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Search Results: 1 - 10 of 9748 matches for " Lianwei Bao "
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Resonant Frequency Calculation and Optimal Design of Peano Fractal Antenna for Partial Discharge Detection
Jian Li,Changkui Cheng,Lianwei Bao,Tianyan Jiang
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/361517
Abstract: Ultra-high-frequency (UHF) approaches have caught increasing attention recently and have been considered as a promising technology for online monitoring partial discharge (PD) signals. This paper presents a Peano fractal antenna for UHF PD online monitoring of transformer with small size and multiband. The approximate formula for calculating the first resonant frequency of the Peano fractal antenna is presented. The results show that the first resonant frequency of the Peano fractal antenna is smaller than the Hilbert fractal antenna when the outer dimensions are equivalent approximately. The optimal geometric parameters of the antenna were obtained through simulation. Actual PD experiments had been carried out for two typically artificial insulation defect models, while the proposed antenna and the existing Hilbert antenna were both used for the PD measurement. The experimental results show that Peano fractal antenna is qualified for PD online UHF monitoring and a little more suitable than the Hilbert fractal antenna for pattern recognition by analyzing the waveforms of detected UHF PD signals.
Influences of Corrosive Sulfur on Copper Wires and Oil-Paper Insulation in Transformers
Jian Li,Zhiman He,Lianwei Bao,Lijun Yang
Energies , 2011, DOI: 10.3390/en4101563
Abstract: Oil-impregnated paper is widely used in power transmission equipment as a reliable insulation. However, copper sulphide deposition on oil-paper insulation can lead to insulation failures in power transformers. This paper presents the influences of copper sulfur corrosion and copper sulphide deposition on copper wires and oil-paper insulation in power transformers. Thermal aging tests of paper-wrapped copper wires and bare copper wires in insulating oil were carried out at 130 °C and 150 °C in laboratory. The corrosive characteristics of paper-wrapped copper wires and bare copper wires were analyzed. Dielectric properties of insulation paper and insulating oil were also analyzed at different stages of the thermal aging tests using a broadband dielectric spectrometer. Experiments and analysis results show that copper sulfide deposition on surfaces of copper wires and insulation paper changes the surface structures of copper wires and insulation paper. Copper sulfur corrosion changes the dielectric properties of oil-paper insulation, and the copper sulfide deposition greatly reduces the electrical breakdown strength of oil-paper insulation. Metal passivator is capable of preventing copper wires from sulfur corrosion. The experimental results are helpful for investigations for fault diagnosis of internal insulation in power transformers.
The Optimized Transport Scheme of Empty and Heavy Containers with Novel Genetic Algorithm
Lianwei Qu,Kang Chen,Bao Hongli,Jingshu Ma
Mathematical Problems in Engineering , 2013, DOI: 10.1155/2013/434125
Fabrication and adhesion of hierarchical micro-seta
Hao Zhang,LianWei Wu,ShiXing Jia,DongJie Guo,ZhenDong Dai
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5076-4
Abstract: Spark-erosion perforating technology was used to fabricate a Cu-based template characterized by pores with radius of 0.5 mm inclined at 75°. A commercial silicone elastomer of poly(dimethylsiloxane) (PDMS) with a rich Si-H content was used to produce an inclined array of primary setae. The technique of argon ion plasma etching on crystalline silicon was used to fabricate negative templates with radii of 5, 10, and 20 μm. The Si-H rich PDMS was used to cast three types of fine array templates, which acted as the secondary setae. A vinyl-rich PDMS precursor was used to bind the primary and secondary setae by a hydrosilylation reaction, thus allowing the formation of three different hierarchical arrangements of setae. Adhesion tests demonstrated that shear adhesion was anisotropic, first increasing in strength then decreasing to a stable level as slippage occurred. The adhesion strength was significantly influenced by the nature of the secondary setae, showing a strong correlation with aspect-ratio and concentration.
A Method for Surface Reconstruction Based on Support Vector Machine
Lianwei Zhang,Wei Wang,Yan Li,Xiaolin Liu
Journal of Computers , 2009, DOI: 10.4304/jcp.4.9.806-812
Abstract: Surface reconstruction is one of the main parts of reverse engineering and environment modeling. In this paper a method for reconstruct surface based on Support Vector Machine (SVM) is proposed. In order to overcome the inefficiency of SVM, a feature-preserved nonuniform simplification method is employed to simplify cloud points set. The points set is reduced while the feature is preserved after simplification. Then a reconstruction method based on segmented data is proposed to accelerate SVM regression process for cloud data. Firstly, the original sampling data set is partitioned to generate several training data subsets and testing data subsets. A segmentation technique is adopted to keep the continuity on the borders. Secondly regression calculation is executed on every training subset to generate a SVM model, from which a segmented mesh is obtained according to the testing data subset. Finally, all the mesh surfaces are stitched into one whole surface. Both theoretical analysis and experimental result show that the segmentation technique presented in this paper is efficient to improve the performance of the SVM regression, while keeping the continuity of the subset borders.
Human Comfort Instrument Design Based on Embedded  [PDF]
Shucheng Chen, Jing Shi, Xiaobo Li, Ming Cui, Lianwei Su
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.76010
The traditional human comfort meter has the following defects: the interface is not uniform; the operation is cumbersome and complicated; the interface is unfriendly, and the stability and adaptability are poor. This paper presents a design scheme for human comfort instrument based on embedded system, using S3C2440 embedded development board and the sensors to collect the real-time temperature, relative humidity and wind speed data and to process the collecting data; then obtaining the human body comfort value according to the basic algorithm of human body comfort instrument; giving the human comfort conclusion according to the diastolic index range of human comfort, and showing the temperature and humidity, wind speed, comfort value and conclusion through writing the Qt graphical user interface program. At the same time, the human comfort instrument has the data storage function. The human comfort instrument is high in integration, strong in real time, high in sensitivity, stable and reliable, and it meets the development goals of the intelligent meteorological service, and meets the demand of the meteorological service that is closer to life, and it has broad development prospect.
On a System of Second-Order Nonlinear Difference Equations  [PDF]
Hongmei Bao
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.37110
Abstract: This paper is concerned with dynamics of the solution to the system of two second-order nonlinear difference equations \"\", \"\", \"\", where \"\", \"\", \"\", i = 0, 1. Moreover, the rate of convergence of a solution that converges to the equilibrium of the system is discussed. Finally, some numerical examples are considered to show the results obtained.
The Status, Potentials and Countermeasures of China’s Carbon Audit  [PDF]
Cuiping Bao
Low Carbon Economy (LCE) , 2016, DOI: 10.4236/lce.2016.73011
Abstract: As an important supervision mechanism of the development of low-carbon economy, carbon audit arises at the historic moment. This paper analyzes the differences of the carbon audit and traditional financial audit, with SWOT method on the basis of analyzing its potential in our country, and puts forward the future development direction of carbon audit. Based on current situations, it is suggested that China should complete the upper construction, establish carbon audit system, reserve the talents and actively encourage carbon audit, in order to push the advancement of carbon audit.
A Chaperonin Subunit with Unique Structures Is Essential for Folding of a Specific Substrate
Lianwei Peng,Yoichiro Fukao,Fumiyoshi Myouga,Reiko Motohashi,Kazuo Shinozaki,Toshiharu Shikanai
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1001040
Abstract: Type I chaperonins are large, double-ring complexes present in bacteria (GroEL), mitochondria (Hsp60), and chloroplasts (Cpn60), which are involved in mediating the folding of newly synthesized, translocated, or stress-denatured proteins. In Escherichia coli, GroEL comprises 14 identical subunits and has been exquisitely optimized to fold its broad range of substrates. However, multiple Cpn60 subunits with different expression profiles have evolved in chloroplasts. Here, we show that, in Arabidopsis thaliana, the minor subunit Cpn60β4 forms a heterooligomeric Cpn60 complex with Cpn60α1 and Cpn60β1–β3 and is specifically required for the folding of NdhH, a subunit of the chloroplast NADH dehydrogenase-like complex (NDH). Other Cpn60β subunits cannot complement the function of Cpn60β4. Furthermore, the unique C-terminus of Cpn60β4 is required for the full activity of the unique Cpn60 complex containing Cpn60β4 for folding of NdhH. Our findings suggest that this unusual kind of subunit enables the Cpn60 complex to assist the folding of some particular substrates, whereas other dominant Cpn60 subunits maintain a housekeeping chaperonin function by facilitating the folding of other obligate substrates.

LIU Hanlong,REN Lianwei,ZHENG Hao,
,任连伟,郑 浩

岩石力学与工程学报 , 2009,
Abstract: 高喷插芯组合桩(JPP)是由高压旋喷桩和预应力混凝土芯桩构成的一种新型组合桩.为了对带承台单桩荷载传递特性有更深入的认识,以自行开发的大型桩基试验模型槽为依托,对带承台单桩进行静载试验.通过埋设在JPP中的监测仪器和承台下传感器得到如下荷载传递特性:与不带承台JPP单桩相比,带承台单桩承载力显著提高,承台可以承担较大比例的荷载;桩土应力比为20~100,且桩顶处桩土应力比基本维持在22左右,为承台与桩截面面积比的2倍;承台的存在限制了桩土相对位移,摩阻力不易发挥;承台对桩侧摩阻力有"削弱"作用,特别是对上部摩阻力,对桩端阻力有"增强"作用,并且与不带承台单桩相比,达到极限摩阻力所需位移增大.这些成果对JPP与承台共同作用特性研究具有一定的意义.
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