全文获取类型
收费全文 | 229篇 |
免费 | 4篇 |
专业分类
化学 | 67篇 |
晶体学 | 87篇 |
力学 | 1篇 |
数学 | 8篇 |
物理学 | 70篇 |
出版年
2023年 | 1篇 |
2022年 | 21篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 13篇 |
2011年 | 14篇 |
2010年 | 10篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 10篇 |
2006年 | 10篇 |
2005年 | 9篇 |
2004年 | 7篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1987年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有233条查询结果,搜索用时 15 毫秒
111.
D. M. Kheiker M. V. Kovalchuk V. N. Korchuganov Yu. N. Shilin V. A. Shishkov S. N. Sulyanov P. V. Dorovatovskiĭ S. V. Rubinsky A. A. Rusakov 《Crystallography Reports》2007,52(6):1108-1115
The design of the station for structural analysis of polycrystalline materials and single crystals (including nanoobjects and macromolecular crystals) on a synchrotron radiation beam from the superconducting wiggler of the Siberia-2 storage ring is described. The wiggler is constructed at the Budker Institute of Nuclear Physics of the Siberian Division of the Russian Academy of Sciences. The X-ray optical scheme of the station involves a (1, ?1) double-crystal monochromator with a fixed position of the monochromatic beam and a sagittal bending of the second crystal, segmented mirrors bent by piezoelectric motors, and a (2θ, ω, φ) three-circle goniometer with a fixed tilt angle. Almost all devices of the station are designed and fabricated at the Shubnikov Institute of Crystallography of the Russian Academy of Sciences. The Bruker APEX11 two-dimensional CCD detector will serve as a detector in the station. 相似文献
112.
A. E. Blagov M. V. Kovalchuk V. G. Kohn Yu. V. Pisarevsky 《Crystallography Reports》2006,51(5):729-733
The X-ray diffraction in the Laue geometry is investigated in germanium and silicon single crystals upon excitation of long-wavelength ultrasonic elastic strain waves traveling along the sample surface. The X-ray diffraction beam is bounded by a slit 0.2 mm in size, which is considerably less than the wavelength of the ultrasonic wave. The use of this slit makes it possible to separate crystal regions with a nearly homogeneous strain. As a consequence, the rocking curves stroboscopically measured in a double-crystal dispersionless scheme at different instants of time almost coincide with those for a perfect crystal with a lattice parameter varying in time. The rocking curves measured in a time-integrated mode turn out to be broadened, but their integrated intensities remain unchanged. Possible applications of the developed method are discussed. 相似文献
113.
Bricks JL Kovalchuk A Trieflinger C Nofz M Büschel M Tolmachev AI Daub J Rurack K 《Journal of the American Chemical Society》2005,127(39):13522-13529
Incorporation of a tailor-made size-restricted dithia-aza-oxa macrocycle, 1-oxa-4,10-dithia-7-aza-cyclododecane, via a phenyl linker into two fluorescent sensor molecules with electronically decoupled, rigidly fixed, and sterically preoriented architectures, a 1,3,5-triaryl-Delta2-pyrazoline and a meso-substituted boron-dipyrromethene (BDP), yields amplified fluorescence in the red-visible spectral range upon binding of Fe(III) ions. The response to Fe(III) and potentially interfering metal ions is studied in highly polar aprotic and protic solvents for both probes as well as in neat and buffered aqueous solution for one of the sensor molecules, the BDP derivative. In organic solvents, the fluorescence of both indicators is quenched by an intramolecular charge or electron transfer in the excited state and coordination of Fe(III) leads to a revival of their fluorescence without pronounced spectral shifts. Most remarkably, the unbound BDP derivative shows dual emission in water and can be employed for the selective ratiometric signaling of Fe(III) in buffered aqueous solutions. 相似文献
114.
Data are reported for the performance of subnanosecond high-pressure gas-discharge switches aimed at generating high-voltage
bipolar voltage pulses with a width of less than 1 ns, an amplitude of up to 200 kV, and a repetition rate of 100 Hz. Pulse
formers, in which the polarity of the current passing through the switch does not change in the course of switching, seem
to be the most appropriate. When the current changes sign, passing through zero, the effect of its momentary interruption
is observed. The explanation of this effect is that, when the voltage across the gap reverses, a certain time interval is
necessary for a cathode layer to form, which can transmit a high discharge current at a low voltage drop across the layer. 相似文献
115.
D. E. Gen K. B. Chernyshov K. A. Prokhorov G. Yu. Nikolaeva E. A. Sagitova P. P. Pashinin A. A. Kovalchuk A. N. Klyamkina P. M. Nedorezova V. A. Optov B. F. Shklyaruk 《Laser Physics》2010,20(6):1354-1367
The polarized Raman spectroscopy is employed in the study of structural modifications in the films of isotactic polypropylene (PP) whose chain contains ethylene, 1-butene, 1-hexene, 1-octene, and 4-metyl-pentene-1, which represents an isomer of 1-hexene. It is demonstrated that the phase and conformational compositions of copolymer molecules depend on the comonomer content and the side-chain length of the second monomer. The content of the PP molecules in the helical conformation in the crystalline and amorphous phases of the copolymers monotonically decreases with increasing content of the second monomer. The decrease in the content of helical macromolecules in the crystalline phase is faster than the decrease in the amorphous phase. At a certain content of comonomers, the total content of the helical fragments decreases with increasing length of the side chain of the second monomer. The structures and Raman spectra of the copolymers of propylene with 1-hexene and 4-methyl-1-pentene are similar. 相似文献
116.
Sergey I. Kovalchuk Nikolay A. Anikanov Olga M. Ivanova Rustam H. Ziganshin Vadim M. Govorun 《Analytica chimica acta》2015
Non-specific binding (NSB) is a well-known problem for any application that deals with ultralow analyte quantities. The modern nano-flow chromatography coupled tandem mass-spectrometry (nanoLC-MS/MS) works with the lowest conceivable analyte concentrations. However, while the NSB problem is widely accepted and investigated for metabolomics and single-peptide medicine-related assays, its impact is not studied for complex peptide mixtures in proteomic applications. In this work peptide NSB to a common plastic autosampler vial was studied for a model mixture of 46 synthetic peptides. A significant NSB level was demonstrated for total peptide concentrations of up to 1 mg mL−1. Different agents were tried for NSB suppression and compatibility with nanoLC-MS/MS analysis: a chaotropic agent, an amino acid mixture, a peptide mixture and a protein solution. The first two were inefficacious. The peptide matrix blocked NSB, however, it also led to analyte ionization suppression in nanoLC-MS/MS. The protein solution (0.1% BSA) efficiently eliminated NSB, while a trap-elute nanoHPLC configuration together with a small-pore reverse-phased sorbent effectively and quantitatively extracted the model peptides and depleted protein material from the sample. Higher protein concentration partially impeded peptide extraction. Thus, the 0.1% BSA solution might be regarded as an effective non-interfering blockader of NSB for sample resuspension and storage in an autosampler prior to LC-MS/MS analysis. 相似文献
117.
N.M. Kovalchuk A. Trybala V. Starov O. Matar N. Ivanova 《Advances in colloid and interface science》2014
Fluorosurfactants are the most effective compounds to lower the surface tension of aqueous solutions, but their wetting properties as related to low energy hydrocarbon solids are inferior to hydrocarbon trisiloxane surfactants, although the latter demonstrate higher surface tension in aqueous solutions. To explain this inconsistency available data on the adsorption of fluorosurfactants on liquid/vapour, solid/liquid and solid/vapour interfaces are discussed in comparison to those of hydrocarbon surfactants. The low free energy of adsorption of fluorosurfactants on hydrocarbon solid/water interface should be of a substantial importance for their wetting properties. 相似文献
118.
Dukhin SS Kovalchuk VI Aksenenko EV Miller R 《Advances in colloid and interface science》2008,137(1):45-56
The analysis of processes taking place in a steady pneumatic (dynamic) foam shows the possibility of different modes of surfactant accumulation within the top layers of bubbles due to rupture of external foam films. An increasing surfactant concentration within the top layers promotes the stabilisation of bubbles and the foam as a whole. Considering the balance of surfactant and water during the bursting of films it is possible to estimate the accumulated surfactant loss caused by a downwards flow through the Plateau borders of the subsurface bubble layer. This effect depends on the particular conditions, especially on the surfactant activity and concentration of the surfactant, water volume fraction in the foam and size of foam bubbles. The process of surfactant accumulation in the top foam bubble layer can be complicated due to the removal of part of the accumulated surfactant through transport with droplets spread out during bubble bursting. 相似文献
119.
Kateryna Fominova Taras Diachuk Dmitry Granat Taras Savchuk Vladyslav Vilchynskyi Oleksiy Svitlychnyi Vladyslav Meliantsev Igor Kovalchuk Eduard Litskan Vadym
V. Levterov Valentyn R. Badlo Ruslan I. Vaskevych Alla I. Vaskevych Andrii V. Bolbut Volodymyr V. Semeno Rustam Iminov Kostiantyn Shvydenko Anastasiia S. Kuznetsova Yurii V. Dmytriv Daniil Vysochyn Vasyl Ripenko Andrei A. Tolmachev Olexandra Pavlova Halyna Kuznietsova Iryna Pishel Petro Borysko Pavel K. Mykhailiuk 《Chemical science》2021,12(34):11294
A general approach to a new generation of spirocyclic molecules – oxa-spirocycles – was developed. The key synthetic step was iodocyclization. More than 150 oxa-spirocyclic compounds were prepared. Incorporation of an oxygen atom into the spirocyclic unit dramatically improved water solubility (by up to 40 times) and lowered lipophilicity. More potent oxa-spirocyclic analogues of antihypertensive drug terazosin were synthesized and studied in vivo.A general practical approach to a new generation of spirocyclic molecules – oxa-spirocycles – is developed. 相似文献
120.
M. V. Kovalchuk 《Crystallography Reports》2014,59(3):297-299
We are celebrating the 70th anniversary of the Shubnikov Institute of Crystallography. The institute has gone from being a small laboratory of piezoelectric crystals to a large internationally known scientific center. The 1990s was a decade of ruin, both literally and figuratively, for our institute; however, it is hard to believe that was the case when walking through the corridors of the institute today. 相似文献