An Experimental Melting—crystallization Study on Basalt at High Pressures

A series of melting-crystallization experiments on alkali basalt samples from Minqing, Fujian Province was carried out in dry and waterbearing systems at high pressures. A high-pressure melting curve was obtained. The results indicate that clinopyroxene crystallized from basalt melt at 13.5–23.7 kbar. spinel at 23.7–28.6 kbar and garnet at > 28.6 kbar. With increasing pressure, the CaSiO₃ contents of clinopyroxenes increase; and the FeSiO₃ decreases, but the chemical composition of garnet does not show any significant difference. The minerals are larger and euhedral in the water-bearing system. Therefore, we consider that natural megacrysts of the basalt can crystallize from the water-bearing basalt magma at high pressure. So the megacrysts may be derived from the upper mantle as a result of magmatic crystallization-fractionation under high pressure. This project was financially supported by the National Natural Science Foundation of China.     

江心洲型河流的成因分析

以往关于江心洲型河流的成因分析,多强调江心洲河型与其它河型的差异性,而忽略了江心洲河型与弯曲型河流在本质上的相似性。本文的研究表明,江心洲河型在其本质上并不是介于弯曲型和游荡型河流之间的一种独立河型。恰恰相反,江心洲型河流只是弯曲型河流在一定条件下,对应于特定范围的含沙量及流量变幅时的扭曲形态。这种属于弯曲河流范畴的因“扭曲”而派生出来的新形态,保留了其母体的几乎所有实质性的内容。运用本文的江心洲型河流的成因论述,不仅能够有效地解释现有河型研究中的一些矛盾,而且也便于把研究得较为充分的弯曲型河流中的有关定量研究方法移植到江心洲河型的研究中来。     

西藏羌塘盆地北部托纳木地区上侏罗统雪山组沉积相

羌塘盆地地处藏北高原,其南、北边界分别为班公错一怒江缝合带与拉竹龙一金沙江缝合带,盆地面积约18×104km2,可进一步分为羌北坳陷、中央隆起带和羌南坳陷3个二级构造单元.双湖托纳木地区地处羌北坳陷南部,与中央隆起带毗连,广泛发育上侏罗统雪山组沉积,垂向上由3个沉积旋回组合构成,总体显示为一个向上变粗的充填序列.雪山组发育扇三角洲相和冲积扇相,其中雪山组一段为前扇三角洲亚相沉积;二段为扇三角洲前缘亚相和扇三角洲平原亚相沉积,扇三角洲前缘亚相分为水下分流河道、河口坝和远砂坝沉积,扇三角洲平原亚相发育天然堤和分流河道沉积;三段为冲积扇相沉积,包括扇端和扇中沉积.雪山组沉积的物源来自西南部的中央隆起带.     

非开挖铺管中钻头泥包问题的分析与对策

非开挖导向铺管过程中,当钻遏较软岩层或泥页岩层时,经常会遇到钻头被泥包的现象,尤其在扩孔过程中,更为明显。针对这种现象,从三个方面认真了分析钻头泥包的原因,并提出从泥浆方面入手的对策。进行室内推力实验,在武汉江夏区的非开挖施工现场提出配方并加以应用,对提高钻进效率有重要的意义。     

大渡河流域梯级水电站场地地震影响特征研究

本文利用四川地区及邻区的烈度衰减关系式,计算了历史强震对大渡河梯级水电站场址的影响烈度和最大烈度。同时,还分析了水电站场址在历史强震发生密集时的地震影响烈度特征,以期为今后梯级水电站的地震安全综合防御和地震应急工作提供参考。     

Northern marine transportation corridors: Creation and analysis of northern marine traffic routes in Canadian waters

The concept of the Northern Marine Transportation Corridors (NMTC) initiative was developed under the Government of Canada World‐Class Tanker Safety System Initiative (WCTSS). The NMTC is an interdepartmental Arctic initiative within the Department of Fisheries and Oceans Canada (DFO), through the Canadian Coast Guard (CCG) and the Canadian Hydrographic Service (CHS), in collaboration with Transport Canada (TC). The NMTC initiative was developed to strengthen the safety of marine navigation in the Arctic, and to offer an efficient planning guide for present and future Arctic investments. Transportation corridors identified through this initiative will provide the Government of Canada the framework needed to better prioritize and deliver on its programs and services, including: nautical charts and products; aids to navigation; icebreaking services; and marine safety regulations. The corridors were generated and analyzed with a Geographic Information System (GIS) using two main data sources: the Automated Identification System (AIS) and CHS's nautical charts and publications. The geographic extent of the NMTC is defined as the Northern Canada Vessel Traffic Service Zone (NORDREG Zone) and the Mackenzie River. With close to 4 million km² of water in the Arctic and 162,000 km of coastline, surveying the Arctic to modern standards represents an enormous challenge to CHS. By adopting a corridor‐based approach, CHS and other government programs can prioritize their efforts on 12% of the Canadian Arctic waters. CHS currently has 32% of the NMTC adequately surveyed, with an additional 3% surveyed to modern standards.     

CINRAD/SC雷达拼图报缺报原因分析

根据CINRAD/SC雷达拼图报生成、发送工作流程,分析了造成上传数据缺报、上传数据逾限和上传数据内容有误等情况产生的原因,并提出了相应的解决方法.     

双翻斗雨量传感器测量数据不确定度评定

根据自动气象站雨量传感器检定规程和测量不确定度评定的过程与方法,以实验室检定SL3-1型双翻斗雨量传感器为例,通过逐项分析误差来源及其引入的不确定度分量,针对各分量分别使用不同的评定方法和数学方法计算了各项标准不确定度,最终给出了实验室检定双翻斗雨量传感器的扩展不确定度:在大小两种雨强下,测量不确定度均为U95=0.14mm,包含因子k95=2.06。经传递比较法验证,评出的测量不确定度结果满足了计量标准考核规范和法定计量检定机构考核规范中的相关要求。该研究完善了雨量传感器的实验室检定工作流程,提高了工作质量。     

山东金伯利岩中深源捕虏体的石榴石和透辉石

一、前言金伯利岩是一种成分复杂的岩石,含有大量幔源,壳源捕虏体。金伯利岩中的矿物既有来自各深度相捕虏体的,也有岩浆期结晶的,还有蚀变的;即使同是岩浆期结晶的矿物还有早、晚晶出之分。因此金伯利利岩中同一种矿物在化学成分、内部结构和物理性质等方面均有一定差异,从而我们有可能判别出与金刚石形成条件相同或相近的那部分最深源矿物,为寻找和评价金刚石矿床提供依据。     

基坑开挖孔隙水压力变化规律试验研究

讨论了基坑开挖及降水过程中,基坑周围土体孔隙水压力的变化过程,根据现场量测数据进行了分段线性拟合,得到了土体中孔隙水压力的变化规律。并对基坑周围土体孔隙水压力的变化机理及过程进行了分析。