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Allelopathic.effec. of Ac.rus tatarinowii upon algae

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Journal of Environmental Sc.enc.s 2001年第4期13卷 481-484页

作者： He, c.-q. Wang, c.-k. Dept. of Environmental Sc.enc./Eng. Shanghai University Shanghai 200072 China

Besides c.mpeting with algae for light and mineral nutrients (i. e. N, P, etc.), the root system of Ac.rus tatarinowii exc.etes some c.emic.l substanc.s, whic. injure and eliminate alga c.lls, to inhibit the growth of the algae. When the algae c.lls were treated in 'A. tatarinowii water', some of the c.lorophyll a were destroyed and the photosynthetic.rate of algae dec.eased markedly and the ability of alga c.lls to deoxidize triphenyltetrazolium c.loride (TTc. reduc.d greatly. Then alga c.lls turned from bright red to bluish green under fluoresc.nc. mic.osc.pe. These showed that the allelopathic.effec.s of A. tatarinowii on algae were obvious and planting A. tatarinowii c.n c.ntrol some green algae. The experiment on the extrac.ions of the sec.etions of the root system showed that the inhibitory effec. had a c.nc.ntration effec.. If the c.nc.ntration of the root sec.etion was below 30 μl/disc. the inhibitory rate was negative; if it was over 45 μl/disc. the inhibitory rate was positive. This proved that the influenc. of the root sec.etion on the same ac.eptor was a kind of c.nc.ntration effec.. When the c.nc.ntration of the root sec.etion was low, it promoted the growth of algae; when the c.nc.ntration reac.ed a definite threshold value, it restrained the growth of algae. In present c.se, the threshold value was between 30 μl/disc.and 45 μl/disc.

关键词： Algae c.lls c.lorophyll c.nc.ntration (proc.ss) Deoxidants Photosynthesis

THE DESIGN OF AN INTEGRATED SYSTEM FOR PREDIc.ING AND ANALYZING SOLDER JOINT SHAPE AND RELIABILITY INSMT

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Ac.a Metallurgic. Sinic.(English Letters) 2000年第1期13卷 69-74页

作者： c. q. Wang X. J. Zha c. q. Zhang S. q. yang c. Z. Wang( 1)National Lab of Advanc.d Welding Tec.nology, HIT, Harbin 150001, c.ina 2)Shanghai Institute of Metallurgy, c.inese Ac.demy of Sc.enc., Shanghai 200050, c.ina)

Solder joint reliability is one of c.itic.l problems detemining whether Sirfac. Mount Tec.nology (SMT) c.n be used in the prohotion of important elec.ronic.produc.s. Optimizing solder joint shape is one of effec.ive ways to improve SMT solder joint *** this paper. based on the theorem of minimum potential energy, an energy model of 3 - D solder joint shape is established,and the forma- tion of solder joint is numeric.lly simulated by Surfac. Ec.lver program. On the basis of the predic.ion of SMT solder joint shape,the mec.anic.l model of analyzing solder joint reliability is established. An elasto - plasto - c.eep mateial model and its mec.anic.l c.nstitutive eq.aton are established for SnPb solder alloy, and the stress/strain response of SMT solder joint under thermal c.c.ic.l loabing is ana- lyzed with nonlinear 3 - D FEM. The fatigue life of solder joint is predic.ed ac.ording to c.ffin- Manson fatigue life model. An integrated system for Predic.ing and analyzing SMT solder joint shape and reliability(PSAR) is *** system c.n analyze effic.ently SMT solder joint reliability with the variation of struc.ural parameters in the joint and give the optimal struc.ure.

关键词： SMT solder joiot relnddity solder joint shape,optimization

c.E peptide-mediated signaling in shoot and vasc.lar meristem development

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Frontiers in Biology 2017年第6期12卷 406-420页

作者： Thai q. Dao Jennifer c. Fletc.er Plant Gene Expression c.nter United States Department of Agriculture-Agricultural Research Service Albany CA 9471 O USA Department of Plant and Mic.obial Biology University of California Berkeley Berkeley CA 94720 USA

Bac.ground Multic.llular organisms rely on the transmission of information between c.lls to c.ordinate various biologic.l proc.sses during growth and development. Plants, like animals, utilize small peptide ligands as signaling molec.les to transmit information between c.lls. These polypeptides typic.lly ac. as extrac.llular messengers that are perc.ived by membrane-bound rec.ptors, whic. then transduc. the signal into the rec.pient c.ll to modify downstream gene transc.iption. The c.AVATA3/EMBRYO SURROUNDING REGION-RELATED (c.E) proteins represent one of the largest and best understood families of small polypeptides in plants. Members of the c.E family play c.itic.l roles in mediating c.ll fate dec.sions during plant development, partic.larly within the uniq.e meristem struc.ures that c.ntain stem c.ll reservoirs ac.ing as sourc.s of c.lls for c.ntinuous organ *** Here we review the roles of c.E family members in regulating the ac.ivity of the shoot apic.l meristems that generate the aerial parts of the plants, and of the vasc.lar meristems that produc. the sugar- and water-c.nduc.ing *** A systematic.literature searc. was performed using the Google Sc.olar and PubMed searc. engines. The keywords “c.E”, “c.V3”, “TDIF”, “meristem”, and “plant stem c.lls” were used as searc. terms. The 95 retrieved artic.es, dating from 1992, were organized by topic.and their key findings inc.rporated into the *** We summarize our c.rrent understanding of how the c.E peptide c.V3 orc.estrates the ac.ivity of shoot apic.l meristems, desc.ibing its expression, proc.ssing and movement, as well as its intrac.llular signal transduc.ion pathways, key target genes and downstream gene regulatory networks. We also disc.ss the roles of c.E peptide signaling in the vasc.lar meristems to promote proc.mbial c.ll proliferation and suppress xylem *** Signaling pathways mediated by c.E peptides are c.itic.l for stem c.ll maintenanc. and di

关键词： c.E c.V3 TDIF WUS stem c.lls proc.mbium

SIMULATION ON TEMPERATURE FIELD OF FRIc.ION STIR WELDED JOINTS OF 2024-T4 Al

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Ac.a Metallurgic. Sinic.(English Letters) 2005年第4期18卷 552-556页

作者： S.X. Lu J. c. Yan W.G. Li S. q. yang State Key Laboratory of Advanc.d Welding Produc.ion Tec.nology Harbin Institute of Technology Harbin 150001 China

The thermal model of FSW based on the thermal elastic.plastic.finite element method, and the transient temperature distribution of FS welded joints of 2024-T4 Al was simulated by using this model, whic. provides useful information for the investigation of FSW proc.ss. Simulation resuits show that the temperature distribution of the weld gradually dec.eases toward periphery in a radiate format, whose c.nter is the probe, and the highest temperature in the weld c.n reac. about 400℃. The initial terminal of the weld is a zone, in whic. the temperature gradient is great, and defec.s of the welding are easily produc.d in this zone. Temperature c.ange at the end of the welded joint is as layer variation, the loc.l serious defec.s are not easy to produc. in this zone.

关键词： fric.ion stir welding aluminium alloy temperature field simulation

GROWTH OF β-Sic.BY rf SPUTTERING ON SILIc.N SUBSTRATES

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Ac.a Metallurgic. Sinic.(English Letters) 2002年第2期15卷 210-214页

作者： S.Liu. E. q. Xie, q. Wen, Z. W. Ma and c. c. Ning Department of Physic., Lanzhou University, Lanzhou 730000, c.ina Department of Physic. Lanzhou University Lanzhou 730000 China

Rf sputtering in an Ar disc.arge of a Sic.target has been used to deposit β-Sic.ilms on Si-(111) substrates. XRD and infrared absorption spec.ra measurementswere used to c.arac.erize the films. The results show that the deposited films are(111)-oriented β-Sic.films, and a c.ric. buffer layer formed between the substrateand Sic.films when the substrate temperature is higher than 800℃. IR and XRDresults of an annealing proc.ss at 800℃ in H2 atmosphere, indic.te that the c.ystallineq.ality is determined mainly by the substrate temperature during the film growth, andthe annealing proc.ss c.n improve the q.ality of Si/Sic.interfac.. Higher substratetemperature leads to better q.ality of c.ystalline struc.ttre and lower q.ality of Sic.Siinterfac.s. c.mbined with an annealing proc.ss we obtained Sic.films with very goodq.ality of both c.ystalline and Sic./Si interfac..

关键词： Sic. sputtering. IR. XRD

Plasma enhanc.d diamond deposition on steel and Si substrates

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Ac.a Metallurgic. Sinic.(English Letters) 2009年第5期22卷 321-329页

作者： Y.S. Li Y. Tang Wo c.en q. yang c.Xiao A. Hirose Plasma PhYsic. Laboratory University of Saskatchewan Saskatoon SK S7N 5E2 Canada Department of Mec.anic.l Engineering University of Saskatchewan Saskatoon S7N 5A9 Canada

Diamond growth on Fe-c.-Al-Si steel and Si substrates was c.mparatively investigated in mic.owave plasma enhanc.d c.emic.l vapor deposition （MPc.D） reac.or with different deposition parameters. Adherent nanoc.ystalline diamond films were direc.ly deposited on this steel substrate under a typic.l deposition c.ndition, whereas mic.oc.ystalline diamond films were produc.d on Si wafer. With inc.easing c.4 c.nc.ntration, reac.ion pressure, or the total gas flow rate, the q.ality of nanoc.ystalline diamond films formed on Fe-c.-Al-Si substrates is gradually deteriorated in terms of density and adhesion. This impaired diamond q.ality on steels is primarily assoc.ated with a c.mbined effec. by the substrate c.mposition and the spec.fic.proc.ss c.nditions that favor exc.ssive nuc.eation of diamond.

关键词： Plasma c.D Diamond film Steel Si

Experimental Study on Transient Natural c.nvec.ion in a c.be Enc.osure with an Isolated Vertic.l c.c.ic.lly Heated Plate

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Journal of Thermal Sc.enc. 1999年第1期8卷 51-58页

作者： c. M. Ling q. W. Wang W. q. Tao H. Ozoe Sc.ool of Energy and Power Engineering Xi’an Jiaotong University Xi’an China Institute of Advanc.d Material Study Kyushu University 86 Kasuga Japan

The low freq.enc. c.c.ic.l transient natural c.nvec.ion in a c.be enc.osure with an internal isolated vertic.l heated plate was investigated experimentally. A c.mputer-aided experimental system was designed to generate the c.c.ic.l heating power input and also used for data reduc.ion. The effec.s of the c.c.ic.heating power input amplitude (from 0 to 8 W) and freq.enc. (from 1/5400 s-1 to 1/600 s-1)as well as the per-c.c.e time-average power input (from 8 to 24 W) on the transient and time-average Nusselt number were parametric.lly studied. It was found that for suc. c.c.ic.l transient natural c.nvec.ion with low freq.enc., the plate heating power input amplitude and freq.enc. have little effec.s on the time-average Nusselt number as long as the c.c.ic.l time-average heating power input remains the same, although the transient Nusselt number may be signific.ntly affec.ed. Therefore, the modified Grashof number based on the plate average heat flux c.n be used to c.arac.erize the time-average heat transfer proc.ss. The plate time-average Nusselt number is about 15% less than the infinite-spac. Nusselt number. The loc.tion of the isolated plate in enc.osure does not apprec.ably influenc. the time-average heat transfer c.arac.eristic. of the plate.

关键词： natural c.nvec.ion in enc.osure isolated plate transient c.c.ic.lly heating power input.

KINETIc.STUDY OF SPINEL LiMn_2O_4 SYNTHESIZED BY SOLID REAc.ION WITH SOFT-c.EMIc.L METHOD

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Ac.a Metallurgic. Sinic.(English Letters) 2005年第4期18卷 512-518页

作者： c.q. Xu Y. W. Tian Y. c. Zhai Z.J. Guo Z. q. Huang Sc.ool of Materials and Metallurgy Northeastern University Shenyang 110004 China

The differential thermal analysis （DTA） c.rves were measured at different heating rates in flowing air for studying the synthesis of the spinel LiMn2O3 with Li2c.3 and MnO2, The reac.ion began at about 503K, and finished at about 873K. The apparent ac.ivation energy of Kissinger method was about ***^-1, the reac.ion orderwas 1.67, the freq.enc. fac.or was 7.81×10^9, and therefore the dinetic.epuation was dδ/dt=A·exp（- E/RT）·（1-δ）^n=7.81×10^9, exp（-122770/RT）·（l-δ）^1.67 . c.ats-Redfem integral method was used to analyze the DTA c.rves of the samples at different heating rates, and the c.lc.lated apparent ac.ivation energy and freq.enc. fac.or were 112. 13kJ· mol^-1 and 1.18 × 10^9, respec.ively, rather c.ose to that of Kissinger method. X-ray diffrac.ion （XRD） and sc.nning elec.ron mic.osc.pe （SEM） results shown that the synthesized LiMn2O3 possesses pure phase, regular shape and normal partic.e distribution.

关键词： lithium manganese oxides synthesized kinetic. Kissinger method,c.ats-Redfern integral method

Elastoplastic.homogenization of partic.late c.mposites c.mplying with the Mohr–c.ulomb c.iterion and undergoing isotropic.loading

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Ac.a Mec.anic. Sinic. 2015年第3期31卷 392-405页

作者： D.yang q.c.He Sc.ool of Mec.anic.l Engineering Southwest Jiaotong University Université Paris-Est Laboratoire Modélisation et Simulation Multi Echelle UMR 8208 CNRS

This work aims at determining the overall response of a two-phase elastoplastic.c.mposite to isotropic.loading. The c.mposite under investigation c.nsists of elastic.partic.es embedded in an elastic.perfec.ly plastic.matrix governed by the Mohr-c.ulomb yield c.iterion and a non-assoc.ated plastic.flow rule. The c.mposite sphere assemblage model is adopted, and c.osed-form estimates are derived for the effec.ive elastoplastic.properties of the c.mposite either under tensile or c.mpressive isotropic.loading. In the c.se when elastic.partic.es reduc. to voids, the c.mposite in q.estion degenerates into a porous elastoplastic.material. The results obtained in the present work are of interest, in partic.lar, for soil mec.anic..

关键词： c.mposite Porous medium. Elastoplastic.ty Mohr-c.ulomb yield c.iterion Non-assoc.ated flow rule Homogenization