香蕉果柄夹持与切割复合执行机构设计与实验

香蕉高位大尺寸特点给香蕉的采摘带来很大的难度,目前以人工采摘作业为主的方式需耗费巨大的人力成本。提出一种香蕉果柄夹持和切割复合执行机构,该复合执行机构主要由夹持与摆切机构、电动链锯、摆头基座和液压系统所组成。夹持与摆切机构和履带行走的驱动动力均来自于安装在履带车底部的液压动力系统。针对香蕉果柄模拟直径为90~120 mm的夹持力学性能实验结果表明：香蕉果柄夹持与切割复合执行机构可以稳定夹持60 kg的负载质量,负载越重需要的最小夹持力就越大,对应的减压阀调节压力也越大,在同一负载下香蕉果柄直径变大需要的夹持力也会增大。将香蕉果柄夹持与切割复合执行机构安装于适配的农业机器人末端,可一次性完成香蕉果柄的夹持、切割和整串香蕉的吊放作业。     

Promotional effects of Ce on NiCe/γAl2O3 for enhancement of H2 in hydrothermal gasification of biomass

This communication presents promotional effects of Ce on a NiCe/γ-Al₂O₃ catalyst for biomass gasification in hydrothermal reaction conditions. The catalyst samples were prepared by an incipient wetness technique using a successive metal loading approach. The TPR/TPO results showed that the presence of Ce minimized metal support interaction and improved the reducibility and thermal stability of the catalyst. The XRD analysis of fresh and reduced (after 10 repeated TPR/TPO cycles) catalyst samples showed unchanged crystal structures of the nickel particles indicating stable properties of the NiCe/γAl₂O₃ catalyst. The hydrothermal biomass gasification experiments were conducted using glucose as a biomass surrogate at various reaction temperature (425–525 °C) and time (5–35 min), while the pressure was maintained at 25.5 MPa. It was observed that the addition of Ce influenced the catalyst surface creating more active nickel sites for steam reforming methane reaction. Ce also increased the activity of Ni/γAl₂O₃ catalysts in terms of hydrogen production by promoting the water gas shift reaction and suppressing the methanation reaction of carbon dioxide.     

Characteristics of hydrochar and liquid fraction from hydrothermal carbonization of cassava rhizome

Hydrothermal carbonization (HTC) of cassava rhizome (CR) was performed to investigate the effect of process parameters including temperature, time, and biomass to water ratio (BTW) on characteristics of hydrochar and liquid fraction products. The effect of temperature was two-fold. First, an increase in reaction temperature from 160 to 180 °C decreased hydrochar yield from 54 to 51%, however, a further increase of temperature from 180 to 200 °C saw an increase in the hydrochar yield to 58%. This was associated to degradation, polymerization, and condensation reactions during HTC. The hydrogen/carbon and oxygen/carbon atomic ratios decreased from 1.4 and 0.6 at 160 °C to 1.2 and 0.4 at 200 °C, respectively. The liquid fraction contained various valuable chemical species including, glucose, furan compounds, (furfural, furfuryl alcohol, hydroxymethylfurfural), volatile fatty acid (succinic acid, lactic acid, formic acid, acetic acid, levulinic acid, and propionic acid) with their highest yields (wt.% dry raw material) of 4.5, 18.5, and 24.3, respectively.     

柿竹园矿区及周边农田土壤重金属形态分布与生物有效性研究

为了解柿竹园矿区及周边农田土壤重金属的生物有效性,采用连续提取法对该矿区及周边的农田土壤重金属Cu、Pb、Zn、Cd、As、Hg的形态分布和生物有效性进行了分析。结果表明:(1)柿竹园矿区及周边农田土壤未见Hg污染情况,但不同程度受到Cu、Pb、Zn、Cd、As的污染,尤以Cd、As污染为重;(2)柿竹园矿区及周边农田土壤中Cu、Pb、Zn以铁锰氧化物结合态为主,分别占其总量的48.3%、67.3%、47.1%,Cd铁锰氧化物结合态含量最高,残渣态、离子交换态和碳酸盐结合态次之;As和Hg以残渣态为主,含量比例在90%以上;(3)矿区及周边土壤中Cd的有效态含量最高,所占比例平均值为31.1%,远高于其他5种重金属元素,生物有效性最高,As的有效态含量最低,生物有效性最低。最后提出了采用稳定化修复技术清理污染源、采用磷酸二氢钙降低土壤中污染最严重元素Pb、Cd的生物有效性、采用香蒲等植物对工矿废弃地及部分未利用土地进行修复的建议。     

Hidden feature extraction for unstructured agricultural environment based on supervised kernel locally linear embedding modeling

An online hidden feature extraction algorithm is proposed for unknown and unstructured agricultural environments based on a supervised kernel locally linear embedding (SKLLE) algorithm. Firstly, an online obtaining method for scene training samples is given to obtain original feature data. Secondly, Bayesian estimation of the a posteriori probability of a cluster center is performed. Thirdly, nonlinear kernel mapping function construction is employed to map the original feature data to hyper-highdimensional kernel space. Fourthly, the automatic determination of hidden feature dimensions is performed using a local manifold learning algorithm. Then, a low-level manifold computation in hidden space is completed. Finally, long-range scene perception is realized using a 1-NN classifier. Experiments are conducted to show the effectiveness and the influence of parameter selection for the proposed algorithm. The kernel principal component analysis (KPCA), locally linear embedding (LLE), and supervised locally linear embedding (SLLE) methods are compared under the same experimental unstructured agricultural environment scene. Test results show that the proposed algorithm is more suitable for unstructured agricultural environments than other existing methods, and that the computational load is significantly reduced.The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-018-0227-8     

Extraction and Characterization of Cellulose Microfibers from Agricultural Wastes of Onion and Garlic

As a new lingo-cellulosic natural fiber sources, agricultural processing wastes of onion and garlic, stalks and skins, were investigated by determining their chemical composition and characterization of their cellulose microfibers extracted by chlorite and alkaline extraction method. The extracted cellulose microfibers were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscope (SEM). The stalks and skins of garlic and onion were composed of cellulose (41–50%), hemicelluloses (16–26%), and lignin (26–39%), which indicates that the predominant polysaccharide in the stalks and skins of onion and garlic is cellulose. The cellulose microfibers extracted from the stalks and skins of onion and garlic were more heat stable than their neat fibers. The result showed that the skin and stalk of onion and garlic have a high potential for the utilization as a new source of biopolymer resources.     

A Bayesian hierarchical spatially explicit modelling framework to examine phosphorus export between contrasting flow regimes

We examine the ability of a SPARROW-based model (SPAtially Referenced Regression On Watershed attributes) to assess regional P export coefficients that can assist with evaluation of nutrient mitigation projects and support adaptive watershed management. Limitations in number of tributary monitoring stations were overcome by assembling multi-agency water quality data from provincial, municipal, citizen science, and academic programs. We introduced a Bayesian hierarchical framework designed to guide parameter estimation from tributary nutrient loading in southern Georgian Bay drainage basin during contrasting flow regimes, such as dry and wet years. Agriculture was identified as a major non-point P source representing between 30 and 48% of delivered P loading. Our source apportionment predicted TP loss rates from croplands that exceeded those from forested areas by 320% during dry years and by 360% during wet years, while low intensity agricultural areas (hay and pasture) exceeded P export from forests by a mere 20% and 30%, respectively. Our study identified urban runoff as another significant non-point nutrient source displaying the highest variability between dry and wet years. In particular, owing to the extensive urbanization in the Lake Simcoe watershed, urban runoff contributed nearly half of delivered P loading from tributaries into the lake. The nutrient loading management plan for Lake Simcoe calls for a reduction in P loading by ～40% from a long-term average of 72 t P y^?1 in 2002–2007 to 44 t P y^?1 by 2045. Our analysis emphasizes the importance of mitigating urban non-point sources together with efforts to control agricultural runoff.     

2022 Top Ten News of China’s Paper Industry

Top 1 On January 27^(th),the "Announcement on Including the Bamboo Pulp and Paper Industry in the Pilot Scope of Verification and Deduction of Agricultural Product Input Tax" was issued by the Sichuan Provincial Taxation Bureau of the State Taxation Administration and Sichuan Provincial Department of Finance.It has been officially implemented since February 1,2022.This announcement provides a signifi cant policy advantage in accelerating the promotion of bamboo resource pulp and papermaking.     

农业院校应用化学专业研究生培养模式的探索与实践

经过多年的探索与实践,总结出适用于农业院校应用化学专业的研究生培养模式,既充分利用农业院校办学资源和学科优势,体现出农业院校的办学特色,又能适应和满足社会对人才的实际需求。通过严把考生进出口关、凝练学科研究方向、强化导师队伍管理、推进教学改革、激发学生创新热情、加强资源共享、鼓励产学研相结合等措施,提高了应用化学专业研究生的培养质量。     

New Patterns in Urban Design

Brian McGrath and VictoriaMarshall discern the newly resilient urban patterns that are emerging in the meta-city, shifting and adjusting to changing local and global conditions. Based on smart infrastructure, self-sufficiency and hybrid local models, highly adaptive design patterns take the form of responsive micropatches rather than overarching masterplans. As demonstrated by the featured projects, ‘pattern recognition’, sensory mapping techniques and sensitivity to a city's ecosystem are becoming essential tools to the urban designer. Copyright © 2009 John Wiley & Sons, Ltd.