资源类型

期刊论文 409

会议视频 1

年份

2024 1

2023 14

2022 23

2021 30

2020 35

2019 32

2018 42

2017 26

2016 36

2015 30

2014 33

2013 19

2012 21

2011 10

2010 10

2009 11

2008 6

2007 6

2006 4

2005 3

展开 ︾

关键词

增材制造 3

S-N曲线 2

可持续性 2

组织工程 2

2R-1C模型；嵌入式系统；参数估计；非迭代方法；二次型 1

3D生物打印 1

ANP 1

CAR19 1

CART19 1

COVID-19 1

Chord图 1

Cu(Inx 1

F-N图 1

Fe、Co、Ru 碳化物 1

Ga1–x)Se2 1

H2S 1

Klee图 1

K型钢管混凝土节点 1

Mittag-Leffler稳定性；分数阶；四元数神经网络；脉冲 1

展开 ︾

检索范围：

排序： 展示方式：

Ductile extension of 3-D external circumferential cracks in pipe structures

Wuchao YANG, Xudong QIAN

《结构与土木工程前沿（英文）》 2011年 第5卷 第3期   页码 294-303 doi: 10.1007/s11709-011-0115-9

摘要： This study investigates the ductile fracture resistance of 3-D external circumferential cracks in the wall of a steel pipe under remote tension, using a damage-mechanism model originally proposed by Gurson and Tvergaard. The ductile crack extension utilizes an element extinction technique implemented in the computational cell framework. The key parameter for the computational cell method, i.e., the initial porosity ratio , is calibrated using both the fracture resistance and the load-deformation responses obtained from fracture tests of multiple single-edge bend [SE(B)] specimens made of high-strength steel, HY80, which has a yield strength of 630 MPa. The fracture resistance along the 3-D semi-elliptical crack front is computed from the calibrated cell model. Based on the similarity concept in the near-tip stress-strain fields, this study demonstrates that an equivalent 2-D axi-symmetric model provides conservative estimations of the fracture resistance for 3-D circumferential cracks in pipes.

关键词： ductile fracture     computational cell method     G-T model     J-R curve    

HTML PDF 收藏

Detection of void and metallic inclusion in 2D piezoelectric cantilever beam using impedance measurements

NANTHAKUMAR, R. K. ANNABATTULA, X. ZHUANG

《结构与土木工程前沿（英文）》 2019年 第13卷 第3期   页码 542-556 doi: 10.1007/s11709-018-0496-0

摘要： The aim of current work is to improve the existing inverse methodology of void-detection based on a target impedance curve, leading to quick-prediction of the parameters of single circular void. In this work, mode-shape dependent shifting phenomenon of peaks of impedance curve with change in void location has been analyzed. A number of initial guesses followed by an iterative optimization algorithm based on univariate method has been used to solve the problem. In each iteration starting from each initial guess, the difference between the computationally obtained impedance curve and the target impedance curve has been reduced. This methodology has been extended to detect single circular metallic inclusion in 2D piezoelectric cantilever beam. A good accuracy level was observed for detection of flaw radius and flaw-location along beam-length, but not the precise location along beam-width.

关键词： piezoelectricity     impedance curve     mode shapes     inverse problem     flaw detection     curve shifting    

HTML PDF 收藏

Availability of wind energy resource potential for power generation at Jos, Nigeria

Ajayi, R. O. Fagbenle, J. Katende, J. O. Okeniyi

《能源前沿（英文）》 2011年 第5卷 第4期   页码 376-385 doi: 10.1007/s11708-011-0167-5

摘要： The objective of this study was to assess the potential viability of the wind resource potential in Jos, Plateau state, Nigeria for power generation. The monthly mean wind speeds that span from 1987 to 2007 were employed to statistically analyze the monthly, annual and seasonal potentials of the wind energy resources at the site. Besides, the results were employed together with two models of wind energy conversion system to simulate the likely average output power. The outcome showed that Jos was suitable as a site for wind farm projects of varying sizes and that MW·h to GW·h of electricity is likely to be produced per period of months, seasons and years. The average wind speed range at the site was also estimated to be between 6.7 and 11.8 m/s across the months, years and seasons.

关键词： green electricity     renewable resources     Weibull statistics     Jos     Nigeria    

HTML PDF 收藏

Modeling of alkali-silica reaction in concrete: a review

J.W. PAN, Y.T. FENG, J.T. WANG, Q.C. SUN, C.H. ZHANG, D.R.J. OWEN

《结构与土木工程前沿（英文）》 2012年 第6卷 第1期   页码 1-18 doi: 10.1007/s11709-012-0141-2

摘要： This paper presents a comprehensive review of modeling of alkali-silica reaction (ASR) in concrete. Such modeling is essential for investigating the chemical expansion mechanism and the subsequent influence on the mechanical aspects of the material. The concept of ASR and the mechanism of expansion are first outlined, and the state-of-the-art of modeling for ASR, the focus of the paper, is then presented in detail. The modeling includes theoretical approaches, meso- and macroscopic models for ASR analysis. The theoretical approaches dealt with the chemical reaction mechanism and were used for predicting pessimum size of aggregate. Mesoscopic models have attempted to explain the mechanism of mechanical deterioration of ASR-affected concrete at material scale. The macroscopic models, chemo-mechanical coupling models, have been generally developed by combining the chemical reaction kinetics with linear or nonlinear mechanical constitutive, and were applied to reproduce and predict the long-term behavior of structures suffering from ASR. Finally, a conclusion and discussion of the modeling are given.

关键词： alkali-silica reaction (ASR)     modeling     concrete     mesoscopic     macroscopic    

HTML PDF 收藏

Carbon dioxide: a renewable feedstock for the synthesis of fine and bulk chemicals

PATIL, Pawan J. TAMBADE, Sachin R. JAGTAP, Bhalchandra M. BHANAGE,

《化学科学与工程前沿（英文）》 2010年 第4卷 第2期   页码 213-235 doi: 10.1007/s11705-009-0227-0

摘要： The syntheses of carbon dioxide (CO) based industrially important chemicals have gained considerable interest in view of the sustainable chemistry and “green chemistry” concepts. In this review, recent developments in the chemical fixation of CO to valuable chemicals are discussed. The synthesis of five-member cyclic carbonates , cycloaddition of CO to epoxides is one of the promising reactions replacing the existing poisonous phosgene-based synthetic route. This review focuses on the synthesis of cyclic carbonates, vinyl carbamates, and quinazoline-2,4(1,3)-diones reaction of CO and epoxide, amines/phenyl acetylene, 2-aminobenzinitrile and other chemicals. Direct synthesis of dimethyl carbonate, 1,3-disubstituted urea and 2-oxazolidinones/2-imidazolidinones have limitations at present because of the reaction equilibrium and chemical inertness of CO. The preferred alternatives for their synthesis like transesterification of ethylene carbonate with methanol, transamination of ethylene carbonate with primary amine and transamination reaction of ethylene carbonate with diamines/-aminoalcohols are discussed. These methodologies offer marked improvements for greener chemical fixation of CO in to industrially important chemicals.

关键词： inertness     CO     phosgene-based synthetic     quinazoline-2     4     equilibrium    

HTML PDF 收藏

Coupling the porous conditional moment closure with the random pore model: applications to gasification and CO

R. CHODANKA, M. J. CLEARY, A. Y. KLIMENKO

《化学科学与工程前沿（英文）》 2012年 第6卷 第1期   页码 84-93 doi: 10.1007/s11705-011-1164-2

摘要： Gasification of coal or biomass with in situ CO capture simultaneously allows production of clean hydrogen at relatively low cost and reduced emission of CO into the atmosphere. Clearly, this technology has a great potential for a future carbon constrained economy. Therefore, the development of a comprehensive, physically-based gasifier model is important. The sub-models that describe reactive transport processes in coal particles as well as in particles of CO sorbent material are among the key sub-models, which provide a necessary input for an overall gasifier model. Both coal and sorbent are materials that have complicated pore structures. The porous conditional moment closure (PCMC) model proves to be adequate for modeling reactive transport through porous media with fixed pore structure. Consumption of coal in the heterogeneous gasification reaction, however, widens the pores and reduces the surface area available for this reaction. At the same time, formation of a carbonate layer narrows the pores in the sorbent material and reduces the reaction rate of CO sorption. In both cases the pore structures are affected. Such changes are not taken into account in the existing PCMC model. In this study, we obtain the parameters of the diffusive tracer distribution based on the pore size distribution given by the widely applied random pore model (RPM), while coupling PCMC with RPM. Such coupling allows taking into account changes in pore structure caused by heterogeneous reactions and thus improves the accuracy of these key sub-models.

关键词： gasification     CO2 capture     PCMC     RPM    

HTML PDF 收藏

Correlation between tension softening relation and crack extension resistance in concrete

Xiufang ZHANG , Shilang XU ,

《结构与土木工程前沿（英文）》 2009年 第3卷 第3期   页码 323-329 doi: 10.1007/s11709-009-0041-2

摘要： Changes of the material fracture energy consumption with crack propagation can be described by a crack extension resistance curve, one of the fundamental fracture criteria in crack mechanics. Recently, experimental observation of the fracture behavior in concrete was used to develop a new fracture criterion, the crack extension resistance curve, to analyze crack propagation during the entire concrete fracture process. The variation of the crack extension resistance is mainly associated with the energy consumption in the fracture process zone ahead of the stress-free crack tip. The crack extension resistance is then a function of the softening curve, which is a basic mechanical property in the fracture process zone. The relationship between the softening curve and the crack extension resistance curve is then analyzed based on results of three-point bending beams tests. The results indicate that the characteristic points of the crack extension resistance curve is closely related to the characteristic point on used tension softening curve.

关键词： concrete     fracture process zone     crack extension GR resistance     tension softening curve    

HTML PDF 收藏

车辆舱室、外表面和机载电子设备的热管理概述 Review

Garrett J. Marshall, Colin P. Mahony, Matthew J. Rhodes, Steve R.

《工程（英文）》 2019年 第5卷 第5期   页码 954-969 doi: 10.1016/j.eng.2019.02.009

摘要：

减少车辆内部的热量积累并确保适当的车辆温度水平可以提高车辆的燃油经济性、行驶里程、可靠性、使用寿命、乘客舒适度和安全性。随着新技术、消费者需求、社会关注和政府法规的出现和发展，汽车热管理的改善仍然是关键。本文总结了汽车热管理技术和建模的最新进展，重点研究了三个关键领域：汽车舱室、电子设备和外部部件。所涵盖的有关舱室的主题包括减少热负荷和改善暖通空调（heating, ventilation, and air-conditioning, HVAC）系统的方法；以及窗户玻璃/着色和车辆表面处理方面的改善。讨论了关于电子设备的热管理，包括电池和绝缘栅双极晶体管（insulatedgate bipolar transistor, IGBT），以及采用热管、散热器、射流冲击、强制对流和相变材料的主动和被动降温方法。最后，在考虑阻力/摩擦力和环境影响的情况下，回顾了建立和增强车辆外部部件传热模型的工作。尽管我们在汽车热管理领域取得了一定的进步，但挑战仍然存在；本文对主要问题进行了概括，并提出了进一步研究的建议。

关键词： 车辆设计     汽车工程     电子产品包装     热管     气候控制     加热、通风和空调     电池降温     热浸    

HTML PDF 收藏

Seismic performance of composite moment-resisting frames achieved with sustainable CFST members

MACEDO,J. M. CASTRO,R. MONTEIRO,N. SILVESTRE

《结构与土木工程前沿（英文）》 2016年 第10卷 第3期   页码 312-332 doi: 10.1007/s11709-016-0345-y

摘要： The main objective of the research presented in this paper is to study the bending behaviour of Concrete Filled Steel Tube (CFST) columns made with Rubberized Concrete (RuC), and to assess the seismic performance of moment-resisting frames with these structural members. The paper describes an experimental campaign where a total of 36 specimens were tested, resorting to a novel testing setup, aimed at reducing both the preparation time and cost of the test specimens. Different geometrical and material parameters were considered, namely cross-section type, cross-section slenderness, aggregate replacement ratio, axial load level and lateral loading type. The members were tested under both monotonic and cyclic lateral loading, with different levels of applied axial loading. The test results show that the bending behaviour of CFST elements is highly dependent on the steel tube properties and that the type of infill does not have a significant influence on the flexural behaviour of the member. It is also found that Eurocode 4 is conservative in predicting the flexural capacity of the tested specimens. Additionally, it was found that the seismic design of composite moment-resisting frames with CFST columns, according to Eurocode 8, not only leads to lighter design solutions but also to enhanced seismic performance in comparison to steel frames.

关键词： concrete filled steel tubes     rubberized concrete     composite frames     seismic performance assessment    

HTML PDF 收藏

Is there an inverted U-shaped curve?Empirical analysis of the Environmental Kuznets Curve in agrochemicals

Fei LI,Suocheng DONG,Fujia LI,Libiao YANG

《环境科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 276-287 doi: 10.1007/s11783-014-0700-y

摘要： As the largest contributor to water impairment, agriculture-related pollution has attracted the attention of scientists as well as policy makers, and quantitative information is being sought to focus and advance the policy debate. This study applies the panel unit root, heterogeneous panel cointegration, and panel-based dynamic ordinary least squares to investigate the Environmental Kuznets Curve on environmental issues resulting from use of agricultural synthetic fertilizer, pesticide, and film for 31 provincial economies in mainland China from 1989 to 2009. The empirical results indicate a positive long-run co-integrated relationship between the environmental index and real GDP per capita. This relationship takes on the inverted U-shaped Environmental Kuznets Curve, and the value of the turning point is approximately 10,000–13,000, 85,000–89,000 and over 160,000 CNY, for synthetic fertilizer nitrogen indicator, fertilizer phosphorus indicator and pesticide indicator, respectively. At present, China is subject to tremendous environmental pressure and should assign more importance to special agriculture-related environmental issues.

关键词： Environmental Kuznets Curve     agrochemical     China    

HTML PDF 收藏

Erratum to: On secondary new particle formation in China

Markku KULMAMA,Tuukka Petäjä,Veli-Matti KERMINEN,Joni KUJANSUU,Taina RUUSKANEN,Aijun DING,Wei NIE,MinHU,Zhibin WANG,Zhijun WU,Lin WANG,Douglas R.

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0857-7

HTML PDF 收藏

一种去除地表水中的磷的浮岛处理系统 Article

Brown, Treavor Boyer, R.J. Sindelar, Sam Arden, Amar Persaud, Sherry Brandt-Williams

《工程（英文）》 2018年 第4卷 第5期   页码 597-609 doi: 10.1016/j.eng.2018.08.002

摘要：

本研究旨在设计、建造和测试一个中试规模的浮动模块化处理系统，并用以对美国佛罗里达州中部富营养化湖泊中的总磷（TP）进行去除。该处理系统由生物和物理-化学处理模块组成。用多种底物和水生大型植物组合构建了13种不同的中宇宙实验（mesocosm），分别测试了总磷（TP）和正磷（PO4
3−）的去除率及潜在的区域去除率。此外本研究对7 种吸附介质进行了小型杯罐实验和柱实验，并对3种商业树脂进行了吸附能力的测试。完成这些独立的测试过程后，在佛罗里达中部的一个湖泊中，设计了一个浮岛处理系统（FITS）并运行了8个月。中宇宙实验对磷的平均去除率为40%~50%，平均去除量为5.0 g·m–2·a–1。其中沉水植物（SAV）系统和藻类洗涤器（AGS）效果最好，分别去除了20 mg·m–2·d–1和50 mg·m–2·d–1的磷，它们对磷的平均去除量分别为5.5 g·m–2·a–1和12.0 g·m–2·a–1。在吸附介质中，明矾渣（AR）的性能最佳，接触5 min 后，PO43−浓度降低了75% 左右。在所测试的商品树脂中，PhosX 树脂的去除效果最好，在30 min后去除了约40%的磷，60 min后去除了约60%的磷。在基线运行条件下展开实验，FITS 对PO43−的平均去除率为53%；使用PO43−去除率的第50百分位和第90百分位以及FITS的环境足迹进行评价，结果表明系统的去除率分别为56%和86%；区域磷去除率在8.9~16.5 g·m–2·a–1之间。

关键词： 除磷     湖泊生态系统     浮岛处理    

HTML PDF 收藏

On secondary new particle formation in China

Markku Kulmala,Tuukka Petäjä,Veli-Matti Kerminen,Joni Kujansuu,Taina Ruuskanen,Aijun Ding,Wei Nie,MinHu,Zhibin Wang,Zhijun Wu,Lin Wang,Douglas R.

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0850-1

摘要： Formation of new atmospheric aerosol particles is a global phenomenon that has been observed to take place in even heavily-polluted environments. In China, new particle production has been observed at very high pollution levels (condensation sink about 0.1s ) in several megacities. A holistic scientific understanding on the atmospheric phenomena associated with air quality as a whole, as well as on the connection between air quality and climate, is lacking at the moment.With a network of observation stations, we will be able to understand the interactions and feedbacks associated with the urban pollution mixture, and ultimately, are ready to make targeted strategies for the pollution control. This paper summaries the recent advances in studying secondary new aerosol formation in China and shows how increased process-level understanding will help us to understand air quality-climate-weather interactions and how the feedbacks and interactions affect the air quality in highly-polluted environments such as those frequently encountered in Chinese megacities. Formation of new atmospheric aerosol particles is a global phenomenon that has been observed to take place in even heavily-polluted environments. However, in all environments there appears to be a threshold value of the condensation sink (due to pre-existing aerosol particles) after which the formation rate of 3 nm particles is no longer detected. In China, new particle production has been observed at very high pollution levels (condensation sink about 0.1 s ) in several megacities, including Beijing, Shanghai and Nanjing as well as in Pearl River Delta (PRD). Here we summarize the recent findings obtained from these studies and discuss the various implications these findings will have on future research and policy.

关键词： Aerosol particles     Heavily-polluted environments     Condensation sink     New particle production     Megacities    

HTML PDF 收藏

Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan Mountain Region, southern Ningxia, China

J. M. R?MKENS, Rui LI, Fang WANG, Jie CHEN

《环境科学与工程前沿（英文）》 2011年 第5卷 第4期   页码 564-572 doi: 10.1007/s11783-011-0348-9

摘要： The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China, that forms an important divide between landforms and bio-geographic regions. The populated part of the Liupan Mountain Region has suffered tremendous ecological damage over time due to population pressure, excessive demand and inappropriate use of agricultural land resources. To present the relationship between land use/cover change and spatio-temporal variation of soil erosion, data sets of land use between the late 1980s and 2000 were obtained from Landsat Thematic Mapper (TM) imagery, and spatial models were used to characterize landscape and soil erosion conditions. Also, soil erosion in response to land use and land cover change were quantified and analyzed using data from geographical information systems and remote sensing. Soil erosion by water was the dominant mode of soil loss, while soil erosion by wind was only present on a relatively small area. The degree of soil erosion was classified into five severity classes: slight, light, moderate, severe, and very severe. Soil erosion in the Liupan Mountain Region increased between the late 1980s and 2000, both in terms of acreage and severity. Moderate, severe, and very severe eroded areas accounted for 54.86% of the total land area. The lightly eroded area decreased, while the moderately eroded area increased by 368817 ha (22%) followed by severe erosion with 146552 ha (8.8%), and very severe erosion by 97067.6 ha (5.8%). Soil loss on sloping cropland increased with slope gradients. About 90% of the cropland was located on slopes less than 15°. Most of the increase in soil erosion on cropland was due to conversion of steep slopes to cropland and degradation of grassland and increased activities. Soil erosion was severe on grassland with a moderate or low grass cover and on dry land. Human activities, cultivation on steep slopes, and overgrazing of pastures were the main reasons for the increase in erosion severity.

关键词： land use/land cover change     soil erosion     geographical information system     remote sensing     Liupan Mountain Region    

HTML PDF 收藏

REINTEGRATION OF CROP-LIVESTOCK SYSTEMS IN EUROPE: AN OVERVIEW

J. VAN DE VEN, Davey L. JONES, David R. CHADWICK

《农业科学与工程前沿（英文）》 2021年 第8卷 第1期   页码 111-129 doi: 10.15302/J-FASE-2020373

摘要： Ongoing specialization of crop and livestock systems provides socioeconomic benefits to the farmer but has led to greater externalization of environmental costs when compared to mixed farming systems. Better integration of crop and livestock systems offers great potential to rebalance the economic and environmental trade-offs in both systems. The aims of this study were to analyze changes in farm structure and review and evaluate the potential for reintegrating specialized intensive crop and livestock systems, with specific emphasis on identifying the co-benefits and barriers to reintegration. Historically, animals were essential to recycle nutrients in the farming system but this became less important with the availability of synthetic fertilisers. Although mixed farm systems can be economically attractive, benefits of scale combined with socio-economic factors have resulted in on-farm and regional specialization with negative environmental impacts. Reintegration is therefore needed to reduce nutrient surpluses at farm, regional and national levels, and to improve soil quality in intensive cropping systems. Reintegration offers practical and cost-effective options to widen crop rotations and promotes the use of organic inputs and associated benefits, reducing dependency on synthetic fertilisers, biocides and manure processing costs. Circular agriculture goes beyond manure management and requires adaptation of both food production and consumption patterns, matching local capacity to produce with food demand. Consequently, feed transport, greenhouse gas emissions, nutrient surpluses and nutrient losses to the environment can be reduced. It is concluded that reintegration of specialized farms within a region can provide benefits to farmers but may also lead to further intensification of land use. New approaches within a food system context offer alternatives for reintegration, but require strong policy incentives which show clear, tangible and lasting benefits for farmers, the environment and the wider community.

关键词： circular agriculture     coupled farming systems     mixed farming     specialised farming systems     GHG    

HTML PDF 收藏

标题 作者 时间 类型 操作

Ductile extension of 3-D external circumferential cracks in pipe structures

Wuchao YANG, Xudong QIAN

期刊论文

Detection of void and metallic inclusion in 2D piezoelectric cantilever beam using impedance measurements

NANTHAKUMAR, R. K. ANNABATTULA, X. ZHUANG

期刊论文

Availability of wind energy resource potential for power generation at Jos, Nigeria

Ajayi, R. O. Fagbenle, J. Katende, J. O. Okeniyi

期刊论文

Modeling of alkali-silica reaction in concrete: a review

J.W. PAN, Y.T. FENG, J.T. WANG, Q.C. SUN, C.H. ZHANG, D.R.J. OWEN

期刊论文

Carbon dioxide: a renewable feedstock for the synthesis of fine and bulk chemicals

PATIL, Pawan J. TAMBADE, Sachin R. JAGTAP, Bhalchandra M. BHANAGE,

期刊论文

Coupling the porous conditional moment closure with the random pore model: applications to gasification and CO

R. CHODANKA, M. J. CLEARY, A. Y. KLIMENKO

期刊论文

Correlation between tension softening relation and crack extension resistance in concrete

Xiufang ZHANG , Shilang XU ,

期刊论文

车辆舱室、外表面和机载电子设备的热管理概述

Garrett J. Marshall, Colin P. Mahony, Matthew J. Rhodes, Steve R.

期刊论文

Seismic performance of composite moment-resisting frames achieved with sustainable CFST members

MACEDO,J. M. CASTRO,R. MONTEIRO,N. SILVESTRE

期刊论文

Is there an inverted U-shaped curve?Empirical analysis of the Environmental Kuznets Curve in agrochemicals

Fei LI,Suocheng DONG,Fujia LI,Libiao YANG

期刊论文

Erratum to: On secondary new particle formation in China

Markku KULMAMA,Tuukka Petäjä,Veli-Matti KERMINEN,Joni KUJANSUU,Taina RUUSKANEN,Aijun DING,Wei NIE,MinHU,Zhibin WANG,Zhijun WU,Lin WANG,Douglas R.

期刊论文

一种去除地表水中的磷的浮岛处理系统

Brown, Treavor Boyer, R.J. Sindelar, Sam Arden, Amar Persaud, Sherry Brandt-Williams

期刊论文

On secondary new particle formation in China

Markku Kulmala,Tuukka Petäjä,Veli-Matti Kerminen,Joni Kujansuu,Taina Ruuskanen,Aijun Ding,Wei Nie,MinHu,Zhibin Wang,Zhijun Wu,Lin Wang,Douglas R.

期刊论文

Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan Mountain Region, southern Ningxia, China

J. M. R?MKENS, Rui LI, Fang WANG, Jie CHEN

期刊论文

REINTEGRATION OF CROP-LIVESTOCK SYSTEMS IN EUROPE: AN OVERVIEW

J. VAN DE VEN, Davey L. JONES, David R. CHADWICK

期刊论文