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Biomedical and Environmental Sciences 2018年第7期31卷 545-550页

作者： Li Ping WONG Haridah Alias Nasrin Aghamohammadi sima Aghazadeh Nik Meriam Nik Sulaiman Julius Centre University of Malaya (JCUM) Department of Social and Preventive Medicine Faculty of Medicine University of Malaya 50603 Kuala Lumpur Malaysia Centre for Occupational and Environmental Health Department of Social and Preventive Medicine Faculty of Medicine University of Malaya 50603 Kuala Lumpur Malaysia Innovative International College Selangor Malaysia Department of Chemical Engineering Faculty of Engineering University of Malaya 50603 Kuala Lumpur Malaysia

The Urban Heat Island Effect（UHI）has now become a commonly observed phenomenon ***,it has become a significant environmental effect of *** Malaysia,research results showed that UHI effects are very evident in severa... 详细信息

关键词： As UHI Psychological and Social Health Impact of Temperature Rise Due to Urban Heat Island Phenomenon and Its Associated Factors Physical

Review of photonic Hilbert transformers

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Frontiers of Optoelectronics 2013年第1期6卷 78-88页

作者： Chaotan sima Optoelectronics Research Centre University of Southampton Southampton SOl 7 1B J UK

This paper reviews the demonstrations of photonic Hilbert transformers (PHTs), describing their progress and recent developments. The physical operating principles of PHTs including fractional Hilbert transformers are discussed, together with device applications in all-optical signal processing. Versatile approaches to realize PHTs are discussed, e.g., discrete free space optics, fiber-based schemes and integrated planar geometry. The numerical designs and experimental performances of these PHTs are analyzed in terms of spectral quality, operating bandwidth, system integration, and mechanical and thermal stability. Recent developments of the monolithically integrated photonic Hilbert transform (HT) devices include directional couplers and planar Bragg gratings which allow all-optical single-sideband (SSB) suppression and sideband switching.

关键词： photonic Hilbert transformer (PHT) Bragg reflectors direct UV writing all-optical signal processing

Correlation Analysis Algorithm for Transmission Line Fault Location Based on Travelling Wave

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高电压技术 2008年第12期34卷 2637-2641页

作者： DU Lin PANG Jun sima Wen-xia State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China

This paper introduced correlation method to locate transmission line *** it described the principle of transmission line fault location based on traveling *** principle of correlation analysis is introduced,then the method using correlation analysis in fault location is *** line model is established with *** on the model,some kinds of fault are *** feasibility of this algorithm is proved based on simulation *** comparing with the classical wavelet analysis,this paper gave the advantages of this algorithm in two cases:noise influence suppression and accuracy of near distance fault *** is established to simulate transmission line grounding *** experiment result showed the correlation algorithm's *** the analysis result indicated that the correlation algorithm have a high precision.

关键词：行波相关法输电线路故障毁损定位

Study of the Influence of Angiostatin Intravitreal Injection on Vascular Leakage in Retina and Iris of the Experimental Diabetic Rats

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眼科学报 2006年第4期22卷 252-258页

作者： Jing sima Jianxing Ma Sarah X.Zhang Jiang Guo Department of Ophthalmology Shenzhen 2nd Peoples Hospital Shenzhen 518035 Department of Medicine Department of Cell Biology The University of Oklahoma Health Science Center Oklahoma City OK 73104 USA.

Purpose: To examine the effect of an intravitreal injection of angiostatin on vascular leakage in retina and iris of the diabetes and study its possible mechanism. Methods: Experimental diabetes was induced in 24 rats by an intravenous injection of streptozotocin (STZ) during 48 adult rats. Three groups were randomization distributed of them. There were 8 of both normal and diabetic rats in each group. STZ-diabetic rats and age-matched normal rats received an intravitreal injection of 5 μl of sterile PBS (Phosphate Buffered Saline) into the right eye, and the left eye was non-injected in the group A; Angiostatin was injected into the vitreous of the right eye (7.5 μg / 5 μl / eye), and the left eye received the same volume of sterile PBS as the control in the group B and C. The vascular permeability of retina and iris was measured using the Evans blue method at 2 days following the injection in the group A and B. Expression of VEGF in retina was evaluated using western blot analysis 24 hours following the injection in the group C. Results: Diabetic rats showed significant increases of vascular permeability in the retina ( P 0.05). Angiostatin injection significantly reduced VEGF level in the retinas of STZ-diabetic rats but did not affect retinal VEGF level in normal rats. Conclusions: Angiostatin significantly reduce pathological vascular permeability in the retina and iris of STZ-diabetic rats but not in normal rats. Angiostatin down-regulates VEGF expression and thus, blocks the major cause of va

关键词： Angiostatin Angiogenic inhibitor Diabetic retinopathy Vascular endothelial growth factor Intravitreal injection

The fabrication and characterization of 4H-SiC power UMOSFETs

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Chinese Physics B 2013年第2期22卷 426-428页

作者：宋庆文张玉明韩吉胜 Philip Tanner sima Dimitrijev 张义门汤晓燕郭辉 School of Technical Physics Xidian University Key Laboratory of Wide Band Gap Semiconductor Materials and Devices Xidian University Queensland Micro and Nanotechnology Center Griffith University Griffith School of Engineering Griffith University

The fabrication of 4H-SiC vertical trench-gate metal-oxide-semiconductor field-effect transistors（UMOSFETs） is reported in this *** device has a 15-μm thick drift layer with 3×10^15 cm^-3 N-type doping concentration and a 3.1μm channel *** measured on-state source-drain current density is 65.4 A/cm^2 at Vg = 40 V and VDS = 15 *** measured threshold voltage（Vth） is 5.5 V by linear extrapolation from the transfer characteristics.A specific on-resistance（Rsp-on） is 181 mΩ·cm^2 at Vg = 40 V and a blocking voltage（BV） is 880 V（IDS = 100 μA@880V） at Vg = 0 V.

关键词： UMOSFETs 4H-SiC specific on-resistance blocking voltage

Classification and Identification of Over-voltage Based on HHT and SVM

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高电压技术 2012年第8期38卷 2068-2075页

作者： WANG Jing YANG Qing CHEN Lin sima Wenxia State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China

This paper proposes an effective method for over-voltage classification based on the Hilbert-Huang transform(HHT) ***-Huang transform method is composed of empirical mode decomposition(EMD) and Hilbert *** kinds of common power system over-voltages are calculated and analyzed by *** on the instantaneous amplitude spectrum,Hilbert marginal spectrum and Hilbert time-frequency spectrum,three kinds of over-voltage characteristic quantities are obtained.A hierarchical classification system is built based on HHT and support vector machine(SVM).This classification system is tested by 106 field over-voltage signals,and the average classification rate is 94.3%.This research shows that HHT is an effective time-frequency analysis algorithms in the application of over-voltage classification and identification.

关键词：局部放电射频信号放电量高电压技术

Flashover Characteristics of Flat Plate Model Under DC Voltage in Wind-sand Condition

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高电压技术 2008年第12期34卷 2570-2574页

作者： sima Wen-xia MA Gao-quan YANG Qing State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China

The influence of sand dust on discharge of external insulation has caused widespread *** present,the research results show wind-sand electricity has a remarkable effect on the discharge characteristics of insulator and has little influence on the discharge characteristics of air *** flashover of insulator strings occurs along the insulator surface and air gaps,and the sand dust deposited on the insulator surface may affect the flashover characteristics of insulator *** paper studies the flashover characteristics of flat plate model under DC voltage in wind-sand *** experimental results show that under positive polarity voltage,the flashover voltage of the flat plate model has a maximum value,while under negative polarity voltage,the flashover voltage of the flat plate model has a minimum value with a certain degree of sand dust *** wind or sand in sand-dust weather has an important effect on the flashover characteristics of the flat plate *** certain variation range of electric charge,electric charge of sand dust has little effect on the flashover voltage of flat plate model under DC *** deposition of sand has significant influence on the flashover process of flat plate model,which is related to the deposition density and moisture content of sand particle.

关键词：风沙条件平板模型直流电放电特性

Time series modeling of animal bites

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Journal of Acute Disease 2023年第3期12卷 121-128页

作者： Fatemeh Rostampour sima Masoudi Department of Biostatistics and Epidemiology Faculty of MedicineUrmia University of Medical SciencesUrmiaIran

Objective:To explore the modeling of time series of animal bite occurrence in northwest ***:In this study,we analyzed surveillance time series data for animal bite cases in the northwest Iran province of Iran from 2011 to *** used decomposition methods to explore seasonality and long-term trends and applied the Autoregressive Integrated Moving Average(ARIMA)model to fit a univariate time series of animal bite *** ARIMA modeling process involved selecting the time series,transforming the series,selecting the appropriate model,estimating parameters,and ***:Our results using the Box Jenkins model showed a significant seasonal trend and an overall increase in animal bite incidents during the study *** best-fitting model for the available data was a seasonal ARIMA model with drift in the form of ARIMA(2,0,0)(1,1,1).This model can be used to forecast the frequency of animal attacks in northwest Iran over the next two years,suggesting that the incidence of animal attacks in the region would continue to increase during this time frame(2018-2019).Conclusion:Our findings suggest that time series analysis is a useful method for investigating animal bite cases and predicting future *** existence of a seasonal trend in animal bites can also aid in planning healthcare services during different seasons of the ***,our study highlights the importance of implementing proactive measures to address the growing issue of animal bites in Iran.

关键词： Animal bites Time series analysis ARIMA modeling Box Jenkins model Northwest Iran

Combination Operation for Neutral Point of 35 kV Power Grids in Mountainous Area

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高电压技术 2008年第12期34卷 2626-2630页

作者： YUAN Tao sima Wen-xia RAN Rui ZHU Wei State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China Linan Electric Power Bureau Linan 311307 China

Based on a lot of measurement and analysis,this paper find that the unbalanced nature of 35 kV grids due to unsymmetrical capacitance values gives difficulty in neutral point operation in mountainous *** compensation of Petersen coil can rectify imbalance of voltage but bring up new problem that Petersen coil can not extinguish grounding arc effectively in *** put down contradiction mentioned above,this paper proposes a combination operation for neutral point of 35 kV grids as neutral point insulated in routine operation and grounding through Petersen coil in fault,then EMTP simulation is carried *** indicates that new neutral operation method can improve lightning withstand level and decrease trip-out rate of grids.

关键词：山区补偿电网消弧线圈投切运行暂态分析

Experimental Analysis on Shielding Effect of the Grounding Electrodes Under Impulse-current

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高电压技术 2008年第12期34卷 2609-2614页

作者： YANG Cai-wei sima Wen-xia YUAN Tao YANG Qing State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China

Generally,the flow of a lightning impulse current from a grounding electrode into ground is a very complicated process determined by many *** order to analyze the mechanism of the impulse current dissipating in the earth from grounding electrode,the experiments that had been carried out by other authors almost used a single horizontal grounding wire or vertical grounding rod for sake of ***,in practical conditions,most of the grounding systems are constructed of grounding electrodes with branches in different *** this study,basing on the principle of dimensional similarity,impulse simulation experiments are performed on the common ground electrodes with conductor *** paper focuses on analyzing the impulse current dispersal regularity of different branches when injecting at one *** with the leakage current distribution of a single ground electrode,it is found that the leakage currents along the branches increase with the distance to the current feed point,and the more conductors near the injection point,the more uneven the leakage current distribution *** work indicates that shielding effect should be taken into account when analyzing the impulse characteristics of grounding electrodes.

关键词：屏蔽效应接地电极冲击电流试验研究