Sharing economy developed soon in China recently.On the basis of analyzing technology spillover between a technologically advanced nation(country)and a less developed one,a technology catching-up model of technologica...Sharing economy developed soon in China recently.On the basis of analyzing technology spillover between a technologically advanced nation(country)and a less developed one,a technology catching-up model of technological capacity and path dependence is proposed based on Verspagen mode.The proposed model can explain how a less developed nation(country)can catch up the advanced one.It is not only to improve its own technological capacity,but also whether it could bread“the locking”of path dependence.For the less developed nation(country),the“conscious behavior”of economic body cannot be ignored to achieve the evolution from path dependence to path creation.Thus,the less developed nation(country)should cultivate the technology ability,furthermore,the creative realization and ability,which could break away the negative impact of technology to path dependence,and catch up the advanced one.展开更多
The congenital yield reduction caused by miss-seeding in spoon-type seed-metering device of small and medium-sized potato planter is huge.Based on the physical mechanism of different measured capacitance values betwee...The congenital yield reduction caused by miss-seeding in spoon-type seed-metering device of small and medium-sized potato planter is huge.Based on the physical mechanism of different measured capacitance values between two fixed capacitor plates with different media,a miss-seeding detection scheme based on a spatial capacitance sensor is proposed first.A simple and efficient spatial capacitance sensor that can obtain as large capacitance measurement value as possible is designed,and a dual CPU coordinated seed-monitoring and compensation control system architecture is adopted.AD7745 is selected for the capacitance measure of the spatial capacitance sensor,and the code of grating encoder is also recorded at the same time.Thereby,when each potato spoon passing through the space surrounded by the capacitor plates,the maximum net capacitance fluctuation and its corresponding position can be acquired.A suitable threshold can distinguish between normal-seeding and miss-seeding effectively.Moreover,it should be emphasized that,this monitoring system only requires one monitoring point.Then,based on obtained information,an improved miss-seeding catching-up compensation plan is put forward.By utilizing the powerful memory capability of the CPU,this system does not need to complete compensation immediately after the miss-seeding identification.Instead,the miss-seeding information and the location of the accident can be just marked in advance,and only when the opportunity arrives,can the miss-seeding catching-up compensation be truly executed.In this way,the position of the seed-monitoring points can be free from restriction,and the control strategy can therefore be significantly simplified.The soil tank test data showed that,the identification accuracy of the miss-seeding detection system was not less than 94%.When the seed-metering chain speeds are 0.2,0.3,and 0.4 m/s,the average success rates of the miss-seeding compensation system are 94.32%,83.65%,and 75.00%,respectively.The final miss-seeding rate can be below 3%,and the average deviation compensation rate was not higher than 30%,the miss-seeding was suppressed significantly.This system is a beneficial try in the non-photoelectric detection field and low complexity miss-seeding compensation for potato seeding.展开更多
Measuring the lifecycle of low-carbon energy technologies is critical to better understanding the innovation pattern.However,previous studies on lifecycle either focus on technical details or just provide a general ov...Measuring the lifecycle of low-carbon energy technologies is critical to better understanding the innovation pattern.However,previous studies on lifecycle either focus on technical details or just provide a general overview,due to the lack of connection with innovation theories.This article attempts to fill this gap by analyzing the lifecycle from a combinatorial innovation perspective,based on patent data of ten low-carbon energy technologies in China from 1999 to 2018.The problem of estimating lifecycle stages can be transformed into analyzing the rise and fall of knowledge combinations.By building the international patent classification(IPC)co-occurrence matrix,this paper demonstrates the lifecycle evolution of technologies and develops an efficient quantitative index to define lifecycle stages.The mathematical measurement can effectively reflect the evolutionary pattern of technologies.Additionally,this article relates the macro evolution of lifecycle to the micro dynamic mechanism of technology paradigms.The sign of technology maturity is that new inventions tend to follow the patterns established by prior ones.Following this logic,this paper identifies different trends of paradigms in each technology field and analyze their transition.Furthermore,catching-up literature shows that drastic transformation of technology paradigms may open“windows of opportunity”for laggard regions.From the results of this paper,it is clear to see that latecomers can catch up with pioneers especially when there is a radical change in paradigms.Therefore,it is important for policy makers to capture such opportunities during the technology lifecycle and coordinate regional innovation resources.展开更多
The yield reduction caused by miss-seeding in potato mechanized sowing is astonishing.The existing research always needs to install a spare compensator on the original seed-metering device.Therefore,problems of comple...The yield reduction caused by miss-seeding in potato mechanized sowing is astonishing.The existing research always needs to install a spare compensator on the original seed-metering device.Therefore,problems of complex planter structure and compensated potato seed poor landing accuracy need to be solved urgently.Consequently,a scheme of integrated seeding and compensating potato planter based on one-way clutch is proposed in this paper.Based on a basic‘improved one raw potato planter’and the working principle of one-way clutch,power of seed-metering system is provided through main power transmission one-way clutch by land wheels when the system works properly.However,when miss-seeding detection system with infrared radiation deciding that a miss-seeding incident has happened,the seed-metering power will be replaced by a compensatory motor through compensating one-way clutch at a higher speed.Thus,the idea of catching-up compensation can be realized.After compensation is completed,the system controller disconnects the compensatory motor,and the seed-metering power will naturally switch to the land wheels again.A prototype based on this idea was built.Field tests showed that the accuracy of seed monitoring system is more than 99.9%;the adoption of catching-up compensation scheme does not bring about empty spoon rate rise significantly.Within the range of 0.2-0.8 m/s of the seed-metering chain speed,although the average success compensation rate decreases evidently with the increase of the chain speed,the success compensation rate is still near 70%even at 0.8 m/s,the vast majority of missed seeds can be compensated effectively.展开更多
基金Beijing Municipal Education Commission Social Science Program General Project of China(SM201811417008)Premium Funding Project for Academic Human Resources Development in Beijing Union University(BPHR2017DS14)+2 种基金Education Teaching Research and Reform Project of Beijing Union University(JJ2018Q018)Social Science Foundation of Beijing(17GLC050)National Social Science Foundation of China(17BGL265).
文摘Sharing economy developed soon in China recently.On the basis of analyzing technology spillover between a technologically advanced nation(country)and a less developed one,a technology catching-up model of technological capacity and path dependence is proposed based on Verspagen mode.The proposed model can explain how a less developed nation(country)can catch up the advanced one.It is not only to improve its own technological capacity,but also whether it could bread“the locking”of path dependence.For the less developed nation(country),the“conscious behavior”of economic body cannot be ignored to achieve the evolution from path dependence to path creation.Thus,the less developed nation(country)should cultivate the technology ability,furthermore,the creative realization and ability,which could break away the negative impact of technology to path dependence,and catch up the advanced one.
基金support of the Industrial support plan of the Gansu Provincial Department of Education(Grant No.2023CYZC-42)the National Natural Science Foundation of China(Grant No.52165028)the Key Scientific and the Technological Program of Gansu Province(Grant No.22ZD6NA046).
文摘The congenital yield reduction caused by miss-seeding in spoon-type seed-metering device of small and medium-sized potato planter is huge.Based on the physical mechanism of different measured capacitance values between two fixed capacitor plates with different media,a miss-seeding detection scheme based on a spatial capacitance sensor is proposed first.A simple and efficient spatial capacitance sensor that can obtain as large capacitance measurement value as possible is designed,and a dual CPU coordinated seed-monitoring and compensation control system architecture is adopted.AD7745 is selected for the capacitance measure of the spatial capacitance sensor,and the code of grating encoder is also recorded at the same time.Thereby,when each potato spoon passing through the space surrounded by the capacitor plates,the maximum net capacitance fluctuation and its corresponding position can be acquired.A suitable threshold can distinguish between normal-seeding and miss-seeding effectively.Moreover,it should be emphasized that,this monitoring system only requires one monitoring point.Then,based on obtained information,an improved miss-seeding catching-up compensation plan is put forward.By utilizing the powerful memory capability of the CPU,this system does not need to complete compensation immediately after the miss-seeding identification.Instead,the miss-seeding information and the location of the accident can be just marked in advance,and only when the opportunity arrives,can the miss-seeding catching-up compensation be truly executed.In this way,the position of the seed-monitoring points can be free from restriction,and the control strategy can therefore be significantly simplified.The soil tank test data showed that,the identification accuracy of the miss-seeding detection system was not less than 94%.When the seed-metering chain speeds are 0.2,0.3,and 0.4 m/s,the average success rates of the miss-seeding compensation system are 94.32%,83.65%,and 75.00%,respectively.The final miss-seeding rate can be below 3%,and the average deviation compensation rate was not higher than 30%,the miss-seeding was suppressed significantly.This system is a beneficial try in the non-photoelectric detection field and low complexity miss-seeding compensation for potato seeding.
基金supported by the Natural Science Foundation of China(Grants No.42122006,42471187).
文摘Measuring the lifecycle of low-carbon energy technologies is critical to better understanding the innovation pattern.However,previous studies on lifecycle either focus on technical details or just provide a general overview,due to the lack of connection with innovation theories.This article attempts to fill this gap by analyzing the lifecycle from a combinatorial innovation perspective,based on patent data of ten low-carbon energy technologies in China from 1999 to 2018.The problem of estimating lifecycle stages can be transformed into analyzing the rise and fall of knowledge combinations.By building the international patent classification(IPC)co-occurrence matrix,this paper demonstrates the lifecycle evolution of technologies and develops an efficient quantitative index to define lifecycle stages.The mathematical measurement can effectively reflect the evolutionary pattern of technologies.Additionally,this article relates the macro evolution of lifecycle to the micro dynamic mechanism of technology paradigms.The sign of technology maturity is that new inventions tend to follow the patterns established by prior ones.Following this logic,this paper identifies different trends of paradigms in each technology field and analyze their transition.Furthermore,catching-up literature shows that drastic transformation of technology paradigms may open“windows of opportunity”for laggard regions.From the results of this paper,it is clear to see that latecomers can catch up with pioneers especially when there is a radical change in paradigms.Therefore,it is important for policy makers to capture such opportunities during the technology lifecycle and coordinate regional innovation resources.
基金We are grateful for the National Natural Science Foundation of China(51765004)the support of Science and Technology Innovation Fund of Gansu Agricultural University(GAU-QDFC-2019-10)+1 种基金the Fuxi Talent Project of Gansu Agricultural University(GAUFX-02J01)and the Sheng Tong Sheng Science and Technology Innovation Fund of Gansu Agricultural University(GSAU-STS-1731).
文摘The yield reduction caused by miss-seeding in potato mechanized sowing is astonishing.The existing research always needs to install a spare compensator on the original seed-metering device.Therefore,problems of complex planter structure and compensated potato seed poor landing accuracy need to be solved urgently.Consequently,a scheme of integrated seeding and compensating potato planter based on one-way clutch is proposed in this paper.Based on a basic‘improved one raw potato planter’and the working principle of one-way clutch,power of seed-metering system is provided through main power transmission one-way clutch by land wheels when the system works properly.However,when miss-seeding detection system with infrared radiation deciding that a miss-seeding incident has happened,the seed-metering power will be replaced by a compensatory motor through compensating one-way clutch at a higher speed.Thus,the idea of catching-up compensation can be realized.After compensation is completed,the system controller disconnects the compensatory motor,and the seed-metering power will naturally switch to the land wheels again.A prototype based on this idea was built.Field tests showed that the accuracy of seed monitoring system is more than 99.9%;the adoption of catching-up compensation scheme does not bring about empty spoon rate rise significantly.Within the range of 0.2-0.8 m/s of the seed-metering chain speed,although the average success compensation rate decreases evidently with the increase of the chain speed,the success compensation rate is still near 70%even at 0.8 m/s,the vast majority of missed seeds can be compensated effectively.
