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Journal of Forestry Research 2014年第4期25卷 835-838页

作者： m.. Abdul Quddus m..h sk. Ahiul Islam..d. Ahsan Habib m.. Golam..oula Plantation Trial Unit Division Bangladesh Forest Research Institute Rupatoli Barisal-8206 Bangladesh

A trial ofAvicennia officinalis L. with five different spacings was conducted in the newly accreted lands along the western coastline （Patuakhali district） of Bangladesh since 1993 to assess growth perform..ance and the effect of spacing on tree growth. Data on tree density, height, diam..er, bole height, crown diam..er were recorded and ana- lyzed when the stand was 19 years old. m..n height ranged from..2.89-13.52 m..nd diam..er at breast height （dbh） from..6.57-32.16 cm..n plots of different spacings. The m..n annual height increm..t ranged from..,67-0.71 m..m..n annual diam..er increm..t from...40-1.69 cm..nd wood volum..from...02-10.04 ***＇*** in different treatm..ts. Significantly greater diam..er （32.16 cm..and wood volum..（10.04 ***.a-1） were obtained with wider （2.13 m.. 2.13 m..spacing than with closer spacings. But tree growth was unaffected by other spacings. Growth data were also recorded from..ther .4. officinalis plantations raised by Forest Departm..t （FD） on different islands in Patuakhali and Bhola districts of Bangladesh. At these sites, m..n annual height incre- m..t ranged from...33-0.62 m..m..n annual diam..er increm..t from...72-1,37 cm..nd wood volum..from...55-5.73 m..ha-1·a·-1. The growth perform..ce of A. offindicated that the newly aecreted lands along the western shoreline m.. be suitable for raising Avicennia planta- tions for the enrichm..t of coastal vegetation.

关键词： growth Avicennia officinalis plantation spacing coastal belt

Genotypic diversity and genotype identity of resident species drive com..nity com..sition

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Journal of Plant Ecology 2020年第2期13卷 224-232页

作者： Věroslava Hadincová Hana sk.lová Zuzana m..zbergová Departm..t of Population Ecology Institute of BotanyAcademy of Sciences of the Czech RepublicCzech Republic Departm..t of Botany Faculty of ScienceCharles UniversityCzech Republic Departm..t of Invasion Ecology Institute of BotanyAcademy of Sciences of the Czech RepublicCzech Republic

Aim..Species-rich plant com..nities are m..e resistant to *** the past decade it was dem..strated that genetic variation also has m..y ecological *** our study we aim.. to test whether the patterns of response to the genetic diversity of a resident species differ between colonizing species of different growth form..and whether the response is affected by soil *** We established experim..tal stands of a com..n grass,Festuca rubra,harbouring three levels of genetic diversity(1,6 or 18 clonal genotypes,referred to as genotypic diversity)under two soil nutrient *** the fourth year after the stands were established,we sowed a m..ture of four colonizers into the stands:a stoloniferous legum..Trifolium..epens),a broad-leaf tussock grass(Anthoxanthum..doratum..a largerosette forb(Plantago lanceolata)and a sm..l-rosette forb(Cam..nula rotundifolia).We observed species establishm..t and growth over 3 *** tested whether colonization success depended on genotypic diversity,specific Festuca genotypes,soil nutrients and colonizer growth *** Findings The colonization success and biom..s of the colonizers were significantly affected by the genotypic diversity and the genotype identity of the resident clonal *** response,however,differed between the *** strongest response to the genotypic diversity of the resident species was observed in the tussock grass with a growth form..nd architecture sim..ar to the resident *** large-rosette species responded in early stages of growth whereas the stoloniferous legum..did not respond at *** intraspecific genotypic diversity and genotype identity of the resident species play an im..rtant role in the assem..y of plant com..nities.

关键词： clonal grass biodiversity effects colonization

Preparation and Structural Properties of ZnAl_xFe_2-xO₄ Spinel Oxide

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Am..ican Journal of Analytical Chem..try 2016年第2期7卷 203-209页

作者： Shahzad Hossain Goutam..ev m... Sanjida Aktar m..am..d Kam..l Hasan A. K. m..Zakaria Tapash Kum.. Datta Im..az Kam.. sk. m.. yunus m.. Habibul Ahsan Abul Kalam..zad Institute of Nuclear Science & Technology Bangladesh Atomic Energy Commission Dhaka Bangladesh Faculty of Integrated Technologies Universiti Brunei Darussalam Gadong Brunei Darussalam Departm..t of Physics Shahjalal University of Science and Technology Sylhet Bangladesh

The ZnAlxFe2-xO4 (x = 0.0, 0.2 and 0.4) spinel ferrites were prepared by the conventional solid state reaction in air at 1350°C. The X-ray diffraction of all the three sam..es showed sharp Bragg peaks indicating the form..ion of a single phase spinel structure. The lattice param..ers of the sam..es were determ..ed from..he X-ray diffraction data using the Nelson-Riley extrapolation m..hod. The lattice param..ers, cation distribution and oxygen position param..ers have also been determ..ed by refining the data by the Rietveld m..hod. Rietveld refinem..t of the XRD data reveals all the sam..es to possess cubic sym..try corresponding to the space group Fd3m..Lattice param..ers were found to decrease with increasing Al concentration, i.e. 8.4322, 8.4002, and 8.3984 Åfor x = 0.0, 0.2 and 0.4, respectively.

关键词： Polycrystalline Ferrite X-Ray Diffraction Spinel Ferrite Rietveld Refinem..t Space Group Fd3m Lattice Param..er

3-D QSAR study on a set of nitroarom..ic com..unds

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Chinese Science Bulletin 2002年第3期47卷 189-193页

作者： Xu, m..hang, AQ Han, sk.Wang, LS Nanjing Univ Sch Environm State Key Lab Pollut Control & Resource Reuse Nanjing 210093 Peoples R China

The 3-D relationships between the structures of 25 nitroarom..ic com..unds and their toxicities have been investigated using the com..rative m..ecular field analysis (Com..) m..hod, and a 3-D QSAR m..el with considerable prediction ability is obtained. In com..rison with traditional 2-D techniques, Com.. helps to give a better interpretation of toxic m..hanism..f tested com..unds.

关键词： nitroarom..ic com..und 3-D QSAR Com...

m..rostructure, Im..ct Toughness and TEm..nalysis in the CGHAZ of HQ130 High Strength Steel

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Journal of m..erials Science & Technology 1999年第6期15卷 555-558页

作者： Zou, ZD Li, YJ Yin, sk Shandong Univ Technol Jinan 250061 Peoples R China

m..rostructure and im..ct toughness in the coarse grain heat-affected zone (CGHAZ) of HQ130 high strength steel were studied by using the weld therm..sim..ation test. Fracture m..phology and fine structure in the CGHAZ were analyzed by m..ns of SEm..TEm..nd electron diffraction. Experim..tal results indicated that the im..ct toughness and hardness in the CGHAZ (T-m.. 1350 degrees C) decreased with increasing cooling tim..(t(8/5)), and fracture m..phology changed from..im..e fracture into cleavage fracture. The reason for the toughness decrease is the form..ion of upper bainite. During application, the welding heat input should be strictly lim..ed, to reduce brittleness in the CGHAZ of HQ130 steel.

关键词： Steel

Effect of Gd addition on the superconducting properties of Ti-based V, Nb, Ta alloys

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Superconductivity 2023年第2期6卷 58-63页

作者： sk.Ram..n LS.Sharath Chandra Rashm..Singh m...Chattopadhyay Free Electron Laser Utilization Laboratory Raja Ramanna Centre for Advanced TechnologyIndore 452013Madhya PradeshIndia Hom..Bhabha National Institute Training School ComplexAnushakti NagarMumbai 400094MaharastraIndia Laser and Functional m..erials Division Raja Ramanna Centre for Advanced TechnologyIndore 452013Madhya PradeshIndia

The critical current density(Jc)of the body centered cubic(bcc)V0.6Ti0.4 alloy enhances significantly after the addition of rare earth Gd as the latter is im..scible in the m..rix[***,***,IEEE ***.31,5(2021)].Very low solubility of Gd in other bcc elem..ts like Ta and Nb is also well known[*** Gschneidner in Prog Sci Technol Rare Earths,vol.1,pp.222–258,1964&m..euberger,*** in Handbook of Electronic m..erials,Vol 4,1972].We use these facts to find the effect of adding 1 at.%Gd into the Nb0.6Ti0.4 and Ta0.4Ti0.6 alloys on the superconducting properties e.g.,the transition tem..rature(Tc),Jc,flux pinning force density(Fp)and the *** spite of Gd being ferrom..netic,the Tc in these alloys change only m..ginally(increase by 0.3 K in Ta0.4Ti0.6 and decrease by 0.15 K in Nb0.6Ti0.4 after Gd *** Jc(H?1 T,T=4 K)increases by 5 and 1.5 tim.. respectively in the Gd containing Nb0.6Ti0.4 and Ta0.4Ti0.6 alloys,which is quite sm..l as com..red to the increase observed in the V0.6Ti0.4(20 tim..)*** Gd addition,the grain size reduces approxim..ely by 65%and 10%respectively in Nb0.6Ti0.4 and *** analysis indicates that grain boundaries are the m..or flux line pinning centres in these alloys and the role of Gd in increasing the Jc depends on the effectiveness of Gd in reducing the grain *** grain boundary density depends strongly on the distribution of Gd precipitates,which is quite different from..ach other for two alloy system..under ***,our results suggest that the addition of Gd to com..rcial Nb‐Ti(Nb0.37Ti0.63)alloy is a new prom..ing route for achieving higher Jc values.

关键词： Critical current density Ferrom..netism Flux pinning Grain boundary

Recovery of m..als and other beneficial products from..oal fly ash： a sustainable approach for fly ash m..agem..t

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International Journal of Coal Science & Technology 2016年第3期3卷 267-283页

作者： Prafulla Kum.. Sahoo Kangjoo Kim... A. Powell sk.m..Equeenuddin Vale Institute of Technology Baventura da Silva BelemPara 66055-090 Brazil Departm..t of Environm..tal Engineering Kunsan NationalUniversity Jeonbuk 573-701 Republic of Korea Prom..eo SDIC Secretary of Higher Education ScienceTechnology and Innovation (SENESCYT) Quito Ecuador Departm..t of m..ing Engineering National Institute ofTechnology Rourkela Orissa 769008 India

Increasing production and disposal of coal fly ash （CFA） is a m..ter of serious environm..t concern. However, CFA contains various beneficial m..als and m..eral m..ters whose dem..d is increasing in the industrialized world, while natural supplies are dim..ishing. Therefore, recovery of these potential resources from..FA can be an alternative way to save m..eral resources, as well as to reduce the environm..tal burden of CFA disposal. There are num..ous m..hods developed for the recovery of beneficial products from..FA. Based on the US patents and journal literatures, the present review describes the recovery status and technologies of m..or elem..ts such as Al, Si, Fe and Ti, and trace elem..ts such as V, Ga, Ge, Se, Li, m.. U, Au, Ag, Pt groups and rare earth elem..ts （REEs） and other beneficial products such as m..netic m..erials, cenospheres, and unburned carbon from..FA. It also highlights the recovery efficiency and drawbacks for their extraction, and suggests future research to develop satisfactory results in term..of selective recovery and purification.

关键词： Coal fly ash Beneficial elem..ts Recovery Hydrom..allurgical m..hods Extraction efficiency

Annealing Effect on m..hanical Properties of Ti_(51)Ni_(13)Pd_(36)High Tem..rature m..ory Alloy

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Journal of m..erials Science & Technology 2000年第5期16卷 531-533页

作者： Xu, HB Hu, SQ Jiang, CB Gong, sk Beijing Univ Aeronaut & Astronaut Dept Mat Sci & Engn Beijing 100083 Peoples R China

The high tem..rature shape m..ory alloy Ti51Ni13Pd36 was subjected to a cold working and annealing treatm..t to im..ove its m..hanical properties and the shape m..ory effect. It was found that recovery of the cold worked alloys started at near 673 K and the recrystallization tem..rature was at about 748 K. The grain size decreased with the increase of annealing tem..rature below 923 K and then increased when above 923 K. The sm..lest average grain size of about 3.5μm..which is approxim..ely 10 tim.. sm..ler than the hot rolled one, perm..ted the best com..nation of the m..hanical properties in the alloy annealed at 923 K for 1h. The cold rolling raised the peak tem..rature of reverse transform..ion. This tem..rature dropped very sharply when the specim.. was annealed at tem..ratures higher than 673 K.

关键词： Alloys

Characterization,spectroscopic investigation of defects by positron annihilation,and possible application of synthesized PbO nanoparticles

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Chinese Physics B 2021年第2期30卷 400-407页

作者： sk.Irsad Ali Anjan Das Apoorva Agrawal Shubharaj m..herjee m..dud Ahm.. P m.. Nam..ssan Sam..an m..dal Atis Chandra m..dal Departm..t of Physics University of BurdwanGolapbagBurdwan 713104West BengalIndia Departm..t of Physics A.P.C.Roy Government CollegeSiliguriDarjeeling 734010West BengalIndia Applied Nuclear Physics Division Saha Institute of Nuclear Physics1/AF BidhannagarKolkata 700064India Departm..t of Physics Government General Degree College at PedongKalimpong 734311West BengalIndia

Nanocrystalline sam..es of highly pure lead oxide were prepared by the sol-gel route of synthesis.X-ray diffraction and transm..sion electron m..roscopic techniques confirm.. the nanocrystallinity of the sam..es,and the average sizes of the crystallites were found within 20 nm..o 35 *** nanocrystallites exhibited specific anom..ous properties,am..g which a prom..ent one is the increased lattice param..ers and unit cell *** optical band gaps also increased when the nanocrystallites becam..sm..ler in *** latter aspect is attributable to the onset of quantum..onfinem..t effects,as seen in a few other m..al oxide *** annihilation was em..oyed to study the vacancy type defects,which were abundant in the sam..es and played crucial roles in m..ulating their *** defect concentrations were significantly larger in the sam..es of sm..ler crystallite *** results suggested the feasibility of tailoring the properties of lead oxide nanocrystallites for technological applications,such as using lead oxide nanoparticles in batteries for better perform..ce in discharge rate and *** also provided the physical insight into the structural build-up process when crystallites were form.. with a finite num..r of atom..whose distributions were governed by the site stabilization energy.

关键词： lead oxide nanocrystals positron annihilation sol-gel processes

Neutron stars:a relativistic study

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Research in Astronom..and Astrophysics 2018年第3期18卷 1-8页

作者： m..edi Kalam..0}m..owar Hossein Sajahan m..la Departm..t of Physics Aliah University Departm..t of m..hem..ics Aliah University

We study the inner structure of a neutron star from.. theoretical point of view and the outcom..results are com..red with observed data. We propose a stiff equation of state relating pressure with m..ter density. From..ur study we calculate m..s（m..com..ctness（u） and surface redshift（Zs） for two binary m..lisecond pulsars,nam..y PSR J1614–2230 and PSR J1903＋327,and four X-ray binaries,nam..y Cen X-3,Sm..X-1,Vela X-1 and Her X-1,and com..re them..ith recent observational ***,we exam..e the stability for such a type of theoretical structure.

关键词： stars neutron - stars m..s function- equation of state