全文获取类型
收费全文 | 1328篇 |
免费 | 27篇 |
国内免费 | 4篇 |
专业分类
化学 | 743篇 |
晶体学 | 20篇 |
力学 | 27篇 |
综合类 | 1篇 |
数学 | 40篇 |
物理学 | 528篇 |
出版年
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 14篇 |
2019年 | 11篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 21篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 60篇 |
2012年 | 57篇 |
2011年 | 87篇 |
2010年 | 59篇 |
2009年 | 43篇 |
2008年 | 96篇 |
2007年 | 95篇 |
2006年 | 96篇 |
2005年 | 74篇 |
2004年 | 66篇 |
2003年 | 55篇 |
2002年 | 48篇 |
2001年 | 29篇 |
2000年 | 28篇 |
1999年 | 14篇 |
1998年 | 11篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 13篇 |
1994年 | 25篇 |
1993年 | 19篇 |
1992年 | 29篇 |
1991年 | 10篇 |
1990年 | 20篇 |
1989年 | 22篇 |
1988年 | 16篇 |
1987年 | 10篇 |
1986年 | 18篇 |
1985年 | 18篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 6篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1969年 | 9篇 |
1968年 | 5篇 |
排序方式: 共有1359条查询结果,搜索用时 31 毫秒
11.
Hiroshi Aoki Ken Hosoya Tomohisa Norisuye Nobuo Tanaka Daisuke Tokuda Norio Ishizuka Kazuki Nakanishi 《Journal of polymer science. Part A, Polymer chemistry》2006,44(2):949-958
An investigation was made of the gelation of dimethacrylate‐type crosslinking agents in view of an application for separation media. The study mainly centered on a crosslinking agent, glycerol dimethacrylate (GDMA), which is relatively hydrophilic because of a hydroxyl group in the middle of its structure. The gelation of GDMA was compared with that of other hydrophobic crosslinking agents such as ethylene glycol dimethacrylate and 1,6‐hexanediol dimethacrylate. The diluents used in the study were toluene, toluene with methanol, and cyclohexanol. The gelation was observed in real time with a charge coupled device camera and dynamic light scattering (DLS). Also, the separated dry gels were extensively characterized with scanning electron microscopy, BET (N2 absorption and desorption isotherm), and Fourier transform infrared. DLS analysis showed a stronger molecular interaction of GDMA gelation in toluene, whereas this interaction was much weaker in an alcoholic solvent such as toluene with methanol or cyclohexanol. This indicated that GDMA gelation might proceed through hydrogen bonding as well as a crosslinking reaction of vinyl groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 949–958, 2006 相似文献
12.
Yosuke Aoki 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2006,82(7):251-256
Addition of azurocidin, a protein in granulocytes similar to serine proteases but has no protease activity because of replacement of the active serine residue by glycine, to the incubation mixture containing medullasin induced elastinolytic activity of medullasin. Both medullasin and human leukocyte elastase were already shown to have negligible elastinolytic activity (Aoki, Y. et al. J. Biochem. 114, 122, 1993). Elastinolytic activity of medullasin was induced dose-dependently by the addition of azurocidin. Medullasin activity determined by using apo-ornithine transaminase or casein as substrates or that by N-methoxy-succinyl-(Ala)2-Pro-Val-p-nitroanilide as substrate remained unchanged when azurocidin was added to the tube containing medullasin. Therefore, azurocidin is considered to cause an appearance of elastinolytic activity of medullasin without affecting the protease activity of it. 相似文献
13.
14.
15.
Takuji Hirose Kumiko Naito Megumi Nakahara Hiroaki Shitara Yoshio Aoki Hiroyuki Nohira Bruce W. Baldwin 《Journal of inclusion phenomena and macrocyclic chemistry》2002,43(1-2):87-93
Two Kemp's acid diamides were synthesized and applied to chiral amine recognition using 1H NMR analysis. One derivative based on 1-(1-naphthyl)ethylamine had good chiral recognition of six amines and was useful to determine the optical purity for three amines, i.e., methylbenzylamine, 1-(1-naphthyl)ethylamine and 1- henylpropylamine,however, the cyclohexylethylamine derivative showed little discrimination for the amines studied. Together with the results for alkylamines, it was shown that aromatic structure was important for aromatic shielding anisotropy and –– interactions between host and guest. The structure of the 1-(1-naphthyl)ethylamine derivative in solution was also considered based on 1H NMR data and computer simulation. 相似文献
16.
Tasuku Nakajima Takayuki Kurokawa Hidemitsu Furukawa Qiu Ming Yu Yoshimi Tanaka Yoshihito Osada Jian Ping Gong 《高分子科学》1996,(1):1-9
Living tissues work with fantastic functions in soft and wet gel-like state. Thus, hydrogels have attracted much attention as excellent soft & wet materials, suitable for making artificial organs for medical treatments.However, conventional hydrogels are mechanically too weak for practical uses. We have created double network (DN) hydrogels with extremely high mechanical strength in order to overcome this problem. DN gels are interpenetrating network (IPN) hydrogels consisting of rigid polyelectrolyte and soft neutral polymer. Their excellent mechanical properties cannot be explained by the standard fracture theories. In this paper, we discuss about the toughening mechanism of DN gels in accordance with their characteristic behavior, such as large hysteresis and necking phenomenon. We also describe the results on tissue engineering application of DN gels. 相似文献
17.
T. Takeuchi Y. Nakano A. Aoki S. Ohmori T. Tsukatani 《Journal of Radioanalytical and Nuclear Chemistry》1987,112(1):259-272
Human hair collected from the mercury, arsenic and cadmium polluted areas has been analysed by instrumental neutron activation method. The concentrations of 27 elements were compared with those of normal Japanese. Correlation coefficients of logarithmic concentrations between the elements were calculated and their significance levels were determined. Factor contribution and factor loadings of the elements were calculated for each factor by making use of principal component analysis. The factor score of each sample was also calculated for each factor to examine the effects of the contamination by heavy metals on individuals. 相似文献
18.
Y. Adachi K. Aoki 《Colloids and surfaces. A, Physicochemical and engineering aspects》2003,230(1-3):37-44
Standardized mixing procedure was applied to the analysis of flocculation of polystyrene latex (PSL) particles with polyelectrolytes. After confirming the initial enhancement of flocculation rate in the very beginning followed by abrupt stop with excess dosage, attention was shifted to the system of moderate dosage. In the former, effects of ionic strength were further analyzed to find the consistency with adsorption isotherm. In the latter, flocculation started slowly in the beginning, sometime slower than salt-induced rapid coagulation, however, the rate gradually increases in the middle stage. Often, the increased rate exceeds that of salt-induced rapid coagulation. This behavior emerged more clearly in the case of lower ionic strength. This is the indication that the rate of relaxation of polymer on the colloidal surface is a function of surface coverage and ionic strength. The ultimate degree of flocculation is usually higher than that observed for excess dosage. The size distribution of flocs was also examined, however, no clear difference between different experimental conditions was confirmed for the same degree of flocculation. 相似文献
19.
20.
Hideki Namba Okihiro Tokunaga Tadashi Tanaka Yoshimi Ogura Shinji Aoki Ryoji Suzuki 《Radiation Physics and Chemistry》1993,42(4-6):669-672
The fundamental research work with simulated coal-fired flue gas was performed in JAERI to get basic data for electron beam treatment of flue gas from thermal power plants in Japan. The standard condition of the experiments was set to be the same as that of next large scale pilot test in Nagoya. The concentrations of NOx and SOx were 225 ppm and 800 ppm, respectively. The temperature of the system was 65°C. The effect of multiple irradiation was observed for NOx removal. The target SOx and NOx removals (94% and 80%, respectively) with low NH3 leakage (less than 10 ppm) were achieved at 9 kGy irradiation with 0.9 NH3 stoichiometry during 7 hours continuous operation. The facility for the pilot plant (12,000 Nm3/hr) has just built at the site of Shin-Nagoya power plant of Chubu Electric Power Company and will be started in full operation in November 1992. 相似文献