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Direction monotonicity for a rational Bézier curve

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Applied Mathematics(A Journal of Chinese Universities) 2016年第1期31卷 1-20页

作者： SHEN Wan-qiang WANG guo-zhao HUANG Fang School of Science Jiangnan University State Key Lab of CAD & CG Zhejiang University Department of Mathematics Zhejiang University

The monotonicity of a rational Bezier curve, usually related to an explicit function, is determined by the used coordinate system. However, the shape of the curve is independent of the coordinate system. To meet the affine invariant property, a kind of generalized mono- tonicity, called direction monotonicity, is introduced for rational Bezier curves. The direction monotonicity is applied to both planar and space curves and to both Cartesian and affine co- ordinate systems, and it includes the traditional monotonicity as a subcase. By means of it, proper affine coordinate systems may be chosen to make some rational Bezier curves monotonic. Direction monotonic interpolation may be realized for some of the traditionally nonmonotonic data as well.

关键词： rational Bezier curve monotonicity explicit function affine coordinate system interpolation.

Ar-Ar geochronology of Late Mesozoic volcanic rocks from the Yanji area, NE China and tectonic implications

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Science China Earth Sciences 2007年第4期50卷 505-518页

作者： LI ChaoWen guo Feng FAN WeiMing GAO XiaoFeng Key Laboratory of Marginal Sea Geology Guangzhou institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Graduate University of the Chinese Academy of Sciences Beijing 100039China

Ar-Ar dating results of late Mesozoic-Cenozoic volcanic rocks from the Yanji area, NE China provide a new volcano-sedimentary stratigraphic framework. The previously defined “Triassic-Jurassic” volcanic rocks (including those from Sanxianling, Tuntianying, Tianqiaoling and Jingouling Fms.) were erupted during 118―106 Ma, corresponding to Early Cretaceous. The new eruption age span is slightly younger than the main stage (130―120 Ma) of the extensive magmatism in the eastern Central Asian Orogenic Belt and its adjacent regions. Subduction-related adakites occurring in the previously defined Quanshuicun Fm. were extruded at ca. 55 Ma. Based on these new Ar-Ar ages, the late Mesozoic to Palaeocene volcano-sedimentary sequences is rebuilt as: Tuopangou Fm., Sanxianling/Tuntianying Fm. (118―115 Ma), Malugou/Tianqiaoling Fm. (K1), Huoshanyan/Jingouling Fm. (108―106 Ma), Changcai Fm. (K2), Quanshuicun Fm. (~55 Ma) and Dalazi Fm. Our results suggest that subduction of the Pa- laeo-Pacific Ocean beneath the East Asian continental margin occurred during 106 to 55 Ma, consistent with the paleomagnetic observations and magmatic records which indicated that the Izanagi-Farallon ridge subduction beneath the southwestern Japan took place during 95―65 Ma.

关键词： Ar-Ar geochronology Late Mesozoic volcanic rocks tectonic implications Yanji area

Iron oxide nanoparticles with photothermal performance and enhanced nanozyme activity for bacteria-infected wound therapy

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Regenerative Biomaterials 2022年第1期9卷 548-559页

作者： Jiaxin guo Wenying Wei Yanan Zhao Honglian Dai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Biomedical Materials and Engineering Research Center of Hubei ProvinceWuhan University of TechnologyWuhan 430070China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen ValleyFoshan 528200China Shenzhen Research Institute of Wuhan University of Technology Shenzhen 518000China

Metal-based nanomaterials usually have broad-spectrum antibacterial properties,low biological toxicity and no drug resistance due to their intrinsic enzyme-like catalytic properties and external field(magnetic,thermal,acoustic,optical and electrical)***,iron oxide(Fe_(3)O_(4))nanoparticles(IONPs)synthesized by us have good biosafety,excellent photothermal conversion ability and peroxidase-like catalytic activity,which can be used to construct a photothermal-enzymes combined antibacterial treatment *** with peroxide-like catalytic activity can induce H_(2)O_(2)to catalyze the production of·OH in a slightly acidic environment,thus achieving certain bactericidal effects and increasing the sensitivity of bacteria to *** stimulated by near-infrared light,the photothermal effect could destroy bacterial cell membranes,resulting in cleavage and inactivation of bacterial protein,DNA or ***,it can also improve the catalytic activity of peroxidase-like and promote IONPs to catalyze the production of more·OH for killing *** IONPs synergistic treatment,the antibacterial rate of Escherichia coli and Staphylococcus aureus reached nearly 100%.It also has an obvious killing effect on bacteria in infected wounds of mice and can effectively promote the healing of *** wounds,which has great application potential in clinical anti-infection treatment.

关键词： antibacterial photothermal therapy peroxidase-like catalytic therapy

cDNA Cloning of Heat Shock Protein Genes and Their Expression in an Indigenous Cryptic Species of the Whitefly Bemisia tabaci Complex from China

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Journal of Integrative Agriculture 2012年第2期11卷 293-302页

作者： YU Hao WAN Fang-hao guo Jian-ying State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences Beijing 100081 P.R. China Department of Entomology Henan Institute of Science and Technology Xinxiang 453003 P.R.China

Thermal adaptation plays a fundamental role in shaping the distribution and abundance of insects,and heat shock proteins（Hsps）play important roles in the temperature adaptation of various *** better understand the temperature tolerance of the indigenous ZHJ2-biotype of whitefly Bemisia tabaci species complex,we obtained complete cDNA sequences for hsp90,hsp70,and hsp20 and analyzed their expression profiles under different high temperature treatments by real-time quantitative polymerase chain *** high temperature tolerance of *** ZHJ2-biotype was determined by survival rate after exposure to different high temperatures for 1 *** results showed that after 41°C heat-shock treatment for 1 h,the survival rates of ZHJ2 adults declined significantly and the estimated temperature required to cause 50% mortality（LT50）is 42.85°C for 1 *** for onset（Ton）or maximal（Tmax）induction of hsps expression in *** ZHJ2-biotype were 35 and 39°C（or 41°C）.Compared with previous studies,indigenous ZHJ2-biotype exhibits lower heat temperature stress tolerance and Ton（or Tmax）than the invasive B-biotype.

关键词： Bemisia tabaci biological invasion thermotolerance indigenous and invasive biotypes heat shock protein (hsp)

Towards the universal defense for query-based audio adversarial attacks on speech recognition system

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Cybersecurity 2024年第1期7卷 53-70页

作者： Feng guo Zheng Sun Yuxuan Chen Lei Ju School of Cyber Science and Technology Shandong UniversityQingdaoChina Quancheng Laboratory QCLJinanChina

Recently,studies show that deep learning-based automatic speech recognition(ASR)systems are vulnerable to adversarial examples(AEs),which add a small amount of noise to the original audio *** AE attacks pose new challenges to deep learning security and have raised significant concerns about deploying ASR systems and *** existing defense methods are either limited in application or only defend on results,but not on *** this work,we propose a novel method to infer the adversary intent and discover audio adversarial examples based on the AEs generation *** insight of this method is based on the observation:many existing audio AE attacks utilize query-based methods,which means the adversary must send continuous and similar queries to target ASR models during the audio AE generation *** by this observation,We propose a memory mechanism by adopting audio fingerprint technology to analyze the similarity of the current query with a certain length of memory ***,we can identify when a sequence of queries appears to be suspectable to generate audio *** extensive evaluation on four state-of-the-art audio AE attacks,we demonstrate that on average our defense identify the adversary’s intent with over 90%*** careful regard for robustness evaluations,we also analyze our proposed defense and its strength to withstand two adaptive ***,our scheme is available out-of-the-box and directly compatible with any ensemble of ASR defense models to uncover audio AE attacks effectively without model retraining.

关键词： Adversarial attacks Defense Memory mechanism Query-based

Acceleration of the EM Algorithm Using the Vector Aitken Method and Its Steffensen Form

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Acta Mathematicae Applicatae Sinica 2017年第1期33卷 175-182页

作者： Xu guo Qiu-yue LI Wang-li XU School of Statistics Beijing Normal University College of Science China Agricultural University Center for Applied Statistics School of StatisticsRenmin University of China

Based on Vector Aitken （VA） method, we propose an acceleration Expectation-Maximization （EM） algorithm, VA-accelerated EM algorithm, whose convergence speed is faster than that of EM algorithm. The VA-accelerated EM algorithm does not use the information matrix but only uses the sequence of estimates obtained from iterations of the EM algorithm, thus it keeps the flexibility and simplicity of the EM algorithm. Considering Steffensen iterative process, we have also given the Steffensen form of the VA-accelerated EM algorithm. It can be proved that the reform process is quadratic convergence. Numerical analysis illustrate the proposed methods are efficient and faster than EM algorithm.

关键词： EM algorithm VA-accelerated EM algorithm convergence rate Steffensen iterative

p-Sulfonatocalix[4]arene-induced amphiphilic aggregation of fluorocarbon surfactant

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Science China Chemistry 2014年第3期57卷 371-378页

作者： CAO Yu WANG YiXuan guo DongSheng LIU Yu State Key Laboratory of Elemento-Organic Chemistry Department of Chemistry Nankai University

Sulfonatocalix[4]arene lowers the critical aggregation concentration of fluorocarbon surfactant pronouncedly by a factor of ca.100 to form binary amphiphilic aggregates on the basis of host-guest complexation,which was identified by1H NMR spectroscopy,fluorescence spectroscopy,optical transmittance spectroscopy,dynamic laser scattering,high-resolution transmission electron microscopy,scanning electron microscopy,and surface tension ***,the resulting aggregates can respond to external stimuli,including temperature and inclusion of competitor ***,the present system may have potential applications in drug delivery systems.

关键词： calixarene-induced aggregates fluorocarbon surfactant supra-amphiphile multi-stimuli responses

Polarization Oblique Projection Based Self-Interference Cancellation against PA Nonlinear Distortion in MIMO Full Duplex System

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China Communications 2016年第11期13卷 49-59页

作者： Wen Zhao Chunyan Feng Fangfang Liu Caili guo Beijing Laboratory of Advanced Information Networks School of Information and Communication EngineeringBeijing University of Posts and Telecommunications

In MIMO full duplex system,power amplifier(PA) nonlinearity limits the self-interference(SI) cancellation seriously. Most existing methods need to model and estimate the PA nonlinearity in order to reconstruct the SI,however the estimation error caused by the mismatch between the estimated PA model and the actual PA property still impacts the cancellation ability,especially when the transmit power is high. In this paper we propose a polarization oblique projection based self-interference cancellation method which does not need to estimate the PA nonlinearity coefficients. It exploits the polarization state information of the signals which is immune to the PA nonlinearity,and establishes an oblique projection operator to cancel the SI. Numerical results and analysis demonstrate that it can cancel the nonlinear SI effectively. Moreover the signal to interfere plus noise ratio(SINR) and the achievable sum rate do not deteriorate when the transmit power is high. Further,the upper bound of the achievable sum rate can be more than twice that of the half duplex.

关键词： full duplex self-interference cancellation PA nonlinearity polarization oblique projection

Shear of molecular deposition films on glass substrates determined by tribometer

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Science China(Technological Sciences) 2011年第4期54卷 1005-1010页

作者： guo YanBao WANG Deguo LIU ShuHai ZHANG SiWei College of Mechanical and Transportation Engineering China University of PetroleumBeijing 102249China

The ultrathin polyelectrolyte molecular deposition films and polyelectrolyte composite nanoparticles molecular deposition films were prepared using layer-by-layer molecular deposition method and in situ growth method.A micro-tribometer has been developed to measure the shear response of those ultrathin molecular deposition *** using a smooth steel sphere in a ball-on-flat configuration,the shear force was determined for molecular deposition films on glass substrate for different *** results indicate that the shear behaviors of molecular deposition film were mainly determined with the contact area and film ***,the composite molecular deposition film with nanoparticles has better shear behaviors than the polyelectrolyte molecular deposition *** shear force of polyelectrolyte molecular deposition film is more dependent on the speed than that of composite nanoparticle molecular deposition film.

关键词： shear force molecular deposition film nanoparticles