ON THE VEGETABLE TISSUES AND FLORA IN THE CHINESE COAL AND THEIR GEOLOGICAL SIGNIFICANCE

1. Altogether about one hundred specimens of coal from 19 different provinces of China proper and two specimens from Mongolia were studied. In quality, these coals vary from lignite to anthracite, and in age they belong to different formations of Tertiary, Cretaceous, Jurassic and Permo-Carboniferous. 2. Four methods of investigation, namely, the thin section, the polished section, the maceration and the etching have been used in the present investigation.3. A great number of vegetable tissues and organs such as parenchymatos cells, stone cells, wood tracheids, scalariform tracheids, bast fiber, bark parenchyma, epidermal cells sometimes with cell contents, cork cells, fungi hyphae, sclerotites, spore exines, pollen grains etc. have been detected in the coals studied.4. One of the exceptionally well preserved wood fibers has been definitely identified to belong to Xenoxylon, an index fossil for upper Jurassic formation. This coniferous wood is now known to be widely distributed in the Mesozoic coal basin of Northern China.5. From the presence of fungi activity in the Tertiary coal a rather dry condition for the coal forming period may be advocated. On the other hand, the usually excellently preserved state of the various tissues in the Palaeozoic coals postulates a contrary condition i.e. a wet surrounding and probably under constant covering of water.     

THE IRON DEPOSITS OF SOUTHERN ANHUI

CONTENTS Ⅰ. Introduction. Ⅱ. The economic aspects of the deposits. Ⅲ. The Tangt'u iron district. 1) General geology. 2) Ore deposits. a) The Tawashan iron deposit.     

廠基工程地質的勘探工作

一、前言以重工業建設為重點的第一個五年計劃開始了,在祖國廣大的原野上,將出现很多規模宏大的工廠;担負這方面工作的工程地質幹部,面臨着光榮而偉大的任務;但廠基工程地質的特點,一般是在地形平緩的地帶進行地質勘探工作,這些地方,很少發現岩石     

Seepage characteristics and mechanical response of shield tunnels under localized leakage and exosmosisEI北大核心

针对有压盾构隧道中接缝水力劣化所引发的内外水力交互渗流问题,基于水力开度理论,通过数值和解析方法研究局部渗流下隧道衬砌与周围地层的渗流特性和力学响应。结果表明:基于镜像法推导的衬砌隧洞多点渗漏下渗流场解析解与数值解吻合良好,验证了给出的局部渗漏数值模型的有效性;局部外水内渗与内水外渗诱发的衬砌与地层共同作用存在较大差异,前者导致局部孔隙水压力降低引起土体挤压衬砌,衬砌轴力减小而弯矩增大从而产生衬砌外凸,后者则相反;多点局部渗漏对渗流场和衬砌响应的影响存在耦合作用,当内水压接近地层水头时可能出现外水内渗与内水外渗并存的特殊水力交互情况;地层渗透系数对局部渗漏行为的影响较大,复合地层下当局部渗漏发生于高渗透性地层时,其诱发的衬砌响应不显著,当渗漏处于下部低渗透性地层时,在地层交界面存在渗流折射现象,上部高渗透性地层起到补(排)水作用。