On the basis of defining the producers in the supply chain of agricultural products,the SWOT analysis is adopted to analyze the advantages,disadvantages,opportunities and threats of producers in the supply chain of Ch...On the basis of defining the producers in the supply chain of agricultural products,the SWOT analysis is adopted to analyze the advantages,disadvantages,opportunities and threats of producers in the supply chain of Chinese agricultural products.The paper analyzes the advantages of producers in the supply chain of agricultural products from three aspects including land resources,technology level of producers and input costs.The disadvantages of producers in the supply chain of agricultural products are analyzed from three aspects including scale level,mechanization and technology level and profit level.The opportunities of producers in the supply chain of agricultural products are analyzed from the aspects of laws,policies,capitals and technologies.The threats confronted by the producers in the supply chain of agricultural products are analyzed from foreign producers,negotiation control of supply chain of agricultural chain,environment protection and quality safety standard.On the basis of the analysis,the relevant suggestions on facilitating the interests of producers in the supply chain of Chinese agricultural products are put forward,including fully displaying the advantages of land resources;improving the knowledge and technology level of supply chain of agricultural production;establishing the alliances of producers of agricultural products to expand production scale;improving the quality of agricultural products to satisfy the relevant safety quality standard and environmental protection standard.展开更多
Following the reform of the governance of irrigation schemes in Niger, producer cooperatives are encountering real difficulties in ensuring effective and efficient management of irrigation water, infrastructure mainte...Following the reform of the governance of irrigation schemes in Niger, producer cooperatives are encountering real difficulties in ensuring effective and efficient management of irrigation water, infrastructure maintenance and renewal of hydromechanical equipment. The objective of this research is to analyze the issues and challenges of capacity building for Konni producers in the context of AHA management reform in Niger. The methodological approach adopted is based on documentary research and field surveys with all the actors directly concerned with the management of the Konni irrigated perimeter. A total of 448 people were interviewed in all the localities selected. Direct observation and interview are the two field data collection techniques adopted. The data collected was processed and on the basis of the established diagnosis, the training needs were identified. The results show that there are several experiences in terms of training and capacity building of actors in charge of the management of irrigation systems at the Konni AHA level. However, the sustainability of the perimeter is threatened by various crises. The main themes that founded the first training were related to the mobilization, transport and distribution of irrigation water, operation and maintenance, and setting and collection of the fee. In view of the expectations of operators, future issues and challenges, the training modules are increasingly oriented towards social management, the integration of gender in management and environmental impacts. Even if technical progress is possible, the real lever is organizational and requires the professionalization of irrigators. This process requires a new pedagogical approach aimed at irrigators.展开更多
The aim of the present study was to evaluate the impact of the technological level in small-scale dual-purpose cow-calf <em>Bos indicus</em> female operations on the resumption of the ovarian activity post...The aim of the present study was to evaluate the impact of the technological level in small-scale dual-purpose cow-calf <em>Bos indicus</em> female operations on the resumption of the ovarian activity post-partum. A total of 13 small scale dual-purpose <em>Bos indicus</em> × <em>Bos taurus</em> operations were included in this experiment and they were classified according to their technological status as: high technological status (HT), medium technological status (MT) and low technological status (LT). Ninety-three mature cows were treated with either a CIDR (controlled internal drug release device) with estradiol benzoate (CIDR+EB) or alone (CIDR). At day 9 all animals received intravaginally a CIDR for nine days. At day 0, the CIDR was withdrawn and 24 hours later one dose of estradiol benzoate was administered to 51 cows (17 in HT, 17 in MT and 17 in LT), the remaining animals (n = 42) did not receive the estradiol benzoate administration (14 in HT, 13 in MT and 15 in LT). Comparisons were performed on serum progesterone concentrations after CIDR treatment. By day 7 after implant withdrawal, the proportion of cows that resume ovarian activity detected by progesterone concentration increased in all technological level farms, no statistical main effect was observed within technological level. By day 17 there was a significant main effect of technological level (P = 0.05) on the proportion of animal that resumed the estrous cycles, but neither a main effect of treatment (P = 0.97) nor an interaction between technological level and treatment (P = 0.98). Furthermore, technological level of the farm showed a tendency (P = 0.07) to affect that resume the estrous activity, and a significant effect of treatment was observed (P = 0.005) but no interaction between technological level and treatment. The proportion of cows that showed estrus was different across technological level (P = 0.02), the highest proportion of cows showing estrus regardless of treatment was in the HT: 90% (40% CIDR and 50% CIDR+EB), MT: 50% (13.3% CIDR and 36.7% CIDR+EB) and in the LT: 50% (18.8% CIDR and 31.3% CIDR+EB). In conclusion, the combination of a progestogen and estradiol benzoate resulted in a high proportion of cows that were induced to resume the ovarian activity and this treatment was particularly beneficial in the medium and low technological status of the farms.展开更多
Music from a piano embodies widetechniques of expression, so thepiano is reputed as the king of musicalinstruments. China’s piano production datesback four decades. At present, there are 20piano production enterprise...Music from a piano embodies widetechniques of expression, so thepiano is reputed as the king of musicalinstruments. China’s piano production datesback four decades. At present, there are 20piano production enterprises in the county,including such backbone enterprises as theGuangzhou Pearl River Piano IndustrialCorporation, the Beijing Xinghai MusicalInstruments Corporation Ltd., the ShanghaiPiano Corporation, the Yingkou NortheastPiano(Group) Corporation and the展开更多
Stricter laws needed> Gao Xiaosong-music producer Piracy is better described as a global problem, and is not unique to China. You never expect to rid the country of music piracy completely [in a short period].China...Stricter laws needed> Gao Xiaosong-music producer Piracy is better described as a global problem, and is not unique to China. You never expect to rid the country of music piracy completely [in a short period].China’s music copyright infringement problems remain more severe than that of展开更多
The issue of "who will grow grain in the future in China" attracts more and more attention. We estimate the structure of China's grain producers at present,and summarize the phenomena and reasons why pe...The issue of "who will grow grain in the future in China" attracts more and more attention. We estimate the structure of China's grain producers at present,and summarize the phenomena and reasons why peasants would not like to grow grain. We analyze the agricultural population at the time of China's total population peak around 2033,and we predict there will be a multi-producer structure of grain growing.The household contracts will be as the basis of grain operations then,and the quantity of small-scale households will decrease but still be huge.The degree of organization of rural households will increase and the role of cooperatives will be strengthened remarkably. We propose the " quality" requirements to ensure the grain production,and note different special groups will be the new forces on farming and grain growing.展开更多
The development of aquaculture is an important way to ensure the diversification of China's food supply and food safety.As a market-oriented risk management tool,aquaculture insurance plays a vital role in enhanci...The development of aquaculture is an important way to ensure the diversification of China's food supply and food safety.As a market-oriented risk management tool,aquaculture insurance plays a vital role in enhancing the risk resistance of China's aquaculture industry and promoting its high-quality development.Although there has been some discussion on aquaculture insurance in existing studies,there is still a lack of research on the influencing factors of fishery producers'willingness to participate in aquaculture insurance.In order to better understand the intrinsic and extrinsic factors affecting fishery producers'participation in aquaculture insurance,in this paper,based on the Theory of Reasoned Action and from the perspectives of external subjective norms and internal risk perceptions,we thoroughly investigate the effects and mechanism of subjective norms and risk perceptions on the willingness of fishery producers to participate in aquaculture insurance,and we further explore the moderating effect of insurance cognition in this relationship,and construct a corresponding theoretical model.By empirically analyzing the sample data of 238 fishery producers in the Yangtze River Delta region,we find that injunctive norms,descriptive norms and risk perception have positive effects on fishery producers'willingness to participate in aquaculture insurance,with descriptive norms having the most significant impact.In addition,insurance cognition positively moderated the effects of subjective norms and risk perception on fishery producers'willingness to participate in aquaculture insurance,and the moderating effect on risk perception and fishery producers'willingness to participate in aquaculture insurance was the most obvious.Based on the above findings,we put forward a series of targeted recommendations,including strengthening the publicity of aquaculture insurance,providing diversified and targeted aquaculture insurance subsidies,constructing grassroots service stations for aquaculture insurance,and strengthening the training of professional knowledge in aquaculture insurance,etc.The above recommendations are intended to provide a scientific theoretical basis and decision-making reference for the high-quality development of the aquaculture industry.展开更多
Dream-Building in Tangwangcheng Chief Director:Chen Xichan Length:Four Episodes Producers:The Third Division of Xinjiang Production and Construction Corps and Hunan Broadcasting System Broadcasting Platforms:Mango TV,...Dream-Building in Tangwangcheng Chief Director:Chen Xichan Length:Four Episodes Producers:The Third Division of Xinjiang Production and Construction Corps and Hunan Broadcasting System Broadcasting Platforms:Mango TV,Tencent Video,Youku,and bilibili.展开更多
Background:Poultry production cluster(PPC)programs are key strategies in many Asian countries to engage small commercial poultry producers in high-value production chains and to control infectious poultry diseases.Thi...Background:Poultry production cluster(PPC)programs are key strategies in many Asian countries to engage small commercial poultry producers in high-value production chains and to control infectious poultry diseases.This study assessed the multiple impacts of PPCs through a transdisciplinary ecohealth approach in four Asian countries,and drew the implications for small producers to improve their livelihoods and reduce the risk of spreading infectious diseases in the poultry sector.Methods:The data collection combined both quantitative and qualitative methods.It comprised:formal structured household survey questionnaires,measuring the biosecurity level of poultry farms with a biosecurity score card;and key informant interviews.Descriptive statistics were used to process the quantitative data and a content analysis was used to process the qualitative data.Results:This research found that poultry farms in clusters do not necessarily have better economic performance than those outside PPCs.Many farmers in PPCs only consider them to be an advantage for expanding the scale of their poultry operations and improving household incomes,and they are less concerned about-and have limited capacities to-enhancing biosecurity and environmental management.We measured the biosecurity level of farms in PPCs through a 14-item checklist and found that biosecurity is generally very low across all sample sites.The increased flies,mosquitoes,rats,and smells in and around PPCs not only pollute the environment,but also cause social conflicts with the surrounding communities.Conclusion:This research concluded that a poultry cluster,mainly driven by economic objectives,is not necessarily a superior model for the control of infectious diseases.The level of biosecurity in PPCs was found to be low.Given the intensity of poultry operations in PPCs(farms are densely packed into clusters),and the close proximity to residential areas of some PPCs,the risk of spreading infectious diseases,in fact,increases.Good management and collective action for implementing biosecurity measures are key for small producers in PPCs to address common challenges and pursue health-based animal production practices.展开更多
Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demand...Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demands for specialty maize varieties,distinctive fresh produce cultivars characterized by unique textures have gained considerable popularity among consumers(Boyer and Shannon 1984).Notably,sweet maize is often referred to as the‘King of fruits and vegetables'due to its richness in polysaccharides,dietary fiber,trace elements,vitamins,linoleic acid,and other essential nutrients(Revilla et al.2021).展开更多
The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish ...The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and cellulose.Herein,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of cellulose.The optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of cellulose.The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to cellulose.Furthermore,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea solvent.The concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.展开更多
Matter and Radiation at Extremes(MRE),is committed to the publication of original and impactful research and review papers that address extreme states of matter and radiation,and the associated science and technology ...Matter and Radiation at Extremes(MRE),is committed to the publication of original and impactful research and review papers that address extreme states of matter and radiation,and the associated science and technology that are employed to produce and diagnose these conditions in the laboratory.Drivers,targets and diagnostics are included along with related numerical simulation and computational methods.It aims to provide a peer-reviewed platform for the international physics community and promote worldwide dissemination of the latest and impactful research in related fields.展开更多
Quasi-hemispherical magnetized collisionless shocks have been generated at the SG-II laser facility through the interaction between a laserproduced supersonic plasma flow and a magnetized ambient plasma,exhibiting an ...Quasi-hemispherical magnetized collisionless shocks have been generated at the SG-II laser facility through the interaction between a laserproduced supersonic plasma flow and a magnetized ambient plasma,exhibiting an angular asymmetric shock profile accompanied by asymmetric ion acceleration.We have conducted test particle simulations using the electromagnetic fields derived from 2D MHD simulations to investigate the asymmetry of ion acceleration.The simulations reproduce the angular asymmetry of the shock and the ion acceleration observed in experiments.The results indicate that shock drift acceleration is the primary mechanism for ion energization in the present quasiperpendicular magnetized shock.The asymmetric shock structure caused by nonuniform ambient plasma forms an asymmetric accelerated electric field,ultimately leading to angular asymmetric ion acceleration,which is consistent with space observations and our experimental results.Our study provides a plausible explanation for the discrepancies reported in previous ion acceleration experiments,and could contribute to understanding of the collisionless shock acceleration.展开更多
High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission ph...High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission phase and identifying the HHG mechanism.However,achieving this feature by applying traditional two-beam far-field interferometry to solid materials remains challenging.In this study,we present a novel interferometric approach that utilizes a single laser beam to excite two ZnO microwires(MWs)simultaneously,thereby generating coherent high-harmonic sources that form interference fringes in the far-field region.We leverage the diameter-dependent field-enhancement effect in MWs to measure the intensity-dependent fringe shift,revealing that the intraband current mechanism dominates the below-bandgap harmonic,whereas the interband polarization mechanism dominates the above-bandgap harmonic.This study offers a robust method for measuring the dipole phase of solid-state HHG and inspires intensity-modulated high-harmonic applications in coherent imaging and microdevice design.展开更多
As cobalt stayed at high price,net profits of 4major cobalt producers in China realizedsignificant growth in H1 of 2018.According to the semiannual report publishedon the evening of August 28,2018 by HanruiCobalt。
The competition among renewable power producers(RPPs)may cause the cleared power of RPPs to be less than the bidding power,while the impact of competition is neglected in the existing price-taker methods.To overcome t...The competition among renewable power producers(RPPs)may cause the cleared power of RPPs to be less than the bidding power,while the impact of competition is neglected in the existing price-taker methods.To overcome the above deficiency,this paper develops an optimal bidding strategy,considering the competition among RPPs.First,a bivariate stochastic optimization(BSO)model for a bidding strategy is proposed by considering the variable power output of RPPs and the competition among RPPs.Particularly,the cleared power estimated by the demand-supply ratio is a random variable in the proposed BSO model.Then,the Newton method and particle swarm optimization(PSO)are combined to solve the BSO model in which various probability distribution functions(PDFs)of renewable energy generation are considered.Finally,the effectiveness of the proposed method is verified based on the results of a case study,which shows that the proposed model performed better than the traditional chance-constrained programming(CCP)model in power market competition.展开更多
To help domestic phosphate fertilizer producer avoid shutdown and bankruptcy,China Phosphate Fertilizer Industry Assoeiation(CPFIA)claims for zero expor-tation tariff since May this year.The current exports tariff for...To help domestic phosphate fertilizer producer avoid shutdown and bankruptcy,China Phosphate Fertilizer Industry Assoeiation(CPFIA)claims for zero expor-tation tariff since May this year.The current exports tariff for phosphate fertilizers is 110% for fast season and 10% for slow season.(CCR2008 No.34)展开更多
基金Supported by the Innovation Fund Project for Graduate Student of Xihua University
文摘On the basis of defining the producers in the supply chain of agricultural products,the SWOT analysis is adopted to analyze the advantages,disadvantages,opportunities and threats of producers in the supply chain of Chinese agricultural products.The paper analyzes the advantages of producers in the supply chain of agricultural products from three aspects including land resources,technology level of producers and input costs.The disadvantages of producers in the supply chain of agricultural products are analyzed from three aspects including scale level,mechanization and technology level and profit level.The opportunities of producers in the supply chain of agricultural products are analyzed from the aspects of laws,policies,capitals and technologies.The threats confronted by the producers in the supply chain of agricultural products are analyzed from foreign producers,negotiation control of supply chain of agricultural chain,environment protection and quality safety standard.On the basis of the analysis,the relevant suggestions on facilitating the interests of producers in the supply chain of Chinese agricultural products are put forward,including fully displaying the advantages of land resources;improving the knowledge and technology level of supply chain of agricultural production;establishing the alliances of producers of agricultural products to expand production scale;improving the quality of agricultural products to satisfy the relevant safety quality standard and environmental protection standard.
文摘Following the reform of the governance of irrigation schemes in Niger, producer cooperatives are encountering real difficulties in ensuring effective and efficient management of irrigation water, infrastructure maintenance and renewal of hydromechanical equipment. The objective of this research is to analyze the issues and challenges of capacity building for Konni producers in the context of AHA management reform in Niger. The methodological approach adopted is based on documentary research and field surveys with all the actors directly concerned with the management of the Konni irrigated perimeter. A total of 448 people were interviewed in all the localities selected. Direct observation and interview are the two field data collection techniques adopted. The data collected was processed and on the basis of the established diagnosis, the training needs were identified. The results show that there are several experiences in terms of training and capacity building of actors in charge of the management of irrigation systems at the Konni AHA level. However, the sustainability of the perimeter is threatened by various crises. The main themes that founded the first training were related to the mobilization, transport and distribution of irrigation water, operation and maintenance, and setting and collection of the fee. In view of the expectations of operators, future issues and challenges, the training modules are increasingly oriented towards social management, the integration of gender in management and environmental impacts. Even if technical progress is possible, the real lever is organizational and requires the professionalization of irrigators. This process requires a new pedagogical approach aimed at irrigators.
文摘The aim of the present study was to evaluate the impact of the technological level in small-scale dual-purpose cow-calf <em>Bos indicus</em> female operations on the resumption of the ovarian activity post-partum. A total of 13 small scale dual-purpose <em>Bos indicus</em> × <em>Bos taurus</em> operations were included in this experiment and they were classified according to their technological status as: high technological status (HT), medium technological status (MT) and low technological status (LT). Ninety-three mature cows were treated with either a CIDR (controlled internal drug release device) with estradiol benzoate (CIDR+EB) or alone (CIDR). At day 9 all animals received intravaginally a CIDR for nine days. At day 0, the CIDR was withdrawn and 24 hours later one dose of estradiol benzoate was administered to 51 cows (17 in HT, 17 in MT and 17 in LT), the remaining animals (n = 42) did not receive the estradiol benzoate administration (14 in HT, 13 in MT and 15 in LT). Comparisons were performed on serum progesterone concentrations after CIDR treatment. By day 7 after implant withdrawal, the proportion of cows that resume ovarian activity detected by progesterone concentration increased in all technological level farms, no statistical main effect was observed within technological level. By day 17 there was a significant main effect of technological level (P = 0.05) on the proportion of animal that resumed the estrous cycles, but neither a main effect of treatment (P = 0.97) nor an interaction between technological level and treatment (P = 0.98). Furthermore, technological level of the farm showed a tendency (P = 0.07) to affect that resume the estrous activity, and a significant effect of treatment was observed (P = 0.005) but no interaction between technological level and treatment. The proportion of cows that showed estrus was different across technological level (P = 0.02), the highest proportion of cows showing estrus regardless of treatment was in the HT: 90% (40% CIDR and 50% CIDR+EB), MT: 50% (13.3% CIDR and 36.7% CIDR+EB) and in the LT: 50% (18.8% CIDR and 31.3% CIDR+EB). In conclusion, the combination of a progestogen and estradiol benzoate resulted in a high proportion of cows that were induced to resume the ovarian activity and this treatment was particularly beneficial in the medium and low technological status of the farms.
文摘Music from a piano embodies widetechniques of expression, so thepiano is reputed as the king of musicalinstruments. China’s piano production datesback four decades. At present, there are 20piano production enterprises in the county,including such backbone enterprises as theGuangzhou Pearl River Piano IndustrialCorporation, the Beijing Xinghai MusicalInstruments Corporation Ltd., the ShanghaiPiano Corporation, the Yingkou NortheastPiano(Group) Corporation and the
文摘Stricter laws needed> Gao Xiaosong-music producer Piracy is better described as a global problem, and is not unique to China. You never expect to rid the country of music piracy completely [in a short period].China’s music copyright infringement problems remain more severe than that of
基金Supported by the National Key Technology R&D Program(2013BAD15B00)
文摘The issue of "who will grow grain in the future in China" attracts more and more attention. We estimate the structure of China's grain producers at present,and summarize the phenomena and reasons why peasants would not like to grow grain. We analyze the agricultural population at the time of China's total population peak around 2033,and we predict there will be a multi-producer structure of grain growing.The household contracts will be as the basis of grain operations then,and the quantity of small-scale households will decrease but still be huge.The degree of organization of rural households will increase and the role of cooperatives will be strengthened remarkably. We propose the " quality" requirements to ensure the grain production,and note different special groups will be the new forces on farming and grain growing.
基金supported by the Freshwater Pearl Industry Development Planning Consulting Service Project.(Project number:D-8005-23-1090).
文摘The development of aquaculture is an important way to ensure the diversification of China's food supply and food safety.As a market-oriented risk management tool,aquaculture insurance plays a vital role in enhancing the risk resistance of China's aquaculture industry and promoting its high-quality development.Although there has been some discussion on aquaculture insurance in existing studies,there is still a lack of research on the influencing factors of fishery producers'willingness to participate in aquaculture insurance.In order to better understand the intrinsic and extrinsic factors affecting fishery producers'participation in aquaculture insurance,in this paper,based on the Theory of Reasoned Action and from the perspectives of external subjective norms and internal risk perceptions,we thoroughly investigate the effects and mechanism of subjective norms and risk perceptions on the willingness of fishery producers to participate in aquaculture insurance,and we further explore the moderating effect of insurance cognition in this relationship,and construct a corresponding theoretical model.By empirically analyzing the sample data of 238 fishery producers in the Yangtze River Delta region,we find that injunctive norms,descriptive norms and risk perception have positive effects on fishery producers'willingness to participate in aquaculture insurance,with descriptive norms having the most significant impact.In addition,insurance cognition positively moderated the effects of subjective norms and risk perception on fishery producers'willingness to participate in aquaculture insurance,and the moderating effect on risk perception and fishery producers'willingness to participate in aquaculture insurance was the most obvious.Based on the above findings,we put forward a series of targeted recommendations,including strengthening the publicity of aquaculture insurance,providing diversified and targeted aquaculture insurance subsidies,constructing grassroots service stations for aquaculture insurance,and strengthening the training of professional knowledge in aquaculture insurance,etc.The above recommendations are intended to provide a scientific theoretical basis and decision-making reference for the high-quality development of the aquaculture industry.
文摘Dream-Building in Tangwangcheng Chief Director:Chen Xichan Length:Four Episodes Producers:The Third Division of Xinjiang Production and Construction Corps and Hunan Broadcasting System Broadcasting Platforms:Mango TV,Tencent Video,Youku,and bilibili.
基金This research was funded by the Ecohealth Emerging Infectious Diseases Initiative(EcoEID),which is a CA$8.9 million global effort funded by Canada’s International Development Research Centre,Foreign Affairs,Trade and Development Canada(through the Global Health Research Initiative) and the Australian Department of Foreign Affairs and Trade.
文摘Background:Poultry production cluster(PPC)programs are key strategies in many Asian countries to engage small commercial poultry producers in high-value production chains and to control infectious poultry diseases.This study assessed the multiple impacts of PPCs through a transdisciplinary ecohealth approach in four Asian countries,and drew the implications for small producers to improve their livelihoods and reduce the risk of spreading infectious diseases in the poultry sector.Methods:The data collection combined both quantitative and qualitative methods.It comprised:formal structured household survey questionnaires,measuring the biosecurity level of poultry farms with a biosecurity score card;and key informant interviews.Descriptive statistics were used to process the quantitative data and a content analysis was used to process the qualitative data.Results:This research found that poultry farms in clusters do not necessarily have better economic performance than those outside PPCs.Many farmers in PPCs only consider them to be an advantage for expanding the scale of their poultry operations and improving household incomes,and they are less concerned about-and have limited capacities to-enhancing biosecurity and environmental management.We measured the biosecurity level of farms in PPCs through a 14-item checklist and found that biosecurity is generally very low across all sample sites.The increased flies,mosquitoes,rats,and smells in and around PPCs not only pollute the environment,but also cause social conflicts with the surrounding communities.Conclusion:This research concluded that a poultry cluster,mainly driven by economic objectives,is not necessarily a superior model for the control of infectious diseases.The level of biosecurity in PPCs was found to be low.Given the intensity of poultry operations in PPCs(farms are densely packed into clusters),and the close proximity to residential areas of some PPCs,the risk of spreading infectious diseases,in fact,increases.Good management and collective action for implementing biosecurity measures are key for small producers in PPCs to address common challenges and pursue health-based animal production practices.
基金supported by the Youth Research Foundation of Beijing Academy of Agriculture and Forestry Sciences,China(QNJJ202420)the Beijing Science and Technology Association Youth Lifting Project,Chinathe Beijing Municipal Rural Revitalization Agricultural Science and Technology Development Project,China(NY2401020224)。
文摘Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demands for specialty maize varieties,distinctive fresh produce cultivars characterized by unique textures have gained considerable popularity among consumers(Boyer and Shannon 1984).Notably,sweet maize is often referred to as the‘King of fruits and vegetables'due to its richness in polysaccharides,dietary fiber,trace elements,vitamins,linoleic acid,and other essential nutrients(Revilla et al.2021).
基金Science and Technology Department of Sichuan Province,Grant/Award Number:2022YFH0094National Natural Science Foundation of China,Grant/Award Numbers:51973141,52033005,U21A2090。
文摘The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and cellulose.Herein,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of cellulose.The optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of cellulose.The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to cellulose.Furthermore,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea solvent.The concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.
文摘Matter and Radiation at Extremes(MRE),is committed to the publication of original and impactful research and review papers that address extreme states of matter and radiation,and the associated science and technology that are employed to produce and diagnose these conditions in the laboratory.Drivers,targets and diagnostics are included along with related numerical simulation and computational methods.It aims to provide a peer-reviewed platform for the international physics community and promote worldwide dissemination of the latest and impactful research in related fields.
基金supported by the National Natural Science Foundation of China(Grant Nos.12205298 and 12175230)the Natural Science Foundation of Heilongjiang Province of China(Grant No.LH2024A010)+1 种基金the Fundamental Research Funds for the Central Universities,Controversial and Disruptive Projects of the Chinese Academy of Sciences(Grant No.FGSDFX-0001)the USTC Research Funds of the Double First-Class Initiative(Grant No.YD2140002006).
文摘Quasi-hemispherical magnetized collisionless shocks have been generated at the SG-II laser facility through the interaction between a laserproduced supersonic plasma flow and a magnetized ambient plasma,exhibiting an angular asymmetric shock profile accompanied by asymmetric ion acceleration.We have conducted test particle simulations using the electromagnetic fields derived from 2D MHD simulations to investigate the asymmetry of ion acceleration.The simulations reproduce the angular asymmetry of the shock and the ion acceleration observed in experiments.The results indicate that shock drift acceleration is the primary mechanism for ion energization in the present quasiperpendicular magnetized shock.The asymmetric shock structure caused by nonuniform ambient plasma forms an asymmetric accelerated electric field,ultimately leading to angular asymmetric ion acceleration,which is consistent with space observations and our experimental results.Our study provides a plausible explanation for the discrepancies reported in previous ion acceleration experiments,and could contribute to understanding of the collisionless shock acceleration.
基金supported by the National Key R&D Program of China (Grant Nos.2023YFA1406801 and 2022YFA1604301)the National Natural Science Foundation of China (Grant Nos.12434013,12595343,12404393,and 12174011)。
文摘High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission phase and identifying the HHG mechanism.However,achieving this feature by applying traditional two-beam far-field interferometry to solid materials remains challenging.In this study,we present a novel interferometric approach that utilizes a single laser beam to excite two ZnO microwires(MWs)simultaneously,thereby generating coherent high-harmonic sources that form interference fringes in the far-field region.We leverage the diameter-dependent field-enhancement effect in MWs to measure the intensity-dependent fringe shift,revealing that the intraband current mechanism dominates the below-bandgap harmonic,whereas the interband polarization mechanism dominates the above-bandgap harmonic.This study offers a robust method for measuring the dipole phase of solid-state HHG and inspires intensity-modulated high-harmonic applications in coherent imaging and microdevice design.
文摘As cobalt stayed at high price,net profits of 4major cobalt producers in China realizedsignificant growth in H1 of 2018.According to the semiannual report publishedon the evening of August 28,2018 by HanruiCobalt。
基金supported by National Key R&D Program of China(Technology and application of wind power/photovoltaic power prediction for promoting renewable energy consumption,2018YFB0904200)Eponymous Complement S&T Program of State Grid Corporation of China(SGLNDKOOKJJS1800266)。
文摘The competition among renewable power producers(RPPs)may cause the cleared power of RPPs to be less than the bidding power,while the impact of competition is neglected in the existing price-taker methods.To overcome the above deficiency,this paper develops an optimal bidding strategy,considering the competition among RPPs.First,a bivariate stochastic optimization(BSO)model for a bidding strategy is proposed by considering the variable power output of RPPs and the competition among RPPs.Particularly,the cleared power estimated by the demand-supply ratio is a random variable in the proposed BSO model.Then,the Newton method and particle swarm optimization(PSO)are combined to solve the BSO model in which various probability distribution functions(PDFs)of renewable energy generation are considered.Finally,the effectiveness of the proposed method is verified based on the results of a case study,which shows that the proposed model performed better than the traditional chance-constrained programming(CCP)model in power market competition.
文摘To help domestic phosphate fertilizer producer avoid shutdown and bankruptcy,China Phosphate Fertilizer Industry Assoeiation(CPFIA)claims for zero expor-tation tariff since May this year.The current exports tariff for phosphate fertilizers is 110% for fast season and 10% for slow season.(CCR2008 No.34)
