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Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

《能源前沿（英文）》 2020年 第14卷 第2期   页码 383-399 doi: 10.1007/s11708-017-0505-3

摘要： Prediction of solar radiation has drawn increasing attention in the recent years. This is because of the lack of solar radiation measurement stations. In the present work, 14 solar radiation models have been used to assess monthly global solar radiation on a horizontal surface as function of three parameters: extraterrestrial solar irradiance ( ), duration sunshine ( ) and daylight hours ( ). Since it has been observed that each model is adequate for some months of the year, one model cannot be used for the prediction of the whole year. Therefore, a smart hybrid system is proposed which selects, based on the intelligent rules, the most suitable prediction model of the 14 models listed in this study. For the test and evaluation of the proposed models, Tamanrasset city, which is located in the south of Algeria, is selected for this study. The meteorological data sets of five years (2000–2004) have been collected from the Algerian National Office of Meteorology (NOM), and two spatial databases. The results indicate that the new hybrid model is capable of predicting the monthly global solar radiation, which offers an excellent measuring accuracy of values ranging from 93% to 97% in this location.

关键词： global solar radiation     statistical indicator     hybrid model     spatial database     correlation coefficients    

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Experimental study of aerodynamic interference effects on aerostatic coefficients of twin deck bridges

Zhiwen LIU , Zhengqing CHEN , Gao LIU , Xinpeng SHAO ,

《结构与土木工程前沿（英文）》 2009年 第3卷 第3期   页码 292-298 doi: 10.1007/s11709-009-0048-8

摘要： The aerodynamic interference effects on aerostatic coefficients of twin deck bridges with large span were investigated in detail by means of wind tunnel test. The distances between the twin decks and wind attack angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin decks. The research results have shown that the drag coefficients of the leeward deck are much smaller than that of a single leeward deck. The drag coefficients of a windward deck decrease slightly compared with that of a single deck. The lift and torque coefficients of windward and leeward decks are also affected slightly by the aerodynamic interference of twin decks. And the aerodynamic interference effects on lift and torque coefficients of twin decks can be neglected.

关键词： twin decks     aerodynamic interference effects     aerostatic coefficients     wind tunnel test    

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Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2014年 第8卷 第1期   页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要： Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词： transimissity     HITEMP     HITRAN     Planck mean absorption coefficients    

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微分和表观静摩擦系数的表式

王渭源

《中国工程科学》 2001年 第3卷 第8期   页码 29-32

摘要：

当前，工程师和科学家都对微牛和纳牛量级载荷静摩擦系数（以下简称微牛纳牛静摩擦系数）很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系，而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发，导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式，并据此广泛讨论这些文献中的实验结果。

关键词： 微分静摩擦系数     微牛纳牛静摩擦系数     表观静摩擦系数     宏观静摩擦系数    

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Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

《化学科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 190-194 doi: 10.1007/s11705-007-0035-3

摘要： The separations of olefin/paraffin, aromatic/aliphatic hydrocarbons or olefin isomers using ionic liquids instead of volatile solvents have interested many researchers. Activity coefficients γ at infinite dilution of a solute in ionic liquid are generally used in the selection of solvents for extraction or extractive distillation. In fact, the measurement of γ by gas-liquid chromatography is a speedy and cost-saving method. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes, alkylbenzenes, styrene, in 1-allyl-3-methylimidazolium tetrafluoroborate ([AMIM][BF]) and 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ([MPMIM][BF]) and [MPMIM][BF]-AgBF have been determined by gas-liquid chromatography using ionic liquids as stationary phase. The measurements were carried out at different temperatures from 298 to 318 K. The separating effects of these ionic liquids for alkanes/hexane, aliphatic hydrocarbons/benzene and hexene isomers have been discussed. The hydrophobic parameter, dipole element, frontier molecular orbital energy gap and hydration energy of these hydrocarbons were calculated with the PM3 semi-empirical quantum chemistry method. The quantitative relations among the computed structure parameters and activity coefficients at infinite dilution were also developed. The experimental activity coefficient data are consistent with the correlated and predicted results using QSPR models.

关键词： cost-saving     consistent     coefficient     measurement     separating    

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Effect of friction coefficients on the dynamic response of gear systems

Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 397-405 doi: 10.1007/s11465-017-0415-4

摘要：

The inevitable deterioration of the lubrication conditions in a gearbox in service can change the tribological properties of the meshing teeth. In turn, such changes can significantly affect the dynamic responses and running status of gear systems. This paper investigates such an effect by utilizing virtual prototype technology to model and simulate the dynamics of a wind turbine gearbox system. The change in the lubrication conditions is modeled by the changes in the friction coefficients, thereby indicating that poor lubrication causes not only increased frictional losses but also significant changes in the dynamic responses. These results are further demonstrated by the mean and root mean square values calculated by the simulated responses under different friction coefficients. In addition, the spectrum exhibits significant changes in the first, second, and third harmonics of the meshing components. The findings and simulation method of this study provide theoretical bases for the development of accurate diagnostic techniques.

关键词： dynamic response     friction coefficient     wind loads     wind turbine gearbox    

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Digital image correlation-based structural state detection through deep learning

《结构与土木工程前沿（英文）》 2022年 第16卷 第1期   页码 45-56 doi: 10.1007/s11709-021-0777-x

摘要： This paper presents a new approach for automatical classification of structural state through deep learning. In this work, a Convolutional Neural Network (CNN) was designed to fuse both the feature extraction and classification blocks into an intelligent and compact learning system and detect the structural state of a steel frame; the input was a series of vibration signals, and the output was a structural state. The digital image correlation (DIC) technology was utilized to collect vibration information of an actual steel frame, and subsequently, the raw signals, without further pre-processing, were directly utilized as the CNN samples. The results show that CNN can achieve 99% classification accuracy for the research model. Besides, compared with the backpropagation neural network (BPNN), the CNN had an accuracy similar to that of the BPNN, but it only consumes 19% of the training time. The outputs of the convolution and pooling layers were visually displayed and discussed as well. It is demonstrated that: 1) the CNN can extract the structural state information from the vibration signals and classify them; 2) the detection and computational performance of the CNN for the incomplete data are better than that of the BPNN; 3) the CNN has better anti-noise ability.

关键词： structural state detection     deep learning     digital image correlation     vibration signal     steel frame    

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Diagnosis method based on wavelet coefficient scale relativity correlation dimension for fault

GU Junjie, TIAN Jin, PENG Xuezhi

《能源前沿（英文）》 2008年 第2卷 第2期   页码 164-168 doi: 10.1007/s11708-008-0031-4

摘要： Correlation dimension as a tool to describe machinery condition is introduced. Vibration signals of the fan under different working conditions are analyzed using a threshold filtering algorithm based on the region relativity of the wavelet coefficients for reducing noise. The result shows that the characteristics of the signal could be preserved completely. The correlation dimension is able to identify conditions of the fan with faults compared with the normal condition, thereby providing an effective technology for condition monitoring and fault diagnosis of mechanical equipment.

关键词： effective technology     monitoring     mechanical equipment     relativity     Correlation    

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Reliability analysis of urban gas transmission and distribution system based on FMEA and correlation

Su LI,Weiguo ZHOU

《能源前沿（英文）》 2014年 第8卷 第4期   页码 443-448 doi: 10.1007/s11708-014-0336-4

摘要： In order to improve the safety management of urban gas transmission and distribution system, failure mode and effects analysis (FMEA) was used to construct the reliability analysis system of the pipeline network. To solve the problem of subjectivity and uncertainty of the multi-expert decision making, the correlation operator was introduced into the calculation of the risk priority number (RPN). Using FMEA along with weight analysis and expert investigation approach, the FMEA evaluation table was given, including five failure modes, risk priority numbers, failure causes and effects, as well as corrective actions. The results show that correlation operator can directly process the linguistic terms and quantify the priority of the risks.

关键词： gas transmission and distribution system     risk evaluation     reliability analysis     failure mode and effects analysis (FMEA)     correlation operator    

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Measurement and correlation of the solid-liquid equilibrium of 2-(

Yanhong SUN, Zhiyong LI, Chuang XIE, Wei CHEN, Cui ZHANG

《化学科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 110-115 doi: 10.1007/s11705-013-1316-7

摘要： In this work, the enthalpy of fusion and melting points of 2-( -butyl)-5-methylphenol (2B5MP) and 2-( -butyl)-4-methylphenol (2B4MP) were measured by differential scanning calorimetry (DSC). The binary solid-liquid equilibrium (SLE) of both compounds were predicted by integrated computer aided system (ICAS) and measured by DSC. The corresponding eutectic molar composition is 0.6998 and the eutectic temperature is 281.96 K. The quasi-static heat capacities of 2B5MP and 2B4MP were evaluated by stochastic temperature modulation DSC technique (TOPEM). The SLE experimental data were correlated using the Margules, Wilson, and non-random two liquid (NRTL) equations and a good agreement between measurement and calculation could be obtained.

关键词： solid-liquid equilibrium (SLE)     eutectic     integrated computer aided system (ICAS)     TOPEM     correlation    

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Deformation field and crack analyses of concrete using digital image correlation method

Yijie HUANG, Xujia HE, Qing WANG, Jianzhuang XIAO

《结构与土木工程前沿（英文）》 2019年 第13卷 第5期   页码 1183-1199 doi: 10.1007/s11709-019-0545-3

摘要： The study on the deformation distribution and crack propagation of concrete under axial compression was conducted by the digital image correlation (DIC) method. The main parameter in this test is the water-cement ( / ) ratio. The novel analysis process and numerical program for DIC method were established. The displacements and strains of coarse aggregate, and cement mortar and interface transition zone (ITZ) were obtained and verified by experimental results. It was found that the axial displacement distributed non-uniformly during the loading stage, and the axial displacements of ITZs and cement mortar were larger than that of coarse aggregates before the occurrence of macro-cracks. The effect of / on the horizontal displacement was not obvious. Test results also showed that the transverse and shear deformation concentration areas (DCAs) were formed when stress reached 30%–40% of the peak stress. The transverse and shear DCAs crossed the cement mortar, and ITZs and coarse aggregates. However, the axial DCA mainly surrounded the coarse aggregate. Generally, the higher / was, the more size and number of DCAs were. The crack propagations of specimens varied with the variation of / . The micro-crack of concrete mainly initiated in the ITZs, irrespective of the / . The number and distribution range of cracks in concrete with high / were larger than those of cracks in specimen adopting low / . However, the value and width of cracks in high / specimen were relatively small. The / had an obvious effect on the characteristics of concrete deterioration. Finally, the characteristics of crack was also evaluated by comparing the calculated results.

关键词： deformation filed distribution     crack development     digital image correlation method     mechanical properties     water-cement ratio     characteristics of deformation and crack    

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Free radical scavenging window of infertile patients with polycystic ovary syndrome: correlation with

null

《医学前沿（英文）》 2017年 第11卷 第2期   页码 247-252 doi: 10.1007/s11684-017-0519-6

摘要：

The activity of free radicals in follicular fluid was related to ovarian responsiveness, in vitro fertilization (IVF), and embryo transfer success rate. However, studies analyzing the relationship between the free radical scavenging capacity and embryo quality of infertile women with polycystic ovarian syndrome (PCOS) were lacking. The aim of this study was to evaluate the relationship between the free radical scavenging window of women with PCOS and their embryo quality. The free radical scavenging capacity of follicular fluid from women with PCOS was determined by a,a-diphenyl-b-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) assay, superoxide radical, and reactive oxygen species (ROS) assay. In the DPPH and ROS assays, the follicular fluid from grades I and II embryos was significantly higher than the follicular fluid from grades III and IV embryos. The lower control limit of DPPH radical scavenging capacity and upper control limit of ROS level were 13.2% and 109.0 cps, respectively. The calculated lower control limit and upper control limit were further confirmed in the follicular fluid of embryos of all grades. These cut-off values of free radical scavenging activity of follicular fluid could assist embryologists in choosing the development of embryos in PCOS patients undergoing IVF.

关键词： in vitro fertilization     PCOS     free radical     embryo quality    

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Characteristic and correlation analysis of influent and energy consumption of wastewater treatment plants

Luxi Zou, Huaibo Li, Shuo Wang, Kaikai Zheng, Yan Wang, Guocheng Du, Ji Li

《环境科学与工程前沿（英文）》 2019年 第13卷 第6期 doi: 10.1007/s11783-019-1167-7

摘要： Poor biodegradability and insufficient carbon source are discovered from influent. Influent indices presented positively normal distribution or skewed distribution. Average energy consumption of WWTPs in Taihu Basin was as high as 0.458 kWh/m3. Energy consumption increases with the increase in influent volume and COD reduction. The total energy consumption decreases with the NH3-N reduction. The water quality and energy consumption of wastewater treatment plants (WWTPs) in Taihu Basin were evaluated on the basis of the operation data from 204 municipal WWTPs in the basin by using various statistical methods. The influent ammonia nitrogen (NH3-N) and total nitrogen (TN) of WWTPs in Taihu Basin showed normal distribution, whereas chemical oxygen demand (COD), biochemical oxygen demand (BOD5), suspended solid (SS), and total phosphorus (TP) showed positively skewed distribution. The influent BOD5/COD was 0.4%–0.6%, only 39.2% SS/BOD5 exceeded the standard by 36.3%, the average BOD5/TN was 3.82, and the probability of influent BOD5/TP>20 was 82.8%. The average energy consumption of WWTPs in Taihu Basin in 2017 was 0.458 kWh/m3. The specific energy consumption of WWTPs with a daily treatment capacity of more than 5 × 104 m3 in Taihu Basin was stable at 0.33 kWh/m3. A power function relationship was observed between the reduction in COD and NH3-N and the specific energy consumption of pollutant reduction, and the higher the pollutant reduction is, the lower the specific energy consumption of pollutant reduction presents. In addition, a linear relationship existed between the energy consumption of WWTPs and the specific energy consumption of influent volume and pollutant reduction. Therefore, upgrading and operation with less energy consumption of WWTPs is imperative and the suggestions for Taihu WWTPs based on stringent discharge standard are proposed in detail.

关键词： Taihu Basin     Wastewater treatment plant     Influent characteristics     Energy consumption evaluation     Specific energy consumption     SPSS correlation analysis    

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Correlation analysis of couple optical paths for micro stereovision with stereo light microscope

WANG Yuezong, LI Desheng, YU Yaping

《机械工程前沿（英文）》 2007年 第2卷 第3期   页码 288-292 doi: 10.1007/s11465-007-0050-6

摘要： A micro stereovision system with a stereo light microscope (SLM) has been applied in micromanipulation systems. There is a coupling connection between two optical paths of a stereo light microscope. The coupling intension corresponds with two factors: the structure of an SLM and the position of an object point in the view of an SLM. In this paper, a correlation function is proposed to describe the coupling intension between the couple optical paths of an SLM. The quantified results are applied to the error analysis of the imaging model. Experiments show that the correlation of the optical paths of a common main objective of stereo light microscope (CMO-SLM) is little more than that of a G-SLM, and the error must be considered when a pinhole imaging model is used to analyze its correlation.

关键词： intension     micromanipulation     correlation function     objective     quantified    

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与特定密码函数线性等价的布尔函数谱和自相关特征

杨锐,曾本胜,李世取

《中国工程科学》 2005年 第7卷 第11期   页码 60-65

摘要：

对线性等价意义下2个布尔函数的密码学性质的异同做了进一步的分析，得到了一个布尔函数线性等价于某个具有m阶相关免疫性的布尔函数的充分必要条件和线性等价于某个满足k次扩散准则的布尔函数的充分必要条件，在线性等价意义上，给出了由不具有相关免疫性且不满足扩散准则的布尔函数，构造既具有相关免疫性、也满足扩散准则的布尔函数的实例。

关键词： 线性等价     Walsh循环谱     自相关函数     相关免疫性     扩散准则     SAC    

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标题 作者 时间 类型 操作

Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

期刊论文

Experimental study of aerodynamic interference effects on aerostatic coefficients of twin deck bridges

Zhiwen LIU , Zhengqing CHEN , Gao LIU , Xinpeng SHAO ,

期刊论文

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

期刊论文

微分和表观静摩擦系数的表式

王渭源

期刊论文

Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

期刊论文

Effect of friction coefficients on the dynamic response of gear systems

Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI

期刊论文

Digital image correlation-based structural state detection through deep learning

期刊论文

Diagnosis method based on wavelet coefficient scale relativity correlation dimension for fault

GU Junjie, TIAN Jin, PENG Xuezhi

期刊论文

Reliability analysis of urban gas transmission and distribution system based on FMEA and correlation

Su LI,Weiguo ZHOU

期刊论文

Measurement and correlation of the solid-liquid equilibrium of 2-(

Yanhong SUN, Zhiyong LI, Chuang XIE, Wei CHEN, Cui ZHANG

期刊论文

Deformation field and crack analyses of concrete using digital image correlation method

Yijie HUANG, Xujia HE, Qing WANG, Jianzhuang XIAO

期刊论文

Free radical scavenging window of infertile patients with polycystic ovary syndrome: correlation with

null

期刊论文

Characteristic and correlation analysis of influent and energy consumption of wastewater treatment plants

Luxi Zou, Huaibo Li, Shuo Wang, Kaikai Zheng, Yan Wang, Guocheng Du, Ji Li

期刊论文

Correlation analysis of couple optical paths for micro stereovision with stereo light microscope

WANG Yuezong, LI Desheng, YU Yaping

期刊论文

与特定密码函数线性等价的布尔函数谱和自相关特征

杨锐,曾本胜,李世取

期刊论文