还原氧化石墨烯/TiO2纳米线复合膜的制备及对Cu2+吸附性的影响

以石墨烯和自制TiO₂粉末为原料,通过两步水热法联合真空抽滤法制备还原氧化石墨烯/TiO₂纳米线(rGO/TiO₂ NWs)复合膜。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、拉曼光谱对rGO/TiO₂ NWs复合膜的形貌、结构进行表征。研究结果表明,还原氧化石墨烯和TiO₂ NWs成功地复合在一起,复合材料中TiO₂ NWs分散性较好。Cu²⁺吸附实验结果表明,复合材料中TiO₂ NWs所占比例、pH值是影响Cu²⁺吸附效果的重要因素,研究复合材料对Cu²⁺的吸附效果应该在pH值为6.0的近中性环境。其中TiO₂ NWs含量为50%时,复合膜对Cu²⁺的吸附量最高,达到rGO薄膜的4倍。复合薄膜有较好的吸附稳定性,重复使用5次后,吸附率是原吸附量的91%。     

基于用户需求垃圾邮件过滤分类模型设计

以朴素贝叶斯理论作为基石并结合信息增益、代价因子等方法,尝试设计一种基于用户需求的垃圾邮件过滤分类模型,在垃圾邮件一次分类基础上提出邮件先过滤后分类方法,进而改进传统邮件分类一次阈值比较,变为两次阈值比较,且应用反馈技术以应对垃圾邮件的日益变化.该模型可能会对垃圾邮件多分类研究具有一定的参考价值.     

舒适性空调系统的颗粒污染物控制--改善IAQ的步骤之一

要改善室内空气品质就必须对室内空气中的污染物质加以控制。针对八成生空调对空气过滤重视不够的现状，本文主要讨论影响室内空气含尘浓度的各个因素及其影响方法，并对舒适性空调系统的粉尘控制进行探讨。通过理论分析，本文首次提出系统临界过滤效率的概念，并从中得出舒适性空调系统空气过滤器的计算和选择方法供参考。     

Statistical analysis of data from accelerated ageing tests of PES UF membranes

In this research, membrane life-time was evaluated by means of accelerated ageing experiments. A pressure pulse unit was used to perform the ageing experiments in an accelerated way. An experimental design has been set up and four ageing factors were varied at two levels. The four ageing factors studied were: fouling status of the membrane, cleaning agent concentration, magnitude of the back pulse and number of applied back pulses. The integrity of the membrane modules was evaluated by means of permeability testing, pressure decay tests and bubble tests. Also tensile tests were performed to investigate the mechanical properties of the membrane modules. The collected data was used for an analysis of variance to determine which ageing factors and which combination of ageing factors influence membrane life time. The analysis showed that the fouling status in combination with the number of applied pressure pulses were significant ageing factors. Additional tensile tests confirmed these results.     

Homotopy theory of spectral categories

We construct a Quillen model structure on the category of spectral categories, where the weak equivalences are the symmetric spectra analogue of the notion of equivalence of categories.     

核信号检测与控制系统中的调制解调信号LabVIEW仿真研究

在核信号检测与控制系统中,从传感器输出的信号,一般都很微弱,为了避免信号在远距离传输过程中衰减、严重失真,这就需要对信号进行调制解调。在Win7系统下,使用LabVIEW2010设计了一个信号调制与解调系统。并且在该系统中分别采用Butterworth滤波器、Chebyeshev(I型)滤波器、椭圆滤波器对信号进行滤波了处理,比较结果发现,使用Butterworth滤波器得到的解调信号较后两种滤波器的好。     

SHEARING FLOW NEAR A BYPASS WITH A BALL IN IT

ＣｈｅｎＹａｏｓｏｎｇ（陈耀松）；ＭａＸｉｎｍｉｎｇ（马新民）；ＬｉａｎｇＧｏｕｐｉｎｇ（梁国平）；ＤａｉＭｉｎｇ（戴民）（ＲｅｃｅｉｖｅｄＭａｙ２３，１９９４；ＣｏｍｍｕｎｉｃａｔｅｄｂｙＤａｉＳｈｉｑｉａｎｇ）ＳＨＥＡＲＩＮＧＦＬＯＷＮＥＡＲＡＢ...     

聚酰胺纳滤膜对黄连中生物碱的截留性能

以盐酸小檗碱为模型分子,考察循环时间、操作压力、料液浓度和离子强度等因素对聚酰胺纳滤膜截留盐酸小檗碱性能的影响。实验表明:聚酰胺纳滤膜对盐酸小檗碱的截留率80min后基本稳定;随着操作压力的增加,膜通量和截留率都增大;随着料液浓度的增加,聚酰胺纳滤膜通量下降,对盐酸小檗碱的截留率先增大后下降;随着溶液中离子强度的增加,膜通量和截留率都减小。在黄连提取液中生物碱含量为0.025g/L、操作压力为0.4MPa条件下,聚酰胺纳滤膜5min可使黄连提取液中生物碱浓缩6.27倍。     

Investigating the Influence of Column Depth on the Treatment of Textile Wastewater Using Natural Zeolite

Textile industry production processes generate one of the most highly polluted wastewaters in the world. Unfortunately, the field is also challenged by the availability of relatively cheap and highly effective technologies for wastewater purification. The application of natural zeolite as a depth filter offers an alternative and potential approach for textile wastewater treatment. The performance of a depth filter treatment system can be deeply affected by the column depth and the characteristics of the wastewater to be treated. Regrettably, the information on the potential of these filter materials for the purification of textile wastewater is still scarce. Therefore, this study investigated the potential applicability of natural zeolite in terms of column depth for the treatment of textile wastewater. From the analysis results, it was observed that the filtration efficiencies were relatively low (6.1 to 13.7%) for some parameters such as total dissolved solids, electrical conductivity, chemical oxygen demand, and sodium chloride when the wastewater samples were subjected to the 0.5 m column depth. Relatively high efficiency of 82 and 93.8% was observed from color and total suspended solids, respectively, when the wastewater samples were subjected to the 0.5 m column depth. Generally, the 0.75 m column depth achieved removal efficiencies ranging from 52.3% to 97.5%, whereas the 1 m column depth achieved removal efficiencies ranging from 86.9% to 99.4%. The highest removal efficiency was achieved with a combination of total suspended solids and 1 m column depth (99.4%). In summary, the treatment approach was observed to be highly effective for the removal of total suspended solids, with a 93.8% removal efficiency when the wastewater was subjected to the 0.5 m column depth, 97.5% for 0.75 m column depth, and 99.4% for 1 m column depth. Moreover, up to 218.233 mg of color per g of the filter material was captured. The results derived in this study provide useful information towards the potential applicability of natural zeolite in the textile wastewater treatment field.