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Search Results: 1 - 10 of 251025 matches for " 张鹏飞 "
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稀疏过程下考虑多因素的比例再保险风险模型
An Insurance Model with Sparse Process Considering Some Factors of the Proportional Reinsurance
 [PDF]

鹏飞, 陈新美
Advances in Applied Mathematics (AAM) , 2014, DOI: 10.12677/AAM.2014.32017
Abstract:

本文针对目前日益复杂多变的保险业务情况,建立了一种在稀疏过程下考虑干扰和破产下限的比例再保险风险模型,同时引入了红利支付,试着使模型能更实际的反映保险公司的运营模式。
In view of the increasingly complex and changeful insurance business situation, a sparse process was established considering interference and lower limit for the bankruptcy of the proportional reinsurance risk model, and at the same time, the dividend payment was introduced to make the model reflect the operation mode of the insurance company more practically.

桃片超声渗透-红外辐射干燥特性及能耗研究
鹏飞
- , 2015, DOI: 10.13982/j.mfst.1673-9078.2015.11.036
Abstract: 超声波的空化效应可提高渗透过程中传质效率。为研究桃片超声渗透-红外辐射干燥特性及干燥能耗,进行了超声渗透后红外60、70、80 ℃干燥试验,得到干燥特性曲线,建立干燥动力学模型;同时,对干燥过程的能耗进行了分析。结果表明:超声可增加桃片渗透脱水速率和固形物渗入率,超声渗透时间选择30 min(T1)及60 min(T2)为宜;Verma et al. 模型较好拟合了桃片超声渗透-红外辐射干燥规律,未经渗透、T1及T2渗透处理桃片在60、70、80 ℃干燥条件下水分有效扩散系数分别为8.8789×10-9~1.3011×10-8、7.1213×10-9~1.0393×10-8、6.6771×10-9~8.7785×10-9 m2?s-1;随着温度升高,干燥所需能耗降低;经超声渗透脱水后,干燥所需能耗增加。不同条件下,干燥能耗均在干基水分含量0.3左右急剧增加,可作为水分转换点,利用其它干燥方式,如变温压差膨化干燥,达到节约能耗、提高产品品质的目的。试验结果为桃片红外辐射干燥工艺参数优化及开发新型果蔬脆片提供参考。
The cavitation effect of ultrasonic waves can improve the efficiency of mass transfer in the process of osmotic dehydration. In order to study the drying characteristics and energy consumption of peach slices during ultrasound-assisted osmotic dehydration in combination with infrared radiation, drying experiments after ultrasound-assisted osmotic dehydration were carried out at 60, 70, and 80 ℃, respectively; the drying curves were obtained, and the mathematical models for the drying kinetics were established. Meanwhile, the energy consumption during the drying process was analyzed. The results showed that ultrasound-assisted osmotic dehydration could improve the ratio of water loss and solid gain. The appropriate ultrasound-assisted osmotic times were set at 30 min (T1) and 60 min (T2), and the Verma et al. model was found to be suitable to describe the drying characteristics of peach slices during the ultrasound-assisted osmotic dehydration and infrared radiation. The effective moisture diffusivity values of non-treated, T1 and T2 treated peach slices at 60, 70, and 80℃ were in the ranges of 8.8789 × 10-9~1.3011 × 10-8 m2?s-1, 7.1213 × 10-9~1.0393 × 10-8 m2?s-1, and 6.6771 × 10-9~8.7785 × 10-9 m2?s-1, respectively. With the increase in temperature, energy consumption reduced but increased after ultrasound-assisted osmotic dehydration. Under different treatments, energy consumption increased rapidly with a moisture content of about 0.3 (dry basis), which can be a moisture conversion point to use other drying methods, such as explosion puffing drying at varied temperatures and pressures, to reduce energy consumption and improve product quality. This study provides a reference for the parameter optimization in the infrared drying of peach slices and the development of new fruit slices.
超声及超声渗透预处理对红外辐射干燥特性研究
鹏飞
- , 2016, DOI: 10.13982/j.mfst.1673-9078.2016.11.030
Abstract: 为探究超声及超声渗透预处理对桃片水分迁移及红外辐射干燥特性的影响,经超声及超声渗透30、60 min预处理后,进行红外辐射80 ℃干燥处理,采用低场核磁共振技术测定预处理后桃片横向弛豫时间T2图谱,分析水分状态及分布变化,得到干燥特性曲线,并分析水分状态及分布对干燥特性的影响。结果表明,超声降低桃片固形物含量,超声渗透明显增加固形物含量并降低水分含量;不同预处理均改变桃片内部水分状态和分布。超声后,桃片不易流动水和自由水弛豫时间增加,水分自由度增加,从而提高干燥速率,增加水分有效扩散系数;超声渗透后,桃片结合水、不易流动水及自由水弛豫时间均减小,且自由水含量明显降低,而不易流动水及结合水含量相对升高,从而降低干燥速率,减小水分有效扩散系数。该研究为超声及超声渗透预处理对红外辐射干燥水分扩散研究提供参考。
To explore the effect of ultrasound (UL) and ultrasound-assisted osmotic dehydration (ULOD) pretreatments on water transfer in peach slices and the drying characteristics of infrared radiation drying, samples were pretreated with UL and ULOD for different time followed by infrared radiation drying at 80 ℃. Low-field nuclear magnetic resonance (LF-NMR) was used to measure the transverse relaxation times (T2) of the pretreated peach slices. Changes in water status and distribution were analyzed, the drying characteristics curve was obtained, and the effects of water status and distribution on the drying characteristics were explored. The results showed that UL decreased the soluble solid content, and ULOD significantly improved the soluble solid content and decreased the water content. Both pretreatments affected the water status and distribution. UL increased the transverse relaxation times of immobilized water (T22) and free water (T23), indicating that the degree of freedom of water increased. As a result, UL enhanced the drying rate and increased the water effective diffusion coefficient (Deff). ULOD decreased the transverse relaxation time of bound water (T21), immobilized water (T22), and free water (T23). The free water content was significantly reduced, and the immobilized water and bound water content increased relatively, thus reducing the drying rate and decreasing the Deff of infrared radiation drying. This study provides the theoretical basis for the study of the effects of UL and ULOD pretreatments on water transfer and diffusion characteristics of fruite slice treated by infrared radiation drying.
基于低能量冲击损伤阻抗的复合材料薄壁结构铺层顺序设计
鹏飞,金海波
复合材料学报 , 2014,
Abstract: 建立了有效的复合材料层合板结构冲击损伤分析方法,层合板面内损伤采用改进的Chang/Chang失效准则做判据,得到面内各类损伤形式。层间损伤采用与Mixed-Mode粘接元等效的TIEBREAK接触模拟。利用此分析方法,从复合材料薄壁结构设计需要出发,研究了在低能量冲击下,铺层的层间角度、铺层方向、铺层重叠对层合板结构冲击损伤阻抗的影响规律,并对它们的综合影响进行了总体分析,得到了能提高层合板结构损伤阻抗的铺层顺序设计指导。最后用该设计指导对某种铺层结构进行了重新设计和有限元模拟,验证了该设计指导的可行性和有效性。
凝胶聚合物电解质的电化学性能
,鹏飞
化工学报 , 2005,
Abstract: 用化学交联法制备了凝胶聚合物电解质.聚烯烃多孔膜支撑的凝胶聚合物电解质具有优良的电化学性能,室温电导率为1.01×10-3S?cm-1,锂离子迁移数为0.41,在Al电极上的氧化起始电位达到4.2V以上.采用聚烯烃多孔膜支撑的凝胶聚合物电解质制备了聚合物锂离子电池,并研究了工艺条件对聚合物锂离子电池电化学性能的影响.研究的工艺条件包括:单体添加量和电极组合方式.优化后的聚合物锂离子电池具有良好的电化学性能,1C放电容量为0.2C放电容量的93.2%,经100次1C循环后的剩余容量仍在80%以上.
普洱茶中黄酮类化学成分研究
,鹏飞
中国中药杂志 , 2013,
Abstract: 目的:研究普洱茶Camelliasinensisvar.assamica中黄酮类化学成分。方法:利用各种色谱技术进行分离,利用波谱方法结合化合物的理化性质确定结构。结果:最终分离、鉴定了11个黄酮类化合物,分别为:山柰酚(1),槲皮素(2),山柰酚-3-O-β-D-葡萄糖苷(3),山柰酚-3-O-β-D-芸香糖苷(4),芹菜素6-C-α-L-阿拉伯糖-8-C-β-D-葡萄糖苷(5),牡荆素-4″-O-β-D-葡萄糖苷(6),山柰酚-3-O-α-L-鼠李糖基(1→3)α-L-鼠李糖基(1→6)β-D-葡萄糖苷(7),槲皮素-3-O-β-D-葡萄糖苷(8),芦丁(9),槲皮素-3-O-α-L-鼠李糖苷(10),杨梅素-3-O-β-D-葡萄糖苷(11)。结论:化合物5~7,10,11均首次从普洱茶中分离得到。
两色金鸡菊头状花序的化学成分研究
,鹏飞
中国中药杂志 , 2012,
Abstract: 目的:研究两色金鸡菊头状花序的化学成分,为其开发利用奠定化学基础。方法:利用硅胶、SephadexLH-20、制备液相等色谱方法进行分离,NMR,MS,CD等波谱技术鉴定化合物的结构。结果:分离鉴定了8个化合物,包括有机酸类成分3个,分别为3,4-二羟基苯甲酸(3,4-dihydroxybenzoicacid,1)、4-羟基苯甲酸(4-hydroxybenzoicacid,2)、咖啡酸(caffeicacid,3);有机酸酯类成分1个,为对羟基桂皮酸甲酯葡萄糖苷(4-O-β-D-glucopyranosyl-p-coumaricacidmethylester,4);二氢黄酮类成分2个,分别为2S-3',5',7-三羟基二氢黄酮(2S-3',5',7-trihydroxyflavanone,5)、(2R,3R)-3,4',5,7-四羟基二氢黄酮[(2R,3R)-3,4',5,7-tetrahydroxylflavanone,6];甾醇类成分2个,分别为豆甾醇葡萄糖苷(stigmasterol-3-O-β-D-glucopyranoside,7)和β-谷甾醇(β-sitosterol,8)。结论:化合物1~7均为首次从该属植物中分离得到,化合物8为首次从该植物中得到。
基于SCI-E数据库的学者学术影响力研究
,鹏飞
科技进步与对策 , 2015, DOI: 10.6049/kjjbydc.2015010509
Abstract: 科研评价对于高等院校、科研机构有着重要意义,学术影响力评价是科研评价中重要的一环,如何对学者学术影响力进行公平合理而又行之有效的评价是众多管理部门面对的棘手问题。以学者的论文及其引文作为学者学术影响力的评价依据,以SCI-E数据库为数据来源,以论文数量、期刊分区和影响因子以及论文被引次数作为评价指标,建立了学者学术影响力评价的层次分析模型,将定性评价与定量评价相结合,综合评价学者的学术影响力,取得了较为满意的结果。SCI论文学术影响力层次分析法
基于改进蚁群算法的城市内涝救援路径优化
姜金贵,鹏飞
计算机应用 , 2014,
Abstract: ?城市内涝灾害发生时,科学调配救援资源能够有效提升城市应急救援的效率,最大限度降低灾害损失。针对城市线路受到地形、路况、内涝积水等因素影响的情况,引入连通系数和畅通系数,从而更好反映城市线路及灾情实际。鉴于蚁群算法收敛速度慢、容易陷入局部最优的缺点,通过随机选择受灾点、引入信息素更新策略改进了蚁群算法,并应用其对内涝救援路径优化模型进行求解。实证分析表明改进蚁群算法对城市内涝救援路径优化具有较好的求解效果。
千米级斜拉桥扁平钢箱梁的局部力学行为
鹏飞,启伟
天津大学学报(自然科学与工程技术版) , 2010,
Abstract: 以世界最大跨径斜拉桥苏通长江大桥为工程背景,通过静载试验与全桥整体及箱梁局部有限元数值计算研究了千米级斜拉桥扁平钢箱梁各主要板件的力学特性.在此基础上,运用子模型法对考虑焊接构造的箱梁局部焊接细节建立精细有限元模型,分析焊缝周围的应力分布规律,并通过试验加以验证.结果表明,扁平钢箱梁剪力滞效应明显,顶底板纵向应力沿横截面呈不均匀分布,顶板和顶板u肋的焊缝周围存在严重的应力集中,是整个钢箱梁疲劳性能研究的重点部位.
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