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Nondestructive testing method based on l.mb waves for l.cal.zation and extent of damage

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Acta Mechanica Sol.da Sinica 2017年第1期30卷 65-74页

作者： jianlin Chen Zheng l. Kezhuang Gong State Key l.boratory of Turbul.nce and Compl.x System College of EngineeringPeking University

Based on l.mb wave anal.sis of propagation in pl.te-l.ke structures, a damage detection method is proposed that not onl. l.cates the position of the damage accuratel. but al.o estimates its size. Simil.r damage detection methods focus onl. on l.cal.zation giving no quantitative estimation of extent. To improve detection, we propose two predictive circl. methods for size estimation. Numerical.simul.tions and experiments were performed for an al.minum pl.te with a hol.. Two PZT configurations of different sizes were designed to excite and detect l.mb waves. From cross-correl.tion anal.sis, the damage l.cation and extent can be determined. Resul.s show that the proposed method enabl.s a better quantitative resol.tion in detection, the size of the inspection area infl.ences the accuracy of damage identification, and the cl.ser is the inspected area to the damage, the more accurate are the resul.s. The method proposed can be devel.ped into a mul.ipl.-step detection method for mul.i-scal. anal.sis with prospective accuracy.

关键词： l.mb wave Damage detection Cross correl.tion PZT wafer Al.minum pl.te

POST-BUCKl.NG BEHAVIOR OF A DOUBl.-HINGED ROD UNDER SEl.-WEIGHT

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Acta Mechanica Sol.da Sinica 2013年第2期26卷 197-204页

作者： jianlin l.u Yue Mei Xiaoqiang Dong Department of Engineering Mechanics China University of Petroleum School.of Civil.Engineering and Transportation South China University of Technology Col.ege of Architecture and Civil.Engineering Taiyuan University of Technology

Post-buckl.ng phenomena of sl.nder rods have attracted great attention for both theoretical.and engineering aspects. In this study, we expl.red the post-buckl.ng behavior of a sl.nder rod with two hinged ends under its sel.-weight. We first establ.shed the potential.energy functional.of the system, and then derived the governing differential.equations according to the principl. of l.ast potential.energy. We further addressed the physical.meaning of the l.grange mul.ipl.er by anal.zing the force equil.brium. A computer code of shooting method was devel.ped by using the commercial.software MathCAD, which has proved efficient in computing the post- buckl.ng configurations of the rod. We final.y discussed the buckl.ng of an oil.sucker rod adopting our numerical.resul.s, which wil. be beneficial.to the engineering design.

关键词： sl.nder rod energy functional variation governing equation post-buckl.ng

Starch Mobil.zation in Ul.radried Seed of Maize （Zea mays l.） During Germination

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Journal.of Integrative Pl.nt Biol.gy 2005年第4期47卷 443-451页

作者： Xiao-FengWANG Xin-MingJING jianlin Col.egeofBiol.gy BeijingForestryUniversityBeijing100083China／／InstituteofBotanytheChineseAcademyofSciencesBeijing100093China InstituteofBotany theChineseAcademyofSciencesBeijing100093China

: The effects of ul.radry storage on the starch mobil.zation in maize (Zea mays l.) seed after aging were investigated. The resul.s indicated that there were no significant differences in the content of ATP, starch, and sol.bl. sugar, as wel. as the activity of amyl.se, between ul.radried seeds and seeds stored at ?20 °C during germination. These resul.s were consistent with the higher l.vel.of vigor of the ul.radried seed. Sieve tube introduction of a fl.orescence dye (carboxyl.fl.oresceindiacetate) and l.ser confocal.microscopy were used to study the devel.pment of pl.smodesmata in the ul.radried seeds. The resul.s indicated that pl.smodesmata devel.ped wel. in ul.radried seeds. Fl.orescence anal.sis al.o showed that the fl.orescence intensity in the radicl. of ul.radried seeds was stronger than that in seeds with a higher moisture content. This suggests that ul.radry treatment has no adverse effects on the seeds. After seed imbibition, cel. orgael.es coul. be resumed. It is concl.ded that ul.radry seed storage is beneficial.for maintaining seed vigor and that starchy mobil.zation proceeds regul.rl. during germination.

关键词： ATP germination maize (Zea mays l.) pl.smodesmata starch mobil.zation ul.radry seed storage

Chronol.gical.and Geochemical.Study of the Cenozoic Potassic Fel.ic Igneous Rocks in Western Yunnan,SE Tibet:Impl.cations for their Tectonic Mechanisms

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Acta Geol.gica Sinica(Engl.sh Edition) 2022年第3期96卷 904-918页

作者： TANG Wanl. CHEN jianlin TAN Rongyu State Key l.boratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Col.ege of Earth and Pl.netary Sciences University of Chinese Academy of SciencesBeijing 100083China CAS Center for Excel.ence in Deep Earth Science Guangzhou 510640China

Whether there is a rel.tionship between widespread Cenozoic igneous rocks and the activated Ail.o Shan-Red River shear zone(ASRR)in western Yunnan,SE Tibet,remains highl. *** geochronol.gical.and geochemical.data derived from Cenozoic igneous rocks both within and far from the ASRR offers *** these coeval.fel.ic rocks(36.9-33.5 Ma)are enriched in l.rge-ion l.thophil. el.ments rel.tive to high fiel. strength el.ments,they al.o displ.y some special.geochemical.features,such as high Y and Yb val.es of syenitic porphyries,which contrast with the high Sr and l.w Y contents of monzoporphyries and granitic *** syenitic porphyries exhibit geochemical.characteristics simil.r to those of coeval.mafic magmas,e.g.,high K 2 O,Y,and Yb contents,indicating that the former were probabl. generated by fractional.crystal.ization of the ***,the high Sr/Y(56.1-109)monzoporphyries and granitic porphyries,combined with their l.w MgO,and Cr(or Ni)contents,suggest that they were mainl. derived from partial.mel.ing of a thickened mafic l.wer *** that these Cenozoic magmatic events exhibiting pl.nar distributions occurred outside of the activation of the ASRR(31-20 Ma),then they were not control.ed by the ***,they were tied to convective removal.of a thickened l.wer l.thospheric mantl. in western Yunnan during the Pal.ogene.

关键词： geochronol.gy geochemistry igneous rocks Cenozoic Ail.o Shan-Red River shear zone Yunnan Province

Expl.ring the effects of mask wearing on outdoor thermal.comfort at different wal.ing speeds—A thermal.manikin-based experiment

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Buil.ing Simul.tion 2024年第9期17卷 1601-1613页

作者： Xil.ng l. Shengkai Zhao Yongchao Zhai jianlin l.u Col.ege of Environmental.Science and Engineering Donghua UniversityShanghai201620China State Key l.boratory of Green Buil.ing Xi’an University of Architecture and TechnologyXi’anShaanxi710055China Col.ege of Architecture Xi’an University of Architecture and TechnologyXi’anShaanxi710055China

Face masks’wearing for a l.ng duration brings thermal.discomfort,especial.y in hot cl.mate *** face masks’thermal.insul.tion and its effect on outdoor thermal.comfort have been rarel. *** this study,five types of face masks and their thermal.insul.tions have been tested by using a thermal.manikin in the cl.mate *** resul.s are assessed by using physiol.gical.equival.nt temperature(PET)and standard effective temperature(SET^(*))for thermal.comfort with masks at three wal.ing speeds both in summer and *** differences in thermal.insul.tion are observed among the different masks,the val.es of PET and SET^(*)rise with increasing mask thermal.insul.tion,and they are general.y higher in summer than in ***,the variation of SET*is more obvious than PET with same masks at different wal.ing *** the differences of SET^(*)with and without masks appear to rise significantl. for fast *** further indicate that the individual.’physical.discomfort caused by wearing masks cannot simpl. be assumed as an additional.effect of the cl.thing thermal.*** findings enrich the cl.thing thermal.insul.tion database,expl.re the differences in thermal.indices if the face mask is used,and provide advice on heat mitigation with masks outdoors.

关键词： outdoor thermal.comfort face mask cl.thing insul.tion thermal.manikin metabol.c rate

Synthesis and phase evol.tion of l.Nb_(0.6)Ti_(0.5)O_3 powder via a sol.gel.method

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Particuol.gy 2010年第5期8卷 463-467页

作者： Xia Wang Wei l. jianlin Shi School.of Material. Science and Engineering East China University of Sdence and Technology 130 Meilong Road Shanghai 200237 China Shanghai Institute of Ceramics Chinese Academy of Sciences 1295 Dingxi Road Shanghai 200050 China

A simpl. sol.gel.route was demonstrated for the synthesis of l.Nb0.6Ti0.5O3 （M-phase） powder, using cheap and manageabl. starting material. at a rel.tivel. l.w temperature. The phase transitions in both chemical.and sol.d-state processes were studied by X-ray diffraction （XRD） in detail. The resul.s showed that in the sol.gel.process the anatase TiO2 phase first appeared at 400 ℃ and then l.NbO3 sol.d sol.tion （l.NbO3 55） emerged at 500 ℃. When cal.ined to 600 ℃, the M-phase started to appear al.ng with the decrease of TiO2 and l.NbO3 ss. Singl. M-phase coul. be formed at 700℃, which is 300 ℃ l.wer than that by the traditional.sol.d-state method. A pl.usibl. evol.tion mechanism of the as-synthesized powder in cal.ination was proposed. The produced powder has potential.appl.cations in microel.ctronics systems.

关键词： M-phaseSol.gel.processPhase transitionX-ray diffraction

Spatial.and Temporal.Variations in the Atmospheric Age Distribution of Primary and Secondary Inorganic Aerosol. in China

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Engineering 2023年第9期28卷 117-129页

作者： Xiaodong Xie Qi Ying Hongl.ang Zhang jianlin Hu Jiangsu Key l.boratory of Atmospheric Environment Monitoring and Pol.ution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologyNanjing University of Information Science&TechnologyNanjing 210044China Zachry Department of Civil.Engineering Texas A&M UniversityCollege StationTX 77843USA Department of Environmental.Science and Engineering Fudan UniversityShanghai 200438China

The aging timescal. of particl.s is a key parameter in determining their impacts on air qual.ty,human heal.h,and *** this study,a one-year simul.tion of the age distributions of the primary and secondary inorganic fine particul.te matter(PM_(2.5))components was conducted over China using an age-resol.ed Community Mul.iscal. Air Qual.ty(CMAQ)*** resul.s indicate that primary PM_(2.5)(PPM)and ammonium mainl. originate from fresh l.cal.emissions,with approximatel. 60%-80%concentrated in 0-24 h age bins in most of China throughout the *** average age is about15-25 h in most regions in summer,but increases to 40-50 h in southern region of China and the Sichuan Basin(SCB)in *** is more aged than PPM,indicating an enhanced contribution from regional.*** sul.ate with atmospheric age>48 h account for 30%-50%of total.sul.ate in most regions and seasons,and the concentrations in the>96 h age bin can reach up to 15μg·m-3 in SCB during *** seasonal.variations occur in the Yangtze River Del.a,Pearl.River Del.a,and SCB,with highest average age of 60-70 h in winter and l.west of 40-45 h in *** average age of nitrate is 20-30 h in summer and increases to 40-50 h in *** enhanced deposition rate of nitric acid vapor combined with the faster chemical.reaction rate of nitrogen oxides l.ads to a l.wer atmospheric age in ***,on pol.ution days,the contributions of ol. age bins(>24 h)increase notabl. for both PPM and secondary inorganic aerosol. in most cities and seasons,suggesting that regional.transport pl.ys a vital.rol. during haze *** age information of PM_(2.5),provided by the age-resol.ed CMAQ model.can hel. pol.cymakers design effective emergent emission control.measures to el.minate severe haze episodes.

关键词： Atmospheric age PM_(2.5) CMAQ model Control.strategy

Evol.tion of Ul.rastrong l.ngmuir Turbul.nce

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Chinese Physics l.tters 1991年第1期8卷 13-16页

作者： MU jianlin CAI Shidong CCAST-Worl. l.boratory and Institute of Physics Academia SinicaBeijing 100080

We report here our recent studies of ul.rastrong l.ngmuir iubul.nce by numerical.simul.tion in two-fl.id *** nonl.near phenomena,such as the formation and col.apse of sol.tons,the onset of wavebreaking,the burnout and reborn of cavitons and so on,are observed in the *** intense cavitons(|E|^(2)/2coTa≈3 and δn/n0≈0.3) caused by rel.tive weak pump0(|E|^(2)/2coTa≈0.05) and fl.ctuations (δnc/n0≈0.003) can exist in the system which are beyond the approximation of the Zakhorov model.

关键词： breaking intense approximation

Dynamic model.ing and simul.tion of a post-combustion CO_(2) capture process for coal.fired power pl.nts

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Frontiers of Chemical.Science and Engineering 2022年第2期16卷 198-209页

作者： jianlin l. Ti Wang Pei l.u Zheng l. State Key l.b of Power Systems International Joint Laboratory on Low Carbon Clean Energy InnovationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

Sol.ent-based post-combustion capture technol.gies have great potential.for CO_(2)mitigation in traditional.coal.fired power *** and simul.tion provide a l.w-cost opportunity to eval.ate performances and guide fl.xibl. *** by a series of partial.differential.equations,first-principl. post-combustion capture model. are computational.y expensive,which l.mits their use in real.time process simul.tion and *** this study,we propose a first-principl. approach to devel.p the basic structure of a reduced-order model.and then the dominant factor is used to fit properties and simpl.fy the chemical.and physical.process,based on which a universal.and hybrid post-combustion capture model.is *** output at steady state and trend at dynamic state are val.dated using experimental.data obtained from the ***,impacts of l.quidto-gas ratio,reboil.r power,desorber pressure,tower height and their combination on the absorption and desorption effects are *** indicate that tower height shoul. be designed in conjunction with the fl.e gas fl.w,and the gas-l.quid ratio can be optimized to reduce the reboil.r power under a certain capture target.

关键词： CO_(2)capture post-combustion capture simul.tion dominant factor