The study area is located between the cities of Comitan (16°10'43"N and 92°04'20''W) a city with 150,000 inhabitants and La Esperanza (16°9'15''N and 91°...The study area is located between the cities of Comitan (16°10'43"N and 92°04'20''W) a city with 150,000 inhabitants and La Esperanza (16°9'15''N and 91°52'5''W) a town with 3000 inhabitants. Both weather stations are 30 km from each other in the Chiapas State, México. 54 years of daily records of the series of maximum (<em>t</em><sub>max</sub>) and minimum temperatures (<em>t</em><sub>min</sub>) of the weather station 07205 Comitan that is on top of a house and 30 years of daily records of the weather station 07374 La Esperanza were analyzed. The objective is to analyze the evidence of climate change in the Comitan valley. 2.07% and 19.04% of missing data were filled, respectively, with the WS method. In order to verify homogeneity three methods were used: Standard Normal Homogeneity Test (SNHT), the Von Neumann method and the Buishand method. The heterogeneous series were homogenized using climatol. The trends of <em>t</em><sub>max</sub> and <em>t</em><sub>min</sub> for both weather stations were analyzed by simple linear regression, Sperman’s rho and Mann-Kendall tests. The Mann-Kendal test method confirmed the warming trend at the Comitan station for both variables with <em>Z<sub>MK</sub></em> statistic values equal to 1.57 (statistically not significant) and 4.64 (statistically significant). However, for the Esperanza station, it determined a cooling trend for tmin and a slight non-significant warming for <em>t</em><sub>max</sub> with a <em>Z</em><sub><em>MK</em></sub> statistic of -2.27 (statistically significant) and 1.16 (statistically not significant), for a significance level <em>α</em> = 0.05.展开更多
The mud film thickness on the outer surface of casing and its distribution laws are important factors affecting the cementation quality at casing-cement interfaces.So far,however,the distribution laws of mud film thic...The mud film thickness on the outer surface of casing and its distribution laws are important factors affecting the cementation quality at casing-cement interfaces.So far,however,the distribution laws of mud film thickness on the outer surface of casing at different inclinations and its effect on the interfacial cementing strength have never been reported in literatures.In this paper,the mud film thickness at different parts on the outer surface of simulated casing(steel pipe)was measured at the inclination of 0°,30°,60°and 86°,respectively,using the independently designed experimental device.Then,the distribution law of mud film thickness on the outer surface of casing and its effect on the interfacial cementing strength were summarized.And the following research results were obtained.First,when the inclination increases from 0°to 86°,the mud film thickness changes from uniform distribution to thin-and-thick distribution,and the area proportions of thinner and thicker mud films both increase.And especially at the inclination of 86°,the mud film thickness on the upper surface is very large,and there are large exposed areas on the left and right surfaces of the steel pipe.Second,the cementing strength at the casing-cement interface of the exposed casing is much higher than that at the interface with mud film.And with the increase of inclination,the interfacial cementing strength with mud film tends to increase.Third,with the increase of inclination,the interfacial cementing strength increases successively,which is closely related to the area proportion of the exposed steel pipe to the solid mud film on the outer surface.In conclusion,the exposed area of the simulated casing on the outer surface is a key factor affecting its interfacial cementing strength.展开更多
文摘The study area is located between the cities of Comitan (16°10'43"N and 92°04'20''W) a city with 150,000 inhabitants and La Esperanza (16°9'15''N and 91°52'5''W) a town with 3000 inhabitants. Both weather stations are 30 km from each other in the Chiapas State, México. 54 years of daily records of the series of maximum (<em>t</em><sub>max</sub>) and minimum temperatures (<em>t</em><sub>min</sub>) of the weather station 07205 Comitan that is on top of a house and 30 years of daily records of the weather station 07374 La Esperanza were analyzed. The objective is to analyze the evidence of climate change in the Comitan valley. 2.07% and 19.04% of missing data were filled, respectively, with the WS method. In order to verify homogeneity three methods were used: Standard Normal Homogeneity Test (SNHT), the Von Neumann method and the Buishand method. The heterogeneous series were homogenized using climatol. The trends of <em>t</em><sub>max</sub> and <em>t</em><sub>min</sub> for both weather stations were analyzed by simple linear regression, Sperman’s rho and Mann-Kendall tests. The Mann-Kendal test method confirmed the warming trend at the Comitan station for both variables with <em>Z<sub>MK</sub></em> statistic values equal to 1.57 (statistically not significant) and 4.64 (statistically significant). However, for the Esperanza station, it determined a cooling trend for tmin and a slight non-significant warming for <em>t</em><sub>max</sub> with a <em>Z</em><sub><em>MK</em></sub> statistic of -2.27 (statistically significant) and 1.16 (statistically not significant), for a significance level <em>α</em> = 0.05.
基金Project supported by the Sub-project of National Major Science and Technology Project(No.:2017ZX05009003-003)the National Natural Science Foundation of China(No.:51774258,41572142).
文摘The mud film thickness on the outer surface of casing and its distribution laws are important factors affecting the cementation quality at casing-cement interfaces.So far,however,the distribution laws of mud film thickness on the outer surface of casing at different inclinations and its effect on the interfacial cementing strength have never been reported in literatures.In this paper,the mud film thickness at different parts on the outer surface of simulated casing(steel pipe)was measured at the inclination of 0°,30°,60°and 86°,respectively,using the independently designed experimental device.Then,the distribution law of mud film thickness on the outer surface of casing and its effect on the interfacial cementing strength were summarized.And the following research results were obtained.First,when the inclination increases from 0°to 86°,the mud film thickness changes from uniform distribution to thin-and-thick distribution,and the area proportions of thinner and thicker mud films both increase.And especially at the inclination of 86°,the mud film thickness on the upper surface is very large,and there are large exposed areas on the left and right surfaces of the steel pipe.Second,the cementing strength at the casing-cement interface of the exposed casing is much higher than that at the interface with mud film.And with the increase of inclination,the interfacial cementing strength with mud film tends to increase.Third,with the increase of inclination,the interfacial cementing strength increases successively,which is closely related to the area proportion of the exposed steel pipe to the solid mud film on the outer surface.In conclusion,the exposed area of the simulated casing on the outer surface is a key factor affecting its interfacial cementing strength.
