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171.
Adsorption characteristics of medicinal carbon powder (JP 14) for acetaminophen were examined at 37 degrees C using conventional incubation in an attempt to obtain an effective oral dosage form. Hydroxypropyl cellulose (HPC) and maltitol (MT), being able to act as a binding agent, were tested as additives. Tablets of medicinal carbon were produced by the wet granulation method. The rate and extent of adsorption of the medicinal carbon powder were roughly similar in water, JP 14 1st fluid (pH 1.2) and JP 14 2nd fluid (pH 6.8). The relationship between concentrations of free and adsorbed acetaminophen indicated that the adsorption followed the Langmuir mode. The maximal adsorption of acetaminophen in water was 0.219 g per gram medicinal carbon powder, little influenced by the addition of MT, but slightly reduced by the addition of HPC. The tablet prepared using MT as a binding agent displayed a favorable hardness and adequate disintegration time. The tablet showed good adsorption potential for acetaminophen, though the adsorption rate and extent of the tablet were reduced to some extent as compared with powder. 相似文献
172.
Novel ruthenium(II) complexes, fac/mer-[Ru(MeCO-5Bpy-R)3]2+ (H-5Bpy-OH = 5'-amino-2,2'-bipyridine-5-carboxylic acid; R = -NHtBu, -NH(cHex), -N(cHex)2), have been synthesized. The fac and mer isomers have been successfully separated using HPLC techniques, and their photophysical/electrochemical properties have been investigated. In the absorption and emission spectra of fac/mer-[Ru(MeCO-5Bpy-R)3]2+ with secondary amines (R = -N(cHex)2) in acetonitrile at room temperature, the maximum wavelengths based on the MLCT are longer than those for the amide derivatives with primary amines (R = -NHtBu, -NH(cHex)). A small solvent effect on the photophysical properties between fac- and mer-[Ru(MeCO-5Bpy-NHtBu)3]2+ has been observed. The excitation polarization spectra, giving P values reflecting the relation between the absorption and the emission oscillators, for the fac- and mer-ruthenium(II) complexes (C3 and C1 symmetry, respectively) have been measured for the first time. Almost no difference in the excitation polarization spectra between the fac and mer complexes is found, and these spectra are similar to that for [Ru(bpy)3]2+ with D3 symmetry. This finding suggests that the orientations of the absorption and emission oscillators, in the case of the ruthenium(II) tris(2,2'-bipyridine) derivatives, would not be affected by the symmetries of the complexes and that the P values for any derivatives would be similar to that for [Ru(bpy)3]2+. 相似文献
173.
Let G be a graph and f be a mapping from V(G) to the positive integers. A subgraph T of G is called an f‐tree if T forms a tree and dT(x)≤f(x) for any x∈V(T). We propose a conjecture on the existence of a spanning f‐tree, and give a partial solution to it. © 2009 Wiley Periodicals, Inc. J Graph Theory 65: 173–184, 2010 相似文献
174.
Haruko Ikeuchi Mitsuhiro Kanakubo Shin Okuno Rika Sato Koichi Fujita Manatsu Hamada Nobuhiro Shoda Kenta Fukui Koji Okada Hikaru Kanazawa Akira Iimori Daisaku Miyake Takeshi Takeda Gen P. Satô 《Journal of solution chemistry》2010,39(10):1428-1453
The densities and the viscosities of tris(acetylacetonato)cobalt(III) solutions in acetonitrile, dichloromethane, chloroform, tetrachloromethane, benzene, toluene, ethylbenzene, and p-xylene were measured in the dilute concentration regions at several temperatures ranging from 278 to 313 K under ambient pressure. The partial molar volumes of the solvents and solute were calculated. They are independent of concentration and increase slightly as the temperature increases. The viscosity A- and B-coefficients of the Jones-Dole equation were obtained. The A-coefficients were found to be zero within experimental error. The B-coefficients are positive and decrease as the temperature increases. Thermodynamic quantities of activation for viscous flow were calculated on the basis of Eyring’s viscosity equation. From the quantities obtained in this study, along with some information from the literature, it is suggested that structure-making interactions occur between the segments of the complex and the solvent molecules. These interactions include electrostatic interactions between the local charge on the complex and the dipole moment of the solvent in solutions of acetonitrile and dichloromethane, interlocking packing interactions along C 3-axis of the complex with solvent in solutions of chloroform and tetrachloromethane, and π-electron interactions between the chelate ring of the complex and the solvent in solutions of benzene, toluene, ethylbenzene, and p-xylene. 相似文献
175.
176.
Mitsunori Asada Takushi Mitsugi Takahiro Ogura Kenta Fujii Yasuhiro Umebayashi Shin-ichi Ishiguro 《Analytical sciences》2007,23(7):835-840
The solvation number and conformation of N,N-dimethylacrylamide (DMAA) in the coordination sphere of the cobalt(II) ion in solution were studied, and compared with those of N,N-dimethylpropionamide (DMPA) by means of FT-Raman and FT-IR spectroscopy. Both solvents are present as either the planar cis or nonplanar staggered conformer in equilibrium, and the former is more stable in the bulk. As these solvents solvate the metal ion through the carbonyl O atom of the acryl (DMAA) or propionyl (DMPA) group, the solvation structure around the metal ion is highly congested to reduce the solvation number and/or to lead to a conformational geometry change of solvent. It turns out that the solvation number of the cobalt(II) ion is 4 for both DMAA and DMPA at 298 K, and that DMPA changes its conformation upon solvation, whereas DMAA hardly changes. The enthalpy of conformational change DeltaH degrees for DMPA is 5 kJ mol(-1) in the bulk, and is -9 kJ mol(-1) in the coordination sphere of the cobalt(II) ion. On the other hand, the DeltaH degrees value for DMAA is 9 kJ mol(-1) in the bulk. 相似文献
177.
178.
Iwao?KatayamaEmail author Yoshihiro?Suzuki Yoshiaki?Yamamoto Toshio?Oishi 《Monatshefte für Chemie / Chemical Monthly》2005,136(11):1955-1961
Summary. The EMF of galvanic cells with stabilized zirconia solid electrolyte was measured to determine the activity of indium in solid
Ni–In alloys in the temperature range of 970–1170 K and composition range of 5–55 mol% In. Activity of indium increases sharply
in the ζ phase and Ni13In9 phase. The activity values are compared with literature data. 相似文献
179.
Yukio Isobe Kenjiro Onimura Hiromori Tsutsumi Tsutomu Oishi 《Journal of polymer science. Part A, Polymer chemistry》2001,39(20):3556-3565
Asymmetric anionic homopolymerizations of N‐1‐naphthylmaleimide (1‐NMI) were performed with chiral ligand/organometal complexes to form optically active polymers. Poly(1‐NMI)s obtained with methylene‐bridged bisoxazoline derivatives (Rbox)‐diethylzinc (Et2Zn) complexes showed high specific optical rotations ([α]) from +152.3 to +191.4°. Circular dichroism spectra of the polymers exhibited a split Cotton effect in the UV absorption‐band region. According to the exciton chirality method, the absolute configuration of the polymer main chain was determined according to the following method: (+)‐poly[N‐substituted maleimides (RMI)] main chains can contain more (S,S)‐ than (R,R)‐configurations. (?)‐Poly(RMI) main chains can contain more (R,R)‐ than (S,S)‐configurations. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3556–3565, 2001 相似文献
180.
A.?Khanal K.?NakashimaEmail author N.?Kawasaki Y.?Oishi M.?Uehara H.?Nakamura Y.?Tajima 《Colloid and polymer science》2005,283(11):1226-1232
New organic–inorganic nano-complexes were produced from a micelle of tri-block polymers; poly(styrene)-b-poly(2-vinylpyridine)- b-poly (ethylene oxide) (PS-PVP-PEO) and tungsten compounds such as tungstate (W12−), undecatungstophospate (PW117−) and undecatungstosilicate (SiW118−) in acidic aqueous solutions. The size and morphology of the complexes were characterized by measurements of dynamic light
scattering, atomic force microscopy, and scanning electron microscopy. This complex is assembled mainly by the charge interaction
between the inorganic polyanions and the positively charged PVP block in the PS-PVP-PEO molecule, which was confirmed by zeta-potential
and fluorescence spectroscopic studies. In the absence of the inorganic anions, the zeta-potential of the micelle was +11 mV
at pH 3 due to the positive charge of the PVP block. When the inorganic anion was mixed with the PS-PVP-PEO micelle, decrease
in the zeta-potential due to charge neutralization occurred with incorporation of inorganic anions into the PS-PVP-PEO micelle.
The minimum zeta-potential was 0, −33, and −35 mV for W12− /PS-PVP-PEO, PW117− /PS-PVP-PEO, and SiW118− /PS-PVP-PEO complexes, respectively. Excess negative charge which occurred in the latter two complexes indicates that PS-PVP-PEO
molecules bound PW117− and SiW118− by forces other than charge interaction. In addition, the incorporation of an inorganic polyanion into the micelle gave a
new morphology to the micelle. In the absence of the polyanion, the PS-PVP-PEO micelles showed an extended conformation due
to repulsive forces working among the positively charged PVP blocks. Addition of the polyanion caused the formation of shrunken
forms of the micelles, since the charge repulsion was cancelled by the polyanion. This feature may be useful in developing
a new type of functioning micelle. 相似文献