樱桃番茄运输包装件振动冲击性能试验   总被引：1，自引：0，他引：1  

张连文  杨传民  王勇  潘道津  孟宪文  佟瞳 《农业机械学报》2011,42(3):125-130,155

针对目前樱桃番茄储运过程中主要包装形式以及造成破损的情况,选择典型运输包装件,进行了正弦扫频、堆码强度、堆码扫频振动传递性能、垂直冲击和跌落试验。通过对单件包装件的扫频振动试验,测出单件的固有频率为26.61Hz;通过堆码强度试验,测出了包装件的最大堆码层数为9层。通过9层堆码扫频振动传递性能试验确定了底层、中间层和顶层包装件的固有频率分别为36.61、10.76和6.44Hz,得到了各层包装件振动加速度、振动传递率随时间的变化曲线,并探讨了固有频率和振动传递率峰值与堆码高度之间的关系。在此基础上,通过垂直冲击试验,测出了产品的脆值为89.58;通过跌落试验,测出了包装件最大允许跌落高度为580mm。  相似文献   

国内外磷指数评价指标体系研究进展   总被引：1，自引：0，他引：1  

李文超  刘申  刘宏斌  翟丽梅  王洪媛  雷秋良  崔超  李华蕾 《土壤通报》2016,(2):489-498

磷是水体富营养化的关键影响因子之一,且农业面源流失的磷是水体中磷的主要来源之一。通过对面源磷的流失风险进行评价,识别其关键区,进而进行针对性管理,是控制面源磷流失的有效手段之一。作为一种评价面源磷流失风险的简单方法,自20世纪90年代以来,磷指数已经在美国、中国及欧洲一些国家得到了广泛的应用。通过采用磷指数法,在评价其流失风险空间分布特征的基础上,可以方便快速地识别出田块或流域内磷流失的关键区。各个国家或地区根据本研究区的情况建立了不同的指标体系,但缺乏统一的磷指数建立标准。从源因子、迁移因子等组成因子及因子等级划分与磷指数计算等几个方面,对国内外的磷指数评价指标体系进行了分析评述,并对其发展进行了展望,旨在为目标研究区磷指数的建立和应用提供借鉴。  相似文献   

乳腺分泌细胞钙转运机制   总被引：1，自引：0，他引：1  

牛惠  钟凯  郭豫杰  王月影 《江西农业学报》2009,21(6):117-119

依据钙转运的模式,综述了乳腺分泌细胞钙转运机制,阐明了参与钙转运过程的关键分子,为今后的研究提供了新思路。  相似文献   

草莓的收获与保鲜技术     

杨吉祥 《青海农林科技》2009,(4):77-78

近年来草莓种植的经济效益有了明显提高,但草莓在收获和运输的过程中易受损伤和微生物侵染,导致大量的草莓腐烂,造成严重的经济损失。本文对草莓采收、果品商品化处理、贮藏保鲜,运输等进行了简单介绍。  相似文献   

农药装盒机说明书的输送机构虚拟装配设计与研究     

卢军党  杨福增  许兵宗 《安徽农业科学》2010,38(22):12160-12161,12217

通过对农药装盒机说明书输送机构组成零件的分析,运用Pro/ENGINEER Wildfire3.0系统进行三维建模、虚拟装配,在装配过程中对之前所设计零件出现不合理的地方进行修改,使其满足所要设计的功能要求。最后生成爆炸图,使其能清楚地看到该装置的内部结构,为实际装配操作做好准备,大大地提高了农药装盒机设计和制造的效率。  相似文献   

Molecular Mechanism of Rice in Response to Salt Stress     

E Zhi-guo  ZHANG Li-jing  WANG Lei  .China National Rice Research Institute  Hangzhou  ;  .State 《农业科学与技术》2011,(6):785-788

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Selective transport of IgE into ovine mammary secretions     

B.C. Hine  P.W. Hunt  R.G. Windon  I.G. Colditz 《Research in veterinary science》2010,89(2):184-190

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Transport and adsorption of antibiotics by marine sediments in a dynamic environment   总被引：1，自引：1，他引：0  

Weihai H. Xu  Gan Zhang  Onyx W. H. Wai  Shichun C. Zou  Xiangdong D. Li 《Journal of Soils and Sediments》2009,9(4):364-373

Background, aim, and scope  Bed sediments are the major sink for many contaminants in aquatic environments. With increasing knowledge of and research on the environmental occurrence of antibiotics, there has been growing interest in their behaviour and fate in aquatic environments. However, there is little information about the behaviour of antibiotics in a dynamic water/sediment environment, such as river and coastal marine water. Therefore, the aims of the present study were: (1) to study the transport and distribution of four common antibiotics between water and sediment in both dynamic and quiescent water/sediment systems and (2) to understand the persistence and possible degradation of the four antibiotics in the two different systems. Materials and methods  A lid-driven elongated annular flume, designed to reduce the centrifugal effect, was used to simulate a dynamic water environment. In addition, a quiescent water/sediment experiment was conducted for comparison with the dynamic water system. The seawater and sediment, used in both experiments of flowing and quiescent water/sediment systems, were collected from Victoria Harbour, a dynamic coastal environment in an urban setting. The four antibiotics selected in this study were ofloxacin (OFL), roxithromycin (RTM), erythromycin (ETM), and sulfamethoxazole (SMZ), the most commonly used antibiotics in South China. Results and discussion  Antibiotics in an overlying solution decreased very quickly in the flume system due to the sorption to suspended particles and surface sediment. There were significant differences in the adsorption of the four antibiotics in sediment. OFL showed a high tendency to be adsorbed by sediment with a high K _d value (2980 L/Kg), while the low K _d values of SMZ indicated that there was a large quantity in water. The four antibiotics reached a depth of 20–30 mm in the sediment over a period of 60 days in the flume system. However, the compounds were only found in surface sediment (above 10 mm) in the quiescent system, indicating the influence of the dynamic flume system on the distribution of antibiotics in sediment. OFL showed a moderate persistence in the dynamic flume system, while other three antibiotics had less persistence in sediment. However, all of the four compounds showed moderate persistence in the quiescent system. Recommendations and perspectives  The study showed the rapid diffusive transfer of antibiotics from water to sediment in the dynamic flume system. The four antibiotics exhibited larger differences in their adsorption to sediment in both dynamic and quiescent systems due to their different K _d values. The high sorption of antibiotics to marine sediment may reduce their availability to benthic invertebrates.  相似文献   

公路对陆生脊椎动物影响的研究     

周靖杰  吴建平  于超 《野生动物》2011,32(2):90-94

公路在推动我国社会、经济发展的同时也对路域（沿带状公路向周围延伸一定距离的空间范围）野生动物产生了严重的负面影响,特别是陆生脊椎动物。本文就如何利用样带法和样方法对路域陆生脊椎动物种类、数量、公路交通造成的动物死亡数等进行调查作了详细阐述。结合国内外相关领域学者的研究成果分析了公路对不同类别或种类陆生脊椎动物的影响。呼吁国内学者开展更多公路对陆生脊椎动物影响的实质性研究,并将成果运用于研究地区以后的路网设计与改造实践中。  相似文献   

牛呼吸疾病综合征及其防治   总被引：2，自引：0，他引：2  

郭爱珍 《中国奶牛》2011,(24):7-11

牛呼吸疾病综合征是严重危害国内外肉牛养殖业的一种重要传染病,该病的致病因素复杂,包括支原体、病毒和细菌等特异性病原以及运输应激等多种因素。美国等发达国家对该病的攻关研究开始于上世纪80年代初,其研究和临床防控均已达到较高水平,但仍认为该病将是未来10～20年养牛业所面临的主要疾病。我国对该病的认识和研究尚处于起步阶段,借鉴世界上发达国家的先进经验将有助于提升我国对该病的防控水平。  相似文献