全文获取类型
收费全文 | 115篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 76篇 |
力学 | 1篇 |
数学 | 3篇 |
物理学 | 12篇 |
无线电 | 25篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 7篇 |
2020年 | 13篇 |
2019年 | 14篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 1篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有117条查询结果,搜索用时 328 毫秒
71.
Shubham Pandey Vineet Kumar Soni Ganpat Choudhary Pragati R. Sharma 《Supramolecular chemistry》2017,29(5):387-394
The present study describes non-covalent interaction and complexation behaviour of sodium ascorbate (SA) with cucurbit[6]uril (CB[6]) at neutral pH in aqueous Na2SO4 solution. The interaction behaviour is investigated using various analytical techniques like NMR, UV–Vis, fluorescence, TGA and DRS. The substantial increase in the intensity of emission and absorption spectra of sodium ascorbate is observed. The Benesi–Hildebrand evaluation method is used to determine the stoichiometry and equilibrium constant of the cucurbit[6]uril–sodium ascorbate complex, which suggested the 1:1 complex. Time-dependent 1H NMR, 13C CP MAS and CD studies also echoed non-covalent interaction between SA with CB[6]. 相似文献
72.
In the present communication glass stability (GS) and glass forming ability (GFA) of Ge25−xSe75Sbx (x = 12, 15, and 18) chalcogenide glasses have been calculated in terms of certain thermal parameters, i.e., reduced glass transition temperature (Trg), Hruby number (H), S-parameter (S), and ΔT. The glassy samples have been prepared by quenching of melt technique. For structure characterization, XRD technique has been used. For thermal analysis Differential Scanning Calorimetery (DSC) has been used. DSC scans have been recorded at different heating rates, i.e., 5, 10, 15, and 20 K min−1. Stability of glassy samples has also been confirmed in terms of activation energy of glass transition calculated by Kissinger relation. All these parameters indicate that GS and GFA both decrease with increase of Sb content in Ge25−xSe75Sbx (x = 12, 15, and 18) glassy series. 相似文献
73.
Journal of Solid State Electrochemistry - Only about 3% of Earth’s water is freshwater out of which only 0.4% is accessible as surface water in the form of lakes, rivers and groundwater. When... 相似文献
74.
Bhowmik Ratul Manaithiya Ajay Vyas Bharti Nath Ranajit Rehman Sara Roy Shubham Roy Ratna 《Structural chemistry》2022,33(3):815-831
Structural Chemistry - The Ebola virus is a deadly pathogen that causes a highly lethal hemorrhagic fever illness in humans, sometimes known as Ebola virus sickness (EVD). The Ebola virus... 相似文献
75.
76.
M.K. Tiwari N. Raghavendra Shubham Agrawal S.K. Goyal 《European Journal of Operational Research》2010
Supply chain network design is considered a strategic decision level problem that provides an optimal platform for the effective and efficient supply chain management. In this research, we have mathematically modeled an integrated supply chain design. To ensure high customer service levels, we propose the inclusion of multiple shipping/transportation options and distributed customer demands with fixed lead times into the supply chain distribution framework and formulated an integer-programming model for the five-tier supply chain design problem considered. The problem has been made additionally complex by including realistic assumptions of nonlinear transportation and inventory holding costs and the presence of economies of scale. In the light of aforementioned facts, this research proposes a novel solution methodology that amalgamates the features of Taguchi technique with Artificial Immune System (AIS) for the optimum or near optimum resolution of the problem at hand. The performance of the proposed solution methodology has been benchmarked against a set of test instances and the obtained results are compared against those obtained by Genetic Algorithm (GA), Hybrid Taguchi–Genetic Algorithm (HTGA) and AIS. Simulation results indicate that the proposed approach can not only search for optimal/near optimal solutions in large search spaces but also has good repeatability and convergence characteristics, thereby proving its superiority. 相似文献
77.
78.
79.
80.
Shubham Dutta Shengwen Yang Rajeshwer Vanjari Rajendra K. Mallick Vincent Gandon Akhila K. Sahoo 《Angewandte Chemie (International ed. in English)》2020,59(27):10785-10790
A three‐component Pd‐catalyzed coupling of ynamides, aryl diazonium salts, and aryl boronic acids for the synthesis of novel triaryl‐substituted enamides is described. This transformation represents the first example of an umpolung regioselective unsymmetrical syn‐1,2‐diarylation/aryl‐olefination of ynamides. The aryl moieties of the diazonium salt (electrophile) and boronic acid (nucleophile) are explicitly incorporated in the electrophilic α‐ and nucleophilic β‐position, respectively, of the ynamide, resulting in a single isomer of the N‐bearing tetrasubstituted olefin. The scope is broad (68 examples), showing excellent functional‐group tolerance. DFT calculations substantiate the rationale of the mechanistic cycle and the regioselectivity. The chemoselectivity and synthetic potential of the enamide products were also studied. 相似文献