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Search Results: 1 - 10 of 38289 matches for " 马永斌 "
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马永,张文
南京林业大学学报(自然科学版) , 2000, DOI: 10.3969/j.jssn.1000-2006.2000.05.007
Abstract: <正>从微观经济学的供需均衡理论出发,运用经济分析和数学推理的方法,在分析以年均木材产量最大化为经营目标的林木最佳采伐年龄数学模型[a(t)=t′(t)=m(t)]以及以木材价格为常量、以木材价值现值最大化为经营目标的林木最佳采伐年龄数学模型[i=t′(t)/t(t)=m(t)/t(t)]的基础上,进一步提出了以木材价格为变量、以木材价值现值最大化为经营目标的林木最佳采伐年龄数学模型[i=t′(t)/t(t)+p′(t)/p(t)=m(t)/t(t)+p′(t)/p(t)],为确定林木最佳采伐年龄、实现经济效益最大化提供了一种比较科学和可行的定量方法。
区域大气环境中PM2.5/PM10空间分布研究
郭涛,马永,贺克
环境工程学报 , 2009,
Abstract: 提出了一种利用移动监测技术研究区域大气环境中PM2.5/PM10空间分布的方法,并在2004年12月进行了宁波市全市域PM2.5/PM10空间分布的研究。数据显示:相同路径所代表的地区PM2.5和PM10具有很好的相关性,多数路径上PM2.5与PM10数据的相关系数平方在0.95以上,而不同路径上PM2.5与PM10的比值不同。文中给出了宁波市PM2.5/PM10污染的空间分布图,直观地显示出PM2.5/PM10污染的空间分布情况,突出了污染的重点点位和地区。
山东省批发和零售业销售总额的预测——基于ARIMA模型
Forecast of the Total Sales of Wholesale and Retail in Shandong Province—Based on ARIMA Model
 [PDF]

马永
Advances in Social Sciences (ASS) , 2016, DOI: 10.12677/ASS.2016.54076
Abstract:
商品批发与零售业销售价格是影响人们生活水平的重要因素之一,因此对商品批发和零售业销售总额进行预测有着积极的意义,时间序列分析提供了一套具有科学依据的动态数据处理方法,就是通过对模型的分析研究去了解数据的内在结构和复杂特性,从而达到预测其发展趋势并进行必要的控制的目的。本文利用Box-Jenkins法的ARIMA模型,对1979~2014年山东省批发和零售业销售总额数据序列进行分析,建立了1979~2014年山东省批发和零售业销售总额的自回归移动平均模型ARIMA(0,1,6)。检验结果显示,ARIMA(0,1,6)模型对原始数据序列有着较好的拟合效果,可用于短期内山东省批发和零售业销售总额的预测,为政府部门制定经济计划提供依据和参考。根据建立的模型预测结果,山东省批发和零售业销售额在未来几年仍将保持较高的增长趋势。
The sales price of wholesale and retail of commodities is one of the important factors that affect people’s living standard. It has positive significance to forecast the total sales of the wholesale and retail of commodities. Time series analysis provides a suit of methods dealing with dynamic data with the scientific basis, namely with the analysis and investigation, we can constitutionally know the structure and complex character of the data, so we can achieve the purpose of forecasting its development trend and putting up essential control. In this paper, using the method of Box-Jen- kins ARMIA model, the date sequence of wholesale and retail sales from 1979 to 2014 of Shandong province is analyzed, the model of auto regressive integrated moving average ARIMA (0,1,6) was established. The results show that the ARIMA model has good fitting effects on the original data sequence. The prediction effect can be used for short-term prediction of the total sales of wholesale and retail in Shandong province. It provides a basis and reference for government departments to formulate economic plans. According to the results of the prediction model established, in Shandong province the wholesale and retail sales remain high growth trend in the coming years.
电除尘器管状芒刺类电晕极电参数模拟计算
郝吉明,贺克,马永
环境科学学报 , 1993,
Abstract: 推导了不等线径、不等线距圆线组合电除尘器伏安特性计算关系,利用不等线径、不等线距圆线组合对管状芒刺类电晕极作了近似简化处理.采用静电场与电晕电场相叠加的办法建立了管状芒刺类电晕极电场分布的一种计算方法.与实验值对比表明,该方法的计算结果是可靠的.
北京PM2.5中多环芳烃的污染特征及来源研究
段凤魁,贺克,马永
环境科学学报 , 2009,
Abstract: 采用GC/MS定量分析了2003年9月至2004年7月期间北京市PM2.5中16种优控PAHs的含量.研究表明,PAHs总浓度年均值139.59ng·m-3,变化范围1.02~776.4ng·m-3.冬季浓度最高271.05ng·m-3,夏季最低26.10ng·m-3,反映了主要源排放(燃煤)变化与气象条件的共同影响.全年平均不同环数PAHs所占总浓度的比例由大到小:4环>5环>6环>3环>2环;冬季4环PAHs所占比例最大(48.7%),其次为5环(32.5%)和6环PAHs(14.9%);夏季5环、6环PAHs所占比例最高(36.5%),其次为4环PAHs(24.1%).源排放特征化合物比值法和主成分分析法结果都表明,燃煤、机动车和油类挥发是多环芳烃的3类主要污染源,能够解释主成分分析法总方差的88%.
宁夏枸杞及甜菜碱对H2O2诱发RBC膜脂质过氧化的影响
任彬彬,马永,沈泳,
中国中药杂志 , 1995,
Abstract: 用H2O2,致大鼠RBC膜发生脂质过氧化,观察加入宁夏枸杞不同组分及甜菜碱后RBC膜的保护作用。结果:各受试物对RBC膜脂质过氧化均有不同程度抑制作用;它们抗氧化效能大小顺序为:枸杞干果>枸杞多糖>枸杞渣>甜菜碱。
安徽省封山育林效益调查与分析
张文,马永,余相,程棠海
南京林业大学学报(自然科学版) , 1999, DOI: 10.3969/j.jssn.1000-2006.1999.05.019
Abstract: <正>通过对安徽省1986年以来实施的封山育林进行定点观测、典型调查与统计分析,结果表明封山育林具有显著的生态、经济、社会三大效益。经测算,年综合效益12?36亿元。在生态问题严重困扰社会经济可持续发展的当今,封山育林具有重要的现实意义。
弹性地基上转动FGM梁自由振动的DTM分析 DTM analysis for free vibration of rotating FGM beams resting on elastic foundations
DTM analysis for free vibration of rotating FGM beams resting on elastic foundations

滕兆春,衡亚洲,张会凯,马永
- , 2017, DOI: 10.7511/jslx201706006
Abstract: 基于Euler-Bernoulli梁理论,利用广义Hamilton原理推导得到弹性地基上转动功能梯度材料(FGM)梁横向自由振动的运动控制微分方程并进行量纲化,采用微分变换法(DTM)对量纲控制微分方程及其边界条件进行变换,计算了弹性地基上转动FGM梁在夹紧-夹紧、夹紧-简支和夹紧-自由三种边界条件下横向自由振动的量纲固有频率,再将控制微分方程退化到转动和地基时的FGM梁,计算其不同梯度指数时第一阶量纲固有频率值,并和已有文献的FEM和Lagrange乘子法计算结果进行比较,数值完全吻合。计算结果表明,三种边界条件下FGM梁的量纲固有频率随量纲转速和量纲弹性地基模量的增大而增大;在一定量纲转速和量纲弹性地基模量下,FGM梁的量纲固有频率随着FGM梯度指数的增大而减小;但在夹紧-简支和夹紧-自由边界条件下,一阶量纲固有频率几乎不变。
Based on Euler-Bernoulli beam theory,the governing differential equation of motion of the lateral free vibration a rotating functionally graded material (FGM) beam on elastic foundation is derived by using generalized Hamilton principle,and differential transform method (DTM) is used to transform the dimensionless governing differential equation and the boundary conditions.At the same time,the dimensionless natural frequencies of transverse free vibration of rotating FGM beam on elastic foundation at the clamped-clamped,clamped-simply supported and clamped-free three boundary conditions are determined,then the governing differential equation is degenerated to the FGM without rotation and elastic foundation.The values of first non-dimensional natural frequency with different FGM gradient index are calculated and they are completely consistent with the results by either the FEM or the Lagrange multipliers method in the literature.The results show:at the above three kinds of the boundary conditions,the dimensionless natural frequencies increase with the growth of the dimensionless rotating speed and the dimensionless elastic foundation modulus.Under a certain dimensionless rotating speed and dimensionless elastic foundation modulus,the dimensionless natural frequencies decrease along with the growth of the FGM gradient index.However,when at clamped-simply supported and clamped-free boundary conditions,the first dimensionless natural frequency is almost constant.
Study on spatial distributions of PM2.5/PM10in regional atomospheric environment
区域大气环境中PM2.5/PM10空间分布研究

Guo Tao,Ma Yongliang,He Kebin,
郭涛
,马永,贺克

环境工程学报 , 2009,
Abstract: In this paper, a new method for the study on regional ambient PM2.5 and PM10 concentrations spatial distribution using mobile monitoring is introduced. Experiments were carried out to survey the spatial distributions of PM2.5 and PM10 concentrations in Ningbo City in December 2004. Results show that there is a high correlation coefficient between PM2.5 and PM10, with r2>0.95 in most routes representing different areas. Ratios of PM2.5 and PM10 vary among routes. Spatial distribution maps of PM2.5 and PM10 concentrations are given, from which the key spots and/or areas with significant pollution problems can be figured out easily.
SIMULATING CALCULATION OF ELECTRIC CONDITIONS FOR ELECTROSTATIC PRECIPITATOR CORONA ELECTRODE WITH TUBE-TYPE SPIKE
电除尘器管状芒刺类电晕极电参数模拟计算

Hao Jiming,He Kebin,Ma Yongliang,
郝吉明
,贺克,马永

环境科学学报 , 1993,
Abstract: A calculation method of the voltage-current relation of electrostatic pre-cipitators was deduced for the corona electrode geometry with different wire diameter and different wire-to-wire spacing. Using the geometry with different wire diameter and different wire-to-wire spacing,the corona electrode with tube-type spike was approximately simplified. A calculation method of electric field strength distribution for corona electrode with tube-type spike is set up by combing the electrostatic field with the corona field. The verification has shown that the calculation results are reliable.
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