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Weierstrass Type Representation of Willmore Surfaces in S^n

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Acta Mathematica Sinica,English Series 2004年第6期20卷 1029-1046页

作者： qiao Ling XIA Yi Bing shen Department of Mathematics Zhejiang University

In this paper,we reformulate the Euler-Lagrange equations of Willmore surfaces in S^n as the flatness of a family of certain loop algebra-valued *** we can give the Weierstrass type representation of conformal Willmore *** also discuss the relations between conformal Willmore surfaces in S^n and minimal surfaces in constant curvature spaces S^n,R^n,H^n,and prove that some special Willmore surfaces can be derived from minimal surfaces in S^n,R^n,H^n.

关键词： Willmore surfaces Extended lift of a conformal Willmore immersion Loop group Weierstrass type representation Minimal surface

Elastoplastic pipe-soil interaction analyses of partially-supported jointed water mains

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第11期9卷 1497-1506页

作者： yu SHAO Tu-qiao ZHANG Department of Civil Engineering Zhejiang University Hangzhou 310027 China

Water distribution networks are essential components of water supply systems. The combination of pipe structural deterioration and mechanics leads to the failure of pipelines. A physical model for estimating the pipe failure must include both the pipe deterioration model and mechanics model. Winkler pipe-soil interaction (WPSI), an analytical mechanics model developed by Rajani and Tesfamariam (2004), takes external and internal loads, temperature changes, loss of bedding support, and the elastoplastic effect of soil into consideration. Based on the WPSI model, a method to evaluate the elastic and plastic areas was proposed in the present study. An FEM model based on pipe-soil interaction (PSI) element was used to verify the analytical model. Sensitivity analyses indicate that the soft soil, long pipe and high temperature induced the axial plastic deformation more likely, which, however, may not occur in normal scenarios. The soft soil, pipes in small diameters, long unsupported bedding are prone to form flexural plastic area. The results show that the pipes subjected to the same loads have smaller stresses in the elastoplastic analysis than elastic analysis. The difference, however, is slight.

关键词： Elastoplastic soil Winkler pipe-soil interaction (WPSI) Jointed water mains

E^2KF Based Joint Multiple CFOs and Channel Estimate for MIMO-OFDM Systems over High Mobility Scenarios

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China Communications 2014年第A01期11卷 56-63页

作者： qiao Jing CHEN Qingchun shen Feifei KeyLabofInformationCoding&Transmission SouthwestJiaotongUniversityChengduSichuan610031China

An enhanced extended Kalman filtering （E2KF） algorithm is proposed in this paper to cope with the joint multiple carrier frequency offsets （CFOs） and time-variant channel estimate for MIMO-OFDM systems over high mobility scenarios. It is unveiled that, the auto-regressive （AR） model not only provides an effective method to capture the dynamics of the channel parameters, which enables the prediction capability in the EKF algorithm, but also suggests an method to incorporate multiple successive pilot symbols for the improved measurement update.

关键词： CFO channel estimate MIMO-OFDM

The protocadherin alpha cluster is required for axon extension and myelination in the developing central nervous system

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Neural Regeneration Research 2018年第3期13卷 427-433页

作者： Wen-cheng Lu yu-xiao Zhou Ping qiao Jin Zheng Qiang Wu Qiang shen Department of Orthopedics Shanghai General Hospital Shanghai Jiao Tong University School of Medicine Center for Comparative Biomedicine Key Laboratory of Systems Biomedicine (Ministry of Education) Institute of Systems Biomedicine Shanghai Center for Systems Biomedicine Shanghai Jiao Tong University Department of Orthopedics People’s Hospital of Zhangqiu

In adult mammals, axon regeneration after central nervous system injury is very poor, resulting in persistent functional loss. Enhancing the ability of axonal outgrowth may be a potential treatment strategy because mature neurons of the adult central nervous system may retain the intrinsic ability to regrow axons after injury. The protocadherin （Pcdh） clusters are thought to function in neuronal morphogenesis and in the assembly of neural circuitry in the brain. We cultured primary hippocampal neurons from E17.5 Pcdhα deletion （del-α） mouse embryos. After culture for 1 day, axon length was obviously shorter in del-α neurons compared with wild-type neurons. RNA sequencing of hippocampal E17.5 RNA showed that expression levels of BDNF, Fmod, Nrp2, OGN, and Sema3d, which are associated with axon extension, were significantly down-regulated in the absence of the Pcdhα gene cluster. Using transmission electron microscopy, the ratio of myelinated nerve fibers in the axons of del-α hippocampal neurons was significantly decreased; myelin sheaths of P21 Pcdhα-del mice showed lamellar disorder, discrete appearance, and vacuoles. These results indicate that the Pcdhα cluster can promote the growth and myelination of axons in the neurodevelopmental stage.

关键词： nerve regeneration spinal cord injury axons protocadherin α cluster hippocampal neurons RNA sequencing real-time quantitative polymerase chain reaction transmission electron microscopy neural regeneration

Modeling method and preliminary model of Asteroid Toutatis from Chang'E-2 optical images

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Acta Mechanica Sinica 2014年第3期30卷 310-315页

作者： Xiang-yu Li Dong qiao School of Aerospace Engineering Beijing Institute of Technology Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of Education

Shape modeling is fundamental to the analysis of dynamic environment and motion around asteroid. Chang＇E- 2 successfully made a flyby of Asteroid 4179 Toutatis and obtained plenty of high-resolution images during the mis- sion. In this paper, the modeling method and preliminary model of Asteroid Toutatis are discussed. First, the optical images obtained by Chang＇E-2 are analyzed. Terrain and silhouette features in images are described. Then, the modeling method based on previous radar model and preliminary information from optical images is proposed. A preliminary polyhedron model of Asteroid Toutatis is established. Finally, the spherical harmonic coefficients of Asteroid Toutatis based on the polyhedron model are obtained. Some parameters of model are analyzed and compared. Although the model proposed in this paper is only a preliminary model, this work offers a valuable reference for future high-resolution models.

关键词： Chang'E-2 Asteroid Toutatis Shape modeling.Polyhedron method

[Solid-phase extraction coupled with high performance liquid chromatography-triple quadrupole mass spectrometry for simultaneous determination of seven coumarins in water samples from drinking water treatment plants]

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Se pu = Chinese journal of chromatography 2025年第1期43卷 78-86页

作者： Wen-Mei Jiao Jing-Ming Yang Ce Xu Fu-Kang Gao Lu-Yao shen yu-Bo yuan Zhi-Fen Guo Guang Huang School of Life Sciences and Chemical Engineering Jiangsu Second Normal University Nanjing 211200 China. School of Stomatology Nanjing Medical University Nanjing 210029 China. School of Public Health Nanjing Medical University Nanjing 211166 China. Key Laboratory of Modern Toxicology Ministry of Education School of Public Health Nanjing Medical University Nanjing 211166 China.

Chlorinated coumarins, which are as cytotoxic as highly toxic halobenzoquinones toward CHO-K1 cells, have recently been identified as disinfection byproducts in drinking water disinfection processes. Therefore, detecting coumarins in water samples collected at various stages from drinking water treatment plants helps assess the formation of chlorinated coumarins in drinking water. Hence, a simple, rapid, accurate, and sensitive method for quantifying coumarins in water samples is required. In this study, a method was developed based on solid-phase extraction coupled with high performance liquid chromatography-triple-quadrupole mass spectrometry for analyzing seven coumarins in water samples from drinking water treatment plants, including 6,7-dihydroxycoumarin, 7-hydroxycoumarin, 6-hydroxy-4-methylcoumarin, 8-chloro-7-hydroxycoumarin, coumarin, 7-chloro-6-hydroxy-4-methylcoumarin, and 3,8-dichloro-7-hydroxycoumarin. Sample pretreatment involved solid-phase extraction using HLB columns, followed by elution with water and methanol, each containing 0.25% formic acid. The extracted solution was separated via gradient elution using a Phenomenex Luna C18 column (100 mm×2.0 mm, 3 mm) with 0.1% formic acid aqueous solution and methanol as the mobile phases, with analytes detected by triple-quadrupole mass spectrometry equipped with electrospray ionization source in multiple reaction monitoring mode. The matrix effect, precision, and accuracy of the developed method were investigated using raw and treated water as matrices. Matrix effects of 0.84-1.12 were recorded for the detection of 6,7-dihydroxycoumarin, 7-hydroxycoumarin, 6-hydroxy-4-methylcoumarin, and coumarin in raw water, while values of 0.67-0.70 were recorded for 8-chloro-7-hydroxycoumarin, 7-chloro-6-hydroxy-4-methylcoumarin, and 3,8-dichloro-7-hydroxycoumarin in finished water. The three chlorinated coumarins exhibited matrix effects above 0.80 after the finished water matrix had been diluted four times. These re

关键词： coumarins disinfection byproducts drinking water high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) solid-phase extraction (SPE)

Iridoid glycosides from the roots of Scrophularia ningpoensis Hemsl

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Chinese Chemical Letters 2014年第10期25卷 1354-1356页

作者： Ling-Juan Zhu Cheng qiao Xiu-yu shen Xue Zhang Xin-sheng Yao College of Traditional Chinese Materia Medica Shenyang Pharmaceutical University Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education Shenyang Pharmaceutical University Institute of Traditional Chinese Medicine & Natural Products College of PharmacyJinan University

Two new iridoid glycosides,named scrophularianoids A（1） and B（2）,were isolated from the roots of Scrophularia *** chemical structures were established on the basis of extensive analyses of spectroscopic *** 1 and ... 详细信息

关键词： Scrophularia ningpoensis lridoid glycosides Scrophularianoid A Scrophularianoid B

Improved HHT and its application in narrowband radar imaging for precession cone-shaped targets

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Journal of Systems Engineering and Electronics 2014年第6期25卷 977-986页

作者： shen Zhao Jie Niu Xiang Li Chunjie qiao College of Mechatronics and Automation National University of Defense Technology Department of Missile Engineering Ordnance Engineering College College of Electronic Science and Engineering National University of Defense Technology

Imaging the spatial precession cone-shaped targets with narrowband radar is a new technical approach in mid-course recognition problem. However, most existing time-frequency methods still have some inevitable deficiencies for extracting microDoppler information in practical applications, which leads to blurring of the image. A new narrowband radar imaging algorithm for the precession cone-shaped targets is proposed. The instantaneous frequency of each scattering point is gained by using the improved Hilbert-Huang transform, then the positions of scattering points in the parameter domain are reconstructed. Numerical simulation and experiment results confirm the effectiveness and high precision of the proposed algorithm.

关键词： improved Hilbert-Huang transform(HHT) instanta-neous frequency narrowband radar imaging precession cone-shaped targets

Adaptive service configuration approach for quality of service management in ubiquitous computing environments

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第7期10卷 964-975页

作者： Yong ZHANG shen-sheng ZHANG Song-qiao HAN Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

Mobility and resource-limitedness pose challenging issues to service configuration for quality of service (QoS) management in ubiquitous computing environments. Previous configuration approaches, such as static resource reservation, dynamic resource allocation and single service composition are not valid in the environments. In this study, we present an adaptive service configuration approach. Firstly, we reduce the dynamic configuration process to a control model which aims to achieve the variation of critical QoS on minimal level with less resource cost. Secondly, to deal with different QoS variations, we design two configuration strategies—service chain reconfiguration and QoS parameter adjustment—and implement them based on fuzzy logic control theory. Finally, a configuration algorithm is developed to flexibly employ the two configuration strategies in tune with the error of critical QoS in configuration process. The results of simulation experiments suggest that our approach outper- forms existing configuration approaches in both QoS improvement and resource utilization.

关键词： Service configuration Ubiquitous computing (UbiComp) Quality of service (QoS) Fuzzy logic control