双马来酰亚胺改性苯并噁嗪树脂的力学性能及摩擦性能

苯并噁嗪(BOZ)树脂作为一种新型的热固性PF(酚醛树脂),具有诸多优异性能,但其韧性和耐磨性较差。以AE-BMI(含烯丙基醚的双马来酰亚胺预聚体)为改性剂制备AE-BMI/BOZ改性树脂,并对其力学性能和摩擦性能进行了研究。结果表明:适量的AE-BMI对BOZ树脂具有明显的增韧增强作用,并且其耐磨性也明显提高;当w(AE-BMI)=15%时,AE-BMI/BOZ改性体系的弯曲强度(125.53 MPa)和冲击强度(11.57 kJ/m2)分别比纯BOZ体系提高了57%和60%,并且其摩擦因数(0.27)和磨损率[18.50×10-6mm3/(N.m)]分别比纯BOZ体系降低了15.6%和50.6%。     

filtering for discrete-time linear systems with bounded time-varying parameters

In this paper, the problem of linear parameter varying (LPV) filter design for time-varying discrete-time polytopic systems with bounded rates of variation is investigated. The design conditions are obtained by means of a parameter-dependent Lyapunov function and extra variables for the filter design, expressed as bilinear matrix inequalities. An LPV filter, which minimizes an upper bound to the performance of the estimation error, is obtained as the solution of an optimization problem. A convex model to represent the parameters and their variations as a polytope is proposed in order to provide less conservative design conditions. Robust filters for time-varying polytopic systems can be obtained as a particular case of the proposed method. Numerical examples illustrate the results.     

烯丙基COPNA-BMI共聚树脂的制备及性能

以对苯二甲醇为交联剂、1-萘酚为单体合成COPNA树脂,经烯丙基化处理后与BMI反应制备烯丙基COPNA-BMI共聚树脂。采用FT-IR研究预聚树脂的化学结构;采用黏度计分析预聚树脂的流变性能;采用DSC研究COPNA-BMI预聚树脂的固化工艺;采用TG-DTG研究了COPNA-BMI共聚树脂的热行为。研究表明,预聚树脂具有良好的流变性能,其固化反应平稳易于控制;共聚树脂具有优良的耐热性,经后处理过的固化树脂其热分解起始温度为450℃。     

PBT和BMI反应性共混制备耐温阻燃材料

用双马来酰亚胺（简称ＢＭＩ） 和聚对苯二甲酸丁二醇脂（ 简称ＰＢＴ） 共混,配合硅烷偶联,用挤出机作为反应器,制备耐温增强阻燃材料,研究了双马来酰亚胺的质量分数、硅烷偶联剂用量与材料力学性能、热学性能的关系,获得了综合性能较好的ＰＢＴ 材料。     

Synthesis and characterization of leather impregnated with bismaleimide (BMI)–Jeffamine® resins

Leather/polymer composites were prepared by impregnating chrome-tanned cattlehide with a solution containing 1,1′-(methylenedi-4,1-phenylene)bismaleimide and Jeffamine® D-230. The mechanical properties in tension, glass transition temperatures, dynamic storage moduli, and moisture absorption of the composites were measured. Impregnated samples showed significant changes in tensile properties, such as the Young's modulus and strain at break, when compared with chrome-tanned cattlehide. In addition, impact energy increased significantly upon formation of the leather/polymer composite over that of the bismaleimide–Jeffamine® resin itself. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1019–1027, 1998     

不确定线性内互联大系统的分散鲁棒H∞控制

讨论含有界不确定性的线性内互联大系统,通过分散状态反馈和分散动态输出反馈的鲁棒Ｈ∞控制问题,首先给出一个重要引理,然后基于有界实引理分别导出放动态输出反馈的分散鲁棒Ｈ∞控制问题有解的充分必要条件,该条件及其问题的求解等价地转化成一个线性矩阵不等式和双线性矩阵不等式的求解。     

一种蒽醌基双马来酰亚胺及其胶粘剂的制备

以2,6—二胺蒽醌及顺丁烯二酸酐为原料合成了一种蒽醌基双马来酰亚胺(DEBMI),以此双马来酰亚胺树脂为主体,以4,4′—双(对氨基苯酮)二苯醚为固化剂,以二烯丙基双酚A为增韧剂,合成耐热胶粘剂,该胶粘剂具有良好的工艺性能和耐热性能。     

刚性聚醚酰亚胺改性双马来酰亚胺的研究

研究了刚性聚醚酰亚胺(PEI)改性双马来酰亚胺(BMI)树脂体系粘度特性和凝胶特性,以及PEI/BMI/RS/玻纤复合材料的力学性能。研究结果表明:PEI的加入使树脂体系的凝胶时间延长,导致树脂熔液在低粘度时的温度范围缩小和粘度增大。在PEI含量5%左右时,复合材料的综合力学性能较佳,弯曲强度提高了28.0%,冲击强度提高了26.1%。     

Differential DNA Methylation in Relation to Age and Health Risks of Obesity

The aim of this study was to evaluate whether genome-wide levels of DNA methylation are associated with age and the health risks of obesity (HRO); defined according to BMI categories as “Low HRO” (overweight and class 1 obesity) versus “High HRO” (class 2 and class 3 obesity). Anthropometric measurements were assessed in a subsample of 48 volunteers from the Metabolic Syndrome Reduction in Navarra (RESMENA) study and 24 women from another independent study, Effects of Lipoic Acid and Eicosapentaenoic Acid in Human Obesity (OBEPALIP study). In the pooled population; the methylation levels of 55 CpG sites were significantly associated with age after Benjamini-Hochberg correction. In addition, DNA methylation of three CpG sites located in ELOVL2; HOXC4 and PI4KB were further negatively associated with their mRNA levels. Although no differentially methylated CpG sites were identified in relation to HRO after multiple testing correction; several nominally significant CpG sites were identified in genes related to insulin signaling; energy and lipid metabolism. Moreover, statistically significant associations between BMI or mRNA levels and two HRO-related CpG sites located in GPR133 and ITGB5 are reported. As a conclusion, these findings from two Spanish cohorts add knowledge about the important role of DNA methylation in the age-related regulation of gene expression. In addition; a relevant influence of age on DNA methylation in white blood cells was found, as well as, on a trend level, novel associations between DNA methylation and obesity.