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Gene Sequence, Soluble Expression and Homologous Comparison of a D-Hydantoinase fromPseudomonas putida YZ-26

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Chemical Research in Chinese Universities 2005年第5期21卷 552-557页

作者： SHI Ya-wei ZHAO Li-xia NIU Li-xi FENG xia YUAN Jing-ming Key Laboratory for Chemical Biology and Molecular Engineering of Ministry of Education Institute of Biotechnology Shanxi University Taiyuan 030006 P. R. China

A 1440bp open-reading frame encoding D-hydantoinase from Pseudomonas putida YZ-26 was cloned and sequenced（ GenBank AY387829）. The DNA fragment was inserted into Nde and BamHI sites of vector pET-3a, yielding a recombinant plasmid, pET-HDT. After being transferred into the host strain, the artificial strain, pET-HDT/ E. coli BL21 can express the D-hydantoinase as the soluble form in the Lura-Bertani medium without addition of any inducers. The activity of the enzyme toward substrate DL-hydantoin can reach 3000-4000 IU per cells from one-liter bacterial culture incubated at 30 ℃ for 10-12 h. By the comparison of amino acid sequence homology, hydrophobic residues analysis and secondary structure prediction, it was found that D-hydantoinase reported herein is quite similar to that from Pseudomonas putdia CCRC12857, and alike to that from Pseudomonas putdia DSM84 or other bacteria. A rapid and efficient purification procedure of the enzyme was performed by a three-step procedure： ammonium sulfate fractionation, phenyl Sepharose hydrophobic interaction chromatography and Sephacryl S-200 gel filtration. The molecular mass of the monomeric enzyme is 52042 Da as determined by MALDI-TOF mass spectrometry.

关键词： D-Hydantoinase Gene sequence Soluble expression Homologous comparison Purification Mass spectrum

Jet Vectoring Control Using a Novel Synthetic Jet Actuator

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Chinese Journal of Aeronautics 2007年第3期20卷 193-201页

作者： LUO zhen-bing xia Zhi-xun xiE Yong-gao College of Aerospace and Materials Engineering National University of Defense Technology Changsha 410073 China

A primary air jet vectoring control system with a novel synthetic jet actuator （SJA） is presented and simulated numerically. The results show that, in comparison with an existing traditional synthetic jet actuator, which is able to perform the duty of either ＂push＂ or ＂pull＂, one novel synthetic jet actuator can fulfill both ＂push＂ and ＂pull＂ functions to vector the primary jet by shifting a slide block inside it. Therefore, because the new actuator possesses greater efficiency, it has potentiality to replace the existing one in various appli- cations, such as thrust vectoring and the reduction of thermal signature. Moreover, as the novel actuator can fulfill those functions that the existing one can not, it may well be expected to popularize it into more flow control systems.

关键词： jet vectoring control synthetic jet actuator slide block flow control

Effect of alginic acid decomposing bacterium on the growth of Laminaria japonica (Phaeophyceae)

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Journal of Environmental Sciences 2006年第3期18卷 543-551页

作者： WANG You TANG Xue-xi YANG zhen YU Zhi-ming College of Marine Life Science Ocean University of China Qingdao 266003 China The Key Laboratory of Marine Ecology and Environmental Sciences Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China

We collected the diseased blades of Larninaria japonica from Yantai Sea Farm from October to December 2002, and the alginic acid decomposing bacterium on the diseased blade was isolated and purified, and was identified as A lteromonas espejiana. This bacterium was applied as the causative pathogen to infect the blades of L. japonica under laboratory conditions. The aim of the present study was to identify the effects of the bacterium on the growth of L. japonica, and to find the possibly effective mechanism. Results showed that：（1）The blades of *** exhibited symptoms of lesion,bleaching and deteriortion when infected by the bacterium. and their growth and photosynthesis were dramatically suppressed. At the same time, the reactive oxygen species （ROS） generation enhanced obviously, and the relative membrane permeability increased significantly. The contents of malonaldehyde （MDA） and free fatty acid in the microsomol membrane greatly elevated, but the phospholipid content decreased. Result suggested an obvious peroxidation and deesterrification in the blades of L. japonica when infected by the bacterium. （2） The simultaneous assay on the antioxidant enzyme activities demonstrated that superoxide dismutase （SOD） and catalase （CAT） increased greatly when infected by the bacterium, but glutathione peroxidase （Gpx） and ascorbate peroxidase （APX） did not exhibit active responses to the bacterium throughout the experiment. （3） The histomorphological observations gave a distinctive evidence of the severity of the lesions as well as the relative abundance in the bacterial population on the blades after infection. The bacterium firstly invaded into the endodermis of L. japonica and gathered around there, and then resulted in the membrane damage, cells corruption and ultimately, the death of L. japonica.

关键词： Laminaria japonica alginic acid decomposing bacterial infection growth mechanism

Security control of Markovian jump neural networks with stochastic sampling subject to false data injection attacks

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Communications in Theoretical Physics 2023年第10期75卷 146-154页

作者： Lan Yao xia Huang zhen Wang Min xiao College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China College of Automation Nanjing University of Posts and TelecommunicationsNanjing 210003China

The security control of Markovian jumping neural networks(MJNNs)is investigated under false data injection attacks that take place in the shared communication *** sampleddata control is employed to research the exponential synchronization of MJNNs under false data injection attacks(FDIAs)since it can alleviate the impact of the FDIAs on the performance of the system by adjusting the sampling periods.A multi-delay error system model is established through the input-delay *** reduce the conservatism of the results,a sampling-periodprobability-dependent looped Lyapunov functional is *** light of some less conservative integral inequalities,a synchronization criterion is derived,and an algorithm is provided that can be solved for determining the controller ***,a numerical simulation is presented to confirm the efficiency of the proposed method.

关键词： Markovian jumping neural networks stochastic sampling looped-functional false data injection attack

Nonconforming Finite Element Method for the Transmission Eigenvalue Problem

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Advances in Applied Mathematics and Mechanics 2017年第1期9卷 92-103页

作者： xia Ji Yingxia xi Hehu xie LSEC NCMISInstitute of Computational MathematicsAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

In this paper,we analyze a nonconforming finite element method for the computation of transmission eigenvalues and the corresponding *** error estimates of the eigenvalue and eigenfunction approximation are given,***,... 详细信息

关键词： Transmission eigenvalue Morley element nonconforming finite element method

In-plane Uniaxial Anisotropy and Magnetization Reversal Mechanism of FeCo Films by Strip Pattern

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1099-1104页

作者： Xuemeng Han Jinhua Ma zhen Wang Yalu Zuo Li xi Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education Lanzhou University

Strip-like Fe Co films were patterned by a traditional lithograph process from intrinsically isotropic continuous Fe Co films. The strip-patterned Fe Co film shows a strong in-plane uniaxial magnetic anisotropy with easy axis along the length direction of the strip. The angular dependences of remanence ratio, switching field, and coercivity indicate that the magnetization reversal mechanism of the strip-patterned Fe Co film is coherent rotation and domain wall depinning when the applied field is near the hard axis and easy axis, respectively. The consistency of the experimental hysteresis loops of the strip-patterned Fe Co film and calculated hysteresis loops with a simple in-plane uniaxial anisotropy model indicates that the strip-patterned Fe Co film behaves as a single domain. The absence of the domain wall and the strong in-plane anisotropy field make the strip-patterned Fe Co films have much potential for high-frequency application.

关键词： In-plane anisotropy Fe Co film Strip patterned Switching field

Adsorption of H2O, OH, and O on CUCl（111） Surface： A Density Functional Theory Study

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Chinese Journal of Chemical Physics 2008年第1期21卷 39-44页

作者： xia Wang Wen-kai Chen Bao-zhen Sun Chun-hai Lu Department of Chemistry Fuzhou University Fuzhou 350002 China China Academy of Engineering Physics Mianyang 621900 China

The adsorption of H2O molecule and its dissociation products, O and OH, on CuCl（111） surface was studied with periodic slab model by PW91 approach of GGA within the framework of density functional theory. The results of geometry optimization indicate that the top site is stable energetically for H2O adsorbed over the CuCl（111） surface. The threefold hollow site is found to be the most stable adsorption site for OH and O, and the calculated adsorption energies are 309.5 and 416.5 kJ/mol, respectively. Adsorption of H20 on oxygen-precovered CuCl（111） surface to form surface hydroxyl groups is predicted to be exothermic by 180.1 kJ/mol. The stretching vibrational frequencies, Mulliken population analysis and density of states analysis are employed to interpret the possible mechanism for the computed results.

关键词： Density functional theory H2O Adsorption CuCl

Three-dimensional cell-based strategies for liver regeneration

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BIOCELL 2024年第7期48卷 1023-1036页

作者： DAN GUO xi xia JIAN YANG Liver Transplant Center Transplant CenterWest China HospitalSichuan UniversityChengdu610041China Frontiers Medical Center Tianfu Jincheng LaboratoryChengdu610212China

Liver regeneration and the development of effective therapies for liver failure remain formidable challenges in modern *** recent years,the utilization of 3D cell-based strategies has emerged as a promising approach for addressing these urgent clinical *** review provides a thorough analysis of the application of 3D cell-based approaches to liver regeneration and their potential impact on patients with end-stage liver ***,we discuss various 3D culture models that incorporate hepatocytes and stem cells to restore liver function and ameliorate the consequences of liver ***,we explored the challenges in transitioning these innovative strategies from preclinical studies to clinical *** collective insights presented herein highlight the signiﬁcance of 3D cell-based strategies as a transformative paradigm for liver regeneration and improved patient care.

关键词： Three-Dimensional Liver regeneration Organoids Stem cells Cell therapy

Advanced Reinforcement Learning and Its Connections with Brain Neuroscience

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Research 2023年第4期2023卷 263-279页

作者： Chaoqiong Fan Li Yao Jiacai Zhang Zonglei zhen xia Wu School of Artificial Intelligence Beijing Normal UniversityBeijingChina Faculty of Psychology Beijing Normal UniversityBeijingChina

In recent years,brain science and neuroscience have greatly propelled the innovation of computer *** particular,knowledge from the neurobiology and neuropsychology of the brain revolutionized the development of reinforcement learning(RL)by providing novel interpretable mechanisms of how the brain achieves intelligent and efficient decision *** by this,there has been a boom in research about advanced RL algorithms that are built upon the inspirations of brain *** this work,to further strengthen the bidirectional link between the 2 communities and especially promote the research on modern RL technology,we provide a comprehensive survey of recent advances in the area of brain-inspired/related RL *** start with basis theories of RL,and present a concise introduction to brain neuroscience related to ***,we classify these advanced RL methodologies into 3 categories according to different connections of the brain,i.e.,micro-neural activity,macro-brain structure,and cognitive *** category is further surveyed by presenting several modern RL algorithms along with their mathematical models,correlations with the brain,and open ***,we introduce several important applications of RL algorithms,followed by the discussions of challenges and opportunities for future research.

关键词： discussions classify category