Efficient Immobilization of Enzymes on Amino Functionalized MIL-125-NH2 Metal Organic Framework

Zichen Wang,Yang Liu,Jinhong Li,Guoqing Meng,Daoyu Zhu,Jiandong Cui,Shi Ru Jia 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.1

As a series of metal organic framework (MOFs), materials of institute lavoisier frameworks (MILs) are expected to be excellent supports for enzyme immobilization due to their good water-stability and acid tolerance. However, enzyme loading on MIL-125-NH2 is very low due to small pore size and few amino groups on the surface of the MIL-125-NH2. In this work, catalase (CAT) was immobilized on the MIL-125-NH2 and amino functionalized MIL-125-NH2 by adsorption (CAT@MIL-125-NH2) and covalent binding (CAT@Amino MIL-125-NH2), respectively. Compared with the CAT@MIL-125-NH2 and free CAT, the CAT@Amino MIL-125-NH2 displayed high activity recovery, good pH stability, stability against denaturants, and thermostability. Furthermore, activity recovery of CAT@Amino MIL-125-NH2 was 56% higher than CAT@MIL-125-NH2. The CAT@Amino MIL-125-NH2 still retained 50% residual activity for 14 days at room temperature, whereas free CAT lost activity after storage for 1 day at the same storage conditions. Furthermore, the CAT@Amino MIL-125-NH2 maintained 62% of its initial activity after 4 consecutive uses, showing good reusability. The results showed that the amino functionalized MIL- 125-NH2 is an excellent carrier of enzyme immobilization.

Enzymatic Transformation of 2-O-α-D-glucopyranosyl-L-ascorbic Acid by α-cyclodextrin Glucanotransferase from Recombinant Escherichia coli

Zichen Zhang,Jianghua Li,Long Liu,Jun Sun,Zhaozhe Hua,Guocheng Du,Jian Chen 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.1

The study aimed to produce 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) via the transglycosylation reaction by α-cyclodextrin glucanotransferase (α-CGTase) from recombinant Escherichia coli with L-ascorbic acid (AA) and β-cyclodextrin (β-CD) as the substrates. Liquid chromatography-tandem mass spectrometry analysis was conducted for AA-2G identification, and the glucoamylase treatment was carried out to produce AA-2G from AA-2-oilgosaccharides. The optimal temperature and pH for the enzymatic AA-2G production were 37°C and 5.5,respectively, and the optimal α-CGTase concentration and substrate mass ratio (AA:β-CD) for AA-2G synthesis were 160 U/mL and 1:1, respectively. At these optimal process conditions, maximal AA-2G production reached 13 g/L. This is the first report regarding the process optimization of enzymatic AA-2G production by α-CGTase from recombinant E. coli. The results may be useful for the industrial scale production of AA-2G.

중국민속학이 걸어온 70년

張紫晨(Zhang Zichen),金錦子(번역자) 한국민속학회 1990 韓國民俗學 Vol.23 No.1

Design and homogenization of metal sandwich tubes with prismatic cores

Kai Zhang,Zichen Deng,Huajiang Ouyang,Jiaxi Zhou 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.4

Hollow cylindrical tubes with a prismatic sandwich lining designed to replace the solid cross-sections are studied in this paper. The sections are divided by a number of revolving periodic unit cells and three topologies of unit cells (Square, Triangle and Kagome) are proposed. Some types of multiple-topology designed materials are also studied. The feasibility and accuracy of a homogenization method for obtaining the equivalent parameters are investigated. As the curved elements of a unit cell are represented by straight elements in the method and the ratios of the lengths of the curved elements to the lengths of the straight elements vary with the changing number of unit cells, some errors may be introduced. The frequencies of the first five modes and responses of the complete and equivalent models under an internal static pressure and an internal step pressure are compared for investigating the scope of applications of the method. The lower bounds and upper bounds of the number of Square, Triangular and Kagome cells in the sections are obtained. It is shown that treating the multiple-topology designed materials as a separate-layer structure is more accurate than treating the structure as a whole.

Experiment investigation on flow characteristics of open natural circulation system

Xiangjie Qi,Zichen Zhao,Peng Ai,Peng Chen,Zhongning Sun,Zhaoming Meng 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.5

Experimental research on flow characteristics of open natural circulation system was performed, tofigure out the mechanism of the open natural circulation behaviors. The influence factors, such as theheating power, the inlet subcooled and the level of cooling tank on the flow characteristics of the systemwere examined. It was shown that within the scope of the experimental conditions, there are five flowtypes: single-phase stable flow, flash and geyser coexisting unstable flow, flash stable flow, flash unstableflow, and flash and boiling coexisting unstable flow. The geyser flow in flash and geyser coexisting unstable flow is different from classic geysers flow. The flow oscillation period and amplitude of the formerare more regular, is a newly discovered flow pattern. By drawing the flow instability boundary diagramand sorting out the flow types, it is found that the two-phase unstable flow is mainly characterized byboiling and flash, which determine the behavior of open natural circulation respectively or jointly. Moreover, compared with full liquid level system, non-full liquid level system is more prone to boilingphenomenon, and the range of heat flux density and undercooling degree corresponding to unstableflow is larger

UDGAN: A new urban design inspiration approach driven by using generative adversarial networks

干薇,Zhao Zichen,Wang Yuankai,Zou Yixuan,Zhou Shiqi,오지강 한국CDE학회 2024 Journal of computational design and engineering Vol.11 No.1

The morphological design of urban space affects the quality of the environment. The traditional experience-based design approach was greatly improved by introducing computational design tools. However, the existing urban design tools are mostly developed on pre-set rules or given targets, which have few contributions to enhance creativity or generate inspiring schemes. Therefore, this paper proposes a new computational urban design approach named UDGAN, integrating generative adversarial networks (GANs) and multi-objective optimization algorithms. This model utilizes urban design scheme plans over the past 20 years from a particular designer as training datasets. Four preference models were trained to autonomously generate stylized urban design schemes. Eight morphological parameters were used to analyze the model performance by comparing generated results with the ground truth. This GAN-based surrogate approach is combined with a morphological indicator alignment process using multi-objective optimization model to obtain better results. The result shows that the R2 predicted by the improved Pix2Pix model reaches 0.798, and the similarity of the generated results can be stably distributed between 0.7 and 0.8, so the design scheme of this preferred style can be effectively learned. At the same time, the pre-trained model greatly reduces the time consumption of the design scheme generation, taking 5 min approximately to complete a generation process. This approach quickly generated the design scheme with preferred features, supporting the designer with creativity and greatly saving the time of design creation, transforming computational design into an inspiration-driven process.

Measure Synchronization in a Huygens’s Non-Dissipative Two-Pendulum Clocks System

Jing Tian,ZiChen Chen,HaiBo Qiu,XiaoQiang Xi 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.2

In this paper, we characterize measure synchronization (MS) in a four-degrees-of-freedom Huygens’s two-pendulum clocks system. The two-pendulum clocks are connected by a massless spring with stiffness constant k. We find that with the stiffness constant k increasing, the coupled pendulums system achieves MS above a threshold value of kc. The energy characteristics of measure synchronization have been discussed, it is found that averaged energy of each pendulum system provide us an easy way to characterize MS transition. Furthermore, we discuss the dependence of the critical value for MS transition on initial conditions and the characteristic parameters of the system.

Evaluating and predicting net energy value of wheat and wheat bran for broiler chickens

Ning Ran,Cheng Zichen,Liu Xingbo,Ban Zhibin,Guo Yuming,Nie Wei 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.11

Objective: It is crucial to accurately determine the net energy (NE) values of feed ingredients because the NE system is expected to be applied to the formulation of broilers feed. The NE values of 5 wheat and 5 wheat brans were determined in 12-to 14-day old Arbor Acres (AA) broilers with substitution method and indirect calorimetry method. Methods: A total of 12 diets, including 2 reference diets (REF) and 10 test diets (5 wheat diets and 5 wheat bran diets) containing 30% of test ingredients, were randomly fed to 864 male AA birds with 6 replicates of 12 birds per treatment. These birds were used to determine metabolizable energy (ME) (8 birds per replicate) in the chicken house and NE (4 birds per replicate) in the chamber respectively at the same time. After a 4-d dietary and environment adaptation period, growth performance, energy values, energy balance and energy utilization were measured during the following 3 d. Multiple linear regression analyses were further performed to generate prediction equations for NE values based on the chemical components and ME values. The NE prediction equation were also validated on another wheat diet and another wheat bran diet with high correlation (r = 0.98, r = 0.75). Results: The NE values of 5 wheat and 5 wheat bran samples are 9.34, 10.02, 10.27, 11.33, and 10.49 MJ/kg, and 5.37, 5.17, 4.87, 5.06, and 4.88 MJ/kg DM, respectively. The equation with the best fit were NE = 1.968AME–0.411×ADF–14.227 (for wheat) and NE = –0.382×CF –0.362×CP–0.244×ADF+20.870 (for wheat bran). Conclusion: The mean NE values of wheat and wheat bran are 10.29 and 5.07 MJ/kg DM in AA broilers. The NE values of ingredients could be predicted by their chemical composition and energy value with good fitness. Objective: It is crucial to accurately determine the net energy (NE) values of feed ingredients because the NE system is expected to be applied to the formulation of broilers feed. The NE values of 5 wheat and 5 wheat brans were determined in 12-to 14-day old Arbor Acres (AA) broilers with substitution method and indirect calorimetry method.Methods: A total of 12 diets, including 2 reference diets (REF) and 10 test diets (5 wheat diets and 5 wheat bran diets) containing 30% of test ingredients, were randomly fed to 864 male AA birds with 6 replicates of 12 birds per treatment. These birds were used to determine metabolizable energy (ME) (8 birds per replicate) in the chicken house and NE (4 birds per replicate) in the chamber respectively at the same time. After a 4-d dietary and environment adaptation period, growth performance, energy values, energy balance and energy utilization were measured during the following 3 d. Multiple linear regression analyses were further performed to generate prediction equations for NE values based on the chemical components and ME values. The NE prediction equation were also validated on another wheat diet and another wheat bran diet with high correlation (r = 0.98, r = 0.75).Results: The NE values of 5 wheat and 5 wheat bran samples are 9.34, 10.02, 10.27, 11.33, and 10.49 MJ/kg, and 5.37, 5.17, 4.87, 5.06, and 4.88 MJ/kg DM, respectively. The equation with the best fit were NE = 1.968AME–0.411×ADF–14.227 (for wheat) and NE = –0.382×CF–0.362×CP–0.244×ADF+20.870 (for wheat bran).Conclusion: The mean NE values of wheat and wheat bran are 10.29 and 5.07 MJ/kg DM in AA broilers. The NE values of ingredients could be predicted by their chemical composition and energy value with good fitness.

Grey fuzzy PI control for packing pressure during injection molding process

Shuo Wang,Ji Ying,Zichen Chen,Kan Cai 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.4

This study presents a grey fuzzy PI (GFPI) controller for packing pressure control during the injection process. The novel controller was designed for solving the problems of large overshoot, static error, and long delay time on servo motor-driven injection molding machines. Based on reasonable assumptions, a mathematical model of injection system was established. According to the nonlinear, severe interferences, and long delay time characteristics in injection process, this paper integrates predictive grey system, robust fuzzy ratiocination,and PI control. Using these mathematical model and control algorithms, a GFPI controller is implemented into an MCU using C programming techniques. The integral discrete PID controller and solid fuzzy controller were realized for contrast experiments. The experimental results show that GFPI controller had better performance on reducing overshoot and static error, increasing both response rate and repeatable accuracy. Such a developed technology would provide helpful references for designing the controller of energy-saving servo motor-driven injection molding equipment.

Broadband mode converter and multiplexer based on dielectric-loaded plasmonic waveguides

Ying Qiu,Jin Tao,Zichen Liu,Xiang Li 한국물리학회 2020 Current Applied Physics Vol.20 No.2

We theoretically demonstrate a broadband mode converter and multiplexer based on plasmonic waveguides loaded with structured dielectrics. The proposed device can realize conversions between a fundamental TM0 mode and a first order TM1 mode, as well as (de)multiplex them with another TM0 mode. Our design exhibits as wide as 400 nm bandwidth and as short as 6~7 μm coupling length. This work has potential application in high density photonic integrated devices for both computing and communication applications.