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41.
42.
介绍了高可靠电镀Ni/Au工艺在PTFE微波印制电路上的应用,并分析了氨基磺酸盐镀软镍和亚硫酸盐镀软金工艺的影响因素及提高Ni/Au镀层之间附着力的措施。通过实验及应用证明了与直接镀金工艺相比,在软基材PTFE敷铜箔板上镀Ni/Au工艺能大大提高微波电路的可焊性,高温稳定性和长期可靠性,并且用其所制作的微波器件的高频性能也优于直接镀金工业。 相似文献
43.
介绍了一种采用改进型的CLS3700数控测井系统对微电阻率扫描仪数据采集与控制接口的设计及实现方法。基于CLS3700数控测井仪和FMS仪采用89C51单片机设计出通信接口,解决了微电阻率方法。基于CLS3700数控测井仪和FMS仪采用89C51单片机设备出通信接口电路,解决了微电阻主扫描仪现现场实时处理中的瓶颈问题。 相似文献
44.
动态波前相位的高分辨率测量 总被引:4,自引:0,他引:4
动态波前相位信息测量是大气光学,气动光学和激光技术等领域的重要实验手段。提出了一种具有高的时间和空间分辨率以及长的测量持续时间的动态波前相位测量方法。应用Hartmann-Shack波前传感器获得高空间分辨率的相位信息,采用高帧频CCD摄象机获得高时间分辨率图象数据。 相似文献
45.
CV Fletcher BK Goodroad LM Cummins K Henry HH Balfour FS Rhame 《Canadian Metallurgical Quarterly》1997,41(7):1571-1574
Hyperimmune anti-human immunodeficiency virus immunoglobulin (HIVIG) is an intravenous immunoglobulin prepared from HIV-infected asymptomatic donors with a CD4 cell count greater than 400 cells/microl and a high titer of antibody to HIV-1 p24 protein. Twelve persons with AIDS received four doses of HMG (two at 50 mg/kg of body weight and then two at 200 mg/kg) every 28 days. Pharmacokinetics were evaluated by measurement of anti-p24 antibody. HIVIG was well tolerated, and all participants completed the study. Three subjects who were not receiving Pneumocystis carinii pneumonia (PCP) prophylaxis developed PCP. The mean value for HIVIG clearance was 3.02 ml/kg/day at 50 mg/kg and 3.65 ml/kg/day at 200 mg/kg (P = 0.027); the mean trough antibody titers (reciprocal units) were 1,442 and 4,428, respectively. This study indicates that high titers of anti-p24 antibody can be maintained with a monthly administration schedule of HIVIG and that short-term safety is acceptable. Comparisons to evaluate the therapeutic potential of HIVIG are justified. 相似文献
46.
F F?ndrich AM Waaga J Schr?der E Schweizer A Schmid S Jacob HH Wacker P Schroeder 《Canadian Metallurgical Quarterly》1995,27(2):1553-1554
47.
The radiation emitted by a time-harmonic elementary current in magnetized electron plasma half-space, bounded by an ideal electric plane, is investigated using an exact formulation. It is found that: conventional image principle holds for vertical magnetization case; while for parallel magnetization case, coupled image principle seems to be valid. 相似文献
48.
HE Vi?tor F Klumper RJ Meerman A Brand HH Kanhai 《Canadian Metallurgical Quarterly》1998,18(4):325-331
Histamine is an important mediator in allergic reactions, gastric acid secretions, and neurotransmission in the central nervous system. Basophils and mast cells are the main sources of histamine, which is formed from L-histidine by histidine decarboxylase (HDC). However, the regulatory mechanism of HDC in these cells remains unclear. We examined the regulation of HDC activity and gene expression using a unique human mast cell line, HMC-1, after stimulation with phorbol 12-myristate 13-acetate (PMA) or ionomycin. HDC activity was increased from 52.1+/-0.4 (mean+/-standard deviation) to 154+/-6.9, or 105.6+/-6.2 pmol/min/mg protein (n = 3), 4 hours after stimulation with PMA (10 ng/mL) or ionomycin (10[-6] M). Although actinomycin D had no effect on this increase, cycloheximide completely inhibited the increase caused by these stimuli. The population of HMC-1 cells containing HDC protein was increased after stimulation with either PMA or ionomycin as evaluated by immunocytochemical analysis with anti-HDC antibody as a marker. HMC-1 constitutively expressed HDC mRNA, and its level was not increased with these stimuli. These results suggest that the increase of HDC activity in HMC-1 induced by PMA or ionomycin is regulated at the translational level. 相似文献
49.
C Perka K Lindenhayn HH Heilmann M Sittinger M Muschik 《Canadian Metallurgical Quarterly》1996,134(6):562-572
Full thickness defects (diameter 1,7 mm; depth 2,5 mm) were created mechanically in articular cartilage and subchondral bone of the condyles of tibiotarsal joints of 9-month old chickens. This full-thickness defects were repaired with cultured allogenic embryonic chick epiphyseal chondrocytes from the tibiae and femura of 10-days-old chicken embryos. The cells were embedded in a collagen-fibrinogen-matrix. Controls were similarly operated, but received either no treatment or implants the delivery substance only. Healing of the defects was observed macroscopically, histologically, histochemically and histomorphometrically after 3, 12 and 24 weeks. This graft was successfully transplanted in mechanically induced defects in 80%. The resulting hyaline cartilage was structurally reorganized according to the host pattern and under the influence of environmental conditions. The articular zone preserved it's cartilaginous phenotype, whereas the subchondral regions were transformed into bone. 12 weeks after the operation the defects in the experimental group were completely filled. In all instances in this group, there was an initial extreme increase of mitotic rate and cell number. After 24 weeks normal and subnormal values were founded. The defects in the control groups healed with fibrocartilage. Our results showed, that only the defects in the experimental group were completely filled with reparative hyaline cartilage tissue. In the present study the mixture of cultured allogenic embryonic chondrocytes and a collagen-fibrinogen-matrix was used successfully as a transplant for repairing defects in articular cartilage of chickens. Thus allogenic transplantation of cultured embryonal chondrocytes appears to be one of the most promising methods for the restoration of articular cartilage. 相似文献
50.
The loss performance of tagged and normal ATM cells at a first-in-first-out (FIFO) buffer is studied. The authors show that if a partial buffer sharing mechanism is adopted the loss probability of normal cells can be firmly guaranteed, regardless of the traffic intensity of tagged cells 相似文献