全文获取类型
收费全文 | 378篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
化学 | 291篇 |
晶体学 | 9篇 |
力学 | 3篇 |
数学 | 17篇 |
物理学 | 69篇 |
出版年
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 9篇 |
2013年 | 17篇 |
2012年 | 15篇 |
2011年 | 14篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 16篇 |
2007年 | 19篇 |
2006年 | 20篇 |
2005年 | 30篇 |
2004年 | 20篇 |
2003年 | 16篇 |
2002年 | 16篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 11篇 |
1994年 | 6篇 |
1993年 | 14篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有389条查询结果,搜索用时 15 毫秒
121.
Long-range forces up to next-to-leading order are computed in the framework of the Einstein–Maxwell-dilaton system by means
of a semiclassical approach to gravity. As has been recently shown, this approach is effective if one of the masses under
consideration is significantly greater than all the energies involved in the system. Further, we obtain the condition for
the equilibrium of charged masses in the system. 相似文献
122.
Masako Koyama Masaharu Shiraishi Koji Sasaki Kijiro Kon-no 《Journal of Dispersion Science and Technology》2013,34(9):1266-1271
Amino acids provide useful foods, medicines, health foods, and nutritional supplements. We studied the morphology control of alanine, an amino acid. We also studied the effects of amino acid addition on the dispersion stability of gold nanoparticles. We then studied hybridization between alanine crystals and arginine-capped gold nanoparticles. Alanine crystal growth in a supersaturated alanine solution was found to increase linearly over time, and alanine crystal growth stopped as supersaturation decreased. Alanine crystals with arginine grew toward the c-axis because arginine was adsorbed onto the face (120) of alanine crystals. Absorption wavelengths of colloidal solutions changed for gold nanoparticles with arginine, suggesting that arginine was adsorbed onto gold nanoparticles. The change in alanine crystal morphology was the same for alanine crystals with arginine-capped gold nanoparticles in that it grew toward the c-axis. Alanine crystals contained arginine-capped gold nanoparticles toward the c-axis. 相似文献
123.
124.
125.
T. Okai Y. Takashima N. Shiraishi N. Matsuoka 《Journal of Radioanalytical and Nuclear Chemistry》1984,81(1):161-165
A portable apparatus was developed for the rapid collection, separation and counting of krypton-85 in the environmental air samples. The apparatus consists of a molecular sieve trap for the elimination of H2O and CO2, a charcoal trap for the collection of krypton, a chromatographic column for the isolation of krypton in the air sample and a vial for the dissolution of krypton in the scintillation solution. With this apparatus, krypton can be collected from half a cubic meter of air with 94% recovery in about 3 hrs. The measurements of krypton-85 have been done several times in Fukuoka area between the periods Jan. 30, 1981 and Dec. 9, 1981. And then, the krypton-85 concentration was found to be approximately 21 pCi/m3 air. The results were compared with those obtained by foregin investigators. 相似文献
126.
We derive a quantum deformation of theW
N algebra and its quantum Miura transformation, whose singular vectors realize the Macdonald polynomials. 相似文献
127.
Kazuo Sugiyama Kohei Shiraishi Takako Matsumoto 《Journal of polymer science. Part A, Polymer chemistry》2003,41(13):1992-2000
Poly[2‐(methacryloyloxy)ethyl phosphorylcholine]s (PMPCs) with one pendant cholesteryl moiety at the polymer end (PMPC‐Chol‐I and PMPC‐Chol‐II) and two pendant cholesteryl moieties at both polymer ends as terminal groups (PMPC‐2Chol‐I and PMPC‐2Chol‐II) were prepared by the radical polymerization of 2‐(methacryloyloxy)ethyl phosphorylcholine initiated with 4,4′‐azobis[(3‐cholesteryl)‐4‐cyanopentanoate] in the presence of 2‐mercaptoethanol or thiocholesterol as chain‐transfer reagents, respectively. The self‐organization of PMPC‐Chol and PMPC‐2Chol was analyzed with fluorescence and 1H NMR measurements. The critical micelle concentrations of PMPC‐Chol‐I with a degree of polymerization (Pn) of 91 and of PMPC‐2Chol‐I with a Pn value of 165 were 250 and 27 mg L?1, respectively. The blood compatibility of PMPC‐2Chol was evaluated from the Michaelis constant (Km) for the enzymatic reaction of thrombin and a synthetic substrate, S‐2238, in the presence of PMPC‐2Chol. Km was 0.07, 0.05, and 0.56 for PMPC‐2Chol‐I with Pn = 165, PMPC‐2Chol‐II with Pn = 38, and PMPC (an intrinsic viscosity of 0.54 dL g?1) initiated with 2,2′‐azobisisobutyronnitrile in the absence of chain transfer agent, respectively. A mixture of PMPC‐2Chol‐II and cholesterol as a drug model formed a lamellar type of complex with an interplanar spacing of d = 35.2 Å. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1992–2000, 2003 相似文献
128.
Letters in Mathematical Physics - 相似文献
129.
Ichiro Seto Tomoaki Ohtsuki Iwao Sasase Shinsaku Mori 《Fiber and Integrated Optics》1993,12(4):381-395
We propose a Polarization Shift Keying (POLSK) phase diversity homo-dyne system with multiplying detection in coherent optical communications. The proposed system uses only one of three Stokes parameters, which is the phase difference between two orthogonal polarizations. Although such systems using only one Stokes parameter are very sensitive to polarization fluctuation, the proposed system becomes insensitive to the linear polarization fluctuation by using the multiplying detection with a combination of in-phase and quadrature optical signal components on two orthogonal polarizations. Furthermore, insensitivity to phase noise and offset frequency and attractiveness due to homodyne type in high-speed transmissions are maintained. The most attractive feature of the proposed system is that neither a polarization controller nor electronic feedback loop for matching the state of polarization (SOP) between transmitted and local oscillator (LO) optical signals is needed. We theoretically analyze the receiver sensitivity and the power penalties of the proposed system for the cases of the elliptical SOP of received optical signals and the imbalance optical 90° hybrid. 相似文献
130.
Yoshifumi Hanada Teizi Tanizaki Minoru Koga Hiroaki Shiraishi Mitsuyuki Soma 《Analytical sciences》2002,18(4):441-444
Liquid chromatography/mass spectrometry (LC/MS) has been applied to analyze N,N'-ethylenebisdithiocarbamate fungicides (EBDCs: manzeb, maneb and zineb) in environmental water samples. The EBDCs that are zinc and/or manganese salts are transformed into readily water-soluble sodium salts by adding an alkaline EDTA solution. The N,N'-ethylenebisdithiocarbamate anion is extracted into chloroform-hexane (3:1) as an ion pair with tetrabutylammonium, and then S-alkylated with methyl iodide. The extraction and derivatization are carried out at room temperature. The derivatized ethylenebisdithiocarbamic acid dimethyl ester is introduced into an LC/MS equipped with a negative ion electrospray ionization interface. Identification of the compound is performed with the specific quasi-molecular ion, and the quantitative analyses are carried out using the peak areas. The average recoveries and coefficients of variation of EBDCs at sub-ppb level are 79.1% and 29.3% (n = 6), respectively. The limit of detection based on standard deviation of 0.043 microg/L for manzeb is achieved. 相似文献