可靠性强化试验技术在某型伺服作动器研制中的适用性探索

目的探索可靠性强化试验技术在典型机电液一体化产品伺服作动器研制过程中的适用性。方法以某型伺服作动器为研究对象,从故障激发的角度对可靠性强化试验技术的应用进行可行性分析,在响应调查和应力分析的基础上,结合产品的工作特点设计适用于该类伺服作动器的可靠性强化试验方案,包含低温步进应力试验、高温步进应力试验、快速温度循环试验10个循环、振动步进应力试验(包含气锤式三轴向六自由度超高斯随机振动方式及电磁振动台随机振动方式)及综合环境应力试验5个循环,并依此进行试验。结果在快速温度循环试验及综合环境应力试验过程中,均有效地激发出了产品的漏油故障,与相似产品外场暴露的漏油故障模式相吻合。结论可靠性强化试验技术可有效地应用于典型机电液一体化产品伺服作动器的研制过程,设计的可靠性强化试验方案可有效地激发外场出现频率较高的故障,可作为该类产品研制的试验手段之一。     

空间站控制力矩陀螺微振动测试技术

目的分析控制力矩陀螺的微振动扰动特性。方法通过获取陀螺连接点对结构的扰振力输出、关键部位的微振动响应来获取产品的微振动扰动特性,通过隔振的方式对外部环境的干扰进行隔离,进而降低测试的背景噪声,通过运用高精度测试传感器来实现微小扰动力信号、加速度信号的测量,利用结构有限元法及单点激励多点响应的模态分析方法校核系统刚度,进而确定测试频率范围是否满足需求。结果可同时获得空间站控制力矩陀螺连接点处的输出扰振力、质心处的输出扰振力合力、合力矩以及关键部位的微振动响应,可有效隔离外部干扰,扰振力背景噪声的时域信号最大值可控制在0.07 N以内,RMS值在0.02 N以内,加速度信号的时域背景噪声最大值可控制在1.5 mg以内,RMS值在0.1 mg以内。可识别微小扰振信号,加速度传感器分辨率为5×10-5 grms,力传感器的测量分辨率为1×10-2 N,力矩测量分辨率小于1×10-2 N·m。测试频带在320 Hz以内。结论满足型号需求,并投入型号使用。     

超声波萃取-高效液相色谱法测定总悬浮颗粒物中的多环芳烃

研究了一种用中流量采样器采样,超声波萃取,硅镁型吸附剂柱层析预分离.高效液谱测定总悬浮颗粒物的实验方法,在16分内可分高萘、蒽、芘、苯并(a)芘、苯并(ghi)苝等15种多环芳烃.已在大气环境的实际监测中得到应用.     

气浮溶气新技术应用研究

介绍对炼油厂净化水车间一级浮选2^#池的改造，并与未改造的1^#池进行工业应用对比试验。试验结果表明，改造后大大提高了气浮处理效果，平均除油率达85％，且除油效果稳定，出水合格率比对比池提高20．4％。     

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency by steroid analysis in the amniotic fluid of mid-pregnancy: Comparison with HLA typing in 17 pregnancies at risk for CAH

Amniotic fluid (AF) levels of 17-hydroxyprogesterone (17OHP) and testosterone (T) were determined at 16–17 weeks in 17 pregnancies at risk for CAH and results compared to 75 normal controls. The fetus was predicted to be unaffected in 12 cases on the findings of normal AF levels of both 17OHP and T and the latter allowed a correct prediction of fetal sex in all instances. HLA typing confirmed normality in 12 cases revealing 5 carriers, 5 homozygous normal and 2 indeterminate. Steroid levels of the 2 groups were similar. Three fetuses were predicted to be CAH affected on unambiguously high levels of 17OHP and T (in female only). HLA typing was in agreement, and the diagnosis was confirmed in 2 abortuses and a female newborn by physical and hormonal studies. In the last 2 cases AF levels of OHP and T were normal but HLA (A/B/C) genotypes were identical to the CAH affected siblings. Normal physical and hormonal findings in the 2 aborted fetuses would exclude the possibility of an in utero virilizing form of CAH. The discrepancy could be explained on the basis that the fetuses had an allelic form of 21-hydroxylase deficiency or on the basis of recombination (not fully tested). It is concluded that a fully informative prenatal diagnosis of CAH should not rely entirely on HLA typing but on hormonal studies.     

水中酚类有机污染物HPLC分析及其应用

超声辐照技术降解水中有机污染物，其降解效率的主平价需要简单、快捷和精确的分析方法。为此研究了5种优先控制酚类污染物的HPLC分离及定量分析方法，方法的定量范围为0.4-100mg/L，检测限介于0.34-0.79ng/μL。4－氯酚的超声降解实验表明，随着反应溶液中4－氯酚初始浓度的降低，降解效率明显提高，因此该方法适用于超声降解过程中酚类污染物的跟踪测定。     

Prenatal diagnosis of spinal muscular atrophy in Russia

Ninety-two families with spinal muscular atrophy (SMA) applied for genetic counselling and further prenatal diagnosis. To minimize expenses, only one tightly linked informative marker was determined in the course of preliminary examination, and non-radioactive allele detection was preferably used. Four prenatal diagnoses of SMA type I, four of SMA type II, and one of SMA type III were made. This trial programme shows the considerable requirements, importance, and potential effectiveness of prenatal prediction of SMA in Russia.     

浅谈进口智能仪表在污水处理厂的使用和维护

对智能仪表的使用和维护进行了详细的介绍和讨论,指出使用智能仪表的优点及需要注意的具体事项并对仪表可能出现的问题进行了研究和探讨。     

Neural tube defects in trisomy 18

In a retrospective survey, the incidence of neural tube defects in liveborn trimsomy 18 was found to be 6·2 per cent. Based on these data one would expect to find trisomy 18 in 1 of the 117 patients with myeloidysplasia; the incidence of trisomy 18 in dysraphic fetuses would be anticipated to be higher. These observations underscore the need for amniocentesis karyotyping of fetuses with neural tube defects, and the importance of careful examination of infants born with neural tube defects.