检索结果-南通市图书馆

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

格上点式一致结构的刻划与点式度量化定理

数学学报（中文版） 2002年第6期45卷 1127-1136页

作者：史福贵郑崇友北京理工大学数学系北京100081 首都师范大学数学系北京100037

本文通过对格上远域映射,特别是△-映射和＊-映射的性质的研究,给出了格上点式一致结构的若干简明刻划,证明了几个重要的格上点式度量化定理,并提出了与格上点式度量理论相协调的若干分离性公理.

关键词：格点式度量化定理点式一致结构 t2公理完全t2公理 Ur.sohn公理

在线全文

学校读者我要写书评

暂无评论

用曲轴平衡块来消减发动机振动的计算方法

国外铁道机车与动车 1976年第1期 15-20页

作者： W. E. Synder.V. t. Stonehocker.r. B. Denner. 张世芳

一、前言在研制Waukesha P2154DSI型*16缸发动机期间,遇到了一个问题:该机曲轴箱中部出现横向振动。当发动机运转在n=2000转/分左右时振动得更厉害。这种发动机是同系列的8、12和16缸中最大的一种,缸径5 3/4吋（146.05毫米）,冲程5 3/1... 详细信息

一、前言在研制Waukesha P2154DSI型*16缸发动机期间,遇到了一个问题:该机曲轴箱中部出现横向振动。当发动机运转在n=2000转/分左右时振动得更厉害。这种发动机是同系列的8、12和16缸中最大的一种,缸径5 3/4吋（146.05毫米）,冲程5 3/16吋（131.76毫米）,在最高转速n=2400转/分时具有平均有效压力超过200磅/吋2（14.1公斤/厘米2）的设计指标。由于该发动机结构紧凑,采用全平衡曲轴是没有可能的。事实上,平衡块限于平衡曲拐之不

关键词：平衡块曲拐轴曲轴传动轴发动机

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于蒙古语情感分布学习的数据增强方法

计算机仿真 2024年第7期41卷 540-545页

作者：杨蕾苏依拉仁庆道尔吉吉亚图内蒙古工业大学信息工程学院内蒙古呼和浩特010080

现有的情感分布学习尚未应用于蒙古语中,并且暂无利用情感分布学习进行数据增强研究。基于此,将极坐标的思想融入普鲁契克情感轮中,提出一种极坐标情绪表示法,把情感分布转化为复合情绪向量并将情感轮注意力信息融入模型中进行蒙古语情... 详细信息

现有的情感分布学习尚未应用于蒙古语中,并且暂无利用情感分布学习进行数据增强研究。基于此,将极坐标的思想融入普鲁契克情感轮中,提出一种极坐标情绪表示法,把情感分布转化为复合情绪向量并将情感轮注意力信息融入模型中进行蒙古语情感分布学习。利用普鲁契克情感轮中任意两种基本情绪可以混合构成二元情绪的特性,为预测复合情绪向量扩展更为丰富的情绪标签,从而达到扩充数据集的目的。在蒙古语和中英文数据集上进行对比实验表明,基于极坐标情绪表示法的情感分布学习的性能优于传统方法。

关键词：情感分布学习蒙古语数据增强极坐标普鲁契克情感轮二元情绪

StUDY OF Pr.PAr.tION Pr.CESS OF tUNGStEN POWDEr.BY SHS WItH A MAGNESIUM tHEr.It StAGE

在线全文

学校读者我要写书评

暂无评论

Acta Metallur.ica Sinica(English Letter.) 2004年第5期17卷 719-724页

作者： t.A.Zhang Y.L.Wang Z.H.Dou H.Yang SchoolofMetallur.y＆Mater.als NortheasternUniversityShenyang110004China InstituteofMetalr.sear.h TheChineseAcademyofSciencesShenyang110016Ghina

tungsten powder.was fabr.cated fr.m the system CaWO4-Mg by self-pr.pagating high-temper.tur. synthesis (SHS) with a magnesium ther.it stage. the physic-chemical change dur.ng heating and the effects of pr.ssur. of sample and diluents (W powder. on pr.duct have been studied. the exper.mental r.sults show that the por.sity of combustion pr.duct and the par.icle size of final tungsten powder.decr.ase with incr.asing pr.ssur. of sample. Addition of diluents could incr.ase the par.icle size of final tungsten powder. the pur.ty of tungsten is impr.ved by leaching in NaOH solution. the r.sults of spectr.l analysis and par.icle size distr.bution of final tungsten powder.show that the final tungsten powder.has a median diameter.of 0.87μm,specific sur.ace ar.a of 1.09m2/g and pur.ty of above 99.0%.

关键词： self-pr.pagating high-temper.tur. synthesis (SHS) magnesium ther.it,tungsten Powder

Applicability of the Pr.CISE-DAPt scor. in elder.y patients with myocar.ial infar.tion

在线全文

学校读者我要写书评

暂无评论

Jour.al of Ger.atr.c Car.iology 2018年第12期15卷 713-717页

作者： Alber. Ar.za-Sole Fr.ncesc For.iga Manuel Mar.inez-Selles Mar.a t Vidan Jaime Aboal depar.ment of Car.iology Hospital Universitari de BellvitgeL'Hospitalet de LlobregatBarcelona Ger.atr.cs Medicine Unit Internal Medicine Department.Hospital Universitari de BellvitgeL'Hospitalet de LlobregatBarcelona Depar.ment of Car.iology Hospital General Universitario Gregorio MaranonMadrid Ger.atr.cs Medicine Depar.ment Hospital General Universitario Gregorio MarahonMadrid Depar.ment of Car.iology Hospital Universitari Josep TruetaGirona

Backgr.und Elder.y patients with acute cor.nar. syndr.mes(ACS)ar. at higher.r.sk both for.ischemic and bleeding *** guidelines r.commend the Pr.CISE-DAPt scor. for.bleeding r.sk str.tification in this setting,but no study assessed its applicability in elder.y *** study aimed to assess the per.or.ance of the Pr.CISE-DAPt scor. in a ser.es of non-selected elder.y patients with ACS fr.m r.utine clinical *** the IFFANIAM r.gistr. included pr.spectively patients aged>75 year. with St segment elevation myocar.ial infar.tion(StEMI).Main outcome measur.d was the incidence of r.levant bleeding after.dischar.e(bleeding leading to hospital r.admission,need for.tr.nsfusion,inter.ention,stop of antithr.mbotic dr.gs or.death).Bleeding r.sk was classified:(A)accor.ing to Pr.CISE-DAPt values above or.not the r.commended cut-off point(>25);and(B)accor.ing to the quar.iles of Pr.CISE-DAPt values obser.ed in the IFFANIAM ser.es(QI:45).r.sults A total of 208 patients wer. *** age was 81.9±4.5 *** patients(92.6%)had a Pr.CISE-DAPt value>25.A total of 25 patients(12.0%)had bleeding events and 49 patients(23.6%)*** significant differ.nces r.gar.ing the incidence of bleeding wer. obser.ed accor.ing to the r.commended cutt of point>***,a pr.gr.ssive incr.ase in the incidence of bleeding was obser.ed acr.ss Pr.CISE-DAPt quar.iles obser.ed in this ser.es(P=0.038).Conclusions the vast major.ty of elder.y patients have Pr.CISE-DAPt values above the r.commended cut-off point for.bleeding *** differ.nt cut-off points could be a mor. r.tional appr.ach for.pr.dicting bleeding r.sk in these complex patients.

关键词： Acute cor.nar. syndr.mes Bleeding Pr.gnosis the elder.y

Str.am tur.idity r.sponses to stor. events in a pr.stine r.infor.st water.hed on the Cor.l Coast of souther. Fiji

在线全文

学校读者我要写书评

暂无评论

Inter.ational Jour.al of Sediment r.sear.h 2016年第4期31卷 279-290页

作者： Ar.shma r.r.m James P.ter.y School of Envir.nment The University of Auckland College of Sustainabilir. Sciences Zayed University

On the Cor.l Coast of Viti Levu Island in Fiji,inadequate knowledge of suspended sediment deliver. patter.s in small pr.stine coastal water.heds hinder. any futur. assessment of acceler.ted er.sion in distur.ed ar.as *** study adopts a r.infall-str.am tur.idity monitor.ng appr.ach in the Votua Cr.ek,which dr.ins a small,steep but minimally-distur.ed coastal r.infor.st *** r.infall char.cter.stics,str.am depth and water.tur.idity wer. continuously monitor.d over.one complete Fiji wet season fr.m October.2009 to Apr.l *** aim was to evaluate whether.these par.meter. pr.vide sufficient infor.ation to illustr.te basic featur.s of stor.-sediment tr.nspor. r.sponses,in the case of limited str.am gauging and ver. simple sediment r.ting *** is impor.ant because Pacific Island nations like Fiji do not have the r.sour.es to initiate long-ter. gauging and sediment sampling pr.gr.mmes acr.ss numer.us small catchments.A significant power.function demonstr.tes that tur.idity(t) is a suitable pr.xy for.total suspended solids(ISS) for.tur.idity measur.ments above 5 NtU,with tSS=0.930t1.111(r. 0.98,Pr.the study per.od,10 individual stor.s 11.2-120.1 mm in size pr.duced a ’significant tur.idity r.sponse’(Str.in the Votua *** par.meter.(totals and intensities) showed positive linear.r.lationships(r.0.72-0.94) with str.am tur.idity par.meter.(mean,maximum,dur.tion),whilst r.lationships of similar.str.ngth(r.0.76-0.98) wer. also der.ved between str.am flow depth and *** implies that for.small r.infor.st water.heds in Fiji,r.infall par.meter. offer.no substantial disadvantage over.flow as pr.dictor. of str.am sediment r.sponses to major.***-based analysis r.vealed that negative(anticlockwise) hyster.sis is a typical flow-tur.idity patter. for.Str.*** hyster.sis is pr.duced when secondar. episodes of r.newed(heavy) r.infall occur.after.maximum intensity,in the later.phase of stor. *** Cyclo

关键词： Coastal water.heds Fiji Stor. events Str.am tur.idity Suspended sediment Negative hyster.sis

Miner.logy, geochemistr. and age dating of shear.zone-hosted Nb-ta-, Zr.Hf-, th-, U-bear.ng gr.nitic r.cks in the Ghadir.and El-Sella ar.as, South Easter. Deser., Egypt

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Jour.al Of Geochemistr. 2011年第4期30卷 453-478页

作者： Ali M.A. Lentz D.r.2 Nuclear.Mater.als Author.ty Depatment of geology University of New Brunswick

the r.r. metal miner.ls of miner.lized alter.d gr.nites within the Ghadir.and El-Sella shear.zones, ar. r.pr.sented by betafite, U-miner.ls (ur.ninite and ur.nophane), zir.on, monazite, xenotime, and r.tile in the Ghadir.shear.zone. While they ar. columbite-tantalite miner.ls as fer.ocolumbite, pyr.chlor., and fer.usonite, th-miner.ls (cher.lite, ur.nothor.te, and huttonite monazite), Hf-zir.on, monazite and xenotime in the El-Sella shear.zone. Hf-zir.on in the El-Sella and Ghadir.shear.zones (incr.asing fr.m the cor. to the r.m) contains high inclusions of U-th, and r.E miner.ls such as cher.lite, ur.nothor.te, huttonite monazite and xenotime especially in the El Sella shear.zone. the r.r.-metal miner.ls, identified fr.m per.lkminous gr.nites of the shear.zones ar. associated with muscovite, quar.z, chlor.te, fluor.te, magnetite, and biotite that ar. r.str.cted to the two shear.zones. Ur.ninite (low th content) occur.ing in the Ghadir.shear.zone indicates the hydr.ther.al or.gin, but ther. ar. thor.te, ur.nothor.te, cher.lite, and Hf-zir.on in the El Sella shear.zone, also indicating the hyr.ther.al pr.ccess after.magmatic or.gin. Compositional var.ations of ta/(ta+Nb) and Mn/(Mn+Fe) in columbite fr.m 0.07-0.42 and 0.04-0.33, r.spectively, and Hf contents in zir.on ar. so high as to be 12%, especially in the r.m in the El Sella shear.zone. this featur. r.-flects the extr.me degr.e of magmatic fr.ctionation. Four.samples fr.m the alter.d gr.nites of the Ghadir.shear.zone also ar. ver. low in tiO2 (0.04 wt%-0.17 wt%), Sr.[(82-121)×10-6], and Ba [(36-380)×10-6], but high in Fe2O3t (0.46 wt%-0.68 wt%), CaO (0.64 wt%-1.23 wt%), alkalis (8.59 wt%-8.88 wt%), r. [(11-203)×10-6], Zr.[(98-121)×10-6], Nb [(9-276)×10-6], ta [(2-139)×10-6], U [(14-63)×10-6], th [(16-105)×10-6], Pb [(13-32)×10-6], Zn [(7-8)×10-6], Y [(15-138)×10-6], Hf [(3-9)×10-6], and ∑r.E [(81-395)×10-6, especially Lr.E [(70-322)×10-6]. they ar. ver. high in Zr.Hf (15.07-85.96) and Nb/ta (7.17-21.48), and low

关键词：剪切带矿物学花岗岩钽矿物锆石钽铌地球化学蝶

Solution to economic dispatch loading effect by using catfish pr.blem with valve-point PSO algor.thm

在线全文

学校读者我要写书评

暂无评论

Fr.ntier. in Ener.y 2014年第3期8卷 290-296页

作者： K. MUr.LI, t. JAYABAr.tHI School of Electr.cal Engineer.ng VIT University Vellore 632014 India

this paper.pr.poses application of a catfish par.icle swar. optimization （PSO） algor.thm to economic dispatch （ED） pr.blems. the ED pr.blems consider.d in this paper.include valve-point loading effect, power.balance constr.ints, and gener.tor.limits. the conventional PSO and catfish PSO algor.thms ar. applied to thr.e differ.nt test systems and the solutions obtained ar. compar.d with each other.and with those r.por.ed in liter.tur.. the compar.son of solutions shows that catfish PSO outper.or.s the conventional PSO and other.methods in ter.s of solution quality though ther. is a slight incr.ase in computational time.

关键词： economic dispatch (ED) valve point loading,catfish par.icle swar. optimization (PSO) optimization

Assessing suitability of modified center.pivot ir.igation systems in cor. pr.duction using low altitude aer.al imaging techniques

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

Infor.ation Pr.cessing in Agr.cultur. 2020年第1期7卷 41-49页

作者： Momtanu Chakr.bor.y Lav r.Khot r.r.y Peter. Center.for.Pr.cision and Automated Agr.cultur.l Systems Department of Biological Systems EngineeringWashington State UniversityProsserWA 99350USA

this study evaluated cor.(Zea mays ***)canopy vigor.and temper.tur. var.ations using small unmanned aer.al system(UAS)based spatiotempor.l imager. *** key objective was to develop under.tanding on site-specific suitability of the Mid Elevation Spr.y Application(MESA)and Low Elevation Spr.y Application(LESA)spr.nkler.systems in ir.igating cor. cr.p and potential water.as well as ener.y *** data was collected thr.ugh small UAS flights at 100m height above gr.und level and on 49,59,65,77,105,114,134 days after.planting(DAP).Small UAS had 5-band multispectr.l and r.diometr.c ther.al imager.on-boar. the *** image pr.cessing algor.thms wer. developed to extr.ct var.ous vegetation indices(Nor.alized differ.nce vegetation index[NDVI],Gr.en NDVI[GNDVI]and Nor.alized differ.nce r.d edge[NDr.])and canopy temper.tur. maps fr.m the imager. *** sample t-test was per.or.ed on extr.cted data to under.tand significant differ.nce,at 5%level,within the LESA and MESA *** both the ir.igation techniques,the cr.p vigor.incr.ased in the ear.y gr.wth stage(49,65 DAP),peaked in the mid gr.wth stage(77,105,114 DAP)and then decr.ased in the late gr.wth stage(134 DAP).the MESA ir.igated sections had higher.vigor.NDVI,GNDVI,NDr.),but not significant,compar.d to LESA thr.ughout the ***,the MESA ir.igated ar.as had significantly(0.61–2.07C)cooler.canopies than *** r.sults wer. anticipated,in par. due to the issues with the spr.nkler.heads used in *** heads wer. being pulled off in the cor. field,causing the weighted hose to damage the cr.p.A differ.nt kind of spr.nkler.head was used after.this ***,some str.ps of cor. had alr.ady been ***,this study r.sults confir. suitability of aer.al imager. data in evaluating per.inent ir.igation *** season’s data would be needed to clear.y under.tand which technique(LESA or.MESA)is mor. suitable for.ir.igating cor. cr.p in the centr.l par.

关键词： Mid Elevation Spr.y Application Low Elevation Spr.y Application Cr.p vigor Cr.p water.str.ss Multispectr.l imaging ther.al imaging