全文获取类型
收费全文 | 308篇 |
免费 | 6篇 |
国内免费 | 4篇 |
专业分类
化学 | 199篇 |
力学 | 7篇 |
数学 | 34篇 |
物理学 | 78篇 |
出版年
2023年 | 4篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 9篇 |
2012年 | 17篇 |
2011年 | 25篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 22篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 21篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1967年 | 2篇 |
1958年 | 1篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1931年 | 1篇 |
排序方式: 共有318条查询结果,搜索用时 0 毫秒
121.
Peter L. Lee Deming Shu Mohan Ramanathan Curt Preissner Jun Wang Mark A. Beno Robert B. Von Dreele Lynn Ribaud Charles Kurtz Sytle M. Antao Xuesong Jiao Brian H. Toby 《Journal of synchrotron radiation》2008,15(5):427-432
A dedicated high‐resolution high‐throughput X‐ray powder diffraction beamline has been constructed at the Advanced Photon Source (APS). In order to achieve the goals of both high resolution and high throughput in a powder instrument, a multi‐analyzer detector system is required. The design and performance of the 12‐analyzer detector system installed on the powder diffractometer at the 11‐BM beamline of APS are presented. 相似文献
122.
Lange PP Goossen LJ Podmore P Underwood T Sciammetta N 《Chemical communications (Cambridge, England)》2011,47(12):3628-3630
A practical protocol was developed that allows performing decarboxylative cross-coupling reactions in continuous flow reactors. Various biaryls were thus synthesized from aromatic carboxylic acids and aryl triflates using a Cu/Pd-catalyst system. 相似文献
123.
We describe two quantum channels that individually cannot send any classical information without some chance of decoding error. But together a single use of each channel can send quantum information perfectly reliably. This proves that the zero-error classical capacity exhibits superactivation, the extreme form of the superadditivity phenomenon in which entangled inputs allow communication over zero-capacity channels. But our result is stronger still, as it even allows zero-error quantum communication when the two channels are combined. Thus our result shows a new remarkable way in which entanglement across two systems can be used to resist noise, in this case perfectly. We also show a new form of superactivation by entanglement shared between sender and receiver. 相似文献
124.
Dr. Khadanand KC Dr. Toby Woods Dr. Lisa Olshansky 《Angewandte Chemie (International ed. in English)》2023,62(45):e202311790
Mononuclear monodioxolene valence tautomeric (VT) cobalt complexes typically exist in their low spin (l.s.) CoIII(cat2−) and high spin (h.s.) CoII(sq⋅−) forms (cat2−=catecholato, and sq⋅−=seminquinonato forms of 3,5−di−tBu-1,2-dioxolene), which reversibly interconvert via temperature-dependent intramolecular electron transfer. Typically, the remaining four coordination sites on cobalt are supported by a tetradentate ligand whose properties influence the temperature at which VT occurs. We report that replacing one chelating pyridyl arm of tris(2-pyridylmethyl)amine (tpa) with a weaker field ortho-anisole moiety facilitates access to a third magnetic state, and examine a series of related complexes. Variable temperature crystallographic, magnetic, calorimetric, and spectroscopic studies support that this third state is consistent with l.s. CoII(sq⋅−). Thus, our ligand modifications not only provide access to the VT transition from l.s. CoIII(cat2−) to l.s. CoII(sq⋅−), but at higher temperatures, the complex undergoes spin crossover from l.s. CoII(sq⋅−) to h.s. CoII(sq⋅−), representing the first example of two-step magnetic switching in a mononuclear monodioxolene cobalt complex. We hypothesize that ligand dynamicity may facilitate access to the rarely observed l.s. CoII(sq⋅−) intermediate state, suggesting a new design criterion in the development of stimulus-responsive multi-state molecular switches. 相似文献
125.
126.
Prof. Steven J. Langford Dr. Toby D. M. Bell 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(10):4133-4140
Two new amino core‐substituted naphthalene diimides (cNDIs) bearing fluorinated side chains have been synthesised. Steady‐state and time‐resolved fluorescence spectroscopy reveals unprecedented optical properties for the cNDIs with high quantum yields of ~0.8 and fluorescence lifetimes of ~13 ns in a range of solvents. These properties are apparent at the level of single molecules, where the compounds also show exceptional photostability under pulsed‐laser excitation. Photon emission is remarkably consistent with very few long timescale (millisecond or longer) interruptions with molecules regularly undergoing >107 cycles of excitation and emission. Intermittencies owing to triplet‐state formation occur on a sub‐millisecond timescale with a low yield of 1–2 %, indicating that the presence of the fluorine atoms does not lead to a significant triplet yield through the heavy‐atom effect. These properties make the compounds excellent candidates for single‐molecule labelling applications. 相似文献
127.
A.B. Anton N.R. Avery B.H. Toby W.H. Weinberg 《Journal of Electron Spectroscopy and Related Phenomena》1983,29(1):181-186
High resolution electron energy loss spectroscopy (EELS), thermal desorption mass spectrometry (TDMS) and low energy electron diffraction (LEED) have been used to investigate the molecular chemisorption of N2 on Ru(001) at 75 K and 95 K. Adsorption at 95 K produces a single chemisorbed state, and, at saturation, a (√3x√3) R30° LEED pattern is observed. Adsorption at 75 K produces an additional chemisorbed state of lower binding energy, and the probability of adsorption increases by a factor of two from its zero coverage value when the second chemisorbed state begins to populate. EEL spectra recorded for all coverages at 75 K show only two dipolar modes — ν(RuN2) at 280–300 cm?1 and ν(NN) at 2200–2250 cm?1 — indicating adsorption at on-top sites with the axis of the molecular standing perpendicular to the surface. The intensities of these loss features increase and ν(NN) decreases with increasing surface coverage of both chemisorbed states. 相似文献
128.
The title compounds were synthesised and characterised as part of a study into new aromatic amines for charge transporting materials. Each compound was characterised by cyclic voltammetry. A qualitative estimate of the intramolecular charge mobility was deduced from the difference between the first and second oxidation potentials. 相似文献
129.
130.