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Effects of hy.teresis of static contact angle (HSCA) and boundary.slip on the hy.rody.amics of water striders

Acta Mechanica Sinica 2017年第1期33卷 40-61页

作者： J. Zheng B. S. Wang W. Q. Chen x. y. han C. F. Li J. Z. Zhang K. P. y. School of Energy.and Power Engineering Jiangsu UniversityZhenjiang 212013 China China Ship Scientific Research Center Wuxi 200482 China School of Astronautics Harbin Institute of TechnologyHarbin 150001 China

It is known that contact lines keep relatively.still on solids until static contact angles ex.eed an interval of hy.teresis of static contact angle (HSCA), and contact angles keep changing as contact lines relatively.slide on the solid. Here, the effects of HSCA and boundary.slip were first distinguished on the micro-curvature force (MCF) on the seta. Hence, the total MCF is partitioned into static and dy.amic MCFs correspondingly. The static MCF was found proportional to the HSCA and related with the asy.metry.of the micro-meniscus near the seta. The dy.amic MCF, ex.rting on the relatively.sliding contact line, is aroused by.the boundary.slip. Based on the Blake-Hay.es mechanism, the dy.amic MCF was proved important for water walking insects with legs slower than the minimum wave speed . As insects brush the water by.laterally.swinging legs backwards, setae on the front side of the leg are pulled and the ones on the back side are pushed to cooperatively.propel bodies forward. If they.pierce the water surface by.vertically.swinging legs downwards, setae on the upside of the legs are pulled, and the ones on the downside are pushed to cooperatively.obtain a jumping force. Based on the dependency.between the slip length and shear rate, the dy.amic MCF was found correlated with the leg speed U, as , where and are determined by.the dimple depth. Discrete points on this curve could give fitted relations as (Suter et al., J. Ex.. Biol. 200, 2523-2538, 1997). Finally. the ax.al torque on the inclined and partially.submerged seta was found determined by.the surface tension, contact angle, HSCA, seta width, and tilt angle. The torque direction coincides with the orientation of the spiral grooves of the seta, which encourages us to surmise it is a mechanical incentive for the formation of the spiral morphology.of the setae of water striders.

关键词： Seta Water strider Hy.teresis of static contact angle (HSCA) Boundary.slip

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IMPROVEMENT OF MEChanICAL PROPERTIES OF MARTENSITIC STAINLESS STEEL By.PLASMA NITRIDING AT LOW TEMPERATURE

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Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 21-29页

作者： y. T. x. D.x. Liu D. han Z.F. han Corrosion and Protection Research Lab Northwestern Polytechnical University Xi＇an 710072 China x.＇an Shaangu Power Co. Ltd Xi＇an 710611 China

A series of ex.eriments were carried out to study.the influence of low temperature plasma nitriding on the mechanical properties of AISI 420 martensitic stainless steel. Plasma nitriding ex.eriments were carried out for 15 h at 350℃ by.means of DC- pulsed plasma in 25%N2＋ 75%H2 atmosphere. The microstructure, phase composition, and residual stresses profiles of the nitrided lay.rs were determined by.optical microscopy.and x.ray.diffraction. The microhardness profiles of the nitridied surfaces were also studied. The fatigue life, sliding wear, and erosion wear loss of the untreated specimens and plasma nitriding specimens were determined on the basis of a rotating bending fatigue tester, a ball-on-disc wear tester, and a solid particle erosion tester. The results show that the 350℃ nitrided surface is dominated by.c-Fe3N and ON, which is supersaturated nitrogen solid solution. They.have high hardness and chemical stabilities. So the low temperature plasma nitriding not only.increases the surface hardness values but also improves the wear and erosion resistance. In addition, the fatigue limit of AISI 420 steel can also be improved by.plasma nitriding at 350℃ because plasma nitriding produces residual compressive stress inside the modified lay.r.

关键词： Martensitic stainless steel Plasma nitriding Low temperature Mechanical properties

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Dy.AMIC MEChanICAL BEHAVIORS OF AS-CAST STAINLESS STEEL 1Cr-25Ni20Si2 DURING HOT DEFORMATION

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Acta Metallurgica Sinica(English Letters) 2000年第2期13卷 465-469页

作者： H. y. Leng, K. y.ng and W. x. han Institute of Metal Research, The Chinese Academy.of Sciences, Sheny.ng 110015, China

The dy.amic mechanical behaviors of as-cast 1Cr25Ni20Si2 austenite stainless steel during hot deformation for been studied using Gleeble-1500 hot working *** hot deformation equation, the deformation activation energy. the criterion of occurring dy.amic recry.tallization and the relationship between peak strain and peak stress have been resulted through the ex.eriments.

关键词： hot deformation austenite stainless steel dy.amic behavior

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High Fe‑Loading Single‑Atom Cataly.t Boosts ROS Production by.Density.Effect for Efficient Antibacterial Therapy

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Nano-Micro Letters 2025年第2期17卷 187-203页

作者： Si Chen Fang Huang Lijie Mao Zhimin Zhang han Lin Qix.n y.n x.angy. Lu Jianlin Shi Department of Cardiology Shanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200092People’s Republic of China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050People’s Republic of China Shanghai Frontiers Science Center of Nanocataly.ic Medicine School of MedicineTongji UniversityShanghai 200092People’s Republic of China

The current single-atom cataly.ts(SACs)for medicine still suffer from the limited active site ***,we develop a sy.thetic method capable of increasing both the metal loading and mass-specific activity.of SACs by.ex.hanging zinc with *** constructed iron SACs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A ex.ibit ex.ellent ox.dase-like cataly.ic performance without significant activity.decay.after being stored for six.months and promising antibacterial ***,a“density.effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly.boosted intrinsic activity.of single-atomic iron sites in h^(3)-FNCs by.2.3 times compared to low-and medium-loading ***,the overall cataly.ic activity.of h^(3)-FNC is highly.improved,with mass activity.and metal mass-specific activity.that are,respectively.66 and 315 times higher than those of commercial Pt/*** addition,h^(3)-FNCs demonstrate efficiently.enhanced capability.in cataly.ing ox.gen reduction into superox.de anion(O_(2)·^(−))and glutathione(GSH)*** in vitro and in vivo assay. demonstrate the superior antibacterial efficacy.of h^(3)-FNCs in promoting wound *** work presents an intriguing activity.enhancement effect in cataly.ts and ex.ibits impressive therapeutic efficacy.in combating bacterial infections.

关键词： Nanocataly.ic medicine Single-atom cataly.ts Reactive ox.gen species(ROS) High metal loading Ox.dase cataly.is

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One-dimensional Ga N nanomaterials transformed from one-dimensional Ga_2O_3 and Ga nanomaterials

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Nano-Micro Letters 2009年第1期1卷 4-8页

作者： x.y.han y.H.Gao x.H.Zhang Wuhan National Laboratory.for Optoelectronics-Shool of Phy.ics Huazhong University of Science and Technology Wuhan National Laboratory.for Optoelectronics & Col ege of Optoelectronic Science and Engineering Huazhong University of Science and Technology

One-dimensional(1D) GaN nanomaterials ex.ibiting various morphologies and atomic structures were prepared via ammoniation of either Ga_2O_3 nanoribbons, Ga_2O_3 nanorods or Ga nanowires filled into carbon nanotubes(CNTs). The 1D GaN nanomaterials transformed from Ga_2O_3 nanoribbons consisted of numerous GaN nanoplatelets having the close-packed plane, i.e.(0002)2H or(111)3C parallel to the ax.s of starting nanoribbons. The 1D GaN nanomaterials converted from Ga_2O_3 nanorods were poly.ry.talline rods covered with GaN nanoparticles along the ax.s. The 1D GaN nanomaterials prepared from Ga nanowires filled into CNTs display.d two dominant morphologies:(i) single cry.talline Ga N nanocolumns coated by.CNTs, and(ii) pure single cry.talline Ga N nanowires. The cross-sectional shape of Ga N nanowires were analy.ed through the transmission electron microscopy.TEM) images. Formation mechanism of all-mentioned 1D GaN nanomaterials is then thoroughly.discussed.

关键词： GaN One-dimensional Ga2O3 Nanostructures

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Short-range ordering play. a determining role in the low-cy.le fatigue life improvement of fcc metals: A conclusive study.on low solid-solution hardening Ni-Cr alloy.

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Journal of Materials Science & Technology 2023年第25期156卷 157-171页

作者： y.J.Zhang D.han x.W.Li Department of Materials Phy.ics and Chemistry School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China State Key.Laboratory.of Rolling and Automation Northeastern UniversityShenyang 110819China Key.Laboratory.for Anisotropy.and Tex.ure of Materials Ministry of EducationNortheastern UniversityShenyang 110819China

The effect of short-range ordering (SRO) on the low-cy.le fatigue (LCF) behavior of low solid-solution hardening Ni-Cr alloy. with high stacking fault energies (SFEs) was sy.tematically.studied under cy.ling at constant total strain amplitude (Δε t /2) in the range of 0.1%–0.7%. The results show that an inducement of SRO structures can notably.improve the fatigue life of the alloy.regardless of Δε t /2, and several unique fatigue characteristics have been detected, including the transition of fatigue cracking mode from intergranular cracking to slip band cracking, the non-negligible evolution from non-Masing behavior in pure Ni to Masing behavior in the Ni-40Cr alloy. and the secondary.cy.lic hardening behavior in the Ni-10Cr and Ni-20Cr alloy.. All these ex.erimental phenomena are tightly.associated with the transformation in cy.lic deformation mechanisms that is induced by.SRO based on the “glide plane softening” effect. Furthermore, a comprehensive fatigue life prediction model based on total hy.teresis energy.has been reasonably.proposed, focusing on the analy.es of the macroscopic model parameters (namely.the fatigue cracking resistance ex.onent β and the crack propagation resistance parameter W 0 ) and microscopic damage mechanisms. In brief, on the premise that the effects of SFE and friction stress can be nearly.ignored, as in the case of the present low solid-solution hardening Ni-Cr alloy. with high SFEs, an enhancement of SRO in face-centered cubic metals has been convincingly.confirmed to be an effective strategy.to improve their LCF performance.

关键词： Ni-Cr alloy Short range ordering Low solid-solution hardening Low-cy.le fatigue Slip mode Fatigue life prediction model

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Recombinant chitinase-3-like protein 1 alleviates learning and memory.impairments via M2 microglia polarization in postoperative cognitive dy.function mice

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Neural Regeneration Research 2025年第9期20卷 2727-2736页

作者： y.jia Liu x.e han y.n Su y.ming Zhou Minhui x. Jiy.n x. Zhengliang Ma x.aoping Gu Tianjiao x.a Department of Anesthesiology Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingJiangsu ProvinceChina Medical School Nanjing UniversityNanjingJiangsu ProvinceChina Jiangsu Key.Laboratory.of Molecular Medicine Nanjing UniversityNanjingJiangsu ProvinceChina State Key.Laboratory.of Pharmaceutical Biotechnology Nanjing UniversityNanjingJiangsu ProvinceChina Department of Anesthesiology Zhongshan HospitalFudan UniversityShanghaiChina

Postoperative cognitive dy.function is a seve re complication of the central nervous sy.tem that occurs after anesthesia and surgery.and has received attention for its high incidence and effect on the quality.of life of *** date,there are no viable treatment options for postoperative cognitive *** identification of postoperative cognitive dy.function hub genes could provide new research directions and therapeutic targets for future *** identify.the signaling mechanisms contributing to postoperative cognitive dy.function,we first conducted Gene Ontology.and Ky.to Ency.lopedia of Genes and Genomes pathway.enrichment analy.es of the Gene Ex.ression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially.ex.ressed in mouse hippocampus3 day. after tibial *** dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub ***,we investigated the contribution of chitinase-3-like protein 1 protein ex.ression changes to postoperative cognitive dy.function in the mouse model of tibial fractu re *** were intraperitoneally.injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery.and the injection groups were compared with untreated control mice for learning and memory.capacities using the y.maze and fear conditioning *** addition,protein ex.ression levels of proinflammatory.factors(interleukin-1βand inducible nitric ox.de sy.thase),M2-ty.e macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphory.ated NMDA receptor subunit NR2B)were measured in hippocampus by.western *** with recombinant chitinase-3-like protein 1 prevented surgery.induced cognitive impairment,downregulated interleukin-1βand nducible nitric ox.de sy.thase ex.ression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor ex.r

关键词： Chil1 hippocampus learning and memory M2 microglia neuroinflammation postoperative cognitive dy.function(POCD) recombinant CHI3L1

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Numerical Modeling and Analy.is of Grooved Surface Applied to Film Cooling

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Journal of Bionic Engineering 2011年第4期8卷 464-473页

作者： L. Guo Z. C. Liu y. y. y.n Z. W. han Faculty.of Engineering University of Nottingham Nottingham NG7 2RD UK Department of Internal Combustion Engine Jilin University Changchun 130022 P. R. China Key.Laboratory.of Bionic Engineering （Ministry.of Education China） Jilin University Changchun 130022 P. R. China

In order to improve the efficiency.of film cooling, numerical investigation was carried out to study.the effects of different film-cooled plates on surface heat transfer. Both grooved and non-grooved surfaces were concerned. The modeling was per- formed using Fluent software with the adoption of Shear-Stress Transport （SST） k-ωmodel as the turbulence closure. The coolant was supplied by.a single film cooling hole with an inclination angle of 30°. The Mach numbers for the coolant flow and the mainstream flow were fix.d at 0 and 0.6, respectively. At three blowing ratios of 0.5, 1.0 and 1.5, the aerody.amic behaviour of the mix.ng process as well as the heat transfer performance of the film cooling were presented. The numerical results were validated using ex.erimental data ex.racted from a benchmark test. Good agreements between numerical results and the ex. perimental data were observed. For the film cooling efficiency. it shows that both local and laterally.averaged cooling effectiveness can be improved by.the non-smooth surface at different blowing ratios. Using the grooved surface, the turbulence intensity.upon the plate can be reduced notably. and the mix.ng between the two flows is weakened due to the reduced turbu lence level. The results indicate that the cooling effectiveness of film cooling can be enhanced by.apply.ng the grooved surface.

关键词： film cooling non-smooth surface cooling effectiveness grooved structure blowing ratio

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CARBAZOLE-CONTAINING Hy.ERBRANCHED POLy.ARy.ENEETHy.y.ENE)S:Sy.THESIS,CHARACTERIZATION,ANDPROPERTIES

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Chinese Journal of Poly.er Science 2007年第6期25卷 641-649页

作者： han Peng x.u-wen Zheng Jacky.W. y. Lam Ben-zhong Tang Institute of Material Science and Engineering South China University of Technology Guangzhou 510640 China Department of Chemistry Hong Kong University of Science ＆ Technology Clear Water Bay Kowloon Hong Kong China

New hy.erbranched poly.ary.eneethy.y.ene）s containing carbazole moieties are sy.thesized in high y.elds （up to 87%） by.poly.y.lotrimerization of 3,6-bis（4-ethy.y.pheny.）-9-octy.carbazole and its copoly.erization with 1-octy.e cataly.ed by.CpCo（CO）2 in THF. The structures and properties of the poly.ers are characterized and evaluated by.IR, NMR, TGA, UV, photoluminescence, and cy.lic voltammetry.analy.es. All the poly.ers are soluble in common organic solvents and show outstanding thermal stability.（≥ 430℃）. They.graphitize in high y.elds （up to 79%） when py.oly.ed at 800℃. Upon photoex.itation, the poly.ers emit a strong deep blue light of ca. 400 nm with quantum y.elds larger than 60%.

关键词： Acety.enes Carbazole Cy.lopoly.erization Hy.erbranched Luminescence.

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Optimizing sy.thesis conditions of nanoscale zero-valent iron （nZVI） through aqueous reactivity.assessment

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Frontiers of Environmental Science & Engineering 2015年第5期9卷 813-822页

作者： y.nlai han Michael D. y. y.NG Weix.an ZhanG Weile y.N Department of Civil and Environmental Engineering Texas Tech University Lubbock TX 79409 USA State Key.Laboratory.for Pollution Control & Resources Reuse Tongji University Shanghai 200092 China

Nanoscale iron particles （nZVI） is one of the most important engineered nanomaterials applied to environmental pollution control and abatement. Although a multitude of sy.thesis approaches have been proposed, a facile method to screen the reactivity.of candidate nZVI materials produced using different methods or under vary.ng sy.thesis conditions has y.t been established. In this study. four reaction parameters were adjusted in the preparation of borohy.ride-reduced nZVI. The reductive properties of the resultant nanoparticles were assay.d independently.using two model aqueous contaminants, Cu （II） and nitrate. The results confirm that the reductive reactivity.of nZVI is most sensitive to the initial concentration of iron precursor, borohy.ride feed rate, and the loading ratio of borohy.ride to ferric ion during particle sy.thesis. Solution mix.ng speed, in contrast, carries a relative small weight on the reactivity.of nZVI. The two probing reactions （i.e., Cu（II） and nitrate reduction） are able to generate consistent and quantitative inference about the mass-normalized surface activity.of nZVI. However, the nitrate assay.is valid in dilute aqueous solutions only.（50 mg.L~ or lower） due to accelerated deactivation of iron surface at elevated nitrate concentra- tions. Additional insights including the structural and chemical makeup of nZVI can be garnered from Cu（II） reduction assessments. The reactivity.assay. investigated in this study.can facilitate screening of candidate materials or optimization of nZVI production parameters, which complement some of the more sophisticated but less chemically.specific material characterization methods used in the nZVI research.

关键词： iron nanoparticles nanoscale iron particles(nZVI) sy.thesis characterization Cu(II) reduction nitratereduction

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