Deformation and compressive strength of corrugated cartons under different indentation shapes: Experimental and simulation study

A new method to enhance the compressive strength of corrugated cartons is proposed in this study. The work aims to carry out compression tests on the corrugated carton to analyze the deformation and compressive capacity of the carton under the indentation condition of different shapes. First, compression tests are carried out on nonindentation cartons, one-line indentation cartons, unclosed rhombus indentation cartons, rhombus indentation cartons, and cross-indentation cartons to record their maximum compressive force. Second, by comparing the deformation of different cartons, it is found that rhombus indentation and cross-indentation have the greatest influence on the compressive strength of cartons. Rhombus indentation will enhance the compressive strength of the carton, while cross-indentation will reduce it. Third, ANSYS Workbench is used to analyze the buckling of cartons, and the maximum compressive force of nonindentation cartons and rhombus indentation cartons is obtained. Finally, through the comparison of the finite element method and experiments, it is concluded that rhombus indentation can improve the compressive strength of cartons, which is of great significance to the industrial production of cartons.     

麦麸多糖的提取工艺研究

以小麦麸皮为原料,并以水为溶剂浸提小麦麸皮水溶性多糖,研究了料液比、提取时间、提取温度等因素对麦麸多糖提取率的影响。通过单因素试验和正交试验,确定出提取麦麸多糖的最佳工艺条件为：料液比：1：25,提取时间4h,提取温度100℃。     

固定化漆酶深度处理制浆造纸废水

采用固定化漆酶深度处理制浆造纸废水,取得了良好的处理效果。最佳工艺条件:控制固定化漆酶的投加量为0.2 g/L,废水pH为6.5,CuSO4投加量为10 mg/L,HBT投加量为4 mg/L,在25℃曝气反应8 h后色度去除率可达85%左右,COD去除率达12.51%。若把HBT改为磷钼酸,控制磷钼酸投加量为500 mg/L,反应8 h后色度去除率达50%左右。     

高透明聚丙烯的发展与应用

聚丙烯（PP）作为一种热塑性通用塑料,具有良好的机械性能、易加工成型等优点,并且价格低廉,因此应用领域非常广泛,尤其是高透明PP以其优异的光学和力学性能,近年来吸引了越来越多研究者的重视。本文主要概述了聚丙烯改性的基本原理、增透改性的主要途径以及国内外高透明聚丙烯的发展现状,并且简单分析了高透明聚丙烯的应用与发展前景,对于进一步研究聚丙烯的透明改性工作具有一定的指导意义。     

The solidification path related columnar-to-equiaxed transition in Ti–Al alloys

Columnar-to-Equiaxed Transition (CET) of binary Ti–Al alloys and multi-component Ti–48Al–2Cr–2Nb alloys is studied using Bridgman solidification technique. The effect of aluminum concentration and growth rate on CET is determined. It is found in Ti–46Al and Ti–50Al alloy ingots equiaxed grains develop ahead of the moving solid–liquid interface with a growth rate of 500 μm/s; microstructures in Ti–49Al alloy stay columnar dendrites with the same growth rate. CET in Ti–Al alloys are not only influenced by growth rate, but also by the solidification path that is related to alloying composition. CET in Ti–Al alloys is predicted using the dendritic growth model based on the criterion of growth at marginal stability. According to the calculated results and directionally solidified microstructures, values of the nucleation undercooling for α and β phases are given. The growth rates to avoid CET in Ti–48Al–2Cr–2Nb alloy are suggested.     

PBS结晶影响因素的研究

采用偏光显微镜对聚丁二酸丁二醇酯(PBS)的结晶影响因素进行了研究。结果表明:在等温结晶时,PBS的最佳结晶温度随着分子量的增大而提高,当分子量增到一定值后,最佳结晶温度受分子量的影响很小。结晶温度一定时,PBS的晶体尺寸随着结晶时间的延长而增大。结晶时间一定时,PBS的晶体尺寸随着结晶温度的提高而先增大后减小。数均分子量为1×103、8×103、6×104、1×105的PBS最佳结晶温度分别为40℃~50℃、80℃、80℃、90℃。低分子量的PBS在较短的结晶时间内晶体尺寸就已较大,而高分子量的PBS在较长的时间内才能形成较大尺寸的晶体,数均分子量为8×103、6×104、1×105的PBS在最佳结晶温度形成较好结晶的时间分别为10min、20min、25min。     

脂肪酶N435在低沸点溶剂中催化合成聚丁二酸丁二醇酯

脂肪酶N435在温和条件下可以有效地催化合成聚丁二酸丁二醇酯.采用溶剂蒸出的多级酶催化法成功在低沸点溶剂正己烷、四氢呋喃、甲苯和乙腈中合成出聚丁二酸丁二醇酯,得到聚丁二酸丁二醇酯的重均分子量分别为1460、1636、3066和4231,多分散系数分别为1.69、1.48、1.78和1.67.低沸点溶剂甲苯和乙腈是N43...     

单体碳数对脂肪酶N435催化合成直链聚酯的影响

通过多级催化法用脂肪酶N435催化不同碳数脂肪族二醇与二酯反应,合成直链聚酯。结果表明:短链二醇与短链二酯难以被脂肪酶催化发生反应,长链二醇与二酯易被催化发生反应。采用脂肪酶N435催化己二酸二乙酯与1,4-丁二醇反应可以获得重均分子量为24 816,相对分子质量分布为1.09的聚酯。脂肪酶催化二醇、二酯与甘油共聚合可以获得重均分子量较高、相对分子质量分布窄的共聚物。     

Directional solidification,nanoindentation and thermionic properties of LaB6(100)-ZrB2 eutectic composite

LaB₆ (100)-ZrB₂ eutectic composite was directionally solidified by optical floating melting zone at solidification rate V= 100 mm/h. It was shown that the stable eutectic growth can be achieved by periodic diverging and convergent growth, indicating that eutectic spacing was not unique value, but existed a limited range under a given rate. The atoms of the LaB₆ (100)/ZrB₂ interface were directly bonded. The mechanical property of the individual eutectic phase was evaluated by the nanoindentation. Both average Berkovich hardness and elastic modulus of LaB₆/ZrB₂ phases was higher than that of LaB₆ phase. Thermionic emission of DS LaB₆(100)-ZrB₂ eutectic obeyed the Longo theory, indicating only the metal ceramic of LaB₆ matrix in the composite emitted the electron. The practical work function distribution of DS LaB₆(100)-ZrB₂ eutectic composite ranged from 2.51 to 3.18 eV, and the lowest work function was located around the LaB₆/ZrB₂ interface, where had the highest current density     

Polyurethane latex modified with polyaniline

The strategy of the modification of polyurethane latex with a conducting polymer, polyaniline, is proposed. It is based on the introduction of the polymer steric stabilizer to the latex. The stabilizer prevents the macroscopic precipitation of a conducting polymer during the polymerization. Polyaniline has been prepared by the oxidative polymerization of aniline in the presence of polyurethane latex with average particle size of 36 nm and poly(N-vinylpyrrolidone). Thus, modified latex produces an aqueous colloidal dispersion having the particle size 100–200 nm. The presence of poly(N-vinylpyrrolidone) was needed to obtain a colloid. In its absence, a polyaniline–polyurethane composite precipitated. The composite coatings obtained after their drying contained 5–18 wt.% polyaniline in a protonated emeraldine form, had the conductivity up to 10⁻² S cm⁻¹, and mechanical properties typical of elastomers.