共查询到20条相似文献,搜索用时 62 毫秒
1.
变电站镉镍电池的管理与维护王家起山东省高青县电业局(256300)镉镍电池使用寿命的长短,主要决定于三个因素:一是厂家制造质量的好坏,进货时应选择国家定点生产的、质量可靠的镉镍电池;二是充电设备能否自动或手动满足镉镍电池充电(或放电)特性的需要;三是... 相似文献
2.
镉镍碱性蓄电池具有可靠性高,输出容量大,运行维护方便等特点,近年来被广泛使用于变电所220V控制和保护直流电源。运行人员掌握镉镍电池的使用性能,正确地进行初充电、浮充电、强充电,保证电池的容量充足和使用寿命,是非常必要的。(1)电解液的配制:电解液的... 相似文献
3.
4.
浅谈镉镍电池在运行和维护中应注意的几个问题黄乃成河南省商城电业局(465350)镉镍电池因具有性能稳定、使用可靠、容量大、瞬时高倍率放电能力强、维护量小等优点,在变电站中应用十分广泛。但是,变电站的使用人员由于对这种新型电池的使用和维护经验不足,不自... 相似文献
5.
铅酸与镍镉电池使用范围广泛,如在通信、UPS、消防、柴油机等领域都起着非常关键的作用。为了使电池运行更加安全可靠,文章对铅酸与镍镉电池因环境温度造成的蓄电池容量及寿命等方面的影响进行了分析,望为今后蓄电池长期有效运行及维护提供参考。 相似文献
6.
7.
双向泵站装置效率换算方法的探讨 总被引:1,自引:0,他引:1
根据水力计算原理,分析了双流道双向泵站效率和流道效率对泵站装置效率的影响;提出了原,模型装置效率换算时仅需考虑沿程损失的比尺效应,并据此推导了新的装置效率换算公式。 相似文献
8.
9.
10.
镉镍蓄电池作为一种新型的直流电源,由于其明显的优点,近年来已广泛应用在水利水电工程中。但基层中一些工作人员对如何正确使用不甚了解,甚至认为与过去传统使用的铅酸蓄电池差不多,从而使镉镍蓄电 相似文献
11.
12.
13.
14.
15.
《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
16.
感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
17.
18.
从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献
19.
The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献