工艺参数对陶瓷注射成型的影响与分析

本研究通过改变注射温度，注射压力，保压压力等几个主要参数，对形状，体积不同的注射成型体，试条，圆柱及子部件进行了一系列注射工艺实验。相应地对成型体的密度，弯曲强度及烧结体的密度和强度进行测量，并从陶瓷注射成型混合物的流动行为，热物理特性方面对注射这一复杂过程进行分析，探讨工艺参数对成型过程的内在影响，从而确定合理的注射工艺条件。     

Kinetic study on the first stage during thermal degradation of polystyrene

The kinetic parameters of the first stage of polystyrene degradation have been investigated to elucidate the reaction mechanisms using the flow reactor system. The decrease in molecular weight of polystyrene was recorded at minute intervals over the temperature range 310°–390°C. Generally, the first and second stages were observed by thermogravimetric analysis (t.g.a.), however in the early stage of the degradation volatile yields of at least 5% occurred. Therefore, using t.g.a. analysis it is difficult to detect this earlier stage. It became evident that the first stage in the earlier part of the reaction could be detected by g.p.c. analysis. We have observed the hidden kinetic parameters of the nature of the first stage of the polystyrene degradation. The results indicate that the main chains were degraded randomly with the small quantitative volatile groups in the first stage and the rates of decrease in molecular weight in the first stage against reaction temperatures were evaluated as log k_s = 12.0 ? 41300/RT.     

考虑边界反射的河流离岸排放污染混合区计算方法

在等强度点源离岸排放条件下,从简化二维移流扩散方程的解析解出发,探讨了考虑两岸反射作用的中宽河流污染混合区的计算方法。给出了污染混合区边界形状曲线与量纲一方程的形式;采用迭代计算和试算比较法,给出了靠岸与离岸两种类型混合区各几何特征参数(坐标)、面积及面积系数与相对离岸距离的关系曲线,提出了以相对离岸距离a'作为判据的排放类型分区条件。给出了河流岸边、离岸与中心排放的分类判别准则:(1)当0≤a'≤a'1时,简化为岸边(近岸)排放类型;(2)当a'1a'a'2时,称为离岸排放类型;(3)当a'2≤a'≤0.5时,简化为中心排放类型,并给出了岸边排放类型与离岸排放类型的临界相对离岸距离a'1和中心排放类型与离岸排放类型的临界相对离岸距离a'2的表达式。通过回归分析,给出了中宽河流离岸排放类型混合区主要特征参数的实用计算公式,可作为中宽河流污染混合区范围计算和排污口位置优化设计的依据。     

泥岩隧道光面爆破的技术参数研究及应用

针对泥岩隧道的特殊性,通过优化光面爆破的爆破参数,讨论泥岩隧道掘进的经济性、安全性。采用预埋振速传感器监测的方式,分析光面爆破对隧道周围岩体的扰动。现场光爆技术应用效果显著,隧道开挖轮廓线内基本未出现超欠挖现象,半孔率达86%以上,爆破进尺提升约15%,孔痕长度基本均匀分布一般都在孔长的66%以上;萨道夫斯基公式的系数K衰减明显、α基本稳定,光爆的振动速度和围岩扰动都得到了有效控制。     

Mixed monolayer and mixed micelle formation in binary mixture of surfactants—Systems for trioxyethylenated dodecyl sulfonate and some polyoxyethylenated fatty alcohol ether nonionic surfactants

The interaction and synergism of some polyoxyethylenated fatty alcohol ether (POE) nonionic surfactants (C₁₂E₂, C₁₂E₃, C₁₀E₅, C₁₀E₇, where C_x indicates number of carbon atoms in the chain and E_y indicates number of oxyethylene glycol ethers) with trioxyethylenated dodecyl sulfonate (C₁₂E₃S) in mixed monolayer formation at the surface and in mixed micelle formation in aqueous solutions were studied at 25 and 40°C by calculating interaction parameters (β_α, β_M) from surface tension-concentration data by use of Rosen's equations based on the nonideal solution theory. All the systems investigated adapt reasonably well to the nonideal model, with negative values of β_σ and β_M (where M means micelle and σ refers to the air-liquid interface) indicating a favorable interaction between the mixed surfactants. Either at a monolayer or in a mixed micelle, the attractive interaction becomes stronger when the alkyl chain in the POE surfactant is longer, i.e., when the POE becomes more hydrophobic. The interaction increases in the order C₁₀E₇<C₁₀E₅<C₁₂E₃, C₁₂E₂. For the two C₁₀E _n (n= 5,7)/C₁₂E₃S systems, as temperature increases from 25 to 40°C, the interaction increases in a mixed micelle, but it decreases in a mixed monolayer. Synergism in mixed micelle formation exists for C₁₂E₃S/C₁₀E _n mixtures when X₁ ^M , the mole fraction of POE in a mixed micelle, is ≈0.4–0.8, whereas synergism does not occur in the systems of C₁₂E₃S/C₁₂E _m due to the large difference between CMC₁ and CMC₂, i.e., large |In(C ₁ ^M /C ₂ ^M )| value (where CMC=critical micelle concentration). The degree of synergism in mixed micelle formation is temperature independent and is 0.23, 0.18, and close to zero for C₁₀E₅/C₁₂E₃S, C₁₀E₇/C₁₂E₃S, and C₁₂E _m (m=2,3)/C₁₂E₃S systems, respectively. Synergism in surface tension reduction effectiveness occurs in C₁₂E₃S/C₁₂E₂ and C₁₂E₃S/C₁₂E₃ systems. The mole fractions of POE in the solution phase are 0.302 and 0.333 for the two mixtures at the point of maximum synergism.     

Molar volume and ultrasonic studies of europium soaps in mixed organic solvents

The ultrasonic velocity and density measurements of europium soaps in a mixture of benzene and methanol (3:2, vol/vol) were used to evaluate various acoustic parameters and molar volume and to determine the critical micelle concentration. The results showed that the ultrasonic velocity, specific acoustic impedance, molar sound velocity, and molar compressibility increase, and intermolecular free length, adiabatic Compressibility, and relative association decrease with increasing concentration and chainlength of the soap. The results were interpreted in terms of soap-solvent interaction.     

Non-conventional treatment of treated municipal wastewater for reverse osmosis

High-quality potable water can be produced at a reasonable cost if reverse osmosis (RO) technology is applied to renovate secondary/tertiary urban wastewater effluent. Such implementation would yield many advantages to Kuwait, namely: satisfying the increasing agricultural, industrial and domestic demands for good quality water that is free from viruses and bacteria and other microbials present preserving the natural strategic water resources; reducing the environmental pollution resulting from the direct discharge of secondary/tertiary municipal effluents to the sea; and meeting unexpected emergency cases of shortages in freshwater produced from the desalination of seawater for certain domestic applications. The main aims of this work are to assess the technical viability and the economic feasibility of implementing RO technology to renovate Kuwaiti wastewater treated effluent. The paper describes the design of pretreatment, experimental set-up, results, and data analysis of desalinating municipal wastewater by RO. The results indicate that wastewater can be treated to produce an excellent permeate quality almost devoid from salts and pollutants.     

化工搅拌器的参数优选

本文提出了确定化工用搅拌器搅拌时间的一种简单试验方法,并用正交表安排寻找最佳搅拌参数的试验和整理试验数据,得到了有实用价值的结果。     

基于广义Hoek-Brown准则的节理岩体力学参数折剪计算

节理化岩体力学参数是矿山工程地质和稳定性分析的重要基础数据,一般在实验室通过单轴、三轴试验只能得到岩石的力学参数,无法得到岩体的力学参数。目前,利用岩石力学参数确定岩体力学参数的方法较多,但都过于烦琐或准确度不高,急需一种新的简易确定方法。因此,通过利用基于广义Hoek-Brown准则的地质强度指标（GSI法）,并结合相应的岩土分析软件,强度折剪岩石力学参数值,从而得到岩体的力学参数。通过将该方法应用于赤峰中色白音诺尔矿业有限公司岩体力学参数的计算中,证明采用该方法考虑岩体的结构面和完整性,可较为准确地反映节理化岩体的力学特性,且方便可行,具有工程实用价值。?