Solution and Estimate to the Angular Velocity of INS Formed only by Linear Accelerometers

Wu Junwei,Liu Jinfeng,Zhang Yunan,Yuan Na 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

At present, most efforts tend to develop a INS which is only based linear accelerometers, because of the low cost micro-machining gyroscopes lack of the accuracy needed for precise navigation application and possible achieving the required levels of precise for micro-machining accelerometer. Although it was known in theory that a minimum of six accelerometers are required for a complete description of a rigid body motion, and any configuration of six accelerometers (except for a “measure zero” set of six-accelero-meter schemes) will work. Studies on the feasible configuration of GF-INS indicate that the errors of angular velocity resolved from the six accelerometers scheme are diverged with time or have multi solutions. The angular velocity errors are induced by the biases together with the position vectors of the accelerometers, therefore, in order to treat with the problem just mentioned, researchers have been doing many efforts, such as the extra three accelerometers or the magnetometers may be taken as the reference information, the extended Kalman filter (EKF) involved to make the angular velocity errors bound and be estimated, and so on. In this paper, the typical configurations of GF-INS are introduced; for each type GF-INS described, the solutions to the angular velocity and the specific force are derived and the characteristic is indicated; one of the corresponding extend Kalman filters are introduced to estimate the angular errors; parts of the simulation results are presented to verify the validity of the equations of angular velocity and specific force and the performance of extend Kalman filter.

AQUEOUS SYNTHESIS OF HIGH QUANTUM YIELD AND MONODISPERSED THIOL-CAPPED CdxZn1-xTe QUANTUM DOTS BASED ON ELECTROCHEMICAL METHOD

JUNWEI LI,YANG JIANG,YUGANG ZHANG,DI WU,ANQI LUO,ZHONGPING ZHANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.2

A facile green approach has been developed to control the growth regime in the aqueous synthesis of CdxZn1-xTe semiconductor quantum dots (QDs) based on the electrochemistry method. The Low growth temperature and slow injection of Te precursor are used to prolong the diffusion controlled stage and thus suppress Ostwald ripening during the nanocrystal growth. The experimental results showed that a low concentration of Te precursor will definitely influence the growth procedure. The UV–visible absorption spectra, as well as transmission electron microscopy (TEM) shows the QDs a good monodispersity at any interval of the reaction procedure. The high-resolution transmission electron microscopy (HRTEM) images and powder X-ray diffraction (XRD) pattern suggested that the as-prepared QDs have high crystallinity and cubic structure. The size and composition-dependent fluorescent emission wavelength of the resultant CdxZn1-xTe alloyed QDs can be tuned from 460 to 610 nm, and their photoluminescent quantum yield can reach up to 70%. Especially in the wavelength range of 510–578 nm, the overall PL QYs of the as-prepared CdxZn1-xTe QDs were above 50%. The current work suggests that electrochemical method is an attractive approach to the synthesis of high-quality II-VI ternary alloyed semiconductor QDs at large-scale with a prominent cost advantage.

NANOSCALE POROUS SILICON MICROCAVITY BIOSENSOR FOR NOVEL LABEL-FREE TUBERCULOSIS ANTIGEN–ANTIBODY DETECTION

BAO WU,GUOGUANG RONG,JUNWEI ZHAO,SHULIN ZHANG,YONGXIN ZHU,BOYONG HE 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.6

One third of the world population is estimated to have Mycobacterium tuberculosis infection. It is urgent to develop a rapid, inexpensive and convenient diagnostic method for detection of tuberculosis. Porous silicon material has taken more and more attention in recent years for biosensing applications and some useful results have been obtained. In this paper, we report the feasibility of applying porous silicon microcavity biosensor in a novel and relatively rapid serodiagnostic approach. Nowadays, most of serodiagnostic tests are based on labeled detection. Applying label-free detection methods can help develop fast and e±cient tuberculosis diagnostic tools, which can meet the current demand. In this study, we use this label-free sensing platform (i.e., porous silicon microcavity) to detect the interaction between 16 kDa antigen and anti-16 kDa antibody. Through a series of experiments, we verify the speci¯city and examine the sensitivity of this new diagnostic technique. The results show that it is feasible to apply porous silicon microcavity in the tests of tuberculosis.

Buckling Modes of Cold-Formed Thin-Walled Steel Beams Under Different Impact Positions

Chang Wu,Junwei Duan,Renhong Wang,Ziheng Yang 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.1

This paper aims to study the buckling mode of cold-formed thin-walled channel steel beams under different impact positions. The impact test of the thin-walled channel steel beams was carried out using a drop hammer to obtain the acceleration of the measuring point and the buckling mode of the member. The experimental results and ANSYS/LS-DYNA numerical simulation results are compared and analyzed. The results show that the acceleration curve change trend obtained from the test is similar to numerical simulation. The difference between the acceleration obtained by numerical simulation and the maximum value obtained by test accounts for 5.86% of the simulated value. Therefore, the dynamic response results of cold-formed thin-walled channel steel beams under numerical simulation can be effectively verified by the test. Numerical simulation methods are used to analyze the dynamic response of two groups of members under impact at different positions and the corresponding buckling modes. The results show that the buckling of the members at 1/2, 1/3, and 1/4 of the flange of the impact member is similar to the O-I mode under the same conditions. The buckling mode is half-O mode when the midpoint of the intersection line between flange and web is impacted. The buckling mode is U-shaped when the midpoint of the intersection line between flange and the curling edge is impact.

Hydrolytic performances of different organic compounds in different lignocellulosic biomass during anaerobic digestion

Haifeng Yang,Rui Deng,Junwei Jin,Yuling Wu,Xin Jiang,Jinhua Shi 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.4

Hydrolytic performances of different organic compounds in lignocellulosic biomass (LB) during anaerobic digestion (AD) are worth investigating due to the complex and refractory structure of lignocellulose. This study aimed to clarify the hydrolytic performances of different lignocellulosic components (hemicellulose, cellulose and lignin) and other typical organics (saccharides, protein and lipid) in AD process. Furthermore, an in-depth study of different lignocellulosic components mono-/co-digestive performances, as well as their effects on digestive systems were also designed to explain the mechanism. Kinetic models were specially applied to evaluate the hydrolytic process and make comparison among different lignocellulosic components. Results showed that hemicellulose obtained high degradation ratio (77.2-85.0%) during anaerobic digestion, while cellulose was difficult to hydrolyze without sufficient acidity. And organics (saccharides, protein and lipid) were much easier to be hydrolyzed than lignocellulose. Results also depicted that lignocellulose addition could efficiently enhance the volatile solid (VS) removals of digestive systems, while lignin existing in systems reduced the VS removal. The limited hydrolysis of lignocellulose hindered the degradation of total VS in digester. It is quite important to obtain high bioenergy conversion, pretreatments, which can destroy the lignin wrapping in LBs digestion. This study could provide a reference for the AD of LBs.

Prediction of exploration targets based on integrated analyses of source rock and simulated hydrocarbon migration direction: a case study from the gentle slope of Shulu Sag, Bohai Bay Basin, northern China

Changqing Ren,Fugui He,Xianzhi Gao,Dongsheng Wu,Wenli Yao,Jianzhang Tian,Huiping Guo,Yuanxin Huang,Li Wang,Han Feng,Junwei Li 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.6

The Shulu Sag which is a rifted sag with NNE trend is located in the south of Jizhong Depression, Bohai Bay Basin, northern China. The gentle slope and three troughs are situated in the west and east of the sag, respectively. Both of the lower part of Shasan Member (Es3x) and the lower part of Shayi Member (Es1x) act as source rocks in this sag. Researches on the type, quantity, quality and thermal maturity of the respective organic matter have been conducted using Rock-Eval pyrolysis data. Type II is the dominant kerogen in Es1x of all troughs. However, Type II1 and III is the dominant kerogen in Es3x of Middle-Southern and Northern trough, respectively. TOC (total organic carbon) and pyrolysis S2 (hydrocarbon) values suggest that the Es1x source rocks in Middle-Southern and Northern trough are fair to good and poor to fair generative potential of hydrocarbon, separately. The Es3x source rocks in Middle-Southern and Northern trough possess fair to excellent and poor to fair generative potential of hydrocarbon, individually. Tmax (pyrolysis temperature at maximum S2) values indicate that most of Es3x samples are thermally mature, but all Es1x samples are thermally immature. Under large scale condition, the hydrocarbon secondary migration in the upper part of Shasan Member (Es3s), Shaer Member (Es2) and the upper part of Shayi Member (Es1s) have been simulated using fluid potential model with Arcgis 9.3 software. The simulation results reveal the direction of hydrocarbon secondary migration and the distribution of hydrocarbon migration-accumulation units (HMAUS), and also suggest that the hydrocarbon migration direction is obviously controlled by nose-like structure belts where most of hydrocarbons accumulate. That shows high reliability because they are consistent with the hydrocarbon exploration result in this area. On the basis of integrated analyses of source rocks and hydrocarbon migration direction, the following five areas in the gentle slope are identified to be the preferred hydrocarbon accumulation area: Taijiazhuang area, northern and southern Xicaogu area, as well as northern and southern Leijiazhuang area. It is considerably helpful to reduce the risk in hydrocarbon exploration of Shulu Sag.

Fuzzy-PID controller for motion control of CFETR multi-functional maintenance platform

Li, Dongyi,Lu, Kun,Cheng, Yong,Zhao, Wenlong,Yang, Songzhu,Zhang, Yu,Li, Junwei,Wu, Huapeng Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.7

The motion control of the divertor maintenance system of the China Fusion Engineering Test Reactor (CFETR) was studied in this paper, in which CFETR Multi-Functional Maintenance Platform (MFMP) was simplified as a parallel robot for the convenience of theoretical analysis. In order to design the motion controller of parallel robot, the kinematics analysis of parallel robot was carried out. After that, the dynamic modeling of the hydraulic system was built. As the large variation of heavy payload on MFMP and highly nonlinearity of the system, A Fuzzy-PID controller was built for self-tuning PID controller parameters by using Fuzzy system to achieve better performance. In order to test the feasibility of the Fuzzy-PID controller, the simulation model of the system was built in Simulink. The results have showed that Fuzzy-PID controller can significantly reduce the angular error of the moving platform and provide the stable motion for transferring the divertor.