基于综合关联度的注塑成型工艺参数多目标优化研究

针对注射成型过程中的两个品质指标(翘曲量和收缩率),提出了基于综合关联度、Kriging模型及自适应遗传-蚁群算法的注射成型工艺参数优化方法。首先给出了综合关联度的定义及计算方法,然后给出了Kriging模型的拟合方法和自适应遗传-蚁群的优化算法。在结合带凸沿杯子的注射成型具体实例研究中,首先给出了注射成型工艺参数的范围,其次给出了基于正交实验的设计变量确定方法,然后基于超拉丁立方实验及Kriging方法进行模型近似,最后利用自适应的遗传-蚁群算法进行优化求解。模流分析及实际注塑实验表明,注射成型工艺参数优化的结果可靠,具有较好的实际意义。     

数据协调中冗余性分析新方法

提出一种数据协调中的冗余性分析新方法 .根据尽量删除带有显著误差的变量 ,同时确保协调精度的原则 ,对所有检测出来的带有显著误差的变量 ,通过计算不同阶次的冗余度 ,按照冗余度的大小逐个选择可以删除的变量 .这样既充分利用了数据信息 ,又确保了协调精度 .仿真结果证实了该方法的有效性 .     

螺旋管内单相液体紊流脉动流动传热

以水为工质对螺旋管内单相液体充分发展紊流脉动传热特性进行了实验研究 ,发现了紊流脉动传热系数与流量脉动相位间的反相关系 ,引进了两个新的准则数 :脉动频率数W0 和脉动振幅率Ap,对紊流脉动传热规律进行了分析讨论 ,并根据紊流脉动传热参数的瞬态变化规律 ,对脉动过程中的管内二次流特征和变化作了详细讨论和分析 .     

T型关联度分析法优化芦丁提取纯化工艺

优化芦丁提取纯化工艺。用T型关联度对芦丁提取纯化工艺进行了研究。根据芦丁得率的关联度结果,各因素相关度大小为：X3〉X4〉X6〉X5〉X2〉X1,最佳工艺为95℃下杀酶40min,除胶水温度90℃,除胶水量（V／w）,渗漉pH11．0,酸沉pH3～4,收率22．3％,含量94．2％。可将T型关联度分析法用于芦丁提取纯化工艺为工业化生产提供实验依据。     

反应挤出聚丙烯接枝马来酸二丁酯的研究

以马来酸二丁酯(DBM)为单体,反应挤出聚丙烯(PP)接枝DBM(PP-g-DBM).研究了口模温度、螺杆转速、单体用量、引发剂过氧化二异丙苯(DCP)对接枝率和熔体流动速率的影响,并用红外光谱(IR)、差示扫描量热等测试方法对接枝物进行了表征与分析.结果表明,DBM是用于反应挤出加工的良好接枝单体;IR表征DBM接枝到PP分子链上,且接枝产物中DBM残留量较少;PP、DBM、DCP接枝的最佳温度为190～200℃,螺杆转速不宜过高,DCP的适宜质量分数为0.04%～0.10%.     

Noncatalytic polymerization of ethylene glycol and epoxy molecules for rigid polyurethane foam applications

The study investigated an approach to incorporate modified epoxidized soy‐based vegetable oil polyol as a replacement for petroleum‐based polyether polyol and to substantially reduce the isocyanate loading in the rigid foam formulation. Noncatalytic polymerization of epoxidized bodied soybean oil and ethylene glycol (EG) was carried out in a closed batch reaction. Cleavage of the oxirane rings and hydroxyl group attachment at optimum conditions provided the desired polyol products. The polyols were characterized based on its hydroxyl numbers, acidity, viscosity, iodine number, and Gardner color index for quality purposes. Reactions of oxirane ring and EG were verified by spectroscopic FTIR. Crosslinking performance was evaluated by extractability analysis on the polyurethane (PU) elastomer wafers. Rigid foaming performed at 50 and 75% petroleum‐based polyether polyol replacements have shown excellent thermoinsulating and mechanical properties compared with epoxidized soybean oil (ESBO) alone or petroleum‐based polyether polyol alone. A reduction of up to 8% of the polymeric diphenylmethane diisocyanate was achieved using the synthesized ESBO‐EG‐based polyols. A higher average functionality polyol is key component to the reduction of isocyanate in PU synthesis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Simulation of dry‐spinning process of polyimide fibers

As one type of high‐performance fibers, the polyimide fibers can be prepared from the precursor polyamic acid via dry‐spinning technology. Unlike the dry‐spinning process of cellulose acetate fiber or polyurethane fiber, thermal cyclization reaction of the precursor in spinline with high temperature results in the relative complex in the dry‐spinning process. However, the spinning process is considered as a steady state due to a slight degree of the imidization reaction from polyamic acid to polyimide, and therefore a one‐dimensional model based on White‐Metzer viscoelastic constitutive equation is adopted to simulate the formation of the fibers. The changes of solvent mass fraction, temperature, axial velocity, tensile stress, imidization degree, and glass transition temperature of the filament along the spinline were predicted. The effects of spinning parameters on glass transition temperature and imidization degree were thus discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Terpolymer resin–III: Synthesis and characterization of 8‐hydroxyquinoline–dithiooxamide–formaldehyde terpolymer resins

Terpolymer resins (8‐HQDF) were synthesized by the condensation of 8‐hydroxyquinoline (8‐HQ) and dithiooxamide (D) with formaldehyde (F) in the presence of acid catalyst and using varied molar ratios of reacting monomers. Terpolymer resins compositions have been determined on the basis of their elemental analysis and the number average molecular weights of these resins were determined by conductometric titration in non‐aqueous medium. Viscometric measurements in dimethyl formamide (DMF) have been carried out with a view to ascertain the characteristic functions and constants. The UV‐visible, FTIR, and proton nuclear magnetic resonance (H⁺ NMR) spectra were studied to elucidate the structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of ultra‐low molecular weight poly(vinyl alcohol) graft copolymer

Graft reaction of acrylamide (AM) and 4‐vinyl pyridine (4‐VP) onto ultra‐low molecular weight poly(vinyl alcohol) by ceric (IV) ion initiation had been systematically investigated; and the graft conditions were optimized by studying the effect of monomer/initiator concentration, solvents composition, reaction time and temperature. At optimized conditions, the maximum grafting efficiency and grafting ratio was ～ 50% and 51%, respectively with the presence of AM, whereas they decreased to 19% and 23%, respectively, without the presence of AM. Thermogravimetric analysis showed that as‐resulted graft copolymer had a lower thermal stability than homopolymer PVA. FTIR and ¹H‐NMR confirmed chemical structure of as‐synthesized graft copolymer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

率值对熟料烧结和氧化钙结合程度的影响研究

以实际生产率值KH=0.92,SM=2.58,IM=1.75为基础,用生产线生料、黏土和调整组份,分别变化其中一个率值制作了三组试件,并经实验电炉1400℃烧制40min而形成水泥熟料。然后对这三组熟料的烧结程度和氧化钙结合程度进行了对比试验研究。结果发现(:1)KH和SM对熟料的烧结程度和氧化钙结合程度的影响要明显大于IM,而IM影响最小;(2)随着KH和SM的升高,熟料的烧结程度明显降低,游离钙含量随之升高。