131 research outputs found
Gate-controlled Multispectral Response in Graphene-Based Heterostructure Photodetector
No full textCopyright © 1999-2023 John Wiley & Sons, Inc. All rights reserved. Multispectral photodetectors are crucial for detecting light across a wide wavelength range, serving applications requiring precise wavelength specificity and spectral imaging capabilities. However, the development of these photodetectors is hindered by several challenges, including material compatibility issues, low responsivity, the complexity of signal processing, and precise bandgap engineering. A strategy is proposed using a MoS2-graphene photodetector to address these issues. Gate-tunable spectral responses are achieved in a graphene photodetector by utilizing carrier transfer from MoS2 and interfacial gating effects from a SiO2/p-doped Si substrate. Precise gate bias manipulation enables selective photocurrent capture in the range of 500–680 nm, identical to the absorption of MoS2. Furthermore, by applying a highly negative gate bias, photocurrent signals below the MoS2 bandgap, i.e., in the 680–800 nm region, are detected, significantly provoking broadband photodetection. The results highlight the versatility of gate-tunable multispectral response, leading to an exceptional responsivity of up to 1.4 × 105 mA W−1. Moreover, through the precise modulation of gate bias and incident wavelength, it seamlessly switches between negative and positive photocurrents. This study provides important insight into carrier photogeneration in sensitized graphene-based multifunctional optoelectronic devices, establishing a versatile platform for detecting a broad range of photocurrents with a single detector. © 2023 The Authors. Advanced Electronic Materials published by Wiley-VCH GmbH.11Ysciescopu
The Regulations on Organized Crimes in the Penal Code of Vietnam and Some Recommendations
No full textAbstract: The law is considered as an important tool in preventing organized crime. Many developed countries have formulated strict rules, even issued the law on organized crime prevention. In the trend of integration and development, many organizations of transnational crimes are formed. Thus, the improvement of the legal system is an inevitable consequence. Within the scope of the article, the author wants to clarify some provisions in the Penal Code, thereby making recommendations to improve the regulations on organized crime. In this article, we analyze some of the situations of the regulations on organized crimes in the penal code of Vietnam and some recommendations
A New Synthetic Route for Preparation of Enantiomers of Gossypol and Apogossypol from Racemic Gossypol
No full textResearch Proposal for Orientation for Urban Opening Planning Area in Ha Dong District, Ha Noi City
No full textSynthesis of 4,7,9-Trihydroxy[1]benzofuro[3,2-d]pyrimidine-6-carboxamide: Evaluation of Cytotoxicity and Inhibition of Protein Kinase C (CaPkc1)
No full textThe protein kinase Pkc1 of Candida albicans (CaPkc1), one of the key proteins involved in MAPK pathway, is described as a regulator of cell wall integrity during growth, morphogenesis, and response to cell wall stress. The (–)-cercosporamide is an antifungal natural product isolated from the phytopathogen fungus Cercosporidium henningsii. This phytoxin was found to inhibit selectively CaPkc1 and constitutes an interesting model for the design of novel antifungal molecules. In this research, 4,7,9-trihydroxy[1]benzofuro[3,2-d]pyrimidine-6-carboxamide (13) derived from (–)-cercosporamide was synthesized via a seven-step procedure by well-known reactions and evaluation of cytotoxicity and inhibition of CaPkc1. The bioassay showed CaPkc1 inhibitory activity 87% higher and cytotoxicity 100 times less than the reference, (–)-cercosporamide
Study of Subsidence detection by DinSAR and evaluation of some factors to the outcome
Get PDFThe paper focuses on determining the subsidence by Differential Interferometric Synthetic Aperture Radar (DInSAR) using two methods (Two-pass and Three-pass) and assessing the effect of some error sources to the results. Errors effecting the result include atmospheric, phase due to signal-to-noise ratios, number of looks, pixel misregistration and baseline decorrelation; however, especially significant is (Digital Elevation Model) DEM error. We proved that application of DEM with low precision would create virtual subsidence. The experiment area is Hanoi city, data was Envisat ASAR image, C band with the wavelength of 5.6cm. By using SARscape software for processing, with Two-pass method a virtual subsidence was found at one site in northern part of Hanoi near the Red River (Song Hong). With the Three-pass method this subsidence site did not occurred. Besides, results of surface subsidence detection using DInSAR methods were compared with those measured directly from monitoring stations located close to water supplying wells. As a result, data acquired from Ha Dinh and Thanh Cong stations were closely distributedto those determined by DInSAR method. Unfortunately, the subsidence data acquired by direct measurement had been conducted continuously only from 2000 to 2003 instead to 2005; whereas the Envisat ASAR subsidence data are available only from 2003 to 2004. Therefore, combination of data of direct measurement at Ha Dinh and Thanh Cong stations, and DInSAR processing should provide a linear correlation. . 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