全文获取类型
收费全文 | 79篇 |
免费 | 1篇 |
专业分类
化学 | 39篇 |
晶体学 | 2篇 |
数学 | 5篇 |
物理学 | 9篇 |
无线电 | 25篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 9篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 4篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 2篇 |
1999年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有80条查询结果,搜索用时 3 毫秒
1.
Photonic Network Communications - Performance of underwater wireless optical communication (UWOC) with different vertical water channel conditions is experimentally analyzed. Experiment has been... 相似文献
2.
The computational reckoning of 2-Chloropyridine-4-carboxylic acid (2CP4CA) was accomplished employing DFT/B3LYP with the root set as 6–311++G(d, p). The impact of polar protic solvents which are eco-friendly solvents (water, methanol, ethanol, 1-propanol) on 2CP4CA were analysed. To examine the solvent effect, vibrational investigations and NLO reports of 2CP4CA in dissimilar solvents were executed. Geometrical properties were also established in gas phase for 2CP4CA. Exercising VEDA program, the entire vibrational assignment was accomplished. Donor-acceptor exchanges were ascertained utilizing NBO scrutiny technique. Thermodynamic properties of 2CP4CA were analysed at different temperatures. By applying TD - DFT approach, theoretic UV–Vis absorption spectrum was procured in different solvents. In order to evaluate the complete electron concentration and sensitive spots of 2CP4CA, MEP coupled with FMO analyses were employed. HOMO along with LUMO orbitals and energy band gap were acquired for 2CP4CA employing dissimilar polar protic solvents. Additionally, ELF, LOL and charge transfer studies were also executed. RDG analysis has been exercised for revealing non-covalent interactions. 相似文献
3.
Khadhar Navaz Umar Basha Shanthi Gnanamani Prakash Shanmugam Sujatha Venugopal Sangeetha Murthy Balagurunathan Ramasamy 《Journal of heterocyclic chemistry》2021,58(10):2000-2008
A simple and convenient method for the one-pot synthesis of 3-(1H-indole-3-carbonyl)-2H-chromen-2-one derivatives from the reaction of 3-cyanoacetyl indole and salicylaldehyde in the presence of Na2CO3 in water: methanol (1:1) is described. Wider substrate scope, high yields, operational simplicity, and simple purification process make the protocol highly applicable in the synthesis of 3-(1H-indole-3-carbonyl)-2H-chromen-2-ones. For the first time, in vitro antioxidant and antimicrobial activity was studied. Compounds 5e , 7a , and 7b exhibits good radical scavenging ability against DPPH free radical. Compounds 7b , 5f , and 5g possess lower EC50 values than the Standards AA and BHA and thus proving their high reducing power. Compounds 5d and 5f show good antibacterial activity against gram-positive bacteria (MRSA) while compounds 5c , 7a , and 7b exhibits good antibacterial activity against Bacillus sp. Compounds 5b and 5e show good antibacterial activity against gram negative bacterial strains (Escherichia coli, Klebsiella pneumoniae) and compounds 5g and 5h exhibits good antifungal activity against Candida albicans. 相似文献
4.
We present techniques for accurately characterizing the frequency response and noise spectral density of integrated continuous-time filters. A 75-MHz fifth-order Chebyshev Gm-C ladder filter designed in a 0.35-mum CMOS process and packaged in a 40-pin DIP is used as a test vehicle to validate the ideas proposed in this work. When compared to conventional frequency response measurement methods, the proposed techniques show a significantly enhanced measurement accuracy in the stopband, while being less sensitive to package characteristics. 相似文献
5.
Gnanamani Shanthi 《Tetrahedron letters》2008,49(50):7139-7142
An InCl3 catalyzed efficient synthesis of novel dispiro[cyclopent-3′-ene]bisoxindoles is accomplished via a one-pot reductive cyclization of isatylidene malononitriles using the Hantzsch ester. 相似文献
6.
Shanthi Pavan 《IEEE transactions on circuits and systems. I, Regular papers》2008,55(6):1412-1420
7.
Karthikeyan Reddy Shanthi Pavan 《Analog Integrated Circuits and Signal Processing》2010,63(3):397-406
A state variable block diagram method is given for the realization of universal biquadratic transfer functions employing second-generation
current-controlled conveyors (CCCIIs). Using minimum number of passive components and properly adjusting the bias currents
of CCCIIs, the proposed circuits can realize all the tunable frequency standard filter functions: high-pass, band-pass, low-pass,
notch-pass, and all-pass by choosing appropriate input branches without changing the passive elements. These presented circuits
are in current-mode and voltage-mode separately. The non-ideality analyses of these configurations are given. Additionally,
a high-order low-pass filter derived from the proposed voltage-mode biquadratic filter is introduced. PSPICE simulation results
are included to verify the theory. 相似文献
8.
Orienteering problem is a well researched routing problem which is a generalization of the traveling salesman problem. Team orienteering problem (TOP) is the extended version of the orienteering problem with more than one member in the team. In this paper the first known discrete particle swarm optimization (DPSO) algorithm has been developed for 2, 3 and 4-member TOP. In the DPSO meta-heuristic novel methods have been introduced for the initial particle generation process. Reduced variable neighborhood search and 2-opt were applied as the local search tools. The efficacy of the algorithm was tested using seven commonly used benchmark problem sets ranging in size from 21 to 102 nodes. The results of the DPSO algorithm were compared against seven other heuristic algorithms that have been developed for TOP. It was concluded that the developed DPSO algorithm for the TOP is competitive and robust across the benchmark problem sets. 相似文献
9.
V. Violet Dhayabaran J. Princy Merlin I. Sharmila Lydia R. Shanthi R. Sivaraj 《Ionics》2004,10(3-4):288-290
The influence of Fluorescein in conjunction with calcium oxide on the corrosion of Aluminium in 1.0 N NaOH was studied by
galvanostatic studies and weight loss studies. It has been found that the inhibition of corrosion of aluminium increased with
the increasing concentration of the inhibitor. The maximum inhibition efficiency of fluorescein alone was found to be 30.80%.
However, the addition of calcium oxide increased the maximum inhibition efficiency to 53.71%. The corrosion process was found
to be under the anodic control, in the presence or in the absence of inhibitor. The inhibition was found to be mixed type.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, Inida, Nov. 28–30, 2003. 相似文献
10.
Wireless Personal Communications - Data storage has been one of the most prevalent services that has been offered by cloud computing. One of the challenges associated with data storage has been the... 相似文献