守株待“虫”的植物

正植物王国,千奇百怪。有很多植物受不了餐风饮露的"寡淡"生活,偏爱以昆虫为"口粮"或"零食",引起生物学家浓厚的兴趣。食虫植物又叫食肉植物,指的是能用身体的某个部位捕捉活的昆虫,并能消化、吸收其营养物质的植物。据统计,自然界共有600余     

小鸡吃虫

小鸡吃虫挺有意思。请你以小鸡、虫子顺序重复4次。从一个进口走到另一个出口（可不理会中心的小猫）,路线不能重复或交叉。     

与虫共眠

我在草中睡着时．我的身体成了众多小虫子的温暖巢穴。那些形态各异的卑小动物．从我的袖口、领口和裤腿钻进去,在我身上爬来爬去,不时地咬两口,把它们的小肚子灌得红红鼓鼓的。吃饱玩够了,便找一个隐秘处酣然而睡——我身体上发生的这些事我一点也不知道。     

叉尾小瓜虫病病因分析及其防治

小瓜虫病是一种广泛流行的寄生原虫病.文章就小瓜虫病在叉尾人工养殖中的发病原因进行了分析,并提出了相应的防治措施,以期为叉尾人工养殖小瓜虫病的防治提供理论与实践依据.     

WAPN: a distributed wormhole attack detection approach for wireless sensor networks

As the applications of wireless sensor networks （WSNs） diversify, providing secure communication is emerging as a critical requirement. In this paper, we investigate the detection of wormhole attack, a serious security issue for WSNs. Wormhole attack is difficult to detect and prevent, as it can work without compromising sensor nodes or breaching the encryption key. We present a wormhole attack detection approach based on the probability distribution of the neighboring-node-number, WAPN, which helps the sensor nodes to judge distributively whether a wormhole attack is taking place and whether they are in the influencing area of the attack. WAPN can be easily implemented in resource-constrained WSNs without any additional requirements such as node localization, tight synchronization, or directional antennas. WAPN uses the neighboring-node-number as the judging criterion, since a wormhole usually results in a significant increase of the neighboring-node-number due to the extra attacking link. Firstly, we model the distribution of the neighboring-node-number in the form of a Bernoulli distribution. Then the model is simplified to meet the sensor nodes＇ constraints in computing and memory capacity. Finally, we propose a simple method to obtain the threshold number, which is used to detect the existence of a wormhole, Simulation results show that WAPN is effective under the conditions of different network topologies and wormhole parameters.     

三种常用药物对欧洲鳗拟指环虫的杀灭效果比较

比较三种常用药物在不同浓度下对欧洲鳗拟指环虫的杀灭效果。结果表明:药浴72h后,最适药物浓度和杀虫率,欧指清、指环特灭、指环杀星分别为:0.20mg·L-1,67.14%;0.40mg·L-1,57.05%;0.50mg·L-1,48.73%。根据厂家建议用量,将欧指清:指环特灭=0.20mg·L-1:0.20mg·L-1进行联合用药,其杀虫率为86.36%。因此,三种药物中欧指清的杀虫率最高,且它与指环特灭合用的效果更佳。     

虫霉的大量生产及其在害虫生物防治中的应用

虫霉是一种重要的昆虫病原真菌,它们流行性强,是生物防治中开发的重要资源。虫霉的培养和生产比较困难,但近年来进展较大,少数已可工业生产。虫霉的休眠孢子、分生孢子和菌丝皆可生产,各具利弊。虫霉的利用主要包括自然流行病、淹没式放菌、接种式放菌诱导和引种定殖等方式。     

贵州遵义大di蝠的核型分析

张维道等曾报道过产于我国海南省的大(虫帝)蝠核型,但因未能确定No.15是单臂还是双臂染色体,因而未能确定染色体总臂数。本文采用骨髓细胞空气干燥法,研究了贵州遵义产大(虫帝)蝠的核型,结果表明,该种大(虫)蝠的染色体数是2n=32,16对同源染色体按其大小可分为三组:大型染色体组(Nos.1～7),中小型染色体组(Nos.8～15)和性染色体(X、Y);其中除No.3、X和Y染色体为亚中部着丝粒染色体外,均为中部着丝粒染色体,因而确定了染色体总臂数为64。