Continuous and Quantitative Polarographic Analysis of Dithionites

Amperometric titration, using either a dropping-mercury electrode or a rotating platinum electrode as the indicator electrode and Rubine as the titrant, has been shown to be a useful method of analysis of sodium and zinc dithionites. From controlled potential electrolysis, it was confirmed that the anodic oxidation of dithionite involves two electrons per dithionite ion, sulphite being identified polarographically as one of the products of the reaction. A continuous voltammetric determination of dithionite is described that could possibly be adapted for the control of industrial processes in which dithionite is used.     

基于ARM9与LEM传感器的蓄电池在线监测硬件平台

阀控蓄电池的广泛使用对于在线监测是非常重要的课题。本文介绍了以LEM公司蓄电池传感器Sentinel模块为基础的蓄电池在线监测硬件平台的构成,并介绍了基于ARM9的蓄电池在线监测主机,现场进行了整机联调,给出了测试结果。实验证明该平台可以应用于蓄电池在线监测。     

The effect of complete versus incomplete information on odour discrimination in a parasitic wasp

We studied the function of learning in the parasitoid Leptopilina heterotoma by looking at discrimination of odour stimuli used in foraging for a host. To optimize the rate of encounters with hosts, these parasitoids are expected to assess the extent to which variation in host-substrate odours is reliably associated with variation in the presence of hosts, that is, substrate profitability. Where the association is reliable, parasitoids should attend to variation in odours and discriminate between them; where it is not, they should ignore it. We hypothesized that foraging decisions are based on the completeness of information the animal has about differences in substrate profitabilities. Our laboratory studies showed that discrimination and non-discrimination of odour stimuli are dynamic behavioural decisions that can be related to the degree of substrate variation and to an animal's informational state. In wind-tunnel studies, females learned to discriminate between odours from substrates that were qualitatively different, for example, between odours from apple and pear substrates or between yeast substrates with different C6 compounds added. They did not discriminate when differences were small (e.g. between odours from two apple varieties or between yeast patches with different concentrations of ethyl acetate), unless unrewarding experiences provided evidence of the absence of hosts in one of the substrates. Hence, we suggest that non-discrimination between odour stimuli in L. heterotoma is not a lack of ability to discriminate but a functional decision by the parasitoid. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.     

蓄电池持续监测保证不间断电源(UPS)可以随时启用

文章分析了阀控铅酸蓄电池(VRLA)失效的主要原因,持续监测是防止不间断电源(UPS)系统故障风险的解决方案;介绍了先进的可持续监测的Sentinel阻抗测试方法。     

有效变革利用传感器技术攀登电流测量精度高峰

磁共振成像（MRI）的发展提升了诊断能力,接着,增加了细胞水平治疗身体疾病数,最明显的可能就是癌症。作为一种诊断方法,MRI继续发展,但是一段时间以来,这种发展已与基础技术的发展同步,尤其是图像采集技术。