Effects of modified clay flocculation on major nutrients and diatom aggregation during Skeletonema costatum blooms in the laboratory   总被引：1，自引：0，他引：1  

卢光远  宋秀贤  俞志明  曹西华  袁涌铨 《中国海洋湖沼学报》2015,33(4):1007-1019

Harmful algal blooms(HABs) can elicit several negative effects on aquatic environment(such as depleting the oxygen, blocking the sunlight, destroying the habitats of organisms) and life health(including poisoning/killing marine mammals, birds and human). Among the various control strategies for HABs(physical manipulation needs lots of manpower and expensive equipment, chemicals treatment has some toxic byproduct and high residual, microbial agents only has limited in laboratory research), the coagulation-flocculation of HAB species by modified clay(MC) has been proven to be an effective, lowcost and environmentally friendly method that has been widely applied in the field, particularly in eastern Asia. In order to examine the long-term effects of MC treatment, this study investigated the alternations in seawater of Skeletonema costatum, a high biomass dominant HAB species along the Chinese coast, by comparing the degradation of S. costatum detritus(A1) with the application of MC treatment(A2) and MC treatment in sediment condition(A3). The low dosage of 0.25 g/L MC could efficiently remove 4×108 cells/L of S. costatum cells within 3.5 h(approximately 97% removal). In addition, the results showed that both inorganic and organic nutrients were effectively reduced from seawater by MC particles. Compared to the total nitrogen(TN) and total phosphorus(TP) concentrations in A1 seawater, 44% of TN and 93% of TP in A2 seawater, as well as 72% of TN and 93% of TP in A3 seawater were removed during the onemonth incubation period. Simultaneously, 64% of DISi in A2 and 44% of DISi in A3 significantly decreased( P 0.001). This study demonstrated that MC treatment was able to significantly increase the downward flux of nutrients and delay the release velocity of inorganic nutrient from MC-algae matrix into the overlying seawater, particularly within sediment environment.  相似文献   

Observational study of surface ozone at an urban site in East China   总被引：4，自引：1，他引：3  

Wenpo Shan  Yongquan Yin  Jianda Zhang  Yuping Ding 《Atmospheric Research》2008,89(3):252-261

In this study, we present the observational data of near surface ozone and some meteorological parameters during 2004, at an urban site (36°42′ N, 117°08′ E, 34.5 m a.s.l.) of Jinan, China. Hourly ozone concentrations exceeding the standard value of China, 100 ppbv, were observed for 65 h (in 23 days) from April to October, and values exceeding US NAAQS (National Ambient Air Quality Standard) for 1 h ozone, 120 ppbv, were observed for 15 h (in 7 days) from late May to early July. Ozone formation presented the phenomenon of “weekend effect”, especially in summer. Monthly variation of ozone coincided with temperature except for July and August. The low ozone levels in July and August may be due to the short sunshine duration and much rainfall during this period. Among these meteorological parameters, daily averaged ozone shows a significant correlation with temperature (r = 0.66) in the year and with relative humidity (r = − 0.75) in summer. Throughout the year, high ozone concentrations were mainly associated with the wind from 180 to 247.5°, while high ozone concentration seemed to have no obvious correlation with a given wind direction in summer. An anomalous nocturnal high ozone episode during 23–25 May 2004 was investigated. Growth fractions of ozone during the nighttime episode were 62.2% and 71.1% for 23 and 24 May, respectively. Synoptic analysis shows that favorable synoptic condition had presumably elevated the background ozone level in this region. Backward trajectory analysis shows that the increase of ozone concentration and the relatively constant high ozone concentrations during the night of May 23 might originate from the transport of ozone rich air mass above boundary layer. Transport of ozone from Yangtze Delta and East Central China might be a significant process for the high ozone level during night May 24 at Jinan.  相似文献   

Immunogenicity and protective efficacy of <Emphasis Type="Italic">Vibrio harveyi</Emphasis> pc<Emphasis Type="Italic">Fla</Emphasis>A DNA vaccine in <Emphasis Type="Italic">Epinephelus awoara</Emphasis>     

覃映雪  苏永全  王世峰  鄢庆枇 《中国海洋湖沼学报》2009,27(4):769-774

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90年代太阳模型和太阳震荡研究进展(II):太阳振荡研究进展(英)     

龚志刚  袁永泉  李焱  W．D　ppen  彭美仙 《天文学进展》1998,(4)

太阳振荡研究现已成为研究太阳内部性质的新手段,也成为检验太阳模型构造时输入物理参量的最重要工具。90年代以来理论与观测日震频率的差别已随输入物理参量及太阳振荡理论的改进而大为减小,可是现有的差别仍远大于观测误差。由日震反演可对太阳内部对流区、表面氦丰度及自转随纬度和径向的分布都有更多了解。太阳振荡的湍动随机激发及激发源的位置都已得到研究,不过现在问题还未完全解决。今后一方面要探测更多的振动方式,另一方面也需要解决不同观测者得到的结果存在系统差的问题,而最外层的非绝热现象及理论与观测存在差别仍是最关键的难题。  相似文献   

陕西榆林侏罗纪层序地层分析及其意义     

赵廷周  崔永泉  赵忠良 《陕西地质》1996,(1)

陕西榆林侏罗系可划分4个层序。通过大断面写真、钻孔断面分析发现，层序－2（延安组）是3种类型小层序的重复叠覆，可归并为9个体系域，与海相地层有较大差异。系统分析其层序地层学特征，对于恢复古盆地水动力循环系统、沉积过程及矿产预测有重要意义。  相似文献   

塔里木盆地中寒武统—下奥陶统泥晶灰岩地球化学与古海洋学   总被引：3，自引：0，他引：3  

陈永权  周新源 《海洋地质与第四纪地质》2009,(1)

塔里木盆地西部台地沉积区中寒武统—下奥陶统发育少量的泥晶灰岩,选择和4井中寒武统与塔中19井下奥陶统泥晶灰岩作为研究对象,旨在对中寒武世—早奥陶世古海水地球化学组成给予重建。地球化学分析结果表明,和4井泥晶灰岩MgO含量较高(2.76%～10.46%),表明和4井泥晶灰岩已被部分白云岩化,塔中19井泥晶灰岩较纯。两口探井泥晶灰岩δ18OPDB值变化在-8.7‰～-7.3‰之间,且δ18OPDB与MgO含量呈线性相关关系,趋势线在δ18O轴的截距为-8.6‰;泥晶灰岩样品的87Sr/86Sr值稳定,平均值为0.708 918;与和4井稀土元素总量(1.68～2.69)×10-6相比,塔中19井稀土元素含量较高,为(6.72～6.8)×10-6。δ18OPDB与MgO含量之间的线性相关关系,指示白云岩化作用可提高灰岩δ18O值,δ18O轴的截距为-8.6‰代表了灰岩原岩的氧同位素组成,根据同位素分馏规律可计算古海水δ18OSMOW值为-8.9‰。稳定的87Sr/86Sr值0.708 918代表中寒武纪—早奥陶世海水的87Sr/86Sr比值特征,与全球海洋87Sr/86Sr值演化线吻合。虽然各泥晶灰岩样品稀土元素总...  相似文献   

Contents of carbohydrates and lipids in the bodies of two planktonic crustaceans     

Su Yongquan  Yan Hong  Zhang Huan 《中国海洋湖沼学报》1990,8(1):46-49

The carbohydrate and lipid contents in two planktonic crustaceans, i. e.Pseudeuphausia sinica andAcetes chinensis sampled from Xiamen coastal waters were estimated. InP. sinica, the contents of carbohydrates (in dry weight) and lipids varied from 2.19–2.33% and 21.2–21.9% respectively; inA. chinensis from 1.74–2.55% and 14.43–15.10% respectively. The analyses of fatty acids by gas-chromatograph (Model 103) showed that eight fatty acids of 14∶0, 15∶0, 16∶0, 17∶0, 18∶0, 18∶2, 20∶2 and 22∶2 were found in these two animals, that 16∶0, 18∶0, 18∶2, and 20∶2 formed the major constituents with 91.08% (P. sinica) and 74.80% (A. chinensis) of the total fatty acids, and that the values of odd carbon types (15∶0 and 17∶0) were fairly low, 4.47% and 3.36% respectively. Three monosaccharides: glucose, fructose, and galactose detected by high-liquid chromatograph (Waters 208) accounted for more than 60% of the total carbohydrates, especially the glucose, exceeding by 40%.  相似文献   

米104盐井对接施工工艺实例     

王增海王永全  崔秀忠吴国强 《中国煤田地质》2007,19(A01):24-26

米104井位于陕西省榆林市米脂县，与米103井相距350m，设计对接靶点垂深2536．05m，造斜点垂深2330m．水平段124．79m。该井设计为三开井身结构，在施工中，根据不同的岩性采用了不同的的施工工艺及不同的钻井液。米104井钻进深度至2789m时，泥浆全部漏失，达到了一次对接成功。  相似文献   

套管开窗侧钻技术在水井施工中的应用     

王永全王玉春  梁凤河张书平 崔秀忠 《中国煤田地质》2007,19(A01):78-80,91

套管开窗侧钻技术是处理井内复杂情况的一种有效手段，某地热井在完井抽水后，因取水段岩层垮塌造成取水井段堵塞，采用冲、扫、捞、等方法处理均无效，地热井几近报废，后采用该技术手段，使该井顺利竣工。  相似文献   

1855年黄河大改道与百年灾害链     

王涌泉 《地学前缘》2007,14(6):6-10

1855年黄河铜瓦厢决口北流,改道从山东入海,是一次百年灾害链形成的巨变,黄淮海平原成为中国水灾的中心。经研究发现:1740—1818年为中国地震宁静期,黄河流域正处于干旱枯水期;1819年印度卡其发生8.3级大地震,黄河出现多泥沙特大洪水,河南兰阳以下近30 km河道严重淤塞;1819—1879年大地震密集出现,并有9级以上特大地震4次,其中1833—1870年大地震主要分布在东亚;黄河因而于1841—1843年连续出现特大洪水,造成下游多次决溢、以致改道。文中第一次以科学和历史结合给出解释,其结论可供当前地球科学灾害链研究及治黄参考。  相似文献