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61.
62.
For the mappings
f:D ? D¢, D, D¢ ì \mathbbRn f:D \to D',\,\,D,\,\,D' \subset {\mathbb{R}^n}
, n ≥ 2, satisfying certain geometric conditions in the fixed domain D, we have proved estimates of the form K
I
(x, f) ≤ Q(x) almost everywhere, where K
I
(x, f) is the inner dilatation of f at a point x, and Q(x) is a fixed real-valued function responsible for the “control” over a distortion of the families of curves in D at a mapping f. 相似文献
63.
A. Yu. Ziganshina G. R. Nasybullina V. V. Yanilkin N. V. Nastapova D. E. Korshin Yu. S. Spiridonova R. R. Kashapov M. Grüner W. D. Habicher A. A. Karasik A. I. Konovalov 《Russian Journal of Electrochemistry》2014,50(2):142-153
The binding of the amphiphilic 1,5-bis(para-sulfonatophenyl)-3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane dianion (APCO2?) with the octacation of the amphiphilic tetramethylviologen calix[4]resorcin having a methyl radical in the resorcinol ring (MVCA-C 1 8+ ) in 30% aqueous DMSO in a 0.1M NaCl supporting solution was studied by various methods. The dianion was bound at the upper rim of calixresorcin due to the donor-acceptor interactions between the viologen acceptor units and the nitrogen- and phosphorus-centered electron-donor fragments of APCO2? and at the lower rim due to hydrophobic interactions. The composition of the complex depended on the MVCA-C 1 8+ : APCO2? ratio. The complexes aggregated, forming insoluble precipitates. MVCA-C 1 8+ -APCO2? is a system with reversibly electro-switchable aggregation. The starting MVCA- 1 8+ octacation partially bound APCO2?, a certain quantity of both substrates remaining in a free state in solution. The MVCA-C 1 4+· tetraradical tetracation formed as a result of the reduction of MVCA-C 1 8+ completely bound APCO2? due to hydrophobic interactions when the MVCA-C 1 8+ : APCO2? ratio was 1: 3. The reversible oxidation of MVCA-C 1 4+· to the starting MVCA-C 1 8+ octacation brought the system back to its starting state 相似文献
64.
Alexandr N. Chernov Tatiana A. Filatenkova Ruslan I. Glushakov Alexandra S. Buntovskaya Diana A. Alaverdian Anna N. Tsapieva Alexandr V. Kim Evgeniy V. Fedorov Sofia S. Skliar Marina V. Matsko Elvira S. Galimova Olga V. Shamova 《Molecules (Basel, Switzerland)》2022,27(15)
Glioblastoma (GBM) is one of the most aggressive and lethal malignancy of the central nervous system. Temozolomide is the standard of care for gliomas, frequently results in resistance to drug and tumor recurrence. Therefore, further research is required for the development of effective drugs in order to guarantee specific treatments to succeed. The aim of current study was to investigate the effects of nerve growth factor (NGF), human cathelicidin (LL-37), protegrin-1 (PG-1), and temozolomide on bioenergetic function of mitochondria, clonogenicity, and migration of human U251 glioma cells. Colony formation assay was used to test the ability of the glioma cells to form colonies in vitro. The U251 glioma cells migration was evaluated using wound-healing assay. To study the mitochondrial metabolism in glioma cells we measured oxygen consumption rates (OCR) and extracellular acidification rates (ECAR) using a Seahorse XF cell Mito stress test kit and Seahorse XF cell Glycolysis stress kit, respectively. We revealed that LL-37, NGF, and TMZ show strong anti-tumorigenic activity on GMB. LL-37 (4 μM), TMZ (155 μM), and NGF (7.55 × 10−3 μM) inhibited 43.9%–60.3%, 73.5%–81.3%, 66.2% the clonogenicity of glioma U251 cells for 1–2 days, respectively. LL-37 (4 μM), and NGF (7.55 × 10−3 μM) inhibited the migration of U251 glioma cells on the third and fourth days. TMZ also inhibited the migration of human glioma U251 cells over 1–3 days. In contrast, PG-1 (16 μM) stimulated the migration of U251 glioma cells on the second, fourth, and sixth days. Anti-mitogenic and anti-migration activities of NGF, LL-37, and TMZ maybe are relation to their capacity to reduce the basal OCR, ATP-synthetase, and maximal respiration of mitochondria in human glioma U251 cells. Glycolysis, glycolytic capacity and glycolytic spare in glioma U251 cells haven`t been changed under the effect of NGF, LL-37, PG-1, and TMZ in regard to control level. Thus, LL-37 and NGF inhibit migration and clonogenicity of U251 glioma cells, which may indicate that these compounds have anti-mitogenic and anti-migration effects on human glioma cells. The study of the mechanisms of these effects may contribute in the future to the use of NGF and LL-37 as therapeutic agents for gliomas. 相似文献
65.
The structures and stability of C-doped boron fullerenes with the three-dimensional arrangement of non-classical pentacoordinated quasi-flat carbon centers were studied using the density functional theory (DFT) B3LYP/6-311+G(d,p) method. The doping with carbon atoms in apical positions above the five-membered rings stabilizes the spherical boron fullerene forms due to multicenter interactions of pz-orbitals of the carbons and adjacent boron atoms. Increasing in the size of the fullerene cluster is accompanied by change in the bonding pattern and by flattening of the hypercoordinated carbon centers. Endohedral metal atoms significantly affect on the structure and stability of the fullerene systems with hypercoordinated carbon centers. 相似文献
66.
Olga A. Gapurenko Vladimir Ya. Lee Ruslan M. Minyaev Vladimir I. Minkin Akira Sekiguchi 《Tetrahedron letters》2017,58(21):2054-2057
Hybrid cationic pyramidanes {E15[E144R4]}+ (E15 = P–Bi; E14 = C–Ge, R = H, SiMe3) have been studied by the DFT calculations, and their structures, electronic properties and bonding nature are discussed. Square-pyramidal geometry in the real neutral compounds {E15[E144(SiMe3)4]}+[AlCl4]? is preserved. 相似文献
67.
Iliya V. Getmanskii Vitaliy V. Koval Alexander I. Boldyrev Ruslan M. Minyaev Vladimir I. Minkin 《Journal of computational chemistry》2019,40(20):1861-1865
A new metastable crystalline form of gallium has been computationally designed using density functional calculations with imposing periodic boundary conditions. The geometric and electronic structures of the predicted new allotrope were calculated on the basis of a diamond lattice in which all carbon atoms are replaced by gallium Ga4 tetrahedra. This form does not have any imaginary phonons, thus it is a metastable crystalline form of gallium. The new form of gallium is a metal and shows high plasticity and low-melting temperature. Molecular dynamics simulations show that this form of gallium will melt at about 273 K with a sharp increase in temperature in the system during the melting process from 273 to 1800 K. This melting process is very different from conventional melting, where temperature stays the same until complete melting. That unusual melting can be explained by the fact that supertetrahedral gallium is a metastable structure that has an excess of strain energy released during melting. If made this new material may find many useful applications as a new low density metal with stored internal energy. © 2019 Wiley Periodicals, Inc. 相似文献
68.
69.
Uvarov MN Kulik LV Bizin MA Ivanova VN Zaripov RB Dzuba SA 《The journal of physical chemistry. A》2008,112(12):2519-2525
Spin-polarized echo-detected electron paramagnetic resonance (EPR) spectra and the transversal relaxation rate T2(-1) of the photoexcited triplet state of fullerene C60 molecules were studied in o-terphenyl, 1-methylnaphthalene, and decalin glassy matrices. The model is composed of a fast (correlation time approximately 10(-12) s) pseudorotation of (3)C60 in a local anisotropic potential created by interaction of the fullerene molecule with the surrounding matrix molecules. In simulations, this potential is assumed to be axially symmetric around some axis of a preferable orientation in a matrix cage. The fitted value of the potential was found to depend on the type of glass and to decrease monotonically with a temperature increase. A sharp increase of the T2(-1) temperature dependence was found near 240 K in glassy o-terphenyl and near 100 K in glassy 1-methylnaphthalene and decalin. This increase probably is related to the influence on the pseudorotation of the onset of large-amplitude vibrational molecular motions (dynamical transition in glass) that are known for glasses from neutron scattering and molecular dynamics studies. The obtained results suggest that molecular and spin dynamics of the triplet fullerene are extremely sensitive to molecular motions in glassy materials. 相似文献
70.
Olga A. Gapurenko Andrey G. Starikov Ruslan M. Minyaev Vladimir I. Minkin 《Journal of computational chemistry》2015,36(29):2193-2199
A series of germanium‐containing triangular molecules have been studied by density functional theory (DFT) calculations. The triangulene topology of the compounds provides for their high‐spin ground states and strong sign alternation of spin density and atomic charge distributions. High values of the exchange coupling constants witness ferromagnetic ordering of electronic structures of all studied triangulenes. The compounds bearing more electronegative atoms in a‐positions of the triangular networks possess higher aromatic character and stronger ferromagnetic ordering. © 2015 Wiley Periodicals, Inc. 相似文献