Study of errors in ultrasonic heat meter measurements caused by impurities of water based on ultrasonic attenuation

Impurity is one of the main factors that affect the measurement accuracy of an ultrasonic heat meter. To study the effects of different impurity species and concentrations on the accuracy of heat meters, flow tests were carried out for the suspending of calcium carbonate and yellow mud. By analyzing the attenuation characteristics of the ultrasound amplitude in different impurity concentrations and species, the influence of the impurities on the heat meter measurement accuracy is evaluated. In order to avoid the inaccuracy caused by the sediment of the reflective bottom surface, a vortex generator is put ahead of the reflective surface. According to the test, the calcium carbonate suspension with a mass concentration of 1%, which influences the heat meter accuracy severely, is used as the flow media. The influence of the vortex generator on the calcium carbonate suspension flow field in the heat meter body is studied with numerical simulations. The results of this paper provide some theoretical guide on improving the heat meter measurement accuracy when the water contains impurities.     

强化监督执法 确保水土资源

三原县有水土流失面积316.8平方公里,占总土地面积的55％。年土壤侵蚀量66.8万吨,年径流量1817万米~3.属中度流失区.多年来在县委、县政府的带领下,全县人民累计治理水土流失面积193.3平方公里,占流失面积的62.2％,年土壤侵蚀量由66.8万吨降为48.3万吨,年径流量由1817万米~3降为908.5万米~3.取得了显著成绩。近年来,随着开矿、采石,修路,建厂和基建活动增加,忽视水土保持工作、肆意毁坏地貌植被、乱堆乱放废土废渣、破坏水土保持设施的现象屡有发生。每年废土废渣排放量达8.82万米~3,年流失量3.55万米~3。开荒402亩,年土壤流失量达1.9万米~3。全县每年人为土壤流失量达7.36万吨,占每年控制土壤侵蚀量18.5万吨的40％,造成严重的后果.三铜一级公路施工中,施工单位将55万米~3的弃土倾倒在郑家沟内,对下游的水利、人饮工程造成不可弥补的损失.1991年6月《中华人民共和国水土保持法》颁     

湖北省城市垃圾处理现状和对策探讨

本文分析了湖北省城市生活垃圾处置状况及存在的问题,提出了加快湖北省垃圾处理技术和产业发展的对策。