水蒸汽二次活化对活性炭中孔结构的影响

以商业活性炭为原料，经水蒸汽二次活化，制备了3个不同温度和不同活化时间的样品，用热重－质谱连用技术对原料的热分解产物进行分析；用N2吸附脱附等温线，BJH中孔分析和as法考察活性炭孔径的变化，用FT－IR技术测定活性炭表面官能团的变化，用XRD技术研究活性炭中的乱层结构，用扫描电镜研究活性炭的表面形态，结果表明，活化时间的延长或活化温度的升高使得活性炭的孔径变大且分布发散，出现两个孔径分布峰，同时，孔容积增加，表面官能团和乱支结构变化不明显，电镜研究发现活性炭的表面逐步光滑，有孔之间的互融现象出现，在735摄氏度活化120min所制样品的孔径较为集中。     

煤矿断层错动型冲击地压研究现状与发展趋势

为深入认识断层错动型冲击地压复杂的致灾机制、降低采矿过程中冲击事故的发生率,通过梳理国内外文献,系统总结和分析了国内外在断层错动型冲击地压方面的研究进展及成果.介绍了国内外一些矿山发生断层错动型冲击地压的严峻形势,并汇总了国内部分煤矿该类型冲击地压实例;从断层活化机制及其判别准则、断层错动型冲击地压理论、发生条件及其孕育过程等4个方面着重分析了断层错动型冲击地压的致灾机制;总结了断层错动型冲击地压的监测预警方法,并介绍了一些具有代表性的可用于断层错动型冲击地压预测预报的监测预警技术及其工程应用情况,包括断层错动型冲击地压监测预警与防治体系、BMS-II型微地震监测系统、多参量实时联合监测预警系统和深部钻孔应变观测技术;论述了断层错动型冲击地压防控技术,包括区域性防御措施和局部解危措施等;在分析以上问题的同时,又提出了一些新的理论观点、见解和建议.最后,指出了当前断层错动型冲击地压研究存在的一些不足,并对该类型冲击地压未来研究的发展趋势进行了多方面展望.     

碳含量对430铁素体不锈钢耐晶间腐蚀性能的影响

利用双环动电位再活化法(DL-EPR)、扫描电子显微镜(SEM)和能谱仪(EDS)研究了碳含量对430铁素体不锈钢耐晶间腐蚀性能的影响。结果表明:单纯的再活化率不能评价430铁素体不锈钢的晶间腐蚀敏感性,需要结合DL-EPR试验后材料表面形貌的电镜观察结果进行综合判断;对430铁素体不锈钢来说,碳含量越高,敏化时间越长,其晶间腐蚀倾向越大。     

浮选分级—抑制及再活化硫化矿混合精矿的分离浮选研究

对从苏州高岭土尾矿中用浮选法得到的硫化矿混合精矿进行了硫及铅锌混合精矿的分离浮选试验研究。在不磨矿的条件下,采用浮选分级-抑制及再活化浮选方法获得了铅、锌品位分别为19.95%、30.1%,回收率分别为82.00%、81.29%的铅锌混合精矿和硫品位和回收率分别为52.49%、75.5%的硫精矿。     

EPR法评价HR3C钢焊接接头的晶间腐蚀敏感性

利用电化学动电位再活化法研究了HR3C钢焊接接头的晶间腐蚀敏感性,并通过金相显微镜、X-射线衍射仪、扫描电子显微镜及能谱仪研究了HR3C钢焊接接头的微观组织.结果表明,HR3C钢焊缝金属和焊接热影响区均为奥氏体+析出相组成,焊接接头具有较低的晶间腐蚀倾向.由于焊缝金属中Cr和Nb等元素含量高及晶界和枝晶界铌、铬元素偏析等原因提高了晶界耐腐蚀性,使其具有优异的抗晶间腐蚀性能;而热影响区由于受焊接热循环作用晶界析出M23C6引起晶界贫铬,具有一定的晶间腐蚀敏感性.     

蒸汽活化改善中温烟气脱硫的机理

用蒸汽处理用于中温烟气脱硫的失去反应活性的脱硫剂可以显著提高钙利用率和脱硫效率。为了探明蒸汽活化机理，借助于成分分析和表观形貌检测，分析了蒸汽处理后的脱硫剂理化特性的变化，用CaO迁移的新观点揭示了中温蒸汽活化提高脱硫剂固硫能力的机理，经过蒸汽活化后，乏脱硫剂颗粒除了发生破碎外，其内部未反应的CaO会与蒸汽水合成Ca(OH）2，继而在体积膨胀作用下迁移到颗粒表面，并在分解温度以下还原和与SO2发生反应，迁移过程还改变了颗粒表层的孔隙结构，改善了SO2与CaO扩散，接触和反应。     

Adaptive Immune Responses in a Multiple Sclerosis Patient with Acute Varicella-Zoster Virus Reactivation during Treatment with Fingolimod

Fingolimod, an oral sphingosine 1-phosphate (S1P) receptor modulator, is approved for the treatment of relapsing forms of multiple sclerosis (MS). The interference with S1P signaling leads to retention particularly of chemokine receptor-7 (CCR7) expressing T cells in lymph nodes. The immunological basis of varicella zoster virus (VZV) infections during fingolimod treatment is unclear. Here, we studied the dynamics of systemic and intrathecal immune responses associated with symptomatic VZV reactivation including cessation of fingolimod and initiation of antiviral therapy. Key features in peripheral blood were an about two-fold increase of VZV-specific IgG at diagnosis of VZV reactivation as compared to the previous months, a relative enrichment of effector CD4+ T cells (36% versus mean 12% in controls), and an accelerated reconstitution of absolute lymphocytes counts including a normalized CD4+/CD8+ ratio and reappearance of CCR7+ T cells. In cerebrospinal fluid (CSF) the lymphocytic pleocytosis and CD4+/CD8+ ratios at diagnosis of reactivation and after nine days of fingolimod discontinuation remained unchanged. During this time CCR7+ T cells were not observed in CSF. Further research into fingolimod-associated VZV reactivation and immune reconstitution is mandatory to prevent morbidity and mortality associated with this potentially life-threatening condition.     

Steam hydration-reactivation of FBC ashes for enhanced in situ desulphurization

Bed and fly ashes originating from industrial-scale fluidized bed combustors (FBCs) were steam hydrated to produce sorbents suitable for further in situ desulphurization. Samples of the hydrated ash were characterized by X-ray diffraction analysis, scanning electron microscopy and porosimetry. Bed ashes were hydrated in a pressure bomb for 30 and 60 min at 200 °C and 250 °C. Fly ash was hydrated in an electrically heated tubular reactor for 10 and 60 min at 200 °C and 300 °C. The results were interpreted by considering the hydration process and the related development of accessible porosity suitable for resulphation. The performance of the reactivated bed ash as sulphur sorbent improved with a decrease of both the hydration temperature and time. For reactivated fly ash, more favourable porosimetric features were observed at longer treatment times and lower hydration temperatures. Finally, it was shown that an ashing treatment (at 850 °C for 20 min) promoted a speeding up of the hydration process and an increase in the accessible porosity.     

Browning in processed yams: peroxidase or polyphenol oxidase?

Polyphenol oxidase and peroxidase were purified from white yam (Dioscorea rotundata) using DEAE‐cellulose ionexchange chromatography. Thermoinactivation curves for polyphenol oxidase showed monophasic kinetics, while those for peroxidase were biphasic. Urea partially stabilised peroxidase against irreversible thermoinactivation, but did not do so in the case of polyphenol oxidase. Only peroxidase was capable of regenerating activity after thermoinactivation. The results showed that thermoinactivation of peroxidase was mainly due to conformational changes, while that of polyphenol oxidase was probably due to covalent damage. Peroxidase reactivation might play an important role in the browning of processed yam. © 2002 Society of Chemical Industry     

天然气和二氧化碳转化制合成气的研究──Ⅱ．催化剂失活与再生

采用ＸＲＤ，ＸＰＳ技术，配合比表面、孔结构测定和催化微反技术，研究了天然气和ＣＯ２转化制合成气催化剂失活机制和再生条件。发现催化剂失活主要是由于活性中心Ｎｉ０聚集并形成晶相，因而降低了催化剂表面活性中心数，其次是由于部分活性中心形成难还原的ＮｉＡ１２Ｏ４物种和催化剂比表面降低。找到了一种催化剂再生的最佳条件，通过使用晶相分散剂Ｂ可以使催化剂恢复到新鲜催化剂的活性。