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Walnut septum-derived hierarchical porous carbon for ultra-high-performance supercapacitors

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Rare Metals 2022年第7期41卷 2280-2291页

作者： Meng Zhou Sheng-Xue Yan Qing Wang Ming-xiu Tan Deng-Yang Wang Zi-Qi Yu Shao-Hua Luo Ya-Hui zhang Xin Liu School of Materials Science and Engineering Northeastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China Hebei Key Laboratory of Dielectric and Electrolyte Functional Material Qinhuangdao 066004China Qinhuangdao Key Laboratory of Advanced Energy Storage and Conversion Technology Qinhuangdao 066004China

The conversion of biomass waste into eco-nomical and high-performance energy storage devices receives significant ***,a facile and green method to prepare porous active carbon from walnut sep-tum is applied to the electrode materials of *** effect of chemical etching reagent(KOH)on the microstructure and specific capacitance of the porous car-bon are *** modified BC-2.0,with a KOH/walnut septum mass ratio of 2∶1,exhibits large specific surface area of 1003.9 m^(2)·g^(-1)with hierarchical micro-mesoporous ***-2.0 reveals a superior specific capacitance of 457 F·g^(-1)at 1 A·g^(-1).The flexible sym-metric supercapacitor in gel electrolyte(KOH/PVA)exhi-bits considerable synergetic energy-power output *** results indicate that walnut septum is a better precursor to obtain activated carbons relative to other biomass carbon *** large mesoporosity after activation effectively boosts the electrochemical properties of ***,the walnut septum has potential to be a superior electrode material for supercapacitors.

关键词： Activation Biocarbon Micro-mesoporous structure Supercapacitor High specific capacitance

Synthesis of Two-Dimensional C–C Bonded Truxene-Based Covalent Organic Frameworks by Irreversible Brønsted Acid-Catalyzed Aldol Cyclotrimerization

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Research 2021年第1期2021卷 860-867页

作者： Qingsong zhang Yunlong Sun Haijing Li Kun Tang Yu-Wu Zhong Dong Wang Yunlong guo Yunqi Liu Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

The synthesis of new C–C bonded two-dimensional(2D)covalent organic frameworks(COFs)is highly ***,a simple but effective synthetic strategy has been developed using an irreversible Brønsted acid-catalyzed aldol cyclotrimerization reaction by virtue of truxene as a *** C–C bonded 2D truxene-based covalent organic frameworks(Tru-COFs)were constructed by polymerization of 1,3,5-triindanonebenzene(TDB).The structure formation was confirmed by wide-angle X-ray scattering,Fourier-transform infrared spectroscopy,and solid-state^(13)C CP/MAS *** results showed that the Tru-COFs were porous(645 m^(2)/g)and chemically *** methylene in conjugated Tru-COFs more effectively produced photoinduced radicals than the model truxene *** to the radical photoresponsiveness,Tru-COFs were efficient catalysts for photocatalytic oxidation of *** expect that this will provide a new synthetic methodology to obtain C–C bonded functional 2D COFs.

关键词： bonded reversible valent

Scalable Reaction-spinning of Rigid-rod Upilex-S^(■) Type Polyimide Fiber with an Ultrahigh T_(g)

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Chinese Journal of Polymer Science 2021年第5期39卷 592-600,I0007页

作者： Sen-Sen Zheng Han Dong Shi-Hua Wang Jie Dong Tao guo Xin Zhao Qing-Hua zhang Shanghai Collaborative Innovation Center for High Performance Fiber Composites Engineering Research Center of Technical TextilesMinistry of EducationDonghua UniversityShanghai201620China Jiangsu Aoshen Hi-Tech Materials Co. Ltd.Lianyungang 222000China

In the family of polyimide(PI)materials,Upilex-S^(■) film has been a shining star through the research PI materials due to its appealing ***,the wholly rigid-rod backbone and easily formed skin-core micromorphology and microvoids of Upilex-S~type PI lead to the high difficulty in melt-and wet-spinning ***,we propose a facile and scalable method,reaction-spinning,to fabricate the Upilex-S^(■) type PI fiber,in which the rapid solidification of spinning dope and partial imidization take place ***,the stability and mechanical strength of as-spun fibers can be improved,and the microvoids in fibers can be greatly reduced in relative to the wet-spun *** resultant Upilex-S^(■) type PI fiber shows higher tensile strength and modulus than most commercial thermal-oxidative polymeric fibers with an ultrahigh glass transition temperature T_(g) of 478℃.Moreover,the WAXS and SAXS results indicate that orthorhombic crystals are formed for Upilex-S^(■) type PI fiber in the post hot-drawing *** the hot-drawing temperature results in a continuous crystallization and high orientation of PI chains in amorphous phase and perfects the existing lamellar structure,which make a great contribution to the improved mechanical property.

关键词： Polyimide fiber Reaction-spinning Ultrahigh T_(g) Crystal structure

Calixarene-integrated nano-drug delivery system for tumortargeted delivery and tracking of anti-cancer drugsin vivo

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Nano Research 2022年第8期15卷 7295-7303页

作者： Lina Xu Jingshan Chai Ying Wang Xinzhi Zhao Dong-Sheng guo Linqi Shi Zhanzhan zhang Yang Liu Key Laboratory of Functional Polymer Materials of Ministry of Education College of ChemistryNankai UniversityTianjin 300071China State Key Laboratory of Medicinal Chemical Biology Nankai UniversityTianjin 300071China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

Nano-drug delivery systems(nanoDDS)have been extensively investigated clinically to improve the therapeutic effect of anticancer ***,the complicated synthesis during the preparation as well as the potential drug leakage during transportation has greatly limited their general *** this work,a calixarene-integrated nanoDDS(CanD)that achieves tumor-targeted delivery and tracking of anti-cancer drugs in vivo is *** hypoxia-responsive calixarene(SAC4A)exhibits high binding affinity to a series of anti-cancer drugs and rhodamine B(RhB)under normoxic condition while decreasing the binding affinity under hypoxic condition,which leads to the drug release and fluorescence recovery ***,the hypoxia-responsiveness of SAC4A conveys CanD with tumor-targeting ability,resulting in the enrichment of the drug in tumors and enhancement in tumor suppression in ***,CanD could become a general platform allowing the delivery of a wide scope of anti-cancer drugs that have strong host-guest interaction with SAC4A.

关键词： drug delivery system calixarene host-guest interaction hypoxia-responsiveness drug tracking

Roles of Cu doping in YbZn_(2)Sb_(2) for thermoelectric performance enhancement

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Rare Metals 2024年第6期43卷 2869-2875页

作者： Xiong zhang Hai-Hui Li Xiao-Liang Cao Bin zhang Hong Wu Yu zhang Guang Han guo-Yu Wang Hao-Shuang Gu Xiao-Yuan Zhou College of Physics and Electronic Science Hubei Normal UniversityHuangshi 435002China Analytical and Testing Center Chongqing UniversityChongqing401331China School of Science Chongqing University of Posts and Telecommunications.Chongqing 400065 China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials-Hubei Key Laboratory of Ferro&Piezoelectric Materials and Devices Faculty of Physical and Electronic SciencesHubei UniversityWuhan 430062China College of Physics Chongqing UniversityChongqing 401331China

Recent research shows that increasing the carrier density after orbital alignment in AZn_(2)Sb_(2) (A=Ca,Yb,Eu,Sr,Mg)Zintl compounds yields remarkable results with regard to enhanced thermoelectric ***,research on carrier density increase via doping in these compounds is *** this study,we introduced Cu into the Zn sites in YbZn_(2)Sb_(2) and examined the thermoelectric properties.

关键词： properties doping performance

Microstructure and mechanical properties of TC4 joints brazed with Ti-Zr-Cu-Sn amorphous filler alloy

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Rare Metals 2021年第7期40卷 1881-1889页

作者： Hui-Hui zhang Zhen-Duo Cui Sheng-Li Zhu Shi-Wei guo Xian-Jin Yang Akihisa Inoue School of Materials Science and Engineering Tianjin UniversityTianjin 30007China Key Laboratory of Advanced Ceramics and Machining Technology Ministry of EducationTianjin 300072China Tianjin Key Laboratory of Composite and Functional Materials Tianjin 300072China Department of Physics King Abdulaziz UniversityJeddah 22254Saudi Arabia

The Ti_(51.44)Zr_(16.26)Cu_(30)Sn_(2.3)(at%)amorphous filler alloy in a ribbon form was prepared by melt *** Ti-6 Al-4 V alloy was brazed in vacuum furnace by using the Ti_(51.44)Zr_(16.26)Cu_(30)Sn_(2.3)amorphous filler *** effects of brazing temperature and holding time on the interfacial microstructure and mechanical properties of the Ti-6 Al-4 V brazed joints were *** brazed joints are composed ofα-Ti,β-Ti,and(Ti,Zr)_(2)Cu *** shear strength of the joints increases with brazing temperature increasing from 1153 to 1193 K and holding time from 10 to 15 min,while decreases with brazing temperature and time further *** temperature brazing results in the formation of microcracks and voids in the seams,which are harmful for the shear strength of the *** the joint brazed at 1193 K for 15 min,a fineα+βWidmansta¨tten structure beneficial to the mechanical property is formed,and the joint exhibits relatively high joint strength of 180 MPa.

关键词： Amorphous alloy Brazing Titanium alloy Microstructure Mechanical property

Kinetic study on microwave-enhanced direct reduction of titanomagnetite concentrate with coal

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Journal of Iron and Steel Research International 2023年第3期30卷 429-445页

作者： Peng Liu Si-yu Gong Yu-wen Chao Bing-guo Liu Li-bo zhang En-hui Wu State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093YunnanChina Yunnan Provincial Key Laboratory of Intensification Metallurgy Kunming 650093YunnanChina National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology Kunming 650093YunnanChina Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Key Laboratory of Unconventional Metallurgy Kunming University of Science and TechnologyKunming 650093YunnanChina Panzhihua University Panzhihua 617000SichuanChina

Titanomagnetite concentrate is one of the important titanium *** apparent activation energy(Ea)of the direct reduction of titanomagnetite concentrate was composed of two parts(average activation energy:E_(a)=E_(a-L)+E_(a-Step1),where E_(a-L) is the lattice energy of titanomagnetite concentrate,and is the activation energy of step 1 for the reduction of titanomagnetite concentrate in the route ***^(3+)→^(Step1)Fe^(2+)→^(Step2)Fe_(2)O^(2)→^(Step3)Fe^(0)).Ea(583.43 kJ/mol),(426.4 kJ/mol),and(157.0 kJ/mol)were calculated by the model-free methods based on thermogravimetry and Dmol3 *** with the analysis of activation energy fluctuation and the shifting trend of related mechanism functions,the reduction kinetic system with three main characteristics,namely nucleation,diffusion and concentration fluctuation,was *** addition,the scanning electron microscopy comparison analysis of the samples from microwave reduction and conventional reduction shows that microwave heating could realize the microstructure Ti-Fe separation and reduce the lattice energy of the titanomagnetite concentrate,thus enhancing the reduction process by 7.68%from the perspective of activation energy.

关键词： Titanomagnetite Kinetics Lattice energy Reduction Microwave Titanium

Harmonic information transitions of spatiotemporal metasurfaces

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Light(Science & Applications) 2020年第1期9卷 58-70页

作者： Haotian Wu Xin Xin Gao Lei zhang guo Dong Bai Qiang Cheng Lianlin Li Tie Jun Cui State Key Laboratory of Millimetre Waves Southeast University210096 NanjingChina Institute of Electromagnetic Space Southeast University210096 NanjingChina State Key Laboratory of Advanced Optical Communication Systems and Networks Department of ElectronicsPeking University100871 BeijingChina

Facilitated by ultrafast dynamic modulations,spatiotemporal metasurfaces have been identified as a pivotal platform for manipulating electromagnetic waves and creating exotic physical phenomena,such as dispersion cancellation,Lorentz reciprocity breakage,and Doppler *** by emerging information-oriented technologies,we hereby probe the information transition mechanisms induced by spatiotemporal variations and present a general model to characterize the information processing capabilities of the spatiotemporal *** theory and abstract number theory are adopted through this investigation,by which the group extension and independent controls of multiple harmonics are proposed and demonstrated as two major tools for information transitions from the spatiotemporal domain to the spectra-wavevector *** incorporating Shannon’s entropy theory into the proposed model,we further discover the corresponding information transition efficiencies and the upper bound of the channel capacity of the spatiotemporal *** results of harmonic information transitions show great potential in achieving high-capacity versatile information processing systems with spatiotemporal metasurfaces.

关键词： surface transitions surfaces

Grain growth behavior and properties of high-entropy pseudobrookite(Mg,Co,Ni,Zn)Ti_(2)O_(5) ceramics

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Journal of Advanced Ceramics 2024年第6期13卷 757-768页

作者： Xiaohui Ma Jinyu Wu Lingyi Meng Jinfeng zhang Heng Chen Liwen Yan Anran guo Jiachen Liu Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300072China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China

It is well known that the grain size of high-entropy ceramics is quite small owing to the sluggish diffusion effect. However, abnormal grain growth often occurs in high-entropy pseudobrookite ceramics, ultimately resulting in the formation of many abnormally grown grains with a grain size as large as 50 μm. To study this phenomenon, the grain growth behavior of high-entropy pseudobrookite ceramics was systematically investigated in this paper. The results demonstrate that the starting material powders first react with each other to form a high-entropy intermediate phase and calcined TiO_(2) powders (TiO_(2)-1100 ℃), and then as the sintering temperature increases, the formed high-entropy intermediate phase further reacts with TiO_(2)-1100 ℃ to form high-entropy pseudobrookite ceramics. Thus, in this system, in addition to the sluggish diffusion effect, the grain sizes of the high-entropy intermediate phase and TiO_(2)-1100 ℃ also affect the morphology of high-entropy pseudobrookite. Compared to nanosized TiO_(2), micron-sized TiO_(2) has a lower sintering activity. Therefore, the high-entropy intermediate phases (Mg,Co,Ni,Zn)TiO_(3) and TiO_(2)-1100 ℃ prepared with micron-sized starting materials exhibit lower grain sizes, finally resulting in the formation of high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with small grain sizes. Moreover, nano-indentation and thermal conductivity tests were carried out on high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with different morphologies. The results show that the hardness of high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) increases from 6.05 to 9.95 GPa as the grain size increases, whereas the thermal conductivity decreases from 2.091±0.006 to 1.583±0.006 W·m^(−1)·K^(−1). All these results indicate that high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with a small grain size is a potential material for thermal protection.

关键词： grain size sluggish diffusion effect two-step solid phase process high-entropy intermediate phase high-entropy pseudobrookite ceramic