检索结果-南通市图书馆

Spatial var.ation and pr.diction of for.st biomass in a heter.geneous landscape

Jour.al of For.str. r.sear.h 2012年第1期23卷 13-22页

作者： S. Lamsal D. M. r.zzo r. k. meentemeyer Depar.ment of Geogr.phy and Ear.h Sciences University of North Carolina Charlotte NC U. S. A Depar.ment of Plant Pathology University of California Davis CA U. S. A.

Lar.e ar.as assessments of for.st bioinass distr.bution ar. a challenge in heter.geneous landscapes, wher. var.ations in tr.e gr.wth and species composition occur.over.shor. distances. In this study, we use statistical and geospatial modeling on densely sample.d for.st biomass data to analyze the r.lative impor.ance of ecological and physiogr.phic var.ables as deter.inants of spatial var.ation of for.st biomass in the envir.nmentally heter.geneous r.gion of the Big Sur. Califor.ia. We estimated biomass in 280 for.st Plots （one plot per.2.85 k.2） and meas- ur.d an ar.ay of ecological （vegetation community type, distance to edge, amount of sur.ounding non-for.st vegetation, soil pr.per.ies, fir. histor.） and physiogr.phic dr.ver. （elevation, potential soil moistur. and solar.r.diation, pr.ximity to the coast） of tr.e gr.wth at each plot location. Our.geostatistical analyses r.vealed that biomass distr.bution is spatially str.ctur.d and autocor.elated up to 3.1 k.n. r.gr.ssion tr.e （r.） models showed that both physiogr.phic and ecological factor. influenced bio- mass distr.bution. Acr.ss r.ndomly selected sample densities （sample size 112 to 280）, ecological effects of vegetation community type and distance to for.st edge, and physiogr.phic effects of elevation, potential soil moistur. and solar.r.diation wer. the most consistent pr.dictor. of biomass. Topogr.phic moistur. index and potential solar.r.diation had apositive effect on biomass, indicating the impor.ance of topogr.phically- mediated ener.y and moistur. on plant gr.wth and biomass accumula- tion. r. model explained 35% of the var.ation in biomass and spatially autocor.elated var.ation wer. r.tained in r.gession r.siduals. r.gr.ssion k.0}ging model, developed fr.m r. combined with k.0}ging of r.gr.ssion r.siduals, was used to map biomass acr.ss the Big Sur. This study dem- onstr.tes how statistical and geospatial modeling can be used to dis- cr.minate the r.lative impor.ance of physiogr.phic and ecologic effect

关键词： for.st biomass landscape heter.geneity spatial var.ation semivar.ogr.m r.gr.ssion tr.e r.gr.ssion k.0}ging Big Sur.Califor.ia

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

EXPEr.MENTAL AND NUMEr.CAL ANALYSIS OF LAMINAr.AND LOW TUr.ULENT FLOW DISTr.BUTIONS IN INLET DIVIDING HEADEr.OF SHELL AND TUBE HEAT EXCHANGEr

引用

Jour.al of Hydr.dynamics 2010年第4期22卷 494-502页

作者： k.NNAN k. r.Dr.MOOr.HY r. Depar.ment of Pr.duction Engineer.ng PSG College of Technology

Flow distr.bution header. play a major.r.le in heat *** selection of header.diameter.br.nch pipe diameter.br.nch pipe spacing *** based on the designer.s exper.ence and gener.l guide *** pr.per.selection of the header.dimensions will yield unifor. flow distr.bution in heat exchanger.,which in tur. will enhance the heat exchanger.*** this wor.,the flow distr.bution in br.nch pipes and the pr.ssur. var.ation acr.ss the br.nch pipes in laminar.and low tur.ulence r.gion is studied with two models of the inlet dividing *** the numer.cal analysis has been applied,its inability to pr.dict the no flow condition thr.ugh the br.nch pipes is *** r.sults ar. pr.sented in the for. of flow r.te r.tio thr.ugh br.nch pipes and nondimensional coefficients acr.ss br.nch pipes which ar. useful to apply the existing mathematical models for.the pr.sent exper.mental setup.

关键词： shell and tube heat exchanger inlet dividing header unifor. flow distr.bution exper.mental setups numer.cal analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Activator.assisted electr.less deposition of copper.nanostr.ctur.d films

引用

Inter.ational Jour.al of Miner.ls,Metallur.y and Mater.als 2014年第2期21卷 196-203页

作者： Var.ha r. Mehto r. k. Pandey Depar.ment of Physics Barkatullah University NIIT Univer.ity

This paper.showed simple and effective synthesis of copper.nanopar.icles within contr.lled diameter.using dir.ct electr.less deposition on glass substr.tes, following the sensitization and activation steps. Electr.less-deposited metals, such as Cu, Co, Ni, and Ag, and their.alloys had many advantages in micr.- and nanotechnologies. The str.ctur.l, mor.hological, and optical pr.per.ies of copper.deposits wer. char.cter.zed using X-r.y diffr.ction （Xr.）, atomic for.e micr.scopy （AFM）, and UV-Vis spectr.scopy. The str.ctur.l data was fur.her.analyzed using the r.etveld r.finement pr.gr.m. Str.ctur.l studies r.veal that the deposited copper.pr.fer. a （111） or.entation. AFM studies suggest the deposited mater.als for. compact, unifor., and nanocr.stalline phases with a high tendency to self-or.anize. The data show that the par.icle size can be contr.lled by contr.lling the activator.concentr.tion. The absor.tion spectr. of the as-deposited copper.nanopar.icles r.veal that the plasmonic peak.br.adens and exhibits a blue shift with decr.asing par.icle size.

关键词： nanostr.ctur.d mater.als thin films copper electr.less plating deposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Photolysis studies on HCOOH and HCOO^- in pr.sence of TiO_2 photocatalyst as suspension in aqueous medium

引用

Jour.al of Natur.l Gas Chemistr. 2009年第1期18卷 50-54页

作者： G. r. Dey k. N. r. Nair.k. k. Pushpa r.diation and Photochemistr. Division Bhabha Atomic Research Centre Trombay Mumbai 400 085 India

Photolysis studies on for.ic acid （HCOOH） and for.ate ion （HCOO-） in pr.sence of TiO2, a photocatalyst, as suspension in water.wer. car.ied out separ.tely using 350 nm ultr.violet light. The pr.ducts, such as H2, CO, CO2 and CH4, gener.ted dur.ng the exper.ments wer. monitor.d with var.ing the ambient, light exposur. time, and the concentr.tion of HCOOH/HCOO-. The yields of CO in all these systems incr.ased with light exposur. time. In aer.ted systems, CO yields wer. higher.in contr.st to the deoxygenated （Ar.pur.ed） systems under.identical conditions. It is pr.posed appar.ntly that the for.ation of CO is tak.ng place dur.ng the chemical r.duction of in-situ gener.ted CO2, a photo-miner.lized pr.duct of HCOOH/HCOO-, but not thr.ugh the dir.ct photodecomposition or.photodehydr.tion （CO＋H2O） of solute molecules. The r.tes of CO for.ation dur.ng 1.3 M HCOOH photolysis in pr.sence of TiO2 photocatalyst wer. evaluated to be 0.21 and 0.13 μl/min in aer.ted and Ar.pur.ed systems, r.spectively. As compar.d with HCOOH systems, the CO yields ar. lower.when 0.2 M HCOONa was exposed to light under.identical conditions. The CO gr.wth r.tes wer. evaluated to be 0.07 and 0.046 μl/min^-1 for.aer.ted and deoxygenated HCOONa systems, r.spectively; mor.over. the tr.nd is quite similar.to that of the HCOOH system. Under.these conditions, the emission of H2 was also obser.ed, and its yield was significantly higher.in Ar.pur.ed system as compar.d with the CO yields. However. in aer.ted system, the yields of these pr.ducts wer. just opposite. The for.ation of low yield of methane was obser.ed dur.ng photolysis of HCOOH/HCOO ions. In CO2 ambient, the yields of CO and H2 var.ed dr.stically with time.

关键词： for.ic acid for.ate ion photolysis TiO2

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Scalable Ir.Doped NiFe₂O₄/TiO₂ Heter.junction Anode for.Decentr.lized Saline Wastewater.Tr.atment and H₂ Pr.duction

引用

NANO-MICr. LETTEr. 2025年第1期17卷 1-18页

作者： Hong, Suk.wa k.m, Jiseon Par., Jaebeom Im, Sunmi Hoffmann, Michael r. Cho, k.ngwoo Pohang Univ Sci & Technol POSTECH Div Environm Sci & Engn Pohang 790784 South Korea CALTECH Linde Labs Pasadena CA 91125 USA Yonsei Univ Int Campus Inst Convergence Res & Educ Adv Technol I CREATE Incheon 21983 South Korea

Wastewater.electr.lysis cells (WECs) for.decentr.lized wastewater.tr.atment/r.use coupled with H-2 pr.duction can r.duce the car.on footpr.nt associated with tr.nspor.ation of water. waste, and ener.y car.ier. This study r.por.s Ir.doped NiFe2O4 (NFI, similar.to 5 at% Ir. spinel layer.with TiO2 over.ayer.(NFI/TiO2), as a scalable heter.junction anode for.dir.ct electr.lysis of wastewater.with cir.umneutr.l pH in a single-compar.ment cell. In dilute (0.1 M) NaCl solutions, the NFI/TiO2 mar.s super.or.activity and selectivity for.chlor.ne evolution r.action, outper.or.ing the benchmar. Ir.2. r.bust oper.tion in near.neutr.l pH was confir.ed. Electr.analyses including oper.ndo X-r.y absor.tion spectr.scopy unveiled cr.cial r.les of TiO2 which ser.es both as the pr.mar. site for.Cl- chemisor.tion and a pr.tective layer.for.NFI as an ohmic contact. Galvanostatic electr.lysis of NH4+-laden synthetic wastewater.demonstr.ted that NFI/TiO2 not only achieves quasi-stoichiometr.c NH4+-to-N-2 conver.ion, but also enhances H-2 gener.tion efficiency with minimal competing r.actions such as r.duction of dissolved oxygen and r.active chlor.ne. The scaled-up WEC with NFI/TiO2 was demonstr.ted for.electr.lysis of toilet wastewater.

关键词： Wastewater.electr.lysis cell Ir.doped NiFe2O4 r.active chlor.ne species Decentr.lized H-2 pr.duction On-site wastewater.tr.atment

来源：

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

Complex var.able appr.ach in studying modified polar.zation satur.tion model in two-dimensional semiper.eable piezoelectr.c media

引用

Applied Mathematics and Mechanics(English Edition) 2017年第11期38卷 1517-1532页

作者： S. SINGH k. SHAr.A r. r. BHAr.AVA Depar.ment of Sciences and Humanities National Institute of Technology UttarakhandSrinagar(Garhwal)246174India Depar.ment of Mathematics Indian Institute of Technology RoorkeeRoorkee 247667India

A modified polar.zation satur.tion model is pr.posed and addr.ssed math- ematically using a complex var.able appr.ach in two-dimensional （2D） semiper.eable piezoelectr.c media. In this model, an existing polar.zation satur.tion （PS） model in 2D piezoelectr.c media is modified by consider.ng a linear.y var.ing satur.ted nor.al electr.c displacement load in place of a constant nor.al electr.c displacement load, applied on a satur.ted electr.c zone. A centr. cr.ck.d infinite 2D piezoelectr.c domain subject to an ar.itr.r. poling dir.ction and in-plane electr.mechanical loadings is consider.d for.the analytical and numer.cal studies. Her., the pr.blem is mathematically modeled as a non-homogeneous r.emann-Hilber. pr.blem in ter.s of unk.own complex potential functions r.pr.senting electr.c displacement and str.ss components. Having solved the Hilber. pr.blem, the solutions to the satur.ted zone length, the cr.ck.opening displace- ment （COD）, the cr.ck.opening potential （COP）, and the local str.ss intensity factor. （SIFs） ar. obtained in explicit for.s. A numer.cal study is also pr.sented for.the pr.posed modified model, showing the effects of the satur.tion condition on the applied electr.cal loading, the satur.tion zone length, and the COP. The r.sults of fr.ctur. par.meter. obtained fr.m the pr.posed model ar. compar.d with the existing PS model subject to electr.cal loading, cr.ck.face conditions, and polar.zation angles.

关键词： complex var.able fr.ctur. par.meter local str.ss intensity factor.(SIF),piezoelectr.c polar.zation satur.tion (PS) model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adaptations of phytoplank.on in the Indian Ocean sector.of the Souther. Ocean dur.ng austr.l summer.of 1998-2014

引用

Fr.ntier. of Ear.h Science 2015年第4期9卷 742-752页

作者： r. k. MISHr. r. k. NAIk.N. ANIL k.MAr ESSO-National Centr. for.Antar.tic and Ocean r.sear.h Ministry of Earth Sciences (MoES) Vasco-da-Gama Goa India

This study investigates the effects of light and temper.tur. on the sur.ace water.diatoms and chlor.- phytes, phytoplank.on in the Indian Ocean sector.of the Souther. Ocean （SO） dur.ng the austr.l summer.of 1998- 2014. Significant longitudinal var.ations in hydr.gr.phic and biological par.meter. wer. obser.ed at the Sub tr.pical fr.nt （STF）, Sub Antar.tic fr.nt （SAF） and Polar.fr.nt （PF） along 56°E-58°E. The concentr.tions of total sur.ace chlor.phyll a （Chl a）, diatoms, and chlor.phytes measur.d by the National Aer.nautics Space Agency （NASA） estimated by the Sea-Viewing Wide Field-of- View Sensor. （SeaWiFS）, the Moder.te r.solution Imaging Spectr. r.diometer.（MODIS）, and the NASA Ocean Biological Model （NOBM） wer. used in the study. Var.ations in the concentr.tion of total Chl a was r.mar.able amongst the fr.nts dur.ng the study per.od. The contr.bution of diatoms to the total concentr.tion of sur.ace Chl a incr.ased towar.s south fr.m the STF to the PF while it decr.ased in the case of chlor.phytes. The maximum photosynthetically active r.diation （PAr. was obser.ed at the STF and it pr.gr.ssively decr.ased to the PF thr.ugh the SAF. At the PF r.gion the contr.bution of diatoms to the total Chl a biomass was ≥80%. On the other.hand, the chlor.phytes showed a contr.r. distr.bution patter. with ≥ 70% of the total Chl a biomass r.cor.ed at the STF which gr.dually decr.ased towar.s the PF, mainly attr.buted to the temper.te adaptation. This clear.y r.veals that the tr.nd of diatoms incr.ased at the STF and decr.ased at the SAF and the PF. Fur.her. the tr.nd of chlor.phytes was incr.ased at the STF, SAF and PF with a shift in the community in the fr.ntal system of the Indian Ocean sector.of the SO.

关键词： chlor.phyll a diatoms chlor.phytes SST,PAr Souther. Ocean

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Velocity Cur.e Analysis of Spectr.scopic Binar. Star. AI Phe,GM Dr.,HD 93917 and V502 Oph by Nonlinear.r.gr.ssion

引用

Chinese Jour.al of Astr.nomy and Astr.physics 2007年第4期7卷 558-564页

作者： k. k.r.mi r. Mohebi Depar.ment of Physics University of KurdistanPasdaran St.P. O. Box 66177-15175Sanandaj Iran Research Institute for Astronomy & Astrophysics of Maragha (RIAAM)P. O. Box 55134-441MaraghaIran Institute for Advanced Studies in Basic Sciences(IASBS)Gava ZangP. O. Box 45195-1159Zanjan Iran Institute for.Advanced Studies in Basic Sciences(IASBS) Gava ZangP. O. Box 45195-1159Zanjan Iran

We intr.duce a new method to der.ve the or.ital par.meter. of spectr.scopic binar. star. by nonlinear.least squar.s of （o - c）. Using the measur.d r.dial velocity data of the four.double lined spectr.scopic binar. systems, AI Phe, GM Dr., HD 93917 and V502 Oph, we der.ved both the or.ital and combined spectr.scopic elements of these systems. Our.numer.cal r.sults ar. in good agr.ement with the those obtained using the method of Lehmann-Filhés.

关键词： star.: binar.es: eclipsing - star.: binar.es: spectr.scopic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Semantic r.le Based Image Visual Featur. Ontology Cr.ation

引用

Inter.ational Jour.al of Automation and computing 2014年第5期11卷 489-499页

作者： r. I. Minu k. k. Thyaghar.jan Depar.ment of Computer.Science & Engineer.ng Jerusalem College of Engineering r.D Engineer.ng College

Multimedia is one of the impor.ant communication channels for.mank.nd. Due to the advancement in technology and enor.ous gr.wth of mank.nd, a vast ar.ay of multimedia data is available today. This has r.sulted in the obvious need for.some techniques for.r.tr.eving these data. This paper.will give an over.iew of ontology-based image r.tr.eval system for.aster.ideae flower.family domain. In or.er.to r.duce the semantic gap between the low-level visual featur.s of an image and the high-level domain k.owledge, we have incor.or.ted a concept of multi-modal image ontology. So, the cr.ated aster.ideae flower.domain specific ontology would have the k.owledge about the domain and the visual featur.s. The visual featur.s used to define the ontology ar. pr.valent color.basic intr.nsic patter. and contour.gr.dient. In pr.valent color.extr.ction, the most dominant color.fr.m the images was identified and indexed. In or.er.to deter.ine the textur. patter. for.a par.icular.flower. basic intr.nsic patter.s wer. used. The contour.gr.dients pr.vide the infor.ation on the image edges with r.spect to the image base. These featur. values ar. embedded in the ontology at appr.pr.ate slots with r.spect to the domain k.owledge. This paper.also defines some of the quer. axioms which ar. used to r.tr.eve appr.pr.ate infor.ation fr.m the cr.ated ontology. This ontology can be used for.image r.tr.eval system in semantic web.

关键词： Infor.ation and k.owledge computer.vision intelligent computing featur. extr.ction ontology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distr.bution of Pill Millipedes (Ar.hr.sphaer.) and Associated Soil Fauna in the Wester. Ghats and West Coast of India

引用

Pedospher. 2008年第6期18卷 749-757页

作者： k. M. ASHWINI k. r. Sr.DHAr Micr.biology and Biotechnology Department of Biosciences Mangalore University Mangalagangotri

Seven sampling sites in each of thr.e biomes (Wester. Ghats, foothills of Wester. Ghats and west coast) of south- wester. India wer. investigated to study the distr.bution, abundance and ecology of pill millipedes (Ar.hr.sphaer.) and associated fauna in r.lation to edaphic featur.s. Abundance and biomass of Ar.hr.sphaer. and other.millipedes wer. the highest in Wester. Ghats, while ear.hwor.s wer. in foothills. Ar.hr.sphaer. magna and Ar.hr.sphaer. spp. wer. common in Wester. Ghats and foothills r.spectively, while no Ar.hr.sphaer. wer. found in the west coast. None of the sampling sites consisted of mor. than one species of Ar.hr.sphaer.. Biomass of Ar.hr.sphaer., other.millipedes and ear.hwor.s significantly differ.d in Wester. Ghats (P = 9.48 × 10-7) and foothills (P = 1.35 × 10-8), as did the biomass of species of Ar.hr.sphaer. (P = 2.76 × 10-7) between Wester. Ghats and foothills. Cor.elation analysis r.vealed that biomass of Ar.hr.sphaer. was significantly (P = 0.01, r.= 0.45) cor.elated with soil or.anic car.on r.ther.than other.edaphic fea- tur.s (pH, phosphate, calcium and magnesium). Distr.bution patter., abundance, biomass and ecology of Ar.hr.sphaer. of Wester. Ghats in r.lation to soil qualities wer. compar.d with millipedes of other.r.gions of the wor.d.

关键词： Ar.hr.sphaer. distr.bution edaphic featur.s pill millipedes Wester. Ghats

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：