Environmentally sustainable production of food,feed and fuel from natural resources in the tropics

Responding to the challenges posed by global warming, peak oil and biofuels will require a paradigm shift in the practice of agriculture and in the role of live stock within the farming system. Farming systems should aim at maximizing plant biomass production from locally available diversified resources, processing of the biomass on farm to provide food, feed and energy and recycling of all waste materials. The approach that is the subject of this paper is that the generation of electricity can be a by-product of food/feed production. The concept is the fractionation of biomass into inedible cell wall material that can be converted to an inflammable gas by gasification, the gas in turn being the source of fuel for internal combustion engines driving electrical generators. The cell contents and related structures such as tree leaves are used as human food or animal feed. As well as providing food and feed the model is highly appropriate for decentralized small scale production of electricity in rural areas. It also offers opportunities for sequestration of carbon in the form of biochar the solid residue remaining after gasification of the biomass.     

The effects of wind turbines on antipredator behavior in California ground squirrels (Spermophilus beecheyi)

Electricity-generating wind turbines are an attractive energy source because they are renewable and produce no emissions. However, they have at least two potentially damaging ecological effects. Their rotating blades are hazardous to raptors which occasionally fly into them. And wind turbines are very noisy when active, a feature that may interfere with the lives of animals beneath them. We studied California ground squirrels (Spermophilus beecheyi) in the Altamont Pass Wind Resource Area of Northern California. These squirrels emit vocalizations that alert others to the presence of a predator, and so may be forced to compensate for turbine noise by modifying antipredator behavior. We compared the antipredator behavior of squirrels at two sites, one close to and the other far from turbines, and under two conditions, during baseline and playback of conspecific alarm calls. We generated composite two variables using principle components analysis, one representing vigilance and one representing another cautionary antipredator tactic, for further statistical comparisons. Animals at the Turbine site exhibited elevated levels of vigilance and showed increased caution demonstrated in part, by returning to the area near their burrows during alarm calling. We conclude that this site difference is probably caused by the disparity in turbine noise, since predator abundance, group size, and vegetation type and density were similar for the two sites. Though population level impacts of these behavioral differences remain to be explored, our results indicate that behavioral impacts of turbines on wildlife should be considered during future turbine development.     

THE EFFECTS OF LAND RESOURCES ON REGIONAL ECONOMIC DEVELOPMENT IN THE DALIUSHU IRRIGATED AREA ON THE YELLOWR

<正> The Daliushu Water Conservancy Project is one of main works on water--power stepdevelopment in upper reaches of the Yellow R.. It is located at exit of Heisan Canyon witha distance of 31 km only to Zongwei County town. This project brings out more functions,such as generating electricity, defencing flood, irrigation, supplying water and shipping etc.     

宿州电网电力负荷与气象条件关系研究及预测系统开发设计

利用宿州电网2008年8月～2010年9月逐日电力负荷和宿州逐日气象资料,系统分析电力负荷与气象条件的关系,分时段建立电力负荷预测模型,开发了宿州气象电力预测预警系统平台。该系统主要研究气象要素与电力负荷的关系,做出短期预测模型;结合WEB的CS和BS终端访问技术、数据挖掘技术、多因子变量回归技术和最优因子集组合技术,根据不同季节的特点,分5个时段对宿州电网负荷进行5d的中短期预测。系统在试运行期间表现稳定、易操作、短期负荷预测预警精度高,该系统增强了宿州电力供应安全的保障能力,推进部门相互间在信息、技术等方面的合作与共享,为宿州电网的规划和运行提供了科学依据,提升了科学经济运营水平。     

两种覆盖对公路路肩土壤含盐量的影响

滨海盐地区公路绿化中,表层覆盖是降低路肩土壤含盐量的重要途径。该试验历时2年,在2004年3月末,分别在国道庄林线大水塘~二道沟段选取35个点。5个点为无覆盖的CK,15个点用10 cm厚的稻草覆盖,另15个点覆盖10 cm厚的秸秆。利用电导法,测定在树木生长季节内(春、夏和秋),路肩表层0~20 cm和覆盖下0~20 cm土壤的含盐量,并监测了秸秆覆盖和稻草覆盖对营口国道庄林线路肩土壤含盐量变化。结果表明:两种覆盖对降低土壤盐分是有效的;稻草和秸秆的物质成分不同,导致两种覆盖的有效期不同。     

低压用电系统中的漏电保护技术措施

漏电是电气事故发生的重要原因，防止漏电事故发生的重要措施是研究和推广漏电保护技术。为此，探讨了低压用电系统中各种漏电保护技术措施的应用。     

不同覆土材料对鸡腿菇出菇性状和产量的影响

通过对不同覆土材料的化学成分和物理结构的测定，分析了不同种类覆土材料对鸡腿菇出菇性状和产量的影响，结果表明：孔隙度、最大持水量和营养成分较高的覆土材料——腐叶土有利于鸡腿菇产质量的提高，随着栽培时间的延长，覆扇叶土的覆土层的电导率呈上升趋势而pH值呈下降趋势较其它两种覆土材料明显。     

Potential conflicts for the reuse of rice husk in Thailand

This study aims to investigate the impact of rice-husk power generation on agricultural uses of rice husk and its ash. We conducted case studies at a rice-husk power plant and organic farming groups in northeast Thailand. The case study on a rice-husk power plant showed that rice husk was useful in generating electricity without consuming fossil fuel, while husk ash, the by-product, could be utilized as silicate supplement for farmland soils. The case study on organic farming groups indicated that rice husk was one of the indispensable materials in conducting organic farming with locally available resources. On the basis of these findings, an analytical study on possible husk uses in Thailand was conducted, in which three potential major uses of rice husk were considered: i.e. (1) fuel use inside rice mills followed by husk-ash reuse, (2) fuel use at power plants followed by husk-ash reuse, and (3) direct reuse of husk for compost production. The result indicated that there would be conflicting demands for rice husk among those uses in the future. Therefore, there needs to be a strategy for balancing husk uses among them.     

汽车及拖拉机电气系统可靠性设计

介绍了汽车和拖拉机电气系统可靠性设计的重要性、设计程序及方法,在传统设计的基础上,运用可靠性设计可以提高汽车及拖拉机电气系统的整体性能。     

DXB_2-12型电镜透镜电源原理分析与故障维修

本文概述了ＤＸＢ２—１２型电镜的透镜电源原理及几例特殊故障的分析要点和检修方法。