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Various Silver Nanostructures on Sapphire Using Plasmon Self-Assembly and Dewetting of Thin Films

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Nano-Micro Letters 2017年第2期9卷 41-57页

作者： Sundar Kunwar Mao Sui Quanzhen Zhang puran pandey Ming-Yu Li Jihoon Lee College of Electronics and Information Kwangwoon University Institute of Nanoscale Science and Engineering University of Arkansas

Silver(Ag) nanostructures demonstrate outstanding optical, electrical, magnetic, and catalytic properties and are utilized in photonic, energy, sensors, and biomedical devices.The target application and the performance can be inherently tuned by control of configuration, shape, and size of Ag nanostructures. In this work, we demonstrate the systematical fabrication of various configurations of Ag nanostructures on sapphire(0001) by controlling the Ag deposition thickness at different annealing environments in a plasma ion coater. In particular, the evolution of Ag particles(between 2 and 20 nm),irregular nanoclusters(between 30 and 60 nm), and nanocluster networks(between 80 and 200 nm) are found be depended on the thickness of Ag thin film. The results were systematically analyzed and explained based on the solid-state dewetting,surface diffusion, Volmer–Weber growth model, coalescence,and surface energy minimization mechanism. The growth behavior of Ag nanostructures is remarkably differentiated at higher annealing temperature(750 ℃) due to the sublimation and temperature-dependent characteristic of dewetting process.In addition, Raman and reflectance spectra analyses reveal that optical properties of Ag nanostructures depend on their morphology.

关键词： Ag nanostructures Surface plasmon Selfassembly Dewetting

川白獭兔和伊拉兔行为、血清生化指标和盲肠微生物菌群的比较研究

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甘肃农业大学学报 2024年第1期59卷 11-21页

作者：符翔陈朴然李静叶鑫吕景智西南大学动物科学技术学院生物饲料与分子营养实验室重庆400715

【目的】比较川白獭兔和伊拉兔行为、血清生化指标和盲肠微生物菌群的差异,并探讨行为与盲肠微生物菌群之间的潜在联系。【方法】选取健康状况良好的35日龄雄性断奶川白獭兔和伊拉兔各72只,各分为24个重复,每个重复3只兔。预饲期7d,正试... 详细信息

【目的】比较川白獭兔和伊拉兔行为、血清生化指标和盲肠微生物菌群的差异,并探讨行为与盲肠微生物菌群之间的潜在联系。【方法】选取健康状况良好的35日龄雄性断奶川白獭兔和伊拉兔各72只,各分为24个重复,每个重复3只兔。预饲期7d,正试期33d,试验共持续40d。宰前24h,观察川白獭兔和伊拉兔的行为。在75日龄时,进行强直不动性行为测试、新物体试验和旷场试验。将75日龄的川白獭兔和伊拉兔进行屠宰,采集血样测定血清生化指标,并采集盲肠内容物测定微生物组。【结果】川白獭兔躺、闻嗅和食粪行为频率显著高于伊拉兔(P0.05)。在旷场试验中,川白獭兔静止不动时间、后腿直立次数显著高于伊拉兔(P0.05),厚壁菌门和拟杆菌门为两个兔品种的优势菌门,拟杆菌门与食粪行为时长呈显著负相关(P<0.05)。【结论】与伊拉兔相比,川白獭兔血清葡萄糖浓度较低,此外,川白獭兔啃咬笼具行为频率低、持续时间短,提示川白獭兔的刻板行为少。

关键词：川白獭兔伊拉兔行为血清生化微生物菌群

Catalytic effects of Cu-Co~* on the thermal decomposition of AN and AN/KDN based green oxidizer and propellant samples

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Defence Technology（防务技术） 2018年第3期14卷 250-260页

作者： Pratim Kumar puran Chandra Joshi Rajiv Kumar Shelly Biswas Department of Space Engineering & Rocketry Birla Institute of Technology Department of Mechanical Engineering Vidya Vihar Institute of Technology

This paper presents the catalytic effects of Cu-Co~* catalyst on the decomposition of AN and AN/KDN based oxidizer and propellant samples. Ozawa-Flynn-Wall(OFW) iso-conversional method was used for the kinetic studies and to compute the activation energy(Ea) values for various decomposition steps of the prepared oxidizer and propellant samples in the temperature range of 50 e500C. TG-DTG experiments were carried out for both oxidizer and propellant samples at the heating rates of 3, 5, and 10C/min. AN/KDN based oxidizer samples were prepared by an evaporative co-crystallization method. Citric acid sol-gel method was used for the synthesis of Cu-Co~* catalyst. The propellant sample contains HTPB as the fuel binder along with other ingredients such as TDI, DOA, and Glycerol. The Cu-Co~* catalyst was used as 2% by weight to the total weight of catalyzed oxidizer and propellant samples. It was observed from the present study that, Cu-Co~* catalyst helps in reducing the Ea values for AN and AN based propellant samples. However, with the percentage increment of KDN in the AN crystals, Ea value increases.Further, it was observed that Cu-Co~* catalyst stabilizes the initial partial decomposition of KDN.

关键词：催化氧化剂催化效果热分解 Cu 燃料取样 TG-DTG 催化剂

Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

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Defence Technology（防务技术） 2016年第4期12卷 297-304页

作者： D. Chaitanya Kumar RAO Narendra YADAV puran Chandra JOSHI Space Engineering and Rocketry Birla Institute of Technology Mesra Ranchi 835215 India

Nano-catalysts containing copper–cobalt oxides(Cu–Co–O) have been synthesized by the citric acid(CA) complexing method. Copper(II) nitrate and Cobalt(II) nitrate were employed in different molar ratios as the starting reactants to prepare three types of nano-catalysts. Well crystalline nano-catalysts were produced after a period of 3 hours by the calcination of CA–Cu–Co–O precursors at 550 °C. The phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope(SEM), Energy Dispersive Spectroscopy(EDS) and Fourier Transform Infrared Spectroscopy(FTIR) methods. The particle size of nano-catalysts was observed in the range of 90 nm–200 nm. The prepared nano-catalysts were used to formulate propellant samples of various compositions which showed high reactivity toward the combustion of HTPB/AP-based composite solid propellants. The catalytic effects on the decomposition of propellant samples were found to be significant at higher temperatures. The combustion characteristics of composite solid propellants were significantly improved by the incorporation of nano-catalysts. Out of the three catalysts studied in the present work, Cu Co-I was found to be the better catalyst in regard to thermal decomposition and burning nature of composite solid propellants. The improved performance of composite solid propellant can be attributed to the high crystallinity, low agglomeration and lowering the decomposition temperature of oxidizer by the addition of Cu Co-I nano-catalyst.

关键词： Metal oxides Nano-catalysts Solid propellant Burn rate Surface morphology Thermal analysis

Development of peptidomimetic hydroxamates as PfA-M1 and PfA-M17 dual inhibitors: Biological evaluation and structural characterization by cocrystallization

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Chinese Chemical Letters 2022年第5期33卷 2550-2554页

作者： Anil Kumar Marapaka Priyanka Sankoju Guozhen Zhang Yongzheng Ding Chunhua Ma Vijaykumar Pillalamarri Renu Sudhakar Bharati Reddi puran Singh Sijwali Yingjie Zhang Anthony Addlagatta Department of Medicinal Chemistry Key Laboratory of Chemical Biology(Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJi’nan 250012China Department Applied Biology CSIR-Indian Institute of Chemical TechnologyTarnakaHyderabadTelangana-500007India Academy of Scientific and Innovative Research(AcSIR) Ghaziabad-201002India CSIR-Centre for Cellular and Molecular Biology TarnakaHyderabadTelangana-500007India

Plasmodium parasites causing malaria have developed resistance to most of the antimalarials in use,in-cluding the artemisinin-based combinations,which are the last line of defense against malaria.This ne-cessitates the discovery of new targets and the development of novel antimalarials.Plasmodium falciparum alanyl aminopeptidase(PfA-M1)and leucyl aminopeptidase(PfA-M17)belong to the M1 and M17 family of metalloproteases respectively and play critical roles in the asexual erythrocytic stage of development.These enzymes have been suggested as potential antimalarial drug targets.Herein we describe the devel-opment of peptidomimetic hydroxamates as PfA-M1 and PfA-M17 dual inhibitors.Most of the compounds described in this study display inhibition at sub-micromolar range against the recombinant PfA-M1 and PfA-M17.More importantly,compound 26 not only exhibits potent malarial aminopeptidases inhibitory activities(PfA-M1 K i=0.11±0.0002μmol/L,PfA-M17 K_(i)=0.05±0.005μmol/L),but also possesses remarkable selectivity over the mammalian counterpart(pAPN K_(i)=17.24±0.08μmol/L),which endows 26 with strong inhibition of the malarial parasite growth and negligible cytotoxicity on human cell lines.Crystal structures of PfA-M1 at atomic resolution in complex with four different compounds including compound 26 establish the structural basis for their inhibitory activities.Notably,the terminal ureidoben-zyl group of 26 explores the S2' region where differences between the malarial and mammalian enzymes are apparent,which rationalizes the selectivity of 26.Together,our data provide important insights for the rational and structure-based design of selective and dual inhibitors of malarial aminopeptidases that will likely lead to novel chemotherapeutics for the treatment of malaria.

关键词： Aminopeptidase Dual inhibitor Antimalaria Peptidomimetic Plasmodium falciparum

SPE-UPLC-MS/MS assay for determination of letrozole in human plasma and its application to bioequivalence study in healthy postmenopausal Indian women

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Journal of Pharmaceutical Analysis 2016年第4期6卷 276-281页

作者： Pravin G.Vanol puran Singhal Priyanka A.Shah Jaivik V.Shah Pranav S.Shrivastav Mallika Sanyal Chemistry Department St.Xavier's College Bioanalytical Department Alkem Laboratories Ltd. Department of Chemistry School of SciencesGujarat University

A rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） method is described for determination of letrozole in human plasma.Following solid phase extraction（SPE） of letrozole and letrozole-d4 on Orochem DVB-LP cartridges,chromatography was performed on Acquity UPLC BEH C_（18）（50 mm × 2.1 mm.1.7 μm） column using methanol-0.1%formic acid in water（85：15,v/v） as the mobile phase.Detection was carried out on a triple quadrupole mass spectrometer with an electrospray source,operated under positive ionization mode.Quantitation of letrozole and letrozole-d4 was done using multiple reaction monitoring（MRM） following the transitions at m/z286.2→217.0 and m/z 290.2→221.0,respectively.The calibration plots were linear through the concentration range of 0.10-100 ng/mL（r^2 ≥ 0.9990） using 100 μL human plasma.The extraction recovery of letrozole ranged from 94.3%to 96.2%and the intra-batch and inter-batch precision was ≤ 5.2%.The method was successfully applied to a bioequivalence study of letrozole after oral administration of2.5 mg tablet formulation to 16 healthy postmenopausal Indian women.The assay reproducibility was also established through incurred sample reanalysis（ISR） of 74 subject samples.

关键词： Letrozole Letrozole-D4 UPLC-MS/MS Solid phase extraction Bioequivalence study

Crop productivity,soil health,and energy dynamics of Indian Himalayan intensified organic maize-based systems

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International Soil and Water Conservation Research 2021年第2期9卷 260-270页

作者： Raghavendra Singh Subhash Babu R.K.Avasthe Gulab Singh Yadav Anup Das K.P.Mohapatra Amit Kumar Vinod K.Singh puran Chandra ICAR-National Organic Farming Research Institute GangtokSikkim737102India Division of Agronomy ICAR-Indian Agricultural Research InstituteNew Delhi110012India ICAR Research Complex for NEH Region Tripura CentreLembucherraTripura799210India ICAR-National Bureau of Plant Genetic Resources New Delhi110012India

The sustainability of prevailing maize-fallow system in rainfed ecosystems of the Eastern Himalayan region(EHR)of India is often questioned due to poor economic return and negative impact on soil health.Hence,the six cropping systems,maize-fallow(M-F),maize t cowpea-rapeseed(M t C-Rs),maize t cowpea-buckwheat(M t C-Bw),maize t cowpea-barley(M t CeB),maize t cowpea-garden pea(M t C-GP)and maize t cowpeaerajmash(M t C-R)in the main plot and three soil moisture conservation measures,no-mulch(NM),maize stover mulch(MSM)and maize stover t weed biomass mulch(MSM t WBM)in sub-plot were evaluated for four consecutive years(2014-18)at a Research Farm in fixed plot fashion.Results indicated that cowpea co-culture with maize and inclusion of winter crop increased maize yield by 6.2e23.5%over M-F.Among the systems,the M t C-GP recorded the highest crop productivity.The residual effect of MSM t WBM increased maize grain yield by 19.1%over NM.Cultivation of maize t cowpea-winter crops significantly improved the available N(3.2e12.9%),P(3.6 e12.7%),K(1.9e26.3%),organic carbon(9.2e16.8%),microbial biomass carbon-MBC(15.2e43.9%)and dehydrogenases-DHA(17.2e42.3%)in soil at 0e15 cm depth as compared to M-F.The M t C-GP also recorded maximum net return(US$2460 ha1),benefit:cost(B:C)ratio(2.86)and energy use efficiency(7.9%).The MSM t WBM recorded higher net return(US$1680 ha1)and B:C ratio(2.46)over NM.Hence,cowpea t maize-garden pea(M t C-GP)along with the application of MSM t WBM is a sustainable production practice to intensify the organically managed maize-fallow system in rainfed regions of the EHR of India and other similar ecosystems.

关键词： Crop intensification Energy productivity Gross return Soil health Water productivity

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冰脊形成过程的离散元模拟及影响因素分析

海洋通报 2022年第6期41卷 630-639页

作者：朱红日张普然刘璐季顺迎大连理工大学工业装备结构分析国家重点实验室辽宁大连116024

冰脊对极地船舶及海洋工程结构的冰载荷设计及冰区安全运行具有重要的影响,其几何形态是重要的考虑因素。为研究冰脊的几何形态,本文基于Voronoi切割算法构造扩展多面体海冰单元,并使其相互冻结形成平整冰;采用离散单元法模拟海冰在相... 详细信息

冰脊对极地船舶及海洋工程结构的冰载荷设计及冰区安全运行具有重要的影响,其几何形态是重要的考虑因素。为研究冰脊的几何形态,本文基于Voronoi切割算法构造扩展多面体海冰单元,并使其相互冻结形成平整冰;采用离散单元法模拟海冰在相向运动时挤压形成冰脊的动力过程,统计分析脊帆高度、龙骨宽度、龙骨深度、龙骨水平倾角等主要几何参数,并确定这些几何参数间的对应关系。将离散元模拟结果同冰脊现场观测资料对比分析以验证扩展多面体离散元方法模拟冰脊形成过程的可行性。在此基础上讨论冰厚、冰速、海冰强度等因素对冰脊形态的影响。本文采用离散元方法对冰脊形成过程及几何特性的数值分析可为深入开展冰脊的形成机理及其对船舶、海洋工程结构物的冰载荷分析提供参考依据。

关键词：冰脊离散元方法扩展多面体 Voronoi切割算法龙骨

Land Use/Land Cover Change Detection in Pokhara Metropolitan, Nepal Using Remote Sensing

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Journal of Geoscience and Environment Protection 2020年第8期8卷 25-35页

作者： Sanjeev Kumar Raut puran Chaudhary Laxmi Thapa Survey Department Ministry of Land Management Co-Operatives and Poverty Alleviation Kathmandu Nepal

Land use and land cover are essential for maintaining and managing the natural resources on the earth surface. A complex set of economic, demographic, social, cultural, technological, and environmental processes usually result in the change in the land use/land cover change (LULC). Pokhara Metropolitan is influenced mainly by the combination of various driving forces: geographical location, high rate of population growth, economic opportunity, globalization, tourism activities, and political activities. In addition to this, geographically steep slope, rugged terrain, and fragile geomorphic conditions and the frequency of earthquakes, floods, and landslides make the Pokhara Metropolitan region a disaster-prone area. The increment of the population along with infrastructure development of a given territory leads towards the urbanization. It has been rapidly changing due to urbanization, industrialization and internal migration since the 1970s. The landscapes and ground patterns are frequently changing on time and prone to disaster. Here a study has been carried to study on LULC for the last 18 years (2000-2018). The supervised classification on Landsat Imagery was performed and verified the classification through computing the error matrix. Besides, the water bodies and vegetation area were extracted through the Normalized Difference Water Index (NDWI) and Normalized Difference Vegetation Index (NDWI) respectively. This research shows that during the last 18 years the agricultural areas diminishing by 15.66% while urban area is increasing by 13.2%. This research is beneficial for preparing the plan and policy in the sustainable development of Pokhara Metropolitan.

关键词： Error Matrix Land Use/Land Cover (LULC) Normalized Difference Vegeta-tion Index (NDVI) Normalized Difference Water Index (NDWI) Supervised Image Classification Remote Sensing Urban Growth