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Back contact interfacial modification mechanism in highly-efficient antimony selenide thin-film solar cells

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Journal of Energy Chemistry 2023年第5期80卷 256-264,I0007页

作者： Junhui Lin Guojie Chen nafees ahmad Muhammad Ishaq Shuo Chen Zhenghua Su Ping Fan Xianghua Zhang Yi Zhang Guangxing Liang Shenzhen Key Laboratory of Advanced Thin Films and Applications Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060GuangdongChina Institute of Fundamental and Frontier Science University of Electronic Science and Technology of ChinaChengdu 610054SichuanChina Univ Rennes CNRSISCR(Institut des Sciences Chimiques de Rennes)UMR 6226Rennes F-35000France Institute of Photoelectronic Thin Film Devices and Technology and Tianjin Key Laboratory of Thin Film Devices and Technology Nankai UniversityTianjin 300350China

Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several *** properties of Sb_(2)Se_(3)absorber and back contact influence the PV performances of Sb_(2)Se_(3)solar ***,optimization of back contact characteristics and absorber orientation are crucial steps in raising the power conversion efficiency(PCE)of Sb_(2)Se_(3)solar *** this work,MoO2was introduced as an intermediate layer(IL)in Sb_(2)Se_(3)solar cells,and comparative investigations were *** growth of(211)-oriented Sb_(2)Se_(3)with large grains was facilitated by introducing the MoO2IL with suitable *** MoO2IL substantially lowered the back contact barrier and prevented the formation of voids at the back contact,which reduced the thickness of the MoSe2interface layer,inhibited carrier recombination,and minimized bulk and interfacial defects in ***,significant optimization enhanced the open-circuit voltage(VOC)of solar cells from 0.481 V to 0.487 V,short-circuit current density(JSC)from 23.81 m A/cm^(2)to 29.29 m A/cm^(2),and fill factor from 50.28%to 57.10%,which boosted the PCE from 5.75%to 8.14%.

关键词： Sb_(2)Se_(3)solar cells MoO_(2)intermediate layer Back contact Defects

Historical variations in autochthonous and allochthonous sediment supplies to the largest freshwater lake in Central India

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International Journal of Sediment Research 2022年第5期37卷 563-575页

作者： nafees ahmad Satinder Pal Singh Aasif Mohmad Lone Abul Qasim Ravi Bhushan Gyana Ranjan Tripathy Chinmay Shah Department of Earth and Environmental Sciences Indian Institute of Science Education and Research Bhopal Geosciences Division Physical Research Laboratory Department of Earth and Climate Science Indian Institute of Science Education and Research

Lacustrine sediment preserves high-resolution biogeochemical records of past variations in watershed processes controlling lake sedimentation. The current study explores historical variations in autochthonous and allochthonous sediment supplies to a large tropical freshwater lake system(Upper Lake, Bhopal) protected under the international Ramsar Convention of 2002 against anthropogenic pressures. For this purpose, multi-proxy biogeochemical data are presented for organic matter(total organic carbon, total nitrogen, phosphorous, and loss on ignition [LOI] at550°C), carbonate(LOI at 950°C), lithic sediment(aluminum, titanium, iron, calcium, magnesium,sodium, potassium, manganese, zirconium, niobium, hafnium, tantalum, thorium, uranium, and rare earth elements), and anthropogenic inputs(lead) measured in a 38 cm long sediment core retrieved from the lake. In addition to the lacustrine sediment core, the samples of catchment bedrock, surface soils, major stream sediment, and eolian dust collected from the lake periphery also are analyzed. The systematic biogeochemical excursions in the upper core section(top ～8 cm) indicate increased anthropogenic inputs, watershed denudation by agricultural activities, artificially reduced fluvial sediment supply, relatively increased dust inputs and lake eutrophication in the last few decades. The current study underscores the roles of anthropogenic land-use and wetland conservation practices in the rapid alteration of autochthonous and allochthonous sediment supplies to open aquatic ecosystems. Further, rising lake eutrophication levels despite a managed reduction in allochthonous sediment supplies seem challenging to control due to dissolved nutrient supply from urban sewage discharge and runoff from agricultural land in the watershed.

关键词： Upper Lake Sediment Geochemistry Sediment provenance Eutrophication Anthropogenic inputs

Efficient Algorithm for Prolonging Network Lifetime of Wireless Sensor Networks

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Tsinghua Science and Technology 2011年第6期16卷 561-568页

作者： Md nafees Rahman M A Matin Department of Electrical Engineering and Computer Science North South University

One of the fundamental design challenges in designing a Wireless Sensor Network （WSN） is to maximize the network lifetime, as each sensor node of the network is equipped with a limited power battery. To overcome this challenge, different methods were developed in the last few years using such techniques as network protocols, data fusion algorithms using low power, energy efficient routing, and locating optimal sink position. This paper focuses on finding the optimal sink position. Relay nodes are introduced in conjunction with the sensor nodes to mitigate network geometric deficiencies since in most other approaches the sensor nodes close to the sink become heavily involved in data forwarding and, thus, their batteries are quickly depleted. A Particle Swarm Optimization （PSO） based algorithm is used to locate the optimal sink position with respect to those relay nodes to make the network more energy efficient. The relay nodes communicate with the sink instead of the sensor nodes. Tests show that this approach can save at least 40% of the energy and prolong the network lifetime.

关键词： wireless sensor network lifetime sensor node relay node particle swarm optimization sink

Nature-inspired Hybrid Optimization Algorithms for Load Flow Analysis of Islanded Microgrids

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Journal of Modern Power Systems and Clean Energy 2020年第6期8卷 1250-1258页

作者： Saad Mohammad Abdullah Ashik Ahmed Quazi nafees Ul Islam the Department of Electrical and Electronic Engineering Islamic University of TechnologyBoard BazarGazipur 1704Bangladesh

Load flow analysis is a significant tool for proper planning,operation,and dynamic analysis of a power system that provides the steady-state values of voltage magnitudes and angles at the fundamental ***,due to the absence of a slack bus in an islanded microgrid,modified load flow algorithms should be adopted considering the system frequency as one of the solution *** paper proposes the application of nature-inspired hybrid optimization algorithms for solving the load flow problem of islanded *** nature-inspired algorithms such as genetic algorithm(GA),differential evolution(DE),flower pollination algorithm(FPA),and grasshopper optimization algorithm(GOA)are separately merged with imperialistic competitive algorithm(ICA)to form four hybrid algorithms named as ICGA,ICDE,ICFPA,and *** of these algorithms are tested on the 6-bus test system and the modified IEEE 37-bus test system.A comparison among the proposed algorithms is carried out in terms of statistical analysis conducted using SPSS statistics *** the statistical analysis,it is identified that on an average,ICDE takes less number of iterations and consequently needs less execution time compared with other algorithms in solving the load flow problem of islanded microgrids.

关键词： Nature-inspired hybrid algorithm global optimization islanded microgrid load flow analysis

Fungi as chemical industries and genetic engineering for the production of biologically active secondary metabolites

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Asian Pacific Journal of Tropical Biomedicine 2014年第11期4卷 859-870页

作者： Abid Ali Khan nafees Bacha Bashir ahmad Ghosia Lutfullah Umar Farooq Russell John Cox Department of Chemistry.COMSATS Institute of Information Technology Centre of Biotechnology and Microbiology University of Peshawar Department of Chemistry.COMSATS Institute of Information Technology Abbottabad School of Chemistry University of Bristol Cantock's Close

Fungi is somewhere in between the micro and macro organisms which is a good source of producing biologically active secondary *** have been used as tool for producing different types of secondary metabolites by providing different nutrients at different laboratory *** fungi have been engineered for the desired secondary metabolites by using different laboratory techniques,for example,homologous and heterologous *** review reported how the fungi are used as chemical industry for the production of secondary metabolites and how they are engineered in laboratory for the production of desirable metabolites:also the biosynthetic pathways of the bio-organic-molecules were reported.

关键词： Fungi Natural products Microbiology Molecular genetics Chemical biology

Identification of Type of a Fault in Distribution System Using Shallow Neural Network with Distributed Generation

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Energy Engineering 2023年第4期120卷 811-829页

作者： Saurabh Awasthi Gagan Singh nafees Ahamad Department of Electrical and Electronics&Communication Engineering DIT UniversityDehradun248001India

A distributed generation system(DG)has several benefits over a traditional centralized power ***,the protection area in the case of the distributed generator requires special attention as it encounters stability loss,failure re-closure,fluctuations in voltage,*** thereby,it demands immediate attention in identifying the location&type of a fault without delay especially when occurred in a small,distributed generation system,as it would adversely affect the overall system and its *** the past,several methods were proposed for classification and localisation of a fault in a distributed generation *** of those methods were accurate in identifying location,but the accuracy in identifying the type of fault was not up to the acceptable *** proposed work here uses a shallow artificial neural network(sANN)model for identifying a particular type of fault that could happen in a specific distribution network when used in conjunction with distributed ***,a distribution network consisting of two similar distributed generators(DG1 and DG2),one grid,and a 100 Km distribution line is ***,different voltages and currents corresponding to various faults(line to line,line to ground)at different locations are tabulated,resulting in a matrix of 500×18 ***,the sANN is formulated for identifying the types of faults in the system in which the above-obtained data is used to train,validate,and test the neural *** overall result shows an unprecedented almost zero percent error in identifying the type of the faults.

关键词： Distribution network distributed generation power system modeling fault identification neural network renewable energy systems

Aspect Extraction Approach for Sentiment Analysis Using Keywords

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Computers, Materials & Continua 2023年第3期74卷 6879-6892页

作者： nafees Ayub Muhammad Ramzan Talib Muhammad Kashif Hanif Muhammad Awais Department of Computer Science Government College UniversityFaisalabad38000Pakistan Department of Software Engineering Government College UniversityFaisalabad38000Pakistan

Sentiment Analysis deals with consumer reviews available on blogs,discussion forums,E-commerce websites,andApp *** online reviews about products are also becoming essential for consumers and companies as *** rely on these reviews to make their decisions about products and companies are also very interested in these reviews to judge their products and *** reviews are also a very precious source of information for requirement *** companies and consumers are not very satisfied with the overall sentiment;they like fine-grained knowledge about consumer *** to this,many researchers have developed approaches for aspect-based sentiment *** existing approaches concentrate on explicit aspects to analyze the sentiment,and only a few studies rely on capturing implicit *** paper proposes a Keywords-Based Aspect Extraction method,which captures both explicit and implicit *** also captures opinion words and classifies the sentiment about each *** applied semantic similarity-basedWordNet and SentiWordNet lexicon to improve aspect *** used different collections of customer reviews for experiment purposes,consisting of eight datasets over seven *** compared our approach with other state-of-the-art approaches,including Rule Selection using Greedy Algorithm(RSG),Conditional Random Fields(CRF),Rule-based Extraction(RubE),and Double Propagation(DP).Our results have shown better performance than all of these approaches.

关键词： Sentiment analysis aspect extraction keywords-based machine learning

Photosynthesis, Growth and Antioxidant Metabolism in Mustard (Brassica juncea L.) Cultivars Differing in Cadmium Tolerance

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Agricultural Sciences in China 2010年第4期9卷 519-527页

作者： Noushina Iqbal Asim Masood Rahat Nazar Shabina Syeed nafees A Khan Department of Botany Aligarh Muslim University

Two mustard （Brassica juncea L. Czern and Coss.） cultivars, Pusa Jai Kisan and SS2 differing in cadmium （Cd） tolerance were treated with 0, 25 and 50 umol L-1 Cd to study the physiological basis of difference in Cd tolerance. Cultivar SS2 （Cd sensitive） accumulated greater Cd in leaves than Pusa Jai Kisan （Cd tolerant）. Further, SS2 also exhibited higher contents of thiobarbituric acid reactive substances （TBARS） and H2O2 and electrolyte leakage. However, the activities of antioxidant enzymes, catalase （CAT）, ascorbate peroxidase （APX）, dehydroascorbate reduetase （DHAR）, and glutathione reductase （GR） were higher in Pusa Jai Kisan than those in SS2. Contrarily, the activity of superoxide dismutase （SOD） was higher in SS2 than that in Pusa Jai Kisan and was the greatest at 25 umol L-1 Cd. Treatment of 25 umol L-1 Cd induced the maximum activity of enzymes. However, the activity of GR increased up to 50 umol L-1 Cd in both the cultivars. The non-enzymatic antioxidants ascorbate （AsA） and glutathione （GSH） were higher in Pusa Jai Kisan than that in SS2, whereas dehydroascorbate （DHA） and oxidized glutathione （GSSG） were higher in SS2. Photosynthesis and growth were adversely and maximally decreased by 50 umol L-1 Cd treatment in both the cultivars, but SS2 exhibited greater reductions. The protection of photosynthesis and growth and lesser reduction in Pusa Jai Kisan were associated with its capacity to restrict accumulation of Cd in leaves resulting in lower level of TBARS and H2O2 and electrolyte leakage. Moreover, Pusa Jai Kisan exhibited efficient antioxidant metabolism for removal of Cd-induced reactive oxygen species.

关键词： antioxidant metabolism cadmium oxidative stress photosynthesis

Interplay between nitric oxide and sulfur assimilation in salt tolerance in plants

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The Crop Journal 2016年第3期4卷 153-161页

作者： Mehar Fatma Asim Masood Tasir S.Per Faisal Rasheed nafees A.Khan Plant Physiology Section Department of BotanyAligarh Muslim University

Nitric oxide(NO),a versatile molecule,plays multiple roles in plant growth and development and is a key signaling molecule in plant response to abiotic *** management strategy is critical for abiotic stress alleviation in ***(S) is important under stress conditions,as its assimilatory products neutralize the imbalances in cells created by excessive generation of reactive oxygen species(ROS).NO abates the harmful effects of ROS by enhancing antioxidant enzymes,stimulating S assimilation,and reacting with other target molecules,and regulates the expression of various stress-responsive genes under salt *** review focuses on the role of NO and S in responses of plants to salt stress,and describes the crosstalk between NO and S assimilation in salt *** regulation of NO and/or S assimilation using molecular biology tools may help crops to withstand salinity stress.

关键词： Abiotic stress Antioxidant system Glutathione Plant hormones Sulfur Signaling