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61.
A Selective RhI‐Catalyzed Substrate‐Controlled C−C Bond Activation of Benzyl Sulfonamide/Alcohol‐Tethered Alkylidenecyclopropanes
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Kai Chen Jia‐Xin Liu Dr. Xiang‐Ying Tang Prof. Min Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(33):11549-11553
Benzyl sulfonamide/alcohol‐tethered alkylidenecyclopropanes undergo a rhodium‐catalyzed and substrate‐controlled selective C?C bond activation, producing three types of common organic structural units: benzo[c]azepine/oxepines, dihydronaphthalen‐1‐amines, and conjugated dienes. Epoxidation and aromatization of these products to construct two useful compounds have also been achieved. 相似文献
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A growing interest in biodegradable polymers and their biomedical and pharmaceutical applications has developed since the past decade. Ring-opening polymerization has been regarded as an efficient route for the synthesis of the biodegradable polymers, such as polyester, polycar- bonates and polyphosphates[1—6]. However, chemical methods for the ring-opening polymerization of biodegradable polymers need extremely pure monomers and anhydrous conditions as well as metallic catalysts, which must … 相似文献
64.
Xin ZHOU Shrong Shi LIN Jin Fang YUAN* Zhe Ming WANG Hong Zhong WANG College of Chemical Molecular Engineering Peking University Beijing Department of Biological Sciences & Biotechnology Tsinghua Univ 《中国化学快报》2001,(10)
A lot of attentions have been paid to the synthesis of benzothiazepines and derivatives1,2 due to their significant physiological activities. It has been reported that b-lactam, a major part of the antibiotic skeleton, can be introduced to a molecule by reaction of an imine moiety with ketene3,4. We introduced a b-lactam skeleton to benzothiazepine and hoped the new compounds may possess certain biological activities. SHNH3ClCHCHCOC2H5OHSNClCla: ortho-Clb: para-Cl+PyridineScheme … 相似文献
65.
通过稀土氯化物与席夫碱钠盐的交换反应制备了一系列以 3,5-二叔丁基水杨醛缩苯胺为配体的稀土席夫碱配合物. 对其中的钕席夫碱配合物进行了 X射线单晶衍射分析, 发现其单晶结构为五角双锥构型, 所得席夫碱稀土配合物可以单组分催化 ?-己内酯开环聚合. 深入研究了钕席夫碱配合物催化己内酯的开环聚合机理, 考察了不同聚合条件对单体转化率、产物分子量及分子量分布的影响. 结果表明, 该聚合反应速率为一级, 聚合反应具有较好的可控性. 聚合物端基分析表明, 聚合反应以配位-插入机理进行. 相似文献
66.
2-Bromo-1-aryl substituted indenes can be synthesized from 1,2-diaryl substituted gem-dibromocyclopropanes via a domino reaction sequence. The cascade reaction involves silver(I) promoted ionization and 2π-disrotatory electrocyclic ring-opening, followed by a 4π-conrotatory electrocyclic ring closing reaction of the allylic carbocation intermediate. Reaction conditions utilize silver tetrafluoroborate (AgBF4) in dichloroethane at 65 °C. Selectivity effects for the electrocyclization were also studied. The 2-bromoindenes can be further functionalized using cross-coupling reactions, such as the Suzuki–Miyaura protocol. The alkene π-bond of the indenes can also be isomerized to give the thermodynamically more stable 2-bromo-3-aryl-1H-indene isomers using triethylamine in dichloromethane at room temperature. 相似文献
67.
Jun LING Yi Feng ZHANG* Zhi Quan SHEN Institute of Polymer Science Zhejiang University Hangzhou 《中国化学快报》2001,(1)
Aliphatic polycarbonate is a series of useful biodegradable materials attracting more interests recently. Poly(2,2-dimethyltrimethylene carbonate) (polyDTC) has been studied for a long time. Polymerization of DTC can be catalyzed by alkyl metals1, trifluoromethanesulfonic acid and its esters2, alcohol/methylaluminum diphenolate system3 and etc. Herein tris(2,6-di-tert-butyl-4-methylphenoxo) lanthanides (Ln(OAr)3, Ln=La, Nd) are firstly applied to initiate the polymerization of DTC. Ln(O… 相似文献
68.
Joseph H. Reibenspies Erach R. Talaty Mashitah M. Yusoff 《Journal of chemical crystallography》1997,27(12):727-730
The crystal and molecular structure of (RS)-N-Tert-butyl-2-anilino-3,3-dimethylbutanamide, a derivative of an amino acid that was obtained by highly selective cleavage of 1,3-di-tert-butylaziridinone by aniline, is described. The racemic mixture of the amide crystallizes in the space groupP 21/n with four molecules per unit cell. Crystal Data:a=10.483(2) Å,b=6.206(1) Å,c=24.767(5) Å,β=90.39(3),V=1611.5(6) A3,R(F)[I>2σ(I)]=0.0679.wR(F 2) [I>2σ(I)]=0.1148. 相似文献
69.
Takeshi Endo Yuji Shibasaki Fumio Sanda 《Journal of polymer science. Part A, Polymer chemistry》2002,40(13):2190-2198
This article reviews recent topics in the controlled synthesis of polycarbonates and polylactones with small polydispersity indices by activated monomer cationic ring-opening polymerizations, especially with new initiator systems, such as alcohol/protonic acid and boron alkoxide/protonic acid. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2190–2198, 2002 相似文献
70.