全文获取类型
收费全文 | 458篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
化学 | 281篇 |
晶体学 | 7篇 |
力学 | 2篇 |
数学 | 15篇 |
物理学 | 161篇 |
出版年
2023年 | 3篇 |
2021年 | 2篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 23篇 |
2010年 | 15篇 |
2009年 | 25篇 |
2008年 | 27篇 |
2007年 | 31篇 |
2006年 | 20篇 |
2005年 | 27篇 |
2004年 | 9篇 |
2003年 | 20篇 |
2002年 | 17篇 |
2001年 | 12篇 |
2000年 | 16篇 |
1999年 | 10篇 |
1998年 | 2篇 |
1997年 | 13篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 8篇 |
1993年 | 2篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1973年 | 1篇 |
1966年 | 1篇 |
1937年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有466条查询结果,搜索用时 15 毫秒
91.
Kikuchi Y Yamada H Kunimori H Tsukada T Hozawa M Yokoyama C Kubo M 《Langmuir : the ACS journal of surfaces and colloids》2005,21(8):3273-3278
In this study, the aggregation and breakup behaviors of latex particles in shear flow confined between two parallel plates were investigated using an in situ observation apparatus with a laser scanning confocal microscope. To investigate the effects of shear rate and the gap width between two parallel plates on the size and structure of the aggregates in the steady state, the distributions of the projected cross-sectional area and perimeter-based fractal dimension of the aggregates were measured. As a result, the average size of the aggregates decreases as shear rate increases and the gap width decreases due to the hydrodynamic effect acting on the aggregates. The size distributions of the aggregates become narrow as the gap width decreases. In addition, the fractal dimension, that is, the structure of the aggregates, was almost independent of shear rate and the gap width and approximately 1.2, which suggests that the aggregates are relatively compact. 相似文献
92.
The optimum conditions for the coupling of proteins were investigated using TSKgel Tresyl-Toyopearl 650M. They were dependent on the proteins coupled. For example, when soybean trypsin inhibitor was coupled at pH 8 the coupling was completed within 1 h and the subsequent adsorption capacity for trypsin was maximal. Longer coupling times decreased the adsorption capacity due to multi-point attachment. The adsorbents obtained were successfully used for affinity chromatography in a short time. 相似文献
93.
Nguyen Chung Thanh Takanori Kajioka Yasunori Taga Satoshi Ogawa Yosuke Miyahara Mitsunori Oda 《Tetrahedron》2006,62(48):11227-11239
After a preliminary search of the reaction conditions for the Suzuki-Miyaura cross-coupling of haloazulenes with arylboronic acids, the title compounds were synthesized either by the direct coupling reaction between 1,3-dihaloazulene and the corresponding N,N-disubstituted 4-aminophenylboronic acids or by a two-step sequence involving the cross-coupling with 4-bromophenylboronic acid and subsequent Pd-catalyzed amination. Application of the title diamines to a hole-injecting material in organic electroluminescent devices was carried out to provide their prominent characteristics as a novel durable, non-cyanine and non-polyamine substance without color fade. The diamine derivatives, extended by an ethynyl unit between the azulenyl core and the 4-aminophenyl moiety, were also synthesized and found, unfortunately, unsuitable for vacuum deposition in preparing a multilayer composite. 相似文献
94.
Mitsunori Honda Yusuke Taniguchi Tomohiro Hayashi Ko-Ki Kunimoto Masahito Segi Takahiro Yamaguchi 《Tetrahedron letters》2017,58(48):4554-4558
The synthesis of a novel class of 3-silyl substituted thiophenes possessing perfluoroalkyl groups on the silicon atom was investigated. The treatment of 3-bromothiophene with n-butyllithium followed by the reaction with halosilanes proceeded to afford the corresponding 3-silyl substituted thiophenes 1 in good yields. The chemical polymerization of the resulting 1 did not work well. However, the electropolymerization of 3-silylthiophenes 1a and 1b provided the corresponding polymers 5a and 5b with head-to-tail regioregularity. The cyclic voltammogram of the resulting polymers 5a and 5b indicated both n- and p-doping properties. 相似文献
95.
Kenichiro Todoroki Yasuhiro Ishii Koji Toyoda Takashi Ikawa Jun Zhe Min Koichi Inoue Shuji Akai Toshimasa Toyo’oka 《Analytical and bioanalytical chemistry》2013,405(25):8121-8129
In this paper, we report a new type of chiral high-performance liquid chromatography (HPLC) column—a so-called dress-up chiral column—featuring a chiral stationary phase adsorbed reversibly in a commercial fluorous HPLC column through fluorous interactions. We synthesized perfluroalkylated proline derivatives as chiral stationary phase compounds and then adsorbed them reversibly in the fluorous HPLC column through the pumping of their solutions. By using this dress-up chiral column and fluorophobic elution of an aqueous copper(II) sulfate/MeOH mixture, we could enantioseparate seven racemic amino acids within 40 min. When we washed the dress-up chiral column with fluorophilic tetrahydrofuran or MeOH, the adsorbed chiral stationary phase compounds desorbed from the column, completely destroying its enantioseparation ability. The relative standard deviation of the retention times, the number of theoretical plates, and the resolution for each of four preparations of the dress-up columns were all less than or equal to 9.53 % in 20-times repeated analysis, and were all less than or equal to 18.7 % in four different preparations, respectively. 相似文献
96.
97.
98.
Joachim Mohn Christina Biasi Samuel Bodé Pascal Boeckx Paul J. Brewer Sarah Eggleston Heike Geilmann Myriam Guillevic Jan Kaiser Kristýna Kantnerová Heiko Moossen Joanna Müller Mayuko Nakagawa Ruth Pearce Isabell von Rein David Steger Sakae Toyoda Wolfgang Wanek Sarah K. Wexler Naohiro Yoshida Longfei Yu 《Rapid communications in mass spectrometry : RCM》2022,36(13):e9296
99.
Kentaro Uesugi Hideyuki Yasuda Barbara Pierscionek Kiyohiko Toyoda Masato Hoshino Naoto Yagi 《Synchrotron Radiation News》2015,28(5):30-35
The medium-length (215 m) bending-magnet beamline 20B2 is allocated to medical applications and various X-ray micro imaging techniques (e.g., angiography, computed tomography, phase contrast imaging and diffraction topography) [1]. The unique properties of BL20B2 are high spatial coherence (large coherent length) and its wide beam cross-section, which come from its long beam transport path and bending magnet light source. The horizontal angular aperture of BL20B2 is 1.5 mrad, as in all bending magnet beamlines at SPring-8. The horizontal beam width at the end station is larger than 300 mm for a 215 m beamline length. 相似文献
100.
Liquid‐Crystalline Biomacromolecular Templates for the Formation of Oriented Thin‐Film Hybrids Composed of Ordered Chitin and Alkaline‐Earth Carbonate 下载免费PDF全文
Dr. Tatsuya Nishimura Ken Toyoda Takahiro Ito Dr. Yuya Oaki Yukiko Namatame Prof. Takashi Kato 《化学:亚洲杂志》2015,10(11):2356-2360
Macroscopically ordered inorganic thin films have been formed on unidirectionally oriented, liquid‐crystalline chitin matrices. In the presence of poly(acrylic acid) (PAA), unidirectionally oriented chitin films act as templates for the formation of oriented thin‐film crystals of alkaline‐earth carbonates such as SrCO3 and BaCO3. The morphology and orientation of crystals are dependent on the metal ion concentration. For SrCO3 crystallization, unidirectional thin films and hexagonal‐shaped thin films have been deposited from 200 and 25 mm concentration strontium solutions, respectively. 相似文献