铌钽矿床类型、特征与研究进展

铌、钽矿产分布较广。内生铌钽矿成矿类型主要为伟晶岩型、稀有金属花岗岩型、碳酸岩型和碱性岩型;外生矿床多为内生矿床经过风化和沉积等外生作用发生二次富集的风化壳型和残坡积、冲积砂矿型。从成矿时代来看,伟晶岩型矿床成矿时代跨度较大,从3.08 Ga到0.19 Ga;碱性岩型矿床主要成矿期分别在2.25~1.35 Ga和0.75~0.19 Ga;碳酸岩型矿床成矿期主要分布在0.75~0.6 Ga和0.4~0.35 Ga;花岗岩型主要分布在0.75~0.19 Ga的中晚期。碳酸岩型铌矿床和伟晶岩型钽矿床是目前勘探的主要目标。     

Risk analysis of tripping accidents of power grid caused by typical natural hazards based on FTA-BN model

As the scale of the power grid becomes larger, the requirements for transmission reliability are getting higher. Due to the large geographical span and the harsh environment of the power transmission line, it has become the most severely affected equipment of the power grid by natural factors. However, the quantitative assessment of transmission line tripping accidents caused by multiple natural hazards has rarely been investigated. In this study, a risk analysis method to probabilistically analyze the tripping accidents of power transmission lines caused by wildfire, lightning, strong wind and ice storm was proposed. The analysis process consists of comprehensively identifying the risk of tripping accidents based on fault tree analysis and dynamically performing the predictive analysis of tripping accident evolution process in transmission line from causes to consequences based on Bayesian network. Critical risk evolution paths corresponding to four natural hazards are determined through a 72-node BN. The source risks of the four critical risk evolution paths are artificial ignition source from the wildfire path, aging from the lightning path, thoughtless of surrounding environment from the strong wind path and wind effect from the ice storm path. The countermeasures of tripping accidents are derived through the source risks and synergy between risks in three scenario analysis. This study is expected to examine the key challenges of risk management in power grid tripping accidents, which provides technical supports for accident preventing, handling and recovering of tripping accidents of the power transmission line according to “scenario–response”-based hazard response strategy.

     

吕梁山——华北克拉通中部中生代基底卷入褶皱系统

位于华北克拉通中部的吕梁山的形成代表了华北克拉通在晚侏罗世-早白垩世的挤压变形事件,为了更好地理解该期变形的样式、时代、机制和背景,对吕梁山地区开展了详细的野外调查,同时搜集了前人的低温热年代学工作.结果表明,吕梁山是一个中生代期间形成的发育有典型单褶（monocline）构造的陆内基底卷入型大型褶皱系统.早前寒武纪造山作用在基底中形成早期面理（片麻理、片理、劈理以及节理）,这些面理在后期近东西向挤压作用下再次活动形成了基底断裂,并导致了上覆沉积地层褶皱变形,吕梁山不同地区褶皱的古应力场方向总体为SE（122°）~NW（302°）.吕梁山单褶构造的构造样式、形成机制以及分布,与北美西部的Laramide造山带中的厚皮构造相似,形成的构造环境也类似.吕梁山褶皱及其单褶构造总体形成于晚侏罗世期间古太平洋板块向西低角度俯冲的环境中,该期俯冲也导致了华北克拉通同期陆内挤压变形.      

Prediction of landslide displacement with step-like behavior based on multialgorithm optimization and a support vector regression model

Landslide prediction is important for mitigating geohazards but is very challenging. In landslide evolution, displacement depends on the local geological conditions and variations in the controlling factors. Such factors have led to the “step-like” deformation of landslides in the Three Gorges Reservoir area of China. Based on displacement monitoring data and the deformation characteristics of the Baishuihe Landslide, an additive time series model was established for landslide displacement prediction. In the model, cumulative displacement was divided into three parts: trend, periodic, and random terms. These terms reflect internal factors (geological environmental, gravity, etc.), external factors (rainfall, reservoir water level, etc.), and random factors (uncertainties). After statistically analyzing the displacement data, a cubic polynomial model was proposed to predict the trend term of displacement. Then, multiple algorithms were used to determine the optimal support vector regression (SVR) model and train and predict the periodic term. The results showed that the landslide displacement values predicted based on data time series and the genetic algorithm (GA-SVR) model are better than those based on grid search (GS-SVR) and particle swarm optimization (PSO-SVR) models. Finally, the random term was accurately predicted by GA-SVR. Therefore, the coupled model based on temporal data series and GA-SVR can be used to predict landslide displacement. Additionally, the GA-SVR model has broad application potential in the prediction of landslide displacement with “step-like” behavior.     

Bibliometric Analysis of Sustainable Livelihoods Research in China

The Sustainable Livelihoods (SLs) is a significant subject and concept within the sustainable development research and it also has the potential to deal with the fundamental challenge in terms of inequalities between inter-generation and intra-generation, now and in the future. This paper adopted bibliometrics to conduct the quantitative analysis of the development, hot topics, and collaboration network in terms of SLs researches. Moreover, the analyzed parameters included publication output, distribution of publications by authors and organizations, subject classification of publication, etc. Some 809 papers were analyzed on various aspects of publication, and the results show that publication output has increased promptly over the past two decades; however, the cooperation network among different organizations and authors on the topic of SLs has not been closely linked. The hot topics of SLs involve three categories, which are ①theoretical research in terms of sustainable livelihoods; ②the research on livelihood strategy (problem-orientated); ③the research of ecological vulnerability. It is important for Chinese scholars to continue the future SLs researches in accordance with the strategy of target poverty alleviation and rural revitalization. Additionally, it is also vital to broaden the theoretical horizons by transitioning from the research on agricultural economy to the exploration of relationship of SLs-ecological environment, SLs-biodiversity, SLs-climate change and adaptation, SLs-human capital development, etc.; to strengthen the academic cooperation and exchanges; to innovate research approach; to improve both quantity and quality of research output for the purpose of providing long-term and scientific decision for the decision makers.     

Annual variations of biogenic element contents of manila clam (Ruditapes philippinarum) bottom-cultivated in Jiaozhou Bay,China

Manila clam(Ruditapes philippinarum) was monthly sampled from its benthic aquaculture area in Jiaozhou Bay from May 2009 to June 2010. The annual variations of major elemental composition, organic content, fatness and element ratio of Manila clam were examined. The element removal effect of clam farming in Jiaozhou Bay was analyzed based on natural mortality and clam harvest. The results indicated that the variation trend of carbon content in shell(Cshell) was similar to that in clam(Cclam). Such a variation was higher in summer and autumn than in other seasons, which ranged from 9.10 ± 0.13 to 10.38 ± 0.09 mmol g-1 and from 11.28 ± 0.29 to 12.36 ± 0.06 mmol g-1, respectively. Carbon content of flesh(Cflesh) showed an opposite variation trend to that of shell in most months, varying from 29.42 ± 0.05 to 33.64 ± 0.62 mmol g-1. Nitrogen content of shell(Nshell) and flesh(Nflesh) changed seasonally, which was relatively low in spring and summer. Nshell and Nflesh varied from 0.07 ± 0.009 to 0.14 ± 0.009 mmol g-1 and from 5.46 ± 0.12 to 7.39 ± 0.43 mmol g-1, respectively. Total nitrogen content of clam ranged from 0.50 ± 0.003 to 0.76 ± 0.10 mmol g-1 with a falling tend except for a high value in March 2010. Phosphorus content of clam(Nclam) fluctuated largely, while phosphorus content of shell(Pshell) was less varied than that of flesh(Pflesh). Pshell varied from 0.006 ± 0.001 to 0.016 ± 0.001 mmol g-1; while Pflesh fluctuated between 0.058 ± 0.017 and 0.293 ± 0.029 mmol g-1. Pclam ranged from 0.015 ± 0.002 to 0.041 ± 0.006 mmol g-1. Carbon and nitrogen content were slightly affected by shell length, width or height. Elemental contents were closely related to the reproduction cycle. The removal amounts of carbon, nitrogen and phosphorus from clam harvest and natural death in Jiaozhou Bay were 2.92×104 t, 1420 t and 145 t, respectively. The nutrient removal may aid to reduce the concentrations of nitrogen and phosphorus, the main causes of eutrophication, and to maintain the ecosystem health of Jiaozhou Bay.     

岷江上游农民收入异质性及其地理影响因子

引入生态学中的异质性概念,选择川西高原岷江上游作为研究区,采用变异系数、Theil指数和探索式空间数据分析方法,以乡镇作为研究单元,分析农民收入异质性及其空间分布特征。研究发现:岷江上游农民收入在2005—2010年呈现收敛趋势,县域内部乡镇间的农民收入差异是构成岷江上游收入差距的主要因素;农民人均纯收入在空间分布上存在明显的高值和低值区,高值区主要集中在南北两侧,低值区集中在中部地区,收入水平相似的乡镇呈现显著空间正相关分布格局。分析表明,地理位置、旅游资源赋存差异、交通通达条件以及2008年的汶川大地震对岷江上游各乡镇的农民收入具有显著影响,是造成农民收入差异的主要原因之一。此外,禁止开发区所在的乡镇多为高收入乡镇,说明环境保护与农民增收之间可以相互促进,由此可以认为,充分利用政策和资源优势是欠开发山区提高农民收入的有效途径。     

Urban expanding pattern and soil organic, inorganic carbon distribution in Shanghai, China

Soil carbon stock changes induced by land-use change play an essential role in the global greenhouse effect and carbon circulation. This paper studies the urban expanding patterns and spatial characteristics of soil organic carbon (SOC) and soil inorganic carbon (SIC) distribution and evolution during the urbanization process of Shanghai, China, based on the data of the regional geochemical survey. Urbanization process in Shanghai, China, has been quickening greatly since the 1980s. The urban area expanded from 193.08 km² in 1980 to 1,570.52 km² in 2005, or up from 3.05 to 24.77% in the past 25 years, and the urban expansion circled the central city region according to the RS images acquired in the periods of 1980, 2000 and 2005. The urban topsoil is slightly enriched with SOC and SIC, which shows obvious spatial variability. By comparison of SOC and SIC distribution in the central urban area, urbanized area during 1980–2000, 2000–2005 and the suburban area, the SOC obviously accumulates in the central urban area, while SOC density in the urbanized area decreases; similarly, the SIC obviously accumulates in central urban area; furthermore, the SIC density increases with urban land use duration extending and urban ecosystem evolving. This paper provides the characteristics of SOC and SIC distribution and evolution during the course of urbanization, which may be useful for assessing the impact of land use and urban development on SOC and SIC pools in urban ecosystem.     

嘉兴市城市地质环境承载力评价体系的构建与应用

以长江三角洲南翼的嘉兴市为例,运用层次分析法对城市地质环境因子进行筛选,通过选取评价指标、确定各评价因子的权重值和各类地质环境因子的单要素分值,建立多要素的地质环境承载力评价体系,借助GIS方法开展了基于K-Means聚类的地质环境承载力强度综合评价.结果表明:(1)按地质环境承载力强度综合评价,将嘉兴市宜建设用地分为...