混合装配线过程平衡研究与仿真

生产过程的混合装配线平衡问题,分为在确定条件下的最小生产循环单元的静态平衡问题和不确定条件修正过后的动平衡问题.针对确定工位条件下的混装生产线,构建其静态平衡模型,分析不确定因素,并以操作工人的操作时间不确定性为例,研究时间不确定性动态平衡.利用Flexsim软件,通过仿真进行了验证.相关实验验证了上述方法和结论的正确性.     

一类高阶非线性差分方程的吸引性

在文献[1-2]的基础上,研究了非线性差分方程xn+1=a-bxpn-k/A-x2n的全局稳定性和正解的周期性,其中a,A为非负实数,b为正实数,k,p∈{1,2,…},p≥2.证明了该方程的一个正平衡点是一个全局吸引子,并给出了相应的吸引域.     

碱金属在烧结过程中的行为规律

高炉碱害频繁出现,影响日益严重,人们对它的关注与日俱增.烧结矿带入的有害元素在高炉中占的比重最大.本文对烧结矿及原料进行现场取样,重点对烧结矿碱金属进行平衡计算,提出降低碱害的方法.实验表明烧结原料中的K经过烧结工序之后,89%的进入了烧结矿,仅11%的有害元素进入粉尘;铁矿石和溶剂中的有害元素Na,近乎100%的进入烧结矿.     

Field tests on mechanical characteristics and strength parameters of red-sandstone

Large-scale field shear tests on ten specimens of the red-sandstone embankment at a highway in Hunan, China, were performed to examine mechanical characteristics and parameters of red-sandstone. The curves of thrust-dispiacement, failure mode, and shear strength parameters for red-sandstone with different water contents, different compactions, and different grain size distributions were obtained from the tests. A practical procedure of in-situ test for red-sandstone embankment was proposed to normalize the test equipment and test steps. Based on three-dimensional thrust-sliding limit equilibrium method, the formulas for calculating strength parameters of red-sandstone considering three-dimensional sliding surface were inferred. The results show that red-sandstone has typical complete curves of stress-strain, strain softening, which are caused by the special structure of red-sandstone; water content and compaction are important factors for strength and failure mode of red-sandstone; The average value of cohesion and internal friction angle of the specimens calculated by three-dimensional technique are 21.56 kPa and 29.29°, respectively, and those by traditional two-dimensional method are 25.52 kPa and 33.76°, respectively.     

Equilibrium and kinetics of adsorption of Ca（ II ） ions onto KCTS and HKCTS

The adsorption of Ca(Ⅱ) ions from aqueous solution by chitosan α-ketoglutaric acid(KCTS) and hydroxamated chitosan α-ketoglutaric acid(HKCTS) was studied in a batch adsorption system.The Langmuir and Freundlich adsorption models were applied to describing the equilibrium isotherms,and isotherm constants were determined.The kinetics of the adsorption with respect to the initial Ca(Ⅱ) ions concentration,temperature and pH was investigated.The pseudo-first-order and second-order kinetic models were used to des...     

平衡序列图的结构

考察了平衡序列图的结构,给出了平衡标号与序列标号的关系,提出了用二部划分确定平衡标号的方法,得到了平衡标号特征与导出边标号最小值的关系式,给出非平衡的序列树。     

偏压隧道CD法导坑开挖顺序数值分析

根据隧道开挖与支护过程中围岩应力变形规律,提出"二次平衡"概念.基于浙江省境内一偏压公路隧道的设计、施工以及地质情况,采用有限元软件ADINA模拟CD法不同顺序开挖导坑的施工过程,对比分析地面、围岩位移以及初期支护和二次衬砌的最大主应力.结果表明:地面沉降以及围岩最大位移都与导坑开挖顺序有关.从埋深大的一侧开挖导坑比从另一侧开挖导坑初期支护最大主应力小21.6%,二次衬砌最大主应力小35%.拱底是支护结构的薄弱部位,在设计、施工时要引起足够的重视.最后经过综合分析,确定了从埋深大的一侧导坑开挖为优选方案,可为同类隧道的设计、施工和研究提供有益的借鉴和参考.     

浅析FIDIC合同条件下不平衡报价的防范策略

在FIDIC合同条件下,低价中标是业主选择承包商的重要原则之一,不平衡报价成为承包商投标报价中一种广泛应用的报价策略。本文针对建设市场出现的不平衡报价现状,通过实例,量化分析了承包商常用的不平衡报价策略,为防范和控制不平衡报价提供了有效的防范策略。     

载流子平衡的低压高效有机白光器件

研究了结构为ITO/m-MTDATA:x%4F-TCNQ/NPB/TBADN:EBDP:DCJTB/Bphen:Liq/LiF/Al的有机白光电致发光器件(WOLED)。分别在ITO与NPB间加入高迁移率的m-MTDATA:4F-TCNQ来增强器件的空穴注入,在阴极和发光层间加入高迁移率的Bphen:Liq层增强器件的电子注入,降低驱动电压,提高器件效率。同时,由于注入的电子和空穴数量偏离平衡,器件的效率也会受到影响。实验中,通过调节4F-TCNQ的掺杂浓度来调控空穴的注入和传输,使载流子达到高度平衡。器件的最大电流效率和流明效率分别达到了9.3cd/A和4.6 lm/W。     

微生物燃料电池处理剩余污泥与同步产电性能

针对全球能源短缺和污泥处理过程中能耗较高等问题,采用微生物燃料电池(microbial fuel cell,MFC)技术处理剩余污泥并将污泥中的化学能直接转化成电能,从而实现污泥的稳定化与资源化利用.构建以铁氰化钾为阴极电子受体的双室型微生物燃料电池,分别考察了微生物燃料电池以城市污水处理厂剩余污泥为底物时的产电性能和对污泥的降解效果,并从缓冲溶液、阳极底物浓度和阳极区搅拌3个方面分析其对电池产电性能和污泥降解效果影响.电池输出电压可达到0.66 V,MFC运行一个周期,对污泥总化学需氧量TCOD(total chemical oxygen demand)的去除率为36.4%,阳极区缓冲溶液的投加和搅拌均可提高电能的输出及对污泥TCOD的去除能力.