全文获取类型
收费全文 | 94篇 |
免费 | 4篇 |
专业分类
化学 | 69篇 |
数学 | 5篇 |
物理学 | 24篇 |
出版年
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1928年 | 1篇 |
1925年 | 1篇 |
排序方式: 共有98条查询结果,搜索用时 9 毫秒
41.
Tsuda T Sakamoto T Nishimura Y Seino S Imanishi A Kuwabata S 《Chemical communications (Cambridge, England)》2012,48(13):1925-1927
Various metal nanoparticles including base metal were produced by a brief accelerated electron beam irradiation of 1-alkyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)amide room-temperature ionic liquid without a stabilizing agent, which is usually employed so as to prevent aggregation. 相似文献
42.
Tetsuya Ono Katsuhiko Sato Yusuke Sasano Kentaro Yoshida Takenori Dairaku Yoshiharu Iwabuchi Yoshitomo Kashiwagi 《Electroanalysis》2019,31(4):603-606
This work investigated a simple triglycerides (TGs) detection method combining an enzymatic reaction, using only lipase, and the electrocatalytic oxidation of glycerol with nortropine‐N‐oxyl (NNO). Tributyrin was employed as a model TG. In this method, TGs are degraded by lipase to glycerol and fatty acids, after which the glycerol reacts with NNO. Preliminary cyclic voltammetry trials demonstrated that the anodic peak current increased along with the glycerol concentration, giving currents of 53.2 and 97.3 μA (at +0.6 V vs. Ag/AgCl) in response to 10 and 100 mM glycerol, respectively. Amperometry confirmed the same response during constant potential electrolysis at+0.6 V vs. Ag/AgCl. This behavior was also observed in a system incorporating tributyrin and lipase, with increases in current proportional to the tributyrin concentration over the range of 0.1 to 10 mM. 相似文献
43.
44.
The batch culture of a newly isolated strain of a green microalga, Chlorella sorokiniana, was carried out using a conical helical tubular photobioreactor. The isolate was capable of good growth at 40°C under an
airstream enriched with 10% CO2. The maximum photosynthetic productivity was 34.4g of dry biomass/(m2 of installation area · d) (12-h light/12-h dark cycle) when the cells were illuminated with an average photosynthetic photon
flux density (photosynthetically active radiation ([PAR] 400–700 nm) simulating the outdoors in central Japan (0.980 mmol
photons/[m2·s]). This corresponded to a photosynthetic efficiency of 8.67% (PAR), which was defined as the percentage of the light energy
recovered as biomass (394 kJ/[reactor·d]) to the total light energy received (4545 kJ/[reactor·d]). A similarly high photosynthetic
efficiency (8.12% [PAR]) was also attained in the combined presence of 10% CO2, 100 ppm of NO, and 25 ppm of SO2. Moreover, good photosynthetic productivity was also obtained under high temperature and high light intensity conditions
(maximum temperature, 46.5°C; 1.737 mmol photons/[m2·s]), when simulating the strong irradiance of the midday summer sun. This strain thus appears well suited for practical application
for converting CO2 present in the stack gases emitted by thermal power plants and should be feasible even during the hot summer weather. 相似文献
45.
Xinjian?Liu Ting?Chen Tomonori?Hoshi Yoshitomo?Kashiwagi Jun-ichi?Anzai Genxi?LiEmail author 《Mikrochimica acta》2005,150(1):73-76
Cinnamtannin B1 (trimeric proanthocyanidin), which is identified and isolated from the effective fraction of the root of Lindera aggregata (Sims) Kosterm, is one kind of condensed tannin used as an effective antipyrotic and antitumor agent. Its electrochemical response can be obtained at a pyrolytic graphite electrode. Consequently, an easily performed and sensitive method for the determination of cinnamtannin B1 is developed. The detection limit is estimated to be 1.0×10–7M with the linear determination range of 2.0×10–7M to 1.8×10–6M. Five replicate analyses of 1.0×10–6M cinnamtannin B1 yields an RSD value of 2.1%. Since the working electrode does not need to be modified with any other species, it is very stable, repeatable and easily treated, and this method therefore potentially useful in real sample analysis. 相似文献
46.
Kittaka A Suhara Y Takayanagi H Fujishima T Kurihara M Takayama H 《Organic letters》2000,2(17):2619-2622
[reaction: see text]A convenient and potentially valuable synthetic approach to the novel 2alpha-functionalized 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] derivatives (1a-c), which are the C2-epimer of ED-71 and its analogues, has been developed. The C2alpha-modified ring A precursors (1,7-enynes 16, n = 0, 1, and 2) were constructed stereoselectively starting from D-glucose in high yield. In the synthesized 2alpha-(omega-hydroxyalkoxy)-1alpha,25(OH)2D3 derivatives, 1a and 1b showed a greater binding affinity to vitamin D receptor (VDR), up to 1.8 times that of the native hormone. 相似文献
47.
Ishii N Okamura Y Chiba S Nogami T Ishida T 《Journal of the American Chemical Society》2008,130(1):24-25
A metal-radical polymer [Co(hfac)2.BPNN] showed a very large coercive field of 52 kOe (4.1 MA m-1) at 6 K, indicating that it is the hardest magnet ever reported. Above 10 K, a soft character appeared, owing to the fast dynamics of magnetization reorientation. 相似文献
48.
49.
Kuo JL Xie ZZ Bing D Fujii A Hamashima T Suhara K Mikami N 《The journal of physical chemistry. A》2008,112(41):10125-10133
Density functional theory (DFT) calculations of protonated methanol-water mixed clusters, H (+)(MeOH) 1(H 2O) n ( n = 1-8), were extensively carried out to analyze the hydrogen bond structures of the clusters. Various structural isomers were energy optimized, and their relative energies with zero point energy corrections and temperature dependence of the free energies were examined. Coexistence of different morphological isomers was suggested. Infrared spectra were simulated on the basis of the optimized structures. The infrared spectra were also experimentally measured for n = 3-9 in the OH stretching vibrational region. The observed broad bands in the hydrogen-bonded OH stretch region were assigned in comparison with the simulations. From the DFT calculations, the preferential proton location was also investigated. Clear correlations between the excess proton location and the cluster morphology were found. 相似文献
50.