一类带θ(t)型核的奇异积分算子的有界性

为了解决θ(t)型奇异积分算子在Lipschitz空间上的有界性问题,通过将标准的奇异积分核K(x,y)改为θ(t)型核K(x,y),得到θ(t)型奇异积分算子Tf(x)=∫K(x,y)f(y)dμ(y)在μ为非双倍测度时,算子Tε在Lipschitz空间上的一个等价条件:‖Tε1‖Λβ≤c1 Tε:Λβ→Λβ有界且‖Tε‖Λβ→Λβ≤c2。     

Some Remarks on Operators and Their Conjugates

We first characterize the range spaces F for which {T':T∈K(E,F)}=K(F',E') holds for all Banach spaces E. Then we present some sufficient conditions for the equality T'=T'. Some related results are also included.     

Design of DC Partial Discharge Detecting System for Electrical Equipment

A balancing method was used to build a DC partial discharge (PD) testing circuit for electrical equipment, and a narrow-band detection system was designed using detection resistance and a filter. After signal accessed a high-speed digital acquisition (DAQ) card, the system was triggered to extract a single partial discharge (PD) signal. To eliminate the interference pulses caused by power supply ripple, etc., the time domain and frequency domain features of pulses were extracted. Based on the features, cluster analysis was used to exclude interference pulses. Two-dimensional and three-dimensional histograms were obtained by use of the Δt method. Then, 22 discharge statistical operators were calculated for the two-dimensional charts. Lastly, the defective system is capable of PD detection in electrical equipment.     

缓冲器对钢筋混凝土桥墩撞击性能影响的试验研究

采用落锤冲击实验装置,进行钢筋混凝土桥墩模型在侧向撞击荷载下的动力性能试验,研究在桥墩模型表面设置缓冲器对试件撞击动力响应的影响.比较了不同缓冲器的缓冲效果,分析了影响桥墩模型冲击裂缝扩展和破坏模式的主要因素,研究了冲击能量和试件峰值动力响应及撞击体平均冲击力的关系.试验证明,所设置的缓冲器可以较大程度地减少构件的冲击动力响应,对撞击区受压钢筋峰值压应变可降低74.60%,受压混凝土峰值压应变可降低54.69%,受拉钢筋峰值拉应变可降低63.02%,跨中峰值位移可降低57.73%,抗开裂冲击能增加180%,撞击体的平均冲击力可降低78.59%.研究结果表明,经合理设计的缓冲器具有高效的缓冲作用,可用以提高桥墩的抗撞能力.     

Effect of LaNiO3 Interlayer on the Dielectric Properties of Ba0.5Sr0.5TiO3 Thin Film on Si Substrate

In this study, (100)-oriented growth of Ba0.5Sr0.5TiO3 (BST) /LaNiO3 (LNO) stacks was obtained on Pt(lll)/SiO2/Si substrates by r.f. magnetron sputtering. The orientation of the subsequently deposited Ba0.5Sr0.5TiO3 thin film was strongly affected by the LNO under layer, and the BST thin film deposited on the (100)LNO-coated Si substrate was also found to have a significant (100)-oriented texture. Effects of LNO interlayer on the dielectric properties of BST thin films were investigated. As a result, the tunability of BST thin film was greatly improved with the insertion of (100)-oriented LNO under layer with proper thickness.     

湮灭算符任意次幂本征态的Wigner函数

用在Fock态表象下的Wigner函数重构了湮灭算符任意次幂本征态的Wigner函数.分析了这些函数在相空间中的分布规律,并据此讨论了湮灭算符任意次幂的本征态的非经典特性.结果表明,Wigner函数的分布与湮灭算符本征值的大小有关;湮灭算符1次幂的本征态(即相干态)为准经典态(其Wigner函数的取值总是非负的),而其高次幂的本征态则具有明显的非经典特性(其Wigner函数均出现了负值).     

油轮艏部结构碰撞特性研究

在船舶碰撞中,船艏是主要作用方.船艏结构的碰撞特性是影响船-船碰撞过程中被撞船舷侧结构损伤程度的决定因素.为减少碰撞事故损失,应从碰撞的观点对船艏结构的特性进行研究,提出一种研究船艏的碰撞特性的方法及表征船艏碰撞特性的特征量,据以改进船艏设计.根据船艏结构本身的碰撞破损过程,对船艏结构碰撞力与破损深度的关系、艏部构件在碰撞过程中的损伤形态和能量耗散进行了研究,指出碰撞力曲线是船艏结构的一种固有特性.提出了碰撞力面积密度曲线的概念,它可以用于定量表达船艏结构对其它结构的破坏能力.利用有限元数值模拟方法计算了一艘4万吨船艏的碰撞损坏实例,显示了上述碰撞特征并讨论了提高碰撞数值模拟计算精度的方法.     

NUCLEAR OPERATORS ON C（Ω，X）

ＮＵＣＬＥＡＲＯＰＥＲＡＴＯＲＳＯＮＣ（Ω，Ｘ）ＨｅＣｈｅｎ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓ）ＡｂｓｔｒａｃｔＴｈｉｓｐａｐｅｒｉｓｔｏｄｅｃｉｄｅｔｈｅｎｕｃｌｅａｒｏｐｅｒａｔｏｒｏｎｔｈｅｓｐａｃｅｏｆｖｅｃｔｏｒ...     

SS4B型电力机车（5）—车体

ＳＳ４Ｂ型电力机车车体在ＳＳ４改进型机车车体的基础上，对主要承载件进行了结构改进，车体底架下部沿车钩中心考虑承受２４５０ｋＮ的静压力，以满足国内外招标车的要求，文章主要介绍了ＳＳ４Ｂ型电力机车车体结构。     

多孔式液气缓冲器单自由度动力学分析

从机械振动学的角度分析了机车车辆多孔式液气缓冲器的结构模型,并建立了单自由度振动模型,然后运用动力学基本知识建立了运动方程,通过方程的求解明确了多孔式液气缓冲器缓冲过程的运动轨迹以及影响参数,为此类缓冲器的优化设计提供了一定的理论参考。