In the evolution of economic growth drivers, technology gaps are a key variable that determines the efficiency of resource allocation. Analysis of an optimal resource allocation path based on an extended endogenous gr...In the evolution of economic growth drivers, technology gaps are a key variable that determines the efficiency of resource allocation. Analysis of an optimal resource allocation path based on an extended endogenous growth model reveals that economic growth drivers evolve from productive investment to R&D investment and a shift from imitation to innovation. Empirical analysis based on China's provincial-level panel data suggests that the effect of productive investment and R&D investment, as well as innovation and imitation, on economic growth and technological progress varies greatly among regions of disparate technology levels. As a late-starting country, China should properly allocate resources between productive investment and R&D investment, and between imitational investment and innovative investment while advancing the transformation of economic growth patterns on a differentiated basis in light of regional technology disparities.展开更多
Using sequential DEA methodology, this paper has measured the variations in the technological gaps of China's industrial sectors compared with the world frontiers of technology. From a temporal dimension, variations ...Using sequential DEA methodology, this paper has measured the variations in the technological gaps of China's industrial sectors compared with the world frontiers of technology. From a temporal dimension, variations in the technological gaps of China's industrial sectors can be divided into the following four stages: slight abatement of technological gaps between 1985 and 1992, and between 1999 and 2007; stagnation in the variation of technological gaps between 1994 and 1999; and continuous abatement of technological gaps between 2008 and 2009. From the industry dimension, by 2009, 58.8% of China's industrial sectors had gradually reached or approached the world frontiers of technology; 29.4% of industrial sectors had experienced technological improvements but still lagged far behind the world frontiers of technology; 11.8% of industrial sectors significantly lagged behind the world frontiers of technology.展开更多
By introducing a knowledge production function which combines both foreign technology imports and domestic research and development (R&D) expenditure into an endogenous technological progress model, this paper exam...By introducing a knowledge production function which combines both foreign technology imports and domestic research and development (R&D) expenditure into an endogenous technological progress model, this paper examines the mechanism that determines enterprises' R&D intensity in developing countries, and explores how factors such as technological gap, technology absorptive capacity, innovation environment and innovation ability would impact Chinese enterprises'decision made on R&D intensity. Our results suggest that technological gap has no significant single impact on enterprises'R&D intensity, but rather influences enterprises'decision on R&D jointly with other factors such as degree of openness and human capital. A relative fall in efficiency of technology imitation recently has a negative effect on total R&D intensity but helps to promote enterprises' independent R&D. In addition, among factors related to R&D innovation environment, industrial R&D intensity has a significantly positive impact on enterprises' independent R&D intensity, while regional economies of scale, proportion of large enterprises and proportion of government R&D investment have some certain negative impacts.展开更多
Recently,the Institute for Radiological protection and Nuclear Safety(IRSN)has launched VSEAL(Vertical SEALing)project to investigate the impact of gas migration on the long-term performance of bentonite based vertica...Recently,the Institute for Radiological protection and Nuclear Safety(IRSN)has launched VSEAL(Vertical SEALing)project to investigate the impact of gas migration on the long-term performance of bentonite based vertical sealing systems(VSS).The first VSEAL in situ test was emplaced in IRSN’s Underground Research Laboratory(URL)in Tournemire(France)in 2019 and was equipped with 76 wired and wireless sensors.The test is still in progress,but the collected set of data provides already valuable information of the hydro-mechanical behavior of VSS during hydration.The swelling core consists of a mixture of highdensity pellets and powder of MX80 bentonite in a ratio of 80/20(in dry mass).An innovative method was adopted to drill a 1-m diameter and w10-m deep shaft in order to minimize the rock perturbation at the sidewalls.Because a specific protocol was adopted to install the bentonite mixture together with a careful characterization of the core during construction,VSEAL 1 constitutes the unique in situ sealing test with a well-known initial structural distribution of the pellets and the powder.Some heterogeneities occurred within the experiment during the installation process:a damaged zone developed around the shaft walls due to the interruption of the installation operations caused by COVID19 lockdown in France;a technological gap with a variable thickness between the last pellets layer and the top confining lid and a heterogeneous distribution of the bentonite powder at some layers inducing large inter pellets voids close to the bentonite-rock interface.Artificially injected water volume,relative humidity,water content and swelling pressure in both radial and axial directions were monitored.Comparison of the results showed that the presence of installation-induced heterogeneities led to the generation of preferential flow paths that influenced the swelling pressure evolution at radial and axial directions.展开更多
Taking the advanced technology of the foreign firm into account, a mixed duopoly three-stage game model is established in the context of research and development(RD)investment subsidies and product subsidies for dom...Taking the advanced technology of the foreign firm into account, a mixed duopoly three-stage game model is established in the context of research and development(RD)investment subsidies and product subsidies for domestic firms provided by the government, and the RD subsidy policy of domestic firms in competition with foreign firms is analyzed.The equilibrium output, RD investment of the domestic firm, social welfare and the value of government subsidies are derived, in the case of the two policies, RD investment subsidies and product subsidies for domestic firms, provided by the government. The results show that, the equilibrium output and the optimal social welfare under the RD investment subsidy policy are both less than those under the product subsidy policy; the optimal RD investment under the RD investment subsidy policy is less than that under the product subsidy policy; and the RD product subsidy has a more obvious incentive effect on firm RD investment. Under the background of the leading edge of technology of foreign firms, the product subsidy policy drawn up by the government to encourage RD innovation of domestic firms is more effective than the RD investment subsidy policy.展开更多
The study was carried out to improve farmers’ awareness, enhance the adoption of full package sorghum production technologies. The large-scale demonstration was implemented at Gololcha woreda of Arsi zone for one yea...The study was carried out to improve farmers’ awareness, enhance the adoption of full package sorghum production technologies. The large-scale demonstration was implemented at Gololcha woreda of Arsi zone for one year (2019/2020) using Melkam variety. The demonstration was implemented in three kebeles and a total of 100 hectares of land was covered by participating 117 household heads (farmers) out of which 12 of them were women-headed. In the demonstration farmers contributed a land size of 0.25 hectares (the minimum) and 2 hectares of land (maximum). Totally, from the demonstration 4030 quintals of sorghum were harvested with 42.3 quintals per hectare average productivity. The yield obtained by farmers practices w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> 18.23 q</span><span style="font-family:""><span style="font-family:Verdana;">·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which is lower as compared to the average yield obtained by large scale demonstration. The technology gap (TG) was 15.70 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which indicated that technologies have not been adopted. Extension gap was 24.07 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and this result indicated that the extension approach should be </span></span><span style="font-family:Verdana;">more </span><span style="font-family:Verdana;">strengthen</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;">. It has been ascertained that </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">Melkam</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> variety is the best fitted variety and promotion of improved sorghum technologies via large scale demonstration has show</span><span style="font-family:Verdana;">n</span><span style="font-family:Verdana;"> a considerable yield increment as compared to farmers practices. According to the farmers’ trait preference, Melkam variety was preferred by farmers because of its high yielding, consumption quality, early maturity, palatability, and drought-tolerant traits respectively. For sustainable production of improved sorghum technologies, the seed system should be taken into consideration to deliver the seed supply for the entire sorghum producers.展开更多
The teaching-learning process may have several obstacles; one of those would be a cultural situation of students. When the author refers to cultural situation, the author means the language or dialect that they speak....The teaching-learning process may have several obstacles; one of those would be a cultural situation of students. When the author refers to cultural situation, the author means the language or dialect that they speak. In the state of Puebla, Mexico, there are primary schools where the courses are taught to students who do not speak Spanish and they only speak their own dialect. On the other hand, the use of information and communication technologies in primary schools in Puebla is a fact but a main concern in schools is that the languages in which they are operated are Spanish. To analyze this situation, the author finds that turns out to be very important and with a negative effect on both the implementation and acceptance of a multimedia program in these schools, generating a technological gap between students. The government efforts are decimated because of this cultural divide prevalent in many communities in the state of Puebla and the increase of this situation when considering the illiterate population.展开更多
A novel broadband metasurface (MTS) antenna array with high front-to-back ratio (FBR) is proposed for 28 GHz millimeter-wave applications. With slot pairs loaded on patch cells, an aperturecoupled slotted-mushroom MTS...A novel broadband metasurface (MTS) antenna array with high front-to-back ratio (FBR) is proposed for 28 GHz millimeter-wave applications. With slot pairs loaded on patch cells, an aperturecoupled slotted-mushroom MTS antenna is designed to obtain broadband radiation characteristicswith a compact size. To suppress the backward radiation of this antenna, the printed ridge gapwaveguide (PRGW) technology with a perfect magnetic conductor (PMC) shielding made ofmushroom unit-cells underneath the microstrip feeding line is applied. On this basis, a 4×4 MTSantenna array with the PRGW feed network is developed. Simulated results show that the FBR canbe highly improved by over 16 dB within the entire bandwidth. To validate the design, a prototypeof the proposed antenna is fabricated. Measured results show that an FBR greater than 28 dB canbe obtained over a 24% impedance bandwidth (from 24.9 GHz to 31.7 GHz) with the reflectioncoefficient less than 10 dB. The measured antenna gain ranges from 17 dBi to 19.2 dBi and thecorresponding measured aperture efficiencies are 35% and 45.6%. The measured results alsosuggest that the proposed MTS antenna possesses -35 dB cross-polarization level and stable radiation patterns. In addition, the proposed antenna remains a very low profile of 1.7 mm (0.17λ_(0) at28 GHz). All the achieved features indicate that the proposed MTS antenna is an importantcandidate for B5G and 6G wireless communication.展开更多
In China,the target setting on loading rate of domestic equipment for shipbuilding industry has not been studied from a perspective of an optimization problem.Based on the constant elasticity of substitution productio...In China,the target setting on loading rate of domestic equipment for shipbuilding industry has not been studied from a perspective of an optimization problem.Based on the constant elasticity of substitution production function,a localization rate model for shipbuilding industry is established to investigate the government's trade-off between the interest of shipbuilding industry and that of ship supporting industry and to set the optimal localization rate.The results show that the market capacity has a significant effect on localization rate.In particular,when the market capacity is too small,the optimal localization rate is zero.When the market capacity is too large,the optimal localization rate is one.When the market capacity is in a certain range,a regular localization rate target exists.Moreover,the optimal localization rate could be affected by the technology gap and prices of domestic and foreign marine equipments.When the market capacity is large and the technology gap between domestic and foreign marine equipments is small,or the price of domestic equipment is too low,a higher localization rate target should be set.Finally,the substitutability of domestic and foreign equipments affects the optimal set of localization rate.If the substitutability of domestic and foreign equipments is too low,the improvement of localization rate caused by technological progress or price reduction of domestic equipment will be limited.This study provides several significant policy suggestions on dynamic adjustment of localization rate,classified implementation,and core technology mastering.展开更多
文摘In the evolution of economic growth drivers, technology gaps are a key variable that determines the efficiency of resource allocation. Analysis of an optimal resource allocation path based on an extended endogenous growth model reveals that economic growth drivers evolve from productive investment to R&D investment and a shift from imitation to innovation. Empirical analysis based on China's provincial-level panel data suggests that the effect of productive investment and R&D investment, as well as innovation and imitation, on economic growth and technological progress varies greatly among regions of disparate technology levels. As a late-starting country, China should properly allocate resources between productive investment and R&D investment, and between imitational investment and innovative investment while advancing the transformation of economic growth patterns on a differentiated basis in light of regional technology disparities.
文摘Using sequential DEA methodology, this paper has measured the variations in the technological gaps of China's industrial sectors compared with the world frontiers of technology. From a temporal dimension, variations in the technological gaps of China's industrial sectors can be divided into the following four stages: slight abatement of technological gaps between 1985 and 1992, and between 1999 and 2007; stagnation in the variation of technological gaps between 1994 and 1999; and continuous abatement of technological gaps between 2008 and 2009. From the industry dimension, by 2009, 58.8% of China's industrial sectors had gradually reached or approached the world frontiers of technology; 29.4% of industrial sectors had experienced technological improvements but still lagged far behind the world frontiers of technology; 11.8% of industrial sectors significantly lagged behind the world frontiers of technology.
基金This study has been supported by “Research on Chinese Enterprises' R&D Efficiency and Its Influencing Factors” under National Natural Science Foundation of China (70902002), “Research on Beijing Enterprises' R&D Efficiency and Its Influencing Factors: Analysis Based on Cutting-edge” under Beijing Natural Science Foundation (9102019), together with “Program for New Century Excellent Talents in University” under the Ministry of Education and Key Project under the “211 Project” for Central University of Finance and Economics.
文摘By introducing a knowledge production function which combines both foreign technology imports and domestic research and development (R&D) expenditure into an endogenous technological progress model, this paper examines the mechanism that determines enterprises' R&D intensity in developing countries, and explores how factors such as technological gap, technology absorptive capacity, innovation environment and innovation ability would impact Chinese enterprises'decision made on R&D intensity. Our results suggest that technological gap has no significant single impact on enterprises'R&D intensity, but rather influences enterprises'decision on R&D jointly with other factors such as degree of openness and human capital. A relative fall in efficiency of technology imitation recently has a negative effect on total R&D intensity but helps to promote enterprises' independent R&D. In addition, among factors related to R&D innovation environment, industrial R&D intensity has a significantly positive impact on enterprises' independent R&D intensity, while regional economies of scale, proportion of large enterprises and proportion of government R&D investment have some certain negative impacts.
文摘Recently,the Institute for Radiological protection and Nuclear Safety(IRSN)has launched VSEAL(Vertical SEALing)project to investigate the impact of gas migration on the long-term performance of bentonite based vertical sealing systems(VSS).The first VSEAL in situ test was emplaced in IRSN’s Underground Research Laboratory(URL)in Tournemire(France)in 2019 and was equipped with 76 wired and wireless sensors.The test is still in progress,but the collected set of data provides already valuable information of the hydro-mechanical behavior of VSS during hydration.The swelling core consists of a mixture of highdensity pellets and powder of MX80 bentonite in a ratio of 80/20(in dry mass).An innovative method was adopted to drill a 1-m diameter and w10-m deep shaft in order to minimize the rock perturbation at the sidewalls.Because a specific protocol was adopted to install the bentonite mixture together with a careful characterization of the core during construction,VSEAL 1 constitutes the unique in situ sealing test with a well-known initial structural distribution of the pellets and the powder.Some heterogeneities occurred within the experiment during the installation process:a damaged zone developed around the shaft walls due to the interruption of the installation operations caused by COVID19 lockdown in France;a technological gap with a variable thickness between the last pellets layer and the top confining lid and a heterogeneous distribution of the bentonite powder at some layers inducing large inter pellets voids close to the bentonite-rock interface.Artificially injected water volume,relative humidity,water content and swelling pressure in both radial and axial directions were monitored.Comparison of the results showed that the presence of installation-induced heterogeneities led to the generation of preferential flow paths that influenced the swelling pressure evolution at radial and axial directions.
基金The Special Project of Innovative Methods and Work Funded by Ministry of National Science and Technology of China(No.2013IM030600)
文摘Taking the advanced technology of the foreign firm into account, a mixed duopoly three-stage game model is established in the context of research and development(RD)investment subsidies and product subsidies for domestic firms provided by the government, and the RD subsidy policy of domestic firms in competition with foreign firms is analyzed.The equilibrium output, RD investment of the domestic firm, social welfare and the value of government subsidies are derived, in the case of the two policies, RD investment subsidies and product subsidies for domestic firms, provided by the government. The results show that, the equilibrium output and the optimal social welfare under the RD investment subsidy policy are both less than those under the product subsidy policy; the optimal RD investment under the RD investment subsidy policy is less than that under the product subsidy policy; and the RD product subsidy has a more obvious incentive effect on firm RD investment. Under the background of the leading edge of technology of foreign firms, the product subsidy policy drawn up by the government to encourage RD innovation of domestic firms is more effective than the RD investment subsidy policy.
文摘The study was carried out to improve farmers’ awareness, enhance the adoption of full package sorghum production technologies. The large-scale demonstration was implemented at Gololcha woreda of Arsi zone for one year (2019/2020) using Melkam variety. The demonstration was implemented in three kebeles and a total of 100 hectares of land was covered by participating 117 household heads (farmers) out of which 12 of them were women-headed. In the demonstration farmers contributed a land size of 0.25 hectares (the minimum) and 2 hectares of land (maximum). Totally, from the demonstration 4030 quintals of sorghum were harvested with 42.3 quintals per hectare average productivity. The yield obtained by farmers practices w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> 18.23 q</span><span style="font-family:""><span style="font-family:Verdana;">·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which is lower as compared to the average yield obtained by large scale demonstration. The technology gap (TG) was 15.70 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which indicated that technologies have not been adopted. Extension gap was 24.07 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and this result indicated that the extension approach should be </span></span><span style="font-family:Verdana;">more </span><span style="font-family:Verdana;">strengthen</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;">. It has been ascertained that </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">Melkam</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> variety is the best fitted variety and promotion of improved sorghum technologies via large scale demonstration has show</span><span style="font-family:Verdana;">n</span><span style="font-family:Verdana;"> a considerable yield increment as compared to farmers practices. According to the farmers’ trait preference, Melkam variety was preferred by farmers because of its high yielding, consumption quality, early maturity, palatability, and drought-tolerant traits respectively. For sustainable production of improved sorghum technologies, the seed system should be taken into consideration to deliver the seed supply for the entire sorghum producers.
文摘The teaching-learning process may have several obstacles; one of those would be a cultural situation of students. When the author refers to cultural situation, the author means the language or dialect that they speak. In the state of Puebla, Mexico, there are primary schools where the courses are taught to students who do not speak Spanish and they only speak their own dialect. On the other hand, the use of information and communication technologies in primary schools in Puebla is a fact but a main concern in schools is that the languages in which they are operated are Spanish. To analyze this situation, the author finds that turns out to be very important and with a negative effect on both the implementation and acceptance of a multimedia program in these schools, generating a technological gap between students. The government efforts are decimated because of this cultural divide prevalent in many communities in the state of Puebla and the increase of this situation when considering the illiterate population.
基金National Natural Science Foundation of China(62288101,62001342)National Key Research and Development Program of China(2021YFA1401001)+1 种基金Key Research and Development Program of Shaanxi(2021TD-07)Fundamental Research Funds for the Central Universities(20103224952).
文摘A novel broadband metasurface (MTS) antenna array with high front-to-back ratio (FBR) is proposed for 28 GHz millimeter-wave applications. With slot pairs loaded on patch cells, an aperturecoupled slotted-mushroom MTS antenna is designed to obtain broadband radiation characteristicswith a compact size. To suppress the backward radiation of this antenna, the printed ridge gapwaveguide (PRGW) technology with a perfect magnetic conductor (PMC) shielding made ofmushroom unit-cells underneath the microstrip feeding line is applied. On this basis, a 4×4 MTSantenna array with the PRGW feed network is developed. Simulated results show that the FBR canbe highly improved by over 16 dB within the entire bandwidth. To validate the design, a prototypeof the proposed antenna is fabricated. Measured results show that an FBR greater than 28 dB canbe obtained over a 24% impedance bandwidth (from 24.9 GHz to 31.7 GHz) with the reflectioncoefficient less than 10 dB. The measured antenna gain ranges from 17 dBi to 19.2 dBi and thecorresponding measured aperture efficiencies are 35% and 45.6%. The measured results alsosuggest that the proposed MTS antenna possesses -35 dB cross-polarization level and stable radiation patterns. In addition, the proposed antenna remains a very low profile of 1.7 mm (0.17λ_(0) at28 GHz). All the achieved features indicate that the proposed MTS antenna is an importantcandidate for B5G and 6G wireless communication.
基金supported in part by National Key R&D Program of China(2019YFB2101804)the National Natural Science Foundation of China(NSFC)under Grants Nos.71725002,72021001,U21B20102,72174186.
文摘In China,the target setting on loading rate of domestic equipment for shipbuilding industry has not been studied from a perspective of an optimization problem.Based on the constant elasticity of substitution production function,a localization rate model for shipbuilding industry is established to investigate the government's trade-off between the interest of shipbuilding industry and that of ship supporting industry and to set the optimal localization rate.The results show that the market capacity has a significant effect on localization rate.In particular,when the market capacity is too small,the optimal localization rate is zero.When the market capacity is too large,the optimal localization rate is one.When the market capacity is in a certain range,a regular localization rate target exists.Moreover,the optimal localization rate could be affected by the technology gap and prices of domestic and foreign marine equipments.When the market capacity is large and the technology gap between domestic and foreign marine equipments is small,or the price of domestic equipment is too low,a higher localization rate target should be set.Finally,the substitutability of domestic and foreign equipments affects the optimal set of localization rate.If the substitutability of domestic and foreign equipments is too low,the improvement of localization rate caused by technological progress or price reduction of domestic equipment will be limited.This study provides several significant policy suggestions on dynamic adjustment of localization rate,classified implementation,and core technology mastering.