实验室模拟海洋环境下印制电路板腐蚀损伤行为

目的 研究实验室模拟海洋环境下,机载设备舱内印制电路板的腐蚀损伤行为和规律.方法 基于实测的某型机机载设备舱海洋环境数据,编制加速腐蚀试验环境谱,针对化学镀镍金印制电路板开展加速腐蚀试验;以宏微观腐蚀形貌、导通电阻以及绝缘电阻等为腐蚀表征行为参数,分析实验室模拟海洋环境下印制电路板腐蚀损伤演变的一般规律.结果 实验室模拟海洋环境下,印制电路板腐蚀首先从元器件引脚、通孔等区域诱发,腐蚀现象严重,严重影响导通电阻和绝缘电阻等电气性能的稳定性.加速腐蚀历程中,印制电路板的导通电阻不断增大,绝缘电阻的阻值不断降低.第6周期,绝缘电阻降低了一个数量级.第14周期,导通电阻的阻值增加了4.32～6.72 m?;绝缘电阻降至0.55～0.78 G?,降低了两个数量级,基本丧失绝缘性能.结论 实验室模拟海洋环境下,印制电路板腐蚀损伤历程可以分为表面镀层腐蚀、基底金属腐蚀发生与扩展、元器件芯腔内腐蚀失效3个阶段.     

Normal fetal growth in women with antiphospholipid syndrome treated with high-dose intravenous immunoglobulin (IVIG)

Antiphospholid antibodies are associated with fetal distress and fetal death. Although different therapeutic regimens have been used, the incidence of fetal growth retardation varies between 30 and 60 per cent of reported cases. We report the evolution of fetal growth in patients with antiphospholipid antibody syndrome treated with high-dose intravenous immunoglobulins (IVIG). Fourteen patients with a history of recurrent spontaneous abortion and immunological diagnosis of antiphospholipid syndrome were followed longitudinally. Intravenous immunoglobulin at a dose of 0.5 g/kg body weight for two consecutive days was started from the fifth week of pregnancy and repeated every 4 weeks until the 33rd week of gestation. Fetal biometry was evaluated longitudinally from the appearance of the gestational sac at 4 weekly intervals. In the period between 26 and 34 weeks, the frequency of evaluation was increased to every 14 days. Data obtained were compared with a control group of 70 fetuses with uneventful pregnancies matched for gestational age. Neonatal weight is shown in relation to the centiles for the normal population. One patient out of 14 (7.1 per cent) developed gestational hypertension and abruptio placentae. No other pregnancy complications were seen. No proteinuria was found. The mean maternal age was 31.2±3.8 years. Median birth weight was 3433 g±287. The median centile of the birth weight was 65.3±18.6. Mean gestational age at delivery was 1.3 weeks. No fetal or neonatal growth retardation was seen. No significant differences were found in the biometrical parameters investigated in the various gestational ages vs. the control group (Student's t-test not significant); a significant increase in head circumference (P< 0.001) and abdominal circumference (P< 0.05) was found at 36–37 weeks gestational age in the IVIG-treated fetuses. The presence of antiphospholipid antibodies is considered detrimental for pregnancy outcome because of their negative effects on placental vascular perfusion and fetal transfer of metabolites. The use of IVIG seems to avoid or inhibit the reduced availability of nutrients for the fetal anabolic functions, as the expected reduction in fetal growth was not seen in our series.     

拱型屋面弯曲回弹变形、强度和稳定性的研究

计算了拱型屋面弯曲回弹变形 ;分析了在对称和非对称载荷作用下拱型屋面弯曲应力 ;计算了在对称载荷作用下拱型屋面临界载荷 ,计算结果表明 :拱型屋面的破坏不是强度不足 ,而是失稳所致。     

利用造纸废物生产全粉煤灰轻质建筑材料研究(Ⅰ)

根据外营力自然成岩理论 ,探讨了利用造纸废物与粉煤灰生产复合材料的新理论、新工艺。在工业性试生产中产生的制品具有容重轻、强度高 ,隔热性能和憎水性良好的优点 ;同时 ,由于其吃灰量大 ( >95 % ) ,又为大规模利用粉煤灰开辟了新途径。     

上海雾天大气污染及雾水组分研究

首次较系统地监测调查了上海市雾天的大气污染状况，并分析了雾水的化学组分，结果表明，上海出现雾天时，不利于大气污染物的扩散，造成雾天大气污染较严重，污染物浓度高值出现的时间与雾的形成至消散基本同步，比起雾前高２－１０倍。     

造纸黑液固化技术及有机复合肥肥效试验研究

研究包括两项发明：黑液固化工艺和黑液固化物生产有机NPK复合肥。黑液固化采用交联技术，在常温常压下，向黑液中投加一定量的胶凝剂和交联剂，经搅拌、使黑液在短时间内由液变为固态；通过对固化物成份的分析，以黑液固化物为原料生产有机NPK复合肥，并与一般NPK复混肥进行水稻、花生的肥效对比试验，得出了以黑液固化物生产的有机NPK复合肥肥效优于一般NPK复混肥的结论。     

A case of partial sirenomelia and possible vitamin A teratogenesis

Prenatal echographical findings of a partial sirenomelic fetus are described. An attempt was made to terminate pregnancy by administration of prostaglandin F₂a, but uterine rupture occurred. The teratogenic role of vitamin A ingested by the mother in the penconceptional period is discussed.     

Applicability of DNA isolated from syncytiotrophoblast vesicles to gene amplification and molecular analysis

Maternal contamination of fetal DNA represents a major problem when highly sensitive molecular techniques are used in the prenatal diagnosis of genetic diseases. For this reason, we have studied the possibility of using DNA isolated from syncytiotrophoblast vesicles as a target of gene amplification (PCR). Three PCR systems were selected which included a repetitive 149 bp fragment of the Y chromosome, the VNTR locus D1S80, and a portion of the β-globin gene. The results of these experiments indicate that DNA isolated from syncytiotrophoblast vesicles is free of maternal contamination and is suitable for gene amplification and DNA analysis.     

利用微生物除臭技术研究与应用

简述了微生物在降解生产和生活中臭气方面的研究与应用,特别着重介绍了EM复合菌群在除臭方面的卓越效果,表明了生物除臭与物理、化学方法除臭相比具有彻底性、实用性与经济性的特点,在环境保护与资源的重复利用方面有着巨大的应用潜力。