竹地板与普通实木地板燃烧性能的锥形量热仪对比实验研究

随着竹地板的广泛应用,竹木地板的火灾燃烧性能也将引起人们的关注.本文采用锥形量热仪对竹木地板的引燃时间、热释放速率、总热释放和一氧化碳的产率及体积比浓度等燃烧性能与普通实木地板进行了比较研究.研究结果表明:在相同条件下,竹木地板试样的引燃时间较短,临界引燃辐射热通量较低,引燃危险相对较大;竹木地板试样燃烧中第一个热释放速率峰值出现的时间短,且峰值相对较大,其潜在的轰燃危险相对较大;此外,竹木试样的一氧化碳的产率和燃烧初期在烟气中的体积比浓度相对较大.     

GC/FTIR-FID测定石化废水中挥发性有机物

所述石化废水中挥发性有机物分析方法 ,以 GC分离 ,FTIR定性 ,FID定量。水样前处理采用大吹脱体积 ,两级捕集的吹脱捕集技术。为解决剖析分析无标样定量问题 ,成功地实现了 GC/FTIR-FID匹配联机 ,使得未知组分定性定量一次完成。方法变异系数低于 5% ,回收率高于 90 % ,最低检出浓度可达 0 .0 0 5mg/L     

沙质滩涂中可溶性油的释放动力学研究

沙质滩涂对石油类污染物的吸附是一种物理吸附过程,在一定的条件下,吸附于沙质滩涂中的石油类污染物又可能释放出来,对滨海环境造成新的污染。在对滨海沙滩（胶州湾）沙质滩涂-水系统石油污染调查的基础上,选择代表性的沙滩进行取样,系统测定不同沙质滩涂对可溶性油的释放动力学过程,并分析了盐度、pH、温度和含沙量对释放作用的影响。结果表明,沙质滩涂对可溶性油的释放动力学曲线符合对数型,即随着时间的延续释放速度逐渐降低,沙质滩涂对可溶性油的释放平衡时间约为10h,沙质滩涂对可溶性油的释放量随盐度和pH的增大而减少,随温度、含沙量和振荡频率的增加而增加。     

重污染感潮河道底泥释放特征及其控制技术研究

以珠江三角洲城市重污染感潮河道为对象,研究了底泥污染物(重金属、有机物和营养盐)在静态、潮汐作用影响及人工曝气扰动下的释放特征.在此基础上,采用曝气充氧、重金属化学固定、激活底泥土著微生物等联合技术对底泥释放进行控制,研究其控制效果.结果表明:①感潮作用加速了底泥污染物的释放,与静态释放相比,Cu、Zn、Pb、Cr、COD、NH 4-N和TP的平均释放速率提高了1～4倍,释放量增加了0.3～1.8倍;底泥平均耗氧速率提高了1.28倍.②人工曝气扰动使底泥污染物局部急剧释放,并使泥水界面由弱碱性变成弱酸性;在有氧环境,NH 4-N、TP的释放得到有效抑制.③投加石灰调节pH至8～9,上覆水体Cu、Zn、Pb、Cr的去除率达到85%～98%,同时还可去除92%的TP和86%的浊度;在微碱性好氧条件下,Cu、Zn、Pb和Cr的释放量稳定在300μg·L-1以下.④底泥土著微生物层对水体及底泥污染物有良好的降解作用,通过间歇曝气COD、NH 4-N、TP去除率分别可达到85%、92%和71%;但微生物层具有较高的耗氧速率,达到45g·m-2·d-1.     

吹扫捕集-GC-MS测定废水中的硝基氯苯

建立了吹扫捕集-GC-MS测定水样中硝基氯苯类化合物的方法.考察了吹扫温度、吹扫时间等对吹扫捕集效率和方法检出限的影响.在室温下,当吹扫时间为30 min时,该方法的最低检出限可达0.002 mg/L,工作曲线的线性范围为2×10 -3 ～2 mg/L,相对标准偏差在2%～6%,加标回收率在97.0%～110.0%.与国家标准方法相比,该法具有操作简便、灵敏度高、线性范围宽且无须使用有毒有机溶剂等优点,可满足工业废水和地表水中硝基氯苯的测定要求.     

Prenatal diagnosis of Schwartz–Jampel syndrome with early manifestation

A mother who had given birth to a child with Schwartz–Jampel syndrome (SJS) with neonatal manifestations (myotonia, congenital contractures, bowing of femora and tibiae) underwent ultrasonic fetal examination during the 17th and 19th week of her second pregnancy. Moderately decreased fetal motor activity and constant flexion of the fingers were observed at both examinations. In addition, there was mild bowing and shortening of the femora. At birth, the child presented with the characteristic pattern of SJS similar to her older brother. Prenatal ultrasonic diagnosis of Schwartz–Jampel syndrome is possible, at least for the form with neonatal onset of myotonia and contractures.     

Germline mosaicism complicates molecular diagnosis of Lesch–Nyhan syndrome

A healthy female with a brother suffering from Lesch–Nyhan syndrome was assigned a carrier status on the basis of haplotype analysis employing flanking and intragenic polymorphic markers of the HPRT gene. Her mother has been confirmed as a definite carrier by cell growth selection studies in cultured fibroblasts. In our proposita's first pregnancy, a male fetus was identified carrying the risk allele. Afterwards, the underlying novel mutation A161E (GCA→GAA at position c482) could be identified in the affected brother and in the heterozygous mother but not in the DNA of the pregnant sister and fetus. The fetus was also confirmed to be normal by uptake of 14C-hypoxanthine in cultured amniotic cells. To test the discrepancy, the investigation was extended by recruiting additional family members. The data obtained showed that the mother had passed her risk haplotype to the affected son as well as to her mutation-carrying and non–mutation-carrying daughters. This provides the first evidence of concomitant somatic and germline mosaicism in Lesch–Nyhan syndrome. The study has a bearing on genetic counselling and cautions against the reliability of only using indirect genetic diagnosis even with intragenic markers. Copyright © 2004 John Wiley & Sons, Ltd.     

围岩散热计算及壁面水分蒸发的处理

笔者采用湿度系数法对壁面水分蒸发进行了处理,对计算壁面处饱和空气含湿量的方法进行了改进,将饱和空气含湿量与温度的关系拟合为二次曲线;建立了在考虑壁面水分蒸发情况下解算巷道围岩温度场分布及围岩向风流的散热量的数学方程,并采用异步长有限差分法对其进行了数值模拟求解;解算出巷道壁面水分蒸发情况下围岩温度分布、壁面温度和围岩散热量的变化规律;并与将饱和空气含湿量与温度的关系拟合为线型关系曲线时的解算结果进行了对比,将饱和空气含湿量和温度之间的关系拟合为线性的计算结果存在一定的误差,通风时间越长,湿度系数越大,风流相对湿度越小,拟合为线性时计算出来的壁面温度和围岩散热量的误差越大。     

Prenatal diagnosis of Niemann–Pick diseases types A,B and C

Prenatal diagnosis of Niemann–Pick disease types A and B is routinely accomplished by sphingomyelinase assay. For Niemann–Pick type C disease, demonstration of an abnormal intracellular cholesterol trafficking is a complex procedure, and mutational analysis (NPC1 or NPC2/HE1 gene), whenever feasible, represents a major advance. Copyright © 2002 John Wiley & Sons, Ltd.