全文获取类型
收费全文 | 97篇 |
免费 | 1篇 |
专业分类
化学 | 45篇 |
晶体学 | 10篇 |
力学 | 1篇 |
数学 | 10篇 |
物理学 | 32篇 |
出版年
2021年 | 2篇 |
2018年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2011年 | 4篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 6篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有98条查询结果,搜索用时 15 毫秒
41.
Carbon-based transparent thin films were prepared from the pyrolysis of silylated graphite oxide containing perfluoroalkyl groups. The saturated amount of n-hexadecylamine molecules which accommodated between the layers of silylated graphite oxide containing larger pefluoroalkyl groups was smaller than that observed for silylated graphite oxide without perfluoroalkyl groups. The resulting intercalation compounds were dispersed in a chloroform/cyclohexane solution and precursor thin films were obtained by a cast method. The sheet resistance of the obtained carbon-based films was about 5 times smaller than that of the films prepared from silylated graphite oxide prepared with the analogous hydrocarbon substituents. The spectroscopic measurements indicated that the number of defects within the carbon layers was larger, however, that of carbon atoms participating π-conjugating system was larger. This probably ascribed to the active fluorine species formed as the result of thermal decomposition of perfluoroalkyl groups. The latter was responsible for the lower sheet resistance of carbon-based thin films. 相似文献
42.
Takayuki Iijima Masahiro Abe Take‐Aki Koizumi Atsushi Fukaya Kyohei Usami Kenichiro Kami Takakazu Yamamoto 《先进技术聚合物》2013,24(10):927-933
The reaction of 2,5‐diiodo‐1,4‐benzenedicarbonyl chloride, C6H2I2(COCl)2‐p, with 4‐hydroxy‐2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO‐ol) gave I–Ph(COO–TEMPO)2–I, Monomer‐1. Pd‐catalyzed polycondensation of Monomer‐1 with Me3Sn‐Th‐SnMe3 (2,5‐bis(trimethylstannyl)thiophene) and Bu3Sn–CH = CH–SnBu3 (1,2‐bis‐(tributylstannyl)ethylene) gave the corresponding π‐conjugated polymers, Polymer‐1 and Polymer‐2, respectively. Monomer‐1 was converted to a diethynyl compound, H–C ≡ C–Ph(COO–TEMPO)2–C ≡ C–H (Monomer‐1'), and Pd‐catalyzed polycondensation between Monomer‐1 and Monomer‐1' gave a π‐conjugated poly(arylene ethynylene) type polymer, Polymer‐3. According to the expansion of the π‐conjugation system by the polymerization, the UV–vis peaks of Monomer‐1 (λmax = 323 nm) and Monomer‐1' (327 nm) are shifted to longer wavelengths (λmax = 365 nm, 385 nm, and 396 nm for Polymer‐1, Polymer‐2, and Polymer‐3, respectively). Polymer‐1–Polymer‐3 showed ESR signals at about g = 2.01 with reasonable intensities. They are electrochemically active and showed a peak current anodic (oxidation) peak at about 0.9 V versus Ag/AgCl, which is reasonable for TEMPO polymers. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
43.
In this paper we consider positive unbounded solutions of second order quasilinear ordinary differential equations. Our objective
is to determine the asymptotic forms of unbounded solutions. An application to exterior Dirichlet problems is also given. 相似文献
44.
In this paper we consider positive solutions of second order quasilinear ordinary differential equations with singular nonlinearities. We obtain asymptotic equivalence theorems for asymptotically superlinear solutions and decaying solutions. By using these theorems, exact asymptotic forms of such solutions are determined. Furthermore, we can establish the uniqueness of decaying solutions as an application of our results. 相似文献
45.
S Ishihara H Moriuma C Mishima M Honda M Tomonobu K Kanao N Usami 《Radioisotopes》1987,36(12):657-660
We studied on the basic performance of a non-extraction coated tube RIA kit, DPC Aldosterone kit (Nippon DPC Corporation). 1. The average binding CVs of the calibrators (25 to 1,200 pg/ml) were stable in a range from 1.4 to 1.9%. 2. The minimum sensitivity was 17 pg/ml from 2SD method of 0 calibrator. 3. The intra-assay reproducibility test showed an average CV as 9.0%, and the inter-assay test showed as 8.8%. 4. The recovery ratios of a recovery test were 85.4 to 121.6%. 5. The correlation test with another maker's kit showed a correlation curve as y = 0.970 x + 19.68 and a correlation coefficiency as r = 0.970. 6. The normal range, the correlation between fasting recumbency and daytime sitting, and the correlation between walking and resting, showed similar results as former reports. 相似文献
46.
47.
Shiro Usami Shigeaki Yamada Bal Krishan Puri Masatada Satake 《Mikrochimica acta》1989,97(5-6):263-270
A method was established for the determination of trace amounts of copper using chromatographic preconcentration of copper(I) with 2,4,6-tri(2-pyridyl)-1,3,5-triazine and tetraphenylborate. Copper is quantitatively adsorbed on this adsorbent in the pH range 1.8–10.5 and at flow-rates of 0.2–10 ml/min. The solid mass consisting of copper complex along with naphthalene is dissolved from the column with 5 ml of dimethylformamide. A calibration curve is obeyed over the concentration range 0.2–10.0 g of copper in 5 ml of dimethylformamide. Eight replicate determinations of 3 g of copper gave a mean absorbance of 0.185 with a relative standard deviation of 1.4%. The characteristic concentration for 1% absorption is 0.0143 g/ml (0.103 gmg/ml for direct AAS in aqueous medium). The interference of various ion and salts has been studied and the proposed method has been employed to the determination of copper in biological and water samples. 相似文献
48.
49.
Y Kafuku Y Matsui J Ohtani Y Usami H Ueda M Doi M Inoue T Ishida 《Chemical & pharmaceutical bulletin》1991,39(10):2487-2490
As part of a series of peptides designed to have binding ability selective for each of the nucleic acid bases, five tripeptides consisting of N-acetyl-Trp-X-Trp-NHCH3 (X = Gly, Asn, Asp, Gln and Glu) were synthesized, and their abilities to form complexes with four different nucleotides were examined by the fluorescence and phase distribution methods. The association constants obtained indicated that, depending on the sort of X residue, the peptides showed a variation in their interaction with guanosine monophosphate (GMP), while no noticeable selectivity was observed for other nucleotides adenosine monophosphate (AMP), uridine monophosphate (UMP) and cytidine monophosphate (CMP). The binding mode of N-acetyl-Trp-Asp-Trp-NHCH3 for the guanine base was further investigated using the proton nuclear magnetic resonance (1H-NMR) method. The mode was suggested to involve intimate cooperation of (1) the hydrogen bond formation between the carboxyl group of the Asp side chain and the guanine C2-amino group, and (2) the stacking interaction of the base with two terminal Trp residues of the peptide. Such interaction was strengthened by the protonation of the guanine base. A tentative binding mode is proposed based on these results. 相似文献
50.