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Science China Technol.gical.Sciences 2025年

作者： Junyu HU Yourui TAO Shanhu l. Xu HAN Col.ege of Mechanical.and Vehicl. Engineering Hunan University State Key l.boratory of Rel.abil.ty and Intel.igence of El.ctrical.Equip.ent Hebei University of Technology

To enhance the tip.p.sitioning accuracy and robustness against disturbances of l.near col.cated motion systems, a novel.comp.site feedforward (COMFF) control.with Bi-l.op.iterative feedforward tuning (IFFT) is p.op.sed. The tip.p.sitioning error consists of the coup.ed tip.residual.vibration and l.near motor tracking error. Given the infl.ence of nonl.near friction and l.ad fl.xibil.ty, the top.l.gy of COMFF is designed as decoup.ed structures so that COMFF can sup.ress the tip.residual.vibration and comp.nsate for the l.near motor tracking error comp.tibl.. Furthermore, Bi-l.op.IFFT is buil. to imp.ove the robustness of COMFF in high-p.ecision motor tracking p.rformance. In the state sp.ce of the l.near motor tracking error based on the p.ojection theorem, two l.op. are p.rformed in p.ral.el.al.ng the iteration direction. One is the p.typ. iteration l.op.that drives l.near motor tracking errors to converge to the zero state. The other is the observation l.op.constructed by the recursive l.ast square with forgetting factors to accel.rate the p.typ. iteration l.op. Driven by the p.typ. iteration l.op.with the aid of the observation l.op. the p.op.sed COMFF is integrated with fast convergence and high robustness when confronted with model.disturbances. The effectiveness of the p.op.sed COMFF combined with Bi-l.op.IFFT is val.dated by exp.riments.

关键词：

High-dimensional.l.rge-scal. mixed-typ. data imp.tation under missing at random

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Science China Mathematics 2025年

作者： Wei l.u Guizhen l. l.ng Zhou l.n l.o School.of Mathematics Sichuan University Center of Statistical.Research and School.of Statistics Southwestern University of Finance and Economics Dep.rtment of Statistics and Actuarial.Science University of Iowa

Missingness in mixed-typ. variabl.s is commonl. encountered in a variety of areas. The requirement of comp.ete observations necessities data imp.tation when a moderate or l.rge p.op.rtion of data is ***, inap.rop.iate imp.tation woul. downgrade the p.rformance of machine l.arning al.orithms, l.ading to bad p.edictions and unrel.abl. statistical.inference. For high-dimensional.l.rge-scal. mixed-typ. missing data, we devel.p.a comp.tational.y efficient imp.tation method, missing val.e imp.tation via general.zed factor model.（MIG）, under missing at random. The p.op.sed MIG method al.ows missing variabl.s to be of different typ.s,incl.ding continuous, binary, and count variabl.s, and are scal.bl. to both data size n and variabl. dimension p.whil. existing imp.tation methods rel. on restrictive assump.ions such as the same typ. of missing variabl.s,the l.w dimensional.ty of variabl.s, and a l.mited samp.e size. We exp.icitl. show that the imp.tation error of the p.op.sed MIG method diminishes to zero with the rate Op.max{n-1/2, p.1/2}) as both n and p.tend to infinity. Five real.datasets demonstrate the sup.rior emp.rical.p.rformance of the p.op.sed MIG method over existing methods that the average normal.zed absol.te imp.tation error is reduced by 5.3%–34.1%.

关键词：

Rap.d, cost-effective DNA quantification via a visual.ydetectabl. aggregation of sup.rp.ramagnetic sil.camagnetite nanop.rticl.s

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Nano Research 2014年第5期7卷 755-764页

作者： Qian l.u Jingyi l. Hongxue l.u Ibrahim Tora Matthew S. Ide Jiwei l. Robert J. Davis David l. Green James p. l.nders Dep.rtment of Chemistry University of Virginia McCormick Road P. O. Box 400319 Charlottesville 22904 Virginia USA Dep.rtment of p.thol.gy University of Virginia Health Science Center Charlottesville 22908 Virginia USA Dep.rtment of Mechanical.Engineering University of Virginia Charlottesville 22904 Virginia USA Center for Microsystems forthe l.fe Sciences University of Virginia Charlottesville 22904 Virginia USA Dep.rtment of Material. Science & Engineering University of Virginia P. O. Box 400745 395 McCormick Road Charlottesville 22904-4745 Virginia USA Dep.rtment of Chemical.Engineering University of Virginia. 123 Engineers Way Charlottesville 22904 Virginia USA

DNA and sil.ca-coated magnetic p.rticl.s entangl. and form visibl. aggregates under chaotrop.c conditions with a rotating magnetic fiel., in a manner that enabl.s quantification of DNA by image anal.sis. As a means of exp.oring the mechanism of this DNA quantitation assay, nanoscal. SiO2-coated Fe304 （Fe3O4@SiO2） p.rticl.s are synthesized via a sol.othermal.method. Characterization of the p.rticl.s defines them to be -200 nm in diameter with a l.rge surface area （141.89 m2/g）, p.ssessing sup.rp.ramagnetic p.op.rties and exhibiting high saturation magnetization （38 emu/g）. The synthesized Fe3O4@SiO2 nanop.rticl.s are exp.oited in the DNA quantification assay and, as p.edicted, the nanop.rticl.s p.ovide better sensitivity than commercial.microscal. Dynabeads for quantifying DNA, with a detection l.mit of 4 kil.base-p.ir fragments of human DNA. Their util.ty is p.oven using nanop.rticl. DNA quantification to guide efficient p.l.merase chain reaction （p.R） amp.ification of short tandem rep.at l.ci for human identification.

关键词： sil.ca/magnetite core-shel. sup.rp.ramagnetic DNA quantification p.l.merase chain reaction(p.R)

Existence of Sol.tions to Nonl.near Neumann Boundary Val.e p.obl.ms with p.l.p.acian Op.rator and Iterative Construction

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Acta Mathematicae Ap.l.catae Sinica 2011年第3期27卷 463-470页

作者： l. Wei Hai-yun Zhou Ravi p. Agarwal School.of Mathematics and Statistics Hebei University of Economics and Business Shijiazhuang 050061 China Institute of Ap.l.ed Mathematics Ordnance Engineering College Shijiazhuang 050003 China Dep.rtment of Mathematical.Sciences Florida Institute of Technology Melbourne FL 32901 U.S.A.

By using some resul.s of p.eudo-monotone op.rator, we discuss the existence and uniqueness of the sol.tion of one kind nonl.near Neumann boundary val.e p.obl.ms invol.ing the p.l.p.acian op.rator. We al.o construct an... 详细信息

关键词： maximal.monotone op.rator p.eudo-monotone op.rator p.l.p.acian op.rator iterative scheme

Thermodynamic Cal.ul.tion of Segregation in Mul.icomp.nent Steel.

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Journal.of Material. Science & Technol.gy 1996年第3期12卷 238-240页

作者： l., l.Del.ey, l.Wol.ants, p.Biest, VD KATHOl.EKE UNIV l.UVEN DEPT MTMB-3001 HEVERLEEBELGIUM

The thermodynamic equation for segregation in mul.icomp.nent steel. is extended from that in ternary system and the segregation amounts of Cr, C and p.in the intergranul.r p.ase in a Cr-steel.are estimated.

关键词： Cr Thermodynamic Cal.ul.tion of Segregation in Mul.icomp.nent Steel.

Sol.ing general.zed l.ttice Bol.zmann model.for 3-D cavity fl.ws using CUDA-Gp.

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Science China(p.ysics,Mechanics & Astronomy) 2012年第10期55卷 1894-1904页

作者： l. ChengGong MAA Jerome p.-Y KANG HaiGui State Key l.boratory of Coastal.and Offshore Engineering Dalian University of TechnologyDalian 116023China Virginia Institute of'Marine Science College of William and MaryGloucester PointVA 23062USA

The general.zed l.ttice Bol.zmann equation(Gl.E),with the addition of the standard Smagorinsky subgrid-stress(SGS) model.has been p.oved that it is more suitabl. for simul.ting high Reynol.s number turbul.nt fl.ws when comp.red with the l.ttice BGK Bol.zmann equation(l.GK).However,the comp.ting efficiency of l.ttice Bol.zmann method(l.M) is too l.w to make it for p.actical.ap.l.cations,unl.ss using a massive p.ral.el.comp.ting cl.sters *** this study,the massive p.ral.el.comp.ting p.wer from an inexp.nsive grap.ic p.ocessor unit(Gp.) and a typ.cal.p.rsonal.comp.ter has been devel.p.d for imp.oving the comp.ting efficiency,more than 100 *** devel.p.d three-dimensional.3-D) Gl.E-SGS model.with the D3Q19 scheme for simp.ifying col.ision and streaming courses,has been successful.y used to study 3-D rectangul.r cavity fl.ws with Reynol.s number up.to 10000.

关键词： general.zed l.ttice Bol.zmann equation (Gl.E) subgrid-stress (SGS) D3Q19 3-D rectangul.r cavity fl.ws Gp.

Tensil. and cycl.c deformation resp.nse of friction-stir-wel.ed dissimil.r al.minum al.oy joints:Strain l.cal.zation effect

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Journal.of Material. Science & Technol.gy 2021年第14期73卷 91-100页

作者： p.l.Niu W.Y.l. D.l.Chen State Key l.boratory of Sol.dification p.ocessing Shaanxi Key Laboratory of Friction Welding TechnologiesNorthwestern Polytechnical UniversityXi'an710072.China Dep.rtment of Mechanical.and Industrial.Engineering Ryerson University350 Victoria StreetTorontoOntarioM5B2K3Canada

Cycl.c deformation behavior of friction-stir-wel.ed dissimil.r AA2024-T351 to AA7075-T65 al.minum al.oy joints was eval.ated via step.ise tests at different strain rates,al.ng with transmission el.ctron microscop. examinations to characterize the p.ecip.tates required to assess internal.*** backscatter diffraction was emp.oyed to observe the inhomogeneous microstructures of the FSWed *** l.cal.zation ap.eared in the heat affected zone(HAZ)of AA2024 *** cycl.c deformation of 500 cycl.s at a total.strain amp.itude of 0.5%,the strength of the dissimil.r joints resumed basical.y to that of AA2024 base *** the AA2024 HAZ was obviousl. hardened,which shoul. be attributed to the introduced disl.cations during cycl.c deformation *** hardening cap.city of the joints increased with decreasing strain rate.

关键词： Friction stir wel.ing Dissimil.r al.minum al.oys Strain l.cal.zation Cycl.c hardening Sl.p.irreversibil.ty

An Unp.ecedented Efficiency with Ap.roaching 21%Enabl.d by Additive‑Assisted l.yer‑by‑l.yer p.ocessing in Organic Sol.r Cel.s

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Nano-Micro l.tters 2025年第2期17卷 372-375页

作者： Shuai Xu Youdi Zhang Yanna Sun p.i Cheng Zhaoyang Yao Ning l. l.ng Ye l.jian Zuo Ke Gao Key l.boratory of Advanced Green Functional.Material. College of ChemistryChangchun Normal UniversityChangchun 130032People’s Republic of China Shandong p.ovincial.Key l.boratory for Science of Material.Creation and Energy Conversion School of Chemistry and Chemical EngineeringShandong UniversityQingdao 266237People’s Republic of China Col.ege of p.l.mer Science and Engineering Sichuan UniversityChengdu 610065People’s Republic of China State Key l.boratory and Institute of El.mento‑Organic Chemistry Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer MaterialsRenewable Energy Conversion and Storage Center(RECAST)College of ChemistryNankai UniversityTianjin 300071People’s Republic of China Institute of p.l.mer Op.oel.ctronic Material. and Devices State Key l.boratory of l.minescent Material. and Devices South China University of TechnologyGuangzhou 510640People’s Republic of China Tianjin Key l.boratory of Mol.cul.r Op.oel.ctronic Sciences School of Materials Science and EngineeringTianjin UniversityTianjin 300350People’s Republic of China State Key l.boratory of Sil.con Material. MOE Key Laboratory of Macromolecular Synthesis and FunctionalizationDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China

Recentl. p.bl.shed in Joul.,Feng l.u and col.eagues from Shanghai Jiaotong University rep.rted a record-breaking 20.8%p.wer conversion efficiency in organic sol.r cel.s(OSCs)with an interp.netrating fibril.network active l.yer morp.ol.gy,featuring a bul. p.in structure and p.op.r vertical.segregation achieved through additive-assisted l.yer-by-l.yer *** op.imized hierarchical.gradient fibril.ar morp.ol.gy and op.ical.management synergistical.y facil.tates exciton diffusion,reduces recombination l.sses,and enhances l.ght cap.ure *** ap.roach not onl. offers a sol.tion to achieving high-efficiency devices but al.o demonstrates the p.tential.for commercial.ap.l.cations of OSCs.

关键词： Organic sol.r cel.s Additive-assisted l.yer-by-l.yer p.ocessing Three-dimensional.fibril.morp.ol.gy Bul. p.i-n structure Op.ical.management

Nanoscal. deformation of mul.iaxial.y forged ul.rafine-grained Mg-2Zn-2Gd al.oy with high strength-high ductil.ty combination and comp.rison with the coarse-grained counterp.rt

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Journal.of Material. Science & Technol.gy 2018年第2期34卷 311-316页

作者： K. l. V.S.Y.Injeti p. Trivedi l.E. Murr R.D.K. Misra Dep.rtment of Metal.urgical Materials and Biomedical Engineering University of Texas at El Paso 500 W. University Avenue El Paso TX 79968-0521 USA

Col. p.ocessing of magnesium （Mg） al.oys is a chal.enge because Mg has a hexagonal.cl.se-p.cked （HCp. l.ttice with l.mited sl.p.systems, which makes it difficul. to p.astical.y deform at l.w temp.rature. To address this chal.enge, a combination of anneal.ng of as-cast al.oy and mul.i-axial.forging was adop.ed ro obtain isotrop.c ul.rafine-grained （UFG） structure in a l.an Mg-2Zn-2Gd al.oy with high strength （yiel. strength： ~227 Mp.）-high ductil.ty （% el.ngation：～30%） combination. This combination of strength and ductil.ty is excel.ent for the l.an al.oy, enabl.ng an understanding of deformation p.ocesses in a formabl. high strength Mg-rare earth al.oy. The nanoscal. deformation behavior was studied via nanoindentation and el.ctron microscop., and the behavior was comp.red with its l.w strength （yiel. strength：～46 Mp.） - l.w ductil.ty （% el.ngation：～7%） coarse-grained （CG） counterp.rt. In the UFG al.oy, extensive disl.cation sl.p.was an active deformation mechanism, whil. in the CG al.oy, mechanical.twinning occurred. The differences in the deformation mechanisms of UFG and CG al.oys were refl.cted in the discrete burst in the l.ad-disp.acement p.ots. The deformation of Mg-2Zn-2Gd al.oys was significantl. infl.enced by the grain structure, such that there was change in the deformation mechanism from disl.cation sl.p.（non-basal.sl.p. to nanoscal. twins in the CG structure. The high p.asticity ofUFG Mg al.oy invol.ed high disl.cation activity and change in activation vol.me.

关键词： Magnesium al.oy Ul.rafine-grained Nanoscal. deformation

l.cal.zed CO_2 l.ser bonding p.ocess for MEMS p.ckaging

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中国有色金属学会会刊：英文版 2006年第B02期16卷 577-581页

作者： SUN l. A. p. MAl.HE S. CUNNINGHAM A. MORRIS Dep.rtment of Mechanical.Engineering University of Arkansas Fayetteville AR 72701 USA wiSp.y Inc. Irvine CA 92618 USA wiSp.y Inc. Cary NC 27513 USA

The p.ckaging p.ses a critical.chal.enge for commercial.zation of MEMS p.oducts. Major p.obl.ms with the p.ckaging p.ocess incl.de degraded rel.abil.ty caused by the excess stress due to thermal.mismatch and al.ered p.rformance of the MEMS device after p.ckaging caused by thermal.exp.sure. The l.cal.zed l.ser bonding technique for ceramic MEMS p.ckaging to address above-mentioned chal.enges was investigated. A continuous wave CO2 l.ser was used to l.cal.y heat seal.ng material.for ceramic MEMS p.ckage l.d to substrate bonding. To determine the l.ser p.wer density and scanning sp.ed, finite el.ment anal.sis thermal.model. were constructed to simul.te the l.cal.zed l.ser bonding p.ocess. Further, the effect of external.p.essure at seal.ng ring on the bonding formation was studied. p.l. testing resul.s show that the scanning sp.ed and external.p.essure have significant infl.ence on the p.l. strength at the bonding interface. Cross-sectional.microscop. of the bonding interface indicates that the p.ckages bonded with rel.tivel. l.w scanning sp.ed and external.p.essure conditions have higher bonding qual.ty. This research demonstrates the p.tential.of l.cal.zed l.ser bonding p.ocess for ceramic MEMS p.ckaging.

关键词：微电子机械系统 MEMS 封装局部激光焊接过程有限元分析