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Journal of Rare Earths 2023年第6期41卷 933-940,I0005页

作者： Ningyuan Wang xiaoqiang Wang Yue Liu Zhongbiao wu Department of Environmental Engineering Zhejiang UniversityHangzhou 310058China College of Biological Chemical Science and EngineeringJiaxing UniversityJiaxing 314001China

Traditional vanadium-based selective catalytic reduction(SCR)deNO_(x) catalyst can hardly adapt to the gas conditions(much high NO_(2)/NO_(x) ratio at lower temperature)of the start-up and low loading periods for a gas turbine.Therefore,a W-Ti-CeO_(x) catalyst with NO_(x) storage and reduction(NSR)function was developed in this work for gas turbine exhaust NO_(x) elimination.The experimental results reveal that W-Ti-CeO_(x) catalyst exhibits high NO_(2) adsorption capacity at relatively low temperature while that is quite low for V-W/TiO_(2).The abundant surface Ce^(3+) species can be mainly responsible for its high adsorption ability owing to the reaction between NO_(2) and Ce^(3+) to form nitrate/nitrite species and NO.Meanwhile,the adsorption capacity of W-Ti-CeO_(x) can easily regenerate at medium-high temperature and NH_(3)-SCR reaction.Furthermore,W-Ti-CeO_(x) also shows good NH_(3)-SCR activity,which can fulfill the deNO_(x) process at high temperature.The addition of W and Ti into ceria can enhance the surface acidity and redox ability,thereby increasing the SCR activity.This work proposes a novel storage-reduction strategy for NO_(x) elimination throughout the operation of gas turbines.

关键词： W-Ti-CeO_(x)catalyst Gas turbine NO_(x)storage and reduction NH_(3)-SCR Reaction process Rare earths

Influence of stealth aircraft dynamic RCS peak on radar detection probability

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Chinese Journal of Aeronautics 2023年第3期36卷 137-145页

作者： xiaoqiang LU Jun HUANG Yacong wu Lei SONG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China

For modern stealth aircraft,it is important to analyze the influence of Radar Cross Section(RCS)peak exposure on penetration for guiding stealth design and penetration trajectory planning,which needs to reflect the RCS statistical uncertainty and the RCS difference with the change of incident angle.Based on the RCS characteristics of typical stealth aircraft,this paper established a simplified RCS dynamic fluctuation statistical model with the parameters log mean and log standard deviation.According to the detection probability algorithm in radar signal processing field,this paper built the algorithm of radar detection probability based on the RCS dynamic fluctuation statistical model.The analysis of examples concluded that the key to successful penetration is to shorten the RCS peak exposure time,which can be reduced by decreasing the RCS peak width or increasing velocity.Based on the conclusion,this paper proposed the method of turning maneuvering to reduce RCS peak exposure time dramatically.

关键词： Maneuver Penetration RCS RCS fluctuation statistical model RCS peak exposure time RCS peak width Stealth Trajectory planning

Pythagorean probabilistic hesitant triangular fuzzy aggregation operators with applications in multiple attribute decision making

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Journal of Systems Engineering and Electronics 2023年第2期34卷 422-438页

作者： LIAO Fuping LI wu LIU Gang ZHOU xiaoqiang School of Information Science and Engineering Hunan Institute of Science and TechnologyYueyang 414006China

As a generalization of fuzzy set,hesitant probabilistic fuzzy set and pythagorean triangular fuzzy set have their own unique advantages in describing decision information.As modern socioeconomic decision-making problems are becoming more and more complex,it also becomes more and more difficult to appropriately depict decision makers’cognitive information in decision-making process.In order to describe the decision information more comprehensively,we define a pythagorean probabilistic hesitant triangular fuzzy set(PPHTFS)by combining the pythagorean triangular fuzzy set and the probabilistic hesitant fuzzy set.Firstly,the basic operation and scoring function of the pythagorean probabilistic hesitant triangular fuzzy element(PPHTFE)are proposed,and the comparison rule of two PPHTFEs is given.Then,some pythagorean probabilistic hesitant triangular fuzzy aggregation operators are developed,and their properties are also studied.Finally,a multi-attribute decision-making(MADM)model is constructed based on the proposed operators under the pythagorean probabilistic hesitant triangular fuzzy information,and an illustration example is given to demonstrate the practicability and validity of the proposed decision-making method.

关键词： pythagorean probabilistic hesitant triangular fuzzy set(PPHTFS) aggregation operator multi-attribute decisionmaking(MADM)

Preparation of Spherical Tungsten Particles Assisted by Hydrothermal Method

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Journal of wuhan University of Technology(Materials Science) 2023年第6期38卷 1457-1462页

作者： GUO Jiawang WEN xiaoqiang wu Ying XU Jianbing ZHOU Jieying Ganzhou Nonferrous Metallurgy Research Institute Co. LtdGanzhou 341000China

We presented a strategy to prepare spherical tungsten powder by the combination of hydrothermal method and H2reduction process.In hydrothermal process,the micelle of tetraethylammonium bromide(TEAB)act as spherical templates for the deposition of tungsten oxide,whereas the excessive TEAB inhibit the formation of spherical tungsten oxide due to the dense molecular layer of TEAB on the tungsten oxide particles.Citric acid(CA)can control the formation rate and structure of the tungsten oxide when its concentration is more than 0.2 mol/L,because of its ability to coordinate with tungsten atoms.The synergistic effect of TEAB and CA facilitates the formation of spherical tungsten oxide with nanorod crown.After being treated by H_(2)at 600 and 650℃,the tungsten oxide particles are reduced to tungsten particles,which maintain the spherical structure of tungsten oxide and have porous structure.

关键词： spherical tungsten particles spherical tungsten oxide hydrothermal method citric acid tetraethylammonium bromide

Tailoring the simultaneous abatement of methanol and NO_(x) on Sb-Ce-Zr catalysts via copper modification

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Frontiers of Environmental Science & Engineering 2022年第10期16卷 65-75页

作者： xiaoqiang Wang Yanye Zhu Yue Liu Xiaole Weng Zhongbiao wu Department of Environmental Engineering Zhejiang UniversityHangzhou 310058China College of Biological Chemical Science and EngineeringJiaxing UniversityJiaxing 314001China

Simultaneously removal of NO_(x)and VOCs over NH3-SCR catalysts have attracted lots of attention recently.However,the presence of VOCs would have negative effect on deNOx efficiency especially at low temperature.In this study,copper modification onto Sb_(0.5)CeZr_(2)O_(x)(SCZ)catalyst were performed to enhance the catalytic performance for simultaneous control of NNO_(x)and methanol.It was obtained that copper addition could improve the low-temperature activity of both NOx conversion and methanol oxidation,where the optimal catalyst(Cu_(0.05)SCZ)exhibited a deNOx activity of 96%and a mineralization rate of 97%at 250℃,which are around 10%higher than that of Cu free sample.The characterization results showed that copper addition could obviously enhance the redox capacity of the catalysts.As such,the inhibition effect of methanol incomplete oxidation on NO adsorption and NH3 activation were then lessened and the conversion of surface formamide species were also accelerated,resulting in the rising of NOx conversion at low temperature.However,excessive copper addition would damage the Sb-Ce-Zr oxides solid solution structure owing to Cu-Ce strong interactions,decreasing the surface area and acidity.Meanwhile,due to easier over-oxidation of NH3 with more Cu addition,the temperature window for NOx conversion would become quite narrow.These findings could provide useful guidelines for the synergistic removal of VOCs over SCR catalyst in real application.

关键词： Copper modification Sb-CeZr_(2)O_(x)catalyst NO_(x) Methanol Simultaneous removal

Flow characteristics of radial inflow in impeller rear cavity with baffle plate

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Chinese Journal of Aeronautics 2024年第2期37卷 270-282页

作者： Yang BAI Xiang LUO Dongdong LIU Zeyu wu xiaoqiang ZHANG Sipeng WANG Research Institute of Aero-Engine Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China

The research purpose of this paper is to explore the influence of the baffle plate on the airflow in the rear cavity of the centrifugal impeller and optimize the performance of the secondary air system’s air bleed section.In this paper,a comprehensive experimental study was carried out on the flow characteristics in the impeller rear cavity with baffle plate.The windage torque,flow structure and pressure drop between inlet and outlet were measured respectively.The experiment was carried out with the condition that the range of rotational Reynolds number was from 8.33×10^(5)to 22.2×10^(5)and the range of mass flow rate coefficient was from 0.92×10^(4)to 2.92×10^(4).The results show that the static cavity and the narrow stator-rotor cavity formed by the baffle plate effectively suppress the overall swirl coefficient in the cavity.Thus,the static pressure and total pressure drop in the rotor-stator cavity were reduced.The influence of the baffle plate on the windage torque of the rotary disk is related to the turbulence parameters.Under large turbulence parameters,the windage torque would be reduced with baffle plate,while under small turbulence parameters,the baffle plate would increase with baffle plate.In general,the baffle plate can improve the flow capacity and optimize the bleed air performance with proper structure and operation conditions.

关键词： Impeller rear cavity Baffle plate Flow structure Windage torque Pressure drop

Integration strategies of hydrogen network in a refinery based on operational optimization of hydrotreating units

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Chinese Journal of Chemical Engineering 2017年第8期25卷 1061-1068页

作者： Le wu xiaoqiang Liang Lixia Kang Yongzhong Liu Department of Chemical Engineering Xi'an Jiaotong University Key Laboratory of Thermo-Fluid Science and Engineering Ministry of Education

Inferior crude oil and fuel oil upgrading lead to escalating increase of hydrogen consumption in refineries.It is imperative to reduce the hydrogen consumption for energy-saving operations of refineries.An integration strategy of hydrogen network and an operational optimization model of hydrotreating(HDT)units are proposed based on the characteristics of reaction kinetics of HDT units.By solving the proposed model,the operating conditions of HDT units are optimized,and the parameters of hydrogen sinks are determined by coupling hydrodesulfurization(HDS),hydrodenitrification(HDN)and aromatic hydrogenation(HDA)kinetics.An example case of a refinery with annual processing capacity of eight million tons is adopted to demonstrate the feasibility of the proposed optimization strategies and the model.Results show that HDS,HDN and HDA reactions are the major source of hydrogen consumption in the refinery.The total hydrogen consumption can be reduced by 18.9%by applying conventional hydrogen network optimization model.When the hydrogen network is optimized after the operational optimization of HDT units is performed,the hydrogen consumption is reduced by28.2%.When the benefit of the fuel gas recovery is further considered,the total annual cost of hydrogen network can be reduced by 3.21×10~7CNY·a^(-1),decreased by 11.9%.Therefore,the operational optimization of the HDT units in refineries should be imposed to determine the parameters of hydrogen sinks base on the characteristics of reaction kinetics of the hydrogenation processes before the optimization of the hydrogen network is performed through the source-sink matching methods.

关键词：网络优化运行优化加氢装置炼油厂氢气集成策略 strategy 反应动力学

Supramolecular interaction controlled and calix[4]arene ligand assisted Pd-catalyzed C(sp3)-H arylation of aliphatic aldehydes

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Chinese Chemical Letters 2022年第12期33卷 5116-5119页

作者： Yao wu Zhiyan Ma Jing Shi xiaoqiang Sun Ke Yang Zheng-Yi Li Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology School of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China

A calix[4]arene ligand assisted directβ-C-H arylation of tertiary aliphatic aldehydes has been developed via a Pd-catalyzed C(sp3)-H functionalization process.This strategy exhibited good functional group compatibility and C-H bond site-selectivity.Mechanism studies have shown that both synergistic effect and cationic-πsupramolecular interaction between calixarene cavity and transition-metal catalytic center may play an important role in this catalytic cycle.This complementary method would be used in organic and medical chemistry due to the importance of tertiary aliphatic aldehydes.

关键词： Supramolecular interaction Palladium-catalyzed C-H activation Calixarene Aliphatic aldehyde

Ni_(3)Fe/Ni_(4)S_(3)/Ni/C Mixed Crystal Composite Nanofibers Prepared by Electrospinning and Heat Treatment Methods for Oxygen Evolution Reaction

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Journal of wuhan University of Technology(Materials Science) 2023年第2期38卷 267-273页

作者： LI Tao ZHONG Shujie LOU Qiongyue LING Shuai CHEN Jian MA Guohua YANG Mao wu xiaoqiang Department of Materials Engineering School of Mechanical EngineeringChengdu UniversityChengdu610106China Material Corrosion and Protection Key Laboratory of Sichuan Province Zigong643000China Analysis and Testing Center Southwest University of Science and TechnologyMianyang621010China

OER catalyst of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C(NiFeSC series)mixed crystal composite nanofibers was prepared by electrospinning and atmospheric heat treatment process.The testing results indicate that the diameters of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C composite nanofibers is about 200 nm,the grains size is about 1-3 nm,and the fiber surface is rough.The electrochemical test results show that the heterojunction of the prepared Ni_(3)Fe/Ni_(4)S_(3)/Ni/C hybrid crystal composite nanofiber has synergistic effect with sulfide,and exhibits good electrocatalytic activity of water decomposition and OER in alkaline system.The OER electrocatalytic performance of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C composite electrode prepared via a heat treatment at 1000℃process was tested in 1 mol/L KOH electrolytes.The results show that the overpotential is about 298 mV,the Tafel slope is about 74 mV?dec-1,and the surface resistance is about 1.69Ω·cm^(2),at the current density of 10 mA·cm^(-2).

关键词： mixed crystal composite material nanofiber NiFeSC oxygen evolution reaction(OER)

Estimation of evaporation losses based on stable isotopes of stream water in a mountain watershed

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Acta Geochimica 2021年第2期40卷 176-183页

作者： Zhongcong Sun Chaochen Hu Di wu Guopeng Chen xiaoqiang Lu Xueyan Liu School of Earth System Science Tianjin UniversityTianjin 300072China College of Forestry Gansu Agricultural UniversityLanzhou 730070Gansu ProvinceChina Key Laboratory of Biosafety Nanjing Institute of Environmental SciencesMinistry of Ecology and EnvironmentNanjing 210042JiangsuChina

Water stable isotopes(δ^(2) H andδ^(18)O)can record surface water evaporation,which is an important hydrological process for understanding watershed structure and function evolution.However,the isotopic estimation of water evaporation losses in the mountain watersheds remains poorly explored,which hinders understanding spatial variations of hydrological processes and their relationships with the temperature and vegetation.Here we investigatedδ^(2) H,δ^(18)O,and d-excess values of stream water along an altitude gradient of 2130 to 3380 m in Guan’egou mountain watershed at the east edge of the Qinghai-Tibet Plateau in China.The meanδ^(2) H(-69.6‰±2.6‰),δ^(18)O(-10.7‰±0.3‰),and dexcess values(16.0‰±1.4‰)of stream water indicate the inland moisture as the major source of precipitation in study area.Water stable isotopes increase linearly with decreasing altitudes,based on which we estimated the fractions of water evaporation losses along with the altitude and their variations in different vegetations.This study provides an isotopic evaluation method of water evaporation status in mountain watersheds,the results are useful for further understanding the relationship between hydrological processes and ecosystem function under the changing climate surrounding the Qinghai-Tibet Plateau.

关键词： Water stable isotopes Mountain watersheds Water evaporation losses Altitude effect Rayleigh fractionation