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911.
Dr. Gang Liao Dr. Tao Zhang Zhi-Keng Lin Prof. Dr. Bing-Feng Shi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(45):19941-19954
Transition metal-catalyzed enantioselective functionalization of C−H bond, the most abundant functionality in organic molecules, has emerged as an expedient synthetic approach to streamline the synthesis of complex chiral molecules. Despite significant progress, traditional directing group-enabled strategies require additional steps for the installation and removal of directing groups from the target molecule. The recently developed asymmetric C−H functionalization using chiral transient directing groups (cTDGs) offers a promising alternative that can circumvent this obstacle and therefore simplify the process. In this Minireview, we briefly discuss the advent and recent advances of this emerging concept, with an emphasis on discussing the creation of various stereogenic centers and the developments of cTDGs. Applications in natural product synthesis and ligand derivatizations are also discussed. We hope this Minireview will highlight the great potential of this strategy and help to inspire further endeavors. 相似文献
912.
Tomáš Čarný Dr. Ronan Rocaboy Dr. Antonin Clemenceau Prof. Dr. Olivier Baudoin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(43):19142-19146
The 1,4-palladium shift strategy allows the functionalization of remote C−H bonds that are difficult to reach directly. Reported here is a domino reaction proceeding by C(sp3)−H activation, 1,4-palladium shift, and amino- or alkoxycarbonylation, which generates a variety of amides and esters bearing a quaternary β-carbon atom. Mechanistic studies showed that the aminocarbonylation of the σ-alkylpalladium intermediate arising from the palladium shift is fast using PPh3 as the ligand, and leads to the amide rather than the previously reported indanone product. 相似文献
913.
Dmytro Strilets Dr. Shixin Fa Arthur Hardiagon Dr. Marc Baaden Prof. Tomoki Ogoshi Dr. Mihail Barboiu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23413-23419
Artificial water channels mimicking natural aquaporins (AQPs) can be used for selective and fast transport of water. Here, we quantify the transport performances of peralkyl-carboxylate-pillar[5]arenes dimers in bilayer membranes. They can transport ≈107 water molecules/channel/second, within one order of magnitude of the transport rates of AQPs, rejecting Na+ and K+ cations. The dimers have a tubular structure, superposing pillar[5]arene pores of 5 Å diameter with twisted carboxy-phenyl pores of 2.8 Å diameter. This biomimetic platform, with variable pore dimensions within the same structure, offers size restriction reminiscent of natural proteins. It allows water molecules to selectively transit and prevents bigger hydrated cations from passing through the 2.8 Å pore. Molecular simulations prove that dimeric or multimeric honeycomb aggregates are stable in the membrane and form water pathways through the bilayer. Over time, a significant shift of the upper vs. lower layer occurs initiating new unexpected water permeation events through toroidal pores. 相似文献
914.
Pengcheng Lian Wenhao Long Jingjing Li Yonggao Zheng Prof. Dr. Xiaobing Wan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23809-23814
This work demonstrates photoredox vicinal dichlorination of alkenes, based on the homolysis of CuCl2 in response to irradiation with visible light. This catalysis proceeds via a ligand to metal charge transfer process and provides an exciting opportunity for the synthesis of 1,2-dichloride compounds using an inexpensive, low-molecular-weight chlorine source. This new process exhibits a wide substrate scope, excellent functional group tolerance, extraordinarily mild conditions and does not require external ligands. Mechanistic studies show that the ready formation of chlorine atom radicals is responsible for the facile formation of C−Cl bonds in this synthetic process. 相似文献
915.
Dr. Yaru Gong Chao Qin Yuteng Zhang Prof. Chunyi Sun Prof. Qinhe Pan Xinlong Wang Zhongmin Su 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22218-22222
Systematic design and self-assembly of metal–organic polyhedra with predictable configurations has been a long-standing challenge in crystal engineering. Herein a concave polyoxovanadate cluster, [V6O6(OCH3)9(SO4)4]5−, which can be generated in situ under specific reaction conditions, is reported. Based on this cluster, a potential trivalent molecular building block, [V6O6(OCH3)9(SO4)(CO2)3]2−, can be obtained by the bridging-ligand-substitution strategy and it possesses appropriate angle information for the design of molecular cubes. Utilizing the face-directed assembly of the trivalent molecular building block and a diverse set of tetratopic carboxylate linkers, a series of metal–organic cubes ( VMOC-1 – VMOC-5 ) with the same topology but different functionalities and dimensions were designed and constructed. An inclusion study using VMOC-3 shows that they are potential molecular receptors for selective capture of size-matching polycyclic aromatic hydrocarbon guest molecules. 相似文献
916.
917.
Tongtong Feng Dr. Yingxiang Ye Xiao Liu Hui Cui Dr. Zhiqiang Li Dr. Ying Zhang Dr. Bin Liang Prof. Huanrong Li Prof. Banglin Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(48):21936-21941
Temperature sensors play a significant role in biology, chemistry, and engineering, especially those that can work accurately in a noninvasive manner. We adopted a photoinduced post-synthetic copolymerization strategy to realize a membranous ratiometric luminescent thermometer based on the emissions of two lanthanide ions. This novel mixed-lanthanide polyMOF membrane exhibits not only the integrity and temperature sensing behaviour of the Ln-MOF powder but also excellent mechanical properties, such as flexibility, elasticity, and processability. Moreover, the polyMOF membrane shows remarkable stability under harsh conditions, including high humidity, strong acid and alkali (pH 0–14), which allowed the mapping of temperature distributions in extreme circumstances. This work highlights a simple strategy for polyMOF membrane formation and pushes forward the further practical application of Ln-MOF-based luminescent thermometers in various fields and conditions. 相似文献
918.
Dr. On Ying Yuen Dr. Chau Ming So 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23644-23650
This study describes the first palladium-catalyzed, site-selective α- and γ-arylation of α,β-unsaturated ketones with (hetero)aryl halides. A wide range of hetero(aryl)halides coupled with α,β-unsaturated ketones, and transformation into the arylated products proceeded with excellent to good yields. The site selectivity of the reaction is switchable by simply changing the phosphine ligand to access either α-arylated or γ-arylated products in good to excellent yields by using a low catalyst loading, and the method demonstrates good functional-group compatibility. 相似文献
919.
920.