The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span interse
The time evolution of coal structure during low temperature oxidation was investigated by oxidizing coal samples in air at 120 ℃ for periods of up to 14 days.T
Fault fracture zones and water-bearing bodies in front of the driving head are the main disasters in mine laneways,thus it is important to perform their advance
In order to study the time-frequency characteristics of blasting vibration signals, measured in milliseconds, we carried out site blasting vibration tests at an
Mining-induced fracture zone will be produced in the overlying strata after the coal was mined.In this article,the mining-induced deformation of overlying strat
<正> 在积极对内搞活经济,坚定不移对外执行开放政策这一新的形势下,商检工作如何更好地为外贸工作服务?在今年春季广州交易会期间,记者访问了张尔端同志,现将她介绍的情况记述如下。
<正> 外贸企业的经济效益,同其他企业一样,概括地说就是以尽量少的劳动消耗换得尽量多的经济效益。说得具体一些,就是既要重视贸易额的增长和外汇收入的增加,又要重视成本核算,努力为国家增加积累。因此,要使对外贸易稳定发展,不仅要促使贸易额不断增长,还要不断提高经济效益,把外贸工作转移到提高经济效益的轨道上来。十一届三中全会以来,北京市在对外开放、对内搞活经济等一系列方针、政策的指引下,进出口贸易发展较快,同世界上130多个国家和地区建立了贸易往来关系。1982年出口额比1978年增长了1.18倍
Engineering geomechanics characteristics of roadways in deep soft rock at Hegang Xing'an Coal Mine were studied and the nature of clay minerals of roadway s
<正> 常州市目前的出口商品仍是以资源、劳动密集型产品为主。这些大宗低档产品和初级加工产品的出口约占全市出口值的70％。而纺织品的出口在我市的对外贸易中又占有举足轻重的地位,一般占市出口数的一半左右。纺织品出口的创汇量较大,换汇率虽然尚可以,但是,如果剔除各类坯布和棉纱的出口,则反而要亏损7,000万元左右。这是因为我们的印染后整理缺少各类优质助剂,再加上信息不灵,交贷期长,花色品种适应不了国外市场上迅速多变的需求。产品结构也适应不了国外对粗厚织物、稀薄织物或各类混纺织物的要求。
The current study tested the gas component and carbon isotopic composition of gas samples from 6 oilgas fields at the northern margin of Qaidam Basin, and estab