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Identification and elucidation of anthropogenic source contribution in PM_(10) pollutant: Insight gain from dispersion and receptor models

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Journal of Environmental Sciences 2016年第10期28卷 69-78页

作者： Debananda Roy Gurdeep Singh Pankaj Yadav Dept. of Environmental Science & Engineering Marwadi Education Foundation & Group of Institutions Centre of Mining Environment /Department of Environmental Science & Engineering Indian School of Mines Dept. of Physics Marwadi Education Foundation & Group of Institutions

Source apportionment study of PM10 （Particulate Matter） in a critically polluted area of Jhafia coalfield, India has been carried out using Dispersion model, Principle Component Analysis （PCA） and Chemical Mass Balance （CMB） techniques. Dispersion model Atmospheric Dispersion Model （AERMOD） was introduced to simplify the complexity of sources in Jharia coalfield. PCA and CMB analysis indicates that monitoring stations near the mining area were mainly affected by the emission from open coal mining and its associated activities such as coal transportation, loading and unloading of coal. Mine fire emission also contributed a considerable amount of particulate matters in monitoring stations. Locations in the city area were mostly affected by vehicular, Liquid Petroleum Gas （LPG）＆ Diesel Generator （DG） set emissions, residential, and commercial activities. The experimental data sampling and their analysis could aid understanding how dispersion based model technique along with receptor model based concept can be strategically used for quantitative analysis of Natural and Anthropogenic sources of PM10.

关键词： Source apportionment PM10 PCAReceptor modelDispersion modelJharia coalfield

Metallurgical analysis of a failed maraging steel shear screw used in the band separation system of a satellite launch vehicle

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Defence Technology（防务技术） 2016年第5期12卷 380-387页

作者： S.V.S. Narayana MURTY Sushant K. MANWATKAR E Ramesh NARAYANAN Material Characterization Division Materials and Metallurgy Group Vikram Sarabhai Space Centre Trivandrum 695 022 India

Maraging steels have excellent combination of strength and toughness and are extensively used for a variety of aerospace applications. In one such critical application, this steel was used to fabricate shear screws of a stage separation system in a satellite launch vehicle. During assembly preparations, one of the shear screws which connected the separation band and band end block has failed at the first thread. Microstructural analysis revealed that the crack originated from the root of the thread and propagated in an intergranular mode. The failure is attributed to combined effect of stress and corrosion leading to stress corrosion cracking.

关键词： M250 grade maraging steel Shear screw Separation system Mermen band Stress corrosion cracking

Synthesis of some new N,N'-diarylsubstituted methylene-bis-dihydro-2H-1,3-benzoxazines

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Chinese Chemical Letters 2008年第12期19卷 1407-1410页

作者： Cherkupally Sanjeeva Reddy Mekala Raghu Department of Chemistry Kakatiya UniversityWarangal 506009India

The synthesis of a new series of six-membered N,N′-diarylsubstituted methylene-bis-dihydro-2H-1,3-benzoxazines （5a-e） was achieved in excellent yields by Mannich-type condensation of N,N′-diarylsubstituted methylene-bis-o-hydroxybenzyl amines （4a- e） with formaldehyde in chloroform at reflux. These amines （4a-e） were obtained by the reduction of N, Nr-diarylsubstituted methylene-bis-o-hydroxybenzyl imines （3a-e） with NaBH4, which inturn were obtained by the condensation of methylene-bissalicylaldehyde （2） with various substituted arylamines.

关键词： Methylene-bis-salicylaldehyde Marmich-type condensation Methylene-bis-1,3-benzoxazines

Time-Resolved Optical Emission Spectroscopy Diagnosis of CO_2 Laser-Produced SnO_2 Plasma

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Plasma Science and Technology 2016年第9期18卷 902-906页

作者：兰慧王新兵左都罗 School of Optical and Electronic Information Huazhong University of Science and Technology School of Physics and Information Engineering Jianghan University Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

The spectral emission and plasma parameters of SnO2 plasmas have been investigated. A planar ceramic SnO2 target was irradiated by a CO2 laser with a full width at half maximmn of 80 ns. The temporal behavior of the specific emission lines from the SnO2 plasma was characterized. The intensities of Sn I and Sn Ⅱ lines first increased, and then decreased with the delay time. The results also showed a faster decay of Sn I atoms than that of Sn II ionic species. The temporal evolutions of the SnO2 plasma parameters （electron temperature and density） were deduced. The measured temperature and density of SnO2 plasma are 4.38 eV to 0.5 eV and 11.38×1017 cm 3 to 1.1×1017^ cm-3, for delay times between 0.1 μs and 2.2 #s. We also investigated the effect of the laser pulse energy on Sn02 plasma.

关键词： optical emission spectroscopy laser produced plasma C02 laser electrontemperature electron density

Decentralized damage diagnostic technique for tall buildings using VARMAX model

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Earthquake Engineering and Engineering Vibration 2022年第2期21卷 417-439页

作者： K.Lakshmi J.Prawin CSIR-Structural Engineering Research Centre CSIR RoadChennai 600113Tamil NaduIndia

Civil infrastructure,especially buildings,are becoming more slender,tall,and multipurpose,creating a need to continuously monitor their health to ensure the safety and security of human lives and *** the majority of structural health monitoring techniques use measurements from the entire structure,in this study,an output-only damage diagnostic technique using a decentralized concept(subdomain-based)for tall buildings and employing a vector form of the autoregressive moving average with exogenous input(VARMAX)model is proposed,which offers reduced instrumentation and data handling *** other decentralized approaches,this technique predicts more than one DOF at a time so the number of subdomains required for the diagnosis of the complete structure is *** proposed subdomain-based damage diagnostic algorithm works with ambient loads and does not require any correlated numerical models since it is solely based on measured *** proposed algorithm can identify the time instant of damage,spatial location(s)and characterize the damage *** have been made to account for confounding factors such as environmental and operational variabilities separate from measurement noise to avoid false positive *** effectiveness of the proposed technique is illustrated using synthetic time history responses from a twenty-story framed structure under ambient loading and an experimental study on a ten-story framed *** numerical and experimental investigations confirm the effectiveness of the method and its robustness to environmental/operational variabilities and measurement noise.

关键词： structural health monitoring subdomain high-rise buildings shear-type buildings VARMAX model environmental and operational variability measurement noise

Synthesis and Single Crystal Structure of RbEr_2Cu_3Se_5

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Chinese Journal of Structural Chemistry 2002年第5期21卷 497-500页

作者：曾卉一董振超等 StateKeyLaboratoryofStructuralChemistry FujianInstituteofResearchontheStructureofMatterTheChineseAcademyofSciencesFuzhou350002China StateKeyLaboratoryofStructuralChemistry FujianInstituteofResearch

Single crystals of a new quaternary rare-earth selenide RbEr2Cu3Se5 have been isolated through the RbCl flux reaction in the RE-Cu-Se system. The title compound crystallizes in an orthorhombic system, space group Cmcm with a = 4.089(2), b = 14.498(6), c = 16.977(2) Angstrom, V = 1006.5(7) Angstrom(3), Z = 4, D-c = 6.63 g/cm(3), F(000) = 1720 and mu(MoKalpha) = 45.51 mm(-1). The final R = 0.0498 and wR = 0.0734 for 1401 observed reflections with I > 3 sigma(1). The structure of RbEr2Cu3Se5 is a three-dimensional tunnel structure composed of ErSe6 and CuSe4 polyhedra with the charge-balanced Rb+ cations stuffing into the one-dimensional channels along the a direction. In the Er2RbCu3Se5 structure, the (1)(infinity) [Er2Se(1)(4/2)SE(2)(2)Se(3)(4/2)] double-octahedral chains are linked into a (2)(infinity) [Er2Cu2Se6] layer in the a-b plane via sharing Se(1)-Se(3) edges with the (1)(infinity) [Cu(2)(2)Se(1)(2)Se(3)(4/2)] double tetrahedral chains, and (2)(infinity)[Er2CU2Se6] layers are further interconnected along the c direction by sharing Se(1)-Se(2) edges with the (1)(infinity) [Cu(1)Se(1)(2)Se(2)(2/2)] tetrahedral chains, forming a three-dimensional framework with the channels along the a axis accommodated by Rb+ ions.

关键词： rare earth chalcogenides flux crystal structure

A Different Opinion on the Geological Age of the Longzhaogou and Jixi Groups of Eastern Heilongjiang, China

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Acta Geologica Sinica(English Edition) 1992年第2期66卷 209-218,223页

作者： Sha Jingeng Nanjing Institute of Geology and Palaeontology, Academia Sinica, Nanjing, Jiangsu Nanjing Institute of Geology and Palaeontology Academia Sinica Nanjing Jiangsu

The age of the Longzhaogou and Jixi Groups of coal measures in eastern Heilongjiang were previouslyconsidered to be Jurassic or mainly Jurassic. But there occur Middle Barremian-Early Albian Aucellina(bivalvia) fossils in the Upper Yunshan Formation of the Longzhaogou Group and the Lower Chengzihe For-mation of the Jixi Group, and the Qihulin Formation of the Longzhaogou Group yields Early Cretaceousbivalve and ammonite fossils. Consequently, the geological ages of the two groups are mainly, or even all, Ear-ly Cretaceous.

关键词： A Different Opinion on the Geological Age of the Longzhaogou and Jixi Groups of Eastern Heilongjiang China

THE BEHAVIOR OF HOMOGENEOUS IRON-BASED CATALYSTS BEARING PYRIDINE DIIMINE LIGANDS FOR ETHYLENE POLYMERIZATION

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Chinese Journal of Polymer Science 2000年第6期18卷 509-513页

作者：李于飞 State Key Laboratory of Engineering Plastics Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The polymerization of ethylene by two iron-based catalysts, {[2,6-ArN=C(Me)(2)C5H3N]FeCl2} (Ar = 2,6-C6H3-Me-2 I; 2,6-C6H3 (i-Pr)(2) II) has been investigated. Catalyst II produces higher molecular weight polyethylene (PE) and broadened polydispersities relative to catalyst I under analogous conditions and all polymers are linear. The kinetic profiles with iron catalysts showed a smooth pattern during both rate build-up and rate lowering, which are different from the metallocene catalysts. The polymerization activity increases with Al/Fe value and an optimum temperature range at 40 similar to 45 degreesC was observed. The molecular weight of PE decreases with the increase of Al/Fe ratio and rise of polymerization temperature.

关键词： ethylene polymerization transition metal catalyst

Synthesis and optical properties of nanostructured Ce(OH)_4

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Journal of Semiconductors 2010年第3期31卷 25-28页

作者： Ansari A A Kaushik A National Physical Laboratory Dr.K.S.Krishnan MargPusaNew Delhi-110012India

Nanocrystalline cerium hydroxide （NCs-Ce（OH）4） is a intermediate product of CeO2, synthesized successfully using a novel and simple wet chemical rout at an ambient temperature for the preparation of NCs CeO2 powder and film on mass scale for various purposes. The synthesized NCs-Ce（OH）4 was characterized using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, thermo-gravimetric analysis （TGA）, Fourier transform infrared （FTIR）, UV-visible and photoluminescence （PL） spectroscopy. The average crystallite size of NCs-Ce（OH）4 has been estimated by the Scherrer equation to be 3-4 nm. The SEM examinations show that the surface texture was uniformly agglom- erated and homogeneous. Thermal analysis suggests that cerium （IV） ion is in the tetra hydrated form. Absorption and luminescence spectroscopic studies have been examined for future application in the development of optical devices.

关键词： NCs-Ce(OH)4 X-ray diffraction thermo-gravimetric analysis optical properties