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8篇 您的检索式:作者名="Yongzhu LIU"
    题名 作者 年代 出处 被引量
1Conjugate Gradient Algorithm in the Four-Dimensional Variational Data Assimilation System in GRAPES显示文摘Minimization algorithms are singular components in four-dimensional variational data assimilation(4DVar).In this paper,the convergence and application of the conjugate gradient algorithm(CGA),which is based on the Lanczos iterative algorithm and the Hessian matrix derived from tangent linear and adjoint models using a non-hydrostatic framework,are investigated in the 4DVar minimization.First,the influence of the Gram-Schmidt orthogonalization of the Lanczos vector on the convergence of the Lanczos algorithm is studied.The results show that the Lanczos algorithm without orthogonalization fails to converge after the ninth iteration in the 4DVar minimization,while the orthogonalized Lanczos algorithm converges stably.Second,the convergence and computational efficiency of the CGA and quasi-Newton method in batch cycling assimilation experiments are compared on the 4DVar platform of the Global/Regional Assimilation and Prediction System(GRAPES).The CGA is 40%more computationally efficient than the quasi-Newton method,although the equivalent analysis results can be obtained by using either the CGA or the quasi-Newton method.Thus,the CGA based on Lanczos iterations is better for solving the optimization problems in the GRAPES 4DVar system.Yongzhu LIU Lin ZHANG Zhihua LIAN 2018Journal of Meteorological Research2018,32,6:9
2Application and Characteristic Analysis of the Moist Singular Vector in GRAPES-GEPS显示文摘The singular vector(SV)initial perturbation method can capture the fastest-growing initial perturbation in a tangent linear model(TLM).Based on the global tangent linear and adjoint model of GRAPES-GEPS(Global/Regional Assimilation and Prediction System-Global Ensemble Prediction System),some experiments were carried out to analyze the structure of the moist SVs from the perspectives of the energy norm,energy spectrum,and vertical structure.The conclusions are as follows:The evolution of the SVs is synchronous with that of the atmospheric circulation,which is flowdependent.The moist and dry SVs are located in unstable regions at mid-to-high latitudes,but the moist SVs are wider,can contain more small-and medium-scale information,and have more energy than the dry SVs.From the energy spectrum analysis,the energy growth caused by the moist SVs is reflected in the relatively small-scale weather system.In addition,moist SVs can generate perturbations associated with large-scale condensation and precipitation,which is not true for dry SVs.For the ensemble forecasts,the average anomaly correlation coefficient of large-scale circulation is better for the forecast based on moist SVs in the Northern Hemisphere,and the low-level variables forecasted by the moist SVs are also improved,especially in the first 72 h.In addition,the moist SVs respond better to short-term precipitation according to statistical precipitation scores based on 10 cases.The inclusion of the large-scale condensation process in the calculation of SVs can improve the short-term weather prediction effectively.Jing WANG Bin WANG Juanjuan LIU Yongzhu LIU Jing CHEN Zhenhua HUO 2020Advances in Atmospheric Sciences2020,37,11:2
3Fine mapping and candidate gene analysis of qGL10 affecting rice grain length显示文摘Grain size influences the yield and quality of rice(Oryza sativa L.),and grain length is one of the component traits of grain size.In this study,a near-isogenic line LB3 with long grain size was constructed using japonica rice cultivar 02428,with short grain size,as the recipient parent and indica rice cultivar ZYX,with long grain size,as the donor parent,by multi-generation backcrossing and selfing.BSA-seq was used for preliminary QTL mapping and InDel markers were developed to fine map the locus.The major QTL,tentatively named qGL10,for grain length was located in a 128.45 kb region of chromosome 10.Combined with haplotype analysis of rice varieties,expression pattern analysis of candidate genes suggested LOC_Os10g39130(OsMADS56)as a candidate gene.Sequence alignment of OsMADS56 in 02428 and LB3 revealed that there were 15 SNPs in the promoter region and four in the coding region.Further haplotype analysis suggested that SNP9(G/A)located in the TGTCACA motif might account for the different expression levels of OsMADS56 in 02428 and LB3.These results lay a foundation for the application of qGL10 in molecular breeding of new rice varieties.Tengkui Chen Lixin Luo Zhe Zhao Hui Wang Chun Chen Yongzhu Liu Xinchang Li Tao Guo Wuming Xiao 2023The Crop Journal2023,11,2:1
4Dual effects of disorder on the strongly-coupled system composed of a single quantum dot and a photonic crystal L3 cavity显示文摘Light-matter interaction in the strong coupling regime enables light control at the single-photon level. We develop numerical method and analytical expressions to calculate the decay kinetics of an initially excited two-level quantum emitter in dielectric nanostructure and single-mode cavity, respectively. We use these methods to discover the dual effects of disorder on the stronglycoupled system composed of a single quantum dot and a photonic crystal L3 cavity. The quality factor is sensitive to disorder,while the g factor and vacuum Rabi splitting are robust against disorder. A small amount of disorder may either decrease or increase the light localization and the light-matter interaction. Our methods offer flexible and efficient theoretical tools for the investigation of light-matter interaction, especially cavity quantum electrodynamics. Our findings significantly lower the requirements for optimization effort and fabrication precision and open up many promising practical possibilities.GengYan Chen Jing-Feng Liu Yi-Cong Yu RenMing Liu GuiXin Zhu YongZhu Chen ZhanXu Chen Xue-Hua Wang 2019Science China(Physics,Mechanics & Astronomy)2019,62,6:1
5New insight into iron biogeochemical cycling in soil-rice plant system using iron isotope fractionation显示文摘Iron (Fe) migration in soil-plants is a critical part of Fe biogeochemical cycling in the earth surface system. Fe isotope fractionation analysis in the soil-rice system is promising for quantitatively assessing various pathways and clarifying Fe transformation processes. However, the mechanisms of Fe isotope fractionation in the soil-rice system are not well understood. In this study, the Fe isotopic compositions (δ^(56)Fe) of rhizosphere soils, pore water, Fe plaque, and rice plant tissues at the jointing and mature stages of the plants were determined. The rice plants were slightly enriched in heavier δ^(56)Fe by 0.3‰ relative to the soil, and the stele and cortex showed similar δ^(56)Fe values, indicating that the uptake of Fe by rice plants predominantly occurred via Fe(III)-phytosiderophores (Fe(III)-PS) chelation, but not Fe(III) reduction. Additionally, at both the jointing and mature stages, the rice plant tissues showed similar δ^(56)Fe values. However, the Fe isotope fractionation between the roots and stems (Δ56Feroot−stem) was 1.39 ± 0.13‰, which is similar to the previously Ab initio-calculated values between Fe(III)-citrate and Fe(III)- 2-deoxymugineic acid (DMA), indicating that both the phloem and xylem have similar δ^(56)Fe values, and the major Fe-chelating substances in the phloem of the rice plants are Fe(III)-DMA and Fe(II)- Nicotianamine (NA). Therefore, this study demonstrates that Fe isotope fractionation can be used as a signature for interpreting the Fe uptake and translocation mechanism in the soil-rice system.Guojun Chen Tongxu Liu Yongzhu Li Ting Gao Fang Huang Xiaomin Li Songxiong Zhong Fangbai Li 2021Fundamental Research2021,1,3:1
6Immune response in cattle inoculated with the recombinant complete polyprotein of foot-and-mouth disease virus from Bombyx mori larvae显示文摘The intact open reading frame (ORF) of foot-and-mouth disease virus (FMDV) Asia I/XJ strain was am- plified by RT-PCR and inserted into the transfer vector pVL1393 to generate plasmid pVL-ORF. Bm-N cells were transfected with pVL-ORF and linearized Bm-BacPAK6 DNA, and the recombinant silkworm baculovirus Bm-ORF containing the full ORF of FMDV was obtained. The results of indirect im- munofluorescence assay (IFA) showed that Bm-ORF could be expressed efficiently in Bm-N cell. After inoculating the early 5th instar larvae of silkworm, the polyprotein of FMDV could be detected by sandwich ELISA and empty capsid-like particles could be observed under the electron microscope. Expression products from silkworm were used as the antigen to immunize the cattle. The specific an- tibody was induced in all vaccinated animals. The immunized cattle were challenged with the virulent FMDV Asia I/XJ strain, two of the four cattle were completely protected and clinical symptoms were alleviated and delayed in the others. The results suggest that this strategy might be used to develop the new subunit FMDV vaccine.LI ZhiYong YI YongZhu YIN XiangPing ZHANG ZhiFang LIU JiXing 2007Chinese Science Bulletin2007,52,20:1
7Ground–Space–Sky Observing System Experiment during Tropical Cyclone Mulan in August 2022显示文摘Forecasting tropical cyclone track and intensity is a great challenge for the meteorological community,and safeguarding the life and property of people living near the coast is an important issue.One major reason for challenging forecasts is the lack of observations over the vast oceans.During tropical cyclone Mulan between 8 and 10 August 2022 over the northern part of the South China Sea,the meteorological authority and research institutes of Chinese mainland collaborated with the meteorological service in Hong Kong on conducting the first-ever ground–space–sky observing system experiment on tropical cyclone Mulan.The enhanced targeted observations collected during the experiment include Geostationary Interferometric Infrared Sounder,round-trip radiosondes,and aircraft-launched dropsondes.This paper describes the campaign,technical details of the meteorological models used,and impact of the additional targeted observation data on the tropical cyclone forecast.Ideally,similar enhanced observation campaigns could be conducted in the future,not only in the northern part of the South China Sea,but also in other ocean basins.Pak-wai CHAN Wei HAN Betty MAK Xiaohao QIN Yongzhu LIU Ruoying YIN Jincheng WANG 2023Advances in Atmospheric Sciences2023,40,2:0
8An Initial Perturbation Method for the Multiscale Singular Vector in Global Ensemble Prediction显示文摘Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial perturbation method tends only to capture synoptic scale initial uncertainty rather than mesoscale uncertainty in global ensemble prediction. To address this issue, a multiscale SV initial perturbation method based on the China Meteorological Administration Global Ensemble Prediction System(CMA-GEPS) is proposed to quantify multiscale initial uncertainty. The multiscale SV initial perturbation approach entails calculating multiscale SVs at different resolutions with multiple linearized physical processes to capture fast-growing perturbations from mesoscale to synoptic scale in target areas and combining these SVs by using a Gaussian sampling method with amplitude coefficients to generate initial perturbations. Following that, the energy norm,energy spectrum, and structure of multiscale SVs and their impact on GEPS are analyzed based on a batch experiment in different seasons. The results show that the multiscale SV initial perturbations can possess more energy and capture more mesoscale uncertainties than the traditional single-SV method. Meanwhile, multiscale SV initial perturbations can reflect the strongest dynamical instability in target areas. Their performances in global ensemble prediction when compared to single-scale SVs are shown to(i) improve the relationship between the ensemble spread and the root-mean-square error and(ii) provide a better probability forecast skill for atmospheric circulation during the late forecast period and for short-to medium-range precipitation. This study provides scientific evidence and application foundations for the design and development of a multiscale SV initial perturbation method for the GEPS.Xin LIU Jing CHEN Yongzhu LIU Zhenhua HUO Zhizhen XU Fajing CHEN Jing WANG Yanan MA Yumeng HAN 2024Advances in Atmospheric Sciences2024,41,3:0
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