全文获取类型
收费全文 | 95篇 |
免费 | 3篇 |
专业分类
化学 | 64篇 |
力学 | 1篇 |
物理学 | 33篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2018年 | 1篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有98条查询结果,搜索用时 46 毫秒
71.
The first enantioselective total synthesis of enokipodins A-D, highly oxidized α-cuparenone-type sesquiterpenoids with antimicrobial activity, was accomplished by using Meyers' diastereoselective alkylation protocol for the construction of the C7-quaternary asymmetric center. The present synthesis also constitutes a formal enantioselective synthesis of (S)-1,4-cuparenediol and (S)-cuparene-1,4-quinone. 相似文献
72.
73.
Kurosawa H Ohnishi H Emoto M Kawasaki Y Murai S 《Journal of the American Chemical Society》1988,110(18):6272-6273
74.
M.H Abraham Priscilla L Grellier John Mana 《The Journal of chemical thermodynamics》1974,6(12):1175-1179
Limiting values of the Raoult's-law activity coefficients of triethylamine in 30 solvents at 298.15 K have been obtained by a simple procedure based on the use of gas-liquid chromatography to determine the mole fraction of triethylamine in the vapour above dilute solutions. Where comparisons can be made, there is good agreement with literature values and with values derived from liquid-liquid distribution coefficients measured in this work. 相似文献
75.
76.
Rapid and selective determination of ammonium by fluorimetric flow injection analysis 总被引:1,自引:0,他引:1
Selective and sensitive procedures for the determination of ammonium in river water and diluted urine were developed by using flow injection analysis equipment. The methods are based on the derivatization of ammonia with o-phthaldehyde (OPA) and thioglycolate under alkaline conditions. The formed isoindole derivative is detected fluorimetrically at an excitation wavelength of 415 nm and an emission wavelength of 485 nm. The derivatization only takes 15 to 20 s at room temperature to achieve the maximum sensitivity. The optimized OPA reagent shows a surprisingly high selectivity for ammonium in the presence of many primary amines. With respect to the analysis of turbid and fluorescent sample solutions the selectivity can be improved by separating the ammonia through a microporous membrane from the OPA reagent. Without this separation step ammonia can be detected in the range between 0.05 and 100 microM with excellent linearity. After the insertion of an optimized membrane separation cell ammonia can be determined in the linear range between 0.2 microM and 20 mM. 相似文献
77.
78.
Suchin Trirongjitmoah Kazuya Iinaga Toshihiro Sakurai Hitoshi Chiba Mana Sriyudthsak Koichi Shimizu 《Optical Review》2016,23(2):265-272
Quantification of small, dense low-density lipoprotein (sdLDL) cholesterol is clinically significant. We propose a practical technique to estimate the amount of sdLDL cholesterol using dynamic light scattering (DLS). An analytical solution in a closed form has newly been obtained to estimate the weight fraction of one species of scatterers in the DLS measurement of two species of scatterers. Using this solution, we can quantify the sdLDL cholesterol amount from the amounts of the low-density lipoprotein cholesterol and the high-density lipoprotein (HDL) cholesterol, which are commonly obtained through clinical tests. The accuracy of the proposed technique was confirmed experimentally using latex spheres with known size distributions. The applicability of the proposed technique was examined using samples of human blood serum. The possibility of estimating the sdLDL amount using the HDL data was demonstrated. These results suggest that the quantitative estimation of sdLDL amounts using DLS is feasible for point-of-care testing in clinical practice. 相似文献
79.
Tsumoru Morimoto Mana Yamashita Ai Tomiie Hiroki Tanimoto Kiyomi Kakiuchi 《化学:亚洲杂志》2020,15(4):473-477
We describe transfer carbonylation reactions of 2‐bromoarenes that contain a carbon‐nucleophile using aldehydes as a substitute for CO, leading to the formation of indanone derivatives. The transformation proceeds efficiently under RhI/Pd0‐hybrid catalytic conditions consisting of two discrete transition metals, rhodium and palladium, which catalyze the decarbonylation of aldehydes and the subsequent carbonylation of bromoarenes using the resulting carbonyl moiety, respectively. The majority of the abstracted CO is transferred directly to the product via a CO‐relay process from rhodium to palladium. 相似文献
80.
G. Mana E. Massa S. Valkiers G.-D. Willenberg 《International journal of mass spectrometry》2010,289(1):6-10
The uncertainty of the Si molar mass measurement is theoretically investigated by means of a two-isotope model, with particular emphasis to the role of this measurement in the determination of the Avogadro constant. This model allows an explicit calibration formula to be given and propagation of error analysis to be made. It also shows that calibration cannot correct for non-linearity. 相似文献