Experimental Study on Modified Activated Carbons for Elemental Mercury Adsorption

在小型固定床实验台上对中孔分子筛(SbA-15)、煤基活性炭(bPl)、不同含水量活性炭、苯酚和苯甲酸改性活性炭进行气态汞的吸附实验。结果表明:相对于中孔而言,微孔更有利于气态汞的吸附。负载羧基样品对气态汞的吸附能力与原始活性炭相比有很大提高。当羧基负载量为28.89Mg羧基/g活性炭时,样品对气态汞的吸附性能达到最佳;经酚羟基改性样品,其对气态汞的吸附能力显著降低,当达到吸附饱和时,原始活性炭的吸附量为306.55μg/g,而酚羟基改性样品最大吸附容量为133.1μg/g,且负载量与气态汞吸附量呈负相关,由此推测酚羟基对气态汞的吸附没有促进作用,而羧基有利于气态汞的吸附。活性炭表面存在适量水分有利于气态汞的吸附,当样品表面含水率为14.49%时,样品的吸附性能达到最佳。A laboratory-scale packed-bed reactor system was used to evaluate the capability of mesoporous molecular sieve(SBA-15),coal-based activated carbon(BPL),activated carbons containing different content of moisture,phenol-modified and carboxyl-modified activated carbons for mercury adsorption.The results show that compared to the mesopore structure,micropore structure on the surface of activated carbons is in favor of capturing mercury from carrier gas.The mercury adsorption capacity of carboxyl-modified activated carbons increases significantly compared to that of original carbons.And the best result obtained at the modification ratio of 28.89 mg carboxyl groups /g activated carbon.While the capacity of phenol-modified activated carbons for mercury adsorption decreases remarkably.When reaches saturation,the mercury adsorption capacity of original activated carbons is 306.55 μg/g,while the highest capacity of phenol-loaded activated carbons is 133.1 μg/g,and there is a positive relation between the amounts of phenol or carboxyl and mercury adsorption.It suggests that the phenol groups may have no effect on mercury adsorption,while the carboxyl groups are beneficial to the mercury adsorption.The presence of moisture on the surface of activated carbons can enhance their mercury adsorption capacities,and when the moisture content is 14.49%,the adsorption capacity reaches the best result.国家自然科学基金项目(20707018);福建省科技重点项目(2008I0024);福建省青年人才项目(2006F3118)---

Oct reotide对门脉血流动力学的影响

摘　要　用彩色多普勒超声波观察静脉注射奥曲肽0. 1mg 对17例门脉高压症患者和6例非门脉高压症患 者门脉血流的影响。结果表明奥曲肽能显著地缩小门脉高压患者的门静脉主干内径( P < 0. 001) , 增加门脉平 均血流速度( 90min及24 h , P 0. 05) ,而平均血流量( P > 0. 05)及血流方向却无变化。非门 脉高压症患者上述指标无统计学意义

法兰攻丝高强度螺栓连接攻丝板牙体强度理论研究

与传统高强度螺栓连接不同,法兰攻丝高强度螺栓连接中因为攻丝板的存在易造成因攻丝板厚度不足导致的牙体弯剪破坏,使得连接强度显著降低。为此,基于能量强度理论和攻丝板的几何特征,研究了不同角度下攻丝板牙体的复合受力和破坏特征,提出了最不利受力状态下攻丝板牙体复合受力分析模型,建立了基于弯剪破坏的攻丝板牙体强度理论公式。为充分发挥法兰攻丝高强度螺栓受拉连接强度,提出了基于高强度螺栓颈缩破坏的最小攻丝板厚度公式。通过建立法兰攻丝高强度螺栓受拉连接的精细化有限元分析模型,研究了不同攻丝板厚度下M16和M20等常见高强度螺栓连接的破坏形态、峰值承载力及变形等参数,最终确定的最小攻丝板厚度分别为14 mm和18 mm,与理论公式计算结果基本吻合,验证了公式的正确性,可供实际工程应用参考