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Assessment of wind energy potential in Gaza Strip

Juma Yousuf ALAYDI

《能源前沿（英文）》 2011年第5卷第3期页码 297-304 doi: 10.1007/s11708-010-0134-6

摘要： The analysis of collected wind data at two sites in the Gaza Strip, namely, Gaza City and Gaza International Airport in Rafah city, is presented. The two sites are candidates for remote area wind energy applications. The purpose of this paper is to present the results of the assessment of wind energy potential in the Gaza Strip in order to evaluate the wind regimes for installing wind energy conversion systems for power generation. The data on wind speed, direction and frequency distribution are used to analyze wind energy characteristics and availability at some stations in the Gaza Strip. The vertical extrapolation was based on the power-law expression, and the wind energy and potential have been estimated at the wind turbine hub height of approximately 50 m. Furthermore, the values of the Weibull parameters and are determined from summary statistics of wind resource. Consequently, the wind power is estimated by adoption of the Weibull distribution expression. Based on the results of this paper, sites are recommended for wind energy exploitation in the Gaza Strip.

关键词： wind data wind resource assessment wind power density wind energy the Weibull distribution and Weibull parameters

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一类基于改进Weibull分布模型的电力电缆寿命评估方法

张铁岩,王承民,孙秋野,张化光

《中国工程科学》 2008年第10卷第10期页码 42-46

摘要：

对电缆的剩余寿命进行评估是电缆寿命管理的关键环节，以往电缆寿命评估的方法中有Arrhenius方法和Weibull分布模型。对这两种方法分别进行分析，特别是确定Arrhenius模型中激活能的计算，以及应用Weibull分布模型对电缆寿命进行评估。

关键词：电缆寿命评估 Arrhenius模型 Weibull分布

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基于MCMC稳态模拟的Weibull共享异质性模型及其可靠性应用

林静,韩玉启,朱慧明

《中国工程科学》 2006年第8卷第2期页码 55-60

摘要：

针对传统假设中个体寿命独立同分布的不足，构建了贝叶斯Weibull共享异质性模型，提出了对寿命服从Weibull分布的产品，运用基于Gibbs抽样的马尔可夫链蒙特卡罗（Markov chain MonteCarlo，MCMC）方法动态模拟出参数后验分布的马尔可夫链，在异质性因子的先验分布为Gamma分布时，给出随机截尾条件下，参数在Weibull共享异质性模型中的贝叶斯估计，提高了计算的精度。

关键词：贝叶斯分析可靠性 MCMC模拟 Gibbs抽样 Weibull分布共享异质性模型

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一种改进的Weibull分布杂波仿真方法

姜斌,和湘,黎湘,王宏强,郭桂蓉

《中国工程科学》 2007年第9卷第1期页码 44-48

摘要：

针对目前Weibull分布杂波仿真中没有考虑线性滤波器物理可实现性问题，首先深入研究了该杂波模型的统计特性及其ZMNL仿真方法；在此基础上，引入最小相位特性与复倒谱技术，提出了一种物理可实现的滤波器产生方法，同时详细阐述了物理可实现Weibull分布杂波随机序列产生的流程；最后，进行了仿真实验，仿真结果证明了该方法的准确性和有效性。

关键词： Weibull分布杂波 ZMNL 复倒谱物理可实现线性滤波器仿真

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Application of Cu nanoparticles as N32 base oil additives

Qiang HE, Jun YE, Hongzhao LIU, Jinling LI,

《机械工程前沿（英文）》 2010年第5卷第1期页码 93-97 doi: 10.1007/s11465-009-0083-0

摘要： Cu nanoparticles as N32 base oil additives are studied in the paper and their structure is characterized by transmission electron microscopy (TEM) and X-ray powder diffraction spectroscopy (XRD). The widely used steel-steel friction system is chosen to test the feasibility and practicality of Cu nanoparticles as bearing lubricant additives. The results show that N32 base oil with 0.5% Cu nanoparticle can improve the test sample contact fatigue life than pure N32 base oil.

关键词： Cu nanoparticle tribological property contact fatigue weibull distribution

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Durability of plasma-sprayed Cr3C2-NiCr coatings under rolling contact conditions

Xiancheng ZHANG, Fuzhen XUAN, Shantung TU, Binshi XU, Yixiong WU

《机械工程前沿（英文）》 2011年第6卷第1期页码 118-135 doi: 10.1007/s11465-011-0127-0

摘要：

The aim of this paper was to address the rolling contact fatigue (RCF) failure mechanisms of plasma-sprayed Cr3C2-NiCr coatings under different tribological conditions of contact stress. Weibull distribution plots of fatigue lives of the coated specimens at different contact stresses were obtained. The failure modes of coatings were identified on the basis of wore surface observations of the failed coatings. Results showed that the RCF failure modes can be classified into four main categories, i.e., surface abrasion, spalling, cohesive delamination, and interfacial delamination. The probabilities of the surface abrasion and spalling type failures were relatively high at low contact stress. When the coatings were subjected to abrasion and spalling type failures, the failure of the coating was depended on the microstrcture of the coating. The stress concentration near the micro-defects in the coating may be the may reason for the formation of spall. The coatings were prone to fail in delamination under higher contact stresses. However, the delamination of coating may be related to distribution of shear stress amplitude within coating. The location of maximum shear stress amplitude can be used as a key parameter to predict the initiation of subsurface cracks within coating in rolling contact.

关键词： rolling contact fatigue coating Weibull distribution failure mode mechanism

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Energy supply for water electrolysis systems using wind and solar energy to produce hydrogen: a case study of Iran

Mostafa REZAEI, Ali MOSTAFAEIPOUR, Mojtaba QOLIPOUR, Mozhgan MOMENI

《能源前沿（英文）》 2019年第13卷第3期页码 539-550 doi: 10.1007/s11708-019-0635-x

摘要： Due to acute problems caused by fossil fuels that threaten the environment, conducting research on other types of energy carriers that are clean and renewable is of great importance. Since in the past few years hydrogen has been introduced as the future fuel, the aim of this study is to evaluate wind and solar energy potentials in prone areas of Iran by the Weibull distribution function (WDF) and the Angstrom-Prescott (AP) equation for hydrogen production. To this end, the meteorological data of solar radiation and wind speed recorded at 10 m height in the time interval of 3 h in a five-year period have been used. The findings indicate that Manjil and Zahedan with yearly wind and solar energy densities of 6004 (kWh/m ) and 2247 (kWh/m ), respectively, have the greatest amount of energy among the other cities. After examining three different types of commercial wind turbines and photovoltaic (PV) systems, it becomes clear that by utilizing one set of Gamesa G47 turbine, 91 kg/d of hydrogen, which provides energy for 91 car/week, can be produced in Manjil and will save about 1347 L of gasoline in the week. Besides, by installing one thousand sets of X21-345 PV systems in Zahedan, 20 kg/d of hydrogen, enough for 20 cars per week, can be generated and 296 L of gasoline can be saved. Finally, the RETScreen software is used to calculate the annual CO emission reduction after replacing gasoline with the produced hydrogen.

关键词： wind energy solar energy water electrolysis hydrogen production Weibull distribution function (WDF) Angstrom-Prescott (AP) equation

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Investigation of wind energy potentials in Brunei Darussalam

M. A. SALAM, M. G. YAZDANI, Q. M. RAHMAN, Dk NURUL, S. F. MEI, Syeed HASAN

《能源前沿（英文）》 2019年第13卷第4期页码 731-741 doi: 10.1007/s11708-018-0528-4

摘要： Conventional power generation mainly depends on natural gas and diesel oil in Brunei Darussalam. The power utility company is now thinking of power generation using natural wind. In this paper, wind energy, being one of the most readily available renewable energy sources, was studied. The wind characteristic, velocity and directions were studied using Weibull distribution based on the measurement of wind speed at two different locations in Brunei Darussalam. These wind speed distributions were modeled using the Wind Power program. The wind rose graph was obtained for the wind direction to analyze the wind power density onshore and offshore. Based on this analysis, it has been found that the wind speed of 3 to 5 m/s has a probability of occurrence of 40%. Besides, the annual energy production at a wind speed of 5 m/s has been found to be in the range between 1000 and 1500 kWh for both the locations in Brunei Darussalam.

关键词： wind speed Weibull distribution wind rose wind energy wind power

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Techno-economic evaluation of wind energy in southwest Nigeria

Muyiwa S. ADARAMOLA, Olarenwaju M. OYEWOLA, Olayinka S. OHUNAKIN, Rufus R. DINRIFO

《能源前沿（英文）》 2012年第6卷第4期页码 366-378 doi: 10.1007/s11708-012-0205-y

摘要： In this study, an analysis of the wind energy potential in the southwest geo-political region of Nigeria was conducted. A 37-year (1971–2007) wind speed data set measured at 10 m height, obtained from eight meteorological stations within the region was analyzed using a 2-parameter Weibull function. Besides, a techno-economic evaluation of large wind energy conversion systems with power ratings ranging from 0.6 to 2 MW at different hub heights based on the levelized unit cost of electricity was made for the different sites considered. The result showed that electricity cost varied from 0.06997 and 0.11195 $/(kW·h) to 2.86611 and 4.58578 $/(kW·h) at limit values of turbine specific cost band intervals of 1000 and 1600 $/kW. It was further shown that Lagos, having the highest accumulated power outputs of 430.10 kW/a from DeWind D7 at 70 m hub height, is the most preferred for economically usable power generation in terms of the levelized unit cost.

关键词： mean wind speed Weibull distributions wind turbine techno-economic analysis southwest geopolitical region Nigeria

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Availability of wind energy resource potential for power generation at Jos, Nigeria

O. O. Ajayi, R. O. Fagbenle, J. Katende, J. O. Okeniyi

《能源前沿（英文）》 2011年第5卷第4期页码 376-385 doi: 10.1007/s11708-011-0167-5

摘要： The objective of this study was to assess the potential viability of the wind resource potential in Jos, Plateau state, Nigeria for power generation. The monthly mean wind speeds that span from 1987 to 2007 were employed to statistically analyze the monthly, annual and seasonal potentials of the wind energy resources at the site. Besides, the results were employed together with two models of wind energy conversion system to simulate the likely average output power. The outcome showed that Jos was suitable as a site for wind farm projects of varying sizes and that MW·h to GW·h of electricity is likely to be produced per period of months, seasons and years. The average wind speed range at the site was also estimated to be between 6.7 and 11.8 m/s across the months, years and seasons.

关键词： green electricity renewable resources Weibull statistics Jos Nigeria

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不完全概率信息的车辆常用弹簧的可靠性灵敏度设计

张义民,刘巧伶,闻邦椿

《中国工程科学》 2004年第6卷第1期页码 74-80

摘要：

将可靠性设计理论与灵敏度分析方法相结合，讨论了车辆常用弹簧的可靠性灵敏度设计问题，提出了可靠性灵敏度设计的计算方法，给出了可靠性灵敏度的变化规律，研究了设计参数的改变对车辆常用弹簧可靠性的影响，为车辆常用弹簧的可靠性设计提供了理论依据。

关键词：车辆常用弹簧可靠性设计灵敏度任意分布参数

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Inverse identification of the mechanical parameters of a pipeline hoop and analysis of the effect of

Ye GAO, Wei SUN

《机械工程前沿（英文）》 2019年第14卷第3期页码 358-368 doi: 10.1007/s11465-019-0539-9

摘要： To create a dynamic model of a pipeline system effectively and analyze its vibration characteristics, the mechanical characteristic parameters of the pipeline hoop, such as support stiffness and damping under dynamic load, must be obtained. In this study, an inverse method was developed by utilizing measured vibration data to identify the support stiffness and damping of a hoop. The procedure of identifying such parameters was described based on the measured natural frequencies and amplitudes of the frequency response functions (FRFs) of a pipeline system supported by two hoops. A dynamic model of the pipe-hoop system was built with the finite element method, and the formulas for solving the FRF of the pipeline system were provided. On the premise of selecting initial values reasonably, an inverse identification algorithm based on sensitivity analysis was proposed. A case study was performed, and the mechanical parameters of the hoop were identified using the proposed method. After introducing the identified values into the analysis model, the reliability of the identification results was validated by comparing the predicted and measured FRFs of the pipeline. Then, the developed method was used to identify the support stiffness and damping of the pipeline hoop under different preloads of the bolts. The influence of preload was also discussed. Results indicated that the support stiffness and damping of the hoop exhibited frequency-dependent characteristics. When the preloads of the bolts increased, the support stiffness increased, whereas the support damping decreased.

关键词： inverse identification pipeline hoop frequency response function mechanical parameters preload

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Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using

《环境科学与工程前沿（英文）》 2022年第16卷第4期 doi: 10.1007/s11783-021-1478-3

摘要：

The Large scale Urban Consumption of energ Y model was updated and coupled with WRF.

关键词： Anthropogenic heat emissions LUCY High-resolution Meteorological parameters Air quality

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Effect of thermodynamic parameters on the performance of refrigerator-ejector

Lihong CAO, Yicai LIU, Chao WAN, Tianlong XIN, Qian HUANG, Mingyan ZHANG

《能源前沿（英文）》 2010年第4卷第4期页码 517-521 doi: 10.1007/s11708-010-0004-2

摘要： A 3D calculation model of a refrigerator-ejector was built and simulated in a compression/injection hybrid refrigeration cycle system by using the FLUENT software of CFD. The effect of thermodynamic parameters (the pressure of primary fluid and secondary fluid) on the performance of the refrigerator-ejector was studied. The boundary conditions were set according to the actual operating condition and the parameters of refrigerator experimental sample. The numerical calculation results show that there is one optimal pressure of primary fluid, i.e., = 0.06612 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.568; and there is one optimal pressure of secondary fluid, i.e., = 0.04837 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.564.

关键词： refrigerator-ejector FLUENT thermodynamic parameters entrainment ratio performance

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Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

《能源前沿（英文）》 2019年第13卷第4期页码 673-683 doi: 10.1007/s11708-019-0630-2

摘要： The optical performance of a receiver has a great influence on the efficiency and stability of a solar thermal power system. Most of the literature focuses on the optical performance of receivers with different geometric shapes, but less research is conducted on the effects of critical geometric parameters. In this paper, the commercial software TracePro was used to investigate the effects of some factors on a conical cavity receiver, such as the conical angle, the number of loops of the helical tube, and the distance between the focal point of the collector and the aperture. These factors affect the optical efficiency, the maximum heat flux density, and the light distribution in the conical cavity. The optical performance of the conical receiver was studied and analyzed using the Monte Carlo ray tracing method. To make a reliable simulation, the helical tube was attached to the inner wall of the cavity in the proposed model. The results showed that the amount of light rays reaching the helical tube increases with the increasing of the conical angle, while the optical efficiency decreases and the maximum heat flux density increases. The increase in the number of loops contributed to an increase in the optical efficiency and a uniform light distribution. The conical cavity receiver had an optimal optical performance when the focal point of the collector was near the aperture.

关键词： parabolic collector conical cavity receiver critical geometric parameters optical performance