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12篇 您的检索式:作者名="Xuefei Tan"
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1Relative Contributions of Boundary-Layer Meteorological Factors to the Explosive Growth of PM2.5 during the Red-Alert Heavy Pollution Episodes in Beijing in December 2016显示文摘Based on observations of urban mass concentration of fine particulate matter smaller than 2.5 μm in diameter(PM_(2.5)), ground meteorological data, vertical measurements of winds, temperature, and relative humidity(RH), and ECMWF reanalysis data, the major changes in the vertical structures of meteorological factors in the boundary layer(BL) during the heavy aerosol pollution episodes(HPEs) that occurred in winter 2016 in the urban Beijing area were analyzed. The HPEs are divided into two stages: the transport of pollutants under prevailing southerly winds, known as the transport stage(TS), and the PM_(2.5) explosive growth and pollution accumulation period characterized by a temperature inversion with low winds and high RH in the lower BL, known as the cumulative stage(CS). During the TS, a surface high lies south of Beijing, and pollutants are transported northwards. During the CS, a stable BL forms and is characterized by weak winds, temperature inversion, and moisture accumulation. Stable atmospheric stratification featured with light/calm winds and accumulated moisture(RH > 80%) below 250 m at the beginning of the CS is closely associated with the inversion, which is strengthened by the considerable decrease in near-surface air temperature due to the interaction between aerosols and radiation after the aerosol pollution occurs. A significant increase in the PLAM(Parameter Linking Aerosol Pollution and Meteorological Elements) index is found, which is linearly related to PM mass change. During the first 10 h of the CS, the more stable BL contributes approximately 84% of the explosive growth of PM_(2.5) mass. Additional accumulated near-surface moisture caused by the ground temperature decrease, weak turbulent diffusion, low BL height, and inhibited vertical mixing of water vapor is conducive to the secondary aerosol formation through chemical reactions, including liquid phase and heterogeneous reactions, which further increases the PM_(2.5) concentration levels. The contribution of these reaction mechanisms to the explosive growth of PM_(2.5) mass during the early CS and subsequent pollution accumulation requires further investigation.junting zhong xiaoye zhang yaqiang wang junying sun yangmei zhang jizhi wang kaiyan tan xiaojing shen haochi che lu zhang zhouxiang zhang xuefei qi huarong zhao sanxue ren yang li 2017Journal of Meteorological Research2017,31,5:25
2First Imported Case of SARS-CoV-2 Omicron Subvariant BA.5—Shanghai Municipality,China,May 13,2022显示文摘On April 27,2022,an international flight KL857 from Amsterdam,the Netherlands arrived at Pudong International Airport,Shanghai Municipality.Passengers were transferred to the quarantine hotel for a routine 14-day medical observation in Songjiang District and regularly tested for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).One of the passengers(a 37-year-old Chinese male)was reported positive and diagnosed as a mild case on April 29.The case set out from Uganda(flight KL535)on April 25 and transferred at Amsterdam,the Netherlands on April 26 and Seoul,the Republic of Korea(KL857)on April 27.The patient has been vaccinated in four doses against coronavirus disease 2019(COVID-19)(Beijing Institute of Biological Products Co.,Ltd)in China and Uganda.After diagnosis,he was transferred to Shanghai Public Health Clinical Center for treatment.He recovered after treatment and was discharged on May 12.Hui Jiang Changcheng Wu Wenbo Xu Hongyou Chen Fanghao Fang Min Chen Chaonan Wang Lingyue Yuan Huanyu Wu Zheng Teng Jinyuan Guo Yaxu Zheng Xihong Lyu Xuefei Qiao Guizhen Wu Wenjie Tan Xi Zhang 2022China CDC weekly2022,4,30:10
3Aerosol Hygroscopicity during the Haze Red-Alert Period in December 2016 at a Rural Site of the North China Plain显示文摘A humidification system was deployed to measure aerosol hygroscopicity at a rural site of the North China Plain during the haze red-alert period 17–22 December 2016. The aerosol scattering coefficients under dry [relative humidity(RH) < 30%] and wet(RH in the range of 40%–85%) conditions were simultaneously measured at wavelengths of450, 550, and 700 nm. It is found that the aerosol scattering coefficient and backscattering coefficient increased by only 29% and 10%, respectively when RH went up from 40% to 80%, while the hemispheric backscatter fraction went down by 14%, implying that the aerosol hygroscopicity represented by the aerosol scattering enhancement factor f(RH) is relatively low and RH exerted little effects on the aerosol light scattering in this case. The scattering enhancement factors do not show significant differences at the three wavelengths, only with an approximate 2% variation, suggesting that the aerosol hygroscopicity is independent of the wavelength. Aerosol hygroscopicity is highly dependent on the aerosol chemical composition. When there is a large mass fraction of inorganics and a small mass fraction of organic matter, f(RH) reaches a high value. The fraction of NO_3^- was strongly correlated with the aerosol scattering coefficient at RH = 80%, which suggests that NO_3^- played an important role in aerosol hygroscopic growth during the heavy pollution period.Xuefei QI Junying SUN Lu ZHANG Xiaojing SHEN Xiaoye ZHANG Yangmei ZHANG Yaqiang WANG Haochi CHE Zhouxiang ZHANG Junting ZHONG Kaiyan TAN Huarong ZHAO Sanxue REN 2018Journal of Meteorological Research2018,32,1:7
4CCAR1 5' UTR as a natural miRancer of miR-1254 overrides tamoxifen resistance显示文摘Gaopeng Li Xiaoli Wu Wenchang Qian Huayong Cai Xinbao Sun Weijie Zhang Sheng Tan Zhengsheng Wu Pengxu Qian Keshuo Ding Xuefei Lu Xiao Zhang Hong Yan Haifeng Song Shouhong Guang Qingfa Wu Peter E Lobie Ge Shan Tao Zhu 2016Cell Research2016,26,6:3
5Comparison of Submicron Particles at a Rural and an Urban Site in the North China Plain during the December 2016 Heavy Pollution Episodes显示文摘An extensive field experiment for measurement of physical and chemical properties of aerosols was conducted at an urban site in the Chinese Academy of Meteorological Sciences(CAMS) in Beijing and at a rural site in Gucheng(GC), Hebei Province in December 2016. This paper compares the number size distribution of submicron particle matter(PM1, diameter < 1 μm) between the two sites. The results show that the mean PM1 number concentration at GC was twice that at CAMS, and the mass concentration was three times the amount at CAMS. It is found that the accumulation mode(100–850 nm) particles constituted the largest fraction of PM1 at GC, which was significantly correlated with the local coal combustion, as confirmed by a significant relationship between the accumulation mode and the absorption coefficient of soot particles. The high PM1 concentration at GC prevented the occurrence of new particle formation(NPF) events, while eight such events were observed at CAMS. During the NPF events, the mass fraction of sulfate increased significantly, indicating that sulfate played an important role in NPF. The contribution of regional transport to PM1 mass concentration was approximately 50% at both sites, same as that of the local emission. However, during the red-alert period when emission control took place, the contribution of regional transport was notably higher.Xiaojing SHEN Junying SUN Xiaoye ZHANG Yangmei ZHANG Yaqiang WANG Kaiyan TAN Peng WANG Lu ZHANG Xuefei QI Haochi CHE Zhouxiang ZHANG Junting ZHONG Huarong ZHAO Sanxue REN 2018Journal of Meteorological Research2018,32,1:2
6Modal characteristics analysis of a doubly clad optical fiber with semi-weakly guiding approximation显示文摘Xuefei Tan Xianglian Liu Wei Zhao Cheng Li Yishan Wang Jianfeng Li 2013Optics Communications2013,,:1
7Characteristics and kinetics of catalytic degradation of immature kerogen in the presence of mineral and salt 显示文摘Li Shuyuan Guo Shaohui Tan Xuefei 1998Organic Geochemistry1998,29,57:1
8Anthropogenic monoterpenes aggravating ozone pollution显示文摘Monoterpenes have been known to have a critical influence on air quality and climate change through their impact on the formation of fine particles.Here we present field evidence that monoterpene oxidations largely enhanced local ozone production in a regional site in eastern China.The observed monoterpene was most likely from biomass burning rather than biogenic emissions,as indicated by the high correlation with CO at night-time,and the observed ratio of these two species was consistent with previously determined values from biomass burning experiments.Fast monoterpene oxidations were determined experimentally based on direct radical measurements,leading to a daily ozone enhancement of 4-18 parts per billion by volume(ppb),which was 6%-16%of the total ozone production,depending on the speciation of monoterpenes.It demonstrates that the previously overlo oked anthropogenic monoterpenes make an important contribution to 0_(3) production in eastern China.The role could possibly be important at similar locations across China and other parts of the world that are characterized by massive emissions,especially where there are high NO_(x) levels.Our results highlight that anthropogenic monoterpenes should be taken into account when proceeding with the coordinated mitigation of O_(3) and particulate matter pollution.Haichao Wang Xuefei Ma Zhaofeng Tan Hongli Wang Xiaorui Chen Shiyi Chen Yaqin Gao Ying Liu Yuhan Liu Xinping Yang Bin Yuan Limin Zeng Cheng Huang Keding Lu Yuanhang Zhang 2022National Science Review2022,9,9:1
9Characteristics and kinetics of catalytic degeradation of immature kerogen in lhe presence of mineral and sail 显示文摘Li Shuyuan C-uo Shaohui Tan Xuefei 1998Organic Geochemistry1998,29,:1
10SOX2 promotes tumorigenesis and increases the anti-apoptotic property of human prostate cancer cell显示文摘SRY-related HMG-box gene 2(SOX2)is one of the key regulatory genes that maintain the pluripotency and self-renewal properties in embryonic stem cells.Here we used immunohistochemistry to analyze the expression of SOX2 in human prostate tissues and found it contributed to tumorigenesis and correlated with histologic grade and Gleason score.We further investigated SOX2’s function in cell growth and apoptosis process by using a human prostate cancer cell line DU145 with SOX2 overexpression or down-regulation.Cell cycle assay revealed that SOX2 promoted cell growth and increased the percentage of cells in S phase.In vitro and in vivo xenograft experiments in NOD/SCID mice further demonstrated that SOX2 increased the apoptosis-resistant properties of DU145 cells with decreased function of store-operated Ca21 entry and reduced expression of Orai1 at both mRNA and protein levels,suggesting a potential mechanism that contributes to the anti-apoptotic property of SOX2.To our knowledge,this study is the first to investigate SOX2’s function in tumorigenesis and apoptosis of human prostate cancer and to elucidate its regulatory effect on the activity of store-operated Ca21 channels.Our results support the concept that SOX2 has the potential to be a significant marker to evaluate the progression of prostate cancer and serve as a potentially useful target for prostate cancer therapy.Xianpei Jia Xuefei Li Yingxi Xu Shu Zhang Wenjun Mou Yanhua Liu Yin Liu Dan Lv Cheng-Hu Liu Xiaoyue Tan Rong Xiang Na Li 2011Journal of Molecular Cell Biology2011,3,4:0
11Fe_(3)C@C/C for catalytic ozonation of silicon-containing wastewater:Dual improvement of silicon resistance and catalytic effect显示文摘The improvement of catalysts’stability under harsh reaction conditions is vital for their practical applica-bility.Herein,iron carbide(Fe_(3)C)nanoparticles were encapsulated in graphitic carbon in situ and a carbon ball served as the carrier.The synthesized Fe_(3)C@C/C was first utilized to treat an m-cresol wastewater containing Si via catalytic ozonation.Compared with the commercial Fe/Al_(2)O_(3)catalyst,the resistance to Si of the Fe_(3)C@C/C was improved 22.68 times,while the TOC removal rate increased by a factor of 2.9,and it remained stable during 10 cycles and 12000 min of continuous reaction,which further demon-strated its potential for diverse applications.The catalyst exhibits improved resistance to Si because of the dual protection from the carbon-encapsulated structure and carbon carrier.Density functional theory calculations show that the encapsulation of Fe_(3)C using carbon significantly increases the resistance to adsorption of Si on its active sites.In addition,the activation of O_(3)is unimpeded on the Fe_(3)C adsorption sites by the protection from C,thus the generation of reactive oxygen species(ROS)by ozone is largely promoted.The mechanism associated with the resistance of the Fe_(3)C@C/C catalyst to Si and its elevated activity are also elucidated.Shengzhe Wang Lei Ma Rui Wang Chengyu Jin Ying Zhao Xuefei Tan Yanan Zhang Mengyang Liu Chenxing Yao Huangzhao Wei Chenglin Sun 2023Journal of Materials Science & Technology2023,,5:0
12Contamination Identification of Lentinula Edodes Logs Based on Improved YOLOv5s显示文摘In order to improve the accuracy and efficiency of Lentinula edodes logs contamination identification,an improved YOLOv5s contamination identification model for Lentinula edodes logs(YOLOv5s-CGGS)is proposed in this paper.Firstly,a CA(coordinate attention)mechanism is introduced in the feature extraction network of YOLOv5s to improve the identifiability of Lentinula edodes logs contamination and the accuracy of target localiza-tion.Then,the CIoU(Complete-IOU)loss function is replaced by an SIoU(SCYLLA-IoU)loss function to improve the model’s convergence speed and inference accuracy.Finally,the GSConv and GhostConv modules are used to improve and optimize the feature fusion network to improve identification efficiency.The method in this paper achieves values of 97.83%,97.20%,and 98.20%in precision,recall,and mAP@0.5,which are 2.33%,3.0%,and 1.5%better than YOLOv5s,respectively.mAP@0.5 is better than YOLOv4,Ghost-YOLOv4,and Mobilenetv3-YOLOv4(improved by 4.61%,5.16%,and 6.04%,respectively),and the FPS increased by two to three times.Xuefei Chen Wenhui Tan Qiulan Wu Feng Zhang Xiumei Guo Zixin Zhu 2023Intelligent Automation & Soft Computing2023,37,9:0
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