富钴结壳分布的分形特征

利用我国在西太平洋国际海底两个海山获得的富钴结壳资料进行分形研究后发现，富钴结壳的分布具有变维分形分布的特点，结壳丰度呈二阶累计和分形分布，结壳厚度呈多阶不定累计和分形分布，通过计算得到了它们各自的分维数，进而对两个海山的结壳资源进行了初步评价。     

Estimating the underwater light field from remote sensing of ocean color

We present a new approach that incorporates two models to estimate the underwater light field from remote sensing of ocean color. The first employs a series of analytical, semi-analytical, and empirical algorithms to retrieve the spectrum of inherent optical properties (IOPs), including the absorption and the backscatter coefficients, from the spectrum of remote sensing reflectance. The second model computes the profile of photosynthetically available radiation E _0,PAR (z) for a vertically homogeneous water column using the information of the retrieved IOPs and the ambient optical environment. This computation is based on an improved look-up table technology that possesses high accuracy, comparable with the full solution of the radiative transfer equation, and meets the computational requirement of remote sensing application. This new approach was validated by in situ measurements and an extensive model-to-model comparison with a wide range of IOPs. We successfully mapped the compensation depth by applying this new approach to process the SeaWiFS imagery. This research suggests that E _0,PAR (z) can be obtained routinely from ocean-color data and may have significant implications for the estimation of global heat and carbon budget.     

Temporal and spatial variations in the biogeochemical cycling of cobalt in two urban estuaries: Hudson River Estuary and San Francisco Bay

Despite the fact that Co is an essential trace element for the growth of marine phytoplankton, there is very limited information on the cycling of this trace metal in the marine environment. We report here the distribution of dissolved (<0.4 μm) and particulate (>0.4 μm) Co in surface waters of the Hudson River Estuary (HRE) and San Francisco Bay (SFB). Samples were collected during several cruises (from 1990 to 1995 in SFB and from 1995 to 1997 in the HRE) along the whole salinity gradient. Dissolved Co concentrations (mean±1 standard deviation) were nearly identical in magnitude in both estuaries despite differences in climate, hydrography, riverine-flow conditions and land-usage (HRE=0.91±0.61 nM; SFB=1.12±0.69 nM). Dissolved Co levels in each system showed non-conservative distributions when plotted as a function of salinity, with increasing concentrations downstream from the riverine end-members. Desorption from suspended particulates and sewage inputs, therefore, seems to be the major processes responsible for the non-conservative behavior of Co observed. Mass balance estimates also indicated that most of the estuarine Co is exported out of both estuaries, indicating that they and other estuarine systems are principal sources of this essential trace element to the open ocean.     

Bioenhancement of cadmium transfer along a multi-level food chain

Previous studies have shown that metal partitioned to a subcellular compartment containing trophically available metal (TAM) is readily available to predators and may be enhanced by increased binding of metal to heat-stable proteins (HSP - e.g., metallothioneins). The aim of the current investigation was to determine the influence of TAM on the trophic transfer of Cd along an experimental, three-level food chain: Artemia franciscana (brine shrimp)-->Palaemonetes pugio (grass shrimp)-->Fundulus heteroclitus (mummichog). P. pugio were fed for 7 days on A. franciscana exposed to Cd in solution (including (109)Cd as radiotracer) and subjected to subcellular fractionation or fed to F. heteroclitus. An HSP-driven increase in the percentage of Cd associated with TAM (TAM-Cd%) in A. franciscana exposed to 1 muM Cd resulted in a bioenhancement (i.e., a greater than linear increase with respect to A. franciscana exposure) of Cd trophic transfer to P. pugio. Increased dietary Cd exposure did not affect TAM-Cd% in P. pugio nor trophic transfer to F. heteroclitus.     

我国钴矿矿产资源及其成矿作用

钴广泛应用于军事、钢铁、电器、机械等方面，它具有亲铁亲硫的双重性，在各类岩浆岩中的分布不均匀，由超基性岩向酸性岩，钴的含量迅速降低。我国钻矿资源呈现富矿少、贫矿多的特点，并且铬矿主要分布在甘肃、青海、新疆、吉林、陕西、云南、四川等地。按照矿床形成的成矿环境、矿床岩石组合，矿床类型划分为：与镁铁质-超镁铁质岩有关的硫化物钻矿、与海相火山喷发有关的钻多金属矿、与斑岩有关的铜钻矿、与砂岩有关的钻矿、与中酸性侵入岩有关的矽卡岩铁钻矿、与风化作用有关的钴矿等六类。     

吉林省土壤中有效锰、铜、钼和锌含量的时空变化

选择吉林省的五个大豆种植区(敦化、桦甸、榆树、农安、白城)、四个水稻种植区(白城、九台、延吉、梅河口)及3个草场分布区(镇赉、洮南、大安)，对其土壤中有效锰、铜、钼和锌的含量在过去20年的变化作了比较和分析。经研究表明：吉林省土壤中有效锰和有效铜含量较20年前有所增高，有效钼含量总体呈降低趋势，中部部分地区和东部地区土壤有效锌含量降低，其余地区含量增高。空间分布东部高于中西部。     

洛阳市水资源可利用量研究

以洛阳市为对象，对区域水资源的可利用量进行了研究。区域水资源量包括地表水实际可利用量和地下水实际可利用量。将地表径流中基流部分按比例划出，与河道汛期弃水量加在一起作为河道的生态需水量，从地表水资源量中扣除生态需水量后可得地表水的实际可利用量。将难以利用的地下水量从地下水资源量中扣除后可得地下水实际可利用量。     

渭河河谷甘肃段水资源承载能力分析

本文在论述渭河河谷甘肃段水资源分布特点及现状利用量和承载量的基础上,分析了水资源的承栽能力,认为区内水资源最佳承载量是355万人,355亿元工业产值和248.5万亩的可灌高效农田.据此提出了城市发展规模的大小,目的是供地方政府规划参考.     

Reevaluating suitability estimates based on dynamics of cropland expansion in the Brazilian Amazon

Agricultural suitability maps are a key input for land use zoning and projections of cropland expansion. Suitability assessments typically consider edaphic conditions, climate, crop characteristics, and sometimes incorporate accessibility to transportation and market infrastructure. However, correct weighting among these disparate factors is challenging, given rapid development of new crop varieties, irrigation, and road networks, as well as changing global demand for agricultural commodities. Here, we compared three independent assessments of cropland suitability to spatial and temporal dynamics of agricultural expansion in the Brazilian state of Mato Grosso during 2001–2012. We found that areas of recent cropland expansion identified using satellite data were generally designated as low to moderate suitability for rainfed crop production. Our analysis highlighted the abrupt nature of suitability boundaries, rather than smooth gradients of agricultural potential, with little additional cropland expansion beyond the extent of the flattest areas (0–2% slope). Satellite-based estimates of the interannual variability in the use of existing crop areas also provided an alternate means to assess suitability. On average, cropland areas in the Cerrado biome had higher utilization (84%) than croplands in the Amazon region of northern Mato Grosso (74%). Areas of more recent expansion had lower utilization than croplands established before 2002, providing empirical evidence for lower suitability or alternative management strategies (e.g., pasture–soya rotations) for lands undergoing more recent land use transitions. This unplanted reserve constitutes a large area of potentially available cropland (PAC) without further expansion, within the management limits imposed for pest management and fallow cycles. Using two key constraints on future cropland expansion, slope and restrictions on further deforestation of Amazon or Cerrado vegetation, we found little available flat land for further legal expansion of crop production in Mato Grosso. Dynamics of cropland expansion from more than a decade of satellite observations indicated narrow ranges of suitability criteria, restricting PAC under current policy conditions, and emphasizing the advantages of field-scale information to assess suitability and utilization.     

东昆仑地区驼路沟钴(金)矿床硅质钠长岩锆石U-Pb定年及Hf同位素特征研究

东昆仑驼路沟钴(金)矿床是青海省发现的首个独立大型喷流沉积型矿床,说明容矿围岩为一套海相火山-沉积岩系。本文在野外调查的基础上,对该矿区短沟矿段YM1坑口的硅质钠长岩进行岩石学、LA-ICP-MS锆石UPb年代学及Hf同位素分析。结果表明,区内钠长岩的形成年龄为(457.3±4.6)Ma,佐证了该矿区喷流作用成岩与成矿的同时性;另外获得9.20~1.10 Ga和2.40~2.50 Ga的2个年龄集中区,说明了研究区基底演化和源区物质的复杂性。Hf同位素显示为两个集中区,其中年龄峰值422~459 Ma的锆石获得εHf(t)值为-0.61~12.72,表明锆石母岩主要为新生的地壳物质,指示硅质钠长岩的形成与海底火山喷发作用密切相关;另外0.85~1.10 Ga的锆石εHf(t)值为-15.09~-0.07,其锆石母岩中主要为再造的古老地壳,表明该区基底源区物质的复杂性。通过区域对比分析,认为驼路沟矿区含矿火山-沉积岩系形成时代与钠长岩年龄、成矿年龄非常接近,喷流沉积时代应为晚奥陶世。