全文获取类型
收费全文 | 243篇 |
免费 | 8篇 |
专业分类
化学 | 196篇 |
晶体学 | 2篇 |
数学 | 6篇 |
物理学 | 47篇 |
出版年
2023年 | 2篇 |
2021年 | 5篇 |
2020年 | 10篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 14篇 |
2011年 | 15篇 |
2010年 | 5篇 |
2009年 | 7篇 |
2008年 | 14篇 |
2007年 | 15篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 19篇 |
2002年 | 10篇 |
2001年 | 1篇 |
2000年 | 10篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 8篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1956年 | 1篇 |
1915年 | 1篇 |
排序方式: 共有251条查询结果,搜索用时 203 毫秒
51.
Yasuhiro Suzuki Yuichi Tohmori Kazutoshi Kato Mitsuo Fukuda Hiromi Oohashi Satoshi Sekine Naoto Uchida Hiromu Toba Masaharu Horiguchi Toshihiko Sugie Yasuhumi Yamada 《Optical and Quantum Electronics》1998,30(3):141-159
Cost-effectiveness is essential in developing optical access network systems. To reduce system costs, both improved system and component technologies are required. Reducing the costs of optical devices and modules in an optical network unit is especially necessary. In this paper, the requirements for optical devices in optical access networks and modules are clarified. Moreover, we also review the recent progress in technologies for semiconductor optical devices and hybrid integration for low-cost optical modules in access networks. 相似文献
52.
53.
Hiromu Saito Motoshi Matsuura Takashi Inoue 《Journal of Polymer Science.Polymer Physics》1991,29(12):1541-1546
Depolarized light scattering measurements on single-phase mixtures of dissimilar polymers, poly(methyl methacrylate) (PMMA)/poly (acrylonitrile-co-styrene) (SAN, AN content = 15 wt %) and PMMA/poly (vinylidene fluoride) (PVDF) were carried out. The effective mean-square optical anisotropy γ2 of the mixtures was found to be much higher than that estimated by the simple additivity of γ2 of component polymers. From the deviation, the order parameter (1 + J12) was estimated to be in a range of 2–13, depending on the blend composition. This suggests local ordering in the single-phase mixtures, i.e., nematic alignment of the locally stretched dissimilar chains. In contrast, the deviation was slight in the polymer/solvent systems, SAN/MMA (monomer) and PVDF/butanone. The degree of ordering decreased with increasing temperature. T. The Specific interaction evidenced by FTIR spectroscopy exhibited a similar temperature dependence. Thus, local ordering seems to be induced by specific interactions and chain connectivity. The temperature dependence of J12 was successfully described by the Landau-de Gennes theory; J ∞ (T + T0)/ T, T0 being the isotropic-nematic transition temperature, as in the case of liquid crystals. 相似文献
54.
Total Synthesis and Biological Evaluation of the Glycosylated Macrocyclic Antibiotic Mangrolide A 下载免费PDF全文
Hiromu Hattori Joel Roesslein Dr. Patrick Caspers Dr. Katja Zerbe Dr. Hideki Miyatake‐Ondozabal Dr. Daniel Ritz Dr. Georg Rueedi Prof. Dr. Karl Gademann 《Angewandte Chemie (International ed. in English)》2018,57(34):11020-11024
The macrocyclic antibiotic mangrolide A has been described to exhibit potent activity against a number of clinically important Gram‐negative pathogens. Reported is the first enantioselective total synthesis of mangrolide A and derivatives. Salient features of this synthesis include a highly convergent macrocycle preparation, stereoselective synthesis of the disaccharide moiety, and two β‐selective glycosylations. The synthesis of mangrolide A and its analogues enabled the re‐examination of its activity against bacterial pathogens, and only minimal activity was observed. 相似文献
55.
Mizuno A Miya M Kamei T Shibata M Tatsuoka T Nakanishi K Takiguchi C Hidaka T Yamaki A Inomata N 《Chemical & pharmaceutical bulletin》2000,48(8):1129-1137
As an extension of our previous investigation, a series of 7-aminoalkylpyrrolo[2,3-c]azepine derivatives was synthesized and evaluated as alpha1-adrenergic- and serotonin 2 (5-HT2)-receptor antagonists, with the aim of finding a novel potent antihypertensive agent with both activities. Among the compounds obtained in this study, (E)-1-ethyl-7-[3-[4-(4-fluorophenyl)piperazin-1-yl]propyl]-4-hy droxyimino-1,4,5,6,7,8-hexahydropyrrolo[2,3-c]azepin-8-on e (16d) displayed potent alpha1-adrenoceptor blocking activity (pA2=7.83+/-0.20) and 5-HT2-receptor blocking activity (pA2=9.47+/-0.17) in isolated guinea pig arteries. At 3 mg/kg oral administration, compound 16d exhibited antihypertensive activity more potent than that of doxazosin in deoxycorticosterone acetate (DOCA)-salt hypertensive dogs. Furthermore, this compound reduced the rate of mouse acute pulmonary thromboembolytic death induced by collagen and serotonin at oral doses of 0.3 mg/kg or more, and its effect lasted for at least 6 h at 3 mg/kg. 相似文献
56.
Tsukasa Ikeda Yuki Inoue Akihito Suehiro Hirofumi Ikeshoji Takenori Ishida Noboru Takiguchi Akio Kuroda Junichi Kato Hisao Ohtake 《Journal of inclusion phenomena and macrocyclic chemistry》2002,44(1-4):381-382
Inclusion complex formation between cyclodextrin and autoinducer of gram negative bacteria in aqueous solution was investigated by 1D 1H-NMR and ROESY spectra. An inhibitioneffect was observed on autoinducer activities of quorum sensing in Pseudomonas aeruginosa by adding cyclodextrins to the bacterial culture medium. 相似文献
57.
Takiguchi Yu Seo Min-Woong Kagawa Keiichiro Takamoto Hisayoshi Inoue Takashi Kawahito Shoji Terakawa Susumu 《Optical Review》2016,23(2):364-368
Optical Review - We propose a novel full-electronically controlled laser confocal microscope in which a liquid-crystal-on-silicon spatial light modulator and a custom CMOS imaging sensor are... 相似文献
58.
59.
60.