福建全新世海滩岩及其地质意义

福建已发现全新世海滩岩１０余处，主要分布于平潭岛以南，笔者选择了具有＾１４Ｃ年龄和海拔高程的海滩岩共２６组数据，建立了全新世海平面变化曲线，讨论了海平面升降特点、新的构造差异运行和古气温的变化。     

高分子材料-钢摩擦副湿磨粒磨损机理的试验研究

采用销盘式试验机对聚四氟乙烯和丁腈橡胶的磨损特性进行了研究。试件浸入水或钻井泥浆中,在不同的正压力和转速下进行试验。在试验中,还采用了固相含量分别为0.02％和0.13％(重量百分比)的两种泥浆。磨损表面用扫描电镜和X射线能谱仪进行了观察。试验结果表明,泥浆的固相含量对高分子材料的湿磨粒磨损起着重要作用,丁腈橡胶在泥浆中的抗磨性比聚四氟乙烯好得多。     

Interpreting grain-size trends associated with bedload transport on the intertidal flats at Dafeng, central Jiangsu coast

IN THE MARINE ENVIRONMENT, IT IS OFTEN DIFFICULT TO IDENTIFY THE NET SEDIMENT TRANSPORT PATHWAY BECAUSE OF THE COMPLICATED HYDRODYNAMICS AND SEDIMENT SOURCES. GAO AND COLLINS HAVE RE-EXAMINED A 1-D MODEL ORIGI- NALLY DERIVED BY MCLAREN AND BOWLES AND DEVE…     

钢格栅喷射混凝土支护方式在矿井滑坡体中的应用研究

在矿井通过滑坡体段施工时,采用钢格栅喷射混凝土支护方式明显优于常用的支护方式,这种方式工艺简单,造价少,支护效果好,施工期间存在安全隐患少,特别适用于表土段、巷道围岩非常破碎区段支护。     

温度骤降对锯缘青蟹可溶性蛋白与可溶性糖含量的影响

锯缘青蟹是生活在河口海区的一种重要经济甲壳动物,其生活的环境温度经常发生温度的骤然增高或降低.本研究采用生物化学的方法对温度骤降后不同时间锯缘青蟹鳃,肝胰腺和肌肉中可溶性蛋白和可溶性糖含量进行测定.结果显示锯缘青蟹可溶性蛋白和可溶性糖含量在骤降温初期(2 h)升高,骤降温2 h后可溶性蛋白虽然呈现波动性变化,但最后出现明显下降;骤降温2 h后可溶性糖含量在鳃中逐渐下降,而在肝胰腺和肌肉中呈现波动性下降.实验结论为锯缘青蟹骤降温初期可溶性蛋白和可溶性糖增高是机体对寒冷应激的一种积极反应,后期下降是生理反应中物质和能量消耗所致.     

左宗棠与林则徐

左宗棠与林则徐作为中国近代史上的两个著名人物 ,其思想和行为都对当时和后世产生了重大的影响 ,且左宗棠又是林则徐思想的继承、发展和实践者。左宗棠创办福州船政局及他后来收复、开发和建设新疆都明显地受到了此前林则徐思想的影响     

中国淤泥质海岸的发育特点

本文试从大地构造、泥沙来源、海岸动力、植被类型和人类活动等角度出发,叙述了中国淤泥质海岸的发育特点及其制约因素。1 引言淤泥质海岸的广泛分布是中国     

中国淤泥质海岸的发育特点

本文试从大地构造、泥沙来源、海岸动力、植被类型和人类活动等角度出发,叙述了中国淤泥质海岸的发育特点及其制约因素.     

两向水平应力不等条件下泥浆密度的确定

降低泥浆液柱压力对油气层的压差和保持井壁稳定是钻井工程亟待解决的问题,对于地应力异常地区显得更为迫切。为了解决油气层污染和井壁稳定的难题,在弹塑性力学理论和岩石力学理论的基础上,应用摩尔—库伦屈服准则,阐述了井眼周围岩石弹塑性状态的形成机理及应力、位移的分布情况,推导出了井眼塑性屈服范围和泥浆液柱压力、水平地应力以及岩石强度的关系式。与其它理论相比,该理论所确定的保持井眼稳定的泥浆密度范围更广,有利于降低对油气层的压差和近平衡钻井。同时,也提出了一些具体技术来保证这一理论的应用。     

Sediment dynamic responses of coastal salt marsh to typhoon “KAEMI” in Quanzhou Bay, Fujian Province, China

−In order to understand the mechanisms of coastal protection by salt marshes during typhoon events, in situ measurements of water level, tidal current speed and direction, and suspended sediment concentration (SSC) were carried out using Electromagnetic Current Meter (EMCM, AEM HR), miniature pressure sensor (MkV/D) and Seapoint Turbidity Meter (STM) sensor on a tidal flat in Quanzhou Bay, during the period when the typhoon “KAEMI” was passing through the region. The analysis of the data obtained shows that the near-bed current speed within the Spartina alterniflora marsh was generally below 5 cm s⁻¹, which was apparently smaller than on the adjacent bare flat (i.e. 5―30 cm s⁻¹). The change in the near-bed current speed in response to the typhoon event was not significant within the S. alterniflora marsh, but the current direction was influenced by the typhoon. The effect of the typhoon on the SSC was highly significant, with the SSC reaching 13 to 19 times the values on the bare flat or within the marsh under fair weather conditions; the near-bed SSC within the marsh was higher than on the bare flat, after the typhoon landed. The near-bed suspended sediment fluxes within the marsh and on the bare flat during the typhoon event were both enhanced, i.e., 4 times larger than under fair weather conditions. During the ebb, the bottom shear stress on the bare flat exceeded the critical shear stress for sediment motion for most of the ebb duration of the tide and, therefore, the bed sediment was eroding, with the erosion flux after the typhoon landed being around 2 to 3 times the value associated with fair weather conditions. In contrast, within the S. alterniflora marsh, the bottom shear stress was mostly lower than the critical shear stress for sediment motion, or lower than the critical shear stress for the maintenance of suspension; hence, the marsh surface was dominated by settling processes, with a settling flux during the typhoon being 3 to 6 times compared with the fair weather situations. The settling flux during the ebb was up to twice the magnitude for the flood. The comparison of sediment dynamic processes between the S. alterniflora marsh and the bare flat demonstrates that during the typhoon event the bare flat was dominated by erosion, whilst the presence of S. alterniflora favored the accretion of suspended sediment.