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Boosting oxygen vacancies by modulating the morphology of Au decorated In_(2)O_(3)with enhanced CO_(2)hydrogenation activity to CH_(3)OH

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Journal of Environmental Sciences 2024年第6期140卷 91-102页

作者： Ruxian hou Jiewen Xiao Qian Wu Tianyu Zhang Qiang Wang Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China Engineering Research Center for Water Pollution Source Control&Eco-remediation College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China

CO_(2)hydrogenation to methanol has become one of the most promising ways for CO_(2)utilization,however,the CO_(2)conversion rate and methanol selectivity of this reaction still need to be improved for industrial *** we investigated the structure-activity relationship for CO_(2)conversion to methanol of In_(2)O_(3)-based catalysts by modulating morphology and decorating *** different Au/In_(2)O_(3)catalysts were prepared,their activity follow the sequence of Au/In_(2)O_(3)-nanosphere(Au/In_(2)O_(3)-NS)>Au/In_(2)O_(3)-nanoplate(Au/In_(2)O_(3)-NP)>Au/In_(2)O_(3)-hollow microsphere(Au/In_(2)O_(3)-HM).Au/In_(2)O_(3)-NS exhibited the best performance with good CO_(2)conversion of 12.7%,high methanol selectivity of 59.8%,and large space time yield of 0.32 g CH_(3)OH/(hr·gcat)at 300℃.The high performance of Au/In_(2)O_(3)-NS was considered as the presence of *** contributes to the creation of more surface oxygen vacancies,which further promoted the CO_(2)adsorption and facilitated CO_(2)activation to form the formate intermediates towards *** work clearly suggests that the activity of In_(2)O_(3)catalyst can be effective enhanced by structure engineering and Au decorating.

关键词： CO_(2)hydrogenation Methanol Au/In_(2)O_(3) Morphology Oxygen vacancies

Grain-boundary segregation and grain growth in nanocrystalline substitutional solid solution alloys

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Journal of Materials Science & Technology 2024年第1期168卷 239-249页

作者： Fawei Tang Chao hou Hao Lu Zhi Zhao Xiaoyan Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were *** on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been *** study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.

关键词： Substitutional solid solution Grain boundary segregation Thermal stabilization Solute concentration Grain size

Bald Eagle Search Optimization Algorithm Combined with Spherical Random Shrinkage Mechanism and Its Application

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Journal of Bionic Engineering 2024年第1期21卷 572-605页

作者： Wenyan Guo Zhuolin hou Fang Dai Xiaoxia Wang Yufan Qiang Department of Applied Mathematics School of ScienceXi'an University of TechnologyXian 710054ShaanxiChina

Over the last two decades,stochastic optimization algorithms have proved to be a very promising approach to solving a variety of complex optimization *** eagle search optimization(BES)as a new stochastic optimization algorithm with fast convergence speed has the ability of prominent optimization and the defect of collapsing in the local *** avoid BES collapse at local optima,inspired by the fact that the volume of the sphere is the largest when the surface area is certain,an improved bald eagle search optimization algorithm(INMBES)integrating the random shrinkage mechanism of the sphere is ***,the INMBES embeds spherical coordinates to design a more accurate parameter update method to modify the coverage and dispersion of the ***,the population splits into elite and non-elite groups and the Bernoulli chaos is applied to elite group to tap around potential solutions of the *** non-elite group is redistributed again and the Nelder-Mead simplex strategy is applied to each group to accelerate the evolution of the worst individual and the convergence process of the *** results of Friedman and Wilcoxon rank sum tests of CEC2017 in 10,30,50,and 100 dimensions numerical optimization confirm that the INMBES has superior performance in convergence accuracy and avoiding falling into local optimization compared with other potential improved algorithms but inferior to the champion algorithm and ranking *** three engineering constraint optimization problems and 26 real world problems and the problem of extracting the best feature subset by encapsulated feature selection method verify that the INMBES’s performance ranks first and has achieved satisfactory accuracy in solving practical problems.

关键词： Bald eagle search optimization algorithm Spherical coordinates Chaotic variation Simplex method Encapsulated feature selection

Wind disturbance compensated path-following control for fixed-wing UAVs in arbitrarily strong winds

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Chinese Journal of Aeronautics 2024年第2期37卷 431-445页

作者： Hao LU Lan GAO Yunda YAN Mingzhe hou Chenliang WANG Hangzhou Innovation Institute Beihang UniversityHangzhou 310051China School of Information Science and Technology Hangzhou Normal UniversityHangzhou 311121China Department of Computer Science University College LondonLondon WC1E 6BTUnited Kingdom Center for Control Theory and Guidance Technology Harbin Institute of TechnologyHarbin 150001China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Wind is the primary challenge for low-speed fixed-wing unmanned aerial vehicles to follow a predefined flight *** cope with various wind conditions,this paper proposes a wind disturbance compensated path following control strategy where the wind disturbance estimate is incorporated with the nominal guiding vector field to provide the desired airspeed direction for the *** the control input vector for the outer-loop kinematic subsystem needs to satisfy a magnitude constraint,a scaling mechanism is introduced to tune the proportions of the compensation and nominal ***,an optimization problem is formulated to pursue a maximum wind compensation in strong winds,which can be solved analytically to yield two scaling factors.A cascaded inner-loop tracking controller is also designed to fulfill the outer-loop wind disturbance compensated guiding vector ***-fidelity simulation results under sensor noises and realistic winds demonstrate that the proposed path following algorithm is less sensitive to sensor noises,achieves promising accuracy in normal winds,and mitigates the deviation from a desired path in wild winds.

关键词： Path following Guiding vector field Wind disturbance Disturbance rejection Fixed wings

Heat Transfer Characteristics of a Microchannel Heat Sink with Highly-Dense Micro-Jet Arrays

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Journal of Thermal Science 2024年第3期33卷 1148-1160页

作者： ZHANG Yu CHEN Xiaoyan MIAO Lin CHEN Liang hou Yu State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China Beijing Aerospace Technology Institute Beijing100083China

This paper proposed a new structure of highly-dense micro-jet arrays for hybrid jet-impingement/microchannel heat sinks(~120 jet per cm^(2) with jet width of 0.35 mm).Parametric study is performed to investigate the influence of structure and flow parameters on the convective heat transfer of water jet cooling in confined *** simulation results show that the optimal jet width,jet spacing and impingement distance are around 0.2 mm,0.2 mm and 0.3 mm,respectively,which can achieve a low thermal resistance as well as a relatively low pressure *** analysis of the heat transfer pathways shows that the micro-fin jet structures can extend the impinging heat transfer area and conduct a considerable proportion of heat,which can reach up to 38.9%with the Reynolds number ranging from 797.1 to *** heat transfer characteristics in the heat sink will shift from impingement dominated heat transfer to the channel-convection dominated heat transfer as the jet impingement distance increases.A correlation is proposed to predict the average Nusselt number on the stagnation area for the heat sink with different structure parameters,and the deviations of predictions from the numerical results are less than 10%.

关键词： hybrid heat sink impingement microchannel thermal management high heat flux

GRIK1 promotes glioblastoma malignancy and is a novel prognostic factor of poor prognosis

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Oncology Research 2024年第4期32卷 727-736页

作者： GUOQIANG hou XINHANG XU WEIXING HU Department of Neurosurgery First Affiliated Hospital of Nanjing Medical UniversityNanjingChina Department of Neurosurgery Renji HospitalShanghai Jiao Tong UniversityShanghaiChina

Primary tumors of the central nervous system(CNS)are classified into over 100 different histological *** most common type of glioma is derived from astrocytes,and the most invasive glioblastoma(WHO IV)accounts for over 57%of these ***(GBM)is the most common and fatal tumor of the CNS,with strong growth and invasion capabilities,which makes complete surgical resection almost *** various treatment methods such as surgery,radiotherapy,and chemotherapy,glioma is still an incurable disease,and the median survival time of patients with GBM is shorter than 15 ***,molecular mechanisms of GBM characteristic invasive growth need to be clarified to improve the poor *** ionotropic receptor kainate type subunit 1(GRIK1)is essential for brain function and is involved in many mental and neurological ***,GRIK1’s pathogenic roles and mechanisms in GBM are still ***-nuclear RNA sequencing of primary and recurrent GBM samples revealed that GRIK1 expression was noticeably higher in the recurrent ***,immunohistochemical staining of an array of GBM samples showed that high levels of GRIK1 correlated with poor prognosis of GBM,consistent with The Cancer Genome Atlas *** of GRIK1 retarded GBM cells growth,migration,and *** together,these findings show that GRIK1 is a unique and important component in the development of GBM and may be considered as a biomarker for the diagnosis and therapy in individuals with GBM.

关键词： Glioblastoma GRIK1 Invasion Proliferation Prognosis

Machine Learning Analysis of Impact of Western US Fires on Central US Hailstorms

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Advances in Atmospheric Sciences 2024年第7期41卷 1450-1462页

作者： Xinming LIN Jiwen FAN Yuwei ZHANG ZJason hou Pacific Northwest National Laboratory RichlandWA 99354USA Argonne National Laboratory LemontIL 60439USA

Fires,including wildfires,harm air quality and essential public services like transportation,communication,and *** fires can also influence atmospheric conditions,including temperature and aerosols,potentially affecting severe convective ***,we investigate the remote impacts of fires in the western United States(WUS)on the occurrence of large hail(size:≥2.54 cm)in the central US(CUS)over the 20-year period of 2001–20 using the machine learning(ML),Random Forest(RF),and Extreme Gradient Boosting(XGB)*** developed RF and XGB models demonstrate high accuracy(>90%)and F1 scores of up to 0.78 in predicting large hail occurrences when WUS fires and CUS hailstorms coincide,particularly in four states(Wyoming,South Dakota,Nebraska,and Kansas).The key contributing variables identified from both ML models include the meteorological variables in the fire region(temperature and moisture),the westerly wind over the plume transport path,and the fire features(i.e.,the maximum fire power and burned area).The results confirm a linkage between WUS fires and severe weather in the CUS,corroborating the findings of our previous modeling study conducted on case simulations with a detailed physics model.

关键词： wildfire severe convective storm hailstorm machine learning

Seamless Indoor-Outdoor Switching Localization Algorithm based on CKF

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Journal of Communications and Information Networks 2024年第1期9卷 88-98页

作者： Gang Yang Guodong hou Ningning Feng Weida Meng School of Communication and Information Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China

To solve the problem of large positioning error and discontinuous positioning of special forces members when moving in cross-region indoors and outdoors, and to compensate for the linearization error and local convergence problem that may exist in the extended Kalman filter(EKF)in nonlinear systems, that is,the iterative results may be trapped in a local optimum situation, a seamless indoor-outdoor switching localization algorithm based on cubature Kalman filter (CKF) is proposed. CKF does not require the computation of Jacobian matrices, which can improve computational efficiency and filtering accuracy to a certain extent. In the system, an inertial measurement unit (IMU) is employed to correct the positioning errors of ultra-wideband (UWB)and BeiDou navigation satellite system(BDS).The positioning data from UWB and BeiDou in cross-region are weighted fused and then fused with the data from the IMU using CKF to obtain the final accurate positioning information. This study designs a scene-switching mechanism to achieve seamless switching between indoor and outdoor positioning scenes. By jointly analyzing the positioning accuracy of UWB and BeiDou,the positioning scene is determined, and appropriate counting thresholds are set to avoid frequent erroneous scene switches. Experimental results show that the proposed algorithm achieves a positioning accuracy of approximately 21.7 cm in cross-region,which can enable seamless integration of indoor and outdoor positioning,avoid positioning jumps, and enhance positioning accuracy.

关键词： cubature Kalman filtering ultra-wideband inertial measurement unit fusion positioning seamless switching

Curved anisotropic polaritons

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Frontiers of physics 2024年第3期19卷 217-224页

作者： Tao hou Yixiao Ge Shuwen Xue Huanyang Chen Department of Physics and Institute of Electromagnetics and Acoustics Xiamen UniversityXiamen 361005China Jiujiang Research Institute of Xiamen University Jiujiang 332000China

The curved surface has emerged as new research platform for understanding and manipulating novel electromagnetic behaviors in complex media. In this paper, we explore the anisotropic polaritons on the spherical surface based on Maxwell’s fish-eye metric through stereographic projection. Additionally, this phenomenon can be extended to spindle surface by conformal mapping. Our calculations and simulations demonstrate the elliptic and hyperbolic polaritons, excited by an electric dipole on the sphere, will self-focus or focus on the poles on the sphere affected by anisotropic permittivity. Furthermore, we reveal the optical singularity nature of the curved hyperbolic polaritons from the perspective of transformation optics by obtaining the equivalent optical refractive index profiles and the particle potential energy. Based on natural anisotropic materials and metamaterials, the curved polaritons have potential applications in curved surface focusing and chaos regulation. This work not only bridges the transformation optics and anisotropic polaritons at curved surface, but also provides a new route to surface optical field manipulation.

关键词： anisotropic polaritons transformation optics curved surface