Cathodic protection of A1 hull ship

Heavy paint coating loss and localized corrosion of the Al alloy hull occur red after less than a year's service of a ship at sea. Examination and analysis showed that the Mg-basic sacrificial anodes originally used for cathodic protection were not suitable as the resulting −1.3V-plus (vs Ag/AgCl) protection potential for the hull was too negative for the purpose. A new protection system was designed in which the protection current densities were 15mA/m² for the hull and 350mA/m² for the propeller. The hull protection potential under actual condition at sea was between −920mV and −1100mV (Ag/AgCl) and the protection efficiency was over 90%. The protection areas were calculated by using the formulas A=1.8×LBP×D+BC×LB×B for the hull and A_s=2Aa_s for the propeller. Contribution No. 1640 from the Institute of Oceanology, Academia Sinica.     

THE GROUNDWATER RESOURCES AND ITSSUSTAINABLE DEVELOPMENTIN THE SOUTH EDGE OF TARIM BASIN

1 INTRODUCTIONSustainability as present understand comes fromword protection strategy commission, which firstly putforward some wide excepted environmental sustainability principles and three important identifications forlife support system: soil, air and water. Then, in thereport of Our Common Future (WCED, 1987), theconcept of sustainable development is put to an outstanding level. Sustainable groundwater resources development is then a great issue in the recent years andthe future (…     

ASSESSMENT OF INDIRECT USE VALUES OF FOREST BIODIVERSITY IN YAOLUOPING NATIONAL NATURE RESERVE, ANHUI PROVINCE

1INTRODUCTIONForestbiodiversityprovidesawiderangeofindirectbenefitstohumanbeing.Whiletheremaybelittlecon-sensusonwhetherthevariouselementsofforestbiodi-versitycanbevaluedineconomicterms, itisincreas-inglyrecognizedthatthesevaluesandtheroleofbio-diversityinmaintainingecologicalservicesareessen-tialtothehumankind.Thenotionofindirectusevalueofbiodiversityhasbeenassociatedwithaminimumlevelofecosysteminfrastructure, withoutwhichtherewouldnotbethegoodsandservicesprovidedbyit(FARNWORTHetal.,1…     

Study on the Determination of Trace Ni（Ⅱ） by the Catalytic Kinetic Spectrophotometric Method

A new kinetic spectrophotometric method has been developed for the determination of trace Ni (II) in natural water.The method is based on the catalytic effect of Ni (II) on the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 in acid medium.The concentration of nickel (II) can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ= 626 nm using the fix-time method.The influencing factors are investigated by the orthogonal experimental design.The obtained optimum analytical conditions are:pH=2.00,c RAWL=5.00×10-5 mol L-1,cKIO 4= 2.00×10-5 mol L-1,the reaction time t=10 min and the temperature T=25℃..Under the optimum conditions,the developed method allows the measurement of Ni (II) in a range of 0-40.0 ng mL-1.The standard deviation of eleven independent measurements of blank reaction is S=3.08×10-3 and the limit of detection is 2.20 ng mL-1.The relative standard deviations (RSDs) in six replicate determinations of 5 ng mL-1 and 8 ng mL-1 Ni (II) are 2.87% and 1.11%,respectively.Moreover,the experiments show few cations and anions can interfere with the measurement of Ni (II).The recovery efficiencies of this method are in a range of 97.0%-102.5% in freshwater samples.But there is a decreasing effect,which is about 0.2 times the added Ni (II) in seawater medium.After reasonable calibration this processing method is used for the determination of Ni (II) in seawater samples successfully.The results show this developed method has high accuracy and precision,high sensitivity,large range of linearity and high speed.The method can,therefore,be employed at room temperature.     

Determination of trace vanadium (V) in seawater and fresh water by the catalytic kinetic spectrophotometric method

A new kinetic spectrophotometric method has been developed for the determination of vanadium (V). The method is based on the catalytic effect of vanadium (V) on the oxidation of weak acid brilliant blue dye (RAWL) by KBrO₃ using the citric acid as activation reagent. The obtained optimum conditions are: c (RAWL) = 1×10⁻⁴ molL⁻¹, c (KBrO₃) = 3×10⁻² molL⁻¹, c (citric acid) = 9×10⁻³ molL⁻¹, pH = 2.50, the reaction time being 7.0 min and the temperature being 25.0°C. Under the optimum conditions, the proposed method allows the determination of vanadium (V) in the range of 0–70.0 ng mL⁻¹ and the detection limit is down to 0.407 ng mL⁻¹. For standard vanadium (V) solution determination, the recovery efficiency is in the range of 98.5%–102% and the RSD ranges from 0.76%–1.25%. Moreover, it is demonstrated that most cations and anions do not interfere with the determination of vanadium (V) under the analytical condition. The new method was successfully applied in the determination of vanadium (V) in fresh water and seawater samples with satisfactory results. Vanadium (V) in the seawater samples from Qingdao offshore was determined using the method and the distribution of vanadium (V) was mapped. Compared with other instrumental analytical methods, the proposed method shows good selectivity, sensitivity, simplicity, lower cost and rapidity. It can be employed on shipboard easily.     

Iron ions increase the thermostability of phycocyanin ofSpirulina maxima

A spectral method to investigate the effect of Fe³⁺, Fe²⁺ on the thermostability of phycocyanin (PC) ofSpirulina maxima showed that iron ions provent decrease of visible light absorbance and fluorescence intensity of PC. Increase in denaturation temperature caused by Fe³⁺ was observed by the micro-differential scanning calorimetric method. All results showed iron ions maintain the aggregation stability of the PC. The absorption spectrum of phycocyanobilin (PCB, a prosthetic group of PC) with Fe³⁺ in chloroform was quite different from that of free PCB.

     

A Kinetic Spectrophotometric Method for the Determination of Iron （Ⅲ） in Water Samples

A new kinetic spectrophotometric method has been developed for the determination of iron (Ⅲ). The method is based on the catalytic effect of iron (Ⅲ) on the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 in acid medium. The advantages of the proposed method are that it is sensitive, accurate, rapid, inexpensive, can be operated under room temperature and has a large determination concentration range compared to other techniques. The obtained optimum conditions are pH 3.15, RAWL (200 mgL-1) 5.00mL, Potassium periodate solution (0.01 molL-1) 0.30mL, phenanthroline (0.02molL-1) 1.00mL, reaction temperature 25℃ and reaction time 7 miu. With this method iron could quantitively be determined in the range 0.00-0.02 mgL-1, the detection limit being 4.10×10-10mL-1. The relative standard deviations (RSD) in five replicate determinations for 3 μgL-1 and 5μgL-1 iron (Ⅲ) are 3.1% and 1.9%, respectively. The method has been applied to the determination of iron (Ⅲ) in tap water samples and seawater samples (from the South China Sea), the recovery rates being 98.0% and 100.5%, respectively.     

Measurement of trace manganese (II) by the catalytic kinetic spectrophotometric method

A new kinetic spectrophotometric method is developed for the measurement of manganese (II) in water. The method is based on the catalytic effect of manganese (II) with the oxidation of weak acid brilliant blue dye (RAWL) by KIO₄ using the Nitrilo triacetic acid (NTA) as an activation reagent. The optimum conditions obtained are 40 mgL⁻¹ RAWL, 1×10⁻⁴molL⁻¹ KIO₄, 2×10⁻⁴ molL⁻¹ Nitrilo triacetic acid (NTA), pH = 5.8, the reaction time of 3.00 min and the temperature of 20.0 °C. Under the optimum conditions, the proposed method allows the measurement of manganese (II) in a range of 0–50.0 ng mL⁻¹ and with a detection limit of down to 0.158 ng mL⁻¹. The recovery efficiency in measuring the standard manganese (II) solution is in a range of 98.5%–102%, and the RSD is in a range of 0.76%–1.25%. The new method has been successfully applied to the measurement of manganese (II) in both fresh water and seawater samples with satisfying results. Moreover, few cations and anions interfere with the measurement of manganese (II). Compared with other kinetic catalytic methods and instrumental methods, the proposed method shows fairly good selectivity and sensitivity, low cost, cheapness, low detection limit and rapidity. It can be applied on boats easily.     

Spatial distribution and dynamics of carbon storage in natural <Emphasis Type="Italic">Larix gmelinii</Emphasis> forest in Daxing’anling mountains of Inner Mongolia,northeastern China

In order to clarify the geographic distribution and change of natural Larix gmelinii forest in carbon storage in Daxing’anling mountains (Great Khingan Range) in North China’s Inner Mongolia, an area-irrelevant conversion equation of biomass from timber volume in the form of B = 0.6966 V was developed by using survey data. Based on the equation, the carbon storage was estimated at 190.172 Tg, and the average carbon density was 41.659 Mg/hm² (area 4.565 × 10⁶ hm²). Carbon stored in standing trees was predominantly distributed in mid-age and mature forests and mainly stocked in the northern part of the study area. Assuming the carbon density of intact area as the maximum value, the potential carbon storage in the entire study area would be 263.674 Tg, approximately 1.4 times of the actual level. Over the period of 1995 to 2010, the carbon storage and carbon density increased by 3.260 Tg and 0.224 Mg/hm², respectively, indicating a weak carbon sink. Comparing with China’s national average level, the carbon density in this area is not as high as expected. Forest quality in terms of carbon capacity is expected to be enhanced by appropriate management schemes under the in-implementation program of forest protection.     

Development of an inactivated iridovirus vaccine against turbot viral reddish body syndrome

Turbot(Scophthalmus maximus L.) reddish body iridovirus(TRBIV) was propagated in turbot fin cells(TF cells) and inactivated as the TRBIV vaccine with its protection efficiency evaluated in this study.TF cells were cultured in 10% bovine calf serum(BCS)-containing MEM medium(pH7.0) at 22℃,in which TRBIV propagated to a titer as high as 105.6 TCID50 mL-1.The TRBIV was inactivated with 0.1% formalin and formulated with 0.5% aluminum hydroxide.The inactivated vaccine caused neither cytopathogenic effect(CPE) on TF cells nor pathogenic effect on turbots.After being administered with the vaccine twice via muscle injection,the turbot developed high-tittered TRBIV neutralizing antibodies in a dose-dependent manner.The vaccine protected the turbot from dying with an immunoprotection rate of 83.3% as was determined via subcutaneous vaccination in the laboratory and 90.5% via bath vaccination in turbot farms,respectively.The inactivated vaccine was very immunogenic,efficiently preventing tur-bot from death.It holds the potential of being applied in aquaculture.     

Speciation analysis of arsenic compounds in seafood by ion chromatography-atomic fluorescence spectrometry

Ion chromatography-ultra violet-hydride generation-Atomic Florescence Spectrometry was applied to detect 5 arsenic species in seafoods. The arsenic species studied include arsenobetaine(As B), arsenite(As(III)), dimethylarsinic acid(DMA), monomethylarsonic acid(MMA), and arsenate(As(V)), which were extracted from samples using 2% formic acid. Gradient elution using 33 mmol L~(-1) CH_3COONH_4 and 15 mmol L~(-1) Na_2CO_3 with 10 mL CH_3CH_2OH at pH 8.4 allowed the chromatographic separation of all the species on a Hamilton PRP-X100 anion-exchange column in less than 8 min. In this study, an ultrasound extraction method was used to extract arsenic species from seafood. The extraction efficiency was good and the recoveries from spiked samples were in the range of 72.6%–109%; the precision between sample replicates was higher than 3.6% for all determinations. The detection limits were 3.543 μg L~(-1) for As B, 0.4261 μg L~(-1) for As(III), 0.216 μg L~(-1) for DMA, 0.211 μg L~(-1) for MMA, and 0.709 μg L~(-1) for As(V), and the linear coefficients were greater than 0.999. We also developed an application of this method for the determination of arsenic species in bonito, Euphausia superba, and Enteromorpha with satisfactory results. Therefore, it was confirmed that this method was appropriate for the detection of arsenic species in seafood.     

^226Ra and ^228Ra in the Seawater of the Western Yellow Sea

1Introduction Therearefourradiumisotopesinnature,ofwhich224Ra,226Raand228Rahavebeenwidelyinvestigated inmarineresearch,butthespecificactivityof223Rais toolowtobemeasured,therefore,itsapplicationsarelimited(Moore,1969;Broeckeretal.,1976;KuandLin,1976;Nozak…     

面向对象方法和多源遥感数据的杭州湾海岸线提取分析

本文以1983-2011年的多源遥感数据为基础,利用GIS空间分析和地图代数功能,提取杭州湾海岸线,分析了其变迁的位置、长度,以及增加和减少的陆地面积。结果表明:受到自然和人为因素的影响,杭州湾南北两岸的海岸线变迁规律不同。杭州湾北岸1983-1993年共有60.2km的海岸线向陆迁移,最大迁移距离0.6km,减少的陆地面积共为23.5km2。1993-2011年由于围垦和工业填海北岸向海迁移。其中,1993-2002年最大迁移距离3.6km,新增陆地面积42.5km2,2002-2011年最大迁移距离2.9km,新增陆地面积61.0km2。由于淤积和围垦,杭州湾南岸海岸线不断向海迁移,1983-1993年、1993-2002年和2002-2011年向海迁移最大距离分别是1.8km、2.7km和5.1km,新增陆地面积分别为34.3km2、230.2km2及331.7km2。海岸线向海迁移的速度越来越快,规模越来越大。研究成果对于地图制图、滨海湿地生态资源管理,以及海岸线保护具有十分重要的意义。     

The intrinsic acidity constants and specific surface area of marine solid particles I. A new method

This paper proposes a new method for determining the intrinsic acidity constantsK _a1 ^int andK _aj ^int . The new method is a great improvement over the modified Langmuir plot method generally adopted in that determination of these constants is not dependent on the specific surface area of the marine solid particles. The new method was used to determineK _a1 ^int ,K _2a ^int and for the main inorganic components of marine solid particles, including illite, montmorillonite, kaolinite, goethite, γ-AlOOH. amorphous ferric oxide, δ-MnO₂, manganite, SiO₂ and calcium carbonate, and can facilitate the study on the effect of solution constituents, solution temperature, ionic strength, etc. on the value of .     

Determination of Trace Copper （Ⅱ） in Water Samples by Kinetic-spectrophotometry

A new kinetic-spectrophotometric method is proposed for the determination of copper （ Ⅱ ）. The method is based on the catalytic effect of copper （ Ⅱ ） on the oxidation of weak acid brilliant blue dye （RAWL） by hydrogen peroxide. The copper （ Ⅱ ） can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ = 626 nm using the fix-time method. The optimum reaction conditions are as follows： pH 7.20, buffer solution NaOH-KH2PO4, RAWL （200 mgL-1） 5.00 mL, H2O2 （30%） 0.50 mL, reaction temperature 80 ？？ and reaction time 20 min. The linear range of this method is between 0 μg L^-1 and 12 μg L^-1 and the limit of detection is 0.011 μg L-1, the relative standard deviation （RSD） in five replicate determinations for 2 and 8 μg L-1 copper （ Ⅱ ） are 3.2% and 2.3%, respectively. Twenty ions do not interfere in the determination of copper （ Ⅱ ）. The method has been applied satisfactorily to the determination of copper （ Ⅱ ） in freshwater samples （tap water and Yellow River water from Lijin, Shandong, China） and seawater samples （from the South China Sea）, the recovery rates are 98.0%, 102.5% and 96.0%, respectively.     

A 150-year isotopic record of lead deposition in Yancheng coastal wetland,China

Radioactive markers are useful in dating lead(Pb) deposition patterns from industrialization in sedimentary archives. As a well-known natural reserve in the world, Yancheng coastal wetland in Jiangsu Province is one of areas most sensitive to global sea level change and is located in the most developed and polluted region of China. Two cores were collected in Yancheng wetland in October 2013 and dated using ~(210)Pb and ~(137)Cs radiometric techniques. Sediments in both cores were sectioned into depth bands and examined systematically for dry bulk density, water content, magnetic susceptibility and grain-size. Multiple elements including Pb were also measured using inductively coupled plasma systems. Unsupported ~(210)Pb activities decreased with depth in both of the two cores, and ~(210)Pb chronologies were established(covering 150 years) using the constant rate of supply(CRS) model. The measured Pb contents ranged from 14.97 mg/kg to 29.40 mg/kg with average values of 17.17–22.79 mg/kg, and the Pb fluxes ranged from 41.70 mg/(m~2·yr) to 172.70 mg/(m~2·yr) with averages of 95.59–123.41 mg/(m~2·yr). Temporal variations of Pb flux, enrichment factors and Pb isotopes show a gradual and continuous increase over time and clearly reflect increased emissions from anthropogenic activities in the region. The Pb isotopic compositions show that most of Pb deposition in Yancheng wetland is input from natural sources by water flows and has the same levels of Pb as in the surface sediment of the Yangtze River and the Pacific mineral aerosol. We also stress the anthropogenic Pb contribution in Yangcheng wetland sediment and the reason of our Pb isotopes not showing anthropogenic signature is likely the instability of anthropogenic Pb in high Fe/Mn oxide conditions. Therefore, more attention should be paid to current local pollution problems, and society should take action to seek a balance between economic development and environmental protection.     

Structural studies on the oligomers from the polysaccharide ofGracilaria textorii (Rhodophyta) using β-agarase and13C-NMR spectroscopy

The 60% ethanolic extract fromGracilaria textorii (Rhodophyta) was degraded with β-agarase, and certain charged (sulfated) and neutral oligosaccharides were separated by using DEAE Sephadex A25 and Bio- gel P6, P2 chromatographic techniques. Some of the charged oligomers were verified to be neoagarotetraose-6³-sulfate (DP2), neoagarohexaose-6³, 6⁵-disulfate (DP3) and neoagarooctaose-6³, 6⁵, 6⁷-trisulfate (DP4) by using¹³C- and¹H-NMR spectroscopy. One neutral oligomer was assumed to be a mixture of methylated neoagarotetraoses (DP2) by¹H-NMR spectroscopy. These oligomers assigned by their chemical shifts may be used as the model compounds for the structural investigation of the agar-type sulfated polysaccharides using the β-agarase degradation method. Contribution No. 1749 from the Institute of Oceanology, Academia Sinica.     

Isolation of plasmid from the blue-green algaSpirulina platensis

CCC plasmid was isolated from an economically important blue-green alga —Spirulina platensis (1.7×10⁶ dalton from the S₆ strain and 1.2×10⁶ dalton from the F₃ strain) using a rapid method based on ultrasonic disruption of algal cells and alkaline removal of chromosomal DNA. The difference in the molecular weight of the CCC DNAs from the two strains differing in form suggests that plasmid may be related with the differentiation of algal form. This modified method, which does not use any lysozyme, is a quick and effective method of plasmid isolation, especially for filamentous blue-green algae. Contribution No. 79 of the Experimental Marine Biology Laboratory and 2153 of the Institute of Oceanology, Academia Sinica. This research was supported in part by The President of the Chinese Academy of Sciences Foundation.     

Ab initio prediction of 29Si-NMR chemical shifts

The ability of several ab initio models to predict experimental ²⁹Si-NMR chemical shift is examined. The shielding values of trimethylsilyl chloride (A), t-butyldimethylsilyl chloride (B) and allytrimethylsilane (C) are calculated by GIAO, CSGT and IGAIM methods, using HF/6–31G^*, B3LYP/6-31G^*, HF/6–311+G^**, B3LYP/6–311+G^** and MPW1PW91/6–311+G^** models respectively. The ²⁹Si chemical shifts calculated by GIAO method using HF/6–311+G^** model are highly in agreement with those obtained experimentally. All of the models above reproduce the trends of chemical shifts in all cases studied, suggesting that the models are of practical value.     

Geomorphologic analysis and physico-dynamic characteristics of Zhatai-Gully debris flows in SW China

Zhatai gully is a typical debris flow channel in Butuo county of Sichuan province, southwestern China. The geomorphologic features are analyzed and the physical-dynamic characteristics are discussed on the basis of field investigation and laboratory tests. Geomorphologic analysis indicates that Zhatai-gully drainage in relation to debris flow can be divided into source area, transport area, and deposition area. The source area has a steep slope and has very limited vegetation cover, which favors runoff, allowing loose solid materials to be mobilized easily and rapidly. In the transport area, there are many small landslides, lateral lobes, and loose materials distributed on both banks. These landslides are active and constantly providing abundant source of soils for the debris flows. In the deposition area, three old debris-flow deposits of different ages can be observed. The dynamic calculation shows that within the recurrence intervals of 50 and 100 years, debris flow discharges are 155.77m³/s and 1y8.19m³/s and deposition volumes are 16.39 x 10⁴ m³ and 18.14 x 10⁴ m³, respectively. The depositional fan of an old debris flow in the outlet of the gully can be subdivided into six layers. There are three debris flow deposits on left and two on the right side of the gully. Grain-size tests of sediments from the soil, gulley bed deposits, and the fresh and old debris flow deposits showed that high amounts of clay and fine gravel were derived from the soil in the source area whereas much of the gravel fraction were sourced from the gully bed deposits. Comprehensive analysis indicates that Zhatai gully is viscous debris-flow gully with moderate to high frequency and moderate to large magnitude debris flows. The risk of a debris flow disaster in Zhatai-gully is moderate and poses a potential threat to the planned hydroelectric dam. Appropriate engineering measures are suggested in the construction and protection of the planned hydroelectric station.