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21.
Cover Picture: Double CaromH Activation Associated with Etheral Oxygen Insertion to Phenazine Architecture in Oxidisable Ruthenium(III) Complexes: A Mechanistic Insight (Chem. Eur. J. 10/2014) 下载免费PDF全文
22.
Back Cover: Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes (Chem. Eur. J. 2/2014) 下载免费PDF全文
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24.
A novel and convenient synthetic route for preparing aza-phthalimidine hydroxylactams (5a–j) by N-bromosuccinimide (NBS) was developed. This method involved the substitution reactions of substrates (3a–j) with NBS via unstable intermediate bromides (4a–j) rapidly hydrolyzed into hydroxyl products in the course of the workup process. 相似文献
25.
Pavel F. Vlad Alexandru G. Ciocarlan Mihai N. Coltsa Alexandr V. Baranovsky Natalya B. Khripach 《合成通讯》2013,43(22):3960-3972
This article describes a new efficient synthesis of drim-7,9(11)-diene and its hydroxylated derivates from drim-8-en-7-one. Reduction of this ketone with NaBO4 in the presence of CeCl3 · 7H2O afforded regio- and stereoselectively drim-8-en-7β-ol in a high yield. Its dehydration with H2SO4 under mild conditions led to drim-7,9(11)-diene. Noncatalytic oxidation of drim-7,9(11)-diene with OsO4 and the catalytic oxidation with the pair OsO4–NMO gave, in a high yield, depending on conditions, driman-7β,8β,9α,11-tetraol or its mixture with drim-7-en-9α,11-diol and drim-9(11)-en-7α,8α-diol. Under optimal conditions the total yield of these diols reached 89%. The separate, noncatalytic oxidation of drim-7-en-9α,11-diol and of drim-9(11)-en-7α,8α-diol with OsO4 afforded driman-7α,8α,9α,11-tetraol. 相似文献
26.
A method is described for the preparation of functional polybutadiene (PB) with hydroxyl groups along the polymer chain. This material can be used directly or as the starting substrate for further polymerization in both academic and industrial processes. We have developed a convenient method to obtain a polymer with a narrow molecular weight distribution and with a known content of hydroxyl groups along the backbone. By controlling the hydroxylation reaction conditions, the appropriate molar ratios of THF, water and acid with the epoxide are 30, 15 and 1.5, respectively. By minimizing the crosslinking reaction, the desired PB was prepared and subsequently characterized. 相似文献
27.
Dr. Yan‐Fen Fang Prof. Wan‐Hong Ma Prof. Ying‐Ping Huang Prof. Gen‐Wei Cheng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(9):3224-3229
The band structure of multicomponent semiconductor photocatalysts, as well as their reactivity distinction under different wavelengths of light, is still unclear. BiOBr, which is a typical multicomponent semiconductor, may have two possible valence‐band structures, that is, two discrete valence bands constructed respectively from O 2p and Br 4p orbitals, or one valence band derived from the hybridization of these orbitals. In this work, aqueous photocatalytic hydroxylation is applied as the probe reaction to investigate the nature and reactions of photogenerated holes in BiOBr. Three organic compounds (microcystin‐LR, aniline, and benzoic acid) with different oxidation potentials were selected as substrates. Isotope labeling (H218O as the solvent) was used to determine the source of the O atom in the hydroxyl group of the products, which distinguishes the contribution of different hydroxylation pathways. Furthermore, a spin‐trapping ESR method was used to quantify the reactive oxygen species (.OH and .OOH) formed in the reaction system. The different isotope abundances of the hydroxyl O atom of the products formed, as well as the reverse trend of the .OH/.OOH ratio with the oxidative resistance of the substrate under UV and visible irradiation, reveal that BiOBr has two separate valence bands, which have different oxidation ability and respond to UV and visible light, respectively. This study shows that the band structure of semiconductor photocatalysts can be reliably analyzed with an isotope labeling method. 相似文献
28.
Minami Odagi Kota Furukori Tatsuya Watanabe Prof. Dr. Kazuo Nagasawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(49):16740-16745
Highly enantioselective catalytic oxidation of 1‐tetralone‐derived β‐keto esters was achieved by using a guanidine–urea bifunctional organocatalyst in the presence of cumene hydroperoxide (CHP), a safe, commercially available oxidant. The α‐hydroxylation products were obtained in 99 % yield with up to 95 % enantiomeric excess (ee). The present oxidation was successfully applied to synthesize a key intermediate of the anti‐cancer agent daunorubicin ( 2 ). 相似文献
29.
Acid catalysed epoxy ring opening of several lupane type triterpenoids leads to unusual allylic hydroxylation. The reaction involves the formation of epoxide by m‐chloroperbenzoic acid followed by the treatment of mineral acid. The simple methodology finds utility to introduce a hydroxyl function at the allylic position in these triterpenoids, which is otherwise quite difficult. 相似文献
30.
杂多酸盐催化苯酚羟基化制备苯二酚反应产物的反相高效液相色谱分析 总被引:1,自引:0,他引:1
建立了反相高效液相色谱法测定杂多酸盐催化苯酚羟基化制备苯二酚反应产物的分析方法。样品经稀释和经滤膜过滤处理后,在Shim-pack CLC ODS色谱柱(4.6 mm i.d.×150 mm,5μm)上,以甲醇-水(V(甲醇)∶V(水)=35∶65)+体积分数1%乙酸为流动相,流速为1.0 mL/min,柱温为40℃,紫外检测波长280nm,8 min内可以将对苯二酚、邻苯二酚和苯酚完全分离并定量,三者的线性范围分别为0.01~0.60,0.01~0.50,0.05~1.00 mg/mL。反应后在及时分析样品的前提下,该法适合进行苯酚羟基化的产物分析。 相似文献