Weld seam inflection points are inevitable in tele-teaching process on many welding occasions. The inflection points identified accurately is one of the prerequisites of ensuring tele-teaching precision. On the basis ...Weld seam inflection points are inevitable in tele-teaching process on many welding occasions. The inflection points identified accurately is one of the prerequisites of ensuring tele-teaching precision. On the basis of the inflection point characters, the concept of inflection point direction coefficient is proposed, the human-simulation intelligent control model of inflection point is established. The algorithms above, the inflection point identifying of box workpiece can be well performed. The experimental results show that the identifying average error of inflection point can be reduced to less than O. 5 mm by using optimal treatment of robot off-line programming system. The identifying control can automatically identify weld seam inflection points which can meet tele-teaching requirements.展开更多
Using vectors between control points(a_i=P_(i+1)-P_i),parameters λ and μ(such that a_(i+1)=λ_(ai+μ_(a_i+2))are used to study the shape classification of planar parametric cubic B-spline curves. The regiosn of λμ...Using vectors between control points(a_i=P_(i+1)-P_i),parameters λ and μ(such that a_(i+1)=λ_(ai+μ_(a_i+2))are used to study the shape classification of planar parametric cubic B-spline curves. The regiosn of λμ space corresponding to different geometric features on the curves are investigated.These results are useful for curve design.展开更多
Shandong Development and Reform Commission recently announced in a documen that based on the enterprise self-inspection and provincial inspection results,it had ordered Shandong Weiqiao Pioneering Group and Xinfa Grou...Shandong Development and Reform Commission recently announced in a documen that based on the enterprise self-inspection and provincial inspection results,it had ordered Shandong Weiqiao Pioneering Group and Xinfa Group to close 3.21 million tons o illegal aluminum production capacity by the end of July.Besides Shandong,other provinces and regions with high aluminum展开更多
A spectrophotometric technique is developed to simultaneously quantify nitrate and nitrite in plasma treated water.The measurement is based on examining the inflection points(wavelengths)in the derivative absorbance o...A spectrophotometric technique is developed to simultaneously quantify nitrate and nitrite in plasma treated water.The measurement is based on examining the inflection points(wavelengths)in the derivative absorbance of the nitrate or nitrite solution.At the inflection points of the pure nitrate solution,the derivative absorbance is zero and independent of the nitrate’s concentration,and thus the nitrite’s concentration in a mixed nitrate and nitrite solution can be obtained by using the Beer’s law at these points.The nitrate’s concentration can also be achieved from the inflection points of nitrite in the same manner.The relation between the tested substance’s(nitrate or nitrite)concentration and the second-or the third-order absorbances is obtained at these inflection points.Test measurements for mixed aqueous solutions of nitrate and nitrite with or without hydrogen peroxide confirm the reliability of this technique.We applied this technique to quantify the nitrate and nitrite generated in air plasma treated aqueous solutions.The results indicate that both nitrate and nitrite concentrations increase with the plasma treatment time,and the nitrite species is found to be generated prior to the nitrate species in the air plasma treated aqueous solution.Moreover,the production rate of total nitrogen species is independent of the solutions’p H value.These results are relevant to diverse applications of plasma activated solutions in materials processing,biotechnology,medicine and other fields.展开更多
China's rapid economic development leads to a series of environmental problems in the long run,such as air pollution.Environmental pollution has become a bottleneck restricting the sustainable development of China...China's rapid economic development leads to a series of environmental problems in the long run,such as air pollution.Environmental pollution has become a bottleneck restricting the sustainable development of China's economy.As such,pollution has become a key issue for China as让tries to continuously improve environmental quality and establish a harmonious coexistence between man and nature.This paper uses spatial econometric analysis to empirically test the existence of the Environmental Kuznets Curve(EKC)in China while also examining the impact of financial development on its inflection point by applying Air Quality Index and PM_(2.5) data of 283 prefecture-level cities in China from 2015 to 2017.Findings from this study indicate that the EKC of air pollution in the whole country presents an inverted U-shape based on both the traditional and new EKC models.After testing the sub-sample in different areas,the EKC still presents an inverted U-shape based on the new EKC model in the eastern and central areas,though not in the western area.In considering the moderating role of financial development based on the new EKC model,we find that the increase of financial depth will cause the EKC inflection point to shift to the left on the national scale and in the eastern region,while the effect of the financial breadth will be largely insignificant.With regard to the central area,both the breadth and the depth of financial development will significantly shift the inflection point to the right,delaying the arrival of the EKC inflection point.Therefore,the local authority of each area should formulate differentiated financial development policies to promote the early arrival of the EKC inflection point.展开更多
During studying the heat capacity of metals and brightening more than the original Lena’s image, the temperature increasing term obtained in binomial expansion is transformed into the adsorption increasing term and t...During studying the heat capacity of metals and brightening more than the original Lena’s image, the temperature increasing term obtained in binomial expansion is transformed into the adsorption increasing term and thereafter we have derived the total adsorption rate equation with it. In the first layer the quantization does not occur and from 2<sup>nd</sup> layer to n<sup>th</sup> layer the quantization occurs. So as to get the total adsorption rate equation we add the quantized terms of the second to n<sup>th</sup> layers to the non-quantized term of the first layer. All terms are based on the unit surface sites. Instead of the unit surface sites, the new adsorption site term appears in the denominator of the adsorption equation. Hence the adsorption equations come out much better than BET equation. The surface area is also calculated through the integration of the adsorption isotherm equation excluding the first layer adsorption equation from the inflection point to the wanted relative pressure.展开更多
Pore volume of Cumulative water injection is one of the factors for evaluating water flood effect in a water flood oil field.In previous study,there were limited lab studies for evaluating oil displacement efficiency....Pore volume of Cumulative water injection is one of the factors for evaluating water flood effect in a water flood oil field.In previous study,there were limited lab studies for evaluating oil displacement efficiency.A method to characterize the distribution of pore volume of cumulative water injection is proposed in this paper,and it is verified by a five-spot water flooding streamline simulation model.The logarithmic relation between pore volume of cumulative water injection and water saturation is established by regression.An inflection point and limit point of cumulative water injection pore volume are identified.Current simulation model indicates inflection point appears after 2e5 pore volume(PV)injection,and limit point appears after 15e25 PV injection.Both inflection and limit point vary in different regions of reservoir.展开更多
In order to achieve accurate non-contact measurement of the mechanical wear of the elevator traction sheave grooves,a wear detection system based on machine vision was developed.The industrial camera was fixed through...In order to achieve accurate non-contact measurement of the mechanical wear of the elevator traction sheave grooves,a wear detection system based on machine vision was developed.The industrial camera was fixed through a special fixture,and the images were collected by aligning each groove.In this paper,target groove is extracted based on normalized correlation coefficient matching.Corner points are extracted to describe the contour of the traction wheel groove.The inflection point of the wheel groove boundary is determined by straight boundary fitting,and the amount of rope groove wear is calculated by geometric knowledge.Based on the physical model structure,a mathematical model is established to eliminate the unavoidable occlusion error.The experimental results show that this system can carry out an accurate quantitative analysis and realize an accurate measurement of the wear of the traction sheave rope groove with convenience and accuracy.展开更多
文摘Weld seam inflection points are inevitable in tele-teaching process on many welding occasions. The inflection points identified accurately is one of the prerequisites of ensuring tele-teaching precision. On the basis of the inflection point characters, the concept of inflection point direction coefficient is proposed, the human-simulation intelligent control model of inflection point is established. The algorithms above, the inflection point identifying of box workpiece can be well performed. The experimental results show that the identifying average error of inflection point can be reduced to less than O. 5 mm by using optimal treatment of robot off-line programming system. The identifying control can automatically identify weld seam inflection points which can meet tele-teaching requirements.
文摘Using vectors between control points(a_i=P_(i+1)-P_i),parameters λ and μ(such that a_(i+1)=λ_(ai+μ_(a_i+2))are used to study the shape classification of planar parametric cubic B-spline curves. The regiosn of λμ space corresponding to different geometric features on the curves are investigated.These results are useful for curve design.
文摘Shandong Development and Reform Commission recently announced in a documen that based on the enterprise self-inspection and provincial inspection results,it had ordered Shandong Weiqiao Pioneering Group and Xinfa Group to close 3.21 million tons o illegal aluminum production capacity by the end of July.Besides Shandong,other provinces and regions with high aluminum
基金National Natural Science Foundation of China(No.52077185)the Basic Research Program of Science and Technology of Shenzhen,China(No.JCYJ20190809162617137)for partial financial support。
文摘A spectrophotometric technique is developed to simultaneously quantify nitrate and nitrite in plasma treated water.The measurement is based on examining the inflection points(wavelengths)in the derivative absorbance of the nitrate or nitrite solution.At the inflection points of the pure nitrate solution,the derivative absorbance is zero and independent of the nitrate’s concentration,and thus the nitrite’s concentration in a mixed nitrate and nitrite solution can be obtained by using the Beer’s law at these points.The nitrate’s concentration can also be achieved from the inflection points of nitrite in the same manner.The relation between the tested substance’s(nitrate or nitrite)concentration and the second-or the third-order absorbances is obtained at these inflection points.Test measurements for mixed aqueous solutions of nitrate and nitrite with or without hydrogen peroxide confirm the reliability of this technique.We applied this technique to quantify the nitrate and nitrite generated in air plasma treated aqueous solutions.The results indicate that both nitrate and nitrite concentrations increase with the plasma treatment time,and the nitrite species is found to be generated prior to the nitrate species in the air plasma treated aqueous solution.Moreover,the production rate of total nitrogen species is independent of the solutions’p H value.These results are relevant to diverse applications of plasma activated solutions in materials processing,biotechnology,medicine and other fields.
基金the financial support of the Humanities and Social Science Foundation of the Chinese Ministry of Education[Grant num-ber.20YJC630104]the National Natural Science Foundation of China[Grant number.71403120,Grant number.72003157]+1 种基金the National Social Science Foundation of China[Grant number.18ZDA052,Grant number.19ZDA074)the Fundamental Research Funds for the Central Universities[Grant number.JBK2002017].
文摘China's rapid economic development leads to a series of environmental problems in the long run,such as air pollution.Environmental pollution has become a bottleneck restricting the sustainable development of China's economy.As such,pollution has become a key issue for China as让tries to continuously improve environmental quality and establish a harmonious coexistence between man and nature.This paper uses spatial econometric analysis to empirically test the existence of the Environmental Kuznets Curve(EKC)in China while also examining the impact of financial development on its inflection point by applying Air Quality Index and PM_(2.5) data of 283 prefecture-level cities in China from 2015 to 2017.Findings from this study indicate that the EKC of air pollution in the whole country presents an inverted U-shape based on both the traditional and new EKC models.After testing the sub-sample in different areas,the EKC still presents an inverted U-shape based on the new EKC model in the eastern and central areas,though not in the western area.In considering the moderating role of financial development based on the new EKC model,we find that the increase of financial depth will cause the EKC inflection point to shift to the left on the national scale and in the eastern region,while the effect of the financial breadth will be largely insignificant.With regard to the central area,both the breadth and the depth of financial development will significantly shift the inflection point to the right,delaying the arrival of the EKC inflection point.Therefore,the local authority of each area should formulate differentiated financial development policies to promote the early arrival of the EKC inflection point.
文摘During studying the heat capacity of metals and brightening more than the original Lena’s image, the temperature increasing term obtained in binomial expansion is transformed into the adsorption increasing term and thereafter we have derived the total adsorption rate equation with it. In the first layer the quantization does not occur and from 2<sup>nd</sup> layer to n<sup>th</sup> layer the quantization occurs. So as to get the total adsorption rate equation we add the quantized terms of the second to n<sup>th</sup> layers to the non-quantized term of the first layer. All terms are based on the unit surface sites. Instead of the unit surface sites, the new adsorption site term appears in the denominator of the adsorption equation. Hence the adsorption equations come out much better than BET equation. The surface area is also calculated through the integration of the adsorption isotherm equation excluding the first layer adsorption equation from the inflection point to the wanted relative pressure.
基金This work was financially supported by the National Basic Research Program of China(973)Program,‘study on water injection in fracture-cave carbonate reservoir’(2011CB201000).
文摘Pore volume of Cumulative water injection is one of the factors for evaluating water flood effect in a water flood oil field.In previous study,there were limited lab studies for evaluating oil displacement efficiency.A method to characterize the distribution of pore volume of cumulative water injection is proposed in this paper,and it is verified by a five-spot water flooding streamline simulation model.The logarithmic relation between pore volume of cumulative water injection and water saturation is established by regression.An inflection point and limit point of cumulative water injection pore volume are identified.Current simulation model indicates inflection point appears after 2e5 pore volume(PV)injection,and limit point appears after 15e25 PV injection.Both inflection and limit point vary in different regions of reservoir.
基金the Anhui Province Quality and Technical Supervision Science and Technology Plan Project(No.2018AHQT26)。
文摘In order to achieve accurate non-contact measurement of the mechanical wear of the elevator traction sheave grooves,a wear detection system based on machine vision was developed.The industrial camera was fixed through a special fixture,and the images were collected by aligning each groove.In this paper,target groove is extracted based on normalized correlation coefficient matching.Corner points are extracted to describe the contour of the traction wheel groove.The inflection point of the wheel groove boundary is determined by straight boundary fitting,and the amount of rope groove wear is calculated by geometric knowledge.Based on the physical model structure,a mathematical model is established to eliminate the unavoidable occlusion error.The experimental results show that this system can carry out an accurate quantitative analysis and realize an accurate measurement of the wear of the traction sheave rope groove with convenience and accuracy.