UV stabilisation of powder clear coats

Powder coatings are gaining importance in exterior applications such as automotive and architectural finishes. The use of additives in powder coating formulations enhance the durability of the coating by reducing the effects of harmful UV light and providing high temperature stability during processing and curing. Customers' increased demands for better retention of aesthetical and mechanical properties has prompted the development of new additives dedicated to powder coatings. This paper presents an overview of the performance of light stabilizers used in powder coatings.     

Particle Transport through Scattering Regions with Clear Layers and Inclusions

This paper introduces generalized diffusion models for the transport of particles in scattering media with nonscattering inclusions. Classical diffusion is known as a good approximation of transport only in scattering media. Based on asymptotic expansions and the coupling of transport and diffusion models, generalized diffusion equations with nonlocal interface conditions are proposed which offer a computationally cheap, yet accurate, alternative to solving the full phase-space transport equations. The paper shows which computational model should be used depending on the size and shape of the nonscattering inclusions in the simplified setting of two space dimensions. An important application is the treatment of clear layers in near-infrared (NIR) spectroscopy, an imaging technique based on the propagation of NIR photons in human tissues.     

Study on dosimetry of bremsstrahlung radiation processing

The dosimetry in high-power bremsstrahlung irradiation for the industrial processing has been studied. The dosimeter systems used are cylindrical ionization chamber to measure average exposure rate and CTA, clear PMMA and alanine dosimeters for routine dosimetry. The results gave some useful information on the measurement of average exposure rate using the ionization chamber. Clear PMMA and alanine dosimeters showed good characteristics for their usefulness as routine dosimeters for X-ray irradiation in the industrial processing.     

利用2Ⅳ^m-p设计的纯净两因子交互效应个数判断低阶混杂

根据纯净两因子交互效应的数量证明某些2Ⅳ^m-p设计在一定条件下具有弱最小低阶混杂，并且给出了一组既具有弱最小低阶混杂又包含最大数量纯净两因子交互效应的2Ⅳ^m-p设计．     

含乙烯氧基柔链的苯并菲盘状液晶清亮点的平均场理论研究

我们前期的合成和实验发现, 对于一系列含端烯氧基醚链的苯并菲分子, 它们没有分子间氢键, 其生成的液晶的清亮点的高低与端烯氧基醚链的数目有关. 本工作采用Gay-Berne势模拟液晶分子的双体势, 用量子化学和分子力学相结合的ONIOM(MP2/6-31G*(0.25):UFF)方法优化含端烯氧基醚链的苯并菲分子的单体和双体的构型和能量, 从而获得Gay-Berne势的参数. 在此基础上, 根据平均场理论, 解一个关于序参量和温度的积分方程, 求出液晶的清亮点. 计算结果与实验趋势相同, 可以解释清亮点和分子端烯氧基醚链数目的关系.     

绝对零位光栅参数的确定和编码的技术指标

本文首次提出了光栅副的有效通光域的概念及有效通光域的测量方法。对编码的技术指标补加了绝对有效通光面积和相对有效通光面积两个量,并阐明了相对有效通光面积较之其它指标更能综合地反映编码的设计质量。对多零位信号的出现和避免也进行了讨论。     

超高压和热杀菌对草莓浊汁及清汁品质的影响

研究超高压(常温下,550MPa,处理5min)、热处理(中心温度90℃,处理1min)及高温短时杀菌(110℃,处理8.6s)对草莓浊汁和清汁品质的影响。结果表明:(1)经超高压处理后,草莓浊汁的黏度、果胶含量和浊度无显著变化,悬浮稳定性显著增加;而热处理和高温短时杀菌处理后,浊汁的黏度和果胶含量显著减小,浊度增大,悬浮稳定性降低,但高温短时杀菌组好于热处理组;(2)草莓浊汁和清汁经超高压处理后Vc分别损失11.09%和13.59%,而热烫结合超高压处理后分别损失7.75%和10.73%;热处理和高温短时杀菌组浊汁和清汁中Vc的损失率高于超高压组,分别为28.86%~38.89%和20.38%~29.02%;(3)超高压处理对草莓浊汁和清汁的单体花色苷、聚合色度及总酚含量、DPPH和FRAP抗氧化活性没有显著影响;热处理和高温短时杀菌处理后草莓浊汁中的花色苷总量分别损失了3.89%~4.63%和7.46%~8.02%,而清汁中分别损失了5.97%~6.02%和8.09%~9.20%;聚合色度和聚合色度百分比增加,总酚含量无显著变化,抗氧化活性显著降低;(4)超高压处理对草莓浊汁和清汁的亮度L*、红值a*、黄值b*、彩度C*及色调角hab均没有显著影响;而热处理和高温短时杀菌处理使L*值和a*值均显著减小。     

Exosomal MicroRNA as Biomarkers for Diagnosing or Monitoring the Progression of Ovarian Clear Cell Carcinoma: A Pilot Study

Ovarian cancer is the most common cause of gynecological malignancy-related mortality since early-stage disease is difficult to diagnose. Advanced clear cell carcinoma of the ovary (CCCO) has dismal prognosis, and its incidence has been increasing in Japan, emphasizing the need for highly sensitive diagnostic and prognostic CCCO biomarkers. Exosomal microRNAs (miRNAs) secreted by tumor cells are known to play a role in carcinogenesis; however, their involvement in ovarian cancer is unclear. In this study, we performed expression profiling of miRNAs from exosomes released by five cell lines representing different histological types of ovarian cancer. Exosomes isolated from culture media of cancer and normal cells were compared for miRNA composition using human miRNA microarray. We detected 143 exosomal miRNAs, whose expression was ≥1.5-fold higher in ovarian cancer cells than in the control. Among them, 28 miRNAs were upregulated in cells of all histological ovarian cancer types compared to control, and three were upregulated in CCCO cells compared to other types. Functional analyses indicated that miR-21 overexpressed in CCCO cells targeted tumor suppressor genes PTEN, TPM1, PDCD4, and MASP1. The identified miRNAs could represent novel candidate biomarkers to diagnose or monitor progression of ovarian cancer, particularly CCCO.     

Acid and scratch resistant coatings for melamine based OEM applications

Increasing the mar resistance of OEM clear coats has been one of the main R&D priorities of paint manufacturers over the last years. Reaching a good mar resistance level without compromising other coating properties such as acid resistance proves to be a major challenge. We investigated the use of branched glycidyl esters in melamine based OEM acrylic formulations. Our results show that systems based on this type of esters lead to good overall coating properties as well as a good balance between acid and scratch resistance.     

Synthesis of Submicron Silicalite‐1 Crystals from Clear Solutions

Discrete and monodisperse submicron crystals of silicalite‐1 with a mean size of 0.3 μ m were synthesized from clear crystallization solutions. The effects of silica content, alkalinity of batch and the nature of silica source on the product yield, crystal morphology and particle size distribution were investigated. The crystal shape was sphere‐like or hexagonal twinned disks when silicic acid was the silica source. Change of silica source to sodium silicate solution leads to the formation of rounded‐edged‐hexahedron crystals. Silica content of batch does not influence crystal morphology. Alkalinity of clear crystallization solution has a strong effect both on the particle size distribution and yield of product. Increase of alkalinity caused bimodal particle size distribution and decrease of yield.