全文获取类型
收费全文 | 887篇 |
免费 | 25篇 |
国内免费 | 3篇 |
专业分类
化学 | 699篇 |
晶体学 | 14篇 |
力学 | 19篇 |
数学 | 46篇 |
物理学 | 137篇 |
出版年
2023年 | 5篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 14篇 |
2015年 | 16篇 |
2014年 | 14篇 |
2013年 | 43篇 |
2012年 | 36篇 |
2011年 | 44篇 |
2010年 | 23篇 |
2009年 | 30篇 |
2008年 | 48篇 |
2007年 | 60篇 |
2006年 | 62篇 |
2005年 | 49篇 |
2004年 | 51篇 |
2003年 | 50篇 |
2002年 | 36篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 9篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 15篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1986年 | 6篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 14篇 |
1976年 | 9篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1967年 | 3篇 |
排序方式: 共有915条查询结果,搜索用时 46 毫秒
911.
Takekazu Ishida Kohei Arai Yukio Akita Mitsunori Miyanari Yusuke Minami Tsutomu Yotsuya Masaru Kato Kazuo Satoh Mayumi Uno Hisashi Shimakage Shigehito Miki Zhen Wang 《Physica C: Superconductivity and its Applications》2010,470(19):730-733
The nanofabrication of superconductors yields various interesting features in superconducting properties. A variety of different imaging techniques have been developed for probing the local superconducting profiles. A scanning pulsed laser microscope has been developed by the combination of the XYZ piezo-driven stages and an optical fiber with an aspheric focusing lens. The scanning laser microscope is used to understand the position-dependent properties of a superconducting MgB2 stripline of length 100 μm and width of 3 μm under constant bias current. Our results show that the superconducting stripline can clearly be seen in the contour image of the scanning laser microscope on the signal voltage. It is suggested from the observed image that the inhomogeneity is relevant in specifying the operating conditions such as detection efficiency of the sensor. 相似文献
912.
Dr. Masaru Kondo Dr. Kento Nakamura Dr. Chandu G. Krishnan Prof. Hiroaki Sasai Assoc. Prof. Shinobu Takizawa 《Chemical record (New York, N.Y.)》2023,23(7):e202300040
This study presents recent advances in photoswitchable chiral organocatalysts and their applications in the photomodulation of enantioselective reactions. Under irradiation with an appropriate wavelength of light, the E/Z-photoisomerization of the photoresponsive units on the catalysts leads to the control of the catalytic activity and/or selectivity of the enantioselective reactions. Additionally, this study elucidates the design, synthesis, and catalytic application of the fabricated azobenzene BINOL-based photoswitchable chiral phase-transfer catalysts. This account will provide insights into the appropriate design of a photoswitchable chiral organocatalyst that can achieve both good enantioselectivity and photocontrol. 相似文献
913.
Jun Manabe Nagisa Sako Mizuki Ito Dr. Masaru Fujibayashi Dr. Chisato Kato Dr. Goulven Cosquer Prof. Katsuya Inoue Dr. Kiyonori Takahashi Prof. Takayoshi Nakamura Prof. Tomoyuki Akutagawa Dr. Seiya Shimono Dr. Hiroki Ishibashi Prof. Yoshiki Kubota Prof. Sadafumi Nishihara 《欧洲无机化学杂志》2023,26(34):e202300449
Materials exhibiting irreversible phase transitions, leading to changes in their properties, have a potential for novel application in electronic components such as a non-rewritable high-security memory. Here, we focused on the two salts, [(9-triptycylammonium)([18]crown-6)][Ni(dmit)2] ( 1 ) and [(9-triptycylammonium)([15]crown-5)][Ni(dmit)2] ( 2 ), which featured 2D sheet structures with alternately stacked cation and anion layers. Both salts exhibit similar cation arrangements, however, their anion arrangements differ significantly. The temperature-dependent magnetic susceptibilities of 1 and 2 were well reproduced by the alternating chain model (JAC1/kB=−306(8), JAC2/kB=−239(3) K) and the Curie-Weiss model (θ=−3.9(1) K), respectively. 1 experience a reversible phase transition around 40–60 K, causing anomalies in magnetic behavior. Moreover, an irreversible single-crystal-to-single-crystal phase transition to 1′ undergo at ~381 K, inducing a rearrangement of [Ni(dmit)2]− anions and a resistivity decrease from 6.5×106 to 6.5×102 Ω cm. The susceptibility curve of 1′ was reproduced by a combination of the Curie-Weiss and dimer models (Jdimer/kB=−407(5), θ=−26.7(5) K). The irreversible transition of 1 is the first example for such supramolecule and [Ni(dmit)2]− system to our knowledge, in opening potential new-type materials. 相似文献
914.
Masato Kurihara Kenya Kubo Tesuo Horikoshi Masaru Kurosawa Takuya Nankawa Takayuki Matsuda Hiroshi Nishihara 《Macromolecular Symposia》2000,156(1):21-29
This paper describes three topics on the π‐conjugated ferrocene oligomers and polymers; the first is the dependence of intervalence‐transfer bands for mixed‐valence oligo(1,1'‐dihexylferrocenylene)s on the oxidation number and the number of ferrocene units, the second is synthesis of azo‐bridged ferrocene oligomers and a polymer and electrochemical and optical analysis of internuclear electronic interactions in their mixed‐valence states and the third is synthesis, redox behaviors and electrodeposition of oligoferrocenylene‐modified gold clusters. 相似文献
915.
Jinhua Chen Shin Hasegawa Hitoshi Ohashi Yasunari Maekawa Masaru Yoshida Ryoichi Katakai Norio Tsubokawa 《Macromolecular rapid communications》2002,23(2):141-144
The impedance effect on the ion transport of lithium chloride through temperature‐ and pH‐sensitive gel membranes was investigated. Both conductance and loss tangent show a relatively high value at temperatures near the lower critical solution temperature (14°C), followed by an abrupt drop with a further rise in temperature. The Figure shows an example of changes in absolute complex conductance (Y ), real conductance (G ), and imaginary conductance (B) for a poly(acryloyl‐L ‐proline methyl ester) gel membrane. 相似文献