全文获取类型
收费全文 | 111篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
化学 | 74篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 7篇 |
物理学 | 34篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1969年 | 1篇 |
1936年 | 1篇 |
1934年 | 1篇 |
1924年 | 1篇 |
1914年 | 2篇 |
1902年 | 2篇 |
1897年 | 2篇 |
排序方式: 共有117条查询结果,搜索用时 31 毫秒
31.
A. W. Hall D. Lacey J. S. Hill K. M. Blackwood M. Jones D. G. McDonnell I. C. Sage 《Liquid crystals》1996,20(4):437-447
The recently published Baylis-Hillman methodology has been used to prepare a number of side chain liquid crystalline poly(allylalcohols) incorporating a ferroelectric mesogenic side chain. These poly(allylalcohols) exhibited wide range S*C phases and, in the case of two of these materials, low glass transition temperatures. The transition temperatures and phase behaviour of the SCLC poly(allylalcohols) were compared to acrylate and methacrylate SCLC oligomers containing a similar mesogenic side chain. The response times for two poly(allylalcohols) exhibiting low glass transition temperatures were also measured over a wide temperature range. Although the poly(allylalcohols) had comparable response times to the analogous acrylate and methacrylate SCLCP, they showed the greater temperature dependence of the response time. However, at 39°C one of the SCLC poly(allylalcohols) showed a response time of 65 ms. 相似文献
32.
We present an analysis of the intensities of the C–H vibrational 0-υ (υ = 2–6) of naphthalene in terms of the local bond mode model. 相似文献
33.
Construction and performance characteristics of a dual frequency oscillator-amplifier system, pumped by the second harmonic of a Nd-YAG laser are described. With 250 mJ pump energy, output energies up to 115 mJ with Rh 6 G have been achieved. Linewidth was 1.2 pm at 589 nm with a 25 ns pump pulse duration. 相似文献
34.
35.
36.
Jae Kwak Brian A. Geier Maomian Fan Sanjay A. Gogate Sage A. Rinehardt Brandy S. Watts Claude C. Grigsby Darrin K. Ott 《Journal of separation science》2015,38(14):2463-2469
Volatile organic compounds were collected and analyzed from a variety of indoor and outdoor air samples to test whether human‐derived compounds can be readily detected in the air and if they can be associated with human occupancy or presence. Compounds were captured with thermal desorption tubes and then analyzed by gas chromatography with mass spectrometry. Isoprene, a major volatile organic compound in exhaled breath, was shown to be the best indicator of human presence. Acetone, another major breath‐borne compound, was higher in unoccupied or minimally occupied areas than in human‐occupied areas, indicating that its majority may be derived from exogenous sources. The association of endogenous skin‐derived compounds with human occupancy was not significant. In contrast, numerous compounds that are found in foods and consumer products were detected at elevated levels in the occupied areas. Our results revealed that isoprene and many exogenous volatile organic compounds consumed by humans are emitted at levels sufficient for detection in the air, which may be indicative of human presence. 相似文献
37.
38.
Li J Peng Q Barabanschikov A Pavlik JW Alp EE Sturhahn W Zhao J Schulz CE Sage JT Scheidt WR 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(40):11178-11185
We report our studies of the vibrational dynamics of iron for three imidazole-ligated oxyheme derivatives that mimic the active sites of histidine-ligated heme proteins complexed with dioxygen. The experimental vibrational data are obtained from nuclear resonance vibrational spectroscopy (NRVS) measurements conducted on both powder samples and oriented single crystals, and which includes several in-plane (ip) and out-of-plane (oop) measurements. Vibrational spectral assignments have been made through a combination of the oriented sample spectra and predictions based on density functional theory (DFT) calculations. The two Fe-O(2) modes that have been previously observed by resonance Raman spectroscopy in heme proteins are clearly shown to be very strongly mixed and are not simply either a bending or stretching mode. In addition, a third Fe-O(2) mode, not previously reported, has been identified. The long-sought Fe-Im stretch, not observed in resonance Raman spectra, has been identified and compared with the frequencies observed for the analogous CO and NO species. The studies also suggest that the in-plane iron motion is anisotropic and is controlled by the orientation of the Fe-O(2) group and not sensitive to the in-plane Fe-N(p) bonds and/or imidazole orientations. 相似文献
39.
40.
Abbasi YA Shahida S. Ali A. Khan MH Khan MI 《Journal of Radioanalytical and Nuclear Chemistry》2019,320(2):273-282
The extraction behavior of Nd(III) and Eu(III) with 0.05 mol dm−3 furosemide in benzyl alcohol as single acidic extractant and then with equimolar (0.05 mol dm−3) synergic mixture of furosemide as acidic extractant and tribenzylamine as neutral donor in benzyl alcohol has been studied from aqueous solutions of pH 1 to 6. The effect of various parameters and of various cations and anions on the extraction of these metal ions was investigated. The composition of the extracted adducts was determined by slope analysis method that came out to be [(M(FS)2)+ (CH3COO)−] and [M(FS)3·3TBA] where M = Nd(III) and Eu(III).
相似文献