用风速观测值参数化干湿表系数A值的尝试

通过试验取得台站风速观测值和１．５ｍ高度百叶箱内外风速值，求其相关。根据干湿表系数Ａ值主要取决于湿球球部通风速度的关系，用台站风速观测值直接参数化干湿表系数Ａ值，探讨将Ａ值作为风速的函数通过计算机处理提高百叶箱干湿表测湿准确度的可能性     

20世纪90年代以来机械防砂技术的新进展

防砂对于出砂油藏有着重要意义，防砂的成功与否直接关系到油气藏是否能够正常开发。随着新科技和新材料的不断发展和完善，机械防砂技术也获得了日新月异的进展。特别是20世纪90年代以来各种新的防砂技术在油田现场应用均取得了良好的效果。论述了20世纪90年代以来机械防砂技术的现状及发展趋势。     

卫星天线的单片机快速对星系统

使用GPS接收机模块得到卫星天线所在位置的经纬度,单片机模块进行数据处理得到对星所需要的方位角、仰角,与电子罗盘测得的天线的方位角、仰角进行比较得到其差值,并用液晶显示模块将其结果全部显示出来,指导天线操作人员实现快速、准确对星。     

Vodyanitskii mud volcano,Sorokin trough,Black Sea: Geological characterization and quantification of gas bubble streams

Vodyanitskii mud volcano is located at a depth of about 2070 m in the Sorokin Trough, Black sea. It is a 500-m wide and 20-m high cone surrounded by a depression, which is typical of many mud volcanoes in the Black Sea. 75 kHz sidescan sonar show different generations of mud flows that include mud breccia, authigenic carbonates, and gas hydrates that were sampled by gravity coring. The fluids that flow through or erupt with the mud are enriched in chloride (up to ∼650 mmol L⁻¹ at ∼150-cm sediment depth) suggesting a deep source, which is similar to the fluids of the close-by Dvurechenskii mud volcano. Direct observation with the remotely operated vehicle Quest revealed gas bubbles emanating at two distinct sites at the crest of the mud volcano, which confirms earlier observations of bubble-induced hydroacoustic anomalies in echosounder records. The sediments at the main bubble emission site show a thermal anomaly with temperatures at ∼60 cm sediment depth that were 0.9 °C warmer than the bottom water. Chemical and isotopic analyses of the emanated gas revealed that it consisted primarily of methane (99.8%) and was of microbial origin (δD-CH₄ = −170.8‰ (SMOW), δ¹³C-CH₄ = −61.0‰ (V-PDB), δ¹³C-C₂H₆ = −44.0‰ (V-PDB)). The gas flux was estimated using the video observations of the ROV. Assuming that the flux is constant with time, about 0.9 ± 0.5 × 10⁶ mol of methane is released every year. This value is of the same order-of-magnitude as reported fluxes of dissolved methane released with pore water at other mud volcanoes. This suggests that bubble emanation is a significant pathway transporting methane from the sediments into the water column.     

触摸屏和PLC相结合的DCS控制系统在自动粉末喷涂生产线的应用

文中主要介绍利用触摸屏和PLC相结合的控制方式,通过可视化的操作界面,控制整个自动粉末喷涂生产线的设计,以及触摸屏和PLC的软件编程过程。     

盾构砂性土层所加泡沫剂替代品的工地试验研究

以上海地铁M8线盾构掘进施工为实例,对掘进过程中所用的进口和国产泡沫剂的性能和效果进行了分析,从中选择有效、经济的泡沫代品,为以后的泡沫法盾构施工提供借鉴和参考。     

A test of the Tate equation to predict bubble size at an orifice in the presence of frother

Air bubbles of uniform size (ca. 1 mm diameter) were generated at a submerged orifice (glass capillary) under controlled frequency (down to ca. 0.06 s^− 1) in aqueous solutions of frother (Dowfroth 250). The bubbles were sized with an imaging technique. One objective was to establish whether the Tate equation (static balance between buoyancy and capillary forces) could be used as a standard sizing calibration method. Another aim was to verify whether with decreasing surface tension (due to increasing frother concentration) the anticipated decrease in bubble size agreed with the equation prediction. An effect of frother was detected compatible with the role of surface tension but divided into two concentration regions, seemingly the result of a gradual change in bubble shape and wetting: > 6 ppm the bubble holds a spherical shape and the capillary appeared to be completely wetted while at ≤ 6 ppm a degree of non-wetting and bubble distortion (neck formation just prior to detachment) were apparent, supported by qualitative observations. In addition, at > 6 ppm the Tate value was only approached by decreasing the bubble frequency but not attained. Plausible causes for the failure to reach the predicted size are discussed.     

Measurement of air temperature in the presence of a large radiant flux: an assessment of passively ventilated thermometer screens

The energy balance of small temperature sensors was modelled to illustrate the effects of sensor characteristics, particularly size, on the accuracy of readings in the presence of strong shortwave or longwave radiant loads. For all but extremely small sensors, radiant exchange may lead to unacceptable errors. The common practice of using passively ventilated instrument screens was evaluated in a series of comparative measurements. The differences resulting from the use of different models of shields may be an order of magnitude greater than the error resulting from sensor calibration. In the absence of technological innovation capable of reducing the error due to radiant exchange to negligible proportions, it is suggested that a standard methodology for calibrating and labelling the error resulting from the characteristics of the screens be adopted, to allow comparison of new data with long-established records.     

一类线性方程组解的条件数估计

利用矩阵范数的性质,给出了一类特殊线性方程组条件数估计,这有助于判别方程组解的灵敏度.     

用MFC快速开发屏幕保护程序

分析了操作系统对屏幕保护程序的调用机制，提出完全使用MFC快速开发屏幕保护程序的方法，并比较该方法与传统实现方法的优缺点之后，利用MFC实现了一个在指定目录查找并装入位图文件，然后定时切换位图显示的屏幕保护示例程序。