基于核偏最小二乘法的动态预测模型在铜转炉吹炼中的应用

为实现铜转炉吹炼过程中的关键操作参数的准确预测,构造一种基于核偏最小二乘法的动态预测模型,并提出一种适用于动态建模的在线式异常样本剔除方法。该动态预测模型使用滑动窗方法不断更新建模数据,再利用核偏最小二乘法对动态模型的参数进行辨识,最后根据反馈的前次计算误差对本次预测值进行修正。仿真研究结果表明：该动态预估模型具有较好的泛化能力和较强的鲁棒性,并具有较好预测精度（风量预测的相对均方根误差小于10%,氧量预测的相对均方根误差小于19%）。目前,该预测模型被用于某转炉的吹炼辅助决策系统中。     

Process optimization of sweet potato pulp‐based biodegradable plastics using response surface methodology

Biodegradable plastics were produced from sweet potato pulp (SPP) and cationic starch (CS) or chitosan composite (CC) by compression molding and their mechanical properties were tested. A universal testing machine, Rockwell hardness tester, and Izod impact tester were used for testing the mechanical properties (flexural strength, Rockwell hardness, and Izod strength) of the plastics. A central composite second‐order design was used to study the effects of temperature, time, and moisture content on the flexural strength, Rockwell hardness, and Izod strength of SPP/CS and SPP/CC blended plastics. The flexural strength, Rockwell hardness, and Izod strength of SPP‐based plastics was 101.1–305.9 kg/cm², R29.0–R96.7, and 0.6–3.0 kg cm cm^?2, respectively. Regression analysis predicted the optimal mechanical properties (flexural strength, Rockwell hardness, and Izod strength) to be attained with a 150–160°C temperature, 15–20‐min reaction time, and 20–23% moisture content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 423–434, 2002     

Conductive Papers Containing Metallized Polyester Fibers for Electromagnetic Interference Shielding

Conductive papers were developed for preventing or reducing electromagnetic interference (EMI), and their shielding efficiency was evaluated. This type of conductive paper consists of wood pulp, synthetic pulp and metallized polyester fibers (0.5–2.0 mm long and 14 m in diameter) whose surfaces are coated with nickel alone (Ni-PET) or copper and nickel double layers (Ni-Cu-PET) by electroless plating. In this report, the effect of the characteristics of these metallized fibers, such as their conductivity, geometry and the concentration of fibers in paper, which lead to high efficiency for shielding effectiveness is discussed. For instance, one of the conductive papers (80 g/m2) which was prepared by mixing 40% Ni-Cu-PET and 60% synthetic polyethylene pulp showed over 40 dB shielding effectiveness between 10 MHz and 1 GHz.     

Comparison of the Effect of a Hydrocarbon Oil and a Terpene Tackifier on the Autohesion of Styrene-Butadiene Rubber

Blends of uncrosslinked styrene-butadiene rubber (SBR) with a terpene tackifier resin or a naphthenic oil have been characterized, and their autohesion and cohesion determined using a T-peel geometry. SBR/oil blends are homogeneous at all proportions, while SBR/resin blends, based on DSC and DMA analysis, undergo bulk phase separation at about 50% resin. However, migration of tackifier to the surface region is proposed at much lower resin contents. Compositions diluted with oil have autohesion similar to the neat SBR. This is attributed to compensating effects; although oil hastens self-bond formation by increasing chain mobility, this is nearly equally balanced by more facile chain separation during bond rupture. In short, oil-diluted compositions are soft and weak. On the other hand, SBR compositions containing small amounts of resin have high autohesion. Resin-diluted specimens deform easily at low strain, just as those containing oil, but intertwined chains of the former have greater resistance to separation, due at least in part to higher glass transition temperatures. It is proposed that autohesion is further enhanced by migration of tackifier to the surface. This causes SBR/resin compositions to be both soft and strong-a necessary condition for high autohesion.     

两极控制图在注塑瓶盖壁厚控制中的应用

针对注塑瓶盖壁厚控制的特点,介绍了统计过程控制(SPC)中的均值-极差(x-R)控制图在塑料瓶盖壁厚控制中的局限性,将两极(L-s)控制图与均值-极差控制图进行了比较,阐述了两极控制图在塑料瓶盖壁厚控制中的优越性,论述了两极控制图的构造原理和控制限计算方法,提出了两极控制图在注塑瓶盖壁厚控制中的应用,并在对两极控制图分析的基础上,对注塑成型的过程能力进行分析和改善。     

Physical characteristics of sweet potato pulp/polycaprolactone blends

Sweet potato pulp (SSP) obtained as a by‐product from starch extraction was blended with polycaprolactone (PCL) to prepare a biodegradable plastic material. In the blends, PCL was used as a reinforcing agent. The SPP/PCL blends were prepared by compression‐molding under high temperature and pressure, at different SPP/PCL ratios, and the mechanical properties of the molded specimens were tested. Matrix structure and thermal properties were measured by using a Fourier transform infrared (FTIR) spectrophotometer, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). Mechanical properties (tensile and flexural properties) were also measured to find the most suitable ratio in a SSP/PCL blend. During compression molding of the SPP/PCL blends under high pressure and temperature, chemical reaction occurred between SPP and PCL, and thus, thermal stability and mechanical strength of the blends increased and water uptake decreased. Also, by increasing the PCL content in the blend, the matrix in the blend became more homogeneous, and consequently, mechanical strength of the molded specimen increased. At 7/3 or 6/4 weight ratio of SSP/PCL, water uptake of the molded specimen became substantially less than that at 8/2. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 861–866, 2004     

Method for characterization of triacylglycerols and fat-soluble vitamins in edible oils and fats by supercritical fluid chromatography

This study demonstrates the usefulness of capillary supercritical fluid chromatography (SFC) for the characterization of triacylglycerols of edible oils and fats. Triacylglycerols were separated according to the acyl carbon number and the degree of unsaturation on a 25% cyanopropyl/25% phenyl/50% methylpolysiloxane stationary phase. Valuable information concerning the triacylglycerol composition of berry oils was obtained, despite the overlapping of certain triacylglycerol peaks. Simultaneous analysis of fat-soluble vitamins and triacylglycerols is not practical by capillary SFC with flame-ionization detection because of the low concentration of naturally-occurring fat-soluble vitamins in edible oils. Therefore, higher loading of the sample, which led to overloading of triacylglycerols, was required to get reasonable peaks for fat-soluble vitamins. The method was applied to the characterization of triacylglycerols and tocopherols in sea buckthorn pulp and seed oil, and cloudberry seed oil without any sample purification prior to SFC. In addition, the stationary phase proved useful for separating the more complex mixtures of triacylglycerols found in milk fat and in fish oil.     

NMR imaging and differential scanning calorimetry study on drying of pine,birch, and reed pulps and their mixtures

Drying, water fractions, and water distribution were investigated for pine, birch, and reed pulps and pine–birch, pine–reed, and pine–birch–reed pulp mixtures. Gravimetrically determined drying times showed that the drying rates of the pulps decreased at two to four inflection points. Characterizations of the dried pulps by differential scanning calorimetry (DSC) showed a faster removal of free water than freezing and nonfreezing bound waters; all decreased simultaneously, however. DSC also revealed the critical water contents at which the free water and freezing bound water disappeared. The gravimetrically determined inflection points of the drying curves corresponded with the critical points determined by DSC. NMR line widths and images produced by ¹H‐NMR imaging revealed the nature and regions of the pulp drying. The constant growth rate of the NMR line widths with decreasing water content appeared to change at two inflection points, which fell approximately in the same water content regions as the inflection points of the drying curves. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 937–945, 2006     

制浆造纸工业用消泡剂的开发及应用进展

制浆造纸工业生产过程中不可避免会产生泡沫,泡沫控制不当会严重影响制浆造纸工艺条件的执行以及设备的正常运转,导致产品产量和质量降低,而控制泡沫最直接有效的措施是添加合适的消泡剂.该文介绍了制浆造纸工业生产中泡沫的产生和稳定机理,泡沫对制浆造纸工业生产过程和产品质量的影响,并针对制浆造纸生产中制浆、抄纸、涂布和脱墨等工段泡沫特性和消泡要求,综述了制浆造纸用消泡剂的发展历程、各工段消泡剂种类和性质,介绍了消泡剂的研制开发和实际应用成本及使用效果等,并对制浆造纸用消泡剂的发展进行了展望.     

Liquid spouting of pulp fibers in a conical vessel

Pulp fibers can be spouted in water in a conical vessel. The entities which are spouted are fiber flocs rather than individual fibers. Synthetic fibers, which do not flocculate, cannot be spouted. For comparison, rigid spherical particles were spouted with water in the same conical vessel. Liquid spouting of rigid particles was similar to gaseous spouting. For pulp spouting, the minimum spouting velocity is proportional to the mass of fibers in the bed and inversely proportional to the diameter of the inlet. For rigid particles, the minimum spouting velocity is proportional to the height of the bed and inversely proportional to the square of the diameter of the inlet. A model for the minimum spouting velocity was developed for pulp spouting.