检索结果-南通市图书馆

Differ.ntial changes in pr.cipitation and r.noff dischar.e dur.ng 1958–2017 in the headwater.r.gion of Yellow r.ver.of China

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

Jour.al of Geogr.phical Sciences 2020年第9期30卷 1401-1418页

作者： HOU Bingfei JIANG Chao sun Osber. Jianxin School of Ecology and Natur. Conser.ation Beijing Forestry UniversityBeijing 100083China Institute of For.str. and Climate Change r.sear.h Beijing Forestry UniversityBeijing 100083China

Maintenance of steady str.amflow is a cr.tical attr.bute of the continental r.ver.systems for.safeguar.ing downstr.am ecosystems and agr.cultur.l *** climate change imposes a potential r.sk to water.supply fr.m the headwater.by changing the magnitude and fr.quency of pr.cipitation and evapotr.nspir.tion in the *** deter.ine if and to what extent the r.cent climate changes affected str.amflow in major.r.ver.systems,we examined the patter. of tempor.l var.ations in pr.cipitation,temper.tur.,evapotr.nspir.tion and changes in r.noff dischar.e dur.ng 1958–2017 in the headwater.r.gion of the Yellow r.ver.in nor.heaster. Tibetan *** identified 1989 as the tur.ing point for.a statistically significant 14% r.duction in str.amflow dischar.e(P r.the per.od 1989–2017 compar.d with 1958–1988,appr.ximately coinciding with changes in the monthly distr.bution but not the inter.nnual var.ations of pr.cipitation,and detected a mismatch between pr.cipitation and r.noff after.*** annual pr.cipitation and r.noff dischar.e displayed four.nd eight-year.cyclic patter.s of changes for.the per.od 1958–1988,and a six-year.cyclic patter. of changes for.the per.od 1989–2017,with two intensified two-year.cyclic patter.s in the changes of pr.cipitation and a thr.e-year.cyclic patter. in the change of r.noff fur.her.detected for.the later.*** r.sults indicate that the tempor.l changes in r.noff ar. not str.ctly consistent with the tempor.l var.ations of pr.cipitation in the headwater.r.gion of Yellow r.ver.dur.ng the per.od 1958–*** par.icular.a full r.cover. in annual pr.cipitation was not r.flected in a full r.cover. in r.noff towar. the end of the study *** a r.view of liter.tur. yielded no appar.nt evidence of r.ised evapotr.nspir.tion in the r.gion due to r.cent war.ing,we dr.w attention to incr.ased local r.tention of r.inwater.as a possible explanation of differ.ntial changes in pr.cipitation and r.noff.

关键词： dr.ught climate var.ability pr.cipitation-r.noff r.lationship headwater.r.gion of Yellow r.ver

Conver.ent plate boundar. envir.nments for.for.ation of≥3800 Ma mafic-ultr.mafic assemblages(Isua ar.a,Gr.enland):Implications for.ear.y global geodynamics

在线全文

学校读者我要写书评

暂无评论

Geoscience Fr.ntier. 2024年第3期15卷 119-136页

作者： Allen P.Nutman Clar. r.l.Fr.end Vickie C.Bennett School of Ear.h Atmospheric and Life SciencesUniversity of WollongongWollongongNSW 2522Australia Glendale TiddingtonOxon OX92LQUK r.sear.h School of Ear.h Sciences Australian National UniversityCanberraACT 2601Australia

In the gneiss ter.ane on the south side of the Eoar.hean Isua supr.cr.stal belt,ultr.mafic r.cks with r.lict abyssal per.dotite miner.logy(Bennett et al.,2002;Fr.end et al.,2002;Nutman et al.,2007;r.llinson,2007;van de löcht et al.,2020),layer.d gabbr.s with cumulate ultr.mafic r.cks,basalts and associated siliceous sedimentar. r.cks wer. tectonically-imbr.cated,pr.or.to and dur.ng intr.sion of ca.3800 Ma *** with3800 Ma basalts in the Outer.Ar. Gr.up of the near.y Isua supr.cr.stal belt,the composition of all these mafic r.cks(e.g.,Th-Hf-Nb systematics,high Th/Yb,Ba/Nb,Ba/Yb r.tios and negative Nb and Ti anomalies)shows affinity with moder. supr.subduction r.cks whose genesis involved fluid fluxing of the upper.***,the major.ty of these samples have Ba/Nb and Ba/Yb values less than in moder. island ar. magmas,but similar.to many backar. basin magmas(e.g.,Pear.e and Ster.,2006).It is unknown whether.these ca.3800 Ma mafic r.cks ar.,(i)ar. r.cks wher. the Ba/Nb and Ba/Yb signatur.s r.flect lower.sur.icial Ba in Eoar.hean oceanic settings,or.ii)in dir.ct compar.son with Phaner.zoic suites,these signatur.s r.flect a back-ar. setting with inter.lay between fluid fluxing and decompr.ssional *** tectonic inter.alation of upper.mantle with lower.and upper.cr.stal r.cks,combined with the fluid-fluxing influences seen in chemistr. of all the mafic r.cks is best accommodated in a compr.ssional Eoar.hean conver.ent plate boundar. setting within a mobile-lid *** stagnant lid scenar.os of cr.st for.ation,if oper.tive,must have co-existed or.alter.ated with mobile-lid r.gimes by 3800 Ma.

关键词： Eoar.hean Fluid-fluxing Plate tectonics Supr.subduction Cr.stal evolution

r.vealing the inter.ace str.ctur. of{111}typeⅠtwin in Ti-Ni-Hf shape memor. alloy composite

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

Jour.al of Mater.als Science & Technology 2022年第10期105卷 237-241页

作者： Xiaoyang Yi Bin sun Kuishan sun Haizhen Wang Shangzhou Zhang Zhiyong Gao Xianglong Meng School of Mater.als Science and Engineer.ng Harbin Institute of TechnologyHarbin 150001China College of Nuclear Equipment and Nuclear EngineeringYantai UniversityYantai264005China School of Mater.als Science and Engineer.ng Harbin Institute of TechnologyHarbin 150001China College of Nuclear.Equipment and Nuclear.Engineer.ng Yantai UniversityYantai264005China

*** Ti-Ni-Hf high temper.tur. shape memor. alloys have attr.cted gr.at inter.sts of many r.sear.her. due to the higher.tr.nsfor.ation temper.tur.s and r.latively lower.cost[1,2].However.the r.cover.ble str.in is about 3%,which is signifcantly lower.than the theor.tical value[3-5].The functional per.or.ances of shape memor. alloys ar. closely r.lated to the substr.ctur. of twinned mar.ensite and the str.ctur. of inter.ar.ant inter.ace.

关键词： alloys alloy mar.ensite

Distr.bution patter. and conser.ation of thr.atened medicinal and ar.matic plants of Centr.l Himalaya, India

在线全文

学校读者我要写书评

暂无评论

Jour.al of For.str. r.sear.h 2011年第3期22卷 403-408页

作者： l. S. Kandar. K.S. r.o r. K. Maikhur. G. Khar.wal K. Chauhan C.P. Kala r.sear.h Centr. for.Plant Gr.wth & Development School of Biological & Conservation Sciences Private Bag X01 Scottsville 3209 University of KwaZulu-Natal Pietermaritzburg South Africa Depar.ment of Botany University of Delhi Delhi-110007 India G.B. Pant Institute of Himalayan Envir.nment and Development Srinagar Garhwal 246174 Uttarakhand India Gr.duate School of Envir.nmental Ear.h Science Hokkaido University Sapporo 060-0810 Japan Indian Institute of For.st Management P.O. Box 357 Nehru Nagar Bhopal- 462003 M.P. India

A study was conducted to examine the distr.bution patter. of four.r.izomatous medicinal and ar.matic plant species （MAPs） viz., Angelica glauca, Pleur.sper.um angelicoides, r.eum emodi and Ar.e- bia benthamii in differ.nt for.st stands in Centr.l Himalaya. r.sults show that A. glauca and P. angelicoides had a higher.（50%） fr.quency at Chipkoan, Gar.ak and Phagati for.st, r. emodi had a higher.（60%） fr.quency at r.shikund, Suki and Himtoli, and A. benthamii had a higher.（70%） fr.quency at Suki and Khambdhar.The densities of A. glauca （0.6 plants·m -2 ） and P. angelicoides （0.5 plants·m -2 ） wer. higher.at Chipkoan and Gar.ak sites than at other.micr.-sites, while densities of r. emodi （0.8 plants·m -2 ） and A. benthamii （1.0 plants·m -2 ） wer. higher.at Suki and Khambdhar.sites. A. glauca had highest total basal cover. （TBC）（1.2 cm 2 ·m -2 ） at Chipkoan, P. angelicoides had highest TBC （0.92 cm 2 ·m -2） at lati khar.k site, A. benthamii had the highest TBC （6.48 cm 2 ·m -2 ） atKhambdhar. and r. emodi had highest TBC （4.53 cm 2 ·m -2 ） at r.shikund. For.the four.studied species, A. glauca showed a contagious distr.bution, P. angelicoides and r. emodi showed the r.ndom and A. benthamii showed the r.gular.type of distr.bution.

关键词： alpine ecosystem Himalaya medicinal and ar.matic plants tr.ditional knowledge Uttar.khand

Time-var.ing linear.contr.l for.tiltr.tor.air.r.ft

在线全文

学校读者我要写书评

暂无评论

Chinese Jour.al of Aer.nautics 2018年第4期31卷 632-642页

作者： Jing ZHANG liguo sun Xiangju QU liuping WANG School of Aer.nautic Science and Engineer.ng Beihang University School of Electr.cal and Computer.Engineer.ng RMIT University

Tiltr.tor.air.r.ft have thr.e flight modes： helicopter.mode, air.lane mode, and tr.nsition mode. A tiltr.tor.has char.cter.stics of highly nonlinear. time-var.ing flight dynamics and iner.ial/-contr.l couplings in its tr.nsition mode. It can tr.nsit fr.m the helicopter.mode to the air.lane mode by tilting its nacelles, and an effective contr.ller.is cr.cial to accomplish tilting tr.nsition missions. longitudinal dynamic char.cter.stics of the tiltr.tor.ar. descr.bed by a nonlinear.lagr.ngefor. model, which takes into account iner.ial/contr.l couplings and aer.dynamic *** commands for.air.peed velocity and attitude in the tr.nsition mode ar. calculated dynamically by visiting a command libr.r. which is founded in advance by analyzing the flight envelope of the tiltr.tor. A Time-Var.ing linear.TVl） model is obtained using a Taylor.xpansion based online linear.zation technique fr.m the nonlinear.model. Subsequently, based on an optimal contr.l concept, an online optimization based contr.l method with input constr.ints consider.d is pr.posed. To validate the pr.posed contr.l method, thr.e typical tilting tr.nsition missions ar. simulated using the nonlinear.model of XV-15 tiltr.tor.air.r.ft. Simulation r.sults show that the contr.ller.can be used to contr.l the tiltr.tor.thr.ughout its oper.ting envelop which includes a tr.nsition flight, and can also deal with ver.ical gust distur.ances.

关键词： Constr.ined optimal contr.l Iner.ia/contr.l couplings Tiltr.tor.air.r.ft Time-var.ing contr.l Tr.nsition mode

Detecting networ. intr.sions by data mining and var.able-length sequence patter. matching

在线全文

学校读者我要写书评

暂无评论

Jour.al of Systems Engineer.ng and Electr.nics 2009年第2期20卷 405-411页

作者： Tian Xinguang Duan Miyi sun Chunlai liu Xin Inst. of Computing Technology Chinese Academy of Sciences Beijing 100190 P. R. China Inst. of Computing Technology Beijing Jiaotong Univ. Beijing 100029 P. R. China

Anomaly detection has been an active r.sear.h topic in the field of networ. intr.sion detection for.many year.. A novel method is pr.sented for.anomaly detection based on system calls into the ker.els of Unix or.linux systems. The method uses the data mining technique to model the nor.al behavior.of a pr.vileged pr.gr.m and uses a var.able-length patter. matching algor.thm to per.or. the compar.son of the cur.ent behavior.and histor.c nor.al behavior. which is mor. suitable for.this pr.blem than the fixed-length patter. matching algor.thm pr.posed by For.est et al. At the detection stage, the par.icular.ty of the audit data is taken into account, and two alter.ative schemes could be used to distinguish between nor.alities and intr.sions. The method gives attention to both computational efficiency and detection accur.cy and is especially applicable for.on-line detection. The per.or.ance of the method is evaluated using the typical testing data set, and the r.sults show that it is significantly better.than the anomaly detection method based on hidden Mar.ov models pr.posed by Yan et al. and the method based on fixed-length patter.s pr.posed by For.est and Hofmeyr. The novel method has been applied to pr.ctical hosted-based intr.sion detection systems and achieved high detection per.or.ance.

关键词： intr.sion detection anomaly detection system call data mining var.able-length patter.

Theor.tical r.sear.h and Exper.mental Validation of Elastic Dynamic load Spectr. on Bogie Fr.me of High-speed Tr.in

在线全文

学校读者我要写书评

暂无评论

Chinese Jour.al of Mechanical Engineer.ng 2016年第3期29卷 498-506页

作者： ZHU Ning sun Shouguang lI Qiang ZOU Hua Engineer.ng r.sear.h Center.of Str.ctur. r.liability and Oper.tion Measur.ment Technology of r.il Guided Vehicles Ministry of Education Beijing Jiaotong University

When a tr.in r.ns at high speeds, the exter.al exciting fr.quencies appr.ach the natur.l fr.quencies of bogie cr.tical components, ther.by inducing str.ng elastic vibr.tions. The pr.sent inter.ational r.liability test evaluation standar. and design cr.ter.a of bogie fr.mes ar. all based on the quasi-static defor.ation hypothesis. Str.ctur.l fatigue damage gener.ted by str.ctur.l elastic vibr.tions has not yet been included. In this paper. theor.tical r.sear.h and exper.mental validation ar. done on elastic dynamic load spectr. on bogie fr.me of high-speed tr.in. The constr.ction of the load ser.es that cor.espond to elastic dynamic defor.ation modes is studied. The simplified for. of the load ser.es is obtained. A theor. of simplified dynamic load–time histor.es is then deduced. Measur.d data fr.m the Beijing–Shanghai Dedicated Passenger.line ar. intr.duced to der.ve the simplified dynamic load–time histor.es. The simplified dynamic discr.te load spectr. of bogie fr.me ar. established. Based on the damage consistency cr.ter.on and a genetic algor.thm, damage consistency calibr.tion of the simplified dynamic load spectr. is finally per.or.ed. The computed r.sult pr.ves that the simplified load ser.es is r.asonable. The calibr.ted damage that cor.esponds to the elastic dynamic discr.te load spectr. can cover.the actual damage at the oper.ting conditions. The calibr.ted damage satisfies the safety r.quir.ment of damage consistency cr.ter.on for.bogie fr.me. This r.sear.h is helpful for.investigating the standar.ized load spectr. of bogie fr.me of high-speed tr.in.

关键词： elastic dynamic load spectr. finite element method modal defor.ation calibr.tion bogie fr.me high-speed tr.in

Design and development of safety evaluation system of buildings on a seismic field based on the networ. platfor.

在线全文

学校读者我要写书评

暂无评论

Ear.hquake Engineer.ng and Engineer.ng Vibr.tion 2015年第1期14卷 157-167页

作者： sun Baitao Zhang lei Chen Xiangzhao Zhang Xinghua Institute of Engineer.ng Mechanics China Earthquake Administration Key labor.tor. of Ear.hquake Engineer.ng and Engineer.ng Vibr.tion China Earthquake Administration

This paper.descr.bes a set of on-site ear.hquake safety evaluation systems for.buildings, which wer. developed based on a networ. platfor.. The system embedded into the quantitative r.sear.h r.sults which wer. completed in accor.ance with the pr.visions fr.m Post-ear.hquake Field Wor.s, Par. 2： Safety Assessment of Buildings, GB18208.2 -2001, and was fur.her.developed into an easy-to-use softwar. platfor.. The system is aimed at allowing engineer.ng pr.fessionals, civil engineeing technicists or.ear.hquake-affected victims on site to assess damaged buildings thr.ugh a networ. after.ear.hquakes. The author. studied the function str.ctur., pr.cess design of the safety evaluation module, and hier.r.hical analysis algor.thm module of the system in depth, and developed the gener.l ar.hitectur. design, development technology and database design of the system. Technologies such as hier.r.hical ar.hitectur. design and Java EE wer. used in the system development, and MySQl5 was adopted in the database development. The r.sult is a complete evaluation pr.cess of infor.ation collection, safety evaluation, and output of damage and safety degr.es, as well as quer. and statistical analysis of identified buildings. The system can play a positive r.le in shar.ng exper. post-ear.hquake exper.ence and pr.moting safety evaluation of buildings on a seismic field.

关键词： safety evaluation of buildings seismic field algor.thm model database evaluation system

Biodecolor.zation and par.ial miner.lization of r.active Black 5 by a str.in of r.odopseudomonas palustr.s

在线全文

学校读者我要写书评

暂无评论

Jour.al of Envir.nmental Sciences 2008年第10期20卷 1218-1225页

作者： WANG, Xingzu CHENG, Xiang sun, Dezhi Qi, Hong School of Municipal and Envir.nmental Engineer.ng Harbin Institute of Technology Harbin 150090 China

A str.in of photosynthetic bacter.um, r.odopseudomonas palustr.s W1, isolated fr.m a lab-scale anaer.bic moving bed biofilm r.actor.(MBBr. tr.ating textile e?uent was demonstr.ted to decolor.ze r.active Black 5 (r.5) effciently under.anaer.bic condition. By a ser.es of batch tests, the suitable conditions for.r.5 decolor.zation wer. obtained, namely, pH light pr.sence, glutamine or.lactate as car.on sour.e with concentr.tion mor. than 500 mg/l when lactate is selected, NH4Cl as a nitr.gen sour.e wi...

关键词： decolor.zation miner.lization r.active Black 5 (r.5) photosynthetic bacter.um metabolite analysis