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71.
72.
E. W. Underhill J. G. Millar R. A. Ring J. W. Wong D. Barton M. Giblin 《Journal of chemical ecology》1987,13(6):1319-1330
A single sex pherormone component was isolated from abdominal tip extracts of female Bruce spanworm.Operophtera bruceata (Hulst). This was identified as (Z,Z,Z)-1,3,6,9-nonadecatetraene by capillary gas chromatography (GC), electroantennography, and mass spectrometry. In addition, hexane extracts of female abdominal tips from Bruce spanworm and the winter moth.O. brumata L., were analyzed by GC coupled to an electroantennographic detector (GC-EAD). The extracts ofO. bruceata andO. brumata females elicited only a single response, at the same retention time, from antennae of their conspecific and reciprocal males. In field tests conducted in Saskatchewan, traps baited with the synthetic tetraene captured Bruce spanworm males. In tests carried out on Vancouver Island, British Columbia, where the two species coexist, both Bruce spanworm and winter moth males were captured. The attractancy of lures containing the synthetic pheromone alone and in combination with several structurally related analogs was field tested at both locations. One of these, an isomer of the natural pheromone, (E,Z,Z)-1,3,6,9-nonadecatetraene, inhibited the capture of Bruce spanworm males but had no effect upon the number of winter moth males which were taken. Thus, populations of these two very similar species can be distinguished by employing traps baited with pheromone ± the inhibitor. Coneorifice Hara traps were found useful for field trapping males of both species.Issued as NRCC No. 26107 相似文献
73.
James N. Seiber Paul M. Tuskes Lincoln P. Brower Carolyn J. Nelson 《Journal of chemical ecology》1980,6(2):321-339
Adult monarch butterflies,Danaus plexippus L. (Lepidoptera: Danaidae), store only some of the cardenolides present in the larval milkweed (Asclepiadaceae) host. Feeding known doses of individual cardenolides to 4th instar monarch larvae led to more efficient larval tissue incorporation at low doses than at high ones, and favored storage of cardenolide glycosides over genins. A qualitative regulation also occurs during larval feeding; calactin and calotropin were stored as such but uscharidin was rapidly converted to a mixture of calactin and calotropin which were the forms stored by the larvae. Two genins, uzarigenin and digitoxigenin, were stored by larvae as polar cardenolide metabolites.Research supported by National Science Foundation grants DEB 7514266 and DEB 7514266-AO2 (U.C. Davis) and DEB 7514265 (Amherst College). 相似文献
74.
75.
丙溴磷,杀螨隆,氟铃脲等防治小菜蛾及菜青虫试验 总被引:2,自引:0,他引:2
试验结果表明,丙溴磷、杀螨隆、氟铃脲等对小菜蛾均有效,且持效期长,丙溴磷具有速效性及对菜青虫高效。 相似文献
76.
高小明 《单片机与嵌入式系统应用》2014,(6):50-53
门禁系统是一种管理人员进出的数字化智能系统,可以实时监控门的状态和合法用户的进出状况,防止非法用户强制闯入。门禁系统作为智能家居系统的一部分,在现代安防领域发挥了巨大作用,也给用户的使用和管理带来了极大的便利性、高效性和安全性。本文介绍了利用具有超低功耗的STM8L微控制器为控制核心,设计了基于125KHz的射频读卡模块,采用EM4100系列ID卡作为用户身份识别卡,实现了对门锁的控制和状态的识别,并通过总线方式与服务器进行通信。实践表明,该系统整体功耗低、性能稳定、使用安全、管理方便。 相似文献
77.
R. F. Brennan 《Nutrient Cycling in Agroecosystems》1992,31(1):35-41
Five field experiments are described which measured the effect of take-all on grain yield of wheat when 5 levels of manganese fertilizer were applied in a factorial combination with 5 different types of nitrogen fertilizer.Ammonium nitrogen fertilizer, either as ammonium sulphate or ammonium chloride, lowered the severity of take-all. By contrast, sodium nitrate had no effect on the incidence and severity of take-all. Ammonium chloride and ammonium sulphate were equally effective at controlling take-all, suggesting that the chloride or sulphate ion had little or no effect on the disease.Manganese sulphate decreased take-all severity at two trial sites. Where manganese was deficient, an application of manganese lowered the severity of take-all, had no effect on the incidence and increased the dry matter and grain yields of the wheat plants. There were no beneficial effects of applied manganese if the wheat plants were adequately supplied with soil manganese.The results suggest that take-all is more severe where plants are deficient in either manganese or nitrogen. The work also suggests that manganese deficiency is not necessarily the reason why the wheat plants grown on the acid soils of south-west Western Australia are prone to take-all. 相似文献
78.
Charles E. Carraher Jr. Theodore S. Sabir Michael R. Roner Kimberely Shahi Robert E. Bleicher Joanne L. Roehr Kelly D. Bassett 《Journal of Inorganic and Organometallic Polymers and Materials》2006,16(3):249-257
Organotin polyamine ethers containing acyclovir in their backbone were synthesized in moderate to high yield employing the aqueous interfacial polycondensation system. The products are high molecular weight polymers. Infrared spectroscopy of the products shows new bands characteristic of the formation of Sn–N and Sn–O bonds consistent with the proposed structure. MALDI-TOF MS below 2000 Da shows the presence of organotin and acyclovir units containing these two moieties. The products show moderate inhibition of a number of cancer cell lines and exhibit the ability to inhibit a number of viruses, particularly the herpes simplex virus-1 and varicella zoster virus that are responsible for herpes, chicken pox and shingles. 相似文献
79.
Large aggregation interval asymptotics are used to investigate the relation between Granger causality in disaggregated vector autoregressions (VARs) and associated contemporaneous correlation among innovations of the aggregated system. One of our main contributions is that we outline various conditions under which the informational content of error covariance matrices yields insight into the causal structure of the VAR. Monte Carlo results suggest that our asymptotic findings are applicable even when the aggregation interval is small, as long as the time series are not characterized by high levels of persistence. 相似文献
80.
A field experiment was conducted on an acid sulfate soil in Thailand to determine the effect of N fertilization practices on the fate of fertilizer-N and yield of lowland rice (Oryza sativa L.). A delayed broadcast application of ammonium phosphate sulfate (16-20-0) or urea was compared with basal incorporation of urea, deep placement of urea as urea supergranules (USG), and amendment of urea with a urease inhibitor. Deep placement of urea as USG significantly reduced floodwater urea- and ammoniacal-N concentrations following N application but did not reduce N loss, as determined from an15N balance, in this experiment where runoff loss was prevented. The urease inhibitor, phenyl phosphorodiamidate (PPD), had little effect on floodwater urea- and ammoniacal-N, and it did not reduce N loss. The floodwater pH never exceeded 4.5 in the 7 days following the first N applications, and application of 16-20-0 reduced floodwater pH by 0.1 to 0.3 units below the no-N control. The low floodwater pH indicated that ammonia volatilization was unimportant for all the N fertilization practices. Floodwater ammoniacal-N concentrations following application of urea or 16-20-0 were greater on this Sulfic Tropaquept than on an Andaqueptic Haplaquoll with near neutral pH and alkaline floodwater. The prolonged, high floodwater N concentrations on this Sulfic Tropaquept suggested that runoff loss of applied N might be a potentially serious problem when heavy rainfall or poor water control follow N fertilization. The unaccounted-for15N in the15N balances, which presumably represented gaseous N losses, ranged from 20 to 26% of the applied N and was unaffected by urea fertilization practice. Grain yield and N uptake were significantly increased with applied N, but grain yield was not significantly affected by urea fertilization practice. Yield was significantly lower (P = 0.05) for 16-20-0 than for urea; however, this difference in yield might be due to later application of P and hence delayed availability of P in the 16-20-0 treatment. 相似文献