稻粉虱的发生及其化学防治药剂筛选     

魏琪  何佳春  赖凤香  王渭霞  万品俊  傅强 《植物保护》2023,49(4):284-292

稻粉虱Aleurocybotus indicus David et Subramaniam, 属半翅目粉虱科, 以刺吸式口器为害水稻叶片而导致产量损失, 是我国闽?赣?浙等稻区的一种偶发性水稻害虫, 近20多年已鲜有报道, 但2019年-2021年在中国水稻研究所富阳试验农场稻田暴发?本文描述了稻粉虱的为害症状和形态特征, 并配以原色照片; 克隆得到了稻粉虱线粒体DNA COⅠ基因片段, 发现其与烟粉虱Bemisia tabaci序列一致性最高(85.80%); 田间调查表明, 富阳试验农场及周边稻田稻粉虱均有不同程度的发生, 但前者发生量明显较高(每个分蘖最高可达251头), 推测可能与农场温室内的稻粉虱越冬虫源有关; 利用稻苗浸渍法评估了不同作用机制的7种杀虫剂对稻粉虱的毒力, 发现双丙环虫酯?氯虫苯甲酰胺?氟啶虫胺腈?氟啶虫酰胺和溴氰虫酰胺对稻粉虱成虫均有较好的杀虫活性, 其中前4种药剂推荐中剂量处理后72 h的校正死亡率均可达100%, 其LC50分别为3.028?3.769?6.405 mg/L和7.894 mg/L?本研究可为我国稻粉虱的识别诊断和化学防治提供重要依据?  相似文献   

Dynamic Modeling and Simulation of 440 t/h Steam-cooled Cyclone Separator for CFB Boiler     

WAN Li-peng  GOU Xiao-long  LI Bo  HAO Xiang-jun 《保鲜与加工》2006,(3):45-47

A dynamic mathematical model of the steam-cooled cyclone separator in a 440 t/h CFB boiler has been established.Based on the mathematical model,simulation model of the cyclone separator is created with the advanced continuous simulation language(ACSL).The validity of this model has been verified by the simulation experiments and analysis.This model can provide a theoretical guidance for operation and optimal design of the cyclone separator.  相似文献   

Portable ECG Monitor Front- ended Design with C8051 F020     

DING Jian-ping  QIN Shu-ren  WAN Xiang-kui  YE Shun-liu  LIANG Xiao-rong 《保鲜与加工》2005,(5):8-11

The electrocardiogram (ECG) signal is a recording of the electrical activity on the body surface generated by the heart frequency of which is weak and low. Many researchers devote themselves to get more perfect ECG in many ways. This article introduces the characterize of an ECG signal , then discusses the requirements for the sampling circuit of an ECG. Since there are some shortcoming in common design means, the authors give an effective circuit. The system is composed of a low-cost , low-power and high-performance MCU C8051F020 , amplifier AD620 , right-leg drive circuit ,communication circuit and power management circuit. Then software design is given which is used to sampling and filtering ECG signal. Levkov filter arithmetic and smooth filter arithmetics are used in this design. In the end , the authors advance a distributing and networking ECG monitor system.  相似文献   

电控喷油器流量特性试验台的设计与试验   总被引：2，自引：0，他引：2  

尹丛勃  张振东  刘志远  王玉顺 《农机化研究》2007,(12):194-196

论述了开发电控喷油器微机测试系统的意义;为检测电喷发动机喷油性能,介绍了所以8098为核心的喷油器流量试验台;阐述了喷油器流量试验台设计思想、硬件结构和软件设计方法.以高阻型喷油器为例,在整个流量范围内对其进行测试,并对测试数据加以分析总结,得出了该喷油器流量特性的一些重要参数.目前,电控喷油器微机测试系统已投入使用,取得了良好的实际效果.  相似文献   

基于DEM的水文模型在沮河流域的应用   总被引：2，自引：0，他引：2  

代荣霞  李兰  刘小莽  王万  武见 《中国农村水利水电》2007,(3):1-3,6

基于DEM的流域水文模型是近年来水文模型的热点,而干旱半干旱地区的水文模型一直是水文研究的一个难题。分析了干旱地区的降雨产流特性,建立了符合该产流特性的数字高程模型和陕北模型相结合的水文模型,并将其应用到沮河流域桃曲坡水库的洪水预报中,计算结果证明该水文模型在干旱地区是切实可行的。  相似文献   

钢丝绳隔振器驾驶座减振性能研究   总被引：2，自引：0，他引：2  

万叶青  杨平  张伟欣 《拖拉机与农用运输车》2006,33(3):22-24

介绍了拖拉机非线性驾驶座动态特性分析和随机振动试验技术。该技术是在大量试验的基础上,根据振动理论和数值分析方法,建立起来的非线性驾驶座振动特性分析和仿真技术。将此技术运用到自行研制的复合阻尼钢丝绳隔振器驾驶座的研制和分析上,取得了良好的效果。  相似文献   

华北平原滴灌灌溉频率对萝卜生长的影响   总被引：9，自引：0，他引：9  

万书勤  康跃虎  刘士平 《灌溉排水学报》2003,22(2):26-30

研究了华北平原秋萝卜滴灌条件下 ,不同滴灌频率处理对萝卜叶面积系数、叶绿素含量、萝卜周径膨大、萝卜干重积累、根长密度、根干重密度等萝卜生长参数的影响并比较了各处理间萝卜产量的差异 ,发现在华北平原下半年降雨较多的情况下种植秋萝卜 ;1滴灌频率无论是 1 d1次还是 8d1次 ,对萝卜生长发育都没有明显影响 ;2滴灌条件下萝卜的平均重量和产量大大高于地面灌溉  相似文献   

Expression of cathepsin C and tumor necrosis factor-α in human coronary artery and their relationships with coronary heart disease     

ZHANG Qiong  WAN Chang-wu  YU Yan-ni  XIA-Bing  LIU Jiang-jin  ZHANG Qiao-jun  LI Zhu  WANG Cheng-fei  DAI Jia-lin  WANG Jie 《园艺学报》2021,36(12):2133-2138

AIM To explore the possible mechanism of cathepsin C （CTSC） and tumor necrosis factor-α （TNF-α） in coronary heart disease （CHD） by detecting the protein expression of CTSC and TNF-α in human coronary artery tissue. METHODS The coronary artery tissues from 52 cases of CHD and 25 cases of accidental death without any heart disease in the Forensic Judicial Expertise Center of Guizhou Medical University from October 2018 to December 2019 were collected as CHD group and control group, respectively. The coronary artery stenosis and intimal plaque formation were examined by histopathology, the protein expression of CTSC and TNF-α was determined by Western blot, and the intracellular expression of CTSC and TNF-α was analyzed by immunohistochemical staining. RESULTS The results of HE staining showed that the intima of coronary artery in control group was smooth, and no thickening or stenosis was observed. In CHD group, the intima thickened irregularly, atherosclerotic plaques formed, the intima became thinner and the lumen showed eccentric stenosis in varying degrees （P<0.05）. The results of Western blot showed that the expression of CTSC and TNF-α in CHD group was significantly higher than that in control group （P<0.05）. Immunohistochemical staining showed that both CTSC and TNF-α were expressed in the cytoplasm of foam cells, and their positive expression was significantly higher than that in control group （P<0.05）. The results of Pearson moment correlation analysis showed that there was positive correlation between the expression of CTSC and TNF-α in CHD （r²=0.743, P<0.05）. CONCLUSION The up-regulated expression of CTSC in coronary artery tissue may promote the expression of TNF-α and affect the occurrence and development of CHD.  相似文献   

春季西瓜留瓜个数和整枝方式对产量的影响     

周利利  张飞雪  赵根  陈丽萍  张建明  沈卫新 《蔬菜》2021,(8):23-25

为探究湖州地区春季西瓜高产优质栽培技术,对小型西瓜的不同留瓜个数和中型西瓜的不同整枝方式进行了比较。结果表明:小型瓜单株留2个瓜,中心糖含量可达10.67%,667 m~2产量达2 419.2 t,既保证了西瓜的品质优良,又保证了生产效益;中型瓜可采用双蔓整枝,在保证产量和品质的同时,简化了田间操作,节约了土地。  相似文献   

政策性森林保险开展的现状·问题及对策研究——以江西吉安市为例     

万千  潘焕学  秦涛  陈荆 《安徽农业科学》2011,39(30):18885-18887

以江西省吉安市为例,阐述了该市政策性森林保险开展的基本情况和特点,并分析了当前存在的主要问题,即森林保险宣传力度不够,林农保险意识低下,森林保险有效需求不足,森林保险技术人才匮乏,经营成本较高,各部门之间的协调配合不到位。针对这些不足与问题,提出了推动吉安市政策性森林保险发展的对策建议。  相似文献