Nonisothermal crystallization,melting behavior,and morphology of PP/EPPE blends

Nonisothermal crystallization, melting behavior, and morphology of polypropylene (PP)/Easy processing polyethylene (EPPE) blends were studied by differential scanning alorimetry (DSC) and scanning electron microscope (SEM). The results showed that PP and EPPE are miscible, and there is no obvious phase separation in microphotographs of the blends. The modified Avrami analysis, Ozawa equation, and also Mo Z.S. method were used to analyze the nonisothermal crystallization kinetics of the blends. Values of Avrami exponent indicated the crystallization nucleation of the blends is homogeneous, the growth of spherulites is tridimensional, and crystallization mechanism of PP is not affected much by EPPE. The crystallization activation energy was estimated by Kissinger method. The result obtained from modified Avrami analysis, Mo Z.S. method, and Kissinger methods were well agreed. The addition of minor EPPE phase favored to decrease the overall crystallization rate of PP, showing some dilution effect of EPPE on PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Electrical conductivity: a new tool for the determination of high hydrostatic pressure-induced starch gelatinisation

The degree of gelatinisation and electrical conductivity of wheat starch and tapioca starch suspensions (5% w/w) were determined after a pressure treatment of up to 530 MPa. With increasing pressure at a constant treatment time the degree of gelatinisation increased resulting in a gelatinisation curve similar to that of thermal gelatinisation. A pressure increase also caused an increase in electrical conductivity. A good linear relationship between the degree of gelatinisation and the electrical conductivity for both starches investigated was found. Since electrical conductivity correlates well with the degree of gelatinisation of starches after pressure treatment it is applicable for the quick and simple determination of pressure-induced starch gelatinisation.     

超高效液相色谱-串联质谱法测定豆芽中7种药物残留

建立了甲醇超声提取,分散固相萃取净化技术（QuEChERS）净化,超高效液相色谱-串联三重四极杆质谱（UPLC-MS/MS）检测豆芽中7种药物（咪鲜胺、头孢氨苄、诺氟沙星、6-苄氨基嘌呤、赤霉酸、2,4-二氯苯氧乙酸和4-氯苯氧乙酸）残留的方法。样品用含0.1%甲酸的甲醇溶液超声提取,QuEChERS（PSA+C18）净化,在UPLC-MS/MS的电喷雾正、负离子分段扫描和多反应监测（MRM）模式下检测,以保留时间和特征离子对定性,外标法定量。结果表明,7种待测物在0.4~100 μg/L范围内线性关系良好;方法定量限（S/N=10）为2.0~5.0 μg/kg;添加水平为2.0~50 μg/kg时,平均回收率在80.7%~115%之间;相对标准偏差（RSD,n=6）为2.6%~13.5%。本方法具有前处理简单、结果准确、回收率高等特点,可以应用于豆芽中7种药物残留的日常监测。     

集中润滑系统在易开盖组合成型中的应用

易开盖组合成型中应用集中润滑系统来替代传统的人工润滑方式,可以在保证设备正常运行的同时,使润滑油用量更加经济合理,设备润滑部分的维护时间和成本大大减少,生产效率有效提高。文中主要对集中润滑系统在易开盖组合成型中的应用进行分析阐述,包括集中润滑系统的特点、组成、设计选型以及控制系统等。     

平底改锥体滚刀钻头及应用效果

以滚刀钻头破岩理论及常规锥底翼状钻头破岩理论为指导，分析提出了平底滚刀钻头在易斜地层钻进偏斜度大的机理，并设计了改进锥底滚刀钻头的关键结构及主要参数，改平底滚刀钻头为锥底滚刀钻头并进行了施工应用，取得了非常理想的工程效果。     

The effects of oxygenation aeration treatment on dissipation behaviors of tricaine mesylate in carp (Cyprinus carpio) muscle and water

Tricaine mesylate (MS-222) is one of the most used anesthetics in fish. It can be absorbed by the human body via food consumption, with related detriments to human health. In this study, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was developed for the determination of MS-222 in carp muscle and water samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). For cleanup procedure, multiplug filtration cleanup (m-PFC) method with n-Hexane delipidation was adopted. The extraction solvent, cleanup methods and sorbents were optimized. All method validation parameters were in the acceptable range. The dissipation behavior study was followed by the method development. Firstly, the anesthesia dose and time were optimized in application study. Secondly, carps were revived for different period of time with (experimental group) and without (control group) the oxygenation aeration treatment to compare the dissipation rate of MS-222. After being anesthetized for 6 h at 50 mg/L and 12 h of elimination, the concentrations of MS-222 in crap muscle and water of experimental group was lower than those of control group. After 36 h of elimination under oxygenation aeration, over 90% of MS-222 was dissipated in carp muscle. The results showed that the half-life of MS-222 in carp muscle was 6.2 h. The findings suggested that the commonly-used oxygenation aeration treatment in aquaculture production had potential effects in accelerating the dissipation of MS-222 in carp and water. In this study, three days of withdrawal period was recommended in carps after MS-222 administration under oxygenation aeration.     

老年人食品包装的易用性设计

老年人食品包装设计未能充分考虑老年人生理和心理上的特殊需求,一般存在难以识别及难以开启等问题。设计师在进行老年人食品的包装设计时,可采用去繁求简、整合设计的方式,使用简单的图形化语言,将零散的信息重组,强化重要信息,设计出老年人易于读取的开口方式,提高包装的易读性;运用提示性设计,在商品包装上有效传达食用方法等说明性文字信息,提升包装的易识别性;对包装结构进行整合,将复杂的结构简单化,强化重要且重复使用的功能结构,突出包装的易拿取性。同时,可在包装中运用符合老年人心理需求的中国传统图案、代表健康长寿的吉祥图案,以及老年人喜爱的＂百子图＂图案等,使老年人形成一种健康、积极乐观的心理暗示。     

组合式梁类教学试验装置及应用

实验作为实践的重要组成部分,在土木工程专业的研究与教学中,起着不可忽视的作用.在土木工程本科专业教学中,对于钢筋混凝土教学,梁的受力性能试验是必需开展的一项试验之一.针对一部分学校因经费紧缺而没有专门实验室进行钢筋混凝土教学梁试验的现状,课题组对钢筋混凝土教学梁试验目的、过程、加栽方式与方法进行研究,设计、制作出了组合式梁类教学试验装置.试验装置采用自平衡系统,可根据需要进行拆卸、组装,可安装于任意教室等狭小空间内.装置的支座跨度可调,加载操作方便且安全可靠.利用组合式梁类教学试验装置,可更方便观察到钢筋混凝土梁在荷载作用下,受拉区混凝土开裂、纵向受拉主筋屈服、受压区混凝土达到极限压应变的破坏全过程,使学生能够对钢筋混凝土梁的受力机理及破坏形态有更深的认识与了解.     

Superparamagnetic Twist‐Type Actuators with Shape‐Independent Magnetic Properties and Surface Functionalization for Advanced Biomedical Applications

Directed nanoparticle self‐organization and two‐photon polymerization are combined to enable three‐dimensional soft‐magnetic microactuators with complex shapes and shape‐independent magnetic properties. Based on the proposed approach, single and double twist‐type swimming microrobots with programmed magnetic anisotropy are demonstrated, and their swimming properties in DI‐water are characterized. The fabricated devices are actuated using weak rotating magnetic fields and are capable of performing wobble‐free corkscrew propulsion. Single twist‐type actuators possess an increase in surface area in excess of 150% over helical actuators with similar feature size without compromising the forward velocity of over one body length per second. A generic and facile combination of glycine grafting and subsequent protein immobilization exploits the actuator's increased surface area, providing for a swimming microrobotic platform with enhanced load capacity desirable for future biomedical applications. Successful surface modification is confirmed by FITC fluorescence.     

PTT针织物的开发优势及前景

PTT纤维是一种新型纤维，具有优异的回弹性和易染性。本文主要介绍了PTT纤维的主要特性，尤其是其优异的弹性回复性，PTT针织服装方面开发优势和前景，指出PTT在针织弹力服装市场中必将有广阔的前景。