全文获取类型
收费全文 | 875篇 |
免费 | 38篇 |
国内免费 | 5篇 |
专业分类
化学 | 697篇 |
晶体学 | 31篇 |
力学 | 5篇 |
数学 | 12篇 |
物理学 | 173篇 |
出版年
2023年 | 11篇 |
2022年 | 12篇 |
2021年 | 17篇 |
2020年 | 11篇 |
2019年 | 33篇 |
2018年 | 16篇 |
2017年 | 13篇 |
2016年 | 18篇 |
2015年 | 16篇 |
2014年 | 30篇 |
2013年 | 60篇 |
2012年 | 41篇 |
2011年 | 47篇 |
2010年 | 36篇 |
2009年 | 35篇 |
2008年 | 55篇 |
2007年 | 45篇 |
2006年 | 64篇 |
2005年 | 47篇 |
2004年 | 46篇 |
2003年 | 35篇 |
2002年 | 30篇 |
2001年 | 26篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 10篇 |
1997年 | 12篇 |
1996年 | 17篇 |
1995年 | 10篇 |
1994年 | 21篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1965年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有918条查询结果,搜索用时 421 毫秒
61.
Yoshiki Nakata Kunio Tsuchida Noriaki Miyanaga 《Optics and Lasers in Engineering》2009,47(7-8):847-849
Combined periodic structures composed of micron-sized periodic structure and nano-sized quasi periodic structure were generated on Ni–Ti target by multiple shots of interfering femtosecond laser beams. The micron-sized structure was generated by the interference pattern of four beams, and the nano-sized quasi period was generated due to the multiple shot effect of femtosecond laser. The structures were investigated in detail by two-dimensional fast Fourier transform (2D-FFT). The power spectra showed small spots and fuzzy spots due to precise period and quasi period, respectively. The most major size of the quasi periodic structure was 580 nm. 相似文献
62.
Front Cover: Construction of a Triangle‐Shaped Trimer and a Tetrahedron Using an α‐Helix‐Inserted Circular Permutant of Cytochrome c555 (Chem. Asian J. 10/2018)
下载免费PDF全文
![点击此处可从《化学:亚洲杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
63.
Masahiro Yamashita Daisuke Kawakami Satoshi Matsunaga Yoshio Nakayama Mari Sasaki Shinya Takaishi Fumiyasu Iwahori Hitoshi Miyasaka Ken‐ichi Sugiura Yoshiki Wada Hiroshi Miyamae Hiroyuki Matsuzaki Hiroshi Okamoto Hisaaki Tanaka Kazuhiro Marumoto Shin‐ichi Kuroda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2004,116(36):4867-4871
64.
65.
The polymer microspheres were synthesized by dispersion copolymerization of divinylbenzene (DVB) with two vinylbenzyl-terminated poly(ethylene glycol methylether) (PEG)/poly(t-butyl methacrylate) (PBMA) macromonomer blends in methanol. In these systems of two macromonomer blends as the emulsifier, the polymer microspheres formed had a very narrow particle size distribution. Two macromonomers formed comicelles with DVB monomer and acted not only as the comonomer but also as the stabilizer. Such polymer microspheres were stabilized sterically with two-component grafted chains, such as PEG and PBMA, in methanol. 相似文献
66.
Yagi S Iwanaga T Kojima H Shoji Y Suzuki S Seno K Mori H Tokura Y Takigawa M Moriwaki S 《Photochemistry and photobiology》2002,76(6):669-671
We have developed a UV monitor with polycrystalline (poly-) gallium nitride (GaN) UV sensors and evaluated its performance from the viewpoint of its effectiveness for use with photosensitive dermatosis patients. The poly-GaN UV sensor is sensitive to UV light from 280 to 410 nm even without optical filters. The UV monitor is a portable self-data-acquisition instrument with a minimum detection level (defined as average UV intensity over 290 to 400 nm) of 2 microW/cm2 and can store UV dose data for 128 days. It allows easy measurement of four orders of magnitude of ambient UV intensity and dose from indoor light to direct solar radiation in summer. Trial use of the UV monitor by five xeroderma pigmentosum patients started in June 2000 and was carried out for 1 year. It was demonstrated that the UV monitor was useful in improving their quality of life. 相似文献
67.
Kato D Masaike M Majima T Hirata Y Mizutani F Sakata M Hirayama C Kunitake M 《Chemical communications (Cambridge, England)》2002,(22):2616-2617
Novel two-dimensional (2D) cross-linked polysiloxane LB films were prepared and applied for glucose sensing as H2O2-permselective films in order to block other electroactive interferences, such as L-ascorbic acid, L-cysteine, uric acid and acetaminophen; the 2D cross-linked polysiloxane monolayers were remarkably effective in eliminating interfering responses and had a rapid response for glucose, even though the films were only a monolayer thick. 相似文献
68.
Hiraoka K Asakawa Y Kawashima Y Okazaki S Nakamura M Yamamoto Y Takamizawa A 《Rapid communications in mass spectrometry : RCM》2004,18(20):2437-2442
The effect of the presence of foreign salts (NaCl, aerosol OT, tetra-n-hexylammonium bromide, and CH3COONH4) on the formation of gaseous ions for electrospray (ES) and laser spray (LS) was studied in the positive and negative modes of operations. The ion signals for amino acids show sudden decrease with the concentration of foreign salts greater than 10(-5) M for both ES and LS. When the surface-active counter ions were added, the signal intensities showed a marked decrease for both ES and LS. This may be due to the enrichment of the surface-active counter ions on the surface of the charged droplets. When CH3COONH4 was added to an aqueous solution of 10(-6) M lysozyme chloride, an increase of the signal intensities for (lysozyme+nH)n+ and a decrease in the values of n were observed. The decrease in n may be due to the salt formation of (lysozyme+nH)n+ with the negative acetate ion leading to the reduction of positive charges. 相似文献
69.
Palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate (4) with a dimethyl malonate-BSA-LiOAc system has been successfully carried out in the presence of chiral phosphine-hydrazone ligands such as 3a in good yields with good enantioselectivities (up to 84% ee). 相似文献
70.