American economist Funon brought forward the theory of industry production lite cycle phases. But from the perspective of China, the developed regions are sill developed, while the low developed regions are still low ...American economist Funon brought forward the theory of industry production lite cycle phases. But from the perspective of China, the developed regions are sill developed, while the low developed regions are still low developed. The factors are as below, relation with people and relation region of the original investment place,＇ the problem of sunk cost, the network of production and cooperation constructed, the weakness of establishment in lower process region, narrow market capability and low degree of market of west and the low work efficiency of government of low grade region Ineffective conduction system of investment information.展开更多
This paper studies Whether the managerial overconfidence have any impact on the Cost management （Characterized by the degree of the Costs Stickiness ） .Using the ample of the A-share listed companies between 2007-20...This paper studies Whether the managerial overconfidence have any impact on the Cost management （Characterized by the degree of the Costs Stickiness ） .Using the ample of the A-share listed companies between 2007-2011 in China, We document that SG＆A cost stickiness decreases in the degree of overconfidence. The further studies show the negative relation is more significant in the state-owned listed companies,which proved our speculation that the manager will cut expenses avoiding significant decline in performance when the sales decline in the state-owned listed company.展开更多
CEO compensation stickiness represents an important indicator to measure the effectiveness of compensation contracts.This study uses CEO career experience data and compensation stickiness data from Shanghai and Shenzh...CEO compensation stickiness represents an important indicator to measure the effectiveness of compensation contracts.This study uses CEO career experience data and compensation stickiness data from Shanghai and Shenzhen A-share listed companies from 2015 to 2020 to investigate the compensation contracts’effectiveness of CEOs with diverse career experiences.The findings are as follows:1)Compensation stickiness is more pronounced for CEOs with diverse career experiences.According to the mechanism test,these CEOs with diverse career experiences can obtain compensation incentives by reducing corporate uncertainty perception and improving total factor productivity.This approach leads to increased compensation stickiness and the effectiveness of compensation contracts.CEOs with diverse career experiences may receive excess compensation by raising agency costs,which intensifies compensation stickiness and weakens the effectiveness of compensation contracts.2)Compensation stickiness of CEOs with diverse career experiences is more significant in companies with lower investor protection,which brings about less effective compensation contracts.In contrast,in companies with higher diversification,the compensation stickiness of CEOs with diverse career experiences is more significant,which delivers more effective compensation contracts.The conclusions deepen the research of CEO compensation contracts and provide a helpful reference for CEO compensation management practices.展开更多
The deep integration of digital technology with the real economy has reconstructed production systems.We explore the impact of digital technology on the resource allocation behavior and efficiency of manufacturing ent...The deep integration of digital technology with the real economy has reconstructed production systems.We explore the impact of digital technology on the resource allocation behavior and efficiency of manufacturing enterprises.Using a sample of Chinese A-share listed manufacturing firms over the 2010–2021 period,we find that digital technology alleviates cost stickiness,especially in enterprises with a high level of Industrial Internet platform usage.This effect occurs by optimizing the labor force structure and improving the economic benefits of labor capital investment.Heterogeneity analysis shows that this effect is pronounced in enterprises with high levels of labor intensity and business complexity.Our findings shed new light on the consequences and mechanism of enterprise cost optimization that is driven by technologydriven reforms.展开更多
Cost and expense stickiness is an important issue in accounting and economics research, and the literature has shown that cost stickiness cannot be separated from managers' motivations. In this paper, we examine t...Cost and expense stickiness is an important issue in accounting and economics research, and the literature has shown that cost stickiness cannot be separated from managers' motivations. In this paper, we examine the effects that earnings management has on expense stickiness. Defining small positive profits or small earnings increases as earnings management, we observe significant expense stickiness in the non-earnings-management sub-sample, compared with the earnings-management sub-sample. When we divide expenses into R&D,advertising and other general expenses, we find that managers control expenses mainly by decreasing general expenses. We further examine corporate governance's effect on expense stickiness. Using factor analysis, we extract eight main factors and find that good corporate governance reduces expense stickiness. Finally, we investigate the interaction effects of earnings management and corporate governance on expense stickiness. The empirical results show that good corporate governance can further reduce cost stickiness,although its effect is not as strong as that of earnings management.展开更多
Do supply chain audits have real effects?We focus on the effect of shared auditors in the supply chain on corporate cost stickiness.When a supplier shares auditors with its customers,the shared auditors provide inform...Do supply chain audits have real effects?We focus on the effect of shared auditors in the supply chain on corporate cost stickiness.When a supplier shares auditors with its customers,the shared auditors provide informational advantages for suppliers’managers,thus revising their optimistic or pessimistic expectations and influencing suppliers’cost stickiness.Using a sample of Chinese A-share listed companies from 2009 to 2017,we explore the relationship between shared auditors and suppliers’cost stickiness conditional on management expectations.The results show that shared auditors in the supply chain reduce suppliers’cost stickiness significantly when suppliers’managers hold optimistic expectations,and increase suppliers’cost stickiness in cases of pessimistic expectations.Furthermore,the greater the number of shared auditors,the stronger the effect.Such effects are more pronounced when supplier firms share auditors with important customers,have higher demand uncertainty,and use big 10 auditors.展开更多
Based on the concept of learning stickiness,this study constructed a model of influencing factors among the elements of online learning content,interaction,incentive,satisfaction,and learning stickiness from Comprehen...Based on the concept of learning stickiness,this study constructed a model of influencing factors among the elements of online learning content,interaction,incentive,satisfaction,and learning stickiness from Comprehensive Learning Theory.Structural equation modeling was used to analyze the interaction and influence effects among the factors.It is found that the content,interaction,and incentive in Comprehensive Learning Theory had a significant positive impact on learning stickiness from the total effect analysis.From the direct effect analysis,the influence of content and interaction on learning stickiness was not substantial,but the influence of incentive and satisfaction on learning stickiness was significant.From the perspective of mediation effect analysis,incentive and satisfaction were critical mediating variables for the influence of content and interaction on learning stickiness.This study put forward suggestions and strategies for online teaching,providing a reference for teachers to carry out online education.展开更多
Adhesion between an elastic body and a smooth,rigid substrate can lead to large tensile stresses between them.However,most macroscopic objects are microscopically rough,which strongly suppresses adhesion.A fierce deba...Adhesion between an elastic body and a smooth,rigid substrate can lead to large tensile stresses between them.However,most macroscopic objects are microscopically rough,which strongly suppresses adhesion.A fierce debate has unfolded recently as to whether local or global parameters determine the crossover between small and large adhesion.Here,we report simulations revealing that the dependence of the pull-off force Fn on the surface energyγdoes not only have two regimes of high and low adhesion but up to four regimes.They are related to contacts,which at the moment of rupture consist of(i)the last individual Hertzian-shaped contact,in which is linear inγ,(ii)a last meso-scale,individual patches with super-linear scaling,(iii)many isolated contact patches with extremely strong scaling,and(iv)a dominating largest contact patch,for which the pull-off stress is no longer negligible compared to the maximum,microscopic pull-off stress.Regime(iii)can be seen as a transition domain.It is located near the point where the surface energy is half the elastic energy per unit area in conformal contact.A criterion for the transition between regimes(i)and(ii)appears difficult to grasp.展开更多
The stickiness effect suffered by chaotic orbits diffusing in the phase space of a dynamical system is studied in this paper.Previous works have shown that the hyperbolic structures in the phase space play an essentia...The stickiness effect suffered by chaotic orbits diffusing in the phase space of a dynamical system is studied in this paper.Previous works have shown that the hyperbolic structures in the phase space play an essential role in causing the stickiness effect.We present in this paper the relationship between the stickiness effect and the geometric property of hyperbolic structures.Using a two-dimensional area-preserving twist mapping as the model,we develop the numerical algorithms for computing the positions of the hyperbolic periodic orbits and for calculating the angle between the stable and unstable manifolds of the hyperbolic periodic orbit.We show how the stickiness effect and the orbital diffusion speed are related to the angle.展开更多
Cruciferous vegetables are important edible vegetable crops.However,they are susceptible to various pests during their growth process,which requires real-time and accurate monitoring of these pests for pest forecastin...Cruciferous vegetables are important edible vegetable crops.However,they are susceptible to various pests during their growth process,which requires real-time and accurate monitoring of these pests for pest forecasting and scientific control.Hanging yellow sticky boards is a common way to monitor and trap those pests which are attracted to the yellow color.To achieve real-time,low-cost,intelligent monitoring of these vegetable pests on the boards,we established an intelligent monitoring system consisting of a smart camera,a web platform and a pest detection algorithm deployed on a server.After the operator sets the monitoring preset points and shooting time of the camera on the system platform,the camera in the field can automatically collect images of multiple yellow sticky boards at fixed places and times every day.The pests trapped on the yellow sticky boards in vegetable fields,Plutella xylostella,Phyllotreta striolata and flies,are very small and susceptible to deterioration and breakage,which increases the difficulty of model detection.To solve the problem of poor recognition due to the small size and breaking of the pest bodies,we propose an intelligent pest detection algorithm based on an improved Cascade R-CNN model for three important cruciferous crop pests.The algorithm uses an overlapping sliding window method,an improved Res2Net network as the backbone network,and a recursive feature pyramid network as the neck network.The results of field tests show that the algorithm achieves good detection results for the three target pests on the yellow sticky board images,with precision levels of 96.5,92.2 and 75.0%,and recall levels of 96.6,93.1 and 74.7%,respectively,and an F_(1) value of 0.880.Compared with other algorithms,our algorithm has a significant advantage in its ability to detect small target pests.To accurately obtain the data for the newly added pests each day,a two-stage pest matching algorithm was proposed.The algorithm performed well and achieved results that were highly consistent with manual counting,with a mean error of only 2.2%.This intelligent monitoring system realizes precision,good visualization,and intelligent vegetable pest monitoring,which is of great significance as it provides an effective pest prevention and control option for farmers.展开更多
One of Cambodia’s leading rice exporters,Apsara Rice,is known for its flagship product Apsara fragrant rice.Nurtured by the country’s fertile red soil and ample sunlight and rainfall thanks to its tropical monsoon c...One of Cambodia’s leading rice exporters,Apsara Rice,is known for its flagship product Apsara fragrant rice.Nurtured by the country’s fertile red soil and ample sunlight and rainfall thanks to its tropical monsoon climate,this rice features plump,translucent grains with a rich aroma and a soft,sticky,and elastic texture.展开更多
Microbially induced carbonate precipitation(MICP)is an eco-friendly soil improvement technique.However,this method still has some drawbacks,such as low conversion efficiency of CaCO_(3) crystallization,insufficient st...Microbially induced carbonate precipitation(MICP)is an eco-friendly soil improvement technique.However,this method still has some drawbacks,such as low conversion efficiency of CaCO_(3) crystallization,insufficient strength for certain applications,and requiring multiple treatments.Previous studies have re-ported that sticky rice can regulate CaCO_(3) crystals(i.e.,chemical CaCO_(3))in the sticky rice-lime mortar,showing potential for improving the bio-cementation.Therefore,this study explored the possibility of using sticky rice to enhance the biocementation effect.Tests were carried out to assess the strength and perme-ability of bio-cemented sand with the inclusion of sticky rice.The results indicated that sticky rice may regulate the type and size of bio-CaCO_(3) crystals,and the use of an appropriate amount of sticky rice as additive could increase the strength of sand columns by regulating CaCO_(3) crystallization.Polyhedral calcites may be more favourable for the increasing strength than some vaterites with a hollow spherical structure.The combination of MICP and sticky rice can significantly decrease the coefficient of permeability to a value that was much lower than that by using sticky rice and MICP alone.Bio-CaCO_(3) immobilized the sticky rice on one end on sand particles,and the reticulated structure of sticky rice divided large pores into small pores,which may be the important cause of the decrease in permeability coefficient.Finally,this study proposed that the MICP with the sticky rice as an additive may enhance the MICP effect and prevent the surface erosion of coarse-grained sand slopes.展开更多
With the rapid development of the digital age,the perceived value of private consumers has changed to varying degrees,which has a profound impact on consumption stickiness.Based on the existing research results,this s...With the rapid development of the digital age,the perceived value of private consumers has changed to varying degrees,which has a profound impact on consumption stickiness.Based on the existing research results,this study constructs a model with four dimensions of perceived value as mechanism variables(namely,perceived functional value,perceived emotional value,perceived economic value,and perceived social value),and studies the influence of private domain consumers’perceived value on consumption sticky behavior in the digital age.The empirical study finds that private domain consumers’perceived functional value,perceived emotional value,and perceived economic value positively affect consumption sticky behavior,showing a relationship that sticky behavior increases with the increase of the above three dimensions,while private domain consumers’perceived social value has a negative effect.展开更多
目的观察侧壁开窗上颌窦底提升术中应用Bio-Oss骨粉、Bio-Oss骨粉+浓缩生长因子(CGF)、Sticky bone 3种植骨材料的临床疗效。方法2021年2月—2022年2月黄河三门峡医院诊治因上颌后牙区牙列缺损且上颌窦底剩余骨高度(RBH)不足需行种植修...目的观察侧壁开窗上颌窦底提升术中应用Bio-Oss骨粉、Bio-Oss骨粉+浓缩生长因子(CGF)、Sticky bone 3种植骨材料的临床疗效。方法2021年2月—2022年2月黄河三门峡医院诊治因上颌后牙区牙列缺损且上颌窦底剩余骨高度(RBH)不足需行种植修复的患者74例,行侧壁开窗上颌窦底提升术、延期行种植体植入术,根据上颌窦底提升术中植骨材料分为Bio-Oss骨粉组(单纯Bio-Oss骨粉)24例、Bio-Oss骨粉+CGF组(Bio-Oss骨粉与自体CGF混合物)25例、Sticky bone组(Bio-Oss骨粉与自体CGF、自体纤维蛋白混合物)25例,比较3组体质量指数及术后疼痛评分、面部肿胀高度等,种植体植入即刻、种植体植入术后6个月及种植体功能负载12个月时种植体稳定系数(ISQ),种植体植入前、种植体植入即刻、种植体植入术后6个月及种植体功能负载12个月时上颌窦底RBH。结果3组糖尿病、冠心病、吸烟比率及体质量指数、术后疼痛评分、面部肿胀高度比较差异均无统计学意义(P>0.05)。种植体植入即刻、种植体植入术后6个月及种植体功能负载12个月时Sticky bone组种植体ISQ值(77.88±0.46、80.34±0.35、82.45±0.31)均高于Bio-Oss+CGF组(76.45±0.25、78.45±0.94、80.11±0.24)、Bio-Oss骨粉组(75.11±0.36、77.22±0.32、79.45±0.37)(P<0.05),Bio-Oss+CGF组均高于Bio-Oss骨粉组(P<0.05);3组种植体植入即刻、种植体植入术后6个月及种植体功能负载12个月时种植体ISQ值均依次升高(P<0.05)。种植体植入前3组上颌窦底RBH比较差异无统计学意义(P>0.05);种植体植入即刻、种植体植入术后6个月及种植体功能负载12个月时Sticky bone组上颌窦底RBH[(13.88±0.45)、(12.75±0.36)、(12.64±0.31)mm]均高于Bio-Oss+CGF组[(13.45±0.25)、(12.41±0.47)、(11.78±0.85)mm]、Bio-Oss骨粉组[(13.17±0.86)、(12.13±0.66)、(11.41±0.14)mm](P<0.05),Bio-Oss+CGF组与Bio-Oss骨粉组比较差异均无统计学意义(P>0.05);Bio-Oss+CGF组、Bio-Oss骨粉组种植体植入前、种植体植入即刻、种植体植入术后6个月及种植体功能负载12个月时上颌窦底RBH均依次降低(P<0.05);Sticky bone组种植体植入前、种植体植入即刻、种植体植入术后6个月时上颌窦底RBH依次降低(P<0.05),种植体功能负载12个月时与种植体植入术后6个月时比较差异无统计学意义(P>0.05)。结论对上颌后牙区牙列缺损且上颌窦底RBH不足患者,侧壁开窗上颌窦底提升术中采用Sticky bone作为植骨材料较单纯Bio-Oss骨粉或Bio-Oss骨粉混合CGF的骨吸收较少,有利于维持种植体稳定性。展开更多
Cement mortar with sticky rice pulp is an innovative composite material.Investigating its mechanical properties and strength mechanism is essential for the future engineering application.Taking the pulp concentration ...Cement mortar with sticky rice pulp is an innovative composite material.Investigating its mechanical properties and strength mechanism is essential for the future engineering application.Taking the pulp concentration and the mortar ages as the variables,we tested five groups of blocks for the compressive strength and flexural strength,and observed their microstructures with a scanning electronic microscope.The results indicated that the microstructure got dense if the added pulp had a concentration of about 0.3%,and thereby its flexural strength would significantly improve,while the hydration products agglomerated and the microstructure got loose if the added pulp had a concentration of more than 1.0%,which caused a substantial decline in flexural strength.Besides,the hydration reaction was hindered at the early stage due to the addition of the pulp;hence the early strength of the mortar is on the low side.According to the strength mechanism analysis,all the results are mainly attributed to the effects:"water-reduction",agglomeration and retarding,caused by the addition of the pulp.展开更多
[Objective] To evaluate the control effect of yellow sticky cards and sex pheromone on Plutella xylostella and Liriomyza spp.,which can provide reference for large area extension of the technique.[Method] The integrat...[Objective] To evaluate the control effect of yellow sticky cards and sex pheromone on Plutella xylostella and Liriomyza spp.,which can provide reference for large area extension of the technique.[Method] The integrated assessment of trapping efficiency of colored sticky cards and sex pheromone on Liriomyza spp.and Plutella xylostella was conducted by field surveys and structured interview in Tonghai County,Yunnan Province,China.[Result] The results showed that yellow sticky cards and sex pheromone have strong power of trapping Liriomyza spp.and Plutella xylostella（3 414±720 and（219±157） head/piece,respectively）;the control cost by the usage of pesticide is the highest,（10 099.5±2 752.5） yuan/hm^2,yellow sticky cards and sex pheromone takes the second place,（1 125.0±465.0） yuan/hm^2,the control cost by the usage of yellow sticky cards is the lowest,（450.0 ±186.0）yuan/hm^2.Without the usage of yellow sticky cards and sex pheromone,pesticide application times and costs are（15.0±2.7） times and（12 070.5±2 136.0） yuan/hm^2;combined with usage of yellow sticky cards and sex pheromone,pesticide application times and costs reduce by 5.7 times and 4 618.5 yuan/hm^2.The ratio of trapped beneficial insects and target pests was 1 ∶1 131,which showed that the negative effect of yellow sticky cards and sex pheromone on the non-target insects was very limited.[Conclusion] The trapping approach has become popular among all the local farmers.Looking at the above factors,the trapping technology has strong application prospect and promotion value in pest control field.展开更多
Prepreg stickiness is the adhesion between prepregs or between a prepreg and a mold in lay-up process.It is critical for automated fiber placement,because the stickiness should be small for smooth transport,as well as...Prepreg stickiness is the adhesion between prepregs or between a prepreg and a mold in lay-up process.It is critical for automated fiber placement,because the stickiness should be small for smooth transport,as well as large enough on the laying surface for a good placement performance.To ensure prepreg stickiness always being in the optimum laying window,placement temperature should be changed according to the laying speed.In our work,the relationship between laying speed and emissive power of heating lamp was studied.The heat transfer process between heating lamp and laying surface was analyzed and the control equation of dynamic temperature was derived.Finally,the infrared heating system was built and its effectiveness was verified based on placement experiment.展开更多
文摘American economist Funon brought forward the theory of industry production lite cycle phases. But from the perspective of China, the developed regions are sill developed, while the low developed regions are still low developed. The factors are as below, relation with people and relation region of the original investment place,＇ the problem of sunk cost, the network of production and cooperation constructed, the weakness of establishment in lower process region, narrow market capability and low degree of market of west and the low work efficiency of government of low grade region Ineffective conduction system of investment information.
文摘This paper studies Whether the managerial overconfidence have any impact on the Cost management （Characterized by the degree of the Costs Stickiness ） .Using the ample of the A-share listed companies between 2007-2011 in China, We document that SG＆A cost stickiness decreases in the degree of overconfidence. The further studies show the negative relation is more significant in the state-owned listed companies,which proved our speculation that the manager will cut expenses avoiding significant decline in performance when the sales decline in the state-owned listed company.
基金the National Social Science Fund of China,under grant No.21BGL017.
文摘CEO compensation stickiness represents an important indicator to measure the effectiveness of compensation contracts.This study uses CEO career experience data and compensation stickiness data from Shanghai and Shenzhen A-share listed companies from 2015 to 2020 to investigate the compensation contracts’effectiveness of CEOs with diverse career experiences.The findings are as follows:1)Compensation stickiness is more pronounced for CEOs with diverse career experiences.According to the mechanism test,these CEOs with diverse career experiences can obtain compensation incentives by reducing corporate uncertainty perception and improving total factor productivity.This approach leads to increased compensation stickiness and the effectiveness of compensation contracts.CEOs with diverse career experiences may receive excess compensation by raising agency costs,which intensifies compensation stickiness and weakens the effectiveness of compensation contracts.2)Compensation stickiness of CEOs with diverse career experiences is more significant in companies with lower investor protection,which brings about less effective compensation contracts.In contrast,in companies with higher diversification,the compensation stickiness of CEOs with diverse career experiences is more significant,which delivers more effective compensation contracts.The conclusions deepen the research of CEO compensation contracts and provide a helpful reference for CEO compensation management practices.
基金Foundation of China Project“Media Attention and Contract Governance of Mixed-Ownership Enterprises:Effect,Mechanism and Path”(Project No.:72172113)Humanities and Social Science Research Project of the Ministry of Education:Research on the effects and mechanisms of Resource Allocation and Sharing in Intelligent Manufacturing Enterprises(Project No.:23YJA630103).
文摘The deep integration of digital technology with the real economy has reconstructed production systems.We explore the impact of digital technology on the resource allocation behavior and efficiency of manufacturing enterprises.Using a sample of Chinese A-share listed manufacturing firms over the 2010–2021 period,we find that digital technology alleviates cost stickiness,especially in enterprises with a high level of Industrial Internet platform usage.This effect occurs by optimizing the labor force structure and improving the economic benefits of labor capital investment.Heterogeneity analysis shows that this effect is pronounced in enterprises with high levels of labor intensity and business complexity.Our findings shed new light on the consequences and mechanism of enterprise cost optimization that is driven by technologydriven reforms.
基金funded by a National Natural Science Grant (No. 71172143)Key Social Science Research Institute Grant of the Ministry of Education (No. 12JJD790037)the Program for New Century Excellent Talents in University (NCET-13-0893)
文摘Cost and expense stickiness is an important issue in accounting and economics research, and the literature has shown that cost stickiness cannot be separated from managers' motivations. In this paper, we examine the effects that earnings management has on expense stickiness. Defining small positive profits or small earnings increases as earnings management, we observe significant expense stickiness in the non-earnings-management sub-sample, compared with the earnings-management sub-sample. When we divide expenses into R&D,advertising and other general expenses, we find that managers control expenses mainly by decreasing general expenses. We further examine corporate governance's effect on expense stickiness. Using factor analysis, we extract eight main factors and find that good corporate governance reduces expense stickiness. Finally, we investigate the interaction effects of earnings management and corporate governance on expense stickiness. The empirical results show that good corporate governance can further reduce cost stickiness,although its effect is not as strong as that of earnings management.
基金the National Social Science Foundation of China(Major Project 13&ZD146)the Fundamental Research Funds for the Central Universities of China(No.JBK19072018153)for their support.
文摘Do supply chain audits have real effects?We focus on the effect of shared auditors in the supply chain on corporate cost stickiness.When a supplier shares auditors with its customers,the shared auditors provide informational advantages for suppliers’managers,thus revising their optimistic or pessimistic expectations and influencing suppliers’cost stickiness.Using a sample of Chinese A-share listed companies from 2009 to 2017,we explore the relationship between shared auditors and suppliers’cost stickiness conditional on management expectations.The results show that shared auditors in the supply chain reduce suppliers’cost stickiness significantly when suppliers’managers hold optimistic expectations,and increase suppliers’cost stickiness in cases of pessimistic expectations.Furthermore,the greater the number of shared auditors,the stronger the effect.Such effects are more pronounced when supplier firms share auditors with important customers,have higher demand uncertainty,and use big 10 auditors.
文摘Based on the concept of learning stickiness,this study constructed a model of influencing factors among the elements of online learning content,interaction,incentive,satisfaction,and learning stickiness from Comprehensive Learning Theory.Structural equation modeling was used to analyze the interaction and influence effects among the factors.It is found that the content,interaction,and incentive in Comprehensive Learning Theory had a significant positive impact on learning stickiness from the total effect analysis.From the direct effect analysis,the influence of content and interaction on learning stickiness was not substantial,but the influence of incentive and satisfaction on learning stickiness was significant.From the perspective of mediation effect analysis,incentive and satisfaction were critical mediating variables for the influence of content and interaction on learning stickiness.This study put forward suggestions and strategies for online teaching,providing a reference for teachers to carry out online education.
文摘Adhesion between an elastic body and a smooth,rigid substrate can lead to large tensile stresses between them.However,most macroscopic objects are microscopically rough,which strongly suppresses adhesion.A fierce debate has unfolded recently as to whether local or global parameters determine the crossover between small and large adhesion.Here,we report simulations revealing that the dependence of the pull-off force Fn on the surface energyγdoes not only have two regimes of high and low adhesion but up to four regimes.They are related to contacts,which at the moment of rupture consist of(i)the last individual Hertzian-shaped contact,in which is linear inγ,(ii)a last meso-scale,individual patches with super-linear scaling,(iii)many isolated contact patches with extremely strong scaling,and(iv)a dominating largest contact patch,for which the pull-off stress is no longer negligible compared to the maximum,microscopic pull-off stress.Regime(iii)can be seen as a transition domain.It is located near the point where the surface energy is half the elastic energy per unit area in conformal contact.A criterion for the transition between regimes(i)and(ii)appears difficult to grasp.
基金supported by the National Natural Science Foundation of China(Grant Nos.11073012,11078001 and 11003008)the Qing Lan Project(Jiangsu Province)the National Basic Research Program of China(Grant Nos.2013CB834103 and 2013CB834904)
文摘The stickiness effect suffered by chaotic orbits diffusing in the phase space of a dynamical system is studied in this paper.Previous works have shown that the hyperbolic structures in the phase space play an essential role in causing the stickiness effect.We present in this paper the relationship between the stickiness effect and the geometric property of hyperbolic structures.Using a two-dimensional area-preserving twist mapping as the model,we develop the numerical algorithms for computing the positions of the hyperbolic periodic orbits and for calculating the angle between the stable and unstable manifolds of the hyperbolic periodic orbit.We show how the stickiness effect and the orbital diffusion speed are related to the angle.
基金supported by the Collaborative Innovation Center Project of Guangdong Academy of Agricultural Sciences,China(XTXM202202).
文摘Cruciferous vegetables are important edible vegetable crops.However,they are susceptible to various pests during their growth process,which requires real-time and accurate monitoring of these pests for pest forecasting and scientific control.Hanging yellow sticky boards is a common way to monitor and trap those pests which are attracted to the yellow color.To achieve real-time,low-cost,intelligent monitoring of these vegetable pests on the boards,we established an intelligent monitoring system consisting of a smart camera,a web platform and a pest detection algorithm deployed on a server.After the operator sets the monitoring preset points and shooting time of the camera on the system platform,the camera in the field can automatically collect images of multiple yellow sticky boards at fixed places and times every day.The pests trapped on the yellow sticky boards in vegetable fields,Plutella xylostella,Phyllotreta striolata and flies,are very small and susceptible to deterioration and breakage,which increases the difficulty of model detection.To solve the problem of poor recognition due to the small size and breaking of the pest bodies,we propose an intelligent pest detection algorithm based on an improved Cascade R-CNN model for three important cruciferous crop pests.The algorithm uses an overlapping sliding window method,an improved Res2Net network as the backbone network,and a recursive feature pyramid network as the neck network.The results of field tests show that the algorithm achieves good detection results for the three target pests on the yellow sticky board images,with precision levels of 96.5,92.2 and 75.0%,and recall levels of 96.6,93.1 and 74.7%,respectively,and an F_(1) value of 0.880.Compared with other algorithms,our algorithm has a significant advantage in its ability to detect small target pests.To accurately obtain the data for the newly added pests each day,a two-stage pest matching algorithm was proposed.The algorithm performed well and achieved results that were highly consistent with manual counting,with a mean error of only 2.2%.This intelligent monitoring system realizes precision,good visualization,and intelligent vegetable pest monitoring,which is of great significance as it provides an effective pest prevention and control option for farmers.
文摘One of Cambodia’s leading rice exporters,Apsara Rice,is known for its flagship product Apsara fragrant rice.Nurtured by the country’s fertile red soil and ample sunlight and rainfall thanks to its tropical monsoon climate,this rice features plump,translucent grains with a rich aroma and a soft,sticky,and elastic texture.
基金supported by the State Scholarship Fund from the China Scholarship Council(CSC)No.202006180076.
文摘Microbially induced carbonate precipitation(MICP)is an eco-friendly soil improvement technique.However,this method still has some drawbacks,such as low conversion efficiency of CaCO_(3) crystallization,insufficient strength for certain applications,and requiring multiple treatments.Previous studies have re-ported that sticky rice can regulate CaCO_(3) crystals(i.e.,chemical CaCO_(3))in the sticky rice-lime mortar,showing potential for improving the bio-cementation.Therefore,this study explored the possibility of using sticky rice to enhance the biocementation effect.Tests were carried out to assess the strength and perme-ability of bio-cemented sand with the inclusion of sticky rice.The results indicated that sticky rice may regulate the type and size of bio-CaCO_(3) crystals,and the use of an appropriate amount of sticky rice as additive could increase the strength of sand columns by regulating CaCO_(3) crystallization.Polyhedral calcites may be more favourable for the increasing strength than some vaterites with a hollow spherical structure.The combination of MICP and sticky rice can significantly decrease the coefficient of permeability to a value that was much lower than that by using sticky rice and MICP alone.Bio-CaCO_(3) immobilized the sticky rice on one end on sand particles,and the reticulated structure of sticky rice divided large pores into small pores,which may be the important cause of the decrease in permeability coefficient.Finally,this study proposed that the MICP with the sticky rice as an additive may enhance the MICP effect and prevent the surface erosion of coarse-grained sand slopes.
文摘With the rapid development of the digital age,the perceived value of private consumers has changed to varying degrees,which has a profound impact on consumption stickiness.Based on the existing research results,this study constructs a model with four dimensions of perceived value as mechanism variables(namely,perceived functional value,perceived emotional value,perceived economic value,and perceived social value),and studies the influence of private domain consumers’perceived value on consumption sticky behavior in the digital age.The empirical study finds that private domain consumers’perceived functional value,perceived emotional value,and perceived economic value positively affect consumption sticky behavior,showing a relationship that sticky behavior increases with the increase of the above three dimensions,while private domain consumers’perceived social value has a negative effect.
基金Supported by the College Students Research Learning and Innovative Experiment Project of Hunan Province(S202012649001)the Natural Science Foundation of Hunan Province(2021JJ30270)。
文摘Cement mortar with sticky rice pulp is an innovative composite material.Investigating its mechanical properties and strength mechanism is essential for the future engineering application.Taking the pulp concentration and the mortar ages as the variables,we tested five groups of blocks for the compressive strength and flexural strength,and observed their microstructures with a scanning electronic microscope.The results indicated that the microstructure got dense if the added pulp had a concentration of about 0.3%,and thereby its flexural strength would significantly improve,while the hydration products agglomerated and the microstructure got loose if the added pulp had a concentration of more than 1.0%,which caused a substantial decline in flexural strength.Besides,the hydration reaction was hindered at the early stage due to the addition of the pulp;hence the early strength of the mortar is on the low side.According to the strength mechanism analysis,all the results are mainly attributed to the effects:"water-reduction",agglomeration and retarding,caused by the addition of the pulp.
基金Supported by Development Program of Misereor Foundation of Germany(335-0311028Z)~~
文摘[Objective] To evaluate the control effect of yellow sticky cards and sex pheromone on Plutella xylostella and Liriomyza spp.,which can provide reference for large area extension of the technique.[Method] The integrated assessment of trapping efficiency of colored sticky cards and sex pheromone on Liriomyza spp.and Plutella xylostella was conducted by field surveys and structured interview in Tonghai County,Yunnan Province,China.[Result] The results showed that yellow sticky cards and sex pheromone have strong power of trapping Liriomyza spp.and Plutella xylostella（3 414±720 and（219±157） head/piece,respectively）;the control cost by the usage of pesticide is the highest,（10 099.5±2 752.5） yuan/hm^2,yellow sticky cards and sex pheromone takes the second place,（1 125.0±465.0） yuan/hm^2,the control cost by the usage of yellow sticky cards is the lowest,（450.0 ±186.0）yuan/hm^2.Without the usage of yellow sticky cards and sex pheromone,pesticide application times and costs are（15.0±2.7） times and（12 070.5±2 136.0） yuan/hm^2;combined with usage of yellow sticky cards and sex pheromone,pesticide application times and costs reduce by 5.7 times and 4 618.5 yuan/hm^2.The ratio of trapped beneficial insects and target pests was 1 ∶1 131,which showed that the negative effect of yellow sticky cards and sex pheromone on the non-target insects was very limited.[Conclusion] The trapping approach has become popular among all the local farmers.Looking at the above factors,the trapping technology has strong application prospect and promotion value in pest control field.
基金supported by the Key Basic Research and Development Program(973)(No.2014CB046501)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Prepreg stickiness is the adhesion between prepregs or between a prepreg and a mold in lay-up process.It is critical for automated fiber placement,because the stickiness should be small for smooth transport,as well as large enough on the laying surface for a good placement performance.To ensure prepreg stickiness always being in the optimum laying window,placement temperature should be changed according to the laying speed.In our work,the relationship between laying speed and emissive power of heating lamp was studied.The heat transfer process between heating lamp and laying surface was analyzed and the control equation of dynamic temperature was derived.Finally,the infrared heating system was built and its effectiveness was verified based on placement experiment.
