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Characterization and Saturable Absorption Property of Graphene Oxide on Optical Fiber by Optical Deposition

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Journal of Wuhan University of Technology(Materials Science) 2017年第4期32卷 882-887页

作者：丁莉芸 xu chuang xu Bing HUANG Jun National Engineering Laboratory for Fiber Optic Sensing Technology Wuhan University of Technology Wuhan 430070 China Key Laboratory of Fiber Optic Sensing Technology and Information Processing Ministy of Education Wuhan University of Technology Wuhan 430070 China

We prepared graphene oxide（GO） saturable absorber（SA） successfully through optical deposition method, which is a simple but effective approach to deposit various materials onto substrate under the effects of light, and investigated several factors that influence the optical deposition result of GO onto optical fiber end, including poly（methyl methacrylate）（PMMA） concentration, light intensity, light mode, and deposition time. The efficient optically deposited GO preserving its nonlinearity guaranteed by GO/PMMA composite formation was also demonstrated. The GO SA prepared by optical deposition shows superior saturable absorption property with modulation depth and nonsaturable loss of 6% and 40%, respectively.

关键词： optical deposition graphene oxide saturable absorption optical fiber

Insight into Urban Faults by Wavelet Multi-Scale Analysis and Modeling of Gravity Data in Shenzhen,China

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Journal of Earth Science 2018年第6期29卷 1340-1348页

作者： chuang xu Haihong Wang Zhicai Luo Hualiang Liu Xiangdong Liu MOE Key Laboratory of Fundamental Physical Quantities Measurement School of PhysicsHuazhong University of Science and Technology School of Geodesy and Geomatics Wuhan University Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan University China Water Resources Beifang Investigation Design and Research Co.Ltd.

Urban faults in Shenzhen are potential threats to city security and sustainable development. In consideration of the importance of the Shenzhen fault zone, the author provide a detailed interpretation on gravity data model. Bouguer gravity covering the whole Shenzhen City was calculated with a 1-km resolution. Wavelet multi-scale analysis（MSA） was applied to the Bouguer gravity data to obtain the multilayer residual anomalies corresponding to different depths. In addition, 2D gravity models were constructed along three profiles. The Bouguer gravity anomaly shows an NE-striking high-low-high pattern from northwest to southeast, strongly related to the main faults. According to the results of MSA, the correlation between gravity anomaly and faults is particularly significant from 4 to 12 km depth. The residual gravity with small amplitude in each layer indicates weak tectonic activity in the crust. In the upper layers, positive anomalies along most of faults reveal the upwelling of high-density materials during the past tectonic movements. The multilayer residual anomalies also yield important information about the faults, such as the vertical extension and the dip direction. The maximum depth of the faults is about 20 km. In general, NE-striking faults extend deeper than NW-striking faults and have a larger dip angle.

关键词： urban faults Bouguer gravity anomaly wavelet multi-scale analysis gravity modeling Shenzhen

A new high-precision gravity solid tidal model for Precision Gravity Measurement Facility

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Geodesy and Geodynamics 2020年第4期11卷 265-272页

作者： chuang xu Rongrui xu Wenrui Zeng Jianguo Yan Department of Surveying Engineering School of Civil and Transportation EngineeringGuangdong University of TechnologyGuangzhou510006China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan430079China Institute of Geophysics Huazhong University of Science and TechnologyWuhan430074China

It is significant for establishing gravity datum to construct precise gravity solid tidal model,A simple method with relatively low performance is to interpolate tidal parameters from the global gravity solid tide models.A competitive approach is to determine local gravity solid tidal model by harmonic analysis using long-time serial gravity *** this paper a new high-precision gravity solid tidal model for Precision Gravity Measurement Facility is estimated from two co-site gravimeters in the cave laboratory using modern international standard data processing techniques,whose accuracy is evaluated further by comparing with previous *** results show that:(1)the determined gravity solid tidal models from two co-site gravimeters are in good agreement with each other,of which the maximum differences for amplitude factors and phase delays don’t exceed 0.01700%and 2.50990°,respectively.(2)the performance of the obtained gravity solid tidal model is 0.00411 for amplitude factors and 0.24120°for phase delays,which is a little better than that of previous publications using superconducting gravity data from Wuhan station.(3)our results and methods are corrective and effective.(4)our model is tiny different from that provided by Wuhan station,which implies that it is necessary to construct a gravity solid tidal model for Precision Gravity Measurement Facility,rather than just adopting existing models at Wuhan *** results are helpful in realizing the goal of Precision Gravity Measurement Facility.

关键词： Gravity solid tidal model Precision gravity measurement facility Amplitude factor Phase delay

Multiple damage zones around hydraulic fractures generated by high-frequency pulsating hydraulic fracturing

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Petroleum Science 2024年第4期21卷 2688-2702页

作者： Yan Peng Sheng-Jie Wei Guang-Qing Zhang Da-Wei Zhou chuang-Chao xu School of Petroleum Engineering China University of Petroleum18 Fuxue RoadChangpingBeijing102249China PetroChina Changqing Oilfield Company Xi'an710018ShaanxiChina

Pulsating hydraulic fracturing(PHF)is a promising fracturing method and can generate a dynamic periodic *** periodic pressure can induce fatigue failure of rocks and decrease initiation pressure of *** the frequency of periodic pressure exceeds 10 Hz,the distribution of pressure along the main fracture will be heterogeneous,which is much different from the one induced by the common fracturing *** this study,the impact of this special spatial feature of pressure on hydraulic fracture is mainly investigated.A coupled numerical simulation model is first proposed and verified through experimental and theoretical *** mechanism of secondary fracture initiation around the main fracture is then *** addition,sensitivity studies are conducted to find out the application potential of this new *** results show that(1)this coupled numerical simulation model is *** comparison with experimental and theoretical data,the average error of this coupled model is less than 1.01%.(2)Even if a reservoir has no natural fracture,this heterogeneous distribution pressure can also cause many secondary fractures around the main fracture.(3)The mechanism of secondary fracture initiation is that this heterogeneous distribution pressure causes tensile stress at many locations along the main fracture.(4)Through adjusting the stimulation parameters,the stimulation efficiency can be *** average and amplitude of pressure can increase possibility of secondary fracture *** frequency of this periodic pressure can increase number of secondary *** 6 secondary fractures along a 100 m-length main fracture can be generated.(5)The influence magnitudes of stimulation parameters are larger than ones of geomechanical properties,therefore,this new fracturing method has a wide application potential.

关键词： Tight reservoir Reservoir stimulation Numerical simulation Secondary fracture Fracture initiation

Fluorescence Detection for H_2PO_4^- based on Carbon Dots/Fe^(3＋) Composite

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Journal of Wuhan University of Technology(Materials Science) 2016年第6期31卷 1226-1229页

作者：范小春 ZHANG Bingyu 丁莉芸 xu chuang HUANG Jun School of Civil Engineering and Architecture Wuhan University of Technology Wuhan 430070 China National Engineering Laboratory for Fiber Optic Sensing Technology Wuhan University of Technology Wuhan 430070 China

A novel fluorescent probe for H_2PO_4^- was designed and fabricated based on the carbon dots/Fe^（3＋） composite. The carbon dots were synthesized by an established one-pot hydrothermal method and characterized by transmission electron microscope, X-ray diffractometer, UV-Vis absorption spectrometer and fluorescence spectrophotometer. The carbon dots/Fe^（3＋） composite was obtained by aqueous mixing of carbon dots and FeCl_3, and its fluorescence property was characterized by fluorescence spectrophotometer. The fluorescence of carbon dots was quenched by aqueous Fe^（3＋） cations, resulting in the low fluorescence intensity of the carbon dots/Fe^（3＋） composite. On the other hand, H_2PO_4^- reduced the concentration of Fe^（3＋） by chemical reaction and enhanced the fluorescence of the carbon dots/Fe^（3＋） composite. The Stern-Volmer equation was introduced to describe the relation between the relative fluorescence intensity of the carbon dots/Fe^（3＋） composite and the concentration of H_2PO_4^-, and a fine linearity（R2=0.997） was found in the range of H_2PO_4^- concentration of 0.4-12 m M.

关键词： H2PO4-detection fluorescence carbon dots/Fe3+ composite

Effectiveness of non-pharmaceutical interventions against local transmission of COVID-19: An individual-based modelling study

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Infectious Disease Modelling 2021年第1期6卷 848-858页

作者： chuang xu Yongzhen Pei Shengqiang Liu Jinzhi Lei School of Computer Science and Technology Tiangong UniversityTianjin300387China School of Mathematical Sciences Center for Applied MathematicsTiangong UniversityTianjin300387China

The outbreak of the novel coronavirus disease 2019(COVID-19),caused by the novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has caused global transmission,and been spread all over the *** those regions that are currently free of infected cases,it is an urgent issue to prevent and control the local outbreak of COVID-19 when there are sporadic *** evaluate the effects of non-pharmaceutical interventions against local transmission of COVID-19,and to forecast the epidemic dynamics after local outbreak of diseases under different control measures,we developed an individual-based model(IBM)to simulate the transmission dynamics of COVID-19 from a microscopic perspective of individual-to-individual contacts to heterogenous among *** on the model,we simulated the effects of different levels of non-pharmaceutical interventions in controlling disease transmission after the appearance of sporadic *** shown that isolation of infected cases and quarantine of close contacts alone would not eliminate the local transmission of COVID-19,and there is a risk of a second wave *** the second-layer close contacts can obviously reduce the size of ***,to effectively eliminate the daily new infections in a short time,it is necessary to reduce the individual-to-individual *** provides a numerical representation for the local transmission of infectious diseases,and extends the compartmental models to include individual heterogeneity and the close contacts *** study suggests that combinations of self-isolation,quarantine of close contacts,and social distancing would be necessary to block the local transmission of COVID-19.

关键词： COVID-19 SARS-CoV-2 Individual-based model Stochastic simulation Non-pharmaceutical intervention

Inhibiting nuclear factor erythroid 2 related factor 2-mediated autophagy in bovine mammary epithelial cells induces oxidative stress in response to exogenous fatty acids

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Journal of Animal Science and Biotechnology 2022年第5期13卷 1458-1468页

作者： Renxu Chang xudong Sun Hongdou Jia Qiushi xu Zhihao Dong Yan Tang Shengbin Luo Qianming Jiang Juan J.Loor chuang xu College of Veterinary Medicine China Agricultural UniversityYuan Ming Yuan West Road No.2Haidian DistrictBeijing 100193China College of Veterinary Medicine Hunan Agricultural UniversityChangsha 410128China Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases College of Animal Science and Veterinary MedicineHeilongjiang Bayi Agricultural UniversityNo.5 Xinyang RoadDaqing 163319Heilongjiang ProvinceChina Mammalian NutriPhysioGenomics Department of Animal Sciences and Division of Nutritional SciencesUniversity of IllinoisUrbana 61801USA

Background:In early lactation,bovine mammary epithelial cells undergo serious metabolic challenges and oxidative stress both of which could be alleviated by activation of *** factor erythroid 2 related factor 2(NFE2L2),a master regulator of cellular redox homeostasis,plays an important role in the regulation of autophagy and oxidative ***,the objective of this study was to investigate the role of NFE2L2-mediated autophagy on oxidative stress of bovine mammary epithelial cells in response to exogenous free fatty acids(FFA).Results:Exogenous FFA induced linear and quadratic decreases in activities of glutathione peroxidase(GSH-Px),catalase(CAT),and superoxide dismutase(SOD),and increases in the contents of reactive oxygen species(ROS)and malondialdehyde(MDA).Protein abundance of LC3-phosphatidylethanolamine conjugate(LC3-Ⅱ)and the number of autophagosomes and autolysosomes decreased in a dose-dependent manner,while protein abundance of p62 increased in cells challenged with *** of autophagy via pre-treatment with Rap attenuated the FFAinduced ROS ***,FFA inhibited protein abundance of NFE2L2 and the translocation of NFE2L2 into the *** of NFE2L2 by siRNA decreased protein abundance of LC3-Ⅱ,while it increased protein abundance of ***,sulforaphane(SFN)pre-treatment attenuated the FFA-induced oxidative stress by activating NFE2L2-mediated ***:The data suggested that NFE2L2-mediated autophagy is an important antioxidant mechanism in bovine mammary epithelial cells experiencing increased FFA loads.

关键词： Autophagy Bovine mammary epithelial cells NFE2L2 Oxidative stress

An improved gravity method to horizontal tectonic stresses and its applications in Tibet

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Geodesy and Geodynamics 2020年第6期11卷 468-473页

作者： chuang xu Hangtao Yu Chaolong Yao Jinbo Li Jianguo Yan Department of Surveying Engineering School of Civil and TransportationGuangdong University of TechnologyGuangzhou 510006China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan430079China College of Natural Resources and Environment South China Agricultural UniversityGuangzhou 510642China

It is significant for identifying mass movement patterns to invert horizontal tectonic stresses at different depths underneath *** recent years,a large number of achievements focusing on two-dimensional tectonic stresses have been obtained from gravity ***,three-dimensional tectonic stresses in Tibet are still unknown or ***,in the present study an improved method to multilayer horizontal tectonic stresses using gravity observations is *** inverted multilayer horizontal tectonic stresses are in agreement with those from previous *** addition,rich tectonic structure and development can be revealed from the inverted multilayer horizontal tectonic stresses:(1)the distribution of horizontal tectonic stresses at various depths shows strong correlation with that of the tectonic elements,where major faults and earthquake epicenters are corresponding with stress highs and the stable basins are consistent with stress lows.(2)the mass movement patterns of whole Tibet present clockwise,and the material movement directions in the west and east are approximately southnorth and east-west,respectively.(3)in eastern Tibet,the eastward materials caused by the south-north extrusion between Indian and Eurasian plates are divided into two parts by the stable Sichuan Block,one flowing nearly southeast and the other moving almost *** inverted multilayer horizontal tectonic stresses may provide direct evidences for mass movement patterns in Tibet.

关键词： Gravity Horizontal tectonic stresses Tibet Multilayer

Transcription factor EB(TFEB)-mediated autophagy protects bovine mammary epithelial cells against H_(2)O_(2)-induced oxidative damage in vitro

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Journal of Animal Science and Biotechnology 2021年第3期12卷 1008-1018页

作者： xudong Sun Renxu Chang Yan Tang Shengbin Luo Chunhui Jiang Hongdou Jia Qiushi xu Zhihao Dong Yusheng Liang Juan J.Loor chuang xu Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases College of Animal Science and Veterinary MedicineHeilongjiang Bayi Agricultural UniversityNo.5 Xinyang RoadDaqing 163319Heilongjiang ProvinceChina College of Veterinary Medicine Hunan Agricultural UniversityChangsha 410128China Mammalian NutriPhysioGenomics Department of Animal Sciences and Division of Nutritional SciencesUniversity of IllinoisUrbana 61801USA

Background:Bovine mammary epithelial cells after calving undergo serious metabolic challenges and oxidative stress both of which could compromise *** factor EB(TFEB)-mediated autophagy is an important cytoprotective mechanism against oxidative ***,effects of TFEB-mediated autophagy on the oxidative stress of bovine mammary epithelial cells remain ***,the main aim of the study was to investigate the role of TFEB-mediated autophagy in bovine mammary epithelial cells experiencing oxidative ***:H_(2)O_(2) challenge of the bovine mammary epithelial cell MAC-T increased protein abundance of LC3-II,increased number of autophagosomes and autolysosomes while decreased protein abundance of *** of autophagy via bafilomycin A1 aggravated H_(2)O_(2)-induced reactive oxygen species(ROS)accumulation and apoptosis in MAC-T ***,H_(2)O_(2) treatment triggered the translocation of TFEB into the *** of TFEB by siRNA reversed the effect of H_(2)O_(2) on protein abundance of LC3-II and p62 as well as the number of autophagosomes and *** of TFEB activated autophagy and attenuated H_(2)O_(2)-induced ROS ***,TFEB overexpression attenuated H_(2)O_(2)-induced apoptosis by downregulating the caspase apoptotic ***:Our results indicate that activation of TFEB mediated autophagy alleviates H_(2)O_(2)-induced oxidative damage by reducing ROS accumulation and inhibiting caspase-dependent apoptosis.

关键词： Apoptosis Autophagy Bovine mammary epithelial cells Oxidative stress TFEB