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Functional ferritin nanoparticles for biomedical applications

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Frontiers of Chemical Science and Engineering 2017年第4期11卷 633-646页

作者： Zhantong Wang Haiyan Gao Yang Zhang gang Liu gang niu Xiaoyuan Chen State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine School of Public Health Xiamen University Xiamen 361102 China. Laboratory of Molecular Imaging and Nanomedicine (LOMIN) National Institute of Biomedical Imaging and Bioengineering (NIBIB) National Institutes of Health Bethesda MD 20892 USA.

Ferritin, a major iron storage protein with a hollow interior cavity, has been reported recently to play many important roles in biomedical and bioengineering applications. Owing to the unique architecture and surface properties, ferritin nanoparticles offer favorable character- istics and can be either genetically or chemically modified to impart functionalities to their surfaces, and therapeutics or probes can be encapsulated in their interiors by controlled and reversible assembly/disassembly. There has been an outburst of interest regarding the employment of functional ferritin nanoparticles in nanomedicine. This review will highlight the recent advances in ferritin nanoparticles for drug delivery, bioassay, and molecular imaging with a particular focus on their biomedical applications.

关键词： nanomedicine ferritin drug delivery bioas-say molecular imaging

Stability and Determination of Metamizole Sodium by Capillary Electrophoresis Analysis Combined with Infra-red Spectroscopy

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Chemical Research in Chinese Universities 2007年第6期23卷 654-658页

作者： XIANG Qian niu gang WU Xian-hua CHEN gang Department of Applied Chemistry Changchun Institute of Technology Changchun 130022 P. R. China Key Laboratory of Automobile Materials of Ministry of Education College of Materials Science and Engineering Jilin University Changchun 130012 P. R. China

Metamizole sodium was chosen as a representative of unstable analytes for investigation by discussing the effects of oxygen and solvent on its degradation reaction using the capillary electmphoresis technique. A possible degradation mechanism was deduced from the observed behavior and was confirmed by infra-red spectroscopic study. The degradation reaction could be inhibited obviously by methanol instead of water as the solvent of analyte. Under the optimized conditions： separation voltage of 20 kV, and 5 mmol/L disodium hydrogen phosphate and 5 mmol/L borax with 10% methanol（pH 9. 12） as the running buffer, the standard curve of metamizole sodium was linear in a range of 3.77- 74. 07 mg/L. A satisfactory result was achieved when the technique was used to detect metamizole sodium in tablet.

关键词： Capillary electmphoresis Metamizole sodium Stability

Cold compression deformation method for reducing residual stress and uniformizing micro-property in ferrite steel

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Journal of Iron and Steel Research International 2022年第3期29卷 503-511页

作者： Bo Ning Hui-bin Wu gang niu Xin-pan Yu Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing100083China

To reduce internal residual stress and homogenize micro-property of hot-rolled ferrite steel,the cold compression deformation method with small reduction rate has been performed in the hot-rolled samples,and X-ray diffraction and nanoindentation test have been used to detect the residual stress and *** samples with deformation rate of 0-5.59%or annealing at 550℃ are *** results show that,due to the coupling effect of thermal expansion and cold contraction and the volume expansion of microstructural transformation from austenite to ferrite,compressive residual stress was found inside the hot-rolled *** the increase in cold compression deformation,the dislocation density increased and the microhardness increased gradually,and there is no obvious rule for the change of mean nano-hardness in micro-zone for the center of ***,the uniformity of nano-hardness in the micro-zone increased first and then decreased,and the value of residual stress has obvious corresponding relationship with the uniformity of micro-zone *** cold compression deformation with appropriate reduction rate can reduce residual stress and improve nano-hardness uniformity of the hot-rolled samples,but more deformation(such as reduction rateε=5.59%)makes residual stress increase and makes uniformity of nano-hardness deteriorate.

关键词： Ferrite Cold compression deformation Residual stress Nano-hardness Uniformity Dislocation density

Reverse-transformation austenite structure control with micro/nanometer size

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International Journal of Minerals,Metallurgy and Materials 2017年第5期24卷 530-537页

作者： Hui-bin Wu gang niu Feng-juan Wu Di Tang Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing Engineering Technology Research Center of Special Steel for Traffic and Energy

To control the reverse-transformation austenite structure through manipulation of the micro/nanometer grain structure, the influences of cold deformation and annealing parameters on the microstructure evolution and mechanical properties of 316L austenitic stainless steel were investigated. The samples were first cold-rolled, and then samples deformed to different extents were annealed at different temperatures. The microstructure evolutions were analyzed by optical microscopy, scanning electron microscopy (SEM), magnetic measurements, and X-ray diffraction (XRD); the mechanical properties are also determined by tensile tests. The results showed that the fraction of stain-induced martensite was approximately 72% in the 90% cold-rolled steel. The micro/nanometric microstructure was obtained after reversion annealing at 820-870A degrees C for 60 s. Nearly 100% reversed austenite was obtained in samples annealed at 850A degrees C, where grains with a diameter ae 500 nm accounted for 30% and those with a diameter > 0.5 mu m accounted for 70%. The micro/nanometer-grain steel exhibited not only a high strength level (approximately 959 MPa) but also a desirable elongation of approximately 45%.

关键词： austenitic stainless steel structure control martensite reverse transformation grain refinement

Investigation of FRP and SFRC Technologies for Efficient Tunnel Reinforcement Using the Cohesive Zone Model

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Structural Durability & Health Monitoring 2024年第2期18卷 161-179页

作者： gang niu Zhaoyang Jin Wei Zhang Yiqun Huang China Communications Construction Investment Development Co. Ltd.Fuzhou350000China Rail Transit Branch of China Communications Construction Co. Ltd.Beijing101317China School of Civil Engineering Fujian University of TechnologyFuzhou350118China

Amid urbanization and the continuous expansion of transportation networks,the necessity for tunnel construction and maintenance has become *** this need requires the investigation of efficient,economical,and robust tunnel reinforcement *** paper explores fiber reinforced polymer(FRP)and steel fiber reinforced concrete(SFRC)technologies,which have emerged as viable solutions for enhancing tunnel *** is celebrated for its lightweight and high-strength attributes,effectively augmenting load-bearing capacity and seismic resistance,while SFRC’s notable crack resistance and longevity potentially enhance the performance of tunnel ***,current research predominantly focuses on experimental analysis,lacking comprehensive theoretical *** bridge this gap,the cohesive zone model(CZM),which utilizes cohesive elements to characterize the potential fracture surfaces of concrete/SFRC,the rebar-concrete interface,and the FRP-concrete interface,was employed.A modeling approach was subsequently proposed to construct a tunnel segment model reinforced with either SFRC or ***,the corresponding mixed-mode constitutive models,considering interfacial friction,were integrated into the proposed *** validation and numerical simulations corroborated the accuracy of the proposed ***,this study examined the reinforcement design of tunnel *** a numerical evaluation,the effectiveness of innovative reinforcement schemes,such as substituting concrete with SFRC and externally bonding FRP sheets,was assessed utilizing a case study from the Fuzhou Metro Shield Tunnel Construction Project.

关键词： Tunnel segment FRP SFRC cohesive zone model constitutive model fracture process

Corrosion behavior of high-strength spring steel for high-speed railway

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International Journal of Minerals,Metallurgy and Materials 2018年第5期25卷 527-535页

作者： gang niu Yin-li Chen Hui-bin Wu Xuan Wang Di Tang Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing Engineering Technology Research Center of Special Steel for Traffic and Energy

The corrosion resistance and evolution of corrosion products in medium-carbon high-strength spring steels were investigated in a neutral salt spray(5 wt% Na Cl solution). A formation model of γ-Fe OOH and a transformation model describing the conversion of γ-Fe OOH to α-Fe OOH were constructed. The results indicated that, at the initial corrosion stage, the corrosion resistance was gradually improved with the addition of Cr; however, with the addition of alloying element V, the corrosion resistance decreased. These results were attributed mainly to the initial corrosion stage being closely related to the matrix microstructure parameters such as grain-boundary character and dislocation density. After the rust layer was formed at a later corrosion stage, the corrosion resistance was reinforced with the addition of Cr and V because Cr strongly influenced the composition, structure, and morphology of the corrosion products. The results presented herein show that Cr was conducive to the transformation of γ-Fe OOH into α-Fe OOH. Moreover, V and Cr exhibited obvious synergy and were enriched in the inner layer of the corrosion products.

关键词： high-strength spring steel corrosion resistance alloying elements rust layers evolution model

Effect of martensitic transformation on nano/ultrafine-grained structure in 304 austenitic stainless steel

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Journal of Iron and Steel Research International 2017年第12期24卷 1231-1237页

作者： Na Gong Hui-bin Wu gang niu Jia-ming Cao Da Zhang Tana Instituted Engineering Technology University of Science and Technology BeijingBeiking 100083China Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Sinohydro Renewable Energy Co. Ltd.Beijing 100083China

304 austenitic stainless steel was cold rolled in the range of 20%-80%reductions and then annealed at 700-900°C for 60 sto obtain nano/ultrafine-grained（NG/UFG）*** electron microscopy,electron backscatter diffraction and X-ray diffraction were used to characterize the resulting *** results showed that with the increase of cold reduction,the content of martensite was *** steel performed work hardening during cold-working owing to the occurrence of strain induced martensite which nucleated in single shear *** rolling broke up the lath-type martensite into dislocation-cell type martensite because of the formation of slip *** annealed at 800-960°C for 60 swere of NG/UFG structure with different percentage of nanocrystalline（60-100 nm）and ultrafine（100-500 nm）grains,submicron size（500-1000 nm）grains and micron size（〉1000 nm）*** value of the Gibbs free energy exhibited that the reversion mechanism of the reversion process was shear controlled by the annealing *** a certain annealing time during the reversion process,austenite nucleated first on dislocation-cell type martensite and the grains grew up subsequently and eventually to be micrometer/submicrometer grains,while the nucleation of austenite on lath-type martensite occurred later resulting in nanocrystalline/ultrafine *** existence of the NG/UFG structure led to a higher strength and toughness during tensile test.

关键词： 304 austenitic stainless steel Nano/ultrafine-grained structure Reversion mechanism Lath-type martensite Dislocation-cell type martensite Martensitic transformation

Assessment of the Influence of Tunnel Settlement on Operational Performance of Subway Vehicles

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Structural Durability & Health Monitoring 2024年第1期18卷 55-71页

作者： gang niu Guangwei Zhang Zhaoyang Jin Wei Zhang Xiang Liu China Communications Construction Rail Transit Subsidiary Beijing100000China China Communications Construction Strait Construction Investment Development Co. Ltd.Fuzhou350000China School of Civil Engineering Fujian University of TechnologyFuzhou350118China

In the realm of subway shield tunnel operations,the impact of tunnel settlement on the operational performance of subway vehicles is a crucial *** study introduces an advanced analytical model to investigate rail geometric deformations caused by settlement within a vehicle-track-tunnel coupled *** model integrates the geometric deformations of the track,attributed to settlement,as track irregularities.A novel“cyclic model”algorithm was employed to enhance computational efficiency without compromising on precision,a claim that was rigorously *** model’s capability extends to analyzing the time-history responses of vehicles traversing settlement-affected *** research primarily focuses on how settlement wavelength,amplitude,and vehicle speed influence operational *** findings indicate that an increase in settlement wavelength can improve vehicle performance,whereas a rise in amplitude can degrade *** study also establishes settlement thresholds,based on vehicle operation comfort and *** insights are pivotal for maintaining and enhancing the safety and efficiency of subway systems,providing a valuable framework for urban infrastructure management and long-term maintenance strategies in metropolitan transit systems.

关键词： Settlement running performance subway tunnel dynamic analysis track irregularity threshold

Effect of the frequency of high-angle grain boundaries on the corrosion performance of 5wt%Cr steel in a CO2 aqueous environment

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 315-324页

作者： Hui-bin Wu Tao Wu gang niu Tao Li Rui-yan Sun Yang Gu Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing 100083 China National Engineering Research Center of Advanced Rolling University of Science and Technology Beijing Beijing 100083 China Survey and Design Institute of Jilin Oilfield Company Jilin 138000 China

The corrosion behavior of 5 wt%Cr steel tempered at different temperatures was investigated by immersion testing and electrochemical testing in a CO_2 aqueous environment. When the tempering temperature exceeded 500℃, the corrosion rate increased. The corrosion layers consisted of Cr-rich compounds, which affected the corrosion behaviors of the steels immersed in the corrosive solution. The results of electrochemical experiments demonstrated that 5 wt%Cr steels with different microstructures exhibited pre-passivation characteristics that decreased their corrosion rate. Analysis by electron back-scattered diffraction showed that the frequency of high-angle grain boundaries(HAGBs) and the corrosion rate were well-correlated in specimens tempered at different temperatures. The corrosion rate increased with increasing HAGB frequency.

关键词： chromium steel grain boundaries microstructure corrosion performance tempering temperature