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Chinese Journal of Chemical Engineering 2024年第6期70卷 54-62页

作者： Qingyu Zhang Leming cheng Kun Li Qixun Kang qiang Guo Chaogang wu Institute for Thermal Power Engineering State Key Laboratory of Clean Energy UtilizationZhejiang UniversityHangzhou 310027China Dongfang Boiler Group Co.Ltd. Zigong 643001China

A multitracer-gas method was proposed to study the secondary air(SA)mixing along the bed height in a circulating fluidized bed(CFB)using carbon monoxide(CO),oxygen(O_(2)),and carbon dioxide(CO_(2))as tracer *** were carried out on a cold CFB test rig with a cross-section of 0.42 m×0.73 m and a height of 5.50 *** effects of superficial velocity,SA ratio,bed inventory,and particle diameter on the SA mixing were *** results indicate that there are some differences in the measurement results obtained using different tracer gases,wherein the deviation between CO and CO_(2) ranges from 42%to 66%and that between O_(2) and CO_(2) ranges from 45%to 71%in the lower part of the fluidized ***,these differences became less pronounced as the bed height ***,the high solid concentration and fine particle diameter in the CFB may weaken the *** measurement results of different tracer gases show the same trends under the variation of operating *** superficial velocity and SA ratio and decreasing particle diameter result in better mixing of the *** effect of bed inventory on SA mixing is not monotonic.

关键词： Circulating fluidized bed Secondary air injection Gas mixing Multitracer-gas method

Corrosion behavior of Al_(2)O_(3)-C bricks in MnO-containing mold slag

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Journal of Iron and Steel Research International 2024年第6期31卷 1486-1492页

作者： Yi-jiang Zhao Guang-qiang Li Yang wu cheng Yuan Ze Meng Xiao-xuan Deng Yu Liu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Research Institute of Technology Shougang Group Co.Ltd.Beijing 100043China

In order to explore the corrosion mechanism of Al_(2)O_(3)-C refractories in the mold flux bearing MnO,the immersion test of Al_(2)O_(3)-C refractories in CaO-SiO2-CaF2-MnO slag with different MnO contents was carried out at 1550℃.The results show that Mn particles were observed in the slag after experiment,due to the reduction of MnO by graphite in *** amounts of graphite were observed at the interface between refractories and slag,indicating that the oxidation of graphite is limited by the poor contact between graphite and molten ***,the oxidation of graphite is not the main cause of damage to refractories.A small quantity of CaO·2Al_(2)O_(3)(CA_(2))and CaO·6Al_(2)O_(3)(CA_(6))adjacent to Al_(2)O_(3) grain was detected at the slag/reaction layer ***_(2) and CA_(6) possess relatively high melting points,which is beneficial to hindering the further penetration of ***,the dissolution of Al_(2)O_(3) into slag is still the main cause for refractories *** increase in the MnO content of mold slag decreases the viscosity and then results in the severe corrosion of Al_(2)O_(3)-C bricks.

关键词： Al_(2)O_(3)-C refractory MnO-containing slag Graphite Corrosion

Exclusive Hypothesis Testing for Cox's Proportional Hazards Model

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Journal of Systems Science & Complexity 2024年第5期37卷 2157-2172页

作者： wu qiang TONG Xingwei DUAN Xiaogang School of Statistics Beijing Normal UniversityBeijing 100875China

Exclusive hypothesis testing is a new and special class of hypothesis *** kind of testing can be applied in survival analysis to understand the association between genomics information and clinical information about the survival ***,it is well known that Cox's proportional hazards model is the most commonly used model for regression analysis of failure *** this paper,the authors consider doing the exclusive hypothesis testing for Cox's proportional hazards model with right-censored *** authors propose the comprehensive test statistics to make decision,and show that the corresponding decision rule can control the asymptotic TypeⅠerrors and have good powers in *** numerical studies indicate that the proposed approach works well for practical situations and it is applied to a set of real data arising from Rotterdam Breast Cancer Data study that motivated this study.

关键词： Comprehensive test statistics Cox’s proportional hazards model exclusive hypothesis testing right-censored data Type I error

“In-N-out” design enabling high-content triethyl phosphate-based non-flammable and high-conductivity electrolytes for lithium-ion batteries

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Science China Chemistry 2024年第2期67卷 724-731页

作者： Mengchuang Liu Fenfen Ma Zicheng Ge Ziqi Zeng qiang wu Hui Yan Yuanke wu Sheng Lei Yanli Zhu Shijie cheng Jia Xie State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan430074China School of Chemistry and Chemical Engineering Huazhong University of Science and TechnologyWuhan430074China GuSu Laboratory of Materials Suzhou215123China Institute of Metal Research Chinese Academy of SciencesShenyang110000China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

Safety issues related to flammable electrolytes in lithium-ion batteries(LIBs) remain a major challenge for their extended *** use of non-flammable phosphate-based electrolytes has proved the validity in inhibiting the combustion of ***,the strong interaction between Li^(+) and phosphate leads to a dominant solid electrolyte interphase(SEI) with limited electronic shielding,resulting in the poor Li^(+) intercalation at the graphite(Gr) anode when using high-phosphate-content *** mitigate this issue and improve Li^(+) insertion,we propose an “In-N-Out” strategy to render phosphates “noncoordinative”.By employing a combination of strongly polar solvents for a “block effect” and weakly polar solvents for a “drag effect”,we reduce the Li^(+)–phosphate *** a result,phosphates remain in the electrolyte phase(“In”),minimizing their impact on the incompatibility with the Gr electrode(“Out”).We have developed a non-flammable electrolyte with high triethyl phosphate(TEP) content(>60 wt.%),demonstrating the excellent ion conductivity(5.94 mS cm^(-1) at 30 ℃) and reversible Li^(+) intercalation at a standard concentration(~1 mol L^(-1)).This approach enables the manipulation of multiple electrolyte functions and holds the promise for the development of safe electrochemical energy storage systems using non-flammable electrolytes.

关键词： lithium-ion batteries graphite anode high-phosphate-content electrolytes non-flammable electrolyte excellent ion conductivity standard concentration

Continuous Orbit Equivalence of Semigroup Actions

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1581-1598页

作者： Xiang Qi qiang cheng Jun HOU School of Mathematical Science Yangzhou UniversityYangzhou 225002P.R.China

We introduce notions of continuous orbit equivalence and its one-sided version for countable left Ore semigroup actions on compact spaces by surjective local homeomorphisms,and characterize them in terms of the corresponding transformation groupoids and their operator *** particular,we show that two essentially free semigroup actions on totally disconnected compact spaces are continuously orbit equivalent if and only if there is a canonical abelian subalgebra preserving C^(∗)-isomorphism between the associated transformation groupoid C^(∗)-*** also give some examples of orbit equivalence,consider the special case of semigroup actions by homeomorphisms and relate continuous orbit equivalence of semigroup actions to that of the associated group actions.

关键词： Semigroup action continuous one-sided orbit equivalence continuous orbit equivalence groupoid C^(∗)-algebras

MOF-mediated synthesis of novel PtFeCoNiMn high-entropy nanoalloy as bifunctional oxygen electrocatalysts for zinc-air battery

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Nano Research 2024年第6期17卷 5288-5297页

作者： Mingkuan Xie Xin Xiao Duojie wu cheng Zhen Chunsheng wu Wenjuan Wang Hao Nian Fayan Li Meng Danny Gu qiang Xu Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials(SKLPM) Shenzhen 518055China Department of Chemistry Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory(SKAEM-JIL) Shenzhen 518055China Key University Laboratory of Highly Efficient Utilization of Solar Energy and Sustainable Development of Guangdong Southern University of Science and TechnologyShenzhen 518055China Eastern Institute for Advanced Study Eastern Institute of TechnologyNingbo 315200China

High-entropy alloy(HEA)-based materials are expected to be promising oxygen electrocatalysts due to their exceptional *** electronic structure regulation of HEAs plays a pivotal role in enhancing their elctrocatalytic ***,PtFeCoNiMn nanoparticles(NPs)with subtle lattice distortions are constructed on metal-organic framework-derived nitrogen-doped carbon by an ultra-rapid Joule heating *** to the modulated electronic structure and the inherent cocktail effect of HEAs,the as-synthesized PtFeCoNiMn/NC exhibits superior bifunctional electrocatalytic performance with a positive half-wave potential of 0.863 V *** hydrogen electrode(RHE)for oxygen reduction reaction and a low overpotential of 357 mV at 10 mA·cm^(-2)for oxygen evolution *** assembled quasi-solid-state zinc-air battery using PtFeCoNiMn/NC as air electrode shows a high peak power density of 192.16 mW·cm^(-2),low charge−discharge voltage gap,and excellent durability over 500 cycles at 5 mA·cm^(-2).This work demonstrates an effective route for rational design of bifunctional nanostructured HEA electrocatalysts with favorable electronic structures,and opens up a fascinating directions for energy storage and conversion,and beyond.

关键词： oxygen reduction reaction oxygen evolution reaction high-entropy nano-alloy zinc-air battery

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong wu qiang Fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Loosely coordinating diluted highly concentrated electrolyte toward -60℃ Li metal batteries

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Journal of Energy Chemistry 2024年第3期90卷 380-387,I0009页

作者： Han Zhang Ziqi Zeng qiang wu Xinlan Wang Mingsheng Qin Sheng Lei Shijie cheng Jia Xie State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina

Lithium metal batteries(LMBs) promise energy density over 400 Wh kg^(-1).However,they suffer severe electrochemical performance deterioration at sub-zero *** failure behavior highly correlates to inferior lithium metal anode(LMA) compatibility and sluggish Li^(+) ***,we demonstrate that cyclopentylmethyl ether(CPME) based diluted high-concentration electrolyte(DHCE)enables-60℃ LMBs *** leveraging the loose coordination between Li^(+) and CPME,such developed electrolyte boosts the formation of ion clusters to derive anion-dominant interfacial chemistry for enhancing LMA compatibility and greatly accelerates Li^(+) desolvation *** resulting electrolyte demonstrates high Coulombic efficiencies(CE),providing over 99.5%,99.1%,98.5% and 95% at 25,-20,-40,and-60℃*** assembled Li-S battery exhibits remarkable cyclic stability in-20,and-40℃ at 0.2 C charging and 0.5 C *** at-60℃,Li-S cell with this designed electrolyte retains> 70% of the initial capacity over 170 ***,lithium metal coin cell and pouch cell with10 mg cm^(-2) high S cathode loading exhibit cycling stability at-20℃.This work offers an opportunity for rational designing electrolytes toward low temperature LMBs.

关键词： Lithium metal batteries -60℃operation Lithium metal anode compatibility Li^(+) desolvation kinetics

Recent Advances in C-F Bond Formation from Carbon-Centered Radicals

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Chinese Journal of Chemistry 2024年第9期42卷 1009-1031页

作者： Jihua Zhang Juanjuan Wang qiang cheng College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei 430072China

Construction of C-F bonds is a direct and efficient method for introducing fluorine into pharmaceuticals,agrochemicals,and *** such as nucleophilic,electrophilic,radical,and transition-metal catalyzed fluorination have been developed to meet the demand of diverse C-F bond *** them,radical fluorination has been witnessed with substantial advancement in a recent ***,we reviewed methods for formation of C-F bonds with carbon-centered radicals as key intermediates,especially in recent five *** introduce in the paper with different fluorinating reagents,strategies for radical generation,and application in late-stage functionalization and synthesis of PET *** also indicate the current limitations and propose the direction of the field for the future development.

关键词： Fluorine Fluorinating reagents Late-stage fluorination [^(18)F]jfluorination Radical reactions Synthetic methods

Macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

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National Science Review 2024年第3期11卷 159-171页

作者： Rui Wen Shao Jun Wei wu Zheng Xing Wang Hui Xu Han Qing Yang qiang cheng Tie Jun Cui Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University Peng cheng Laboratory Pazhou Laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model