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Predicting corn digestible and metabolizable energy content from its chemical composition in growing pigs 被引量:2
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作者 Quanfeng Li Jianjun Zang +3 位作者 Dewen Liu Xiangshu Piao Chanqhua Lai Defa Li 《Journal of Animal Science and Biotechnology》 SCIE CAS 2014年第3期357-364,共8页
Background: The nutrient composition of corn is variable. To prevent unforeseen reductions in growth performance, grading and analytical methods are used to minimize nutrient variability between calculated and analyz... Background: The nutrient composition of corn is variable. To prevent unforeseen reductions in growth performance, grading and analytical methods are used to minimize nutrient variability between calculated and analyzed values. This experiment was carried out to define the sources of variation in the energy content of corn and to develop a practical method to accurately estimate the digestible energy (DE) and metabolisable energy (ME) content of individual corn samples for growing pigs. Twenty samples were taken from each of five provinces in China (Jilin, Hebei, Shandong, Liaoning, and Henan) to obtain a range of quality. Results: The DE and ME contents of the 100 corn samples were measured in 3.5.3 ±1.92 kg growing pigs (six pigs per corn sample). Sixty corn samples were used to build the prediction model; the remaining forty samples were used to test the suitability of these models. The chemical composition of each corn sample was determined, and the results were used to establish prediction equations for DE or ME content from chemical characteristics. The mean DE and ME content of the 100 samples were 4,053 and 3,923 kcal/kg (dry matter basis), respectively. The physical characteristics were determined, as well, and the results indicated that the bulk weight and 1,000-kernel weight were not associated with energy content. The DE and ME values could be accurately predicted from chemical characteristics. The best fit equations were as follows: DE, kcal/kg of DM = 1062.68 + (49.72 ×EE) + (0.54 × GE) + (9.1 ] x starch), with R^2 = 0.62, residual standard deviation (RSD) = 48 kcal/kg, and P 〈 0.01; ME, kcal/kg of dry matter basis (DM) = 671.54 + (0.89 ×DE) - (5.57 × NDF) - (191.39 ×ash), with R^2 = 0.87, RSD = 18 kcal/kg, and P〈 0.01. Conclusion: This experiment confirms the large variation in the energy content of corn, describes the factors that influence this variation, and presents equations based on chemical measurements that may be used to predict the DE and ME content of individual corn samples. 展开更多
关键词 CORN Digestible energy Metabolizable energy PIGS Prediction equation 1
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A simulation-based nonlinear site amplification model for ground-motion prediction equations in Japan 被引量:1
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作者 Ruibin Hou John Xingquan Zhao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第4期843-862,共20页
In this manuscript we present a nonlinear site amplification model for ground-motion prediction equations(GMPEs)in Japan,using a site period-based site class and a site impedance ratio as site parameters.We used a lar... In this manuscript we present a nonlinear site amplification model for ground-motion prediction equations(GMPEs)in Japan,using a site period-based site class and a site impedance ratio as site parameters.We used a large number of shear-wave velocity profiles from the Kiban-Kyoshin network(KiK-net)and the Kyoshin network(K-NET)to construct the one-dimensional(1D)numerical models.The strong-motion records from rock-sites in Japan with different earthquake categories and taken from the Pacific Earthquake Engineering Research Center dataset were used in this study.We fit a set of 1D site amplification models using the spectral amplification ratios derived from 1D equivalent linear analyses.Parameters of site impedance ratios for both linear and nonlinear site response were included in the 1D model.The 1D model could be implemented into GMPEs using a new proposed adjustment method.The adjusted site amplification ratios retain the nonlinear characteristics of the 1D model for strong motions and match the linear amplification ratio in GMPE for weak motions.The nonlinearity of the present site model is reasonably similar to that of the historical models,and the present site model could satisfactorily capture the nonlinear site response in empirical data. 展开更多
关键词 nonlinear site amplification model ground-motion prediction equations site class site impedance ratio site response analysis
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Rapid assessment of the September 5,2022 M_(S)6.8 Luding earthquake in Sichuan,China 被引量:2
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作者 Dengjie Kang Wenkai Chen +1 位作者 Huaiqun Zhao Dun Wang 《Earthquake Research Advances》 CSCD 2023年第2期1-7,共7页
At 12:52,September 5,2022,an M_(S)6.8 earthquake occurred in Luding,Sichuan.The earthquake caused serious casualties and property loss,and was determined to have an epicenter intensity of Ⅸ degree.In this study,we us... At 12:52,September 5,2022,an M_(S)6.8 earthquake occurred in Luding,Sichuan.The earthquake caused serious casualties and property loss,and was determined to have an epicenter intensity of Ⅸ degree.In this study,we used three earthquake intensity rapid assessment methods(i.e.WFM,BPM and ASM) to evaluate the intensity of this earthquake.Then,we comparatively analyzed the three methods based on strong ground motion observation data and actual intensity maps.The results show that:(1) The earthquake is associated with a southeast-oriented single-sided rupture.The WFM method can only evaluate earthquakes with two-sided ruptures,which has some limitations;(2) The intensity of BPM and ASM was overestimated on the southwest and north sides of the epicenter,but other high-intensity zones were similar to the intensities measured by actual surveys;(3) The residuals of the three intensity assessment methods were all between-0.5 and 1.Although a small number of stations were underestimated,the overall residuals were good,and the residuals gradually approached 0 with the increase of distance;(4) The number of towns and villages evaluated by the three methods in the earthquake area was almost all lower than the field survey results.One exception is the area of Ⅷ degree,where the BPM and ASM were higher than the survey results;(5) The area of the earthquake area evaluated by the three methods was low in Ⅵ and Ⅶ degree,moderate in Ⅷ degree,and low in Ⅸ degree(the area from ASM is similar to the area measured by actual survey).Overall,ASM is applicable to this earthquake intensity assessment. 展开更多
关键词 Luding earthquake Seismic intensity Rapid assessment Ground-Motion prediction equation BACK-PROJECTION AFTERSHOCK
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Effect of Recycled Aggregate and Slag as Substitutes for Natural Aggregate and Cement on the Properties of Concrete:A Review
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作者 Peng Zhang Wenshuai Wang +1 位作者 Yuanxun Zheng Shaowei Hu 《Journal of Renewable Materials》 SCIE EI 2023年第4期1853-1879,共27页
Using recycled aggregate(RA)and slag instead of natural aggregate(NA)and cement can reduce greenhouse gas emissions(GHGE)and achieve effective waste recovery.In recent years,RA has been widely used to replace NA in co... Using recycled aggregate(RA)and slag instead of natural aggregate(NA)and cement can reduce greenhouse gas emissions(GHGE)and achieve effective waste recovery.In recent years,RA has been widely used to replace NA in concrete.Every year,several researchers conduct investigations on the mechanical performance and durability of recycled aggregate concrete(RAC).Due to the loose and porous material properties of RA,the mechanical properties and durability of RAC,such as strength,carbonation resistance,permeability resistance and chloride ion penetration resistance,are greatly reduced compared with natural aggregate concrete.In contrast,concrete containing slag instead of NA and cement generally improved the strength of concrete and reduced the internal porosity of materials.Herein,we discuss the effects of RA and slag on the workability,compressive strength,splitting tensile strength,ultrasonic pulse velocity(UPV)value,and elastic modulus of concrete.The relationships between the compressive strength and the splitting tensile strength,UPV value,and elastic modulus are discussed,and the optimal substitution method is proposed.In addition,various equations for calculating the compressive strength of concrete based on performance factors related to the compressive strength are summarized. 展开更多
关键词 Recycled aggregate concrete slag concrete WORKABILITY mechanical performance prediction equations
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An investigation of the influence of near-fault ground motion parameters on the pile's response in liquefiable soil 被引量:7
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作者 Hui Shuqing Tang Liang +3 位作者 Zhang Xiaoyu Wang Youqing Ling Xianzhang Xu Bowen 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第4期729-745,共17页
The performance of a soil-pile system can be significantly influenced by ground motion parameters. However, few research efforts have been performed to provide a complete description of the influence of key ground mot... The performance of a soil-pile system can be significantly influenced by ground motion parameters. However, few research efforts have been performed to provide a complete description of the influence of key ground motion parameters on the pile’s behavior in liquefiable soil. In this study, a three-dimensional finite element(FE) model, incorporating a multisurface plasticity solid-fluid fully coupled formulation soil constitutive model, is developed and calibrated based on centrifuge test data. Seventy-two near-fault non-pulse-like(NF-NP) and seventy-two near-fault pulse-like(NF-P) ground motion records are studied with the calibrated FE model to distinguish the effects of several common ground motion parameters soon afterwards. Base on the parametric study results, a simple index, RPGV/PGA(i.e., the ratio of peak ground velocity(PGV) to peak ground acceleration(PGA)), shows its capability on characterizing the pile behavior under both NF-NP and NF-P ground motions. Furthermore, two equations are developed to characterize the relationships between the RPGV/PGA as well as the maximum pile’s moments and displacements. In general, this study can be helpful to gain new insights on the influence of typical index parameters for near-field ground motions on the response of the pile foundation in liquefiable soil. 展开更多
关键词 seismic response predictive equations near-fault ground motion pile foundation LIQUEFACTION
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Comparison of dominant frequency attenuation of blasting vibration for different charge structures 被引量:5
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作者 Pengchang Sun Wenbo Lu +3 位作者 Junru Zhou Xincheng Huang Ming Chen Qi Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第2期448-459,共12页
Dominant frequency attenuation is a significant concern for frequency-based criteria of blasting vibration control.It is necessary to develop a concise and practical prediction equation describing dominant frequency a... Dominant frequency attenuation is a significant concern for frequency-based criteria of blasting vibration control.It is necessary to develop a concise and practical prediction equation describing dominant frequency attenuation.In this paper,a prediction equation of dominant frequency that accounts for primary parameters influencing the dominant frequency was proposed based on theoretical and dimensional analyses.Three blasting experiments were carried out in the Chiwan parking lot for collecting blasting vibration data used to conduct regression analysis of the proposed prediction equation.The fitting equations were further adopted to compare the reliability of three different types of dominant frequencies in the proposed equation and to explore the effects of different charge structures on the dominant frequency attenuation.The apparent frequency proved to be more reliable to express the attenuation law of the dominant frequency.The reliability and superiority of the proposed equation employing the apparent frequency were verified by comparison with the other five prediction equations.The smaller blasthole diameter or decoupling ratio leads to the higher initial value and corresponding faster attenuation of the dominant frequency.The blasthole diameter has a greater influence on the dominant frequency attenuation than the decoupling ratio does.Among the charge structures applied in the experiments,the charge structure with decoupling ratio of 1.5 and blasthole diameter of 48 mm results in the greatest initial value and corresponding fastest attenuation of the dominant frequency. 展开更多
关键词 Dominant frequency Blasting vibration Attenuation law Prediction equation Charge structures
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Quantification and prediction of enteric methane emissions from Chinese lactating Holstein dairy cows fed diets with different dietary neutral detergent fiber/non-fibrous carbohydrate(NDF/NFC)ratios 被引量:3
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作者 DONG Li-feng JIA Peng +4 位作者 LI Bin-chang WANG Bei YANG Chun-lei LIU Zhi-hao DIAO Qi-yu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第3期797-811,共15页
Methane(CH_(4))emissions from ruminant production are a significant source of anthropogenic greenhouse gas production,but few studies have examined the enteric CH_(4)emissions of lactating dairy cows under different f... Methane(CH_(4))emissions from ruminant production are a significant source of anthropogenic greenhouse gas production,but few studies have examined the enteric CH_(4)emissions of lactating dairy cows under different feeding regimes in China.This study aimed to investigate the influence of different dietary neutral detergent fiber/non-fibrous carbohydrate(NDF/NFC)ratios on production performance,nutrient digestibility,and CH_(4)emissions for Holstein dairy cows at various stages of lactation.It evaluated the performance of CH_(4)prediction equations developed using local dietary and milk production variables compared to previously published prediction equations developed in other production regimes.For this purpose,36 lactating cows were assigned to one of three treatments with differing dietary NDF/NFC ratios:low(NDF/NFC=1.19),medium(NDF/NFC=1.54),and high(NDF/NFC=1.68).A modified acid-insoluble ash method was used to determine nutrient digestibility,while the sulfur hexafluoride technique was used to measure enteric CH4 emissions.The results showed that the dry matter(DM)intake of cows at the early,middle,and late stages of lactation decreased significantly(P<0.01)from 20.9 to 15.4 kg d^(–1),15.3 to 11.6 kg d^(–1),and 16.4 to 15.0 kg d^(–1),respectively,as dietary NDF/NFC ratios increased.Across all three treatments,DM and gross energy(GE)digestibility values were the highest(P<0.05)for cows at the middle and late lactation stages.Daily CH_(4)emissions increased linearly(P<0.05),from 325.2 to 391.9 kg d^(–1),261.0 to 399.8 kg d^(–1),and 241.8 to 390.6 kg d^(–1),respectively,as dietary NDF/NFC ratios increased during the early,middle,and late stages of lactation.CH_(4)emissions expressed per unit of metabolic body weight,DM intake,NDF intake,or fat-corrected milk yield increased with increasing dietary NDF/NFC ratios.In addition,CH_(4)emissions expressed per unit of GE intake increased significantly(P<0.05),from 4.87 to 8.12%,5.16 to 9.25%,and 5.06 to 8.17%respectively,as dietary NDF/NFC ratios increased during the early,middle,and late lactation stages.The modelling results showed that the equation using DM intake as the single variable yielded a greater R^(2)than equations using other dietary or milk production variables.When data obtained from each lactation stage were combined,DM intake remained a better predictor of CH_(4)emissions(R^(2)=0.786,P=0.026)than any other variables tested.Compared to the prediction equations developed herein,previously published equations had a greater root mean square prediction error,reflecting their inability to predict CH_(4)emissions for Chinese Holstein dairy cows accurately.The quantification of CH_(4)production by lactating dairy cows under Chinese production systems and the development of associated prediction equations will help establish regional or national CH_(4)inventories and improve mitigation approaches to dairy production. 展开更多
关键词 methane emission feeding regime prediction equation lactating dairy cow
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Hysteretic energy prediction method for mainshock-aftershock sequences 被引量:3
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作者 Zhai Changhai Ji Duofa +3 位作者 Wen Weiping Li Cuihua Lei Weidong Xie Lili 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第2期277-291,共15页
Structures located in seismically active regions may be subjected to mainshock-aftershock(MSAS)sequences.present study selected two kinds of MSAS sequences,with one aftershock and two aftershocks,respectively.The af... Structures located in seismically active regions may be subjected to mainshock-aftershock(MSAS)sequences.present study selected two kinds of MSAS sequences,with one aftershock and two aftershocks,respectively.The aftershocksThe MSAS sequence with one aftershock exhibited a 10%to 30%hysteretic energy increase,whereas the MSAS sequence with two aftershocks presented a 20%to 40%hysteretic energy increase.Finally,a hysteretic energy prediction equation is proposed as a function of the vibration period,ductility value,and damping ratio to estimate hysteretic energy for mainshockaftershock sequences. 展开更多
关键词 hysteretic energy mainshock-aftershock sequences SDOF system relative intensity prediction equation
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Conductivity Prediction of Sodium and Potassium Hydrogen Tartrates in Aqueous Solution at Low Concentration 被引量:2
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作者 倪良 蒋文华 韩世钧 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第2期159-162,共4页
An ionic conductivity prediction equation at low concentration for two acid salts is proposed taking into account the dissociation and association equilibria among ions. The salts considered are sodium and potassium h... An ionic conductivity prediction equation at low concentration for two acid salts is proposed taking into account the dissociation and association equilibria among ions. The salts considered are sodium and potassium hydrogen tartrates. There is no additional parameter of high order terms except for the Onsager's coefficient of limited term in the new equation. Results show a complex conductance of acidic tartrates in aqueous solution. The molar conductivities of metal ions are nearly constant such that the contributions from hydrogen and tartrate ions decrease with concentration, while the molar conductivity of bitartrate ion increases with concentration. 展开更多
关键词 sodium hydrogen tartrate potassium hydrogen tartrate prediction equation molar conductivity
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Probabilistic seismic hazard assessment of Kazakhstan and Almaty city in peak ground accelerations 被引量:3
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作者 N.V.Silacheva U.K.Kulbayeva N.A.Kravchenko 《Geodesy and Geodynamics》 2018年第2期131-141,共11页
As for many post-soviet countries, Kazakhstan’s building code for seismic design was based on a deterministic approach. Recently, Kazakhstan seismologists are engaged to adapt the PSHA(probabilistic hazard assessment... As for many post-soviet countries, Kazakhstan’s building code for seismic design was based on a deterministic approach. Recently, Kazakhstan seismologists are engaged to adapt the PSHA(probabilistic hazard assessment) procedure to the large amount of available geological, geophysical and tectonic Kazakh data and to meet standard requirements for the Eurocode 8. The new procedure has been used within National projects to develop the Probabilistic GSZ(General Seismic Zoning) maps of the Kazakhstan territory and the SMZ(Probabilistic Seismic Microzoning) maps of Almaty city. They agree with the seismic design principles of Eurocode 8 and are expressed in terms of not only seismic intensity,but also engineering parameters(peak ground acceleration PGA). The whole packet of maps has been developed by the Institute of Seismology, together with other Kazakhstan Institutions. Our group was responsible for making analysis in PGA. The GSZ maps and hazard assessment maps for SMZ in terms of PGA for return periods 475 and 2475 years are considered in the article. 展开更多
关键词 Probabilistic seismic hazard assessment Seismic zoning map Peak ground acceleration Seismic sources Seismotectonic setting Seismic regime Ground motion prediction equations
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Basal Energy Expenditure of Chinese Healthy Adults:Comparison of Measured and Predicted Values 被引量:2
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作者 MAO De Qian WU Jing Huan +8 位作者 HUANG Cheng Yu LI Ke Ji LIU Xiao Li ZHANG Shi Lian WANG Yan Ling CHEN Wei LI Ming YANG Xiao Guang PIAO Jian Hua 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2020年第8期566-572,共7页
Objective This study aimed to measure the basal energy expenditure(BEE)of Chinese healthy adults and establish an accurate predictive equation for this population.Methods In total,470 Chinese healthy adults had their ... Objective This study aimed to measure the basal energy expenditure(BEE)of Chinese healthy adults and establish an accurate predictive equation for this population.Methods In total,470 Chinese healthy adults had their BEE measured using the Cosmed K4b2 portable metabolic system.Multiple linear regression analysis was applied to develop new optimal equations for predicting BEE.The bias,accuracy rate,concordance correlation coefficient(CCC),and root mean square error(RMSE)were used to evaluate the accuracy of the predictive equations.Results There was a significant difference in BEE between males and females,with 5,954 kJ/d and 5,089 kJ/d,respectively.People living in rural areas expended significantly higher BEE(5,885 kJ/d)than those in urban areas(5,279 kJ/d).Previous equations developed by Henry,Schofield,Harris-Benedict(HB),and Liu overestimated the BEE of Chinese healthy adults.The new equations derived from the present study displayed the smallest average bias and RMSE from the measured basal energy expenditure(mBEE).The CCC of the new equations was higher than other predictive equations,but it was lower than 0.8.There was no significant difference in the accuracy rate among all predictive equations.Conclusions Sex and regional differences in BEE were observed in Chinese healthy adults.Neither the widely used previous predictive equations nor the one derived in the present study were accurate enough for estimating the BEE of Chinese healthy adults.Further study is required to develop more accurate equations for predicting the BEE of Chinese healthy adults aged between 20–45 years. 展开更多
关键词 Basal energy expenditure Chinese healthy adults Indirect calorimetry Predictive equations
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The correlationship between the metabolizable energy content,chemical composition and color score in different sources of corn DDGS 被引量:2
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作者 Yong-Z Jie Jian-Y Zhang +2 位作者 Li-H Zhao Qiu-G Ma Cheng Ji 《Journal of Animal Science and Biotechnology》 SCIE CAS 2014年第3期340-347,共8页
Background: This study was conducted to evaluate the apparent metabolizable energy (AME) and true metabolizable energy (TME) contents in 30 sources of corn distillers dried grains with solubles (DDGS) in adult ... Background: This study was conducted to evaluate the apparent metabolizable energy (AME) and true metabolizable energy (TME) contents in 30 sources of corn distillers dried grains with solubles (DDGS) in adult roosters, and establish the prediction equations to estimate the AME and TME value based on its chemical composition and color score. Methods: Twenty-eight sources of corn DDGS made from several processing plants in 11 provinces of China and others imported from the United States. DDGS were analyzed for their metabolizable energy (ME) contents, measured for color score and chemical composition (crude protein, crude fat, ash, neutral detergent fiber, acid detergent fiber), to predict the equation of ME in DDGS. A precision-fed rooster assay was used, each DDGS sample was tube fed (50 g) to adult roosters. The experiment was conducted as a randomized incomplete block design with 3 periods. Ninety-five adult roosters were used in each period, with 90 being fed the DDGS samples and 5 being fasted to estimate basal endogenous energy losses. Results: Results showed that the AME ranged from 5.93 to 12.19 MJ/kg, TME ranged from 7.28 to 13.54 MJ/kg. Correlations were found between ME and ash content (-0.64, P 〈 0.0]) and between ME and yellowness score (0.39, P 〈 0.05) of the DDGS samples. Furthermore, the best-fit regression equation for AME content of DDGS based on chemical composition and color score was AME = 6.57111 + 0.5]475 GE - 0.10003 NDF + 0.1 3380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R^2 = 0.70). The best-fit regression equation for TME content of DDGS was TME = 7.92283 + 0.51475 GE - 0.10003 NDF + 0.13380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R2 = 0.70). Conclusions: This experiment suggested that measuring the chemical composition and color score of a corn DDGS sample may provide a quality parameter for identifying corn DDGS sources energy digestibility and metabolizable energy content. 展开更多
关键词 Metabolizable energy Distillers dried grains with solubles Rooster Predictive equation
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Characteristics of horizontal ground motion measures along principal directions 被引量:1
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作者 K.Goda 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第1期9-22,共14页
Ground motion records are often used to develop ground motion prediction equations (GMPEs) for a randomly oriented horizontal component, and to assess the principal directions of ground motions based on the Arias in... Ground motion records are often used to develop ground motion prediction equations (GMPEs) for a randomly oriented horizontal component, and to assess the principal directions of ground motions based on the Arias intensity tensor or the orientation of the major response axis. The former is needed for seismic hazard assessment, whereas the latter can be important for assessing structural responses under multi-directional excitations. However, a comprehensive investigation of the pseudo-spectral acceleration (PSA) and of GMPEs conditioned on different axes is currently lacking. This study investigates the principal directions of strong ground motions and their relation to the orientation of the major response axis, statistics of the PSA along the principal directions on the horizontal plane, and correlation of the PSA along the principal directions on the horizontal plane. For these, three sets of strong ground motion records, including intraplate California earthquakes, inslab Mexican earthquakes, and interface Mexican earthquakes, are used. The results indicate that one of the principal directions could be considered as quasi-vertical. By focusing on seismic excitations on the horizontal plane, the statistics of the angles between the major response axis and the major principal axis are obtained; GMPEs along the principal axes are provided and compared with those obtained for a randomly oriented horizontal component; and statistical analysis of residuals associated with GMPEs along the principal directions is carried out. 展开更多
关键词 Arias intensity attenuation relation bi-directional seismic excitation ground motion prediction equation principal direction pseudo-spectral acceleration response axis
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Comparison of strong-motion records and damage implications between the 2014 Yunnan M_S6.5 Ludian earthquake and M_S6.6 Jinggu earthquake 被引量:1
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作者 Peibin Xu Ruizhi Wen Yefei Ren 《Earthquake Science》 CSCD 2018年第1期12-18,共7页
Serial destructive earthquakes have caused heavy casualties and economic losses to the city in southwestern of China. The Ludian Ms 6.5 earthquake and the Jinggu Ms 6.6 earthquake occurred in Yunnan province in 2014. ... Serial destructive earthquakes have caused heavy casualties and economic losses to the city in southwestern of China. The Ludian Ms 6.5 earthquake and the Jinggu Ms 6.6 earthquake occurred in Yunnan province in 2014. There is a question of why the two events with almost the same level of magnitude caused differences in earthquake damage. To understand the uniqueness of the phenomenon, this paper focuses on the characteristics of the ground motions and post-earthquake field investigation for the two events. Firstly, we present an overview of the residuals between the Ludian earthquake and the Jinggu earthquake based on the YW06 Ground Motion Prediction Equation (GMPE), and explain the unusual destructiveness of the strong ground motion. Then we analyze the ground motion recordings at selected typical station, based on the strong motion parameters: equivalent predominant frequency and Arias intensity. The result exhibits a good agreement with the Chinese seismic intensity scale. This study would be helpful to gain a better knowledge of the characteristics and variability of ground motions for Ms6 class earthquakes in China and to understand the implications to future earthquakes with similar focal mechanism and local condition. 展开更多
关键词 Ludian earthquake Jinggu earthquake ground motion prediction equation earthquake damage
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A Modified Mixing Rule for PSRK Model and Application for the Prediction of Vapor-Liquid Equilibria of Polymer Solutions 被引量:1
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作者 李敏 王利生 J.Gmehling 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第3期454-457,共4页
To extend the PSRK (predictive Soave-Redlich-Kwong equation of state) model to vapor-liquid equilibria of polymer solutions, a new EOS-gE mixing rule is applied in which the term ∑ xi ln(b/bi) in the PSRK mixing rule... To extend the PSRK (predictive Soave-Redlich-Kwong equation of state) model to vapor-liquid equilibria of polymer solutions, a new EOS-gE mixing rule is applied in which the term ∑ xi ln(b/bi) in the PSRK mixing rule for the parameter a, and the combinatorial part in the original universal functional activity coefficient (UNIFAC) model are cancelled. To take into account the free volume contribution to the excess Gibbs energy in polymer solution, a quadratic mixing rule for the cross co-volume bij with an exponent equals to 1/2 is applied[bij1/2= 1/2(bi1/2+bj1/2)]. The literature reported Soave-Redlich-Kwong equation of state (SRK EOS) parameters ofpure polymer are employed. The PSRK model with the modified mixing rule is used to predict the vapor-liquid equilibrium (VLE) of 37 solvent-polymer systems over a large range of temperature and pressure with satisfactory results. 展开更多
关键词 predictive Soave-Redlich-Kwong equation of state mixing rule vapor-liquid equilibrium polymer solutions
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Improved Quality Prediction Model for Multistage Machining Process Based on Geometric Constraint Equation 被引量:5
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作者 ZHU Limin HE Gaiyun SONG Zhanjie 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第2期430-438,共9页
Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process(MMP). However, due to the variation accumulation and propagation, it becomes qui... Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process(MMP). However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP. 展开更多
关键词 quality prediction variation reduction geometric constraint equation deviation matrix multistage machining process
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Bi-variable damage model for fatigue life prediction of metal components 被引量:1
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作者 Miao Zhang Qing-Chun Meng Xing Zhang Wei-Ping Hu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第3期416-425,共10页
Based on the theory of continuum damage mechanics,a bi-variable damage mechanics model is developed,which,according to thermodynamics,is accessible to derivation of damage driving force,damage evolution equation and d... Based on the theory of continuum damage mechanics,a bi-variable damage mechanics model is developed,which,according to thermodynamics,is accessible to derivation of damage driving force,damage evolution equation and damage evolution criteria. Furthermore,damage evolution equations of time rate are established by the generalized Drucker's postulate. The damage evolution equation of cycle rate is obtained by integrating the time damage evolution equations,and the fatigue life prediction method for smooth specimens under repeated loading with constant strain amplitude is constructed. Likewise,for notched specimens under the repeated loading with constant strain amplitude,the fatigue life prediction method is obtained on the ground of the theory of conservative integral in damage mechanics. Thus,the material parameters in the damage evolution equation can be obtained by reference to the fatigue test results of standard specimens with stress concentration factor equal to 1,2 and 3. 展开更多
关键词 Bi-variable damage model - Damage evolution equation . Life prediction - Fatigue . Damage mechanics
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Densities and Viscosities of the Quaternary System Mannitol-Sorbitol- D-Glucose-H2O and Its Ternary Subsystems at 298.15K
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作者 刘艳升 时铭显 +2 位作者 曹睿 张耀辉 胡玉峰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第5期703-709,共7页
To check the applicabilities of the simple density equation and viscosity equation in the semi-ideal solution theory to nonelectrolyte solutions, the densities and viscosities were measured for the quaternary system m... To check the applicabilities of the simple density equation and viscosity equation in the semi-ideal solution theory to nonelectrolyte solutions, the densities and viscosities were measured for the quaternary system mannitol-sorbitol-D-glucose-HzO and its ternary subsystems mannitol-D-glucose-H2O and sorbitol-D-glucose-H2O at 298.15K. The results were used to test the applicability of the simple equations for the density and viscosity of the multicomponent nonelectrolyte solution. The agreements between the predicted and measured results are good. 展开更多
关键词 density viscosity MANNITOL SORBITOL D-GLUCOSE simple predictive equations
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Engineering Analysis of Strong Motion Data from Recent Earthquakes in Sichuan, China
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作者 HUANG Chen GALASSO Carmine 《工程科学与技术》 EI CAS CSCD 北大核心 2018年第3期112-124,共13页
Recent earthquakes in the Sichuan Province have contributed to significantly expand the existing ground-motion database for China with new,high-quality ground-motion records.This study investigated the compatibility o... Recent earthquakes in the Sichuan Province have contributed to significantly expand the existing ground-motion database for China with new,high-quality ground-motion records.This study investigated the compatibility of ground-motion prediction equations(GMPEs)established by the NGA-West2 project in the US and local GMPEs for China,with respect to magnitude scaling,distance scaling,and site scaling implied by recent Chinese strong-motion data.The NGA-West2 GMPEs for shallow crustal earthquakes in tectonically active regions are considerably more sophisticated than widely used previous models,particularly in China.Using a mixed-effects procedure,the study evaluated event terms(inter-event residuals)and intra-event residuals of Chinese data relative to the NGA-West2 GMPEs.Distance scaling was investigated by examining trends of intra-event residuals with source-to-site distance.Scaling with respect to site conditions was investigated by examining trends of intra-event residuals with soil type.The study also investigated other engineering characteristics of Chinese strong ground motions.In particular,the records were analyzed for evidence of pulse-like forward-directivity effects.The elastic median response spectra of the selected stations were compared to code-mandated design spectra for various mean return periods.Results showed that international and local GMPEs can be applied for seismic hazard analysis in Sichuan with minor modification of the regression coefficients related to the source-to-site distance and soil scaling.Specifically,the Chinese data attenuated faster than implied by the considered GMPEs and the differences were statistically significant in some cases.Near-source,pulse-like ground motions were identified at two recording stations for the 2008 Wenchuan earthquake,possibly implying rupture directivity.The median recorded spectra were consistent with the code-based spectra in terms of amplitude and shape.The new ground-motion data can be used to develop advanced ground-motion models for China and worldwide and,ultimately,for advancing probabilistic seismic hazard assessment(PSHA). 展开更多
关键词 ground motion prediction equations NGA-West2 project code-based spectrum pulse-like ground motions
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The dependence of response spectrum on the tectonic ambient shear stress field
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作者 李保昆 陈培善 白彤霞 《Acta Seismologica Sinica(English Edition)》 CSCD 2005年第3期313-321,378,共10页
It has been analyzed the influence of the tectonic ambient shear stress value on response spectrum based on the previous theory. Based on the prediction equation BJF94 presented by the famous American researchers, CLB... It has been analyzed the influence of the tectonic ambient shear stress value on response spectrum based on the previous theory. Based on the prediction equation BJF94 presented by the famous American researchers, CLB20, a new prediction formula is proposed by us, where it is introduced the influence of tectonic ambient shear stress value on response spectrum. BJF94 is the prediction equation, which mainly depends on strong ground motion data from western USA, while the prediction equation SEA99 is based on the strong ground motion data from exten-sional region all over the world. Comparing these two prediction equations in detail, it is found that after BJF94′s prediction value lg(Y) minus 0.16 logarithmic units, the value is very close to SEA99′s one. This case demonstrates that lg(Y) in extensional region is smaller; the differences of prediction equation are mainly owe to the differences of tectonic ambient shear stress value. If the factor of tectonic ambient shear stress value is included into the pre-diction equation, and the magnitude is used seismic moment magnitude to express, which is universal used around the world, and the distance is used the distance of fault project, which commonly used by many people, then re-gional differences of prediction equation will become much less, even vanish, and it can be constructed the uni-versal prediction equation proper to all over the world. The error in the earthquake-resistant design in China will be small if we directly use the results of response spectrum of USA (e.g. BJF94 or SEA99). 展开更多
关键词 acceleration response spectrum tectonic ambient shear stress field prediction equation of re-sponse spectrum seismic moment magnitude distance of fault project
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