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1.
Michael X. Yang Phillip W. Kash Dong-Hong Sun George W. Flynn Brian E. Bent Michael T. Holbrook Simon R. Bare Daniel A. Fischer John L. Gland 《Surface science》1997,380(2-3):151-164
The bonding and reactions of chloroethylenes (vinyl chloride, trans- and cis-dichloroethylene, trichloroethylene) on a Cu(100) surface have been investigated by temperature-programmed desorption and reaction, near-edge X-ray absorption fine structure (NEXAFS) studies and measurements of changes of the surface work function. The monolayer molecules adsorb molecularly intact at 95 K via π coordination. The molecules orient with their molecular planes parallel to the surface with little increase (<0.02 Å) in the C---C bond distance compared with the gas phase values. The degree of thermal dissociation increases with the extent of halogenation, and no chlorine is present in the hydrocarbon reaction products liberated from the surface. Both cis- and trans-1.2-chloroethylene produce acetylene and a small amount of benzene, while dissociation of trichloroethylene generates acetylene and deposits a carbon residue on the surface. Vinyl chloride desorbs from Cu(100) without reaction. 相似文献
2.
《合成通讯》2013,43(24):4477-4482
Abstract Regioselective synthesis of α‐iodoacetates from alkenes, ammonium acetate, and iodine in acetic acid is reported. The reaction is facile, fast, environmentally, friendly, and cost effective. α‐Iodoacetates are obtained from both acyclic and cyclic alkenes in high yields ranging from 80–95% within 10–20 min. 相似文献
3.
Shang Wu Hongheng Yu Qinzheng Hu Quanlu Yang Shouwang Xu Tian Liu 《Tetrahedron letters》2017,58(51):4763-4765
A silver-catalyzed decarboxylative cross-coupling of α-keto acids with alkenes is reported. The method, with a wide range of substrate tolerance and mild operational conditions, can produce various chalcone derivatives in moderate to high yields from easily available starting materials. 相似文献
4.
Kiyoshi Tanemura 《Tetrahedron letters》2018,59(49):4293-4298
Silica gel-mediated hydrochlorination of unactivated alkenes using 35% hydrochloric acid under organic solvent-free conditions proceeded to give the corresponding chlorides in good yields. Hydrobromination or hydriodination using 47% hydrobromic acid or 55% hydriodic acid afforded the corresponding halides, respectively. Silica gel could be recycled five times without any significant loss of activities. 相似文献
5.
Yun Shi Rongshun Chen Kang Guo Fei Meng Shujun Cao Chen Gu Yingguang Zhu 《Tetrahedron letters》2018,59(21):2062-2065
A metal-free direct aerobic oxyphosphorylation of alkenes with H-phosphine oxides has been developed utilizing visible light photoredox catalysis. A variety of β-ketophosphine oxides have been obtained in good yields from simple olefins under air with inexpensive rhodamine B as the non-metallic photocatalyst. This method provides a mild, green, and practical synthetic approach to valuable β-ketophosphine oxides. 相似文献
6.
The dibromination of alkenes and alkynes with bromosuccinimide and sodium bromide catalyzed by FeBr3 under mild conditions has been developed.The trans-dibromo compounds were exclusively obtained with excellent yields. 相似文献
7.
The intramolecular hydroacylation of 1,2-disubstituted alkenes was considered to be a challenging task due to the side reactions resulted from the lack of additional substituent at 1-position and the low activity caused by the steric hindrance of substituent at 2-position, and an asymmetric version has not been considered possible due to problems associated with the racemization of the products. We have partially solved these problems. Catalyzed by an activated diphosphine-Rh complex and reacted in a selected dihalogenated solvent, the intramolecular hydroacylation of o-(2-arylvinyl)benzaldehydes provided the corresponding 2-aryl-1-indanones in high yields, and its asymmetric variant using o-(2-alkylvinyl)benzaldehydes afforded chiral 2-alkyl-1-indanones in high yields and with moderate enantioselectivities. 相似文献
8.
A mild, efficient, and highly regio- and stereoselective method for the methoxy and ethoxy bromination of olefins has been developed using NH4Br as a bromine source and Oxone as an oxidant. Various kinds of olefins (aromatic, linear, and cyclic olefins) afforded the corresponding alkoxy brominated products in moderate to excellent yields. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.] 相似文献
9.
Two new classes of proline‐based P,O and P,N ligands were prepared and applied in the iridium‐catalyzed asymmetric hydrogenation of alkenes. Both types of ligands induced high enantioselectivities in the hydrogenation of trisubstituted C?C bonds. Iridium complexes derived from P,O ligands bearing sterically demanding amide or urea groups at the pyrrolidine N‐atom proved to be especially efficient catalysts for the conjugate reduction of α,β‐unsaturated esters and ketones, whereas analogous P,N ligands led to better results with dialkyl‐phenyl‐substituted alkenes and an allylic alcohol as substrates. 相似文献
10.
Takumi Abe Hiroyuki Takeda Yoshihisa Miwa Koji Yamada Reiko Yanada Minoru Ishikura 《Helvetica chimica acta》2010,93(2):233-241
It was shown that dichloramine‐T ( 1 ) reacted with cyclohexene in acetonitrile to give N1‐(2‐chlorocyclohexyl) amidine 2a and N‐(2‐chlorocyclohexyl)acetamide ( 3 ) via the competitive addition of acetonitrile and N‐chloro‐N‐tosylamino anion to cyclohexenechloronium ion. This reaction can be catalyzed by Cu(OAc)2, primarily affording 2a . Furthermore, the resulting 2a can be cyclized to benzimidazol 14a in good yield by treating with KOH in dioxane. 相似文献