船用夹层板芯材的动态力学性能实验研究

基于分离式霍普金森压杆实验装置,对船用夹层板系统(SPS)的芯材-聚氨酯弹性体的动态力学性能进行了实验分析。在实验满足一维、均匀性的前提下,计算得到了聚氨酯弹性体在不同应变率下的应力—应变关系,讨论了试样尺寸对结果的影响;考虑聚氨酯弹性体不同于金属的动态力学性能,以及准静态力学性能与动态力学性能的差异,确定运用朱—王—唐(ZWT)方程描述聚氨酯弹性体的本构关系,能够准确反应聚氨酯弹性体的非线性粘弹性特性,拟合结果与实验结果吻合较好。     

Analysis of mathematical model for micromechanical vibratory wheel gyroscope

By the sketch of structure of MVWG,the working laws of this kind of gyroscope were explained. To the aid of Euler‘‘s Dynamics Equation,a mathematical model of the gyroscope was constructed, and then by the basic working laws of MVWG the model was simplified. Under the conditions of the three axial direction rotations and general rotation, the mathematical model was resolved. And finally by the solutions, the working laws of the gyroscope, the working disparity among all sorts of gyrations and the influences from the gyrations in the axial directions were analysed.     

可控硅励磁装置换流回路设计

本文对舰船用直流电动机可控硅励磁装置主回路的工作原理进行了阐述,并对换流电路部分的参数进行了分析、计算,提出了一种可控硅励磁装置换流电路的设计方法。     

Variations in ectoenzymatic hydrolytic activity in an oligotrophic environment (Southern Tyrrhenian Sea, W Mediterranean)

The variations in the expression of two hydrolytic ectoenzymes (leucine aminopeptidase – LA – and β glucosidase — BG) were studied in the southern Tyrrhenian Sea during spring 2004. This area is characterised by a complex morphology and hydrodynamism, which generate significant differences between different sectors, particularly in the 0–100 m layer. However, the area generally exhibits oligotrophic features such as low autotrophic pigment and organic matter concentrations and a higher bacterial biomass than the phytoplanktonic one. Despite this general bottom-up pressure, adaptations by the microbial consumers were indicated by the ectoenzymatic activities and by the relationships between the enzymes, their organic substrates and their producers (namely the bacteria). In particular, bacteria were able to exploit the inorganic N supply (nitrite + nitrate provided by irregular intrusions of intermediate waters) to escape the bottom-up limitation and produce enzymes such as BG devoted to the degradation of cellulose remnants and, therefore, also able to take advantage on this refractory organic matter. In the 200–800 m layer, where trophic limitation was strong due to the low values of potentially-labile organic matter (namely proteins), the peculiar hydrodynamism led to the formation of nepheloid layers rich in organic matter, which provided the bacteria with substrates and allowed the development of a significant correlation between LA activity and its own organic substrate. Furthermore, a reduction of the bottom-up pressure was also indicated by a higher mean bacteria cell size in the entire water column of the central and eastern sectors, and a significantly increased expression of BG related to the increase in the cell size.The ectoenzymatic activities, therefore, suggested that the southern Tyrrhenian Sea should be considered as a mosaic of subsystems, where the peculiar hydrological features stimulate bacterial adaptations and enhance the channelling of energy embedded in refractory materials into the food web.     

硅粉混凝土路面应用性能试验研究

以普通硅酸盐水泥掺加硅粉和早强减水剂配制的硅粉混凝土为研究对象,通过原材料试验、力学性能试验、收缩试验等,系统研究了硅粉混凝土的路面应用性能。结果表明：按最佳的硅粉与高效减水剂比例配置的硅粉混凝土能够满足路面应用性能要求,且可以达到尽早开放交通的条件。硅粉混凝土是铺筑新水泥路面或者修补旧路面的新材料,将会带来很大的社会效益与经济效益。     

微孔聚氨酯弹性体实验研究

研究了以聚合接枝聚醚多元醇和改性MDI为主要原材料,通过添加一定量的发泡剂、表面活性剂、醇胺交联剂等辅助原材料采用反应注射成型工艺制备出微孔聚氨酯弹性体,并对微孔聚氨酯弹性体的性能与实体聚氨酯弹性体进行对比。结果表明微孔聚氨酯弹性体具有与实体聚氨酯弹性体相当的机械性能和耐海水腐蚀性能,但微孔聚氨酯弹性体具有更高的能量吸收和较低的密度,适合用做舰船防撞抗振缓冲材料。     

某型履带式车辆电源系统故障分析与排除

某型履带式车辆中修后,原地试车时电源系统出现故障,针对其故障,阐述了工作原理,分析了故障原因,排除了故障,提出了预防故障的方法技巧。     

激光切割硅钢片工艺试验研究

采用CO2基模连续激光器,用不同辅助切割气体对硅钢片进行了切割工艺试验,探讨熔渣形成的原因和消除的方法。同时对切割效率作了评判。     

耐久性综合治理在某大型高桩码头及引桥工程中的应用

指出海工混凝土结构耐久性差的原因,并结合工程实例,介绍耐久性综合治理在海军某大型高桩码头及引桥工程中的应用情况。