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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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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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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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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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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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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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Copper and zinc interaction on water clearance and tissue metal distribution in the freshwater mussel

Tianxiang XIA, Xuehua LIU

《环境科学与工程前沿（英文）》 2011年第5卷第2期页码 236-242 doi: 10.1007/s11783-010-0218-8

摘要： Copper and zinc interaction on clearance from water and distribution in different tissues was investigated for the freshwater mussel, , under laboratory conditions. Clearance rate of Cu or Zn from water was highly dependent on exposure concentration. Interaction effect was most evident at 300 μg·L Cu exposure and depressed the Zn clearance rate significantly ( <0.05). However, the presence of 100 μg·L and 300 μg·L Zn hardly affected the Cu clearance rate. The 300 μg·L Cu presence enhanced Cu accumulation in each tissue most significantly ( <0.01), but caused Zn content to decrease in the gills by 62% ( <0.05), viscera by 49% ( <0.05) and foot by 31% ( <0.05), and increase in the mantle by 97% ( <0.05) and the muscles by 243% ( <0.05) for different Zn exposure treatments. The response of metal accumulation in various tissues of the test mussels indicated that Zn transferred from the gills, viscera and foot to the mantle and muscles might be one of the important characteristics of the Zn regulatory mechanism by leading to a narrow range of Zn concentration in the different tissues.

关键词： interaction mussel copper zinc clearance distribution

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Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

《化学科学与工程前沿（英文）》 2022年第16卷第6期页码 985-995 doi: 10.1007/s11705-021-2126-y

摘要： The high contents of nitrogen-containing organic compounds in biocrude obtained from hydrothermal liquefaction of microalgae are one of the most concerned issues on the applications and environment. In the project, Chlorella sp. and Spirulina sp. were selected as raw materials to investigate the influence of different reaction conditions (i.e., reaction temperature, residence time, solid loading rate) on the distribution of nitrogen in the oil phase and aqueous phase. Three main forms of nitrogen-containing organic compounds including nitrogen-heterocyclic compounds, amide, and amine were detected in biocrudes. The contents of nitrogen-heterocyclic compounds decreased with temperature while amide kept increasing. The effect of residence time on the components of nitrogen-containing organic compounds was similar with that of temperature. However, the influence of solid loading rate was insignificant. Moreover, it was also found that the differences of amino acids in the protein components in the two microalgae might affect the nitrogen distribution in products. For example, nitrogen in basic amino acids of Spirulina sp. preferred to go into the aqueous phase comparing with the nitrogen in neutral amino acids of Chlorella sp. In summary, a brief reaction map was proposed to describe the nitrogen pathway during microalgae hydrothermal liquefaction.

关键词： microalgae hydrothermal liquefaction biocrude nitrogen distribution

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Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady

Xiyan GUO, Yongping YANG

《能源前沿（英文）》 2011年第5卷第1期页码 69-74 doi: 10.1007/s11708-010-0117-7

摘要： A coal-fired power unit frequently operates under unsteady conditions; thus, in order to acquire scientific energy analysis of the unit, thermodynamic analysis of a single-phase heated surface in a boiler under such conditions requires investigation. Processes are analyzed, and distributions of energy and exergy are qualitatively revealed. Models for energy analysis, entropy analysis, and exergy analysis of control volumes and irreversible heat transfer processes are established. Taking the low-temperature superheater of a 610 t/h-boiler as an example, the distribution of energy, entropy production, and exergy is depicted quantitatively, and the results are analyzed.

关键词： thermodynamic model energy distribution boiler unsteady conditions

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Estimation of distribution algorithm enhanced particle swarm optimization for water distribution network

Xuewei QI,Ke LI,Walter D. POTTER

《环境科学与工程前沿（英文）》 2016年第10卷第2期页码 341-351 doi: 10.1007/s11783-015-0776-z

摘要： The optimization of a water distribution network (WDN) is a highly nonlinear, multi-modal, and constrained combinatorial problem. Particle swarm optimization (PSO) has been shown to be a fast converging algorithm for WDN optimization. An improved estimation of distribution algorithm (EDA) using historic best positions to construct a sample space is hybridized with PSO both in sequential and in parallel to improve population diversity control and avoid premature convergence. Two water distribution network benchmark examples from the literature are adopted to evaluate the performance of the proposed hybrid algorithms. The experimental results indicate that the proposed algorithms achieved the literature record minimum (6.081 M$) for the small size Hanoi network. For the large size Balerma network, the parallel hybrid achieved a slightly lower minimum (1.921M?) than the current literature reported best minimum (1.923M?). The average number of evaluations needed to achieve the minimum is one order smaller than most existing algorithms. With a fixed, small number of evaluations, the sequential hybrid outperforms the parallel hybrid showing its capability for fast convergence. The fitness and diversity of the populations were tracked for the proposed algorithms. The track record suggests that constructing an EDA sample space with historic best positions can improve diversity control significantly. Parallel hybridization also helps to improve diversity control yet its effect is relatively less significant.

关键词： particle swarm optimization (PSO) diversity control estimation of distribution algorithm (EDA) water distribution network (WDN) premature convergence hybrid strategy

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Hazard and vulnerability evaluation of water distribution system in cases of contamination intrusion

Kunlun XIN, Tao TAO, Yong WANG, Suiqing LIU

《环境科学与工程前沿（英文）》 2012年第6卷第6期页码 839-848 doi: 10.1007/s11783-012-0409-8

摘要： In this paper, it proposed an index system for hazard and vulnerability evaluations of water distribution networks, based on the simulation of contamination events caused by pollutant injections at different junctions. It attempted to answer the following two questions in the case of contamination events: 1) Which are the most hazardous junctions? 2) Which are the most vulnerable junctions? With EPANET toolkit, it simulated the propagation of the contaminant, and calculated the peak concentration of the contaminant and mass delivered at different nodes. According to types of consumers, different weights were assigned to the consumer nodes for assessing the influence of the contaminant on the consumers. Using the method proposed herein, both the hazard index and vulnerability index were calculated for each node in the pipe network. The presented method was therefore applied to the water network of the city of Zhenjiang, which contains two water plants, two booster pump stations with storage tanks. In conclusion, the response time, the relationships between the peak concentration of contaminant and the total absorption are the most important factors in hazard and vulnerability evaluation of the water distribution network.

关键词： water distribution network hazard vulnerability contaminant accident

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Calculation method of load distribution on pipe threaded connections under tension load

Shoujun CHEN, Lianxin GAO, Qi AN

《机械工程前沿（英文）》 2011年第6卷第2期页码 241-248 doi: 10.1007/s11465-011-0219-x

摘要：

This paper presents a new calculation method that can calculate the load distribution on pipe threaded connections under tension load. On the basis of elastic mechanics, the new method was developed by analyzing each thread tooth, and a new deformation and covariant equation by making a mechanics analysis on each thread tooth was obtained. Compared with the traditional method proposed by the previous references, the new deformation and covariant equation could be used to describe the relation between the previous and the next thread tooth. By applying the new method on the sample of P-110S pipe threaded connection, the obtained results show that the load on thread tooth mainly concentrates on the four or five threads engaged and the middle teeth were not utilized well to bear the loads. The model offers a new way to calculate the loads carried on the thread teeth under tension load.

关键词： load distribution calculation method pipe threaded connections tension load