钟房控温的一种方法及结果分析   总被引：1，自引：1，他引：0  

刘宏良  柯熙政 《时间频率学报》1998,21(1):42-45

环境温度对原子钟特性的影响已经得到了人们的重视。现对陕西天文台守时钟房的一种温控实验作一介绍,并对温控的结果进行了评价。  相似文献   

链子崖危岩体相对位移监测温度效应   总被引：2，自引：0，他引：2  

高幼龙  王洪德 《中国地质灾害与防治学报》1998,9(4):25-31

本文从实测资料分析预报需要角出发,提出了温度对岩体相对位移监测结果产生的异变影响和次生影响问题。分析了引起这些影响的原因,并提出了进行校正的具体方法,通过实例验证了校正效果。  相似文献   

环境温度对石油污染滨海盐渍土强度及变形特性的影响     

谢首斌  李敏  杜红普  李达  张静怡 《工程地质学报》2016,24(4):616-621

环境温度影响石油黏滞性,改变石油污染土的力学特性。借助无侧限抗压强度试验,研究不同温度条件下石油污染滨海盐渍土的强度及变形特性。结果证实:温度对石油污染盐渍土力学性质影响显著,温度越高,污染土抗压强度越低,20℃时,含油率15%污染土的抗压强度较未污染土下降近70%;石油污染滨海盐渍土的抗压强度随含油率的增加先增大后减小,环境温度与污染土强度峰值点处的含油率反相关,10℃、20℃、30℃条件下,强度峰值点处的含油率分别为15%、10%和5%;石油污染盐渍土表现为应变软化型破坏,含油率及环境温度影响石油污染盐渍土的抗变形能力,土样的破坏面积和裂缝宽度随含油率增加及温度升高而增大。  相似文献   

我国气候家畜类型划分的初探     

樊锦沼 《内蒙古气象》1990,(4):18-22

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马蹄莲大棚小气象适应性评估   总被引：3，自引：0，他引：3  

钱妙芬  唐胜富 《成都气象学院学报》1994,9(3):67-71

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Structural condition assessment of long-span suspension bridges using long-term monitoring data     

Deng Yang  Ding Youliang  Li Aiqun 《地震工程与工程振动(英文版)》2010,9(1):123-131

<正>This paper focuses on developing an online structural condition assessment technique using long-term monitoring data measured by a structural health monitoring system.The seasonal correlations of frequency-temperature and beam-end displacement-temperature for the Runyang Suspension Bridge are performed,first.Then,a statistical modeling technique using a six-order polynomial is further applied to formulate the correlations of frequency-temperature and displacement-temperature,from which abnormal changes of measured frequencies and displacements are detected using the mean value control chart.Analysis results show that modal frequencies of higher vibration modes and displacements have remarkable seasonal correlations with the environmental temperature and the proposed method exhibits a good capability for detecting the micro damage-induced changes of modal frequencies and displacements.The results demonstrate that the proposed method can effectively eliminate temperature complications from frequency and displacement time series and is well suited for online condition monitoring of long-span suspension bridges.  相似文献   

特种气象观测数据处理系统     

杜佳林郭淑芳  王力平 《吉林气象》2004,(3):37-41

为了更好地开拓气象服务领域,加快特种气象观测的建设,我省从2002年5月起,先后开展了季节性的柏油路面温度、露天环境温度及草面(雪面)温度等项目的观测和发报工作,并从2004年初起执行全年开展特种气象观测项目的手工编发报及月报表编制工作。目前,这些特种气象观测项目的观测资料已逐步投入到业务使用,为开展特种项目预报提供了可靠的依据。  相似文献   

环境温度对地震数据采集器时间精度的影响测试     

叶世山  谢剑波  陈洁  赵圣麟  吕金水  冯俊鹏  陈建涛  关作金  罗新恒  卢子晋  邓金  廖一帆  劳谦  丁莉莎 《大地测量与地球动力学》2022,42(4):431-435

为适应地震数据采集器时间精度测试的需要,采用特定电路将普通参考时钟源输出的分脉冲信号扩展至占空比为50％,再利用扩展后的分脉冲信号在室温、低温恒温及高温恒温环境中对地震数据采集器时间精度进行测试,研究环境温度对地震数据采集器时间精度的影响.结果表明,地震数据采集器时间精度及漂移趋势受环境温度变化影响,0.5 h内发生约...  相似文献   

Water Intake and Utilization in Mithun （Bosfrontalis）： Effect of Environmental Temperature,Rearing System and Concentrate Feed Supplement     

D. T. Pal  ;A. Dhali  ;S. K. Mondal  ;C. Rajkhowa  ;K. M. Bujarbaruah 《山地科学学报》2008,5(2):178-188

Seasonal and sexual variations as well as the effect of dry feed supplement on total drinking water intake and its utilization were observed in mithun （Bosfrontalis） - a semi-wild animal found in North Eastern Hill Region （NEHR） of India. In a completely randomized design, twelve adult mithuns （B. frontalis） as per their sex and body weight were assigned in two different rearing systems （free grazing and free grazing with dry concentrate feed supplementation）, and ten growing male mithuns as per their body weight assigned in two different levels of dry concentrate feed supplementation （1.o kg and 2.0 kg dry concentrate feeds on green forage based diet） and in two different seasons （summer and winter）. It was observed that the environmental temperature had a significant effect on drinking water intake by mithuns. Drinking water consumption （per unit of body weight） was significantly （P 〈 0.05） higher in summer than in winter. Supplementation of concentrate feed on free grazing animals resulted in increase in water consumption. Total water consumption （drinking as well as performed water） was found to be 15.18 litres per 100 kg body weight by growing mithun. Feed dry matter and digestible nutrient intakes by growing mithun were observed to be increased with the increase of supplementation of dry concentrate feed. Roughage to concentrate ratio did not affect the nutrient digestibility. Mithun calves drank an average of 4.30 litres water for each kg of dry matter intake. Metabolic water was significantly （P〈0.01） increased with the increase of supplementation of concentrate feed whereas water turn over, which depends upon the body weight of the animals, did not differ significantly on offering of lower or higher level of dry feed. Faecal water loss of growing mithun was decreased with the increase in intake of concentrate feed and was estimated to be 33 - 46 % of total water intake. Excretion of water through faeces of mithun was about 3.8 % of body weight. It could, there  相似文献   

不同环境温度和含砂率对黏性土干缩开裂影响试验研究     

卢毅  卜凡  蔡田露  龚绪龙  陆华  万佳俊  王梓  顾凯 《高校地质学报》2022,28(6):902-910

在工程建设与自然环境中,土体因失水而产生收缩、开裂的过程受多重因素的影响,且各因素之间的相互作用关系十分复杂。其中,环境温度在土体开裂的起始与结束中,起至关重要的影响;同时,鲜见关于土体内部黏土、砂粒配比对于裂隙发育影响的研究。故本研究设置了不同环境温度、含砂率条件,展开一系列室内蒸发试验,通过记录试验过程中土体内部水分散失以及表面裂隙发育、发展情况,利用相关图形分析软件,对裂隙率、裂隙网络的几何形态进行定量分析,进而探究不同温度、含砂率对土体干缩、开裂的影响机理。研究结果表明：（1）砂粒的存在,导致土体内部的结构发生改变,部分输水通道被堵塞,从而延长了自由水的运移路径,水分蒸发速率随着含砂率的增加而降低。（2）砂粒的存在将导致土体表面提前产生开裂,此现象受含砂率的影响较小,与是否含砂有关。（3）土体内部含砂率越高,裂隙发育纵深越小,延伸长度越短,同时裂隙的宽度与含砂率呈反比。（4）相同含砂率条件下,环境温度越高,水分蒸发速率、土体表面形成的裂隙宽度越大,且在一定程度上促使表面裂隙提前产生。  相似文献