Adsorption of antimony(V) on kaolinite as a function of pH,ionic strength and humic acid

The present work investigated the adsorption and mobility (desorption) of Sb(V) on kaolinite using batch experiments. The adsorption of Sb(V) on kaolinite was studied as a function of contact time, pH, ionic strength, humic acid (HA), initial Sb(V) concentration and temperature. Kinetic studies suggest that the equilibrium is achieved within 24 h. The adsorption of Sb(V) was strongly affected by changes in I at low ionic strength and unaffected at high ionic strength. The adsorption is weakly dependent on the presence of humic acid, but is strongly dependent on pH. Within the range tested, the optimal pH for Sb(V) adsorption is 3.6, and close to 75% removal can be achieved. Desorption is dependent on the original suspension pH. The addition sequence of Sb(V)/HA do not influence the adsorption of Sb(V) on kaolinite. The adsorption data fit both the Freundlich and Langmuir isotherm. The thermodynamic parameters (ΔH ⁰, ΔS ⁰ and ΔG ⁰) were calculated from the temperature dependence, and the results suggest the endothermic and spontaneous nature of the process.     

Automated multi-scale classification of the terrain units of the Jiaxie Guyots and their mineral resource characteristics

Given the advances in satellite altimetry and multibeam bathymetry, benthic terrain classification based on digital bathymetric models (DBMs) has been widely used for the mapping of benthic topographies. For instance, cobalt-rich crusts (CRCs) are important mineral resources found on seamounts and guyots in the western Pacific Ocean. Thick, plate-like CRCs are known to form on the summit and slopes of seamounts at the 1 000–3 000 m depth, while the relationship between seamount topography and spatial distribution of CRCs remains unclear. The benthic terrain classification of seamounts can solve this problem, thereby, facilitating the rapid exploration of seamount CRCs. Our study used an EM122 multibeam echosounder to retrieve high-resolution bathymetry data in the CRCs contract license area of China, i.e., the Jiaxie Guyots in 2015 and 2016. Based on the DBM construted by bathymetirc data, broad- and fine-scale bathymetric position indices were utilized for quantitative classification of the terrain units of the Jiaxie Guyots on multiple scales. The classification revealed four first-order terrain units (e.g., flat, crest, slope, and depression) and eleven second-order terrain units (e.g., local crests, depressions on crests, gentle slopes, crests on slopes, and local depressions, etc.). Furthermore, the classification of the terrain and geological analysis indicated that the Weijia Guyot has a large flat summit, with local crests at the southern summit, whereas most of the guyot flanks were covered by gentle slopes. “Radial” mountain ridges have developed on the eastern side, while large-scale gravitational landslides have developed on the western and southern flanks. Additionally, landslide masses can be observed at the bottom of these slopes. The coverage of local crests on the seamount is ~1 000 km2, and the local crests on the peak and flanks of the guyots may be the areas where thick and continuous plate-like CRCs are likely to occur.     

空心块体水沙动力及泥沙淤积特性研究

空心块体具有良好的阻水和促淤功能,近年来被广泛用于生态修复工程。本文结合水槽试验及Flow-3D数值模拟,分析了开敞型和半封闭型空心块体的阻水效应和泥沙淤积特性。结果表明:空心块体的开孔率对内部水流流速、紊动强度起主导作用,开孔率较小的半开敞型空心块体减速、制紊效果更强;开敞型和半封闭型空心块体近底层悬沙浓度分别增大56%和75%,两者均有利于促进泥沙在块体内部淤积,近底层水流紊动越强,泥沙淤积形态差异越大;空心块体所营造的低流速、泥沙微淤、内外连通的水沙环境是大型底栖生物的生境需求,半封闭型空心块体内部的低紊动水流结构更有利于大型底栖生物的栖息、繁衍。     

Dynamic Response Analysis and Vibration Control for A Fixed-Bottom Offshore Wind Turbine Subjected to Multiple External Excitations

For the offshore wind turbines installed in earthquake areas, their operation is affected by seismic loads in addition to wind and wave loads. Therefore, it is necessary to study the dynamic responses and vibration control of the wind turbines. In previous studies, the structural responses of offshore wind turbines are usually investigated in the parked case, while the blade rotation effect is usually not considered. The evaluation on the structural responses may be inaccurate under this conditi...     

Spatial distribution of turbulent diapycnal mixing along the Mindanao current inferred from rapid-sampling Argo floats

The Mindanao Current (MC) bridges the North Pacific low-latitude western boundary current system region and the Indonesian Seas by supplying the North Pacific waters to the Indonesian Throughflow. Although the previous study speculated that the diapycnal mixing along the MC might be strong on the basis of the water mass analysis of the gridded climatologic dataset, the real spatial distribution of diapycnal mixing along the MC has remained to be clarified. We tackle this question here by applying a finescale parameterization to temperature and salinity profiles obtained using two rapid-sampling profiling Argo floats that drifted along the MC. The western boundary (WB) region close to the Mindanao Islands and the Sangihe Strait are the two mixing hotspots along the MC, with energy dissipation rate ε and diapycnal diffusivity K_ρ enhanced up to?~?10^–6 W kg^?1 and?~?10^–3 m² s^?1, respectively. Except for the above two mixing hotspots, the turbulent mixing along the MC is mostly weak, with ε and K_ρ to be 10^–11–10^–9 W kg^?1 and 10^–6–10^–5 m² s^?1, respectively. Strong mixing in the Sangihe Strait can be basically attributed to the existence of internal tides, whereas strong mixing in the WB region suggests the existence of internal lee waves. We also find that water mass transformation along the MC mainly occurs in the Sangihe Strait where the water masses are subjected to strong turbulent mixing during a long residence time.

     

Karyological observations of Ulva linza chromosomes

Journal of Oceanology and Limnology - Ulva linza is one of the species that causes green tides in the Yellow Sea, China. Due to the difficulties in chromosomal preparation, the large numbers of...     

山东省油页岩资源特征及开发利用前景

随着石油资源可用量的不断减少,页岩气、油页岩、油砂与稠油作为一种新能源,近年来备受人们的重视。山东省存在着丰富的油页岩资源。近年来笔者通过收集前人相关资料、野外地质填图、钻探编录、典型矿区考察、关键样品化验分析等手段对其进行了初步研究,初步认识了山东地区油页岩的资源特征及其形成环境,对未来山东地区油页岩矿的预测及潜力的评价具有一定的指导与借鉴作用。     

酸性流体作用下斜长石的稳定性

通过紫外分光光度计分析和扫描电镜观察,开展不同温度下酸性流体与斜长石相互作用实验得出：①在低温条件下斜长石较稳定,以溶解为主;在高温条件下,斜长石不稳定,以溶蚀、溶解为主;随反应温度升高,质量损失增大。②斜长石沿解理形成条带状溶孔,沿表面形成粒内溶孔。③在160℃和190℃条件下,形成新生高岭石沉淀,温度升高高岭石晶形变好,实验反应强度增大。④随反应温度升高, K＋、 SiO2和矿化度浓度升高。     

中国国家地质公园空间分布及其演化研究

2001年4月至2013年12月,国土资源部正式批准授牌了七批共240处国家地质公园。随着国家地质公园数量的增长,其在空间上呈现出一定的分布结构和演化规律。通过GIS空间分析发现:中国国家地质公园在空间上呈现显著凝聚分布;空间分布不均,具有空间集群分布的特征;分布的高密度地区为1个带状区域和4个块状区域。通过对不同阶段国家地质公园空间分布的分析,发现中国国家地质公园分布重心向北迁移、与区域中心城市的关系日趋紧密。地质构造条件、地质公园的旅游化以及拟建地政府部门认知水平是影响国家地质公园空间分布演化的重要因素。     

蒙古韭(Allium mongolicum)的分布和结实特性

为掌握蒙古韭(Allium mongolicum)在中国的分布现状和种群发展趋势,采用野外踏查和栽培实验相结合的方法,对其地理分布范围进行了界定;以结实量调查数据为基础,分析了不同分布区域蒙古韭的结实特点以及影响因素。结果显示:(1)蒙古韭在中国的分布区约在36°28′—46°14′N、88°39′—116°05′E之间,包括陕西、甘肃、宁夏、内蒙古、新疆、青海6省(区)。(2)由于生境差异,蒙古韭不同群落中物种组成差异很大,蒙古韭多为伴生种或偶见种,很少为优势种。(3)不同生境条件下蒙古韭的结实特性差异较大,多数地区没有结实或结实率很小,主要是因为干旱导致其生殖生长受阻,加之人为因素干扰,使蒙古韭不能正常完成其生活史。