In this paper, we consider the numerical treatment of an inverse acoustic scattering problem that involves an impenetrable obstacle embedded in a layered medium. We begin by employing a modified version of the well kn...In this paper, we consider the numerical treatment of an inverse acoustic scattering problem that involves an impenetrable obstacle embedded in a layered medium. We begin by employing a modified version of the well known <em>factorization method</em>, in which a computationally effective numerical scheme for the reconstruction of the shape of the scatterer is presented. This is possible, due to a <em>mixed reciprocity principle</em>, which renders the computation of the Green function at the background medium unnecessary. Moreover, to further refine our inversion algorithm, an efficient Tikhonov parameter choice technique, called <em>Improved Maximum Product Criterion</em> (IMPC) is exploited. Our regularization parameter is computed via a fast iterative algorithm which requires no <em>a priori</em> knowledge of the noise level in the far-field data. Finally, the effectiveness of IMPC is illustrated with various numerical examples.展开更多
The fully anisotropic molecular overall tumbling model with methyl conformation jumps internal rotation among three equivalent sites is proposed,the overall tumbling rotation rates and the methyl internal rotation rat...The fully anisotropic molecular overall tumbling model with methyl conformation jumps internal rotation among three equivalent sites is proposed,the overall tumbling rotation rates and the methyl internal rotation rates of ponicidin are computed with this model from ~C relaxation parameters.展开更多
The use of a natural white juice, taken from magrabe banana stem, as concrete admixture to improve mechanical and physicrvchemical properties of concrete has been studied. The compressive strength, bulk density the fr...The use of a natural white juice, taken from magrabe banana stem, as concrete admixture to improve mechanical and physicrvchemical properties of concrete has been studied. The compressive strength, bulk density the free lime liberated during hydration and the combined water content were determined. The results indicate that the admixture acts as a retarder in most cases and as accelerator in some ones. Also, the admixture effect on the corrosion resistance of the reinforcing steel against surrounding aggressive media has been investigated using galvanostatic polarization technique. The addition of 0.2% admixture leads to the more inhibition of the steel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
Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the a...Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters (AGP) has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. Numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are (3-4 weeks age) exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coil These acids are the intermediary products in Kreb's cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth performance. It is concluded that organic acids and their salts increase the protein utilization especially in weaner pigs and improves production indices.展开更多
In C3 plants, photorespiration is an energyexpensive process, including the oxygenation of ribulose-1,5-bisphosphate(RuBP) by ribulose 1,5-bisphosphate carboxylase/oxygenase(Rubisco) and the ensuing multiorganellar ph...In C3 plants, photorespiration is an energyexpensive process, including the oxygenation of ribulose-1,5-bisphosphate(RuBP) by ribulose 1,5-bisphosphate carboxylase/oxygenase(Rubisco) and the ensuing multiorganellar photorespiratory pathway required to recycle the toxic byproducts and recapture a portion of the fixed carbon. Photorespiration significantly impacts crop productivity through reducing yields in C3 crops by as much as 50%under severe conditions. Thus, reducing the flux through, or weive R improving the efficiency of photorespiration has the potential of large improvements in C3 crop productivity.Here, we review an array of approaches intended to engineer photorespiration in a range of plant systems with the goal of increasing crop productivity. Approaches include optimizing flux through the native photorespiratory pathway, installing non-native alternative photorespiratory pathways, and lowering or even eliminating Rubiscocatalyzed oxygenation of RuBP to reduce substrate entrance into the photorespiratory cycle. Some proposed designs have been successful at the proof of concept level.A plant systems-engineering approach, based on new opportunities available from synthetic biology to implement in silico designs, holds promise for further progress toward delivering more productive crops to farmer’s fields.展开更多
In recent years, the Chinese government has highlighted the importance of adopting hog safety/quality traceability, and a growing amount of research continues to entice firms to adopt traceability systems. In this stu...In recent years, the Chinese government has highlighted the importance of adopting hog safety/quality traceability, and a growing amount of research continues to entice firms to adopt traceability systems. In this study, a survey was conducted on a sample of pig slaughtering and processing firms in Zhejiang, China through personal interviews and emails. The aim of this study was to examine the determinants of firm behavior on the implementation of voluntary traceability systems with more stringent standards and controls than those of the mandatory system in China. The results revealed that motivation based on product quality improvement, capital ability and role perception (business type) had significantly positive relationships with a firm's voluntary traceability. Other incentives, such as operation improvement, recall risk reduction, reduced occurrence of safety issues, and technical strength were not found to be supportive in our study. This study provides an opportunity to better understand the determinants of firm behavior on voluntary traceability, particularly in light of the fact that some Chinese firms are facing the threat of criminal action for the use of illegal additives and the abuse of Clenbuterol. Policy recommendations on encouraging the implementation of pork safety voluntary traceability by hog slaughtering and processing firms are also discussed.展开更多
A short visit to the Bayanbuluk Grassland in the Tianshan Mountains, Xinjiang, PRC, revealed a number of environmental and livestock production problems, including grassland degradation, loss of grassland biodiversity...A short visit to the Bayanbuluk Grassland in the Tianshan Mountains, Xinjiang, PRC, revealed a number of environmental and livestock production problems, including grassland degradation, loss of grassland biodiversity, soil erosion and flash flooding downstream, decreased pasture productivity, and poor livestock nutrition (especially in winter) leading to stock losses and flocks and herds of low productivity. This paper describes those problems and then suggests some solutions. Short duration, high intensity grazing could be one of the solutions to both improving grassland condition and improving livestock nutrition. Local production of fodder crops for feeding in winter and spring deserves testing, using adapted strains of Alfalfa (Medicago sativa) and trialling fodder root crop production. It is important to realise that the land management objectives of scientists, administrators, herders and farmers may be similar, and that there are opportunities for land improvement through working together.展开更多
In this work, a survey of companies has been produc ed from a questionnaire and in-depth inter-views. The aimof the paper is to give a current view of the use of DES (Discrete- Event Simulation) in the indust ry. The ...In this work, a survey of companies has been produc ed from a questionnaire and in-depth inter-views. The aimof the paper is to give a current view of the use of DES (Discrete- Event Simulation) in the indust ry. The companies have been selected in a wide range in e.g. size, capital turno ver and employees. The survey was restricted to Sweden, although the results may be applicable to other countries with similar industrial structure. Some of the companies investigated are also multinational with branches around the world. T o illustrate the differences in production systems different sectors have be en investigated, e.g. the manufacturing industry and energy sector. The manufact uring systems generally differ in that the energy sector is more known for high reliability in their systems and the manufacturing sector tends to work more wit h lean production. Previous surveys of manufacturing efficiency illustrate different aspects. Accor ding to one survey, more than one-third (34%) of the disturbances in two countr ies (the U.S. and Finland) were mainly caused by design-based errors and flaws. The survey also showed the scope of safety problems experienced in the implemen tation and use of flexible manufacturing systems (Jrvinen et al., 1996). Another survey in Germany reports a gap between users and non-users of DES. Man y companies that are not familiar with simulation are not aware of its benefits. The study suggested integrating simulation into the planning processes as a reg ular tool. So far, DES is mostly used in system planning, resource planning and scheduling and production planning (Hirschberg & Heitmann, 1997). The disposition of the accomplished questionnaire had been multiple-choice ques tions in a strict order. The respondents gave their views on what the interviewe r considered relevant for the survey. The questionnaire was mailed to 220 person s in May 2001; a second round for unanswered surveys was dispatched in August 20 01. Replies came from 114 respondents; thus, the reply rate to all questionnaire s sent out was 52%. The replies came in from 80 different companies. Questionswere raised regarding what kinds of decisions are taken from a simulation projec t and questions were also asked regarding the tool itself. Some common problems encountered based on the authors’ knowledge were asked in the questionnaire. The questions were sent to those who had reasonable knowledge of how to work with D ES. Supplementary in-depth interviews were also accomplished. On the question if DES facilitates the decision-making process 79% of totally 3 8 answered to a very large or a large extent. Regarding the question if DES is a useful tool for measuring the availability of equipment for example system verification 73% of 33 responded to a very large or a large extent. A majority o f the respondents genuinely see an advantage with the use of simulation, which i s an important result from the study. The cost reduction aspect of the productio n is also an advantage of DES. On the question eight answered to a very large ex tent and 23 to a large extent of total 39 replies. The question demonstrates tha t the results of a simulation model are indeed used in the real world. Finally, in the question of DES is used for staffing it is indicated that it is not so co mmonly used as for other functions asked for. The staffing issue requires good k nowledge about time measurement of manual labor. The option, however, to include manual work in a simulation model is in many programs extensive and must be a v aluable option to evaluate work intensive parts of production lines and their im provement. To conclude, it could be mentioned that DES is a tool with potential. The use is increasing and 12 of 80 companies investigated in Sweden 2001 are using it, an increase compared to previous stud-ies. Of those 12 companies, four are using t he tool to a large extent. The main advantage according to the survey beside the visualization part is that the knowledge about a system is investigated and doc umented.展开更多
Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and tw...Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India) to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N fertilizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C:N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites (R2=0.92, p<0.01), and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.展开更多
Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and...Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India) to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N ferti- lizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C:N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites (R^2=0.92/ p〈0.01), and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.展开更多
In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep ...In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep loosening and not disturbing soil layer,granular soil,soil not easy to bond and harden,and one-time land preparation.It is a significant path to deeply develop and use the"five natural resources"not fully utilized by human beings(soil resources at plough bottom and below,saline-alkali land,natural rainfall,solar energy,oxygen)and realize"mitigation"of five natural disasters(flood,drought,high temperature,low temperature and climate warming).In the past 10 years,the farming tools have been applied in 40 kinds of crops in 26 provinces of China.Compared with vertical breaking of soil by traditional"plow",the amount of loose soil,water storage and dissolved oxygen in cultivated land increased by more than one time,and yield increased by 10%-50%.They have been applied in transformation of saline-alkali land in 10 provinces,and yield increased by 30%-150%.After Fenlong treatment for 1 and 2 years,biomass of sugarcane increased by 68.9%and 50.1%respectively.Net photosynthetic rates of Gramineous crops were improved by 6.82%-11.94%,while net photosynthetic rates of Legume crops were improved by 20.32%-32.08%.After"spiral drill","vertical two-knife drill","vertical three-knife drill"and other hollow series of Fenlong farming toolss were invented newly.They were the most advanced farming tools with large soil discharge and small resistance,and could be equipped in large-,medium-and small-size modern Fenlong agricultural machinery as key technology,thereby setting up a new"standard stalk"for world agricultural reform and bringing benefit to mankind.展开更多
Purpose-This paper aims to analyze high-quality papers on the research of electronic word-of-mouth(eWOM)for product and service quality improvement from 2009 to 2022,in order to fully understand theirhistorical progre...Purpose-This paper aims to analyze high-quality papers on the research of electronic word-of-mouth(eWOM)for product and service quality improvement from 2009 to 2022,in order to fully understand theirhistorical progress,current situation and future development trend.Design/Methodology/Approach-This paper adopts the bibliometrics method to analyze the relevantliterature,including publishing trend and citation status,regional and discipline area distribution,andinfluential publications.Secondly,the VOSviewer is used for literature co-citation analysis and keywordco-occurrence analysis to obtain the basic literature and research hotspots in this research field.Findings-Firstly,the study finds that the number of publications basically shows an increasing trend,and thosepublications are mainly published in tourism journals.In addition,among these papers,China has the largestnumber of publications,followed by the USA and South Korea.Through co-citation analysis of literature andkeyword co-occurrence analysis,22 foundational papers and six main research topics are obtained in this paper.Finally,this paper elaborates on the development trend of the research topic and future research directions in detail.Originality/value-This is the first paper that uses bibliometrics to analyze and review relevant researcheson eWOM for product and service quality improvement,which is helpful for researchers to quickly understandits development status and trend.This review also provides some future research directions and provides areference for further research.展开更多
Grafting is a green,environmentally friendly,and sustainable way to prevent soil-borne diseases.Although artificial grafting is the main grafting approach used for grafting production,it has some problems which are lo...Grafting is a green,environmentally friendly,and sustainable way to prevent soil-borne diseases.Although artificial grafting is the main grafting approach used for grafting production,it has some problems which are low productivity,unstable operating quality and labor-intensive.Hence,some countries have been engaged in the development of grafting robots for the past two decades;however,the productivity of these grafting robots has no advantage when compared to artificial grafting.This study aims to develop a high-productivity grafting robot(HPR)for Solanaceae.To improve grafting productivity,this paper adopted plug trays to feed crown-removed rootstocks automatically and carried out multi-plant simultaneous grafting to improve grafting productivity and extensibility.Manipulators were employed to take out rootstocks,increase the distance between them,and transfer them to transfer cups for the simultaneous multi-plant grafting.At the same time,negative pressure mechanisms were designed for speeding up the auxiliary feeding of root-removed scions.Although the HPR was designed in a two-operator mode,a one-operator mode can also be implemented by adjusting the control program.Tests were conducted by varying the artificial feeding speed to analyze the performance of the grafting robot.The results showed that the productivity of the robot in the two-operator mode was 2250 plants/h,and 1542 plants/h in one-operator mode;comparing the artificial feeding productivity with auto grafting productivity,it was found that the capacity of the grafting robot was higher than the feeding speed of the one-operator mode but lower than that of the two-operator mode.展开更多
A simple data assimilation method for improving estimation of moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) time-series data products based on the gradient inverse weighted filter and...A simple data assimilation method for improving estimation of moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) time-series data products based on the gradient inverse weighted filter and object analysis is proposed. The properties and quality control (QC) of MODIS LAI data products are introduced. Also, the gradient inverse weighted filter and object analysis are analyzed. An experiment based on the simple data assimilation method is performed using MODIS LAI data sets from 2000 to 2005 of Guizhou Province in China.展开更多
文摘In this paper, we consider the numerical treatment of an inverse acoustic scattering problem that involves an impenetrable obstacle embedded in a layered medium. We begin by employing a modified version of the well known <em>factorization method</em>, in which a computationally effective numerical scheme for the reconstruction of the shape of the scatterer is presented. This is possible, due to a <em>mixed reciprocity principle</em>, which renders the computation of the Green function at the background medium unnecessary. Moreover, to further refine our inversion algorithm, an efficient Tikhonov parameter choice technique, called <em>Improved Maximum Product Criterion</em> (IMPC) is exploited. Our regularization parameter is computed via a fast iterative algorithm which requires no <em>a priori</em> knowledge of the noise level in the far-field data. Finally, the effectiveness of IMPC is illustrated with various numerical examples.
文摘The fully anisotropic molecular overall tumbling model with methyl conformation jumps internal rotation among three equivalent sites is proposed,the overall tumbling rotation rates and the methyl internal rotation rates of ponicidin are computed with this model from ~C relaxation parameters.
文摘The use of a natural white juice, taken from magrabe banana stem, as concrete admixture to improve mechanical and physicrvchemical properties of concrete has been studied. The compressive strength, bulk density the free lime liberated during hydration and the combined water content were determined. The results indicate that the admixture acts as a retarder in most cases and as accelerator in some ones. Also, the admixture effect on the corrosion resistance of the reinforcing steel against surrounding aggressive media has been investigated using galvanostatic polarization technique. The addition of 0.2% admixture leads to the more inhibition of the steel
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Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters (AGP) has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. Numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are (3-4 weeks age) exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coil These acids are the intermediary products in Kreb's cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth performance. It is concluded that organic acids and their salts increase the protein utilization especially in weaner pigs and improves production indices.
基金supported by the research grant OPP1172157 Realizing Increased Photosynthetic Efficiency (RIPE) that is funded by the Bill & Melinda Gates Foundation, Foundation for Food and Agriculture Research, and the UK Department for International Development
文摘In C3 plants, photorespiration is an energyexpensive process, including the oxygenation of ribulose-1,5-bisphosphate(RuBP) by ribulose 1,5-bisphosphate carboxylase/oxygenase(Rubisco) and the ensuing multiorganellar photorespiratory pathway required to recycle the toxic byproducts and recapture a portion of the fixed carbon. Photorespiration significantly impacts crop productivity through reducing yields in C3 crops by as much as 50%under severe conditions. Thus, reducing the flux through, or weive R improving the efficiency of photorespiration has the potential of large improvements in C3 crop productivity.Here, we review an array of approaches intended to engineer photorespiration in a range of plant systems with the goal of increasing crop productivity. Approaches include optimizing flux through the native photorespiratory pathway, installing non-native alternative photorespiratory pathways, and lowering or even eliminating Rubiscocatalyzed oxygenation of RuBP to reduce substrate entrance into the photorespiratory cycle. Some proposed designs have been successful at the proof of concept level.A plant systems-engineering approach, based on new opportunities available from synthetic biology to implement in silico designs, holds promise for further progress toward delivering more productive crops to farmer’s fields.
基金support from the National Natural Science Foundation of China(71273234)the Development of Chinese Farmer Cooperatives under Globalization:Operation Pattern,Governance Structure+2 种基金Comparative Analysis under National Natural Science Foundation of China(71020107028)Zhejiang Provincial Natural Science Foundation of China(LZ12G03003)Extending Agricultural Standardization and Study on the Management System of Agricultural Product Quality and Safety under Key Project of Zhejiang Provincial Government Office for the Coordination of Agricultural Product Safety
文摘In recent years, the Chinese government has highlighted the importance of adopting hog safety/quality traceability, and a growing amount of research continues to entice firms to adopt traceability systems. In this study, a survey was conducted on a sample of pig slaughtering and processing firms in Zhejiang, China through personal interviews and emails. The aim of this study was to examine the determinants of firm behavior on the implementation of voluntary traceability systems with more stringent standards and controls than those of the mandatory system in China. The results revealed that motivation based on product quality improvement, capital ability and role perception (business type) had significantly positive relationships with a firm's voluntary traceability. Other incentives, such as operation improvement, recall risk reduction, reduced occurrence of safety issues, and technical strength were not found to be supportive in our study. This study provides an opportunity to better understand the determinants of firm behavior on voluntary traceability, particularly in light of the fact that some Chinese firms are facing the threat of criminal action for the use of illegal additives and the abuse of Clenbuterol. Policy recommendations on encouraging the implementation of pork safety voluntary traceability by hog slaughtering and processing firms are also discussed.
文摘A short visit to the Bayanbuluk Grassland in the Tianshan Mountains, Xinjiang, PRC, revealed a number of environmental and livestock production problems, including grassland degradation, loss of grassland biodiversity, soil erosion and flash flooding downstream, decreased pasture productivity, and poor livestock nutrition (especially in winter) leading to stock losses and flocks and herds of low productivity. This paper describes those problems and then suggests some solutions. Short duration, high intensity grazing could be one of the solutions to both improving grassland condition and improving livestock nutrition. Local production of fodder crops for feeding in winter and spring deserves testing, using adapted strains of Alfalfa (Medicago sativa) and trialling fodder root crop production. It is important to realise that the land management objectives of scientists, administrators, herders and farmers may be similar, and that there are opportunities for land improvement through working together.
文摘In this work, a survey of companies has been produc ed from a questionnaire and in-depth inter-views. The aimof the paper is to give a current view of the use of DES (Discrete- Event Simulation) in the indust ry. The companies have been selected in a wide range in e.g. size, capital turno ver and employees. The survey was restricted to Sweden, although the results may be applicable to other countries with similar industrial structure. Some of the companies investigated are also multinational with branches around the world. T o illustrate the differences in production systems different sectors have be en investigated, e.g. the manufacturing industry and energy sector. The manufact uring systems generally differ in that the energy sector is more known for high reliability in their systems and the manufacturing sector tends to work more wit h lean production. Previous surveys of manufacturing efficiency illustrate different aspects. Accor ding to one survey, more than one-third (34%) of the disturbances in two countr ies (the U.S. and Finland) were mainly caused by design-based errors and flaws. The survey also showed the scope of safety problems experienced in the implemen tation and use of flexible manufacturing systems (Jrvinen et al., 1996). Another survey in Germany reports a gap between users and non-users of DES. Man y companies that are not familiar with simulation are not aware of its benefits. The study suggested integrating simulation into the planning processes as a reg ular tool. So far, DES is mostly used in system planning, resource planning and scheduling and production planning (Hirschberg & Heitmann, 1997). The disposition of the accomplished questionnaire had been multiple-choice ques tions in a strict order. The respondents gave their views on what the interviewe r considered relevant for the survey. The questionnaire was mailed to 220 person s in May 2001; a second round for unanswered surveys was dispatched in August 20 01. Replies came from 114 respondents; thus, the reply rate to all questionnaire s sent out was 52%. The replies came in from 80 different companies. Questionswere raised regarding what kinds of decisions are taken from a simulation projec t and questions were also asked regarding the tool itself. Some common problems encountered based on the authors’ knowledge were asked in the questionnaire. The questions were sent to those who had reasonable knowledge of how to work with D ES. Supplementary in-depth interviews were also accomplished. On the question if DES facilitates the decision-making process 79% of totally 3 8 answered to a very large or a large extent. Regarding the question if DES is a useful tool for measuring the availability of equipment for example system verification 73% of 33 responded to a very large or a large extent. A majority o f the respondents genuinely see an advantage with the use of simulation, which i s an important result from the study. The cost reduction aspect of the productio n is also an advantage of DES. On the question eight answered to a very large ex tent and 23 to a large extent of total 39 replies. The question demonstrates tha t the results of a simulation model are indeed used in the real world. Finally, in the question of DES is used for staffing it is indicated that it is not so co mmonly used as for other functions asked for. The staffing issue requires good k nowledge about time measurement of manual labor. The option, however, to include manual work in a simulation model is in many programs extensive and must be a v aluable option to evaluate work intensive parts of production lines and their im provement. To conclude, it could be mentioned that DES is a tool with potential. The use is increasing and 12 of 80 companies investigated in Sweden 2001 are using it, an increase compared to previous stud-ies. Of those 12 companies, four are using t he tool to a large extent. The main advantage according to the survey beside the visualization part is that the knowledge about a system is investigated and doc umented.
基金supported by the Australian Centrefor International Agricultural Research
文摘Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India) to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N fertilizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C:N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites (R2=0.92, p<0.01), and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.
文摘Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India) to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N ferti- lizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C:N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites (R^2=0.92/ p〈0.01), and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.
基金Special Fund Project of Guangxi Innovation Driven Development(Guike AA17204037)Major Science and Technology Projects in Guangxi(Guike AA16380017)Team Project of Guangxi Academy of Agricultural Sciences(2015YT60).
文摘In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep loosening and not disturbing soil layer,granular soil,soil not easy to bond and harden,and one-time land preparation.It is a significant path to deeply develop and use the"five natural resources"not fully utilized by human beings(soil resources at plough bottom and below,saline-alkali land,natural rainfall,solar energy,oxygen)and realize"mitigation"of five natural disasters(flood,drought,high temperature,low temperature and climate warming).In the past 10 years,the farming tools have been applied in 40 kinds of crops in 26 provinces of China.Compared with vertical breaking of soil by traditional"plow",the amount of loose soil,water storage and dissolved oxygen in cultivated land increased by more than one time,and yield increased by 10%-50%.They have been applied in transformation of saline-alkali land in 10 provinces,and yield increased by 30%-150%.After Fenlong treatment for 1 and 2 years,biomass of sugarcane increased by 68.9%and 50.1%respectively.Net photosynthetic rates of Gramineous crops were improved by 6.82%-11.94%,while net photosynthetic rates of Legume crops were improved by 20.32%-32.08%.After"spiral drill","vertical two-knife drill","vertical three-knife drill"and other hollow series of Fenlong farming toolss were invented newly.They were the most advanced farming tools with large soil discharge and small resistance,and could be equipped in large-,medium-and small-size modern Fenlong agricultural machinery as key technology,thereby setting up a new"standard stalk"for world agricultural reform and bringing benefit to mankind.
文摘Purpose-This paper aims to analyze high-quality papers on the research of electronic word-of-mouth(eWOM)for product and service quality improvement from 2009 to 2022,in order to fully understand theirhistorical progress,current situation and future development trend.Design/Methodology/Approach-This paper adopts the bibliometrics method to analyze the relevantliterature,including publishing trend and citation status,regional and discipline area distribution,andinfluential publications.Secondly,the VOSviewer is used for literature co-citation analysis and keywordco-occurrence analysis to obtain the basic literature and research hotspots in this research field.Findings-Firstly,the study finds that the number of publications basically shows an increasing trend,and thosepublications are mainly published in tourism journals.In addition,among these papers,China has the largestnumber of publications,followed by the USA and South Korea.Through co-citation analysis of literature andkeyword co-occurrence analysis,22 foundational papers and six main research topics are obtained in this paper.Finally,this paper elaborates on the development trend of the research topic and future research directions in detail.Originality/value-This is the first paper that uses bibliometrics to analyze and review relevant researcheson eWOM for product and service quality improvement,which is helpful for researchers to quickly understandits development status and trend.This review also provides some future research directions and provides areference for further research.
基金This work was supported by grants from the National Key Research and Development Program of the 13th Five-year Plan(2017YFD0701301)National“863”Plan(2013AA102406-03)+1 种基金and the Guangdong Province Modern Agriculture Innovation Team of Protected Agriculture for Generic Key Technology Systems(2019-2023)The authors would also like to acknowledge technical support from Guangzhou Sky Mechanical&Electrical Technology Co.Ltd.
文摘Grafting is a green,environmentally friendly,and sustainable way to prevent soil-borne diseases.Although artificial grafting is the main grafting approach used for grafting production,it has some problems which are low productivity,unstable operating quality and labor-intensive.Hence,some countries have been engaged in the development of grafting robots for the past two decades;however,the productivity of these grafting robots has no advantage when compared to artificial grafting.This study aims to develop a high-productivity grafting robot(HPR)for Solanaceae.To improve grafting productivity,this paper adopted plug trays to feed crown-removed rootstocks automatically and carried out multi-plant simultaneous grafting to improve grafting productivity and extensibility.Manipulators were employed to take out rootstocks,increase the distance between them,and transfer them to transfer cups for the simultaneous multi-plant grafting.At the same time,negative pressure mechanisms were designed for speeding up the auxiliary feeding of root-removed scions.Although the HPR was designed in a two-operator mode,a one-operator mode can also be implemented by adjusting the control program.Tests were conducted by varying the artificial feeding speed to analyze the performance of the grafting robot.The results showed that the productivity of the robot in the two-operator mode was 2250 plants/h,and 1542 plants/h in one-operator mode;comparing the artificial feeding productivity with auto grafting productivity,it was found that the capacity of the grafting robot was higher than the feeding speed of the one-operator mode but lower than that of the two-operator mode.
基金This work was supported by the China Postdoctoral Science Foundation(No.20060390326)the key international S&T cooperation project of China(No.2004DFA06300).
文摘A simple data assimilation method for improving estimation of moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) time-series data products based on the gradient inverse weighted filter and object analysis is proposed. The properties and quality control (QC) of MODIS LAI data products are introduced. Also, the gradient inverse weighted filter and object analysis are analyzed. An experiment based on the simple data assimilation method is performed using MODIS LAI data sets from 2000 to 2005 of Guizhou Province in China.