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71.
72.
Solutions of gum rosin and acetone reproduce the volatile- and temperature-dependent viscosity, together with the phase behaviour, of hydrated magmas. A range of experimental exsolution conditions was investigated, including the variation of supersaturation, rate of decompression, solution temperature and volatile content. Degassing processese were controlled by the formation of an exsolution interface above a supersaturated liquid. The end-products ranged from a mildly degassed liquid to a solid foam, which preserved strained vesicles. Solutions of gum rosin and acetone are proposed as a suitable analogue system with which to study magma degassing processes. 相似文献
73.
A reversed‐phase fractionation method with subsequent biological and chemical analysis has been developed to estimate the contributions of the most potent estrogens to observed estrogenic effect potentials. Surface water samples were taken in the German Baltic Sea (Inner Wismar Bay and Darss Peninsula, sampling campaign July 2003) and were separated into seven individual fractions. Three fractions showed significant estrogenic activities and clear dose‐dependant responses were obtained in the yeast estrogen screen (YES). In the 2nd fractions liquid chromatographic‐electrospray‐tandem mass spectrometric (LC‐ESI‐MS‐MS) analyses showed the presence of bisphenol A (Inner Wismar Bay: 4.8 ng L–1 and 6 ng L–1; Darss Peninsula: 0.91 ng L–1 and 1.7 ng L–1) and ethinylestradiol (Inner Wismar Bay: 2.0 ng L–1 and 6.0 ng L–1; Darss Peninsula: < MDL and 1.7 ng L–1), whereas estrogenic activities in the YES were only around 10% of the positive control E2. Although not identified prior in the total extract the natural hormones estradiol (Inner Wismar Bay: 0.13 ng L–1 and 0.19 ng L–1; Darss Peninsula: 0.12 ng L–1 and 0.16 ng L–1) and estriol (Inner Wismar Bay: < MDL and 0.33 ng L–1; Darss Peninsula: < MDL) could be detected in the 3rd fractions, where high estrogenic potentials could be observed. The 4th fractions showed high responses as well and estrone were herein quantified with concentrations of 0.16 ng L–1 and 0.18 ng L–1 (Darss Peninsula) up to 0.37 ng L–1 (Inner Wismar Bay). Measured and calculated estradiol equivalents for individual fractions correlated very well (R2 = 0.78), when disregarding results of the 2nd fraction, where high deviations occurred. 相似文献
74.
The effect of operating parameters on the hydrodynamics of three geometrically similar Rushton turbine flotation cells with volumes of 2.25, 10 and 50 dm3 was determined. The operating parameters investigated were superficial gas velocity (Jg), impeller rotational speed (N), and frother (methyl isobutyl carbinol, MIBC) concentration. 相似文献
75.
采用在均生函数基础上的正交化筛选方法建模,对分布于全国各区域34个台站的降水量资料序列进行了序列订正的试验与分析。结果表明,年序列的订正效果最好,季降水量序列次之,最差的是月序列的订正。一般说来相对拟合误差随序列的相对标准差的增减而增减。对于年降水量序列而言,除西北9站中的6个站平均相对拟合误差达0.09以上外,其余各均在0.08以下,相对拟合误差还随样本年数增加而减少,样本数为15年以上时,比较 相似文献
76.
The main characteristic of the bubble dynamics near a rigid wall is the development of a high speed liquid jet, generating highly localized pressure on the wall. In present study, the bubble dynamic behaviors and the pressure impulses are investigated through experimental and numerical methods. In the experiment, the dynamics of a spark-generated bubble near a steel plate are captured by a high-speed camera with up to 650,000 frames per second. Numerical studies are conducted using a boundary integral method with incompressible assumption, and the vortex ring model is introduced to handle the discontinued potential of the toroidal bubble. Meanwhile, the pressure on the rigid wall is calculated by an auxiliary function. Calculated results with two different stand-off parameters show excellent agreement with experimental observations. A double-peaked or multiple-peaked structure occurs in the pressure profile during the collapse and rebounding phase. Generally, the pressure at the wall center reaches the first peak soon after the jet impact, and the second peak is caused by the rapid migration of the bubble toward the wall, and the subsequent peaks may be caused by the splashing effect and the rebounding of the toroidal bubble. At last, both agreements and differences are found in the comparison between the present model and a hybrid incompressible–compressible method in Hsiao et al. (2014). The differences show that the compressibility of the flow is another influence factor of the jet impact. However, the main features of the jet impact could be simulated using the present model. 相似文献
77.
不同于常规广义屏传播算子的推导中使用散射理论,本文利用单平方根算子的渐近展开,推导出了单程波方程广义屏传播算子的高阶表达式.高阶广义屏传播算子不仅可提高常规广义屏传播算子的计算精度,而且还能改善广义屏传播算子对速度强横向变化介质的适应性.把高阶广义屏传播算子应用于波动方程叠前深度偏移,可得到比常规广义屏传播算子更好的效果.高阶广义屏传播算子的阶数越高,计算精度越高,但计算量也越多.以SEG EAGE二维盐丘模型数据的波动方程叠前深度偏移为例,二阶广义屏传播算子相对于常规(一阶)广义屏传播算子增加了30%的计算量.高阶广义屏传播算子是常规广义屏传播算子理论的发展和完善. 相似文献
78.
79.
The energy radiation process of an airgun seismic source in land reservoir is studied based on the underwater wavelet data collected in the airgun excitation experiments in Binchuan, Yunnan, China. The empirical formula for calculating the bubble pulsation period and the maximum radius of the underwater airgun seismic source is obtained. The results show that: ① The energy radiation efficiency is higher vertically than horizontally. ② The vertical bubble energy radiation efficiency increases with the increase of the air supply pressure. ③ The vertical energy radiation efficiency of the airgun seismic source is 9.4% when the air supply pressure is 15 MPa. ④ The higher the air supply pressure, the further the propagating distance of the superposition-enhanced pressure wave of an airgun source. 相似文献
80.
气泡帷幕在水下噪声抑制方面有非常广泛的应用。为了更好地利用气泡帷幕的衰减特性,在实验室水槽设备中采用气泵法产生气泡帷幕,通过对不同深度、气流量接收信号的时频分析,利用共振谱法对气泡分布进行反演。研究表明:(1)气泡的分布可以利用高斯分布近似描述。(2)随着深度增加,气泡含量也有略微增加。(3)气泵法产生的气泡帷幕的气流量大小对衰减的峰值所在的频段基本没有影响,但气流量的改变会影响声波衰减的强弱,气流量大的情况下,气泡帷幕对声波衰减效果更强。通过掌握气泵法生成气泡帷幕中气泡的分布规律,可以有效指导气泡帷幕的设计。 相似文献