3O, H, and p-CF3 on the 7-aryl group increases in this order. The result is consistent with the prediction from the π-acceptor strength of the aryl group estimated by INDO calculations. 相似文献
6.
Andrzej Skowronski Kunio Yamagata 《Proceedings of the American Mathematical Society》2004,132(3):659-667
We prove that a large class of self-injective algebras of tilted type is invariant under stable equivalences of module categories.
7.
8.
T.R. Saitoh N. Hashimoto G. Sletten R.A. Bark S. Törmänen M. Bergström K. Furuno K. Furutaka G.B. Hagemann T. Hayakawa T. Komatsubara A. Maj S. Mitarai M. Oshima J. Sampson T. Shizuma P.G. Varmette 《The European Physical Journal A - Hadrons and Nuclei》1998,3(3):197-199
High-spin states in 181Ta have been studied via the 176Yb(11B,α2n) reaction at 52 MeV using the PEX array and at 57 MeV using the NORDBALL array, with α-particle detection. The previously
known, Kπ=(7/2)+ ground state band and Kπ=(9/2)− band have been extended to spins (29/2)+ and (31/2)−, respectively. Two new one-quasiparticle bands, the Kπ=(5/2)+ band built on the known (5/2)+ isomer and a Kπ=((1/2)−) band have been observed. Two other rotational bands with three-quasiparticle structure, Kπ=(15/2)− and ((19/2)+ with π(7/2)[404]ν2(1/2)[510](9/2)[624] and π(9/2)[514]ν2(1/2)[510](9/2)[624] configurations, respectively, have been newly observed. The half-life of the Kπ=((19/2)+) bandhead which decays to the head of the (15/2)− band has been measured to be 140(36) ns. However, transitions from the ((19/2)+) state to the (15/2)− band have not been observed.
Received: 26 August 1998 相似文献
9.
10.
A highly sensitive fluorescence quenching method for the determination of silicate based on the formation of an ion associate between molybdosilicate and Rhodamine B (RB) in nitric acid medium was developed. A flow injection system coupled with a fluorescence detector was used for the measurement of fluorescence intensity at 560 and 580 nm as excitation and emission wavelengths, respectively. The calibration graph for Si showed a linear range of 0.1–5 ng cm−3 with correlation coefficient of 0.9999, and the detection limit of 0.06 ng cm−3. The proposed method was successfully applied to the determination of silicate in ultrapurified water with satisfactory results. 相似文献