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71.
72.
We carried out the purification of C-phycocyanin and allophycocyanin from Spirulina platensis taking advantage of the adsorption properties of the expanded beds. Initially, phycobiliproteins were released from the microalga
cells by osmotic shock. Next, phycocyanins were recovered by applying the centrifuged cell suspension directly to the anion
exchanger Streamline-DEAE using expanded bed columns, equilibrated with 50 mM sodium phosphate buffer, pH 7.0. After adsorption,
washing was carried out in the expanded-bed mode. Having removed unbound proteins and cellular debris, the bed was allowed
to sediment and phycocyanins rich solution was eluted with a downward flow of 500 mM sodium phosphate buffer, pH 7.0. Finally,
we utilized conventional gel filtration and ion exchange chromatography methods for separation and purification of C-phycocyanin
and allophycocyanin. The purification steps were monitored using sodium dodecyl sulfate-polyacrylamide gel electrophoresis,
and the purity of recovered phycocyanins was confirmed by absorption and emission spectroscopy. The main advantage of this
new method is the high yield achieved in the steps of product extraction and adsorption by expanded bed adsorption, so reducing
both processing times and costs. 相似文献
73.
Summary Three new pyridazine complexes of manganese(I): [MnBr(pyr)2(CO)3] (1), [Mn(pyr)(CO)5][ClO4] (2) and [Mn(pyr)3(CO)3][ClO4] (3) (pyr=pyridazine) have been prepared and their i.r. and variable-temperature1H n.m.r. spectra investigated. 相似文献
74.
75.
Lobana TS Rekha R Butcher RJ Castineiras A Bermejo E Bharatam PV 《Inorganic chemistry》2006,45(4):1535-1542
Reactions of copper(I) halides with a series of thiosemicarbazone ligands (Htsc) in the presence of triphenylphosphine (Ph(3)P) in acetonitrile have yielded three types of complexes: (i) monomers, [CuX(eta1-S-Htsc)(Ph3P)2] [X, Htsc = I (1), Br (2), benzaldehyde thiosemicarbazone (Hbtsc); I (5), Br (6), Cl (7), pyridine-2-carbaldehyde thiosemicarbazone (Hpytsc)], (ii) halogen-bridged dimers, [Cu2(mu2-X)2(eta1-S-Htsc)2(Ph3P)2] [X, Htsc = Br (3), Hbtsc; I (8), furan-2-carbaldehyde thiosemicarbazone (Hftsc); I (11), thiophene-2-carbaldehyde thiosemicarbazone (Httsc)], and (iii) sulfur-bridged dimers, [Cu2X2(mu2-S-Htsc)2(Ph3P)2] [X, Htsc = Cl (4), Hbtsc; Br (9), Cl (10), pyrrole-2-carbaldehyde thiosemicarbazone (Hptsc); Br (12), Httsc]. All of these complexes have been characterized with the help of elemental analysis, IR, 1H, 13C, or 31P NMR spectroscopy, and X-ray crystallography (1-12). In all of the complexes, thiosemicarbazones are acting as neutral S-donor ligands in eta()S or mu2-S bonding modes. The Cu...Cu separations in the Cu(mu2-X)2Cu and Cu(mu2-S)2Cu cores lie in the ranges 2.981(1)-3.2247(6) and 2.813(1)-3.2329(8) Angstroms, respectively. The geometry around each Cu center in monomers and dimers may be treated as distorted tetrahedral. Ab initio density functional theory calculations on model monomeric and dimeric complexes of the simplest thiosemicarbazone [H2C=N-NH-C(S)-NH2, Htsc] have revealed that monomers and halogen-bridged dimers have similar stability and that sulfur-bridged dimers are stable only when halogen atoms are engaged in hydrogen bonding with the solvent of crystallization or H2O molecules. 相似文献
76.
A. Alkadrou M. Rotger D. Bermejo J. L. Domnech V. Boudon 《Journal of Raman spectroscopy : JRS》2016,47(7):839-844
High‐resolution stimulated Raman spectra of13C2H4 in the regions of the ν2 and ν3 Raman active modes have been recorded at two temperatures (145 and 296 K) based on the quasi continuous‐wave (cw) stimulated Raman spectrometer at Instituto de Estructura de la Materia IEM‐CSIC in Madrid. A tensorial formalism adapted to X2Y4 planar asymmetric tops with D2h symmetry (developed in Dijon) and a program suite called D2hTDS (now part of the XTDS/SPVIEW spectroscopic software) were proposed to analyze and calculate the high‐resolution spectra. A total of 103 and 51 lines corresponding to ν2 and ν3 Raman active modes have been assigned and fitted in wavenumber with a global root mean square deviation of 0.54 × 10−3 and 0.36 × 10−3 cm−1, respectively. Due to the fact that the Raman scattering effect is weak, we did not perform in this contribution the line intensities analysis. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
77.
Ángel Martín David Méndez María Dolores Bermejo 《The Journal of chemical thermodynamics》2010,42(4):524-529
The properties of ionic liquids (ILs) can be modified by appropriate selection of cations and anions. Even if an infinite number of ionic liquids can be generated, only a limited number of families of anions and cations are used. The group contribution equation of state (GC-EoS) is a promising method for calculating the phase behavior of systems with ILs. If the parameters of the characteristic functional group of a IL family are fitted by using data of a reduced number of ILs of the family, then the phase behavior of all the ILs of the same family can be predicted using exclusively the data of the pure components. Previously, the parameters of the IL families with an imidazolium-based cation and the anions PF6, BF4NO3, and Tf2N were fitted to experimental data [19], and some ternary systems (CO2 + organics + ionic liquid [bmim][BF4]) were also modeled [22]. In this work, the GC-EoS was used to calculate phase behavior of gases {(CO2, O2, or SO2) + ionic liquids} with Tf2N anion and cations of the families 2,3-dimethyl-imidazolium, 1-alkyl-1-methyl-pyrrolidinium, and 1-alkyl-3-methyl-pyridinium. The GC-EoS was able to reproduce experimental data with deviations of the same order of experimental uncertainty. With the correlated parameters it will be possible to predict the phase behavior of systems with ILs of the families considered in this work. 相似文献
78.
Martínez-Calvo M Vázquez López M Pedrido R González-Noya AM Bermejo MR Monzani E Casella L Sorace L 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(47):14175-14180
A novel neutral triple-stranded hexanuclear copper(I) cluster helicate [Cu(I)(6)L(3)]·2CH(3)CN derived from a thiosemicarbazone ligand could be synthesized and crystallographically characterized. The MALDI mass spectrum of this complex suggests that the tetranuclear copper(I) cluster helicate [Cu(I)(4)L(2)] is also present in solution. These copper(I) cluster helicates are capable, in the presence of O(2), of hydroxylating the arene linker of their supporting ligand strands. The resulting dinuclear complex [Cu(II)(2)L'(OH)] is formed by two copper(II) centers, a new ligand arising from the hydroxylation reaction, and one hydroxide group. The magnetic investigation of this compound shows a strong antiferromagnetic coupling between the two Cu(II) centers. The kinetic studies for the hydroxylation process show values of ΔH(≠)=-70 kJ mol(-1), similar to those mediated by the tyrosinase enzymes. 相似文献
79.
María Jesús Tabernero Maria Linda Felli Ana María Bermejo Marcello Chiarotti 《Analytical and bioanalytical chemistry》2009,395(8):2547-2557
A liquid chromatography-tandem mass spectrometry method was developed for the determination of ketamine (with its metabolite
norketamine) and some amphetamines (amphetamine, methamphetamine, methylenedioxyamphetamine, and 3,4-methylenedioxymethamphetamine).
This method was developed to determine these compounds in hair and is able to simultaneously quantify all of them in human
hair. Hair samples (20 mg) were washed and pulverized, and an extraction with formic acid (0.01%) and ultrasonication for
4 h was used. Deuterated analogs of the analytes were used as internal standards for quantification. Linearity from 0.5 to
25 ng/mg was obtained for both ketamine (and norketamine) and amphetamines with correlation coefficients exceeding 0.99. The
limit of detection and the limit of quantification obtained were 0.1 and 0.5 ng/mg, respectively, for ketamine and amphetamines.
A total of 25 hair samples from known drug abusers (relating to designer drug consumption or consumption of amphetamines)
were examined by this validated method. The results show that the proposed method is suitable for testing these drugs in a
single sample of hair. In addition, it is simpler and faster than analysis by conventional methods such as gas chromatography-mass
spectrometry, which usually require a more laborious extraction procedure and, in most of cases, an additional derivatization
process. 相似文献
80.
The high-resolution Raman spectra of the nu4 bands of 11B2H6 and 11B10BH6 have been recorded and analyzed. The recordings have been made using a high-resolution spectrometer based on the inverse Raman effect. Q branches have been observed, but P and R branches were too weak to be seen, and simulations of the observed band contour have been necessary to complete the analysis. A weak Coriolis resonance with the 2nu10 level is present in the 11B2H6 spectrum. The band centers obtained are 790.9829(12) and 804.76985(27) cm-1 for 11B2H6 and 10B11BH6, respectively (uncertainties are type A with a coverage factor k = 1, i.e., 1 standard deviation). Copyright 1999 Academic Press. 相似文献