Water and salt permeability of reinforcement polymer‐gel composite membrane

The charged mosaic polymer membrane (CMM) without reinforcement and the composite charged mosaic polymer membrane (CCMM) with reinforcement were investigated in terms of salt and water transport (permeability). The composite charged mosaic polymer membrane (CCMM) with reinforcement showed a unique transport behavior such as preferential material transport L_p and ω. Water permeability coefficient, L_p and salt permeability coefficient, ω were estimated by taking account of active layer thickness of composite polymer gel. The L_p and ω values of CCMM with reinforcement were larger than those of CMM without reinforcement. On the other hand, the reflection coefficient of CCMM, σ, showed negative value, which suggested preferential material transport to solvent transport. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Surface-based Transport Model for Mixed-Size Sediment

We present a transport model for mixed sand/gravel sediments. Fractional transport rates are referenced to the size distribution of the bed surface, rather than subsurface, making the model completely explicit and capable of predicting transient conditions. The model is developed using a new data set of 48 coupled observations of flow, transport, and bed surface grain size using five different sediments. The model incorporates a hiding function that resolves discrepancies observed among earlier hiding functions. The model uses the full size distribution of the bed surface, including sand, and incorporates a nonlinear effect of sand content on gravel transport rate not included in previous models. The model shares some common elements with two previous surface-based transport models, but differs in using the full surface size distribution and in that it is directly developed from a relatively comprehensive data set with unambiguous measurement of surface grain size over a range of flow, transport rate, and sediments.     

油煤浆的管道输送特性与管路设计原则

通过理论分析和管道实验，探讨了油煤浆在工业管道输送中的流变特性、流动状态和阻力特性，得出了油煤浆的物性参数、表观参数、管道阻力参数的测定值和计算公式，并在此基础上探讨了油煤浆管道输送的设计原则，为油煤浆管路的设计提供基础数据、计算方法和一般原则。     

Efficiency of sediment transport by flood and its control in the Lower Yellow River

1IntroductionIntheriversystemwithsediment-ladenflow,WaterUseforSedimentTransport(WUST)isaveryimportantcomponentofecologicalwaterdemands,whichmaintainfundamentalfunctionofallecosystemcomponentsataspecificlevelofcondition[1].EnoughWUSTisthepremisetokeepthestableriver-bedandhealthyriverecosystem;alsoitisthebaseflowofriverfortheexploitationofwaterresources.Comparingwithotherrespectsrelatedwithwaterdemandsofriverecosystemsuchastheminimumflowforfishesorripariantrees,researchesontheWUSTarequite…     

The desorption of O2 during NO and N2O decomposition on Cu- and Fe-zeolites

The decomposition of NO and of N₂O over a CuZSM-5 zeolite and a Fe-mordenite, respectively, has been studied using tracer techniques. The results demonstrate the high mobility of the lattice oxygen ions in self-diffusion. They afford a possible explanation for the problem of how two extralattice oxygens located at positions remote from each other may combine to form the O₂ molecules which are spontaneously desorbed in these redox reactions. They show that a portion of the lattice oxygen mixes into the O₂ released on decomposition. The data also show that N¹⁸O and N₂ ¹⁸O undergo exchange with the catalyst oxygen under reaction conditions.On leave from Central Research Institute for Chemistry, Hungarian Academy of Sciences, H-1525 Budapest, Hungary.     

单线循环客运索道设计参数研讨(续三)

论证客运索道设计中的几个重要参数,建立抱索器钳口夹紧力计算公式,第一次给出钳口夹紧力与钢索金属断面积的比值,并进行了钢索弯曲应力计算公式的推导.     

创新铁路运输方式实现750m^3高炉富余铁水分流

针对750m^3高炉铁水生产富余状况，制订了富余铁水向铸铁机铸铁的调送方案，通过创新思维、系统挖潜、优化资源配置等措施的实施，保证了750m^3高炉的正常生产，取得了良好效果。     

Biophysical Model of Larval Yellow Perch Advection and Settlement in Lake Michigan

Potential for large-scale physical transport processes to affect recruitment of Lake Michigan yellow perch (Perca flavescens) was studied by examining the variation in larval distribution, growth rate, and settlement during June–August 1998–2003 using a 3D particle transport model linked with an individual-based bioenergetics growth model. In all years, virtual larvae were released nearshore in southwestern Lake Michigan, a known and important spawning region for yellow perch. For any given year, the same circulation pattern and water temperature either promoted or reduced yellow perch settlement depending on the consumption rates and settlement size chosen in the growth model. Increased consumption increased the number of settled larvae and expanded the total area where larvae settled, whereas increased settlement size reduced the number of settled larvae and reduced the overall settlement area. Interannual variability in circulation patterns and water temperature also resulted in contrasting larval settlement rates, settlement locations, and size of settlement areas between years. Model predictions were most consistent with field observations of age-0 yellow perch from Illinois and Michigan waters when settlement was assumed to occur at 50 mm. Moreover, our model suggests that larvae originating from southwestern Lake Michigan can recruit anywhere within the southern basin and even in the northern basin. Future model improvement will require information on the relative contribution of various sectors to the larval pool, their distribution with reference to the hydrodynamic landscape, the feeding and growth of yellow perch during their pelagic phase, and the size at transition to demersal stage.     

Electron transport in direct methanol fuel cells

A three-dimensional (3D), two-phase, isothermal model of direct methanol fuel cells (DMFCs) was employed to investigate effects of electron transport through the backing layer and the land in bipolar plates. It was found that the electronic resistance of the backing layer, affected by backing layer electronic conductivity, backing layer thickness and flow channel width, played a relatively important role in determining the current density distribution and cell performance. In order to ignore the electron transport effect on the average current density, the minimum electronic conductivity of the backing layer has to be 1000 S m⁻¹, with the relative error in the average current density less than 5%, under the given conditions.     

汽相平衡扩散时LiNbO_3晶体的改性

本文从ＬｉＮｂＯ３晶体的宽固溶特性出发，采用汽相平衡扩散（ＶＴＥ）方法，摸索出具体改善ＬｉＮｂＯ３组成的实验条件，研制出用于扩散的扩散源坩埚，对一系列同成分ＬｉＮｂＯ３晶体进行了改性研究，结果表明，经本方法处理的ＬｉＮｂＯ３晶体的均匀性、一致性得到大大的提高，并获得了均匀富锂的ＬｉＮｂＯ３晶体，能够很好地满足集成光学需要．