检索结果-南通市图书馆

Photonic properties and applications of multi-functional organo-lanthanide complexes:Recent advances

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 16-27,I0001页

作者： virender Archana Chauhan Ashwani Kumar Gurjaspreet singh Alexander A.Solovev Jichuan Xiong Xuefeng Liu Brij Mohan Department of Chemistry Kurukshetra University KurukshetraKurukshetra136119India Aggarwal College Ballabhgarh121004Department of Higher EducationHaryanaIndia Department of Chemistry&Centre for Advanced Studies in Chemistry Panjab UniversityChandigarh160014India Department of Materials Science Fudan UniversityShanghai200433China School of Electronic and Optical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Ocean Food and Biological Engineering Jimei UniversityXiamen361021China

Lanthanides(Ln(Ⅲ))based compounds as light-emitting materials have emerged as successful agents in high-performance defense and lighting systems,magnets,bio-markers,and ***,they have recently gained much attention as energy-saving and cost-effective luminescent materials and their applications in analyte *** present review summarizes powerful features and recent developments of organo-lanthanide complexes in lighting applications with a particular focus on visible light emitters,including Eu(Ⅲ),Tb(Ⅲ),Sm(Ⅲ),and Dy(Ⅲ)*** addition,this review discusses the most relevant aspects of photosensitization,such as the structure,property,functionalization of primary and secondary ligands,and molecular *** addition,coordination sites of organo-lanthanide complexes and their applications collectively contribute to the improved performance of innovative luminescent ***,the current challenges and key recommendations for advancing organolanthanides in material science are provided.

关键词： Lanthanides Organometallic Luminescent Lifetime OLED Rare earths

Hazard assessment of landslide disaster using information value method and analytical hierarchy process in highly tectonic Chamba region in bosom of Himalaya

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2018年第4期15卷 808-824页

作者： Kanwarpreet singh virender KUMAR Civil Engineering Department National Institute of Technology

The present study is focused on a comparative evaluation of landslide disaster using analytical hierarchy process and information value method for hazard assessment in highly tectonic Chamba region in bosom of Himalaya. During study, the information about the causative factors was generated and the landslide hazard zonation maps were delineated using Information Value Method(IV) and Analytical Hierarchy Process(AHP) using Arc GIS(ESRI). For this purpose, the study area was selected in a part of Ravi river catchment along one of the landslide prone Chamba to Bharmour road corridor of National Highway(NH^(-1)54 A) in Himachal Pradesh, India. A numeral landslide triggering geoenvironmental factors i.e. slope, aspect, relative relief, soil, curvature, land use and land cover(LULC), lithology, drainage density, and lineament density were selected for landslide hazard mapping based on landslide inventory. Landslide hazard zonation map was categorized namely "very high hazard, high hazard, medium hazard, low hazard, and very low hazard". The results from these two methods were validated using Area Under Curve(AUC) plots. It is found that hazard zonation map prepared using information value method and analytical hierarchy process methods possess the prediction rate of 78.87% and 75.42%, respectively. Hence, landslide hazardzonation map obtained using information value method is proposed to be more useful for the study area. These final hazard zonation maps can be used by various stakeholders like engineers and administrators for proper maintenance and smooth traffic flow between Chamba and Bharmour cities, which is the only route connecting these tourist places.

关键词： Information value Analytical Hierarchy Process Landslide hazard zonation GIS Remote sensing Himalaya

Synthesis and Characterization of CdO–SnO_2 Nanocomposites Prepared by Hydrothermal Method

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第3期31卷 254-262页

作者： Kapil Sirohi Suresh Kumar virender singh Anil Vohra Department of Electronic Science Kurukshetra University

In this work,（1-x）CdO-xSnO2 nanocomposites（≤0.15）have been synthesized via hydrothermal *** structural study reveals that CdO nanostructures possess crystalline phase and cubic *** CdO-SnO2 nanocomposites possess both cubic and orthorhombic structure with good *** crystallite size in the nanocomposites was found to be in the range of 9.6-19.6 *** emission scanning electronic microscopy and high-resolution tunnelling microscopy analysis confirm the presence of both cubic and orthorhombic structures which is also confirmed from X-ray diffraction *** transform infrared spectroscopy（FFIR）studies confirm that CdO-SnO2 nanocomposites possess the characteristics band of both CdO and SnO2 *** UV-visible absorption studies confirm that the optical absorption band in CdO-SnO2 nanocomposites possesses both blue and red shift as compared to that of CdO *** spectroscopy studies reveal the appearance of strong emission peak at 513,469 and 369 nm corresponding to green,blue and violet emission spectrum,respectively,in CdO-SnO2 *** FTIR studies confirm the presence of hydroxyl and water functional group due to atmospheric water vapours and chemical bonding in CdO and CdO-SnO2 *** spectroscopy confirms the presence of Raman bands of both CdO and SnO2 phases in the CdO-SnO2 nanocomposites.

关键词： Hydrothermal Nanocomposite CdO-SnO2 XRD FESEM HRTEM Optical properties

Assessment of glacier stored water in Karakoram Himalaya using satellite remote sensing and field investigation

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2019年第4期16卷 836-849页

作者： Kamal Kant singh Harendra singh negi Dhiraj Kumar singh Snow and Avalanche Study Establishment

Karakoram Himalaya(KH) has continental climatic conditions and possesses largest concentration of glaciers outside the polar regions. The melt water from these glaciers is a major contributor to the Indus river. In this study, various methods have been used to estimate the ice volume in the Karakoram Range of glaciers such as Coregistration of Optically Sensed Images and Correlation(COSI-Corr) method and Area-Volume relations. Landsat 8 satellite data has been used to generate the ice displacement, velocity and thickness map. Our study for 558 Karakoram glaciers revealed that the average ice thickness in Karakoram is 90 m. Ground Penetrating Radar(GPR) survey has been conducted in one of the KH glacier i.e. Saser La glacier and the collected GPR data is used for the validation of satellite derived thickness map. GPR measured glacier thickness values are found comparable with satellite estimated values with RMSE of 4.3 m. The total ice volume of the Karakoram glaciers is estimated to be 1607±19 km3(1473±17 Gt), which is equivalent to 1473±17 km3 of water equivalent. Present study also covers the analysis of glacier surface displacement, velocity and ice thickness values with reference to glacier mean slope.

关键词： Glacier COSI-Corr Karakoram Range Ground Penetrating Radar GPR Volume-Area

Effects of irregularity and initial stresses on the dynamic response of viscoelastic half-space due to a moving load

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2017年第3期30卷 306-317页

作者： A.K. singh A. Das A. Lakshman A. negi A. Chattopadhyay Department of Applied Mathematics Indian Institute of Technology (Indian School of Mines) Dhanbad 826004 Jharkhand India

The present article deals with the stresses developed in an initially stressed irregular viscoelastic half-space clue to a load moving with a constant velocity at a rough free surface. Expressions for normal and shear stresses are obtained in closed form. The substantial effects of influence parameters, viz., depth （from the free surface）, irregularity factor, maximum depth of irregularity, viscoelastic parameter, horizontal and vertical initial stresses, and frictional coefficient, on normal and shear stresses are investigated. Moreover, comparative study is carried out for three different cases of irregularity, viz., rectangular irregularity, parabolic irregulariW and no irregularity, which is manifested through graphs.

关键词： Viscoelastic Irregularity Moving load Frictional coefficient Stresses

A new flavone C-glucoside from Glycosmis arborea(Rutaceae)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2010年第12期21卷 1443-1445页

作者： Rajni Kant Sharma Sushma Semwal Devendra singh negi Department of Chemistry HNB Garhwal Central University SrinagarUttarakhandIndia Department of Chemistry University of Cape TownCape TownRondebosch 7701South Africa

A new C-glycosyl flavone 7,4＇-dihydroxy-5-methoxyflavone-6-C-β-D-glucopyranoside 1 has been isolated and characterized form ethanolic extract of leaves part of Glycosmis *** structure of compound was verified by mea... 详细信息

关键词： Glycosmis arborea Rutaceae Flavone C-glucoside

Colloidal lead-free Cs_(2)AgBiBr_(6)double perovskite nanocrystals:Synthesis,uniform thin-film fabrication,and application in solution-processed solar cells

在线全文

学校读者我要写书评

暂无评论

Nano Research 2021年第4期14卷 1126-1134页

作者： Razi Ahmad Gautam virender Nutan Dinesh singh Govind Gupta Udit Soni Sameer Sapra Ritu Srivastava Advanced Materials and Devices Metrology Division CSIR-National Physical LaboratoryDr.K.S.Krishnan RoadNew Delhi-110012India Indian Reference Materials Division CSIR-National Physical LaboratoryDr.K.S.Krishnan RoadNew Delhi-110012India Department of Biotechnology TERI School of Advanced studiesNew Delhi 110070India Department ofChemistryy Indian Institute of Technology Delhi New Delhi 110016India Regional Centre of Advanced Technologies and Materials Faculty of SciencePalacky University OlomoucSlechtitelu 2778371 OlomoucCzech Republic

Recently developed lead-free double perovskite nanocrystals(NCs)have been proposed for the possible application in solutionprocessed optoelectronic ***,the optoelectronic applications of double perovskite NCs have been hampered due to the structural and chemical instability in the presence of polar ***,we report a facile strategy for the synthesis and purification of Cs_(2)AgBiBr_(6)double perovskite NCs that remained stable even after washing with polar *** is realized with our efficient colloidal route to synthesize Cs_(2)AgBiBr_(6)NCs that involve stable and strongly coordinated precursor such as silvertrioctyl phosphine complex together with bismuth neodecanoate,which leads to a significantly improved chemical and colloidal *** layer-by-layer solid-state ligand exchange technique,a compact and crack-free thin film of Cs_(2)AgBiBr_(6)NCs were ***,perovskite solar cells consisting of Cs_(2)AgBiBr_(6)as an absorber layer were fabricated and tested.

关键词： double perovskite nanocrystals colloidal and chemical stability thin film solar cells

Ethnobotanical and Indigenous Knowledge of Important Plants in East Hararghe, Eastern Ethiopia

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2015年第6期12卷 1521-1533页

作者： Laxman singh KANDARI Tripti negi Ashok Kumar THAKUR Eshetu YILMA Department of Forestry Himgiri Zee University Don Paramedical college and Hospital School of Plant Science College of Agriculture and Environmental Sciences Haramaya University

An ethnobotanical study was conducted in East Hararghe, Ethiopia to identify and investigate the use of various plants by the traditional healers and communities engaged in domestic, pesticide and medicinal use. A total of 78 species were observed to be used by the local inhabitants in the region for the treatments of various ailments. Out of these, herbs constitute 49% followed by trees(36%) and shrubs only 15%. However, most frequently used plant parts were leaf and aerial parts(20) followed by seed(13), fruit(12), other parts(10), rhizome(7) and bark(1). Most of the plants were found to be used for medicinal, aromatic and food flavouring(spices, condiments) purposes. Out of 78 species recorded in the present study, 11 were reported to cure stomachache, seven for cold, cough and respiratory problem, six for diarrhoea and five species were found capable of curing fever. Fabaceae was the largest family contributing to medicinal plant use with seven species followed by Solanaceae, Myrtaceae,(5 spp.), and Zingiberaceae, Asteraceae, Liliaceae(4 spp. each). Some of the important plants utilized for taking care of variety of ailments are Azadirachta indica, Brassica nigra, Balanites aegyptiaca, Maytenus ovatus, Rosmarinus officinalis and Trigonella foenum graecum. Most of these medicinal and aromatic plants(MAPs) play a significant role in the household economy and were observed to be very popular among the people. Unpopular plants were left out of the study. This study provides useful and basic information on usage of different plants for conducting further studies aimed at conservation and documentation of traditional medicine system and economic welfare of rural peoples of the East Hararghe, Ethiopia. It also revealed that indigenous practices contributed to sustainable management of plants.

关键词： Ethnobotany Medicinal plants Primary health care Traditional knowledge East Hararghe

Impact of source and drain contact thickness on the performance of organic thin film transistors

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2014年第12期35卷 21-27页

作者： Poornima Mittal Y.S.negi R.K.singh Department of Electronics & Communication Engineering Graphic Era UniversityDehradun–248002 India Department of Electronics & Communication Engineering Uttarakhand Technical UniversityDehradun–248002 India Department of Polymer and Process Engineering Indian Institute of Technology Roorkee–246776 India

This paper analyzes the impact of source（ts） and drain（td） contact thicknesses on top contact（TC） and bottom contact（BC） organic thin film transistors（OTFTs） with a gate in the bottom, using a benchmarked industry standard Atlas 2-D numerical device simulator. The parameters including drive current（Ids）, mobility（μ）, threshold voltage（Vt）and current on-off ratio（ION/IOFF） are analyzed from the device physics point of view on different electrode thicknesses, ranging from infinitesimal to 50 nm, for both top and bottom contact structures. Observations demonstrate that the performance of the BC structure is more affected by scaling of ts=din comparison to its counterpart. In the linear region, the mobility is almost constant at all the values of ts=dfor both structures. However,an increment of 18% and 83% in saturation region mobility is found for TC andBC structures, respectively with scaling down ts=dfrom 50–0 nm. Besides this, the current on-off ratio increases more sharply in the BC *** analysis simplifies a number of issues related to the design and fabrication of organic material based devices and circuits.

关键词： contact thickness organic semiconductor organic thin film transistor bottom contact top contact structure