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Hybrid Dextran-gadolinium Nano-suitcases as High-relaxivity MRI Contrast Agents

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Chinese Journal of Polymer Science 2018年第3期36卷 391-398页

作者： Hao Wang Ting-Ting Dai Bo-Lun Lu Sheng-Li Li Qing Lu Vincent Mukwaya hong-jing dou The State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Plastic and Reconstructive Surgery Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai Key Laboratory of Tissue EngineeringShanghai 200011China Department of Radiology Renji HospitalShanghai Jiao Tong University School of MedicineShanghai 200127 China

Dextran-poly（glycidyl methacrylate）（Dex-PGMA） nano-suitcases were synthesized efficiently via a graft copolymerization induced self-assembly （GISA） approach. On this basis, the Dex-PGMA nano-suitcases were modified with hydrazide, and the attachment of multiple chelated Gd（III） ions to the interior of the nano-suitcases affords nanoscale MRI contrast agents with high relaxivity values. The highly fenestrated dextran shell of the nano-suitcases assures water exchange which readily occurs between the surrounding environment and the Gd（III） ions encapsulated within the hybrid nano-suitcases. The complexation between the hydrophilic hydrazide interior of the nano-suitcases and Gd（III） ions results in an impressive Gd payload at 22.6 wt% in the hybrid nano-suitcases. The longitudinal relaxivity （rl） of the hybrid nano-suitcases is reported as 44.4 L/（mmol-s）, which is 9-14 folds of that of commercial Gd-DTPA agents. In vivo MRI studies demonstrate that the hybrid nano-suitcases accumulated in the lymph node of the rat due to their nanoscale dimensions and displayed strong signals in vivo. The results indicated that the hybrid nano-suitcases provide a promising platform for the diagnosis of lymph node related diseases.

关键词： Crosslinked polymer nanoparticles Gadolinium(llI) MRI contrast agents Lymph node imaging

Parametric“non-nested”discriminants for multiplicities of univariate polynomials

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Science China Mathematics 2024年第8期67卷 1911-1932页

作者： Hoon hong jing Yang Department of Mathematics North Carolina State UniversityRaleighNC 27695USA SMS-HCIC-School of Mathematics and Physics Center for Applied Mathematics of GuangxiGuangxi Minzu UniversityNanning 530006China

We consider the problem of complex root classification,i.e.,finding the conditions on the coefficients of a univariate polynomial for all possible multiplicity structures on its complex *** is well known that such conditions can be written as conjunctions of several polynomial equalities and one inequality in the *** polynomials in the coefficients are called discriminants for *** is also known that discriminants can be obtained using repeated parametric greatest common *** resulting discriminants are usually nested determinants,i.e.,determinants of matrices whose entries are determinants,and so *** this paper,we give a new type of discriminant that is not based on repeated greatest common *** new discriminants are simpler in the sense that they are non-nested determinants and have smaller maximum degrees.

关键词： parametric polynomial complex roots discriminant multiplicity resultant

Dual-filler reinforced PVDF-HFP based polymer electrolyte enabling high-safety design of lithium metal batteries

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Nano Research 2024年第6期17卷 5251-5260页

作者： Chang Fang Kangsheng Huang jing Zhao Shiqi Tian Hui dou Xiaogang Zhang Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China

Despite the high energy density of lithium metal batteries(LMBs),their application in rechargeable batteries is still hampered due to insufficient ***,we present a novel flame-retardant solid-state electrolyte based on polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)with nano SiO_(2)aerogel as an inert filler but Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)as an auxiliary component to enhance the ion *** introduction of SiO_(2)aerogels imparts the polymer electrolyte with exceptional thermal stability and flame ***,the interaction between hydroxyl groups of SiO_(2)particles and PVDF-HFP creates a strong cross-linking structure,enhancing the mechanical strength and stability of the ***,the presence of SiO_(2)aerogel and LLZTO facilitates the dissociation of lithium salts through Lewis acid-base interactions,resulting in a high ionic conductivity of 1.01×10^(−3)S·cm^(−1)and a wide electrochemical window of~5.0 V at room temperature for the prepared ***,the assembled Li|Li cell demonstrates the excellent resistance to lithium dendrite and runs stablly for over 1500 h at a current density of 0.25 mA·cm^(−2).Thus,we prepare a pouch cell with high safety,which can work normally after short-circuiting under the external folding and cutting.

关键词： polymer electrolyte SiO_(2)/Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)dual-filler non-flammable long cycle life lithium metal battery

Ballistic performance of spherical fragments penetrating PCrNi3MoV target plates

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Defence Technology（防务技术） 2024年第3期33卷 295-307页

作者： dou hong Wenbin Li Yu Zheng Yiming Li Ning Jiang Kebin Zhang Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjingChina

PCrNi3MoV steel is a medium-carbon,low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation *** study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres,tungsten spheres of various diameters(5 mm,8 mm,and 10 mm)were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm,9 mm,and 14 *** penetration performance of the spheres was analyzed for different velocities,and the ultimate penetration velocity of the plate was *** was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear *** the dimensional analysis method,a relationship between the bulge height of the steel plate and the fragment velocity,an equation for the ultimate penetration velocity,and a relationship between the target penetration energy and the fragment velocity were ***,a projectile-target action index was proposed to describe the process of tungsten spheres with different velocities impacting target *** results suggested that under the same thickness of the target plate,a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter *** equations obtained through dimensional analysis predicted values that agreed well with experimental values,indicating that these equations can be applied to engineering applications.

关键词： Impact damage Ultimate penetration velocity Bulge height Target penetration energy Failure modes

Effect of slag composition on kinetic behavior of deep deoxidation of 5 wt.% Si high-silicon austenitic stainless steel

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Journal of Iron and Steel Research International 2024年第8期31卷 1873-1885页

作者： Guan-xiong dou Han-jie Guo jing Guo Xue-cheng Peng Qing-yun Chen School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing 100083China

Based on a thermodynamic study of 5 wt.%Si high-silicon austenitic stainless steel(SS-5Si)smelting using CaF_(2)-CaO-Al_(2)0_(3)-Mg-Si0_(2) slag to obtain a low oxygen content of less than 10×10^(-4) wt.%,a kinetic mass transfer model for deep deoxidation was established through laboratory studies,and the effects of slag components and temperature on deoxidation during the slag-steel reaction process of sS-5Si were systematically *** experimental data verified the accuracy of the model *** results showed that the final oxygen content in the steel at 1873 K was mainly controlled by the oxygen content derived from the activity of SiO_(2) regulated by the[Si]-[O]equilibrium reaction in the slag system;in particular,when the slag basicity R(R=w(CaO)/w(SiO2),where w(CaO)and w(SiO_(2))are the contents of CaO and SiO_(2) in the slag,respectively)is 3,the Al2O3 content in the slag needs to be less than 2.7%.The mass transfer rate equation for the kinetics of the deoxidation reaction revealed that the mass transfer of oxygen in the liquid metal is the rate-controlling step under different slag conditions at 1873 K,and the oxygen transfer coefficient ko.m increases with increasing the slag basicity from 4.0×10^(-6)m s^(-1)(R=1)to 4.3×10^(-5) m s^(-1)(R=3).ko.m values at R=2 and R=3 are almost the same,indicating that high slag basicity has little *** integral of the mass transfer rate equation for the deoxidation reaction of SS-5Si under different slag conditions is *** total oxygen content of the molten steel decreases with increasing basicity from an initial content of 22×10^(-4) to 3.2×10^(-4) wt.%(R=3),consistent with the change in ko.m with slag *** R=2,the slag-steel reaction takes 15 min to reach equilibrium(w[O]=5.5×10^(-4) wt.%),whereas at R=3,the slag-steel reaction takes 30 min to reach equilibrium(w[0]=3.2×10^(-4) wt.%).Considering the depth of deoxidation and reaction time of SS-5Si smelting,it is recommended the slag b

关键词： Slag-steel reaction Kinetics Rate-controlling step Deep deoxidation Transfer coefficient

A systematic understanding of microbial reductive dechlorination towards an improved “one health” soil bioremediation: A review and perspective

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Science China Technological Sciences 2024年第10期67卷 3009-3031页

作者： HE Yan LI ShuYao YUAN jing CHENG Jie dou JiBo YANG XueLing XU JianMing Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Institute of Soil and Water Resources and Environmental ScienceCollege of Environmental and Resource SciencesZhejiang University Key Laboratory of Environment Remediation and Ecological Health Ministry of Education Microbiome Network and Department of Agricultural Biology Colorado State University Departments of Chemistry and Chemical & Biomolecular Engineering Institute for Functional Intelligent Materials (I-FIM)National University of Singapore

Chlorinated organic pollutants(COPs), both emerging and traditional, are typical persistent pollutants that harm soil health worldwide. Dechlorinators mediated reductive dechlorination is the optimal way to completely remove COPs from anaerobic soil through a redox reaction driven by electron transfer during microbial anaerobic respiration. Generally, the dechlorinated depletion of COPs in situ often interacts with multiple element biogeochemical activities, e.g., methanogenesis, sulfate reduction, iron reduction, and denitrification. Elucidating the relevance of biogeochemical cycles between COPs and multiple elements and the coupled mechanisms involved, thus, helps to develop effective pollution control strategies with the balance between pollution degradation and element cycles in heterogeneous soil, ultimately contributing to “one health” goal. In this review, we summarized the microbial-chemical coupling redox processes and the driving factors, elucidated the interspecies metabolites exchange and electron transfer mechanisms within COP-dechlorinating communities, and further proposed a detailed design, construction, and analysis framework of engineering COP-dechlorinating microbiomes via “top-down” selfassembly and “bottom-up” synthesis to pave the way from laboratory to practical field application. Especially, we delve into the major challenges and perspectives surrounding the design of state-of-the-art synthetic microbial communities. Our goal is to improve the understanding of the microbial-mediated coupling between reductive dechlorination and element biogeochemical cycling, with a particular focus on the implications for health-integrated soil bioremediation under the “one health” concept.

关键词： reductive dechlorination biogeochemical redox processes interspecies interaction synthetic microbiomes, anaerobic soils

Oxidation behavior of Ni-based superalloy GH4738 under tensile stress

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Rare Metals 2024年第8期43卷 3913-3920页

作者： Ji-Chong Hu Hai-Liang Huang Chong-Chong Wu Xiao-Yu Sun Jie Wang Yan-hong Yang jing-Long Qu Liang Jiang Jin-He dou Yang Chen Institute for Advanced Studies in Precision Materials Yantai UniversityYantai 264005China Department of Management and Engineering Linkoping University58183LinkopingSweden Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Gaona Aero Material Co. LtdBeijing 100081China College of Artificial Intelligence and Big Data Shandong First Medical University and Shandong Academy of Medical SciencesJinan250117China

Revealing the oxidation behavior of superalloys is crucial for optimizing material properties and extending service *** study investigated the oxidation behavior of superalloy GH4738 under stress states at 850℃.High-throughput specimens were fabricated to withstand different stresses at the same *** oxidation s amples were analyzed using the mass gain method to obtain oxidation kinetic *** results show that the external stress below 200 MPa could improve the oxidation resistance of the *** tensile stress increasing,the oxide layer becomes thinner,denser and more complete,while internal oxidation *** tensile stress alters the structure of the external oxide layer from a two-layer to a threelayer *** Cr_(2)O_(3) oxide layer inhibits the outward diffusion of Ti,leading to Ti enrichment at the oxide-matrix interface and altering the oxidation mechanism of GH4738.

关键词： Ni-based Superalloy Oxidation behavior Tensile stress Oxide layer

Vacancy healing for stable perovskite solar cells via bifunctional potassium tartrate

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Journal of Energy Chemistry 2024年第1期88卷 64-70,I0002页

作者： jing dou Yue Ma Xiuxiu Niu Wentao Zhou Xueyuan Wei Jie dou Zhenhua Cui Qizhen Song Tinglu Song Huanping Zhou Cheng Zhu Yang Bai Qi Chen Experimental Centre for Advanced Materials School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationBIC-ESATSchool of Materials Science and EngineeringPeking UniversityBeijing 100871China

Perovskite solar cell has gained widespread attention as a promising technology for renewable ***, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein, we demonstrate a bifunctional passivator of the potassium tartrate(PT) to address both challenges. PT minimizes the Pb leakage in perovskites and also heals cationic vacancy defects, resulting in improved device performance and stability. Benefiting from PT modification, the power conversion efficiency(PCE) is improved to 23.26% and the Pb leakage in unencapsulated films is significantly reduced to 9.79 ppm. Furthermore, the corresponding device exhibits no significant decay in PCE after tracking at the maximum power point(MPP) for 2000 h under illumination(LED source, 100 mW cm^(-2)).

关键词： Perovskite Potassium tartrate Lead leakage Long-term stability

Effect of temperature and reaction path interaction on fluidization reduction kinetics of iron ore powder

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Journal of Iron and Steel Research International 2024年第8期31卷 1840-1849页

作者： Guo-min Zhu Ming-wei Hu An-nan dou Jin-yu Huang jing Ding Qi-yan Xu School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina

Due to the instability of FeO at temperatures below 843 K,the fuidization reduction pathway of iron ore powder changes with the reduction ***,the effect of temperature and reaction pathway interaction on the kinetics of fuidization reduction of iron ore powder under low-temperature conditions ranging from 783 to 903 K was investigated to describe the fluidization reduction rate of iron ore powder from three aspects:microstructure change,reaction limiting link,and apparent activation energy of the reaction,exploring their internal *** experimental results revealed that in a temperature range of 783-813 K,the formation of a dense iron layer hindered the internal diffusion of reducing gas,resulting in relatively high gas diffusion *** addition,due to the differences in limiting links and reaction pathways in the intermediate stage of reduction,the apparent activation energy of the reaction *** apparent activation energy of the reaction ranged from 23.36 to 89.13 kJ/mol at temperature ranging from 783 to 813 K,while it ranged from 14.30 to 68.34 kJ/mol at temperature ranging from 873 to 903 K.

关键词： Reaction limiting link Gas internal diffusion Interface reaction Apparent activation energy Iron ore powder Reaction pathway Fluidization reduction