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Catalytic behavior of Mo-Bi-Fe-Co-K-M-O(M=Ce,Gd,CeGd)catalysts for selective oxidation of isobutene

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Journal of Rare Earths 2024年第1期42卷 84-93,I0003页

作者： Qinghui Li Huahua zhao Jian Yang Jun zhao Liang Yan Huanling Song Lingjun Chou State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Beijing100049China

The further improvement of methacrolein(MAL)selectivity from isobutene(IB)oxidation is crucial and *** this study,based on the typical Mo-Bi-Fe-Co-K-O mixed metal oxide,the rare earth element Gd-doped,Ce-doped and CeGd co-doped catalysts were prepared by co-precipitation strategy to increase the selectivity of MAL from 47.9%to 49.8%,64.2% and 68.6%,*** order to elucidate in-depth the promoting effect of Ce and/or Gd,various characterizations were utilized including X-ray diffraction patterns(XRD),Raman,X-ray fluorescence spectrometry(XRF),X-ray photoelectron spectroscopy(XPS),O_(2)-temperature programmed desorption(O_(2)-TPD),H2-temperature programmed reduction(H2-TPR),CO_(2)-temperature programmed desorption(CO_(2)-TPD),IB-temperature programmed desorption(i-C4-TPD)and in-situ IB-Fourier transform infrared spectroscopy(IB-FTIR).Both Ce and Gd finely regulate the bulk and surface structure of the catalyst,thus altering the redox ability,oxygen mobility and storage ability and *** with Ce,Gd addition slightly regulates the variation of Co^(2+)/Co^(3+)redox couples,greatly enhances the interaction among the components on the catalyst,thus only increases the content of surface oxygen species and has little effect on their *** Cecontaining catalyst performs stronger oxygen storage and migration ability,thus leading to the overproduction of surface Odefectspecies,which are proposed to be the active sites for the production of MAL and *** CeGd co-doped catalyst possesses the proper content of surface Odefectspecies,thus exhibits much higher MAL ***,the promoting mechanism of Ce and/or Gd over IB oxidation is ***,this work is helpful for understanding the influence of rare earth elements on the structure of mixed metal oxides and the olefin selective oxidation reaction.

关键词： Mixed metal oxide catalyst Rare earth element Isobutene Selective oxidation Methacrolein

Essentially Commuting Truncated Toeplitz Operators

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Acta Mathematica Sinica,English Series 2024年第10期40卷 2453-2480页

作者： Xi zhao Tao YU School of Mathematics and Science Hebei GEO University School of Mathematical Sciences Dalian University of Technology

A model space is a subspace of the Hardy space which is invariant under the backward shift,and a truncated Toeplitz operator is the compression of a Toeplitz operator on some model space. In this paper we prove a necessary and sufficient condition for the commutator of two truncated Toeplitz operators on a model space to be compact.

关键词： 47B32 47B35 commutator compact operator maximal ideal space model space Truncated Toeplitz operator

The effect of thermal treatment on the transformation and transportation of arsenic and cadmium in soil

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Journal of Environmental Sciences 2024年第11期145卷 205-215页

作者： Fengping Zhou Meina Guo Nan zhao Qianting Xu Tuokun zhao Weihua Zhang Rongliang Qiu Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology Guangdong Provincial Engineering Research Center for Heavy Metal Contaminated Soil RemediationSchool of Environmental Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Shenzhen Research Institute Sun Yat-sen UniversityShenzhen 518057China National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and ManagementInstitute of Eco-environmental and Soil SciencesGuangdong Academy of SciencesGuangzhou 510650China Guangdong Provincial Key Laboratory of Agricultural&Rural Pollution Abatement and Environmental Safety School of Natural Resources and EnvironmentSouth China Agricultural UniversityGuangzhou 510642China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China

Thermal treatment can effectively decontaminate soils but alter their *** research mainly focused on volatile organic compounds andmetals,***,neglecting nonvolatile metal(loid)*** study aimed to investigate Cd and As transformation during aerobic and anaerobic *** results showed that both aerobic and anaerobic calcination increased soil pH by reducing soil organic matter(SOM)content,which also influenced the cation exchange capacity(CEC)and the leaching behavior of Cd and As in the *** total concentrations of Cd and As in the calcined soils varied depending on the calcination temperature and *** the aerobic calcination temperature exceeded 700℃,Cd volatilized as CdCl_(2),while anaerobic calcination at relatively low temperatures(600℃)involved reductive reactions,resulting in the formation of metallic Cd with a lower boiling ***,As volatilized at 800℃aerobically and 600℃*** formation of As-based minerals,particularly Ca3(AsO4)2,hindered its gasification,whereas anaerobic calcination promoted volatilization efficiency through the generation of C-As(III)based gaseous components with lower boiling *** trends were observed in the TCLP-extractable Cd and As contents of the calcined *** 70%of TCLP-extractable Cd contents were suppressed after thermal treatment,attributed to the elevated pH and reduced CEC of the soil,as well as ***,TCLP-extractable As contents increased with elevated temperatures,likely due to the desorption of AsO43−and re-adsorption of gaseous As2O3 during *** findings have implications for assessing the environmental impact of thermal treatment and provide insights for remediation strategies concerning Cd and As-contaminated soils.

关键词： Thermal treatment Soil Cadmium Arsenic Transformation

Exploring the relevance between load-bearing capacity and surface friction behavior based on a layered hydrogel cartilage prototype

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Friction 2024年第8期12卷 1757-1770页

作者： Yunlei ZHANG Weiyi zhao Xiaoduo zhao Jinshuai ZHANG Bo YU Shuanhong MA Feng ZHOU State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China Shandong Laboratory of Yantai Advanced Materials and Green Manufacture Yantai Zhongke Research Institute of Advanced Materials and Green Chemical EngineeringYantai 264006China

Cartilage is well lubricated over a lifetime and this phenomenon is attributed to both of the surface hydration lubrication and the matrix load-bearing *** hydrogels with a layered structure are designed to mimic cartilage as potential *** many studies have concentrated on improving surface hydration to reduce friction,few have experimentally detected the relationship between load-bearing capacity of hydrogels and their interface friction *** this work,a bilayer hydrogel,serving as a cartilage prototype consisted of a top thick hydrated polymer brush layer and a bottom hydrogel matrix with tunable modulus was designed to investigate this *** coefficient of friction(COF,μ)is defined as the sum of interfacial component(μInt)and deformation/hysteresis component(μHyst).The presence of the top hydration layer effectively dissipates contact stress and reduces the interface interaction(μInt),leading to a stable and low *** contribution of mechanical deformation(μHyst)during the sliding shearing process to COF can be significantly reduced by increasing the local mechanical modulus,thereby enhancing the load-bearing *** results show that the strategy of coupling surface hydration layer with a high load-bearing matrix can indeed enhance the lubrication performance of hydrogel cartilage prototypes,and implies a promising routine for designing robust soft matter lubrication system and friction-control devices.

关键词： soft contact hydration,deformation load-bearing friction control

Enhanced stability of nitrogen-doped carbon-supported palladium catalyst for oxidative carbonylation of phenol

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Chinese Journal of Chemical Engineering 2024年第1期65卷 19-28页

作者： Xiaojing Liu Ruohan zhao Hao zhao Zhimiao Wang Fang Li Wei Xue Yanji Wang Hebei Provincial Key Laboratory of Green Chemical Technology and High Efficient Energy Saving School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China Tianjin Key Laboratory of Chemical Process Safety Tianjin 300130China Hebei Industrial Technology Research Institute of Green Chemical Industry Huanghua 061100China

Enhancing the stability of supported noble metal catalysts emerges is a major challenge in both science and ***,a heterogeneous Pd catalyst(Pd/NCF)was prepared by supporting Pd ultrafine metal nanoparticles(NPs)on nitrogen-doped carbon;synthesized by using F127 as a stabilizer,as well as chitosan as a carbon and nitrogen *** Pd/NCF catalyst was efficient and recyclable for oxidative carbonylation of phenol to diphenyl carbonate,exhibiting higher stability than Pd/NC prepared without F127 *** hydrogen bond between chitosan(CTS)and F127 was enhanced by F127,which anchored the N in the free amino group,increasing the N content of the carbon material and ensuring that the support could provide sufficient N sites for the deposition of Pd *** process helped to improve metal *** increased metal-support interaction,which limits the leaching and coarsening of Pd NPs,improves the stability of the Pd/NCF ***,density functional theory calculations indicated that pyridine N stabilized the Pd^(2+)species,significantly inhibiting the loss of Pd^(2+)in Pd/NCF during the reaction *** work provides a promising avenue towards enhancing the stability of nitrogen-doped carbon-supported metal catalysts.

关键词： Supported Pd catalyst N-doped carbon Amphiphilic triblock copolymer Pyridinic nitrogen Stability

A sub-grid scale model for Burgers turbulence based on the artificial neural network method

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 162-165页

作者： Xin zhao Kaiyi Yin Department of Mechanics Beijing Institute of TechnologyBeijing 100081China

The present study proposes a sub-grid scale model for the one-dimensional Burgers turbulence based on the neuralnetwork and deep learning *** filtered data of the direct numerical simulation is used to establish thetraining data set,the validation data set,and the test data *** artificial neural network(ANN)methodand Back Propagation method are employed to train parameters in the *** developed ANN is applied toconstruct the sub-grid scale model for the large eddy simulation of the Burgers turbulence in the *** proposed model well predicts the time correlation and the space correlation of the Burgers turbulence.

关键词： Artificial neural network Back propagation method Burgers turbulence Large eddy simulation Sub-grid scale model

Monolayer mesoporous nanosheets with surface asymmetry via a dual-emulsion-directed monomicelle assembly

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A Lightweight, Searchable, and Controllable EMR Sharing Scheme

结构化学 2024年第2期43卷 1-3页

作者： Yujuan zhao Zaiwang zhao College of Energy Materials and Chemistry College of Chemistry and Chemical EngineeringInner Mongolia UniversityHohhot010070China

Functional mesoporous materials,based on IUPAC,are a type of porous materials with a uniform pore size ranging from 2 to 50 *** the 1980s,the existing zeolites or microporous materials with small pore sizes(less than 1.2 nm)have some limitations in practical applications,especially for large molecule conversion and *** by these motivations,the exploration of mesoporous materials has been widely *** the early 1990s,the mesoporous materials including or-dered M41S[1]mesoporous silicate molecular sieves and large-pore mesoporous silica SBA-15[2]were prepared when templated by the quaternary ammonium cationic surfactant or the amphiphilic triblock copolymer *** high thermal stability of such porous materials and good repeatability of methods have aroused widespread interest in both academic and industrial domains.

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Computers, Materials & Continua 2024年第4期79卷 1521-1538页

作者： Xiaohui Yang Peiyin zhao School of Cyber Security and Computer Hebei UniversityBaoding071000China

Electronic medical records (EMR) facilitate the sharing of medical data, but existing sharing schemes suffer fromprivacy leakage and inefficiency. This article proposes a lightweight, searchable, and controllable EMR sharingscheme, which employs a large attribute domain and a linear secret sharing structure (LSSS), the computationaloverhead of encryption and decryption reaches a lightweight constant level, and supports keyword search andpolicy hiding, which improves the high efficiency of medical data sharing. The dynamic accumulator technologyis utilized to enable data owners to flexibly authorize or revoke the access rights of data visitors to the datato achieve controllability of the data. Meanwhile, the data is re-encrypted by Intel Software Guard Extensions(SGX) technology to realize resistance to offline dictionary guessing attacks. In addition, blockchain technology isutilized to achieve credible accountability for abnormal behaviors in the sharing process. The experiments reflectthe obvious advantages of the scheme in terms of encryption and decryption computation overhead and storageoverhead, and theoretically prove the security and controllability in the sharing process, providing a feasible solutionfor the safe and efficient sharing of EMR.

关键词： Lightweight keyword search large attribute domain controllability blockchain

Perenniality:From model plants to applications in agriculture

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Molecular Plant 2024年第1期17卷 141-157页

作者： Bo zhao Jia-Wei Wang National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant Sciences(CEMPS)Institute of Plant Physiology and Ecology(SIPPE)Chinese Academy of Sciences(CAS)Shanghai 200032China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China Key Laboratory of Plant Carbon Capture CASShanghai 200032China New Cornerstone Science Laboratory Shanghai 200032China

To compensate for their sessile nature,plants have evolved sophisticated mechanisms enabling them to adapt to ever-changing *** such prominent feature is the evolution of diverse life history strategies,particularly such that annuals reproduce once followed by seasonal death,while perennials live longer by cycling growth *** intrinsic phenology is primarily genetic and can be altered by environmental *** evolutionary transitions between annual and perennial life history strategies are common,perennials account for most species in nature because they survive well under year-round *** proportion,however,is reversed in ***,perennial crops promise to likewise protect and enhance the resilience of agricultural ecosystems in response to climate *** significant endeavors that have been made to generate perennial crops,progress is slow because of barriers in studying perennials,and many developed species await further *** findings in model species have illustrated that simply rewiring existing genetic networks can lead to lifestyle *** implies that engineering plant life history strategy can be achieved by manipulating only a few key *** this review,we summarize our current understanding of genetic basis of perenniality and discuss major questions and challenges that remain to be addressed.

关键词： perenniality developmental plasticity flowering time poplar Arabis alpina perennial crops life history strategy