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Insight into the Role of Isolated Gold Atoms-Ceria Conjunction in Catalyzing the Water-Gas Shift Reaction

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Chinese Journal of Chemistry 2024年第6期42卷 636-644页

作者： Xin-Pu fu Hui-Zhao wei-wei Wang Chun-Jiang Jia Key Laboratory for Colloid and Interface Chemistry Key Laboratory of Special Aggregated MaterialsSchool of Chemistry and Chemical EngineeringShandong UniversityJinanShandong250100 China

As the promising catalysts for the water-gas shift(WGS)reaction,the activity of Au-CeO_(2) composites is susceptible to the aggregation size and electronic state of Au *** reports were extensively focused on the discrepancy between nonmetallic Au and metallic Au nanoparticles,whereas the understanding of the authentic role of the isolated Au atoms was ***,we investigated the catalytic behavior and structural information over two types of Au/CeO_(2) catalysts,in which the predominant conjunctions were isolated Au1-CeO_(2) and Aun-CeO_(2),*** on comprehensive characterizations,particularly by in-situ Raman and in-situ DRIFTS,we found that the isolated Au atoms were responsible for enhancing the reducibility of the CeO_(2) *** CO adsorption ability on the isolated Au sites was significantly inferior to clustered Au atoms,especially at relatively high temperatures(>200°C).As a result,the boosted O vacancy on the isolated Au1-CeO_(2) conjunctions could improve the H2O activation ability for the Au-CeO_(2) catalysts and demonstrate a comparable activity to the clustered Aun-CeO_(2) *** work might deepen understanding of the catalytic function for the isolated Au1 site within Au/CeO_(2) systems while catalyzing the WGS reaction.

关键词： Isolated Au atoms Ceria-based catalysts Water-gas shift reaction Defect Adsorption

Bed inventory balance and stability of dual circulating fluidized bed systems

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Particuology 2024年第1期84卷 98-106页

作者： Yangjun wei Leming cheng David Pallares Bo Leckner Institute for Thermal Power Engineering State Key Laboratory of Clean Energy UtilizationZhejiang UniversityHangzhou310027China Department of Space Earth and EnvironmentChalmers University of TechnologyS-41296GöteborgSweden

Experiments and modelling are conducted for general understanding on the imbalance phenomenon and for discussion on the strategies to improve the bed inventory balance and stability of a dual circulating fluidized bed(DCFB)*** experiments are carried out in a 15.5 m high pilot-scale DCFB cold test system.A fluid-dynamic DCFB model is developed based on a 1.5-dimensional semi-empirical model of an industrial CFB boiler,validated by experimental *** effects of control methods and operation conditions on the bed inventory balance and on the stability of the pilot-and large-scale DCFB systems are discussed.A"stable-unbalanced"state,where the system reaches a steady state,consisting of un-balanced bed inventories,is observed in both experiments and model *** maintain a balanced state and similar bed inventory in the DCFB systems with similar cross-sectional areas,it is recom-mended to keep similar total pressure drops or gas velocities in both reactors.

关键词： Bed inventory balance Stability Dual circulating fluidized bed(DCFB) Experiment Modelling

Machine learning-assisted efficient design of Cu-based shape memory alloy with specific phase transition temperature

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 773-785页

作者： Mengwei Wu wei Yong Cunqin fu Chunmei Ma Ruiping Liu Department of Materials Science and Engineering China University of Mining&Technology(Beijing)Beijing 100083China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China

The martensitic transformation temperature is the basis for the application of shape memory alloys(SMAs),and the ability to quickly and accurately predict the transformation temperature of SMAs has very important practical *** this work,machine learning(ML)methods were utilized to accelerate the search for shape memory alloys with targeted properties(phase transition temperature).A group of component data was selected to design shape memory alloys using reverse design method from numerous unexplored *** modeling and feature modeling were used to predict the phase transition temperature of the shape memory *** experimental results of the shape memory alloys were obtained to verify the effectiveness of the support vector regression(SVR)*** results show that the machine learning model can obtain target materials more efficiently and pertinently,and realize the accurate and rapid design of shape memory alloys with specific target phase transition *** this basis,the relationship between phase transition temperature and material descriptors is analyzed,and it is proved that the key factors affecting the phase transition temperature of shape memory alloys are based on the strength of the bond energy between *** work provides new ideas for the controllable design and performance optimization of Cu-based shape memory alloys.

关键词： machine learning support vector regression shape memory alloys martensitic transformation temperature

Manipulating the Phase Transition Behavior of Dual Temperature-Responsive Block Copolymers by Adjusting Composition and Sequence

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Chinese Journal of Polymer Science 2024年第2期42卷 176-187,I0006页

作者： Zhi Zou Xiang Xu Hai-Tao Zhao Jian-Nan cheng wei-wei He Li-Fen Zhang Zhen-Ping cheng Suzhou key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationState and Local Joint Engineering Laboratory for Novel Functional Polymeric MaterialsCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of JiangsuSoochow UniversitySuzhou215123China

Temperature-responsive polymers have garnered significant attention due to their ability to respond to external *** this work,dual temperature-responsive block copolymers are synthesized via reversible addition-fragmentation chain transfer polymerization(RAFT)polymerization utilizing zwitterionic monomer methacryloyl ethyl sulfobetaine(SBMA) and N-isopropyl acrylamide(NIPAAm) as *** thermal responsive behaviors can be easily modulated by incorporating additional hydrophobic monomer benzyl acrylate(BN) or hydrophilic monomer acrylic acid(AA),adjusting concentration or pH,or varying the degree of polymerization of the block chain *** cloud points of the copolymers are determined by UV-Vis spectrophotometry,and these copolymers exhibit both controlled upper and lower critical solu bility temperatures(LCST and UCST) in aqueous *** study analyzes and summarizes the influencing factors of dual temperature responsive block copolymers by exploring the effects of various conditions on the phase transition temperature of temperature-sensitive polymers to explore the relationship between their properties and environment and structure to make them more selective in terms of temperature application range and regulation *** is very interesting that the introduction of poly-acrylic acid(PAA) segments in the middle of di-block copolymer PSBMA_(55)-b-PNIPAAm_(80) to form PSBMA_(55)-b-PAA_(x)-b-PNIPAAm_(80) results in a reversal of temperature-responsive behaviors from 'U'(LCST UCST) type,while the copolymer PSBMA_(55)-b-P(NIPAAm_(80)-co-AA_(x)) *** work provides a clue for tuning the phase transition behavior of polymers for manufacture of extreme smart materials.

关键词： Temperature responsive polymers High critical solubility temperature(UCST) Low critical solubility temperature(LCST) Block copolymers

Force-position collaborative optimization of rope-driven snake manipulator for capturing non-cooperative space targets

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 369-384页

作者： Li, Xiaofeng Tian, Jian wei, cheng Cao, Xibin Harbin Inst Technol Sch Astronaut Harbin 150001 Peoples R China China Acad Space Technol Beijing Inst Spacecraft Syst Engn Beijing 100094 Peoples R China

With the rapid development of space activities, non-cooperative space targets increase swiftly, such as failed satellites and upper stages, threating normal spacecrafts seriously. As there are some problems in the capture process, such as excessive collision and fast tumbling of targets, manipulator with redundant Degrees of Freedom (DOFs) can be used to improve the compliance and therefore solve these problems. The Rope-Driven Snake Manipulator (RDSM) is a combination of hyper-redundant DOFs and better compliance, and therefore it is suitable for capturing mission. In this paper, a snake manipulator mechanism is designed, and the complete kinematic model and system dynamic model considering RDSM, target and contact is established. Then, to obtain the configuration of joint with hyper-redundant DOFs, an improved motion dexterity index is proposed as the joint motion optimization target. Besides, the force-position collaborative optimization index is designed to adjust active stiffness, and the impedance control method based on the modified index is used to capture the space target. Finally, the proposed force-position collaborative optimization method is verified by virtual prototype co-simulation. The results demonstrate that based on the proposed method, the collision force is reduced by about 25% compared to normal impedance control, showing higher safety. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： Capturing non-cooperative space targets Rope-driven snake manipu- lator Force-position collaborative optimization Redundant degrees of free- dom Active stiffness adjustment DUAL-ARM SPACE IMPEDANCE CONTROL ROBOT DEXTERITY INDEX

Fault-tolerant identity-based encryption from SM9

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Science China(Information Sciences) 2024年第2期67卷 104-117页

作者： Xiaohong LIU Xinyi HUANG Zhaohui cheng wei WU fujian Provincial Key Laboratory of Network Security and Cryptology College of Computer and Cyber SecurityFujian Normal University Artificial Intelligence Thrust Information HubThe Hong Kong University of Science and Technology (Guangzhou) Olym Information Security Technology Ltd. Center for Applied Mathematics of fujian Province School of Mathematics and StatisticsFujian Normal University

This paper initiates the formal study of attribute-based encryption within the framework of SM9,the Chinese National Cryptography Standard for Identity-Based Cryptography, by presenting two new faulttolerant identity-based encryption(FIBE) schemes. Our first scheme uses the same private-key/ciphertext structure as the original SM9 algorithm and operates in a small attribute universe. As a result, it can be effectively and smoothly integrated into the information systems using SM9. In the random oracle model,we prove that our scheme is ciphertext-indistinguishable against fuzzy selective-identity and chosen-plaintext attacks under the(k + 3)-DBDHI assumption. Our second design is a large universe FIBE scheme based on SM9 that is ciphertext-indistinguishable against chosen-plaintext attacks in the random oracle model under the(f, g)-GDDHE assumption. Finally, we compare the communication and computing costs of our schemes to those of other classical ones. The comparison shows that our schemes have comparable performance as others. We believe that our findings will accelerate the applications of SM9 in modern information systems such as cloud computing and blockchain.

关键词： attribute-based encryption identity-based encryption fault-tolerant SM9

Mechanisms of fracture propagation from multi-cluster using a phase field based HMD coupling model in fractured reservoir

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Petroleum Science 2024年第3期21卷 1829-1851页

作者： Yun-Jin Wang Bo Wang Hang Su Tu Chang Ren-cheng Dong Li-Zhe Li wei-Yu Tang Ting-Xue Jiang fu-Jian Zhou State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBejing2249China China University of Petroleum-Beijing at Karamay Karamay834000XinjiangChina China National Oil and Gas Exploration and Development Corporation Ltd. Beijing100034China University of Texas at Austin United States SINOPEC Research Institute of Petroleum Engineering Beijing100101China

Natural fractures(NFs)are common in shale and tight reservoirs,where staged multi-cluster fracturing of horizontal wells is a prevalent technique for reservoir *** NFs and stress interference are recognized as significant factors affecting hydraulic fracture(HF)propagation,the combined influence of these factors remains poorly *** address this knowledge gap,a novel coupled hydromechanical-damage(HMD)model based on the phase field method is developed to investigate the propagation of multi-cluster HFs in fractured *** comprehensive energy functional and control functions are established,while incorporating dynamic fluid distribution between multiple perforation clusters and refined changes in rock mechanical parameters during hydraulic *** HMD coupled multi-cluster HF propagation model investigates various scenarios,including single HF and single NF,reservoir heterogeneity,single HF and NF clusters,and multi-cluster HFs with NF *** results show that the HMD coupling model can accurately capture the impact of approach angle(θ),stress difference and cementation strength on the interaction of HF and *** criterion of the open and cross zones is not *** NF angle(a)is not a decisive parameter to discriminate the *** to the relationship between approach angle(θ)and NF angle(a),the contact relationship of HF can be divided into three categories(θ=a,θa).The connected NF can increase the complexity of HF by inducing it to form branch fracture,resulting in a fractal dimension of HF as high as2.1280 at angles of±45°.Inter-fracture interference from the heel to the toe of HF shows the phenomenon of no,strong and weak ***,under the influence of NFs,distant HFs from the injection can become dominant ***,as a gradually increases,inter-fracture stress interference becomes the primary factor influencing HF propagation,gradually superseding the dominance of NF

关键词： HMD coupling Phase field Natural fracture Flow distribution Hydraulic fracturing Inter-fracture interference

Huangqin Decoction Delays Progress of Colitis-Associated Carcinogenesis by Regulating Nrf2/HO-1 Antioxidant Signal Pathwayin Mice

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Chinese Journal of Integrative Medicine 2024年第2期30卷 135-142页

作者： GU Li-mei LI He-zhong GAO Lei LI Hui wei Lan-fu PAN cheng-yu WU Ke-xuan TIAN Yao-zhou Department of Gastrointestinal Endoscopy Affiliated Hospital of Nanjing University of Chinese MedicineNanjing(210029)China Department of Gastroenterology Affiliated Hospital of Integrated Traditional Chinese and Western MedicineNanjing University of Chinese MedicineNanjing(210028)China School of Integrated Chinese and Western Medicine Nanjing University of Chinese MedicineNanjing(210023)China

Objective:To investigate the effect of Huangqin Decoction(HQD)on nuclear factor erythroid 2 related-factor 2(Nrf2)/heme oxygenase(HO-1)signaling pathway by inducing the colitis-associated carcinogenesis(CAC)model mice with azoxymethane(AOM)/dextran sodium sulfate(DSS).Methods:The chemical components of HQD were analyzed by liquid chromatography-quadrupole-time-of-flight mass spectrometry(LC-Q-TOF-MS/MS)to determine the molecular constituents of *** 48 C57BL/6J mice were randomly divided into 6 groups by a random number table,including control,model(AOM/DSS),mesalazine(MS),low-,medium-,and high-dose HQD(HQD-L,HQD-M,and HQD-H)groups,8 mice in each *** for the control group,the mice in the other groups were intraperitoneally injected with AOM(10 mg/kg)and administrated with 2.5%DSS orally for 1 week every two weeks(totally 3 rounds of DSS)to construct a colitis-associated carcinogenesis mouse *** mice in the HQD-L,HQD-M and HQD-H groups were given HQD by gavage at doses of 2.925,5.85,and 11.7 g/kg,respectively;the mice in the MS group was given a suspension of MS at a dose of 0.043 g/kg(totally 11 weeks).The serum levels of malondialdehyde(MDA)and superoxide dismutase(SOD)were measured by enzyme-linked immunosorbent *** mRNA and protein expression levels of Nrf2,HO-1,and inhibitory KELCH like ECH-related protein 1(Keap1)in colon tissue were detected by quantitative real-time PCR,immunohistochemistry,and Westem blot,***:LC-Q-TOF-MS/MS analysis revealed that the chemical constituents of HQD include baicalin,paeoniflorin,and glycyrrhizic *** to the control group,significantly higher MDA levels and lower SOD levels were observed in the model group(P<0.05),whereas the expressions of Nrf2 and HO-1 were significantly decreased,and the expression of Keap1 increased(P<0.01).Compared with the model group,serum MDA level was decreased and SOD level was increased in the HQD-M,HQD-H and MS groups(P<0.05).Higher expressions of

关键词： Huangqin Decoction colitis-associated carcinogenesis nuclear factor erythroid 2 related-factor 2/heme oxygenase signaling pathway oxidative stress Chinese medicine

Reactive molecular dynamics insight into the thermal decomposition mechanism of 2,6-Bis(picrylamino)-3,5-dinitropyridine

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Defence Technology（防务技术） 2024年第3期33卷 134-146页

作者： Jianbo fu Hui Ren Xinzhou Wu Yongjin Chen Mi Zhang Yazhi cheng State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

2,6-bis(picrylamino)-3,5-dinitropyridine(PYX)has excellent thermostability,which makes its thermal decomposition mechanism receive much *** this paper,the mechanism of PYX thermal decomposition was investigated thoroughly by the ReaxFF-lg force field combined with DFT-B3LYP(6-311++G)*** detailed decomposition mechanism,small-molecule product evolution,and cluster evolution of PYX were mainly *** the initial stage of decomposition,the intramolecular hydrogen transfer reaction and the formation of dimerized clusters are earlier than the denitration *** the progress of the reaction,one side of the bitter amino group is removed from the pyridine ring,and then the pyridine ring is *** final products produced in the thermal decomposition process are CO_(2),H_(2)O,N_(2),and H_(2).Among them,H_(2)O has the earliest generation time,and the reaction rate constant(k_(3))is the *** clusters are formed during the decomposition of PYX,and the formation,aggregation,and decomposition of these clusters are strongly affected by *** low temperatures(2500 K-2750 K),many clusters are *** high temperatures(2750 K-3250 K),the clusters aggregate to form larger *** 3500 K,the large clusters decompose and become *** the late stage of the reaction,H and N in the clusters escaped almost entirely,but more O was trapped in the clusters,which affected the auto-oxidation process of ***'s initial decomposition activation energy(E_(a))was calculated to be 126.58 kJ/*** work contributes to a theoretical understanding of PYX's entire thermal decomposition process.

关键词： PYX Thermal decomposition ReaxFF-lg MD simulations Excellent thermostable explosives