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621.
Schiff-base type N,P-chelating ligands, phosphorus analogues of imino–anilido ligands, were designed and synthesized as a new type of ligands toward transition metals, and the rhodium–carbonyl complexes bearing the novel imino–phosphido and phosphaalkenyl-anilido ligands were synthesized as stable crystalline compounds. Their structures were definitively revealed by X-ray crystallographic analysis, showing the unique electronic features of the ligands. In addition, the effective trans-influence of the phosphorus atom was suggested on the basis of the structural parameters and spectroscopic features of the isolated complexes. 相似文献
622.
The bipair neutrino mixing describes the observed solar and atmospheric mixings; however, it predicts vanishing reactor mixing angle, which is inconsistent with the observed data. We explore the ways of minimally modifying the bipair neutrino mixing by including charged lepton contributions. There are two categories of the bipair neutrino mixing which are referred to as case 1 and case 2. It turns out that, without arbitrary phases, a minimal modification is realized by just considering one e–τ contribution from the charged lepton sector in the case 1. On the other hand, not only e–τ contribution but also μ–τ contribution is required to realize a minimal modification in the case 2. 相似文献
623.
Ryoichi HAYAKAWA Teruyuki HAYAKAWA Kohsuke TAKEDA Hidenori ICHIJO 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2012,88(8):434-453
Apoptosis signal-regulating kinase 1 (ASK1) is a member of the mitogen-activated protein
kinase kinase kinase (MAP3K) family that activates downstream MAP kinases (MAPKs), c-Jun
N-terminal kinases (JNKs) and p38 MAPKs, in response to various stresses, such as reactive
oxygen species (ROS), endoplasmic reticulum (ER) stress, lipopolysaccharide, and calcium
overload. Activation of the JNK and p38 pathways induces stress responses such as cell death,
differentiation, and the production of inflammatory cytokines. A series of studies using
ASK1-deficient mice have indicated that ASK1 plays important roles in many stress-related
diseases, including cardiovascular and neurodegenerative diseases, suggesting that small
compounds that inhibit ASK1 activity could possibly be used for the amelioration of the
development and/or progression of these diseases. In this review, we provide an overview of the
pathophysiological roles of ASK1-dependent signaling pathways and discuss the mechanistic basis
for how these could serve as potential therapeutic targets. 相似文献
624.
Yasuna Kawasaki Keita Deguchi Satoshi Demura Tohru Watanabe Hiroyuki Okazaki Toshinori Ozaki Takahide Yamaguchi Hiroyuki Takeya Yoshihiko Takano 《Solid State Communications》2012,152(13):1135-1138
Phase diagrams of as-grown and O2-annealed FeTe1?xSex determined from magnetic susceptibility measurement were obtained. For as-grown samples, the antiferromagnetic order was fully suppressed in the range region x≥0.15, and weak superconductivity appeared when x≥0.1. Beginning at x=0.5, weak superconductivity was found to evolve into bulk superconductivity. Interestingly, for O2-annealed samples, complete suppression of magnetic order and the occurrence of bulk superconductivity were observed when x≥0.1. We found that O2-annealing induces bulk superconductivity for FeTe1?xSex. Oxygen probably plays a key role in the suppression of the magnetic order and the appearance of bulk superconductivity. 相似文献
625.
K K Laali T Okazaki S E Galembeck J S Siegel 《The Journal of organic chemistry》2001,66(26):8701-8708
First examples of persistent oxidation dications from fluoranthene-PAHs namely 1,3,4,6,7,10-hexamethyl- 2 and 3,4-dichloro-1,6,7,10-tetramethylfluoranthene 3, benzo[k]fluoranthene 6, and 3,6-dimethyldibenzo[j,l]fluoranthene 9 are reported. Charge delocalization mode and tropicity in the resulting nonalternant dications are examined. Quenching of the superacid solutions of the dications resulted in the formation of novel 8,8'-bifluoranthenyls 2a-4a. AM1 was used as an initial guide for dication generation (DeltaDeltaH(f) degrees and ionization potentials) and for probing the structures of the crowded fluoranthene substrates and their bifluoranthenyls. In selected cases, the dications and their neutral precursors were calculated at the B3LYP/6-31G(d,p) level. Charge delocalization mode (difference in NPA charges) and DFT/GIAO-derived NMR chemical shifts were obtained for comparison with experiment; aromaticity was assessed via nucleus independent chemical shift (NICS) calculations. 相似文献
626.
Ultrafast temperature rise after the deactivation of the electronically excited state of 2-hydroxybenzophenone in various solvents is investigated by two photothermal techniques; temperature lens and acoustic peak delay methods, and by the population grating technique. The results from these methods show that the thermalization process takes place by two phases; fast (<1 ps) and rather slow (30 ps) processes. From the solvent dependence of the thermalization rate, we suggest that these processes are related with the intermolecular interaction and the solvation structure around the photoexcited molecules. 相似文献
627.
本文选择了三种分子结构相同而母核杂原子不同的近红外吸收菁染料,对它们的光谱性能特征及光氧化稳定性能进行了研究。结果表明,具有三种不同母核杂原子的菁染料,其光氧化稳定性顺序为:苯并 唑>苯并噻唑>苯并硒唑。通过猝灭实验给出,在三种菁染料的光氧化反应机制中,具有反应活性的单线态氧和超氧负离子同时存在,其中单线态氧是导致菁染料褪色的主要因素。 相似文献
628.
629.
Fumitoshi Sato Yasuhiro Shigemitsu Isao Okazaki Shuuichi Yahiro Masahiro Fukue Shingo Kozuru Hiroshi Kashiwagi 《International journal of quantum chemistry》1997,63(1):245-256
In this article, we propose a new molecular orbital program for all-electron calculation of proteins which is based on density functional theory. To carry it out in a fully analytical way, we adopted the (pure-) analytical Xα method and modified it for saving a lot of memories for large-scale calculations. The recent software technology sophisticated in information science is inevitably applied to achieve calculations of large molecular systems. The program is coded by the object-oriented language C + +, its output is shown graphically, and the most of the procedures in this program are controlled through an efficient graphical user interface developed by ourselves. Such technology supports the safe construction of the huge software, the tidy representation of enormous data, and the ready control of complex calculations. Test calculations with various sizes of glycine polypeptides indicate that the computation time is proportional to the 1.7 powers of the number of residues. This result suggests that the all-electron calculations of proteins consisting of over 1000 atoms could be performed with distributed and/or massively parallel computers. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 245–256, 1997 相似文献
630.
Tadashi Okazaki Fumio Sanda Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1997,35(12):2487-2492
Radical polyadditions of vinylcyclopropane having spiroacetal moiety, 1,10-divinyl-4,8,12,15-tetraoxatrispiro[2.2.2.2.2.2] pentadecane ( 1 ), and various dithiols were examined. 1 was prepared by the reaction of 1,1-dichloro-2-vinylcyclopropane and pentaerythritol, and radical polyadditions of 1 and dithiols were carried out at 60 and 120°C for 20 h in the presence of an appropriate initiator (3 mol % vs. 1 ) in degassed sealed ampoules or at 20°C under photo irradiation by using a 400 W high-pressure mercury lamp. Poly( 1 ), pale yellow transparent viscous polymers was isolated by reprecipitation with ether containing a small amount of triethylamine to avoid hydrolysis of the polymer. The obtained polymers were soluble in chlorobenzene, DMF, and chloroform but insoluble in ether and n-hexane. The molecular weights of the polymers obtained from aliphatic dithiols were smaller than those from aromatic ones. The structure of the polymer was determined by comparing the NMR spectra with those of the model compounds, which were obtained by radical addition of 1 and benzyl mercaptan. The reaction proceeded through radical polyaddition of dithiol to 1 via radical ring-opening polymerization of the cyclopropane ring. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2487–2492, 1997 相似文献