热态内装物对纸箱抗压强度的影响研究

目的研究内装物温度对瓦楞纸箱抗压强度的影响。方法采用理论与实验相结合的方式,分析60℃的热装物对瓦楞纸箱抗压强度的影响,并提出了改善措施。实验主要包括:常温环境和恒温恒湿室内的对比实验;0201型六层复合的普通纸箱与内层涂布防水层纸箱的对比实验。结果 66.7%的普通纸箱实验中,装热态物的纸箱抗压强度平均下降5.5%左右;防水涂布实验箱的抗压强度平均高于常规纸箱20%左右。结论防水涂料涂布的纸箱可以有效地抵消热装物对纸箱强度的影响。     

电商小型瓦楞纸箱循环使用次数的研究

目的为了获得易碎品包装在不同的内装物密度的情况下的气泡袋使用层数及纸箱最多循环使用次数。方法本文采用跌落试验方法来研究内装物密度对瓦楞纸箱循环使用次数和气泡袋使用层数的影响。结果当内装物密度为80kg/m~3的情况下,气泡袋的最佳使用层数为3层,瓦楞纸箱的最佳循环使用次数为5次;当内装物密度为160kg/m~3的情况下,气泡袋的最佳使用层数为7层,瓦楞纸箱的最佳循环使用次数为3次;当内装物密度为230kg/m~3的情况下,气泡袋的最佳使用层数为9层,瓦楞纸箱的最佳循环使用次数为2次。结论随着内装物密度的增大,气泡袋的最佳使用层数会增大,瓦楞纸箱的最佳循环使用次数会减少,并且给出了不同内装物密度下的合理参考值。     

涂布两种施胶剂对抄制纸板物理性能的影响

目的对涂布氧化淀粉胶纸板、聚乙烯醇胶纸板和未涂布纸板的耐破强度、戳穿强度、挺度、防水防潮性等物理性能进行研究。方法实验选用表面施胶的方法来增强纸板的物理性能。通过抄制不同定量的化学机械浆和化学浆纸板,在纸板表面涂布相同体积的氧化淀粉胶和聚乙烯醇胶,测试纸板的物理性能。结果在相同温度、相对湿度条件下涂布施胶剂的纸板,其耐破强度、戳穿强度、挺度和防水防潮性要优于未涂布纸板;涂布聚乙烯醇的纸板其耐破强度、戳穿强度和防水防潮性要优于涂布氧化淀粉胶的纸板,涂布氧化淀粉胶的纸板挺度要优于涂布聚乙烯醇胶的纸板。结论涂布施胶剂后纸板的物理性能均有所提高,涂布聚乙烯醇胶的纸板强度较强,涂布氧化淀粉胶的纸板韧性较好。     

精油复配防霉剂在纸质文献储藏包装上的应用

目的 研究牛至、 柠檬草精油复配防霉剂应用于纸质文献储藏包装。方法 在高温高湿加速实验条件下, 通过GC-MS分析纸盒内防霉剂浓度变化, 并检测纸样表面菌落总数的变化。结果 防霉剂配方为柠檬草精油 （0.25 μL/mL） +牛至精油 （0.25 μL/mL） 时, 与对照组相比, 内壁涂布防霉剂的纸盒可将内装纸质文献霉变周期延后3.7倍, 内置防霉小包的纸盒可将其霉变周期延后4.6倍。结论 无论是将防霉剂涂布于包装盒内表面,还是内置防霉剂小包于纸盒内, 都能有效抑制内装纸制品表面霉菌的生长。     

环保超疏水防潮瓦楞纸箱的制备及性能研究

目的 针对瓦楞纸箱易受潮而使其失去原有性能的问题,对其进行超疏水防潮改性,并研究改性方法对其性能的影响。方法 通过真空吸附涂布的方式,采用具有低表面能的硬脂酸与可构建表面粗糙度的纳米二氧化硅粒子结合,再引入聚二甲基硅氧烷增强涂层与纸板之间粘合力的方法制备超疏水防潮纸箱,对其进行润湿性和力学性能的表征。结果 改性后的纸板水接触角可达到150°以上,水分吸附率大幅降低,在此基础之上其边压强度未受到不良影响,且耐磨性能优良。结论 文中所述超疏水涂层的制备工艺简单,材料绿色环保,所得纸箱防潮性能、力学性能良好。     

高性能防静电瓦楞纸板及其影响因素的研究

目的研制一种高性能的防静电瓦楞纸板、纸箱,并研究涂布量,运输环境的温度、相对湿度及机械摩擦对其防静电性能的影响。方法采用定量涂布的方式将防静电涂料均匀涂覆在原纸表面,通过改变涂布量研究其与纸板防静电等级的关系;通过改变环境温度、相对湿度、摩擦参数(次数和强度)来模拟研究实际运输途中温度、相对湿度及摩擦参数(振动、冲击等机械力造成的)对瓦楞纸箱防静电性能的影响。结果在研究的范围内,随着温度、相对湿度的增加,防静电纸板表面电阻率也增加,但是材料的防静电等级未发生变化,仍为导静电材料,其中相对湿度对防静电的影响较温度的影响更为明显;摩擦对防静电性能的影响比相对温湿度明显。结论温度、相对湿度及摩擦参数对瓦楞纸板的防静电性能均有不同程度的影响,但仍为静电防护型材料,能够有效保护内装物不受静电的危害。     

基于PE复合工艺的冷冻水产瓦楞纸箱

冷冻水产瓦楞纸箱是由一张瓦楞纸板模切折叠而成,纸板面纸为复合纸,由超薄压光牛皮纸、薄膜形态的聚乙烯PE、国产牛皮纸复合而成,纸板里纸表面涂布防水涂料,部分防水涂料被压入里纸浅表层,形成新的物质层,使涂料与里纸浅表层紧密结合在一起。本产品防水、防潮性能优异,印刷效果好,经济效益高,可广泛应用于自动包装线上机械开箱、装箱、打包等。     

出口纸箱表面省去涂油论证通过评审

一、出口包装商品的瓦楞纸箱(以下简称纸箱),为了防潮,目前还有很大一部分的纸箱表面涂上一层油。这一工艺是五十年代生产方式沿用至今,当时纸箱表面使用的材料是国产的黄板纸,没有防潮性能,每只纸箱表面涂上一层桐油,后来桐油紧张,而     

包卷式纸箱封合质量标准体系研究

目的 根据纸板粘合机理,从纸板特性指标角度进行研究,建立包卷式纸箱封合质量标准评价体系,实现通过纸板表面性能相关指标测试,即可评判预测包卷式纸箱在线封合质量的目的。方法 通过设计不同试样进行直角粘合模拟测试及拉力测试,研究瓦楞纸板的表面性能参数对包卷式纸箱封箱效果的影响,找到纸板表面吸水渗透性、表面张力、纸纤维内结合强度等指标的合理范围,建立包卷式纸箱封合质量标准评价体系。结果 根据试验结果预测,纸板印刷面吸水量低于1 g/m2,表面张力低于38 mN/m,内结合强度低于100 J/m2的纸板,包卷式纸箱粘合封箱强度较低。结论 可以通过增加测试纸板表面吸水渗透性、表面张力、纸纤维内结合强度等指标,建立包卷式纸箱的封合质量标准评价体系,对包卷式纸箱在线封合质量进行预测。     

丁香精油涂布纸箱对水蜜桃的保鲜效果

目的研发一种以丁香精油为抑菌剂的涂布纸箱,并研究不同浓度丁香精油对水蜜桃保鲜效果的影响。方法将不同浓度的丁香精油与聚乙烯醇涂布到瓦楞纸板上制备成涂布纸箱,测试抗菌纸板对灰霉、交链孢、黑曲霉的熏蒸抑菌效果;并以水蜜桃为研究对象,研究不同浓度丁香精油对水蜜桃保鲜效果的影响。结果抗菌纸板的抑菌率随着丁香精油浓度的增加而逐渐增强,丁香精油涂布纸箱可明显降低水蜜桃的腐烂率,并维持其感官品质,贮藏13 d后,体积分数为0.6%的丁香精油涂布纸箱对水蜜桃的保鲜效果最佳,其感官品质分数为6.2,腐烂率仅为26%。结论丁香精油涂布纸箱对灰霉、交链孢霉、黑曲霉等霉菌具有抑制作用,可减缓水蜜桃的腐烂,延长其货架寿命4~5 d。     

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成，凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求，以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究，并介绍了其中某些方面和展望了可能的发展趋势。     

Creation and motion of dislocations and fracture in metal and silicon crystals

By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.     

Development and challenges of planning and scheduling for petroleum and petrochemical production

Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.     

The Candela and Photometric and Radiometric Measurements

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.     

PSD和PWELCH函数的分析改进及应用

针对MATLAB中两个内建功率谱密度计算函数psd()和pwelch()计算结果迥异的现象,在功率谱密度估计理论的基础上,根据经典的周期图理论和Welch平均周期图方法,通过详细分析源程序,解析计算方法,发现psd()计算的并不是工程单边功率谱密度,而是采样信号双边谱,故与pwelch()结果迥异,另外pwelch()不能对分段信号数据进行预处理。就上述不足提出了相应的改进措施,比较验证表明改进措施行之有效。     

甲壳素与壳聚糖的改性及应用

甲壳素、壳聚糖及其衍生物是一种天然高分子,随着对其研究的深入发展,涉及的内容和应用范围越来越广泛.概述了甲壳素、壳聚糖的结构、性质及其化学改性和共混改性的方法,简单介绍了它们的应用领域.     

ATP-Responsive and ATP-Fueled Self-Assembling Systems and Materials

Adenosine triphosphate (ATP) is a central metabolite that plays an indispensable role in various cellular processes, from energy supply to cell-to-cell signaling. Nature has developed sophisticated strategies to use the energy stored in ATP for many metabolic and non-equilibrium processes, and to sense and bind ATP for biological signaling. The variations in the ATP concentrations from one organelle to another, from extracellular to intracellular environments, and from normal cells to cancer cells are one motivation for designing ATP-triggered and ATP-fueled systems and materials, because they show great potential for applications in biological systems by using ATP as a trigger or chemical fuel. Over the last decade, ATP has been emerging as an attractive co-assembling component for man-made stimuli-responsive as well as for fuel-driven active systems and materials. Herein, current advances and emerging concepts for ATP-triggered and ATP-fueled self-assemblies and materials are discussed, shedding light on applications and highlighting future developments. By bringing together concepts of different domains, that is from supramolecular chemistry to DNA nanoscience, from equilibrium to non-equilibrium self-assembly, and from fundamental sciences to applications, the aim is to cross-fertilize current approaches with the ultimate aim to bring synthetic ATP-dependent systems closer to living systems.     

Miniature and MEMS-type vacuum sensors and pumps

In the paper, the observable trends of the actual research and development of selected types of miniature and MEMS-type vacuum sensors are presented. Some information about the new types of active vacuum gauges, which are offered by the leading manufacturers of the vacuum measurement instruments, is given. Next, the list of MEMS devices that need vacuum for proper operation is presented. Some aspects of vacuum-encapsulation of MEMS devices, on wafer level and package level are shown. The new conceptions of obtaining and maintenance of high and ultra-high vacuum in MEMS devices are described. They concern the conception of integration of a miniature orbitron pump on-chip with MEMS-type device or with vacuum part of the portable advanced instruments such as electron microscope, ion mass spectrometer, and free electron laser.