全文获取类型
收费全文 | 209篇 |
免费 | 8篇 |
国内免费 | 3篇 |
专业分类
化学 | 110篇 |
晶体学 | 1篇 |
力学 | 7篇 |
数学 | 51篇 |
物理学 | 51篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 11篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 6篇 |
2012年 | 19篇 |
2011年 | 22篇 |
2010年 | 13篇 |
2009年 | 8篇 |
2008年 | 15篇 |
2007年 | 12篇 |
2006年 | 16篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1890年 | 1篇 |
排序方式: 共有220条查询结果,搜索用时 0 毫秒
31.
Noah Arbesfeld 《Discrete Mathematics》2013,313(22):2614-2625
32.
We investigate the continuity of expected exponential utility maximization with respect to perturbation of the Sharpe ratio of markets. By focusing only on continuity, we impose weaker regularity conditions than those found in the literature. Specifically, we require, in addition to the V-compactness hypothesis of Larsen and ?itkovi? (2007) [13], a local bmo hypothesis, a condition which is essentially implicit in the setting of [13]. For markets of the form S=M+∫λd〈M〉, these conditions are simultaneously implied by the existence of a uniform bound on the norm of λ⋅M in a suitable bmo space. 相似文献
33.
We have designed, microfabricated, and characterized a diffractive optical element that reproduces the infrared spectrum of HF from 3600 to 4300 cm(-1) . The reflection-mode diffractive optic consists of 4096 lines, each 4.5mum wide, at 16 discrete depths relative to the substrate from 0 to 1.2 mum and was fabricated upon a silicon wafer by anisotropic reactive ion-beam etching in a four-mask-level process. We envisage the use of diffractive optical elements of this type as the basis for a new class of miniaturized, remote chemical sensor systems based on correlation spectroscopy. 相似文献
34.
A. K. Dadivanyan O. V. Noah D. N. Chausov Yu. A. Ignatov 《Polymer Science Series B》2008,50(1-2):39-43
The contribution of short-range orientation order to the chemical potentials of components in a polymer-solvent system was determined. The temperature dependence of the degree of orientation of solvent molecules relative to polymer chains in a polyisobutylene-benzene system was obtained. It was shown that the short-range order in the polymer-solvent system fails with temperature to a much lesser extent than in the pure solvent. The expressions for the upper and lower critical solution temperatures with allowance for the contribution of short-range order to the entropy and the free energy of solution, as well as to the chemical potentials of components, were found. It was demonstrated that, in the polymer-solvent system, two upper and two lower critical solution temperatures can exist. 相似文献
35.
Poulsen A William A Lee A Blanchard S Teo E Deng W Tu N Tan E Sun E Goh KL Ong WC Ng CP Goh KC Bonday Z 《Journal of computer-aided molecular design》2008,22(12):897-906
The Aurora family of serine/threonine kinases are mitotic regulators involved in centrosome duplication, formation of the
bipolar mitotic spindle and the alignment of the chromosomes along the spindle. These proteins are frequently overexpressed
in tumor cells as compared to normal cells and are therefore potential therapeutic oncology targets. An Aurora A high throughput
screen revealed a promising sub-micromolar indazole-benzimidazole lead. Modification of the benzimidazole portion of the lead
to a C2 linker with a phenyl ring was proposed to achieve novelty. Docking revealed that a conjugated linker was optimal and
the resulting compounds were equipotent with the lead. Further structure-guided optimization of substituents on the 5 & 6
position of the indazole led to single digit nanomolar potency. The homology between the Aurora A & Aurora B kinase domains
is 71% but their binding sites only differ at residues 212 & 217 (Aurora A numbering). However interactions with only the
latter residue may be used for obtaining selectivity. An analysis of published Aurora A and Aurora B X-ray structures reveals
subtle differences in the shape of the binding sites. This was exploited by introduction of appropriately sized substituents
in the 4 & 6 position of the indazole leading to Aurora B selective inhibitors. Finally we calculate the conformational energy
penalty of the putative bioactive conformation of our inhibitors and show that this property correlates well with the Aurora
A binding affinity. 相似文献
36.
37.
38.
Noah Z. Burns Phil S. Baran Prof. Dr. Reinhard W. Hoffmann Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(16):2854-2867
Stimulus package for organic synthesis : The economy of step and atom usage has been widely reviewed and acknowledged as being useful frameworks to evaluate the efficiency of synthesis. This Review brings to attention another form of economy which should be considered in the planning and evaluation of a multistep synthesis: redox economy. Several guidelines and examples are included to illustrate the logic of this approach and to stimulate the design of syntheses.
39.
Robinson NE Zabrouskov V Zhang J Lampi KJ Robinson AB 《Rapid communications in mass spectrometry : RCM》2006,20(23):3535-3541
After synthesis and folding, proteins undergo many post-synthetic modifications, including cleavage, oxidation, glycosylation, methylation, racemization, phosphorylation, and deamidation. Of these modifications, non-enymatic deamidation is the most prevalent. Each asparaginyl and glutaminyl residue in a protein is a miniature molecular clock that deamidates with a genetically determined half-time. These half-times vary from a few hours to more than a century, depending on a primary, secondary, tertiary, and quaternary structure near the amide residue. It has been suggested that these clocks regulate many biological processes. A few such processes have been discovered. These discoveries have been difficult because deamidation is inconvenient to measure. While most post-synthetic changes are easily measured by mass spectrometry, deamidation increases molecular mass by only one nominal Dalton, so the deamidated isotopic envelope overlaps the undeamidated isotopic envelope. While peptide deamidation rate determination through deconvolution of these envelopes has been accomplished for several hundred peptides, deconvolution becomes more difficult as the molecular weight increases. In high-resolution mass spectrometers, this deconvolution is possible for larger molecules and an alternative method based on the 19 mDa mass defect between the deamidated envelope and the isotopic envelope of protein fragments can also be utilized. We herein report a comparison of the envelope deconvolution and the mass defect methods for measurement of deamidation in human eye lens crystallins, with special emphasis on betaB2 crystallin and gammaS crystallin. Measurement of extent of deamidation of betaB2 crystallin in a 7 Tesla ion cyclotron resonance Fourier transform mass spectrometer is found to be accurate to a relative standard deviation in a single measurement of about 4% for each method. The envelope deconvolution method is further illustrated by detection of deamidation in intact gammaS crystallin, a 20 904 Da protein, and discovery of the principal gammaS deamidation site. 相似文献
40.
Matthew R. Begley Noah R. Philips Brett G. Compton David V. Wilbrink Robert O. Ritchie Marcel Utz 《Journal of the mechanics and physics of solids》2012,60(8):1545-1560
This paper describes a micromechanical analysis of the uniaxial response of composites comprising elastic platelets (bricks) bonded together with thin elastic perfectly plastic layers (mortar). The model yields closed-form results for the spatial variation of displacements in the bricks as a function of constituent properties, which can be used to calculate the effective properties of the composite, including elastic modulus, strength and work-to-failure. Regime maps are presented which indicate critical stresses for failure of the bricks and mortar as a function of constituent properties and brick architecture. The solution illustrates trade-offs between elastic modulus, strength and dissipated work that are a result of transitions between various failure mechanisms associated with brick rupture and rupture of the interfaces. Detailed scaling relationships are presented with the goal of providing material developers with a straightforward means to identify synthesis targets that balance competing mechanical behaviors and optimize material response. Ashby maps are presented to compare potential brick and mortar composites with existing materials, and identify future directions for material development. 相似文献