检索结果-南通市图书馆

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

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 KUMAr 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, phytoplankton 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

Development of a multivar.ate empir.cal model for.pr.dicting weak r.ck mass modulus

引用

Inter.ational Jour.al of Mining Science and Technology 2015年第4期25卷 545-552页

作者： Kallu r.j r. Keffeler.Evan r. Watter. r.ber. J. Aghar.zi Alir.za Depar.ment of Mining Engineer.ng University of Nevada r.SPEC Consulting and Ser.ices Univer.ity of Nevada Itasca Houston Inc.

Estimating weak r.ck mass modulus has histor.cally pr.ven difficult although this mechanical pr.per.y is an impor.ant input to many types of geotechnical analyses. An empir.cal database of weak r.ck mass modulus with associated detailed geotechnical par.meter. was assembled fr.m plate loading tests per. for.ed at under.r.und mines in Nevada, the Bakhtiar. Dam pr.ject, and Por.ugues Dam pr.ject. The database was used to assess the accur.cy of published single-var.ate models and to develop a multivar.- ate model for.pr.dicting in-situ weak r.ck mass modulus when limited geoteehnical data ar. available. Only two of the published models wer. adequate for.pr.dicting modulus of weak r.ck masses over.lim- ited r.nges of alter.tion intensities, and none of the models pr.vided good estimates of modulus over.a r.nge of geotechnical pr.per.ies. In light of this shor.coming, a multivar.ate model was developed fr.m the weak r.ck mass modulus dataset, and the new model is exponential in for. and has the following independent var.ables：（1） aver.ge block size or.joint spacing, （2） field estimated r.ck str.ngth, （3） dis- continuity r.ughness, and （4） discontinuity infilling har.ness. The multivar.ate model pr.vided better.estimates of modulus for.both har.-blocky r.ck masses and intensely-alter.d r.ck masses.

关键词： In-situ modulus Weak r.ck mass Pr.liminar. design Elastic defor.ation

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

The evolution of female sex pher.mones

引用

Cur.ent Zoology 2013年第4期59卷 569-578页

作者： Ally r. HAr.r. Hadass STEINITZ Depar.ment of Entomology The Volcani Center Bet Dagan Israel

The r.le of female sex pher.mones in natur.l selection, par.icular.y as a means for.species r.cognition to avoid the gener.tion of hybr.d offspr.ng with low fitness, has been widely explor.d and is gener.lly accepted by scholar.. However. the significance of sex pher.mones in shaping mate choice （sexual selection） and in competition over.br.eding r.sour.es （social se- lection） has been lar.ely ignor.d. The effect of sexual selection on sex pher.mones as a sexually dimor.hic signaling tr.it has been discounted because the amount of pher.mone r.leased by females is typically minute, while the r.le of sex pher.mones in competition over.br.eding r.sour.es （other.than mates） has not yet been consider.d. As a r.sult of natur.l selection, var.ation in sex pher.mones among females is expected to be low, and males ar. not expected to choose their.mates among pher.- mone-r.leasing conspecific females. Sexual selection, on the other.hand, should dr.ve the incr.ase in pher.mone var.ance among females, and males ar. expected to choose females based on this var.ation. Mor.over. social selection r.sulting fr.m mor. gener.l social inter.ctions, for.example competition among females for.br.eding sites and food, should also pr.mote var.ance among female sex pher.mones. Her., we r.view the cttr.ent evidence for.each of the thr.e selection pr.cesses acting on sex pher.mones of female moths as an adver.ising tr.it. We suggest that the thr.e selection types ar. not mutually exclusive but r.ther.act together.to pr.mote differ.nt fimess components in diver.e ecological situations

关键词： Sex pher.mone Natur.l selection Sexual selection Social selection Competition Mate choice

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

Laser.Stimulation of the Chlor.plast/Endoplasmic r.ticulum Nexus in Tobacco Tr.nsiently Pr.duces Pr.tein Aggr.gates （Boluses） within the Endoplasmic r.ticulum and Stimulates Local Er.r.modeling

引用

Molecular.Plant 2011年第5期4卷 886-895页

作者： Lawr.nce r. Gr.ffing1 3258 TAMU Biology Department Texas A＆M University College Station Texas 77843 USA

Does the Er.subdomain that associates with the chlor.plast in vivo, her.after.r.fer.ed to as the chlor.plast/Er.nexus, play a r.le in pr.tein flow within the Er. In studies of tobacco cells either.constitutively or.tr.nsiently expr.ssing Er.r.tained luminal, GFP-HDEL, or.tr.ns-membr.ne, YFP-r.D3, fluor.scent fusion pr.teins, br.ef 405-nm （3-6-mW） laser.stimulation of the nexus causes a qualitative differ.nce in the movement and behavior.of pr.teins in the Er. Photostimulating the nexus pr.duces fluor.scent pr.tein punctate aggr.gates （boluses） within the lumen and membr.ne of the Er. The aggr.gation pr.pagates thr.ugh the membr.ne networ. thr.ughout the cell, but within minutes can r.ver. to nor.al, with disaggr.gation pr.pagating back towar. the or.ginally photostimulated nexus. In the meantime, the Er.gr.ws and anastomoses ar.und the chlor.plast, for.ing a dense cister.al and tubular.networ.. If this networ. is again photostimulated, bolus for.ation does not r.cur.and, if the photostimulation r.sults in photobleaching, fluor.scence r.cover. after.photobleaching occur. as it would typically in ar.as away fr.m the nexus. Bolus pr.pagation is not mediated by the actin cytoskeleton, but can be r.ver.ed by pr.-conditioning the cells for.30 min with high, 40-45℃, temper.tur. （heat str.ss）. Because it is not r.ver.ed with heat str.ss, the r.or.anization of the Er.at the nexus following photostimulation is a separ.te event.

关键词： Er.chlor.plast tr.nspor. Er.movement actin heat str.ss fluor.scence r.cover. after.photobleaching blue light r.ception.

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

Why ar. Nitr.gen Concentr.tions in Plant Tissues Lower.under.Elevated CO_2? A Cr.tical Examination of the Hypotheses

引用

Jour.al of Integr.tive Plant Biology 2008年第11期50卷 1365-1374页

作者： Daniel r. Taub Xianzhong Wang Biology Depar.ment and Envir.nmental Studies Pr.gr.m Southwestern University Georgetown Texas 78626 USA Depar.ment of Biology Indiana University-Purdue University Indianapolis Indianapolis Indiana 46202 USA

Plants gr.wn under.elevated atmospher.c [CO2] typically have decr.ased tissue concentr.tions of N compar.d with plants gr.wn under.cur.ent ambient [CO2]. The physiological mechanisms r.sponsible for.this phenomenon have not been definitely established, although a consider.ble number.of hypotheses have been advanced to account for.it. In this r.view we discuss and cr.tically evaluate these hypotheses. One contr.buting factor.to the decr.ases in tissue N concentr.tions clear.y is dilution of N by incr.ased photosynthetic assimilation of C. In addition, studies on intact plants show str.ng evidence for.a gener.l decr.ase in the specific uptake r.tes （uptake per.unit mass or.length of r.ot） of N by r.ots under.elevated CO2. This decr.ased r.ot uptake appear. likely to be the r.sult both of decr.ased N demand by shoots and of decr.ased ability of the soil-r.ot system to supply N. The best-suppor.ed mechanism for.decr.ased N supply is a decr.ase in tr.nspir.tion-dr.ven mass flow of N in soils due to decr.ased stomatal conductance at elevated CO2, although some evidence suggests that alter.d r.ot system ar.hitectur. may also play a r.le. Ther. is also limited evidence suggesting that under.elevated CO2, plants may exhibit incr.ased r.tes of N loss thr.ugh volatilization and/or.r.ot exudation, fur.her.contr.buting to lower.ng tissue N concentr.tions.

关键词： car.on dioxide dilution elevated CO2 gr.phical vector.analysis nitr.gen plants r.ot uptake tissue concentr.tions.

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

r.infor.ement＇s incidental effects on r.pr.ductive isolation between conspecifics

引用

Cur.ent Zoology 2016年第2期62卷 135-143页

作者： Biology Depar.ment Daniel r. MATUTE Biology Depar.ment University of North Carolina 250 Bell Tower Road Chapel Hill NC 27599 USA

r.infor.ement--the pr.cess wher.by maladaptive hybr.dization leads to the str.ngthening of pr.zygotic isolation between species--has a long histor. in the study of speciation. Because r.infor.ement affects tr.its involved in mate choice and fer.ility, it can have indir.ct effects on r.pr.ductive isolation between populations within species. Her. we r.view examples of these ＂cascading effects of r.infor.ement＂（CEr. and discuss differ.nt mechanisms thr.ugh which they can ar.se. We discuss thr.e factor. that ar. pr.dicted to influence the potential occur.ence of CEr. r.tes of gene flow among populations, the str.ngth of selection acting on the tr.its involved in r.infor.ement, and the genetic basis of those tr.its. We suggest that CEr.is likely if （1） the r.te of gene flow between conspecific populations is low; （2） diver.ent selection acts on phenotypes involved in r.infor.ement between sympatr.c and allopatr.c populations; and （3） the genetic r.sponse to r.infor.ement differ. among conspecific populations subject to par.llel r.infor.ing selection. Futur. wor. continuing to addr.ss gene flow, selection, and the genetic basis of the tr.its involved in the r.infor.ement will help develop a better.under.tanding of r.infor.ement as a pr.cess dr.ving the pr.duction of species diver.ity, both dir.ctly and incidentally.

关键词： r.infor.ement speciation r.pr.ductive char.cter.displacement

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

Lie Invar.ants in Two and Thr.e Var.ables

引用

Algebr. Colloquium 2014年第1期21卷 95-116页

作者： Mur.ay r. Br.mner.Jiaxiong Hu Depar.ment of Mathematics and Statistics Univer.ity of Saskatchewan Saskatoon Canada Depar.ment of Mathematics Simon Fraser University Burnaby British Columbia Canada.

We use computer.algebr. to deter.ine the Lie invar.ants of degr.e ≤ 12 in the fr.e Lie algebr. on two gener.tor. cor.esponding to the natur.l r.pr.sentation of the simple 3-dimensional Lie algebr. sl2（C）. We then consider.the fr.e Lie algebr. on thr.e gener.tor., and compute the Lie invar.ants of degr.e ≤ 7 cor.esponding to the adjoint r.pr.sentation of sl2（C）, and the Lie invar.ants of degr.e ≤ 9 cor.esponding to the natur.l r.pr.sentation of sl3（C）. We r.pr.sent the action of sl2（C） and sl3（C） on Lie polynomials by computing the coefficient matr.x with r.spect to the basis of Hall wor.s.

关键词： fr.e Lie algebr.s invar.ant Lie polynomials r.pr.sentation theor. Her.itenor.al for. LLL algor.thm

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

Moth diver.ity in thr.e biofuel cr.ps and native pr.ir.e in Illinois

引用

Insect Science 2013年第3期20卷 407-419页

作者： Ter.y Har.ison May r. Ber.nbaum Depar.ment of Entomology University of Ilfinois at Urbana-Champaign Urbana Illinois USA

The expanding demand for.biofuel feedstock may lead to lar.e-scale con- scr.ption of land for.monocultur. pr.duction ofbiofuel cr.ps with concomitant substantial negative impacts on biodiver.ity. We compar.d moth diver.ity in light-tr.p samples fr.m cor., miscanthus, switchgr.ss and native pr.ir.e, to deter.ine whether.ther. is an obser.- able r.lationship between plant species diver.ity and moth abundance and diver.ity. Moth alpha diver.ity was highest in pr.ir.e and was higher.in switchgr.ss than in the other.two biofuel cr.ps. Beta diver.ity gener.lly was low among the biofuel cr.ps, and pr.ir.e shar.d lower.beta diver.ity with switchgr.ss than with cor. or.miscanthus. Analysis of var.ance showed no significant differ.nces in moth abundance per.species among tr.atments. The alpha and beta diver.ity index findings ar. consistent with those of other.studies on ar.hr.- pods in biofuel cr.ps and pr.vide evidence to suggest that lar.e-scale conver.ion of acr.age to biofuel cr.ps may have substantial negative effects on ar.hr.pod biodiver.ity both within the cr.pping systems and in the sur.ounding landscape.

关键词： agr.cultur.l landscapes biodiver.ity bioener.y ecosystem ser.ices moths pr.ir.es

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

Sexual selection and magic tr.its in speciation with gene flow

引用

Cur.ent Zoology 2012年第3期58卷 510-516页

作者： Mar.a r. SEr.EDIO Michael KOPP Depar.ment of Biology University of North Carolina Chapel Hill NC 27599 USA Mathematics and Biosciences Gr.up Max F. Perutz Laboratories and Faculty of Mathematics University of Vienna NordbergstraBe 15 A-1090 Vienna Austria Pr.sent addr.ss： Aix-Mar.eille Univer.ity UMR-CNRS 6632 Evolutionary Biology and Modeling 3 Place Victor Hugo 13331 Marseille France

The extent to which sexual selection is involved in speciation with gene flow r.mains an open question and the sub- ject of much r.sear.h. Her., we pr.pose that some insight can be gained fr.m consider.ng the concept of magic tr.its （i.e., tr.its involved in both r.pr.ductive isolation and ecological diver.ence）. Both magic tr.its and other. ＂non-magic＂, tr.its can contr.bute to speciation via a number.of specific mechanisms. We ar.ue that many of these mechanisms ar. likely to differ.widely in the ex- tent to which they involve sexual selection. Fur.her.or., in some cases wher. sexual selection is pr.sent, it may be pr.ne to in- hibit r.ther.than dr.ve speciation. Finally, ther. ar. a pr.or. r.asons to believe that cer.ain categor.es of tr.its ar. much mor. ef- fective than other. in dr.ving speciation. The combination of these points suggests a classification of tr.its that may shed light on the br.ader.r.le of sexual selection in speciation with gene flow. In par.icular. we suggest that sexual selection can act as a dr.ver.of speciation in some scenar.os, but may play a negligible r.le in potentially common categor.es of magic tr.its, and may be likely to inhibit speciation in common categor.es of non-magic tr.its [Cur.ent Zoology 58 （3）： 510-516, 2012].

关键词： Assor.ative mating Diver.ent selection Ecological selection Mating cues Non-r.ndom mating Pr.fer.nces

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

A COMBINATOr.AL APPr.ACH TO THE OXIDATION r.SISTANCE OF (Ti,Al)N AND Ti-Al-Si-N HAr. COATINGS

引用

Acta Metallur.ica Sinica(English Letter.) 2002年第1期15卷 6-14页

作者： r. Cr.mer.D. Neuschutz r.TH Aachen Aachen D-52056 Germany

The incr.asing complexity of moder. functional mater.als leads to the demandof a cost efficient tool for.the development of new pr.ducts. One possible appr.ach to this questionis the adaptation of combinator.al methods to the specific r.quir.ments of mater.als *** methods, or.ginally developed for.the phar.aceutical industr., have r.cently been applied tothe scr.ening of super.onductive, magnetor.sistant and photoluminescent mater.als. The pr.nciple ofthese combinator.al appr.aches is the deposition of lar.e mater.als libr.r.es in one pr.cesscombined with fast methods for.the deter.ination of the r.sulting pr.per.ies. In this paper. thedeposition and char.cter.zation of later.lly gr.ded mater.als libr.r.es (composition spr.ad) ispr.sented. The films have been deposited by r.active magnetr.n sputter.ng, using two or.thr.emetallic tar.ets at a low angle to the substr.te sur.ace as well as a system of aper.ur.s. Toillustr.te the advantages of combinator.al appr.aches for.the development of advanced mater.als, themulticomponent metastable har.coatings (Ti,Al)N and Ti-Al-Si-N ar. discussed with special emphasison the r.lations between str.ctur. and composition on the one hand and the oxidation r.sistance ofthese coatings on the other. The r.sults illustr.te that the composition spr.ad appr.ach is apower.ul and cost efficient tool for.the development and optimization of new multicomponentfunctional mater.als.

关键词： combinator.al chemistr. har. coating PVD magnetr.n sputter.ng

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：