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Automatic global path generation for large-scale 3D scene exploration

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第6期11卷 45-77页

作者： li che F.J.Kang Army Aviation Institute Beijing 100123P.R.China School of Marine Science and Technology Northwestern Polytechnical University Xi’an 710072 P.R.China

Large-scale virtual scene exploration is still a challenging task. The novice users caneasily get distracted and disorientated, which results in being lost in space. Assistedcamera control technology is the most effective solution for virtual environment exploration problems which requires viewpoint computation and path planning. In this paper,a novel approach for large-scale virtual scene based on viewpoint scoring is ***, the scene was adaptively divided into several meaningful and easily analyzedsubregions according to the optimal view distance criterion. Second, a novel viewpointscoring method based on visual perception and information entropy fusion was developed for optimal viewpoint determination and greedy N-Best viewpoint selection algorithm was utilized for visual perceptibility calculation. Then evolutionary programmingapproach for the Traveling Salesman problem was applied for intra-subregion and intersubregion exploring path optimization. Finally, the Cubic Hermite Curve was introduced to smoothen the inflection point on the exploration path. The experimental resultsdemonstrate that the proposed method can effectively generate an automatic smooth,informative, aesthetic and non-intersecting path, with the characteristics of good exploring comfort, strong immersion and high scene information perception.

关键词： Automatic exploration visual perception viewpoint scoring N-Best viewpoint path optimization large-scale virtual scene

Monitoring the frozen duration of Qinghai Lake using satellite passive microwave remote sensing low frequency data

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Chinese Science Bulletin 2009年第13期54卷 2294-2299页

作者： che Tao li Xin JIN Rui Cold and Arid Regions Environment and Engineering Research Institute Chinese Academy of Sciences Lanzhou 710000 China

The Qinghai Lake is the largest inland lake in *** significant difference of dielectric properties between water and ice suggests that a simple method of monitoring the Qinghai lake freeze-up and break-up dates using satellite passive microwave remote sensing data could be *** freeze-up and break-up dates from the Qinghai Lake hydrological station and the MODIS L1B reflectance data were used to validate the passive microwave remote sensing *** validation shows that passive microwave remote sensing data can accurately monitor the lake *** uncertainty comes mainly from the revisit frequency of satellite *** data from 1978 to 2006 show that lake ice duration is reduced by about 14―15 *** freeze-up dates are about 4 days later and break-up dates about 10 days *** regression analyses show that,at the 0.05 significance level,the correlations are 0.83,0.66 and 0.89 between monthly mean air temperature(MMAT) and lake ice duration days,freeze-up dates,break-up dates,***,inter-annual variations of the Qinghai Lake ice duration days can significantly reflect the regional climate variation.

关键词：被动微波遥感遥感数据冻结卫星期限监测 MODIS数据低频

Activation of sonic hedgehog signaling pathway is an independent potential prognosis predictor in human hepatocellular carcinoma patients

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Chinese Journal of Cancer Research 2012年第4期24卷 323-331页

作者： li che Yan-Hua Yuan Jun Jia Jun Ren Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education) Department of Medical OncologyPeking University Cancer Hospital & Institute

Objective： The activation of hedgehog （HH） pathway is implicated in the development of human malignancies including hepatocellular carcinoma （HCC）. However, the clinical impact of HH activation in HCC patients is still unclear. This study was conducted to confirm whether the expression of HH pathway components was associated with HCC progression and clinical outcome. Methods： This study was a sample-expanded and prolonged follow up of one of our previous studies. It included 46 HCC patients who underwent surgical treatment from 2002 to 2005. The expression of sonic HH （SHIq）, patched-1 （PTCHI）, smoothened （SMOH） and glioma-associated oncogene-1 （Gli1） genes in tumor and adjacent normal tissues extracted from the patients were examined by reverse transcription- polymerase chain reaction （RT-PCR） to explore the relationship between these genes and the clinical prognosis of HCC. Results： The expression levels ofSHH, PTCH1, SMOH and Gli1 in HCC tissues were 60.87%, 50.00%, 32.61% and 54.35%, respectively. The expression levels of SHH-related molecules were relatively intense in cancer tissue, but insignificantly correlated with any clinicopathological factors of tumor. Transcriptional factor Gli1 was the only molecule associated with poor prognosis among the HCC patients. The expression of Gli1 gene in tumor tissues was significantly related with disease-free survival （DFS）（P=0.042） and overall survival （OS）（P=0.030）. The simultaneous expression of Gli1 in tumor and adjacent normal liver tissues correlated with DFS （P〈0.029） and OS （P〈0.025）. Conclusions： HH signaling activation is an important event in the development of human HCC. The expression of Gli1 in SHH pathway is possibly involved in HCC progression, which may be a useful prognostic indicator of HCC.

关键词： Hepatocellular carcinoma hedgehog GliI sonic hedgehog patched smoothened prognosis

Effects of selective cyclooxygenase-2 inhibitor on C6 glioma cell proliferation and apoptosis

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Neural Regeneration Research 2009年第11期4卷 923-927页

作者： Shiwen Guo Tao li Hongmin che Wenzhi li Minxue lian Yuliang Han Department of Neurosurgery First Affiliated Hospital Medical School Xi'an Jiaotong University Xi'an 710061 Shaanxi Province China

BACKGROUND： Studies have shown that cyclooxygenase-2 is associated with proliferation and apoptosis of glioma cells. OBJECTIVE： To investigate the effects of selective cyclooxygenase-2 inhibitor celecoxib on proliferation and apoptosis of C6 glioma cells in vitro. DESIGN, TIME AND SETTING： A cellular, molecular, controlled study was performed at the Central Laboratory and Room of Electron Microscope, Medical School, Xi＇an Jiaotong University, China from March 2007 to March 2008. MATERIALS： C6 glioma cells during in vitro log phase were assigned to control and experimental groups. Celecoxib （Pfizer, USA）, dimethyl sulfoxide （Sigma, USA）, and MTT （Sigma, USA） were used for this study. METHODS： The control group was subdivided into blank control and dimethyl sulfoxide control groups. C6 glioma cells in the blank control and dimethyl sulfoxide control groups were incubated in Dulbecco＇s modified Eagle＇s medium supplemented with 10% calf serum and 0.3% dimethyl sulfoxide respectively. C6 glioma cells in the experimental group were separately treated with 60, 80 and 100 μmol/L celecoxib. MAIN OUTCOME MEASURES： Activity of C6 glioma cells was examined by MTT assay. C6 glioma cell cycle and apoptosis were determined by annexin V-fluorescein isothiocyanate/propidium iodide double-staining, followed by flow cytometry. Morphology and ultrastructure of C6 glioma cells were observed with an inverted microscope and a transmission electron microscope, respectively. RESULTS： Compared with the blank control group, cell density was reduced, adherence ability weakened, and irregular nuclei were visible, with the presence of chromatin condensation, margination, and some apoptotic bodies in the experimental group. Activity of C6 glioma cells was significantly decreased （P 〈 0.05）, cell number was reduced during S phase, cell number was significantly increased during G2/M phase （P 〈 0.01 ）, and the apoptotic rate was significantly increased （P 〈 0.05） in the experimental group. These res

关键词： celecoxib C6 glioma cells proliferation apoptosis

Molecular Modification of a HSV-1 Protein and Its Associated Gene Transcriptional Regulation

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Virologica Sinica 2008年第6期23卷 394-398页

作者： Yan-chun che li JIANG Qi-han li Institute of Medical Biology Chinese Academy of Medical Sciences ＆ Peking Union Medical College No. 379 Jiao Ling Road Kunming 650118 China

The molecular modifications of Herpes Simplex Virus Type I （HSV-1） proteins represented by acetylation and phosphorylation are essential to its biological functions. The cellular chromatin-remodeling/ assembly is involved in HSV-1 associated gene transcriptional regulation in human cells harboring HSV-1 lytic or latent infections. Further investigation on these biological events would provide a better understanding of the mechanisms of HSV-1 viral gene transcriptional regulation

关键词： Modification Herpes simplex virus type (HSV- 1) Transcriptional regulation

Ab Initio Study on Structural and Magnetic Properties of Ni-Pd and Ni-Pt linear and Zigzag Nanowires

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Communications in Theoretical Physics 2009年第7期52卷 123-127页

作者： che Xing-Lai li Jia-Hao DAI Ye liU Bai-Xin Advanced Materials Laboratory Department of Materials Science and Engineering Tsinghua University Beijing 100084China

Employing the accurate frozen-core full-potential projector augmented-wave method,the self-consistentelectronic structure calculations were carried out on pure Ni,Pd,Pt and mixed Ni-Pd and Ni-Pt free-standing linear andzigzag *** bond lengths for all these systems are generally increased as their structures change from the linearto the zigzag *** bond lengths for Ni-Pd and Ni-Pt wires are in between the values of corresponding pure systemand the bond angles around 60° suggesting the possible formation of Ni-Pd and Ni-Pt bimetallic *** mixedNi-Pd and Ni-Pt chains,the Ni,Pd,and Pt atoms have quite high local magnetic *** calculations suggestthat the magnetic moments in linear nanowires are generally larger than the ones of corresponding zigzag *** found that there is hybridization between Ni 3d and Pd 4d,Ni 3d and Pt 5d states,which may significantly affectstructural stability and magnetism of Ni-Pd and Ni-Pt nanowires.

关键词： Ab initio study magnetism nanowires

An Adaptive Bandwidth Allocation for Energy Efficient Wireless Communication Systems

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Journal of Electronic Science and Technology 2015年第1期13卷 27-32页

作者： Yung-Fa Huang che-Hao li Chuan-Bi lin Chia-Chi Chang Department of Information and Communication Engineering Chaoyang University of Technology

In this paper, an energy efficient bandwidth allocation scheme is proposed for wireless communication systems. An optimal bandwidth expansion（OBE） scheme is proposed to assign the available system bandwidth for users. When the system bandwidth does not reach the full load, the remaining bandwidth can be energy-efficiently assigned to the other users. Simulation results show that the energy efficiency of the proposed OBE scheme outperforms the traditional same bandwidth expansion（SBE） scheme. Thus, the proposed OBE can effectively assign the system bandwidth and improve energy efficiency.

关键词： Bandwidth resource allocation energy efficiency optimal bandwidth expansion same bandwidth expansion

Theoretical study on stereodynamics of H+NeH^+(v=0,j=0)→H_2^++Ne reaction

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Chinese Science Bulletin 2012年第36期57卷 4712-4717页

作者： YIN ShuHui ZOU JingHan GUO MingXing XU XueSong GAO Hong li Lei che li Department of Physics Dalian Maritime UniversityDalian 116026China Environmental Science and Engineering College Dalian Maritime UniversityDalian 116026China

Stereodynamics of reaction H + NeH+(v = 0,j = 0) → H2+ + Ne is investigated by quasi-classical trajectory method using a new potential energy surface constructed by Lv et *** distributions of P(r),P(r) and PDDCSs are calculated at four different collision *** rotational polarization of product H2+ presents different characters at different collision *** product rotational angular momentum vector j' is not only aligned,but also oriented along the direction perpendicular to the scattering *** the increase of collision energy,the rotation of product molecule has a preference of changing from the "in-plane" mechanism to the "out-of-plane" *** the title reaction is mainly dominated by the direct reaction mechanism,the indirect mechanism plays a role when the collision energies are low.

关键词：反应机制立体碰撞能量 NE 经典轨迹分布计算势能面角动量

SOliD STATE VOLTAMMETRY OF ELECTROACTIVE SOLUTES IN POLYMER SOLVENTS(PEO)AT MICROELECTRODE

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Chinese chemical Letters 1993年第5期4卷 445-448页

作者： Guang li che Shao Jun DONG Laboratory of Electroanalytical chemistry Changchun Institute of Applied ChemistryAcademia SinicaChangchun130022

The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly(ethylene oxide)(PEO) film can be used as gas sensor.

关键词： PEO)AT MICROELECTRODE SOliD STATE VOLTAMMETRY OF ELECTROACTIVE SOLUTES IN POLYMER SOLVENTS AT