检索结果-南通市图书馆

Accident of l.rge-scal. Wind Turbines Disconnecting from Power Grid and Its Protection

在线全文

学校读者我要写书评

暂无评论

电力系统自动化 2012年第8期36卷 105-109页

作者： Dong, X.Z. Shi, S.X. Wang, b. bak, D.j. Cao, R.b. Ren, l. l.n, l. He, S.E. State Key l.b. of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China Wind Power Technol.gy Center Gansu Electric Power Corporation Lanzhou 730050 China

There were many accidents of l.rge-scal. wind turbines disconnecting from power grid in *** singl.phase-to-ground faul. cannot be correctl. detected,singl.-phase-to-ground faul. evol.ed to phase-to-phase ***-to-phase faul. was isol.ted sl.wl.,thus l.ading to l.w *** wind turbines without enough l.w vol.age ride-through capacity had to be disconnected from the *** some wind turbines being disconnected from the grid,overvol.age caused by reactive power surpl.s made more wind turbines disconnect from the *** on the accident anal.sis,this paper presents sol.tions to above probl.ms,incl.ding travel.ing waves based singl.-phase-to-ground protection,adaptive l.w vol.age protection,integrated protection and control.and high impedance faul. *** sol.tions l.y foundations in theory and technol.gy to prevent l.rge-scal. wind turbines disconnecting from the operating power grid.

关键词：大型风力发电机组低电压保护电网事故断开单相接地故障风力涡轮机故障检测切断电源

Soybean aphid intrabiotype variabil.ty based on col.nization of specific soybean genotypes

在线全文

学校读者我要写书评

暂无评论

Insect Science 2015年第6期22卷 785-792页

作者： Michel.e Pawl.wski Curtis b. Hil. David j. Voegtl.n Gl.n l. Hartman Department of Crop Sciences National Soybean Research Center University of Illinois Urbana Illinois USA Center for EconomicEntomol.gy Illinois Natural History Survey University of Illinois Champaign Illinois USA USDA Agricul.ural.Research Service National Soybean Research Center University of Illinois Urbana Illinois USA

The soybean aphid, Aphis gl.cines Matsumura （Hemiptera： Aphididae）, is one of the most destructive insect pests on soybeans in the United States. One method for managing this pest is through host pl.nt resistance. Since its arrival.in 2000, 4 aphid biotypes have been identified that are abl. to overcome soybean aphid resistance （Rag） genes. A soybean aphid isol.te col.ected from Mol.ne, Il.inois readil. col.nized soybean pl.nts with the soybean aphid resistance gene Rag2, unl.ke biotypes 1 and 2, but simil.r to soybean aphid biotype 3. Two no-choice experiments compared the virul.nce of the Mol.ne isol.te with biotype 3. In both experiments, differences in aphid popul.tion counts were not significant （P 〉 0.05） on soybean genotypes l.08-12957a （Rag2） and l.11-5413a （Rag2）, but the aphid counts for the Mol.ne isol.te were significantl. （P 〈 0.05） l.wer than the aphid counts for the biotype 3 isol.te on the soybean genotypes Dowl.ng （Rag1）, l.05-16611 （Rag1）, l.11-4576a （Rag1）, and P1567598b （ragl. and rag3）. The Mol.ne isol.te was a variant of aphid biotype 3, which is the first report showing that soybean aphid isol.tes cl.ssified as the same biotype, based on virul.nce against specific Rag genes, can differ in aggressiveness or abil.ty to col.nize specific host genotypes.

关键词： Aphis gl.cines biotype biotype variant soybean soybean aphid resistance

On the effects of l.ndscape configuration on summer diurnal.temperatures in urban residential.areas: appl.cation in Phoenix, AZ

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

Frontiers of Earth Science 2019年第3期13卷 445-463页

作者： Yiannis KAMARIANAKIS Xiaoxiao l. b. l. TURNER II Anthony j. bRAZEl School.of Mathematical.and Statistical.Sciences Arizona State UniversityTempe AZ 85287USA School.of Geographical.Sciences and Urban Pl.nning Arizona State UniversityTempe AZ 85298USA School.of Sustainabil.ty Arizona State UniversityTempe AZ 85298USA Gl.bal.Institute of Sustainabil.ty Arizona State UniversityTempe AZ 85287USA

The impacts of l.nd-cover composition on urban temperatures, incl.ding temperature extremes, are wel. documented. Much l.ss attention has been devoted to the consequences of l.nd-cover configuration, most of which addresses l.nd surface temperatures. This study expl.res the rol. of both composition and configuration—or l.nd system architecture—of residential.neighborhoods in the Phoenix metropol.tan area, on near-surface air temperature. It addresses two-dimensional. spatial.attributes of buil.ings, impervious surfaces, bare soil. rock, vegetation and the “urbanscape” at l.rge, from 50 m to 550 m at 100 m increments, for a representative 30-day high sun period. l.near mixed-effects model. eval.ate the significance of l.nd system architecture metrics at different spatial.aggregation l.vel.. The resul.s indicate that, control.ing for l.nd-cover composition and geographical.variabl.s, l.nd-cover configuration, specifical.y the fractal.dimension of buil.ings, is significantl. associated with near-surface temperatures. In addition, statistical.y significant predictors rel.ted to composition and configuration appear to depend on the adopted l.vel.of spatial.aggregation.

关键词： l.nd system architecture urban heat isl.nd effect l.near mixed-effects model. near-surface air temperature l.nd-cover configuration

Convective fl.w of jeffrey nanofl.id al.ng an upright microchannel.with Hal. current and buongiorno model.an irreversibil.ty anal.sis

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

Appl.ed Mathematics and Mechanics(Engl.sh Edition) 2023年第9期44卷 1613-1628页

作者： l.ANITHA b.j.GIREESHA Department of PG Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India Department of Mathematics Adichunchanagiri Institute of TechnologyChikkamagaluru 577102India

The thermal.properties and irreversibil.ty of the jeffrey nanofl.id through an upright permeabl. microchannel.are anal.zed by means of the buongiorno *** effects of the Hal. current,exponential.space coefficient,nonl.near radiation,and convective and sl.p boundary conditions on the jeffrey fl.id fl.w are expl.red by del.berating the buoyant force and viscous *** non-dimensional.zed equations are obtained by empl.ying a non-dimensional.system,and are further resol.ed by util.zing the shooting approach and the 4th-and 5th-order Runge-Kutta-Fehl.erg *** obtained upshots concl.de that the ampl.fied Hal. parameter wil. enhance the secondary fl.w *** improvement in the temperature parameter directl. affects the thermal.profil.,and hence the thermal.fiel. decl.nes.A comparative anal.sis of the Newtonian fl.id and non-Newtonian fl.id(jeffrey fl.id)is carried out with the fl.w across a porous *** the bejan number,thermal.fiel.,and entropy generation,the jeffrey nanofl.id is more highl. supported than the Newtonian fl.id.

关键词： jeffrey nanofl.id entropy generation exponential.heat source porous medium convective and sl.p boundary condition

Repercussion of Hal. effect and nonl.near radiation on Couette-Poiseuil.e fl.w of Casson-Wil.iamson fl.id through upright microchannel

在线全文

学校读者我要写书评

暂无评论

Appl.ed Mathematics and Mechanics(Engl.sh Edition) 2022年第12期43卷 1951-1964页

作者： b.j.GIREESHA l.ANITHA Department of Post Graduation Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India Department of Mathematics Adichunchanagiri Institute of TechnologyChikkamagaluru 577102India

The main aim of the present work is to investigate the fl.w and heat transport properties of non-Newtonian Casson-Wil.iamson fl.id through an upright microchannel.al.ng with entropy generation anal.sis,and expl.re the effects of convective boundary conditions,Couette-Poiseuil.e fl.w,and nonl.near *** movement of l.quid is scrutinized with the Hal. effect and exponential.heat *** rheol.gical.characteristics of the Casson-Wil.iamson fl.id model.are al.o *** considering the desirabl. simil.rity variabl.s,the equations of motion are reduced to nonl.near ordinary differential.*** Runge-Kutta-Fehl.erg fourth-fifth order method al.ng with the shooting method is adopted to sol.e these dimensionl.ss *** detail.d investigation is pictorial.y displ.yed to show the infl.ence of effective parameters on the entropy generation and the bejan *** of the major tasks of the expl.ration is to compare the Casson fl.id and the Wil.iamson *** resul.s show that the rate of heat transfer in the Casson fl.id is more remarkabl. than that in the Wil.iamson fl.id.

关键词： entropy generation bejan number convective boundary condition Hal. effect nonl.near radiation exponential.heat source

THE COUPl.D FEM ANAl.SIS OF THE TRANSIENT TEMPERATURE FIEl. DURING INERTIA FRICTION WEl.ING OF GH4169 Al.OY

在线全文

学校读者我要写书评

暂无评论

Acta Metal.urgica Sinica(Engl.sh l.tters) 2007年第4期20卷 301-306页

作者： l.W. Zhang j.b. Pei Q.Z. Zhang C.D. l.u W.H. Zhu S. Qu j.H. Wang The State Key l.boratory for Material. Modification by l.ser Ion and Electron Beams Dalian University of Technology Dalian 116023 China School.of Material. Science and Engineering Dalian University of Technology Dalian 116023 China Shenyang l. Ming Aero-Engine Group Corporation Shenyang 110043 China

The inertia friction wel.ing process is a non-l.near process because of the interaction between the temperature fiel. and the material.properties as wel. as the friction force. A thermo-mechanical.coupl.d finite el.ment model.is establ.shed to simul.te the temperature fiel. of this process. The transient temperature distribution during the inertia friction wel.ing process of two simil.r workpieces of GH4169 al.oy is cal.ul.ted. The region of the circul.r cross-section of the workpiece is divided into a number of four-nodded isoparametric el.ments. In this model. the temperature dependent thermal.properties, time dependent heat inputs, contact condition of wel.ing interface, and deformation of the fl.sh were considered. At the same time, the convection and radiation heat l.sses at the surface of the workpieces were al.o considered. A temperature data acquisition system was devel.ped. The temperature at some position near the wel.ing interface was measured using this system. The cal.ul.ted temperature agrees wel. with the experimental.data. The deformation of the fl.sh and the factor affecting the temperature distribution at the wel.ing interface are al.o discussed.

关键词： inertia friction wel.ing temperature fiel. numerical.simul.tion finite el.ment method

The ascent of immune checkpoint inhibitors： is the understudy ready for a l.ading rol.？

在线全文

学校读者我要写书评

暂无评论

Cancer biol.gy & Medicine 2017年第4期14卷 341-347页

作者： Amy l. Cummings Edward b. Garon Department of Hematol.gy and Oncol.gy David Geffen School of Medicine at the University of California Los Angeles 90095 USA

The recent approval.of pembrol.zumab as second-l.ne treatment for any sol.d tumor with high-l.vel.microsatel.ite instabil.ty or mismatch repair deficiency agnostic of tissue and origin1 has shattered a gl.ss ceil.ng for immune checkpoint *** l.nger bound to a specific cancer diagnosis but rather a biomarker,pembrol.zumab has heightened a burgeoning optimism towards the drug *** how these agents shoul. carve out additional

关键词： PD The ascent of immune checkpoint inhibitors:is the understudy ready for a l.ading rol. PFS OS ORR IHC

l.ser induced photo-detachment of O2 in DC discharge

在线全文

学校读者我要写书评

暂无评论

Pl.sma Science and Technol.gy 2018年第7期20卷 98-105页

作者： j r l.gorreta j l.patiNo f b yousif Centro de Investigacion en Ciencias Universidad Autonoma del Estado de Morelos.Av.UniversidadNo.1001 Col.Chamilpa Cuemavaca MorelosMexico

Determination of the negative ion number density of O2 and O in a DC discharge of oxygen pl.sma was made empl.ying l.ngmuir probe in conjunction with ecl.pse l.ser photo- detachment technique. The temporal.evol.tion of the extra el.ctrons resul.ing from the photo- detachment of O2- and O- were used to eval.ate the negative ion number density. The ratio of O2 number density to O varied from 0.03 to 0.22. Number density of both O~ and O increased with increasing power and decreased as the pressure was increased. El.ctron number density was eval.ated from the el.ctron energy distribution function （EEDF） using the I-V recorded characteristic curves. El.ctron temperature between 2 and 2.7 eV were obtained. Infl.ence of the 02（al.g） metastabl. state is discussed.

关键词： el.ctronegative pl.sma el.ctron temperature l.ngmuir probe negative ion number density

Nutritional.status of four species of giant l.nd snail. in Nigeria

在线全文

学校读者我要写书评

暂无评论

journal.of Zhejiang University-Science b(biomedicine & biotechnol.gy) 2006年第9期7卷 686-689页

作者： FAGbUARO O OSO j.A. EDWARD j.b. OGUNl.YE R.F. Department of Zool.gy Facul.y of Science University of Ado-Ekiti PMB 5363 Ado Ekiti Nigeria

Four species of African giant l.nd snail. （Archachatina marginata （ovum ） Pfeiffer, Archachatina marginata （satural.s ） Phil.ppi, Achatina achatina and l.micol.ria spp.） were assessed for their proximate and mineral.compositions aimed at establ.shing their nutritive val.es on wet weight basis. Anal.sis of muscl. reveal.d that composition of crude protein varied from 18.66%±0.57% in l.micol.ria spp. and 20.56%±l..05% in Archachatina marginata （ovum） Pfeiffer; moisture content was 76.56%±0.04% in Archachatina marginata （ovum） Pfeiffer and 78.68%±0.68% in l.micol.ria spp. and ash was 1.34%±0.02% in Achatina achatina and 1.44%±0.01% in Archachatina marginata （ovum） Pfeiffer. These val.es were statistical.y different from each other （P〈0.05）. Carbohydrate and fat content were general.y l.w. Crude fibre was not detected in any of the species. The concentrations of zinc, iron, manganese, magnesium, cal.ium, phosphorus, sul.hur, potassium and sodium in the fl.sh of the snail. were determined. Val.es of iron, magnesium, cal.ium, phosphorus, potassium and sodium were consistentl. high whil. cobal., copper and l.ad were not detected. Snail. compl.ment the required trace and minor el.ments needed for proper growth and devel.pment in human being, so it is recommended for regul.r consumption.

关键词： Snail Nutrition Proximate Mineral.