朝鲜南部地区农业资源及粮食生产水平分析

朝鲜南部地区的降雨量、日照和热量等农业气候资源相对充足,但60%～70%的土壤偏酸性,土壤肥力差,粮食单产水平很低,而造成当地农业生产水平低下的原因可能是多方面的,需要采取综合措施加以解决。     

The effect of conditions of storage on the respiration of apples. V. The relationship between temperature,rate of respiration,and composition of the internal atmosphere of the fruit

Change of rate of production of CO₂ leads to change in the composition of the internal atmosphere of apple fruits, and therefore the gross effect of temperature is a complex phenomenon which involves change in other parameters of the cellular environment.

An attempt has been made to determine the effect of temperature alone on the cellular rate of respiration, but it does not appear to be possible to do this for a bulky organ.

Over the range from 0° to 12 °C, the concentration of CO₂ in the intercellular spaces of an apple varied directly with the rate of production of CO₂, thus satisfying Fick’s law. Temperature appeared to have no effect on the porosity of the skin.     

基于SDRAM的FPGA实时图像采集系统的设计

针对基于FPGA的实时图像采集系统提出了一种基于SDRAM的实现方法,FPGA中采用模块化设计方法,详细给出了系统的硬件框图,并对SDRAM控制器的控制方法、各模块功能和软件部分进行了具体的设计.仿真结果表明,该系统设计灵活、工作稳定可靠、体积小、成本低,完成了高速数据的大容量存储,可满足于高性能的实时图像采集系统要求.     

Mapping radiation interception in row-structured orchards using 3D simulation and high-resolution airborne imagery acquired from a UAV

This study was conducted to model the fraction of intercepted photosynthetically active radiation (fIPAR) in heterogeneous row-structured orchards, and to develop methodologies for accurate mapping of the instantaneous fIPAR at field scale using remote sensing imagery. The generation of high-resolution maps delineating the spatial variation of the radiation interception is critical for precision agriculture purposes such as adjusting management actions and harvesting in homogeneous within-field areas. Scaling-up and model inversion methods were investigated to estimate fIPAR using the 3D radiative transfer model, Forest Light Interaction Model (FLIGHT). The model was tested against airborne and field measurements of canopy reflectance and fIPAR acquired on two commercial peach and citrus orchards, where study plots showing a gradient in the canopy structure were selected. High-resolution airborne multi-spectral imagery was acquired at 10?nm bandwidth and 150?mm spatial resolution using a miniaturized multi-spectral camera on board an unmanned aerial vehicle (UAV). In addition, simulations of the land surface bidirectional reflectance were conducted to understand the relationships between canopy architecture and fIPAR. Input parameters used for the canopy model, such as the leaf and soil optical properties, canopy architecture, and sun geometry were studied in order to assess the effect of these inputs on canopy reflectance, vegetation indices and fIPAR. The 3D canopy model approach used to simulate the discontinuous row-tree canopies yielded spectral RMSE values below 0.03 (visible region) and below 0.05 (near-infrared) when compared against airborne canopy reflectance imagery acquired over the sites under study. The FLIGHT model assessment conducted for fIPAR estimation against field measurements yielded RMSE values below 0.08. The simulations conducted suggested the usefulness of these modeling methods in heterogeneous row-structured orchards, and the high sensitivity of the normalized difference vegetation index and fIPAR to background, row orientation, percentage cover and sun geometry. Mapping fIPAR from high-resolution airborne imagery through scaling-up and model inversion methods conducted with the 3D model yielded RMSE error values below 0.09 for the scaling-up approach, and below 0.10 for the model inversion conducted with a look-up table. The generation of intercepted radiation maps in row-structured tree orchards is demonstrated to be feasible using a miniaturized multi-spectral camera on board UAV platforms for precision agriculture purposes.     

Pesticides in cereal production

A cereal grower will normally attempt to maximise his returns from resources used without prejudicing the future. Historically, for the control of weeds, pests and diseases growers have preferred husbandry methods and the use of ‘resistant’ varieties. Economic pressures, technical developments and subsequent changes in farming systems demand more reliance on pesticides. The adoption of the Common Agricultural Policy and the relatively higher cereal prices improve the cost: benefit ratio from their more extensive use. Additionally, quality standards arising directly or indirectly from EEC legislation, where these can be influenced by pesticide application, will further encourage their routine application. In the longer term, increased fixed costs will encourage the grower to insure against crop losses by the use of prophylactic pesticide applications where appropriate. New systems of production to reduce fixed costs will be adopted, probably involving further use of pesticides. Growers will always wish to contain variable costs as far as is possible: as better forecasting of disease and pest epidemics is developed prophylactic treatments will be discarded. Examples of the economic benefits or penalties of adopting alternatives to pesticides are given.     

从家蝇幼虫饲料残渣中分离提取生物活性物质的研究(简报)

家蝇(Musca domastica vicina)幼虫在生长发育过程中,能分泌有广泛抑菌作用的活性物质。这种活性物质对多种严重的农作物病害亦有显著抑制作用,而对有益生物无害。深入研究这种活性物质的分离提纯方法、理化性质、结构特点、活性特征等,对生物合成或仿生合成新一代完全无公害农药,对家蝇在生态系的作用和综合利用,都有重要理论意义和实用价值,本文简报近几年作者从家蝇幼虫饲料残渣中提取分离这种活性物质的方法及其性质的初步探讨。1 材料与方法     

Efficacy of ivermectin in a controlled-release capsule for the control of breech strike in sheep

Objective To investigate the efficacy of ivermectin in an intraruminal controlled-release capsule (CRC) against blowfly strike.
Design Pen and field trials with controls.
Animals Pen studies: Two breech strike trials involving 60 Romney and 60 Merino sheep. One body strike trial using 100 Merino sheep.
Field trials: Eight trials in New Zealand used 1000 Romney and Romney-cross sheep. Fifty Merino lambs in one trial in Australia.
Procedure Pen studies: Sheep were allocated to two equal groups. One was not treated, the other sheep received a CRC that delivered ivermectin at 20 μg/kg/day for 100 days. In the breech strike trials, each animal was given an oral laxative 2 days before exposure to adult Lucilia cuprina . In the body-strike trial, the sheep sheep were kept wet to increase susceptibility prior to the release of blowflies.
Field trials: Fifty or 200 sheep allocated to equal groups of nontreated or treated with the CRC and grazed at pasture exposed to natural blowfly challenge.
Results Pen studies: Breech strikes developed in 24 of 60 controls but in none of 60 CRC-treated sheep. There was a 35% reduction in the number of CRC-treated sheep struck on the body.
Field trials: The average number of breech strikes in CRC-treated sheep was reduced by 86% (P < 0.001). The number of body strikes in the treated groups was a reduced by 27% (P < 0.05).
Conclusion The ivermectin CRC is a useful aid in controlling breech strike, but provides only moderate reduction in the incidence of body strike.