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| 1 | Magnetohydrodynamics (MHD) numerical simulations on the interaction of the solar wind with the magnetosphere: A review显示文摘The magnetosphere is the outermost layer of the geospace, and the interaction of the solar wind with the magnetosphere is the key element of the space weather cause-and-effect chain process from the Sun to Earth, which is one of the most challenging scientific problems in the geospace weather study. The nonlinearity, multiple component, and time-dependent nature of the geospace make it very difficult to describe the physical process in geospace using traditional analytic analysis approach. Numerical simulations, a new research tool developed in recent decades, have a deep impact on the theory and application of the geospace. MHD simulations started at the end of the 1970s, and the initial study was limited to two-dimensional (2D) cases. Due to the intrinsic three-dimensional (3D) characteristics of the geospace, 3D MHD simulations emerged in the 1980s, in an attempt to model the large-scale structures and fundamental physical processes in the magnetosphere. They started to combine with the space exploration missions in the 1990s and make comparisons with observations. Physics-based space weather forecast models started to be developed in the 21st century. Currently only a few space-power countries such as USA and Japan have developed 3D magnetospheric MHD models. With the rapid advance of space science in China, we have developed a new global MHD model, namely PPMLR-MHD, which has high order spatial accuracy and low numerical dissipation. In this review, we will briefly introduce the global 3D MHD modeling, especially the PPMLR-MHD code, and summarize our recent work based on the PPMLR-MHD model, with an emphasis on the interaction of interplanetary shocks with the magnetosphere, large-scale current systems, reconnection voltage and transpolar potential drop, and Kelvin-Helmholtz (K-H) instability at the magnetopause. | WANG Chi GUO XiaoCheng PENG Zhong TANG BinBin SUN TianRan LI WenYa HU YouQiu | 2013 | Science China Earth Sciences2013，56，7： | 10 |
| 2 | Minimum Structural Similarity Distortion for Reversible Data Hiding显示文摘Until now, most Reversible data hiding(RDH) techniques have been evaluated by Peak signal-tonoise ratio(PSNR), which based on Mean squared error(MSE). Unfortunately, MSE turns out to be an extremely poor measure when the purpose is to predict perceived signal fidelity or quality. The Structural similarity(SSIM)index has gained widespread popularity as an alternative motivating principle for the design of image quality measures. How to utilize the characterize of SSIM to design RDH algorithm is very critical. We propose an optimal RDH algorithm under structural similarity constraint. We deduce the metric of the structural similarity constraint,and further we prove it does not hold Non-crossing-edges(NCE) property. We construct the rate-distortion function of optimal structural similarity constraint, which is equivalent to minimize the average distortion for a given embedding rate, and then we can obtain the optimal transition probability matrix under the structural similarity constraint. Experiments show that our proposed method can be used to improve the performance of previous RDH schemes evaluated by SSIM. | XU Jiajia ZHANG Weiming JIANG Ruiqi YU Nenghai HU Xiaocheng | 2018 | Chinese Journal of Electronics2018，27，3： | 2 |
| 3 | Multivariate similarity clustering analysis:a new method regarding biogeography and its application in global insects显示文摘A new method,multivariate similarity clustering analysis(MSCA)method,was established for biogeographical distribution analyzing.General similarity formula(GSF),the core of MSCA method,can be used to calculate the similarity coefficients between 2 and among any≥3 geographical units.Taking the global insects as example,we introduced the steps to use of GSF and consequent clustering processes of this method in details.Firstly,geographical distributions of certain taxa(e.g.Insecta)were categorized into basic geographical units(BGUs);Secondly,similarity coefficients between 2 and among n BGUs were calculated using GSF.Thirdly,hierarchical clustering was conducted according to values of similarity coefficients(from high to low);then a clustering diagram was generated.Finally,a framework of biogeographical division map was established for the target taxa(e.g.Insecta).We concluded that the MSCA method was efficiently applied in analyzing the biogeographical distribution of given biological taxa;the geographical regions regarding global insects were categorized into 7 Realms with 20 sub-Realms based on the results of MSCA method. | Xiaocheng SHEN Shujie ZHANG Qi SHEN Guilin HU Jiqi LU | 2021 | Integrative Zoology2021，16，3： | 2 |
| 4 | Joint observation results of Na layer and ionosphere in Wuhan during the Total Solar Eclipse显示文摘During the total solar eclipse on July 22, 2009 in Wuhan, the joint observation test of Na layer and ionosphere was conducted by using the daytime observation atmospheric lidar and the GPS ionosphere detector. The results show that the full width at half maximum(FWHM) of Na layer density slightly narrowed during the total solar eclipse and broadened after the eclipse, while the height of Na peak slightly decreased in the eclipse and increased after the eclipse. These implying that Na layer changes reflect the rapid process of sunrise and sunset. The ionosphere total electron content(TEC) and the sky background light noise also presented an obvious fluctuation characteristic with the changes of solar irradiation during the process of total solar eclipse. The difference lies in that the changes of FWHM of Na layer atoms are much slower than that of ionosphere, the reason for this might be that the Na layer, after being disturbed by the total solar eclipse, will generate a series of complicated photochemical reactions and momentum transport processes, and then recombine the Na atoms. The Na atoms to be detected by the lidar need a lag process, which rightly conforms to the theoretical simulated results. | CHENG XueWu YANG Yong WANG ZeLong LI FaQuan YANG GuoTao ZHAO ZhengYu GONG Wei WANG JiHong HU Xiong LIN Xin WU XiaoCheng SONG ShaLei GONG ShunSheng | 2016 | Science China Earth Sciences2016，59，2： | 1 |
| 5 | Effects of estimating the ionospheric and thermospheric parameters on electron density forecasts显示文摘Based on the thermosphere-Ionosphere-Electrodynamics General Circulation Model(TIEGCM), a thermosphericionospheric data assimilation and forecast system is developed. Using this system, we estimated the oxygen ions, neutral temperature, wind, and composition by assimilating the simulated data from Formosa Satellite 3/Constellation Observing System for Meteorology, Ionosphere, and Climate(COSMIC) occultation electron density profiles to evaluate their effects on the ionospheric forecast. An ensemble Kalman filter data assimilation scheme and combined state and parameter estimation methods are used to estimate the unobserved parameters in the model. The statistical results show that the neutral and ion compositions are more effective than the neutral temperature and wind for improving the forecast of the ionospheric electron density, whose root mean square errors in the assimilation period decreased by approximately 40%, 30%, and 10% due to the estimations of the neutral composition, oxygen ions, and neutral temperature, respectively. Due to the different physical and chemical processes that these parameters primarily affect, their e-folding times differ greatly from longer than 12 h for neutral composition to approximately 6 h for oxygen ions and 3 h for neutral temperature. The effect of estimating the neutral composition on improving the ionospheric forecast is greater than that of estimating the oxygen ions, which can be also be seen in an actual data assimilation experiment. This indicates that the neutral composition is the most important thermospheric parameter in ionospheric data assimilations and forecasts. | Yanan ZHANG Xiaocheng WU Xiong HU | 2018 | Science China Earth Sciences2018，61，12： | 1 |
| 6 | Analysis of inversion errors of ionospheric radio occultation显示文摘 | Xiaocheng Wu Xiong Hu Xiaoyan Gong Xunxie Zhang Xin Wang | 2009 | GPS Solutions2009，，3： | 1 |
| 7 | The Solar Upper Transition Region Imager(SUTRI)Onboard the SATech-01 Satellite显示文摘The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections. | Xianyong Bai Hui Tian Yuanyong Deng Zhanshan Wang Jianfeng Yang Xiaofeng Zhang Yonghe Zhang Runze Qi Nange Wang Yang Gao Jun Yu Chunling He Zhengxiang Shen Lun Shen Song Guo Zhenyong Hou Kaifan Ji Xingzi Bi Wei Duan Xiao Yang Jiaben Lin Ziyao Hu Qian Song Zihao Yang Yajie Chen Weidong Qiao Wei Ge Fu Li Lei Jin Jiawei He Xiaobo Chen Xiaocheng Zhu Junwang He Qi Shi Liu Liu Jinsong Li Dongxiao Xu Rui Liu Taijie Li Zhenggong Feng Yamin Wang Chengcheng Fan Shuo Liu Sifan Guo Zheng Sun Yuchuan Wu Haiyu Li Qi Yang Yuyang Ye Weichen Gu Jiali Wu Zhe Zhang Yue Yu Zeyi Ye Pengfeng Sheng Yifan Wang Wenbin Li Qiushi Huang Zhong Zhang | 2023 | Research in Astronomy and Astrophysics2023，23，6： | 1 |
| 8 | Aspirin reduces the apoptotic effect of etoposide via Akt activationand up-regulation of p21cip显示文摘 | Xiaocheng Feng Bin Lu Yingying Xu Qin Li Wenbai Zhou Zhihong Yang Zeng Yang Weiwei Zhao Zonghou Shen Renming Hu | 2011 | International Journal of Molecular Medicine2011，，4： | 1 |
| 9 | Rhesus monkeys exhibiting spontaneous ritualistic behaviors resembling obsessive-compulsive disorder显示文摘Obsessive-compulsive disorder(OCD)is a chronic and debilitating psychiatric disorder that affects∼2%–3%of the population globally.Studying spontaneous OCD-like behaviors in non-human primates may improve our understanding of the disorder.In large rhesus monkey colonies,we found 10 monkeys spontaneously exhibiting persistent sequential motor behaviors(SMBs)in individual-specific sequences that were repetitive,time-consuming and stable over prolonged periods.Genetic analysis revealed severely damaging mutations in genes associated with OCD risk in humans.Brain imaging showed that monkeys with SMBs had larger gray matter(GM)volumes in the left caudate nucleus and lower fractional anisotropy of the corpus callosum.The GM volume of the left caudate nucleus correlated positively with the daily duration of SMBs.Notably,exposure to a stressor(human presence)significantly increased SMBs.In addition,fluoxetine,a serotonergic medication commonly used for OCD,decreased SMBs in these monkeys.These findings provide a novel foundation for developing better understanding and treatment of OCD. | Rongwei Zhai Geya Tong Zheqin Li Weichen Song Yang Hu Sha Xu Qiqi Wei Xiaocheng Zhang Yi Li Bingbing Liao Chenyu Yuan Yinqing Fan Ge Song Yinyin Ouyang Wenxuan Zhang Yaqiu Tang Minghui Jin Yuxian Zhang He Li Zhi Yang Guan Ning Lin Dan JStein Zhi-Qi Xiong Zhen Wang | 2023 | National Science Review2023，10，11： | 1 |
| 10 | Bevacizumab in the Treatment of Pterygium: A Meta-Analysis显示文摘 | Qiongwen Hu Yanbing Qiao Xin Nie Xiaocheng Cheng Yongping Ma | 2014 | Cornea2014，，2： | 1 |
| 11 | Recursive histo- gram modification: establishing equivalency between reversible data hiding and lossless data compression 显示文摘 | Zhang Weiming Hu Xiaocheng Li Xiaolong | 2013 | IEEE Trans on Image Processing2013，22，7： | 1 |
| 12 | Inclusion Size Effect on Mechanical Properties of Particle Hydrogel Composite显示文摘Particle hydrogel composite(PHC)combines the characteristics of at least two mat erials and has pot ential applications in many fields.Different functions require the particle size to range from nanometer to millimeter,which has a noticeable effect on the mechanical properties of the hydrogel composites.In this paper,the mechanical properties of silica-inlaid PAAM hydrogel are measured with various particle diameters from 75 nm to 50|im.Experimental results show no obvious size effect on the mechanical properties of PHC when the particle diameter falls in micron scale.However,as the particle size decreases to nanoscale,the modulus of the PHC begins to increase rapidly.The size-irrelevant moduli and stress fields of PHCs with random and uniform particle distributions under different loading conditions are obtained based on the finite element method.Meanwhile,the toughening mechanism and the failure of the PHC are investigated.The size-irrelevant modulus of the PHC is also predicted by the equivalent inclusion theory.Finally,the interaction between the hydrogel polymer chains and the particles is described from the microscopic point of view,requiring the nanoscale size-dependent theory and new experimental approach to further explore the mechanical proper ties of PHC. | Xiaocheng Hu Shaoxing Qu | 2019 | Acta Mechanica Solida Sinica2019，32，5： | 0 |
| 13 | Real-Time Control Allocation for Autonomous Surface Vehicle Using Constrained Quadratic Programming显示文摘Control system is very important for each autonomous surface vehicle(ASV),which involves the problem of maintaining the vehicle's position and heading using feedback controller and achieving the desired forces through thrust allocation.In this paper,we present a practical thrust allocator for under-actuated and fully-actuated vehicles,which can be represented as a quadratic programming(QP)problem with linear constraints.Such an optimization method allows us to consider common propulsion system,including tunnel thruster,azimuth thruster,and-xed propeller with rudder.These linear constraints enable us to explicitly account for the rate,amplitude and azimuth constraints of each propeller on the vessel.The proposed methods have been illustrated by simulated and experimental maneuvers for di®erent thruster layout of a vehicle. | Xiaocheng Liu Zhihuan Hu Ziheng Yang Weidong Zhang | 2021 | Guidance, Navigation and Control2021，1，4： | 0 |
| 14 | Applications of the double-barreled data in whole-genome shotgun sequence assembly and analysis显示文摘Double-barreled (DB) data have been widely used for the assembly of large ge- nomes. Based on the experience of building the whole-genome working draft of Oryza sativa L. ssp. Indica, we present here the prevailing and improved uses of DB data in the assembly pro- cedure and report on novel applications during the following data-mining processes such as ac- quiring precise insert fragment information of each clone across the genome, and a new kind of low-cost whole-genome microarray. With the increasing number of organisms being sequenced, we believe that DB data will play an important role both in other assembly procedures and in future genomic studies. | HAN Yujun 1,2 , NI Peixiang 2 , Lü Hong 2 , YE Jia 3 , HU Jianfei 1 , CHEN Chen 2 , HUANG Xiangang 2 , CONG Lijuan 2 , LI Guangyuan 2 , WANG Jing 1 , GU Xiaocheng 1 , YU Jun 2 & LI Songgang 1,2 1. College of Life Sciences, Peking University, Beijing 100871, China 2. Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300, China 3. James D. Watson Institute of Genome Sciences, Zhejiang University, Hangzhou 310012, China | 2005 | Science China(Life Sciences)2005，48，3： | 0 |
| 15 | Safeguarding text generation API’s intellectual property through meaning-preserving lexical watermarks显示文摘1 Introduction Recent advancements in encoder-decoder based text generation technology,like ChatGPT by OpenAI,and PaLM[1]by Google,have garnered attention in the AI community.Pay-per-use APIs offer access to these models,but research shows they are prone to imitation attacks,where malicious users train their models through skillfully crafted queries to get responses from lawful APIs.Such attacks violate the intellectual property(IP)and deter further research[2].Recent work introduced lexical watermarking(LW)methods to protect legal APIs’IP.LW modifies the original outputs and uses null-hypothesis test for ownership verification on imitation models[2,3].High-frequency words are selected,and WordNet synonyms replace them,but this one-size-fits-all approach neglects rational substitutes. | Shiyu ZHU Yun LI Xiaoye OUYANG Xiaocheng HU Jipeng QIANG | 2023 | Frontiers of Computer Science2023，17，6： | 0 |
| 16 | Existence and Finite Time Stability of Nonlinear Riemann-Liouville Fractional Delay Differential Equations显示文摘This article explores the existence results and finite time stability of nonlinear Riemann-Liouville fractional oscillatory differential equations of order 1<■<2 with pure delay.The approaches we adopted to explore the existence results are fixed point theorems.What’s more,based on some important inequalities,we explore the finite time stability of the system.In the end,the rationality of our conclusion is verified by a case. | Renjie PAN Xiaocheng HU Zhenbin FAN | 2024 | Journal of Mathematical Research with Applications2024，44，2： | 0 |
| 17 | Receptivity and structural sensitivity study of the wide vaneless diffuser flow with adjoint method显示文摘The stability of the flow in the vaneless diffuser of a centrifugal compressor is studied with the linear theory. The characteristics of direct and adjoint perturbation modes are investigated,and the receptivity of the instability mode to momentum forcing or mass injection is identified based on the adjoint modes. Analysis shows that the perturbation with the largest amplitude is located at the outlet of the vaneless diffuser, while the highest-receptivity region is located in the middle of the vaneless diffuser along the radial direction. The large difference between the direct and adjoint modes indicates that the instability mechanism cannot be identified from a study of either eigenmode separately. Therefore, the structural sensitivity analysis is adopted to study the feedback of the instability mode. The structural sensitivity of the eigenvalue which is proportional to the perturbation pressure and velocity is used to explain the mechanism of flow control for the vaneless diffuser. | Xiaocheng ZHU Chenxing HU Zezhao LIU Hao LIU Zhaohui DU | 2018 | Chinese Journal of Aeronautics2018，31，8： | 0 |
| 18 | Diagnosis and Prevention of Colibacillosis in Chickens显示文摘The characteristics of chicken colibacillosis are introduced from the aspects of pathogen,epidemiology,clinical symptoms and necropsy,and clinical comprehensive diagnosis and laboratory diagnosis methods are given.The disease is distinguished from diseases with similar symptoms such as chicken chlamydia,chicken streptococcus,chicken necrotic enteritis,broiler ascites syndrome and chicken paratyphoid infections.Eventually,the preventive and therapeutic measures against the disease are put forward. | Shen Xuehuai Zhang Danjun Zhao Ruihong Pan Xiaocheng Yin Lei Hu Xiaomiao | 2019 | Animal Husbandry and Feed Science2019，11，5： | 0 |
| 19 | Earthquake geochemical scientific expedition and research显示文摘Large earthquakes can cause both casualties and economic losses, but they also provide invaluable opportunities for earthquake scientific research. Geofluids, due to their wide distribution, sensitive response to underground conditions, and ease of observation, are widely applied in field investigations after earthquakes. Analyzing the origin of fluids, energy transfer processes, temperature/pressure conditions, and the spatial-temporal evolution of geofluids can provide valuable information concerning the mechanism of earthquake precursor anomalies, shortterm prediction methods, identification of the seismogenic faults, determination of earthquake risk, and the environmental impact of post-earthquake fluids. This article details post-earthquake scientific expeditions and research on fluid geochemistry in China and abroad, aimed at providing ideas and guidance for future scientific expedition work and geochemistry-related earthquake studies. | Chang Lu Xiaocheng Zhou Zhi Chen Zhaofei Liu Le Hu Fengxia Sun Giovanni Martinelli Ying Li | 2023 | Earthquake Research Advances2023，3，4： | 0 |
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