氧化亚铜的氧化动力学

本文以亚硫酸盐和硫酸铜制备的氧化亚铜为样品,用Kissinger法和FWO法研究了氧化亚铜的氧化动力学行为,结果表明:氧化亚铜氧化反应生成氧化铜的表观活化能E=174.52 kJ·mol-1,指前因子lnA=195.526 8,相对应的反应级数n=0.99.     

光助Fenton氧化法去除水中两种氯乙酸及其动力学研究

以二氯乙酸和三氯乙酸为目标污染物,研究了光助Fenton氧化去除水中卤乙酸的可行性及影响因素,并对其动力学进行了初步研究.结果表明,影响光助Fenton氧化的因素很多,氙灯功率500 W、H2O2和Fe2+投加量分别为5.0和1.0 mmol·L-1、pH=4.0反应60 min是所考察范围内的最佳降解条件,浓度为100 μg·L-1的二氯乙酸和三氯乙酸的降解率分别为90.32％、87.77％;在实际水质pH=7.0时,相同浓度的二氯乙酸和三氯乙酸的降解率分别为75.34％、68.80％.紫外辐射与Fenton氧化对二氯乙酸和三氯乙酸的降解具有协同效应.光助Fenton氧化对二氯乙酸和三氯乙酸的降解符合一级反应动力学,表观活化能分别为30.11、31.09 kJ·mo1-1,受温度影响不大.     

一种合成2,2-二甲基-4-戊烯酸的方法

报道一种合成２,２－二甲基－４－戊烯酸的新方法。由异丁醛与烯丙醇缩合得到２,２－二甲基－４－戊烯醛,后者经氧化银选择氧化生成２,２－二甲基－４－戊烯酸。此法氧化产率（９６％）高于分子氧氧化法（６１％）和歧化法（４１％）。反应中析出的金属银能定量回收,循环使用。     

甘露醇分光光度测定法的改进

前言在甘露醇分析工作中,应用最普遍的是过碘酸氧化法和基于这种氧化反应而提出的各种改良方法。这类方法不仅收率不稳定,而且要求取样数量的范围狭窄。因此,对于一个未知浓度的甘露醇溶液,往往要试测多次才能得到结果。此外,由于藻类中天然含存的有机物和无机物很多,有的能与过碘酸起反应而导致不正确的分析结果。 Evtushenko等(1962)曾利用硫酸铜和甘露醇,在碱性溶液中形成可溶性络合物的原     

氟改性聚苯乙烯树脂在柴油光催化氧化脱硫中的应用

为了降低柴油的硫含量,制备了氟改性聚苯乙烯树脂,并以此为载体负载磷钨酸作为催化剂,采用氧气氧化法,对柴油进行了光催化氧化脱硫的研究。结果表明,125W高压汞灯照射下,氧气流量为150mL/min,90℃反应2h,柴油的脱硫率最优达到61.52%,不改变其他条件下将萃取剂90%N-甲基吡咯烷酮水溶液一同加入反应体系中,可进一步提高柴油的脱硫率达68.55%。     

海水中总氮和总磷的同时测定

早期总氮和总磷的过硫酸钾法氧化分析分别是在碱性和酸性介质中进行［１,２］,样品分别保存,然后分别氧化测定,工作较繁琐。１９７７年Ｋｏｒｏｌｅｆｆ用过硫酸钾氧化法同时氧化水体中的总氮和总磷,使样品的保存和氧化分析工作简化。１９８１年Ｖａｌｄｅｒｒａｍａ对该方法测定天然海水中的总氮和总磷做了进一步研究,总氮和总磷同时氧化后,水样中的硝酸盐和磷酸盐用手工分别进行分析。Ｗａｌｓｈ１９８９年和Ｋａｒｌ等１９９３年曾采用ＵＶ光氧化法对海水中总溶解氮和总溶解磷进行同时氧化后,用自动分析对氧化后的无机氮和磷进行…     

海水中溶解有机碳的测定方法

海水中溶解有机碳(DOC)的测定方法主要有过硫酸盐氧化法;紫外光氧化法和高温氧化法。近年来,随着仪器分析的进步,国外已出现能自动连续测定DOC的商售设备。 Menzel等发展的过硫酸钾氧化法,由于设备简单,容易实施,至今仍为很多人采用。     

响应曲面法优化电化学氧化处理染料废水工艺参数的研究

采用响应曲面分析中的Box-Behnken设计法,以电流密度、初始pH值、氯化钠浓度和反应时间为实验因素,以电化学氧化处理酸性粒子元青染料废水过程中的TOC去除率和能耗为响应值,通过响应曲面法结合优化期望函数得出电化学氧化最优效能的工艺参数。结果表明,分析得出的TOC去除率与反应能耗的多元二次回归模型均达到显著并有很好的相关性。电化学氧化最优工艺参数为电流密度55mA/cm~2,初始pH值为6,氯化钠浓度0.15mol/L,反应时间120min,在此条件下,TOC去除率为80.20%,能耗为19.85kWh/g(TOC),预测值与实际值之间的相对误差分别为2.2%与4.6%。表明此方法可用于优化电化学氧化处理染料废水工艺参数,为实际工程应用中制定高效节能的处理方案提供参考。     

水溶液中二甲基硫的化学氧化过程研究

实验研究水溶液中二甲基硫（ＤＭＳ）和Ｈ２Ｏ２进行氧化反应的动力学。结果表明ＤＭＳ被Ｈ２Ｏ２氧化的速率会受到介质、ｐＨ以及重金属离子的影响。其二级反应速率常数为２．２１×１０－２～４．９０×１０－２Ｌ·ｍｏｌ－１·Ｓ－１．Ｈｇ２＋的存在会加快反应速率，特别在人工海水条件下十分明显。ＤＭＳ易被Ｈ２Ｏ２氧化的事实说明，在海水中化学氧化过程会对ＤＭＳ的浓度和分布产生重要影响     

次溴酸盐氧化法不适用于污染海水中NH4-N测定

海水中NH_4-N的测定,经历了奈氏法、靛酚兰法,直到目前的氧化法各阶段。在氧化法中所使用的氧化剂有次氯酸钠和次溴酸钠。李逢熙曾对这两种方法进行过比较研究,认为次溴酸盐氧化法(以下称溴法)快速灵敏、转化率高、精密度和准确度较好。1984年溴法被列入《海洋污染调查暂行规范》,被海洋界和     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Net Sand Transport Direction in a Tidal Inlet, using Foraminiferal Tests as Natural Tracers

The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance.