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Oxygen vacancies enriched Ir/WOx catalysts for the directly chem-catalytic conversion of cellulose to ethanol

Tungsten 2025年第1期7卷 88-99页

作者： Yu-Jing Weng zhao-Ying Ding Ying-Chao Li Yuan-Feng Wu Yuan-Yang Xu Rui Chen Xiao-lei zhao Hai-Yong Wang Da-lei Zhang Yu-Long Zhang Henan Key Laboratory of Coal Green Conversion and International Joint Laboratory of Coal Clean Utilization College of Chemistry and Chemical Engineering Henan Polytechnic University Key Laboratory of Renewable Energy Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Liaoning Institute of Energy Technology

Tungsten and its oxides are highly versatile catalysts with unique properties that hold great promise for a wide array of applications,including biological pathways and chemical *** chemo-catalysis of cellulose to ethanol presents a promising avenue for ethanol synthesis with the potential for enhanced efficiency compared to conventional methods,offering a sustainable and carbon-neutral alternative to existing petrochemical and biological ***,Ir/WOxcatalysts enriched with oxygen vacancies were meticulously prepared and demonstrated remarkable catalytic performance in converting cellulose to ethanol directly in the presence of tungstic *** catalyst achieved a high ethanol yield of 66.5%under optimal reaction conditions,approaching the theoretical yield limit of traditional ethanol *** results revealed the presence of oxygen defects,Bronsted/Lewis acidity,and Ir nanoclusters on the catalyst surface,working synergistically to facilitate the cascade catalysis of cellulose hydrolysis,sugar retro-aldol condensation reaction,and C2 intermediate hydrodeoxygenation to *** situ Fourier transform infrared spectrometer analysis confirmed the catalyst's ability to enhance the adsorption and activation of ethylene glycol for ethanol *** manipulating subtle structural features,this study offers a fresh perspective on tungsten group catalyst design and underscores the importance of synergistic effects among catalytic sites for the efficient production of ethanol from cellulose.

关键词： Cellulosic ethanol Chem-catalysis Hydrogenolysis Retro-aldol condensation Tungsten

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负载黑米花色苷的纳米颗粒对Caco-2细胞损伤的保护作用

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食品科学 2025年第3期46卷 102-109页

作者：刘雅琪周娜冯蒙蒙艾欣赵磊赵亮北京工商大学老年营养与健康教育部重点实验室北京市食品添加剂工程技术研究中心北京100048 菏泽职业学院山东菏泽274002

为提高黑米花色苷(black rice anthocyanins,BRA)的稳定性和生物活性,本研究利用牛血清白蛋白(bovine serum albumin,BSA)和京尼平(genipin,GP)制备负载BRA的纳米颗粒(BRA-BSAGP),并分析BSAGP与BRA的相互作用,探究BRA-BSAGP在模拟胃肠道消化环境中的释放特性,以及对葡聚糖硫酸钠(dextran sulfate sodium,DSS)诱导Caco-2细胞损伤的改善效果及作用机制。结果表明,BRA-BSA_(GP)形态呈较均一的球形,其BRA包埋率为(81.10±0.08)%;傅里叶变换红外光谱和X射线衍射分析结果显示,BRA被成功包埋在BSA中。体外胃肠道释放实验证实BRA-BSA_(GP)纳米颗粒能够有效减缓BRA的释放,在模拟空腹和进食状态下最终释放量仅分别为22.51%和20.10%。细胞实验结果表明,BRA-BSAGP显著提高了DSS诱导损伤的Caco-2细胞的存活率,并增加了紧密连接蛋白(Claudin-1、Occludin和ZO-1)的表达水平。本研究结果可为BRA的应用和开发缓解溃疡性结肠炎损伤的功能性食品提供理论依据。

关键词：黑米花色苷牛血清白蛋白京尼平 Caco-2细胞

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Approximate Nonlinear Modeling of Aircraft Engine Surge Margin Based on Equilibrium Manifold Expansion

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Chinese Journal of Aeronautics 2012年第5期25卷 663-674页

作者： LIU Xiaofeng zhao lei School of Transportation Science and Engineering Beihang UniversityBeijing 100191China

Stable operation of aircraft engine compressions is constrained by rotating surge. In this paper, an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is presented. Firstly, this paper gives an overview of the current state of modeling aerodynamic flow instabilities in engine compressors. Secondly, the expansion form of equilibrium manifold is introduced, and the choosing scheduling variable method is discussed. Then, this paper also gives the identification procedure of modeling the approximate nonlinear model. Finally, the modeling and simulations with high pressure （liP） compressor surge margin of the aircraft engine show that this real-time model has the same accuracy with the thermody- namic model, but has simpler structure and shorter computation time.

关键词： aircraft engine surge margin system identification equilibrium manifold scheduling variable perpendicular expan-sion

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General series expression of eddy-current impedance for coil placed above multi-layer plate conductor

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Chinese Physics B 2018年第6期27卷 179-184页

作者： Yin-zhao lei School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China

This paper presents a closed expression of the layered-plate factor used to calculate the coil eddy-current impedance over the multi-layer plate conductor. By using this expression, the general series of eddy-current impedance can be written directly without solving the undetermined constant equations. The series expression is easy to use for theoretical analysis and programming. Experimental results show that calculated values and measured values are in agreement. As an application, when the bottom layer of the layered plate is a non-ferromagnetic thin layer conductor and the product of the thickness and conductivity of the layer remains unchanged, using the layered-plate factor expression proposed in this paper, it can be theoretically predicted that the eddy-current impedance curves corresponding to different thin layer thickness values will coincide.

关键词： multi-layer plate conductor layered-plate factor series expression eddy-current impedance

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Robotic Walker for Slope Mobility Assistance with Active-Passive Hybrid Actuator

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Chinese Journal of Mechanical Engineering 2021年第5期34卷 185-194页

作者： Junqiang Li lei zhao Tiejun Li School of Mechanical Engineering Hebei University of Technology Tianjin China

Walking assistance can be realized by active and passive robotic walkers when their users walk on even ***,fast signal processing and real-time control are necessary for active robotic walkers when the users walk on slopes,while assistive forces cannot be provided by passive robotic walkers when the users walk uphill.A robotic walker with an active-passive hybrid actuator(APHA)was developed in this *** APHA,which consists of a rotary magnetorheological(MR)brake and a DC motor,can provide mobility assistance to users walking both uphill and downhill via the cooperative operation of the MR brake and DC *** rotary MR brake was designed with a T-shaped configuration,and the system was optimized to minimize the brake *** of the APHA and robotic walker were constructed.A control algorithm for the robotic walker was developed based on the characteristics of the APHA and the structure of the robotic *** mechanical properties of the APHA were characterized,and experiments were conducted to evaluate the mobility assistance supplied by the robotic walker on different *** results show that the APHA can meet the requirements of the robotic walker,and suitable assistive forces can be provided by the robotic walker,which has a simple mechanical structure and control method.

关键词： Robotic walker Active-passive hybrid actuator MR brake Slope mobility assistance

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On-Machine Measurement of the Straightness and Tilt Errors of a Linear Slideway Using a New Four-Sensor Method

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Chinese Journal of Mechanical Engineering 2019年第2期32卷 122-132页

作者： lei zhao Kai Cheng Hui Ding Liang zhao School of Mechatronics Engineering Harbin Institute of Technology College of Engineering Design and Physical Sciences Brunel University

Although there are some multi-sensor methods for measuring the straightness and tilt errors of a linear slideway, they need to be further improved in some aspects, such as suppressing measurement noise and reducing *** this paper, a new four-sensor method with an improved measurement system is proposed to on-machine separate the straightness and tilt errors of a linear slideway from the sensor outputs, considering the influences of the reference surface profile and the zero-adjustment values. The improved system is achieved by adjusting a single sensor to di erent positions. Based on the system, a system of linear equations is built by fusing the sensor outputs to cancel out the e ects of the straightness and tilt errors. Three constraints are then derived and supplemented into the linear system to make the coe cient matrix full rank. To restrain the sensitivity of the solution of the linear system to the measurement noise in the sensor outputs, the Tikhonov regularization method is utilized. After the surface profile is obtained from the solution, the straightness and tilt errors are identified from the sensor outputs. To analyze the e ects of the measurement noise and the positioning errors of the sensor and the linear slideway, a series of computer simulations are carried out. An experiment is conducted for validation, showing good consistency. The new four-sensor method with the improved measurement system provides a new way to measure the straightness and tilt errors of a linear slideway, which can guarantee favorable propagations of the residuals induced by the noise and the positioning errors.

关键词： Multi-sensor method Straightness error Tilt error On-machine measurement Linear slideway Error separation technique

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Optimization of porous structures via machine learning for solar thermochemical fuel production

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Progress in Natural Science:Materials International 2024年第5期34卷 895-906页

作者： Da Xu lei zhao Meng Lin Harbin Institute of Technology Department of Mechanical and Energy Engineering Southern University of Science and Technology SUSTech Energy Institute for Carbon Neutrality Southern University of Science and Technology

Porous reactant is the key component in solar thermochemical reactions, significantly affecting the solar energy conversion and fuel production performance. Triply periodic minimal surface（TPMS） structures, with analytical expressions and predictable structure-property relationships, can facilitate the design and optimization of such structures. This work proposes a machine learning-assisted framework to optimize TPMS structures for enhanced reaction efficiency, increased fuel production,and reduced temperature gradients. To mitigate the computational cost of conventional high-throughput optimization, neural network regression models were used to for performance prediction based on input features. The training dataset was generated using a three-dimensional multiphysics model for the thermochemical reduction driven by concentrated solar energy considering fluid flow, heat and mass transfer, and chemical reacions. Both uniform and gradient structures were initially assessed by the three-dimensional model showing gradient design in c and ω were necessary for performance enhancement. Further, with our proposed optimization framework, we found that structures with parameters c1= c2= 0.5（uniform in c） and ω1= 0.2, ω2= 0.8（gradient in ω） achieved the highest relative efficiency(fchem/fchem,ref) of 1.58, a relative fuel production(Δδ/Δδref) of 7.94, and a max relative temperature gradient（dT/dy）/（dT/dy）refof 0.26. Kinetic properties,i.e., bulk diffusion and surface exchange coefficient, were also studied showing that for materilas with slow kinetics, the design space in terms of c and ω were highly limited compared to fast kinetics materials. Our framework is adaptable to diverse porous structures and operational conditions, making it a versatile tool for screening porous structures for solar thermochemical applications. This work has the potential to advance the development of efficient solar fuel production systems and scalable industrial applications in renewable energy

关键词： Regression analysis

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Extension of e^N method to general three-dimensional boundary layers

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Applied Mathematics and Mechanics(English Edition) 2017年第7期38卷 1007-1018页

作者： lei zhao Gaotong YU Jisheng LUO Department of Mechanics Tianjin University The 41st Institute of No.6 Academy China Aerospace Science & Industry Corporation

In order to extend the eN method to general three-dimensional boundary layers, the conservation law of the imaginary parts for the wave parameters with a fixed wave vector is deduced. The compatibility relationship （CR） and the general theory of ray tracing （RT）, which have been extensively used in conservative systems, are applied to a general three-dimensional boundary layer belonging to non-conservative systems. Two kinds of eN methods, i.e., the eN-CR method and the eN-RT method, are established. Both the two kinds of methods can wavenumber and the amplitude of the be used to predict the evolutions of the spanwise disturbances in general three-dimensional boundary layers. The reliability of the proposed methods is verified and validated by performing a direct numerical simulation （DNS） in a hypersonic general three-dimensional boundary layer over an aircraft model. The results are also compared with those obtained by other eN methods, indicating that the proposed methods have great potential applications in improving the transition prediction accuracy in general three-dimensional boundary layers.

关键词： eN method ray tracing theory transition prediction three-dimensionalboundary layer

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Effects of substrate temperature and annealing treatment on the microstructure and magnetic characteristics of TbDyFe films

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Rare Metals 2007年第5期26卷 408-413页

作者： DU zhaofu WANG lei zhao Dongliang Functional Materials Research Institute Central Iron and Steel Research Institute Beijing 100081 China

A series of TbDyFe films were prepared by DC magnetron sputtering. The effects of substrate temperature and annealing temperature on the phase structure and the magnetic properties of the sample films were investigated. The an-nealing treatment has a significant influence on the microstructure and the magnetic properties of the sample. The results obtained by XRD indicate that the films deposited at a temperature lower than 525℃ are amorphous and have an easy magnetization direction perpendicular to the film plane. An RFe2 phase is formed in the sample annealed at 550℃ and the residual phases observed are Fe and rare earth oxide. The magnetic properties Hc and Mr/Ms of the film annealed at 550℃ obtain the maximum values,for which the formation of the RFe2 phase is mainly responsible. An annealing treatment leads to a rotation of the sample’s easy axis from being parallel to the film surface to becoming vertical.

关键词： TbDyFe thin film amorphous substrate temperature annealing temperature

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Conservation relation of generalized growth rate in boundary layers

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Applied Mathematics and Mechanics(English Edition) 2018年第12期39卷 1755-1768页

作者： Runjie SONG lei zhao Zhangfeng HUANG Department of Mechanics Tianjin University Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development Center

The elementary task is to calculate the growth rates of disturbances when the e;method in transition prediction is performed. However, there is no unified knowledge to determine the growth rates of disturbances in three-dimensional（3 D） flows. In this paper, we study the relation among the wave parameters of the disturbance in boundary layers in which the imaginary parts of wave parameters are far smaller than the real *** generalized growth rate（GGR） in the direction of group velocity is introduced, and the conservation relation of GGR is strictly deduced in theory. This conservation relation manifests that the GGR only depends on the real parts of wave parameters instead of the imaginary parts. Numerical validations for GGR conservation are also provided in the cases of first/second modes and crossflow modes. The application of GGR to the eN method in 3 D flows is discussed, and the puzzle of determining growth rates in 3 D flows is clarified. A convenient method is also proposed to calculate growth rates of disturbances in 3 D flows. Good agreement between this convenient method and existing methods is found except the condition that the angle between the group velocity direction and the x-direction is close to 90?which can be easily avoided in practical application.

关键词： generalized growth rate(GGR) boundary layer stability e^N method

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