997 resultados para 339
Resumo:
The experiments regarding the contact angle behavior of pendant and sessile evaporating drops were carried out in microgravity environment. All the experiments were performed in the Drop Tower of Beijing, which could supply about 3.6 s of microgravity (free-fall) time. In the experiments, firstly, drops were injected to create before microgravity. The wettability at different surfaces, contact angles dependance on the surface temperature, contact angle variety in sessile and pendant drops were measured. Different influence of the surface temperature on the contact angle of the drops were found for different substrates. To verify the feasibility of drops creation in microgravity and obtain effective techniques for the forthcoming satellite experiments, we tried to inject liquid to create bigger drop as soon as the drop entering microgravity condition. The contact angle behaviors during injection in microgravity were also obtained.
Resumo:
用能量为80MeV的19F束通过反应76Ge(19F,5n)90Nb布居了90Nb的高自旋态.通过在束γ测量分析90Nb退激γ射线的符合级联关系,发现了19条新的属于90Nb的γ跃迁,建立了90Nb的高自旋态能级纲图.通过经验壳模型计算指定了部分能级的组态,并结合实验DCO比值和与相邻N=49核素的系统比较,确认了新能级的自旋和宇称.
Resumo:
According to the method of path integral quantization for the canonical constrained system in Becchi-Rouet-Stora-Tyutin scheme, the supersymmetric electromagnetic interaction system was quantized. Both the Hamiltonian of the supersymmetric electromagnetic interaction system in phase space and the quantization procedure were simplified. The BRST generator was constructed, and the BRST transformations of supersymmetric fields were gotten; the effective action was calculated, and the generating functional for the Green function was achieved; also, the gauge generator was constructed, and the gauge transformation of the system was obtained. Finally, the Ward-Takahashi identities based on the canonical Noether theorem were calculated, and two relations between proper vertices and propagators were obtained.
Resumo:
利用在束γ谱学技术和 173Yb(18O, 4n) 熔合蒸发反应研究了 187Pt 的高自旋态能级结构。在 78 和 85 MeV 束流能量下进行了X-γ-t和γ-γ-t符合测量。实验观测到基于νi13/2,ν7/2−[503],νi213/2νj, ν3/2−[512] 和ν1/2−[521] 组态的转动带,并且利用推转壳模型(CSM) 和总Routhian面(TRS) 模型对这些转动带的带交叉,形状共存等性质进行了解释。总Routhian面(TRS)计算表明νi13/2转动带具有显著的负γ形变;负宇称带具有近似长椭球的形变。通过比较带内B(M1)/B(E2)比率的实验值和由 Dönau 和 Frauendorf 的半经典公式得到的理论值,发现ν7/2−[503] 转动带在低转动频率下的带交叉是由一对 h9/2 质子顺排引起的
Resumo:
The molar heat capacity of the azeotropic mixture composed of water and benzene was measured by an adiabatic calorimeter in the temperature range from 80 to 320 K. The phase transitions took place in the temperature range from 265.409 to 275.165 K and 275.165 to 279.399 K. The phase transition temperatures were determined to be 272.945 and 278.339 K, which were corresponding to the solid-liquid phase transitions of water and benzene, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature 298.15 K were derived from the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.
Resumo:
研究结果表明 ,椴树叶分解过程适合用指数衰减方程来表达 .随海拔和植被类型的上升 ,在 1~ 5号标准地 ,椴树叶分解常数分别为 -0 .391、-0 .339、-0 .2 5 7、-0 .198和 -0 .12 5 ,即随海拔升高 ,分解速度下降 .光水条件的实验表明 ,60 %~ 80 %的庇荫条件下 ,分解较快 .浇水多的比浇水少的分解快 .在实验区条件下 ,水分条件比光照条件影响更明显 .与红松针叶的分解实验相比 ,二者规律极为相似 ,而且分解速率相差甚微 .
Resumo:
The heat capacities of berberine sulphate [(C20H18NO4)(2)SO4.3H(2)O] were measured from 80 to 390 K by means of an automated adiabatic calorimeter. Smoothed heat capacities,{H-T-H-298.15} and {S-T-S-298.15} were calculated. The loss of crystalline water started at about 339.3+/-0.2 K, and its peak temperature was 365.8+/-0.6 K. The peak temperature of decomposition for berberine sulphate was at about 391.4+/-0.4 K by DSC curve. TG-DTG analysis of this material was carried out in temperature range from 310 to 970 K. TG and DSC curves show that there is no melting in the whole heating process.