全文获取类型
收费全文 | 151篇 |
免费 | 7篇 |
专业分类
化学 | 94篇 |
晶体学 | 1篇 |
力学 | 6篇 |
数学 | 11篇 |
物理学 | 46篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 3篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 3篇 |
排序方式: 共有158条查询结果,搜索用时 31 毫秒
91.
92.
We introduce the notion of asymmetric programmable hash functions (APHFs, for short), which adapts Programmable hash functions, introduced by Hofheinz and Kiltz (Crypto 2008, Springer, 2008), with two main differences. First, an APHF works over bilinear groups, and it is asymmetric in the sense that, while only secretly computable, it admits an isomorphic copy which is publicly computable. Second, in addition to the usual programmability, APHFs may have an alternative property that we call programmable pseudorandomness. In a nutshell, this property states that it is possible to embed a pseudorandom value as part of the function’s output, akin to a random oracle. In spite of the apparent limitation of being only secretly computable, APHFs turn out to be surprisingly powerful objects. We show that they can be used to generically implement both regular and linearly-homomorphic signature schemes in a simple and elegant way. More importantly, when instantiating these generic constructions with our concrete realizations of APHFs, we obtain: (1) the first linearly-homomorphic signature (in the standard model) whose public key is sub-linear in both the dataset size and the dimension of the signed vectors; (2) short signatures (in the standard model) whose public key is shorter than those by Hofheinz–Jager–Kiltz (Asiacrypt 2011, Springer, 2011) and essentially the same as those by Yamada et al. (CT-RSA 2012, Springer, 2012). 相似文献
93.
Inside Cover: Natural Abundance 15N and 13C Solid‐State NMR Chemical Shifts: High Sensitivity Probes of the Halogen Bond Geometry (Chem. Eur. J. 47/2016)
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
94.
Gerardo Perozziello Giuseppina Simone Natalia Malara Rosanna La Rocca Rossana Tallerico Rossella Catalano Francesca Pardeo Patrizio Candeloro Giovanni Cuda Ennio Carbone Enzo Di Fabrizio 《Electrophoresis》2013,34(13):1845-1851
In this study, we propose a fast, simple method to biofunctionalise microfluidic systems for cellomic investigations based on micro‐fluidic protocols. Many available processes either require expensive and time‐consuming protocols or are incompatible with the fabrication of microfluidic systems. Our method differs from the existing since it is applicable to an assembled system, uses few microlitres of reagents and it is based on the use of microbeads. The microbeads have specific surface moieties to link the biomolecules and couple cell receptors. Furthermore, the microbeads serve as arm spacer and offer the benefit of the multi‐valent interaction. Microfluidics was adapted together with topology and biochemistry surface modifications to offer the microenvironment for cellomic studies. Based on this principle, we exploit the streptavidin–biotin interaction to couple antibodies to the biofunctionalised microfluidic environment within 5 h using 200 μL of reagents and biomolecules. We selected the antibodies able to form complexes with the MHC class I (MHC‐I) molecules present on the cell membrane and involved in the immune surveillance. To test the microfluidic system, tumour cell lines (RMA) were rolled across the coupled antibodies to recognise and strip MHC‐I molecules. As result, we show that cell rolling performed inside a microfluidic chamber functionalised with beads and the opportune antibody facilitate the removal of MHC class I molecules. We showed that the level of median fluorescent intensity of the MHC‐I molecules is 300 for cells treated in a not biofunctionalised surface. It decreased to 275 for cells treated in a flat biofunctionalised surface and to 250 for cells treated on a surface where biofunctionalised microbeads were immobilised. The cells with reduced expression of MHC‐I molecules showed, after cytotoxicity tests, susceptibility 3.5 times higher than normal cells. 相似文献
95.
Dr. Valeria Di Tullio Dr. Nicholas Zumbulyadis Dr. Silvia A. Centeno Prof. Jaclyn Catalano Molly Wagner Prof. Cecil Dybowski 《Chemphyschem》2020,21(1):113-119
Heavy metal carboxylate degradation severely affects thousands of oil paintings. Relative humidity has been reported to accelerate the rate of the reactions. To evaluate its role further, water diffusion and molecular mobility of protons in linseed oil-based lead white paints were studied by unilateral NMR and 1H HRMAS spectroscopy. The results indicate that exposure to high %RH for relatively long times affects the dynamics of the oil paint's mobile fraction and that the effect is more pronounced as the thickness of the film increases. It was found that the paint can absorb appreciable amounts of water and has a porosity of approximately 6 % available for the diffusion of water, for which a regime of restricted diffusion was observed. Furthermore, the presence of bound and free-moving water, due to the possible formation of hydrated ionic-group clusters, supports the hypothesis of a polymeric/ionomeric network, as well as regions of essentially water free to move as in the bulk. The findings allow a better understanding of the role of water as a factor activating the degradation process in linseed oil-based lead white paints. 相似文献
96.
Domenico A. Catalano Marston D. E. Conder Shao Fei Du Young Soo Kwon Roman Nedela Steve Wilson 《Journal of Algebraic Combinatorics》2011,33(2):215-238
An orientably-regular map is a 2-cell embedding of a connected graph or multigraph into an orientable surface, such that the
group of all orientation-preserving automorphisms of the embedding has a single orbit on the set of all arcs (incident vertex-edge
pairs). Such embeddings of the n-dimensional cubes Q
n
were classified for all odd n by Du, Kwak and Nedela in 2005, and in 2007, Jing Xu proved that for n=2m where m is odd, they are precisely the embeddings constructed by Kwon in 2004. Here, we give a classification of orientably-regular
embeddings of Q
n
for all n. In particular, we show that for all even n (=2m), these embeddings are in one-to-one correspondence with elements σ of order 1 or 2 in the symmetric group S
n
such that σ fixes n, preserves the set of all pairs B
i
={i,i+m} for 1≤i≤m, and induces the same permutation on this set as the permutation B
i
↦
B
f(i) for some additive bijection f:ℤ
m
→ℤ
m
. We also give formulae for the numbers of embeddings that are reflexible and chiral, respectively, showing that the ratio
of reflexible to chiral embeddings tends to zero for large even n. 相似文献
97.
David M. Ermert Dr. Ion Ghiviriga Prof. Dr. Vincent J. Catalano Prof. Dr. Jason Shearer Prof. Dr. Leslie J. Murray 《Angewandte Chemie (International ed. in English)》2015,54(24):7047-7050
The reaction of [Zn3Cl3 L ], in which L 3? is a tris(β‐diketiminate) cyclophane, with K(sBu)3BH afforded [Zn3(μ‐H)3 L ] ( 2 ), as confirmed by NMR spectroscopy, NOESY, and X‐ray crystallography. The complex 2 was air‐stable and unreactive towards water, methanol, and other substrates (e.g., nitriles) at room temperature over 24 h but reacted with CO2 (ca. 1 atm) to generate [Zn3(μ‐H)2(μ‐1,1‐O2CH)] ( 3 ). In contrast, [Zn3(OH)3 L ] ( 4 ) was found to be unreactive toward CO2 over the course of several days at 90 °C. 相似文献
98.
Reversed-phase nonporous silica (RP-NPS) of 1.5 microm dp is employed to demonstrate rapid and efficient separations in packed capillary electrochromatography (CEC). Two methods for packing capillaries and two techniques to manufacture frits used to hold the packing in place are evaluated for their effect upon separation performance using polyaromatic hydrocarbons (PAHs) and polar neutral pharmaceutical compounds. Attention is given to conditioning of the packed capillaries for high efficiency separations without necessity for sodium dodecyl sulfate (SDS). Separation conditions for the nonporous materials were modified from those previously determined on porous reversed-phase silica. Feasibility for method development and validation of a parent pharmaceutical compound and related impurities in the range of 0.1-120% of a 5 mg/mL concentration was assessed and reported. An approach to improving detection sensitivity through use of large-bore capillaries is briefly discussed. 相似文献
99.
Favia Pietro Vulpio Michele Marino Rosamaria d'Agostino Riccardo Mota Rogerio Pinto Catalano Massimo 《Plasmas and Polymers》2000,5(1):1-14
Ag-containing polyethyleneoxide (PEO)-like thin films have been deposited in Radio Frequency Glow Discharges fed with vapors of diethyleneglycol-dimethylether and argon. Proper experimental conditions have been utilized in order to fragment the monomer in the glow and, at the same time, sputter Ag from the silver RF cathode of the reactor, in a way that polyethyleneoxide(PEO)-like coatings with embedded Ag clusters have been deposited at the ground electrode. The compostion of the coatings has been investigated by means of different techniques; the plasma process has been investigated by means of Actinometric Optical Emission Spectroscopy. A correlation has been found between the amount of silver embedded in the coatings and that sputtered in the discharge, monitored by actinometry, that could eventually be utilized to control in situ the deposition process. 相似文献
100.
M. Lomascolo M. De Giorgi M. Anni R. Rinaldi A. Passaseo M. De Vittorio A. Taurino M. Catalano A. Lorenzoni L. C. Andreani R. Cingolani 《Physica E: Low-dimensional Systems and Nanostructures》2000,7(3-4)
In this work we present a time-resolved magneto-luminescence investigation (up to 8 T) of InGaAs V-shaped quantum wires (QWRs) with different In content, as a function of temperature and the applied magnetic field. The states of the wires were investigated by CW PL and quantitatively compared with the results of a numerical solution of the two-dimensional Schrodinger equation. Time-resolved experiments performed in magnetic field at different temperatures indicate the existence of a competition between the electron confinement occurring in deep QWRs at low temperature, and the magnetic confinement prevailing in shallower QWRs. 相似文献