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Review on drivers, trends and emerging issues of the food wastage in China

Lin MA,Wei QIN,Tara GARNETT,Fusuo ZHANG

《农业科学与工程前沿（英文）》 2015年 第2卷 第2期   页码 159-167 doi: 10.15302/J-FASE-2015066

摘要： China has successfully achieved food self-sufficiency over the past 50 years, however, with large inputs and losses. To meet the challenge of feeding a growing population with limited resources, many studies have explored options for improving productivity and efficiency of the food production. However, there have been few studies into the potential of reducing food loss along the whole food production-consumption chain. Here we review the literature on food waste in China. We briefly analyze (1) the drivers that influence levels of food waste in the food chain, (2) examine trends in the volumes and types of food wasted at different stages in the food chain, (3) assess the environmental and resource consequences of food waste in the food chain, and (4) evaluate the policy and stakeholder responses to the emerging challenges. It is concluded that reducing food loss and meeting food security in China requires a coherent institutional structure that promotes the synergistic outcomes of research, policy and education. Suggested key actions include (1) improving machinery and facility for sowing, harvesting, transportation and storage, which can reduce food loss by up to 50%, and (2) improving food waste recycling management, based on coupled food production and consumption systems.

关键词： food security     food chain     food wastes and losses     environmental impacts    

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Development and challenges of green food in China

Mahmood ul HASSAN, Xin WEN, Jiuliang XU, Jiahui ZHONG, Xuexian LI

《农业科学与工程前沿（英文）》 2020年 第7卷 第1期   页码 56-66 doi: 10.15302/J-FASE-2019296

摘要：

Green food in China refers to a wide array of primary and processed agricultural products that are safe, nutritious and of high quality for human consumption. Green food has been certified and produced following the principle of sustainability since the 1990s, making historic achievements in providing quality food, protecting the environment, increasing farmer income, and nurturing agricultural brands over the past 30 years in China. Today, the green food industry enters a steady-growth stage in terms of cultivation area, product number and sales. This article summarizes the history of the development of green food in China and current achievements, analyze major challenges that may hamper further development of the industry, and propose strategies to address these challenges, i.e., optimization of the food supply chain, deep food processing, and utilization of food wastes.

关键词： green food     food losses     storage     processing     transportation     sustainability    

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Development of an analytical model to estimate the churning losses in high-speed axial piston pumps

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-021-0671-1

摘要： The axial piston pumps in aerospace applications are often characterized by high-speed rotation to achieve great power density. However, their internal rotating parts are fully immersed in the casing oil during operation, leading to considerable churning losses (more than 10% of total power losses) at high rotational speeds. The churning losses deserve much attention at the design stage of high-speed axial piston pumps, but accurate analytical models are not available to estimate the drag torque associated with the churning losses. In this paper, we derive the analytical expressions of the drag torque acting on the key rotating parts immersed in oil, including the cylinder block and the multiple pistons in a circular array. The calculated drag torque agrees well with the experimental data over a wide range of rotational speeds from 1500 to 12000 r/min. The presented analytical model provides practical guidelines for reducing the churning losses in high-speed axial piston pumps or motors.

关键词： axial piston pump     rotating parts     high rotational speed     churning losses     drag torque    

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NUTRIENT USE EFFICIENCY AND LOSSES OF INDUSTRIAL FARMS AND MIXED SMALLHOLDINGS: LESSONS FROM THE NORTH

《农业科学与工程前沿（英文）》 2021年 第8卷 第1期

摘要：

• Degree of integration of crop and livestock was insufficient on mixed smallholdings.

• Liquid manure discharges on industrial farms hamper the closing of nutrient loops.

• Coupling with local crop farms is encouraged to achieve integration of crop-livestock systems.

 

The proportion of industrial livestock in China has increased over the past 30 years, which increases animal performance but causes the decoupling of crop and livestock production. Here, we aimed to quantify nutrient flows, nutrient use efficiency, and nutrient losses in different livestock systems in the North China Plain based on the NUFER-farm model. Activity data were collected by face-to-face surveys on pig and dairy (41 livestock farms) during 2016–2018. The two systems included industrial farms and mixed smallholdings. In mixed smallholdings, 4.0% and 9.6% of pig and dairy feed dry matter (DM) were derived from household farmland, but 4.8% and 9.3% of manure DM recycled to household farmland. Nutrient use efficiency in industrial farms was higher than in mixed smallholdings at animal level, herd level, and system level. To produce 1 kg N and P in animal products, nutrient losses in industrial pig farms (2.0 kg N and 1.3 kg P) were lower than in mixed pig smallholdings, nutrient losses in industrial dairy farms (2.7 kg N and 2.2 kg P) were slightly higher than in mixed dairy smallholdings. Liquid manure discharge in industrial farms was the main losses pathway in contrast to mixed smallholdings. This study suggests that feed localization can reduce nutrient surpluses at the district level. It is necessary to improve manure management and increase the degree of integrated crop-livestock in smallholdings. In industrial farms, it is desirable to increase the liquid manure recycling ratio through cooperating livestock and crop production at the district level.

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HOTSPOTS OF NUTRIENT LOSSES TO AIR AND WATER: AN INTEGRATED MODELING APPROACH FOR EUROPEAN RIVER BASINS

《农业科学与工程前沿（英文）》 2023年 第10卷 第4期   页码 579-592 doi: 10.15302/J-FASE-2023526

摘要：

Nutrient pollution of air and water is a persistent problem in Europe. However, the pollution sources are often analyzed separately, preventing the formulation of integrative solutions. This study aimed to quantify the contribution of agriculture to air, river and coastal water pollution by nutrients. A new MARINA-Nutrients model was developed for Europe to calculate inputs of nitrogen (N) and phosphorus (P) to land and rivers, N emissions to air, and nutrient export to seas by river basins. Under current practice, inputs of N and P to land were 34.4 and 1.8 Tg·yr–1, respectively. However, only 12% of N and 3% of P reached the rivers. Agriculture was responsible for 55% of N and sewage for 67% of P in rivers. Reactive N emissions to air from agriculture were calculated at 4.0 Tg·yr–1. Almost two-fifths of N emissions to air were from animal housing and storage. Nearly a third of the basin area was considered as pollution hotspots and generated over half of N emissions to air and nutrient pollution in rivers. Over 25% of river export of N ended up in the Atlantic Ocean and of P in the Mediterranean Sea. These results could support environmental policies to reduce both air and water pollution simultaneously, and avoid pollution swapping.

关键词： agriculture     air-water modeling     European rivers     nutrient pollution     sewage systems     source attribution    

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GASEOUS REACTIVE NITROGEN LOSSES FROM ORCHARDS, VEGETABLES AND TEA PLANTATIONS

《农业科学与工程前沿（英文）》 2023年 第10卷 第2期   页码 155-166 doi: 10.15302/J-FASE-2022477

摘要：

● Gaseous N emissions from orchards, vegetables and tea plantations (OVT) are reviewed.

关键词： fruit     greenhouse gas     green development     fertilizer management     climate change    

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Exergy losses in premixed flames of dimethyl ether and hydrogen blends

Tongbin ZHAO, Jiabo ZHANG, Dehao JU, Zhen HUANG, Dong HAN

《能源前沿（英文）》 2019年 第13卷 第4期   页码 658-666 doi: 10.1007/s11708-019-0645-8

摘要： A second-law thermodynamic analysis was conducted for stoichiometric premixed dimethyl ether (DME)/hydrogen (H )/air flames at atmospheric pressure. The exergy losses from the irreversibility sources, i.e., chemical reaction, heat conduction and species diffusion, and those from partial combustion products were analyzed in the flames with changed fuel blends. It is observed that, regardless of the fuel blends, chemical reaction contributes most to the exergy losses, followed by incomplete combustion, and heat conduction, while mass diffusion has the least contribution to exergy loss. The results also indicate that increased H substitution decreases the exergy losses from reactions, conduction, and diffusion, primarily because of the flame thickness reduction at elevated H substitution. The decreases in exergy losses by chemical reactions and heat conduction are higher, but the exergy loss reduction by diffusion is slight. However, the exergy losses from incomplete combustion increase with H substitution, because the fractions of the unburned fuels and combustion intermediates, e.g., H and OH radical, increase. The overall exergy losses in the DME/H flames decrease by about 5% with increased H substitution from 0% to 100%.

关键词： second law analysis     flame     dimethyl ether (DME)     hydrogen     binary fuels    

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Test investigation on hydraulic losses in the discharge passage of an axial-flow pump

QIU Baoyun, CAO Haihong, JIANG Wei, GAO Zhaohui, WANG Fei

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 50-56 doi: 10.1007/s11465-007-0008-8

摘要： In a discharge passage with a guide blade discharge circulation and secondary flow because of bend pipe, the flow in a 1-channel discharge passage of an axial flow pump is a complicated spiral flow. For a 2-channel passage, the discharge in the left channel is bigger than that in the right, and the passage hydraulic losses are abnormal. In this study, the section current energy of the passage is accurately measured and determined with a 5-hole probe. The hydraulic loss characteristics are determined and analyzed. The methods deducing the hydraulic losses are investigated. The results indicate that the passage hydraulic losses are not proportional to the flow discharge. Compared with a circular pipe, the hydraulic losses of a divergent discharge passage are smaller and the pump assembly efficiency is 10% 30% higher. As for the 1-channel passage, the axial-flow pump outlet circulation is usually too big; the passage hydraulic losses are also big, but a small circulation can slightly reduce hydraulic losses. As for the 2-channel passage, discharges in the two channels are not equal and the hydraulic losses increase. The outlet guide blade with a small discharge circulation or without circulation could reduce discharge passage hydraulic losses and increase pump assembly efficiency by 6% 11%.
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Development and testing of a weather-based model to determine potential yield losses caused by potato

Alexey FILIPPOV, Maria KUZNETSOVA, Alexander ROGOZHIN, Olga IAKUSHEVA, Valentina DEMIDOVA, Natalia STATSYUK

《农业科学与工程前沿（英文）》 2018年 第5卷 第4期   页码 462-468 doi: 10.15302/J-FASE-2018239

摘要：

Late blight is one of the most important potato diseases. To minimize yield losses, various protective measures are used including fungicide application. Active use of fungicides results in a contamination of the environment. Therefore, crop protection strategies optimizing the number of treatments are of great interest. Using information about late blight development in an experimental potato field recorded over 30 seasons, a simulator to forecast yield losses caused by the disease was developed based on the number of 5-d periods favorable for reinfection of plants during a vegetation season. The simulator was successfully verified using independent data on the disease development from nine unprotected potato fields in the Netherlands and Germany. The average difference between the calculated and real yield losses did not exceed 5%. Using the simulator and weather data for a period of 2007-2017, yield losses were calculated for several areas of the Bryansk, Tambov, and Orenburg Regions of Russia. The results revealed differences in disease development between these regions and may be used to develop recommendations for a frequency of fungicide applications according to the regional risk of epidemics, leading to a significant reduction in fungicide use.

关键词： potato     late blight     Phytophthora infestans     yield losses     retrospective analysis     mathematical model    

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CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 457-464 doi: 10.15302/J-FASE-2022452

摘要：

● A simple model was used to evaluate how increasing temporal variability in precipitation influences crop yields and nitrogen losses.

关键词： crop yield     fertilizer timing     nitrogen loss     precipitation variability     toy model    

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Numerical study of conduction and radiation heat losses from vacuum annulus in parabolic trough receivers

Dongqiang LEI, Yucong REN, Zhifeng WANG

《能源前沿（英文）》 2022年 第16卷 第6期   页码 1048-1059 doi: 10.1007/s11708-020-0670-7

摘要： Parabolic trough receiver is a key component to convert solar energy into thermal energy in the parabolic trough solar system. The heat loss of the receiver has an important influence on the thermal efficiency and the operating cost of the power station. In this paper, conduction and radiation heat losses are analyzed respectively to identify the heat loss mechanism of the receiver. A 2-D heat transfer model is established by using the direct simulation Monte Carlo method for rarefied gas flow and heat transfer within the annulus of the receiver to predict the conduction heat loss caused by residual gases. The numerical results conform to the experimental results, and show the temperature of the glass envelope and heat loss for various conditions in detail. The effects of annulus pressure, gas species, temperature of heat transfer fluid, and annulus size on the conduction and radiation heat losses are systematically analyzed. Besides, the main factors that cause heat loss are analyzed, providing a theoretical basis for guiding the improvement of receiver, as well as the operation and maintenance strategy to reduce heat loss.

关键词： parabolic trough receiver     vacuum annulus     rarefied gas     DSMC (direct simulation Monte Carlo)     heat loss    

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TRANSFORMING CHINESE FOOD AND AGRICULTURE: A SYSTEMS PERSPECTIVE

《农业科学与工程前沿（英文）》 2023年 第10卷 第1期   页码 4-15 doi: 10.15302/J-FASE-2023493

摘要：

● The goals of Chinese food and agriculture have shifted from grain self-sufficiency to diversified goals, including protecting natural resources, reducing pollution and greenhouse gas emissions, and improving food safety and nutrition.

关键词： food systems     food security     nutrition     climate change    

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Soil security and global food security

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023530

摘要：

● Much of the world’s agricultural land has been degraded through soil loss and degradation of soil organic matter.

关键词： Agriculture     soil security     food security     regenerative    

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NUTRIENT USE EFFICIENCY AND LOSSES OF INDUSTRIAL FARMS AND MIXED SMALLHOLDINGS: LESSONS FROM THE NORTH

Yifei MA, Ling ZHANG, Zhaohai BAI, Rongfeng JIANG, Yong HOU, Lin MA

《农业科学与工程前沿（英文）》 2021年 第8卷 第1期   页码 58-71 doi: 10.15302/J-FASE-2020371

摘要： The proportion of industrial livestock in China has increased over the past 30 years, which increases animal performance but causes the decoupling of crop and livestock production. Here, we aimed to quantify nutrient flows, nutrient use efficiency, and nutrient losses in different livestock systems in the North China Plain based on the NUFER-farm model. Activity data were collected by face-to-face surveys on pig and dairy (41 livestock farms) during 2016–2018. The two systems included industrial farms and mixed smallholdings. In mixed smallholdings, 4.0% and 9.6% of pig and dairy feed dry matter (DM) were derived from household farmland, but 4.8% and 9.3% of manure DM recycled to household farmland. Nutrient use efficiency in industrial farms was higher than in mixed smallholdings at animal level, herd level, and system level. To produce 1 kg N and P in animal products, nutrient losses in industrial pig farms (2.0 kg N and 1.3 kg P) were lower than in mixed pig smallholdings, nutrient losses in industrial dairy farms (2.7 kg N and 2.2 kg P) were slightly higher than in mixed dairy smallholdings. Liquid manure discharge in industrial farms was the main losses pathway in contrast to mixed smallholdings. This study suggests that feed localization can reduce nutrient surpluses at the district level. It is necessary to improve manure management and increase the degree of integrated crop-livestock in smallholdings. In industrial farms, it is desirable to increase the liquid manure recycling ratio through cooperating livestock and crop production at the district level.

关键词： industrial farms     mixed smallholdings     pig     dairy     nutrient management    

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Global challenges of food safety for China

Joseph J. JEN

《农业科学与工程前沿（英文）》 2018年 第5卷 第3期   页码 291-293 doi: 10.15302/J-FASE-2017167

摘要：

Ever since the Melamine event, China has faced challenges of food safety both domestically and globally. With the economic development, the Chinese consumers are demanding high quality, nutritious, and safe foods from the food industry but are not willing to pay higher prices. The Chinese food chain system of mostly small and medium enterprises presents challenges to the government to monitor and implement food safety laws and regulations. The academia and media are learning to take on their responsibilities with some success. Discussions and potential solutions of the global challenges of the five pillars for the food safety in China are presented here.

关键词： food safety     challenges     food industry     government     academia     media     consumer    

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标题 作者 时间 类型 操作

Review on drivers, trends and emerging issues of the food wastage in China

Lin MA,Wei QIN,Tara GARNETT,Fusuo ZHANG

期刊论文

Development and challenges of green food in China

Mahmood ul HASSAN, Xin WEN, Jiuliang XU, Jiahui ZHONG, Xuexian LI

期刊论文

Development of an analytical model to estimate the churning losses in high-speed axial piston pumps

期刊论文

NUTRIENT USE EFFICIENCY AND LOSSES OF INDUSTRIAL FARMS AND MIXED SMALLHOLDINGS: LESSONS FROM THE NORTH

期刊论文

HOTSPOTS OF NUTRIENT LOSSES TO AIR AND WATER: AN INTEGRATED MODELING APPROACH FOR EUROPEAN RIVER BASINS

期刊论文

GASEOUS REACTIVE NITROGEN LOSSES FROM ORCHARDS, VEGETABLES AND TEA PLANTATIONS

期刊论文

Exergy losses in premixed flames of dimethyl ether and hydrogen blends

Tongbin ZHAO, Jiabo ZHANG, Dehao JU, Zhen HUANG, Dong HAN

期刊论文

Test investigation on hydraulic losses in the discharge passage of an axial-flow pump

QIU Baoyun, CAO Haihong, JIANG Wei, GAO Zhaohui, WANG Fei

期刊论文

Development and testing of a weather-based model to determine potential yield losses caused by potato

Alexey FILIPPOV, Maria KUZNETSOVA, Alexander ROGOZHIN, Olga IAKUSHEVA, Valentina DEMIDOVA, Natalia STATSYUK

期刊论文

CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

期刊论文

Numerical study of conduction and radiation heat losses from vacuum annulus in parabolic trough receivers

Dongqiang LEI, Yucong REN, Zhifeng WANG

期刊论文

TRANSFORMING CHINESE FOOD AND AGRICULTURE: A SYSTEMS PERSPECTIVE

期刊论文

Soil security and global food security

期刊论文

NUTRIENT USE EFFICIENCY AND LOSSES OF INDUSTRIAL FARMS AND MIXED SMALLHOLDINGS: LESSONS FROM THE NORTH

Yifei MA, Ling ZHANG, Zhaohai BAI, Rongfeng JIANG, Yong HOU, Lin MA

期刊论文

Global challenges of food safety for China

Joseph J. JEN

期刊论文