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Interface constitutive modeling and failure propagation mechanisms of integrated polymer-metal hybrid (PMH) structures

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cOMPOSITE STRUcTURES 2023年第1期306卷

作者： Pan, Wenfeng Sun, Lingyu Mu, Along Lv, Wenting Beihang Univ Sch Transportat Sci & Engn 37 Xueyuan Rd Beijing 100191 Peoples R China Beihang Univ Beijing Key Lab High efficient Power Transmiss & S 37 Xueyuan Rd Beijing 100191 Peoples R China Beijing Hangshu Vehicle Data Res Inst Co LTD Beijing 100062 Peoples R China

This paper studies the polymer-metal hybrid (PMH) structures, formed by direct injection over-molding the glass fiber-reinforced polymer (GFRP) composite on the surface of high-strength steel (HSS), which integrate the advantage of HSS and GFRP, and have been applied in the lightweight design of vehicles. However, the existence of an interface between GFRP and HSS weakens the ultimate carrying capacity of the overall PMH structures, and hence, the interface needs further improvement. First, five kinds of PMH specimens with different micro -interlock features were designed and fabricated, and the corresponding interfacial tensile and shear strength (oIc and ocII) and fracture toughness (GcI and GcII) were characterized experimentally. An interface constitutive model suitable for describing different mechanical interlocks was established, and the general program for parameter identification was developed in a finite element code. Using this model, the crack evolution mecha-nisms of PMH structures under tensile and bending loading were revealed. Finally, the micro-macro mapping rule between the interlock features and the ultimate loading of overall PMH structures is proposed. These results are conducive to the lightweight design and performance prediction of PMH structures.

关键词： A Hybrid B Interface c Damage mechanics E Surface treatments

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A metal-based microencapsulated phase change material (MEPcM) with high thermal reliability and its performance regulation

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cOMPOSITES PART A-APPLIED ScIENcE AND MANUFAcTURING 2023年第1期168卷

作者： Lei, Ke Wang, Shuo Wang, Zhiyuan Wang, Hao Zou, Deqiu Ningbo Univ Fac Maritime & Transportat Ningbo 315211 Zhejiang Peoples R China China MCC17 Grp Co Ltd Maanshan 243000 Anhui Peoples R China

An ideal microencapsulated phase change material (MEPcM) should have the characteristics of high thermal reliability, low supercooling degree and high thermal conductivity. Herein, we report a novel metal-based MEPcM with high thermal reliability based on "double-layer coating, sacrificial inner layer" method, solving the problem of MEPcM cracking caused by thermal expansion. Furthermore, synergistic regulation of super-cooling and thermal conductivity was studied by loading nanoparticles into shell. The results showed that the supercooling degree was reduced by 81.8% when the nano-co loading was 0.8%, which achieved the best supercooling suppression effect so far, and the properties kept stable after 200 thermal cycles. Furthermore, thermal performance of MEPcM loaded/unloaded with 0.8% co was compared. The results demonstrated that the MEPcM loaded with 0.8% co showed a 12.6% increase in thermal conductivity and a faster thermal response rate. This paper provides a novel strategy for the preparation and performance regulation of metal-based MEPcM.

关键词： Microencapsulated phase change material (MEPcM) A Metal-matrix composites (MMcs) B Thermal properties c Micro-mechanics

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Efficiently Light-Driven Nonoxidative coupling of Methane on Ag/ NaTaO3: A case for Molecular-Level Understanding of the coupling Mechanism

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AcS cATALYSIS 2023年第3期13卷 2094-2105页

作者： Zhang, Jiangjie Shen, Jinni Li, Dongmiao Long, Jinlin Gao, Xiaochen Feng, Wenhui Zhang, Shiying Zhang, Zizhong Wang, Xuxu Yang, Weimin Fuzhou Univ Coll Chem State Key Lab Photocatalysis Energy & Environm Fuzhou 350106 Peoples R China SINOPEC Shanghai Res Inst Petrochem Technol State Key Lab Green Chem Engn & Ind Catalysis Shanghai 201208 Peoples R China Changsha Univ Hunan Prov Key Lab Appl Environm Photocatalysis Changsha 410022 Peoples R China Qingyuan Innovat Lab Quanzhou 362801 Peoples R China

Metal-decorated oxide semiconductors are overwhelming photocatalysts for nonoxidative coupling of methane (NOcM). However, the overall NOcM mechanism remains an unopened black box, which hinders the design of high-performance catalysts. Herein, we systematically studied a series of noble metal (Ag, Au, Pt, Pd, cu, and Ni)-decorated oxides (NaTaO3, caTiO3, LiNbO3, and TiO2) for NOcM. We proposed that the active sites for H abstraction and c-c coupling of cH4 are spatially separated. Specifically, NaTaO3 only completes the initial H abstraction of cH4 activation, while metal nanoparticles are responsible for the final c-c coupling. Noble metals dominate NOcM by significantly decreasing the energy barrier of cH4 dissociation and promoting c-c coupling. Among various metals, Ag is preferential for the weak adsorption of center dot cH3 intermediates and subsequent metal-induced cc coupling. This contributes to Ag/NaTaO3 the highest c2H(6) yield of 194 mu mol g-1 h(-1) and stoichiometric H-2 with 11.2% quantum efficiency. This work provides a molecular-level insight into the cH4 coupling mechanism on metal-decorated photocatalysts.

关键词： photocatalytic methane c H activation c coupling mechanism

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The relationship between electric processing condition and microstructure in the solidification of multicomponent oxides

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cERAMIcS INTERNATIONAL 2023年第12期49卷 20096-20103页

作者： Bhagurkar, Ashutosh Qin, Rongshan Open Univ Sch Engn & Innovat Walton Hall Milton Keynes MK7 6AA England

Systematic characterization for the relationship between the electropulse processing conditions and microstructure has been carried out in the present work. It is found that electropulse can refine porosity and alter grain morphology considerably. A processing with optimum electropulsing parameters can reduce over 75% volume fraction of porosity and more than 70% average pore diameter in comparison with that of reference sample without electric treatment. Electric current treatment promotes the growth of dendrites with smaller thickness of primary arms dendrite and prevents the liquid entrapping between the growing solid grains. The former is caused by the effect of electricity-enhanced kinetic mobility on the radius of curvature at the tip of dendrite. The latter is attributed to the effects of electric thermodynamics on the microstructural formation such as the enhanced connectivity of conductive phase. The microstructures obtained by electropulsing treatment are favourable for heat conduction, structural strength and crack prohibition. However, the excess pulse frequency and pulse width can generate unwanted heat to counteract electric effect. The research reveals the relationship between electric processing conditions and microstructure in a perfectly controversial solidification condition in oxide materials to that of the metals and alloys. The results confirm from the opposite side the validity of the pulsated solidification.

关键词： A Grain growth B Porosity c Thermal conductivity E Refractories

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Gradient evolution in graphene reinforced carbon/carbon composites

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cARBON 2023年 206卷 295-302页

作者： Duan, Ke Li, Ziyong chen, Juzheng Li, Li Hu, Yujin Zhang, Yang Zhang, Jianwei Lu, Yang Huazhong Univ Sci & Technol Sch Mech Sci & Engn Wuhan 430074 Peoples R China City Univ Hong Kong Dept Mech Engn Shenzhen 999077 Peoples R China City Univ Hong Kong Shenzhen Res Inst Micro Nanomfg Shenzhen 518057 Peoples R China Natl Univ Def Technol Coll Aerosp Sci & Engn Dept Mat Sci & Engn Changsha 410073 Peoples R China City Univ Hong Kong Chengdu Res Inst Chengdu 610200 Peoples R China Univ Hong Kong Dept Mech Engn Pokfulam Rd Hong Kong Peoples R China Yanshan Univ Ctr High Pressure Sci CHiPS State Key Lab Metastable Mat Sci & Technol Qinhuangdao 066004 Peoples R China

Graphene-guided carbonization is an effective route to achieve carbon-reinforcement/carbon matrix (c/c) composites with high mechanical performance at lower energy consumption, due to the reduced anneal temperatures required. However, the underlying microstructure evolution mechanisms associated with this phenomenon remain mysterious. Here, through large-scale reactive molecular dynamics simulations, we revealed a "gradient evolution"effect occurred in carbon matrix, which gives rise to the formation of additional stacked graphene layers in the vicinity of the original introduced graphene sheet. Two microstructure evolution pathways correlated with such effect are identified: specialIntscript near the introduced graphene surface, one or two graphene-like layers rapidly developed due to the growth of curved carbon nanosheets via edge-crosslinking, specialIntscript away from the graphene surface, graphene-like layers progressively promoted by reconstruction of dissociated disordered carbon nanosheets. As a result, the graphene reinforced c/c composites exhibit significantly improved tensile modulus , strength in comparison to those without graphene. Our study not only provides fundamental insights into the graphene-induced carbonization phenomenon, but also emphasizes the unprecedented potential of graphene as an excellent reinforcement for c/c composites.

关键词： Gradient evolution effect c c composites Graphene Microstructure evolution

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Multigenerational effects of co-exposure to dimethylarsinic acid and polystyrene microplastics on the nematode caenorhabditis elegans

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ENVIRONMENTAL ScIENcE AND POLLUTION RESEARcH 2023年第36期30卷 85359-85372页

作者： Muller, Larissa Josende, Marcelo Estrella Soares, Gabriela correa Monserrat, Jose Maria Ventura-Lima, Juliane Univ Fed Rio Grande FURG Inst Ciencias Biol ICB Av ItaliaKm 08 BR-96201900 Rio Grande RS Brazil Programa Posgrad Ciencias Fisiol FURG Rio Grande RS Brazil

In the current study, we assessed the impact of DMA (dimethylarsinic acid) and MPs (microplastics) interactions in c. elegans over the course of five generations. We found that the redox state of the organisms changed over generations as a result of exposure to both pollutants. From the third generation onward, exposure to MPs reduced GST activity, indicating reduced detoxifying abilities of these organisms. Additionally, dimethylarsinic exposure decreased the growth of organisms in the second, fourth, and fifth generations. In comparison to isolated pollutants, the cumulative effects of co-exposure to DMA and MPs seem to have been more harmful to the organisms, as demonstrated by correlation analysis. These findings demonstrate that DMA, despite being considered less hazardous than its inorganic equivalents, can still have toxic effects on species at low concentrations and the presence of MPs, can worsen these effects.

关键词： c elegans Multigenerational Dimethylarsinic acid Microplastic co-exposure Ecotoxicology

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Experimental investigation on the performance of circumferential corrugations helical tubes based on thermodynamic and economic analyses

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PROcEEDINGS OF THE INSTITUTION OF MEcHANIcAL ENGINEERS PART c-JOURNAL OF MEcHANIcAL ENGINEERING ScIENcE 2023年第6期237卷 1499-1509页

作者： Rezaei, Razieh Abbasgholi Urmia Univ Dept Mech Engn Orumiyeh 571794451 Iran

In this study, the impact of applying circumferential corrugations on the helical tubes is experimentally probed and frictional and thermal performance of the circumferentially corrugated helical tubes are studied. For this purpose, water flow rates at 2, 3, 4, 5, and 6 L/min with 25 degrees c enter assumed helical tubes. These tubes are exposed to constant heat flux of 800 W, produced by heater wire evenly wrapped around them. corrugations with three different pitches and heights of 6, 9, and 12 cm, and 0.8, 1, and 1.2 mm are considered, respectively. The results revealed that in comparison to smooth helical tube, the increment of the corrugation height at constant corrugation pitch and decrement of corrugation pitch at constant corrugation height improves the pressure drop to the maximum of 2.054 and 1.488 and also improves heat transfer coefficient to the maximum of 1.702 and 1.456 at Reynolds of 4687. Moreover, from the Benefit-cost Ratio point of view, at Re = 2147 applying corrugation height of 1.2 mm at corrugation pitch of 6 cm is 1.27 times more economical than the smooth helical ones.

关键词： circumferential corrugations helical tubes Reynolds number frictional and thermal performance B c R

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Tuning the active interface in TiO2 thin film-based memristors prepared by PVD

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cERAMIcS INTERNATIONAL 2023年第9期49卷 14563-14570页

作者： Kleiman, A. Peralta, c. Abinzano, I. Vega, D. Halac, E. Marques, A. Acha, c. Univ Buenos Aires Fac Ciencias Exactas & Nat Dept Fis Ciudad Univ Pab 1 RA-1428 Buenos Aires Argentina Univ Buenos Aires CONICET Inst Fis Plasma INFIP Ciudad Univ Pab 1 RA-1428 Buenos Aires Argentina Comis Nacl Energia Atom Dept Fis Mat Condensada Gerencia Invest & Aplicac Ave Gral Paz 1499 RA-1650 San Martin Buenos Aires Argentina Univ Nacl San Martin Escuela Ciencia & Tecnol San Martin Buenos Aires Argentina Univ Buenos Aires CONICET Inst Fis Buenos Aires IFIBA Ciudad Univ Pab 1 RA-1428 Buenos Aires Argentina

In this work, the resistive switching and the conducting mechanism of forming-free TiO2 thin films between Ti and Pt electrodes were investigated. The devices were fabricated employing Physical Vapor Deposition (PVD) methods. Ti/TiO2 films were prepared with a cathodic arc system while Pt contacts were deposited by sputtering. Different TiO2 structures (amorphous, anatase, rutile) and thicknesses (60-240 nm) were analyzed through current-voltage (IV) characteristic curves and resistance hysteresis switching loops (RHSL). Amorphous TiO2 produced more conductive devices, with a circulation path, both in IV and RHSL, opposite to that of crystalline TiO2. From these results, the TiO2-Ti was found to be the active interface in devices based on the amorphous phase, while the Pt-TiO2 interface was the active one for anatase and rutile. The results showed that the selection of the TiO2 growth conditions allows to tune which will be the active interface that produces the resistive changes by choosing the structure of the films, as well as the degree of non-linearity of the electrical conduction of the device by varying the thickness of the TiO2 (anatase) film.

关键词： A Films c Electrical properties D TiO2 Resistive switching

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Effects of Al2O3 addition on microstructure and luminescence of transparent germanosilicate glass-ceramics with incorporated spinel Ga-oxide nanocrystals

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cERAMIcS INTERNATIONAL 2023年第2期49卷 1657-1666页

作者： Golubev, N. V. Ignat'eva, E. S. Lipatiev, A. S. Ziaytdinova, M. Z. Lapushkin, G. I. Sigaev, V. N. Poliakov, M. V. Paleari, A. Lorenzi, R. Mendeleev Univ Chem Technol Russia PD Sarkisov Int Lab Glass based Funct Mat 9 Miusskaya Sq Moscow 125047 Russia Russian Acad Sci PN Lebedev Phys Inst 53 Leninskii Pr Moscow 119991 Russia Moscow Inst Phys & Technol MIPT 9 Inst Skiy Per Dolgoprudnyi 141700 Russia Russian Acad Sci Inst Nanotechnol Microelect 32A Leninsky Prospekt Moscow 119991 Russia Univ Milano Bicocca Dept Mat Sci Via Cozzi 55 I-20125 Milan Italy

Ga-oxide spinel nanocrystals are wide band gap systems, which can be incorporated in a glass matrix by phase separation mechanisms. In suitable conditions, this kind of processes can give rise to transparent nanostructured glass-ceramics with UV excitation and luminescence properties potentially interesting in several technological areas. Nanophase size dispersion and volume fraction have been demonstrated to be controllable, at some extent, by suitable thermal treatments for nucleation and nano-crystallization in low-alkali gallium germanosilicate system. Here we report the results on the role of Al2O3 additions on the microstructure and optical response of the glass-ceramics fabricated in this system. Data of differential scanning calorimetry, X-ray diffraction, trans-mission electron microscopy, absorption and fluorescence spectroscopy show that Al2O3 addition, up to 4.5 mol %, turns out to have a considerable impact on the size and number density of precipitated nanocrystals, which are solid solutions of & gamma;-Ga2-xAlxO3 resulting from the partial incorporation of Al3+ ions into the crystalline phase. We show that the use of Al2O3 as an additive in the composition of gallium germanosilicates facilitates glass melting and leads to glass-ceramics with significantly modified photoluminescence characteristics such as decay lifetime and integrated intensity of light emission. The possible reasons are discussed.

关键词： c optical properties D Glass ceramics Spinels

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Ammoniated straw incorporation coupled with N management synergistically enhanced soil structure and crop productivity in a desert oasis farmland

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LAND DEGRADATION & DEVELOPMENT 2023年第16期34卷 4977-4989页

作者： Zhou, Lifeng chang, Wenlong Yang, Rong Feng, Hao Yang, Qiliang Kunming Univ Sci & Technol Fac Modern Agr Engn Kunming Peoples R China Chinese Acad Sci Northwest Inst Ecoenvironm & Resources Linze Inland River Basin Res Stn Chinese Ecosyst Res Network Lanzhou Peoples R China Chinese Acad Sci & Minist Water Resources Inst Soil & Water Conservat State Key Lab Soil Eros & Dryland Farming Loess P Yangling Peoples R China

Straw return is the simplest and the most economic method to improve soil structure. Slow decomposition rate limits straw return in sandy fields, which has becoming one of the obstacles in sandy land reclamation. Ammonification of straw before return accelerates straw decomposition, but it requires the use of extra N fertilizer, however, little is known about N fertilizer management in fields with ammoniated straw incorporation. So, a 3-year field experiment was conducted with different proportions of N fertilizer aimed to maize straw ammonification and field broadcasting, and evaluated straw decomposition proportion, straw N release, soil organic carbon content, soil aggregates, soil water and N availability, and grain yield. Total N application rate was 300 kg per hectare, with five N input amounts for straw per hectare ammonification: 0 (SN0), 40 (SN40), 80 (SN80), 120 (SN120), and 160 (SN160) kg, and the rest of N broadcasted in soil during maize growing season. Ammonification accelerated straw decomposition and N release, and these effects showed no significant difference between SN80, SN120, and SN160. After straw decomposition for 150 days, the decomposition proportion was 62.1%, 53.0%, and 39.2% in SN80, SN40, and SN0, respectively. After 3 years of straw return, SN80 exhibited a significantly higher mean weight diameter of soil aggregates (35.6% higher), organic carbon content (18.4% higher), water-holding capacity (17.4% higher), and soil water storage (17.2% higher) than SN0. Additionally, SN80 and SN120 showed the most significant effect on "N slow-release" in soil. The above effects resulted with more available soil water and N used for crop growth, and increased grain yields (18.1% higher) and water use efficiency (18.6% higher) in SN80, compared with SN0. Hence, we conclude that a proper N allocation between straw and soil can synergistically enhance soil structure and crop productivity in sandy farmlands. This founding would provide scientific and te

关键词： c N ratio land reclamation sandy soil soil structure straw ammonification

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