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Novel titanium particles reinforced Zr-based bulk metallic glass composites prepared by infiltration casting

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Journal of University of Science and Technology Beijing 2008年第4期15卷 505-508页

作者： Cuimei Zhang Xidong Hui meiling wang Guoliang Chen State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

A novel Ti/Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 composite was successfully prepared by infiltrating the melt into sintered Ti preform. It shows that the introduction of Ti particles into the composite results in an increase in elastic strain to 3% and an enhancement of the strength up to 2.1 GPa. High specific strength has been obtained because of the decrease in density of the composite. It is suggested that an improvement in the mechanical properties of the composite may be attributed to the generation of multiple shear bands and some deformation in the Ti particles.

关键词： melt infiltration bulk metallic-glass Ti particles mechanical properties

A necessary and sufficient condition of convexity for SOC reformulation of trust-region subproblem with two intersecting cuts

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Science China Mathematics 2016年第6期59卷 1127-1140页

作者： YUAN JianHua wang meiling AI WenBao SHUAI TianPing School of Science Beijing University of Posts and Telecommunications Automation School Beijing University of Posts and Telecommunications

We consider the extended trust-region subproblem with two linear inequalities. In the "nonintersecting" case of this problem, Burer and Yang(2015) have proved that its semi-definite programming relaxation with second-order-cone reformulation(SDPR-SOCR) is a tight relaxation. In the more complicated "intersecting" case, which is discussed in this paper, so far there is no result except for a counterexample for the SDPR-SOCR. We present a necessary and sufficient condition for the SDPR-SOCR to be a tight relaxation in both the "nonintersecting" and "intersecting" cases. As an application of this condition, it is verified easily that the "nonintersecting" SDPR-SOCR is a tight relaxation indeed. Furthermore, as another application of the condition, we prove that there exist at least three regions among the four regions in the trust-region ball divided by the two intersecting linear cuts, on which the SDPR-SOCR must be a tight relaxation. Finally, the results of numerical experiments show that the SDPR-SOCR can work efficiently in decreasing or even eliminating the duality gap of the nonconvex extended trust-region subproblem with two intersecting linear inequalities indeed.

关键词： trust-region subproblem linear inequality constraints global solutions second-order-cone refor-mulation SDP relaxation

Sialoglycoproteins Isolated from the Eggs of Gadus morhua Inhibit Bone Resorption in Ovariectomized Rats by Suppressing the MAPK and NF-κB Pathways

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Journal of Ocean University of China 2019年第5期18卷 1174-1184页

作者： MAO Lei wang Yiming wang meiling DAI Yufeng wang Jingfeng XUE Changhu College of Food Science and Engineering Ocean University of China

The present study investigated the anti-osteoporosis function and the mechanism of sialoglycoproteins isolated from the eggs of Gadus morhua(Gm-SGP)on ovariectomized(OVX)*** 3 months of Gm-SGP treatment,OVX-induced bone loss was suppressed and uncoupling bone turnover was balanced,as indicated by systemic biomarkers of bone metabolism;no uterine estrogenicity was ***,rats administered with Gm-SGP exhibited increased bone mineral density and biomechanical strength and significant restoration of the trabecular microarchitecture compared with rats in the control ***-SGP significantly decreased bone resorption-related indicators in *** of the associated mechanisms revealed that Gm-SGP significantly increases the OPG/RANKL ratio at the mRNA and protein *** research suggested that Gm-SGP inhibits the mRNA and protein expressions of important transcription factors of the MAPK and NF-κB signaling *** also attenuates the activation of related transduction signaling pathways by inhibiting phosphorylation of JNK,ERK,p38,and NF-κB,and ultimately suppresses the induction of c-Fos and ***,these results demonstrate that Gm-SGP inhibits bone resorption by suppressing osteoclastogenesis-related MAPK and NF-κB pathways,thereby improving osteoporosis.

关键词： Sialoglycoprotein osteoporosis MAPKs NF-κB bone resorption

From surface loading to precise confinement of polyoxometalates for electrochemical energy storage

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Chinese Chemical Letters 2023年第12期34卷 29-41页

作者： Chongji wang Yanhui Song Wenhua Cong Yuanyuan Yan meiling wang Jiadong Zhou College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Instituteof TechnologyBeijing100081China Instrumental Analysis Center Taiyuan University of TechnologyTaiyuan 030024China

Because of abundant redox activity,broad tunability,and specific atomic structure,polyoxometalates(POMs or POM)clusters have attracted burgeoning interests in electrochemical especially energy stor-age ***,due to the high solubility and fully oxidized state,they often suffer from elec-trically insulation as well as chemical and electrochemical *** noncovalent loading or covalent grafting of POMs on conductive substrates have been successfully performed to overcome this ***,severe shedding or agglomeration of POMs arising from weak interactions with substrates or excessive entrapment or weak destruction in conductive supports cause significantly re-duced availability and *** this end,precise confinement of POMs into conductive supports has been tried to improve their dispersibility and ***,recent progress of PoMs from surface loading to precise confinement in the electrochemistry energy storage field is ***,we il-lustrate the typical non-confinement methods(*** and non-covalent)for supported POMs in energy storage ***,different strategies for precise confinement of PoMs in organic and inorganic materials for related applications are also ***,future research directions and opportunities for confined POMs,and derived ultrafine nanostructures are also *** re-view seeks to point out future research directions of supported PoMs in the electrochemistry-related fields.

关键词： Polyoxometalates Non-confinement Confinement Electrochemical energy storage Supercapacitor Battery

Double spatial confinement on ruthenium nanoparticles inside carbon frameworks as durable catalysts for a quasi-solid-state Li–O_(2) battery

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Carbon Energy 2023年第8期5卷 114-125页

作者： meiling wang Ying Yao Feiyang Yang Zhenwu Tang Jingjie Ren Cunzhong Zhang Feng Wu Xiangke wang Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science&EngineeringBeijing Institute of TechnologyBeijingChina Beijing Institute of Technology Chongqing Innovation Center ChongqingChina College of Life and Environmental Sciences Minzu University of ChinaBeijingChina College of Environmental Science and Engineering North China Electric Power UniversityBeijingChina

The rational design of large-area exposure,nonagglomeration,and longrange dispersion of metal nanoparticles(NPs)in the catalysts is critical for the development of energy storage and conversion *** attention has been focused on modulating and developing catalyst interface contact engineering between a carbon substrate and dispersed ***,a highly dispersed ultrafine ruthenium(Ru)NP strategy by double spatial confinement is proposed,that is,incorporating directed growth of metal–organic framework crystals into a bacterial cellulose templating substrate to integrate their respective merits as an excellent electrocatalytic cathode catalyst for a quasi-solid-state Li–O_(2) *** porous carbon matrix with highly dispersed ultrafine Ru NPs is well designed and used as cathode catalysts in a Li–O_(2) battery,demonstrating a high discharge areal capacity of 6.82 mAh cm^(–2) at 0.02 mA cm^(–2),a high-rate capability of 4.93 mAh cm^(–2) at 0.2 mA cm^(–2),and stable discharge/charge cycling for up to 500 cycles(2000 h)with low overpotentials of~1.4 *** fundamental understanding of the structure–performance relationship demonstrates a new and promising approach to optimize highly efficient cathode catalysts for solid-state Li–O_(2) batteries.

关键词： bacterial cellulose cathode materials metal-organic frameworks Ru nanoparticles solid-state Li-O_(2)batteries

Minor alloying behavior in bulk metallic glasses and high-entropy alloys

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Science China(Physics,Mechanics & Astronomy) 2008年第4期51卷 427-437页

作者： ZHANG Yong ZHOU YunJun HUI XiDong wang meiling CHEN GuoLiang State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

The effect of minor alloying on several bulk metallic glasses and high-entropy al-loys was studied. It was found that minor Nb addition can optimize the interface structure between the W fiber and the Zr-based bulk metallic glass in the compos-ites,and improve the mechanical properties. Minor Y addition can destabilize the crystalline phases by inducing lattice distortion as a result to improve the glass-forming ability,and the lattice distortion energy is closely related to the effi-ciency of space filling of the competing crystalline phases. A long-period ordered structure can precipitate in the Mg-based bulk metallic glass by yttrium alloying. For the high-entropy alloys,solid solution can be formed by alloying,and its me-chanical properties can be comparable to most of the bulk metallic glasses.

关键词： bulk metallic glasses high-entropy alloys solid solution lattice distortion entropy of mixing glass forming ability

Drag derived altitude aided navigation method

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Chinese Journal of Aeronautics 2017年第5期30卷 1750-1764页

作者： Hua SONG meiling wang Jing YANG Dantong SUN Longtao KONG Chunling WEI School of Automation Science and Electrical Engineering Beihang University Beijing 100083 China Collaborative Innovation Center of Advanced Aero-Engine Beihang University Beijing 100083 China National Key Laboratory of Space Intelligent Control Technology Beijing 100094 China

The navigation problem of the lifting reentry vehicles has attracted much research interest in the past decade. This paper researches the navigation in the blackout zone during the reentry phase of the aircraft, when the communication signals are attenuated and even interrupted by the blackout zone. However, when calculating altitude, a pure classic inertial navigation algorithm appears imprecise and divergent. In order to obtain a more precise aircraft altitude, this paper applies an integrated navigation method based on inertial navigation algorithms, which uses drag derived altitude to aid the inertial navigation during the blackout zone. This method can overcome the shortcomings of the inertial navigation system and improve the navigation accuracy. To further improve the navigation accuracy, the applicable condition and the main error factors, such as the atmospheric coefficient error and drag coefficient error are analyzed in detail. Then the damping circuit design of the navigation control system and the damping coefficients determination is introduced. The feasibility of the method is verified by the typical reentry trajectory simulation, and the influence of the iterative times on the accuracy is analyzed. Simulation results show that iterative three times achieves the best effect.

关键词： Aided navigation system Blackout zone Drag derived altitude Inertial navigation Integrated navigation Reentry vehicles

Extended State Observer based Attitude Control of a Bird-like Flapping-wing Flying Robot

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Journal of Bionic Engineering 2020年第4期17卷 708-717页

作者： Keqiang Bai YunZhi Luo Zhihong Dan Song Zhang meiling wang Qiumeng Qian Jun Zhong School of Information Engineering Southwest University of Science and TechnologyRobot Technology Used for Special Environment Key Laboratory of Sichuan ProvinceMianyang 621010China Automation Research Institute Co. Ltd.of China South Industries Group CorporationMianyang 621000China Science and Technology on Altitude Simulation Laboratory AECC Sichuan Gas Turbine EstablishmentMianyang 621703China AECC Sichuan Gas Turbine Establishment Mianyang 621703China Chinese Academy of Sciences Hefei Institutes of Physical Science Hefei 230022China College of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213022China

The attitude control system of a flapping-wing flying robot plays an important role in the precise orientation and tracking of the *** this paper,the modeling of a bird-like micro flapping-wing system is introduced,and the design of a sliding mode controller based on an Extended State Observer(ESO)is *** main design difficulties are the control law and the adaptive law for the attitude control *** address this problem,a sliding mode adaptive extended state observer algorithm is ***,a new extended state approximation method is used to estimate the final output as a disturbance ***,a sliding mode observer with good robustness to the model approximation error and external disturbance is used to estimate the system *** with traditional algorithms,this method is not only suitable for more general cases,but also effectively reduces the influence of the approximation error and ***,the simulation and experiment example is given to illustrate the implementation *** results show that the algorithm can effectively estimate the state of the attitude control system of the flapping-wing flying robot,and further guarantee the robustness of the model regarding error and external disturbance.

关键词： bionic attitude control flapping-wing flying robot sliding mode adaptive control extended state observer

Nitrogen-doped TiO_(2)/Graphene Composites Synthesized via the Vapour-thermal Method

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Journal of Wuhan University of Technology(Materials Science) 2022年第6期37卷 1105-1113页

作者： TANG Hailong wang Min JU Tangtong DAI Yue wang meiling MA Yongqing ZHENG Ganhong School of Materials Science and Engineering Anhui UniversityHefei 230039China School of Physics and Optoelectronic Engineering Anhui UniversityHefei 230039China Institute of Physical Science and Information Technology Anhui UniversityHefei 230039China

TiO_(2)/graphene composite was synthesized in the vapor environment of *** order to improve the properties of composite,N-doped of TiO_(2)/graphene with different N/Ti molar ratio was prepared in the vapor environment of deionized water and used urea as the source of *** N-doped occupies in the interstitial sites of TiO_(2) lattice,substitutes for O element in TiO_(2) and for C element in graphene,and simultaneously changes the chemical states of Ti and O elements in TiO_(2).N-doped changes the morphology of TiO_(2) from nano-sheets to nanoparticles,accompanying with the decrease in specific surface area of the composites,first increases the particle size of TiO_(2) and then decreases,and alters the vibration modes of *** composite with RN/Ti=2 exhibits the enhanced photocatalytic degradation performance to methylene blue,and the degradation rate increases from 7.7×10^(−2) min^(−1) for the undoped composite to 9.6×10^(−2) min^(−1).

关键词： TiO_(2)/graphene vapor-thermal nitrogen-doped photocatalytic performance