木粉增强聚丙烯力学性能的改善方法

以废弃木粉为增强材料,制备了木粉增强聚丙烯复合材料,研究了改善废弃木粉增强聚丙烯复合材料力学性能的途径。结果表明,通过适当的处理方法对木粉进行表面处理、对基体树脂进行改性,可以有效地提高复合体系的界面粘接强度,能大幅度改善复合体系的力学性能;采用短切玻璃纤维及玻璃纤维毡与废弃木粉组合,可以获得力学性能很高、能作为结构材料使用的复合材料。     

混炼硅橡胶的配合技术(四)

介绍了几种胶辊用混炼硅橡胶的配制,包括低硬度胶辊用混炼硅橡胶、低环硅氧烷含量的胶辊用混炼硅橡胶、送纸胶辊用混炼硅橡胶及工业胶辊用混炼硅橡胶的配制。     

网络考试系统设计

文章研究了网络考试系统的需求,设计了试卷生成算法。     

Solvent extraction of oil from soybean flour II— pilot plant and two-solvent extractions

The process of grinding soybeans to a fine flour and extracting the flour with hexane was studied on a pilot plant scale. The crude oil from the pilot plant study had 15 ppm phosphorus and was suitable for physical refining after a light acid pretreatment and bleaching. The refined oil showed a Lovibond color of 1.4 yellow and 0.3 red. The pilot plant study also showed that grinding of the soybeans and the separation of solid from miscella were the most difficult steps in solvent extraction with fine flour. A laboratory study on separation of miscella from meal by aqueous ethanol reduced the hold-up volume, but it did not remove all the miscella. A test with betacarotene showed that only the miscella outside the flour particles was displaced. Aqueous ethanol solutions used as a second solvent extracted additional nontriglyceride materials (primarily phospholipids) from the meal. Also, the free fatty acid content of the oil was increased with aqueous ethanol solution wash. The quality of the extracted crude oil was lowered by using a second solvent, but it had the advantage of needing only one centrifugation to separate miscella from meal.     

安钢二炼焦加热集散控制系统

安钢二炼焦焦炉加热控制系统根据蓄热室温度，建立了可靠的数学模型，通过控制加热煤气的压力和烟道废气吸力实现加热的自动控制，并实现参数无纸记录，日报表的自动生成，设备巡检的记录等功能。     

基于遗传算法的自动组卷研究与应用

随着在线考试系统的广泛应用,组卷算法决定了自动组卷的性能。为提高组卷成功率,提出基于遗传算法的自动组卷模型,根据总分、题型、难度、区分度等要求建立多目标、多约束条件的数学模型。采用ASP.NET编程实现,并进行编码、选择、交叉、变异等操作,使遗传算法能满足自动组卷要求。     

Characterization of pedicel,paper, and larval silk from nest ofPolistes annularis (L.)

The pedicel, nest paper, and larval silk ofPolistes annularis nests were analyzed by high-resolution solid-state [¹³C]NMR. The pedicel was found to have a high nitrogen content (11%), and the NMR spectra indicated that it is a mixture of carbohydrate and protein. The pedicel protein has an amino acid composition that is very rich in glycine, alanine, serine, and proline (67% of identified residues), similar to that of some insect silks. Solid-state [¹³C]NMR indicated that the nest paper is composed predominantly of cellulose. Silk, spun by matureP. annularis larvae, was shown by [¹³C] NMR and amino acid analysis to be a protein very high in serine and alanine (53%), but the amino acid composition is distinct from that of the pedicel protein.     

Preparation of HDPE/SEBS‐g‐MAH and its effect on mechanical properties of HDPE/wood flour composites

In this article, high density polyethylene/styrene‐ethylene‐butylene‐styrene block copolymer blends (HDPE/SEBS) grafted by maleic anhydride (HDPE/SEBS‐g‐MAH), which is an effective compatibilizer for HDPE/wood flour composites was prepared by means of torque rheometer with different contents of maleic anhydride (MAH). The experimental results indicated that MAH indeed grafted on HDPE/SEBS by FTIR analysis and the torque increased with increasing the content of maleic anhydride and dicumyl peroxide (DCP). Styrene may increase the graft reaction rate of MAH and HDPE/SEBS. When HDPE/SEBS MAH was added to HDPE/wood flour composites, tensile strength and flexural strength of composites can reach 25.9 and 34.8 MPa in comparison of 16.5 and 23.8 MPa (without HDPE/SEBS‐g‐MAH), increasing by 157 and 146%, respectively. Due to incorporation of thermoplastic elastomer in HDPE/SEBS‐g‐MAH, the Notched Izod impact strength reached 5.08 kJ m^?2, increasing by 145% in comparison of system without compatibilizer. That HDPE/SEBS‐g‐MAH improved the compatibility was also conformed by dynamic mechanical measurement. Scanning electron micrographs provided evidence for strong adhesion between wood flour and HDPE matrix with addition of HDPE/SEBS‐g‐MAH. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

分子荧光光度法测定面粉中的核黄素

采用分子荧光光度法测定三种面粉中的核黄素。最佳实验条件为：核黄素的最大激发波长和最大发射波长分别为449nm和525 nm;确定最佳的提取液种类、体积和时间等条件。核黄素在二个数量级的范围内呈良好线性关系,该方法成功的被应用于实际样品的分析,获得令人满意的结果.     

电感耦合等离子体原子发射光谱法测定魔芋精粉中的重金属元素

采用电感耦合等离子体原子发射光谱法同时测定魔芋精粉中铅、铬、镉、砷、汞5种元素的含量,其检出限分别为0.0102、0.0009、0.001、0.028、0.004 mg.L-1,测定回收率在98.0%~103.0%之间,RSD（n=10）为0.5%~1.6%。所建立的元素分析方法其准确度和精密度均符合要求,应用本方法测定实际样品,结果令人满意。