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121.
Among Professor Kiyosi Itô’s achievements, there is the Itô–Nisio theorem, a completely general theorem relative to the Fourier series decomposition of Brownian motion. In this paper, some of its applications will be reviewed, and new applications to 1-soliton solutions to the Korteweg–de Vries (KdV for short) equation and Eulerian polynomials will be given. 相似文献
122.
Yoshiki Wada Nobuyuki Matsushita Masahiro Yamashita 《Molecular Crystals and Liquid Crystals》2013,570(1):891-896
Abstract Photo-induced absorption (PA) spectra of [Pt (en)2] [Pt (en)2X2] (SO2)2. 6H2O (X=Cl and Br) have been measured. Large excitation photon energy dependent changes were found in the features of the PA spectra. The excitation photon energy dependences are considered to be due to the difference between the relaxation processes of the charge transfer excitons and those of the higher energy excited states. Several new PA bands have been found. 相似文献
123.
Yuto Suzuki Mario Gutirrez Senri Tanaka Eduardo Gomez Norimitsu Tohnai Nobuhiro Yasuda Nobuyuki Matubayasi Abderrazzak Douhal Ichiro Hisaki 《Chemical science》2021,12(28):9607
The library of isostructural porous frameworks enables a systematic survey to optimize the structure and functionality of porous materials. In contrary to metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), a handful of isostructural frameworks have been reported for hydrogen-bonded organic frameworks (HOFs) due to the weakness of the bonds. Herein, we provide a rule-of-thumb to develop isostructural HOFs, where we demonstrate the construction of the third and fourth generation of isostructural HAT-based HOFs (TolHAT-1 and ThiaHAT-1) by considering three important structural factors, that are (1) directional H-bonding, (2) shape-fitted docking of the HAT core, and (3) modulation of peripheral moieties. Their structural and photo-physical properties including HCl vapor detection are presented. Moreover, TolHAT-1, ThiaHAT-1, and other isostructural HOFs (CPHAT-1 and CBPHAT-1) were thoroughly compared from the viewpoints of structures and properties. Importantly, molecular dynamics (MD) simulation proves to be rationally capable of evaluating the stability of isostructural HOFs. These results can accelerate the development of various isostructural molecular porous materials.The library of isostructural porous frameworks enables a systematic survey to optimize the structure and functionality of porous materials. 相似文献
124.
125.
Inside Cover: Stimuli‐Responsive Dual‐Color Photon Upconversion: A Singlet‐to‐Triplet Absorption Sensitizer in a Soft Luminescent Cyclophane (Angew. Chem. Int. Ed. 11/2018) 下载免费PDF全文
126.
127.
Kunihiko Takabe Takashi Yamada Takenori Miyamoto Nobuyuki Mase 《Tetrahedron letters》2008,49(41):6016-6018
Acid promoted cyclization of the geranylamine N-oxide (E)-4 followed by base-catalyzed intramolecular aldol condensation afforded 1-acetyl-4,4-dimethyl-1-cyclohexene (7) in one-pot operation. Reduction of 7, which possess strong fruity odor, followed by lipase-catalyzed kinetic resolution furnished the acetate (R)-26 (>49.9% yield, >99% ee) and the recovered alcohol (S)-25 (>49.9% yield, >99% ee, herbal odor). 相似文献
128.
Reaction pathways and kinetics of C2 (carbon-two) aldehyde, acetaldehyde (CH3CHO), and formic acid HCOOH or HOCHO, are studied in neutral and acidic subcritical water at 200-250 degrees C. Acetaldehyde is found to exhibit (i) the acid-catalyzed C-C bond formation between acetaldehyde and formic acid, which generates lactic acid (CH3CH(OH)COOH), (ii) the cross-disproportionation, where formic acid reduces acetaldehyde into ethanol, and (iii) the aldol condensation. The lactic acid formation is a green C-C bond formation, proceeding without any organic solvents or metal catalysts. The new C-C bond formation takes place between formic acid and aldehydes irrespective of the presence of alpha-hydrogens. The hydrothermal cross-disproportionation produces ethanol without base catalysts and proceeds even in acidic condition, in sharp contrast to the classical base-catalyzed Cannizzaro reaction. The rate constants of the reactions (i)-(iii) and the equilibrium constant of the lactic acid formation are determined in the temperature range of 200-250 degrees C and at HCl concentrations of 0.2-0.6 M (mol/dm(3)). The reaction pathways are controlled so that the lactic acid or ethanol yield may be maximized by tuning the reactant concentrations and the temperature. A high lactic acid yield of 68% is achieved when acetaldehyde and formic acid are mixed in hot water, respectively, at 0.01 and 2.0 M in the presence of 0.6 M HCl at 225 degrees C. The ethanol yield attained 75% by the disproportionation of acetaldehyde (0.3 M) and formic acid (2.0 M) at 225 degrees C in the absence of added HCl. 相似文献
129.
Otomo T Iwase H Kameda Y Matubayasi N Itoh K Ikeda S Nakahara M 《The journal of physical chemistry. B》2008,112(15):4687-4693
Neutron diffraction measurements were carried out on H/ D isotopically substituted water in the low-density supercritical condition (T = 673 K, P = 26.3 MPa, and rho = 0.0068 molecules.A-3) in order to obtain direct information on the intermolecular partial structure functions, gHH inter(r), gOH inter(r), and gOO inter(r). In correspondence to the high-density supercritical water previously reported, the intermolecular nearest neighbor peaks in gHH inter(r), gOH inter(r), and gOO inter(r) are diffuse compared with the ambient ones. The nearest neighbor O...O distance (3.3 A) and its coordination number (2.6) were determined from the observed gOO inter(r). These results indicate that the orientational correlation between neighboring water molecules is considerably lost in low-density supercritical water. Small clusters involving a few water molecules are preferentially formed in low-density supercritical water, which is consistent with results obtained by previous IR and NMR studies. 相似文献
130.
In this report, for the first time, a planar chiral photoresponsive compound has been employed in commercially available nematic liquid crystals to achieve phototunable reflection colors. We designed an azobenzenophane compound having conformational restriction on the free rotation of naphthalene moiety to impose an element of planar chirality and the corresponding enantiomers were resolved by HPLC on chiral column. We have determined the absolute configuration by comparison of density functional theory (DFT) calculations of its electronic circular dichroism (ECD) spectrum and specific rotation [alpha] D to experimental ECD and [alpha] D data. Enantiomers exhibit photochemically reversible isomerization in solution without undergoing thermal or photoinduced racemization. As chiroptic switches in different host nematic liquid crystals, they exhibit good solubility, moderately high helical twisting power, as well as a large change in helical twisting power due to photoisomerization. A unique feature of these chiral photochromic compounds is that no other auxiliary chiral agents is required to achieve a fast photon mode reversible full-range color control in induced cholesterics, that is, both the hypsochromic and bathochromic shift can be obtained from a single LC formulation by reversible photoisomerization of the single chiral compound. 相似文献