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Simultaneous measurement of thermal conductivity, heat capacity, and interfacial thermal conductance by leveraging negative delay-time data in time-domain thermoreflectance

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Progress in Natural Science:Materials International 2025年第2期35卷 375-384页

作者： Mingzhen Zhang Tao Chen Ao Zeng Jialin Tang Ruiqiang Guo Puqing Jiang School of Energy and Power Engineering Huazhong University of Science and Technology Thermal Science Research Center Shandong Institute of Advanced Technology Institute of Advanced Technology Shandong University

Time-domain thermoreflectance（TDTR） is a widely used technique for characterizing the thermal properties of bulk and thin-film materials. Traditional TDTR analyses typically focus on positive delay time data for fitting,often requiring multiple-frequency measurements to simultaneously determine thermal conductivity and heat capacity. However, this multiple-frequency approach is cumbersome and may introduce potential errors due to practical challenges to ensure consistent measurements across different frequencies. In this study, we propose a novel solution to these challenges by harnessing the underexplored negative delay time data in TDTR. By integrating these data points, we offer a streamlined, single-frequency method that simultaneously measures thermal conductivity, heat capacity, and interfacial thermal conductance for both bulk and thin-film materials, enhancing measurement efficiency and accuracy. We demonstrate the effectiveness of this method by measuring several bulk samples including sapphire, silicon, diamond, and Si0.992Ge0.008, and several thin-film samples including a 1.76-μm-thick gallium nitride（Ga N） film epitaxially grown on a silicon substrate, a 320-nm-thick gallium oxide（ε-Ga2O3） film epitaxially grown on a silicon carbide substrate, and a 330-nm-thick tantalum nitride（Ta N） film deposited on a sapphire substrate, all coated with an aluminum（Al） transducer layer on the surface. Our results show that the new method accurately determines the thermal conductivity and heat capacity of these samples as well as the Al/sample interfacial thermal conductance using a single modulation frequency, except for the Si0.992Ge0.008sample. This study sheds light on the untapped potential of TDTR, offering a new, efficient, and accurate avenue for thermal analysis in material science.

关键词： Heat capacity Negative delay time TDTR Thermal conductivity Time-domain thermoreflectance

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Microstructure evolution and strengthening mechanism of high -performance powder metallurgy TA15 titanium alloy by hot rolling

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1426-1436页

作者： Ying Gao Ce Zhang Jiazhen Zhang Xin Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsInstitute for Advanced Ma-terials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China National Engineering Research Center for Advanced Rolling Technology National Engineering Research Center for Flat Rolling EquipmentInstitute of Engin-eering TechnologyUniversity of Science and Technology BeijingBeijing 100083China

Hot deformation of sintered billets by powder metallurgy(PM)is an effective preparation technique for titanium alloys,which is more significant for high-alloying *** this study,Ti–6.5Al–2Zr–Mo–V(TA15)titanium alloy plates were prepared by cold press-ing sintering combined with high-temperature hot *** microstructure and mechanical properties under different process paramet-ers were *** microscope,electron backscatter diffraction,and others were applied to characterize the microstructure evolution and mechanical properties strengthening *** results showed that the chemical compositions were uniformly dif-fused without segregation during sintering,and the closing of the matrix craters was accelerated by increasing the sintering *** block was hot rolled at 1200℃ with an 80%reduction under only two passes without *** strength and elongation of the plate at 20–25℃ after solution and aging were 1247 MPa and 14.0%,respectively,which were increased by 24.5%and 40.0%,respect-ively,compared with the as-sintered alloy at 1300℃.The microstructure was significantly refined by continuous dynamic recrystalliza-tion,which was completed by the rotation and dislocation absorption of the substructure surrounded by low-angle grain *** hot rolling combined with heat treatment,the strength and plasticity of PM-TA15 were significantly improved,which resulted from the dense,uniform,and fine recrystallization structure and the synergistic effect of multiple slip systems.

关键词： elemental powder powder metallurgy titanium alloy hot rolling strength and plasticity

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Role of Stretching-induced Crystallization on Mesoscale Morphology Transition of UHMWPE during Hot Stretching

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Chinese Journal of Polymer Science 2025年第1期43卷 188-198,I0013页

作者： Kai Huang Jia-Jia Mo Wen-Jing Shi Shi-Tong Wang Hong-Hui Shi Chun-Guang Shao Chun-Tai Liu Bao-Bao Chang National Engineering Research Center for Advanced Polymer Processing Technology Zhengzhou UniversityZhengzhou450002China

In this work,a morphology transition mode is revealed in ultra-high molecular weight polyethylene(UHMWPE)when stretching at 120℃:moving from the slightly deformed region to the necked region,the morphology transfers from small spherulites to a mixture of transcrystalline and enlarged spherulites,and finally to pure transcrystalline;meanwhile,the lamellae making up the transcrystalline or spherulite were fragmented into smaller ones;spatial scan by wide-angle X-ray scattering(WAXS)and small angle X-ray scattering(SAXS)revealed that the crystallinity is increased from 25.3%to 30.1%and the crystal orientation was enhanced greatly,but the lamellae orientation was quite *** rise of enlarged spherulites or a mixture of transcrystalline and spherulites can also be found in UHMWPE stretched at 140 and 148℃,whereas absent in UHMWPE stretched at 30℃.In situ WAXS/SAXS measurements suggest that during stretching at 30℃,the crystallinity is reduced drastically,and a few voids are formed as the size increases from 50 nm to 210 nm;during stretching at 120℃,the crystallinity is reduced only slightly,and the kinking of lamellae occurs at large Hencky strain;during stretching at 140 and 148℃,an increase in crystallinity with stretching strain can be found,and the lamellae are also *** the microstructure and morphology transition into consideration,a mesoscale morphology transition mode is proposed,in the stretching-induced crystallization the fragmented lamellae can be rearranged into new supra-structures such as spherulite or transcrystalline during hot stretching.

关键词： UHMWPE Stretching induced crystallization Lamellae fragmentation Mesoscale structural transition

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Processing,microstructure,mechanical properties,and hydrogen embrittlement of medium-Mn steels:A review

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Journal of Materials Science & technology 2024年第34期201卷 44-57页

作者： Yan Zhang Qizhe Ye Yu Yan Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Corrosion and Protection Center Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China

As a representative of steels available in the market,medium-Mn steel shows vast application prospects in lightweight automobile *** review details the research progress of medium-Mn steels,focusing on the following *** roles of common adding elements,rolling technologies,and various heat treatments on the microstructure and mechanical properties of medium-Mn steel are analyzed,thus pro-viding references for designing tailored medium-Mn steel with excellent *** that hydrogen embrittlement is a challenge faced in the development of high-strength steel,the hydrogen embrittlement behavior of medium-Mn steel is also discussed,particularly emphasizing the influence of microstructure,hydrogen concentration,strain,***,practical strategies to improve resistance to hydrogen embrittlement are ***,this review provides prospects for the development and research prospects of medium-Mn steel.

关键词： Medium-Mn steel Composition design Rolling technologies Heat treatments Hydrogen embrittlement

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Enrichment of anammox biomass during mainstream wastewater treatment driven by achievement of partial denitrification through the addition of bio-carriers

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Journal of Environmental Sciences 2024年第3期137卷 181-194页

作者： Yuqing Ma Bo Wang Xiaodi Li Shuo Wang Wen Wang Yongzhen Peng National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen ***,how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application,especially in mainstream wastewater *** this study,the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of *** using ordinary activated sludge,a sequencing batch reactor(SBR)followed by an up-fow anaerobic sludge bed(UASB)was operated at 25±2℃ for 214 *** long-term operation was divided into five phases,in which SBR and UASB were started-up in Phases I and II,*** eliminating oxygen and adjusting the infow ratios in Phases III-V,advanced nitrogen removal was achieved with the effuent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5%in Phase *** in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and ***,16S rRNA high-throughput sequencing analysis revealed that Candidatus Brocadia was enriched from below the detection limit to in biofilms(0.4%in SBR,2.2%in UASB)and the foc sludge(0.2%in SBR,1.3%in UASB),while Thauera was mainly detected in the foc sludge(8.1%in SBR,8.8%in UASB),which might play a key role in partial ***,this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers,which will improve large-scale application of anammox processes in mainstream wastewater treatment.

关键词： Enrichment Anammox biomass Bio-carriers Partial denitrification Mainstream wastewater

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Significant influence of trace Li on the mechanical properties, corrosion behavior, and antibacterial properties of biodegradable Zn–4Cu alloys

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Journal of Materials Science & technology 2023年第20期151卷 245-257页

作者： Shiyu Huang Heng Liu Yanjing Su Lijie Qiao Yu Yan Beijing Advanced Innovation Center for Materials Genome Engineering Corrosion and Protection CenterInstitute for Advanced Materials and TechnologyUniversity of Science and TechnologyBeijing 100083China

In this work,trace Li was introduced to strengthen Zn–4Cu *** results indicated that trace amounts of Li contributed to a significant increase in strength,resulting in an acceptable loss of elongation at ***,Li in the form of LiZn_(4) led to more intensive galvanic corrosion,which accelerated the early corrosion *** release of a large amount of Zn^(2+),caused by the addition of Li,affected the phase composition of the main Zn-containing corrosion ***,the inhibition effect of the alloy on Staphylococcus aureus(***)was enhanced by the addition of 0.02 wt.%Li.

关键词： Microalloying Zn-Cu alloy LiZn_(4)/Zn pairs Biodegradable mechanism SKPFM

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Enhanced strength and ductility in a powder metallurgy Ti material by the oxygen scavenger of CaB_(6)

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Journal of Materials Science & technology 2023年第6期137卷 132-142页

作者： Yu Pan Jinshan Zhang Jianzhuo Sun Yanjun Liu Ce Zhang Rui Li Fan Kuang Xinxin Wu Xin Lu Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Engineering TechnologyNational Engineering Research Center for Advanced Rolling TechnologyUniversity of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167China

The challenge of producing a high-ductility titanium(Ti)material using inexpensive high-oxygen hydride-dehydride(HDH)Ti powder is hereby addressed by the incorporation of CaB_(6)*** oxygen-scavenging behavior,microstructure evolution,mechanical behavior and improvement mechanism were systematically investigated.A continuous TiO_(2)oxide layer with a thickness of approximately 9.3 nm is presented on the HDH Ti powder *** oxide layer will dissolve into Ti matrix during sintering,making the increase of c/a value and leading to the Ti-Ti bonds developing from plastic metal bonds to-ward brittle covalent *** CaB_(6)addition can scavenge O impurity and make a significant increase in tensile ductility forα-Ti matrix.A small addition of 0.2 wt.%CaB_(6)provides a superior tensile elongation of 22.2%for Ti material,almost three times as high as that of pure Ti(7.5%).The increase of defor-mation twining activity and grain refinement are responsible for the improved ***,the CaB_(6)oxygen-scavenger can react with the surface oxide layer to in-situ form rod-like TiB and granular CaTiO_(3)reinforcements,refining the coarse near equiaxed grain ofα-Ti matrix into fine equiaxed *** multiple mechanisms of grain-boundary strengthening,load-bearing strengthening of TiB and Orowan strengthening of CaTiO_(3)nanoparticles work together to increase the tensile strength of Ti/CaB_(6)*** work offers an effective method to fabricate high-performance Ti material using inex-pensive high-oxygen HDH Ti powder.

关键词： Titanium Powder metallurgy Sintering Oxygen Mechanical properties

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The Characteristics of Recycled Concrete Powder and Its Influences on the Properties of Cement-based Materials

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Journal of Wuhan University of technology(Materials Science) 2025年第2期40卷 496-508页

作者： XUE Cuizhen WANG Zhe QIAO Hongxia SU Li FENG Qiong School of Civil Engineering Lanzhou University of TechnologyLanzhou 730050China Gansu Advanced Civil Engineering Materials Engineering Research Center Lanzhou 730050China

To guarantee the efficient and high-value reutilization of waste concrete from construction waste,the waste concrete was mechanically ground,and three degrees of fineness recycled concrete powder(RCP)were obtained by different grinding *** analyzing the particle characteristics of RCP with different fineness,the filling-densification effect of cement-RCP cementitious material system was quantitatively investigated based on Andreasen,Fuller,and Aim-Goff *** addition,the macroscopic mechanical properties of cement paste mixed with RCP were studied,and the influencing mechanisms of RCP on the microstructure of cement paste was *** research results show that the particle fineness of RCP after grinding is smaller than that of *** the RCP replaces 0%to 20%cement,the packing density based on the Aim-Goff model increases with the increase of RCP content,whereas the macro-mechanical properties first improve and then degrade with the increase of RCP *** results show that at 5%RCP content,beneficial hydration products such as C-S-H and beneficial pore increase in cement-RCP paste;while at>15%content,beneficial products decrease and harmful substances such as Ca(OH)_(2)and harmful pore *** research findings suggest that the incorporation of RCP can make the cementitious system denser,and the appropriate RCP content can improve the macro-and microscopic properties of cement-based materials.

关键词： recycled concrete powder(RCP) aim-Goff models filling-densification effect mechanical properties microstructure packing density

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Inverse Kinematics of 2(3RPS) and 2(3SPR)Serial-Parallel Manipulators

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Chinese Journal of Mechanical engineering 2025年第2期38卷 321-331页

作者： Bo Hu Ziwei Xu Ren Wang Miaomiao Feng Nijia Ye School of Mechanical Engineering Yanshan University National-Local Joint Engineering Research Center for Advanced Manufacturing Forming Technology and EquipmentYanshan University

Serial-parallel manipulators are of great interest to academic community in recent years, especially those composed of classical parallel mechanisms. There have been many studies around 2(3RPS) and 2(3SPR) S-PMs, but unfortunately their inverse kinematics have not yet been resolved. This paper discovers that the unknown kinematic parameters of middle platform are responsible for the unresolvable of inverse kinematics, meanwhile the unknown kinematic parameters of middle platform also have huge coupling relationships. Therefore, to break through this challenges, the huge coupling relationships are decoupled layer by layer, the kinematic parameters of middle platform are solved by combining Sylvester's elimination method, and the inverse displacements of 2(3RPS) and 2(3SPR) S-PMs are obtained subsequently. This paper not only solves the inverse kinematics of classical 2(3RPS) and 2(3SPR) S-PMs, but also reveals the essence of the inverse kinematics of general(3-DOF)+(3-DOF) 6-DOF S-PMs and proposes a corresponding solution.

关键词： 2 (3RPS) serial-parallel manipulators 2 (3SPR) serial-parallel manipulators Inverse kinematics Serial-parallel manipulator Sylvester’s elimination method

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Improving flangeability of multiphase steel by increasing microstructural homogeneity

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Journal of Iron and Steel Research International 2024年第7期31卷 1736-1745页

作者： Xiao-yu Yang Yong-gang Yang Xing Fang Han-long Zhang Zhen-li Mi Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Engineering TechnologyUniversity of Science and Technology BeijingBeijing 100083China Shanghai Baosteel Group Corp.Technology Center Shanghai 201900China

Multiphase microstructure significantly increases the strength,usually at the expense of flangeability because of lacking microstructure *** further improve the strength-flangeability of multiphase steel,the microstructural homogeneity was advanced by adjusting the hard martensite/austenite(M/A)*** strength-flangeability was measured via uniaxial tensile tests and hole expansion *** microstructures were characterized using a scanning electron microscope equipped with an electron backscatter diffraction detector and a transmission electron *** tests were supplementally used to quantitatively reveal the microstructural homogeneity of the *** show that the adjusted multiphase steel achieves an excellent ultimate tensile strength(~800 MPa)and flangeability(~135%hole expansion ratio).A promising homogeneous multiphase microstructure was obtained by controlling undercooled austenite transformed at about 600℃.This microstructure consists of soft polygonal ferrite,blocky bainitic ferrite,and hard M/A *** volume fraction of M/A islands is around 5%,and the average size is less than l *** nanoindentation analysis indicated that the participation of M/A islands impressively influenced the microstructural *** strain partition and better mechanical compatibility were present in the adjusted multiphase steel since the plasticity initiation started late,which resulted in a positive ***,avoiding M/A islands distributed in the chain along the rolling direction on the matrix hindered the possibility of voids coalescing into cracks and stabilized the flanging performance.

关键词： Multiphase steel Flangeability Martensite/austenite island-Microstructural homogeneity-Microstructure Compact strip production process

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