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Evaluation of mental fatigue based on multipsychophysiological parameters and kernel learning algorithms

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Chinese Science Bulletin 2008年第12期53卷 1835-1847页

作者： ZHANG chong zheng chongXun YU XiaoLin Key Laboratory of Biomedical Information Engineering of Education Ministry Xi'an Jiaotong University Xi'an 710049 China

Mental fatigue is an extremely sophisticated phenomenon, which is influenced by the environment, the state of health, vitality and the capability of recovery. A single parameter cannot fully describe it. In this paper, the effects of long time sustained low-workload visual display terminal (VDT) task on psychology are investigated by subjective self-reporting measures. Then power spectral indices of HRV, the P300 components based on visual oddball and wavelet packet parameters of EEG are combined to analyze the impacts of prolonged visual display terminal (VDT) activity on autonomic nervous system and cen-tral nervous system. Finally, wavelet packet parameters of EEG are extracted as the features of brain activity in different mental fatigue states. Kernel principal component analysis (KPCA) and support vector machine (SVM) are jointly applied to differentiate two states. The statistic results show that the level of both subjective sleepiness and fatigue increase significantly from pre-task to post-task, which indicate that the long time VDT task induces the mental fatigue to the subjects. The predominant activ-ity of autonomic nervous system of subjects turns to the sympathetic activity from parasympathetic activity after the task. The P300 components and wavelet packet parameters of EEG are strongly related with mental fatigue. Moreover, the joint KPCA-SVM method is able to effectively reduce the dimension-ality of the feature vectors, speed up the convergence in the training of SVM and achieve a high rec-ognition accuracy (87%) of mental fatigue state. Multipsychophysiological measures and KPCA-SVM method could be a promising tool for the evaluation of mental fatigue.

关键词：心理疲劳脑电图心率诊断方法

Research on the falling film flow and heat transfer characteristics of FLNG spiral wound heat exchanger under sea conditions

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Petroleum Science 2022年第3期19卷 1276-1290页

作者： chong-zheng Sun Liang Liu Yu-Xing Li Jian-Lu Zhu College of Pipeline and Civil Engineering/Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety/Qingdao Key Laboratory of Circle Sea Oil&Gas Storage and Transportation Technology China University of PetroleumQingdaoShandong266580China

As the key equipment of floating liquefied natural gas(FLNG)process,the performance of spiral wound heat exchanger(SWHE)influences operation costs and reliability of the whole *** sea conditions destroy the falling film flow state of the refrigeration and then affect the heat transfer performance of FLNG *** order to design and optimize the SWHE,a cryogenic experimental device of FLNG process and a numerical model of falling film flow have been constructed to study the effects of sea conditions on the falling film flow and heat transfer characteristics of *** cryogenic experimental results show that the pitching conditions have larger effects on the heat transfer performance than *** the pitching angle of 7°,the natural gas temperature and gaseous refrigerant temperature increase by 3.22°C and 7.42°C,*** flow rates of refrigerant and feed natural gas have a great impact on the heat transfer performance of SWHE under pitching and compound sloshing *** the tilt angle increases to 9°,the tube structure with outer diameter D=8 mm and pipe spacing S=4 mm is recommended to reduce the drying area of the pipe wall surface.

关键词： FLNG Spiral wound heat exchanger Falling film flow Cryogenic heat transfer Sea condition

Review:Anaerobic ammonium oxidation for treatment of ammonium-rich wastewaters

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第5期9卷 416-426页

作者： Lei ZHANG Ping zheng chong-jian TANG Ren-cun JIN Department of Environmental Engineering Zhejiang University Hangzhou 310029 China

The concept of anaerobic ammonium oxidation(ANAMMOX) is presently of great interest. The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists. Meanwhile,the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters. Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite(CANON) have been developed,and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control. Successful full-scale practice in the Netherlands will ac-celerate application of the process in future. This review introduces the microbiology and more focuses on application of the ANAMMOX process.

关键词： Anaerobic ammonium oxidation (ANAMMOX) bacteria Metabolism Partial nitritation-ANAMMOX Completelyautotrophic nitrogen removal over nitrite (CANON) Application

Numerical and experimental study on the falling film flow characteristics with the effect of co-current gas flow in hydrogen liquefaction process

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Petroleum Science 2024年第2期21卷 1369-1384页

作者： chong-zheng Sun Yu-Xing Li Hui Han Xiao-Yi Geng Xiao Lu College of Energy Storage Technology Shandong University of Science and TechnologyQingdao 266590ShandongChina College of Pipeline and Civil Engineering/Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety China University of PetroleumQingdao 266580ShandongChina

Liquid hydrogen storage and transportation is an effective method for large-scale transportation and utilization of hydrogen energy. Revealing the flow mechanism of cryogenic working fluid is the key to optimize heat exchanger structure and hydrogen liquefaction process(LH2). The methods of cryogenic visualization experiment, theoretical analysis and numerical simulation are conducted to study the falling film flow characteristics with the effect of co-current gas flow in LH2spiral wound heat *** results show that the flow rate of mixed refrigerant has a great influence on liquid film spreading process, falling film flow pattern and heat transfer performance. The liquid film of LH2mixed refrigerant with column flow pattern can not uniformly and completely cover the tube wall surface. As liquid flow rate increases, the falling film flow pattern evolves into sheet-column flow and sheet flow, and liquid film completely covers the surface of tube wall. With the increase of shear effect of gas-phase mixed refrigerant in the same direction, the liquid film gradually becomes unstable, and the flow pattern eventually evolves into a mist flow.

关键词： Hydrogen liquefaction Spiral wound heat exchanger Flow pattern transition Falling film flow

dbEMT 2.0:An updated database for epithelial-mesenchymal transition genes with experimentally verified information and precalculated regulation information for cancer metastasis

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Journal of Genetics and Genomics 2019年第12期46卷 595-597页

作者： Min Zhao Yining Liu chong zheng Hong Qu School of Science and EngineeringUniversity of the Sunshine CoastMaroochydore DCQueensland4558Australia The School of Public Health Institute for Chemical CarcinogenesisGuangzhou Medical UniversityGuangzhou 510182China Center for Bioinformatics State Key Laboratory of Protein and Plant Gene ResearchCollege of Life SciencesPeking UniversityBeijing 100871China

Epithelial-mesenchymal transition(EMT)is a critical cellular process in embryonic development and is also the basis for wound repair,tissue regeneration,and cancer metastasis(Zhao et al.,2015).During cancer migration and invasion,EMT involved comprehensive reprogramming processes related to cytoskeletal remodeling,cell differentiation,epigenetic regulation and metabolism(Plikus et al.,2015).In fact,the understanding of EMT in cancer development is still *** 2015.

关键词： dbEMT 2.0 epithelial-mesenchymal cancer metastasis

Effects of Chronic Stress and Phenytoin on the Long-term Potentiation (LTP) in Rat Hippocampal CA1 Region

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Acta Biochimica et Biophysica Sinica 2004年第5期36卷 375-378页

作者： Hui zheng*, Quan YANG, and chong-Tao XU Mental Health Center, Shantou University Medical College, Shantou 515063, China Mental Health Center Shantou University Medical College Shantou 515063 China

To investigate the changes of LTP in hippocampal CA1 region induced by chronic stress and the effect of phenytoin on them, thirty-two adult male Sprague-Dawley rats were randomly divided equally into four groups: control group, control-phenytoin group, stress-saline group and stress-phenytoin group. Isolated hippocampal slices of rats were used to observe the changes of long-term potentiation (LTP) in hippocampal CA1 field using electrophysiological technique. Amplitude of population spike (PS) and field excitatory postsynaptic potentials (fEPSPs) slope were used to indicate the changes of LTP. High-frequency stimulation (HFS) was applied to Schaffer collaterals of hippocampal CA3 field, and the changes of PS amplitude and fEPSPs slope in CA1 field were observed. The results showed that the LTP induction rate, the increases of PS amplitude and fEPSPs slope after HFS in control and stress-phenytoin groups were significantly greater than those in stress-saline group (P0.05). It is suggested that chronic stress can damage the development of LTP in hippocampal CA1 field, while phenytoin can protect the LTP of stressed hippocampal slices in normal state.

关键词： phenytoin long-term potentiation hippocampus stress

Introducing sulfur vacancies and in-plane SnS_(2)/SnO_(2) heterojunction in SnS_(2) nanosheets to promote photocatalytic activity

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Chinese Chemical Letters 2020年第10期31卷 2809-2813页

作者： Keyan Hu Chen Ming Yiting Liu chong zheng Shaoning Zhang Dong Wang Wei Zhao Fuqiang Huang State Key Laboratory of High-Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China School of Mechanical and Electrical Engineering Jingdezhen Ceramic InstituteJingdezhen 333403China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China Department of Chemistry and Biochemistry Northern Illinois UniversityDeKalbIllinois 60115United States Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Due to the relatively sluggish charge carrier separation in metal sulfides,the photocatalytic activity of them is still far lower than ***,sulfur vacancies and in-plane SnS_(2)/SnO_(2) heterojunction were successfully introduced into the SnS_(2) nanosheets through high energy *** defective structures were studied by the electron paramagnetic resonance,Raman spectra,X-ray photoelectron spectroscopy,and high-resolution transmission electron microscope *** sulfur vacancies and in-plane heterojunctions strongly accelerate the separation of photoexcited electron-hole pairs,as confirmed by the photo luminesce nce emission spectra and time-resolved photoluminescence decay *** introduction of sulfur vacancies and in-plane heterojunction in SnS_(2) nanosheets results in roughly six times higher photodegrading rate for methyl orange and four times higher photocatalytic reduction rate of Cr6+than those of pure SnS_(2) nanosheets.

关键词： Sulfur vacancies In-plane heterojunction SnS_(2)Nanosheets Ball-milling Charge carrier separation

A Detail Investigation on the Antarctic Wind Energy

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China Ocean Engineering 2023年第4期37卷 698-708页

作者： WANG Kai-shan WU Di zheng chong-wei TAO Gui-sheng LI Wei GAO Yuan-bo YU Yue WU Kai Dalian Naval Academy Dalian 116018China Marine Resources and Environment Research Group on the Maritime Silk Road Dalian 116018China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China

The scientific development of wind energy based on local conditions is conducive to the urgent energy demand and environmental protection of Antarctic *** this study,the ERA5 reanalysis data are used to evaluate the wind energy resources in the Antarctic region.A series of key indicators,such as wind power density,effective wind speed occurrence,energy level occurrence and stability,are comprehensively considered by using climate statistical analysis methods to analyze the temporal and spatial distribution characteristics of Antarctic wind energy *** results show that the Antarctic region contains abundant wind energy resources,which benefits the construction of scientific research *** superior areas are the Southern Ocean and the coast of the East Antarctica,followed by the Transantarctic Mountains,the coast of the Bellingshausen Sea and Amundsen *** areas have advantages in terms of wind power density(500-2500 W/m2),effective wind speed occurrence(80%-90%),energy level occur-rence(60%-90%)and stability(Cv:0.6-1,Mv:1.2-1.8,Sv:0.8-1.2).The Antarctic’s wind energy resources in wind power density,effective wind speed occurrence and energy level occurrence in autumn and winter are better than those in summer,while the coefficient of variation in summer is worse than that in autumn and winter.

关键词： Antarctic wind energy resource evaluation temporal and spatial characteristics

A facile and general approach for the synthesis of fluorescent silica nanoparticles doped with inert dyes

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Chinese Science Bulletin 2011年第31期56卷 3242-3246页

作者： MU Xue WU ChuanLiu LAI JinPing CHEN JianBin zheng JinSheng LI chong ZHAO YiBing Department of Chemistry and the Key Laboratory of Analytical Sciences of Xiamen University College of Chemistry and Chemical EngineeringXiamen University Xiamen 361005 China

A general and facile approach was developed for the synthesis of almost monodisperse fluorescent silica nanoparticles (NPs) doped with inert dyes, which are organic fluorophores that are strongly fluorescent but are hydrophobic or lack a covalent binding group. The prepared NPs were mesoporous and the dye molecules were encapsulated in the pores via hydrophobic interaction with the CTAB template. The NPs were stable and highly fluorescent in aqueous solution, and have potential applications in bioanalysis and fluorescence encoding.

关键词：有机荧光染料纳米颗粒惰性合成硅胶轻便纳米粒子疏水相互作用