The green innovation value chain is a key step in transforming green,innovative scientific,and technological achievements into productive forces.The establishment of green innovation value chains based on value distri...The green innovation value chain is a key step in transforming green,innovative scientific,and technological achievements into productive forces.The establishment of green innovation value chains based on value distribution rather than technical conditions can effectively overcome the common bottleneck faced by different nations during their green innovation endeavors,namely,the substitution of conventional products with green alternatives.This study investigates the impeded diffusion of green products and their underlying causes,analyzes the internal structure and mechanism of the green innovation value chain,and explores the establishment of regional green innovation value chains and the models available for value chain upgrading.展开更多
This study evaluated the effectiveness of donor supported agricultural value chain development projects in sustainably narrowing yield gaps for banana smallholder farmer producers in Manicaland, Zimbabwe. The study us...This study evaluated the effectiveness of donor supported agricultural value chain development projects in sustainably narrowing yield gaps for banana smallholder farmer producers in Manicaland, Zimbabwe. The study used a mixed methods research design that relied on farmers records for the quantitative analysis and focus group discussion and in-depth interviews for key experts for the qualitative aspects. A mix of regression analysis, t-tests, Pearsons’s correlation and analysis of variance statistical methods were used for the quantitative analysis while thematic response analysis was used for the qualitative engagements. The findings showed that by the end of the activity, the project had successfully narrowed the banana yield gaps to 18.66 tons per hectare working with a potential yield base of 40 tons. However, 5 years after the project closure the yield gap had fallen to 24.7 tons indicating a lack of sustainability of yield gap reduction. However, the yield gap slump does not override the fact that farmers on average were still able to sell approximately 5 tons per every 6 months after 5 years from the project closure which is beyond any poverty threshold. This suggests genuine upward economic mobility. Additionally, in analyzing what factors had the greatest influence on yield gap reduction, the access to fertilizer ranked highest where genetics, irrigation and improved agronomy followed in that respective order. The study further showed that farmers who receive value chain development support whilst at an already commercialized state tend to maintain productivity thresholds higher in comparison to those who are at a pre commercial state. This is evidenced by the fact that the pre commercial farmers had a yield reduction of 30.83 percent after 5 years of the project closure whereas the former realized a productivity growth of 7.84%. In conclusion, whilst the intervention was successful in transitioning farmers out of poverty, more investment should be made towards transitioning smallholder farmers to integrated soil fertility management practices and improvement of agronomic efficiency through stronger on field collaboration between research institutions, the government and development institutions.展开更多
With the Uruguay Round bringing agricultural trade into multilateral regulation,the major countries have actively participated in agricultural global value chains(AGVC)and occupied an important position according to t...With the Uruguay Round bringing agricultural trade into multilateral regulation,the major countries have actively participated in agricultural global value chains(AGVC)and occupied an important position according to their comparative advantages.Utilizing bilateral agricultural trade data of 66 countries based on the OECD Inter-Country-Input-Output Tables(OECD ICIO)from 2010 to 2018,this study applies social network analysis indicators to measure each country’s eigenvector centrality within AGVC and to examine the current global agricultural trade patterns,with particular attention to the changes in the status of world powers within AGVC.The main findings are as follows:first,with the multilateral and regional trade liberalization,growing numbers of developing nations,including China and India,are engaging in international agricultural trade,which contributes to its diversification;second,as AGVC develops,the structure of global agricultural trade networks has become more decentralized and balanced.This is evidenced by the emergence of additional central nodes,and large nations like the United States,which formerly held the most central position as indicated by a drop in its centrality,are becoming less dominant.展开更多
Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study ...Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study uses the social network analysis method,entropy method,multi-index comprehensive evaluation method,and quadratic assignment procedure analysis method to examine the characteristics and influencing factors of the urban networks of research and development(R&D),production,and sales formed as a result of the overseas investments of listed manufacturing companies in western China.Results showed that the three types of investment networks involved multiple industry types and multiple central cities with differentiated diversity and multicentrality.The R&D urban network’s leading sub-industries were the mechanical equipment and instruments,medicine and biological products,and metal and nonmetal industries.The destination cities were mostly those home to educational and scientific research centers.The production urban network’s leading sub-industries were the mechanical equipment,instrument,and food and beverage industries.The destination cities were mostly regional central cities in developing countries.The sales urban network’s leading sub-industries were the mechanical equipment and instrument,metal and nonmetal,and petrochemical and plastics industries.The destination cities were numerous and scattered.In addition,the R&D urban network easily formed specialized clusters,core nodes easily controlled the production urban network,and individual nodes did not easily control the sales urban network.Technological and economic system advantages greatly impacted the three network types.Considering the different influencing factors,this study suggests optimizing the institutional investment environment to narrow the institutional gap,adjusting and optimizing the investment layout to expand overseas markets,and increasing R&D funds to stimulate technological progress and overseas investments in western China.展开更多
Poultry production has important economic, social and cultural benefits and plays a significant role in family nutrition in developing countries. In most tropical countries it is based mainly on scavenging production ...Poultry production has important economic, social and cultural benefits and plays a significant role in family nutrition in developing countries. In most tropical countries it is based mainly on scavenging production systems, which makes substantial contributions to household food security throughout the developing world. All over the developing world, these low-input and low-output poultry-husbandry systems are an integral component of the livelihoods of most rural, peri-urban, and some urban households and are likely to continue to meet this role for the foreseeable future. Although the contributions of chicken farming to household food security and income as well as its potential contribution to the income of rural communities are known, chicken production is practiced very little in Somaliland. Therefore, the purpose of this project was to carry out a baseline study on the potential of chicken production (eggs and meats) in Somaliland and its existing chain gaps in order to identify whether chicken production could be a successful income source for women and boost female economic activity in the project areas of Saaxil, MaroodiJeex and Togdheer. The result from this assessment showed that rural chicken production was a women-related activity that helped them to be the sole decision-makers and also users of the benefits regarding chicken and chicken products. The main purposes for keeping chicken were egg production for income generating, home consumption and meat provision. The major constraints for rural poultry keeping were the lack of extension and veterinary services, predators, poor housing, poor breeds, and lack of financial services among others. Women in all the selected villages made remarkable contributions to the local chicken production system. The result of the assessments showed that indigenous poultry value chain consisted of producers, collectors/retaileres, shops and consumers/restaurents. However, the absence of processors along the chain means that chickens are sold live and consequently cannot be retailed through formal channels like supermarkets leading to the exclusion of potential customers in the middle and high income categories who normally shop from supermarkets. Furthermore, as population and incomes grow, demand for indigenous chicken is likely to continue growing, especially among the high income groups who not only prefer it for its taste but also for health reasons due to its low fat content. Finally, although the value chain for indigenous chickens shows potential growth for all the players along the chain, there is a need to address the various constraints affecting the value chain for indigenous chickens in order to improve the operation of the chain hence leading to increased incomes for the value chain actors and at the same time ensuring cheap delivery of indigenous chicken in a more convenient form and in formal outlets.展开更多
Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of ci...Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical structures.This paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well removed.Hence,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental datasets.The first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC.展开更多
This paper develops a conceptual model to assess effect of outsourcing by integrating the theories of industrial upgrading and global value chain (GVC) governance. Contrary to the widely accepted perception that outso...This paper develops a conceptual model to assess effect of outsourcing by integrating the theories of industrial upgrading and global value chain (GVC) governance. Contrary to the widely accepted perception that outsourcing is expected to generate positive spillover in particular, the findings indicate that outsourcing has different effects in different GVC governance modes. Excess outsourcing could structurally inhibit technology and management spillovers to subcontractors within the emerging economy context. Based on a case study of the Chinese textile and apparel (T & A) industry, it is found that the Chinese T & A industry has been trapped in the captive governance relationship with foreign buyers, and at the same time is capped below the function upgrading level. Consequences of the situation and implication are then discussed.展开更多
This study aims to assess the small ruminant value chain in Al-Ruwaished District,Jordan,to identify the potential intervention areas that could improve the production efficiency and guarantee the sustainability of th...This study aims to assess the small ruminant value chain in Al-Ruwaished District,Jordan,to identify the potential intervention areas that could improve the production efficiency and guarantee the sustainability of the small ruminant sector in this area.Sheep breeding is the source of livelihood for most of the people in Al-Ruwaished District,which is characterized by the large number of sheep and goats.We surveyed 5.0% of the small ruminant holders in the study area and conducted individual interviews and surveys with the potential actors in the value chain to undertake a small ruminant value chain analysis.From the survey,we found that the small ruminant value chain consists of five core functions,namely,input supply,production management,marketing,processing,and consumption.Despite the stable impression given by the large number of holdings in the small ruminant sector,the surveyed results show a clear fragility in the value chain of small ruminants in this area.The small ruminant production system is negatively impacted by climate change,especially continuous drought.In addition,the high prices of feed that the farmer cannot afford with clear and real absence of the governmental and non-governmental support activities also impact the development of the value chain.The results of strengths,weaknesses,opportunities,and threats(SWOT)analysis reveal that the major constraints faced by this value chain could be divided into external and internal threats.Specifically,the most prominent external threats are the nature of the desert land and continuous drought,while the major internal threats are the absence of appropriate infrastructure,shortage of inputs,and weakness in the production management and marketing.We proposed solutions to these challenges to ensure the sustainability and effectiveness of the sector,such as the formulation of emergency response plans to severe weather,qualifying farmers’skills,and establishment of agricultural cooperative societies.展开更多
Cruise value chain is to take the exchange of cruise products and services as the core in a certain spatial scope,and enterprises with core advantages within or between different industries establish associations in a...Cruise value chain is to take the exchange of cruise products and services as the core in a certain spatial scope,and enterprises with core advantages within or between different industries establish associations in accordance with certain technical and economic conditions,so as to realise the multi-dimensional extension and value appreciation of the cruise value chain in the vertical and horizontal links,and ultimately establish a chain-network type of enterprise strategic alliance.This paper tries to analyse the value-added factors of the cruise industry chain by constructing a multi-level hierarchical structural model with reference to the influencing factor analysis methods of relevant literature-DEMATEL(Decision Making Experiment and Evaluation Experiment)and ISM(Interpretative Structural Model).The study shows that the innovation and scale value-added module in the upstream of the cruise industry chain is the core module of value-added of the whole cruise industry chain,and the value-added mainly originates from the design and manufacturing of cruise ships.The middle reaches of the cruise industry chain are mainly cruise operation enterprises,and the specificity of cruise operation determines that its brand value-added is mainly accomplished through the global layout of multinational corporations,and the cruise brand is able to drive the consumption demand and has value-added ability.The downstream value-added of the cruise industry chain is mainly realised through the increase in profits of cruise tourism service products.展开更多
Productivity and international energy price shocks are reflected in PPI and CPI via industrial chains.China’s in-depth participation into the global value chains has increasingly lengthened its industrial production ...Productivity and international energy price shocks are reflected in PPI and CPI via industrial chains.China’s in-depth participation into the global value chains has increasingly lengthened its industrial production chains.The question is how the changing length of production chains will affect CPI and PPI,as well as CPI-PPI correlation?By constructing a global input-output price model,this paper offers a theoretical discussion on the impact of production chain length on the CPI-PPI divergence.Our findings suggest that the price shock of international bulk commodities has a greater impact on China’s PPI than that on CPI.The effects on both China’s PPI and CPI estimated by using the single-country input-output model are higher than the results estimated with the global input-output model.However,the difference between CPI and PPI variations estimated with the global input-output model is greater than the result estimated with the single-country input-output model,which supports the view that the lengthening of production chains,especially international production chains,leads to a divergence between CPI and PPI.Empirical results based on cross-national panel data also suggest that the lengthening of production chains has reduced the CPI-PPI correlation for countries,i.e.the lengthening of production chains has increased the PPI-CPI divergence.That is to say,policymakers should target not just CPI in maintaining price stability,but instead focus on the stability of both PPI and CPI.Efforts can be made to proactively adjust the price index system,and formulate the industrial chain price index.展开更多
Establishing a sense of ritual within tourism consumption scenarios offers tourists the opportunity for interactive engagement.Drawing upon the value co-creation theory,this study constructed an influence mechanism mo...Establishing a sense of ritual within tourism consumption scenarios offers tourists the opportunity for interactive engagement.Drawing upon the value co-creation theory,this study constructed an influence mechanism model to examine tourists'active engagement in the process of co-creating tourism experience values.It employed Partial Least Squares Structural Equation Modeling(PLS-SEM)to empirically test the proposed hypotheses.The findings demonstrate that the model constructed in the present study exhibits robust reliability,validity,and explanatory power.The perception of the sense of ritual in tourism exerts a significant positive influence on tourists’co-creation of tourism experience values,thereby significantly enhancing both the communitas and flow experienced by tourists during their travels.Moreover,such communitas and flow can mediate the influence of the sense of ritual in tourism on tourists’co-creation of tourism experience values.This study contributes to advancing the current research on tourists’co-creation of tourism experience values and the sense of ritual in tourism,thereby providing theoretical foundations for cultivating a sense of ritual within tourism consumption scenarios.展开更多
In recent years,with the complexity and variability of international finance,debt,and geopolitical risks,the growth rate of domestic economic operations has slowed down.More enterprise groups are facing the transforma...In recent years,with the complexity and variability of international finance,debt,and geopolitical risks,the growth rate of domestic economic operations has slowed down.More enterprise groups are facing the transformation and upgrading from domestic leadership to internationalization,achieving revenue growth of nearly 10 billion yuan per year against the trend.The severe and complex internal and external environment has brought many challenges to the supply chain for enterprises.This article focuses on the goal of an“enterprise supply chain system focusing on value creation,strengthening system linkage,and improving overall chain efficiency,”aiming to find solutions to problems such as strong demand variability,frequent emergency needs,coexistence of project shortages and inventory surplus,long material turnover cycles,and high organizational complexity.By searching for key activities in the entire business chain of demand,design,production,service,and finance,implementing source planning,process control,system linkage,analysis and summary,and team collaboration,we have achieved more scientific demand forecasting,more accurate planning,more effective procurement cost reduction,more stable production performance supply,more convenient inventory sharing services,and more efficient integration of business and financial policies.展开更多
Global value chains(GVCs)have entered a new stage of restructuring characterized by trends towards localization,regionalization and diversification.These trends can be attributed to the evolution of the international ...Global value chains(GVCs)have entered a new stage of restructuring characterized by trends towards localization,regionalization and diversification.These trends can be attributed to the evolution of the international division,irrational responses to crisis shocks,and trade protectionism.In this context,China’s industrial and supply chain upgrades face both opportunities and challenges which require navigating the adverse effects of industrial re-shoring,unfair technology competition,and changes in the global industrial layout.Yet,such challenges may create pressures for China to accelerate innovation,overcome the low-end lock-up effect by creating regional value chains,and broaden international cooperation.China needs to explore an effective strategy to defuse risks and seize opportunities.On one hand,China should influence the restructuring of GVCs evolution and strengthen its supply chains by playing an active role in economic globalization and the international division.On the other hand,China should proactively respond to GVCs restructuring amid rising trade protectionism,defuse risks from trade protectionism by opening wider to the outside world,and strive to upgrade industrial and supply chains while enhancing the security and stability of their nation.展开更多
By use of the Hartree approximation and the method of multiple scales, we investigate quantum solitons and intrinsic localized modes in a one-dimensional antiferromagnetic chain. It is shown that there exist solitons ...By use of the Hartree approximation and the method of multiple scales, we investigate quantum solitons and intrinsic localized modes in a one-dimensional antiferromagnetic chain. It is shown that there exist solitons of two different quantum frequency bands: i.e., magnetic optical solitons and acoustic solitons. At the boundary of the Brillouin zone, these solitons becornc quantum intrinsic localized modes: their quantum eigenfrequencics are below the bottom of the harmonic optical frequency band and above the top of the harmonic acoustic frequency band.展开更多
This paper is concerned with the free boundary value problem for multidimensional Navier-Stokes equations with density-dependent viscosity where the flow density vanishes continuously across the free boundary. Local ...This paper is concerned with the free boundary value problem for multidimensional Navier-Stokes equations with density-dependent viscosity where the flow density vanishes continuously across the free boundary. Local (in time) existence of a weak solution is established; in particular, the density is positive and the solution is regular away from the free boundary.展开更多
Two soluble isomerized polyimides(PIs) synthesized from 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA) with either 2,2'-dimethylbenzidine(2,2'-DMB) or 3,3'-DMB were investigated by means ...Two soluble isomerized polyimides(PIs) synthesized from 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA) with either 2,2'-dimethylbenzidine(2,2'-DMB) or 3,3'-DMB were investigated by means of size-exclusion chromatography coupled with multi-angle laser light scattering,a viscometer and a refractive index detector in tetrahydrofuran(THF) with tetrabutylammonium bromide(TBAB) at 35 ℃.The corresponding parameters related to conformations α and ν,evaluated from the scaling relationships [η]=K η M α and R g =K g M ν,respectively,were 0.66±0.01 and 0.55±0.02 for poly(6FDA/3,3'-DMB),and 0.67±0.01 and 0.56±0.01 for poly(6FDA/2,2'-DMB),indicating a random coil conformation for both the samples in this mobile system.The persistence length l p and shift factor M L(relative molecular weight per unit contour length) were estimated from the relationship between intrinsic viscosity and molecular weight for the wormlike cylinder model proposed by Bohdanecky.Both l p and M L showed that the two PIs in THF are flexible chains and exhibit some local rigidity to some extent.展开更多
Given the vital importance of global value chains(GVCs)position for a country's international competitiveness,this paper tries to investigate the impacts of environmental regulation on the GVCs position of China...Given the vital importance of global value chains(GVCs)position for a country's international competitiveness,this paper tries to investigate the impacts of environmental regulation on the GVCs position of China's industrial sector.Using the latest value-added decomposition method,we first measure the GVCs position of China's industrial sector from 2003 to 2014.Subsequently,both two-stage least squares(2 SLS)method with panel data and mediating effect model are employed to empirically examine the effects of environmental regulation on China's position in GVCs.The results indicate that environmental regulation has significantly upgraded the GVCs position of China's industrial sector,and the effect is more evident for the sub-sectors with originally lower GVCs position.The mediation effect test shows that increasing R&D investment is an important channel through which environmental regulation affects the GVCs position of China's industrial sector,which verifies the existence of the Porter hypothesis.Further analysis finds that the enhancement of GVCs position of China's industrial sector caused by environmental regulation is mainly achieved through reducing the backward GVCs position.展开更多
A comprehensive understanding of the spatial interaction between the industrial undertaking capability and the position of the global value chain of the 12 East Asian countries is conducive to strengthening regional c...A comprehensive understanding of the spatial interaction between the industrial undertaking capability and the position of the global value chain of the 12 East Asian countries is conducive to strengthening regional cooperation, gaining a say in foreign trade and becoming the dominant player in the global division of labor system. The article reveals the operating rules of the interaction between the industrial undertaking capacity and the global value chain position of East Asian countries by calculating the Global Moran Index(Moran’s I), coupling coordination degree and other indicators. The results show that: in time, the values of industrial undertaking capacity and the positions of global value chain in East Asian countries showed a sustained and stable growth trend, and have a consistent trend of change. Spatially, both of the two indexes had significant positive spatial correlation, with Moran’s I showing an ‘inverted U’pattern, and the spatial aggregation distribution of global value chain position lagged behind the spatial aggregation distribution of industrial undertaking capacity by one year. In terms of spatial coupling coordination, the coupling coordination values of the two indicators show a steady upward trend. Combined with the comparative advantage of each country, this paper provides suggestions for promoting the positions of Chinese and other East Asian industries in the global value chain from the perspectives of enhancing independent innovation capability and upgrading industrial structure.展开更多
By means of the Glauber's coherent state method combined with multiple-scale method, this paper investigates the localized modes in a quantum one-dimensional Klein-Gordon chain and finds that the equation of motion o...By means of the Glauber's coherent state method combined with multiple-scale method, this paper investigates the localized modes in a quantum one-dimensional Klein-Gordon chain and finds that the equation of motion of annihilation operator is reduced to the nonlinear Schroedinger equation. Interestingly, the model can support both bright and dark small amplitude travelling and non-travelling nonlinear localized modes in different parameter spaces.展开更多
基金the part of the“Research on Paths to High-quality Development in Agriculture Against the Backdrop of Rural Revitalization,”a project of the Publicity Department of the CPC Central Committee for Young Talents in Publicity,Socialist Thought and Cultural Promotionthe National Social Science Fund of China-supported project,“Research on Theoretical Logic and Realization Path of Urban-Rural Integration Based on Industrial Internet”(21XJL001)+1 种基金the major project of Sichuan province in philosophy and social science planning,“Research on the Innovation and Policy Adaptation of Sichuan’s Agricultural Green Development System under the‘Dual Carbon’Goal”(SC22ZDYC44)the key project of Sichuan province in soft science research and planning,“Research on the Path to Peak Carbon and Carbon Neutrality of the Agricultural Sector in Rural Areas of Sichuan Province”(2022JDR0157).
文摘The green innovation value chain is a key step in transforming green,innovative scientific,and technological achievements into productive forces.The establishment of green innovation value chains based on value distribution rather than technical conditions can effectively overcome the common bottleneck faced by different nations during their green innovation endeavors,namely,the substitution of conventional products with green alternatives.This study investigates the impeded diffusion of green products and their underlying causes,analyzes the internal structure and mechanism of the green innovation value chain,and explores the establishment of regional green innovation value chains and the models available for value chain upgrading.
文摘This study evaluated the effectiveness of donor supported agricultural value chain development projects in sustainably narrowing yield gaps for banana smallholder farmer producers in Manicaland, Zimbabwe. The study used a mixed methods research design that relied on farmers records for the quantitative analysis and focus group discussion and in-depth interviews for key experts for the qualitative aspects. A mix of regression analysis, t-tests, Pearsons’s correlation and analysis of variance statistical methods were used for the quantitative analysis while thematic response analysis was used for the qualitative engagements. The findings showed that by the end of the activity, the project had successfully narrowed the banana yield gaps to 18.66 tons per hectare working with a potential yield base of 40 tons. However, 5 years after the project closure the yield gap had fallen to 24.7 tons indicating a lack of sustainability of yield gap reduction. However, the yield gap slump does not override the fact that farmers on average were still able to sell approximately 5 tons per every 6 months after 5 years from the project closure which is beyond any poverty threshold. This suggests genuine upward economic mobility. Additionally, in analyzing what factors had the greatest influence on yield gap reduction, the access to fertilizer ranked highest where genetics, irrigation and improved agronomy followed in that respective order. The study further showed that farmers who receive value chain development support whilst at an already commercialized state tend to maintain productivity thresholds higher in comparison to those who are at a pre commercial state. This is evidenced by the fact that the pre commercial farmers had a yield reduction of 30.83 percent after 5 years of the project closure whereas the former realized a productivity growth of 7.84%. In conclusion, whilst the intervention was successful in transitioning farmers out of poverty, more investment should be made towards transitioning smallholder farmers to integrated soil fertility management practices and improvement of agronomic efficiency through stronger on field collaboration between research institutions, the government and development institutions.
文摘With the Uruguay Round bringing agricultural trade into multilateral regulation,the major countries have actively participated in agricultural global value chains(AGVC)and occupied an important position according to their comparative advantages.Utilizing bilateral agricultural trade data of 66 countries based on the OECD Inter-Country-Input-Output Tables(OECD ICIO)from 2010 to 2018,this study applies social network analysis indicators to measure each country’s eigenvector centrality within AGVC and to examine the current global agricultural trade patterns,with particular attention to the changes in the status of world powers within AGVC.The main findings are as follows:first,with the multilateral and regional trade liberalization,growing numbers of developing nations,including China and India,are engaging in international agricultural trade,which contributes to its diversification;second,as AGVC develops,the structure of global agricultural trade networks has become more decentralized and balanced.This is evidenced by the emergence of additional central nodes,and large nations like the United States,which formerly held the most central position as indicated by a drop in its centrality,are becoming less dominant.
基金Under the auspices of National Natural Science Foundation of China(No.41971198)。
文摘Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study uses the social network analysis method,entropy method,multi-index comprehensive evaluation method,and quadratic assignment procedure analysis method to examine the characteristics and influencing factors of the urban networks of research and development(R&D),production,and sales formed as a result of the overseas investments of listed manufacturing companies in western China.Results showed that the three types of investment networks involved multiple industry types and multiple central cities with differentiated diversity and multicentrality.The R&D urban network’s leading sub-industries were the mechanical equipment and instruments,medicine and biological products,and metal and nonmetal industries.The destination cities were mostly those home to educational and scientific research centers.The production urban network’s leading sub-industries were the mechanical equipment,instrument,and food and beverage industries.The destination cities were mostly regional central cities in developing countries.The sales urban network’s leading sub-industries were the mechanical equipment and instrument,metal and nonmetal,and petrochemical and plastics industries.The destination cities were numerous and scattered.In addition,the R&D urban network easily formed specialized clusters,core nodes easily controlled the production urban network,and individual nodes did not easily control the sales urban network.Technological and economic system advantages greatly impacted the three network types.Considering the different influencing factors,this study suggests optimizing the institutional investment environment to narrow the institutional gap,adjusting and optimizing the investment layout to expand overseas markets,and increasing R&D funds to stimulate technological progress and overseas investments in western China.
文摘Poultry production has important economic, social and cultural benefits and plays a significant role in family nutrition in developing countries. In most tropical countries it is based mainly on scavenging production systems, which makes substantial contributions to household food security throughout the developing world. All over the developing world, these low-input and low-output poultry-husbandry systems are an integral component of the livelihoods of most rural, peri-urban, and some urban households and are likely to continue to meet this role for the foreseeable future. Although the contributions of chicken farming to household food security and income as well as its potential contribution to the income of rural communities are known, chicken production is practiced very little in Somaliland. Therefore, the purpose of this project was to carry out a baseline study on the potential of chicken production (eggs and meats) in Somaliland and its existing chain gaps in order to identify whether chicken production could be a successful income source for women and boost female economic activity in the project areas of Saaxil, MaroodiJeex and Togdheer. The result from this assessment showed that rural chicken production was a women-related activity that helped them to be the sole decision-makers and also users of the benefits regarding chicken and chicken products. The main purposes for keeping chicken were egg production for income generating, home consumption and meat provision. The major constraints for rural poultry keeping were the lack of extension and veterinary services, predators, poor housing, poor breeds, and lack of financial services among others. Women in all the selected villages made remarkable contributions to the local chicken production system. The result of the assessments showed that indigenous poultry value chain consisted of producers, collectors/retaileres, shops and consumers/restaurents. However, the absence of processors along the chain means that chickens are sold live and consequently cannot be retailed through formal channels like supermarkets leading to the exclusion of potential customers in the middle and high income categories who normally shop from supermarkets. Furthermore, as population and incomes grow, demand for indigenous chicken is likely to continue growing, especially among the high income groups who not only prefer it for its taste but also for health reasons due to its low fat content. Finally, although the value chain for indigenous chickens shows potential growth for all the players along the chain, there is a need to address the various constraints affecting the value chain for indigenous chickens in order to improve the operation of the chain hence leading to increased incomes for the value chain actors and at the same time ensuring cheap delivery of indigenous chicken in a more convenient form and in formal outlets.
基金Supported by National Natural Science Foundation of China(Grant Nos.52272433 and 11874110)Jiangsu Provincial Key R&D Program(Grant No.BE2021084)Technical Support Special Project of State Administration for Market Regulation(Grant No.2022YJ11).
文摘Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical structures.This paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well removed.Hence,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental datasets.The first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC.
基金National Social Science Foundation of China(No.09CGJ011)the Fundamental Research Funds for the Central Universities,China
文摘This paper develops a conceptual model to assess effect of outsourcing by integrating the theories of industrial upgrading and global value chain (GVC) governance. Contrary to the widely accepted perception that outsourcing is expected to generate positive spillover in particular, the findings indicate that outsourcing has different effects in different GVC governance modes. Excess outsourcing could structurally inhibit technology and management spillovers to subcontractors within the emerging economy context. Based on a case study of the Chinese textile and apparel (T & A) industry, it is found that the Chinese T & A industry has been trapped in the captive governance relationship with foreign buyers, and at the same time is capped below the function upgrading level. Consequences of the situation and implication are then discussed.
文摘This study aims to assess the small ruminant value chain in Al-Ruwaished District,Jordan,to identify the potential intervention areas that could improve the production efficiency and guarantee the sustainability of the small ruminant sector in this area.Sheep breeding is the source of livelihood for most of the people in Al-Ruwaished District,which is characterized by the large number of sheep and goats.We surveyed 5.0% of the small ruminant holders in the study area and conducted individual interviews and surveys with the potential actors in the value chain to undertake a small ruminant value chain analysis.From the survey,we found that the small ruminant value chain consists of five core functions,namely,input supply,production management,marketing,processing,and consumption.Despite the stable impression given by the large number of holdings in the small ruminant sector,the surveyed results show a clear fragility in the value chain of small ruminants in this area.The small ruminant production system is negatively impacted by climate change,especially continuous drought.In addition,the high prices of feed that the farmer cannot afford with clear and real absence of the governmental and non-governmental support activities also impact the development of the value chain.The results of strengths,weaknesses,opportunities,and threats(SWOT)analysis reveal that the major constraints faced by this value chain could be divided into external and internal threats.Specifically,the most prominent external threats are the nature of the desert land and continuous drought,while the major internal threats are the absence of appropriate infrastructure,shortage of inputs,and weakness in the production management and marketing.We proposed solutions to these challenges to ensure the sustainability and effectiveness of the sector,such as the formulation of emergency response plans to severe weather,qualifying farmers’skills,and establishment of agricultural cooperative societies.
基金Tropical Ocean University 2023 Provincial Key Discipline Construction Project-Business Administration.Project of the National Social Science Foundation:Research on the Cooperation Mechanism and Realisation Path for the Cooperative Development of the Cruise Industry in the Countries Surrounding the South China Sea(19XJY001)Key Laboratory of the Ministry of Culture and Tourism on Data Mining,Monitoring and Early Warning Technology for Island Tourism Resources(KLITRDMM 2022-15).
文摘Cruise value chain is to take the exchange of cruise products and services as the core in a certain spatial scope,and enterprises with core advantages within or between different industries establish associations in accordance with certain technical and economic conditions,so as to realise the multi-dimensional extension and value appreciation of the cruise value chain in the vertical and horizontal links,and ultimately establish a chain-network type of enterprise strategic alliance.This paper tries to analyse the value-added factors of the cruise industry chain by constructing a multi-level hierarchical structural model with reference to the influencing factor analysis methods of relevant literature-DEMATEL(Decision Making Experiment and Evaluation Experiment)and ISM(Interpretative Structural Model).The study shows that the innovation and scale value-added module in the upstream of the cruise industry chain is the core module of value-added of the whole cruise industry chain,and the value-added mainly originates from the design and manufacturing of cruise ships.The middle reaches of the cruise industry chain are mainly cruise operation enterprises,and the specificity of cruise operation determines that its brand value-added is mainly accomplished through the global layout of multinational corporations,and the cruise brand is able to drive the consumption demand and has value-added ability.The downstream value-added of the cruise industry chain is mainly realised through the increase in profits of cruise tourism service products.
基金the Special Project of the National Science Foundation of China(NSFC)“Open Development of China’s Trade and Investment:Basic Patterns,Overall Effects,and the Dual Circulations Paradigm”(Grant No.72141309)NSFC General Project“GVC Restructuring Effect of Emergent Public Health Incidents:Based on the General Equilibrium Model Approach of the Production Networks Structure”(Grant No.72073142)+1 种基金NSFC General Project“China’s Industrialization Towards Mid-and High-End Value Chains:Theoretical Implications,Measurement and Analysis”(Grant No.71873142)the Youth project of The National Social Science Fund of China“Research on the green and low-carbon development path and policy optimization of China’s foreign trade under the goal of‘dual carbon’”(Grant No.22CJY019).
文摘Productivity and international energy price shocks are reflected in PPI and CPI via industrial chains.China’s in-depth participation into the global value chains has increasingly lengthened its industrial production chains.The question is how the changing length of production chains will affect CPI and PPI,as well as CPI-PPI correlation?By constructing a global input-output price model,this paper offers a theoretical discussion on the impact of production chain length on the CPI-PPI divergence.Our findings suggest that the price shock of international bulk commodities has a greater impact on China’s PPI than that on CPI.The effects on both China’s PPI and CPI estimated by using the single-country input-output model are higher than the results estimated with the global input-output model.However,the difference between CPI and PPI variations estimated with the global input-output model is greater than the result estimated with the single-country input-output model,which supports the view that the lengthening of production chains,especially international production chains,leads to a divergence between CPI and PPI.Empirical results based on cross-national panel data also suggest that the lengthening of production chains has reduced the CPI-PPI correlation for countries,i.e.the lengthening of production chains has increased the PPI-CPI divergence.That is to say,policymakers should target not just CPI in maintaining price stability,but instead focus on the stability of both PPI and CPI.Efforts can be made to proactively adjust the price index system,and formulate the industrial chain price index.
基金This study was supported by the Humanities and Social Sciences Project of the Ministry of Education(No.23YJA790070)the Graduate Innovation Research Project of Southwest Minzu University(No.YB2022621)the Research Project of BCIMY(No.BCIMY1910).
文摘Establishing a sense of ritual within tourism consumption scenarios offers tourists the opportunity for interactive engagement.Drawing upon the value co-creation theory,this study constructed an influence mechanism model to examine tourists'active engagement in the process of co-creating tourism experience values.It employed Partial Least Squares Structural Equation Modeling(PLS-SEM)to empirically test the proposed hypotheses.The findings demonstrate that the model constructed in the present study exhibits robust reliability,validity,and explanatory power.The perception of the sense of ritual in tourism exerts a significant positive influence on tourists’co-creation of tourism experience values,thereby significantly enhancing both the communitas and flow experienced by tourists during their travels.Moreover,such communitas and flow can mediate the influence of the sense of ritual in tourism on tourists’co-creation of tourism experience values.This study contributes to advancing the current research on tourists’co-creation of tourism experience values and the sense of ritual in tourism,thereby providing theoretical foundations for cultivating a sense of ritual within tourism consumption scenarios.
文摘In recent years,with the complexity and variability of international finance,debt,and geopolitical risks,the growth rate of domestic economic operations has slowed down.More enterprise groups are facing the transformation and upgrading from domestic leadership to internationalization,achieving revenue growth of nearly 10 billion yuan per year against the trend.The severe and complex internal and external environment has brought many challenges to the supply chain for enterprises.This article focuses on the goal of an“enterprise supply chain system focusing on value creation,strengthening system linkage,and improving overall chain efficiency,”aiming to find solutions to problems such as strong demand variability,frequent emergency needs,coexistence of project shortages and inventory surplus,long material turnover cycles,and high organizational complexity.By searching for key activities in the entire business chain of demand,design,production,service,and finance,implementing source planning,process control,system linkage,analysis and summary,and team collaboration,we have achieved more scientific demand forecasting,more accurate planning,more effective procurement cost reduction,more stable production performance supply,more convenient inventory sharing services,and more efficient integration of business and financial policies.
文摘Global value chains(GVCs)have entered a new stage of restructuring characterized by trends towards localization,regionalization and diversification.These trends can be attributed to the evolution of the international division,irrational responses to crisis shocks,and trade protectionism.In this context,China’s industrial and supply chain upgrades face both opportunities and challenges which require navigating the adverse effects of industrial re-shoring,unfair technology competition,and changes in the global industrial layout.Yet,such challenges may create pressures for China to accelerate innovation,overcome the low-end lock-up effect by creating regional value chains,and broaden international cooperation.China needs to explore an effective strategy to defuse risks and seize opportunities.On one hand,China should influence the restructuring of GVCs evolution and strengthen its supply chains by playing an active role in economic globalization and the international division.On the other hand,China should proactively respond to GVCs restructuring amid rising trade protectionism,defuse risks from trade protectionism by opening wider to the outside world,and strive to upgrade industrial and supply chains while enhancing the security and stability of their nation.
基金Project supported by the Natural Science Foundation of Hunan Province, China (Grant No 03JJY6008).
文摘By use of the Hartree approximation and the method of multiple scales, we investigate quantum solitons and intrinsic localized modes in a one-dimensional antiferromagnetic chain. It is shown that there exist solitons of two different quantum frequency bands: i.e., magnetic optical solitons and acoustic solitons. At the boundary of the Brillouin zone, these solitons becornc quantum intrinsic localized modes: their quantum eigenfrequencics are below the bottom of the harmonic optical frequency band and above the top of the harmonic acoustic frequency band.
基金partially supported by the NSFC(10871134)the AHRDIHL Project of Beijing Municipality (PHR201006107)
文摘This paper is concerned with the free boundary value problem for multidimensional Navier-Stokes equations with density-dependent viscosity where the flow density vanishes continuously across the free boundary. Local (in time) existence of a weak solution is established; in particular, the density is positive and the solution is regular away from the free boundary.
基金Supported by the National Natural Science Foundation of China(No.20674085)the Funds for Creative Researth Groups of China(No.50921062)the Project of Bureau of Science and Technology of Jilin Province,China(No.20101535)
文摘Two soluble isomerized polyimides(PIs) synthesized from 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA) with either 2,2'-dimethylbenzidine(2,2'-DMB) or 3,3'-DMB were investigated by means of size-exclusion chromatography coupled with multi-angle laser light scattering,a viscometer and a refractive index detector in tetrahydrofuran(THF) with tetrabutylammonium bromide(TBAB) at 35 ℃.The corresponding parameters related to conformations α and ν,evaluated from the scaling relationships [η]=K η M α and R g =K g M ν,respectively,were 0.66±0.01 and 0.55±0.02 for poly(6FDA/3,3'-DMB),and 0.67±0.01 and 0.56±0.01 for poly(6FDA/2,2'-DMB),indicating a random coil conformation for both the samples in this mobile system.The persistence length l p and shift factor M L(relative molecular weight per unit contour length) were estimated from the relationship between intrinsic viscosity and molecular weight for the wormlike cylinder model proposed by Bohdanecky.Both l p and M L showed that the two PIs in THF are flexible chains and exhibit some local rigidity to some extent.
基金Financial supports from the National Natural Science Foundation of China(under Grants No.72073105,71774122 and 71874064)。
文摘Given the vital importance of global value chains(GVCs)position for a country's international competitiveness,this paper tries to investigate the impacts of environmental regulation on the GVCs position of China's industrial sector.Using the latest value-added decomposition method,we first measure the GVCs position of China's industrial sector from 2003 to 2014.Subsequently,both two-stage least squares(2 SLS)method with panel data and mediating effect model are employed to empirically examine the effects of environmental regulation on China's position in GVCs.The results indicate that environmental regulation has significantly upgraded the GVCs position of China's industrial sector,and the effect is more evident for the sub-sectors with originally lower GVCs position.The mediation effect test shows that increasing R&D investment is an important channel through which environmental regulation affects the GVCs position of China's industrial sector,which verifies the existence of the Porter hypothesis.Further analysis finds that the enhancement of GVCs position of China's industrial sector caused by environmental regulation is mainly achieved through reducing the backward GVCs position.
基金Under the auspices of China’s National Social Science Research Grant(No.16BTJ025)。
文摘A comprehensive understanding of the spatial interaction between the industrial undertaking capability and the position of the global value chain of the 12 East Asian countries is conducive to strengthening regional cooperation, gaining a say in foreign trade and becoming the dominant player in the global division of labor system. The article reveals the operating rules of the interaction between the industrial undertaking capacity and the global value chain position of East Asian countries by calculating the Global Moran Index(Moran’s I), coupling coordination degree and other indicators. The results show that: in time, the values of industrial undertaking capacity and the positions of global value chain in East Asian countries showed a sustained and stable growth trend, and have a consistent trend of change. Spatially, both of the two indexes had significant positive spatial correlation, with Moran’s I showing an ‘inverted U’pattern, and the spatial aggregation distribution of global value chain position lagged behind the spatial aggregation distribution of industrial undertaking capacity by one year. In terms of spatial coupling coordination, the coupling coordination values of the two indicators show a steady upward trend. Combined with the comparative advantage of each country, this paper provides suggestions for promoting the positions of Chinese and other East Asian industries in the global value chain from the perspectives of enhancing independent innovation capability and upgrading industrial structure.
基金Project supported by the Key Project of Hunan Provincial Educational Department of China (Grant No 04A058)
文摘By means of the Glauber's coherent state method combined with multiple-scale method, this paper investigates the localized modes in a quantum one-dimensional Klein-Gordon chain and finds that the equation of motion of annihilation operator is reduced to the nonlinear Schroedinger equation. Interestingly, the model can support both bright and dark small amplitude travelling and non-travelling nonlinear localized modes in different parameter spaces.