Low temperature plasma treatments were applied to linen with oxygen and argon, various level of discharge power and exposure time. Tbe fabric weight loss increased with the exposure time. Their effects on surface chem...Low temperature plasma treatments were applied to linen with oxygen and argon, various level of discharge power and exposure time. Tbe fabric weight loss increased with the exposure time. Their effects on surface chemical properties and morphology of flax fiber, and fabric wickability were investigated. X - ray photoelec-tron spectroscopy discovered that the surface oxygen content of the plasma treated sample was increased. Formation of voids and cracks on the fiber surface was revealed by the scanning electron microscopy. Fabric wickability first was increased and then decreased with the prolonged exposure.展开更多
Gel point or pour point is widely used to evaluate the low temperature flowability of crude oil. However, it is not adequate to describe the gelling properties of waxy crude oils under flow conditions with gel point o...Gel point or pour point is widely used to evaluate the low temperature flowability of crude oil. However, it is not adequate to describe the gelling properties of waxy crude oils under flow conditions with gel point or pour point, since the theological behavior of crude oils is dependent on shear history. Waxy crude oils tend to gel at a low temperature. Based on gelation theory, the characteristic temperature of waxy crude oil was determined by analyzing viscosity-temperature data. Two mathematical models were developed for calculating characteristic temperatures of virgin crude oils and pour point depressants （PPD） beneficiated crude oils, respectively. By using these two models, the characteristic temperatures of crude oils that have experienced shearing and thermal histories can be predicted. The model for predicting the characteristic temperature of virgin crude oils has an average relative deviation of 4.5%, and all predicted values have a deviation within 2 ℃. Tested by 42 sets of data, the prediction model for crude oil treated with PPD has a high accuracy, with an average relative deviation of 4.2%, and 95.2 percent of predicted values have a deviation within 2 ℃. These two models provide useful ways for predicting the flowability of crude oils in pipelines when only wax content, wax appearance point and gel point are available.展开更多
采用固含量及pH值、SEM、IR、TGA/DSC等分析方法对两种木素进行理化性能分析。对分别采用这两种木素的12 V 70 Ah样品电池进行低温放电性能、充电接受能力和循环寿命性能验证。结果发现:两种木素在官能团及热重分析的第1个吸热峰存在差...采用固含量及pH值、SEM、IR、TGA/DSC等分析方法对两种木素进行理化性能分析。对分别采用这两种木素的12 V 70 Ah样品电池进行低温放电性能、充电接受能力和循环寿命性能验证。结果发现:两种木素在官能团及热重分析的第1个吸热峰存在差异。木素B对铅酸蓄电池的低温放电性能、25℃下17.5%DoD循环寿命和60℃下17.5%DoD循环寿命更有利。通过综合分析木素B的理化性能和电化学性能得出了木素B的最佳添加量。展开更多
文摘Low temperature plasma treatments were applied to linen with oxygen and argon, various level of discharge power and exposure time. Tbe fabric weight loss increased with the exposure time. Their effects on surface chemical properties and morphology of flax fiber, and fabric wickability were investigated. X - ray photoelec-tron spectroscopy discovered that the surface oxygen content of the plasma treated sample was increased. Formation of voids and cracks on the fiber surface was revealed by the scanning electron microscopy. Fabric wickability first was increased and then decreased with the prolonged exposure.
文摘Gel point or pour point is widely used to evaluate the low temperature flowability of crude oil. However, it is not adequate to describe the gelling properties of waxy crude oils under flow conditions with gel point or pour point, since the theological behavior of crude oils is dependent on shear history. Waxy crude oils tend to gel at a low temperature. Based on gelation theory, the characteristic temperature of waxy crude oil was determined by analyzing viscosity-temperature data. Two mathematical models were developed for calculating characteristic temperatures of virgin crude oils and pour point depressants （PPD） beneficiated crude oils, respectively. By using these two models, the characteristic temperatures of crude oils that have experienced shearing and thermal histories can be predicted. The model for predicting the characteristic temperature of virgin crude oils has an average relative deviation of 4.5%, and all predicted values have a deviation within 2 ℃. Tested by 42 sets of data, the prediction model for crude oil treated with PPD has a high accuracy, with an average relative deviation of 4.2%, and 95.2 percent of predicted values have a deviation within 2 ℃. These two models provide useful ways for predicting the flowability of crude oils in pipelines when only wax content, wax appearance point and gel point are available.
文摘采用固含量及pH值、SEM、IR、TGA/DSC等分析方法对两种木素进行理化性能分析。对分别采用这两种木素的12 V 70 Ah样品电池进行低温放电性能、充电接受能力和循环寿命性能验证。结果发现:两种木素在官能团及热重分析的第1个吸热峰存在差异。木素B对铅酸蓄电池的低温放电性能、25℃下17.5%DoD循环寿命和60℃下17.5%DoD循环寿命更有利。通过综合分析木素B的理化性能和电化学性能得出了木素B的最佳添加量。
