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991.
Yunlong Liu Prof. Chunfeng Zhang Rui Wang Bo Zhang Prof. Zhanao Tan Prof. Xiaoyong Wang Prof. Min Xiao 《Angewandte Chemie (International ed. in English)》2015,54(21):6222-6226
By creating two triplet excitons from one photo‐excited singlet exciton, singlet fission in organic semiconductors has drawn tremendous attention for its potential applications in boosting the efficiency of solar conversion. Here, we show that this carrier‐multiplication effect can also be used to dramatically improve the nonlinear optical response in organic materials. We have observed large optical nonlinearity with a magnitude of χ(3) up to 10?9 esu in pentacene films, which is further shown to be a result of singlet fission by monitoring the temporal dynamics. The potential application of such efficient nonlinear optical response has been demonstrated with a singlet‐fission‐induced polarization rotation. 相似文献
992.
Crystalline Hetero‐Stereocomplexed Polycarbonates Produced from Amorphous Opposite Enantiomers Having Different Chemical Structures 下载免费PDF全文
Dr. Ye Liu Meng Wang Wei‐Min Ren Yue‐Chao Xu Prof. Dr. Xiao‐Bing Lu 《Angewandte Chemie (International ed. in English)》2015,54(24):7042-7046
Stereocomplexation is the stereoselective interaction between two opposite enantiomeric polymers through an interlocked orderly assembly. Most studies focus on the stereocomplex formation from the crystalline opposite enantiomers having the identical structure; nevertheless, rare examples were reported regarding the crystalline stereocomplexes from enantiomeric polymers having different chemical structures. Herein we show a strategy for polymer orderly assembly through the formation of crystalline hetero‐stereocomplexed polymeric materials by the cocrystallization of amorphous isotactic polycarbonates with different chemical structures and opposite configurations. The behaviors in the crystalline state are significantly different from that of the component enantiomeric polymers or their homo‐stereocomplexes. This study is expected to open up a new way to prepare various semicrystalline materials having a wide variety of physical properties and degradability. 相似文献
993.
Rhodium(III)‐Catalyzed [3+2]/[5+2] Annulation of 4‐Aryl 1,2,3‐Triazoles with Internal Alkynes through Dual C(sp2)H Functionalization 下载免费PDF全文
Yuan Yang Ming‐Bo Zhou Xuan‐Hui Ouyang Rui Pi Dr. Ren‐Jie Song Prof. Dr. Jin‐Heng Li 《Angewandte Chemie (International ed. in English)》2015,54(22):6595-6599
A rhodium(III)‐catalyzed [3+2]/[5+2] annulation of 4‐aryl 1‐tosyl‐1,2,3‐triazoles with internal alkynes is presented. This transformation provides straightforward access to indeno[1,7‐cd]azepine architectures through a sequence involving the formation of a rhodium(III) azavinyl carbene, dual C(sp2)? H functionalization, and [3+2]/[5+2] annulation. 相似文献
994.
Rhodium‐Catalyzed Enantioselective Intramolecular CH Silylation for the Syntheses of Planar‐Chiral Metallocene Siloles 下载免费PDF全文
Dr. Qing‐Wei Zhang Kun An Li‐Chuan Liu Yuan Yue Prof. Dr. Wei He 《Angewandte Chemie (International ed. in English)》2015,54(23):6918-6921
Reported herein is the rhodium‐catalyzed enantioselective C? H bond silylation of the cyclopentadiene rings in Fe and Ru metallocenes. Thus, in the presence of (S)‐TMS‐Segphos, the reactions took place under very mild conditions to afford metallocene‐fused siloles in good to excellent yields and with ee values of up to 97 %. During this study it was observed that the steric hindrance of chiral ligands had a profound influence on the reactivity and enantioselectivity of the reaction, and might hold the key to accomplishing conventionally challenging asymmetric C? H silylations. 相似文献
995.
Cover Picture: Reconstitution of Biosynthetic Machinery for the Synthesis of the Highly Elaborated Indole Diterpene Penitrem (Angew. Chem. Int. Ed. 19/2015) 下载免费PDF全文
996.
White‐Light Emission Strategy of a Single Organic Compound with Aggregation‐Induced Emission and Delayed Fluorescence Properties 下载免费PDF全文
Dr. Zongliang Xie Dr. Chengjian Chen Shidang Xu Jun Li Prof. Yi Zhang Prof. Siwei Liu Prof. Jiarui Xu Prof. Zhenguo Chi 《Angewandte Chemie (International ed. in English)》2015,54(24):7181-7184
A novel white‐light‐emitting organic molecule, which consists of carbazolyl‐ and phenothiazinyl‐substituted benzophenone (OPC) and exhibits aggregation‐induced emission‐delayed fluorescence (AIE‐DF) and mechanofluorochromic properties was synthesized. The CIE color coordinates of OPC were directly measured with a non‐doped powder, which presented white‐emission coordinates (0.33, 0.33) at 244 K to 252 K and (0.35, 0.35) at 298 K. The asymmetric donor–acceptor–donor′ (D‐A‐D′) type of OPC exhibits an accurate inherited relationship from dicarbazolyl‐substituted benzophenone (O2C, D‐A‐D) and diphenothiazinyl‐substituted benzophenone (O2P, D′‐A‐D′). By purposefully selecting the two parent molecules, that is, O2C (blue) and O2P (yellow), the white‐light emission of OPC can be achieved in a single molecule. This finding provides a feasible molecular strategy to design new AIE‐DF white‐light‐emitting organic molecules. 相似文献
997.
Wen Shao He Li Chuan Liu Prof. Dr. Chen‐Jiang Liu Prof. Dr. Shu‐Li You 《Angewandte Chemie (International ed. in English)》2015,54(26):7684-7687
The first copper‐catalyzed intermolecular dearomatization of indoles by an asymmetric propargylic substitution reaction was developed. This method provides a highly efficient synthesis of versatile furoindoline and pyrroloindoline derivatives containing a quaternary carbon stereogenic center and a terminal alkyne moiety with up to 86 % yield and 98 % ee. 相似文献
998.
Synthesis and Intracellular Redox Cycling of Natural Quinones and Their Analogues and Identification of Indoleamine‐2,3‐dioxygenase (IDO) as Potential Target for Anticancer Activity 下载免费PDF全文
Christopher E. Blunt Dr. Canan Torcuk Dr. Yang Liu Dr. William Lewis Dr. David Siegel Prof. Dr. David Ross Prof. Dr. Christopher J. Moody 《Angewandte Chemie (International ed. in English)》2015,54(30):8740-8745
Natural quinones, often linked with cellular oxidation processes, exhibit pronounced biological activity. In particular, the structurally unique isothiazolonaphthoquinone aulosirazole, isolated from blue‐green alga, possesses selective antitumor cytotoxicity, although its mechanism of action is unknown. The first synthesis of aulosirazole uses a route centered upon a late‐stage regioselective Diels–Alder reaction. The structurally related natural product pronqodine A, an inhibitor of prostaglandin release, and analogues thereof, were also prepared for comparison. Biological evaluation of the compounds identified one potential target as the immunoregulatory enzyme indoleamine‐2,3‐dioxygenase (IDO). The isothiazoloquinones are also efficient substrates for the human quinone reductase NQO1, and undergo intracellular NQO1‐dependent redox cycling resulting in the generation of reactive oxygen species, and at lower doses have the potential to alter the ratio of intracellular oxidized to reduced pyridine nucleotides. 相似文献
999.
Cover Picture: Stabilizing Two Classical Antiaromatic Frameworks: Demonstration of Photoacoustic Imaging and the Photothermal Effect in Metalla‐aromatics (Angew. Chem. Int. Ed. 21/2015) 下载免费PDF全文
1000.
Integrating NiCo Alloys with Their Oxides as Efficient Bifunctional Cathode Catalysts for Rechargeable Zinc–Air Batteries 下载免费PDF全文
Dr. Xien Liu Minjoon Park Dr. Min Gyu Kim Shiva Gupta Prof. Gang Wu Prof. Jaephil Cho 《Angewandte Chemie (International ed. in English)》2015,54(33):9654-9658
The lack of high‐efficient, low‐cost, and durable bifunctional electrocatalysts that act simultaneously for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is currently one of the major obstacles to commercializing the electrical rechargeability of zinc–air batteries. A nanocomposite CoO‐NiO‐NiCo bifunctional electrocatalyst supported by nitrogen‐doped multiwall carbon nanotubes (NCNT/CoO‐NiO‐NiCo) exhibits excellent activity and stability for the ORR/OER in alkaline media. More importantly, real air cathodes made from the bifunctional NCNT/CoO‐NiO‐NiCo catalysts further demonstrated superior performance to state‐of‐the‐art Pt/C or Pt/C+IrO2 catalysts in primary and rechargeable zinc–air batteries. 相似文献