Assessing seawater quality with a variable fuzzy recognition model     

柯丽娜  王权明  盖美  周惠成 《中国海洋湖沼学报》2014,32(3):645-655

With the rapid development of the marine economy industry, human exploitation of marine resources is increasing, which is contributing to the growing trend of eutrophication and frequent occurrence of red tide. Accordingly, investigations of seawater quality have attracted a great deal of attention. This study was conducted to construct a seawater environmental quality assessment model based on the variable fuzzy recognition model. The uncertainty and ambiguity of the seawater quality assessment were then considered, combining the monitoring values of evaluation indicators with the standard values of seawater quality. Laizhou Bay was subsequently selected for a case study. In this study, the correct variable model for different parameters was obtained according to the linear and nonlinear features of evaluation objects. Application of the variable fuzzy recognition model for Laizhou Bay, water quality evaluation and comparison with performance obtained using other approaches revealed that the generated model is more reliable than traditional methods, can more reasonably determine the water quality of various samples, and is more suitable for evaluation of a multi-index, multi-level, nonlinear marine environment system; accordingly, the generated model will be an effective tool for seawater quality evaluation.  相似文献   

Marine bacterium strain screening and pyrethroid insecticide-degrading efficiency analysis     

孙爱丽  刘菁华  史西志  李德祥  陈炯  唐道军 《中国海洋湖沼学报》2014,32(5):1029-1035

A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin(CYP) and deltamethrin(DEL), was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28°C. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments.  相似文献   

基于指标规范值的海水水质评价的SVR模型   总被引：1，自引：0，他引：1  

梁晓龙  李祚泳  汪嘉杨 《成都信息工程学院学报》2014,(2):208-212

为了建立具有普适通用的海水水质评价的支持向量机模型,在设置各指标参照值和指标规范变换式,并对指标进行规范变换的基础上,应用免疫进化优化算法,建立基于指标规范值的海水水质评价的回归支持向量机模型。将优化好的模型用于珠江口海水水质的评价,其评价结果与BP神经网络的评价结果基本一致,从而表明基于指标规范值的支持向量机模型用于海水水质评价是可行的,且该模型较传统的支持向量机评价模型具有较好的普适性和通用性。  相似文献   

Research on the critical conditions for clay particle release during saline aquifer freshening process     

Xilai Zheng  Ran Chen 《中国海洋大学学报(英文版)》2014,13(4):628-636

Water sensitivity phenomenon occurs during saline aquifer freshening process in seawater intrusion area, and clay particles released in the phenomenon can damage the infiltration capacity of the aquifer. In order to find out the factors and mechanisms for clay particle release, laboratory column infiltration experiments simulating saline aquifer freshening process were designed to measure the critical conditions(critical flow velocity, critical salt concentration and critical ionic strength) and force analysis for clay particle according to DLVO electric double layer theory was employed to illustrate the mechanisms for particle release. The research results showed that critical flow velocity for clay particle release is influenced by salt concentration of injecting solution. When salt concentration of injecting solution is very high, clay particles are not released, indicating that there does not exist a critical flow velocity in this situation. As salt concentration of injecting solution decreases, particles start to be released. The critical salt concentration for clay particle release is 0.052 mol L-1 in our work, which was determined by a constant-flux experiment for stepwise displacement of high concentration Na Cl solution. The critical ionic strength for clay particle release decreases as Ca2+ molar content percentage of the mixed solution of Na Cl and Ca Cl2 increases following the first-order exponential decay equation y = 0.0391e-0.266 x + 0.0015.  相似文献   

Molecularly imprinted polymers for selective extraction of crystal violet from natural seawater coupled with high-performance liquid chromatographic determination     

LIAN Ziru  and WANG Jiangtao 《中国海洋大学学报(英文版)》2014,13(2):236-242

Molecularly imprinted polymers(MIPs) were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Systematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high affinity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction(MISPE) method followed by high-performance liquid chromatography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 μg L-1(R2 0.99). Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation(n=3) being in the range of 2.89%-5.96%.  相似文献   

Calcium,Na, K and Mg Concentrations in Seawater by Inductively Coupled Plasma‐Atomic Emission Spectrometry: Applications to IAPSO Seawater Reference Material,Hydrothermal Fluids and Synthetic Seawater Solutions     

Philippe Besson  Jefferson Degboe  Benjamin Berge  Valérie Chavagnac  Sébastien Fabre  Gilles Berger 《Geostandards and Geoanalytical Research》2014,38(3):355-362

We report a measurement procedure to determine simultaneously the major cation concentrations (Na, Ca, K and Mg) of seawater‐derived solutions by inductively coupled plasma‐atomic emission spectrometry. The best results were obtained when the IAPSO (‘standard’) seawater reference material was diluted by thirty times with Milli‐Q^® water. We obtained an average reference value r_K (the ratio of the mass fraction of potassium to that of chlorine, i.e., (g kg^?1)/(g kg^?1)) for IAPSO seawater of 0.0205 ± 0.0006 (2.9% RSD), not significantly different from 0.0206 ± 0.0005 (2.4% RSD) for seawater composition reported in the literature. The measured Na, Ca and Mg concentrations correspond to r_Na, r_Ca and r_Mg values of 0.5406 ± 0.0026 (0.5% RSD), 0.02192 ± 0.00048 (2.2% RSD) and 0.06830 ± 0.00047 (0.7% RSD), respectively, in line with previous values measured by wet‐chemistry and atomic absorption spectrophotometry or wet‐chemical titration. Our measurement procedure was used successfully on synthetic seawater solutions and high‐temperature hydrothermal fluids.  相似文献   

海水养殖池海洋原甲藻水华前后水化条件的变化   总被引：2，自引：0，他引：2  

徐永健  李德尚  王伟良  刘剑昭 《海洋湖沼通报》2000,(1):41-46

本文研究了海水养殖池塘实验围隔中海洋原甲藻水华暴发前、后水化条件的变化,得出了如下结果：海洋原甲藻水华一般多发生在连续晴朗的天气,而常在阴雨天气崩溃;从水化条件方面来说,该藻水华也常发生于ＮＯ３－Ｎ浓度以及Ｎ／Ｐ比较大时。在扁灌等绿藻类与海洋原甲藻交替成为优势种时,可以利用水体中Ｃh１。总量及Ｃｈ１．ｂ、Ｃｈ１．ｃ之间 的波动情况来反映该水华的发生与崩溃。  相似文献   

夏季长江口南北支溶解有机质的比较     

郭丽霞  王亚松  乔德会  韩露露  郁建春  许云平 《海洋科学》2022,46(11):67-82

本文以2021年5月长江口南北支采集的表层水为研究对象,通过测定氢、氧同位素,溶解有机碳(DOC)浓度,有色溶解有机质(CDOM)的吸收光谱和荧光光谱参数,探讨了夏季长江口北支、南支(北港、北槽、南槽)水体溶解有机质的组成、分布及其影响因素。沿长江下游到河口近海,南、北支DOC浓度分别为1.68±0.16mg/L和1.46±0.31mg/L,CDOM的吸光系数a₃₅₀分别为2.37±0.61m^-1和1.59±0.24m^-1。南支整体具有“高类腐殖质、低类蛋白”的特征,北支则具有“低类腐殖质、低类蛋白”的特征,这可能与南北支的径流量差异有关。在南北支不同分汊河道(北支、南支北港、南支北槽和南支南槽)中,南槽和北支有类似的海水入侵特征,但南槽具有较强的类蛋白组分输入,而南支北港和北槽样品间无显著差异,均表现为河流有机质为主的特征。对比2011年长江南北支DOC和CDOM数据显示,作为长江主河道的南支在2021年无明显变化,而北支有显著的变化。这些结果综合表明长江口DOM的变化格局可能受水动力条件(径流量)、人类活动因素共同作用的影响。比较全球河口DOC和CDOM浓度数据后发现,不同区域的河口具有明显的差异,这可能是因为不同流域在植被覆盖、工农业生产水平、水利工程强度、以及气候变化对土壤侵蚀作用等方面的差异。  相似文献   

海洋透光率仪的设计及其在初级生产力研究中的应用*     

许占堂  施震  谢栢成  廖健祖  杨跃忠  周雯  李彩  杨顶田 《热带海洋学报》2022,41(3):38-45

海洋浮游植物光合作用固碳在全球碳循环中扮演着极为重要的角色, 获取不同光衰减对应的海水深度, 对于采集水样用于海洋初级生产力的研究具有重要意义。本研究于国际上首次开发了无缆便携式海洋透光率仪, 特殊的光学结构设计和光谱滤光技术使得光谱响应在波段400~700nm范围内超过了同类海洋传感器, 特定光衰减下对应的深度误差小于0.5m。将本设备应用于南海中尺度涡旋初级生产力的研究中, 在采样率和自动化方面验证了仪器的便携性; 通过对涡旋中初级生产力的空间分布规律进行分析, 检验了仪器数据结果的可靠性。海洋透光率仪在价格、准确性、可靠度和操作的便携性上具有不可比拟的优势, 将在未来海洋生态环境的研究中发挥重要作用。  相似文献   

Field Detection of Chiorophyll-a Concentration in the Sea Surface Layer by an Airborne Oceanographic Lidar   总被引：2，自引：0，他引：2  

LIU Zhishen MA Sen WANG Xin LI Zhigang 《中国海洋大学学报(英文版)》2008,7(1):108-112

An airborne oceanographic lidar, with a frequency-tripled Q-switched Nd： YAG laser of 355 nm, has been designed to measure chlorophyll-a （Chl-a） concentration in the sea surface layer by the Ocean Remote Sensing Institute, OUC. The field experiment was carried out in the bay which is located south of the Liaodong Peninsula on the 10th of September 2005. After the flight, the raw data were processed and analyzed by the fluorescence-to-Raman ratio method with seawater attenuation coefficients calculated from signal profiles. The results of Chl-a concentration sea water were also compared with those of Chl-a concentration by measurements by lidar are shown. The measurements in clear a Moderate Resolution Imaging Spectroradiometer （MODIS）.  相似文献