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Kinetics insights into size effects of carbon nanotubes'growth and their supported platinum catalysts for 4,6-dinitroresorcinol hydrogenation

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Chinese Journal of Chemical Engineering 2024年第8期72卷 133-140页

作者： Yan zhang Xiangxue zhang Keng Sang Wenyao Chen Gang Qian Jing zhang Xuezhi duan Xinggui Zhou Weikang Yuan State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Size effects are a well-documented phenomenon in heterogeneous catalysis,typically attributed to alterations in geometric and electronic *** this study,we investigate the influence of catalyst size in the preparation of carbon nanotube(CNT)and the hydrogenation of 4,6-dinitroresorcinol(DNR)using Fe_(2)O_(3)and Pt catalysts,*** Fe_(2)O_(3)/Al_(2)O_(3)catalysts were synthesized for CNT growth through catalytic chemical vapor *** findings reveal a significant influence of Fe_(2)O_(3)nanoparticle size on the structure and yield of ***,CNT produced with Fe_(2)O_(3)/Al_(2)O_(3)containing 28%(mass)Fe loading exhibits abundant surface defects,an increased area for metal-particle immobilization,and a high carbon *** makes it a promising candidate for DNR *** this catalyst support,we further investigate the size effects of Pt nanoparticles on DNR *** Pt catalysts demonstrate a preference for 4,6-diaminoresorcinol generation at(100)sites,whereas smaller Pt catalysts are more susceptible to electronic *** kinetics insights obtained from this study have the potential to pave the way for the development of more efficient catalysts for both CNT synthesis and DNR hydrogenation.

关键词： Kinetics Size effects Catalytic hydrogenation Active site

Precise Asymptotics in Limit Theorems for a Supercritical Branching Process with Immigration in a Random Environment

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1850-1874页

作者： Chun Mao HUANG Rui zhang zhi Qiang GAO Department of Mathematics Harbin Institute of Technology(Weihai)Weihai 264209P.R.China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

Let(Zn)be a supercritical branching process with immigration in an independent and identically distributed random *** necessary moment conditions,we show the exact convergence rate in the central limit theorem on log Zn and establish the corresponding local limit theorem by using the moments of the natural submartingale and the convergence rates of its *** similar approach and with the help of a change of measure,we also present the so-called integrolocal theorem and integral large deviation theorem to characterize the precise asymptotics of the upper large deviations.

关键词： Branching process with immigration random environment central limit theorem large deviation

Carrying Capacity and Coupling Coordination of Water and Land Resources Systems in Arid and Semi-arid Areas: A Case Study of Yulin City, China

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Chinese Geographical Science 2024年第5期34卷 931-950页

作者： zhang Qianxi CAO zhi WANG Yongsheng HUANG Yijia Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Quantitatively assessing the carrying capacity of water and land resources systems in arid and semi-arid areas is crucial for achieving the 2030 Sustainable Development *** this work,taking Yulin City in China as a case study and employing the Criteria Importance Through Intercriteria Correlation(CRITIC)method,a modified model of coupling degree was developed to evaluate the car-rying capacity of water and land resources systems endowment and utilization,as well as their coupling coordination degree from 2013 to *** findings indicate that the water and land resources of Yulin are diminishing due to declines in agriculture,higher industrial water use,and wetland ***,reallocating domestic water for ecological sustainability and reducing sloping farmland can mitigate this trend of ***,as the coupling coordination between water and land resources system endowment in Yulin continuously improved,the coupling coordination between water and land resources system utilization first decreased and then in-creased with 2016 as the turning ***,the carrying capacity of water and land resources systems,the coupling coordination degree between water and land resources system endowment,and the coupling coordination degree between water and land resources system utilization in Yulin exhibited the same pattern of being higher in the six northern counties than in the six southern *** the water resources endowment is vital for the highly efficient use of water and land resources.

关键词： water and land resources systems carrying capacity coupling coordination human-earth system sustainable development Yulin City,China

Metal–Organic Framework‑Based Photodetectors

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Nano-Micro Letters 2024年第11期16卷 675-703页

作者： Jin‑Biao zhang Yi‑Bo Tian zhi‑Gang Gu Jian zhang State Key Laboratory of Structural Chemistry Structure of MatterFujian Institute of ResearchChinese Academy of SciencesFuzhouFujian 350002People’s Republic of China College of Chemistry and Materials Science Fujian Nornal UniversityFuzhou 350007FujianPeople’s Republic of China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108FujianPeople’s Republic of China University of Chinese Academy of Science Beijing 100049People’s Republic of China

The unique and interesting physical and chemical properties of metal–organic framework(MOF)materials have recently attracted extensive attention in a new generation of photoelectric *** this review,we summarized and discussed the research progress on MOF-based *** methods of preparing MOF-based photodetectors and various types of MOF single crystals and thin film as well as MOF composites are introduced in ***,the photodetectors applications for X-ray,ultraviolet and infrared light,biological detectors,and circularly polarized light photodetectors are ***,summaries and challenges are provided for this important research field.

关键词： Metal-organic frameworks Semiconductor Photodetectors

EDU-GAN:Edge Enhancement Generative Adversarial Networks with Dual-Domain Discriminators for Inscription Images Denoising

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Computers, Materials & Continua 2024年第7期80卷 1633-1653页

作者： Yunjing Liu Erhu zhang Jingjing Wang Guangfeng Lin Jinghong duan School of Mechanical and Precision Instrument Engineering Xi’an University of TechnologyXi’an710048China Department of Information Science Xi’an University of TechnologyXi’an710054China School of Faculty of Painting Packaging Engineering and Digital MediaXi’an University of TechnologyXi’an710048China School of Computer Science and Engineering Xi’an University of TechnologyXi’an710048China

Recovering high-quality inscription images from unknown and complex inscription noisy images is a challenging research *** fromnatural images,character images pay more attention to stroke ***,existingmodelsmainly consider pixel-level informationwhile ignoring structural information of the character,such as its edge and glyph,resulting in reconstructed images with mottled local structure and character *** solve these problems,we propose a novel generative adversarial network(GAN)framework based on an edge-guided generator and a discriminator constructed by a dual-domain U-Net framework,i.e.,*** existing frameworks,the generator introduces the edge extractionmodule,guiding it into the denoising process through the attention mechanism,which maintains the edge detail of the restored inscription ***,a dual-domain U-Net-based discriminator is proposed to learn the global and local discrepancy between the denoised and the label images in both image and morphological domains,which is helpful to blind denoising *** proposed dual-domain discriminator and generator for adversarial training can reduce local artifacts and keep the denoised character structure *** to the lack of a real-inscription image,we built the real-inscription dataset to provide an effective benchmark for studying inscription image *** experimental results show the superiority of our method both in the synthetic and real-inscription datasets.

关键词： Dual-domain discriminators inscription images denoising edge-guided generator

Double enzyme mimetic activities of multifunctional Ag nanoparticle-decorated Co_(3)V_(2)O_(8)hollow hexagonal prismatic pencils for application in colorimetric sensors and disinfection

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Nano Materials Science 2024年第2期6卷 244-255页

作者： Ying Gao Peng Ju Yu zhang Yuxin zhang Xiaofan Zhai Jizhou duan Baorong Hou Key Laboratory of Marine Environmental Corrosion and Bio-fouling Institute of OceanologyChinese Academy of SciencesQingdao266071PR China Key Laboratory of Marine Eco-Environmental Science and Technology Marine Bioresource and Environment Research CenterFirst Institute of OceanographyMinistry of Natural ResourcesQingdao266061PR China University of Chinese Academy of Sciences Beijing100049PR China Open Studio for Marine Corrosion and Protection Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao266071PR China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao266071PR China College of Materials Science and Engineering Chongqing UniversityChongqing400044China

Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like *** this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme *** were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic *** Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic *** can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue *** enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic *** were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic *** enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic *** work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.

关键词： Co_(3)V_(2)O_(8) Ag NPs Enzyme mimetic Colorimetric sensor Disinfection

Distributed Cooperative Secondary Voltage Control in an Unbalanced Microgrid

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 222-234页

作者： Xiangzhen Yang Haixi Zhao Mengke duan Yan Du Haining Wang Jian zhang School of Electrical Engineering and Automation Hefei University of TechnologyHefei 23009China

The negative-sequence reactive power-conductance(Q^(−)-G) droop control strategy is a conventional method to compensate for the output unbalanced voltages in an islanded ***, the conflict between unbalanced voltage compensation and negative-sequence reactive power sharing, caused bythe impedance mismatching of distribution lines and distributedgenerators, has not been solved only by Q^(−)-G droop *** this paper, a distributed cooperative secondary unbalancedvoltage control strategy is proposed to decrease the outputvoltage unbalance factor (VUF) of each droop-controlled DG,as well as to further enhance the negative-sequence reactivepower sharing effectiveness among DGs by properly shiftingup and down the Q^(−)-G droop characteristics of each *** algorithm for adaptive VUF weight coefficient is proposedto better suppress VUF under severe imbalance ***, a negative-sequence small-signal model of an MGunder an unbalanced condition, considering the communicationdelay time of the proposed SUVC, is established to analyze thesystem’s stability and transient performance under the influenceof some critical parameters. Finally, the effectiveness of theproposed strategy is validated by the simulation results froma real-time emulator of StarSim HIL.

关键词： Distributed cooperative control MG negativesequence reactive power starsim real-time platform time delay voltage unbalance compensation

Engineering and dynamics of heterogeneous catalysts via metal single atoms as promoters/precursors

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Science China Chemistry 2024年第8期67卷 2547-2565页

作者： Jiwei Li Junli Xu Jingyun Yang Zitao duan Zhun zhang Haifeng Xiong State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province Xiamen 361102China

Metal single-atom catalysts(SACs) have emerged as a focal point of research, captivating the scientific community due to their distinctive electronic properties and unparalleled catalytic prowess in the realm of heterogeneous catalysis. However, their significance transcends their role as mere active sites. Recent investigations have illuminated the multifaceted capabilities of metal single atoms as catalyst promoters and precursors, paving the way for the engineering of highly efficient heterogeneous catalysts. Single-atom promoters not only enhance the stabilization of active metals and tailor the support material, but regulate the reactive interfacial structure, eventually tuning the catalytic performance. Furthermore, SACs were also used as catalyst precursors to design new catalyst active sites. During the pretreatment or catalytic reaction, the structure of the metal single sites is changed significantly and transformed into the new and more active state, which improve the adsorption and reactive ability of reactants or intermediates. In this critical review, we comment the recent development of metal SACs used as catalyst promoters/precursors in engineering heterogeneous catalysts, including thermal catalysis and electrocatalysis. Furthermore, the dynamic evolution of the SACs during the pretreatment or catalytic reaction is also discussed. Finally, we provide our insight to potentially guide the future development on this emerging field.

关键词： single-atom catalysts single-atom promoter single-atom precursor dynamic evolution

Hybrid response surface method for system reliability analysis of pile-reinforced slopes

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JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING 2024年第9期16卷 3395-3406页

作者： duan, Xiangrui zhang, Jie Liu, Leilei Hu, Jinzheng Xue, Yadong Tongji Univ Dept Geotech Engn Key Lab Geotech & Underground Engn Minist Educ Shanghai 200092 Peoples R China Cent South Univ Sch Geosci & Info Phys Key Lab Metallogen Predict Nonferrous Met & Geol E Minist Educ Changsha 410083 Peoples R China

To consider the complex soil-structure interaction in a pile-slope system, it is necessary to analyze the performance of pile-slope systems based on a three-dimensional (3D) numerical model. Reliability analysis of a pile-slope system based on 3D numerical modeling is very challenging because it is computationally expensive and the performance function of the pile failure mode is only defined in the safe domain of soil stability. In this paper, an efficient hybrid response surface method is suggested to study the system reliability of pile-reinforced slopes, where the support vector machine and the Kriging model are used to approximate performance functions of soil failure and pile failure, respectively. The versatility of the suggested method is illustrated in detail with an example. For the example examined in this paper, it is found that the pile failure can significantly contribute to system failure, and the reinforcement ratio can effectively reduce the probability of pile failure. There exists a critical reinforcement ratio beyond which the system failure probability is not sensitive to the reinforcement ratio. The pile spacing affects both the probabilities of soil failure and pile failure of the pile-reinforced slope. There exists an optimal location and an optimal length for the stabilizing piles.

关键词： Slope Piles System reliability Support vector machine Ordinary kriging STABILITY ANALYSIS CONSTITUTIVE MODEL ONE ROW DESIGN STABILIZATION INTERFACE