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191篇 您的检索式:作者名="Xiaofeng Zheng"
    题名 作者 年代 出处 被引量
1A Review of Modular Multilevel Converters显示文摘模块组合多电平变换器(modular multilevel converter,MMC)具有高度模块化、易于扩展、输出电压波形好等特点,尤其适用于中高压大功率系统应用。首先介绍MMC的电路拓扑和工作原理,总结MMC的主要技术特点;然后分别回顾MMC在脉冲调制、直流电压控制、预充电、环流、谐波、数学模型、主电路参数设计、故障保护等关键问题的最新研究进展,以及其在电力传动、电能质量问题治理领域的工程应用现状,在此基础上指出MMC今后亟待研究的关键问题。相关研究结果表明,MMC在电力系统中有广泛的应用前景,是未来中高压大功率系统,尤其是高压输电技术的重要发展方向。YANG Xiaofeng LIN Zhiqin ZHENG Trillion Q. YOU Xiaojie 2013中国电机工程学报2013,33,6:99
2Towards 6G wireless communication networks:vision,enabling technologies,and new paradigm shifts显示文摘The fifth generation(5G)wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized,such as mass connectivity,ultra-reliability,and guaranteed low latency.However,5G will not meet all requirements of the future in 2030 and beyond,and sixth generation(6G)wireless communication networks are expected to provide global coverage,enhanced spectral/energy/cost efficiency,better intelligence level and security,etc.To meet these requirements,6G networks will rely on new enabling technologies,i.e.,air interface and transmission technologies and novel network architecture,such as waveform design,multiple access,channel coding schemes,multi-antenna technologies,network slicing,cell-free architecture,and cloud/fog/edge computing.Our vision on 6G is that it will have four new paradigm shifts.First,to satisfy the requirement of global coverage,6G will not be limited to terrestrial communication networks,which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle(UAV)communication networks,thus achieving a space-airground-sea integrated communication network.Second,all spectra will be fully explored to further increase data rates and connection density,including the sub-6GHz,millimeter wave(mmWave),terahertz(THz),and optical frequency bands.Third,facing the big datasets generated by the use of extremely heterogeneous networks,diverse communication scenarios,large numbers of antennas,wide bandwidths,and new service requirements,6G networks will enable a new range of smart applications with the aid of artificial intelligence(AI)and big data technologies.Fourth,network security will have to be strengthened when developing 6G networks.This article provides a comprehensive survey of recent advances and future trends in these four aspects.Clearly,6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.Xiaohu YOU Cheng-Xiang WANG Jie HUANG Xiqi GAO Zaichen ZHANG Mao WANG Yongming HUANG Chuan ZHANG Yanxiang JIANG Jiaheng WANG Min ZHU Bin SHENG Dongming WANG Zhiwen PAN Pengcheng ZHU Yang YANG Zening LIU Ping ZHANG Xiaofeng TAO Shaoqian LI Zhi CHEN Xinying MA Chih-Lin I Shuangfeng HAN Ke LI Chengkang PAN Zhimin ZHENG Lajos HANZO Xuemin(Sherman)SHEN Yingjie Jay GUO Zhiguo DING Harald HAAS Wen TONG Peiying ZHU Ganghua YANG Jun WANG Erik GLARSSON Hien Quoc NGO Wei HONG Haiming WANG Debin HOU Jixin CHEN Zhe CHEN Zhangcheng HAO Geoffrey Ye LI Rahim TAFAZOLLI Yue GAO HVincent POOR Gerhard P.FETTWEIS Ying-Chang LIANG 2021Science China(Information Sciences)2021,64,1:122
3Deep-learning-based information mining from ocean remote-sensing imagery显示文摘With the continuous development of space and sensor technologies during the last 40 years,ocean remote sensing has entered into the big-data era with typical five-V(volume,variety,value,velocity and veracity)characteristics.Ocean remote-sensing data archives reach several tens of petabytes and massive satellite data are acquired worldwide daily.To precisely,efficiently and intelligently mine the useful information submerged in such ocean remote-sensing data sets is a big challenge.Deep learning-a powerful technology recently emerging in the machine-learning field-has demonstrated its more significant superiority over traditional physical-or statistical-based algorithms for image-information extraction in many industrial-field applications and starts to draw interest in ocean remote-sensing applications.In this review paper,we first systematically reviewed two deep-learning frameworks that carry out ocean remote-sensing-image classifications and then presented eight typical applications in ocean internal-wave/eddy/oil-spill/coastal-inundation/sea-ice/green-algae/ship/coral-reef mapping from different types of ocean remote-sensing imagery to show how effective these deep-learning frameworks are.Researchers can also readily modify these existing frameworks for information mining of other kinds of remote-sensing imagery.Xiaofeng Li Bin Liu Gang Zheng Yibin Ren Shuangshang Zhang Yingjie Liu Le Gao Yuhai Liu Bin Zhang Fan Wang 2020National Science Review2020,7,10:19
4N6-Methyladenine DNA Methylation in Japonica and Indica Rice Genomes and Its Association with Gene Expression,Plant Development, and Stress Responses显示文摘N6-Methyladenine (6mA)DNA methylation has recently been implicated as a potential new epigenetic marker in eukaryotes,including the dioot modelArabidopsis thaliana.However,the conservation and divergence of 6mA distribution patterns and functions in plants remain elusive.Here we report high-quality 6mA methylomes at single-nucleotide resolution in rice based on substantially improved genome sequences of two rice cultivars,Nipponbare (Nip;Japonica)and 93-11 (Indica).Analysis of 6mA genomic distribution and its association with transcription suggest that 6mA distribution and function is rather conserved between rice and Arabidopsis.We found that 6mA levels are positively correlated with the expression of key stressrelated genes,which may be responsible for the difference in stress tolerance between Nip and 93-11. Moreover,we showed that mutations in DDM1 cause defects in plant growth and decreased 6mA level. Our results reveal that 6mA is a conserved DNA modification that is positively associated with gene expression and contributes to key agronomic traits in plants.Qian Zhang Zhe Liang Xuean Cui Changmian Ji Yun Li Pingxian Zhang Jingrong Liu Adeel Riaz Pu Yao Min Liu Yunpeng Wang Tiegang Lu Hao Yu Donglei Yang Hongkun Zheng Xiaofeng Gu 2018Molecular Plant2018,11,12:18
5Human monoclonal antibodies block the binding of SARS-CoV-2 spike protein to angiotensin converting enzyme 2 receptor显示文摘According to the World Health Organization(WHO)newly updated situation report on March 18th,2020,the coronavirus disease 2019(COVID-19)pandemic has confirmed 191,127 cases and claimed 7807 deaths worldwide.1 The etiological agent of COVID-19 has been identified as a novel coronavirus,the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),belonging to Sarbecovirus subgenus(genus Betacoronavirus,family Coronaviridae)and showing 79.6 and 96.2%sequence identity in nucleotide to SARS-CoV and a bat coronavirus(BatCoV RaTG13),respectively.2–4 Like SARS-CoV infection,a substantial fraction of COVID-19 patients exhibits severe respiratory symptoms and has to be hospitalized in intensive care unit.5–8 Although the mortality rate of COVID-19 is significantly lower than that of SARS-CoV infection,SARS-CoV-2 shows much higher human-to-human transmission rate,rapidly leading to a global pandemic declared by WHO on March 11th,2020.Xiangyu Chen Ren Li Zhiwei Pan Chunfang Qian Yang Yang Renrong You Jing Zhao Pinghuang Liu Leiqiong Gao Zhirong Li Qizhao Huang Lifan Xu Jianfang Tang Qin Tian Wei Yao Li Hu Xiaofeng Yan Xinyuan Zhou Yuzhang Wu Kai Deng Zheng Zhang Zhaohui Qian Yaokai Chen Lilin Ye 2020Cellular & Molecular Immunology2020,17,6:17
6Thermal fatigue behavior of K465 superalloy显示文摘The thermal fatigue behavior of K465 superalloy was investigated at the peak temperature of 1050°C. By scan-ning electron microscopy (SEM) and optical microscopy, the main crack length was observed and measured. The initiation sites of the tested alloys are different in as-cast (named as K465) and solution heat treatment (named as SK465) conditions. In K465 alloy, most thermal fatigue cracks nucleate at (Nb,W,Ti)C carbides. In SK465 alloy, thermal fatigue cracks initiate in interdendritic regions, MC-type carbides and some interfaces. Thermal fatigue cracks propagate in transdendritic mode, and M6C-type carbides could retard thermal fatigue crack growth for SK465 superalloy.YANG Jinxia ZHENG Qi SUN Xiaofeng GUAN Hengrong HU Zhuangqi 2006Rare Metals2006,25,3:15
7Laser performance of the SG-Ⅲ laser facility显示文摘SG-Ⅲ laser facility is now the largest laser driver for inertial confinement fusion research in China. The whole laser facility can deliver 180 kJ energy and 60 TW power ultraviolet laser onto target, with power balance better than 10%.We review the laser system and introduce the SG-Ⅲ laser performance here.Wanguo Zheng Xiaofeng Wei Qihua Zhu Feng Jing Dongxia Hu Jingqin Su Kuixing Zheng Xiaodong Yuan Hai Zhou Wanjun Dai Wei Zhou Fang Wang Dangpeng Xu Xudong Xie Bin Feng Zhitao Peng Liangfu Guo Yuanbin Chen Xiongjun Zhang Lanqin Liu Donghui Lin Zhao Dang Yong Xiang Xuewei Deng 2016High Power Laser Science and Engineering2016,4,3:13
8TALEN-based generation of a cynomolgus monkey disease model for human microcephaly显示文摘基因在非人类的首领编辑可以为在人探索病原学和遗传上基于的神经病学的混乱的治疗学的策略导致珍贵模型。然而,仔细在人模仿病理学、行为的赤字的神经病学的混乱的一个猴子模型成功地还没被产生了。Microcephalin 1 (MCPH1 ) 在人的大脑,和智力迟钝伴随的 MCPH1 变化原因头小畸型的进化被含有。这里,我们产生了用抄写带 biallelic MCPH1 变化的一只 cynomolgus 猴子(Macaca fascicularis ) 像使活跃之物的受动器核酸酶。猴子概括了大多数在病人观察的重要临床的特征,包括在头圆周,早熟的染色体冷凝作用(PCC ) ,语料库 callosum 的发育不全和上面的手足 spasticity 的显著减小。而且,在变异的真皮的成纤维细胞的 MCPH1 的 overexpression 救了 PCC 症候群。这个猴子模型可以帮助我们阐明在人的头小畸型并且更好的致病的 MCPH1 的角色在首领大脑尺寸的进化理解这蛋白质的功能。Qiong Ke Weiqiang Li Xingqiang Lai Hong Chen Lihua Huang Zhuang Kang Kai Li Jie Ren Xiaofeng Lin Haiqing Zheng Weijun Huang Yunhan Ma Dongdong Xu Zheng Chen Xinming Song Xinyi Lin Min Zhuang Tao Wang Fengfeng Zhuang Jianzhong Xi Frank Fuxiang Mao Huimin Xia Bruce T Lahn Qi Zhou Shihua Yang Andy Peng Xiang 2016Cell Research2016,26,9:13
9Light scattering and surface plasmons on small spherical particles显示文摘Light scattering by small particles has a long and interesting history in physics.Nonetheless,it continues to surprise with new insights and applications.This includes new discoveries,such as novel plasmonic effects,as well as exciting theoretical and experimental developments such as optical trapping,anomalous light scattering,optical tweezers,nanospasers,and novel aspects and realizations of Fano resonances.These have led to important new applications,including several ones in the biomedical area and in sensing techniques at the single-molecule level.There are additionally many potential future applications in optical devices and solar energy technologies.Here we review the fundamental aspects of light scattering by small spherical particles,emphasizing the phenomenological treatments and new developments in this field.Xiaofeng Fan Weitao Zheng David J Singh 2014Light(Science & Applications)2014,3,1:13
10Laser performance upgrade for precise ICF experiment in SG-Ⅲ laser facility显示文摘The SG-Ⅲlaser facility(SG-Ⅲ)is the largest laser driver for inertial confinement fusion(ICF)researches in China,which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns.In order to meet the requirements of precise physics experiments,some new functionalities need to be added to SG-Ⅲand some intrinsic laser performances need upgrade.So at the end of SG-Ⅲ's engineering construction,the 2-year laser performance upgrade project started.This paper will introduce the newly added functionalities and the latest laser performance of SG-Ⅲ.With these function extensions and performance upgrade,SG-Ⅲis now fully prepared for precise ICF experiments and solidly paves the way towards fusion ignition.Wanguo Zheng Xiaofeng Wei Qihua Zhu Feng Jing Dongxia Hu Xiaodong Yuan Wanjun Dai Wei Zhou Fang Wang Dangpeng Xu Xudong Xie Bin Feng Zhitao Peng Liangfu Guo Yuanbin Chen Xiongjun Zhang Lanqin Liu Donghui Lin Zhao Dang Yong Xiang Rui Zhang Fang Wang Huaiting Jia Xuewei Deng 2017Matter and Radiation at Extremes2017,2,5:13
11Neuroprotective effects of Ginkgo biloba extract and GinkgoUde B against oxygen-glucose deprivation/reoxygenation and glucose injury in a new in vitro multicellular network model显示文摘Xiaohan Yang Tiezheng Zheng Hao Hong Nan Cai Xiaofeng Zhou Changkai Sun Liying Wu Shuhong Liu Yongqi Zhao Lingling Zhu Ming Fan Xuezhong Zhou Fengxie Jin 2018Frontiers of Medicine2018,12,3:12
12Characteristics of strike-slip inversion structures of the Karatau fault and their petroleum geological significances in the South Turgay Basin,Kazakhstan显示文摘The Karatau fault is one of the important strike-slip faults in central Asia,and the South Turgay Basin is located towards its northern end.Detailed seismic interpretation indicated that the strikeslip tectonism of the Karatau fault weakened gradually from west to east in the South Turgay Basin.Typical flower structures developed on the section,and strike-slip faults showed an echelon pattern on planar view.The Karatau strike-slip fault affected the South Turgay Basin in two periods:(1) The South Turgay strike-slip pull-apart rift basin formed as a result of regional extensive stress in the Early-Middle Jurassic,characterized by the juxtaposition of horsts and grabens.The formation of horsts provided favorable reservoir spaces for later hydrocarbon accumulation,and different filling stages of grabens controlled different reservoir-forming factors in grabens.(2) Two stages of tectonic inversion occurred in the Late Jurassic and Late Cretaceous and played a crucial role in the final shape of the structure in the South Turgay Basin.The oil and gas migrated to form reservoirs and mainly concentrated in the horsts,graben slopes and in both sides of the strike-slip fault zone.In the case of the degree of accumulation of petroleum,the factor explaining why horsts are better than grabens is the strike-slip pull-apart of the South Turgay Basin,and the structure inversion of the South Turgay Basin explains why the west graben is better than the east one.Overall,the Karatau strike-slip fault played a very important role in the formation of the South Turgay Basin and its hydrocarbon accumulations.Yin Wei Fan Zifei Zheng Junzhang Yin Jiquan Zhang Mingjun Sheng Xiaofeng Guo Jianjun Li Qiyan Lin yaping 2012Petroleum Science2012,9,4:11
13Low-mature gases and typical low-mature gas fields in China显示文摘No natural gas pool of industrial importance could be formed at the low-evolution stage of organic matter. In the 1980s, on the basis of the development in exploration practice, the hypotheses of bio-thermo-catalytic transitional zone gases and early thermogenic gases were proposed. The lower-limit Ro values for the formation and accumulation of natural gases of industrial importance have been expanded to 0.3%―0.4%. In the light of the two-stage model established on the basis of carbon isotope fractionation in coal-type natural gases, the upper-limit Ro values have been set at 0.8%―1.0%. In terms of the geological practice in the low-mature gas zones and China's main coal-type gas fields, it is feasible and proper to set the upper-limit Ro value of low-mature gases at 0.8%. Supper-large gas fields such as the Urengoy gas field in western Siberian Basin should belong to low-mature gas fields, of which the natural gas reserves account for more than 20% of the global proven reserves, providing strong evidence for the significance of such a type of resources. The proven natural gas reserves in the Turpan-Hami Basin of China have almost reached 1000 × 108 m3. The main source rocks in this area are the Jurassic Xishanyao Formation, which occurs as a suite of coal series strata. The corresponding thermal evolution indices (Ro ) are mainly within the range of about 0.4%―0.8%, the δ 13C1 values of methane vary between-44‰ and-39‰ (correspondingly Ro =0.6%―0.8%), and those of ethane are within the range of-29‰―-26‰, indicating that natural gases in the Turpan-Hami Basin should be designated to coal-type low-mature gases. The light hydrocarbon evolution indices of natural gases also fall within the area of low evolution while the precursor type of light hydrocarbons also shows the characteristics of the coal-type. The geological background, carbon isotopic composition and light hydrocarbon index all provide strong evidence suggesting that the proven natural gases in the Turpan-Hami Basin are low-mature gases. In China a gas field with the gas reserves reaching 300 ×108 m3 can be defined as a large gas field, and thus the proven low-mature gases in the Turpan-Hami Basin are equivalent to the reserves of three large gas fields. Its existence is of great significance in research on and exploration of low-mature gases in China.XU YongChang WANG ZhiYong WANG XiaoFeng ZHENG JianJing DU HongYu 2008Science China Earth Sciences2008,51,2:11
14Identification of botanical origin of Chinese unifloral honeys by free amino acid profiles and chemometric methods显示文摘The amino acid contents of five floral sources Chinese honeys(jujube, rape, chaste, acacia, and lungan) were measured using reversed phase high-performance liquid chromatography(RP-HPLC). The results showed that proline was the main amino acid in most of the analyzed samples. Phenylalanine presents at the highest content in chaste honey samples, and the total amino acid contents of chaste honeys were also significantly higher than those of other honey samples. Based on the amino acid contents, honey samples were classified using chemometric methods(cluster analysis(CA), principal component analysis(PCA), and discriminant analysis(DA)). According to the CA results, chaste honeys could be separated from other honeys, while the remaining samples were correctly grouped together when the chaste honey data were excluded. By using DA, the overall correct classification rate reached 100%. The results revealed that amino acid contents could potentially be used as indicators to identify the botanical origin of unifloral honeys.Zheng Sun Lingling Zhao Ni Cheng Xiaofeng Xue Liming Wu Jianbin Zheng Wei Cao 2017Journal of Pharmaceutical Analysis2017,7,5:9
15Experimental investigations on the power extraction of a turbine driven by a pulse detonation combustor显示文摘In order to grasp the interaction mechanism between the pulse detonation combustor(PDC)and the turbine,the experimental work in this paper investigates the key factors on the power extraction of a turbocharger turbine driven by a PDC.A PDC consisting of an unvalved tube is integrated with a turbocharger turbine which has a nominal mass flow rate of 0.6 kg/s and50000 r/min.The PDC–turbine hybrid engine is operated on gasoline-air mixtures and runs for6+min to achieve a thermal steady state,and then the engine performance is evaluated under different operating conditions.Results show that the momentum difference per unit area between the turbine inlet and outlet plays an important role in the power extraction,while the pressure peak of the detonation has little effect.The equivalence ratio of fuel and air mixture and the transition structure between PDC and turbine are also important to the power extraction of the turbine.The present work is promising as it suggests that the performance beneft of a PDC–turbine hybrid engine can be realized by increasing the momentum difference per unit area through the optimal design of transition section between the PDC and turbine.Li Xiaofeng Zheng Longxi Qiu Hua Chen Jingbin 2013Chinese Journal of Aeronautics2013,26,6:9
16A Novel Square-wave Pulse Rotation Modulation Strategy for Modular Multilevel Converters显示文摘悬浮直流电容电压的均衡问题是模块组合多电平变换器(modular multilevel converter,MMC)的关键问题之一。提出一种可实现MMC直流电容电压平衡的方波脉冲循环调制(square-wave pulse rotation modulation,SWPRM)策略,在保证合成的阶梯波输出波形不变的前提下,根据MMC的拓扑结构和工作原理,对传统方波脉冲列进行脉冲优化,并按照一定的次序和切换周期进行循环和判断反相调整,获得的循环方波脉冲列作为最终驱动脉冲用于实现对MMC的控制。实验结果表明,采用提出的方波脉冲循环调制策略无需任何电容电压控制措施,在较低开关频率下,实现了MMC各功率单元间有功能量的平均分配和直流电容电压的均衡。YANG Xiaofeng LIN Zhiqin ZHENG Trillion Q YOU Xiaojie 2013中国电机工程学报2013,33,9:9
17Myelin protein zero and its antibody in serum as biomarkers of n-hexane-induced peripheral neuropathy and neurotoxicity effects显示文摘Jia Xiaowei Liu Qingjun Zhang Yanshu Dai Yufei Duan Huawei Bin Ping Niu Yong Liu Jie Zhong Liuzhen Guo Jisheng Liu Xiaofeng Zheng Yuxin 2014Chinese Medical Journal2014,,8:8
18Diagenesis and Metamorphism of Triassic Flysch Along Profile Zoige-Lushan,Northwest Sichuan,China显示文摘We used iilite and chlorite crystallinities,index minerals,mineral assemblages,polytype and domain size of white mica,electron microprobe analysis(EMPA),b_0 geobarometer and chlorite geothermometer to quantify the diagenetic and metamorphic overprint on the Triassic flysch formations in the Songpan-Garzêorogen along profile Zoigê-Lushan,northwest Sichuan.Two anchizones,two epizones,one diagenetic zone and a transition belt in-between them are defined on the basis of the obtained data.Illite crystallinity correlates strongly with the best mean domain size of mica and moderately with chlorite crystallinity.2M_1 white mica polytype are observed within the epizone whilst 2M_1 and 1M polytypes occur in the anchizone and diagenetic zone.Epizonal metamorphism reached maximum temperatures of 370℃±21℃at low-to intermediate pressure conditions.Clay minerals underwent Ostwald ripening during metamorphism.Rocks from both sides of the Longmenshan fault reveal contrasting degrees of metamorphic overprint:on the northwest side of the Longmenshan fault,epimetamorphic conditions contrast with diagenetic rocks on the southeast side.WANG Hejing M. RAHN TAO Xiaofeng ZHENG Nan XU Tingjing 2008Acta Geologica Sinica(English Edition)2008,82,4:7
19Overactive bladder symptom score to evaluate efficacy of solifenacin for the treatment of overactive bladder symptoms显示文摘Liu Ming Wang Jianye Yang Yong An Ruihua Wen Jianguo Guan Zhichen Zheng Shaobin Wang Dongwen Song Bo Liao Limin Guo Hongqian Xiao Jiaquan Sun Yinghao Shen Zhoujun Kong Chuize He Dalin Huang Yiran Wang Xiaofeng Zhang Xu Li Hanzhong Huang Jian Zhao Xiaokun Zeng Puqing Song Xishuang Ye Zhangqun 2014Chinese Medical Journal2014,,2:7
20Epidemiological serosurvey of Hepatitis B in China—Declining HBV prevalence due to Hepatitis B vaccination显示文摘Xiaofeng Liang Shengli Bi Weizhong Yang Longde Wang Gang Cui Fuqiang Cui Yong Zhang Jianhua Liu Xiaohong Gong Yuansheng Chen Fuzhen Wang Hui Zheng Feng Wang Jing Guo Zhiyuan Jia Jingchen Ma Huaqing Wang Huiming Luo Li Li Shuigao Jin Stephen C. Hadler Yu W 2009Vaccine2009,,47:7
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