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34篇 您的检索式:作者名="Fan Lifeng"
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1Spatial gradient distributions of thermal shock-induced damage to granite显示文摘In this study,we attempted to investigate the spatial gradient distributions of thermal shock-induced damage to granite with respect to associated deterioration mechanisms.First,thermal shock experiments were conducted on granite specimens by slowly preheating the specimens to high temperatures,followed by rapid cooling in tap water.Then,the spatial gradient distributions of thermal shock-induced damage were investigated by computed tomography(CT)and image analysis techniques.Finally,the influence of the preheating temperature on the spatial gradients of the damage was discussed.The results show that the thermal shock induced by rapid cooling can cause more damage to granite than that induced by slow cooling.The thermal shock induced by rapid cooling can cause spatial gradient distributions of the damage to granite.The damage near the specimen surface was at a maximum,while the damage inside the specimen was at a minimum.In addition,the preheating temperature can significantly influence the spatial gradient distributions of the thermal shock-induced damage.The spatial gradient distribution of damage increased as the preheating temperature increased and then decreased significantly over 600C.When the preheating temperature was sufficiently high(e.g.800C),the gradient can be ignored.Lifeng Fan Jingwei Gao Xiuli Du Zhijun Wu 2020Journal of Rock Mechanics and Geotechnical Engineering2020,12,5:11
2Insulin enhances apoptosis induced by cisplatin in human esophageal squamous cell carcinoma EC9706 cells related to inhibition of autophagy显示文摘Yang Yang Wen Fengbiao Dang Lifeng Fan Yuxia Liu Donglei Wu Kai Zhao Song 2014Chinese Medical Journal2014,,2:6
3Theoretical and simulation research of hydrodynamic instabilities in inertial-confinement fusion implosions显示文摘Inertial fusion energy(IFE)has been considered a promising,nearly inexhaustible source of sustainable carbon-free power for the world's energy future.It has long been recognized that the control of hydrodynamic instabilities is of critical importance for ignition and high-gain in the inertial-confinement fusion(ICF)hot-spot ignition scheme.In this mini-review,we summarize the progress of theoretical and simulation research of hydrodynamic instabilities in the ICF central hot-spot implosion in our group over the past decade.In order to obtain sufficient understanding of the growth of hydrodynamic instabilities in ICF,we first decompose the problem into different stages according to the implosion physics processes.The decomposed essential physics processes that are associated with ICF implosions,such as Rayleigh-Taylor instability(RTI),Richtmyer-Meshkov instability(RMI),Kelvin-Helmholtz instability(KHI),convergent geometry effects,as well as perturbation feed-through are reviewed.Analytical models in planar,cylindrical,and spherical geometries have been established to study different physical aspects,including density-gradient,interface-coupling,geometry,and convergent effects.The influence of ablation in the presence of preheating on the RTI has been extensively studied by numerical simulations.The KHI considering the ablation effect has been discussed in detail for the first time.A series of single-mode ablative RTI experiments has been performed on the Shenguang-Ⅱlaser facility.The theoretical and simulation research provides us the physical insights of linear and weakly nonlinear growths,and nonlinear evolutions of the hydrodynamic instabilities in ICF implosions,which has directly supported the research of ICF ignition target design.The ICF hot-spot ignition implosion design that uses several controlling features,based on our current understanding of hydrodynamic instabilities,to address shell implosion stability,has been briefly described,several of which are novel.LiFeng Wang WenHua Ye XianTu He JunFeng Wu ZhengFeng Fan Chuang Xue HongYu Guo WenYong Miao YongTeng Yuan JiaQin Dong Guo Jia Jing Zhang YingJun Li Jie Liu Min Wang YongKun Ding WeiYan Zhang 2017Science China(Physics,Mechanics & Astronomy)2017,60,5:4
4The Genomes of the Allohexaploid Echinochloa crus-galli and Its Progenitors Provide Insights into Polyploidization-Driven Adaptation显示文摘The hexaploid species Echinochloa crus-galli is one of the most detrimental weeds in crop fields,especially in rice paddies.Its evolutionary history is similar to that of bread wheat,arising through polyploidization after hybridization between a tetraploid and a diploid species.In this study,we generated and analyzed high-quality genome sequences of diploid(E.haploclada),tetraploid(E.oryzicola),and hexaploid(E.crus-galli)Echinochloa species.Gene family analysis showed a significant loss of disease-resistance genes such as those encoding NB-ARC domain-containing proteins during Echinochloa polyploidization,contrary to their significant expansionduring wheat polyploidization,suggesting that natural selection might favor reduced investment in resistance in this weed to maximize its growth and reproduction.In contrast to the asymmetric patterns of genome evolution observed in wheat and other crops,no significant differences in selection pressure were detected between the subgenomes in E.oryzicola and E.crus-galli.In addition,distinctive differences in subgenome transcriptome dynamics during hexaploidization were observed between E.crus-galli and bread wheat.Collectively,our study documents genomic mechanisms underlying the adaptation of a major agricultural weed during polyploidization.The genomic and transcriptomic resources of three Echinochloa species and new insights into the polyploidization-driven adaptive evolution would be useful for future breeding cereal crops.Chu-Yu Ye Dongya Wu Lingfeng Mao Lei Jia Jie Qiu Sangting Lao Meihong Chen Bowen Jiang Wei Tang Qiong Peng Lang Pan Lifeng Wang Xiaoxiao Feng Longbiao Guo Chulong Zhang Elizabeth A.Kellogg Kenneth M.Olsen Lianyang Bai Longjiang Fan 2020Molecular Plant2020,13,9:4
5Involvement of long non-coding RNAs in the progression of esophageal cancer显示文摘Esophageal cancer(EC)is one of the most common malignant tumors of the digestive system with high incidence and mortality rate worldwide.Therefore,exploring the pathogenesis of ECand searching for new targeted therapies are the current research hotspot for EC treatment.Long non-coding RNAs(lncRNAs)are endogenous RNAs with more than 200 nucleotides,but without proteincoding function.In recent years,lncRNAs have gradually become the focuses in the field of non-coding RNA.Some lncRNAs have been proved to be closely related to the pathogenesis of EC.Many lncRNAs are abnormally expressed in EC and participate in many biological processes including cell proliferation,apoptosis,and metastasis by inhibiting or promoting target gene expression.LncRNAs can also regulate the progression of EC through epithelial-mesenchymal transformation(EMT),which is closely related to the occurrence,development,and prognosis of EC.In this article,we review and discuss the involvement of lncRNAs in the progression of EC.Wenhua Xue Yuanyuan Zheng Zhibo Shen Lifeng Li Zhirui Fan Wenbin Wang Zijia Zhu Yunkai Zhai Jie Zhao Quancheng Kan 2021Cancer Communications2021,41,5:4
6Rapid on-line non-destructive detection of the moisture content of corn ear by bioelectrical impedance spectroscopy显示文摘Moisture content of corn directly affects its quality and storage time,and the rapid on-line detection of the moisture content of corn ears not threshed or in vivo in the fields is required.Because of the special shape of corn ear,the rapid,low cost and non-destructive bioelectrical impedance measurement is more suitable for its moisture content detection.Using the four-electrode method with the Agilent E4980A precision LCR meter,the electrical impedance spectroscopies of the sweet corn ears and waxy corn ears at different moisture contents were acquired.The frequency range of the detection was from 20 Hz to 2 MHz and to enhance the contact,the attached-type electrodes were wrapped in cotton soaked with 0.1%NaCl solution.The impedance data over the frequency range from 300 Hz to 5 kHz were used to obtain the parameters of the bio-impedance Cole-Cole model.The results showed a good linear correlation(coefficient of determination R2=0.960)between the equivalent parallel resistance R∞of sweet corn ear and the moisture content value determined by standard chemical method.The research proved that the bioelectrical impedance spectroscopy can be used for detecting the moisture content of corn ear.Zhao Pengfei Zhang Hanlin Zhao Dongjie Wang Zhijie Fan Lifeng Huang Lan Ma Qin Wang Zhongyi 2015International Journal of Agricultural and Biological Engineering2015,8,6:3
7Dark,Beyond Deep:A Paradigm Shift to Cognitive AI with Humanlike Common Sense显示文摘Recent progress in deep learning is essentially based on a“big data for small tasks”paradigm,under which massive amounts of data are used to train a classifier for a single narrow task.In this paper,we call for a shift that flips this paradigm upside down.Specifically,we propose a“small data for big tasks”paradigm,wherein a single artificial intelligence(AI)system is challenged to develop“common sense,”enabling it to solve a wide range of tasks with little training data.We illustrate the potential power of this new paradigm by reviewing models of common sense that synthesize recent breakthroughs in both machine and human vision.We identify functionality,physics,intent,causality,and utility(FPICU)as the five core domains of cognitive AI with humanlike common sense.When taken as a unified concept,FPICU is concerned with the questions of“why”and“how,”beyond the dominant“what”and“where”framework for understanding vision.They are invisible in terms of pixels but nevertheless drive the creation,maintenance,and development of visual scenes.We therefore coin them the“dark matter”of vision.Just as our universe cannot be understood by merely studying observable matter,we argue that vision cannot be understood without studying FPICU.We demonstrate the power of this perspective to develop cognitive AI systems with humanlike common sense by showing how to observe and apply FPICU with little training data to solve a wide range of challenging tasks,including tool use,planning,utility inference,and social learning.In summary,we argue that the next generation of AI must embrace“dark”humanlike common sense for solving novel tasks.Yixin Zhu Tao Gao Lifeng Fan Siyuan Huang Mark Edmonds Hangxin Liu Feng Gao Chi Zhang Siyuan Qi Ying Nian Wu Joshua B.Tenenbaum Song-Chun Zhu 2020Engineering2020,6,3:3
8Simulation of viscoelastic behavior of defected rock by using numerical manifold method显示文摘Numerical simulations of longitudinal wave propagation in a rock bar with microcracks are conducted by using the numerical manifold method which has great advantages in the simulation of discontinuities.Firstly,validation of the numerical manifold method is carried out by simulations of a longitudinal stress wave propagating through intact and cracked rock bars.The behavior of the stress wave traveling in a one-dimensional rock bar with randomly distributed microcracks is subsequently studied.It is revealed that the highly defected rock bar has significant viscoelasticity to the stress wave propagation.Wave attenuation as well as time delay is affected by the length,quantity,specific stiffness of the distributed microcracks as well as the incident stress wave frequency.The storage and loss moduli of the defected rock are also affected by the microcrack properties;however,they are independent of incident stress wave frequency.Feng REN Lifeng FAN Guowei MA 2011Frontiers of Structural and Civil Engineering2011,5,2:3
9Ultrasound speed and attenuation in progressive trypsin digested articular cartilage显示文摘Subtle changes of articular cartilage(AC) can lead to tissue degeneration and even osteoarthritis(OA).The early degeneration of AC is closely related to a change in proteoglycans(PG) content.The observation of PG is therefore an appropriate way of studying OA and evaluating the degree of AC degeneration.In this study,20 cartilage-bone samples were prepared from normal porcine femoral condyle cartilage and 10 samples were digested over 2 h using 0.25% trypsin solution.The dynamic process of PG-digestion was explored using a conventional A-mode ultrasound(US) experimental system with a 10 MHz center frequency.Quantitative acoustic parameters were calculated from ultrasonic radio-frequency echo signals and included US speed(USS),US amplitude attenuation coefficient(UAA) and broadband US attenuation coefficient(BUA).The experimental results showed that the conventional A-mode ultrasound is valuable for tracking the degree of PG-digestion.Histology also confirmed the validity of the ultrasound observations.For every AC sample,the degree of PG-digestion within a given time was different and was affected by individual differences.After two hours of degeneration,USS showed a mean decrease of 0.4%(P<0.05).UAA was significantly lower after a two-hour PG depletion period(from(2.45±0.23) to(2.28±0.41) dB mm?1).BUA showed no significant differences during this process.In conclusion,conventional ultrasound can provide useful information about trypsin-induced progressive PG depletion in AC and can reflect variations of PG content via the quantitative acoustic parameters USS and UAA.The results of this study may be used to identify an indirect indicator of cartilage matrix integrity and OA disease progression.NIU HaiJun LI LiFeng SUN Feng YAN Yan WANG YueXiang LI DeYu FAN YuBo 2011Science China(Life Sciences)2011,54,11:3
10Hypoxia-induced GBE1 expression promotes tumor progression through metabolic reprogramming in lung adenocarcinoma显示文摘Hypoxia mediates a metabolic switch from oxidative phosphorylation to glycolysis and increases glycogen synthesis.We previously found that glycogen branching enzyme(GBE1)is downstream of the hypoxia-inducible factor-1(HIF1)signaling pathway in lung adenocarcinoma(LUAD)cells;however,the molecular mechanism underlying HIF1 regulation of GBE1 expression remains unknown.Herein,the effect of GBE1 on tumor progression via changes in metabolic signaling under hypoxia in vitro and in vivo was evaluated,and GBE1-related genes from human specimens and data sets were analyzed.Hypoxia induced GBE1 upregulation in LUAD cells.GBE1-knockdown A549 cells showed impaired cell proliferation,clone formation,cell migration and invasion,angiogenesis,tumor growth,and metastasis.GBE1 mediated the metabolic reprogramming of LUAD cells.The expression of gluconeogenesis pathway molecules,especially fructose-1,6-bisphosphatase(FBP1),was markedly higher in shGBE1 A549 cells than it was in the control cells.FBP1 inhibited the tumor progression of LUAD.GBE1-mediated FBP1 suppression via promoter methylation enhanced HIF1αlevels through NF-κB signaling.GBE1 may be a negative prognostic biomarker for LUAD patients.Altogether,hypoxia-induced HIF1αmediated GBE1 upregulation,suppressing FBP1 expression by promoter methylation via NF-κB signaling in LUAD cells.FBP1 blockade upregulated HIF1α,triggered the switch to anaerobic glycolysis,and enhanced glucose uptake.Therefore,targeting HIF1α/GBE1/NF-κB/FBP1 signaling may be a potential therapeutic strategy for LUAD.Lifeng Li Li Yang Zhirui Fan Wenhua Xue Zhibo Shen Yongliang Yuan Xiangdong Sun Dan Wang Jingyao Lian Liping Wang Jie Zhao Yi Zhang 2020Signal Transduction and Targeted Therapy2020,5,1:3
11Quality Control on Crimping of Large Diameter Welding Pipe显示文摘Crimping is used in production of large diameter submerged-arc welding pipes. Many researches are focused on crimping in certain manufacturing mode of welding pipe. The application scopes of research achievements become limited due to lack of uniformity in theoretical analysis. In order to propose a crimping prediction method in order to control forming quality, the theory model of crimping based on elastic-plastic mechanics is established. The main technical parameters are determined by theoretical analysis, including length of crimping, base radius of punch, terminal angle of punch, base radius of die, terminal angle of die and horizontal distance between punch and die. In addition, a method used to evaluate the forming quality is presented, which investigates the bending angle after springback, forming force, straight edge length and equivalent radius of curvature. In order to investigate the effects of technical parameters on forming quality, a two-dimensional finite element model is established by finite element software ABAQUS. The finite element model is verified in that its shapes error is less than 5% by comparable experiments, which shows that their geometric precision meets demand. The crimping characteristics is obtained, such as the distribution of stress and strain and the changes of forming force, and the relation curves of technical parameters on forming quality are given by simulation analysis. The sensitivity analysis indicates that the effects of length of crimping, technical parameters of punch on forming quality are significant. In particular, the data from simulation analysis are regressed by response surface method (RSM) to establish prediction model. The feasible technical parameters are obtained from the prediction model. This method presented provides a new thought used to design technical parameters of crimping forming and makes a basis for improving crimping forming quality.FAN Lifeng GAO Ying LI Qiang XU Hongshen 2012Chinese Journal of Mechanical Engineering2012,25,6:3
12Optimal selection of channel sensing order in cognitive radios显示文摘Jiang Hai Lai Lifeng Fan Rongfei 2009IEEE Transac- tions on Wireless Communications2009,8,1:1
13Influence of real gas effects on ablative Rayleigh-Taylor instability in plastic target显示文摘Fan Zhengfeng Xue Chuang Wang Lifeng 0,,:1
14Optimal selection of channel sensing order in cognitive radio 显示文摘JIANG Hai LAI Lifeng FAN Rongfei 2009IEEE Transactions on Wireless Communications2009,8,1:1
15Feasibility,Acceptability and Effects of a Foot Self-Care Educational Interventionon Minor Foot Problems in Adult Patients with Diabetes at Low Risk forFoot Ulceration: A Pilot Study显示文摘Lifeng Fan Souraya Sidani Angela Cooper-Brathwaite 2013Canadian Journal of Diabetes2013,37,3:1
16Forecasting Multi-Step Ahead Monthly Reference Evapotranspiration Using Hybrid Extreme Gradient Boosting with Grey Wolf Optimization Algorithm显示文摘It is important for regional water resources management to know the agricultural water consumption information several months in advance.Forecasting reference evapotranspiration(ET_(0))in the next few months is important for irrigation and reservoir management.Studies on forecasting of multiple-month ahead ET_(0) using machine learning models have not been reported yet.Besides,machine learning models such as the XGBoost model has multiple parameters that need to be tuned,and traditional methods can get stuck in a regional optimal solution and fail to obtain a global optimal solution.This study investigated the performance of the hybrid extreme gradient boosting(XGBoost)model coupled with the Grey Wolf Optimizer(GWO)algorithm for forecasting multi-step ahead ET_(0)(1-3 months ahead),compared with three conventional machine learning models,i.e.,standalone XGBoost,multi-layer perceptron(MLP)and M5 model tree(M5)models in the subtropical zone of China.The results showed that theGWO-XGB model generally performed better than the other three machine learning models in forecasting 1-3 months ahead ET_(0),followed by the XGB,M5 and MLP models with very small differences among the three models.The GWO-XGB model performed best in autumn,while the MLP model performed slightly better than the other three models in summer.It is thus suggested to apply the MLP model for ET_(0) forecasting in summer but use the GWO-XGB model in other seasons.Xianghui Lu Junliang Fan Lifeng Wu Jianhua Dong 2020Computer Modeling in Engineering & Sciences2020,,11:1
17Spatially distributed damage in sandstone under stress-freeze-thaw coupling conditions显示文摘In the present study,we tried to understand the spatially distributed damage in sandstone samples under the coupled stress-freeze-thaw(SFT)conditions.Firstly,uniaxial compressive stresses(i.e.0 MPa,10 MPa,20 MPa,and 25 MPa)were applied to the samples,and then freeze-thaw(FT)cycles(0,8,16,and 24)were performed on the uniaxially stressed samples to realize the SFT coupling.Next,real-time CT scanning was conducted to observe the induced damage.The total porosity was introduced to quantitatively evaluate the damage degree.The local porosity variation,with the distance from the center of the sandstone sample,was analyzed to understand the spatial distribution of damage.Finally,the coupling effects of SFT on the damage gradient were discussed.The results indicate that the porosity rises with FT cycles,and the applied stresses can accelerate the increase in porosity.The damage increases exponentially with the distance from the center of the sample.The damage presents a spatial gradient distribution,not the commonly used uniform distribution in various studies.The damage gradient increases with FT cycles,and the increasing rate in damage gradient decreases at uniaxial stress of 0 MPa and 10 MPa first,but the increasing rate in damage gradient increases with FT cycles then at stress increasing to 20 MPa.Lifeng Fan Yiding Fan Yan Xi Jingwei Gao 2022Journal of Rock Mechanics and Geotechnical Engineering2022,14,6:1
18Determination of sterols in tobacco leaves by gas chromatography-tandem mass spectrometry显示文摘The purpose of the study was to establish an analytical method to simultaneously determine multiple sterols in tobacco leaves rapidly and accurately.In this gas chromatography-triple quadruple tandem mass spectrometry(GC-MS/MS)based method,various conditions for sterols extraction were assessed and the instrumental operation parameters were optimized with 5α-cholane as an internal standard.Using this method,eight plant sterols,namely lanosterol,campesterol,chenodeoxycholic acid,cholesterol,β-sitosterol,stigmasterol,dihydrotachysterol and ergosterol,were separated in less than 30 min.The linear correlation coefficients were over 0.998 9,the low detection limits were in the range of 0.010 3-0.141 4 μg/g.The recoveries were from 87.30% to 115.60%,with low standard deviations.In conclusion,this method demonstrates good repeatability,accuracy,and high sensitivity,and is best suited for rapid analysis of multiple sterols in tobacco leaves.CHEN Qiansi LIU Pingping ZHAI Niu ZHENG Qingxia XU Guoyun WANG Chen FAN Kai JIN Lifeng ZHANG Hui ZHOU Huina 2018烟草科技2018,51,A01:0
19Optimization method to obtain appropriate spacing parameters for crop cultivation显示文摘Considering the time-consuming and tedious work of the current methods to control plant layout,which is mostly based on expert experience or field trials,we propose an algorithm to optimize and simulate a planting layout based on a virtual plant model and an optimization algorithm.A functional-structural plant model,which combines the structure and physiological function of plants,is used to construct a planting scene.The planting and row spacing are set as the genetic factors and the chromosomes of the genetic algorithm are encoded with a binary method.The photosynthetic yield of the unit planting area is denoted as the fitness value.By using this method,the intercropping of maize and soybean plants and the sole cropping of rice plants are studied.Experimental results show that the proposed method can obtain a high yield planting plan.Weilong Ding Chengcheng Fan Lifeng Xu Tao Xie Yang Liu Zangxin Wan Nelson Max 2020International Journal of Agricultural and Biological Engineering2020,13,1:0
20Invasion and defense of the basic social unit in a nonhuman primate society leads to sexual differences in the gut microbiome显示文摘Multilevel society is one of the most complex social systems in natural ecosystems and is a typical feature among some primates.Given the potential connection between social behavior and gut microbiome composition,the multilevel social system could affect the primate gut microbiome.Here,based on long-term observation(e.g.social unit dynamics,transfer,and behavior),we investigated this potential integrating 16S rRNA gene amplicon sequencing and behavior data in Yunnan snub-nosed monkeys(Rhinopithecus bieti),which possess a multilevel social group based on one male units(OMUs,each unit with several breeding females and their offspring)and all-male unit(AMU,several bachelor males residing together).We found that the mean unweighted Unifrac distance between adult males from different OMUs was significantly lower than that between adult females from different OMUs(paired Wilcoxon test,P=0.007).There was no significant difference in the mean unweighted Unifrac distance between females within the same OMU or between females from different OMUs.These findings indicated the potential connection between the defense and invasion of social units and the gut microbiome community in wild Yunnan snub-nosed monkeys.We speculated that the resident males of OMUs displaying a significantly higher similarity in the gut microbial community than that of adult females in separate OMUs might be associated with the sexual differences in their interactions and from previously having cohabitated together in the AMU.Therefore,this study suggested that multilevel societies might have an effect on the gut microbial community in this wild nonhuman primate species.Wancai XIA Mei ZHAO Dali WANG Fan WANG Hua CHEN Guoqi LIU Lifeng ZHU Dayong LI 2022Integrative Zoology2022,17,1:0
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