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The common characteristics of rock-breaking under the action ofpounding were exposed in this paper: The quantity of fine particles (l) varies as an exponent of thenumber of poundirgs (n); To avoid the influence of resident of fine particles, the rumber ofpoundings (k), needed to increase a unit length of fine particles, canexpress the relative strergth of rocks, and by this, rocks may be div-ided into eight dasses; At last, a simple method of determination of "k", obtained wouldbe conyenient for practical... The common characteristics of rock-breaking under the action ofpounding were exposed in this paper: The quantity of fine particles (l) varies as an exponent of thenumber of poundirgs (n); To avoid the influence of resident of fine particles, the rumber ofpoundings (k), needed to increase a unit length of fine particles, canexpress the relative strergth of rocks, and by this, rocks may be div-ided into eight dasses; At last, a simple method of determination of "k", obtained wouldbe conyenient for practical use and wide-spreading. 本文揭露了各种岩石在夯捣作用下破碎的共同规律:粉末量l是随夯捣次数n按指数关系变化的;提出了用没有捣碎的粉末阻碍影响时每增加单位粉末量所需的夯捣次数k来表征岩石的坚固性,各种岩石按此指标可分为八级;最后制定出测定k值的简化方案,方法简单易行,便于推广。 Studies were carried out in Beijing ( 80m ) , Germu ( 2800m ) and Kunlun Pass (4500-4600 m above sea level) .Altogether, 400 young male nonnative residents, were examined. The items of investigation were as follows: physical examination, electrocardiography,vectorcardiography, cardiac systolic interval, pulmonary rheo-graphy, echocardiography etc. It was demomstrated that they main characteristic features of the left axis deviation and incomplete right bundle-branch block at high altitude were different... Studies were carried out in Beijing ( 80m ) , Germu ( 2800m ) and Kunlun Pass (4500-4600 m above sea level) .Altogether, 400 young male nonnative residents, were examined. The items of investigation were as follows: physical examination, electrocardiography,vectorcardiography, cardiac systolic interval, pulmonary rheo-graphy, echocardiography etc. It was demomstrated that they main characteristic features of the left axis deviation and incomplete right bundle-branch block at high altitude were different from those observed at sea level, A classification and diagnostic criteria of right ventricular hypertrophy at high altitude were suggested, and the chronic and acute effects of high altitude environment on the right and left heart were discussed. 本文报告高原环境对400例移居高原的男青年心脏影响的研究结果,并提出关于高原右心室肥厚分型方案和诊断标准的建议。各项研究的详细资料将陆续发表。 The results obtained from investigations in the field and laboratory showed that selenium deficiency plays an important role in the causation of Keshan disease. This conclusion is based on: ( 1 ) Oral administration of sodium selenite was highly effective in the prevention of Keshan disease. In Mianning county of Sichuan province, the incidence rate of Keshan disease in the selenium treated children were 2.2% and 1.0% in 1974 and 1975 respectively, while those of the control group were 13.5% and 9.5%, both differences... The results obtained from investigations in the field and laboratory showed that selenium deficiency plays an important role in the causation of Keshan disease. This conclusion is based on: ( 1 ) Oral administration of sodium selenite was highly effective in the prevention of Keshan disease. In Mianning county of Sichuan province, the incidence rate of Keshan disease in the selenium treated children were 2.2% and 1.0% in 1974 and 1975 respectively, while those of the control group were 13.5% and 9.5%, both differences being statistically significant. Up to the end of 1977, 21 cases of this disease occurred in selenium treated children, only 3 of them died: whereas, 106 cases occurred in the control group, of which 53 were fatal. ( 2 ) Selenium content of blood, hair and staple cereals in the affected areas was regularly lower than that in non-affected areas. (3 ) Urinary loading test and whole blood glutathione peroxidase activity of residents in the affected areas were also indicative of deficiency in selenium. However there were also evidences to suggest that selenium deficiency is not the only factor involved in the etiology of the disease. There may be some other etiolgical factors. 本文报告了硒与克山病关系的初步研究结果。根据(1)口服亚硒酸钠对预防急型和亚急型克山病的发病有显著效果;(2)克山病病区人血、头发和粮食中硒含量普遍低于非病区;(3)尿硒负荷试验和全血谷胱甘肽过氧化物酶活性测定表明,克山病病区居民体内处于贫硒状态,认为硒缺乏对克山病发病有重要的、但不是唯一的作用。
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