INVESTIGATION OF THE USE OF LASER-DOPPLER VELOCIMETRY IN TWO-PHASE BUBBLY FLOWS

Understanding the dynamic phenomena of viability loss of shear sensitive cells and bubble breakage and coalescence within airlift reactors requires knowledge of local, liquid-phase hydrodynamics. The laser-Doppler velocimeter (LDV) is a non-invasive instrument which may be used to obtain this information. Experimental procedures and software were developed to detect and measure Doppler bursts in two-phase flow in a split-cylinder airlift reactor. Off-line analysis of the data indicated a detection rate approximately one order of magnitude greater than that observed using an available commercial frequency tracker. Approximately 400 to 500 observations are needed for the ensemble mean to characterize the local mean velocity to within ±5% for a superficial gas velocity of 10.4 cm/s, the highest superficial gas velocity used in these studies. The limitations, prospects, and signal-processing options for LDV in this application are also discussed     

窑炉用热电阻、热电偶智能温度测量板的设计

温度是影响陶瓷烧成质量的关键因素,介绍了一种适用于测量各种窑炉不同部位温度的智能温度测量板,由于该系统在不同的测温部位分别采用了热电阻和热电偶,克服了一般测温系统在连接不同的测温传感器需要更换不同的测温模板、成本高、使用不方便等不足,并具有适用性强、测温精度高等优点。     

利用ADCP回波强度估算河流悬移质含沙量的应用研究

通过简要介绍利用声学多普勒水流剖面仪(ADCP)回波强度估算悬移质含沙量的基本原理,结合梧州水文站的应用实例,利用ADCP的回波强度数据和现场采集的水样含沙量建立相关关系,根据相关关系由回波强度反演估算的水体悬移质含沙量验证了利用ADCP的回波强度估算悬移质含沙量的可行性。应用于梧州水文站的实践表明,左河道推算的系统误差为-0.1%,右河道推算的系统误差为1.5%。这种方法具有不扰动流场、测量剖面同步性较好、数据空间分辨率较高的优点,与传统的取样过滤称量法相比,计算效率显著提高。     

高效液相色谱法测定卷柏中的穗花杉双黄酮

用反相高效液相色谱法测定卷柏提取物中的穗花杉双黄酮。结果表明：穗花杉双黄酮在质量浓度为41.2mg／L～206mg／L时，峰面积Y与其质量浓度X的线性关系良好，回归方程为Y=547．028X 15．4895(r=0.9999)，最低检测限为2．0μg/L；穗花杉双黄酮的平均回收率为99．42％(n=3)，相对标准偏差RSD为0．79％；连续进样、日内进样和日间进样所得检测结果的RSD分别为0．12％、0．11％和0．11％。     

纤维素衍生物液晶相转变和织态结构

本文综述了纤维素衍生物液晶态相转变和织态结构。描述了纤维素衍生物从各向同性态向液晶态的转变过程和液晶态的织构特征。讨论了溶液浓度和温度对液晶相织构的影响。探讨了各种因素,如溶剂、取代基含量、外加力场和外加磁场等对液晶相的形成及织态结构的影响。     

Proposal of a uniform color scale for virgin olive oils

A new color scale was developed from a broad data set of 1700 virgin olive oil samples over four crop seasons, which can be considered highly representative of the whole color range of virgin olive oils available in Spain. This color scale provides a new set of 60 color standards, improving the results achieved by the old 60-color standards proposed by the bromthymol blue method. Seeking the greatest possibility of including a near match between colors of virgin olive oils and proposed standards, we developed our new color scale using a recent uniform color space, with standards placed in a regular rhombohedral lattice like the one employed by the Uniform Color Scales of the Optical Society of America. The average color difference between each of the 1700 virgin olive oils and its nearest standard is reduced from 8.17 CIELAB units, using the bromthymol blue standards, to 3.99 CIELAB units using the new standards. Within a color tolerance of 7.0 CIELAB units, 93.2% of our virgin olive oils can be classified with the new standards, but only 59.1% with the bromthymol blue ones. In the interest of future adoption, the performance of the new color standards should be tested by industry and researchers.     

Gas hold-up in non-newtonian solutions in a bubble column with internals

Bubble characteristics and gas hold-up were studied in a two phase (air-aqueous CMC solution) bubble column provided with helical coils and straight tubes as internals. The effects of superficial gas velocity, rheological properties, and volume fraction covered by the internals, on gas hold-up were studied. Hold-up values determined directly and by simultaneous pressure drop measurements matched well. Enhancement of gas hold-up values up to 55 per cent was achieved in systems using internals. The gas hold-up results were also compared with the values obtained from correlations reported in the literature.     

反相高效液相色谱法测定meso-四苯基卟啉钴的纯度

采用反相高效液相色谱法测定合成meso-四苯基卟啉钴的纯度;以甲醇乙腈二氯甲烷(体积比为55∶35∶10)为流动相,ShimpackCLCODS柱(150mm×6.0mmi.d,5μm)为分离柱,流速为1.5mL/min,检测波长420nm;meso四苯基卟啉钴的测定在1.0～10μg/mL时线性关系良好(相关系数r=0.9993),加标回收率为97.03%～101.42%,重复进样的相对标准偏差RSD为0.64%～2.92%(n=5)。方法的准确度高,精密度好,实际应用效果好。     

莫达非尼的绿色化学合成

采用[bm im]BF4离子液体作为反应溶剂,以二苯甲硫醇为原料,经醚化、氨解、氧化得到新型提神醒脑药物莫达非尼。讨论了不同的氯乙酸酯和反应温度对醚化反应收率的影响,讨论了不同的二苯甲硫乙酸酯对氨解反应收率的影响,及离子液体的回收使用。研究表明,采用氯乙酸甲酯作为醚化试剂,反应时间4 h,反应温度100℃,二苯甲硫醇∶氯乙酸甲酯=1∶1.5(摩尔比),室温下氨解反应20 h,二苯甲硫乙酰胺收率76%;采用过氧化氢作为氧化试剂,反应时间3 h,反应温度60℃,过氧化氢∶二苯甲硫乙酰胺=1∶1(摩尔比),莫达非尼收率79%,反应总收率可达48%。