竹炭制备高比表面积活性炭及其电容性质研究

[目的]研究竹炭制备高比表面积活性炭及其电容性质.[方法]采用竹材加工剩余物制成的竹炭为原料,以氢氧化钾为活化剂制备了双电层电容器用活性炭,并通过正交试验研究了液固比、活化温度、活化时间及升温速率对产品吸附性能的影响.[结果]得到最优的活化工艺参数如下:碱炭比为4∶ 1,活化温度为770 ℃,活化时间为60 min,升温速率为10 ℃/min,比表面积高达2 379 m2/g,但其质量比电容不是最大.当比表面积为2 121 m2/g时,质量比电容最大(323 F/g),但其体积比电容偏小.[结论]为研制高比电容量且具有实际应用价值的电极材料提供了依据.     

烟杆活性炭的制备及其乙醇吸附特性研究

云南省作为全国最大的烟草种植省份,每年产生大量的烟草废弃物,其中以烟杆为主,用烟杆制备活性炭可以实现废弃物资源化利用。本研究以烟杆为试验原料,通过炭化——KOH活化制备活性炭,探索最佳制备工艺条件,分析了活性炭的结构特征及活化条件对炭孔结构的影响,同时研究了活性炭对乙醇吸附的吸附特性。试验表明,活化温度保持在700℃,KOH与炭化料之比为3的条件下制备的活性炭有较高的比表面积和总孔容,分别为1 256 m2/g和0.588 cm3/g,此时微孔孔容最大,可达0.470 cm3/g,样品表面呈现无定形碳结构,对乙醇的吸附最有利。乙醇吸附测试表明,最佳工艺条件下制得的活性炭对乙醇的平衡吸附容量最大,可达382.93mg/g,该活性炭在太阳能吸附制冷领域具有一定的应用前景。     

乏风瓦斯分离富集用椰壳基活性炭的制备

以椰壳为原料、酚醛树脂为粘结剂及聚乙二醇（PEG）为造孔剂和分散剂,采用水蒸气活化制备活性炭,以所制备的活性炭为吸附剂,采用真空变压吸附法（VPSA）对乏风瓦斯进行分离富集.分别考察了不同活化条件对活性炭孔结构性能的影响,以及不同VPSA操作条件对乏风瓦斯富集效果的影响.结果表明:以酚醛树脂与粉体炭的质量比为0.5 g/g制备的成型炭作为炭质前驱体进行活化,在活化时间为5 h、通入水量为1.96 cm3/min和活化温度为825 ℃的条件下制备的活性炭,其对应的比表面积、微孔体积及微孔率分别达到795 m2/g、0.37 cm3/g和84.1%;并以该活性炭为吸附剂,在最佳操作条件下,乏风瓦斯（甲烷含量约0.5%）经富集后,产气中CH₄浓度和回收率分别为1.51%和96%.      

二氧化碳活化制备烟杆基颗粒活性炭的研究

进行了以烟杆废弃物为原料、木焦油为主的复合黏结剂、二氧化碳为活化剂制备颗粒活性炭的研究。系统地研究了活化温度、活化时间、二氧化碳流量等因素对烟杆基颗粒活性炭活化效果的影响，得到了该试验条件下最佳工艺条件：活化温度为900℃，活化时间为100min，二氧化碳流量为0．5L／min。该工艺条件下制备的颗粒活性炭碘吸附值为901．36mg／g，亚甲基蓝吸附值为80ml/g，活性炭得率为38.53％。同时，测定了该活性炭氮吸附，通过BET计算了活性炭的比表面积，并通过密度函数理论（DFT）表征了活性炭的孔结构。结果表明：制备的活性炭为微孔型，BET比表面积为947.81m^2／g，总孔容为0．48ml／g。     

水蒸气活化对活性炭电吸附脱盐性能的影响

用硝酸对活性炭进行去灰分处理,并用水蒸气进行二次活化,将活性炭制成电极,在电吸附装置中进行电吸附测试.结果表明,二次活化可以提高活性炭的比表面积和孔容,并使得活性炭的单位吸附量从2.92 mg/g提高到4.55 mg/g.活化效果受活化时间和活化温度共同影响,活化1h的效果最好,提高活化温度有利于提高吸附性能.     

掺钴氧化钌（RuO2/Co3O4）·nH2O复合薄膜电极的制备与表征

以六水合氯化钴(CoCl2.6H2O)和水合三氯化钌(RuCl3.3H2O)为前驱体,采用胶体法制备超级电容器用(RuO2/Co3O4)·nH2O复合薄膜电极材料。用X射线衍射仪以及CHI660C电化学工作站对该复合薄膜的物相结构及电化学性能进行表征。结果表明:当CoCl2·6H2O和RuCl3·3H2O的物质的量比n(Co):n(Ru)为2:1时,于350℃下热处理2.5 h制备的复合薄膜电极具有优良的性能,在浓度为0.5mol/L的H2SO4电解液中其比电容达到512 F/g,500次充放电循环后比电容量保持在充放电循环前的96.1%;充放电电流为0.01A时,内阻为1.2。     

活性炭孔分布对其电容衰减性能的影响

以8种不同孔结构的活性炭为实验对象,利用低温N2(77 K)吸附法测定活性炭的比表面积和孔径分布,并将其涂布到铝箔集流体上组装成双电层超级电容器。以1 mol/L四氟硼酸四乙基铵的乙腈溶液(Et4NBF4/AN)为电解液,利用循环伏安和恒流充放电技术研究活性炭的比表面积、中孔和微孔分布以及孔容等对双电层电容器倍率衰减性能的影响。结果表明:活性炭的比表面积、孔径和孔容的适量增大均能提高活性炭的比容量;中孔的适量增加不仅可以减小超级电容器的电阻,还可以提高活性炭的大电流充放电性能,降低大电流充放电时的电容衰减。当电流密度从0.15 A/g增大到9.6 A/g时:中孔活性炭的比电容衰减率平均为14.13%,而微孔活性炭的平均衰减率为20.58%;中孔表面积对比电容的贡献由10.10μF/cm2下降至9.95μF/cm2,而微孔表面积的贡献则由5.68μF/cm2下降至4.21μF/cm2。     

α-MnO2的机械化学法合成及其电容性质

以高锰酸钾与乙酸锰为原料,采用机械化学法制备MnO2.利用SEM、BET、XRD、交流阻抗法、循环伏安以及恒电流充放电对电极材料结构与性能表征,对充放电曲线求斜率分析.结果表明产物为弱结晶型α-MnO2,其比表面积为385.5 m2,平均孔径为3.4 nm.α-MnO2电化学电容器表现出法拉第电容与双电层电容的双重特征;随着循环次数增加,Mn3O4生成,交换电流密度从177 mA/g减少到69.8 mA/g,微分电容从2.40×10-1 F减少到1.91×10-3 F;电极过程主要受电极电位状态变量影响;电极最大比容量达到416 F/g,经过近500次循环后,比容量为220 F/g.     

聚醋酸乙烯酯制备成型活性炭性能的初步研究

以聚醋酸乙烯酯为黏结剂,乙醇为助剂,去离子水为溶剂,对2种不同比表面积的粉体活性炭成型过程进行系统的研究,并探讨了成型活性炭的相关性能,主要有:比表面积、径向强度和耐水性.分别考察了聚醋酸乙烯酯用量、乙醇用量、加水量、固化温度及固化时间对成型活性炭的径向强度、比表面积及耐水性能的影响,确定成型的较优实验条件,并结合红外分析,对成型过程机理进行了初步探讨.结果表明,对比表面积为2 634 m2/g的活性炭,在聚醋酸乙烯酯用量为0.45 g/g(黏结剂/活性炭)、乙醇用量为5 g/g(乙醇/黏结剂)、加水量为3 g/g(水/黏结剂)、固化温度为100 ℃和固化时间60 min条件下制备的成型炭,径向强度达到89.4 N/cm,比表面积约为2 168 m2/g,比表面积收率达到82 %以上,碘值约为982 mg/g,苯值达404 mg/g.对比实验结果发现,乙醇的加入可以有效地提高成型炭的耐水性能,成型炭在沸水中浸泡10 h后,不会破损.      

半焦制备活性炭的新工艺

摘要：基于煤基直接还原过程,以半焦为原料,利用铁矿预热氧化球团还原产生的气体为活化剂,开发一步法炭化、活化制备高性能活性炭新工艺,并通过优化制备温度、制备时间及还原剂用量等工艺参数,可同时得到优质还原球团。结果表明：在制备温度850℃、时间1h,半焦/球团的质量比为1∶1～4∶1的条件下,活性炭产率大于67%,耐磨强度达90%以上,比表面积和碘吸附值分别高于330m2/g、500mg/g,远优于商品活性炭,同时可得到金属化率为85%以上的预还原球团。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.