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
Efforts to speed up China's coal bed methane (CBM) exploration developments related to production safety, optimization of energy structures, prevention of e