井震联合技术在断层精细解释中的应用

测井资料在横向上连续性差,在断层解释方面存在着无法组合孤立断点、多解性断点和井间小断层等缺陷。与测井解释断层相比,地震资料在横向上精度高,具有断层空间组合方面的优势。但地震资料属于时间域,不能被油田开发直接应用。井震联合建模通过时深转化技术将深度域上的测井数据转换到时间域上,并通过方差体分析、蚂蚁追踪、断点归位等技术综合解释断层的空间形态。井震联合技术应用于大庆油田某区块的地质构造精细解释,成功地解决了孤立断点、多解性断点、井间小断层无法解释等问题,实现了测井资料与地震资料的优势互补。

Regression analysis of major parameters affecting the intensity of coal and gas outbursts in laboratory

Estimating the intensity of outbursts of coal and gas is important as the intensity and frequency of outbursts of coal and gas tend to increase in deep mining. Fully understanding the major factors contributing to coal and gas outbursts is significant in the evaluation of the intensity of the outburst. In this paper, we discuss the correlation between these major factors and the intensity of the outburst using Analysis of Variance(ANOVA) and Contingency Table Analysis(CTA). Regression analysis is used to evaluate the impact of these major factors on the intensity of outbursts based on physical experiments. Based on the evaluation, two simple models in terms of multiple linear and nonlinear regression were constructed for the prediction of the intensity of the outburst. The results show that the gas pressure and initial moisture in the coal mass could be the most significant factors compared to the weakest factor-porosity. The P values from Fisher's exact test in CTA are: moisture(0.019), geostress(0.290), porosity(0.650), and gas pressure(0.031). P values from ANOVA are moisture(0.094), geostress(0.077), porosity(0.420), and gas pressure(0.051). Furthermore, the multiple nonlinear regression model(RMSE: 3.870) is more accurate than the linear regression model(RMSE: 4.091).

Metabolism of polychaete Neanthes japonica Izuka: relations to temperature,salinity and body weight

Polychaete Neanthes japonica is a species geographically specific in China and Japan with important scientific implication and commercial value. In this study, the relations of body weight, salinity and temperature to oxygen consumption and ammonia excretion of N. japonica were determined. Three different groups in body weight （large： 2.34±0.36 g, middle： 1.50±0.21 g and small： 0.62±0.12 g） were set for all experiments. Results show that the body weight is negatively related to the rates of oxygen consumption and ammonia excretion; and the relationship is significant. The oxygen consumption and ammonia excretion at 24℃ decreased at salinity from 5 to 30 and increased above 30, indicating that both lower and higher salinity are adverse and certain degree of salinity stress is necessary for enhancing the energy demand. At salinity 30, rising temperature from 18℃ to 30℃, the oxygen consumption increased before 27℃ and then decreased. However, the relation of ammonia excretion and temperature seems more complex. Two-way ANOVA shows that salinity, temperature and body weight all have a significant effect on the oxygen consumption and ammonia excretion of the worm. Moreover, interaction between salinity/temperature and body weight is also significant. O：N （oxygen/nitrogen） ratio varies greatly in this case from 5.97 to 463.22, indicating that N. japonica can regulate the type of metabolic substrate against environment changes.

A Comparative Analysis of Emission of Methane from Livestock Farms in Enugu, Eastern Nigeria

This study compares CH4 emissions from different livestock farms （poultry, cattle and swine farms） in Enugu, Eastern Nigeria. Data on animal type, number and age were obtained by direct observations while the concentrations of CH4 in the livestock farms were measured with the Gasman Crowcrown Gas Monitor. Daily ambient air temperature and rainfall data were obtained from the Nigerian Meteorological Agency （NIMET） Enugu. Regression analysis was used to determine possible relationships existing between weather parameters and CH4 emissions while the One-Way ANOVA was used to determine variance equality in means of greenhouse gas emission spatially at P 〈 0.05. Minimum and maximum temperatures ranged between 21.9 and 22.7 ℃ and 26.2 and 30.6 ℃ respectively, with rainfall ranging between 0.0 and 12.5 mm during the study period. Of the livestock farms sampled, swine farm emitted the highest concentrations of the greenhouse gas at both the livestock house （2.88 ± 0.28 ppm） and feaces decomposition site （2.30 ±0.30 ppm）, while poultry emitted the least concentrations of 1.96 ± 0.23 and 1.92 ± 0.10 ppm in the livestock house and faeces decomposition locations respectively. Age and number of livestock did not affect emissions of greenhouse gas. Though the prevailing weather parameters measured （temperature and rainfall） did not exert significant influences on greenhouse gas emissions, significant spatial variations in emissions in the feaces decomposition sites of the farmhouses was observed at P 〈 0.05. CH4emission in cattle farmhouse （2.80 ± 0.46 ppm） and swine farmhouse （2.88 ± 0.28 ppm） as well as those measured in the faeces decomposition locations of swine farmhouse （2.30 ± 0.30 ppm） exceeded the CH4 concentration level of 2.0 ppm measured in dry air at sea level. There is need for a further research on the effects of animal age, growth rate and biochemistry on CH4 emissions at the farmhouses.

Some recent advances on vertex centered finite volume element methods for elliptic equations

In this paper, we report our recent advances on vertex centered finite volume element methods （FVEMs） for second order partial differential equations （PDEs）. We begin with a brief review on linear and quadratic finite volume schemes. Then we present our recent advances on finite volume schemes of arbitrary order. For each scheme, we first explain its construction and then perform its error analysis under both HI and L2 norms along with study of superconvergence properties.