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Construction of Split-Plot Designs with General Minimum Lower Order Confounding
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作者 kexin li Beichen Han Zhenzhen Niu 《Open Journal of Applied Sciences》 CAS 2023年第3期261-274,共14页
Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attracti... Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions. 展开更多
关键词 Fractional Factorial Design General Minimum Lower Order Confounding Criterion Split-Plot Design
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The anti-cancerous mechanism of licochalcone A on human hepatoma cell HepG2 based on the miRNA omics
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作者 Jun Wang Xiuxiu Zhang +6 位作者 Zhijing Ni Elnur Elam Kiran Thakur kexin li Chuyan Wang Jianguo Zhang Zhaojun Wei 《Food Science and Human Wellness》 SCIE CSCD 2023年第4期1136-1148,共13页
To explore the function of licochalcone A as an anticancer phytochemical on HepG2 cells and investigate its potential mechanisms,we analyzed the microRNAs(miRNAs)expression profile of HepG2 cells in response to licoch... To explore the function of licochalcone A as an anticancer phytochemical on HepG2 cells and investigate its potential mechanisms,we analyzed the microRNAs(miRNAs)expression profile of HepG2 cells in response to licochalcone A(70μmol/L)in vitro.102 dysregulated miRNAs were detected,and SP1 was expected as the transcription factor that regulates the functions of most screened miRNAs.A sum of 431 targets,the overlap of predicted mRNAs from TargetScan,miRDB,and miRtarbase were detected as the targets for these dysregulated miRNAs.FoxO signaling pathway was the hub pathway for the targets.A protein-protein interaction network was structured on the STRING platform to discover the hub genes.Among them,PIK3R1,CDC42,ESR1,SMAD4,SUMO1,KRAS,AGO1,etc.were screened out.Afterwards,the miRNA-target networks were established to screen key dysregulated miRNAs.Two key miRNAs(hsa-miR-133b and hsa-miR-145-5p)were filtered.Finally,the miRNA-target-transcription factor networks were constructed for these key miRNAs.The networks for these key miRNAs included three and two transcription factors,respectively.These identified miRNAs,transcription factors,targets,and regulatory networks may offer hints to understand the molecular mechanism of licochalcone A as a natural anticarcinogen. 展开更多
关键词 Licochalcone A HepG2 cells Dysregulated miRNAs Transcription factors TARGETS Regulatory networks
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El Niño and the AMO Sparked the Astonishingly Large Margin of Warming in the Global Mean Surface Temperature in 2023 被引量:2
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作者 kexin li Fei ZHENG +1 位作者 Jiang ZHU Qing-Cun ZENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第6期1017-1022,共6页
In 2023,the majority of the Earth witnessed its warmest boreal summer and autumn since 1850.Whether 2023 will indeed turn out to be the warmest year on record and what caused the astonishingly large margin of warming ... In 2023,the majority of the Earth witnessed its warmest boreal summer and autumn since 1850.Whether 2023 will indeed turn out to be the warmest year on record and what caused the astonishingly large margin of warming has become one of the hottest topics in the scientific community and is closely connected to the future development of human society.We analyzed the monthly varying global mean surface temperature(GMST)in 2023 and found that the globe,the land,and the oceans in 2023 all exhibit extraordinary warming,which is distinct from any previous year in recorded history.Based on the GMST statistical ensemble prediction model developed at the Institute of Atmospheric Physics,the GMST in 2023 is predicted to be 1.41℃±0.07℃,which will certainly surpass that in 2016 as the warmest year since 1850,and is approaching the 1.5℃ global warming threshold.Compared to 2022,the GMST in 2023 will increase by 0.24℃,with 88%of the increment contributed by the annual variability as mostly affected by El Niño.Moreover,the multidecadal variability related to the Atlantic Multidecadal Oscillation(AMO)in 2023 also provided an important warming background for sparking the GMST rise.As a result,the GMST in 2023 is projected to be 1.15℃±0.07℃,with only a 0.02℃ increment,if the effects of natural variability—including El Niño and the AMO—are eliminated and only the global warming trend is considered. 展开更多
关键词 record-breaking temperature global mean surface temperature El Niño AMO global warming
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Will the Globe Encounter the Warmest Winter after the Hottest Summer in 2023? 被引量:2
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作者 Fei ZHENG Shuai HU +17 位作者 Jiehua MA lin WANG kexin li Bo WU Qing BAO Jingbei PENG Chaofan li Haifeng ZONG Yao YAO Baoqiang TIAN Hong CHEN Xianmei LANG Fangxing FAN Xiao DONG Yanling ZHAN Tao ZHU Tianjun ZHOU Jiang ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期581-586,共6页
In the boreal summer and autumn of 2023,the globe experienced an extremely hot period across both oceans and continents.The consecutive record-breaking mean surface temperature has caused many to speculate upon how th... In the boreal summer and autumn of 2023,the globe experienced an extremely hot period across both oceans and continents.The consecutive record-breaking mean surface temperature has caused many to speculate upon how the global temperature will evolve in the coming 2023/24 boreal winter.In this report,as shown in the multi-model ensemble mean(MME)prediction released by the Institute of Atmospheric Physics at the Chinese Academy of Sciences,a medium-to-strong eastern Pacific El Niño event will reach its mature phase in the following 2−3 months,which tends to excite an anomalous anticyclone over the western North Pacific and the Pacific-North American teleconnection,thus serving to modulate the winter climate in East Asia and North America.Despite some uncertainty due to unpredictable internal atmospheric variability,the global mean surface temperature(GMST)in the 2023/24 winter will likely be the warmest in recorded history as a consequence of both the El Niño event and the long-term global warming trend.Specifically,the middle and low latitudes of Eurasia are expected to experience an anomalously warm winter,and the surface air temperature anomaly in China will likely exceed 2.4 standard deviations above climatology and subsequently be recorded as the warmest winter since 1991.Moreover,the necessary early warnings are still reliable in the timely updated mediumterm numerical weather forecasts and sub-seasonal-to-seasonal prediction. 展开更多
关键词 winter climate El Niño seasonal forecast GMST
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The incidence rate and histological characteristics of intimal hyperplasia in elastase-induced experimental abdominal aortic aneurysms in mice
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作者 Meng li Panpan Wei +8 位作者 kexin li Haole liu Naqash Alam Haiwen Hou Jie Deng Baohui Xu Enqi liu Sihai Zhao Yankui li 《Animal Models and Experimental Medicine》 CAS CSCD 2024年第3期388-395,共8页
Intimal hyperplasia(IH)is a negative vascular remodeling after arterial injury.IH occasionally occurs in elastase-induced abdominal aortic aneurysm(AAA)mouse models.This study aims to clarify the incidence and histolo... Intimal hyperplasia(IH)is a negative vascular remodeling after arterial injury.IH occasionally occurs in elastase-induced abdominal aortic aneurysm(AAA)mouse models.This study aims to clarify the incidence and histological characteristics of IH in aneurysmal mice.A retrospective study was conducted by including 42 male elastaseinduced mouse AAA models.The IH incidence,aortic diameters with or without IH,and hyperplasia lesional features of mice were analyzed.Among 42 elastase-induced AAA mouse models,10 mice developed mild IH(24%)and severe IH was found in only 2 mice(5%).The outer diameters of the AAA segments in mice with and without IH did not show significant difference.Both mild and severe IH lesions show strong smooth muscle cell positive staining,but endothelial cells were occasionally observed in severe IH lesions.There was obvious macrophage infiltration in the IH lesions of the AAA mouse models,especially in mice with severe IH.However,only a lower numbers of T cells and B cells were found in the IH lesion.Local cell-secreted matrix metalloproteinases(MMP)2 was highly expressed in all IH lesions,but MMP9 was only overexpressed in severe lesions.In conclusion,this study is the first to demonstrate the occurrence of aneurysmal IH and its histological characteristics in an elastaseinduced mouse AAA model.This will help researchers better understand this model,and optimize it for use in AAA-related research. 展开更多
关键词 abdominal aortic aneurysms animal model HISTOLOGY intimal hyperplasia
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Improved edge lightweight YOLOv4 and its application in on-site power system work 被引量:5
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作者 kexin li liang Qin +3 位作者 Qiang li Feng Zhao Zhongping Xu Kaipei liu 《Global Energy Interconnection》 EI CAS CSCD 2022年第2期168-180,共13页
A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithm... A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithms for on-site risk assessment and alert.Owing to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge computing equipment for real-time video stream detection;however,its accuracy is relatively low.This study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without compromising the speed.Specifically,a convolution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature utilization.Moreover,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved algorithm.Finally,an edge computing equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on it.According to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress code compliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%. 展开更多
关键词 On-site power system work YOLOv4-Tiny Convolution block attention mechanism Efficient channel attention Optimized training methods.
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Microfluidic chips for the endothelial biomechanics and mechanobiology of the vascular system 被引量:2
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作者 HAORAN SU kexin li +4 位作者 XIAO liU JING DU li WANG XIAOYAN DENG YUBO FAN 《BIOCELL》 SCIE 2021年第4期797-811,共15页
Endothelial cells arranged on the vessel lumen are constantly stimulated by blood flow,blood pressure and pressureinduced cyclic stretch.These stimuli are sensed through mechanical sensory structures and converted int... Endothelial cells arranged on the vessel lumen are constantly stimulated by blood flow,blood pressure and pressureinduced cyclic stretch.These stimuli are sensed through mechanical sensory structures and converted into a series of functional responses through mechanotransduction pathways.The process will eventually affect vascular health.Therefore,there has been an urgent need to establish in vitro endothelial biomechanics and mechanobiology of models,which reproduce three-dimensional structure vascular system.In recent years,the rapid development in microfluidic technology makes it possible to replicate the key structural and functionally biomechanical characteristics of vessels.Here,we summarized the progress of microfluidic chips used for the investigation of endothelial biomechanics and mechanobiology of the vascular system.Firstly,we elucidated the contribution of shear stress and circumferential stress,to vascular physiology.Then,we reviewed some applications using microfluidic technology in angiogenesis and vasculogenesis,endothelial permeability and mechanotransduction,as well as the blood-brain barrier under these physical forces.Finally,we discussed the future obstacles in terms of the development and application of microfluidic vascular chips. 展开更多
关键词 Endothelial cells Vascular system MECHANOTRANSDUCTION Microfluidic chip
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Cooperative effect of polyvinylpyrrolidone and HPMC E5 on dissolution and bioavailability of nimodipine solid dispersions and tablets 被引量:1
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作者 Zhisu Sun Huicong Zhang +5 位作者 Huiyang He lingling Sun Xiaorui Zhang Qun Wang kexin li Zhonggui He 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2019年第6期668-676,共9页
Solid dispersion(SD)systems have been extensively used to increase the dissolution and bioavailability of poorly water-soluble drugs.To circumvent the limitations of polyvinylpyrrolidone(PVP)dispersions,HPMC E5 was ap... Solid dispersion(SD)systems have been extensively used to increase the dissolution and bioavailability of poorly water-soluble drugs.To circumvent the limitations of polyvinylpyrrolidone(PVP)dispersions,HPMC E5 was applied in the formulation process and scaling-up techniques,simultaneously.In this study,SD of nimodipine(NMP)and corresponding tablets were prepared through solvent method and fluid bed granulating one step technique,respectively.Discriminatory dissolution media were used to obtain reliable dissolution results.Meanwhile,the stability study of SDs was investigated with storage under high temperature and humidity conditions.Moreover,the solubility of SDs was measured to explore the effect of carriers.The preparations were characterized by DSC,PXRD,and FTIR.Dramatical improvements in the dissolution rate of NMP were achieved by the ingenious combination of the two polymers.Binary NMP/PVP/HPMC-SDs released steadily,while the dissolution of single NMP/PVP-SDs decreased rapidly in water.The fluid-bed tablets(FB-T)possessed a similar dissolution behavior to the commercial Nimotop TM tablets.The characterization patterns implied that NMP existed in an amorphous state in our SDs.Furthermore,the results of stability tests suggested a better stability of the binary SDs.A special cooperative effect of PVP and HPMC was discovered on dissolution characteristics of NMP SDs and tablets,which could be extended to other drugs henceforth.Finally,the bioavailability of FB-T was evaluated in beagle dogs with Nimotop TM as the reference,and the results showed a higher AUC 0–12h value for FB-T. 展开更多
关键词 Solid dispersion NIMODIPINE HPMC E5 Fluid-bed BIOAVAILABILITY
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The Influence Factors of Collective Intelligence Emergence in Knowledge Communities Based on Social Network Analysis 被引量:1
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作者 Zhihong li Ya’nan Xu kexin li 《International Journal of Intelligence Science》 2019年第1期23-43,共21页
The advent of the age of Information shifts the environment we live in from off-line to on-line. The prospect of Collective Intelligence (CI) is promising. Based on this background, the aim of this paper is to discove... The advent of the age of Information shifts the environment we live in from off-line to on-line. The prospect of Collective Intelligence (CI) is promising. Based on this background, the aim of this paper is to discover the emergence mechanism and influence factors of CI in knowledge communities using the method of quantitative and qualitative analysis. On the basis of the previous research work, our model theorizes that the two dimensions of social network (i.e., interactive network structure and participant’s characteristics) affect two references of effectiveness (i.e. group knowledge production and participation of group decision). And this hypothetical model is validated with simulation data from “Zhihu” community. Our model has been useful since it offers some inspirations and directions to promote the level of CI in knowledge communities. 展开更多
关键词 COLLECTIVE INTELLIGENCE KNOWLEDGE Community SOCIAL Network Analysis Zhihu
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Fabrication of supported acid catalytic composite fibers by a simple and low-cost method and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural
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作者 Yinhua Yan Huiqin Guo +1 位作者 kexin li liushui Yan 《Green Energy & Environment》 SCIE EI CSCD 2022年第1期165-171,共7页
In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully ... In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully fabricated by a simple method using low-cost raw materials.The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation.Subsequently,the as-prepared A-BCMSs-SO_(3)H@PTFE fibers were applied to the acidcatalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural.The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO_(3)H@PTFE fibers.The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60%after 72 h of acid-catalyzed reaction.The stability test showed that the as-prepared A-BCMSs-SO_(3)H@PTFE fibers still maintained a stable acid catalytic activity after four recycles. 展开更多
关键词 Acid catalysis Waste Camellia oleifera shells Sulfonic groups Polytetrafluoroethylene fibers 5-Ethoxymethylfurfural
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Protective effects of Dioscin on TNF-α-induced collagen-induced arthritis rat fibroblast-like synoviocytes involves in regulating the LTB4/BLT pathway
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作者 ZHIPING WEI YAJUN liU +6 位作者 MEIWEN YANG MENGDI li kexin li LUXI ZHENG HUIQIONG GUO FENFANG HONG SHULONG YANG 《BIOCELL》 SCIE 2021年第4期1005-1012,共8页
Background and Objective:LTB4 has been shown to be involved in rheumatoid arthritis(RA)pathogenesis.The effect of Dioscin(Dio)on the LTB4 pathway of RA have not been reported yet.This study aimed at further exploring ... Background and Objective:LTB4 has been shown to be involved in rheumatoid arthritis(RA)pathogenesis.The effect of Dioscin(Dio)on the LTB4 pathway of RA have not been reported yet.This study aimed at further exploring whether Dioscin’s effects on TNF-αinduced collagen-induced arthritis(CIA)rat fibroblast-like synoviocytes(FLS)connected with the LTB4 and its receptor pathway.Materials&Methods:In this experiment,control group,TNF-αgroup,and different concentrations of Dioscin groups were established.Cell viability was evaluated using MTT assay.The levels of LTB4 in the samples of above groups were measured using ELISA.The mRNA expression levels of LTA4H,BLT1,and BLT2 were detected by quantitative real time PCR,while the expression level of LTA4H proteins were detected using western blot.The distribution of LTA4H was assessed by immunofluorescence assay.Results:the LTB4 level of TNF-αgroup in sample supernatant was higher than both control group and Dioscin groups with decreased LTB4 levels(p<0.05).Compared with the control group,the expression of LTA4H was significantly increased in TNF-αgroup(p<0.05),whereas LTA4H expressions were significantly decreased in all Dioscin groups when compared to TNF-αgroup(p<0.05).The mRNA expressions of BLT1 and BLT2 were markedly higher in TNF-αgroup than those in control group while Dioscin treatment significantly inhibited the increased expressions of BLT1 and BLT2 induced by TNF-α(p<0.05).Conclusions:These results firstly demonstrate that the protective effect of Dioscin on TNF-αinduced FLS may involve in its reducing LTB4 production by down-regulating LTA4H expression,and may inhibit its downstream pathway by decreasing LTB4 receptors levels.This findings suggest that dioscin produces a potential therapeutic effects for RA via its influencing LTA4H/LTB4/BLT pathway. 展开更多
关键词 Rheumatoid arthritis DIOSCIN Fibroblast-like synoviocytes Leukotriene B4 LTA4 hydrolase Leukotriene B4 receptor
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Fabrication of biobased heterogeneous solid Br?nsted acid catalysts and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural from fructose
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作者 Yingying Wen Zhou Yu +3 位作者 kexin li Huiqin Guo Yuhua Dai liushui Yan 《Green Energy & Environment》 SCIE 2018年第4期384-391,共8页
A series of biobased heterogeneous solid Br?nsted acid catalysts with perfect spherical microstructures are successfully fabricated directly from waste Camellia oleifera shells by a simple hydrothermal carbonization-a... A series of biobased heterogeneous solid Br?nsted acid catalysts with perfect spherical microstructures are successfully fabricated directly from waste Camellia oleifera shells by a simple hydrothermal carbonization-annealing-sulfonation process. 350℃ low temperature annealing process helps to increase the activity of the catalyst due to the simultaneous maintenance of the spherical microstructure and aromatic carbon framework. As a renewable catalyst with low cost, the as-prepared materials are successfully applied on the synthesis of green renewable liquid biofuel 5-ethoxymethylfurfural(EMF) directly from fructose. In the catalytic test, the influences of reaction time and temperature, fructose concentration, and adding amount of the catalyst on the yield of EMF are investigated systematically. As a result, the optimal reaction temperature is 100℃, the EMF yield monotonically increases with prolonging the reaction time from 3 to 24 h, the optimal fructose concentration is0.5 mmol, and the EMF yield gradually increases with increasing the adding amount of the catalyst from 50 to 150 mg. In addition, the asprepared catalysts exhibit considerably high stability in the current EMF synthesis system, and they can maintain a similar level of reactivity after four catalytic cycles. 展开更多
关键词 HYDROTHERMAL CARBONIZATION ANNEALING SULFONATION 5-Ethoxymethylfurfural FRUCTOSE
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Will the Historic Southeasterly Wind over the Equatorial Pacific in March 2022 Trigger a Third-year La Niña Event? 被引量:2
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作者 Xianghui FANG Fei ZHENG +9 位作者 kexin li Zeng-Zhen HU Hongli REN Jie WU Xingrong CHEN Weiren LAN Yuan YUAN licheng FENG Qifa CAI Jiang ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第1期6-13,共8页
Based on the updates of the Climate Prediction Center and International Research Institute for Climate and Society(CPC/IRI)and the China Multi-Model Ensemble(CMME)El Niño-Southern Oscillation(ENSO)Outlook issued ... Based on the updates of the Climate Prediction Center and International Research Institute for Climate and Society(CPC/IRI)and the China Multi-Model Ensemble(CMME)El Niño-Southern Oscillation(ENSO)Outlook issued in April 2022,La Niña is favored to continue through the boreal summer and fall,indicating a high possibility of a three-year La Niña(2020-23).It would be the first three-year La Niña since the 1998-2001 event,which is the only observed three-year La Niña event since 1980.By examining the status of air-sea fields over the tropical Pacific in March 2022,it can be seen that while the thermocline depths were near average,the southeasterly wind stress was at its strongest since 1980.Here,based on a quaternary linear regression model that includes various relevant air-sea variables over the equatorial Pacific in March,we argue that the historic southeasterly winds over the equatorial Pacific are favorable for the emergence of the third-year La Niña,and both the anomalous easterly and southerly wind stress components are important and contribute~50%of the third-year La Niña growth,respectively.Additionally,the possible global climate impacts of this event are discussed. 展开更多
关键词 El Niño-Southern Oscillation three-year La Niña strongest southeasterly wind air-sea interaction
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A binder-free CF|PANI composite electrode with excellent capacitance for asymmetric supercapacitors 被引量:1
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作者 kexin li Gentian Yue Furui Tan 《Journal of Semiconductors》 EI CAS CSCD 2023年第3期95-103,共9页
In this work,carbon fiber and polyaniline(CF|PANI)composites are prepared by using an electrochemical polymeriza-tion method.The morphology and composition characterization results show that the PANI nanospheres are s... In this work,carbon fiber and polyaniline(CF|PANI)composites are prepared by using an electrochemical polymeriza-tion method.The morphology and composition characterization results show that the PANI nanospheres are successfully syn-thesized and uniformly coated on the CF.When the electrodeposition period is 300 cycles,the as-prepared CF|PANI electrode ex-hibits good specific capacitance of 231.63 F/g at 1 A/g,high performance of 98.14%retention rate from 0.5 to 20 A/g,and excel-lent cycle stability with only 0.96%capacity loss after 1000 cycles.This is ascribed to the internal resistance that was signific-antly reduced without binders,which helps to the CF|PANI electrode maintains high operating potential and pseudo-capacit-ance performance at high current density.The symmetrical supercapacitor based on two CF|PANI electrodes connecting by acid-ic PVA-H2SO4 gel electrolyte exhibits an energy density of 6.55 W·h/kg at a power density of 564.37 W/kg.In addition,the asym-metric supercapacitor based on MoS2|MWCNTs and CF|PANI electrodes with neutral PVA-Na2SO4 gel electrolyte shows an en-ergy density of 16.12 W·h/kg at a power density of 525.03 W/kg.These results indicate that the low internal resistance contrib-utes to the high energy density of symmetrical supercapacitors and asymmetric supercapacitors at high current density and high power density,which is significant for its practical application. 展开更多
关键词 quasi-solid state supercapacitor carbon fibers binder-free POLYANILINE
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Adaptive Fault Estimation for Dynamics of High Speed Train Based on Robust UKF Algorithm 被引量:1
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作者 kexin li Tiantian liang 《Journal of Harbin Institute of Technology(New Series)》 CAS 2023年第1期61-72,共12页
This paper proposes an adaptive unscented Kalman filter algorithm(ARUKF)to implement fault estimation for the dynamics of high⁃speed train(HST)with measurement uncertainty and time⁃varying noise with unknown statistic... This paper proposes an adaptive unscented Kalman filter algorithm(ARUKF)to implement fault estimation for the dynamics of high⁃speed train(HST)with measurement uncertainty and time⁃varying noise with unknown statistics.Firstly,regarding the actuator and sensor fault as the auxiliary variables of the dynamics of HST,an augmented system is established,and the fault estimation problem for dynamics of HST is formulated as the state estimation of the augmented system.Then,considering the measurement uncertainties,a robust lower bound is proposed to modify the update of the UKF to decrease the influence of measurement uncertainty on the filtering accuracy.Further,considering the unknown time⁃varying noise of the dynamics of HST,an adaptive UKF algorithm based on moving window is proposed to estimate the time⁃varying noise so that accurate concurrent actuator and sensor fault estimations of dynamics of HST is implemented.Finally,a five-car model of HST is given to show the effectiveness of this method. 展开更多
关键词 high speed train Kalman filter adaptive algorithm robust algorithm unknown noise measurement uncertainty
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Phloem unloading in cultivated melon fruits follows an apoplasmic pathway during enlargement and ripening 被引量:1
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作者 Yixuan Zhou kexin li +6 位作者 Suying Wen Dong Yang Jun Gao Ziwei Wang Peilu Zhu Zhilong Bie Jintao Cheng 《Horticulture Research》 SCIE CSCD 2023年第8期72-84,共13页
Melon(Cucumis melo L.)has a long history of cultivation worldwide.During cultivation,domestication,and selection breeding,the sugar content of mature melon fruits has been significantly increased.Compared with unsweet... Melon(Cucumis melo L.)has a long history of cultivation worldwide.During cultivation,domestication,and selection breeding,the sugar content of mature melon fruits has been significantly increased.Compared with unsweet melon and wild melon,rapid sucrose accumulation can occur in the middle and late stages of sweet melon fruit development.The phloem unloading pathway during the evolution and development of melon fruit has not been identified and analyzed.In this study,the phloem unloading pathway and the function of related sugar transporters in cultivated and wild melon fruits were analyzed by CFDA[5(6)-carbofluorescein diacetate]and esculin tracing,cytological pathway observation,qRT–PCR,and gene function analysis,etc.Results show that the phloem unloading pathway of wild melon fruit is largely symplastic,whereas the phloem unloading pathway of cultivated melon fruit shifts from symplastic to apoplasmic during development.According to a fruit grafting experiment,the fruit sink accumulates sugars independently.Correlation analysis showed that the expression amounts of several sucrose transporter genes were positively correlated with the sucrose content of melon fruit.Furthermore,CmSWEET10 was proved to be a sucrose transporter located on the plasma membrane of the phloem and highly expressed in the premature stage of sweet melon fruits,which means it may be involved in phloem apoplast unloading and sucrose accumulation in sweet melon fruits.Finally,we summarize a functional model of related enzymes and sugar transporters involved in the apoplast unloading of sweet melon fruits during enlargement and sucrose accumulation. 展开更多
关键词 DEVELOPMENT BREEDING SUGAR
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原位光还原法制备高分散铂沉积多孔氮化碳复合材料及其降解水中4-氟苯酚的高效可见光光催化活性(英文) 被引量:10
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作者 曾振兴 李可心 +4 位作者 魏凯 戴玉华 颜流水 郭会琴 罗旭彪 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期29-38,共10页
作为一种新型水中有机污染物,有机氟化物中C–F共价键的键能较大,因而很难通过传统的可见光光催化剂降解.因此,开发高效可见光光催化剂是实现在可见光照射下成功降解水中有机氟化物的关键.作为一种非金属半导体光催化剂,石墨相氮化碳(g-... 作为一种新型水中有机污染物,有机氟化物中C–F共价键的键能较大,因而很难通过传统的可见光光催化剂降解.因此,开发高效可见光光催化剂是实现在可见光照射下成功降解水中有机氟化物的关键.作为一种非金属半导体光催化剂,石墨相氮化碳(g-C_3N_4)因具有可见光响应、环境友好及低成本等优点而广泛应用于水中有机污染物去除.然而,体相层状结构严重限制了g-C_3N_4的可见光活性.这是由于体相层状结构不利于光生电子的表面迁移,同时增加了光催化反应过程的传质阻力.为了开发一种可重复使用且具有优异可见光活性的光催化剂,进而实现在可见光照射下水中有机氟化物的高效降解及矿化,本文以氯铂酸和多孔氮化碳(pg-C_3N_4)为前驱体,运用简单的原位光还原法成功制备出一系列高分散铂沉积多孔氮化碳复合材料(Pt/pg-C_3N_4),而pg-C_3N_4则是以三聚氰胺为原料采用前驱体预处理法制备.与传统铂沉积石墨相氮化碳(Pt/g-C_3N_4)复合材料相比,由于多孔氮化碳前驱体具有暴露的几何内外表面,铂纳米粒子可高度分散于其上.因此,铂纳米粒子的电子捕获效应显著增强.另外,与其他传统还原法相比,原位光还原技术还可有效抑制铂纳米粒子的自凝聚.我们对制备的Pt/pg-C_3N_4复合材料的形貌、孔隙率、相结构、化学组成及光电性质进行了详细表征.结果显示,与传统Pt/g-C_3N_4复合材料相比,由于多孔微观结构的构建以及高度分散铂纳米粒子的沉积,制备的Pt/pg-C_3N_4复合材料的BET比表面积显著增大,光吸收能力明显增强,光催化量子效率显著提高.在可见光条件下,初步评价了该复合材料光催化降解水中偶氮染料甲基橙的活性,然后将其进一步应用于水中4-氟苯酚的降解及矿化.结果表明,由于多孔微观结构的构建以及高度分散铂纳米粒子的沉积,所制备Pt/pg-C_3N_4复合材料具有相当高的可见光光催化活性.结果还显示,所制复合材料具有很高的稳定性,连续使用4次均保持相似的活性.作为一种可见光催化剂,所制Pt/pg-C_3N_4复合材料有望广泛应用于水中持久性有机污染物的降解以及光催化劈裂水产氢、NO分解和CO_2还原等领域. 展开更多
关键词 光催化作用 多孔氮化碳 光还原 铂沉积 4-氟苯酚
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在Cr(Ⅵ)和4-氯酚复合污染系统中多孔石墨相氮化碳的协同光催化效应(英文) 被引量:1
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作者 魏凯 李可心 +4 位作者 曾振兴 戴玉华 颜流水 郭会琴 罗旭彪 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第11期1804-1811,共8页
随着工农业的迅速发展,多组分复合污染系统广泛分布于自然环境中,例如电镀废水、污水处理厂污泥、城市生活垃圾等.自1972年光催化劈裂水产氢被发现以来,光催化技术已被广泛应用于解决环境污染问题.一方面,光生电子在酸性条件下能将重铬... 随着工农业的迅速发展,多组分复合污染系统广泛分布于自然环境中,例如电镀废水、污水处理厂污泥、城市生活垃圾等.自1972年光催化劈裂水产氢被发现以来,光催化技术已被广泛应用于解决环境污染问题.一方面,光生电子在酸性条件下能将重铬酸根(Cr_2O_7^(2–))中高毒性的Cr(Ⅵ)还原成低毒性的Cr(Ⅲ).另一方面,水中有机污染物通过光催化氧化过程可被降解为二氧化碳和水.然而在目前的光催化领域,大部分研究者专注于新型光催化剂的开发,并在单组份光催化系统中测试所开发材料的光催化活性,而忽视了蕴藏在光催化反应本身中的科学问题.事实上,将光催化技术应用于复合污染系统具有非常大的现实意义.少数研究者试图通过光催化过程处理多组分废水.然而,在复合污染系统中的协同光催化效应和机理尚未明确.近几年,基于可见光响应、环境友好、成本低等优点,作为一种不含金属的半导体光催化剂,石墨相氮化碳(g-C_3N_4)已被广泛应用于环境光催化领域.然而在实际应用中,g-C_3N_4的光催化活性却较差,因为聚集态层状结构不但限制了光生载流子的表面迁移,而且还增加了光催化反应的传质阻力.因此,人们尝试形貌控制策略来提高g-C_3N_4的光催化活性,例如氮化碳纳米片、空心球、量子点的构建.在前期工作中,我们通过一种简单的前驱体预处理策略使用盐酸和乙二醇共处理的三聚氰胺作原料成功制备出了多孔石墨相氮化碳(pg-C_3N_4),因其具有丰富的多孔微观结构而表现出了卓越的光催化活性.本文初步研究了在酸性条件下使用所制备g-C_3N_4或pg-C_3N_4光催化还原水中Cr(Ⅵ)成Cr(Ⅲ)的反应.然后在不同p H条件下进一步研究了在Cr(Ⅵ)和4-氯酚(4-CP)复合污染系统中的协同光催化效应.结果发现,与单组分光催化系统相比,在Cr(Ⅵ)和4-CP复合污染系统中Cr(Ⅵ)的还原效率和4-CP的降解效率同时提高,即在Cr(Ⅵ)和4-CP复合污染系统中存在协同光催化效应.最后讨论了在Cr(Ⅵ)和4-CP复合污染系统中的协同光催化效应可归因于pg-C_3N_4的电子转移作用加速了Cr_2O_7^(2–)和4-CP之间的氧化还原反应.在用稀H_2SO_4调节p H至3的Cr(Ⅵ)和4-CP复合污染系统中,由于Cr_2O_7^(2–)中氧原子的电子云密度较低,因此Cr_2O_7^(2–)和4-CP之间的氧化还原反应通过pg-C_3N_4的电子转移作用易于进行,因而表现出明显的协同光催化效应. 展开更多
关键词 复合污染 协同光催化作用 多孔石墨相氮化碳 CR(VI) 4-氯酚
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含氟丙烯酸酯乳液的制备及对织物的整理与应用 被引量:11
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作者 郑君红 李可昕 +2 位作者 黄婵娟 龙柱 张丹 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2019年第2期29-35,40,共8页
采用三元乳液聚合方法,选用丙烯酸十三氟辛酯作为含氟单体,并以甲基丙烯酸甲酯和苯乙烯作为辅助单体在水中进行自由基共聚制得含氟共聚物(FP)乳液。在对其结构性能和微观形貌进行研究的基础上,将FP整理在不同纤维织物基材上。利用红外... 采用三元乳液聚合方法,选用丙烯酸十三氟辛酯作为含氟单体,并以甲基丙烯酸甲酯和苯乙烯作为辅助单体在水中进行自由基共聚制得含氟共聚物(FP)乳液。在对其结构性能和微观形貌进行研究的基础上,将FP整理在不同纤维织物基材上。利用红外光谱、电子显微镜及接触角等手段研究了高聚物的表面形貌,考察了织物在整理前后的静态接触角、耐水洗性及透湿性等性能的变化。结果表明,FP膜具有纳米尺寸;整理的棉、涤纶、涤棉、锦纶和羊毛织物具有良好的超疏水性能;完成30次皂洗后,涤纶、锦纶和羊毛织物相比于棉和涤棉织物仍表现出较好的疏水效果。 展开更多
关键词 丙烯酸十三氟辛酯 乳液聚合 红外光谱 超疏水
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母猪低温综合征
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作者 牛绪东 侯占民 +4 位作者 李克鑫 李克钦 佟庆东 刘建柱 张元瑞 《猪业科学》 2020年第6期98-100,共3页
母猪低温综合征是由多种原因引起的母猪在孕期和哺乳期,体温突然低于正常体温临界值37.5℃为特征的一种代谢障碍性疾病[1]。本病属于疑难性疾病,其主要原因有生理性因素、营养性因素、环境与管理因素和某些疾病因素等。其特征性症状是... 母猪低温综合征是由多种原因引起的母猪在孕期和哺乳期,体温突然低于正常体温临界值37.5℃为特征的一种代谢障碍性疾病[1]。本病属于疑难性疾病,其主要原因有生理性因素、营养性因素、环境与管理因素和某些疾病因素等。其特征性症状是体温持续下降,喜卧,食欲降低或废绝,贫血等。母猪低温综合征在寒冷季节时有发生,如果治疗不及时可危及母仔生命,定会造成较大的经济损失。作者根据自己的临床诊疗经验及大量临床资料,经过综合分析现总结如下,供同行们参考。 展开更多
关键词 疾病因素 寒冷季节 特征性症状 正常体温 代谢障碍性疾病 母猪 临界值 临床诊疗经验
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