Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental e...Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental externalities. This paper quantiifes the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data col ected in 2012 and 2013, both Cobb-Douglas and Weibul damage control speciifcations are used to estimate the production function. Results show that pesticides have statistical y signiifcant pro-ductivity effect on crop yield. On the condition of Weibul damage control speciifcations, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17%of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas speciifcation without incorporating a damage control agent.展开更多
High photosynthetic productivity and widephotosynthetic adaptability are two importantphysiological characteristics for the sustained highyield and wider growing range of rice.Preliminaryexperiments indicated that the...High photosynthetic productivity and widephotosynthetic adaptability are two importantphysiological characteristics for the sustained highyield and wider growing range of rice.Preliminaryexperiments indicated that the utilization ofbeterosis between two different ecotype rices,US展开更多
Roselle calyces(RC)are a major crop for export and used to make a common drink in Egypt.Dried RC are commercially available and appreciated to obtain concentrated extracts which might be used in the food and pharmaceu...Roselle calyces(RC)are a major crop for export and used to make a common drink in Egypt.Dried RC are commercially available and appreciated to obtain concentrated extracts which might be used in the food and pharmaceutical industries for color and heath benefits.The objective of this research was to determine the chemical and the sensory properties of cupcakes formulated with Roselle calyces extract(RCE).Proximate analysis,anthocyanins,ascorbic acid,titrable acidity,%retaining of anthocyanins,color and sensory evaluations were done.RC cupcakes had high sensory scores(P<0.05)compared to control cupcakes.The parameter a*was significantly red in the RC cupcakes compared to control cupcakes along with 77%retaining of anthocyanins.The consumption of 100 g of the RC cupcakes would provide 465 mg/100 g dry matter anthocyanin that is more than 2 folds of the minimum average of the daily intake of anthocyanins for Americans,along∼1/3 of the daily dietary fiber intake to achieve fiber adequacy according to the Scientific Advisory Committee on Nutrition.RC cupcake can be a functional food and would have a“clean”label with cost effective advantage.展开更多
Cadmium （Cd） is an elemental heavy metal with widely recognized toxicity. Its long-term use in industrial processes and daily activities has caused alarming levels of Cd contamination in the natural environment. Acc...Cadmium （Cd） is an elemental heavy metal with widely recognized toxicity. Its long-term use in industrial processes and daily activities has caused alarming levels of Cd contamination in the natural environment. According to the estimates by the Agency of Toxic Substances and Disease Registry in the US, 25 000 to 30 000 metric tons of Cd is annually released to the environment . Results of previous studies have demonstrated that several organs are targets of Cd, but the most important of these targeted organs may be the testes.展开更多
This study determined the effects of selenium on the growth of Fusorium strains and the effects of products extracted from the fungal cultures on relevant indicators of chondrocytes injury.
Applying mathematic models to evaluate absorbed-N effects on dry matter production at different developmental stages would help determine proper nitrogen management according to crop demands and yield target. Two fiel...Applying mathematic models to evaluate absorbed-N effects on dry matter production at different developmental stages would help determine proper nitrogen management according to crop demands and yield target. Two field trials were carried out for establishing absorbed-N effects on dry matter production（ANEDr） model, using uniform design in 2010–2011and 2012–2013 winter wheat growing seasons in Hebei Province, China. Another field trial was carried out in 2010–2011for model validation. Dry matter and N concentration in leaf and non-leaf organs were measured at setting, jointing, anthesis, and maturity. Theory of best linear unbiased prediction（BLUP） was applied to analyse the N effects of leaf and non-leaf organs on dry matter production. Within ANEDr model, four N-affected phases at each stage were concerned,leaf absorbed-N effect before this stage, non-leaf organ absorbed-N effect before this stage,leaf absorbed-N effect at this stage, and non-leaf organ absorbed-N effect at this stage. In addition, developmental processes, genotype characters and temperature were three factors that determine each N effect. It was demonstrated that ANEDr model can precisely quantify absorbed-N effects on dry matter production with high correlation coefficient（r=0.95）. Comparing with other models, ANEDr model considered both leaf and non-leaf organs according to developmental processes of winter wheat, showed higher flexibility and simplicity, thus could be applied to different environments, cultivars and crops after parameter adjustment.展开更多
We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ...We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar展开更多
Background:Organic carbon stored in forest soils(SOC)represents an important element of the global C cycle.It is thought that the C storage capacity of the stable pool can be enhanced by increasing forest productivity...Background:Organic carbon stored in forest soils(SOC)represents an important element of the global C cycle.It is thought that the C storage capacity of the stable pool can be enhanced by increasing forest productivity,but empirical evidence in support of this assumption from forests differing in tree species and productivity,while stocking on similar substrate,is scarce.Methods:We determined the stocks of SOC and macro-nutrients(nitrogen,phosphorus,calcium,potassium and magnesium)in nine paired European beech/Scots pine stands on similar Pleistocene sandy substrates across a precipitation gradient(560–820mm∙yr−1)in northern Germany and explored the influence of tree species,forest history,climate,and soil pH on SOC and nutrient pools.Results:While the organic layer stored on average about 80%more C under pine than beech,the pools of SOC and total N in the total profile(organic layer plus mineral soil measured to 60 cm and extrapolated to 100 cm)were greater under pine by about 40%and 20%,respectively.This contrasts with a higher annual production of foliar litter and a much higher fine root biomass in beech stands,indicating that soil C sequestration is unrelated to the production of leaf litter and fine roots in these stands on Pleistocene sandy soils.The pools of available P and basic cations tended to be higher under beech.Neither precipitation nor temperature influenced the SOC pool,whereas tree species was a key driver.An extended data set(which included additional pine stands established more recently on former agricultural soil)revealed that,besides tree species identity,forest continuity is an important factor determining the SOC and nutrient pools of these stands.Conclusion:We conclude that tree species identity can exert a considerable influence on the stocks of SOC and macronutrients,which may be unrelated to productivity but closely linked to species-specific forest management histories,thus masking weaker climate and soil chemistry effects on pool sizes.展开更多
An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, clo...An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.展开更多
The objective of current study was to investigate the influence of brand related attributes on customer loyalty and repurchase intention in agricultural product marketing in Pakistan. Results of current study would he...The objective of current study was to investigate the influence of brand related attributes on customer loyalty and repurchase intention in agricultural product marketing in Pakistan. Results of current study would help the management of branded agricultural products, in Pakistan specifically and in developing countries generally, to formulate the best strategies to enhance customer loyalty in order to induce repurchase intention of them. Future research could be conducted in the same field by adopting larger sample size and this research can be replicated with specific product category.展开更多
The significance of cultural awareness in foreign language learning is an issue that earns hot discussion in the both fields of linguistics and instructional science. Being different from others, the observing angle i...The significance of cultural awareness in foreign language learning is an issue that earns hot discussion in the both fields of linguistics and instructional science. Being different from others, the observing angle in this paper lies in how the signal is processed. The four skills of listening, speaking, reading and writing are classified, by ways of signal processing, into two categorizes, namely receptive skills to which listening and reading belong, and productive skills to which speaking and writing belong. By analyzing the signal processing progress occurred in each of the four skills, the author is to argue the functions of cultural awareness in each of these four skills, in order to reinforce the importance of emphasizing cultural awareness in the new standards for English in China.展开更多
This study presents a theoretical investigation of a novel Ge/Si tunneling avalanche photodiode（TAPD）with an ultra-thin barrier layer between the absorption and p＋ contact layer. A high-frequency tunneling effect i...This study presents a theoretical investigation of a novel Ge/Si tunneling avalanche photodiode（TAPD）with an ultra-thin barrier layer between the absorption and p＋ contact layer. A high-frequency tunneling effect is introduced into the structure of the barrier layer to increase the high-frequency response when frequency is larger than 0.1 GHz, and the-3 dB bandwidth of the device increases evidently. The results demonstrate that the avalanche gain and-3 dB bandwidth of the TAPD can be influenced by the thickness and bandgap of the barrier layer.When the barrier thickness is 2 nm and the bandgap is 4.5 eV, the avalanche gain loss is negligible and the gainbandwidth product of the TAPD is 286 GHz, which is 18% higher than that of an avalanche photodiode without a barrier layer. The total noise in the TAPD was an order of magnitude smaller than that in APD without barrier layer.展开更多
We let a set of beam splitters of vacuum mode with a chosen transmittance parameter η in interaction with a separable coherent states.This model induces the production of an attenuated quantum channels based on entan...We let a set of beam splitters of vacuum mode with a chosen transmittance parameter η in interaction with a separable coherent states.This model induces the production of an attenuated quantum channels based on entangled optical states.Indeed,the decoherence effect is exploited positively here to generate such kind of quantum channels.Next,the amplitude damping and the entanglement amount of these produced channels are enhanced thereafter by a probabilistic quasi amplification process using again a 50 : 50 beam splitter.展开更多
Background:Sustainable land management is considered as one of the useful approaches to combat the threat of various forms of land degradation in Ethiopia.Despite this,there is scant information regarding households’...Background:Sustainable land management is considered as one of the useful approaches to combat the threat of various forms of land degradation in Ethiopia.Despite this,there is scant information regarding households’decision towards the implementation of sustainable land management practices.This paper,therefore,looks into the determinants for the continued use and choice of the sustainable land management practices by smallholder farmers and its productivity effect in three randomly chosen districts in Tigrai region,Ethiopia.The study uses data from household survey and key informant interviews.The paper employs a binary logit to analyze the determinants for the decision of continued use of sustainable land management practices,and a multivariate probit to analyze the simultaneous adoption decision of sustainable land management practices using cross sectional data collected from 230 randomly selected households.The impact of sustainable land management practices was also evaluated using propensity score matching.Results:Farming techniques,wealth status,agro-ecological variations,and plot level characteristics were found to be associated with the implementation decision of sustainable land management practices by rural households.Besides,institutional supports and access to basic infrastructures influenced the overall continued use of sustainable land management practices and the preference of households toward these practices.The study also finds that the value of crop production of sustainable land management users was on average 77–100%higher than that of nonusers.Conclusions:The results of the current study confirm that the implementation of various sustainable land management practices are influenced by farming technologies deployed by rural households,agro-ecological variations,plot characteristics,and institutional supports.The findings also affirm that most of the sustainable land management practices are complementary to one another,and implementing two or more sustainable land management practices on a given plot is highly associated with higher value of crop production.Such complementarity highlights that the productivity effect of a given sustainable land management practice is enhanced by the use of the other ones.展开更多
基金financial support from the National Natural Science Foundation of China (71173014 and 71210004)the China Scholarship Council (201306030053)
文摘Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental externalities. This paper quantiifes the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data col ected in 2012 and 2013, both Cobb-Douglas and Weibul damage control speciifcations are used to estimate the production function. Results show that pesticides have statistical y signiifcant pro-ductivity effect on crop yield. On the condition of Weibul damage control speciifcations, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17%of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas speciifcation without incorporating a damage control agent.
文摘High photosynthetic productivity and widephotosynthetic adaptability are two importantphysiological characteristics for the sustained highyield and wider growing range of rice.Preliminaryexperiments indicated that the utilization ofbeterosis between two different ecotype rices,US
文摘Roselle calyces(RC)are a major crop for export and used to make a common drink in Egypt.Dried RC are commercially available and appreciated to obtain concentrated extracts which might be used in the food and pharmaceutical industries for color and heath benefits.The objective of this research was to determine the chemical and the sensory properties of cupcakes formulated with Roselle calyces extract(RCE).Proximate analysis,anthocyanins,ascorbic acid,titrable acidity,%retaining of anthocyanins,color and sensory evaluations were done.RC cupcakes had high sensory scores(P<0.05)compared to control cupcakes.The parameter a*was significantly red in the RC cupcakes compared to control cupcakes along with 77%retaining of anthocyanins.The consumption of 100 g of the RC cupcakes would provide 465 mg/100 g dry matter anthocyanin that is more than 2 folds of the minimum average of the daily intake of anthocyanins for Americans,along∼1/3 of the daily dietary fiber intake to achieve fiber adequacy according to the Scientific Advisory Committee on Nutrition.RC cupcake can be a functional food and would have a“clean”label with cost effective advantage.
基金supported by the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China(No.08KJD230002)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Cadmium （Cd） is an elemental heavy metal with widely recognized toxicity. Its long-term use in industrial processes and daily activities has caused alarming levels of Cd contamination in the natural environment. According to the estimates by the Agency of Toxic Substances and Disease Registry in the US, 25 000 to 30 000 metric tons of Cd is annually released to the environment . Results of previous studies have demonstrated that several organs are targets of Cd, but the most important of these targeted organs may be the testes.
基金funded by the Natural Science Basic Research Plan of Shaanxi Province,China(2014JM4170)the Department of disease control of Shaanxi Health and Family Planning Commission,China(2010/2012)
文摘This study determined the effects of selenium on the growth of Fusorium strains and the effects of products extracted from the fungal cultures on relevant indicators of chondrocytes injury.
基金supported by the Special Fund for Agro-Scientific Research in the Public Interest, China (201203031)the China Agriculture Research System (CARS-02-26)
文摘Applying mathematic models to evaluate absorbed-N effects on dry matter production at different developmental stages would help determine proper nitrogen management according to crop demands and yield target. Two field trials were carried out for establishing absorbed-N effects on dry matter production（ANEDr） model, using uniform design in 2010–2011and 2012–2013 winter wheat growing seasons in Hebei Province, China. Another field trial was carried out in 2010–2011for model validation. Dry matter and N concentration in leaf and non-leaf organs were measured at setting, jointing, anthesis, and maturity. Theory of best linear unbiased prediction（BLUP） was applied to analyse the N effects of leaf and non-leaf organs on dry matter production. Within ANEDr model, four N-affected phases at each stage were concerned,leaf absorbed-N effect before this stage, non-leaf organ absorbed-N effect before this stage,leaf absorbed-N effect at this stage, and non-leaf organ absorbed-N effect at this stage. In addition, developmental processes, genotype characters and temperature were three factors that determine each N effect. It was demonstrated that ANEDr model can precisely quantify absorbed-N effects on dry matter production with high correlation coefficient（r=0.95）. Comparing with other models, ANEDr model considered both leaf and non-leaf organs according to developmental processes of winter wheat, showed higher flexibility and simplicity, thus could be applied to different environments, cultivars and crops after parameter adjustment.
文摘We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar
基金funded by the Federal Ministry for Education and Research(BMBF)through a grant to CL(project number:01LC1314B).
文摘Background:Organic carbon stored in forest soils(SOC)represents an important element of the global C cycle.It is thought that the C storage capacity of the stable pool can be enhanced by increasing forest productivity,but empirical evidence in support of this assumption from forests differing in tree species and productivity,while stocking on similar substrate,is scarce.Methods:We determined the stocks of SOC and macro-nutrients(nitrogen,phosphorus,calcium,potassium and magnesium)in nine paired European beech/Scots pine stands on similar Pleistocene sandy substrates across a precipitation gradient(560–820mm∙yr−1)in northern Germany and explored the influence of tree species,forest history,climate,and soil pH on SOC and nutrient pools.Results:While the organic layer stored on average about 80%more C under pine than beech,the pools of SOC and total N in the total profile(organic layer plus mineral soil measured to 60 cm and extrapolated to 100 cm)were greater under pine by about 40%and 20%,respectively.This contrasts with a higher annual production of foliar litter and a much higher fine root biomass in beech stands,indicating that soil C sequestration is unrelated to the production of leaf litter and fine roots in these stands on Pleistocene sandy soils.The pools of available P and basic cations tended to be higher under beech.Neither precipitation nor temperature influenced the SOC pool,whereas tree species was a key driver.An extended data set(which included additional pine stands established more recently on former agricultural soil)revealed that,besides tree species identity,forest continuity is an important factor determining the SOC and nutrient pools of these stands.Conclusion:We conclude that tree species identity can exert a considerable influence on the stocks of SOC and macronutrients,which may be unrelated to productivity but closely linked to species-specific forest management histories,thus masking weaker climate and soil chemistry effects on pool sizes.
基金Project(51274250)supported by the National Natural Science Foundation of ChinaProject(2012BAK09B02-05)supported by the National Key Technology R&D Program during the 12th Five-year Plan of China
文摘An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.
文摘The objective of current study was to investigate the influence of brand related attributes on customer loyalty and repurchase intention in agricultural product marketing in Pakistan. Results of current study would help the management of branded agricultural products, in Pakistan specifically and in developing countries generally, to formulate the best strategies to enhance customer loyalty in order to induce repurchase intention of them. Future research could be conducted in the same field by adopting larger sample size and this research can be replicated with specific product category.
文摘The significance of cultural awareness in foreign language learning is an issue that earns hot discussion in the both fields of linguistics and instructional science. Being different from others, the observing angle in this paper lies in how the signal is processed. The four skills of listening, speaking, reading and writing are classified, by ways of signal processing, into two categorizes, namely receptive skills to which listening and reading belong, and productive skills to which speaking and writing belong. By analyzing the signal processing progress occurred in each of the four skills, the author is to argue the functions of cultural awareness in each of these four skills, in order to reinforce the importance of emphasizing cultural awareness in the new standards for English in China.
基金Project supported by in part by the National Natural Science Foundation of China(Nos.61534005,61675195)the Beijing Science and Technology Commission(No.Z151100003315019)the Natural Science Foundation of Beijing Municipality(No.4162063)
文摘This study presents a theoretical investigation of a novel Ge/Si tunneling avalanche photodiode（TAPD）with an ultra-thin barrier layer between the absorption and p＋ contact layer. A high-frequency tunneling effect is introduced into the structure of the barrier layer to increase the high-frequency response when frequency is larger than 0.1 GHz, and the-3 dB bandwidth of the device increases evidently. The results demonstrate that the avalanche gain and-3 dB bandwidth of the TAPD can be influenced by the thickness and bandgap of the barrier layer.When the barrier thickness is 2 nm and the bandgap is 4.5 eV, the avalanche gain loss is negligible and the gainbandwidth product of the TAPD is 286 GHz, which is 18% higher than that of an avalanche photodiode without a barrier layer. The total noise in the TAPD was an order of magnitude smaller than that in APD without barrier layer.
文摘We let a set of beam splitters of vacuum mode with a chosen transmittance parameter η in interaction with a separable coherent states.This model induces the production of an attenuated quantum channels based on entangled optical states.Indeed,the decoherence effect is exploited positively here to generate such kind of quantum channels.Next,the amplitude damping and the entanglement amount of these produced channels are enhanced thereafter by a probabilistic quasi amplification process using again a 50 : 50 beam splitter.
文摘Background:Sustainable land management is considered as one of the useful approaches to combat the threat of various forms of land degradation in Ethiopia.Despite this,there is scant information regarding households’decision towards the implementation of sustainable land management practices.This paper,therefore,looks into the determinants for the continued use and choice of the sustainable land management practices by smallholder farmers and its productivity effect in three randomly chosen districts in Tigrai region,Ethiopia.The study uses data from household survey and key informant interviews.The paper employs a binary logit to analyze the determinants for the decision of continued use of sustainable land management practices,and a multivariate probit to analyze the simultaneous adoption decision of sustainable land management practices using cross sectional data collected from 230 randomly selected households.The impact of sustainable land management practices was also evaluated using propensity score matching.Results:Farming techniques,wealth status,agro-ecological variations,and plot level characteristics were found to be associated with the implementation decision of sustainable land management practices by rural households.Besides,institutional supports and access to basic infrastructures influenced the overall continued use of sustainable land management practices and the preference of households toward these practices.The study also finds that the value of crop production of sustainable land management users was on average 77–100%higher than that of nonusers.Conclusions:The results of the current study confirm that the implementation of various sustainable land management practices are influenced by farming technologies deployed by rural households,agro-ecological variations,plot characteristics,and institutional supports.The findings also affirm that most of the sustainable land management practices are complementary to one another,and implementing two or more sustainable land management practices on a given plot is highly associated with higher value of crop production.Such complementarity highlights that the productivity effect of a given sustainable land management practice is enhanced by the use of the other ones.
