离子交换法生产碳酸钾的工艺探讨

本文讨论以工业KCI和NH4HCO3为原料、采用离子交换法（国产732钠型树脂）生产K2CO3的工艺。小试验的结果：以20％KCI溶液上柱，以分段交换率在50％以前为穿漏点、流速为0．033(ml/min.ml树脂）时，总交换率达83．3％，工作交换容量达2．24（毫摩尔钾／ml树脂）；当以饱和NH4HCO3溶液进行解脱、流速在0．033(ml/min.ml树脂）时，解脱率达91．8％，产品的含量为98．2％。     

大义山西北端硼矿床特征及其控矿因素

湖南大义山西北端的硼矿属接触交代—热液叠加型。矿体赋存于大义山花岗岩体中上石炭统壶天群白云岩接触带中,呈层状、似层状,局部为透镜状,分枝复合明显。矿石组分复杂,结构构造多样。富镁的碳酸盐岩是有利的成矿围岩;富含硼、氟的大义山花岗岩体是成矿母岩;广泛发育的节理裂隙是容矿构造。外围尚有一定的找矿远景。     

山地自然灾害（以泥石流为主）及其防治

我国是一个山地自然灾害严重的国家,尤其是泥石流、滑坡灾害。八十年代以来山地自然灾害频繁,泥石流、滑坡所造成经济损失超过30亿元。本文分析了灾害成因、分布特征以及山地自然灾害的预报和防治。     

中国岩浆硫化物矿床的主要成矿机制

深部熔离—贯入成矿机制,即指母岩浆侵入现存空间之前,在深部就发生了熔离作用和部分结晶作用,使母岩浆分离为不含矿岩浆、含矿岩浆、富矿岩浆、矿浆几部分,然后对现存空间一次或多次上侵贯入成矿。一般来说,经过深部熔离后的不含矿岩浆的体积,比含矿岩浆、富矿岩浆和矿浆的体积要大得多,在上侵过程中,不含矿岩浆大部分都侵入到不同的空间或喷溢出地表,形成岩群或岩流,剩余的岩浆、含矿岩浆、富矿岩浆和矿浆可以多次贯入同一空间成岩、成矿(金川),也可以分别贯入不同的空间成岩、成矿(红旗岭)。比照就地熔离的矿床,这种深部熔离—贯入矿床的岩体体积就小得多,含矿率和矿石品位也高得多,所以这种成矿作用导致形成小岩体,大矿床。     

Coronal Loops Above a Sunspot Region

By analysing the data of Yohkoh soft X-ray images, vector magnetograms and 2D spectral observations, coronal loops above a large sunspot on 16–19 May 1994 have been studied. It is shown that the loops follow generally the alignment of concentrated magnetic flux. The results indicate that the soft X-ray emission is low just above the sunspot, while some loops connecting regions with opposite magnetic polarities show strong soft X-ray emission. Especially, the part of the loops near the weaker magnetic field region tends to be brighter than the one near the stronger magnetic field. The temperature around the top of the loops is typically 3 × 10⁶ K, which is higher than that at the legs of the loops by a factor of 1.5–2.0. The density near the top of the loops is about 5 x 10⁹ cm^-3, which is higher than that of the leg parts of the loops. These loops represent probably the sites where strong magnetic flux and/or current are concentrated.     

硅岩研究的进展

回顾了国外硅岩的研究历史，概述了当今的研究现状和未来的发展趋势，并与我国同一领域的研究状况作了对比分析，提出了改变国内硅岩研究落后现状的几点建议。     

Potentials of community-based tourism in transformations towards green economies after the 2008 Wenchuan earthquake in West China

This study investigates the contrasting sceneries of community-based tourism after the 2008 Wenchuan earthquake and focuses on the potentials of tourism in transformations towards green economies. How are tourism and environment linked in a sustainable relationship? And how can potentials of community-based tourism be directed in transformations towards green economies? A qualitative research design is used to examine contrasting sceneries and specific green elements of community-based tourism in a Qiang people's fortress village in Mao County, Sichuan Province, West China and further discuss how tourism can be compatible with human wellbeing through demonstrating a commitment to sustainable development. The study argues that potential economic, social and environmental costs of tourism need to be considered when evaluating the loss of community benefits toward sustainability. The green elements suggest the potential of community-based tourism in transformations towards green economies, involving green agricultural, green building, and green energy, green governance, green service and green consumption. This study will contribute to the debate about the relationship between tourism and environment sustainability in the green economies, as well as the critique of what can be learned for community development from green tourism in mountainous regions after the inevitable natural disasters.     

Evolution of the Late Cretaceous Yongfeng-Chongren Basin in Jiangxi Province,southeast China: insights from sedimentary facies analysis and pebble counting

The Gan-Hang Belt in Southeast China is characterized by several igneous and siliciclastic basins associated with crustal extension during Late Mesozoic. The sedimentary evolution of the red basins is still poorly understood. In this study, sedimentary facies analysis and pebble counting were performed on outcrop sections of the Late Cretaceous Guifeng Group in the Yongfeng-Chongren Basin in central Jiangxi Province. Thirty-five conglomerate outcrops were chosen to measure pebble lithology, size, roundness, weathering degree and preferred orientation. Results show that gravels are mostly fine to coarse pebbles and comprise dominantly quartzites, metamorphic rocks, granitoids and sandstones. Rose diagrams based on imbricated pebbles indicate variable paleocurrent directions. Combining with typical sedimentary structures and vertical successions, we suggest that the Guifeng Group were deposited in alluvial fan, river and playa lake depositional systems. The proposed depositional model indicates that the Hekou Formation represents the start-up stage of the faulted basin, accompanied by sedimentation in alluvial fan and braided river environments. Then this basin turned into a stable expansion stage during the deposition of the Tangbian Formation. Except for minor coarse sediments at the basin margin, the other area is covered with fine-grained sediments of lake and river environments. The Lianhe Formation, however, is once again featured by conglomerates, suggesting a probable tectonic event. Therefore, the study region possibly suffered two tectonic events represented by the conglomerates of the Hekou and Lianhe formations in the context of the crustal extension in Southeast China.     

Matched field localization based on CS-MUSIC algorithm

The problem caused by shortness or excessiveness of snapshots and by coherent sources in underwater acoustic positioning is considered. A matched field localization algorithm based on CS-MUSIC (Compressive Sensing Multiple Signal Classification) is proposed based on the sparse mathematical model of the underwater positioning. The signal matrix is calculated through the SVD (Singular Value Decomposition) of the observation matrix. The observation matrix in the sparse mathematical model is replaced by the signal matrix, and a new concise sparse mathematical model is obtained, which means not only the scale of the localization problem but also the noise level is reduced; then the new sparse mathematical model is solved by the CS-MUSIC algorithm which is a combination of CS (Compressive Sensing) method and MUSIC (Multiple Signal Classification) method. The algorithm proposed in this paper can overcome effectively the difficulties caused by correlated sources and shortness of snapshots, and it can also reduce the time complexity and noise level of the localization problem by using the SVD of the observation matrix when the number of snapshots is large, which will be proved in this paper.     

西藏甲玛斑岩矿床系统地质、蚀变、矿化的三维地质模型

甲玛矿床位于西藏冈底斯成矿带东段,是公益性与商业性勘查结合取得的重要成果。目前已累计探明和控制铜资源量超过700万吨,共伴生钼、铅锌、金、银资源量均达到大型以上规模。本文在充分收集、整理甲玛矿床最新勘查资料、研究成果的基础上,运用MICROMINE软件三维建模及可视化技术,遵循点→线→面→体的构建原则,进行人机交互分析,构建了甲玛矿床地质、蚀变、矿体三维实体模型,并根据不同矿体品位分布变化的实际情况,对矿体模块模型进行克里格法或距离反比加权法品位插值,构建各种元素的矿化模型。并综合国内外对斑岩、矽卡岩矿床的研究新趋向对模型进行了地质解译,认为甲玛斑岩矿床是由斑岩钼铜矿体、矽卡岩铜多金属矿体、角岩铜钼矿体以及破碎带中独立金矿体构成的"四位一体"典型斑岩成矿系统产物,其中矽卡岩主要有接触带近端矽卡岩、层间构造中的远端矽卡岩以及受控于推滑覆构造产出的矽卡岩三种产出型式,由岩浆热液沿层间构造和推滑覆构造扩散交代大理岩和角岩形成;研究认为甲玛斑岩矿床具有典型的斑岩矿床蚀变系统,但蚀变分带有所差异,钾化带与青磐岩化带是在相对碱性条件下形成,而绢英岩化带与泥化带趋向于在相对酸性条件下形成。此外,大规模的角岩、矽卡岩对寻找深部斑岩矿体具有指示意义,甲玛斑岩矿体、角岩矿体仍具巨大的找矿潜力。因此,本研究构建的甲玛三维模型直观地展示了矿区地层、岩体、构造分布情况、赋矿层位、矿化品位分布规律以及蚀变分带特征,为甲玛矿床的成因、成矿规律总结、找矿勘查、矿山生成开发等综合研究提供重要的科学依据。