检索结果-南通市图书馆

Re.ucing the.loss of ge.e.ic dive.sity associate. with assiste. colonization-like.introductions of animals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Curre.t Zoology 2015年第5期61卷 827-834页

作者： Jaana Ke.KONe. Jon e. BROMMe. De.artme.t of Bioscie.ce. University of Helsinki Helsinki Finland De.artme.t of Biology University of Turku Turku Finland

Translocations, e.pe.ially assiste. colonizations, of animals are.incre.singly use. as a conse.vation manage.e.t tool. In many case., howe.e., limite. funding and othe. logistic challe.ge. limit the.numbe. of individuals available.for transloe.tion. In conse.vation ge.e.ics, small populations are.pre.icte. to rapidly lose.ge.e.ic dive.sity which can de.e.iorate.population survival. Thus, how worrie. should we.be.about the.loss of ge.e.ic dive.sity whe. introducing small, isolate. populations？ Historical spe.ie. introductions provide.a me.ns to asse.s the.e.issue.. He.e.we.re.ie. 13 studie. of ＂assiste. colonization-like. introductions of animals, whe.e.only a small known numbe. of founde.s e.tablishe. an isolate. population without se.ondary contact to the.source.population. We.te.t which factors could be.important in re.aining ge.e.ic dive.sity in the.e.case.. In many case., loss in he.e.ozygosity （-12.1%） was de.e.te., and more.se.iously the.loss in alle.ic richne.s （-27.8 %）. Numbe. of founde.s se.me. to have.an e.fe.t but it also indicate. that high population growth rate.could he.p to re.ain ge.e.ic dive.sity, i.e. future.manage.e.t actions could be.e.fe.tive.e.e. with a limite. numbe. of founde.s if population growth would be.e.hance.. On the.contrary, translocate. organisms with longe. ge.e.ation time. did not se.m to re.ain more.ge.e.ic dive.sity. We.advocate.that, whe.e.possible. future.studie. on translocate. animals should re.ort the.loss of ge.e.ic dive.sity （both he.e.ozygosity and alle.ic richne.s）, which is e.se.tial for me.a-analyse. like.this one.for de.pe.ing our unde.standing of the.ge.e.ic conse.ue.ce. of assiste. colonization, and justifying manage.e.t de.isions [Curre.t Zoology 61 （5）： 827-834, 2015].

关键词： Introduce. spe.ie. Loss of ge.e.ic dive.sity Numbe. of founde.s Conse.vation manage.e.t Population growth rate Ge.e.ation time

Propose. GSSP for the.base.of Cambrian Stage.9,coinciding with the.first appe.rance.of Agnostote. orie.talis, at Duibian, Zhe.iang, China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Scie.ce.China e.rth Scie.ce. 2009年第4期52卷 434-451页

作者： Lore. e. BABCOCK Gabrie.la BAGNOLI School of e.rth Scie.ce. The Ohio State University De.artme.t of e.rth Scie.ce. of Pisa Unive.sity

e.pose. in natural outcrops ne.r the.Duibian Village. Jiangshan County, Zhe.iang Province. China, the.Duibian B se.tion is propose. as the.boundary stratotype.for the.base.of an unname. stage.te.me. provisionally Cambrian Stage.9. The.propose. position of the.GSSP is 108.12 m above.the.base.of the.Huayansi Formation, at a horizon coinciding with the.first appe.rance.of the.cosmopolitan agnostoid trilobite.Agnostote. orie.talis. This horizon coincide. also with the.first appe.rance.of the.cosmopoli-tan polyme.id trilobite.Irvinge.la angustilimbata. The.se.tion fulfills all the.re.uire.e.ts for a GSSP, and the.horizon can be.constraine. not only by the.primary stratigraphic marke. (A. orie.talis) but also with se.ondary biostratigraphic, che.ostratigraphic, and se.ue.ce.stratigraphic corre.ation tools. The.first appe.rance.of A. orie.talis is one.of the.most re.dily re.ognizable.le.e.s in Cambrian, and can be.corre.ate. with pre.ision to all pale.contine.ts.

关键词： Cambrian GSSP FAD of Agnostote. orie.talis China chronostratigraphy

On Quasi-Re.uce. Quadratic Forms

在线全文

学校读者我要写书评

暂无评论

Acta Mathe.atica Sinica,e.glish Se.ie. 2010年第8期26卷 1425-1448页

作者： e. DUBOIS C. Le.e.QUe e.ge.e.Dubois UMR 6138 CNRS Dep. de mathematiques et mecanique BP 5186 U. de Caen Basse-Normandie 14032 Caen France Claude.Le.e.que CICMA et Departement de mathematiques et de statistique U. Laval Quebec P. Qudbec Canada G1K 7P4

With the.he.p of continue. fractions, we.plan to list all the.e.e.e.ts of the.se. Q△ = {aX2 ＋ bXY ＋ cY2 ： a,b, c ∈Z, b2 - 4ac = △ with 0 ≤ b 〈 √△}of quasi-re.uce. quadratic forms of fundame.tal discriminant △. As a matte. of fact, we.show that for e.ch re.uce. quadratic form f = aX2 ＋ bXY ＋ cY2 = （a, b, c） of discriminant △〉0（and of sign σ（f） e.ual to the.sign of a）, the.quadratic forms associate. with f and de.ine. by {〈a＋bu＋cu2,b＋2cu.c〉},with 1≤σ（f）u≤b/2｜c｜（whe.e.e. the. e.ist）, 〈c,-b-2cu,a＋bu＋cu2〉 with b/2｜c｜≤σ（f）u≤[w（f）]=[b＋√△/2｜c｜], are.all diffe.e.t from one.anothe. and build a se. I（f） whose.cardinality is #I（f）={1＋[ω（f）],whe.（2c）｜b,[ω（f）],whe. （2c）｜b. If f and g are.two diffe.e.t re.uce. quadratic forms, we.show that I（f） ∩ I（g） = Ф. Our main re.ult is that the.se. Q△ is give. by the.disjoint union of all I（f） with f running through the.se. of re.uce. quadratic forms of discriminant △〉0. This allows us to de.uce.a formula for #（Q△） involving sums of partial quotie.ts of ce.tain continue. fractions.

关键词： Quadratic forms re.uce. forms e.uivale.ce.of forms class numbe.s quadratic fie.ds,continue. fractions

AMS studie. on a 450 km long 2216 Ma dyke.from Dharwar craton, India:Implications to magma flow

在线全文

学校读者我要写书评

暂无评论

Ge.scie.ce.Frontie.s 2019年第5期10卷 1931-1939页

作者： e. Nagaraju V. Parashuramulu Pale.magne.ism Division CSIR-National Geophysical Research InstituteUppal RoadHyderabad-500007India TSMS Jr. Colle.e BaswapurPulkalSangareddy DistrictTelanganaIndia

Anisotropy of magne.ic susce.tibility (AMS) studie. we.e.carrie. out on a pre.ise.y date. (2216.0 ± 0.9 Ma),450 km long Ne. striking dyke.in the.Dharwar Craton,to de.e.mine.the.magma flow dire.tion along the.dyke.*** orde. to use.the.imbrication of the.magne.ic foliation,forty e.ght sample. we.e.colle.te. from 13 locations along the.le.gth of the.*** studie. show that AMS fabric is dominate. by me.ium graine. inte.stitial Ti-poor multidomain *** corre.te. anisotropy de.re. (Pj) of the.sample. was found to be.low to mode.ate.be.we.n 1.007 and 1.072,which indicate. primary magne.ic *** magne.ic e.lipsoid is e.the. triaxial,prolate.or oblate.and cle.rly de.ine. normal,inte.me.iate.and inve.se.magne.ic fabrics re.ate. to magma flow during the.dyke.*** maximum susce.tibility axe. (Kmax) of the.AMS te.sor of the.dyke.is pre.ominantly incline. at low angle. (e.atic variation in de.th along the.Ne. profile.indicating sub-horizontal flow e.e. at mid crustal le.e.s which could probably be.gove.ne. by location of the.focal re.ion of the.magma source.(mantle.plume.),flow dynamics toge.he. with the.compre.sive.stre.se. e.e.te. by the.ove.lying crust.

关键词： Anisotropy of magne.ic susce.tibility Dharwar craton Dyke swarms

The.lacustrine.se.ime.tary re.ords of coal-burning atmosphe.ic pollution

在线全文

学校读者我要写书评

暂无评论

Scie.ce.China e.rth Scie.ce. 2005年第10期48卷 1740-1746页

作者： e. Appe. V. Hoffmann Institut für Ge.wisse.schafte. Universitt Tübingen 72076 Tübingen GermanyInstitut für Geowissenschaften Universitt Tübingen 72076 Tübingen Germany

Base. on the.studie. on diatom, ostracods and magne.ism on a core.acquire. from lacustrine.se.ime.ts, as we.l as corre.ation analysis be.we.n conce.tration of acid diatom and the.instantane.us lowe.t pH value. the.proce.se. of e.vironme.t e.olution in Lake.Yangzonghai we.e.re.onstructe.. The.lacustrine.e.vironme.t was favorable.in the.1950s, and be.an to be.pollute. by a coal-burning powe. plant since.1960. During 1965―1980, the.instantane.us lowe.t pH value.of lake.wate. de.re.se. to 5―6 whe. he.vily pollute.. The.e.was a de.re.se.tre.d in the.pollution from 1983 to 1999, but coal-burning atmosphe.ic pollution was still a main proble. for e.vironme.tal re.rie.ing. As acid pre.ipitate., acid-tole.ant spe.ie. ove.spre.d, and she.lfish disappe.re., as we.l as fe.romagne.ic particulate. dissolve. be.ause.of the.conse.ue.t change.of pH-e. value. in the.inte.face.of wate. and soil, which re.ults in the.change.of e.vironme.tal proxie. ve.sus de.th. Thus, the.e.vironme.tal e.olution of Lake.Yangzonghai is re.onstructe. in this pape. base. on the.infe.e.ce. me.tione. above.

关键词： atmosphe.ic pollution, proxie., e.vironme.tal re.onstruction, lacustrine se.ime.t, Lake Yangzonghai.

Drag re.uction be.avior of hydrolyze. polyacrylamide.xanthan gum mixe. polyme. solutions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pe.role.m Scie.ce 2017年第2期14卷 412-423页

作者： Me.di Habibpour Pe.e. e. Clark School of Che.ical e.gine.ring Oklahoma State University Stillwater OK 74078 USA

Partially hydrolyze. polyacrylamide.HPAM）as the.main compone.t of slickwate. fracturing fluid is a she.r-se.sitive.polyme.,which suffe.s from me.hanical de.radation at turbule.t flow *** diffe.e.t conce.trations of HPAM as we.l as mixture. of polyacrylamide.xanthan gum we.e.pre.are. to inve.tigate.the.possibility of improving she.r stability of *** re.uction（DR）me.sure.e.ts we.e.pe.forme. in a close. flow *** HPAM solutions,the.e.te.t of DR incre.se. from 30%to67%with incre.sing HPAM conce.tration from 100 to1000 *** the.HPAM solutions suffe.e. from me.hanical de.radation and loss of DR e.ficie.cy ove. the.she.ring *** indicate. that the.re.istance.to she.r de.radation incre.se. with incre.sing polyme. *** e.ficie.cy of 600 wppm xanthan gum（XG）was 38%,indicating that XG was not as good a drag re.uce. as *** with only 6%DR de.line.XG solution e.hibite. a be.te. she.r stability compare. to HPAM *** HPAM/XG solutions initially e.hibite. gre.te. DR（40%and 55%）compare. to XG,but due.to she.r de.radation,DR%droppe. for HPAM/XG *** to 200 wppm HPAM solution,addition of XG did not improve.the.drag re.uction e.ficie.cy of HPAM/XG mixe. solutions though XG slightly improve. the.re.istance.against me.hanical de.radation in HPAM/XG mixe. polyme. solutions.

关键词： Slickwate. Polyacrylamide Xanthan gum Drag re.uction She.r stability

Biomate.ials for spinal cord re.air

在线全文

学校读者我要写书评

暂无评论

Ne.roscie.ce.Bulle.in 2013年第4期29卷 445-459页

作者： Agne. e. Hagge.ty Martin oude.a De.artme.ts of Bioe.gine.ring University of Pittsburgh De.artme.ts of the.Ce.te. for the.Ne.ral Basis of Cognition University of Pittsburgh De.artme.ts of Physical Me.icine.and Re.abilitation University of Pittsburgh De.artme.ts of Ne.robiology University of Pittsburgh

Spinal cord injury （SCI） re.ults in pe.mane.t loss of function le.ding to ofte. de.astating pe.sonal, e.onomic and social proble.s. A contributing factor to the.pe.mane.ce.of SCI is that damage. axons do not re.e.e.ate. which pre.e.ts the.re.e.tablishme.t of axonal circuits involve. in function. Many groups are.working to de.e.op tre.tme.ts that addre.s the.lack of axon re.e.e.ation afte. SCI. The.e.e.ge.ce.of biomate.ials for re.e.e.ation and incre.se. collaboration be.we.n e.gine.rs, basic and translational scie.tists, and clinicians hold promise.for the.de.e.opme.t of e.fe.tive.the.apie. for SCI. A ple.hora of biomate.ials is available.and has be.n te.te. in various mode.s of SCI. Conside.ing the.clinical re.e.ance.of contusion injurie., we.primarily focus on polyme.s that me.t the.spe.ific crite.ia for addre.sing this type.of injury. Biomate.ials may provide.structural support and/or se.ve.as a de.ive.y ve.icle.for factors to arre.t growth inhibition and promote.axonal growth. De.igning mate.ials to addre.s the.spe.ific ne.ds of the.damage. ce.tral ne.vous syste. is crucial and possible.with curre.t te.hnology. He.e. we.re.ie. the.most promine.t mate.ials, the.r optimal characte.istics, and the.r pote.tial role. in re.airing and re.e.e.ating damage. axons following SCI.

关键词： spinal cord injury axon re.e.e.ation biode.radable.mate.ials e.trace.lular matrix prote.ns functionalre.ove.y growth factor guidance injury and re.air spinal motor ne.ron

e.fe.t of losing a fight on late. agonistic be.avior toward unfamiliar conspe.ifics in male.Syrian hamste.s

在线全文

学校读者我要写书评

暂无评论

Curre.t Zoology 2011年第4期57卷 449-452页

作者： Javie. De.BARCO-TRILLO Robe.t e. JOHNSTON Come.l Unive.sity Department of Psychology Uris Hall Ithaca NY 14853 USA

In many spe.ie., agonistic inte.actions re.ult in social re.ationships that are.stable.ove. time. In Syrian hamste.s, two unfamiliar male. that are.place. toge.he. will fight vigorously and a cle.r winne./lose. re.ationship is usually e.tablishe.. In subse.ue.t inte.actions, the.lose. will fle. soon afte. de.e.ting the.familiar winne.. He.e.we.te.te. the.hypothe.is that losing a fight with a conspe.ific will affe.t future.agonistic inte.actions not only toward that individual （i.e., the.familiar winne.） but also toward unfamiliar conspe.ifics. To te.t this hypothe.is we.paire. two Syrian hamste. male. in thre. trials on one.day in which the.lose. had tile.opportunity to e.cape.the.winne.. The.ne.t day the.lose. was paire. with an unfarniliar male. also for thre. trials. If he.lost again, he.was te.te. on a third day with a third unfamiliar male. Subje.ts we.e.those.male. that we.e.lose.s on all thre. days. The.late.cy to e.cape.on the.first trial on Days 2 and 3 was significantly shorte. than on the.first trial on Day l, indicating that losing against the.first male.affe.te. the.re.ponse.toward unfamiliar male.. Howe.e., the.late.cy to e.cape.on the.first trial on Days 2 and 3 was significantly longe. than that on the.third trial on the.pre.e.ing day, indicating that a lose. tre.ts unfamiliar male. diffe.e.tly than a familiar winne.. The.e.re.ults sugge.t that a de.e.t during an inte.action with one.male.affe.ts late. agonistic be.avior towards othe., unfamiliar male. [Curre.t Zoology 57 （4）： 449-452, 2011].

关键词： Agonistic be.avior Lose. Hamste.s Me.ocrice.us

An e.ficie.t Boron Source.Activation Strate.y for the.Low‑Te.pe.ature.Synthe.is of Boron Nitride.Nanotube.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Le.te.s 2025年第1期17卷 548-558页

作者： Ying Wang Kai Zhang Liping Ding Liyun Wu Songfe.g e.Qian He.Nanyang Wang Hui Zuo Zhe.gyang Zhou Fe.g Ding Yue.Hu Jin Zhang Yagang Yao National Laboratory of Solid State.Microstructure. College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional Materialsand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093People’s Republic of China School of e.e.tronic Information and Artificial Inte.lige.ce Shaanxi University of Science&TechnologyXian 710000People’s Republic of China Colle.e.of Biore.ource. Che.ical and Mate.ials e.gine.ring Shaanxi University of Science&TechnologyXian 710000People’s Republic of China Ke. Laboratory of Carbon Mate.ials of Zhe.iang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325000People’s Republic of China She.zhe. Institute. of Advance. Te.hnology Chinese Academy of SciencesShenzhen 518000People’s Republic of China Colle.e.of Che.ical and Mole.ular e.gine.ring Peking UniversityBeijing 100871People’s Republic of China

Lowe.ing the.synthe.is te.pe.ature.of boron nitride.nanotube.(BNNTs)is crucial for the.r *** primary re.son for adopting a high te.pe.ature.is to e.able.the.e.fe.tive.activation of highme.ting-point solid *** this study,we.de.e.ope. a nove. approach for e.ficie.tly activating boron by introducing alkali me.al compounds into the.conve.tional MgO–B *** approach can be.adopte. to form various low-me.ting-point AM–Mg–B–O growth *** growth syste.s have.improve. catalytic capability and re.ctivity e.e. unde. low-te.pe.ature.conditions,facilitating the.synthe.is of BNNTs at te.pe.ature. as low as 850℃.In addition,mole.ular dynamics simulations base. on de.sity functional the.ry the.re.ically de.onstrate.that the.syste.s maintain a liquid state.at low te.pe.ature. and inte.act with N atoms to form BN *** findings offe. nove. insights into the.de.ign of boron activation and are.e.pe.te. to facilitate.re.e.rch on the.low-te.pe.ature.synthe.is of BNNTs.

关键词： Boron nitride.nanotube. Low-te.pe.ature Boron activation De.sity functional the.ry