全文获取类型
收费全文 | 92篇 |
免费 | 0篇 |
专业分类
化学 | 53篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 5篇 |
物理学 | 32篇 |
出版年
2023年 | 2篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2001年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1942年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有92条查询结果,搜索用时 0 毫秒
11.
Using the method of moments for dissipative optical solitons, we show that there are two disjoint sets of fixed points. These correspond to stationary solitons of the complex cubic–quintic Ginzburg–Landau equation with concave and convex phase profiles respectively. Numerical simulations confirm the predictions of the method of moments for the existence of two types of solutions which we call solitons and antisolitons. Their characteristics are distinctly different. 相似文献
12.
13.
14.
J.S. Chen A. Kadic-Galeb M. Ferrari T.M. Devine 《Mechanics Research Communications》1992,19(6):555-561
A dealloyed surface layer formed on a Cu-30 Au alloy due to a corrosion process is capable of inducing intergranular cleavage of the normally ductile substrate during subsequent mechanical loading. The structure of the dealloyed layer consists of nanoscale pores that were formed by the selective removal of copper atoms during the anodic polarization. To contribute to the understanding of environmentally — induced embrittlement, we presently compute the stress state within the porous layer and in the bulk substrate due to the eigenstraining by the dealloying. The results of the calculations shows that a tensile stress state exists in the porous dealloyed layer while a compressive stress state is generated in the substrate. Implications on the “film-induced cleavage” model of stress corrosion cracking mechanism are discussed. 相似文献
15.
Song ZJ Tellers DM Journet M Kuethe JT Lieberman D Humphrey G Zhang F Peng Z Waters MS Zewge D Nolting A Zhao D Reamer RA Dormer PG Belyk KM Davies IW Devine PN Tschaen DM 《The Journal of organic chemistry》2011,76(19):7804-7815
Development of a practical synthesis of MK-7009, a 20-membered [corrected] macrocycle, is described. A variety of ring-closing strategies were evaluated, including ring-closing metathesis, intermolecular palladium-catalyzed cross-couplings, and macrolactamization. Ring closure via macrolactamization was found to give the highest yields under relatively high reaction concentrations. Optimization of the ring formation step and the synthesis of key intermediates en route to MK-7009 are reported. 相似文献
16.
Daniel A. Holland‐Moritz Michael K. Wismer Benjamin F. Mann Iman Farasat Paul Devine Erik D. Guetschow Ian Mangion Christopher J. Welch Jeffrey C. Moore Shuwen Sun Robert T. Kennedy 《Angewandte Chemie (International ed. in English)》2020,59(11):4470-4477
Microfluidic droplet sorting enables the high‐throughput screening and selection of water‐in‐oil microreactors at speeds and volumes unparalleled by traditional well‐plate approaches. Most such systems sort using fluorescent reporters on modified substrates or reactions that are rarely industrially relevant. We describe a microfluidic system for high‐throughput sorting of nanoliter droplets based on direct detection using electrospray ionization mass spectrometry (ESI‐MS). Droplets are split, one portion is analyzed by ESI‐MS, and the second portion is sorted based on the MS result. Throughput of 0.7 samples s?1 is achieved with 98 % accuracy using a self‐correcting and adaptive sorting algorithm. We use the system to screen ≈15 000 samples in 6 h and demonstrate its utility by sorting 25 nL droplets containing transaminase expressed in vitro. Label‐free ESI‐MS droplet screening expands the toolbox for droplet detection and recovery, improving the applicability of droplet sorting to protein engineering, drug discovery, and diagnostic workflows. 相似文献
17.
18.
From electrical resistivity measurements on PdH samples we have separated out the optical and acoustic phonon contributions. The onset of optical resistivity coincides with the occurence of superconductivity, supporting the recent evidence that optical phonons play the major role in the formation of superconductivity in PdH system. 相似文献
19.
Background
The effects of negative emotion on different processing periods in spatial and verbal working memory (WM) and the possible brain mechanism of the interaction between negative emotion and WM were explored using a high-time resolution event-related potential (ERP) technique and time-locked delayed matching-to-sample task (DMST). 相似文献20.
Chiral fluorinated hydroxyketones were synthesized with excellent ee (>98%) and yield by a chemo- and stereoselective reduction of prochiral methyl/trifluoromethyl diketones using commercially available ketoreductase enzymes. By using p- and m-trifluoroacetyl substituted acetophenones, we demonstrate that ketoreductases can selectively differentiate between methyl and trifluoromethyl ketones within the same molecule. As a result, useful catalysts were identified that eliminated the need for costly and time-consuming protection/deprotection of the ketone moiety, enabling a more convergent synthesis of hydroxyketones. Further, a route to chiral methyl hydroxyketones is provided where an enzyme selectively reduces the unactivated ketone. 相似文献