聚甲基丙烯酸氨基乙酯的合成及染色性能

以白油为分散介质,偶氮二异丁腈为引发剂,甲基丙烯酸氨基乙酯为单体,采用反相悬浮聚合法合成聚甲基丙烯酸氨基乙酯(PTAM),研究了引发剂用量、反应温度、反应时间、单体浓度对PTAM特性粘数的影响。将PTAM与聚丙烯腈(PAN)共混纺丝制得共混纤维,用酸性染料染色,考察其上染率。结果表明:合成PTAM的最佳工艺条件为引发剂质量分数0.05%,单体质量分数60%,反应温度65℃,反应时间2h,所得PTAM的特性粘数为690mL/g。染色实验结果表明,PTAM质量分数为7%时,PAN共混纤维的上染率达88%。     

海洋资源开发高级专门人才培养实验教学方法探索——以膜集成分离技术为例

专业实验是考查学生掌握理论知识程度及为本科毕业论文的开展奠定基础的一个重要实践教学环节。依托传统优势,着眼于学科交叉,在海洋技术专业实验中开设集成膜分离技术实验,是必要的和可行的。教学实践结果表明,集成膜分离技术实验有助于培养学生的能力,促进学生结合实际生产进行独立思维、团队协作和创新探索。     

Preparation of semirigid polyurethane foam with liquefied bamboo residues

Bamboo residues were liquefied by using a solvent mixture consisting of polyethylene glycol 400 and crude glycerol (4/1, w/w) with 98% sulfuric acid as catalyst at 160°C for 120 min. The liquefied bamboo had hydroxyl values from 178 to 200 mg KOH/g and viscosities from 507 to 2201 mPa S. The obtained bamboo‐based polyols were reacted with various amounts of polyaryl polymethylene isocyanate (PAPI), using distilled water as blowing agent, silicone as surfactant, and triethylenediamine and dibutyltine dilaurate as cocatalyst to produce semirigid polyurethane (PU) foams. The [NCO]/[OH] ratio was found to be an important factor to control the mechanical properties of PU foams. At a fixed [NCO]/[OH] ratio, both density and compressive strength of PU foams decreased with the increase of bamboo content. The microstructure of PU foams indicates that [NCO]/[OH] ratios are important for cell formation and chemical reactions. The uniformity and cell structure of the foams are comparable to their corresponding compressive strengths. Moreover, the thermogravimetry analysis showed that all the semirigid PU foams had approximately the same degradation temperature of about 250 to 440°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

机械产品设计重用策略研究

设计重用是指将过去的设计及设计知识应用到当前的设计活动。产品设计的本质特征及市场竞争环境决定了设计重用的意义。设计重用可有效缩短设计周期,提高设计质量,从而实现快速响应设计与制造。研究了机械产品设计重用的策略,给出了机械产品设计重用层次与设计重用空间的概念,总结概括出设计重用的使能技术,即CAD技术、AI技术和Web技术,并提出了基于这些使能技术的机械产品设计重用框架、模型和策略,对机械产品设计重用的进一步研究与应用具有理论指导意义。     

新型高效捕收剂EM-2及其在包头矿石浮选中的应用

研制合成了一种含芳基、羧基及磺酸基团的新型浮选药剂EM—2。该药剂与氧化石腊皂混合(称之为SLM)作捕收剂,水玻璃作调整剂,用于包头白云鄂博红铁矿反浮选萤石中,工业分流试验在原矿铁品位35.11%时,获得铁精矿品位61.10%,回收率80.31%,精矿含氟0.74%,含磷0.14%的良好技术指标。工业应用获得的生产指标为:原矿铁品位31.32%,精矿铁品位60.38%,回收率为73.43%,精矿含氟0.58%,含磷0.124%。     

哌啶对MO/MCM-41催化剂上二苯并噻吩加氢脱硫反应的影响

在固定床反应器上考察了哌啶对二苯并噻吩(DBT)的加氢脱硫(HDS)反应活性及反应路径的影响。反应所用催化剂为MCM-41分子筛担载的Co-Mo或Ni-Mo硫化物,MoO3的负载量为20%,Co(Ni)与Mo的摩尔比为0.75。反应前,催化剂用10% H2S和90% H2的混合气进行硫化,硫化温度为400℃,硫化时间为3 h。HDS反应压力为5.0 MPa,温度为260-340℃,催化剂用量为0.2 g。反应原料为含哌啶和DBT分别为0-0.3%和0.8%的十氢萘溶液,液时空速为27 h-1。研究结果表明,无论是在Co-Mo／MCM-41 催化剂上还是在Ni-Mo／MCM-41催化剂上进行DBT的HDS反应,少量哌啶的存在都会大幅度降低催化剂的活性。由DBT的HDS反应产物的选择性分析发现,哌啶对HDS的抑制作用主要体现在对加氢反应路径的毒害作用。随着反应温度的升高,哌啶的加氢脱氮活性提高,HDS的反应活性接近于原料中没有哌啶时的活性,说明哌啶的毒害作用可能是因为它与含硫化合物竞争吸附而低温下加氢脱氮活性较低所致。     

曲率驱动的基于亥姆霍兹涡量方程的图像修复模型

图像修复模型根据已知区域信息自动修复目标区域,且保证修复后的图像满足人眼视觉系统的要求,目标区域轮廓自然.理论分析证明,流体力学中无粘亥姆霍兹涡量方程可以实现图像修复.根据曲线和曲面运动方程,使用曲率驱动亥姆霍兹修复模型中的等照度线传输方向.曲率是图像几何特征作用的结果,所以新模型可以很好地保持图像中的线性特征.图像中涡量为平滑程度的度量,二维图像域中涡量具有扩散性,对涡量方程的结果做各向异性扩散,使等照度线间的图像信息交互.亥姆霍兹涡量方程修复模型中的各个参数及扩散过程是涡量扩散性和耗散性以及图像几何特征作用的结果,扩散后的修复模型稳定且不存在错误的传输方向.理论和实验证明了曲率驱动的亥姆霍兹涡量方程模型在图像修复中的有效性.     

Doxycycline Decreases Atherosclerotic Lesions in the Aorta of ApoE-⁄- and Ovariectomized Mice with Correlation to Reduced MMP-2 Activity

Atherogenic events promote changes in vessel walls, with alteration of the redox state, and increased activity of matrix metalloproteinases (MMPs). Thus, this study aims to evaluate aortic remodeling, MMP activity, and reactive oxygen species (ROS) levels after treatment with doxycycline in ApoE^-⁄- and ovariectomized mice (OVX). Female ApoE^-⁄--knockout mice (5 weeks) were submitted to ovariectomy surgery to induce experimental menopause. They then received chow enriched with 1% cholesterol to induce hypercholesterolemia. The animals were divided into two experimental groups: ApoE^-⁄-/OVX vehicle and ApoE^-⁄-/OVX doxycycline (30 mg/kg) administered by gavage once a day for 28 days (15th to the 18th week of life). Blood samples were collected to measure total cholesterol and fractions. The aorta was used for morphometry and to measure the activity and expression of MMP-2 and ROS levels. The ApoE^-⁄-/OVX doxycycline group showed no change in total and fraction cholesterol levels. However, there was a reduction in ROS levels, MMP-2 expression, and activity that correlated with a decrease in atherosclerotic lesions relative to the ApoE^-⁄-/OVX vehicle (p > 0.05). Therefore, we conclude that doxycycline in ApoE^-⁄-/OVX animals promotes a reduction in atherosclerotic lesions by reducing ROS and MMP-2 activity and expression.     

螺旋藻(Spirulina Platensis)多糖蛋白对辐射诱发小鼠PCE微核率及白细胞数的影响

本试验通过对NIH小鼠骨髓细胞微核分析及外周血白细胞计数表明,螺旋藻多糖蛋白能显著减轻辐射对小鼠PCE微核率及白细胞数的影响。故螺旋藻多糖蛋白有可能作为一种新的有效的天然辐射防护剂。