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61篇 您的检索式:作者名="Lingfeng Liu"
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1Orbit determination and time synchronization for a GEO/IGSO satellite navigation constellation with regional tracking network显示文摘Aiming at regional services,the space segment of COMPASS (Phase I) satellite navigation system is a constellation of Geostationary Earth Orbit (GEO),Inclined Geostationary Earth Orbit (IGSO) and Medium Earth Orbit (MEO) satellites.Precise orbit determination (POD) for the satellites is limited by the geographic distribution of regional tracking stations.Independent time synchronization (TS) system is developed to supplement the regional tracking network,and satellite clock errors and orbit data may be obtained by simultaneously processing both tracking data and TS data.Consequently,inconsistency between tracking system and TS system caused by remaining instrumental errors not calibrated may decrease navigation accuracy.On the other hand,POD for the mixed constellation of GEO/IGSO/MEO with the regional tracking network leads to parameter estimations that are highly correlated.Notorious example of correlation is found between GEO's orbital elements and its clock errors.We estimate orbital elements and clock errors for a 3GEO+2IGSO constellation in this study using a multi-satellite precise orbit determination (MPOD) strategy,with which clock error elimination algorithm is applied to separate orbital and clock estimates to improve numerical efficiency.Satellite Laser Ranging (SLR) data are used to evaluate User Ranging Error (URE),which is the orbital error projected on a receiver's line-of-sight direction.Two-way radio-wave time transfer measurements are used to evaluate clock errors.Experimenting with data from the regional tracking network,we conclude that the fitting of code data is better than 1 m in terms of Root-Mean-Square (RMS),and fitting of carrier phase is better than 1 cm.For orbital evaluation,difference between computed receiver-satellite ranging based on estimated orbits and SLR measurements is better than 1 m (RMS).For clock estimates evaluation,2-hour linear-fitting shows that the satellite clock rates are about 1.E-10 s/s,while receiver clock rates are about 1×10 13-1×10 12 s/s.For the 72-hour POD experiment,the average differences between POD satellite clock rates estimates and clock measurements based on TS system are about 1×10 13 s/s,and for receiver clock rates,the differences are about 1×10 15 s/s.ZHOU ShanShi HU XiaoGong WU Bin LIU Li QU WeiJing GUO Rui HE Feng CAO YueLing Wu XiaoLi ZHU LingFeng SHI Xin TAN HongLi 2011Science China(Physics,Mechanics & Astronomy)2011,54,6:44
2Determination of rice panicle numbers during heading by multi-angle imaging显示文摘Plant phenomics has the potential to accelerate progress in understanding gene functions and environmental responses. Progress has been made in automating high-throughput plant phenotyping. However, few studies have investigated automated rice panicle counting. This paper describes a novel method for automatically and nonintrusively determining rice panicle numbers during the full heading stage by analyzing color images of rice plants taken from multiple angles. Pot-grown rice plants were transferred via an industrial conveyer to an imaging chamber. Color images from different angles were automatically acquired as a turntable rotated the plant. The images were then analyzed and the panicle number of each plant was determined. The image analysis pipeline consisted of extracting the i2 plane from the original color image, segmenting the image, discriminating the panicles from the rest of the plant using an artificial neural network, and calculating the panicle number in the current image. The panicle number of the plant was taken as the maximum of the panicle numbers extracted from all 12 multi-angle images. A total of 105 rice plants during the full heading stage were examined to test the performance of the method. The mean absolute error of the manual and automatic count was 0.5, with 95.3% of the plants yielding absolute errors within ± 1. The method will be useful for evaluating rice panicles and will serve as an important supplementary method for high-throughput rice phenotyping.Lingfeng Duan Chenglong Huang Guoxing Chen Lizhong Xiong Qian Liu Wanneng Yang 2015The Crop Journal2015,3,3:18
3PlantcircBase: A Database for Plant Circular RNAs显示文摘Qinjie Chu Xingchen Zhang Xintian Zhu Chen Liu Lingfeng Mao Chuyu Ye Qian-Hao Zhu Longjiang Fan 2017Molecular Plant2017,10,8:15
4Transcriptome analysis and metabolic profiling reveal the key role of carotenoids in the petal coloration of Liriodendron tulipifera显示文摘Liriodendron tulipifera,also known as tuliptree,is a popular ornamental horticultural plant with extraordinary tulipshaped flowers characterized by an orange band near their base.The mechanisms underlying petal band-specific pigmentation during L.tulipifera flower development are unclear.Here,we combined nontargeted and targeted metabolomics and transcriptomics to identify a pathway cascade leading to carotenoid biosynthesis that is specifically activated in the petal band.The comparative analysis of carotenoid metabolites between L.tulipifera and Liriodendron hybrids indicates thatγ-carotene,a rare carotene in plants,is the most likely orange pigment responsible for the coloration of the petal band.Phenotypic and transcriptomic analyses of developing petals reveal that the band area is first predefined by the loss of green color.Later,the band is maintained by locally activating and repressing carotenoid and chlorophyll biosynthesis genes,respectively.Two rate-limiting genes of carotene biosynthesis,carotenoid isomerase(CRTISO)and epsilon lycopene cyclase(ε-LCY),encode the core enzymes responsible for petal band-specific orange pigmentation in L.tulipifera.In particular,a putative additionalε-LCY copy specific to L.tulipifera may contribute to the distinct petal coloration pattern,compared with L.chinense.Taken together,our work provides a first glimpse of the metabolome and transcriptome dynamics in tuliptree flower coloration and provides a valuable resource for flower breeding or metabolic engineering as well as for understanding flower evolution in an early woody angiosperm.Zhaodong Hao Siqin Liu Lingfeng Hu Jisen Shi Jinhui Chen 2020Horticulture Research2020,7,1:7
5A deep learning-integrated micro-CT image analysis pipeline for quantifying rice lodging resistance-related traits显示文摘Lodging is a common problemin rice,reducing its yield andmechanical harvesting efficiency.Rice architecture is a key aspect of its domestication and a major factor that limits its high productivity.The ideal rice culm structure,includingmajor_axis_culm,minor axis_culm,andwall thickness_culm,is critical for improving lodging resistance.However,the traditionalmethod ofmeasuring rice culms is destructive,time consuming,and labor intensive.In this study,we used a high-throughput micro-CT-RGB imaging system and deep learning(SegNet)todevelopa high-throughputmicro-CTimageanalysis pipelinethatcanextract 24 riceculmmorphological traits and lodging resistance-related traits.When manual and automatic measurements were compared at themature stage,the mean absolute percentage errors for major_axis_culm,minor_axis_culm,andwall_thickness_culmin 104 indica rice accessionswere 6.03%,5.60%,and 9.85%,respectively,and the R^(2) valueswere 0.799,0.818,and 0.623.We also builtmodels of bending stress using culmtraits at the mature and tillering stages,and the R^(2) values were 0.722 and 0.544,respectively.The modeling results indicated that this method can quantify lodging resistance nondestructively,even at an early growth stage.In addition,we also evaluated the relationships of bending stress toshoot dryweight,culm density,and drought-related traits and found that plants with greater resistance to bending stress had slightly higher biomass,culm density,and culm area but poorer drought resistance.In conclusion,we developed a deep learning-integrated micro-CT image analysis pipeline to accurately quantify the phenotypic traits of rice culms in4.6 min per plant;this pipeline will assist in future high-throughput screening of large rice populations for lodging resistance.Di Wu Dan Wu Hui Feng Lingfeng Duan Guoxing Dai Xiao Liu Kang Wang Peng Yang Guoxing Chen Alan P.Gay John H.Doonan Zhiyou Niu Lizhong Xiong Wanneng Yang 2021Plant Communications2021,2,2:7
6Applications of two-way satellite time and frequency transfer in the BeiDou navigation satellite system显示文摘A two-way satellite time and frequency transfer(TWSTFT) device equipped in the BeiDou navigation satellite system(BDS)can calculate clock error between satellite and ground master clock. TWSTFT is a real-time method with high accuracy because most system errors such as orbital error, station position error, and tropospheric and ionospheric delay error can be eliminated by calculating the two-way pseudorange difference. Another method, the multi-satellite precision orbit determination(MPOD)method, can be applied to estimate satellite clock errors. By comparison with MPOD clock estimations, this paper discusses the applications of the BDS TWSTFT clock observations in satellite clock measurement, satellite clock prediction, navigation system time monitor, and satellite clock performance assessment in orbit. The results show that with TWSTFT clock observations, the accuracy of satellite clock prediction is higher than MPOD. Five continuous weeks of comparisons with three international GNSS Service(IGS) analysis centers(ACs) show that the reference time difference between BeiDou time(BDT) and golbal positoning system(GPS) time(GPST) realized IGS ACs is in the tens of nanoseconds. Applying the TWSTFT clock error observations may obtain more accurate satellite clock performance evaluation in the 104 s interval because the accuracy of the MPOD clock estimation is not sufficiently high. By comparing the BDS and GPS satellite clock performance, we found that the BDS clock stability at the 103 s interval is approximately 10.12, which is similar to the GPS IIR.ShanShi Zhou XiaoGong Hu Li Liu Rui Guo LingFeng Zhu ZhiQiao Chang ChengPan Tang XiuQiang Gong Ran Li Yang Yu 2016Science China(Physics,Mechanics & Astronomy)2016,59,10:6
760 Years of Development of the Journal of Integrative Plant Biology显示文摘In celebration of JIPB's 60 th anniversary,this paper summarizes and reviews the development process of the journal.To start,we offer our heartfelt thanks to JIPB's pioneer Editors-in-Chief who helped get the journal off the ground and make it successful.Academic achievement is the soul of academic journals,and this paper summarizes JIPB's course of academic development by analyzing it in four stages:the first two stages are mostly qualitative analyses,and the latter two stages are dedicated to quantitative analyses.Most-cited papers were statistically analyzed.Improvements in editing,publication,distribution and online accessibility-which are detailed in this paper-contribute to JIPB's sustainable development.In addition,JIPB's evaluation index and awards are provided with accompanying pictures.At the end of the paper,JIPB's milestones are listed chronologically.We believe that JIPB's development,from a national journal to an international one,parallels the development of the Chinese plant sciences.Jinzhong Cui Ping He Fenghong Liu Jingjing Tan Lingfeng Chen Joshua Fenn 2012Journal of Integrative Plant Biology2012,54,10:5
8A Two-stage Robust Optimal Allocation Model of Distributed Generation Considering Capacity Curve and Real-time Price Based Demand Response显示文摘Demand response, the reactive power output of distributed generation(DG), and network reconfiguration have significant impacts on a DG allocation strategy. In this context, a novel real-time price-based demand response formulation is integrated into the allocation model of DG. The tariff is regulated by the difference between the load and active power of renewable energy. Meanwhile, network reconfiguration and the capacity curve describing the active and reactive power limits of DG are included in the optimization model for promoting the allocation of DG.With these measures, the optimal allocation model of DG is established with the goal of maximizing the net annual profit while guaranteeing the efficient utilization of renewable energy. In addition, the uncertainties of renewable energy are considered on the basis of a two-stage robust optimization method. Finally, the entire optimization model is solved by the column and constraint generation algorithm in the IEEE 33-bus distribution system and a practical 99-bus distribution system. Numerical simulations show that the proposed model is effective in terms of improving both the usage of renewable energy and net annual profit.Shuaijia He Hongjun Gao Hao Tian Lingfeng Wang Youbo Liu Junyong Liu 2021Journal of Modern Power Systems and Clean Energy2021,9,1:5
9Relationship Between Single Nucleotide Polymorphism of Glycogen Synthase Gene of Pacific Oyster Crassostrea gigas and Its Glycogen Content显示文摘Glycogen is important not only for the energy supplementary of oysters, but also for human consumption. High glycogen content can improve the stress survival of oyster. A key enzyme in glycogenesis is glycogen synthase that is encoded by glycogen synthase gene GYS. In this study, the relationship between single nucleotide polymorphisms(SNPs) in coding regions of Crassostrea gigas GYS(Cg-GYS) and individual glycogen content was investigated with 321 individuals from five full-sib families. Single-strand conformation polymorphism(SSCP) procedure was combined with sequencing to confirm individual SNP genotypes of Cg-GYS. Least-square analysis of variance was performed to assess the relationship of variation in glycogen content of C. gigas with single SNP genotype and SNP haplotype. As a consequence, six SNPs were found in coding regions to be significantly associated with glycogen content(P < 0.01), from which we constructed four main haplotypes due to linkage disequilibrium. Furthermore, the most effective haplotype H2(GAGGAT) had extremely significant relationship with high glycogen content(P < 0.0001). These findings revealed the potential influence of Cg-GYS polymorphism on the glycogen content and provided molecular biological information for the selective breeding of good quality traits of C. gigas.LIU Siwei LI Qi YU Hong KONG Lingfeng 2017Journal of Ocean University of China2017,16,1:3
10Temporal and spatial comparisons of angiosperm diversity between eastern Asia and North America显示文摘Comparative approaches that examine floras with similar environments, but different diversity patterns, provide good opportunities to elucidate how uneven distributions of biodiversity were assembled. Eastern Asia(EA) and North America north of Mexico(NA;see definitions of EA and NA in Fig. S1 A) share similar geographical environments with comparable latitude, land area and climate.Haihua Hu Jianfei Ye Bing Liu Lingfeng Mao Stephen A.Smith Russell L.Barrett Pamela S.Soltis Douglas E.Soltis Zhiduan Chen Limin Lu 2022National Science Review2022,9,6:3
11Periodic performance of the chaotic spread spectrum sequence on finite precision显示文摘It is well known that the periodic performance of spread spectrum sequence heavily affects the cor-relative and secure characteristics of communication systems.The chaotic binary sequence is paid more and more attention since it is one kind of applicable spread spectrum sequences.However,there are unavoidable short cyclic problems for chaotic binary sequences in finite precision.The chaotic binary sequence generating methods are studied first.Then the short cyclic behavior of the chaotic sequences is analyzed in detail,which are generated by quantification approaches with finite word-length.At the same time,a chaotic similar function is defined for presenting the cyclic characteristics of the sequences.Based on these efforts,an improved method with scrambling control for generating chaotic binary sequences is proposed.To quantitatively describe the improvement of periodic performance of the sequences,an orthogonal estimator is also defined.Some simulating results are provided.From the theoretical deduction and the experimental results,it is concluded that the proposed method can effectively increase the period and raise the complexity of the chaotic sequences to some extent.Zhu Canyan Zhang Lihua Wang Yiming Liu Jiasheng Mao Lingfeng 2008Journal of Systems Engineering and Electronics2008,19,4:3
12Reproductive Cycle and Seasonal Variations in Lipid Content and Fatty Acid Composition in Gonad of the Cockle Fulvia mutica in Relation to Temperature and Food显示文摘From March 2004 to February 2005,seasonal variations in lipid content and fatty acid composition of gonad of the cockle Fulvia mutica(Reeve) were studied on the eastern coast of China in relation to the reproductive cycle and environment conditions(e.g.,temperature and food availability).Histological analysis as well as lipid and fatty acid analyses were performed on neutral and polar lipids of the gonad.Results showed that gametogenesis occurred in winter and spring at the expense of lipids previously accumulated in summer and autumn,whereas spawning occurred in summer(20.4-24.6℃).The seasonal variation in lipid content was similar to that of the mean oocyte diameter.In both neutral and polar lipids,the 20:5n-3 and 22:6n-3 levels were relatively higher than saturated fatty acids,and polyunsaturated fatty acids were abundant,with series n-3 as the predominant component.Seasonal variations in the 20:5n-3 and 22:6n-3 levels and the principal n-3 fatty acids were clearly related to the reproductive cycle.The ∑(n-3) and ∑(n-6) values were relatively high during January-May,and the associated unsaturation index was significantly higher than that in other months.The results suggest that fatty acids play an important role in the gametogenesis of F.mutica.LIU Wenguang LI Qi KONG Lingfeng 2013Journal of Ocean University of China2013,12,3:3
13The method and experiment analysis of two-way common-view satellite time transfer for compass system显示文摘Time synchronization between ground and satellites is a key technology for satellite navigation system. With dual-channel satellite, a method called Two-Way Common-View(TWCV) satellite time transfer for Compass system is proposed, which combines both characteristics of satellite common-view and two-way satellite-ground time transfer. By satellite-ground two-way pseudo-range differencing and two stations common-view differencing, this TWCV method can completely eliminate the influence of common errors, such as satellite clock offset, ephemeris errors, troposphere delay and station coordinates errors. At the same time, ionosphere delay related to signal frequency is also weakened significantly. So the precision of time transfer is improved much more greatly than before. In this paper, the basic principle is introduced in detail, the effect of major errors is analyzed and the practical calculation model in the Earth-fixed coordinate system for this new method is provided. Finally, experiment analysis is conducted with actual Compass observing data. The results show that the deviation and the stability of the satellite dual channel can be better than 0.1 ns, and the accuracy of the two-way common-view satellite time transfer can achieve 0.4 ns. All these results have verified the correctness of this TWCV method and model. In addition, we compare this TWCV satellite time transfer with the independent C-band TWSTFT(Two-Way Satellite Time and Frequency Transfer). It shows that the result of the TWCV satellite time transfer is in accordance with the C-band TWSTFT result, which further suggests that the TWCV method is a remote high precision time transfer technique. The research results in this paper are very important references for the development and application of Compass satellite navigation system.LIU Li TANG GuiFen HAN ChunHao SHI Xin GUO Rui ZHU LingFeng 2015Science China(Physics,Mechanics & Astronomy)2015,58,8:2
14High-Performance Photo-Modulated Thin-Film Transistor Based on Quantum dots/Reduced Graphene Oxide Fragment-Decorated ZnO Nanowires显示文摘In this paper, a photo-modulated transistor based on the thin-film transistor structure was fabricated on the flexible substrate by spin-coating and magnetron sputtering. A novel hybrid material that composed of Cd Se quantum dots and reduced graphene oxide(RGO) fragment-decorated ZnO nanowires was synthesized to overcome the narrow optical sensitive waveband and enhance the photo-responsivity. Due to the enrichment of the interface and heterostructure by RGO fragments being utilized, the photo-responsivity of the transistor was improved to 2000 AW^(-1) and the photo-sensitive wavelength was extended from ultraviolet to visible. In addition, a positive back-gate voltage was employed to reduce the Schottky barrier width of RGO fragments and ZnO nanowires. As a result, the amount of carriers was increased by 10 folds via the modulation of back-gate voltage. With these inherent properties, such as integrated circuit capability and wide optical sensitive waveband, the transistor will manifest great potential in the future applications in photodetectors.Zhi Tao Yi-an Huang Xiang Liu Jing Chen Wei Lei Xiaofeng Wang Lingfeng Pan Jiangyong Pan Qianqian Huang Zichen Zhang 2016Nano-Micro Letters2016,8,3:2
15Wheat MADS-box gene TaSEP3-D1 negatively regulates heading date显示文摘The MADS-box gene plays an important role in regulating plant growth and development.In this study,a SEP3-like MADS-box gene TaSEP3-1 was isolated from bread wheat.The expression patterns of the three homoeologs TaSEP3-A1,TaSEP3-B1,and TaSEP3-D1 were similar,and higher expression levels were detected in floral organs and developing kernels.TaSEP3-D1 was located in the nucleus and cytoplasm and possessed transactivation activity in yeast.Homoeolog sequence polymorphism analysis identified four,three,and four haplotypes of TaSEP3-A1,TaSEP3-B1,and TaSEP3-D1,respectively,and the haplotypes of TaSEP3-D1 had larger effects on agronomic traits than those of TaSEP3-A1 and TaSEP3-B1.D1_h4,significantly associated with heading date,plant height,and other yield-related traits,was the favored haplotype of TaSEP3-D1.Transgenic wheat genotypes overexpressing TaSEP3-D1 exhibited delayed heading and reduced plant height,indicating a role in regulating heading date and plant development.These results shed light on the role of TaSEP3-D1 in wheat plant development.The favored haplotype of TaSEP3-D1 can be applied in breeding to improve plant architecture and yield in wheat.Lei Zhang Hao Zhang Linyi Qiao Lingfeng Miao Dong Yan Pan Liu Guangyao Zhao Jizeng Jia Lifeng Gao 2021The Crop Journal2021,9,5:2
16Distributed adaptive direct position determination based on diffusion framework显示文摘The conventional direct position determination(DPD) algorithm processes all received signals on a single sensor.When sensors have limited computational capabilities or energy storage,it is desirable to distribute the computation among other sensors.A distributed adaptive DPD(DADPD)algorithm based on diffusion framework is proposed for emitter localization.Unlike the corresponding centralized adaptive DPD(CADPD) algorithm,all but one sensor in the proposed algorithm participate in processing the received signals and estimating the common emitter position,respectively.The computational load and energy consumption on a single sensor in the CADPD algorithm is distributed among other computing sensors in a balanced manner.Exactly the same iterative localization algorithm is carried out in each computing sensor,respectively,and the algorithm in each computing sensor exhibits quite similar convergence behavior.The difference of the localization and tracking performance between the proposed distributed algorithm and the corresponding CADPD algorithm is negligible through simulation evaluations.Wei Xia Wei Liu Lingfeng Zhu 2016Journal of Systems Engineering and Electronics2016,27,1:2
17Optical Fiber Grating Sensor for Force Measurement of Anchor Cable显示文摘The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed in the laboratory - optical fiber grating sensor for force measurement of anchor cable (OFBFMAC). No similar report about this kind of sensor has been found up to now in China and other countries. This sensor is proved to be an effective way of monitoring in processes of anchor cable installation, cable cutting, cable force regulation, etc, with the accurate and repeatable measuring results. Its successful application in the tie bar cable force safety monitoring for Wuhan Qingchuan bridge is a new exploration of optical fiber grating sensing technology in bridge tie bar monitoring system.JIANG Desheng FU Jinghua LIU Shengchun SUI Lingfeng FU Rong 2006Wuhan University Journal of Natural Sciences2006,11,3:2
18PseudoRandom Bit Generator Based on Non-Stationary LogisticMaps 显示文摘Liu Lingfeng Miao Suoxiao Hu Hanping 2016IET Information Security2016,10,2:1
19miRNA-200c increases the sensitivity of breast cancer cells to doxorubicinthrough the suppression of E-cadherin-mediated PTEN/Akt signaling显示文摘Yong Chen Ying Sun Longbang Chen Xingxiang Xu Xizhi Zhang Buhai Wang Lingfeng Min Wei Liu 2013Molecular Medicine Reports2013,,5:1
20Quantitative information measurement and application for machine eomponent classification eodes显示文摘LI Lingfeng TAN Jianrong LIU Bo 2005Journal of Zhejiang University: Science A2005,21,6:1
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