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Real-time programmable metasurface for terahertz multifunctional wave front engineering

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Light(Science & Applications) 2023年第9期12卷 1795-1806页

作者： Feng Lan Luyang Wang Hongxin Zeng Shixiong Liang Tianyang Song Wenxin Liu pinaki mazumder Ziqiang Yang Yaxin Zhang Daniel M.Mittleman Sichuan THz Communication Technology Engineering Research Center School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengdu 611731China Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313000China Zhangjiang Laboratory Shanghai 201204China National Key Laboratory of Solid-State Microwave Devices and Circuits Hebei Semiconductor Research InstituteShijiazhuang 050051China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China University of Chinese Academy of Sciences School of ElectronicElectrical and Communication EngineeringBeijing 101408China Department of Electrical Engineering and Computer Science University of MichiganAnn ArborMI 48109USA School of Engineering Brown UniversityProvidenceRI 02912USA

Terahertz(THz)technologies have become a focus of research in recent years due to their prominent role in envisioned future communication and sensing *** of the key challenges facing the field is the need for tools to enable agile engineering of THz wave ***,we describe a reconfigurable metasurface based on GaN technology with an array-of-subarrays *** subwavelength-spaced array,under the control of a 1-bit digital coding sequence,can switch between an enormous range of possible configurations,providing facile access to nearly arbitrary wave front control for signals near 0.34 *** demonstrate wide-angle beam scanning with 1°of angular precision over 70 GHz of bandwidth,as well as the generation of multi-beam and diffuse wave fronts,with a switching speed up to 100 *** device,offering the ability to rapidly reconfigure a propagating wave front for beam-forming or diffusively scattered wide-angle coverage of a scene,will open new realms of possibilities in sensing,imaging,and networking.

关键词： wave scattered arbitrary

Exploring the combination of biochar‐amended soil and automated irrigation technology for water regulation and preservation in green infrastructure

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Deep Underground Science and Engineering 2024年第1期3卷 39-52页

作者： Honghu Zhu Yuanxu Huang Haihong Song Jian Chen Songlei Han Tanwee mazumder Ankit Garg School of Earth Sciences and Engineering Nanjing UniversityNanjingChina Department of Civil and Smart Engineering Construction Guangdong Engineering Center for Structure Safety and Health MonitoringShantou UniversityShantouChina Shanghai Municipal Engineering Design Co. LtdShanghaiChina Indian Institute of Technology Madras ChennaiIndia

Biochar is a carbon sink material with the potential to improve water retention in various ***,for the long‐term maintenance of green infrastructure,there is an additional need to regulate the water contents in the covers to maintain vegetation growth in semiarid *** this study,biochar‐amended soil was combined with subsurface drip irrigation,and the water preservation characteristics of this treatment were investigated through a series of one‐dimensional soil column *** ascertain the best treatment method specific to semiarid climatic conditions,the test soil was amended with 0%,1%,3%,and 5%*** irrigation devices equipped with soil moisture sensors were used to control the subsurface water content with the aim of enhancing vegetation *** soil column test lasted 150 h,during which the volumetric water contents and soil suction data were *** experimental results reveal that the soil specimen amended with 3%biochar is the most water‐saving regardless of the time *** with a higher biochar content(e.g.,5%)consumes a more significant amount of water due to the enhancement of the water‐holding *** on the experimental results,it can be concluded that the appropriate ratio can be determined within 1%–3%,which can reduce not only the amount of irrigated/used water but also the time *** technology can be explored for water content regulation in green infrastructure and the development of barriers for protecting the environment around deep underground waste containment.

关键词： biochar drip irrigation underground water preservation water regulation

忆阻器阻变随机存取存储器及其在信息存储中的应用

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中国科学：信息科学 2012年第6期42卷 754-769页

作者：段书凯胡小方王丽丹李传东 mazumder pinaki 西南大学电子信息工程学院重庆400715 Department of Electrical Engineering and Computer Science University of Michigan 重庆大学计算机学院重庆400044

忆阻器具有依赖于激励历史的动态电阻,可以用来构造少晶体管的非易失性半导体存储器(NVSM),也称为阻变随机存取存储器(RRAM).本文提出了一种基于忆阻器的阻变随机存取存储器(MRRAM)——可与现代计算系统相兼容的纳米级二值存储器实现方... 详细信息

忆阻器具有依赖于激励历史的动态电阻,可以用来构造少晶体管的非易失性半导体存储器(NVSM),也称为阻变随机存取存储器(RRAM).本文提出了一种基于忆阻器的阻变随机存取存储器(MRRAM)——可与现代计算系统相兼容的纳米级二值存储器实现方案,其结构与静态随机存取存储器(SRAM)类似,但用忆阻器替代基本RS触发器存储信息.在此基础上,通过改进该MRRAM,可以实现在一个存储单元中存储多比特信息(以灰度级形式)的多值存储器,大大提高了存储密度.给出的计算机仿真和数值分析验证了本方案在存储ASCII字符和图像中的有效性,探讨了灰度图像存储的新方法.

关键词：忆阻器阻变随机存取存储器(RRAM) 电路设计二值存储多值存储计算机仿真

Upper gastrointestinal bleeding in Bangladeshi children:Analysis of 100 cases

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World Journal of Gastrointestinal Endoscopy 2024年第1期16卷 44-50页

作者： Md Wahiduzzaman mazumder Md Benzamin Department of Pediatric Gastroenterology and Nutrition Bangabandhu Sheikh Mujib Medical UniversityDhaka 1000Bangladesh Department of Pediatric Gastroenterology and Nutrition Sylhet M A G Osmani Medical College HospitalSylhet 3100Bangladesh

BACKGROUND Upper gastrointestinal bleeding(UGIB)is defined as bleeding that occurs proximal to the ligament of Treitz and can sometimes lead to potentially serious and life-threatening clinical situations in ***,the cause of UGIB differs significantly depending on the geographic location,patient population and presence of comorbid *** To observe endoscopic findings of UGIB in children at a tertiary care center of *** This retrospective study was carried out in the department of Pediatric Gastroenterology and Nutrition of Bangabandhu Shiekh Mujib Medical University,a tertiary care hospital of Bangladesh,between January 2017 and January *** collected from hospital records of 100 children who were 16 years of age or younger,came with hematemesis,melena or both hematemesis and *** patients underwent upper gastrointestinal endoscopy(Olympus CV 1000 upper gastrointestinal video endoscope)after initial *** investigations to diagnose portal hypertension and chronic liver disease with underlying causes for management purposes were also *** A total of 100 patients were *** was common in the age group 5-10 years(42%),followed by above 10 years(37%).Hematemesis was the most common presenting symptom(75%)followed by both hematemesis and melena(25%).UGIB from ruptured esophageal varices was the most common cause(65%)on UGI endoscopy followed by gastric erosion(5%)and prolapsed gastropathy(2%).We observed that 23%of children were normal after endoscopic *** Ruptured esophageal varices were the most common cause of UGIB in children in *** causes included gastric erosions and prolapsed gastropathy syndrome.

关键词： Bangladeshi Children Endoscopy Upper gastrointestinal bleeding Esophageal varices

Phytochemical Screening and Evaluation of Pharmacological Potential of Baliospermum solanifolium Leaf Extract

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Clinical Complementary Medicine and Pharmacology 2024年第1期4卷 69-75页

作者： Amit mazumder Rabindra Nath Acharyya Milton Kumar Kundu Pritam Kundu Md.Amirul Islam Md.Mustafizur Rahman Pharmacy Discipline Khulna UniversityKhulna-9208Bangladesh

Background:Baliospermum solanifolium is a traditional medicinal plant,locally known as“dantigaacha”from Eu-phorbiaceae family,and has been used in different diseases treatments likes helminthiasis,skin diseases,diabetes,snake-bite,and ***:Depending on the traditional uses of *** and the lack of scientific works,we aimed to conduct some pharmacological tests on its ***:Active constituents of *** were assessed by qualitative ***(2,2-diphenyl-1-picrylhydrazyl)was used for free radical scavenging *** change and mortality rate were used as indicators to assess the toxicity of *** antidiabetic potential was evaluated by oral glucose toler-ance test(OGTT)and alpha-glucosidase enzyme inhibitory *** antidiarrheal activity,castor oil-induced mice were *** test was carried out by disk diffusion assay and MIC ***,analgesic activity was done by acetic acid-induced writhing ***:*** contains alkaloids,carbohydrates,glycosides,flavonoids,tannis,phenolics *** toxicity test ensured the safety of the *** DPPH,the extract showed antioxidant activity with an IC50(con-centration needed to scavenge 50%DPPH)value of 61.65μg/*** phenolic,flavonoid and tannin contents were determined as 124 mg GAE/g,440 mg QE/g and 344 mg GAE/g dried extract,*** OGTT,the ex-tract reduced the blood glucose level *** the alpha-glucosidase inhibitory activity,the plant showed a concentration-dependent reduction of the enzyme at IC50 of 8.53 mg/*** the antidiarrheal test,*** inhibit defecation 30.69%and 53.41%at dose 250 mg/kg and 500 mg/kg,*** extract also showed antibacterial activity against four bacterial strains in the disk diffusion method and minimum inhibitory concen-tration(MIC)values were 62.5μg/mL,62.5μg/mL,125μg/mL and 62.5μg/mL against four bacterial strains,*** an

关键词： Baliospermum solanifolium Antioxidant Antidiabetic Antidiarrheal Antibacterial Analgesic

Sliding Mode Control in Power Converters and Drives: A Review

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IEEE/CAA Journal of Automatica Sinica 2022年第3期9卷 392-406页

作者： Ligang Wu Jianxing Liu Sergio Vazquez Sudip K.mazumder IEEE Department of Control Science and Engineering Harbin Institute of TechnologyHarbin 150001China Electronic Engineering Department Universidad de Sevilla41092 SevillaSpain Electrical and Computer Engineering Department University of Illinois ChicagoChicagoIL 60607 USA

Sliding mode control(SMC)has been studied since the 1950s and widely used in practical applications due to its insensitivity to matched *** aim of this paper is to present a review of SMC describing the key developments and examining the new trends and challenges for its application to power electronic *** fundamental theory of SMC is briefly reviewed and the key technical problems associated with the implementation of SMC to power converters and drives,such chattering phenomenon and variable switching frequency,are discussed and *** recent developments in SMC systems,future challenges and perspectives of SMC for power converters are discussed.

关键词： Motor drive power electronics systems sliding mode control

Multi-scale analysis for transport of fine settling particles through an ice-covered channel in a laminar flow condition

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International Journal of Sediment Research 2022年第6期37卷 794-808页

作者： Subham Dhar Nanda Poddar B.S.mazumder Kajal Kumar Mondal Department of Mathematics Cooch Behar Panchanan Barma University Physics and Applied Mathematics Unit Indian Statistical Institute Department of Civil Engineering Indian Institute of Technology Bombay

The current research deals with the dispersion of fine settling particles in a fluid flowing through an icecovered channel under the laminar flow condition. An analytical solution of the two-dimensional convection-diffusion equation, based on the multi-scale homogenization technique, is obtained. To validate the current study, analytical results for the dispersion coefficient are compared with the available earlier research work. Moreover, the proposed analytical solutions for mean concentration distributions of the tracers are compared with the numerical results obtained from the finite difference technique. From the industrial and environmental points of view, the vertical concentration distribution provides a very significant information. The downstream evolution of the concentration distribution also is shown for typical time periods at different values of the settling velocity. The approach to the vertical uniformity shows that it is too slow a process in comparison to that of longitudinal normality. It was found that settling velocities of particles disturb the vertical uniformity and the centroid of the solute cloud rises due to the increase in settling velocity. Results illustrate that in the downstream direction, the vertical concentration distribution increases near the bed surface and it decreases in the proximity of the ice-covered surface of the channel with the increase of settling velocity, but the mean concentration of the solute increases. The current study may play an important role to understand the mechanism of the sedimentation process in a closed channel system.

关键词： Sediment transport Dispersion Ice-covered channel Vertical uniformity Multi-scale analysis

Prospects of a β-SiC based IMPATT oscillator for application in THz communication and growth of aβ-SiC p-n junction on a Ge modified Si〈100〉substrate to realize THz IMPATTs

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Journal of Semiconductors 2010年第12期31卷 20-27页

作者： Moumita Mukherjee Nilratan mazumder Centre of Millimeter-Wave Semiconductor Devices and Systems Centre of Advanced Study in Radiophysics and ElectronicsUniversity of CalcuttaGirish Vidyaratna LaneKolkata 700009West BengalIndia IERCEM Institute of Information Technology West Bengal University of TechnologyKolkata 700017India

The prospects ofa p＋nn＋ cubic silicon carbide （3C-SiC/fl-SiC） based IMPATT diode as a potential solidstate terahertz source is studied for the first time through a modified generalized simulation scheme. The simulation predicts that the device is capable of generating an RF power output of 63.0 W at 0.33 THz with an efficiency of 13%. The effects of parasitic series resistance on the device performance and exploitable RF power level are further simulated. The studies clearly establish the potential of 3C-SiC as a base semiconductor material for a high-power THz IMPATT device. Based on the simulation results, an attempt has been made to fabricate β-SiC based IMPATT devices in the THz region. Single crystalline, epitaxial 3C-SiC films are deposited on silicon （Si）（100） substrates by rapid thermal chemical vapour deposition （RTPCVD） at a temperature as low as 800 ℃ using a single precursor methylsilane, which contains Si and C atoms in the same molecule. No initial surface carbonization step is required in this method. A p-n junction with an n-type doping concentration of 4 × 10^24 m-3 （which is similar to the simulated design data） has been grown successfully and the characterization of the grown 3C-SiC film is reported in this paper. It is found that the inclusion of Ge improves the crystal quality and reduces the surface roughness.

关键词： cubic (β)-SiC single drift IMPATT diode parasitic resistance terahertz oscillation RTPCVD growth p-n junction formation

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GAITing the GUT

Cellular & Molecular Immunology 2018年第12期15卷 1082-1084页

作者： Barsanjit mazumder Center for Gene Regulation in Health and Disease Department of BiologyGeology and Environmental SciencesCleveland State UniversityClevelandOHUSA

The gastrointestinal tract contains one of the most abundant populations of macrophages in the body.1 These cells play a critical role in the maintenance of gut homeostasis and defend the integrity of epithelial crypts and the mucosal *** disruption of gut homeostasis can cause sustained inflammation mediated by intestinal *** inflammation plays a key role in ulcerative colitis(UC)and other forms of inflammatory bowel disease(IBD),2–4 an improved understanding of how inflammation is regulated in the gut is essential for the development of effective therapies for such diseases.

关键词： inflammation homeostasis sustained