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论“更”字比较句中三项比较的程式模型——兼论认知模式下“最”的比较方案
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作者 田家隆 《励耘语言学刊》 CSSCI 2015年第2期158-172,共15页
含有三个或多个比较项的“更”字比较句,都是两两多次比较的复句,而并非各项一起比较。从格式看,存在承式递较、逆式递较、交式递较三种;从形式看,存在肯定式和否定式两种;从对象看,存在主观性和客观性两种。基于认知模式,由于比较内容... 含有三个或多个比较项的“更”字比较句,都是两两多次比较的复句,而并非各项一起比较。从格式看,存在承式递较、逆式递较、交式递较三种;从形式看,存在肯定式和否定式两种;从对象看,存在主观性和客观性两种。基于认知模式,由于比较内容的主客观性,使得“最”的比较更加依靠完形感知与和谐整合。 展开更多
关键词 “更” 三项比较 比较程式 认知模式 “最” 完形感知
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“最是一年春好处”之“最”的语义与语序 被引量:1
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作者 吴茂刚 《牡丹江师范学院学报(社会科学版)》 2009年第4期59-61,共3页
现在一些论著认为韩愈"最是一年春好处"一句的"最"是时间副词,这种解释不妥;此句是"一年春最是好处"的非常规语序;副词"最"在古代汉语中处于非常规位置是一种较常见的现象,起强调状态达到顶点... 现在一些论著认为韩愈"最是一年春好处"一句的"最"是时间副词,这种解释不妥;此句是"一年春最是好处"的非常规语序;副词"最"在古代汉语中处于非常规位置是一种较常见的现象,起强调状态达到顶点或动作行为程度最高的作用,不能简单地理解为时间副词"正"。 展开更多
关键词 汉语语法史 “最” 非常规位置 强调
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State of China’s climate in 2023
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作者 Linhai Sun Xiaying Zhu +8 位作者 Wei Li Wanxiu Ai Xianyan Chen Yundi Jiang Ling Wang Xukai Zou Shanshan Zhao Hongling Zeng Hailing Zhong 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第5期54-60,共7页
China witnessed a warm and dry climate in 2023.The annual surface air temperature reached a new high of 10.71℃,with the hottest autumn and the second hottest summer since 1961.Meanwhile,the annual precipitation was t... China witnessed a warm and dry climate in 2023.The annual surface air temperature reached a new high of 10.71℃,with the hottest autumn and the second hottest summer since 1961.Meanwhile,the annual precipitation was the second lowest since 2012,at 615.0 mm.Precipitation was less than normal from winter to summer,but more in autumn.Consistent with the annual condition,precipitation in the flood season from May to September was also the second lowest since 2012,which was 4.3%less than normal,with the anomalies in the central and eastern parts of China being higher in central areas and lower in the north and south.On the contrary,the West China Autumn Rain brought much more rainfall than normal,with an earlier start and later end.Although there was less annual precipitation in 2023,China suffered seriously from heavy precipitation events and floods.In particular,from the end of July to the beginning of August,a rare,extremely strong rainstorm caused by Typhoon Dussuri hit Beijing,Tianjin,and Hebei,causing an abrupt alteration from drought to flood conditions in North China.By contrast,Southwest China experienced continuous drought from the previous autumn to current spring.In early summer,North China and the Huanghuai region experienced the strongest high-temperature process since 1961.Nevertheless,there were more cold-air processes than normal impacting China,with the most severe of the year occurring in mid-January.Unexpectedly,in spring,there were more sand and dust occurrences in northern China. 展开更多
关键词 Climate in China Hottest year Extreme events Dussuri
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Optimal Control for Age Distribution and Weighted Size Competitive Species in a Polluted Environment
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作者 WANG Zhanping 《应用数学》 北大核心 2024年第4期1014-1026,共13页
In the paper,we study an optimal control for a system representing a competitive species model with fertility and mortality depending on a weighted size in a polluted environment.A fixed point theorem is applied to ob... In the paper,we study an optimal control for a system representing a competitive species model with fertility and mortality depending on a weighted size in a polluted environment.A fixed point theorem is applied to obtain the existence and uniqueness exhibited by a non-negative solution of above mentioned model.A maximum principle helps to carefully verify the existence of the optimal control policy,and tangent-normal cone techniques help to obtain the optimal condition specific to control issue. 展开更多
关键词 Optimal control Competitive species POLLUTION Maximum principle
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Research on the Mechanism of Multi-Sensor Fusion Configuration Based on the Optimal Principle of the Vehicle
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作者 Zhao Binggen Zeng Dong +2 位作者 Lin Haoyu Qiu Xubo Hu Pijie 《汽车技术》 CSCD 北大核心 2024年第10期28-37,共10页
In order to address the issue of sensor configuration redundancy in intelligent driving,this paper constructs a multi-objective optimization model that considers cost,coverage ability,and perception performance.And th... In order to address the issue of sensor configuration redundancy in intelligent driving,this paper constructs a multi-objective optimization model that considers cost,coverage ability,and perception performance.And then,combining a specific set of parameters,the NSGA-II algorithm is used to solve the multi-objective model established in this paper,and a Pareto front containing 24 typical configuration schemes is extracted after considering empirical constraints.Finally,using the decision preference method proposed in this paper that combines subjective and objective factors,decision scores are calculated and ranked for various configuration schemes from both cost and performance preferences.The research results indicate that the multi-objective optimization model established in this paper can screen and optimize various configuration schemes from the optimal principle of the vehicle,and the optimized configuration schemes can be quantitatively ranked to obtain the decision results for the vehicle under different preference tendencies. 展开更多
关键词 Multi-sensor fusion Intelligent driving Multi-objective optimization Vehicle optimization
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Numerical Methods for a Class of Quadratic Matrix Equations
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作者 GUAN Jinrui WANG Zhixin SHAO Rongxia 《应用数学》 北大核心 2024年第4期962-970,共9页
Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of... Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of minimal nonnegative solution for this quadratic matrix equation,and then propose some numerical methods for solving it.Convergence analysis and numerical examples are given to verify the theories and the numerical methods of this paper. 展开更多
关键词 Quadratic matrix equation M-MATRIX Minimal nonnegative solution Newton method Bernoulli method
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Trigonometric Regularization and Continuation Method Based Time-Optimal Control of Hypersonic Vehicles
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作者 LIN Yujie HAN Yanhua 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第S01期52-59,共8页
Aiming at the time-optimal control problem of hypersonic vehicles(HSV)in ascending stage,a trigonometric regularization method(TRM)is introduced based on the indirect method of optimal control.This method avoids analy... Aiming at the time-optimal control problem of hypersonic vehicles(HSV)in ascending stage,a trigonometric regularization method(TRM)is introduced based on the indirect method of optimal control.This method avoids analyzing the switching function and distinguishing between singular control and bang-bang control,where the singular control problem is more complicated.While in bang-bang control,the costate variables are unsmooth due to the control jumping,resulting in difficulty in solving the two-point boundary value problem(TPBVP)induced by the indirect method.Aiming at the easy divergence when solving the TPBVP,the continuation method is introduced.This method uses the solution of the simplified problem as the initial value of the iteration.Then through solving a series of TPBVP,it approximates to the solution of the original complex problem.The calculation results show that through the above two methods,the time-optimal control problem of HSV in ascending stage under the complex model can be solved conveniently. 展开更多
关键词 hypersonic vehicle(HSV) optimal control trigonometric regularization method(TRM) continuation method
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Improved AVOA based on LSSVM for wind power prediction
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作者 ZHANG Zhonglin WEI Fan +1 位作者 YAN Guanghui MA Haiyun 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第3期344-359,共16页
Improving the prediction accuracy of wind power is an effective means to reduce the impact of wind power on power grid.Therefore,we proposed an improved African vulture optimization algorithm(AVOA)to realize the predi... Improving the prediction accuracy of wind power is an effective means to reduce the impact of wind power on power grid.Therefore,we proposed an improved African vulture optimization algorithm(AVOA)to realize the prediction model of multi-objective optimization least squares support vector machine(LSSVM).Firstly,the original wind power time series was decomposed into a certain number of intrinsic modal components(IMFs)using variational modal decomposition(VMD).Secondly,random numbers in population initialization were replaced by Tent chaotic mapping,multi-objective LSSVM optimization was introduced by AVOA improved by elitist non-dominated sorting and crowding operator,and then each component was predicted.Finally,Tent multi-objective AVOA-LSSVM(TMOALSSVM)method was used to sum each component to obtain the final prediction result.The simulation results show that the improved AVOA based on Tent chaotic mapping,the improved non-dominated sorting algorithm with elite strategy,and the improved crowding operator are the optimal models for single-objective and multi-objective prediction.Among them,TMOALSSVM model has the smallest average error of stroke power values in four seasons,which are 0.0694,0.0545 and 0.0211,respectively.The average value of DS statistics in the four seasons is 0.9902,and the statistical value is the largest.The proposed model effectively predicts four seasons of wind power values on lateral and longitudinal precision,and faster and more accurately finds the optimal solution on the current solution space sets,which proves that the method has a certain scientific significance in the development of wind power prediction technology. 展开更多
关键词 African vulture optimization algorithm(AVOA) least squares support vector machine(LSSVM) variational mode decomposition(VMD) multi-objective prediction wind power
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Techno-economic and Environmental Assessments of SAF from Bioamss:An Review
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作者 MAHMOOD T.M.N.Saeed PANG Shusheng CHEN Qiang 《林产化学与工业》 CAS CSCD 北大核心 2024年第5期29-51,共23页
This review presents a comprehensive techno-economic and life-cycle assessment of sustainable aviation fuel(SAF)production from biomass.The critical need for transitioning towards environmentally sustainable alternati... This review presents a comprehensive techno-economic and life-cycle assessment of sustainable aviation fuel(SAF)production from biomass.The critical need for transitioning towards environmentally sustainable alternatives for liquid fuel and aviation industry is first discussed.Key insights encompass the evolutionary progression of biofuel production from first-generation to second-generation biofuels,with a focus on utilizing non-food sources like woody biomass for enhanced sustainability.Available data from the literature on techno-economic assessments of various SAF production pathways are analyzed including production costs,conversion efficiency,and scalability.Moreover,results of lifecycle assessments associated with different SAF production pathways are presented,providing essential insights for decision-making processes.The challenges of scaling up woody biomass-based SAF production are discussed based on the assessment results,and recommendations are proposed to steer stakeholders towards a greener and more sustainable trajectory for aviation operations. 展开更多
关键词 sustainable aviation fuel woody biomass production costs minimum fuel selling price lifecycle assessment greenhouse gas emissions climate change
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程度副词“顶”进入现代汉语的过程 被引量:1
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作者 聂志军 唐亚慧 《重庆工商大学学报(社会科学版)》 2011年第1期110-116,共7页
程度副词"顶"在南宋时期已经产生,经历过元代和明代前期的沉寂以后,在明末开始获得发展,一扫长时期可能只在南方口语中流行的颓势,并且有了向北方渗透的苗头。随着时间的推移,在清末至民国时期,程度副词"顶"获得了... 程度副词"顶"在南宋时期已经产生,经历过元代和明代前期的沉寂以后,在明末开始获得发展,一扫长时期可能只在南方口语中流行的颓势,并且有了向北方渗透的苗头。随着时间的推移,在清末至民国时期,程度副词"顶"获得了很好的发展,到20世纪三、四十年代,它已经完成了进入现代汉语的过程。当然,目前在和"最"的竞争中仍然出于劣势,但是,必须肯定已经进入到现代汉语普通话之中。 展开更多
关键词 程度副词 “顶” “最” 方言进入说
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Geophysical data sparse reconstruction based on L0-norm minimization 被引量:6
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作者 陈国新 陈生昌 +1 位作者 王汉闯 张博 《Applied Geophysics》 SCIE CSCD 2013年第2期181-190,236,共11页
Missing data are a problem in geophysical surveys, and interpolation and reconstruction of missing data is part of the data processing and interpretation. Based on the sparseness of the geophysical data or the transfo... Missing data are a problem in geophysical surveys, and interpolation and reconstruction of missing data is part of the data processing and interpretation. Based on the sparseness of the geophysical data or the transform domain, we can improve the accuracy and stability of the reconstruction by transforming it to a sparse optimization problem. In this paper, we propose a mathematical model for the sparse reconstruction of data based on the LO-norm minimization. Furthermore, we discuss two types of the approximation algorithm for the LO- norm minimization according to the size and characteristics of the geophysical data: namely, the iteratively reweighted least-squares algorithm and the fast iterative hard thresholding algorithm. Theoretical and numerical analysis showed that applying the iteratively reweighted least-squares algorithm to the reconstruction of potential field data exploits its fast convergence rate, short calculation time, and high precision, whereas the fast iterative hard thresholding algorithm is more suitable for processing seismic data, moreover, its computational efficiency is better than that of the traditional iterative hard thresholding algorithm. 展开更多
关键词 Geophysical data sparse reconstruction LO-norm minimization iterativelyreweighted least squares fast iterative hard thresholding
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The optimal fractional Gabor transform based on the adaptive window function and its application 被引量:4
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作者 陈颖频 彭真明 +2 位作者 贺振华 田琳 张洞君 《Applied Geophysics》 SCIE CSCD 2013年第3期305-313,358,共10页
We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractiona... We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractional domain and improved the time-frequency concentration of the Gabor transform. The algorithm first searches for the optimal rotation factor, then performs the p-th FrFT of the signal and, finally, performs time and frequency analysis of the FrFT result. Finally, the algorithm rotates the plane in the fractional domain back to the normal time-frequency plane. This promotes the application of FrFT in the field of high-resolution reservoir prediction. Additionally, we proposed an adaptive search method for the optimal rotation factor using the Parseval principle in the fractional domain, which simplifies the algorithm. We carried out spectrum decomposition of the seismic signal, which showed that the instantaneous frequency slices obtained by the proposed algorithm are superior to the ones obtained by the traditional Gabor transform. The adaptive time frequency analysis is of great significance to seismic signal processing. 展开更多
关键词 FrFT generalized time bandwidth product optimal rotation factor search adaptive optimal Gabor transform spectral decomposition seismic signals
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Ultimate pit optimization with ecological cost for open pit metal mines 被引量:3
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作者 胥孝川 顾晓薇 +2 位作者 王青 刘剑平 王俊 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第5期1531-1537,共7页
The ecological costs of open pit metal mining are quantified, which include lost value of direct eco-services, lost value of indirect eco-services, prevention and restoration costs, and cost of carbon emission from en... The ecological costs of open pit metal mining are quantified, which include lost value of direct eco-services, lost value of indirect eco-services, prevention and restoration costs, and cost of carbon emission from energy consumption. These ecological costs are incorporated in an iterative ultimate pit optimization algorithm. A case study is presented to demonstrate the influence of ecological costs on pit design outcome. The results show that it is possible to internalize ecological costs in mine designs. The pit optimization outcome shifts considerably to the conservative side and the profitability decreases substantially when ecological costs are accounted for. 展开更多
关键词 ultimate pit OPTIMIZATION ecological cost open pit metal mine
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Effects of parameters of asphalt concrete surfacing on mechanical property of paving layer 被引量:6
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作者 钱振东 黄卫 《Journal of Southeast University(English Edition)》 EI CAS 2003年第1期79-82,共4页
The important parameters that influence the mechanical property of the pavinglayer on an orthotropic steel bridge deck are the paving layer thickness and modulus of the asphaltconcrete surfacing. Three important indic... The important parameters that influence the mechanical property of the pavinglayer on an orthotropic steel bridge deck are the paving layer thickness and modulus of the asphaltconcrete surfacing. Three important indices that control the typical failures of the paving layerare the maximum tensile stress of paving layer, the maximum shear stress between the steel deck andthe paving layer, and the maximum deflection on the paving surface. In this paper, the analyticalmodel of paving systems on orthotropic steel bridge deck is established, and the finite elementmethod is adopted to study the stress and strain of paving system. With the variation of asphaltconcrete modulus in high or low temperature season, the influences of paving layer thickness onthree control indices are researched. The results provide a theoretical basis for the determinationof thickness of the paving layer on the steel bridge deck. 展开更多
关键词 paving layer othotropic steel deck stress strain surface deflection finite element
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Grain Yield Prediction for Irrigation District Based on LS-SVM 被引量:5
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作者 宰松梅 贾艳辉 +1 位作者 温季 郭冬冬 《Agricultural Science & Technology》 CAS 2009年第6期1-3,6,共4页
Commonly used grain yield forecasting models were briefly reviewed, and a yield prediction model of irrigation district was established based on least squares support vector machines (LS-SVM). The grain yield in irr... Commonly used grain yield forecasting models were briefly reviewed, and a yield prediction model of irrigation district was established based on least squares support vector machines (LS-SVM). The grain yield in irrigation district was analog calculated. And the test samples were used to compare with gray prediction, and neural network model. The maximum predicted error of least squares SVM was 7.12%, with an average error of 4.81%. The results showed that LS-SVM model has high prediction accuracy and strong generalization ability. So it could be used as a new method for irrigation district yield prediction 展开更多
关键词 YIELD PREDICTION LS-SVM MODEL
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AVAILABILITY SIMULATION OF MULTI-COMPONENT SYSTEM BASED ON OPPORTUNISTIC MAINTENANCE POLICY 被引量:5
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作者 蔡景 左洪福 吕德峰 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2009年第3期219-223,共5页
A multi-component system has the long fixed maintenance time, so the opportunistic maintenance policy is adopted to put preventive replacement and corrective replacement together, so that the long fixed maintenance ti... A multi-component system has the long fixed maintenance time, so the opportunistic maintenance policy is adopted to put preventive replacement and corrective replacement together, so that the long fixed maintenance time can be shared by more than one component, and the system availability can be improved. Then, the generation characteristics of the random failure time are researched based on the replacement maintenance and the minima[ maintenance. Furthermore, by choosing the opportunistic replacement ages of each component as opti- mized variables, a simulation algorithm based on an opportunistic maintenance policy is designed to maximize the total availability. Finally, the simulation result shows the validity of the algorithm by an example. 展开更多
关键词 AVAILABILITY multi-component system ALGORITHMS opportunistic maintenance minimal maintenance
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离心风机的旋转脱流及其风道振动 被引量:4
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作者 李晓芸 王秉仁 曹振禄 《流体机械》 CSCD 北大核心 1994年第9期7-12,共6页
结合治理离心风机的旋转脱流所引起的风机一风道系统振动的实践,对处于低流量工况区工作的离心风机所出现的旋转脱流的特点进行了分析,并论述了振动产生的机理及治理方法。
关键词 离心风机 旋转脱流 锅炉 振动
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Noise filtering of full-gravity gradient tensor data 被引量:8
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作者 袁园 黄大年 +1 位作者 余青露 耿美霞 《Applied Geophysics》 SCIE CSCD 2013年第3期241-250,357,共11页
In oil and mineral exploration, gravity gradient tensor data include higher- frequency signals than gravity data, which can be used to delineate small-scale anomalies. However, full-tensor gradiometry (FTG) data are... In oil and mineral exploration, gravity gradient tensor data include higher- frequency signals than gravity data, which can be used to delineate small-scale anomalies. However, full-tensor gradiometry (FTG) data are contaminated by high-frequency random noise. The separation of noise from high-frequency signals is one of the most challenging tasks in processing of gravity gradient tensor data. We first derive the Cartesian equations of gravity gradient tensors under the constraint of the Laplace equation and the expression for the gravitational potential, and then we use the Cartesian equations to fit the measured gradient tensor data by using optimal linear inversion and remove the noise from the measured data. Based on model tests, we confirm that not only this method removes the high- frequency random noise but also enhances the weak anomaly signals masked by the noise. Compared with traditional low-pass filtering methods, this method avoids removing noise by sacrificing resolution. Finally, we apply our method to real gravity gradient tensor data acquired by Bell Geospace for the Vinton Dome at the Texas-Louisiana border. 展开更多
关键词 Gravity gradient tensor Laplace equation optimal linear inversion low-passfilter high frequency signal
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EFFECT OF COOLING/LUBRICATION MEDIUM ON MACHINABILITY OF Ti6Al4V 被引量:5
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作者 戚宝运 何宁 李亮 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第3期225-230,共6页
To better understand and know the roles of cooling/lubrication medium in the cutting process and expand their applicability,uncoated cemented carbide tools are used in high-speed turning Ti6Al4V.Dry,cold air,minimal q... To better understand and know the roles of cooling/lubrication medium in the cutting process and expand their applicability,uncoated cemented carbide tools are used in high-speed turning Ti6Al4V.Dry,cold air,minimal quantity lubrication(MQL),cryogenic MQL,and ionized air as the cooling/lubrication conditions are studied.Experimental results show that at speed 120 m/min turning Ti6Al4V,the cutting force under ionized air is smallest under all lubricant conditions,and tool life is best,next is cryogenic MQL.MQL and cold air almost have the same effect,a little better than dry.Meanwhile the smallest surface roughness is also obtained under ionized air condition.Flank wear and crater wear are the dominant failure modes when high-speed turning Ti6Al4V by SEM analysis.Finally the conclusion is drawn that ionized air and cryogenic MQL have better cooling/lubrication effects and can effectively improve the tool life. 展开更多
关键词 cooling/lubrication high-speed turning TI6AL4V minimal quantity lubrication(MQL) ionized air
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Theoretical analysis of minimum metal foil thickness achievable by asymmetric rolling with fixed identical roll diameters 被引量:3
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作者 刘鑫 刘相华 +2 位作者 宋孟 孙祥坤 刘立忠 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第2期501-507,共7页
A novel approach is proposed for computing the minimum thickness of a metal foil that can be achieved by asymmetric rolling using rolls with identical diameter. This approach is based on simultaneously solving Tseliko... A novel approach is proposed for computing the minimum thickness of a metal foil that can be achieved by asymmetric rolling using rolls with identical diameter. This approach is based on simultaneously solving Tselikov equation for the rolling pressure and the modified Hitchcock equation for the roller flattening. To minimize the effect of the elastic deformation on the equal flow per second during the ultrathin foil rolling process, the law of conservation of mass was employed to compute the proportions of the forward slip, backward slip, and the cross shear zones in the contact arc, and then a formula was derived for computing the minimum thickness for asymmetric rolling. Experiment was conducted to find the foil minimum thickness for 304 steel by asymmetric rolling under the asymmetry ratios of 1.05, 1.15 and 1.30. The experimental results are in good agreement with the calculated ones. It was validated that the proposed formula can be used to calculate the foil minimum thickness under the asymmetric rolling condition. 展开更多
关键词 minimum thickness metal foil law of mass conservation asymmetric rolling
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