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Search Results: 1 - 10 of 427262 matches for " <br>刘鹏飞 "
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复杂环境下CFRP-高强混凝土界面性能有限元分析
Finite element analysis on the interfacial properties of high- strength concrete strengthened with CFRP under complex environmental conditions

王苏岩,鹏飞<br>WANG Suyan, LIU Pengfei
- , 2016,
Abstract: 利用ABAQUS有限元分析软件,对持续荷载与冻融循环耦合作用下以及持续荷载与干湿循环耦合作用下CFRP加固高强混凝土双面剪切试件的界面黏结性能试验进行有限元模拟,将模拟结果与已有试验结果进行对比。结果表明:有限元模拟的计算值与试验结果吻合较好,2种复杂环境均会造成黏结界面的损伤,随着冻融循环与干湿循环作用次数的增加,试件界面的极限荷载、极限端部黏结滑移均随之降低,持续荷载的施加使降低程度加剧。在验证模拟结果正确的基础上,进一步分析试件的破坏形态的变化规律,在冻融循环作用下,试件发生混凝土内部剪切破坏;随着干湿循环作用次数的增加,试件的破坏方式由混凝土内部剪切破坏逐渐转变为界面的黏结破坏。
This paper conducted a numerical simulation about the double-sided shear test, made a finite element analysis about the interfacial bond performance between CFRP and high strength concrete under coupling function of sustaining load and freeze-thaw cycle, coupling function of sustaining load and dry-wet cycle.The simulation results were compared with the experimental results. Freeze-thaw cycle and dry-wet cycle both damage the interfacial bond performance. With the increase of freeze-thaw cycles, specimen limit load and ultimate end of the interface bond-slip decreases, continuous load can make the damage degree increased. On the basis of correctness about the result of simulation, a further analysis about the change rule of the damage form of specimens was made. Specimens failed from concrete shearing failures under the function of freeze-thaw cycle. Failure mode was changed by the shift to adhesive failure between resin and concrete from concrete shearing failures when the dry-wet cycle increases
利润-CVaR准则下考虑缺货成本的报童模型研究
Study on Newsvendor Model with Lost Sale Penalty Cost under Criterion of Profit-CVaR
 [PDF]

鹏飞, 贺思云
Management Science and Engineering (MSE) , 2015, DOI: 10.12677/MSE.2015.42004
Abstract:
本文研究了在利润-CVaR准则下,缺货惩罚成本和期望利润权重对厌恶风险的报童的最优订货量的影响。提出了一种组合的期望收益和风险,既反映报童追求高利润的愿望,又反映其对潜在风险的控制。采用该组合为目标函数,对报童的订货策略进行了研究。研究表明,考虑缺货惩罚时,最优订货量依赖于风险厌恶程度、期望利润值权重以及单位缺货惩罚成本,并通过数值算例进行验证。
In this paper, in a profit-CVaR framework, we study the impact of lost sale penalty cost and expected profit weight on a risk aversion newsvendor’s optimal ordering quantity. A combination of the expected profit and CVaR is proposed, which reflects the desire of the risk-averse newsvendor to maximize the profit on the one hand and minimize the downside risk of the profit on the other hand. By using the combination as an objective function, the ordering strategies of the newsvendor are studied. We show that when there is lost sale penalty cost, the optimal ordering quantity depends on degree of risk aversion, expected profit weight and value of shortage cost. And then we illustrate our findings by examples.
基于利润-CVaR的供应链价格补贴契约优化与协调研究
Research on Markdown Money Contract Optimization and Coordination of Supply Chain Based on the Profit-CVaR
 [PDF]

鹏飞, 谢梦洁
Management Science and Engineering (MSE) , 2016, DOI: 10.12677/MSE.2016.52009
Abstract: 本文研究风险中性供应商和风险厌恶零售商组成的二级供应链协调问题。运用利润-CVaR度量零售商风险厌恶,建立随机需求下供应链价格补贴协调模型。在一定范围内,最优订购量随风险厌恶因子和CVaR权重的增加而减少,价格补贴随CVaR权重和风险厌恶因子的增加而增加,价格补贴契约能完美协调供应链并通过数值算例进行验证。
This paper studied the coordination of a two-echelon supply chain with a risk-neutral supplier and a risk-averse retailer. The risk aversion of the retailer was measured by profit-CVaR. We construct the markdown money contract coordination model of supply chain under stochastic demand. At a certain range, the optimal ordering quantity is reduced along with the increase of risk aversion factor and weight of CVaR; and markdown money is increased with the increase of risk aversion factor and weight of CVaR. Markdown money contract can perfectly coordinate supply chain. And we verify the conclusions through a numerical example.
Maximal metabolic rate in Apodemus chevrieri born in current year
当年生高山姬鼠最大代谢率

liupengfei,wangzhengkun,<br>柳鹏飞,王政昆,王睿,朱万龙,春燕
生态学报 , 2010,
Abstract: The cold-induced Maximal Metabolic Rate(MMR) and locomotion-induced MMR of Apodemus Chevrieri born in current year and in past years are measured with the open-respiratory analyzer. Cold-induced MMR and locomotion-induced MMR of Apodemus Chevrieri born in current year are (7.25±0.25)mLO2/(g?h) and (9.22±0.27)mLO2/(g?h) respectively.There was no significant difference between males and females in cold-induced MMR, whereas locomotion-induced MMR in males was higher than females obviously. Cold-induced MMR of animals born in current year was lower than those born in past years, but Locomotion-induced MMR is the opposite. The results suggested that: the cold-induced MMR of males and females born in current year are almost the same, but lower than those born in past years because of the adaptation to the lower annual average temperature in Heng-duan mountain region. Locomotion-induced MMR in males was higher than that in females, it is possibly the result of long time adaptation in natural dispersing process after maturation to avoid inbreeding and competition.
A review of syntrophic fatty acids oxidation in anoxic paddy soil
水稻土中脂肪酸互营氧化的研究进展

LIU Peng-Fei,LU Ya-Hai,<br>鹏飞,陆雅海
微生物学通报 , 2013,
Abstract: Flooded rice field is one of major biogenic sources of greenhouse gas CH4. Complex organic matter is degraded to CH4 and CO2 by the co-operation of anaerobic microorganisms of several metabolic guilds involving the syntrophic oxidation of short-chain fatty acids like propionate, butyrate and acetate. Due to the fastidious nature of cultivation, the diversity and ecology of microorganisms involved in syntrophic oxidation in natural environments like paddy soils remain largely unexplored. Stable isotope probing (SIP), which links microbial identity and function, is a powerful tool to investigate the syntrophic oxidation of fatty acids in flooded paddy soils. This article reviews the recent research progresses in the thermodynamic principles, the interspecies interactions in the syntrophic oxidation of fatty acids, and paddy soils employing SIP technology. The knowledge acquired suggests that phylogenetically diverse bacterial groups are active in the syntrophic oxidation: except classic syntrophic bacteria, organisms belonging to uncultivated phylogenetic groups are also detected, which can serve as candidate syntrophs. Among archaea, Methanocella is the major methanogen partner in syntrophic oxidation of different fatty acids, indicating the importance of this group in CH4 production of paddy field soil.
STUDY ON THE PHYSICAL ENTRAPPING OF GOD VIA PRE IRRADIATION POLYMERIZATION AT ROOM TEMPERATURE
常温预辐射聚合法物理包埋葡萄糖氧化酶的研究

LIU Peng-fei,HA Hong-fei,<br>鹏飞,哈鸿飞
高分子学报 , 1992,
Abstract: Most of bioactive species such as enzyme and antibody will be damaged and lose part of their bioactivity when they are irradiated by ionizing radiation at room temperature. Low temperature could somewhat control the effect, so kaetsu and his co-workers developed an entrapping technique at low temperature ( - 78℃). On the other hand, some enzymes such as catalase and house radish peroxidase have so-called radiation-induced post-deactivation effect as well. In order to avoid the trouble in performance and loss of bioactivity, a physical ent-rapping of bioactive species via preirradiation polymerization at room temperature were deve-loped in the Authors'lab. In this work we developed this technique. The glucose oxidase was entrapped in polyacrylamide hydrogel ind uced by pre-irradiation. Experiments under several different conditions such as absorbed dose and concentrations of enzymes,monomer and crosslinking agent were carried out. The results showed that this technique can be used ex-tensively in various enzyme.
Parameters Identification and Uncertainty Analysis for Environmental Model
环境模型参数识别与不确定性分析

Liu Yi,Chen Jining,Du Pengfei,<br>,陈吉宁,鹏飞
环境科学 , 2002,
Abstract: This paper examined a case study of hydrological model for identifying parameter uncertainty by using three sensitivity analysis methods: HSY algorithm, linear regressional method and coupling analysis method. The results showed that optimal algorithms cannot give a sound explanation for complexity of model structure and identifying model parameters via uncertainty analysis methods presented an effective alternative to understand model system.
High capacity blind information hiding algorithm based on DCT
基于离散余弦变换的大容量信息隐藏盲提取算法

YU Peng-fei,LIU Bing,<br>余鹏飞,
计算机应用 , 2006,
Abstract: The AC coefficients of an image's Discrete Cosine Transform(DCT) are best approximated by Laplacian distribution model. Based on this model,the blind information hiding algorithm was proposed. Using a novel data embedding rule, this algorithm adjusted coefficients of DCT,whose absolute value is relative smaller than others. Positive numbers were used to denote one and negative numbers were used to represent zero respectively. Furthermore, the original image was not needed to extract secret data. The experiment results show that the algorithm has high capacity attribute, which is suitable for applications of secret communication.
长大列车通过弹性曲线轨道仿真求解方法研究
Simulation Solution Method for Long and Heavy-Haul Trains Negotiating Elastic Curved Tracks

鹏飞, 王开云, 翟婉明<br>LIU Pengfei, WANG Kaiyun, ZHAI Wanming
- , 2018, DOI: 10.3969/j.issn.0258-2724.2018.01.004
Abstract: 为解决长大列车与连续长弹性轨道的同步仿真问题,以列车通过曲线轨道为例,采用重载列车-轨道耦合动力学模型,分析了压钩力作用下轨道结构与30 t轴重列车的动态特性,提出了长大重载列车与轨道动态相互作用仿真时模型的简化求解方法.该方法将庞大的列车/轨道耦合振动系统以有限数目的三维车辆模型代替,并考虑其轨下基础结构弹性,从而极大缩减系统运动自由度.研究结果表明:列车可简化为单质点车辆模型和三维车辆模型混合的短编组列车,当模型中只包含一个三维车辆模型,且其前、后车辆均以单质点模拟时,计算结果偏低;列车承受2 200 kN压钩力并通过400 m半径曲线线路时,货车最大轮轨横向力和垂向力较多节三维货车编组模型的计算结果分别低估了24%和4%,钢轨横向、垂向位移则被低估了20%和8%;端部车辆采用单质点模型、中部采用三维车辆模型的车辆数至少为3时,才能较为准确地反映中间目标车辆处轮轨作用力和其下部轨道结构的动态特性.
:To solve the synchronisation simulation problem for long trains and continuous elastic tracks, a representative case employing a train curving negotiation is used. A heavy-haul train-track coupled dynamic model is used to analyse the dynamic performance of the track structure with a 30 t axle-load train, when a coupler compressive force is applied to it. As implified principle is presented to simulate the dynamic interaction between the long heavy-haul train and the track. The general concept behind this method is replacing the large train-track coupled dynamic system by a finite number of three dimensional vehicle models, considering the foundation structure elasticity under the corresponding models. Thus, the motion freedom of the system can be significantly reduced.The results indicate that a long train can be treated as a shorter mixed train, composed of a single-mass vehicle model and a three-dimensional wagon model. As only one wagon is simulated by the detailed dynamics model, with the front and rear connected wagons considered as a single-mass model, conservative results are obtained. As the train negotiates a 400 m radius curve, simultaneously bearing a 2 200 kN coupler force, the lateral and vertical wheel-rail forces in the outer wheel of the wagon are underestimated by about 24% and 4% respectively, relative to the results calculated using a train model composed of several three-dimensional wagons. Correspondingly, the lateral and vertical displacement of outer rail are sequentially underestimated by nearly 20% and 8%. When a single-mass model is used at the ends of the train, and the number of the additional wagons simulated by the three-dimensional dynamic model is 3, both the wheel-rail dynamic interaction of the middle target wagon and the track dynamic behaviour, can be reflected accurately
基于数学形态学的直流接地极引线C型行波故障测距
C Type Traveling Wave Fault Location for HVDC Grounding Lines Based on Mathematical Morphology
 [PDF]

鹏飞, 谭博学,
Smart Grid (SG) , 2016, DOI: 10.12677/SG.2016.65028
Abstract:
本文在介绍C型行波测距原理和数学形态学理论的基础上,根据脉冲信号在接地极线路上的传播特性,提出了一种基于数学形态学的C型行波故障测距方法,该方法首先对脉冲信号在线路上的传播过程进行模量分离,再根据形态学算法进行滤波,并利用梯度变换分离出正反向行波浪涌,不仅具有一定的抗干扰性,而且能准确地识别第一个反射脉冲到达测量点的时刻。通过PSCAD仿真验证和MATLAB图形处理表明,该方法是可行的,且有利于提高高压直流接地极引线故障测距的可靠性和准确性。
On the basis of introducing the principle of C type traveling wave fault location and mathematical morphology theory, this paper proposes a C type traveling wave fault location method based on mathematical morphology according to the propagation characteristics of the pulse signal in the grounding line. Firstly, this method carries on modulus separation of propagation process of the pulse signal on line, then, it uses the morphological algorithm for wave filtering, and the forward and backward waves are separated by the gradient transform. This method not only has certain anti-interference ability, but also can accurately distinguish the moment of the first reflection pulse reaching to the measuring point. Results show that the method is not only feasible but also helpful to improve the reliability and accuracy of the fault location for high voltage DC grounding wire through simulation of PSCAD and graphics processing of MATLAB.
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