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Preparation of CIP@TiO_(2) composite with broadband electromagnetic wave absorption properties

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 197-205页

作者： Qiang su Hanqun wang Yunfei He Dongdong Liu Xiaoxiao Huang Bo zhong School of Materials Science and Engineering Harbin Institute of TechnologyWeihaiWeihai 264209China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Scholars aim for the improved impedance matching (Z) of materials while maintaining their excellent wave absorption properties. Based on the hydrolysis characteristics of isopropyl titanate, a simple preparation process for the coating of carbonyl iron powder(CIP) with TiO_(2) was designed. Given the TiO2coating, the Z of the CIP@TiO_(2) composite was adjusted well by decreasing the dielectric constant. Moreover, the interfacial polarization of CIP@TiO_(2) was enhanced. Ultimately, the electromagnetic-wave (EMW) absorption property of the CIP@TiO_(2)composite was improved substantially, the minimum reflection loss reached-46.07 dB, and the effective absorption bandwidth can reach 8 GHz at the composite thickness of 1.5 mm. Moreover, compared with CIP, the oxidation resistance of CIP@TiO_(2)showed remarkable improvement. The results revealed that the oxidation starting temperature of CIP@TiO_(2) as about 400℃,whereas the uncoated CIP had an oxidation starting temperature of approximately 250℃. Moreover, the largest oxidation rate temperature of CIP@TiO_(2) increased to around 550℃. This work opens up a novel strategy for the production of high-performance EMW absorbers via structural design.

关键词： carbonyl iron@titanium dioxide electromagnetic-wave absorption impedance matching oxidation resistance

Precise Planar-Twisted Molecular Engineering to Construct Semiconducting Polymers with Balanced Absorption and Quantum Yield for Efficient Phototheranostics

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Research 2024年第2期2023卷 227-238页

作者： Xiang su Zhirong Bao Wei Xie Deliang wang Ting Han Dong wang Ben zhong Tang Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China Department of Radiation and Medical Oncology Hubei Key Laboratory of Tumor Biological BehaviorsHubei Cancer Clinical Study CenterZhongnan Hospital of Wuhan UniversityWuhan 430071China Department of Materials Chemistry Huzhou UniversityHuzhou 313000China School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenGuangdong 518172China

Semiconducting polymers(SPs)have shown great feasibility as candidates for near-infrared-II(NIR-Ⅱ)fluorescence imaging-navigated photothermal therapy due to their strong light-harvesting ability and flexible ***,the fluorescence signal of traditional SPs tends to quench in their aggregate states owing to the strongπ-πstacking,which can lead to the radiative decay pathway shutting *** address this issue,aggregation-induced emission effect has been used as a rational tactic to boost the aggregate-state fluorescence of NIR-Ⅱ*** this contribution,we developed a precise molecular engineering tactic based on the block copolymerizations that integrate planar and twisted segments into one conjugated polymer backbone,providing great flexibility in tuning the photophysical properties and photothermal conversion capacity of *** monomers featured with twisted and planar architectures,respectively,were tactfully incorporated via a ternary copolymerization approach to produce a series of new *** optimal copolymer(SP2)synchronously shows desirable absorption ability and good NIR-Ⅱquantum yield on the premise of maintaining typical aggregation-induced emission characteristics,resulting in balanced NIR-Ⅱfluorescence brightness and photothermal ***-dispersible nanoparticles fabricated from the optimal SP2 show efficient photothermal therapeutic effects both in vitro and in *** in vivo investigation reveals the distinguished NIR-Ⅱfluorescence imaging performance of SP2 nanoparticles and their photothermal ablation toward tumor with prominent tumor accumulation ability and excellent biocompatibility.

关键词： property conducting twisted

Research on the navigation method of large-scale differential tail-control improvised guided munitions based on rotational speed constraints

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Defence Technology（防务技术） 2024年第8期38卷 155-170页

作者： Ning Liu Wenjiang Zhao Yao wang Kai Shen zhong su Wenhao Qi Yuedong Xie Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science and Technology UniversityBeijing100192China Hua an Industry Group Co. Ltd.Qiqihar161006China Integrated Navigation and Intelligent Navigation Laboratory Beijing Institute of TechnologyBeijing100081China Beijing Institute of Technology Beijing100081China

In the process of launching guided projectile under the conventional system, it is difficult to effectively obtain the precise navigation parameters of the projectile in the high dynamic environment. Aiming at this problem, this paper describes a new system of guided ammunition based on tail spin reduction. After analyzing the mechanism of the ammunition's tail spin reduction, a navigation method of large scale difference tail control simple guided ammunition based on speed constraint is proposed. In this method,the corresponding navigation constraints can be carried out by combining the rotation speed state of the ammunition itself, and the optimal solution of navigation parameters during the flight of the missile can be obtained by Extended Kalman Filter(EKF). Finally, the performance of the proposed method was verified by the simulation environment, and the hardware-in-the-loop simulation test and flight test were carried out to verify the performance of the method in the real environment. The experimental results show that the proposed method can achieve the optimal estimation of navigation parameters for simple guided ammunition with large-scale difference tail control. Under the conditions of simulation test and hardware-in-loop simulation test, the position and velocity errors calculated by the method in this paper converged. Under the condition of flight test, the spatial average error calculated by the method described in this paper is 6.17 m, and the spatial error of the final landing point is 3.50 *** this method, the accurate acquisition of navigation parameters in the process of projectile launching is effectively realized.

关键词： Guided projectiles Tail spin reduction RPM constraints Combined navigation Extended Kalman filter(EKF)

Exploring the impact of Nafion modifier on electrocatalytic CO_(2) reduction over Cu catalyst

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Journal of Energy Chemistry 2024年第1期88卷 543-551,I0012页

作者： Yingshi su Yonghui Cheng Zhen Li Yanjia Cui Caili Yang Ziyi zhong Yibing Song Gongwei wang Lin Zhuang College of Chemistry&Chemical Engineering and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou 515063GuangdongChina College of Chemistry and Molecular Sciences Hubei Key Lab of Electrochemical Power SourcesWuhan UniversityWuhan 430072HubeiChina The Institute for Advanced Studies Wuhan UniversityWuhan 430072HubeiChina Department of Chemistry Engineering Guangdong Technion-Israel Institute of Technology(GTIIT)Shantou 515063GuangdongChina Technion-Israel Institute of Technology(IIT) Haifa 32000Israel

Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode ***,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)***,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)*** found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product *** to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology ***,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.

关键词： Nafion modifier CO_(2)reduction Cu nanoparticles In situ ATR-SEIRAS C_(2)product

Contrasting strategies of optimizing carrier concentration in bulk InSe for enhanced thermoelectric performance

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Rare Metals 2024年第9期43卷 4425-4432页

作者： Hao-Nan Shi Shu-Lin Bai Yu-Ping wang Li-zhong su Qian Cao Cheng Chang Li-Dong Zhao School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Huabei Cooling Device Co.Ltd. Hebei 065400China

Indium selenide(InSe),as a wide-bandgap semiconductor,has received extensive attention in the flexible electronics field in recent years due to its exceptional plasticity and promising thermoelectric ***,the low carrier concentration severely limits its thermoelectric performance *** this work,we conducted contrasting strategies that can be employed to increase the carrier concentration of InSe,including bandgap narrowing and heterovalent ***,the carrier concentration initially increases as a result of the reduced bandgap upon Te alloying and then slightly decreases due to the weak electronegativity of *** Br doping realizes high carrier concentration by pushing the Fermi level into the conduction bands and activating the multiple *** the other hand,both Te and Br obviously suppress the thermal conductivity due to the point defect *** contrast,Br doping realizes a higher thermoelectric performance with a maximum ZT of~0.13 at 773 K benefiting from the better optimization of carrier *** work elucidates the strategies for enhancing carrier concentration at anion sites and demonstrates the high efficiency of halogen doping in ***,the carrier concentration of InSe is promising to be further optimized,and future work should focus on employing approaches such as cation doping or secondphase compositing.

关键词： Thermoelectric InSe Carrier concentration Bandgap Heterovalent doping

NiO@Ni nanoparticles embedded in N-doped carbon for efficient photothermal CO_(2) methanation coupled with H_(2)O splitting

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Nano Research 2024年第4期17卷 2283-2290页

作者： Yun Zhou Peng Zheng Fang wang Fangna Gu Wenqing Xu Qinyang Lu Tingyu Zhu Ziyi zhong Guangwen Xu Fabing su Institute of Process Engineering Chinese Academy of SciencesBeijing 100190China Key Laboratory on Resources Chemicals and Materials of Ministry of Education Shenyang University of Chemical TechnologyShenyang 110142China Institute of Industrial Chemistry and Energy Technology Shenyang University of Chemical TechnologyShenyang 110142China School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China Beijing Key Laboratory of Enze Biomass Fine Chemicals College of New Materials and Chemical EngineeringBeijing Institute of Petrochemical TechnologyBeijing 102617China International School of Beijing 10 An Hua Street Shunyi DistrictBeijing 100048China Department of Chemical Engineering Guangdong Technion Israel Institute of Technology(GTIIT)Shantou 515063China Technion Israel Institute of Technology(IIT) Haifa32000Israel

Photothermal carbon dioxide(CO_(2))methanation has attracted increasing interest in solar fuel synthesis,which employs the advantages of photocatalytic H_(2)O splitting as a hydrogen source and photothermal catalytic CO_(2) *** work prepared three-dimensional(3D)honeycomb N-doped carbon(NC)loaded with core–shell NiO@Ni nanoparticles generated in situ at 500℃(NiO@Ni/NC-500).Under the photothermal catalysis(200℃,1.5 W/cm^(2)),the CH_(4) evolution rate of NiO@Ni/NC-500 reached 5.5 mmol/(g·h),which is much higher than that of the photocatalysis(0.8 mmol/(g·h))and the thermal catalysis(3.7 mmol/(g·h)).It is found that the generated localized surface plasmon resonance enhances the injection of hot electrons from Ni to NiO,while thermal heating accelerates the thermal motion of radicals,thus generating a strong photo-thermal synergistic effect on the *** CO_(2) reduction to CH_(4) follows the*OCH *** work demonstrates the synergistic effect of NiO@Ni and NC can enhance the catalytic performance of photothermal CO_(2) reduction reaction coupled with water splitting reaction.

关键词： Ni localized surface plasmon resonance photothermal methanation

The Adsorption Behavior of Lithium Cationon Polyacene and Its Influenceon Conductive Property

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Chemical Research in Chinese Universities 1994年第3期10卷 244-249页

作者： su zhong-min, wang Rong-shun , JIANG Xiao-dongSHI zhong-liang and XIE De-min(Department of Chemistry , Northeast Hormal University , Changchun , 130024 )

he adsorption beliavior of lithium cation (Li￣+) on the surface of polyacenesemiconductor (PAS) molecule was investigated using quantum chemistry MNDOand CNDO/2 methods. There are two stable adsorption sites of Li￣+ over C=Cbond and benzene ring center of PAS. In the second site, adsorption energy is larg-er. Lithium adsorbed at other sites can easily migrate towards the two sites. Thecalculation of EHMO-CO energy band structures indicated that after lithium wasadsorbed at other different sites on the surface of PAS, the energy gap of the sys-tem had a little increase in most cases , but when Li￣+ was adsorbed at the hole site ,the energy gap had a little decrease, which is in favor of furtlier improvement ofconductive property. As an electrode material , the hole site may be the best site ofLi￣+ being adsorbed and desorbed.

关键词： Polyacene Lithium cation Adsorption

Structures and ion transport mechanisms of plant high-affinity potassium transporters

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Molecular Plant 2024年第3期17卷 409-422页

作者： Jiangqin wang Yanping Luo Fan Ye zhong Jie Ding Shao Jian Zheng Shuai Qiao Yong wang Jiangtao Guo Wei Yang Nannan su international Institutes of Medicine the Fourth Affiliated HospitalZhejang University School of MedicineYiwuZhejiang 322000China Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital Zhejiang University School of MedicineHangzhouZhejang 310058China State Key Laboratory of Plant Environmental Resilience College of Life SciencesZhejang UniversityHangzhouZhejang 310058China College of Life Sciences Zhejiang UniversityHangzhouZhejiang 310058China NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Science and Brain-machine IntegrationSchool of Brain Science and Brain MedicineZhejiang UniversityHangzhouZhejiang 310058China Nanhu Brain-computer Interface Institute Hangzhou.Zheiang 311100.China

Plant high-affinity K^(+) transporters(HKTs)mediate Na^(+) and K^(+) uptake,maintain Na^(+)/K^(+) homeostasis,and therefore play crucial roles in plant salt *** this study,we present cryoelectron microscopy structures of HKTs from two classes,classI HKT1;1 from Arabidopsis thaliana(AtHKT1;1)and class II HKT2;1 from Triticum aestivum(TaHKT2;1),in both Na^(+) -and K^(+) -bound states at 2.6-to 3.0-A ***1;1and TaHKT2;1function *** HKT subunit consists of four tan-dem domain units(D1-D4)with a repeated K^(+) -channel-like M-P-M *** each subunit,D1-D4 assemble into an ion conduction pore with a pseudo-four-fold *** both TaHKT2;1and AtHKT1;1 have only one putative Na^(+) ion bound in the selectivity filter with a similar coordination pattern,the two HKTs display different K^(+) binding modes in the ***2;1 has three K^(+) ions bound in the selec-tivity filter,but AtHKT1;1 has only two K^(+) ions bound in the filter,which has a narrowed external entrance due to the presence of a Ser residue in the first filter *** structures,along with compu-tational,mutational,and electrophysiological analyses,enable us to pinpoint key residues that are critical for the ion selectivity of *** findings provide new insights into the ion selectivity and ion transport mechanisms of plant HKTs and improve our understanding about how HKTs mediate plant salt tolerance and enhance crop growth.

关键词： HKTs structure ion selectivity mechanism salt tolerance

Controlling the Si/C ratio in SiC matrix based on the modified polymethysilane for C/C-SiC composites with enhanced mechanical properties

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Journal of Advanced Ceramics 2024年第2期13卷 220-236页

作者： Mingdong Liao Xiebo Hu Chenghao zhong Ping Xu Xiaodong wang Ze Zhang Peng Zhou Mingyu Zhang Zhean su Qizhong Huang National Key Laboratory of Science and Technology on High-Strength Structural Materials Central South UniversityChangsha 410083China

Fabricating SiC matrix with controllable Si/C ratio for C/C-SiC composites via precursor infiltration and pyrolysis is difficult to realize due to the absence of suitable ***,SiC precursors with Si-rich(Si/C=1.23),nearstoichiometric(Si/C=1.01),and C-rich(Si/C=0.88)pyrolyzed ceramics at 1200℃ were successfully synthesized by the novel modification of *** structure and ceramization of synthesized SiC precursors were studied,and C/C-SiC composites with similar Si/C ratio in SiC matrix were also *** results revealed that the defects and Young’s modulus of SiC matrix and the thermal residual stress on pyrolytic carbon coated carbon fiber were determined by the Si/C *** a result,the Si/C ratio exerted significant effects on the crack deflection behavior and the mechanical properties of the *** composites with near-stoichiometric SiC matrix showed excellent mechanical properties because of the effective crack deflection and the moderate Young’s modulus of their SiC *** flexural strength,flexural modulus,and compressive strength were 423±27 MPa,33.41±4.52 GPa,and 393±8 MPa,***,after a heat treatment at 1600℃,the role of carbon fiber toughening was improved and accompanied by a decrease in mechanical properties for all composites,which was attributed to the increased defects in SiC matrix and the damaged interfaces by the thermal residual stress.

关键词： SiC precursor Si/C ratio polymethysilane C/C–SiC composites mechanical properties