全文获取类型
收费全文 | 495篇 |
免费 | 20篇 |
国内免费 | 6篇 |
专业分类
化学 | 405篇 |
晶体学 | 4篇 |
力学 | 11篇 |
数学 | 28篇 |
物理学 | 73篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 13篇 |
2015年 | 14篇 |
2014年 | 7篇 |
2013年 | 25篇 |
2012年 | 14篇 |
2011年 | 31篇 |
2010年 | 13篇 |
2009年 | 15篇 |
2008年 | 30篇 |
2007年 | 29篇 |
2006年 | 35篇 |
2005年 | 31篇 |
2004年 | 34篇 |
2003年 | 25篇 |
2002年 | 31篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 12篇 |
1997年 | 6篇 |
1996年 | 11篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1973年 | 5篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有521条查询结果,搜索用时 15 毫秒
91.
92.
Soh N Yoshida K Nakajima H Nakano K Imato T Fukaminato T Irie M 《Chemical communications (Cambridge, England)》2007,(48):5206-5208
A fluorescent photochromic compound, composed of diarylethene, fluorescein and succinimidyl ester units, was developed for the controllable fluorescent labeling of biomolecules based on a small molecule. 相似文献
93.
Zhang R Nakajima H Soh N Nakano K Masadome T Nagata K Sakamoto K Imato T 《Analytica chimica acta》2007,600(1-2):105-113
A rapid and sensitive immunoassay based on a sequential injection analysis (SIA) using magnetic microbeads for the determination of alkylphenol polyethoxylates (APnEOs) is described. An SIA system was constructed from a syringe pump, a switching valve, a flow-through type immunoreaction cell equipped with a photon counting unit and a neodymium magnet. Magnetic beads, to which an anti-APnEOs monoclonal antibody was immobilized, were used as a solid support in an immunoassay. The introduction, trapping and release of the magnetic beads in and from the immunoreaction cell were controlled by means of a neodymium magnet and adjusting the flow of a carrier solution. The immunoassay was based on an indirect competitive immunoreaction of an anti-APnEOs monoclonal antibody immobilized on the magnetic beads with a sample APnEOs and a horseradish peroxidase (HRP)-labeled APnEOs in the same sample solution, and was based on the subsequent chemiluminscence reaction of HRP on the magnetic microbeads with a luminol solution containing hydrogen peroxide and p-iodophenol. The anti-APnEOs antibody was immobilized on the magnetic microbeads by coupling the antibody with the magnetic beads after activation of a carboxylate moiety on the surface of the magnetic beads that had been coated with a polylactic acid film. The antibody immobilized magnetic beads were introduced in the immunoreaction cell and trapped in it by the neodymium magnet, which was equipped beneath the immunoreaction cell. An APnEOs sample solution containing the HRP-labeled APnEOs at a constant concentration, and a luminol solution containing hydrogen peroxide and p-iodophenol were sequentially introduced into the immunoreaction cell, according to an SIA programmed sequence. Chemiluminescence emission was monitored by means of a photon counting unit located at the upper side of the immunoreaction cell by collecting the emitted light with a lens. A typical sigmoidal calibration curve was obtained, when the logarithm of the concentration of APnEOs was plotted against the chemiluminescence intensity as the number of photons in 100 ms using standard APnEOs sample solutions at various concentrations (0–1000 ppb) under optimum conditions. The lower detection limit defined as IC80 is ca 10 ppb. The time required for analysis is less than 15 min per a sample. The present method was successfully applied to the determination of APnEOs in river water. 相似文献
94.
Methane derivatives of CH(3)-X (X: H, F, Cl, Br, I, and CN) were ionized and fragmented by an intense femtosecond laser with a 40 fs pulse at 0.8 microm in intensities of 10(13)-10(15) W cm(-2). The curves of the ionization yields of CH(3)-X versus laser intensities have been found to be fitted with an atomic ionization theory (the theory of Perelomov, Popov, and Terent'ev) that has been established to reproduce experimental results well for rare gas atoms. The saturation intensities have been reproduced within a factor of 1.6 of the calculated ones. For molecules with low ionization potentials such as amines, another atomic ionization theory (the theory of Ammosov, Delone, and Krainov) reproduced the saturation intensities. The atomiclike ionization behavior of molecules indicates that the fragmentation occurs after the ionization. The fragmentation mechanisms after the ionization of some molecular ions are discussed. 相似文献
95.
96.
97.
On the basis of the quantum white noise theory we introduce the notion of creation- and annihilation-derivatives of Fock space
operators and study the differentiability of white noise operators. We define the Hitsuda–Skorohod quantum stochastic integrals
by the adjoint actions of quantum stochastic gradients and show explicit formulas for their creation- and annihilation-derivatives.
As an application, we derive direct formulas for the integrands in the quantum stochastic integral representation of a regular
quantum martingale.
Work supported by the Korea–Japan Basic Scientific Cooperation Program “Noncommutative Stochastic Analysis and Its Applications
to Network Science.” 相似文献
98.
99.
By the use of catalytic amounts of a nickel salt and a 1,3-butadiene, primary and secondary alkyl Grignard reagents undergo cross-coupling with alkyl bromides, iodide, and tosylate carrying a functional group such as amide, ester, and ketone at 0 °C in THF. The present procedure provides a simple, convenient, and practical method for construction of carbon chains in the presence of various functional groups. PhMgBr also gave the corresponding coupling product in a moderate yield. 相似文献
100.
De Lie An Qiang Chen Hong Yan Nobuaki Miura Kenji Monde Junzo Otera 《Tetrahedron letters》2009,50(15):1689-1692
Stereochemical study of cyclophynes, which is otherwise rather difficult to perform, can be achieved by vibrational CD spectroscopy. 相似文献