Reactions of Cowpea to Meloidogyne incognita in Eastern Nigeria

Abstract

One hundred and three cultivars of cowpea (Vigna unguiculata) were rated in replicated trials in the field and glasshouse for their reactions to the root-knot nematode, Meloidogyne incognita. Forty-one cultivars consistently showed some resistance to the nematode in both field and glasshouse trials; 25 were consistently susceptible and the remaining 37 were inconsistent.     

一种淡水鱼头尾与腹背定向装置的研究

本文设计了一种淡水鱼头尾与腹背定向装置,并以鲢鱼为定向对象,根据鲢鱼的摩擦特性,通过理论分析,分别对利用倾斜振动台面实现头尾定向和利用渐变滑道实现腹背定向过程的机理进行了探讨,并采用体重为0.75-1.0kg的新鲜鲢鱼进行了试验研究。理论分析和试验结果均表明,这种定向装置可以实现鲢鱼的头尾和腹背定向。并对影响鱼体鱼体头尾定向因素：进入振动台面的体位、电动机频率、激振力和筛面角,以及影响鱼体腹背定向因素：滑道夹角、电机频率、激振力和滑道倾斜角分别进行了试验研究,得出各因素对定位时间均具有显著的影响,试验中,头尾定向的总定位率达到了97.53%,定向动作可在0.65-3.75s内完成;腹背定位的总定位率达97.2%,定向动作可在0.39-5.03s内完成。     

利用GIS进行耕地质量评等定级方法的探讨

在对耕地的质量传统评估方法分析的基础上,按照耕地质量评估的基本原则,提出了利用GIS技术进行耕地质量的评等定级的思想,重点阐述了基于域和基于对象两种耕地质量评等定级的方法,评等定级的基础工作是建立各参评项目的地理数据库;叠加分析则是评等定级的关键工作;最后提出了以耕地质量评等定级成果为基础建立耕地信息管理系统的设想。     

关于森林经理学的正名,定位与开拓

森林经理学二字的释义,不一定视为经营与管理二词的缩写,而应是度量与筹划,森林经理学是森林资源度量与筹划的技术科学。     

平衡取样积分电路分析及应用

通过对平衡取样积分电路工作过程的分析,讨论了电路各个器件在电路中的作用及其对电路性能的影响,阐述了电路中各关键器件的参数选择和电路调试方法,并将该电路应用于探地雷达回波采集系统。在实验室内对取样积分电路进行调试,取得了良好的工作性能。     

Spray Drying of Chitosan Acid Salts: Process Development,Scaling Up and Physicochemical Material Characterization

We investigated a spray drying process for preparing water-soluble salts of high molecular weight chitosan (CH) intended for pharmaceutical excipient applications. CH was derived from chitin of marine lobster origin (Panulirus argus). The effects of organic acid (acetic or lactic acid) and the ratio (difference) of inlet/outlet air temperature (140/90 °C or 160/100 °C) on spray drying were studied. The yield of spray-dried CH salt powders ranged from 50% to 99% in laboratory and industrial-scale processes. The spray-dried dry powder of CH salts consisted of spherical agglomerated particles with an average diameter of 36.2 ± 7.0 µm (CH acetate) and 108.6 ± 11.5 µm (CH lactate). After dispersing the spray-dried CH salt powder samples in purified water, the mean particle sizes obtained for the CH acetate salts were 31.4 nm (batch A001), 33.0 nm (A002) and 44.2 nm (A003), and for the CH lactate salts 100.8 nm (batch L001), 103.2 nm (L002) and 121.8 nm (L003). The optimum process conditions for spray drying were found: an inlet air temperature of 160 ± 5 °C, an outlet temperature of 100 ± 5 °C and an atomizer disk rotational speed of 18,200 min⁻¹. The X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) results confirmed the amorphous state of the CH salts. The ¹H nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectra of CH acetate and lactate salts verified that the spray drying process does not affect the polymer backbone. In conclusion, both laboratory and industrial-scale spray drying methods for preparing water-soluble acid salts of CH are reproducible, and the physicochemical properties of the corresponding CH acid salts are uniform.     

农大108和晋单34光合特性与 产量关系比较分析

采用单因素随机区组试验,研究了农大108和晋单34的叶面积指数、光合势、干物质积累,以及影响产量的产量构成因素。得出以下结论:农大108与晋单34号的叶面积增大趋势基本一致,先升高后逐渐下降,叶面积最大时农大108是10955.22cm2/株,晋单34是8762.86cm2/株;光合势、干物质积累等指标晋单34低于农大108,产量构成因素(穗数、穗重、穗粒数、百粒重等)低于农大108,耐密性与抗倒伏性,及稳定性均比农大108差,农大108的产量大于晋单34。     

论农业可持续发展及其评价指标体系的建立

从农业可持续发展的内涵出发,阐述了建立农业可持续发展评价指标体系的原则、指标的选择依据和指标体系的设置框架。     

Developing the Regulatory Detailed Planning and Drawing up for Promoting the Urban Development--Some Ideas on Urban Construction of Middle and Small Cities in Underdevelopment Districts

This paper is directed against the traditional two-phase planning and drawing-up system widespread in the towns and cities of underdeveloped districts and suggests that the regulatory detailed planning and drawing up should be developed. During the planning and drawing up, the characteristic of town and city of underdeveloped districts should be taken into account and a choice and emphasis should be made for strengthening the urban planning administration and accelerating the urban development.