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Pd catalysts supported on rGO-TiO_2 composites for direct synthesis of H_2O_2: Modification of Pd^(2+)/Pd^0 ratio and hydrophilic property

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Chinese Journal of Chemical Engineering 2018年第3期26卷 534-539页

作者： Shuying Chen rui tu Jun Li Xiaohua Lu State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University

The use of nanostructured composites as catalyst supports is a promising route to prepare catalysts with high selectivity and productivity. In this work, reduced graphene oxide-TiO_2(rGP-x) composites with a variation of reduced graphene oxide(rGO) content were synthesized by hydrothermal method. Pd/rGP-x catalysts were prepared in incipient-wetness impregnation method for the direct synthesis of H_2O_2 from H2 and O_2. The morphology and electronic properties of catalysts were investigated by XPS, TEM, and Raman *** ratio of Pd^(2+)/Pd^0 and the hydrophobicity of the catalysts were increased with the rising content of rGO. As the amount of rGO in the catalysts varied in the range of 0.025 wt%–2 wt%, the selectivity of H_2O_2 exhibited a tendency of increasing firstly and then decreasing from 0.1 wt% to 2 wt%. It indicates that good catalytic performance for H_2O_2 synthesis can be achieved only when appropriate amount of rGO is introduced. The H_2O_2 selectivity and productivity of Pd/r GP-0.025 both improved remarkably compared with Pd/P25. This enhancement originated from the combined effects of the proper ratio of Pd^(2+)/Pd^0 and hydrophobicity of the catalyst.

关键词： Direct H2O2 synthesis Reduced graphene oxide Hydrothermal Electronic structure Desorption Selectivity

Recover the abnormal positioning,velocity and timing services caused by BDS satellite orbital maneuvers

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Satellite Navigation 2021年第1期2卷 227-237页

作者： rui tu rui Zhang Pengfei Zhang Junqiang Han Lihong Fan Xiaochun Lu National Time Service Center Chinese Academy of SciencesShu Yuan RoadXi’An 710600China Key Laboratory of Precision Navigation and Timing Technology Chinese Academy of SciencesShu Yuan RoadXi’An 710600China University of Chinese Academy of Sciences Yu Quan RoadBei’Jing 100049China.

The BeiDou Navigation Satellite System(BDS)provides global Positioning,Velocity,And Timing(PVT)services that are widely used in various *** BDS satellites frequently need the orbit maneuvers due to various perturbations to keep satellites in their designed *** these maneuvers,PVT services may be abnormal if the data from a maneuvering satellite is *** this paper we developed an approach to recover the abnormal PVT *** using BDS observations from multiple tracking stations,the orbital errors of a maneuvering satellite can be in real time obtained and corrected,thereby avoiding any influence on the performance of PVT *** tests show that the average precision of position,velocity and timing services are improved by 0.8 m,0.1 mm/s and 0.16 ns,respectively,using the developed orbital maneuver recovery *** addition,the approach can also be used for the orbital maneuver detection and monitoring.

关键词： BeiDou Navigation Satellite System Satellite orbital maneuvers Velocity estimation Carrier phase observation

Morphologies of Al_4Sr Intermetallic Phase and Its Modification Property upon A356 Alloys

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Journal of Materials Science & Technology 2012年第6期28卷 524-530页

作者： Chengwei Liao Jianchun Chun Yang Li rui tu Chunxu Pan School of Physics and Technology and Center for Electron Microscopy Wuhan UniversityWuhan 430072China Hunan Jinlianxing Specially Materials Technology Co.Ltd Yueyang 414005China

In general, the modification performance of AI-Sr master alloys is primarily dependent upon the morphologies and sizes of the AI4Sr intermetallic phase. In this paper, the crystal structure, morphologies, sizes, hardness and elastic modulus of AI4Sr in AI-Sr master alloys prepared from variant processes were studied by means of optical metallurgical microscope, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and nanoindentation system. The results revealed that the microstructures and modification performance of the AI4Sr phase were related to the preparation processes. That is to say, when a ＂direct reaction-hot extrusion＂ process was used, the AI4Sr phase exhibited a homogeneous distribution in the AI matrix with small size and roundish shapes, which ensured the AI-Sr master alloy wire advantages involving high recovery, good reproducibility, no delitescence of modification, no corrosion on equipments, and good workability. However, in the case of the traditional ＂direct reaction＂ process, the AI4Sr phase was in large size with shapes of rectangular stripe and plates, which limited the Sr content increasing due to the brittleness of the AI-Sr alloy. It was also found that the morphology and size of the AI4Sr phases changed during heat treatment at high temperature up to 600℃.

关键词： Intermetallics Modification Hot extrusion Heat treatment Microstructure

GNSS rapid precise point positioning enhanced by low Earth orbit satellites

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Satellite Navigation 2023年第1期4卷 41-53,I0003页

作者： Ju Hong rui tu Pengfei Zhang rui Zhang Junqiang Han Lihong Fan Siyao Wang Xiaochun Lu National Time Service Center Chinese Academy of SciencesShu Yuan RoadXi’an 710600China University of Chinese Academy of Sciences Yu Quan RoadBeijing 100049China

The Low Earth Orbit(LEO)satellites can be used to efectively speed up Precise Point Positioning(PPP)*** this study,180 LEO satellites with a global distribution are simulated to evaluate their contribution to the PPP *** satellites can give more redundant observations and improve satellite geometric distributions,particularly for a single Global Navigation Satellite System(GNSS).The convergence speed of the PPP foat solution using the Global Positioning System(GPS,G)or BeiDou Navigation Satellite System(BDS,C)single system as well as the G/C/Galileo navigation satellite system(Galileo,E)/GLObal NAvigation Satellite System(GLONASS,R)combined system with LEO satellites added is improved by 90.0%,91.0%,and 90.7%,respectively,with respect to the system without LEO satellites *** introduced LEO observations to assist GNSS in PPP-AR(Ambiguity Resolution)and PPP-RTK(Real Time Kinematic).The success fx rate of a single system is signifcantly improved,and the Time-To-First-Fix(TTFF)of G and G/C/E is reduced by 86.4%and 82.8%,respectively,for the PPP-AR *** analyzed the positioning performance of LEO satellite assisted G/C/E PPP-RTK in the reference networks of diferent scales,namely diferent atmospheric delay interpolation *** success fx rate of the G/C/E combined system is improved from 86.8 to 94.9%,and the TTFF is reduced by 36.8%,with the addition of LEO satellites in the 57 km reference *** the 110 km reference network,the success fx rate of the G/C/E combined system is improved from 64.0 to 88.6%,and the TTFF is reduced by 32.1%.GNSS PPP-RTK with adding the LEO satellites in the reference networks of diferent scales shows obvious improvement because the atmospheric correlation decreases with increasing distance from the reference networks.

关键词： Precise point positioning Low earth orbit LEO enhanced global navigation satellite system Rapid positioning

Extraction of ocean tide semidiurnal constituents’ vertical displacement parameters based on GPS PPP and harmonic analysis method

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Extraction of ocean tide semidiurnal constituents’ vertical...

Real-time and fast retrieve the coseismic wave by GPS, strong-motion combined measurements and broadcast ephemeris

第五届中国卫星导航学术年会

作者： Zhao Hong Zhang Qin Zhang Ming Zhang Shuangcheng Qu Wei tu rui Liu Zhi College of Geology Engineering and Geomatics Chang'an University GFZ German Reasearch Centre for Geosciences China JK Institute Of Engineering Investigation And Design

ISBN: (纸本)9783642547423

Using GPS data of 4 CORS stations in Hong Kong 2012, four ocean tide semidiurnal constituents’ vertical displacement parameters of every station were calculated. Firstly, 4 stations’ displacement time series were extracted by GPS PPP algorithm. Next, combined with harmonic analysis method, the vertical displacement parameters of semidiurnal constituents were obtained. Simultaneously, in order to evaluate accuracy and reliability of ocean loading displacement parameters determined by PPP technology, we compared the results with ocean loading displacement parameters provided by HAMTIDE11A.2011 global ocean tide model refined by local tidal data of eastern and southern sea of China and the difference was less than 1mm. Therefore, PPP techniques can be used for measuring ocean tide loading displacement parameters, and it has implications for precision modeling of tides and high-precision geodetic measurements.

关键词： GPS technology PPP Harmonic Analysis Ocean loading displacement parameters

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Real-time and fast retrieve the coseismic wave by GPS, stron...

An Identifier-Based Network Access Control Mechanism Based on Locator/Identifier Split

第五届中国卫星导航学术年会

作者： rui tu The Germany Research Center for Geosciences

In this study, we propose an approach of real-time and fast retrieving the coseismic waves by GPS, strong-motion combined measurements and broadcast ephemeris. Firstly, the velocity observation equations and state equations of the strong-motion measurements are introduced into Precise Point Positioning （PPP） solution model, the baseline shifts of the strong-motion are real-time estimated as unknown parameters like other positioning parameters by a Kalman filter. Then, the true velocity wave was retrieved by correcting the estimated baseline shifts, the true displacement wave was recovered by the velocity integrated displacement after de-trending a linear correction. The series of validation results have shown that, this method can fast and accurate retrieve the coseismic wave, the convergence time is smaller than one minute, and the precision are better than 2 mm/s and 2.5 cm for velocity and displacement respectively.

关键词： GPS and Strong-motion combined measurements Broadcast ephemeris Coseismic wave retrieving Real-time

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International Journal of Communications, Network and System Sciences 2009年第7期2卷 641-644页

作者： rui tu Jinshu SU Ruoshan KONG School of Computer Science National University of Defense Technology International School of Software Wuhan University

Legacy IP address-based access control has met many challenges, because the network nodes cannot be identified accurately based on their variable IP addresses. “Locator/Identifier Split” has made it possible to build a network access control mechanism based on the permanent identifier. With the support of “Locator/Identifier Split” routing and addressing concept, the Identifier-based Access Control (IBAC) makes net-work access control more accurate and efficient, and fits for mobile nodes’ access control quite well. Moreover, Self-verifying Identifier makes it possible for the receiver to verify the packet sender’s identity without the third part authentication, which greatly reduces the probability of “Identifier Spoofing”.

关键词： Access Control Locator/Identifier Split IBAC Self-Verifying Identifier Identifier Spoofing

On ionosphere-delay processing methods for single-frequency precise-point positioning

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Geodesy and Geodynamics 2011年第1期2卷 71-76页

作者： tu rui Zhang Qin Huang Guanwen Zhao Hong College of Geology Engineering and Geomatics Chang＇an University Xi＇an 710054 China

In single-frequency precise-point positioning of a satellite,ionosphere delay is one of the most important factors impacting the accuracy. Because of the instability of the ionosphere and uncertainty of its physical properties, the positioning accuracy is seriously limited when using a precision-limited model for correction. In order to reduce the error, we propose to introduce some ionosphere parameter for real-time ionosphere-delay estimation by applying various mapping functions. Through calculation with data from the IGS（ International GPS Service） tracking station and comparison among results of using several different models and mapping functions, the feasibility and effectiveness of the new method are verified.

关键词： single-frequency precise-point positioning ionosphere delay model correction mapping function parameter estimation

从2010国际大电网会议看直流输电技术的发展方向

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高电压技术 2010年第12期36卷 3070-3077页

作者：徐政屠卿瑞裘鹏浙江大学电气工程学院杭州310027

根据2010国际大电网会议与高压直流输电和电力电子技术对应的B4技术委员会发表的论文,探讨了直流输电技术的发展方向以及代表性的工程,论述了基于两端直流输电技术的多端直流输电技术、±1000kV及以上的直流输电技术、模块化多电平电压... 详细信息

根据2010国际大电网会议与高压直流输电和电力电子技术对应的B4技术委员会发表的论文,探讨了直流输电技术的发展方向以及代表性的工程,论述了基于两端直流输电技术的多端直流输电技术、±1000kV及以上的直流输电技术、模块化多电平电压源换流器型直流输电技术、基于两电平级联式换流器型直流输电技术、混合式电压源换流器型直流输电技术以及基于电压源换流器的多端直流输电技术。

关键词：两端直流输电多端直流输电特高压直流输电电压源换流器型直流输电模块化多电平电压源换流器型直流输电两电平级联式换流器型直流输电混合式电压源换流器型直流输电