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61.
62.
63.
Samori S Tojo S Fujitsuka M Yang SW Ho TI Yang JS Majima T 《The journal of physical chemistry. B》2006,110(26):13296-13303
Emission from several 1-(arylethynyl)pyrenes with a substituent on the aryl group (REPy, R = phenyl (PEPy), 4-dimethylaminophenyl (NPEPy), 4-isopropoxyphenyl (OPEPy), 2-quinonyl (QEPy), and 9-(10-cyanoanthracenyl) (AEPy)) was studied with time-resolved fluorescence measurements during pulse radiolysis in benzene. NPEPy and AEPy showed only monomer emission, while PEPy, OPEPy, and QEPy showed both monomer and excimer emissions during pulse radiolysis. In addition, REPy's also showed long-lived emissions with very weak intensities in the absence of oxygen, which were assigned to the "P-type" delayed fluorescence derived from the triplet-triplet annihilation. The formation of REPy's in the singlet excited state (1REPy*) can be interpreted as the charge recombination between the REPy radical cation and anion (REPy*+ and REPy*-, respectively), which are initially generated from the radiolytic reaction in benzene. Both the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of PEPy are localized on the 1-pyrenyl (Py) moiety, while the HOMO of REPy's with an electron donating or withdrawing substituent on the benzene ring (R(D)EPy such as NPEPy and OPEPy or R(A)EPy such as QEPy and AEPy) is mainly localized on the donor moieties (R(D) or Py) and the LUMO on the acceptor ones (Py or R(A), respectively). Therefore, it is suggested that the one-electron oxidation and reduction of REPy's can occur from the donor and acceptor moieties, respectively. This scheme reasonably explains the relationship between the annihilation enthalpy changes (-Delta H' degrees) for the charge recombination of REPy*+ and REPy*- and the singlet excitation energies (E'(S1) of the REPy's. The results are compared with those in electrogenerated chemiluminescence. 相似文献
64.
Tachikawa T Takai Y Tojo S Fujitsuka M Irie H Hashimoto K Majima T 《The journal of physical chemistry. B》2006,110(26):13158-13165
The photocatalytic degradation processes of ethylene glycol (EG) during the UV or visible light irradiation of pure anatase and nitrogen (N)-doped TiO2 powders (TiO(2-x)N(x), x = 0, 0.002, 0.003, and 0.007) were investigated using time-resolved diffuse reflectance (TDR) and solid-state NMR spectroscopies. The TDR spectra and time traces observed for the charge carriers indicated that the scavenging of photogenerated holes (h+) by EG occurred during the 355-nm laser photolysis of the N-doped TiO2 powders, while no direct oxidation reaction of EG by h+ occurred during the 460-nm laser photolysis, although the charge carriers were sufficiently generated upon excitation. The solid-state magic-angle spinning (MAS) NMR measurements revealed that EG is preferentially chemisorbed on the surface of the N-doped TiO2 powders, in contrast to the pure TiO2, and degrades under visible light irradiation. 相似文献
65.
Y. Kondo T. Nakamura Y. Satou T. Matsumoto N. Aoi N. Endo N. Fukuda T. Gomi Y. Hashimoto M. Ishihara S. Kawai M. Kitayama T. Kobayashi Y. Matsuda N. Matsui T. Motobayashi T. Nakabayashi T. Okumura H.J. Ong T.K. Onishi K. Ogata H. Otsu H. Sakurai S. Shimoura M. Shinohara T. Sugimoto S. Takeuchi M. Tamaki Y. Togano Y. Yanagisawa 《Physics letters. [Part B]》2010
66.
Yuto Ogata Tamaki Tanaka Yutaka Saito Gue Myung Lee Jae Hyoung Lee 《Optimization》2018,67(7):1067-1075
AbstractThis paper contains a generalized Gordan-type alternative theorem for set-valued maps which characterizes set relations without any convexity assumptions using certain evaluation functions. As a direct consequence and as a good example, we discuss robustness (or stability) of linear programming problems for modelling error. Moreover, this theorem can be utilized for that of general vector optimization problems in special cases due to reformation of the evaluation functions. 相似文献
67.
Tojo S Kitagawa M Enomoto K Kato Y Takasu Y Kumakura M Takahashi Y 《Physical review letters》2006,96(15):153201
We observed high-resolution photoassociation spectra of laser-cooled ytterbium (Yb) atoms in the spin-forbidden 1S0 - 3P1 intercombination line. The rovibrational levels in the 0u+ state were measured for red detunings of the photoassociation laser ranging from 2.9 MHz to 1.97 GHz with respect to the atomic resonance. The rotational splitting of the vibrational levels near the dissociation limit were fully resolved due to the sub-MHz linewidth of the spectra in contrast to previous measurements using the spin-allowed singlet transition. In addition, from a comparison between the spectra of 174Yb and those of 176Yb, a d-wave shape resonance for 174Yb is strongly suggested. 相似文献
68.
Chan Kim Takemasa Fujino Yoshiyuki Nishimura Toshio Tamaki Morinobu Endo Mildred S. Dresselhaus 《Molecular Crystals and Liquid Crystals》2013,570(1):505-510
Abstract The microstructure of milled mesophase pitch-based carbon fibers (mMPCFs) that have been developed as an anode material for Li ion batteries have been studied as a function of heat treatment temperature (HTT), by SEM, X-ray diffraction, and Raman spectroscopy. And the results obtained are compared with those by X-ray diffraction (XRD) and SEM observations, for the characterization of specific structural features of mMPCFs as a promising anode material. 相似文献
69.
Kei Kamogawa Yuushi Shimoda Kiyoshi Miyata Ken Onda Yasuomi Yamazaki Yusuke Tamaki Osamu Ishitani 《Chemical science》2021,12(28):9682
Supramolecular photocatalysts comprising [Ru(diimine)3]2+ photosensitiser and fac-[Re(diimine)(CO)3{OC(O)OC2H4NR2}] catalyst units can be used to reduce CO2 to CO with high selectivity, durability and efficiency. In the presence of triethanolamine, the Re catalyst unit efficiently takes up CO2 to form a carbonate ester complex, and then direct photocatalytic reduction of a low concentration of CO2, e.g., 10% CO2, can be achieved using this type of supramolecular photocatalyst. In this work, the mechanism of the photocatalytic reduction of CO2 was investigated applying such a supramolecular photocatalyst, RuC2Re with a carbonate ester ligand, using time-resolved visible and infrared spectroscopies and electrochemical methods. Using time-resolved spectroscopic measurements, the kinetics of the photochemical formation processes of the one-electron-reduced species RuC2(Re)−, which is an essential intermediate in the photocatalytic reaction, were clarified in detail and its electronic structure was elucidated. These studies also showed that RuC2(Re)− is stable for 10 ms in the reaction solution. Cyclic voltammograms measured at various scan rates besides temperature and kinetic analyses of RuC2(Re)− produced by steady-state irradiation indicated that the subsequent reaction of RuC2(Re)− proceeds with an observed first-order rate constant of approximately 1.8 s−1 at 298 K and is a unimolecular reaction, independent of the concentrations of both CO2 and RuC2(Re)−.Formation processes and reactivity of an important intermediate of photocatalytic CO2 reduction, one-electron reduced species of a Ru(ii)–Re(i) supramolecular photocatalyst with a carbonate ester ligand, were investigated in detail. 相似文献
70.
S. Matsunaga S. Tamaki 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,63(4):417-424
The theory of the pre-melting phenomena in ionic crystals on the basis of the concept of the hetero phase fluctuation has
been applied to KCl and AgCl crystal. The large scale molecular dynamics simulations (MD) in KCl and AgCl crystals are also
performed to examine the ionic configuration in premelting region in the vicinity of their melting points. The size of the
liquid like clusters are estimated by the theory and MD. The structural features of liquid like clusters are discussed by
MD results using the Lindemann instability condition. The ionic conductivities in the pre-melting region are also discussed
on the same theoretical basis. 相似文献