乐果、三硫磷等杀虫药剂对苹果害虫的防治效果

乐果和三硫磷对为害苹果树的山楂紅蜘蛛和苹果紅蜘蛛均具较高的杀虫效力,后者尚有杀卵效能。这两种药剂对苹小食心虫显示良好的杀卵效力,乐果稍高于三硫磷。对初孵化幼虫同样具有一定的杀虫效力,也是乐果稍高于三硫磷。从田间防治試驗中初步看出,乐果和三硫磷对防治山楂红蜘蛛的效果良好,但逊于內吸磷。乐果防治苹小食心虫的效果接近于对硫磷,对卷叶虫較差;三硫磷防治卷叶虫的效果接近于对硫磷,对苹小食心虫较差。     

大麦籽粒灌浆期β-淀粉酶积累动态与气象因子关系研究

为了明确大麦籽粒灌浆期β-淀粉酶动态与气象因子的内在联系,对两年间5个大麦品种籽粒灌浆期β-淀粉酶动态与气象因子进行了相关分析。结果表明,大麦籽粒灌浆期的β-淀粉酶活性呈升–降–升的动态过程,在成熟期达到最大值。偏相关分析和多元回归分析表明,大麦籽粒灌浆期β-淀粉酶活性与总积温呈极显著正相关,与总日照时数和日均日照时数的互作呈显著相关,与日均温、日均日照时数呈显著负相关,与总积温和日均温的互作、总雨量和日均日照时数互作呈极显著负相关,偏相关系数从大到小依次为总积温、总雨量和日均日照时数交互作用、总积温和日均温交互作用、总日照时数和日均日照时数交互作用、日均日照时数、日均温。     

仓储稻谷热湿耦合传递及黄变的数值模拟

为了研究稻谷在整个储藏周期的温度、含水率分布规律以及黄变情况,该研究以南昌地区混凝土结构浅圆仓为研究对象,基于多孔介质的传热传质理论和局部热平衡原理,建立了仓储稻谷储藏过程中粮堆内部流动和热湿耦合传递的数学模型,并结合稻谷黄变数学模型,采用数值预测的方法模拟分析了全年自然(密闭)储藏和全年自然(密闭)储藏加机械通风时仓...     

粮堆通风阻力的研究方法及阻力模型研究进展

粮食储存过程中,干燥和通风是重要的单元操作。对粮堆进行强制通风,可以干燥或冷却粮堆,调节粮堆的温度和水分。探究气流通过粮堆的流动和压力分布规律、计算粮堆通风阻力是科学设计通风系统的关键之一。本文简要地介绍了国内外研究储粮通风流动和阻力的方法,重点综述了国内外通风阻力的理论、半理论和经验模型,分析了各种模型的优缺点,探讨了影响通风阻力的各种因素,可以为储粮通风阻力的研究、通风系统的设计和优化提供借鉴。     

当心食用处理不当的蔬菜会中毒

马铃薯、腌酸菜是青海农民及市民冬春季节最喜食的副食品，营养丰富，可口。但是马铃薯、腌酸菜，在贮存与腌渍过程中，会产生一些有害物质，如果食用不当就会发生中毒，甚至会致人中毒死亡。这主要是绿皮马铃薯中的龙葵素和腌咸菜中的亚硝酸盐所致。因此在加工、食用时应多加注意，少食或不食变质、腐烂蔬菜、腌渍不透的蔬菜和发芽、晒绿的马铃薯。     

福州菜区农业生态环境现状研究

参照有关标准及背景值分析了福州菜区四大水系、渠沟灌溉水、菜园土、城镇农用垃圾的硝酸盐和重金属元素的污染特征，结果表明，四大水系水质晋安河为轻污染，白马河和闽江下游福州水段为微污染，八一水库存为清洁，均可灌溉；渠沟灌溉水污染分布不均，东片的岳峰、鹤龄2个点Hg含量临界超标值，西片的长汀点Pb含量严重超标。菜园土除Cd外，其他重金属元素均有不同程度污染。城镇农用垃圾重金属含量虽符合国家标准，但Cr、Pb、Hg、As4种元素含量高于一般菜园土，这是造成福州菜区菜园土和蔬菜重金属污染的重要原因。     

Sources of data for rural health research: development of an inventory of Canadian databases

Secondary data sources can often be used to help address questions about the health status, health behavior, health resources allocation, and utilization of health services of rural Canadians. But the task of deciding which Canadian databases are amenable to rural health research remains a challenge. As part of a larger research project titled "Canada's Rural Communities: Understanding Rural Health and Its Determinants," an inventory of 51 Canadian databases that have the potential of being used for rural health research was compiled, and it continues to be maintained and updated. The websites maintained by two of Canada's leading statistical data centers were systematically searched, along with other published articles and national reports, to produce this inventory. The criteria used to determine which data sources to include in this inventory are: (1) databases containing data at the national level that can be accessed by researchers, (2) databases containing data that are relevant to a variety of rural health issues, and (3) databases containing data that could be partitioned into rural and non-rural geographies. Detailed information is available by searching the inventory of national rural health research-related databases through the internet (www.cranhr.ca) or by contacting the lead author of this article. This article examines some of the issues in developing this resource and demonstrates the usefulness of its contents to Canadian and other rural health researchers.     

Investigations of anemia of male rearing calves. 1. Reference conditions and anemia frequency

In a longitudinal investigation (3 points of time n = 214, 206 resp. 202) the hemoglobin quota (Hb), the hematocrit (Hct) resp. the average corpuscular hemoglobin concentration (MCHC) were analysed at male calves receiving semi-liquid feed in the transitional period from pre-ruminal to ruminal digestion (56d). Breed, live weight development, consumption of milk, concentrated feed resp. dried forage, diseases of the calves as well as the father and the milk yield resp. the lactation age of the mother were registered as reference conditions. The percentage of calves with an Hb less than 10.5 g/dl was at the three points of time 50.00%, 86.41% resp. 41.58%, of calves with an Hct less than 33,5% it was 43.46%, 66.02% resp. 31.68% and of calves with an MCHC less than 30.5 g Hg/dl erythrocytes 51.87%, 76,21 resp. 47,03%. 21.50%, 33.50% resp. 4.46% of all test animals even had an Hb of less than 8.5 g/dl.     

Oral and intramuscular ferric dextran administration in male rearing calves. 5. Live weight gain during maintenance in fluid feed and weaning ranges

195 rearing calves, which immediately after their gathering from various dairy farms had an anaemia frequency of 57.4% and an average age of 22 d and an average live weight of 43 kg, were at random divided into 3 groups and received in addition to the iron in the rations oral (B), intramuscular (C) or no (A) ferridextrane applications during their 56-day stay in the fluid feed range of a rearing farm. The average live weight gain of the calves during these 56 days in groups A, B, and C was 882 +/- 171, 949 +/- 145 and 912 +/- 170 g/d resp. and during the 57-day stay in the weaning range 664 +/- 205, 715 +/- 222 and 670 +/- 226 g/d resp. The significant advantage in the development reached by the calves in group B over those in group A during their stay in the fluid feed range did not get lost after the change to the weaning range. Based on the cost of medicine and on the development of the live weight of the calves in the 3 test groups in the fluid feed and weaning ranges the economic effect of ferridextrane applications was calculated. Under the rearing conditions given, iron intervention proved to be sensible for both health and economic reasons.