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1.
动载荷下金属板表面的微物质喷射   总被引:4,自引:4,他引:0       下载免费PDF全文
 用石英晶体传感器技术,测量了冲击波作用下铝合金(Ly-12)和纯铅样品自由表面的微物质喷射量。在冲击压力为32 GPa时,测得光洁度为3.2、0.4、0.1 μm的铝合金的微物质喷射量分别为1.53~3.28 g/m2,0.2~0.3 g/m2和0.053~0.096 g/m2,对光洁度为3.2 μm的纯铅样品,在压力为13 GPa和47 GPa时,微物质喷射量分别微26.4~42.4 g/m2和183~328 g/m2。在最高冲击压力约为20 GPa时,做了多次冲击下的微物质喷射量测量,发现比单次冲击加载下的喷射量有很大的减少。结果表明,微物质喷射量与自由表面的加工条件、局部熔化和加载方式等因素有关。  相似文献   

2.
镀膜锰铜计的压阻性能研究   总被引:4,自引:2,他引:4       下载免费PDF全文
 用磁控阴极等离子体溅射技术在云母基底上制作镀膜锰铜压阻计。5~56 GPa冲击应力的标定实验表明,该计的压阻性能稳定。压阻系数的拟合式为p(GPa)=-0.14+90.63(ΔR/R0)+10.81(ΔR/R0)2-7.64(ΔR/R0)3,式中R0为锰铜计初始电阻,ΔR为受压时的电阻变化值。  相似文献   

3.
本文内容包括:(ⅰ)进一步给出SU(2)×U(1)×S3模型的结果S2≈S3≈(ms2)/(mb2);sin δ≤(mumd)/(mcms),并预言b夸克的主要衰变道是b→u+W,b夸克的寿命可能长到10-9秒.(ⅱ)给出类K0-K0系统混合时的精确表达式ρ=错号事例数/对号事例数=(1/2)(|p/q|2+|q/p|2)([Γ2+(Δm)2]2-(γ1γ2)2)/([Γ2+(Δm)2]2+(γ1γ2)2);并给出CP破坏的精确表达式:A=(1-ρ')/(1+ρ')=(IM12Γ12*)/(|M12|2+1/4|Γ12|2),这里ρ′=(负电错号事例数)/(正电错号事例数)。  相似文献   

4.
 为分析不同数量铁电体的输出电流特征,进行了多片并联PZT95/5铁电体冲击去极化实验,测量了电阻负载下铁电体的输出电流;建立了并联铁电体输出电流的计算模型,计算了并联铁电体的输出电流。通过比较计算和实验结果,分析了铁电体数量和冲击波状态对铁电体输出电流的影响。结果表明:若进入铁电体的冲击波为平面波,铁电体输出电流的波形接近方波,电流峰值随铁电体并联数量的增加成比例增加,冲击波波形和侧向稀疏波对铁电体输出电流波形和去极化率有很大的影响。  相似文献   

5.
水中放电等离子体状态方程的理论研究   总被引:5,自引:0,他引:5       下载免费PDF全文
 水中放电等离子体通道内温度达2×104~5×104 K、而压力达1~10 GPa。在这样的参数下,等离子体的状态方程已不能用理想气体状态方程来描述。首次考虑了粒子间的相互作用对水中放电等离子体参数下粒子电离能的影响,计算了电子的简并性、带电粒子间的库仑相互作用、原子内部能级扰动所产生的压力。计算结果表明:当H、O原子和离子的总密度n=1029 m-3时,若考虑电离能漂移,则电子密度提高的最大幅度达70%;电子的简并性对压力的影响很小;粒子间的库仑相互作用在高温区使总压减小较显著,但在所计算的参数范围内,其幅值也不大于10%;当n=1029 m-3、T≈2×104 K时,原子内部能级的扰动使总压增大约30%。  相似文献   

6.
李炳安 《中国物理 C》1984,8(3):279-284
本文用MIT口袋模型和波包方法计算了π0→2γ过程的宽度. 计算发现mπ→0是一个好的近似. MIT口袋模型给出, Γ(π0→2γ)∝m3π/F2π, 这种形式与Adler的结果相符合, 但数字结果显示, Γ(π0→2γ)的理论值是实验值的2.7倍, 这个差主要来自Fπ的理论值与实验值的差. 而这个差很强地依赖于MIT口袋模型的方程和边界条件, 从而对MIT口袋模型构成了一个检验.  相似文献   

7.
本文从e+e湮灭的次级粒子的横动量分布的表示式中, 导出了当m>>T时横质量m的平均无标度性.  相似文献   

8.
中子能量为14.8±0.4MeV, 用直接测定产物核活性的方法, 测定了45Sc(n, 2n) 44Sc反应和86Sr(n,2n)85Sr反应中产生的44mSc, 44gSc, 85mSr和85gSr的绝对截面, 总截面及其比值. 用Huizenga和Vandenbosch[1]统计模型的方法进行理论计算, 从而得到产物核的自旋切割因子σ.  相似文献   

9.
李炳安 《中国物理 C》1987,11(3):426-429
在这篇文章中证明, 即使在mπ≠0的情况下, 在Skyrme模型中仍可得到Goldberger-Treiman关系, 核子的强作用半径2>1/2被计算出来为0.8frm.  相似文献   

10.
Utilizing the cross sections for 93Nb(n, 2n)93mNb or 27Al(n, a)24Na reactions as monitors, the cross sections for the reactions 115Sn(n, p)115mIn, 116Sn(n, p)116mIn, 117Sn(n, p)117In and 117Sn(n, p)117mIn have been measured at neutron energy ranging from 13.5 to 14.6 MeV through activation technology. Then, the results of present work were compared with the published experimental data.  相似文献   

11.
为了保障EAST快控电源系统的稳定运行,提出了一种适用于EAST快控电源的高频高压工作环境的交流绝缘监测技术.此方法利用电阻不平衡桥,通过交替投切电阻造成分压的变化,实时采集电压,计算出绝缘电阻值.搭建了Simulink仿真平台,分别将~220V市电和EAST快控电源输出作为电压输入进行实时绝缘监测仿真分析,波形与预期相符.经过实验验证,新方法能够准确完成220V市电交流输入的绝缘监测,并且在快控电源现场能正常工作,达到绝缘监测的精度要求.  相似文献   

12.
为了保障EAST快控电源系统的稳定运行,提出了一种适用于EAST快控电源的高频高压工作环境的交流绝缘监测技术。此方法利用电阻不平衡桥,通过交替投切电阻造成分压的变化,实时采集电压,计算出绝缘电阻值。搭建了Simulink仿真平台,分别将~220V市电和EAST快控电源输出作为电压输入进行实时绝缘监测仿真分析,波形与预期相符。经过实验验证,新方法能够准确完成220V市电交流输入的绝缘监测,并且在快控电源现场能正常工作,达到绝缘监测的精度要求。  相似文献   

13.
《Composite Interfaces》2013,20(3):235-245
Adhesion between glass/epoxy composite substrate and copper foil was evaluated by 90° peeling test. Effect of fracture behavior and the peel strength on copper foil style was experimentally investigated using copper foils with various surface roughness. As mechanical anchoring effect increases with increased surface roughness, the surface roughness increased the surface roughness of copper foil strongly affected the peeling strength and local load variation during the test. The fracture behavior was characterized by secondary electron image and reflective electron image techniques of scanning electron microscopy (SEM). All of the specimens were found to fracture at the anchor points formed in the resin layer on the surface of the substrate. The experimental results were correlated to a formulation based on the theory of beams on elastic foundation, which is presented for predicting the adhesive strength in the adherend- adhesive system. In order to apply this formulation to a no adhesive system, such as FR-4/copper foil, an analytical model was proposed. In this model, a mixture phase of the copper with the surface resin in the substrate was regarded as the adhesive. The calculated results were in relatively good agreement with the experimental results. It was confirmed that the analysis model and evaluation method is useful to predict the peel strength due to the mechanical anchoring effect.  相似文献   

14.
The elemental copper vapour laser is a widely used laser from a family of metal vapour lasers for applications such as dye laser pumping, micromachining etc. In this paper, we report the development and performance of IGBT-based pulsed power supply that replaced conventional thyratron-based power supply for 4.7 cm diameter, 150 cm long copper vapour laser. The laser tube delivered an average power of 51 W, which with conventional power supply was giving 40 W. The IGBT-based power supply offers considerable reduction in the running cost of the laser. It is more user-friendly when compared with the conventional power supply.  相似文献   

15.
基于高功率重复频率脉冲功率源的需求,开展了高功率脉冲充电电源的重复频率特性研究,分析了基于全桥串联谐振充电原理的恒流充电技术。根据高功率Marx型脉冲功率源的工作要求,计算了串联谐振充电的各个关键参数。研制的紧凑型高功率脉冲充电电源,最大输出电压±50 kV,充电电流2.5 A,重复频率1~50 Hz连续可调,可在重复频率条件下长时间稳定运行。该充电电源体积小、质量轻、抗干扰能力和抗负载短路能力强,已经应用于高功率重复频率脉冲功率源技术研究,实现了10万次重复频率无故障运行。  相似文献   

16.
Performance of graphite foil electrodes coated by porous carbon black (i.e., Vulcan) was investigated in comparison with metal electrodes for reverse electrodialysis (RED) application. The electrode slurry that was used for fabrication of the porous carbon-coated graphite foil is composed of 7.2 wt% of carbon black (Vulcan X-72), 0.8 wt% of a polymer binder (polyvinylidene fluoride, PVdF), and 92.0 wt% of a mixing solvent (dimethylacetamide, DMAc). Cyclic voltammograms of both the porous carbon (i.e., Vulcan)-coated graphite foil electrode and the graphite foil electrode without Vulcan showed good reversibility in the hexacyanoferrate(III) (i.e., Fe(CN)63−) and hexacyanoferrate(II) (i.e., Fe(CN)64−) redox couple and 1 M Na2SO4 at room temperature. However, anodic and cathodic current of the Vulcan-coated graphite foil electrode was much higher than those of the graphite foil electrode. Using a bench-scale RED stack, the current–voltage polarization curve of the Vulcan-coated graphite electrode was compared to that of metal electrodes such as iridium (Ir) and platinum (Pt). From the results, it was confirmed that resistance of four different electrodes increased with the following order: the Vulcan-coated graphite foil<the Ir-coated titanium (Ti) mesh<the Pt-coated Ti plate<the graphite foil. Moreover, the Vulcan-coated graphite foil showed 5–10% higher power density than the metal mesh electrodes. From the polarization curve of the Vulcan-coated graphite foil electrode, it was found that total resistance decreased as thickness and geometric surface area of the electrode increased.  相似文献   

17.
灯丝电源是中性束注入器等离子体发生器电源系统的重要组成部分,为了满足其低电压大电流输出特性要求,提出了带平衡电抗器双反星形整流电路的拓扑结构的电源设计方案。该拓扑结构与三相桥式整流电路相比较在采用相同器件下可达到更高功率,减少交流侧输入电流谐波并提高功率因素。分析了该拓扑结构下整流输出特性和所含的谐波分量,根据设计指标计算了整流变压器和平衡电抗器的相关参数,最后通过仿真和实验结果验证了这一拓扑结构的可行性。  相似文献   

18.
电动势以及内阻是直流稳压电源的两个主要特性参数,惠斯登电桥中的直流稳压电源特性与电桥特性直接相关,如何相关这正是本文所要探讨的问题.  相似文献   

19.
A simplified process for the bus electrodes of low resistance in passive matrix OLEDs using cathode separators is presented. The cathode separators are patterned both in a peripheral area and in an active area so that the bus electrodes can be formed out of a cathode metal of low resistance when the cathode metal is deposited. Using this simplified process, a single and bi-layer of aluminum and copper were tried out to form the bus and cathode electrodes and the results were analyzed. This method reduces the fabrication processes and lowers the power consumption.  相似文献   

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