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931.
通过对国内外中压网络电压等级应用情况及供电能力的分析,结合国内既有城市轨道交通的中压网络电压等级现状,提出选择电压等级的思路。  相似文献   
932.
Objective To study the effects of MMP-9 (Matrix Metalloproteinase-9, MMP-9) in the pathogenesis of abdominal aortic aneurysms (AAAs) by localizing the expression of MMP-9 in the aneurysmal tissues. Methods By , the frozen sections (5μm) with aneurysmal tissues (n = 10) were incubated with MMP-9 antibody-added agents, then the sections were stained and observed under the microscope to localize the expression of MMP-9, which displayed a brown precipitate within the arterial walls. The normal arterial wall tissues(n= 10) and the diseased arterial wall tissues from the arterial occlusive diseases (AODs) (n= 15) were also immunized exactly the same way as control. Results A quantity of positive granules which appeared within the aortic media showed the strong expression of MMP-9 in the AAAs, with the positive rate reaching 95 % (19/20), while no expression of MMP- 9 was observed in the normal artery. However, the scattered distributed positive granules were seen within the arterial wall of some cases of the AOI)s, implying the weak positive expression of MMP-9 in this disease with the positive rate of 26.7% (4/15). There was a significant difference of the expression of MMP-9 within the arterial wall between the AAAs and AODs(P〈0.01 ). Conclusion High expression of MMP-9 within the aortic media faciliatates the degradation of collagen and elustin fibres and subsequent dilation of the aortic artery , thus playing an important role in the pathogenesis of AAAs. To refrain MMP-9 from enhanced expressing within the aortic wall is of clinical significance in the prevention and treatment of AAAs.  相似文献   
933.
汽车结构用钢的进展   总被引:4,自引:0,他引:4  
马鸣图 《汽车工程》2005,27(3):269-273
概述了汽车结构钢的研究进展,列举了与提高汽车、发动机可靠性相关的合金结构钢、调质钢、非调质钢、渗碳钢等钢种的发展;较详细论述了与汽车的轻量化、节能、降低排放、提高安全性等密切相关的高强度钢和先进高强度钢的研究概况、典型应用以及今后的发展趋势。  相似文献   
934.
海漫公路路基病害及防治措施   总被引:3,自引:0,他引:3  
分析了海漫公路路基病害产生的多种原因,并针对泥石流,滑坡提出了防治措施。  相似文献   
935.
我国周边安全环境的深刻变化及国防建设面临的新形势,对铁路交通战备队伍应急保障能力建设提出了新的战略要求。铁路交通战备系统必须紧紧围绕担负任务和铁路经营管理体制变化,以做好军事斗争准备为牵引,对铁路国防交通战备建设存在的问题归纳为“四个不适应”,对其形成的原因进行了深入细致的分析、研究,提出应有针对性地优化应急专业力量体系,完善遂行应急任务的法规制度,加强军民融合应急保障机制建设,加快推进应急保障训练改革,大力开展实战化应急保障训练演练,以提高国防交通队伍的应急保障能力,顺利完成遂行任务。  相似文献   
936.
基于现有风帆助航船舶的设计方案,根据横向力系数和推力系数随拱度比的变化趋势选定风帆参数。该文设计了可折叠帆面、双列布置的风帆方案,解决风帆助航船舶风帆装置对甲板空间占用过大的问题,风况不利、船舶进出港以及装卸货物时亦可实现良好的收帆效果。该文以80000t船为例检验该设计方案对船体稳定性的影响,得出了该新型风帆设计方案可有效降低燃油消耗实现船舶节能减排,并满足船舶安全要求的结论。  相似文献   
937.
以大跨径斜拉桥为例,运用流固耦合分析得到了不同等级炸药在内车道以及外车道爆炸后主梁承受的爆炸荷载力。建立混凝土箱梁、钢箱梁局部分析模型,分析不同等级爆炸发生后主梁的损伤。结果表明:主梁损伤范围主要受主梁类型以及爆炸质量影响,与爆炸发生水平位置的关联度很小。进一步建立全桥分析模型,根据爆炸荷载时域模型,开展了动力响应分析。结果表明:振动作用下主梁轴向应力变化很小,靠近爆炸点附近的拉索有较高的断索风险。  相似文献   
938.
The purpose of the study was to test the biomechanical differences between a lateral wedge and a valgus knee bracing on the knee joint moment during walking in patients with early stage of medial compartment knee osteoarthritis (OA). We conducted a crossover randomized design to compare gait parameters of 32 patients (with early stage medial compartment knee OA) in three different conditions during walking: with a custom-made lateral wedge of 5° (in standard shoes), with a valgus knee bracing (in standard shoes), and with control condition (in standard shoes). Both two-orthose conditions showed decreased loading patterns (knee adduction moment and knee adduction angular impulse) on the knee joint in dynamic condition (statistic probability P < 0.05). The decreased loading on OA knee in wedge condition was associated with a laterally shifted location of centre of pressure and increased ankle valgus degree and moment at the same foot (P < 0.05). It was not found significant differences in loading of the knee between these two-orthose conditions. These results indicated that, under dynamic condition, patients wearing lateral wedge and valgus knee bracing showed changes of moments on knee joints. Lateral wedge was as effective as valgus knee bracing in the treatment of early stage of knee OA.  相似文献   
939.
提出公交事件管理的含义、目的和目标,介绍了车载智能终端以及公交事件的检测方法。针对公交运行中出现的交通事故,车辆故障,道路交通拥堵,客流突变等紧急事件,提出了相应的应急方案。从而保证公交车辆的正常运行,使公交车辆运行达到安全、迅速、经济、舒适的目的。  相似文献   
940.
Objective To study the clinical effects of vacuum-compression therapy for ischemic disease of the extremities. Methods A total of 40 cases of peripheral arterial disorders, including 23 thromboangiitis obliterans (31 limbs) and 17 arteriosclerosis obliterans (23 limit), were treated by a self-made vacuum-compression therapeutic apparatus. Results The effective rate in thromboangiltis obliterans and arteriosclerosis obliterans groups was 96.77% and 92.23%, respectively. The cuffs on the apparatus were improved to eliminate discomfort in the patients during treatment. "Rebound symptom" was observed during treatment, which had not been reported previously. Conclusion Vacuum-compression therapy has a good prospect for treating ischemia of the extremities.  相似文献   
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