全文获取类型
收费全文 | 199篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
化学 | 117篇 |
力学 | 2篇 |
数学 | 22篇 |
物理学 | 62篇 |
出版年
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 9篇 |
2009年 | 6篇 |
2008年 | 16篇 |
2007年 | 13篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 4篇 |
1979年 | 6篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1966年 | 1篇 |
1910年 | 1篇 |
1909年 | 1篇 |
1874年 | 1篇 |
排序方式: 共有203条查询结果,搜索用时 31 毫秒
71.
Sheps L Miller EM Horvath S Thompson MA Parson R McCoy AB Lineberger WC 《The Journal of chemical physics》2011,134(18):184311
A combined experimental and theoretical investigation of photodissociation dynamics of IBr(-) and IBr(-)(CO(2)) on the B ((2)Σ(1/2)(+)) excited electronic state is presented. Time-resolved photoelectron spectroscopy reveals that in bare IBr(-) prompt dissociation forms exclusively I? + Br(-). Compared to earlier dissociation studies of IBr(-) excited to the A' ((2)Π(1∕2)) state, the signal rise is delayed by 200 ± 20 fs. In the case of IBr(-)(CO(2)), the product distribution shows the existence of a second major (~40%) dissociation pathway, Br? + I(-). In contrast to the primary product channel, the signal rise associated with this pathway shows only a 50 ± 20 fs delay. The altered product branching ratio indicates that the presence of one solvent-like CO(2) molecule dramatically affects the electronic structure of the dissociating IBr(-). We explore the origins of this phenomenon with classical trajectories, quantum wave packet studies, and MR-SO-CISD calculations of the six lowest-energy electronic states of IBr(-) and 36 lowest-energy states of IBr. We find that the CO(2) molecule provides sufficient solvation energy to bring the initially excited state close in energy to a lower-lying state. The splitting between these states and the time at which the crossing takes place depend on the location of the solvating CO(2) molecule. 相似文献
72.
The nonexistence of various points of ternary azeotropy calculated for the donor-acceptor terpolymer system acrylonitrile, styrene, and maleic anhydride, published in the literature, is demonstrated by gas chromatographic residual monomer analysis. 相似文献
73.
Computation using noise-based logic: efficient string verification over a slow communication channel
L. B. Kish S. Khatri T. Horvath 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,79(1):85-90
Utilizing the hyperspace of noise-based logic, we show two string verification methods
with low communication complexity. One of them is based on continuum noise-based logic. The other
one utilizes noise-based logic with random telegraph signals where a mathematical analysis of the
error probability is also given. The last operation can also be interpreted as computing universal
hash functions with noise-based logic and using them for string comparison. To find out with
10-25 error probability that two strings with arbitrary length are different (this value is
similar to the error probability of an idealistic gate in today's computer) Alice and Bob need to
compare only 83 bits of the noise-based hyperspace. 相似文献
74.
A. Horvath 《Fresenius' Journal of Analytical Chemistry》1874,13(1):43-44
Ohne Zusammenfassung 相似文献
75.
Alexey V. Rayevsky Andrii S. Poturai Iryna O. Kravets Alexander E. Pashenko Tatiana A. Borisova Ganna M. Tolstanova Dmitriy M. Volochnyuk Petro O. Borysko Olga B. Vadzyuk Diana O. Alieksieieva Yuliana Zabolotna Olga Klimchuk Dragos Horvath Gilles Marcou Sergey V. Ryabukhin Alexandre Varnek 《Molecules (Basel, Switzerland)》2022,27(17)
New models for ACE2 receptor binding, based on QSAR and docking algorithms were developed, using XRD structural data and ChEMBL 26 database hits as training sets. The selectivity of the potential ACE2-binding ligands towards Neprilysin (NEP) and ACE was evaluated. The Enamine screening collection (3.2 million compounds) was virtually screened according to the above models, in order to find possible ACE2-chemical probes, useful for the study of SARS-CoV2-induced neurological disorders. An enzymology inhibition assay for ACE2 was optimized, and the combined diversified set of predicted selective ACE2-binding molecules from QSAR modeling, docking, and ultrafast docking was screened in vitro. The in vitro hits included two novel chemotypes suitable for further optimization. 相似文献
76.
Reversibility of state transitions is intensively studied topic in many scientific disciplines over many years. In cell biology, it plays an important role in epigenetic variation of phenotypes, known as phenotypic plasticity. More interestingly, the cell state reversibility is probably crucial in the adaptation of population phenotypic heterogeneity to environmental fluctuations by evolving bet-hedging strategy, which might confer to cancer cells resistance to therapy. In this article, we propose a formalization of the evolution of highly reversible states in the environments of periodic variability. Two interrelated models of heterogeneous cell populations are proposed and their behavior is studied. The first model captures selection dynamics of the cell clones for the respective levels of phenotypic reversibility. The second model focuses on the interplay between reversibility and drug resistance in the particular case of cancer. Overall, our results show that the threshold dependencies are emergent features of the investigated model with eventual therapeutic relevance. Presented examples demonstrate importance of taking into account cell to cell heterogeneity within a system of clones with different reversibility quantified by appropriately chosen genetic and epigenetic entropy measures. 相似文献
77.
78.
79.
RJ Davidson EW Ainscough AM Brodie GB Jameson MR Waterland HR Allcock MD Hindenlang B Moubaraki KS Murray KC Gordon R Horvath GN Jameson 《Inorganic chemistry》2012,51(15):8307-8316
Two new cyclotriphosphazene ligands with pendant 2,2':6',2″-terpyridine (Terpy) moieties, namely, (pentaphenoxy){4-[2,6-bis(2-pyridyl)]pyridoxy}cyclotriphosphazene (L(1)), (pentaphenoxy){4-[2,6-terpyridin-4-yl]phenoxy}cyclotriphosphazene (L(2)), and their respective polymeric analogues, L(1P) and L(2P), were synthesized. These ligands were used to form iron(II) complexes with an Fe(II)Terpy(2) core. Variable-temperature resonance Raman, UV-visible, and M?ssbauer spectroscopies with magnetic measurements aided by density functional theory calculations were used to understand the physical characteristics of the complexes. By a comparison of measurements, the polymers were shown to behave in the same way as the cyclotriphosphazene analogues. The results showed that spin crossover (SCO) can be induced to start at high temperatures by extending the spacer length of the ligand to that in L(2) and L(2P); this combination provides a route to forming a malleable SCO material. 相似文献
80.