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The RCH Method for Computing Minimal Polynomials of Polynomial Matrices

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Journal of Systems Science & Complexity 2015年第1期28卷 190-209页

作者： YU Bo ZHANG Jintao xu yanyan School of Mathematical Sciences Dalian University of Technology School of Science Dalian University of Technology

In this paper,a randomized Cayley-Hamilton theorem based method(abbreviated by RCH method) for computing the minimal polynomial of a polynomial matrix is *** determines the coefficient polynomials term by term from lower to higher *** using a random vector and randomly shifting,it requires no condition on the input matrix and works with probability *** the case that coefficients of entries of the given polynomial matrix are all integers and that the algorithm is performed in exact computation,by using the modular technique,a parallelized version of the RCH method is also *** with other algorithms in both theoretical complexity analysis and computational tests are given to show its effectiveness.

关键词： Characteristic polynomial minimal polynomial polynomial matrix.

Controllable preparation of 2D metal-semiconductor layered metal dichalcogenides heterostructures

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Science China Chemistry 2019年第3期62卷 295-298页

作者： Gonglei Shao yanyan xu Song Liu Institute of Chemical Biology and Nanomedicine (ICBN) State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Hunan University

1 Introduction Graphene is the first demonstration of a truly 2D atomic layer crystal, and has shown various excellent properties (e.g., ultrahigh carrier mobility, superior toughness, unique thermal conductivity, and good optics performance). The family of 2D crystals has grown to include metals (e.g., NbS2, VS2, TaS2), semiconductors (e.g., MoS2, WS2, ZrS2), and insulators (e.g., hexagonal boron nitride (hBN)), many of which are stable at ambient conditions [1]. 2D layered metal dichalcogenides (LMDs) materials [2].

关键词： Introduction Graphene the first demonstration shown

Tunable Synthesis of Core-shell a-Fe2O3/TiO2 Composite Nanoparticles and Their Visible-light Photocatalytic Activity

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Chemical Research in Chinese Universities 2016年第6期32卷 882-888页

作者： SUN Dandan CAO yanyan xu yanyan ZHANG Guoying SUN Yaqiu Tianjin Key Laboratory of Structure and Performance for Functional Molecules Key Laboratory of Inorganic-organic Hybrid Functional Material Chemistry Ministry of Education College of Chemistry Tianjin Normal University Tianjin 300387 P. R. China

Uniform a-Fe203/amorphous TiO2 core-shell nanocomposites were prepared via a hydrolysis method anda-Fe2OJanatase TiO2 core-shell nanocomposites were obtained via a post-calcination process. The structure andmorphology of the products were characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy,transmission electron microscopy and scanning electron microscopy. Amorphous TiO2 nanoparticles with diametersof ten to several tens nanometer were formed on the surface of a-Fe203 nanoparticles and the coverage density of thesecondary TiO2 nanoparticles in the composite can be controlled by varying the concentration of Ti（BuO）4 m theethanol solution. The visible-light photocatalytic properties of different products towards Rhodamine B（RhB） wereinvestigated. The results show that the a-Fe203/amorphous TiO2 exhibits a good photocatalytic property owing to theextension of the light response range to visible light and the efficient separation of photogenerated electrons and holesbetween a-Fe203 and amorphous TiO2.

关键词： a-Fe2O3/TiO2 Core-shell nanostrueture Photocatalytic activity Rhodamine B

Targeted nanomedicines remodeling immunosuppressive tumor microenvironment for enhanced cancer immunotherapy

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Acta Pharmaceutica Sinica B 2022年第12期12卷 4327-4347页

作者： yanyan xu Jingyuan Xiong Xiyang Sun Huile Gao Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial TechnologyWest China School of PharmacySichuan UniversityChengdu 610041China Healthy Food Evaluation Research Center West China School of Public Health and West China Fourth HospitalSichuan UniversityChengdu 610041China Hongqiao International Institute of Medicine Tongren HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200336China

Cancer immunotherapy has significantly flourished and revolutionized the limited conventional tumor therapies,on account of its good safety and long-term memory ***,low patient response rates and potential immune-related side effects make it rather challenging to literally bring immunotherapy from bench to ***,it has become evident that,although the immunosuppressive tumor microenvironment(TME)plays a pivotal role in facilitating tumor progression and metastasis,it also provides various potential targets for remodeling the immunosuppressive TME,which can consequently bolster the effectiveness of antitumor response and tumor ***,the particular characteristics of TME,in turn,can be exploited as avenues for designing diverse precise targeting *** general,it is of urgent necessity to deliver nanomedicines for remodeling the immunosuppressive TME,thus improving the therapeutic outcomes and clinical translation prospects of ***,we will illustrate several formation mechanisms of immunosuppressive *** importantly,a variety of strategies concerning remodeling immunosuppressive TME and strengthening patients'immune systems,will be ***,we will discuss the existing obstacles and future perspectives in the development of antitumor ***,the thriving bloom of immunotherapy will bring vibrancy to further exploration of comprehensive cancer treatment.

关键词： Cancer immunotherapy Immunosuppressive tumor microenvironment Tumor microenvironment normalization Targeted nanomedicines Drug delivery Environment-responsive nanoparticles Combinational therapy Tumor treatment

Estimation of Vehicle Pose and Position with Monocular Camera at Urban Road Intersections

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Journal of Computer Science & Technology 2017年第6期32卷 1150-1161页

作者： Jin-Zhao Yuan Hui Chen Bin Zhao yanyan xu School of Information Science and Engineering Shandong University Jinan 250100 China Beijing xuanlongding-xun Technology Co. Ltd. Beijing 100041 China Department of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge 02139 U.S.A.

With the rapid development of urban, the scale of the city is expanding day by day. The road environment is becoming more and more complicated. The vehicle ego-localization in complex road environment puts forward imperative requirements for intelligent driving technology. The reliable vehicle ego-localization, including the lane recognition and the vehicle position and attitude estimation, at the complex traffic intersection is significant for the intelligent driving of the vehicle. In this article, we focus on the complex road environment of the city, and propose a pose and position estimation method based on the road sign using only a monocular camera and a common GPS （global positioning system）. Associated with the multi-sensor cascade system, this method can be a stable and reliable alternative when the precision of multi-sensor cascade system decreases. The experimental results show that, within 100 meters distance to the road signs, the pose error is less than 2 degrees, and the position error is less than one meter, which can reach the lane-level positioning accuracy. Through the comparison with the Beidou high-precision positioning system L202, our method is more accurate for detecting which lane the vehicle is driving on.

关键词： vehicle pose and position estimation road sign detection homograph matrix road intersection urban envi-ronment

Steganography algorithm for adaptive multi-rate wideband speech based on algebraic codebook search

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The Journal of China Universities of Posts and Telecommunications 2018年第3期25卷 71-79页

作者： Ruan Ye xu yanyan Ke Dengfeng Su Kaile School of Information Science and Technology Beijing Forestry University National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of Sciences Institute for Integrated and Intelligent Systems Griffith University College of Information Science and Technology Jinan University

With the popularity of adaptive multi-rate wideband （AMR-WB） audio in mobile communication, many AMR- WB based techniques, such as a similar compression architecture to transmit secret information during the process of compression, were proposed to transmit covert messages. However, if a sender does not have the original waveform audio format （WAV） audio, the architecture cannot be used. In this paper, a new covert message method, which takes effect after WAV audio is compressed into AMR-WB speech, is proposed. This method takes advantage of algebraic codebook search. Aiming at improving speed and reducing search space, it does not perform algebraic codebook search using the optimal search algorithm, and it does not reach the positions of non-zero pulses via depth-first tree search that characterizes the energy of audio. According to the features of search methods and the codebook index construction, every track in each subframe is analyzed to find the proper positions for embedding secret information. Experimental results show that the proposed method has satisfactory capacity and simplicity regardless of compression process.

关键词： steganography algorithm WAV audio compressed audio adaptive multi-rate wideband speech

Simulation of the direct effects of dust aerosol on climate in East Asia

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Particuology 2010年第4期8卷 301-307页

作者： Jian Wu Congbin Fu Zhiwei Han Jianping Tang yanyan xu Renjian Zhang Department of Atmospheric Science Yunnan University Kunming 650091 China Key Laboratory of Regional Climate-Environment Research for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of SdencesBeijing 100029 China Department of Atmaspheric Science Nanfing University Nanfing 210093 China Yunnan Meteorological Bureau Kunming 650031 China

The results from some general circulation models show distinct radiative forcing （RF） by dust aerosol, which potentially has an effect on climate change. The direct RF and regional climatic effects of dust aerosol over the East Asian region are investigated in this study using NCAR＇s Community Atmospheric Model version 3.1. The negative RF at the top of the atmosphere （TOA） and the surface （SRF） has been revealed except for some high-albedo regions, which leads to a decrease in the surface air temperature and brings an increase of atmospheric radiative heating under both clear- and all-sky conditions. The decrease in the surface air temperature can be found over a wide region that includes the Indian peninsula and northwest China. It accompanies an increase in eastern China and the Korean peninsula, and temperature changes are not limited to regions with a large dust optical depth. A belt of vapor increase is revealed from the Indian peninsula extending east to northern China, while vapor content evidently deceases in southwest China. An increase in precipitation can also be found in the belt of increased vapor accompanying the reduction of precipitation across the regions to the south of 30~N. The pattern of rainfall change helps to offset the trend of increasing wetness in the south and increasing dryness in the north of China in recent years.

关键词： Dust Radiative forcing Temperature Precipitation East Asia

Syntheses, Crystal Structures, Magnetic and Near-infrared Luminescence Properties of 3d-4f Coordination Polymers Cu2Pr2, Cu2Eu2 and Cu4Tb2

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Chemical Research in Chinese Universities 2019年第4期35卷 693-699页

作者： ZHONG Liangxuan LIU Mingyue ZHANG Bowei SUN Yaqiu xu yanyan Tianjin Key Laboratory of Structure and Performance for Functional Molecule College of Chemistry Tianjin Normal UniversityTianjin 300387P. R.China Key Laboratory of Advanced Energy Materials Chemistry Ministry of EducationNankai University Tianjin 300071P. R.China

Three new 3d-4f heterometallic coordination polymers(CPs), namely,[Pr2(CuL)2(nipt)3(H2O)]·2H2O (Cu2Pr2,1),[Eu2(CuL)2(nipt)3(H2O)]-2H2O(Cu2Eu2, 2) and [Tb2(CuL)4(nipt)3]-8.3H2O(Cu4Tb2,3)(CuL,H2L= 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien;nipt^2-= 5-nitroisophthalate) were obtained by a solvothermal method and structurally characterized by single-crystal X-ray diffraction analyses, elemental analyses, Fourier transform infrared spectra and ultraviolet visible absorption spectra. In Cu2Pr2 and Cu2Eu2,μ3-bridged and μ5-bridged nipt^2- ligands alternately linked three Ln^3+ and five metal ions(three Ln^3+ and two Cu^2+ ions) to generate a 2D heterometallic framework with 3,3,4,5-connected (3.4.5)(3^2.4^2.5.6^3.72)(4^2.6^3.8)(4^2.6) topology. In Cu4Tb2,μ2-bridged and μ4-bridged nipt2- ligands alternately connected two Tb3+ and four metal ions(two Tb^3+ and two Cu^2+ ions) by carboxylating into a corrugated heterometallic 2D layer with 3-connected (63) topology. The magnetic properties of Cu2Pr2 and Cu2Eu2 were also discussed, the results show tliat both CPs have a weak antimagnetic interaction. Moreover, the near-iiifrared luminescence properties of Cu2Pr2 and Cu2Eu2 were also studied.

关键词： Heterometallic coordination polymer Crystal structure Magnetic property

Survivability of Components Assembly in Architecture

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Wuhan University Journal of Natural Sciences 2008年第5期13卷 533-538页

作者： GUO Wei ZHENG yanyan xu Renzuo School of Computer Wuhan University Wuhan 430072Wuhan China

Based on the in-depth analysis of the interaction patterns between the components of software system in architecture, this paper illustrates that the association among them is complex and usually changeable during the running period. So we assume the interactions between two adjacency components are grouped into a single connector, which can be used to analyze the influence of components assembly on the survivability for software architecture. The survivability of the components assembly is mapped into the connectivity of graph model. We also bring forward a simplicity method to calculate and quantify the survivability of architecture that could provide a more usable model for designers to evaluate the architecture.

关键词： survivability software architecture component-based software graph connectivity