Expanding Application of Immobilized Candida Antarctica Lipase B: A Green Enzyme Catalyst for Knoevenagel Condensation Reaction

Cuie Wang,Ning Wang,Xinhua Liu,Peng Wan,Xinwei He,Yongjia Shang 한국섬유공학회 2018 Fibers and polymers Vol.19 No.8

We propose a green synthesis of benzopyran compound based on immobilized lipase. Firstly, by using a combined electrospun membrane and biocompatible chitosan, we show that the chitosan-functionalized electrospun PMA-co-PAA fibrous membrane can provide effective anchoring sites for immobilization of the Candida antarctica lipase B (CALB), and a maximum loading amount of CALB (152 mg/g) can be achieved. Then, the resulting membrane displays enhanced stability in catalyzing Knoevenagel condensation reaction of salicylaldehyde with active methylene compound in mixed aqueousorganic media. The catalytic activity and stability of the CALB on chitosan-modified fiber is better than its non-immobilized counterpart. Furthermore, this immobilize CALB catalyst still retained about 45 % of the initial activity after 5 cycles, which potentially had implications for the design of “green” enzyme catalyst for sustainable organic synthesis.

Study on Wheel-Side Drive System with a Single Trailing Arm

Wang Bin,Chen Xinbo,Lyu Hongming,Niu Xinwei 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.5

In order to reduce unsprung mass and ensure driving comfortability, a novel electrical vehicle (EV) drive system, which integrated the wheel-side reducer and a single trailing arm, was studied in this paper. Firstly, the general structure of the drive system was studied, in which the reducer not only worked as a wheel-side reducer but also as the single trailing arm. Then, the transmission power losses were modeled by integrating different load-independent and load-independent models of power losses. Next, the experiment of the power losses test for the wheel-side drive system was conducted, which declared the patterns of power losses of electric motor and the whole drive system. Finally, the power losses of wheel-side reducer based on NEDC are studied, which illustrates oil churning and gear sliding power losses are the main types of transmission power losses. At low rotational velocities, gear friction power losses are larger than oil churning power losses. While at high rotational velocities, oil churning power losses are dominant. The transmission efficiency of the reducer based on NEDC varies among the range of 78 ~ 95 %, which depends on the torque and rotational velocity transmitted from the driving motor to EV’s wheel.

PROLONG THE SERVICE LIFE OF SWITCH RAIL BY IMPROVED INDUCTION HEAT TREATMENT

Xinwei Zhan,Shuqing Wang 한국철도학회 2007 한국철도학회 학술발표대회논문집 Vol.- No.-

Switch rail is a very important part on the railway track, which not only accounts for the safety of the passing trains but also greatly influences the speed of the train. The higher the speed and the loads of the train the more it demands on the properties of the switch rail. Research shows that the higher mechanical properties of switch rail the longer the service life. Induction heat treatment is a good way of improving the mechanical properties of metallic materials. But the switch rail’s section area changes gradually across the lengthways, which is difficult for induction heating especially for the small section. And the mechanical property of small section of the switch rail is the most important for its service life. The induction heat treatment used past always brings the low hardness on small section which can cause low service life of switch for wearing, or too high hardness because of martensite microstructure which can cause the shelling or even breaking of the switch rail. To prolong the service life of switch rail by higher mechanical properties, we researched the improved induction heat treatment for switch rail by adjusting speed of heating, and adopting compressed air cooling. The results showed that switch rail obtain almost the same high hardness across the length way after the improved induction heat treatment, which is very helpful to extend the service life of switch rail.

Dark Soliton Solution of the Three-dimensional Gross-Pitaevskii Equation with an Isotropic Harmonic Potential and Nonlinearity in Polytropic Approximation

Xinwei Fan,Yu Zhou,Yalun Li,Ying Wang,Shuyu Zhou 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.3

We study the three-dimensional Fermi gas in an isotropic harmonic trap during the Bardeen- Cooper-Schrieffer superfluid to Bose-Einstein condensate (BCS-BEC) crossover, which is modeled by using the generalized Gross-Pitaevskii equation (GGPE) in the polytropic approximation. We analytically solved the 3D GGPE with a coupled modulus-phase transformation without introducing any additional integrability constraint, reaching the dark soliton-like solution. We find that the dark soliton identified undergoes an oscillation with a constant period over the whole BCS-BEC crossover region, although the amplitude of the dark soliton varies with polytropic index, demonstrating the peculiar nonlinear properties for the system modeled by using the 3D GGPE.

韩国平安社区建设经验及对中国的启示

Wang Biao,Cheng Xinwei,郑 푸 름,김정문 인문사회 21 2023 인문사회 21 Vol.14 No.3

This study introduces the “Anxin Community Demonstration Project”, a resident-led initiative in South Korea, in order to provide valuable experience and intellectual support for promoting similar resident-led safe communities in China. Firstly, the study reviews the background, organizational structure, and scope of work of the Anxin Village project, and summarizes the key characteristics of its development. Secondly, the study provides a detailed analysis of three exemplary cases from the Anxin Community project, suggesting that their successful experiences could serve as a reference for the construction of safe communities in China. Finally, the study proposes adaptive solutions based on the current state of development of safe communities in China.

Adaptive Frequency-Regualtion Strategy of a DFIG for Enhancing Frequency Support Capability

Mingyi Sun,Xinwei Li,Dejian Yang,Gangui Yan,Lin Yue,Xin Wang 제어로봇시스템학회 2023 제어로봇시스템학회 국제학술대회 논문집 Vol.2023 No.10

Stress concentrations around a circular hole in an infinite plate of arbitrary thickness

Longchao Dai,Xinwei Wang,Feng Liu 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.2

This paper presents theoretical solutions for the three-dimensional (3D) stress field in an infinite isotropic elastic plate containing a through-the-thickness circular hole subjected to far-field inplane loads by using Kane and Mindlin’s assumption. The dangerous position, where the premature fracture or failure of the plate will take place, the expressions of the tangential stress at the surface of the hole and the out-of-plane stress constraint factor are found in a concise, explicit form. Based on the present theoretical solutions, a comprehensive analysis is performed on the deviated degree of the in-plane stresses from the related plane stress solutions, stress concentration and out-of-plane constraint, and the emphasis has been placed on the effects of the plate thickness, Poisson’s ratio and the far-field in-plane loads on the stress field. The analytical solution shows that the effects of the plate thickness and Poisson’s ratio on the deviation of the 3D in-plane stress components is obvious and could not be ignored, although their effects on distributions of the in-plane stress components are slight, and that the effect of the farfield in-plane loads is just on the contrary of that of the above two. When only the shear stress is loaded at far field, the stress concentration factor reach its peak value about 8.9% higher than that of the plane stress solutions, and the out-of-plane stress constraint factor can reach 1 at the surface of the hole and is the biggest among all cases considered.

Research on Human Driving Characterised Trajectory Planning and Trajectory Tracking Control Based on a Test Track

Xing Xu,Xinwei Jiang,Ju Xie,Feng Wang,Minglei Li 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4

The trajectory planning plays an important role in realizing the autonomous driving process. The trajectory that reflects the driving habits of human drivers and conforms with people’s driving intuition enables a vehicle to operate smoother and more comfortable when passing through corners, which could improve the acceptability of autonomous vehicles in the market in the future. The research of this paper focuses on planning a human driving characterised trajectory along a road based on the test track that could reflect natural driving behaviour in corners considering the sense of natural and comfortable for the occupants. Firstly, the data collected of the test track are processed and the coordinate system transformation is completed, and the human tested trajectories in the test track is extracted and analysed. Then, the human driving characterised trajectory planning is completed based on optimal control in a lane section on the test track. The trajectory tracking control algorithm based on LQR is designed, and a CarSim/Simulink co-simulation platform is established to track the optimal trajectory generated in a lane and the lane centreline trajectory to verify the superiority of the planned trajectory. The results show that compared with the centreline trajectory, the human driving characterised trajectory planned enables the autonomous vehicle operates smoother and more comfortable, and reflects the characteristic of human drivers to a large extent.

Wideband Lamb wave analysis based on continuous wavelet transform

Lihua Shi,Xinwei Wang,Gang Li,Lingyan Zhang 국제구조공학회 2005 Smart Structures and Systems, An International Jou Vol.1 No.3

In Lamb wave detection of damages in smart structures, the excitation pulse is usually designed as a narrow band burst wave for the convenience of analysis and recognition. However, the wideband excitation can excite more modes in plate/shell structure and thus provides extra information for changes of the structure. This paper presents a method that can extract information in wideband Lamb wave signals. By transforming the detected signals into various sub-frequency band, the measured signal can be converted to its equivalences of narrow band excitations, therefore, the information in different frequency bands can be acquired from a single test and in the same time the complicity of wideband signal can be simplified. Some test results are provided to verify this method.

Wideband Lamb wave analysis based on continuous wavelet transform

Shi, Lihua,Wang, Xinwei,Li, Gang,Zhang, Lingyan Techno-Press 2005 Smart Structures and Systems, An International Jou Vol.1 No.3

In Lamb wave detection of damages in smart structures, the excitation pulse is usually designed as a narrow band burst wave for the convenience of analysis and recognition. However, the wideband excitation can excite more modes in plate/shell structure and thus provides extra information for changes of the structure. This paper presents a method that can extract information in wideband Lamb wave signals. By transforming the detected signals into various sub-frequency band, the measured signal can be converted to its equivalences of narrow band excitations, therefore, the information in different frequency bands can be acquired from a single test and in the same time the complicity of wideband signal can be simplified. Some test results are provided to verify this method.