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期刊论文 61

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Phosphorus status, use and recycling in a Chinese peri-urban region with intensive animal husbandry and cropping systems

Marco ROELCKE, Lisa HEIMANN, Yong HOU, Jianbin GUO, Qiaoyun XUE, Wei JIA, Anne OSTERMANN, Roxana Mendoza HUAITALLA, Moritz ENGBERS, Clemens OLBRICH, Roland W. SCHOLZ, Joachim CLEMENS, Frank SCHUCHARDT, Rolf NIEDER, Xuejun LIU, Fusuo ZHANG

《农业科学与工程前沿(英文)》 2019年 第6卷 第4期   页码 388-402 doi: 10.15302/J-FASE-2019286

摘要:

The Sino-German research collaboration project, “Recycling of organic residues from agricultural and municipal origin in China” (2008–2012), comprising different interdisciplinary research groups, and also German small and medium-sized enterprises, aimed at developing integrated strategies and solutions for the recycling of organic residues in China. In an intensive crop-livestock agricultural region in the Shunyi District of Beijing, five typical cropping systems were investigated. The research was conducted in the form of analyses of phosphorus (P) in soil, plants, animal feed, animal products, manures, mineral and organic fertilizers and the derivation of the corresponding nutrient balances and P flows. The mean annual P balance surplus was 492 kg·ha ·yr P for the vegetable production system, significantly higher ( <0.05) than that for orchards (130 kg·ha ·yr P) and cereal crops (83 kg·ha ·yr P). Plant-available P (Olsen-P) concentrations of topsoils (0–20 cm) had good correlations with the amounts of P applied (from mineral and organic sources). Compared to results from the Second Chinese National Soil Survey of 1981, mean concentrations of available P in soils of 19 plots investigated in Shunyi District increased 10-fold (from 7.3 to 60 mg·kg ) from 1981 to 2009. On average, the critical limit for Olsen-P concentrations (>30 mg·kg ) that can lead to increased risk of P loss was exceeded in all five cropping systems. With feed additives, the “natural background value” (Chinese Environmental Quality Standard for Soils) of copper and zinc in topsoils was exceeded at several sites. Screening for several substances in the veterinary antibiotic classes of sulfonamides, tetracyclines, and fluoroquinolones revealed widespread topsoil contamination. Calculated livestock densities were 10.6 livestock units per ha arable land in 2007. Animal husbandry is increasingly conducted in large operations, making traditional ways of reuse difficult to apply. Comparing three management systems for treatment of organic residues from a pig farm via aerobic (composting) or anaerobic (biogas) treatment in a life cycle assessment, the resulting cropland demand for a sustainable land application of biogas effluent varied between 139 and 288 ha·yr , well above the cropland area owned by the farm (10 ha). The mismatch problems in the above context between business-as-usual and improving performance are framed and discussed as (1) the mismatch between centralized animal husbandry and smallholder farming, (2) the mismatch between livestock density and cropland, (3) nutrient (including P) recycling and increasing organic matter content versus energy production, (4) subsidies for compost production and biogas, as well as (5) advances in the regulatory framework in China.

关键词: cropping systems     life cycle assessment     North China Plain     balances and nutrient flows     transdisciplinary approach    

Cylindrical particulate internal flows: A review

Lizhong HUANG, Xiang GAO, Jianzhong LIN

《机械工程前沿(英文)》 2012年 第7卷 第4期   页码 385-393 doi: 10.1007/s11465-012-0354-z

摘要:

The study of cylindrical particulate internal flows has wide industrial applicability hence received much attention. This article reviews the cylindrical particulate internal flows over the past twenty years. The research is related to the cylindrical particulate flows in the straight channel, curved channel and rotational channel. Finally, several open research issues have been identified.

关键词: cylindrical particulate flow     internal flow    

Supersonic flows over cavities

FANG Tianwen, DING Meng, ZHOU Jin

《能源前沿(英文)》 2008年 第2卷 第4期   页码 528-533 doi: 10.1007/s11708-008-0055-9

摘要: The characteristics of supersonic cold flows over cavities were investigated experimentally and numerically, and the effects of cavities of different sizes on supersonic flow field were analyzed. The results indicate that the ratio

关键词: supersonic     different     ratio    

Managing nutrient for both food security and environmental sustainability in China: an experiment for

Fusuo ZHANG, Zhenling CUI, Weifeng ZHANG

《农业科学与工程前沿(英文)》 2014年 第1卷 第1期   页码 53-61 doi: 10.15302/J-FASE-2014006

摘要: The challenges of how to simultaneously ensure global food security, improve nitrogen use efficiency (NUE) and protect the environment have received increasing attention. However, the dominant agricultural paradigm still considers high yield and reducing environmental impacts to be in conflict with one another. Here we examine a Three-Step-Strategy of past 20 years to produce more with less in China, showing that tremendous progress has been made to reduce N fertilizer input without sacrificing crop yield. The first step is to use technology for in-season root-zone nutrient management to significantly increase NUE. The second is to use technology for integrated nutrient management to increase both yield and NUE by 15%–20%. The third step is to use technology for integrated soil-crop system management to increase yield and NUE by 30%–50% simultaneously. These advances can thus be considered an effective agricultural paradigm to ensure food security, while increasing NUE and improving environmental quality.

关键词: integrated nutrient management     integrated soil-crop system management     environmental protection     food security     resource use efficiency    

IMPROVING NITROGEN SAFETY IN CHINA: NITROGEN FLOWS, POLLUTION AND CONTROL

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 465-474 doi: 10.15302/J-FASE-2022454

摘要:

● It is necessary to address the N flows and their impacts on environment in China for sustainable N management.

关键词: barriers     future management     ammonia emissions     nitrogen input     water N pollution    

Investigation of vortical flows over oscillating body using fast Lagrangian vortex method

Baoshan ZHU ,

《能源前沿(英文)》 2009年 第3卷 第3期   页码 297-306 doi: 10.1007/s11708-009-0010-4

摘要: A computational method facilitating long-time and high-resolution unsteady vortical flows is developed with the advantages of the discrete vortex methods. Both the velocity and pressure distribution of the flow field are calculated by integral formulations in combination with a fast summation algorithm. The vorticity field is described by Lagrangian representation, which is well suited to the moving boundary. Viscosity diffusion of the vorticity is considered with the core spreading model corrected by an adaptive splitting and merging algorithm. The effectiveness of the present method is examined by comparing the numerical results of unsteady separated flows which pass a cylinder and a thin cambered blade undergoing rotational oscillations with available experimental results. Interesting results about vortex shedding patterns and lock-in characteristics are provided for the thin cambered blade.

关键词: unsteady vortical flows     fast vortex method     vortex shedding     rotational oscillation     thin cambered blade    

Porosity model for flows in CMP

ZHANG Chao-hui, YE Wei, LUO Jian-bin, WEN Shi-zhu

《机械工程前沿(英文)》 2006年 第1卷 第4期   页码 418-423 doi: 10.1007/s11465-006-0050-y

摘要: In an effort to explore the contribution of the pad, which is usually full of pores, to the performance of CMP (chemical mechanical polishing), a three-dimensional flow model of CMP is presented by assuming that the fluids in the porous layer comply with Darcy s law, which states that the flow velocity is proportional to the pressure gradient and inverse proportional to the viscosity. The flow equation is deduced accordingly and, by taking advantage of the multilevel technique and line relaxation technique, numerical simulations are carried out to reveal the relationships between the load capacities and operational parameters (including pivot height, roll angle and pitch angle), under conditions with different porous parameters and different thicknesses of the porous layer. The little porous parameter will lead to a prominent increase of load capability (for instance, the load and the moment predicted), which is still augmented by the thicker layer parameter. This will result in a higher material removal ratio of CMP. A pad full of large pores will be used to deduce load capability, facilitating the free flow of the fluids through the pores. The research will add some insights on the mechanism of the CMP technique.

关键词: multilevel technique     three-dimensional     proportional     research     thicker    

MANURE AND METROPOLES---A GLOBAL FRAMEWORK FOR NUTRIENT CYCLING IN FOOD SYSTEMS

《农业科学与工程前沿(英文)》 2021年 第8卷 第1期

Dynamic analysis of free-surface thin film flows driven by gravity over undulated substrate

Zhaomiao LIU, Xin LIU, Guobin WANG, Hong LIAO,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 219-225 doi: 10.1007/s11465-010-0010-4

摘要: This paper studies thin film flows with free surfaces driven by gravity through two types of undulated planes: periodically sinusoidal plane and triangle. The substrate plane is fixed and inclined to a certain angle and the flow with a free surface. Through finite element method (FEM), commenced from Navier-Stokes equations and continuity equation, the exact numerical results of free-surface film flows are obtained through discretization solution to finite equations in flowing areas. Based on the numerical calculations, the streamlines and wall shearing stress during the flowing process are visualized via post-proceeding, and the streamlines separation, the onset and evolution of vortex near the substrate boundary during the flow are also analyzed. The influences from the waviness of the substrate planes profile, height of the triangle plane, and change of the film height on film flow dynamics properties are shown.

关键词: waviness     triangle height     film thickness     streamlines separation     vortex    

Unintended nutrient imbalance induced by wastewater effluent inputs to receiving water and its ecological

《环境科学与工程前沿(英文)》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1584-x

摘要: Eutrophication is the most widespread water quality issue globally. To date, most efforts to control eutrophication have focused on reductions of external nutrient inputs, yet importance of nutrient stoichiometry and subsequent shift in plankton composition in aquatic ecosystem has been largely neglected. To address eutrophication, improved sanitation is one of the United Nations Sustainable Development Goals, spurring the constructions of wastewater treatment facilities that have improved water quality in many lakes and rivers. However, control measures are often targeted at and effective in removing a single nutrient from sewage and thus are less effective in removing the others, resulting in the changes of nutrient stoichiometry. In general, more effective phosphorus removal relative to nitrogen has occurred in wastewater treatment leading to substantial increases in N/P ratios in effluent relative to the influent. Unfortunately, high N/P ratios in receiving waters can impose negative influences on ecosystems. Thus, long-term strategies for domestic wastewater management should not merely focus on the total reduction of nutrient discharge but also consider their stoichiometric balances in receiving waters.

关键词: Nutrient stoichiometry     Wastewater treatment     Ecosystem functioning     Water quality management    

Pelagic-benthic coupling of the microbial food web modifies nutrient cycles along a cascade-dammed river

《环境科学与工程前沿(英文)》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1484-5

摘要:

• Structure of multi-trophic microbial groups were analyzed using DNA metabarcoding.

关键词: Reservoir     Multi-trophic     Beta diversity     Predator-prey     Nutrient accumulation    

Coupling analysis of passenger and train flows for a large-scale urban rail transit system

《工程管理前沿(英文)》 doi: 10.1007/s42524-021-0180-2

摘要: Coupling analysis of passenger and train flows is an important approach in evaluating and optimizing the operation efficiency of large-scale urban rail transit (URT) systems. This study proposes a passenger–train interaction simulation approach to determine the coupling relationship between passenger and train flows. On the bases of time-varying origin–destination demand, train timetable, and network topology, the proposed approach can restore passenger behaviors in URT systems. Upstream priority, queuing process with first-in-first-serve principle, and capacity constraints are considered in the proposed simulation mechanism. This approach can also obtain each passenger’s complete travel chain, which can be used to analyze (including but not limited to) various indicators discussed in this research to effectively support train schedule optimization and capacity evaluation for urban rail managers. Lastly, the proposed model and its potential application are demonstrated via numerical experiments using real-world data from the Beijing URT system (i.e., rail network with the world’s highest passenger ridership).

关键词: urban rail transit     coupling analysis     passenger–train interaction     large-scale simulation    

bioaccumulations based on a global data set and the implications for aquatic systems with aggravating nutrient

《环境科学与工程前沿(英文)》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1471-x

摘要:

• Hg bioaccumulation by phytoplankton varies among aquatic ecosystems.

关键词: Plankton     Hg bioaccumulation     Physiological characteristics     A cross-system analysis     Nutrient compositions     Global data set    

Effects of riparian vegetation patterns on the distribution and potential loss of soil nutrients: a case study of the Wenyu River in Beijing

Erhui GUO,Liding CHEN,Ranhao SUN,Zhaoming WANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 279-287 doi: 10.1007/s11783-014-0667-8

摘要: A riparian ecosystem is an ecological transition zone between a river channel and terrestrial ecosystems. Riparian ecosystems play a vital role in maintaining stream health and bank stabilization. The types of riparian vegetation have changed greatly because of human activities along the Wenyu River. This study examines the impact of riparian vegetation patterns on water pollution due to soil nutrient loss. Four riparian vegetation patterns from the river channel to the upland were chosen as the focus of this study: grassland, cropland, grassland-cropland, and grassland-manmade lawn. The different distributions of soil nutrients along vegetation patterns and the potential risk of nutrient loss were observed and compared. The results showed that riparian cropland has the lowest value of total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and organic matter (OM), but it has the highest soil bulk density (BD). The distributions of soil TN, TP, AN, AP, and OM exhibited a declining trend from the upland toward the river channel for riparian cropland, whereas a different trend was observed for the riparian grassland. The vegetation patterns of grassland-cropland and grassland-manmade lawn show that the grassland in the lower slope has more nutrients and OM but lower soil BD than the cropland or manmade lawn in the upper slope. So, the lower-slope grassland may intercept and infiltrate surface runoff from the upland. The lower-slope grassland has higher levels of soil TN, TP, AN, and AP, and thus it may become a new source of nutrient loss. Our results suggest that the management of the riparian vegetation should be improved, particularly in densely populated areas, to control soil erosion and river pollution.

关键词: riparian     vegetation patterns     soil nutrient distribution     nutrient loss     management    

蓄流分离式灌溉模式研究与实践

张江辉,周和平,徐小波,姚新华

《中国工程科学》 2008年 第10卷 第9期   页码 25-30

摘要:

蓄流分离式灌溉是基于稀植性果树园艺类经济作物需水特性和要求,近年创新提出并实施技术试验与实践的节水灌溉新模式。综述了蓄流分离式灌溉模式基本理念;阐述了蓄流灌溉系统关键技术——蓄流分离式灌水器;分析了蓄流灌溉模式的节水增产、节能降耗、提升灌溉水温以及解决低水头条件下的灌溉均匀性等综合技术效应,指出今后蓄流灌溉模式应着力研究的主要问题。

关键词: 节水农业     蓄流分离式灌溉模式     创新研究     实践    

标题 作者 时间 类型 操作

Phosphorus status, use and recycling in a Chinese peri-urban region with intensive animal husbandry and cropping systems

Marco ROELCKE, Lisa HEIMANN, Yong HOU, Jianbin GUO, Qiaoyun XUE, Wei JIA, Anne OSTERMANN, Roxana Mendoza HUAITALLA, Moritz ENGBERS, Clemens OLBRICH, Roland W. SCHOLZ, Joachim CLEMENS, Frank SCHUCHARDT, Rolf NIEDER, Xuejun LIU, Fusuo ZHANG

期刊论文

Cylindrical particulate internal flows: A review

Lizhong HUANG, Xiang GAO, Jianzhong LIN

期刊论文

Supersonic flows over cavities

FANG Tianwen, DING Meng, ZHOU Jin

期刊论文

Managing nutrient for both food security and environmental sustainability in China: an experiment for

Fusuo ZHANG, Zhenling CUI, Weifeng ZHANG

期刊论文

IMPROVING NITROGEN SAFETY IN CHINA: NITROGEN FLOWS, POLLUTION AND CONTROL

期刊论文

Investigation of vortical flows over oscillating body using fast Lagrangian vortex method

Baoshan ZHU ,

期刊论文

Porosity model for flows in CMP

ZHANG Chao-hui, YE Wei, LUO Jian-bin, WEN Shi-zhu

期刊论文

MANURE AND METROPOLES---A GLOBAL FRAMEWORK FOR NUTRIENT CYCLING IN FOOD SYSTEMS

期刊论文

Dynamic analysis of free-surface thin film flows driven by gravity over undulated substrate

Zhaomiao LIU, Xin LIU, Guobin WANG, Hong LIAO,

期刊论文

Unintended nutrient imbalance induced by wastewater effluent inputs to receiving water and its ecological

期刊论文

Pelagic-benthic coupling of the microbial food web modifies nutrient cycles along a cascade-dammed river

期刊论文

Coupling analysis of passenger and train flows for a large-scale urban rail transit system

期刊论文

bioaccumulations based on a global data set and the implications for aquatic systems with aggravating nutrient

期刊论文

Effects of riparian vegetation patterns on the distribution and potential loss of soil nutrients: a case study of the Wenyu River in Beijing

Erhui GUO,Liding CHEN,Ranhao SUN,Zhaoming WANG

期刊论文

蓄流分离式灌溉模式研究与实践

张江辉,周和平,徐小波,姚新华

期刊论文