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China Petroleum Processing & Petrochemical Technology 2024年第2期26卷 57-71页

作者： Zhao Wenjie Du Chengxin Song Yu Zhou Yafen Wang Qing Zhou Limei xu bin Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province College of Chemistry and Chemical EngineeringChina West Normal UniversityNanchongChina Key Laboratory of Green Chemistry of Sichuan Institutes of Higher Education Sichuan University of Science&EngineeringZigongChina

Organic-inorganic MoO_(3)/PI(MoPI)composites were prepared using a simple one-pot thermal copolymerization method.The resulting composites exhibited enhanced photocatalytic activity for the selective oxidation of benzylamine to N-benzylidene benzylamine(N-BDBA)in ambient air under simulated solar light irradiation compared to pristine MoO_(3) or polyimide(PI).In particular,the MoPI composite with a 0.3:1 molar ratio of Mo to melamine,referred to as MoPI-0.3,demonstrated the best performance in the photo-oxidation of benzylamine,achieving a benzylamine conversion of 95%with a N-BDBA selectivity exceeding 99%after 3 h irradiation.The enhanced photocatalytic activity of the MoPI-0.3 catalyst was attributed to the formation of a direct Z-scheme heterojunction between MoO_(3) and PI,facilitating more efficient separation of the photoinduced electrons and holes.Additionally,the MoPI-0.3 composite maintained considerably high activity over four consecutive cycles,highlighting its good stability and recyclability.Furthermore,the MoPI-0.3 composite could photo-oxidize benzylamine derivatives and heterocyclic amines to their corresponding imines,demonstrating the universal applicability of this composite catalyst.

关键词： MoO3/PI composite photocatalysis amine oxidation imine

Scattering for the Radial Schrodinger Equation with Combined Power-type and Choquard-type Nonlinearities

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1029-1041页

作者： Ying WANG Cheng bin xu The Graduate School of China Academy of Engineering Physics Beijing 100088P.R.China School of Mathematics and Statistics Qinghai Normal UniversityXining 810008P.R.China

In this paper,we show the scattering of the radial solution for the nonlinear Schrodinger equation with combined power-type and Choquard-type nonlinearities iut+△u=λ1|u|p1-1u+λ2(Iα*|u|^(p2))|u|p^(2-2)u.in the energy space H^(1)(R^(N))forλ_(1)λ_(2)=-1.We establish a scattering criterion for radial solution together with Morawetz estimate which implies the scattering theory.Results show that the defocusing perturbation terms does not determine the scattering solution in energy space.

关键词： Schrodinger equation Choquard-type Scattering theory

Gut-targeted therapies for type 2 diabetes mellitus: A review

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World Journal of Clinical Cases 2024年第1期12卷 1-8页

作者： Tian-Cheng xu Yun Liu Zhi Yu bin xu Key Laboratory of Acupuncture and Medicine Research of Ministry of Education Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina

Type 2 diabetes mellitus(T2DM)is a chronic metabolic disorder characterized by hyperglycemia and insulin resistance.The global prevalence of T2DM has reached epidemic proportions,affecting approximately 463 million adults worldwide in 2019.Current treatments for T2DM include lifestyle modifications,oral antidiabetic agents,and insulin therapy.However,these therapies may carry side effects and fail to achieve optimal glycemic control in some patients.Therefore,there is a growing interest in the role of gut microbiota and more gut-targeted therapies in the management of T2DM.The gut microbiota,which refers to the community of microorganisms that inhabit the human gut,has been shown to play a crucial role in the regulation of glucose metabolism and insulin sensitivity.Alterations in gut microbiota composition and diversity have been observed in T2DM patients,with a reduction in beneficial bacteria and an increase in pathogenic bacteria.This dysbiosis may contribute to the pathogenesis of the disease by promoting inflammation and impairing gut barrier function.Several gut-targeted therapies have been developed to modulate the gut microbiota and improve glycemic control in T2DM.One potential approach is the use of probio-tics,which are live microorganisms that confer health benefits to the host when administered in adequate amounts.Several randomized controlled trials have demonstrated that certain probiotics,such as Lactobacillus and Bifidobacterium species,can improve glycemic control and insulin sensitivity in T2DM patients.Mechanisms may include the production of short-chain fatty acids,the improvement of gut barrier function,and the reduction of inflammation.Another gut-targeted therapy is fecal microbiota transplantation(FMT),which involves the transfer of fecal material from a healthy donor to a recipient.FMT has been used successfully in the treatment of Clostridioides difficile infection and is now being investigated as a potential therapy for T2DM.A recent randomized controlled trial showed that FMT from lea

关键词： Type 2 diabetes mellitus Gastroenterology Bacteria Implanted device

Hybrid Network Model Based on Data Enhancement for Short-term Power Prediction of New PV Plants

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 77-88页

作者： Shangpeng Zhong Xiaoming Wang bin xu Hongbin Wu Ming Ding the Anhui Province Key Laboratory of Renewable Energy Utilization and Energy Saving Hefei University of TechnologyHefei 230009China the State Grid Anhui Electric Power Research Institute Hefei 230061China

This study proposes a hybrid network model based on data enhancement to address the problem of low accuracy in photovoltaic(PV)power prediction that arises due to insuffi cient data samples for new PV plants.First,a time-series gener ative adversarial network(TimeGAN)is used to learn the distri bution law of the original PV data samples and the temporal correlations between their features,and these are then used to generate new samples to enhance the training set.Subsequently,a hybrid network model that fuses bi-directional long-short term memory(BiLSTM)network with attention mechanism(AM)in the framework of deep&cross network(DCN)is con structed to effectively extract deep information from the origi nal features while enhancing the impact of important informa tion on the prediction results.Finally,the hyperparameters in the hybrid network model are optimized using the whale optimi zation algorithm(WOA),which prevents the network model from falling into a local optimum and gives the best prediction results.The simulation results show that after data enhance ment by TimeGAN,the hybrid prediction model proposed in this paper can effectively improve the accuracy of short-term PV power prediction and has wide applicability.

关键词： New photovoltaic(PV)plant short-term predic tion time-series generative adversarial network(TimeGAN) hy brid network hyperparameter

Optimizing evasive maneuvering of planes using a flight quality driven model

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Science China(Information Sciences) 2024年第3期67卷 197-208页

作者： Chang LIU Shaoshan SUN Chenggang TAO Yingxin SHOU bin xu School of Automation Northwestern Polytechnical University Chengdu Aircraft Design & Research Institute of AVIC

This paper investigates the optimal evasive maneuver for a plane to avoid an incoming missile. To accurately model the system dynamics while improving computational efficiency, a simplified plane model based on flight quality is established. A missile model with proportional guidance is also formulated.The problem of determining the optimal evasion plane maneuver is formulated. The Gauss pseudospectral method(GPM) is proposed as a solution to find the optimal maneuver. The optimized maneuver is validated by testing it on a high-fidelity 6-degree-of-freedom(6-DOF) model, which demonstrates the effectiveness of the proposed simplified plane model. The Monte Carlo method is employed to evaluate the capability of the plane to evade missiles in various scenarios and elucidate general principles for successful evasion.

关键词： optimal maneuver flying quality evasive strategy pursuit-evasion game air-to-air combat

Mussel-inspired PTW@PDA composites for developing high-energy gun propellants with reduced erosion and enhanced mechanical strength

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Defence Technology（防务技术） 2024年第2期32卷 675-690页

作者： Xijin Wang Zhitao Liu Pengfei Sun Feiyun Chen bin xu Xin Liao School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina China North Industries Group Corporation Limited Beijing 100045China

The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing fillers.The interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW materials.Compared to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded steel.And 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of propellants.Despite the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic activity.This strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.

关键词： High energy gun propellant Potassium titanate whiskers Polydopamine modification Erosion inhibitors Mechanical reinforcing fillers

Numerical analysis of wind effects on aerodynamic characteristics of a ducted fan

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Chinese Journal of Aeronautics 2024年第5期37卷 263-280页

作者： Yiwei LUO Tianfu AI Yuhang HE bin xu Yuping QIAN Yangjun ZHANG State Key Laboratory of Intelligent Green Vehicle and Mobility School of Vehicle and MobilityTsinghua UniversityBeijing 100084China Key Laboratory of Conveyance and Equipment Ministry of Education East China Jiaotong UniversityNanchang 330013China Vehicle Research Center School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Ducted fans have been extensively used in Unmanned Aerial Vehicles(UAVs)for a variety of missions because of high efficiency,high safety and low noise.Wind,as a kind of typical meteorological condition,brings significant aerodynamic interference to the ducted fan,which seriously threatens flight stability and safety.In this work,the numerical simulation with the Unsteady Reynolds Averaged Navier-Stokes(URANS)method and the sliding mesh technique is performed to evaluate the steady wind effect.The results show that the wind will lead to serious unsteady effects in the flow field,and the thrust fluctuates at the blade passing frequency of 200 Hz.As the wind speed increases,the rotor thrust increases,the duct thrust decreases,and the total thrust changes little.Flow instability may occur when the wind speed exceeds 8 m/s.As the angle of low-speed wind increases,the rotor thrust changes little,the duct thrust increases,and the total thrust increases.In addition,we figure out that cases with the same crosswind ratio are similar in results,and increasing the rotating speed or fan radius is beneficial to performance improvement in wind.The findings are essential to the ducted fan design and UAV flight control design for stable and safe operations in wind conditions.

关键词： Unmanned Aerial Vehicle(UAV) Ducted fan Wind effect Thrust fluctuations Computational Fluid Dynamics(CFD)

Cerium refinement of grains and primary carbides during solidification of Cr_(4)Mo_(4)V bearing steel

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Journal of Rare Earths 2024年第4期42卷 783-792页

作者： Weifeng Liu Jianqiang Wang Mingyue Sun bin xu Jiahao Yao Qunbo Fan Dianzhong Li Chongqing Innovation Center Beijing Institute of TechnologyChongqing401135China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The effect of cerium(Ce)on the solidification microstructure of Cr_(4)Mo_(4)V bearing steel was investigated via a combined experimental and theoretical method.With a trace amount(0.056 wt%)of Ce addition,the coarse columnar grains in as-cast microstructure transform into equiaxed ones,and the average diameter is reduced from 56 to 27μm.The network-like and bulky primary MC and M2C carbides at the interdendritic regions become disconnected and refined,and their volume percentage decreases from4.15 vol%to 2.1 vol%.Ce-inclusions acting as heterogeneous nucleation agents of prior-austenite grains and Ce atoms segregating at grain boundaries,both contribute to the refinement of grains.Thermodynamic calculations reveal that primary carbides are precipitated afterγ-austenite forms near the end of the solidification process.The modification of primary carbides in size and amount is mainly attributed to the isolated remaining melt separated by refinedγ-austenite grains in which the nucleation of carbides is promoted,while the growth is restrained owing to the less segregation of alloying elements.

关键词： Cr_(4)Mo_(4)V bearing steel Rare Earths Grains Primary carbides Refinement

Oxidative cyclization of allyl compounds and isocyanide: A facile entry to polysubstituted 2-cyanopyrroles

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Chinese Chemical Letters 2024年第4期35卷 330-335页

作者： Yaping Zhang Wei Zhou Mingchun Gao Tianqi Liu bingxin Liu Chang-Hua Ding bin xu Department of Chemistry Affiliated Nantong Hospital of Shanghai University(The Sixth People's Hospital of Nantong)Shanghai Engineering Research Center of Organ RepairInnovative Drug Research CenterSchool of MedicineShanghai UniversityShanghai 200444China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A facile Tf OH-catalyzed oxidative cyclization of allyl compounds and isocyanide has been developed with the assistance of DDQ, where isocyanide is used as the crucial "N" and "CN" sources. Highly functionalized 2-cyanopyrroles are constructed efficiently through a new formal [3 + 2] mode, demonstrating diverse reactivity and synthetic utility in organic chemistry. 2-Cyanopyrrole is converted into a nucleobase analogue of Remdesivir and 5H-pyrrolo[2,1-a]isoindole through a three-step or a two-step sequence, respectively. This protocol features broad substrate scope, operational simplicity and good functional group tolerance.

关键词： Isocyanide Cyanopyrrole Insertion Allyl compound Bronsted acid catalysis

A direct electrochemical biosensor for rapid glucose detection based on nitrogen-doped carbon nanocages

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Rare Metals 2024年第5期43卷 2184-2192页

作者： Lan-Lan Li Yu Zhao Li-Jia Pan Jian-bin xu Yi Shi College of Mechanical and Electrical Engineering Henan Agricultural University School of Electronic Science and Engineering Collaborative Innovation Center of Advanced Microstructures Nanjing University Department of Electronic Engineering The Chinese University of Hong Kong

Given the increasing number of diabetic patients,rapid and accurate detection of glucose in body fluids is critical.This study developed a direct electrochemical biosensor for glucose based on nitrogen-doped carbon nanocages （NCNCs）.NCNCs possess a large specific surface area of 1395 m2·g-1,a high N atomic content of 9.37%and good biocompatibility,which is favorable for enzyme loading and electron transfer.The surface average concentration of electroactive glucose oxidase on NCNCs was 2.82×10–10mol·cm-2.The NCNC-based direct electrochemical biosensor exhibited a high sensitivity of 13.7μA·(mmol·L-1)-1·cm-2,rapid response time of 5 s and an impressive electron-transferrate constant （ks） of 1.87 s-1.Furthermore,we investigated an NCNC-based direct electron transfer （DET） biosensor for sweat glucose detection,which demonstrated tremendous promise for non-invasive wearable diabetes diagnosis

关键词： Direct electron transfer (DET) Nitrogen-doped carbon nanocages (NCNCs) Glucose oxidase Biosensor