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101.
Equilibria of EuO dissolution and dissociation in molten (NaBr + NaI) mixtures of 0.77:0.23 and 0.31:0.69 compositions at T = 973 K were studied by potentiometric titration method using Pt(O2)|ZrO2(Y2O3) indicator electrode. The solubility product indices of EuO are (7.81 ± 0.08) and (8.43 ± 0.16) in the melts of 0.77:0.23 and 0.31:0.69 compositions. The corresponding dissociation constant indices are (4.96 ± 0.04) and (5.54 ± 0.06), respectively (all the parameters are in molality). Non-dissociated EuO is the prevailing form in all the saturated solutions of europium monoxide. The decrease of the iodide ion concentration in the melts results in strengthening of EuO dissociation that is explained by introduction of harder Pearson’s base (Br−) in sodium iodide melt. In its turn this increases the fixation degree of Eu2+ in mixed halide complexes. The total solubility of EuO decreases going from NaI melt to the (bromide + iodide) mixtures that is caused by the decrease of ‘physical’ solubility of non-dissociated oxide which occupies hollow spaces of enough large size in the ionic solvents. The quantity of these hollow spaces diminishes at the sequential Br− → I− substitution. 相似文献
102.
Rong-Liang Liang Xu-Ping Xu Tian-Cai Liu Jian-Wei Zhou Xian-Guo Wang Zhi-Qi Ren Fen Hao Ying-Song Wu 《Analytica chimica acta》2015
Alpha-fetoprotein (AFP), a primary marker for many diseases including various cancers, is important in clinical tumor diagnosis and antenatal screening. Most immunoassays provide high sensitivity and accuracy for determining AFP, but they are expensive, often complex, time-consuming procedures. A simple and rapid point-of-care system that integrates Eu (III) chelate microparticles with lateral flow immunoassay (LFIA) has been developed to determine AFP in serum with an assay time of 15 min. The approach is based on a sandwich immunoassay performed on lateral flow test strips. A fluorescence strip reader was used to measure the fluorescence peak heights of the test line (HT) and the control line (HC); the HT/HC ratio was used for quantitation. The Eu (III) chelate microparticles-based LFIA assay exhibited a wide linear range (1.0–1000 IU mL−1) for AFP with a low limit of detection (0.1 IU mL−1) based on 5ul of serum. Satisfactory specificity and accuracy were demonstrated and the intra- and inter-assay coefficients of variation (CV) for AFP were both <10%. Furthermore, in the analysis of human serum samples, excellent correlation (n = 284, r = 0.9860, p < 0.0001) was obtained between the proposed method and a commercially available CLIA kit. Results indicated that the Eu (III) chelate microparticles-based LFIA system provided a rapid, sensitive and reliable method for determining AFP in serum, indicating that it would be suitable for development in point-of-care testing. 相似文献
103.
Selective Alkylation of C‐Rich Bulge Motifs in Nucleic Acids by Quinone Methide Derivatives
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Dr. Tuomas Lönnberg Mark Hutchinson Prof. Dr. Steven Rokita 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):13127-13136
A quinone methide precursor featuring a bis‐cyclen anchoring moiety has been synthesized and its capacity to alkylate oligonucleotide targets quantified in the presence and absence of divalent metal ions (Zn2+, Ni2+ and Cd2+). The oligonucleotides were designed for testing the sequence and secondary structure specificity of the reaction. Gel electrophoretic analysis revealed predominant alkylation of C‐rich bulges, regardless of the presence of divalent metal ions or even the bis‐cyclen anchor. This C‐selectivity appears to be an intrinsic property of the quinone methide electrophile as reflected by its reaction with an equimolar mixture of the 2′‐deoxynucleosides. Only dA‐N1 and dC‐N3 alkylation products were detected initially and only the dC adduct persisted for detection under conditions of the gel electrophoretic analysis. 相似文献
104.
Zhenhu Cao Yan ZhangPingan Song Yuanzheng Cai Qi GuoZhengping Fang Mao Peng 《Journal of Analytical and Applied Pyrolysis》2011,92(2):339-346
A novel metal chelate complex containing phosphorus, nitrogen and zinc (II) ion was synthesized and used as the flame retardant of low density polyethylene (LDPE). The zinc chelate complex was synthesized by reacting zinc acetate with the ligand of tetraethyl (1,2-phenylenebis(azanediyl)) bis (2-hydroxylphenylmethylene) diphosphonate (TEPAPM). The chemical structure of the target Zn-TEPAPM was confirmed by FTIR, 1H NMR, 13C NMR and 31P NMR spectra. The flame retardancy and thermal behavior of LDPE containing various amount of Zn-TEPAPM were investigated by limiting oxygen index test, thermogravimetric (TG) analysis and cone calorimetry. The results show that Zn-TEPAPM can greatly increase the thermal stability, the char formation and smoke suppression ability of LDPE. The TG curves show that even when the filler content of Zn-TEPAPM is as low as 1 wt% in LDPE, the onset degradation temperature of LDPE is increased from 429 °C to 442 °C, and the maximum degradation temperature is increased from 469 °C to 488 °C. Also, a reduction of 32% for the peak heat release rate (PHRR) is obtained in the cone test. Moreover, Zn-TEPAPM is demonstrated to be a very effective synergist of ammonium polyphosphate (APP). When 1 wt% of Zn-TEPAPM was introduced into the LDPE/APP (mass ratio 80/19) blend, the PHRR value is reduced by 32%, compared with that of LDPE/APP blend without Zn-TEPAPM, and the char layer becomes more compact and intact. 相似文献
105.
Yoshitaka Misawa 《Journal of solid state chemistry》2011,184(6):1478-1483
Structures and magnetic properties of double perovskite-type oxides Eu2LnTaO6 (Ln=Eu, Dy-Lu) were investigated. These compounds adopt a distorted double perovskite structure with space group P21/n. Magnetic susceptibility, specific heat, and 151Eu Mössbauer spectrum measurements show that the Eu2+ ions at the 12-coordinate sites of the perovskite structure are antiferromagnetically ordered at ∼4 K, and that Ln3+ ions at the 6-coordinate site are in the paramagnetic state down to 1.8 K. 相似文献
106.
Rong Li Yan Wang Guo‐Liang Chen Mei‐Shi Xiao‐Gang Wang Jian‐Bin Zheng Bin Chen 《中国化学会会志》2011,58(2):215-221
The chromatographic behaviors of proteins on iminodiacetic acid (IDA) column with and without immobilized metal ion were examined in detail. Comparing the effects of pI, solution pH, and salt concentration on retention of proteins in cation‐exchange chromatography (CEC) and metal chelate affinity chromatography (MCAC), the retention mechanism of proteins was investigated in MCAC. By aid of observing the retention characteristics of proteins on naked IDA and metal chelate columns in high concentration salt‐out salt solution, the hydrophobic interaction in MCAC and the influence of metal ion on it were proved. In terms of the comparison of the thermodynamics of proteins in CEC and MCAC, the thermostability, the conformational change entropy Δ(ΔS0) and enthalpy Δ(ΔH0), compensation temperature β, the driving force and caloritic effect of proteins in MCAC were discussed. The identity of retention mechanism at protein thermal denaturation in CEC and MCAC was demonstrated by using the compensation relationship between ΔH0 and ΔS0. 相似文献
107.
Abstract The IR spectra of the linkage isomers [Pd(bipy)(SCN)2] and [Pd(bipy)(NCS)2] have been determined in the C≡N stretching region (2200–2000 cm?1) and below 500 cm?1. The band shifts resulting from deuteration of the 2,2′-bipyridine (bipy) ring and 15NCS-labelling are shown to provide a ready means for distinguishing between the internal ligand modes, the μPd-N(bipy) and μPd-SCN/μPd-NCS vibrations. The assignment technique has been further extended to the complexes [Pt(bipy)(SCN)2] and [Pd(phen)(SCN)2] (phen = 1,10-phenanthroline). Finally, a comparison between the IR spectra of [Pd(bipy)(NCO)2], [Pd(bipy)(NCS)2] and [Pd(bipy)(SCN)2] reveals that the frequencies μM-NCO, μM-NCS and μM-SCN decrease in the sequence NCO > NCS > SCN. 相似文献
108.
Patricia Sakon Williams Frederick J. Troendle Kunisi S. Venkatasubban Robert Rothchild 《光谱学快报》2013,46(7):1229-1251
The 200 MHz 1H NMR spectra of the analgesic, famprofazone, 1, have been studied in CDCl3 solution at ambient temperatures with the achiral lanthanide shift reagent (LSR) tris (6, 6, 7, 7, 8, 8, 8-heptaf luoro-2, 2-dimethyl-3, 5-octanedionato) europium (III), Eu(FOD)3, 2, for spectral simplification, and with the chiral LSR, tris [3-(heptafluoropropylhydroxymethylene) - (+) camphorato] europium (III), Eu (HFC)3, 3. Lanthanide induced shift (LIS) magnitudes suggested predominant LSR binding at the carbonyl oxygen. Substantial enantiomeric shift differences were observed for several nuclei of 1 with added 3 which could permit direct determinations of enantiomeric excess. 相似文献
109.
The 1H and 13C NMR spectra of methaqualone, 1, have been extensively studied using one and two-dimensional techniques. These 300 MHz 1H and 75 MHz 13C studies have allowed rigorous assignments to be made for the methyl groups and the quinazolinone nucleus. The 60 MHz 1H spectra for 1 in CDCl3 have been examined with 相似文献
110.
V. V. Bakovets L. F. Bakhturova T. M. Levashova I. P. Dolgovesova V. O. Borisov 《Journal of Applied Spectroscopy》1998,65(5):812-817
We have studied IR absorption spectra (within the spectral range of 4000-200 cm−1 of the intracomplex chelate compounds Ni(II) bis-acetylacetonate, Ni(II) bis-ketoiminate, and Ni(II) bis-trifluoroacetylacetonate
and have given a full interpretation and comparison of the spectra of these compounds in dissolved and solid states. The reasons
for the differences in the spectra are discussed. The molar coefficients of extinction for the absorption bands are calculated.
Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Akad. Lavrent’ev Ave., Novosibirsk,
630090, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 775–780, September–October, 1998. 相似文献