Protonated Hydroxylamine-Assisted Iron Catalytic Activation of Persulfate for the Rapid Removal of Persistent Organics from Wastewater

This research aims at optimizing the effects of processing conditions, salts, natural organic materials, and water matrices quality on the effectiveness of the Fe(II)/K₂S₂O₈/hydroxylamine process in the degradation of pararosaniline. Assisting the Fe(II)/KPS (potassium persulfate) treatment with protonated hydroxylamine (H₃NOH⁺) increases the degradation rate of pararosaniline by more than 100%. Radical scavenger experiments show that the SO₄^●− radical dominates pararosaniline degradation in the Fe(II)/KPS system, whereas ^●OH is the dominant reactive species in the presence of H₃NOH⁺. The disparity in pararosaniline removal effectiveness upon the Fe(II)/KPS/H₃NOH⁺ and Fe(II)/KPS systems gets more significant with increasing reactants doses (i.e., H₃NOH⁺, H₂O₂, Fe(II)) and solution pH (2–7). Interestingly, H₃NOH⁺ increased the working pH to 6 instead of pH 4 for the Fe(II)/KPS process. Moreover, mineral anions such as Cl⁻, NO₃⁻, NO₂⁻, and SO₄⁻ (up to 10 × 10⁻³ m ) do not affect the efficiency of the Fe(II)/KPS/H₃NOH⁺ process. In contrast, acid humic decreases the performance of the process by ≈20%. In natural mineral water, treated wastewater, and river water samples, the Fe(II)/KPS/H₃NOH⁺ process maintains higher degradation performance (≈95%), whereas the process efficiency is greatly amortized in seawater. The efficiency of the Fe(II)/KPS process was drastically decreased in the various water matrices.     

洞庭湖湖滩矮埂保水生态灭螺水域育珠性能的试验研究

在湖滩矮埂保水生态灭螺水域中,进行育珠性能试验研究的结果表明,本水域特别对三角帆蚌具有优良的育珠性能;在冬、春两季湖滩落水干枯期间,矮围能保水50cm以上,活螺和螺卵淹死率达100％。     

Ba II lines as luminosity indicators: s-Cepheids and non-variable supergiants

Ba II line equivalent widths appear to be well correlated with the absolute magnitudes for yellow supergiants. Two Ba II lines 5853.6 Å and 6141.7 Å were applied for investigation of the possible relation between their equivalent widths and M_v for small-amplitude Cepheids and non-variable supergiants.     

On the possibility of radio emission from quasi-parallel and quasi-perpendicular propagation of shocks

A set of 21 solar type II radio bursts observed using Hiraiso radio spectrograph have been analysed to study the direction of propagation of coronal shocks. A simple analysis is carried out to find the approximate angle between the shock normal and magnetic field by solving the Rankine-Hugoniot MHD relation with assumption of Alfven speed and plasma beta. From this analysis, it is suggested that both quasi-parallel shocks (favourable) and quasi-perpendicular shocks can generate type II bursts depending upon the circumstances of the corona.     

关于立体集约生态用海的案例借鉴与制度探索

随着海洋经济的发展,海域资源的开发从单一立体开发逐渐向多层立体开发转变,且开发的力度和密度不断加大,海洋生态环境面临着巨大压力。为缓解当前用海紧张与生态环境保护之间的矛盾,提高海域利用综合效益,亟须探索符合生态化、集约化、立体化和现代化的用海模式。在此背景下,“立体集约生态用海”的概念应运而生。文章通过列举国内外立体集约生态用海的典型案例,总结归纳其用海特点,对其未来的应用进行讨论。立体集约生态用海的出现将带来海域管理制度体系一系列的调整与改革,对中国未来走出一条海洋空间高质量发展与高水平保护的协同道路具有重要意义。     

Diatom distribution in surface sediments from Chinese inshore waters and the relationship to modern environmental variables

Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil diatom species derived from modem surface sediments. The best-fit relationships between two multivariate datasets （diatom species and environmental variables） were identified using canonical correspondence analysis （CCA）, which is a constrained ordination technique. The absolute abundance of diatoms in the Chinese inshore waters ranged from 500 to 48 000 valves/g, and the average absolute abundance of all the 29 sites was l l 300 valves/g. 153 species and varieties of diatoms belonging to 42 genera in all were identified in the Chinese inshore waters. There were 28 dominant diatom species in all. According to the absolute abundance of the dominant species and the spatial distribution of the currents from the Chinese inshore waters, 12 diatom assemblages were distinguished from north to south, which reflected the different oceanographic conditions at the regional scale. Of the eight environmental variables considered, the most important environmental variable is winter sea surface salinity （WSS）, which was also the only environmental variable with statistical significance. Therefore, it may be used to establish a transfer functions for the Chinese inshore waters in future paleoclimate studies.     

A Kalman Filter Approach to Realize the Lowest Astronomical Tide Surface

In this paper , we present a novel Kalman filter approach to combine a hydrodynamic model-derived lowest astronomical tide (LAT) surface with tide gauge record-derived LAT values. In the approach, tidal water levels are assimilated into the model. As such, the combination is guided by the model physics. When validating the obtained “Kalman-filtered LAT realization” at all tide gauges, we obtained an overall root-mean-square (RMS) difference of 15.1 cm. At the tide gauges not used in the data assimilation, the RMS is 17.9 cm. We found that the assimilation reduces the overall RMS difference by ～ 31% and ～ 22%, respectively. In the Dutch North Sea and Wadden Sea, the RMS differences are 6.6 and 14.8 cm (all tide gauges), respectively. Furthermore, we address the problem of LAT realization in intertidal waters where LAT is not defined. We propose to replace LAT by pseudo-LAT, which we suggest to realize similarly as LAT except that all water level boundary conditions and assimilated tidal water levels have to be enlarged by a constant value that is removed afterward. Using this approach, we obtained a smooth reference surface for the Dutch Wadden Sea that fits LAT at the North Sea boundary within a few centimeters.     

Seawall case studies and failure analysis of sloped concrete walls under static and dynamic loads

Concrete seawalls are structures in coastal facilities for shore and slope protections. Owing to several advantages of sloped or inclined walls such as minimum soil disturbance and less required earthworks, they can be considered as an appropriate alternative to vertical cantilever retaining walls. The combination of slab and strip semideep foundation instead of heel–toe slab foundations increases their capability for stability, erosion control, and storm wave energy dissipation. In this paper, three case studies from seawalls in which failure has occurred are presented and discussed. Technical performance of sloped walls against different internal and external instability factors is investigated, and comparisons are made between vertical and sloped (inclined) walls with respect to geotechnical and structural aspects through parametric study. Analysis indicates that the sloped retaining walls perform better from technical, practical, and economical standpoints. It was found that for identical static and dynamic loads, including earthquake and wave loads, inclined walls provide relatively higher safety factors against different criteria and exhibit more stable and practical performance compared with commonly used walls in practice. The case studies in this paper illustrate causes of failure in each case and gives suggestions for improving instability prevention of walls against static and dynamic loads.     

基于卫星高度计资料提取浙江近海的潮汐信息

利用Topex/Poseidon(T/P)、Jason-1和Jason-2卫星24a的原始轨道及6a的变轨轨道高度计资料,对浙江近海区域内进行潮汐调和分析,得到8个主要分潮(Q_1、O_1、P_1、K_1、N_2、M_2、S_2和K_2)的调和常数.比较卫星轨道交叉点处潮汐调和常数结果显示,8个分潮总体综合误差在原始轨道,变轨轨道及原始轨道与变轨轨道交叉点处的和方根RSS值分别为3.16、7.02、5.54cm;用卫星高度计资料及31个近岸验潮站得到的潮汐分布与21个验潮站资料结果进行比较,M_2、S_2、N_2、K_1和O_1主要分潮的多点向量均方根偏差分别为4.32、3.64、1.97、2.61、1.83 cm;本研究结果与前人数值模拟结果比较显示M2、S2分潮在对比点处的多点向量均方根偏差在11、8 cm左右,最后给出了浙江近岸及近海区域更为精确的5个主要分潮(M_2、S_2、N_2、K_1和O_1)的同潮图.