全文获取类型
收费全文 | 574篇 |
免费 | 15篇 |
国内免费 | 3篇 |
专业分类
化学 | 390篇 |
晶体学 | 4篇 |
力学 | 3篇 |
数学 | 39篇 |
物理学 | 156篇 |
出版年
2022年 | 7篇 |
2020年 | 3篇 |
2019年 | 10篇 |
2017年 | 3篇 |
2016年 | 14篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 15篇 |
2012年 | 26篇 |
2011年 | 30篇 |
2010年 | 17篇 |
2009年 | 18篇 |
2008年 | 22篇 |
2007年 | 27篇 |
2006年 | 34篇 |
2005年 | 18篇 |
2004年 | 17篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 16篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 11篇 |
1994年 | 12篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 13篇 |
1985年 | 18篇 |
1984年 | 18篇 |
1983年 | 4篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 11篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1973年 | 12篇 |
1971年 | 4篇 |
1926年 | 2篇 |
排序方式: 共有592条查询结果,搜索用时 15 毫秒
131.
Akito Nakai Dr. Takayuki Tanaka Prof. Dr. Atsuhiro Osuka 《Angewandte Chemie (International ed. in English)》2023,62(28):e202302662
Internally-bridged octaphyrin(1.1.1.1.1.1.1.1) underwent a rearrangement to meso-meso linked porphyrin dimer as a new metamorphosis. Extensive examination suggests that hydride-addition is a key step for the rearrangements to afford thermodynamically more stable porphyrin framework. Further, β-tetrabromo[36]octaphyrin was transformed to meso-meso, β-β, β-β triply linked porphyrin dimer via a similar mechanism combined with Pd-mediated reductive homocoupling. 相似文献
132.
Yuichi Shimoikeda Hiroaki Utsumi Koji Saito Tadashi Shimizu Toshihito Nakai 《Analytical sciences》2007,23(8):1007-1009
A method using fullerene for adjusting the NMR spectral resolution for multiple quantum magic angle spinning (MQMAS) experiments is proposed. To observe its (13)C MAS signal, it is not necessary to apply (1)H decoupling, unavailable with single-resonance MQMAS probes. Although (13)C T(1) of fullerene is rather long, a recycle time of 5 s in shimming yields its signal with sufficiently high sensitivity if setting the appropriate Ernst angles corresponding to magnetic fields. It is demonstrated that so-adjusted high resolution is reflected in the (87)Rb MQMAS spectra of RbNO(3). 相似文献
133.
Hiromitsu Kiriyama Michiaki Mori Yoshiki Nakai Takuya Shimomura Manabu Tanoue Atushi Akutsu Hajime Okada Tomohiro Motomura Shuji Kondo Shuhei Kanazawa Akito Sagisaka Jinglong Ma Izuru Daito Hideyuki Kotaki Hiroyuki Daido Sergei Bulanov Toyoaki Kimura Toshiki Tajima 《Optics Communications》2009,282(4):625-2346
We demonstrate a high-contrast, high-intensity double chirped-pulse amplification (CPA) Ti:sapphire laser system using an optical parametric chirped-pulse (OPCPA) pre- amplifier. By injecting cleaned microjoule seed pulses into the OPCPA, a temporal contrast greater than 1010 within picosecond times before the main femtosecond pulse is demonstrated with an output pulse energy of 1.7 J and a pulse duration of 30 fs, corresponding to a peak power of 60 TW at a 10 Hz repetition rate. This system uses a cryogenically-cooled Ti:sapphire final amplifier and generates focused peak intensities in excess of 1020 W/cm2. 相似文献
134.
135.
The relationship between the thermal history and the waiting time in nucleation decided for the aqueous solution of sodium chlorate was verified for the aqueous solution of copper sulfate using pilot crystallizers. The following items were clarified as the result of the experiments.
- (1) The cooling method is more stable to nucleation in comparison with the vacuum cooling method even at the same operational conditions.
- (2) The desirable effect of the thermal history is recognized only in the case in which the solution is heated up to a high degree of undersaturation.
- (3) The residence time at an undersaturated state has an important role to dissociate embryos in solution.
136.
137.
An accurate method for measuring the wafer surface height is required for wafer inspection systems to adjust the focus of inspection optics quickly and precisely. A method for projecting a laser spot onto the wafer surface obliquely and for detecting its image displacement using a one-dimensional position-sensitive detector is known, and a variety of methods have been proposed for improving the accuracy by compensating the measurement error due to the surface patterns. We have developed a simple and accurate method in which an image of a reticle with eight slits is projected on the wafer surface and its reflected image is detected using an image sensor. The surface height is calculated by averaging the coordinates of the images of the slits in both the two directions in the captured image. Pattern-related measurement error was reduced by applying the coordinates averaging to the multiple-slit-projection method. Accuracy of better than 0.35 μm was achieved for a patterned wafer at the reference height and ±0.1 mm from the reference height in a simple configuration. 相似文献
138.
139.
140.
Lesbani A Kondo H Yabusaki Y Nakai M Yamanoi Y Nishihara H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(45):13519-13527
A convenient procedure has been developed for the preparation of Group 14 compounds by integrated palladium-catalyzed cross-coupling of aromatic iodides with the corresponding Group 14 hydrides in the presence of a base. The reaction conditions can be applied to the cross-coupling of tertiary, secondary, and primary Group 14 compounds. In most cases, the desired arylated products were obtained in synthetically useful yields. Even in the case of aryl iodides containing OH, NH(2), CN, or CO(2)R groups, the reactions proceeded with good to high yields with tolerance of these reactive functional groups. A possible application of this method is the unique synthesis of a fungicidal diarylmethyl(1H-1,2,4-triazol-1-ylmethyl)silane derivative. 相似文献