全文获取类型
收费全文 | 169篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
化学 | 138篇 |
晶体学 | 2篇 |
数学 | 23篇 |
物理学 | 17篇 |
出版年
2023年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 6篇 |
2018年 | 1篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 5篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 13篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有180条查询结果,搜索用时 187 毫秒
21.
22.
23.
Application of Solid Immersion Lens to Submicron Resolution Imaging of Nano-Scale Quantum Wells 总被引:1,自引:0,他引:1
We have discussed the resolution of submicron photoluminescence (PL) imaging using a solid immersion lens (SIL), which collects an evanescent light field. We apply the SIL microscope to measure PL image of a strip-line-patterned GaAs quantum well structure at low temperature. An improved resolution beyond diffraction limit and high collection efficiency of PL are realized.This paper was originally presented at the 5th International Conference on NEAR FIELD OPTICS and RELATED TECHNOLOGIES (NFO-5), which was held on December 6–10, 1998 at Coganoi Bay Hotel, Shirahama, Japan, in cooperation with the Japan Society of Applied Physics and Mombusho Grant-in Aid for Scientific Research on Priority Areas “Nearfield Nano-optics” Project, sponsored by Japan Society for the Promotion of Science. 相似文献
24.
Kenji Yamada Masahiko Minoda Takeshi Fukuda Takeaki Miyamoto 《Journal of polymer science. Part A, Polymer chemistry》2001,39(4):459-467
Amphiphilic block and statistical copolymers of vinyl ethers (VEs) with pendant glucose residues were synthesized by the living cationic polymerization of isobutyl VE (IBVE) and a VE carrying 1,2:5,6‐di‐O‐isopropylidene‐D ‐glucose (IpGlcVE), followed by deprotection. The block copolymer was prepared by a two‐stage sequential block copolymerization, whereas the statistical copolymer was obtained by the copolymerization of a mixture of the two monomers. The monomer reactivity ratios estimated with the statistical copolymerization were r1 (IBVE) = 1.65 and r2 (IpGlcVE) = 1.15. The obtained statistical copolymers were nearly uniform with the comonomer composition along the main chain. Both the block and statistical copolymers had narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight ∼ 1.1). Gel permeation chromatography, static light scattering, and spin–lattice relaxation time measurements in a selective solvent revealed that the block copolymer formed multimolecular micelles, possibly with a hydrophobic poly(IBVE) core and a glucose‐carrying poly(VE) shell, whereas the statistical copolymer with nearly the same molecular weight and segment composition was molecularly dispersed in solution. The surface properties of the solvent‐cast films of the block and statistical copolymer were also investigated with the contact‐angle measurement. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 459–467, 2001 相似文献
25.
Kenji Yamada Katsushi Yamaoka Masahiko Minoda Takeaki Miyamoto 《Journal of polymer science. Part A, Polymer chemistry》1997,35(2):255-261
Amphiphilic block copolymers of vinyl ethers (VEs) of the type —[CH2CH(OCH2CH2OR)]m—[CH2CH(OiBu)]n—were synthesized by living cationic polymerization, where R is a D-glucose residue, and m and n are the degrees of polymerization (m = 20–50; n = 11–89). To obtain them, sequential living block copolymerization of isobutyl vinyl ether (IBVE) and the vinyl ether carrying 1,2:5,6-diisopropylidene-D -glucose residue was conducted by using the HCl adduct of IBVE, CH3CH(OiBu)Cl, as initiator in conjunction with zinc iodide. These precursor block copolymers had a narrow molecular weight distribution (M̄w/M̄n ∼ 1.1) and a controlled composition. Treatment of them with a trifluoroacetic acid/water mixture led to the target amphiphiles. The solubility of the amphiphilic block copolymers in various solvents depended strongly on composition or the m/n ratio. Their solvent-cast thin films were observed, under a transmission electron microscope, to exhibit various microphase-separated surface morphologies such as spheres, cylinders, and lamellae, depending on composition. © 1997 John Wiley & Sons, Inc. 相似文献
26.
Takashi Okada Naoki Fujiwara Takeaki Ogata Osamu Haba Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》1997,35(11):2259-2266
Poly(4,6-di-n-butoxy-1,3-phenylene) ( 6 ) was prepared by oxidative coupling polymerization of 1,3-di-n-butoxybenzene ( 1 ) or 2,2′,4,4′-tetra-n-butoxy biphenyl (3). Polymerizations were conducted in nitrobenzene in the presence of FeCl3 at room temperature and produced polymers with number-average molecular weights up to 42,000. The effects of various factors, such as amount of FeCl3 and reaction temperature and time were studied. The structure of polymer 6 was characterized by 270 MHz 1H- and 68.5 MHz 13C-NMR spectroscopies and was estimated to consist of almost completely 1,3-linkage. The regiocontrolled polymer was readily soluble in common organic solvents. Thermogravimetric analysis of polymer 6 showed 10% weight loss at 390°C in nitrogen. © 1997 John Wiley & Sons, Inc. J Polym Chem 35 : 2259–2266, 1997 相似文献
27.
Kenji Yamada Masahiko Minoda Takeaki Miyamoto 《Journal of polymer science. Part A, Polymer chemistry》1997,35(4):751-757
D -glucosamine-containing glycopolymers with well-controlled structure were synthesized by living cationic polymerization. To this end, D -glucosamine-containing vinyl ether (VE) of the type [CH2()CH(OCH2CH2OR)] was prepared, where R denotes a 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimide-β-D -glucopyranoside, i.e., the hydroxyl and amino groups in D -glucosamine residues are protected by acetyl and phthaloyl groups, respectively. It was found that (1) the efficient living cationic polymerization of VE monomer is achieved by a combination of ethylaluminum dichloride (EtAlCl2) with an adduct of trifluoroacetic acid (TFA) and isobutyl VE (IBVE) [CH3CH(OiBu)OCOCF3] (i.e., TFA/EtAlCl2 initiating system); and (2) the polymerization in toluene at the elevated temperature (0°C) is most suitable to proceed the homogeneous polymerization over the whole conversion range. The molecular weight distribution of the resulting polymers was very narrow ($ {\bar M}_w/{\bar M}_n \sim 1.1 $). Quantitative deprotection of the resulting precursor polymers was successfully achieved with hydrazine monohydrate to afford the corresponding water-soluble polymers with pendant D -glucosamine residues. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 751–757, 1997 相似文献
28.
Haruyuki Okamura Kouki Miyazono Masahiko Minoda Takeaki Miyamoto 《Macromolecular rapid communications》1999,20(2):41-45
Water‐soluble fullerene‐bearing pullulans were successfully prepared by the addition reaction of azide‐substituted pullulans with fullerene C60 . The chemical structure of the products was characterized by IR, UV, and NMR spectroscopy. It was found that the saturation solubility of the C60 moiety strongly depends on the degree of substitution (DS) of the sample, indicating that an optimum DS value of the C60 moiety exists for its aqueous solubility. 相似文献
29.
30.