全文获取类型
收费全文 | 17478篇 |
免费 | 2413篇 |
国内免费 | 2862篇 |
专业分类
化学 | 13882篇 |
晶体学 | 275篇 |
力学 | 734篇 |
综合类 | 264篇 |
数学 | 1953篇 |
物理学 | 5645篇 |
出版年
2024年 | 6篇 |
2023年 | 157篇 |
2022年 | 257篇 |
2021年 | 400篇 |
2020年 | 477篇 |
2019年 | 539篇 |
2018年 | 449篇 |
2017年 | 405篇 |
2016年 | 695篇 |
2015年 | 753篇 |
2014年 | 903篇 |
2013年 | 1288篇 |
2012年 | 1451篇 |
2011年 | 1512篇 |
2010年 | 1161篇 |
2009年 | 1125篇 |
2008年 | 1384篇 |
2007年 | 1272篇 |
2006年 | 1160篇 |
2005年 | 970篇 |
2004年 | 914篇 |
2003年 | 824篇 |
2002年 | 924篇 |
2001年 | 719篇 |
2000年 | 517篇 |
1999年 | 419篇 |
1998年 | 257篇 |
1997年 | 273篇 |
1996年 | 222篇 |
1995年 | 205篇 |
1994年 | 182篇 |
1993年 | 169篇 |
1992年 | 157篇 |
1991年 | 110篇 |
1990年 | 101篇 |
1989年 | 86篇 |
1988年 | 49篇 |
1987年 | 52篇 |
1986年 | 40篇 |
1985年 | 36篇 |
1984年 | 26篇 |
1983年 | 16篇 |
1982年 | 12篇 |
1981年 | 14篇 |
1980年 | 9篇 |
1978年 | 11篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1974年 | 5篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Hong Zhang Chenxu Zhao Jianxi Yao Wallace C. H. Choy 《Angewandte Chemie (International ed. in English)》2023,62(24):e202219307
Advancing inverted (p-i-n) perovskite solar cells (PSCs) is critical for commercial applications given their compatibility with different bottom cells for tandem photovoltaics, low-temperature processability (≤100 °C), and promising operational stability. Although inverted PSCs have achieved an efficiency of over 25 % using doped or expensive organic hole transport materials (HTMs), their synthesis cost and stability still cannot meet the requirements for their commercialization. Recently, dopant-free and low-cost non-stoichiometric nickel oxide nanocrystals (NiOx NCs) have been extensively studied as a low-cost and effective HTM in perovskite optoelectronics. In this minireview, we summarize the synthesis and surface-functionalization methods of NiOx NCs. Then, the applications of NiOx NCs in other perovskite optoelectronics beyond photovoltaics are discussed. Finally, we provide a perspective for the future development of NiOx NCs for the commercialization of perovskite optoelectronics. 相似文献
92.
Ye Qian Mi Wei Deng Chaohui He Prof. Dr. Osman Eksik Yi Ping Zheng De Kun Yao Dr. Xian Bin Liu Yan Hong Yin Ye Sheng Li Prof. Dr. Bao Yu Xia Prof. Dr. Zi Ping Wu 《Angewandte Chemie (International ed. in English)》2023,62(12):e202218621
Solid-state lithium batteries are promising and safe energy storage devices for mobile electronics and electric vehicles. In this work, we report a facile in situ polymerization of 1,3-dioxolane electrolytes to fabricate integrated solid-state lithium batteries. The in situ polymerization and formation of solid-state dioxolane electrolytes on interconnected carbon nanotubes (CNTs) and active materials is the key to realizing a high-performance battery with excellent interfacial contact among CNTs, active materials and electrolytes. Therefore, the electrodes could be tightly integrated into batteries through the CNTs and electrolyte. Electrons/ions enable full access to active materials in the whole electrode. Electrodes with a low resistance of 4.5 Ω □−1 and high lithium-ion diffusion efficiency of 2.5×10−11 cm2 s−1 can significantly improve the electrochemical kinetics. Subsequently, the batteries demonstrated high energy density, amazing charge/discharge rate and long cycle life. 相似文献
93.
Haoran Dong Dachao Hu Dr. Benke Hong Dr. Jin Wang Prof. Dr. Xiaoguang Lei 《Angewandte Chemie (International ed. in English)》2023,62(20):e202301872
We report herein the first total syntheses of four natural antibiotics, vermisporin, PF1052/AB4015-A, AB4015-L, AB4015-B, and one hydrogenated natural product derivative, AB4015-A2, that all feature a tetramic acid bearing cis-decalin ring. The construction of the functionalized cis-decalin ring was achieved by a diastereoselective intramolecular Diels-Alder (IMDA) reaction, which proceeded via a rare endo-boat transition state. Through an intramolecular neighboring-group-oriented strategy, the sterically hindered epoxy group in vermisporin, PF1052/AB4015-A and AB4015-L was installed efficiently. A one-pot aminolysis/Dieckmann condensation cascade using l -amino acid derivatives afforded the desired tetramic acid structure. The total synthesis led to the unambiguous verification of the absolute configuration of these natural products. 相似文献
94.
Dr. Hyun June Choi Elliott L. Bruce Kevin S. Kencana Jingeon Hong Prof. Paul A. Wright Prof. Suk Bong Hong 《Angewandte Chemie (International ed. in English)》2023,62(36):e202305816
An understanding of the CO2 adsorption mechanisms on small-pore zeolites is of practical importance in the development of more efficient adsorbents for the separation of CO2 from N2 or CH4. Here we report that the CO2 isotherms at 25–75 °C on cesium-exchanged phillipsite zeolite with a Si/Al ratio of 2.5 (Cs-PHI-2.5) are characterized by a rectilinear step shape: limited uptake at low CO2 pressure (PCO2) is followed by highly cooperative uptake at a critical pressure, above which adsorption rapidly approaches capacity (2.0 mmol g−1). Structural analysis reveals that this isotherm behavior is attributed to the high concentration and large size of Cs+ ions in dehydrated Cs-PHI-2.5. This results in Cs+ cation crowding and subsequent dispersal at a critical loading of CO2, which allows the PHI framework to relax to its wide pore form and enables its pores to fill with CO2 over a very narrow range of PCO2. Such a highly cooperative phenomenon has not been observed for other zeolites. 相似文献
95.
Qiao Zhang Hsin Jung Tsai Fuhua Li Zhiming Wei Qinye He Dr. Jie Ding Yuhang Liu Zih-Yi Lin Xiaoju Yang Dr. Zhaoyang Chen Prof. Fangxin Hu Prof. Xuan Yang Prof. Qing Tang Prof. Hong Bin Yang Prof. Sung-Fu Hung Prof. Yueming Zhai 《Angewandte Chemie (International ed. in English)》2023,62(44):e202311550
Single-atom catalysts exhibit superior CO2-to-CO catalytic activity, but poor kinetics of proton-coupled electron transfer (PCET) steps still limit the overall performance toward the industrial scale. Here, we constructed a Fe−P atom paired catalyst onto nitrogen doped graphitic layer (Fe1/PNG) to accelerate PCET step. Fe1/PNG delivers an industrial CO current of 1 A with FECO over 90 % at 2.5 V in a membrane-electrode assembly, overperforming the CO current of Fe1/NG by more than 300 %. We also decrypted the synergistic effects of the P atom in the Fe−P atom pair using operando techniques and density functional theory, revealing that the P atom provides additional adsorption sites for accelerating water dissociation, boosting the hydrogenation of CO2, and enhancing the activity of CO2 reduction. This atom-pair catalytic strategy can modulate multiple reactants and intermediates to break through the inherent limitations of single-atom catalysts. 相似文献
96.
Dr. Shi Xuan Leong Dr. Ya-Chuan Kao Dr. Xuemei Han Dr. Zhong Wei Poh Jaslyn Ru Ting Chen Emily Xi Tan Yong Xiang Leong Dr. Yih Hong Lee Dr. Wei Xuan Teo Prof. George W. Yip Prof. Yulin Lam Prof. Xing Yi Ling 《Angewandte Chemie (International ed. in English)》2023,62(44):e202309610
Molecular recognition of complex isomeric biomolecules remains challenging in surface-enhanced Raman scattering (SERS) spectroscopy due to their small Raman cross-sections and/or poor surface affinities. To date, the use of molecular probes has achieved excellent molecular sensitivities but still suffers from poor spectral specificity. Here, we induce “charge and geometry complementarity” between probe and analyte as a key strategy to achieve high spectral specificity for effective SERS molecular recognition of structural analogues. We employ 4-mercaptopyridine (MPY) as the probe, and chondroitin sulfate (CS) disaccharides with isomeric sulfation patterns as our proof-of-concept study. Our experimental and in silico studies reveal that “charge and geometry complementarity” between MPY's binding pocket and the CS sulfation patterns drives the formation of site-specific, multidentate interactions at the respective CS isomerism sites, which “locks” each CS in its analogue-specific complex geometry, akin to molecular docking events. Leveraging the resultant spectral fingerprints, we achieve > 97 % classification accuracy for 4 CSs and 5 potential structural interferences, as well as attain multiplex CS quantification with < 3 % prediction error. These insights could enable practical SERS differentiation of biologically important isomers to meet the burgeoning demand for fast-responding applications across various fields such as biodiagnostics, food and environmental surveillance. 相似文献
97.
Xuwen Cao Caixia Zhu Qing Hong Xinghua Chen Kaiyuan Wang Prof. Yanfei Shen Prof. Songqin Liu Prof. Yuanjian Zhang 《Angewandte Chemie (International ed. in English)》2023,62(27):e202302463
Ascorbate (H2A) is a well-known antioxidant to protect cellular components from free radical damage and has also emerged as a pro-oxidant in cancer therapies. However, such “contradictory” mechanisms underlying H2A oxidation are not well understood. Herein, we report Fe leaching during catalytic H2A oxidation using an Fe−N−C nanozyme as a ferritin mimic and its influence on the selectivity of the oxygen reduction reaction (ORR). Owing to the heterogeneity, the Fe-Nx sites in Fe−N−C primarily catalyzed H2A oxidation and 4 e− ORR via an iron-oxo intermediate. Nonetheless, trace O2⋅− produced by marginal N−C sites through 2 e− ORR accumulated and attacked Fe-Nx sites, leading to the linear leakage of unstable Fe ions up to 420 ppb when the H2A concentration increased to 2 mM. As a result, a substantial fraction (ca. 40 %) of the N−C sites on Fe−N−C were activated, and a new 2+2 e− ORR path was finally enabled, along with Fenton-type H2A oxidation. Consequently, after Fe ions diffused into the bulk solution, the ORR at the N−C sites stopped at H2O2 production, which was the origin of the pro-oxidant effect of H2A. 相似文献
98.
Mingjie Zeng Changyue Yu Yibing Wang Jingjing Wang Jiang Wang Hong Liu 《Angewandte Chemie (International ed. in English)》2023,62(22):e202300424
We report a ligand-controlled CoII-catalyzed C(sp3)−C(sp3) coupling hydroalkylation for direct and β-selective synthesis of 2-deoxy-C-glycosides from glycals. This reaction proceeds by a radical pathway for alkyl halide activation and is β-selective through ligand control. This approach may inspire the development of further stereoselective coupling reactions with potential application in the field of carbohydrates. 相似文献
99.
Bingyu Huang Xiannong Tang Yaoshuai Hong Longbin Li Prof. Ting Hu Prof. Kai Yuan Prof. Yiwang Chen 《Angewandte Chemie (International ed. in English)》2023,62(33):e202306667
Catalysts with metal-Nx sites have long been considered as effective electrocatalysts for oxygen reduction reaction (ORR), yet the accurate structure-property correlations of these active sites remain debatable. Report here is a proof-of-concept method to construct 1,4,8,11-tetraaza[14]annulene (TAA)-based polymer nanocomposites with well-managed electronic microenvironment via electron-donors/acceptors interaction of altering electron-withdrawing β-site substituents. DFT calculation proves the optimal −Cl substituted catalyst (CoTAA−Cl@GR) tailored the key OH* intermediate interaction with Co−N4 sites under the d-orbital regulation, hence reaching the top of ORR performance with excellent turnover frequency (0.49 e s−1 site−1). The combination of in situ scanning electrochemical microscopy and variable-frequency square wave voltammetry techniques contribute the great ORR kinetics of CoTAA−Cl@GR to the relatively high accessible site density (7.71×1019 site g−1) and fast electron outbound propagation mechanism. This work provides theoretical guidance for rational design of high-performance catalysts for ORR and beyond. 相似文献
100.
Jindou Tian Prof. Dr. Qihui Chen Prof. Dr. Feilong Jiang Prof. Dr. Daqiang Yuan Prof. Dr. Maochun Hong 《Angewandte Chemie (International ed. in English)》2023,62(7):e202215253
Developing practical storage technologies for acetylene (C2H2) is important but challenging because C2H2 is useful but explosive. Here, a novel metal–organic framework (MOF) ( FJI-H36 ) with adaptive channels was prepared. It can effectively capture C2H2 (159.9 cm3 cm−3) at 1 atm and 298 K, possessing a record-high storage density (561 g L−1) but a very low adsorption enthalpy (28 kJ mol−1) among all the reported MOFs. Structural analyses show that such excellent adsorption performance comes from the synergism of active sites, flexible framework, and matched pores; where the adsorbed-C2H2 can drive FJI-H36 to undergo induced-fit transformations step by step, including deformation/reconstruction of channels, contraction of pores, and transformation of active sites, finally leading to dense packing of C2H2. Moreover, FJI-H36 has excellent chemical stability and recyclability, and can be prepared on a large scale, enabling it as a practical adsorbent for C2H2. This will provide a useful strategy for developing practical and efficient adsorbents for C2H2 storage. 相似文献