Energy performance of wood-burning cookstoves in Michoacan, Mexico

There have been few detailed assessments of the actual impacts of improved stove interventions in rural communities, although many improved stove projects have reported overall efficiencies from tests in simulated kitchens using water-boiling tests (WBTs). This paper presents an integrated energy evaluation of the Patsari cookstove, an efficient wood-burning cookstove developed in Mexico that has recently obtained international recognition, in comparison to traditional cookstoves in rural communities of Michoacan, Mexico. The evaluation uses three standard protocols: the WBT, which quantifies thermal efficiency and firepower; the controlled cooking test (CCT), which measures specific energy consumption associated with local cooking tasks, and the kitchen performance test (KPT), which evaluates the behavior of the stoves in-field conditions and estimates fuel savings. The results showed that the WBT gave little indication of the overall performance of the stove in rural communities. Field testing in rural communities is of critical importance, therefore, in estimating the benefits of improved stoves. In the CCT for tortilla making, the main cooking task in Mexican rural households, Patsari stoves showed fuelwood savings ranging from 44% to 65% in relation to traditional open fires (n=6; P<0.05). These savings were similar in magnitude to the average energy savings from KPT before and after Patsari adoption of 67% (n=23; P<0.05) in rural households exclusively using fuelwood. Similar energy savings of 66% for fuelwood and 64% for LPG, respectively, were also observed in households using mixed fuels. With sound technical design, critical input from local users and proper dissemination strategies, therefore, improved stoves can significantly contribute to improvements in the quality of life of rural people with potential benefits to the surrounding environment.     

对美国肥料施用技术的考察

为吸取国外先进经验、在我国更好地实施平衡施肥技术,全国农业技术推广服务中心对以密西根州为代表的美国农业、肥料施用技术进行了考察。本文介绍了美国农业现状、肥料施用现状及施肥技术研究的情况。     

美国洗涤剂市场的新动向(英)

随着人们对洗涤剂市场关注程度的提高,商家之间的竞争越演越烈。新产品层出不穷。液体洗涤剂的市场正在逐步扩大。新型的销售模式,消费趋势及巨大的成本压力极大地动着美国洗涤剂市场的发展,针对个人性消费的新产品开发变得日益重要。     

ADXL05型加速度计在倾角测量中的应用

ＡＤＸＬ０５是美国ＡＤＩ公司生产的单片集成加速度传感器,该传感器外形小巧、精度高、抗震性能强,特别适合于倾角测量。文章对期 原理及倾角测量电路作了详细介绍。     

提高DFM—480数字现场监视记录仪功能的方法

数字现场监视记录仪是地震采集系统的一个重要组成部分,是监视和处理野外地震资料,控制记录质量的必要手段。改进记录仪功能,充分发挥其效能,使地震采集更上一个新台阶。     

Recombinant Landscapes in the American City

How are urban actors, such as landscape designers, community groups, developers and local politicians, actively restructuring their environments to meet the challenges of the American city in the new global context? Grahame Shane outlines the approaches to landscape that have been emerging since the mid-20th century and are set to recombine urban assemblages whether they are located in historic city centres, postindustrial waterfronts or suburban sprawl. Copyright © 2007 John Wiley & Sons, Ltd.     

试析建国前后中美关系调整失败的原因

对新中国成立前后中美关系调整失败的原因进行了分析。美国对华政策目标与中国的民族利益尖锐对立,其在对华具体政策上又频频失误,国际冷战的格局进一步对中美关系的改善造成不良影响,美国国内的反共反华浪潮严重影响了美国政府的决策,这些因素,导致中美双方改善关系的努力彻底失败,最终在朝鲜战场上兵戎相向。     

Reassessing the role of climate change in the Tupi expansion (South America, 5000–500 BP)

The expansion of forest farmers across tropical lowland South America during the Late Holocene has long been connected to climate change. The more humid conditions established during the Late Holocene are assumed to have driven the expansion of forests, which would have facilitated the dispersal of cultures that practised agroforestry. The Tupi, a language family of widespread distribution in South America, occupies a central place in the debate. Not only are they one of the largest families in the continent, but their expansion from an Amazonian homeland has long been hypothesized to have followed forested environments wherever they settled. Here, we assess that hypothesis using a simulation approach. We employ equation-based and cellular automaton models, simulating demic-diffusion processes under two different scenarios: a null model in which all land cells can be equally settled, and an alternative model in which non-forested cells cannot be settled or delay the expansion. We show that including land cover as a constraint to movement results in a better approximation of the Tupi expansion as reconstructed by archaeology and linguistics.     

Further mycotoxin effects from climate change

Climate change will affect mycotoxins in food. The 2007 Intergovernmental Panel on Climate Change report is reinterpreted herein to account for what may occur with mycotoxins. Warmer weather, heat waves, greater precipitation and drought will have various impacts, depending on which regions of the world and mycotoxin systems are considered. The humidity issues are more complex as some areas will experience drought and others greater precipitation: in vivo data on the effects of moisture on mycotoxins in crops are more ambiguous than those for temperature. In vitro data on fungal growth and mycotoxin production may not relate directly to the situation in the field or post harvest, but are useful for base-line assumptions. The effects of climate in various regions of the world, i.e. Africa, Europe, Asia, Latin America and North America are considered in terms of mycotoxin contamination. Crops introduced to exploit altered climate may be subject to fewer mycotoxin producing fungi (the “Parasites Lost” phenomenon). Increased mycotoxins and UV radiation may cause fungi to mutate on crops and produce different mycotoxins. Whereas there is relevant information on aflatoxins, deoxynivalenol, and ochratoxin A, more mycotoxins require to be considered: Data on patulin are missing. The current paper considers uniquely ergot alkaloids. Amelioration strategies are provided. There is considerable urgency in the need to address these issues.     

美国FDA食品召回分析及提示——以2019年为证

目的 研究美国FDA食品召回现状,为我国开展相应工作提供可借鉴的经验.方法 从FDA官方网站收集2019年食品召回信息,对数据进行筛选、整理,用EXCEL 2013进行数据分析.结果 从2019年FDA发布的每周执法报告中收集到的有效数据,共涉及461起召回事件和1734种次召回食品.约60％的召回属于Ⅱ级,Ⅰ级大约占...