四川省盐源县泸沽湖地区地热开发的可行性研究

在对泸沽湖地质构造、水文地质特征、地热异常、已有温泉分布及成因分析基础上,重点研究了寻找地热的可行性,初步认为泸沽湖具有较完善的热源、热储和盖层条件,通过钻探有可能探获地下热矿水。因此,研究区有进一步深入勘查的价值和意义。     

山地人工林择伐技术研究进展

为促进人工林可持续经营,归纳国内外山地人工林择伐技术的研究现状,并针对其存在的问题,提出适合我国山地人工林择伐作业技术的对策,展望我国今后山地人工林择伐研究的前景。     

山地杉木人工林不同强度择伐后生长动态仿真

基于山地杉木人工林择伐长期固定样地实测数据,构建了单木胸径生长模型,以及树高、枝下高、冠幅与胸径的关系模型,结合Onyx TREE和3Ds MAX技术,实现了不同强度择伐下,不同时期的林分生长动态仿真,可直观、生动地观察杉木的生长状态,对山地杉木人工林的科学经营决策具有实用价值.     

变异函数中指数,高斯模型的拟合

本文探讨了用积分变换拟合指数模型和高斯模型，对实现过程的关键细节进行了深入的分析。最后用实例证明了该方法的可行性。     

东海盆地的变质岩

东海盆地处于欧亚板块和太平洋板块的交接部位,是全球岩石圈结构和动力学机制研究中涉及众多基础问题的关键地区。它的生成及发展对深化中国东南陆缘地区地壳构造演化的认识,且为能源勘查,研究海平面变化,预测自然灾害,保护环境及国土主权均有重大意义。就其构造机制及性质说法不一,有待商榷。该盆地内已钻井30余口,随改革开放以来,局部凹陷对外公开招标,已施工10余口井,涉及变质岩的仅2口井。变质岩为黑云斜长片麻岩类,原岩恢复为变质火成岩(中性侵入岩,包括石英闪长岩及其相关的浅成岩),属吕梁期,原岩经多期变质或混合岩化作用所致,是中国大陆的自然延伸部位。     

Molecular genetic diversity of bacteria in the bottom section of arctic sea ice from the Canada Basin

PCR-DGGE approach was used to analyze bacterial diversity in the bottom section of seven arctic sea ice samples colleted from the Canada Basin. Thirty-two 16S rDNA sequences were obtained from prominent DGGE bands. The closest relatives of these sequences are found to be those of cultivated or uncultured bacteria from antarctic or arctic sea ice. Phylogenetic analysis clustered these sequences or phylotypes within α- proteobacteria, γ-proteobacteria and CFB (cytophaga-flexibacter-bacteroides) group. Sequences belonging to γ-proteobacteria were dominant and members of the CFB group were highly abundant. It was suggested that the CFB group was the representative of the bottom section of sea ice samples.     

Preliminary genome analysis bacterium Pseudoalteromonas potential applications of psychrotolerant marine sp. BSw20308 reveals its

The genus Pseudoalteromonas is ubiquitous in the marine environment and can synthesize a wide range of extracellular compounds. Psychrotolerant Pseudoalteromonas sp. BSw20308 was isolated from the Chukchi Sea, a marginal sea of the Arctic Ocean. It produces a number of extracellular enzymes that can degrade polysaccharides and proteins. The BSw20308 genome was sequenced to 38.1-fold coverage, and the sequences were assembled into 146 contigs （〉~500 bp）. In total, 4 172 open reading frames （ORFs） with an average gene length of 987 bp were detected. At least 86 ORFs were predicted by sequence analysis to encode a variety of catalytic modules involved in the degradation of polysaccharides, proteins, and lipids. In addition, 36 ORFs were predicted to encode catalytic modules involved in the degradation of organic pollutants and halogenated compounds, and in the production of bioactive compounds. The draft genome sequence of BSw20308 provides new information about the ecological function and adaptation of the genus Pseudoalteromonas in Arctic marine environments, and also indicates its potential applica- tions in the biotechnology industries （e.g., enzymology, and pollutant degradation）.     

Application of fuzzy clustering method to determining sub-fault planes of earthquake from aftershocks sequence

Earthquake rupture process generally involves several faults activities instead of a single fault. A new method using both fuzzy clustering and principal component analysis makes it possible to reconstruct three dimensional structure of involved faults in earthquake if the aftershocks around the active fault planes distribute uniformly. When seismic events are given, the optimal faults structures can be determined by our new method. Each of sub-fault planes is fully characterized by its central location, length, width, strike and dip. The resolution determines the number of fault segments needed to describe the earthquake catalog. The higher the resolution, the finer the structure of the reconstructed fault segments. The new method successfully reconstructs the fault segments using synthetic earthquake catalogs. By taking the 28 June 1992 Landers earthquake occured in southern California as an example, the reconstructed fault segments are consistent with the faults already known on geological maps or blind faults that appeared quite frequently in longer-term catalogs.     

Site response analysis with two‐dimensional numerical discontinuous deformation analysis method

The capability of the numerical discontinuous deformation analysis (DDA) method to perform site response analysis is tested. We begin with modeling one‐dimensional shear wave propagation through a stack of horizontal layers and compare the obtained resonance frequency and amplification with results obtained with SHAKE. We use the algorithmic damping in DDA to condition the damping ratio in DDA by changing the time step size and use the same damping ratio in SHAKE to enable meaningful comparisons. We obtain a good agreement between DDA and SHAKE, even though DDA is used with first order approximation and with simply deformable blocks, proving that the original DDA formulation is suitable for modeling one‐dimensional wave propagation problems. The ability of DDA to simulate wave propagation through structures is tested by comparing the resonance frequency obtained for a multidrum column when modeling it with DDA and testing it in the field using geophysical site response survey. When the numerical control parameters are properly selected, we obtain a reasonable agreement between DDA and the site response experiment in the field. We find that the choice of the contact spring stiffness, or the numerical penalty parameter, is directly related to the obtained resonance frequency in DDA. The best agreement with the field experiment is obtained with a relatively soft contact spring stiffness of k = (1/25)(E × L) where E and L are the Young's modulus and mean diameter of the drums in the tested column. Copyright © 2013 John Wiley & Sons, Ltd.     

近30年来珠江河口岸线演变时空特征及效应

基于珠江河口近30年来实测水下地形、航测地形以及海图、卫星影像等大量资料,建立多时段、大范围河口岸线图谱,分区研究河口岸线向水域延伸的速度及速率,以定量表征珠江河口岸线演变时空特征,并简要分析岸线演变对河口地貌轮廓、水沙流路、滩涂湿地等产生的效应。结果显示:20世纪70年代至21世纪初,磨刀门岸线延伸速度最大,年均向东南延伸226m;其次为伶仃洋西岸大角山至珠海金星铜鼓角段,年均向东延伸190m;黄茅海西岸崖门出口至烽火角段年均延伸45m,是珠江河口中延伸速度最小的区域。河口岸线延伸对区域泄洪纳潮及水环境造成较大程度的影响。