网页实时防篡改系统研究

为了解决网页篡改的问题,并对发生问题的web页面进行自动恢复．本文基于时间轮询技术与核心内嵌技术,设计并实现了一种网页防篡改系统．该系统能够实时的检测网页被篡改并进行实时阻断及后台恢复;系统能定时的对网站的文件进行扫描,并根据不同的扫描结果进行相应的处理．采用时间轮询技术与核心内嵌技术有效的弥补了采用一种技术带来的缺陷,保证网页的完整性及安全性,并且使网页的防护达到了实时性．     

5S管理理论在高校宿舍管理中的引进研究

高校宿舍管理是高校管理的一项重要内容。大学生宿舍是大学生学习、生活、成长的重要场所,是他们思想交流、心灵沟通的舞台。大学生宿舍管理的现状给管理者提出了新的问题,所以,如何在高校宿舍管理中引进和推行5S管理,是一个亟待研究的课题。     

联苯双酯中间体的合成

为考查联苯双酯中间体2-溴-3,4-亚甲二氧基-5-甲氧基苯甲酸甲酯的合成方法,采用先环合后溴代的合成路线．以没食子酸为原料,经甲酯化、甲醚化、二氯甲烷环合和溴代得2-溴-3,4-亚甲二氧基-5-甲氧基苯甲酸甲酯,总收率约37％,经IR和^1HNMR确证了结构．此合成工艺具有生产应用价值．     

毛细柱气相色谱法分析水中甲醇的研究

采用PC-5（固定相为交联5％苯基-95％甲基聚硅氧烷）毛细柱直接进样分析环境（水和空气）中的甲醇,实现甲醇及共存物干扰物质（甲醛、乙醇、丙酮、丙酮、异丙醇）的分离,利用高浓度（分流比5．0）和低浓度（分离比1．0）两个工作曲线对环境中甲醇进行准确测定。     

高碳水化合物条件下鼠肌GLUT4表达与CaMK／HDAC5关系的研究

观察Caffeine诱导骨骼肌细胞GLUT4表达的潜在分子调控机制是否是Caffeine—Ca2＋-CaMKII—HDAC5信号通路。8周龄雄性Wistar大鼠42只,随机分为高碳Caffeine组（HGC）、高碳KN62组（HGK）、低碳Caffeine组（LGC）和低碳KN62组（LGK）,每组12只。分别给予不同饮食加Caffeine或KN62刺激。检测caMKⅡ（Thr286）位点、HDAC5（sel498）位点和HDAC5（Ser259）位点磷酸化水平以及GLUT4蛋白表达水平。与HGc组相比LGC组GLUT4蛋白表达、CaMKⅡ（Thr286）、HDAC5（Se-98）HDAC5（Ser259）磷酸化水平都显著增加性高于HGC组和LGK组。无论是在低碳还是在高碳浓度下骨骼肌细胞GLUT4蛋白表达变化都对应着上游caMKⅡ蛋白位点（Thr286）磷酸化水平和下游HDAC5蛋白位点（Ser498）和（Ser259）磷酸化的变化,所以CaMKⅡ调节GLUT4表达的机制至少涉及到CaMKⅡ征用转录抑制子HDAC5。     

5,7-二羟基黄烷酮的流动氢化仪法合成

针对常规氢化反应釜合成匹诺塞林的合成工艺中容易发生过度还原生成副产物、不易控制反应的进程、重现性差、副产物难纯化分离等问题,为提高匹诺塞林合成收率,利用H-Cube TM流动氢化仪具有连续流动可实时监测从而实现高选择性、反应条件容易优化的特点,以5,7-二羟基黄酮为原料,四氢呋喃为溶剂,还原氢化得到5,7-二羟基黄烷酮.考察了反应液流速、温度、压力对反应收率的影响.结果表明,当反应温度为100℃,压力为2 000kPa,反应液流速为0.5mL/min时,5,7-二羟基黄烷酮的合成收率最高,达到96%,纯度为98.5%.影响黄烷酮合成收率因素顺序为温度>流速>压力.化合物的结构经过熔点、质谱分析法、氢-核磁共振确定,纯度经过液相色谱确证.该方法具有安全、易控制、操作简便、后处理简单等优点,更适合工业化生产.     

Synergistic Enhancement and Separation of Zirconium(IV) and Hafnium(IV) with 3-Phenyl-4-Benzoyl-5-Isoxazolone in the Presence of Crown Ethers

Abstract

3-Phenyl-4-benzoyl-5-isoxazolone (HPBI) was synthesized and examined with regard to the synergistic solvent extraction behavior of zirconium(IV) and hafnium(IV) in the presence of various crown ethers (CEs), namely, 18-crown-6 (18C6), dicylohexano-18-crown-6 (DC18C6) and benzo-15-crown-5 (B15C5) from hydrochloric acid solutions. The results demonstrated that zirconium(IV) and hafnium(IV) were synergistically extracted into chloroform with mixtures of HPBI and CEs as ZrO(PBI)₂ · CE and HfO(PBI)₂ · CE, respectively. The complexation strength follows the order DC18C6 >18C6 > B15C5. The addition of CEs not only enhances the extraction efficiency of zirconium(IV) and hafnium(IV) but also significantly, especially in the presence of B15C5, improves the selectivity (Zr/Hf = 4.73) between these metal ions as compared to HPBI alone (Zr/Hf = 2.09). On the other hand, selectivity has been moderately decreased by the addition of 18C6 or DC18C6 to the metal-chelate system.     

Magnetic and Dielectric Properties of YIG/HDPE Composites for High-Frequency Applications

A low loss high-frequency magnetic composite with Y₃Fe₅O₁₂ (YIG) ultrafine particles embedded in a high-density polyethylene (HDPE) matrix was fabricated by using a simple low-temperature hot-pressing technique. The magnetic and dielectric properties of the as-prepared composites were investigated in detail. The results indicate that as the volume of the ceramic fillers increases, the permittivity, permeability, dielectric and magnetic loss of the composite all increase. The cut-off frequencies of the composites are all above 700 MHz. Since the low resistivity of YIG, the dielectric losses of the composites are high and decrease with frequency in the lower frequency range. Good frequency stability of the permittivities and permeabilities, and low dielectric and magnetic losses within the measurement range have been observed.