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941.
Ultraviolet‐Light‐Induced Reversible and Stable Carrier Modulation in MoS2 Field‐Effect Transistors 下载免费PDF全文
Arun Kumar Singh Shaista Andleeb Jai Singh Hoang Tien Dung Yongho Seo Jonghwa Eom 《Advanced functional materials》2014,24(45):7125-7132
The tuning of charge carrier concentrations in semiconductor is necessary in order to approach high performance of the electronic and optoelectronic devices. It is demonstrated that the charge‐carrier density of single‐layer (SL), bilayer (BL), and few‐layer (FL) MoS2 nanosheets can be finely and reversibly tuned with N2 and O2 gas in the presence of deep‐ultraviolet (DUV) light. After exposure to N2 gas in the presence of DUV light, the threshold voltages of SL, BL, and FL MoS2 field‐effect transistors (FETs) shift towards negative gate voltages. The exposure to N2 gas in the presence of DUV light notably improves the drain‐to‐source current, carrier density, and charge‐carrier mobility for SL, BL, and FL MoS2 FETs. Subsequently, the same devices are exposed to O2 gas in the presence of DUV light for different periods and the electrical characteristics are completely recovered after a certain time. The doping by using the combination of N2 and O2 gas with DUV light provides a stable, effective, and facile approach for improving the performance of MoS2 electronic devices. 相似文献
942.
A novel instantaneous frequency-based time–frequency representation is proposed for the analysis of multicomponent signals. The concept of frequency translation is innovatively combined with the empirical mode decomposition algorithm to formulate an iterative procedure, referred to as the iterative empirical mode decomposition, to separate the components present in a signal at a suitably selected frequency resolution. The instantaneous frequency and amplitude estimated on the separated components are used to form the new time–frequency representation. The iterative empirical mode decomposition is assessed for component resolvability, and the performance of the aforementioned time–frequency representation is compared with several other time–frequency representations based on visual inspection and using objective criteria. The Hilbert spectrum formed using the iterative empirical mode decomposition not only provides high concentration of energy about the components’ instantaneous frequencies at high signal-to-noise ratio, but also good resolution while keeping the interference terms at a minimum. 相似文献
943.
This paper proposes a new two dimensional(2D) analytical model for a germanium(Ge) single gate silicon-on-insulator tunnel field effect transistor(SG SOI TFET). The parabolic approximation technique is used to solve the 2D Poisson equation with suitable boundary conditions and analytical expressions are derived for the surfacepotential,theelectricfieldalongthechannelandtheverticalelectricfield.Thedeviceoutputtunnellingcurrent is derived further by using the electric fields. The results show that Ge based TFETs have significant improvements inon-currentcharacteristics.Theeffectivenessoftheproposedmodelhasbeenverifiedbycomparingtheanalytical model results with the technology computer aided design(TCAD) simulation results and also comparing them with results from a silicon based TFET. 相似文献
944.
945.
A. Sen Y. Nazeer Ahammed B. C. Arya Tirthankar Banerjee G. Reshma Begam B. P. Baruah A. Chatterjee Anil K. Choudhuri Amit Dhir Trupti Das Pitamber Prasad Dhyani N. C. Deb Ranu Gadi Mangesh Gauns Sanjay Kumar Ghosh Abhishek Gupta K. C. Sharma A. H. Khan K. Maharaj Kumari Manish Kumar Arun Kumar Jagdish Chandra Kuniyal Anita Lakhani R. K. Meena P. S. Mahapatra S. W. A. Naqvi Dharam Pal Singh S. Pal Sipra Panda Rohtash J. Saikia P. Saikia A. Sharma Priyanka Sharma M. Saxena D. M. Shenoy C. Viswanatha Vachaspati S. K. Sharma T. K. Mandal 《Mapan》2014,29(4):273-284
In this paper, we present mass concentrations of particulate matter [PM2.5, PM10 size fractions and total suspended particulates (TSP)] measured simultaneously over land stations (Kullu, Patiala, Delhi, Ajmer, Agra, Lucknow, Varanasi, Giridih, Kolkata, Darjeeling, Jorhat, Itanagar, Imphal, Bhubaneswar, and Kadapa), mostly distributed across the Indo-Gangetic plain (IGP) of India as well as in the marine atmosphere over Bay of Bengal (BoB) in the period from 20 January to 3 February, 2014. The main objective of this study was to quantify the continental outflow of particulates (PM2.5, PM10 and TSP) from IGP and associated regions into the BoB along with low level north-east wind flow during winter monsoon period. The present study provides a glimpse of the aerosol loading over the IGP region. During this campaign, the highest average PM2.5 (187.8 ± 36.5 µg m?3, range 125.6–256.2 µg m?3), PM10 (272.6 ± 102.9 µg m?3, range 147.6–520.1 µg m?3) and TSP (325.0 ± 71.5 µg m?3, range 220.4–536.6 µg m?3) mass concentrations were recorded at Varanasi, Kolkata and Lucknow over middle and lower IGP regions. The PM2.5 (average 41.3 ± 11.9 µg m?3; range 15.0–54.4 µg m?3), PM10 (average 53.9 ± 18.9 µg m?3; range 30.1–82.1 µg m?3) and TSP (average 78.8 ± 29.7 µg m?3; range 49.1–184.5 µg m?3) loading over BoB were found to be comparable to land stations and suggests possible continental outflow. Over the continental region, the highest PM2.5/PM10 ratio was recorded at Delhi (0.87). The PM2.5/PM10 ratio over BoB (0.77) was found to be quite high and comparable to Varanasi (0.80) and Agra (0.79). 相似文献
946.
Fluorescent silver nanoclusters (Ag NCs) have been bio-labeled to bovine serum albumin (BSA) protein by wet chemistry. The conformational changes of protein were studied using circular dichroism spectroscopy. The spectroscopic and chemical properties of these BSA-Ag NCs are explored to study their chemical sensing behavior. These NCs exhibit an intense fluorescence peak at 650 nm. Fluorescence behavior of Ag NCs has been explored for sensitive and selective detection of hydrogen peroxide. 相似文献
947.
The pulsed plasma deposition can increase the deposition rate of amorphous silicon (a-Si) without an increase in the particulate count in the plasma which is an important factor determining the yield of commercial products such as active matrix displays. In this paper, we report the deposition of a-Si at rates of up to 15 Å/sec, using a modulation frequency in the range of 1–100 kHz and the impact it has on solar cell conversion efficiency. The hot wire CVD deposition technique has attracted a considerable amount of interest because of the ability to produce a-Si at a high deposition rate and with low hydrogen concentration which could minimize the instability phenomena. Further, under suitable conditions, low temperature polycrystalline silicon can be produced. We present data of high deposition rates for a-Si (>15 A/s) and polycrystalline Si and discuss their usefulness to photovoltaic applications. 相似文献
948.
Strawberries were dehydrated in a two-stage combination drying consisting of vacuum freeze drying (FD) followed by hot air drying (AD), and in a two-stage hybrid method involving FD and finish AD(FAD) to obtain dehydrated strawberries of high quality at reduced cost. Energy consumption and physicochemical properties of the FAD product were compared with single-stage AD and single-stage FD. The quality parameters of the products were also analyzed. It was found that the quality of combined FAD-dried products approximated that of single-stage FD. Hence, the proposed two-stage combination drying method is recommended for dehydration of strawberries to obtain a high-quality product at lower cost when compared with vacuum freeze drying alone. 相似文献
949.
Malware phylogeny generation using permutations of code 总被引:1,自引:1,他引:0
Md. Enamul. Karim Andrew Walenstein Arun Lakhotia Laxmi Parida 《Journal in Computer Virology》2005,1(1-2):13-23
Malicious programs, such as viruses and worms, are frequently related to previous programs through evolutionary relationships. Discovering those relationships and constructing a phylogeny model is expected to be helpful for analyzing new malware and for establishing a principled naming scheme. Matching permutations of code may help build better models in cases where malware evolution does not keep things in the same order. We describe methods for constructing phylogeny models that uses features called n-perms to match possibly permuted codes. An experiment was performed to compare the relative effectiveness of vector similarity measures using n-perms and n-grams when comparing permuted variants of programs. The similarity measures using n-perms maintained a greater separation between the similarity scores of permuted families of specimens versus unrelated specimens. A subsequent study using a tree generated through n-perms suggests that phylogeny models based on n-perms may help forensic analysts investigate new specimens, and assist in reconciling malware naming inconsistencies 相似文献
950.
This work presents the development of a model-based controller design called Multiple Model Predictive Control (MMPC) based on a set of linear, time-varying, state space models to regulate batch processes according to multiple, pre-specified reference profiles. Sufficient conditions for stability and boundedness of the dynamic evolution of the forced nonlinear system are provided. The performance of the MMPC design is demonstrated on a model of a batch reactor that represents the production of a polymer product. 相似文献