污水地下渗滤系统强化脱氮试验研究

构建了3套以5%炉渣+95%草甸棕壤为基质的地下渗滤系统室内模拟试验装置,在水力负荷为0.1m3/(m2·d)条件下进行了生活污水处理试验.结果表明,当分流位置位于系统内110cm处,分流比为1:1时,可提高地下渗滤对总氮的去除效率,总氮的去除率由59.37%提高至68.41%,且对COD和总磷的去除效果没有影响.     

In utero therapy for lower urinary tract obstruction

Lower urinary tract obstruction has a significant impact on neonatal and child health. Pulmonary hyperplasia and renal impairment could be direct or indirect consequences of this condition leading to significant morbidity and mortality. Evaluation of fetuses with suspected lower urinary tract obstruction is performed not only to confirm the diagnosis but also to assess renal prognosis. Ultrasound examination and urinary analysis aid in the evaluation of these fetuses. The decision to perform fetal intervention in these cases is a difficult one. Vesico‒amniotic fetal shunting, open fetal surgery and more recently endoscopic fetal surgery for this condition are available as possible modalities of fetal intervention. Case selection for fetal intervention is extremely important in order to both avoid unnecessary intervention in those unlikely to survive, and also to avoid procedure related complications in fetuses likely to do well without intervention. Vesico‒amniotic shunting has the advantage of bypassing the obstruction, however it is often associated with complications. Open fetal surgery is not usually recommended because of the complications and high fetal loss rate. Endoscopic surgery to visualise and treat the cause of lower urinary tract obstruction has been tried. Fetal endoscopic surgery is in its infancy and endoscopic procedures are limited to a few groups. This current review addresses evaluation, case selection and therapeutic options for lower urinary tract obstruction in utero. It also discusses the limited data against which the efficacy of the various options can be assessed. The current state of fetal intervention is detailed in the present review. Copyright © 2001 John Wiley & Sons, Ltd.     

浮顶储罐导电片间隙放电危险性研究

储罐在实际运行中,受浮盘的上下移动、机械应力、老化、油污、金属腐蚀等因素的影响,很难确保导电片与罐壁紧密贴合,容易形成微小间隙,在这种情况下遭受雷击易产生间隙放电,出现打火现象.为了分析导电片与储罐罐壁导电片产生间隙放电的危险性,根据Townsend气体放电理论计算了导电片和储罐罐壁间的击穿电压,采用1.2/50μs冲击电压波开展了导电片间隙放电实验,分析了导电片击穿电压与空气间隙距离的关系.结果证明:当导电片和罐壁贴合不良时,导电片和罐壁之间极易产生火花放电;当空气间隙d=0.1cm时,平均空气击穿电压仅为5280V;随着间隙的增大,空气击穿电压也随之增大;导电片间隙放电实验数据与Townsend气体放电理论值吻合.最后,根据以上结论,针对浮顶储罐导电片间隙放电的危险性,提出了改进措施.     

35kV并联电抗器工频电磁场分布特性研究

针对500kV变电站内产生较高工频磁场强度的电气设备——35kV并联电抗器,研究不同类型、不同排列方式下35kV并联电抗器周围工频电磁场分布规律。结果表明,35kV并联电抗器的电磁场强度随着离开电抗器中心距离的增加而降低,三角形排列的电抗器磁场强度大于水平排列的。     

Prenatal interventions for fetal lung lesions

The widespread availability of high resolution ultrasound equipment and almost universal routine anatomy scanning in all pregnant women in the developed world has lead to increased detection of abnormalities in the fetal thorax. Already in the 1980s, large pleural effusions and significant macrocystic lesions in the fetus were easily detected on ultrasound. However, smaller lung tumours were often missed. Nowadays, fetal medicine centres receive many referrals for evaluation of fetal lung lesions, of which the most common are congenital cystic adenomatoid malformation and bronchopulmonary sequestration. Almost invariably, both the parents and the referring physicians experience anxiety after detection of large lung masses in the fetus. However, the vast majority of the currently detected fetal lung lesions have an excellent prognosis without the need for prenatal intervention. In the small group of fetuses in which the prognosis is poor, almost exclusively those with concomitant fetal hydrops and cardiac failure, several options for fetal therapy exist, often with a more than 50% survival rate. Indications, techniques, complications and outcomes of these interventions will be described in this review. Copyright © 2011 John Wiley & Sons, Ltd.     

硫酸盐废水处理产电过程中的电子分流机制研究

为探讨废水中硫酸盐对微生物燃料电池（MFC）产电效能的影响,采用单室空气阴极MFC反应器处理模拟硫酸盐废水,并对硫酸盐的电子分流过程进行了监测。结果表明,在一定范围内,提高硫酸盐浓度能使MFC的稳定电压上升,电池持续时间延长,MFC输出功率增大。随着进水硫酸盐浓度提高,微生物产生的电子总量中,硫酸盐还原捕获的电子和通过外电路的电子所占的比例均下降,分别由12．54％和31．45％下降至7_32％和8．49％。研究表明,较低浓度硫酸盐能够提高MFC的电能输出功率,但由于硫酸盐的还原将消耗掉大量电子,进而降低MFC的库伦效率。     

Successful early in utero management of fetal hydrothorax in a twin pregnancy

We present a case of dichorionic diamniotic twin pregnancy in which one of the fetuses was found to have a major pleural effusion at 15 weeks of gestation. A single-needle pleural fluid aspiration was performed at 15 and 16 weeks, but the fluid reaccumulated quickly after each procedure and at 16 weeks, the fetus was found to become progressively hydropic. A shunt was then successfully inserted at 17 weeks, which is the earliest gestation reported so far in the literature for such a procedure to treat isolated hydrothorax. Because we felt that the fetus would be too small for a classical double-pigtail pleuroamniotic shunt, we used a multilength double-pigtail bladder stent (Harrison drain; Cook; Spencer; Indiana; USA) via a 13-gauge echo tip trocar. This shunt could be used for both singleton and twin pregnancies presenting with fetal pleural effusion from as early as 16 to 17 weeks to prevent the development of fetal hydrops and polyhydramnios and subsequent premature delivery. Treatment at this stage of gestation would also minimize the risk of lung hypoplasia, which is the main clinical issue when shunts are inserted after 24 weeks. Copyright © 2003 John Wiley & Sons, Ltd.     

Fetal surgery for severe lower urinary tract obstruction

Fetal interventions have been proposed for treatment of severe lower urinary tract obstruction (LUTO), as this condition is associated with high rates of perinatal mortality and postnatal renal impairment. The rationale for in utero treatment for those cases is based on the possibility of relieving the obstruction, improving the amniotic fluid volume, and preventing renal and bladder damage. Candidates for fetal intervention should be rigorously selected based on the confirmation of severe LUTO (dilated bladder and bilateral hydronephrosis), oligohydramnios or anyhydramnios and ‘favorable’ fetal urinalysis (dependent on gestational age). Nowadays there are two different therapeutic options with specific technical approaches. Vesico-amniotic shunting is an easier procedure, but with a higher frequency of related complications. Fetal cystoscopy can be used for diagnostic purpose and for treatment of posterior urethral valves, with suggestive advantage of allowing a more physiological release of the obstruction. According to the literature, estimated survival rates and postnatal normal renal function frequencies are approximately 40 and 50% after vesico-amniotic shunting and 75 and 65% after fetal cystoscopy, respectively. Copyright © 2011 John Wiley & Sons, Ltd.