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    题名 作者 年代 出处 被引量
1Microstructure and mechanical properties of NZ30K alloy by semi-continuous direct chill and sand mould casting processes显示文摘The Mg-3.0Nd-0.2Zn-0.4Zr (NZ30K) alloys were prepared by direct-chill casting (DCC) and sand mould casting (SMC) processes,respectively and their microstructures and mechanical properties were investigated.The results indicate that casting method plays a remarkable influence on the microstructure and mechanical properties of as-cast NZ30K alloy.The grain size increases from 35-40μm in the billets made by the DCC to about 100-120μm in the billets by the SMC.The aggregation of Mg12Nd usually found at the triple joints of grain boundaries in the billets prepared by SMC while is not observable from the billets by DCC.The tensile strengths and elongations of the billets are 195.2 MPa and 15.5% by DCC,and 162.5 MPa and 3.2% by SMC,respectively.The tensile strength of the alloy by DCC is remarkably enhanced by T6 heat treatment,which reached 308.5 MPa.Fracture surfaces of NZ30K alloy have been characterized as intergranular fracture by SMC and quasi-cleavage fracture by DCC,respectively.Zheng Xingwei Dong Jie Liu Wencai Ding Wenjiang 2011China Foundry2011,8,1:25
2Three-dimensional human facial morphologies as robust aging markers显示文摘老化与许多复杂疾病被联系。变老的过程的可靠预言为估计联系老化的疾病的风险是重要的。然而尽管有强烈研究,到目前为止没有可靠老化标记。这里,我们由检验人的 3D 美容成像特征是否能被用作可靠老化标记处理了这个问题。我们收集了 >300 幅 3D 人美容图象和越过 17 ~ 77 年的年龄散布得好的血侧面。由分析词法侧面,我们产生了变老的人的面部 phenome 的第一张全面地图。我们鉴别量的面部特征例如眼睛斜坡,高度与年龄联系了。我们构造了一个柔韧的年龄预言者并且发现平均,一样的按年代先后的年龄的人由 ± 不同;在美容的 6 年变老,与在年龄 40 以后增加的偏差。用这个预言者,我们识别了被健康指示物的层次显著地支持的慢、快的蒸化机。尽管有在在血的面部词法特征和健康指示物之间的一种靠近的关系,面部特征比血侧面是更可靠的老化 biomarkers 并且能更好比按年代先后的年龄反映一般健康地位。Weiyang Chen Wei Qian Gang Wu Weizhong Chen Bo Xian Xingwei Chen Yaqiang Cao Christopher D Green Fanghong Zhao Kun Tang Jing-Dong J Han 2015Cell Research2015,25,5:17
3Mobile-robotic machining for large complex components:A review study显示文摘Even though the robotic machining has achieved great success in machining of small components, it lacks the competence to machine large complex components, such as wind turbine blade, train carriage, and aircraft wing. In order to cope with this issue,the mobile machining robot system, which consists of a robot arm integrated with a mobile platform, is proposed to achieve the large workspace and high dexterity, and thus has the potential to machine the large complex components. However, due to the limitation of motion accuracy and structural stiffness, the current mobile-robots are hard to satisfy the high precision requirement of machining tasks. In this paper, some historical mobile-robotic machining systems are reviewed firstly, followed by some key techniques related to structure optimization, dynamics of the machining process, localization, and control techniques, which are fundamental for the structural stiffness and motion accuracy of mobile-robots. Finally, the prospect of mobile-robotic machining and the open questions are addressed.TAO Bo ZHAO XingWei DING Han 2019Science China(Technological Sciences)2019,62,8:17
4Stretching characteristics and its dynamic significance of the northern continental margin of South China Sea显示文摘To investigate the thinning of the whole crust, and the contribution of the upper versus lower crust to the stretching since Cenozoic, we calculated the stretching factor of the northern margin of South China Sea with data such as whole crustal thickness, depth of Cenozoic sedimentary basement and the horizontal displacement of faults. An isometric line drawing on whole crustal stretching factor is then obtained. Along the seismic Line 1530 in Baiyun sag, we also calculated the stretching factors of the upper and lower crust. The results suggest that the whole crustal thickness decreases seaward while the whole crustal stretching factor increases from shelf to slope. The Moho upwells highest beneath where the crust is thinned most. The value of the whole crustal stretching factor ranges from 1.5 to 6. Two areas were thinned intensely: the center of Yinggehai Basin, and the Baiyun sag in the Pearl River Mouth Basin. The calculation of the upper and lower crustal stretching factors from DSP1530 in Baiyun sag shows that the original crust of Baiyun sag should be thinned before deformation. Its pre-Cenozoic evolution as well as tectonic position during Cenozoic might be responsible for that.ZHANG YunFan SUN Zhen ZHOU Di GUO XingWei SHI XiaoBin WU XiangJie PANG Xiong 2008Science China Earth Sciences2008,51,3:15
5Model and Algorithm for the Optimal Controlled Partitioning of Power Systems显示文摘解列是电力系统在故障时结构完整性得不到保证的情况下分裂为2个或多个孤立稳定运行子系统的过程或操作。及时恰当的主动解列操作将能有效地避免因保护连锁动作使得电力系统被动解列而崩溃所造成的巨额经济损失。结合图论中的相关概念和输电网最优解列的物理过程,建立电力系统最优主动解列断面选择问题的完整数学模型,并基于含连通图约束的背包问题(connected graph constrained knapsack problem,CGKP)及其求解算法提出“搜索+调整”的2阶段求解方法。为降低问题的复杂性,将完整数学模型分解成图的最优平衡分割问题和基于优化潮流的调节问题,并分2个阶段分别求解。其中,图的最优平衡分割问题又被分解成多个CGKP,利用基于含CGKP的图分割方法进行求解。所提出的主动解列策略具有较强理论基础,计算复杂度低,算例的计算结果证明了该模型及算法的正确性和有效性。LIN Jikeng LI Shengwen WU Peng WANG Xudong SHAO Guanghui XU Xingwei MA Xin 2012中国电机工程学报2012,32,13:15
6Real-time drogue recognition and 3D locating for UAV autonomous aerial refueling based on monocular machine vision显示文摘Drogue recognition and 3D locating is a key problem during the docking phase of the autonomous aerial refueling(AAR). To solve this problem, a novel and effective method based on monocular vision is presented in this paper. Firstly, by employing computer vision with red-ring-shape feature, a drogue detection and recognition algorithm is proposed to guarantee safety and ensure the robustness to the drogue diversity and the changes in environmental conditions, without using a set of infrared light emitting diodes(LEDs) on the parachute part of the drogue. Secondly, considering camera lens distortion, a monocular vision measurement algorithm for drogue 3D locating is designed to ensure the accuracy and real-time performance of the system,with the drogue attitude provided. Finally, experiments are conducted to demonstrate the effectiveness of the proposed method. Experimental results show the performances of the entire system in contrast with other methods, which validates that the proposed method can recognize and locate the drogue three dimensionally, rapidly and precisely.Wang Xufeng Kong Xingwei Zhi Jianhui Chen Yong Dong Xinmin 2015Chinese Journal of Aeronautics2015,28,6:15
7Characteristics of Meso-Cenozoic Igneous Complexes in the South Yellow Sea Basin,Lower Yangtze Craton of Eastern China and the Tectonic Setting显示文摘The South Yellow Sea Basin is partially surrounded by the East Asian continental MesoCenozoic widespread igneous rocks belt.Magnetic anomaly and multi-channel seismic data both reveal the prevalent occurrence of igneous rocks.We preliminarily defined the coupling relation between magnetic anomalies and igneous rock bodies.Some igneous complexes were also recognized by using multi-channel seismic and drilling data.We identified various intrusive and extrusive igneous rock bodies,such as stocks,sills,dikes,laccoliths and volcanic edifice relics through seismic facies analysis.We also forecasted the distribution characteristics of igneous complexes.More than fifty hypabyssal intrusions and volcanic relics were delineated based on the interpretation of magnetic anomaly and dense intersecting multi-channel seismic data.It is an important supplement to regional geology and basin evolution research.Spatial matching relations between igneous rock belts and fractures document that extensional N-E and N-NE-trending deep fractures may be effective pathways for magma intrusion.These fractures formed under the influence of regional extension during the MesoCenozoic after the Indosinian movement.Isotopic ages and crosscutting relations between igneous rock bodies and the surrounding bedded sedimentary strata both indicate that igneous activities might have initiated during the Late Jurassic,peaked in the Early Cretaceous,gradually weakened in the Late Cretaceous,and continued until the Miocene.Combined with previous studies,it is considered that the Meso-Cenozoic igneous activities,especially the intensive igneous activity of the Early Cretaceous,are closely associated with the subduction of the Paleo-Pacific Plate.PANG Yumao ZHANG Xunhua XIAO Guolin GUO Xingwei WEN Zhenhe WU Zhiqiang ZHU Xiaoqing 2017Acta Geologica Sinica(English Edition)2017,91,3:15
8Skeleton pruning as trade-off between skeleton simplicity and reconstruction error显示文摘Skeletons can be viewed as a compact shape representation in that each shape can be completely reconstructed from its skeleton.However,the usefulness of a skeletal representation is strongly limited by its instability.Skeletons suffer from contour noise in that small contour deformation may lead to large structural changes in the skeleton.A large number of skeleton computation and skeleton pruning approaches has been proposed to address this issue.Our approach differs fundamentally in the fact that we cast skeleton pruning as a trade-off between skeleton simplicity and shape reconstruction error.An ideal skeleton of a given shape should be the skeleton with a simplest possible structure that provides a best possible reconstruction of a given shape.To quantify this trade-off,we propose that the skeleton simplicity corresponds to model simplicity in the Bayesian framework,and the shape reconstruction accuracy is expressed as goodness of fit to the data.We also provide a simple algorithm to approximate the maximum of the Bayesian posterior probability which defines an order for iteratively removing the end branches to obtain the pruned skeleton.Presented experimental results obtained without any parameter tuning clearly demonstrate that the resulting skeletons are stable to boundary deformations and intra class shape variability.SHEN Wei BAI Xiang YANG XingWei LATECKI Longin Jan 2013Science China(Information Sciences)2013,56,4:11
9Aberrant DNA methylation in 5′ regions of DNA methyltransferase genes in aborted bovine clones显示文摘High rate of abortion and developmental abnormalities is thought to be closely associated with inefficient epigenetic reprogramming of the transplanted nuclei during bovine cloning. It is known that one of the important mechanisms for epigenetic reprogramming is DNA methylation. DNA methylation is established and maintained by DNA methyltransferases (DNMTs), therefore, it is postulated that the inefficient epigenetic reprogramming of transplanted nuclei may be due to abnormal expression of DNMTs. Since DNA methylation can strongly inhibit gene expression, aberrant DNA methylation of DNMT genes may disturb gene expression. But presently, it is not clear whether the methylation abnormality of DNMT genes is related to developmental failure of somatic cell nuclear transfer embryos. In our study, we analyzed methylation patterns of the 5′ regions of four DNMT genes including Dnmt3a, Dnmt3b, Dnmt1 and Dnmt2 in four aborted bovine clones. Using bisulfite sequencing method, we found that 3 out of 4 aborted bovine clones (AF1, AF2 and AF3) showed either hypermethylation or hypomethylation in the 5′ regions of Dnmt3a and Dnmt3b, indicating that Dnmt3a and Dnmt3b genes are not properly reprogrammed. However, the individual AF4 exhibited similar methylation level and pattern to age-matched in vitro fertilized (IVF) fetuses. Besides, we found that the 5′ regions of Dnmt1 and Dnmt2 were nearly completely unmethylated in all normal adults, IVF fetuses, sperm and aborted clones. Together, our results suggest that the aberrant methylation of Dnmt3a and Dnmt3b 5′ regions is probably associated with the high abortion of bovine clones.Jinghe Liu Xingwei Liang Jiaqiao Zhu Liang Wei Yi Hou Da-Yuan Chen Qing-Yuan Sun 2008Journal of Genetics and Genomics2008,35,9:10
10The HY-2 satellite and its preliminary assessment显示文摘The HY-2 satellite was successfully launched on 16 August 2011.It carried four microwave instruments into space for operationally observing dynamic ocean environment parameters on a global scale.The HY-2 satellite altimeter provides sea surface height(SSH),significant wave height(SWH),sea surface wind(SSW)speed,and polar ice sheet elevation,while the HY-2 satellite scatterometer provides SSW fields.At the same time,other oceanic and atmospheric parameters such as sea surface temperature(SST)and wind speed,water vapor and liquid water content can also be obtained by its onboard scanning microwave radiometer.In this paper,we show the data processing methods of the HY-2 satellite’s payloads.The preliminary results show that wind vector,SSH,SWH,and SST conform to the designed technical specifications.Xingwei Jiang Mingsen Lin Jianqiang Liu Youguang Zhang Xuetong Xie Hailong Peng Wu Zhou 2012International Journal of Digital Earth2012,5,3:10
11Basin modeling in the initial stage of exploration: a case study from the North Subbasin of the South Yellow Sea Basin显示文摘Basin modeling has become an important tool for analyzing sedimentary basins. The North Subbasin of the South Yellow Sea Basin is filled with thick Meso-Cenozoic terrigenous deposits during the rift evolution stage. The accumulation of data and achievements of geological investigations in recent years have provided the preconditions for basin modeling. The necessary parameters and geological elements for simulations are collated and summarized. Modeling of tectono-thermal evolution is performed and the related trend in heat flow is reconstructed and calibrated. The heat flow value commences from an average level of 61 m W/m^2 during MiddleLate Jurassic, rises to about 80 m W/m^2 from circa 145 Ma to circa 74 Ma, and then undergoes a gradual decline to65 m W/m^2 until the end of Oligocene.Three evolutionary phases, namely, the initial rifting phase, syn-rifting phase, and post-rifting phase, have been identified. The modeling results show that the North Subbasin generally enters into a stage of strong rifting during Cretaceous and undergoes rapid subsidence until the Late Cretaceous,then follows by a stage of moderate rifting during the Paleogene. The input and general workflow involved in 3-D modeling are introduced. Reconstruction of the petroleum system in the North Subbasin reveals that the threshold depth of hydrocarbon generation is located near the top of the Paleogene Funing formation, and the underlying Jurassic and Cretaceous source rocks have reached or exceeded peak oil generation and have almost completed the generation and expulsion of hydrocarbons. The main generation and expulsion in the Jurassic source rocks take place during the syn-rifting and post-rifting phases, whereas the peak generation and expulsion in the Cretaceous and Paleogene source rocks take place during the post-rifting phase. Although the study area is still a relatively less explored sedimentary basin, the results of modeling can provide valuable information for exploration. A preliminary discussion of the main uncertainty factors is also presented.PANG Yumao ZHANG Xunhua GUO Xingwei XIAO Guolin HAN Zuozhen 2017Acta Oceanologica Sinica2017,36,9:10
12Photonics-based radar with balanced I/Q de-chirping for interference-suppressed high-resolution detection and imaging显示文摘Photonics-based radar with a photonic de-chirp receiver has the advantages of broadband operation and real-time signal processing, but it suffers from interference from image frequencies and other undesired frequency-mixing components, due to single-channel real-valued photonic frequency mixing. In this paper, we propose a photonicsbased radar with a photonic frequency-doubling transmitter and a balanced in-phase and quadrature(I/Q)de-chirp receiver. This radar transmits broadband linearly frequency-modulated signals generated by photonic frequency doubling and performs I/Q de-chirping of the radar echoes based on a balanced photonic I/Q frequency mixer, which is realized by applying a 90° optical hybrid followed by balanced photodetectors. The proposed radar has a high range resolution because of the large operation bandwidth and achieves interference-free detection by suppressing the image frequencies and other undesired frequency-mixing components. In the experiment, a photonics-based K-band radar with a bandwidth of 8 GHz is demonstrated. The balanced I/Q de-chirping receiver achieves an image-rejection ratio of over 30 dB and successfully eliminates the interference due to the baseband envelope and the frequency mixing between radar echoes of different targets. In addition, the desired dechirped signal power is also enhanced with balanced detection. Based on the established photonics-based radar,inverse synthetic aperture radar imaging is also implemented, through which the advantages of the proposed radar are verified.XINGWEI YE FANGZHENG ZHANG YUE YANG SHILONG PAN 2019Photonics Research2019,7,3:9
13A quantitative approach to monitoring new sand cay migration in Nansha Islands显示文摘Sand cay is a special kind of islet formed by coral detritus and bioclast, which is common in Nansha Islands of China. Some sand cays play an important role in ocean strategy and economy, but surprisingly we know little about them, especially those recently formed sand cays. In this research, we monitor migration of a new sand cay in Nanxun Jiao(Gaven Reef) using a series of Quick Bird and World View-2 satellite images between June 2006 and August 2013. We conduct a regression between migration distance and wind observational data to examine the migration patterns of the new sand cay. The migration distance is calculated based on the sand cay locations extracted based on Normalized Difference Water Index(NDWI). The wind observational data downloaded from NOAA are reformed into four wind direction vectors. Based on the results of regression, we concluded that the migration of the new sand cay on Nanxun Jiao was significantly associated with the east, west and north wind.East wind was the main influence factor of the migration; its impact strength was almost twice as the west and north wind. The south wind has little effect on the migration of the sand cay, which is partly blocked by the artificial structure in the south.ZHU Haitian JIANG Xingwei MENG Xuelian FENG Qian CUI Songxue LIANG Chao 2016Acta Oceanologica Sinica2016,35,3:9
14Phosphate Availability Alters Lateral Root Anatomy and Root Architecture of Fraxinus mandshurica Rupr. Seedlings显示文摘Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition.Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under conditions of low phosphorus availability, the length of cells in the meristem zone of the lateral roots was longer, but the length of cells in the elongation and mature zones of the lateral roots was shorter,compared with seedlings grown under conditions of high phosphorus availability. The elongation rates of primary roots increased as phosphorus availability increased, but the elongation rates of the branched zones of the primary roots decreased. The number of lateral root primordia and the length of the lateral roots decreased as phosphorus availability increased. The topological index (altitude slope) decreased as phosphorus availability increased, suggesting that root architecture tended to be herringbone-like when seedlings were grown under conditions of low phosphate availability. Herringbone-like root systems exploit nutrients more efficiently, but they have higher construction costs than root systems with a branching pattern.ChuWU XingWEI Hai-LongSUN Zheng-QuanWANG 2005Journal of Integrative Plant Biology2005,47,3:7
15Neural network wind retrieval from ERS-1/2 scatterometer data显示文摘A neural network methodology is presented to retrieve wind vectors from ERS-1/2 scatterometer data. The wind directional ambiguities are eliminated by a circular median filter algorithm. All data come from ERS-1/2 scatterometer data collocated pairs with CMCD4 vector. Comparing the results with CMCD4 and ECMWF wind vector,they agree well, which indicates that it is possible to extract wind vector from the ERS1/2 scatterometer with the neural network method.LIN Mingsen SONG Xingai JIANG Xingwei 2006Acta Oceanologica Sinica2006,25,3:7
16Enabling an intrinsically safe and high-energy-density 4.5 V-class Li-ion battery with nonflammable electrolyte显示文摘Developing nonflammable electrolyte with a wide electrochemical window has become an urgent demand for high-energy-density and high-safe lithium-ion batteries(LIBs).Herein,a fluorinated nonflammable phosphate electrolyte is developed to construct a safe 4.5 V-class LIB(Si-SiC-C/0.35Li2MnO3-0.65LiNi0.5Mn0.5O2).The proposed fluorinated phosphate electrolyte,0.8 M LiPF6/tris(2,2,2-trifluoroethyl)phosphate(TFEP)+5 vol%fluoroethylene carbonate(FEC)+5 vol%vinylene carbonate(VC),is not only completely nonflammable but also exhibits excellent oxidative/reductive stability on 0.35Li2MnO30.65LiNi0.5Mn0.5O2 cathode and Si-SiC-C anode.The in situ differential electrochemical mass spectrometry and X-ray photoelectron spectroscopy proved that TFEP-based electrolyte does not decompose into gases but forms a high-quality electrode-electrolyte interface on cathode surface at high working potential.The 4.5 V-class LIBs using 0.8 M LiPF6 TFEP-based nonflammable electrolyte shed some light on potential application for high-safe and low-cost larger-scale energy storage.Ziqi Zeng Xingwei Liu Xiaoyu Jiang Zhenjie Liu Zhangquan Peng Xiangming Feng Weihua Chen Dingguo Xia Xinping Ai Hanxi Yang Yuliang Cao 2020InfoMat2020,2,5:6
17Drogue detection for autonomous aerial refueling based on convolutional neural networks显示文摘Drogue detection is a fundamental issue during the close docking phase of autonomous aerial refueling(AAR). To cope with this issue, a novel and effective method based on deep learning with convolutional neural networks(CNNs) is proposed. In order to ensure its robustness and wide application, a deep learning dataset of images was prepared by utilizing real data of ‘‘Probe and Drogue' aerial refueling, which contains diverse drogues in various environmental conditions without artificial features placed on the drogues. By employing deep learning ideas and graphics processing units(GPUs), a model for drogue detection using a Caffe deep learning framework with CNNs was designed to ensure the method's accuracy and real-time performance. Experiments were conducted to demonstrate the effectiveness of the proposed method, and results based on real AAR data compare its performance to other methods, validating the accuracy, speed, and robustness of its drogue detection ability.Wang Xufeng Dong Xinmin Kong Xingwei Li Jianmin Zhang Bo 2017Chinese Journal of Aeronautics2017,30,1:6
18Safety study of Folfox-HAIC in relieving bed restriction显示文摘Objective:To investigate the safety of relieving bed restriction in hepatic arterial infusion chemotherapy(HAIC)and its effects on patient comfort.Methods:A prospective study was conducted.Patients with malignant liver tumors,who met the enrollment criteria,were randomly divided into experimental and control groups.During HAIC treatment,the patients in the experimental group,who were not confined to bed and could get out of bed,used electronic injection pumps to infuse chemotherapy drugs.The patients in the control group,who were strictly confined to bed and prohibited from getting out of bed,used infusion pumps to infuse chemotherapy drugs.The complications of the two groups were observed.The Christenson standard improved method was used to evaluate the bleeding and hematoma of limbs on the operation side.The Kolcaba General Comfort Questionnaire(GCQ)and Barthel Index(BI)were used to evaluate the two groups.Results:Ninety patients with malignant liver tumors were enrolled,including 53 with primary liver cancer and 37 with colorectal liver metastasis.There were 70 males and 20 females,aged 41-81 years old,with an average age of 61.6±9.248 years old.There were 60 patients in the experimental group and 30 patients in the control group.All patients underwent HAIC.The study showed that,during the treatment period,there were 3 cases of postoperative puncture point hematoma formation in the two groups,including 2 cases in the experimental group(2/60,3.3%)and 1 case in the control group(1/30,3.3%).The difference was not statistically significant(p>0.05).There were 5 cases of postoperative puncture point bleeding,including 4 cases in the experimental group(4/60,6.7%)and 1 case in the control group(1/30,3.3%),and the difference was not statistically significant(p>0.05).A total of 23 cases,with 6 cases in the experimental group(6/60,10%)and 17 cases in the control group(17/30,56.7%),complained of back pain after the operation,and the difference was statistically significant(p<0.05).Twenty-one cases complained of poor defecation after the operation,including 10 cases in the experimental group(10/60,16.7%)and 11 cases in the control group(11/30,36.7%).The difference was statistically significant(p<0.05).During the period of infusion chemotherapy,the two groups of patients had there was a significant difference between the two groups in terms of comfort status(GCQ)(88.78±6.705,78.47±9.519,p<0.001)and self-care ability(BI)(74.25±9.152,66.83±6.628,p<0.001).Conclusion:During HAIC treatment,getting out of bed is safe and reliable and can increase the patients’comfort and self-care ability.Hence,it merits clinical application.Xiaoyun Zhao Xingwei Sun Jian Jing Huimin Zhou Yong Jin 2021Journal of Interventional Medicine2021,4,4:6
19The HY-1 satellite and ground system in China显示文摘INTRODUCTION With the coming of the 21st century, we are faced the problems of the environment, resources and population. The ocean is regarded as supplier of resources such as food, minerals, energy and space, and plays an important role in sustainable economic development. At the same time the ocean has a very important effect on the worldwide environmental changes.Liu Jianqiang , Jiang Xingwei, Lin Mingsen National Satellite Ocean Application Service of State Oceanic Administration, Beijing 100081, China, 2003Acta Oceanologica Sinica2003,22,2:6
20Draft genome sequence of cauliflower(Brassica oleracea L.var.botrytis)provides new insights into the C genome in Brassica species显示文摘Cauliflower is an important variety of Brassica oleracea and is planted worldwide.Here,the high-quality genome sequence of cauliflower was reported.The assembled cauliflower genome was 584.60 Mb in size,with a contig N50 of 2.11 Mb,and contained 47,772 genes;56.65%of the genome was composed of repetitive sequences.Among these sequences,long terminal repeats(LTRs)were the most abundant(32.71%of the genome),followed by transposable elements(TEs)(12.62%).Comparative genomic analysis confirmed that after an ancient paleohexaploidy(γ)event,cauliflower underwent two whole-genome duplication(WGD)events shared with Arabidopsis and an additional whole-genome triplication(WGT)event shared with other Brassica species.The present cultivated cauliflower diverged from the ancestral B.oleracea species~3.0 million years ago(Mya).The speciation of cauliflower(~2.0 Mya)was later than that of B.oleracea L.var.capitata(approximately 2.6 Mya)and other Brassica species(over 2.0 Mya).Chromosome no.03 of cauliflower shared the most syntenic blocks with the A,B,and C genomes of Brassica species and its eight other chromosomes,implying that chromosome no.03 might be the most ancient one in the cauliflower genome,which was consistent with the chromosome being inherited from the common ancestor of Brassica species.In addition,2,718 specific genes,228 expanded genes,2 contracted genes,and 1,065 positively selected genes in cauliflower were identified and functionally annotated.These findings provide new insights into the genomic diversity of Brassica species and serve as a valuable reference for molecular breeding of cauliflower.Deling Sun Chunguo Wang Xiaoli Zhang Wenlin Zhang Hanmin Jiang Xingwei Yao Lili Liu Zhenghua Wen Guobao Niu Xiaozheng Shan 2019Horticulture Research2019,6,1:6
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