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Synergic catalysis of W and Ni originating from substitution of trivacant phosphotungstate for the selective oxidation of aniline to azoxybenzene

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Chinese Chemical Letters 2024年第2期35卷 558-563页

作者： Sheng cai Xiao-Yuan Wu Weiming Wu sa-sa Wang Can-Zhong Lu CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350117China Xiamen Institute of Rare Earth Materials Chinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China

Partial substitution of polyoxometalate(POM)is an efficient route to modulate the catalytic property of maternal *** this work,a new Keggin type POM involving{Ni 6}cluster,{[Ni(H_(2)O)_(2)(Dach)_(2)][Ni(Dach)_(2)]_(2)}{[Ni_(6)Cl(μ-OH)_(3)(H_(2)O)(Dach)_(3)(WO_(4))(PW9 O_(3)_(4))][Ni_(6)(μ-OH)_(3)(H_(2)O)_(2)(Dach)_(3)(WO_(4))(PW9 O_(3)_(4))]}Cl·27H_(2)O,(1,Dach=1,2-diaminocyclohexane)was *** 1 shows excellent catalytic performance in the selective oxidation of aniline to azoxybenzene(AOB)in *** apparently different results from that with the matrix{PW_(9)O_(34)}({PW9})suggest the successful regulation of the catalytic property of{PW9}by the introduction of the{Ni6}cluster into the *** experimental results indicate that the highlighted performance of 1 is contributed by the synergy of W and Ni sites,which are respectively responsible for the oxidation and condensation steps in the production of *** good selectivity to AOB is essentially attributed to the effective modulation of the reaction rates of oxidation and condensation steps by W and Ni sites,respectively.

关键词： Polyoxometalate {Ni_(6)}cluster Modulated catalytic property Aniline oxidation Azoxybenzene

Experimental and theoretical analysis of loading characteristics of electret fi lter media for charged particles

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PARTICUOLOGY 2024年第10期93卷 87-98页

作者： cai, Yiqi cai, Rongrong Zhang, Lizhi South China Univ Technol Sch Chem & Chem Engn Key Lab Enhanced Heat Transfer & Energy Conservat Educ Minist Guangzhou 510640 Peoples R China South China Univ Technol State Key Lab Subtrop Bldg Sci Guangzhou 510640 Peoples R China

The degradation of filtration performance in electret filter media during usage poses a significant challenge. Pre-charging of aerosols has been identified as an effective method to mitigate this issue. However, the effects of particle charging characteristics on the loading characteristics of electret filters still need a comprehensive understanding. In this study, a needle-cylinder corona charger was employed to pre-charge aerosols, and the particle charge state was determined by multiphysics simulation. The effects of particle charge polarity and charge quantity on the loading performance of the electret filter were quantitatively investigated. The results showed that the particle charge polarity had a negligible impact on the loading performance under the condition of the equivalent particle charge quantity. In addition, the charged particles effectively improved the efficiency degradation during the loading process of electret media, with higher charge quantities resulting in more pronounced improvements. The electrostatic attenuation factor showed a negative exponential correlation with the particle charge quantity. This was attributed to the uneven particle deposition on fiber surface due to the attraction of charged particles by the opposite charges on the electret fibers, which alleviated the effect of electrostatic shielding. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences.

关键词： Electret filter Charged particles Loading characteristic Corona charging Electrostatic screening NUMERICAL-SIMULATION FILTER FILTRATION AEROSOL PERFORMANCE COLLECTION TRANSPORT MODEL

Shor's algorithm does not factor large integers in the presence of noise

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Science China(Information Sciences) 2024年第7期67卷 305-320页

作者： Jin-Yi cai College of Letters and Science University of Wisconsin

We consider Shor's quantum factoring algorithm in the setting of noisy quantum gates. Under a generic model of random noise for(controlled) rotation gates, we prove that the algorithm does not factor integers of the form pq when the noise exceeds a vanishingly small level in terms of n—the number of bits of the integer to be factored, where p and q are from a well-defined set of primes of positive density. We further prove that with probability 1-o(1) over random prime pairs(p, q), Shor's factoring algorithm does not factor numbers of the form pq, with the same level of random noise present.

关键词： random noise Shor's algorithm rotation gates quantum computing prime factorization

Whittle’s Index Based Sensor Scheduling for Multiprocess Systems Under DoS Attacks

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Journal of Systems Science & Complexity 2024年第1期37卷 329-350页

作者： cai Zai DING Kemi Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China.

In this paper,the authors consider how to design defensive countermeasures against DoS attacks for remote state estimation of multiprocess *** each system,a sensor will measure its state and transmits the data packets through an unreliable channel which is vulnerable to be jammed by an *** limited communication bandwidth,only a subset of sensors are allowed for data transmission,and how to select the optimal one to maximize the accuracy of remote state estimation is the focus of the proposed *** authors first formulate this problem as a Markov decision process and investigate the existence of optimal ***,the authors demonstrate the piecewise monotonicity structure of optimal *** the difficulty of obtaining an optimal policy of large-scale problems,the authors develop a suboptimal heuristic policy based on the aforementioned policy structure and Whittle’s ***,a closed form of the indices is derived in order to reduce implementation complexity of proposed scheduling policy and numerical examples are provided to illustrate the proposed developed results.

关键词： DoS attacks Kalman filter remote state estimation Whittle’s index.

Polarized imaging dynamic light scattering for simultaneous measurement of nanoparticle size and morphology

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Particuology 2024年第2期85卷 213-223页

作者： Bingyao Wang Tianyi cai Xiaoshu cai Wu Zhou Zeqi Liu Schoolof Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093China Jiaxing MeaParTech Instrument Technology Co. LtdZhejiang314000China

The performance of nanoparticles is often affected by particle size and ***,electron microscopy or atomic force microscopy is typically utilized to determine the size and morphology of ***,there are issues such as difficult sample preparation,long processing times,and challenges in quantitative ***,it is of great significance to develop a fast,accu-rate,and statistical method to measure the size and morphology of *** this study,a new method,called polarized imaging dynamic light scattering(PIDLS),is *** nanoparticles are irradiated with a vertical linearly polarized laser beam,and a polarization camera collected the dynamic light scattering images of particles at four different polarization directions(0°,45°,90°,and 135°)at a scattering angle of 90°.The average particle size and distribution are obtained using the imaging dy-namic light scattering method at 0°polarization direction,and the morphology of the particles is ob-tained based on the depolarization patterns of the scattered *** optical sphericityΦis defined based on the degree of linear polarization(DoLP).It is also implemented for the quantitative evaluation of the sphericity of the nanoparticles,including spherical,octahedral,nanoplate,nanorod,and linear *** with the Poincarésphere parameterψ,the morphology of the nanoparticles can be roughly *** addition,PIDLS enables the measurement of particle size and morphology distributions simultaneously for evaluating the uniformity of *** effectiveness of PIDLS is verified by the measurement of five kinds of industrial titanium dioxide as well.

关键词： Imaging dynamic light scattering Polarized light scattering Non-spherical nanoparticles Morphology Online measurement

Mathematical framework of nonlinear elastic waves propagating in pre-stressed media

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1705-1716页

作者： Jiangcheng cai Mingxi DENG College of Aerospace Engineering Chongqing University

Acoustic nonlinearity holds potential as a method for assessing material stress. Analogous to the acoustoelastic effect, where the velocity of elastic waves is influenced by third-order elastic constants, the propagation of nonlinear acoustic waves in pre-stressed materials would be influenced by higher-order elastic constants. Despite this,there has been a notable absence of research exploring this phenomenon. Consequently,this paper aims to establish a theoretical framework for governing the propagation of nonlinear acoustic waves in pre-stressed materials. It delves into the impact of pre-stress on higher-order material parameters, and specifically examines the propagation of onedimensional acoustic waves within the contexts of the uniaxial stress and the biaxial stress. This paper establishes a theoretical foundation for exploring the application of nonlinear ultrasonic techniques to measure pre-stress in materials.

关键词： 74J30 acoustoelastic effect higherorder elastic constant nonlinear elastic wave O343 pre-stress medium

An ultra-porous g-C_(3)N_(4) micro-tube coupled with MXene(Ti_(3)C_(2)TX)nanosheets for efficient degradation of organics under natural sunlight

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Journal of Environmental Sciences 2024年第3期137卷 258-270页

作者： Zongyang Ya Qiyou Wang Jingjin cai Peng Wang Xinyu Jiang Zhiyin cai Shanglin Xiang Tingwei Wang Dongyu cai College of Materials Science&Engineering Nanjing Tech University30 South PuZhu RoadNanjing 211816China Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech University30 South PuZhu RoadNanjing 211816China

It remains as a challenge for realizing efficient photo-responsive catalysts towards largescale degradation of organic pollutants under natural *** work reports a new pore engineering strategy for creating ultra-porous g-C_(3)N_(4) micro-tubes with an unprecedentedly high specific surface area of 152.96 m^(2)/*** is mainly associated with releasing internal vapor pressure in the autoclave where the hydrothermal treatment of the urea/melamine mixture is *** by microscopic observation,porosity measurement and spectroscopic characterization,it is found that releasing the pressure at halfway of hydrothermal process is vital for forming exfoliated rod-like precursors and the de-aggregation of these rods presents substantial benefits on the production of mesopores on g-C_(3)N_(4) microtubes during the calcination of *** offers a large number of reactive sites required by photocatalytic *** these micro-tubes with Ti_(3)C_(2)T_(X) nanosheets via electrostatic interaction yields a 1D/2D heterojunction with a close interfacial *** addition of metallically conductive Ti_(3)C_(2)T_(X) nanosheets accelerates the separation between electrons and holes,and also enhances the light *** these merits of structural design lead to forming a group of highly efficient catalysts demonstrating an excellent photocatalytic degradation rate of k=0.0560 min^(-1)for RhB dyes under 100 mW/cm~2 visible light radiation that micks sunlight *** laboratory valuation is further supported by an outdoor test that shows a fast degradation rate of 0.0744 min^(-1)under natural sunlight.

关键词： Carbon nitride MXene Heterojunction Photocatalysis

Review of dynamics and active control of large-scale space membrane antenna

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Astrodynamics 2024年第1期8卷 1-26页

作者： Xiang Liu Guoping cai Department of Engineering Mechanics MOE Key Laboratory of HydrodynamicsChongqing Research InstituteShanghai Jiao Tong UniversityShanghai200240China

Large-scale space membrane antennas have significant potential in satellite communication,space-based early warning,and Earth *** of their large size and high flexibility,the dynamic analysis and control of membrane antenna are *** maintain the working performance of the antenna,the pointing and surface accuracies must be strictly ***,the accurate dynamic modeling and effective active control of large-scale space membrane antennas have great theoretical significance and practical value,and have attracted considerable interest in recent *** paper reviews the dynamics and active control of large-scale space membrane ***,the development and status of large-scale space membrane antennas are ***,the key problems in the dynamics and active control of large membrane antennas,including the dynamics of wrinkled membranes,large-amplitude nonlinear vibration,nonlinear model reduction,rigid-flexible-thermal coupling dynamic modeling,on-orbit modal parameter identification,active vibration control,and wave-based vibration control,are discussed in ***,the research outlook and future trends are presented.

关键词： large-scale space membrane antenna dynamicmodeling active control

Microbial carbon pump shapes chemical signatures of refractory dissolved organic carbon in ocean water column

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Science China Earth Sciences 2024年第7期67卷 2408-2410页

作者： Ruanhong cai Nianzhi JIAO Fujian Key Laboratory of Marine Carbon Sequestration Xiamen UniversityXiamen 361102China Department of Ocean Science The Hong Kong Universityof Science and TechnologyHong Kong SAR 999077China Carbon Neutral Innovation Research Center Xiamen UniversityXiamen 361102China

The global ocean sequesters a great amount of dissolved organic carbon(DOC),which is mainly originated from indigenous microbial activities(such as photosynthesis and chemoautotrophy)in the water column,as well as various exogenous sources such as riverine input,sediment mobilization,aerosol dissolution,hydrothermal vent effusion,and others(cai and Jiao,2023).

关键词： ocean originated aerosol