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Ce-Ti catalysts modified with copper and vanadium to effectively remove slip NH_(3) and NO_x from coal-fired plants

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Journal of Rare Earths 2023年第7期41卷 1022-1030,I0002页

作者： Wenjie Liu Yifei Long Shinian Liu Yongyan Zhou Xin Tong Yajie Yin Xiaoyi Li Kang hu Jiangjun hu School of Resource and Environmental Sciences Wuhan UniversityWuhan 430079China China Southern Power Grid Technology Co. Ltd.Guangzhou 510080China Electric Power Research Institute of Guangdong Power Grid Co.Ltd. Guangzhou 510080China

In this work,V/Ce-Ti catalysts were modified with different kinds of transition metals(Cu,Fe,Co,Mn) by sol-gel and impregnation *** NH_(3) oxidation performance of them was tested to select the most active catalyst in NH_(3)-selective catalytic oxidation(NH_(3)-SCO).The effect of NO,SO_(2) and H_(2)O was also *** experimental results indicate that 1% Cu-V/Ce-Ti catalyst exhibits the most significant ability to remove slip ammonia discharged from coal-fired plants and its NH_(3) conversion efficiency reaches90% at 300℃.In additio n,97% NO_x can be removed when NO is introduced in the ***-V/Ce-Ti catalyst also obtains good resistance to H_(2)O and SO_(2).Based on the characterization experiment,the introduced Cu and V are highly dispersed on Ce-Ti catalyst and they can increase the redox properties and the number of acidic ***,the redox cycles among Cu,V and Ce species on Cu-V/Ce-Ti catalyst surface are conducive to generating more active oxygen and promoting the oxidation capacity of the catalyst.

关键词： Ce-Ti catalyst Transition metals Slip ammonia NO reduction Rare earths

High-efficiency magnetophoretic separation based on synergy of magnetic force field and flow field in microchannels

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Science China(Technological Sciences) 2011年第12期54卷 3311-3319页

作者： WU XinYu WU huiYing hu Dinghua School of Mechanical and Power Engineering Shanghai Jiao Tong University Shanghai 200240 China

Magnetophoresis is one of the most important separation methods in biological and chemical engineering. In this paper,a novel impact parameter on separation efficiency,i.e.,the angle between the vectors of magnetic force and fluid velocity,was derived from the basic equation describing the motion of magnetic beads in microchannels. It is proposed that one of the most important approaches for separation efficiency enhancement is to improve the coordination of magnetic force field and fluid flow field. A T-shaped microchannel magnetophoretic separator was designed based on the angle. And then a two-dimensional dynamic model of magnetic beads moving in microchannels was established to study the separation efficiency of T-shaped microseparator by combined use of finite element method and Runge-Kutta method. The results show that the capture effi-ciency of T-shaped microseparator is much higher than that of the straight microseparator at the same conditions. For small magnetic beads at high fluid velocities,the designed T-shaped microseparator could still keep high separation efficiency whereas the conventional straight microseparator fails to separate the magnetic beads. Further analysis shows that the mechanism of separation efficiency enhancement lies in the synergy of magnetic force field and flow field,which directly leads to large deflected velocity of the magnetic beads from the main stream,and thus increasing the separation efficiency. It is anticipated that the results in this paper are theoretically helpful for the optimum design of highly efficient magnetophoretic separators.

关键词： magnetophoretic separation T-shaped microchannel field synergy separation efficiency

Semi-gas kinetics model for performance modeling of flowing chemical oxygen-iodine lasers(COIL)

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Science China(Physics,Mechanics & Astronomy) 2004年第3期47卷 338-351页

作者： GAO Zhi hu Limin SHEN Yiqing Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

A semi-gas kinetics (SGK) model for performance analyses of flowing chemical oxygen-iodine laser (COIL) is presented. In this model, the oxygen-iodine reaction gas flow is treated as a continuous medium, and the effect of thermal motions of particles of different laser energy levels on the performances of the COIL is included and the velocity distribution function equations are solved by using the double-parameter perturbational method. For a premixed flow, effects of different chemical reaction systems, different gain saturation models and temperature, pressure, yield of excited oxygen, iodine concentration and frequency-shift on the performances of the COIL are computed, and the calculated output power agrees well with the experimental data. The results indicate that the power extraction of the SGK model considering 21 reactions is close to those when only the reversible pumping reaction is considered, while different gain saturation models and adjustable parameters greatly affect the output power, the optimal threshold gain range, and the length of power extraction.

关键词： chemical oxygen-iodine laser (COIL), semi-gas kinetics (SGK) model, rate equation (RE) model, homogeneous broadening, inhomogeneous broadening, performance analysis, spectral line broadening (SLB) model.

Design and Implementation of an SDN-Enabled DNS Security Framework

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China Communications 2019年第2期16卷 233-245页

作者： Zhenpeng Wang hongchao hu Guozhen Cheng National Digital Switching System Engineering and Technological Research Center

The Domain Name System(DNS) is suffering from the vulnerabilities exploited to launch the cache poisoning attack. Inspired by biodiversity, we design and implement a non-intrusive and tolerant secure architecture Multi-DNS(MDNS) to deal with it. MDNS consists of Scheduling Proxy and DNS server pool with heterogeneous DNSs in it. And the Scheduling Proxy dynamically schedules m DNSs to provide service in parallel and adopts the vote results from majority of DNSs to decide valid replies. And benefit from the centralized control of software defined networking(SDN), we implement a proof of concept for it. Evaluation results prove the validity and availability of MDNS and its intrusion/fault tolerance, while the average delay can be controlled in 0.3s.

关键词： DNS cache poisoning attack software defined networking moving target defense dynamic heterogeneous redundant

Copper-Mediated Di- and Monofluoromethanesulfonylation of Arenediazonium Tetrafluoroborates： Probing the Fluorine Effect

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Chinese Journal of Chemistry 2018年第3期36卷 206-212页

作者： Bo Xing Chuanfa Ni Jinbo hu Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences 345Lingling Lu Shanghai 200032 China

A copper-mediated di- and monoffuoromethanesulfonylation of arenediazonium tetrafluoroborates using di- and monofluoromethanesul- finate reagents provides aryl difluoromethyl （or monofluoromethyl） sulfones in 8ood yields. It was found that the relative reactivity of these sodium fluoroalkanesulfinates in the present reactions decreases in the followin8 order： CH2FSO2Na 〉 CF2HSO2Na 〉 CF3SO2Na.

关键词： difluoromethanesulfonylation fluoromethanesulfonylation arenediazonlum sodium sulfinate fluorine effect

GPS/CAPS dual-mode software receiver

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Science China(Physics,Mechanics & Astronomy) 2009年第3期52卷 360-367页

作者： NING chunLin SHI huLi hu Chao National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Graduate University of Chinese Academy of Sciences Beijing 100049China

The positioning of the GPS or Chinese Area Positioning System (CAPS) software receiver was developed on a software receiver platform. The structure of the GPS/CAPS dual-mode software receiver was put forward after analyzing the differences in the satellite identification, ranging code, spread spectrum, coordinate system, time system, carrier band, and navigation data between GPS and CAPS. Based on Matlab software on a personal computer, baseband signal processing and positioning procedures were completed using real GPS and CAPS radio frequency signals received by two antennas. Three kinds of experiments including GPS positioning, CAPS positioning, and GPS/CAPS positioning were carried out. Stability and precision of the results were analyzed and compared. The experimental results show that the precision of CAPS is similar to that of GPS, while the positioning precision of the GPS/CAPS dual-mode software receiver is 1-2 m higher than that of CAPS or GPS. The smallest average variance of the positioning can be obtained by using the GPS/CAPS dual-mode software receiver.

关键词： Chinese area positioning system global navigation satellite system dual-mode software receiver

Efficient dechlorination of 2,4-dichlorophenol in an aqueous media with a mild pH using a Pd/TiO2NTs/Ti cathode

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Frontiers of Environmental Science & Engineering 2015年第5期9卷 919-928页

作者： Jiangkun DU Jianguo BAO Wei hu School of Environmental Studies China University of Geosciences Wuhan 430074 China

In this study, palladium-loaded titania nano- tubes was fabricated on a titanium plate （Pd/TiO2NTs/Ti） for efficient electrodechlorination of 2,4-chlorophenol with a mild pH condition. The nature of PdYTiO2NTs/Ti electrodes was characterized by field-emission scanning electron microscope （FESEM）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and cyclic voltammetry （CV） techniques. The characterization results indicated the generation of Pd~ nanoparticles which were evenly dispersed on titania nanotubes arrays on the Pd/ TiO2NTs/Ti surface. An effective degradation efficiency of up to 91% was achieved within 60 min at cathode potential of -0.7 V （vs. SCE） and initial pH of 5.5. The effects of the applied cathode potential and initial pH on the degradation efficiency were studied. A near neutral condition was more favorable since very low and very high pHs were not conducive to the dechlorination process. Furthermore, the intermediates analysis showed that the Pd/TiO2NTs/Ti electrode could completely remove chlor- ine from 2, 4-dichlorophenol since only phenol was detected as the byproduct and the concentration of released chlorine ions indicated near-complete dechlorination. This work presents a good alternative technique for eliminating persistent chlorophenols in polluted wastewater without maintaining strong acidic environment.

关键词： Pd/TiO2NTs/Ti cathode chlorophenols electrocatalytic dechlorination wastewater treatment

Molecular basis of the silkworm mutant re^(l) causing red egg color and embryonic death

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Insect Science 2021年第5期28卷 1290-1299页

作者： Jiang-Wen Luo Er-Xia An Ya-Ru Lu Ling Yang Ting-Ting Gai Song-Zhen He Song-Yuan Wu Hai hu chun-Lin Li Cheng Lu Xiao-Ling Tong Fang-Yin Dai State Key Laboratory of Silkworm Genome Biology Key Laboratory of Sericultural Biology and Genetic BreedingCollege of BiotechnologySouthwest UniversityChongqing400715 China

The coloration and hatchability of insect eggs can affect individual and population ***,few genetic loci have been documented to affect both traits,and the genes involved in regulating these two traits are *** silkworm recessive mutant re^(l)shows both red egg color and embryo *** studied the molecular basis of the re^(l)phenotype *** genetic analysis,gene screening and sequencing,we found that two closely linked genes,BGIBMGA003497(Bmre)and BGIBMG4003697(Bm-Semala),control egg color and embryo mortality,*** base pairs of the Bm-re gene are deleted in its open reading frame,and BmSemala is expressed at abnormally low levels in mutant re^(l).BmSemala gene function verification was performed using RNA interference and clustered randomly interspersed palindromic repeats(CRISPR)/CRISPR-associate protein *** of the BmSemala gene can cause the death of silkworm *** study revealed the molecular basis of silkworm re^(l)mutant formation and indicated that the Semala gene is essential for insect embryo development.

关键词： BmSemala CRISPR/Cas9 embryonic mortality red egg silkworm

The Coupled CFD/Free-Wake Method for Numerical Prediction of Rotor BVI Noise

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第5期35卷 800-811页

作者： Wang Fei Xu Guohua hu Zhiyuan National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics College of Aerospace EngineeringNanjing University of Aeronautics and Astronautics

A coupled Navier-Stokes/free-wake method is developed to predict the rotor aerodynamics and *** widely-used Farassat 1 Aformulation is adopted to predict the rotor *** the coupled method,the Reynolds-averaged Navier-Stokes(RANS)solver is established to simulate complex aerodynamic phenomena around blade and the tip-wake is captured by a free-wake model without numerical dissipation in the off-body wake *** overcome the time-consuming of the coupling strategy in previous studies,a more efficient coupling strategy is presented,by which only the induced velocity on the outer boundary grid need to be *** order to obtain blade control settings,a delta trimming procedure is developed,which is more efficient than traditional trim method in the calculation of Jacobian *** flight conditions are simulated to demonstrate the validity of the coupled *** the rotor noise of operational load survey(OLS)is studied by the developed method as an application and the computational results are shown to be in good agreements with the available experimental data.

关键词： helicopter rotor coupled N-S/free-wake method delta trim method BVI noise