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1.
Alterations to nomenclature for two common intertidal New Zealand ‘top shells’ necessitated by re‐examination of type material have been confused by ambiguities in the way the alterations were first presented. We draw attention to recent misinterpretations and clarify the nomenclature. Condensed synonymies that indicate names used for each species during the interregnum are given, allowing papers dealing with these trochids to be read without uncertainty as to which species were really meant by the authors. 相似文献
2.
About ScienceDirect 《Coastal Engineering》2005,52(12):1175-1187
3.
Abstract. The distribution of the thalassinidean shrimp Upogebia pusilla was studied at four sites in the North Adriatic Sea: 1) a tidal flat in the lagoon of Grado, 2) a tidal flat at Lido di Staranzano near the mouth of the Isonzo, 3) a mud flat seawards of a salt marsh in a protected bay north of Rovinj, and 4) a sublittoral station in 6m depth near Aurisina. Information on grain size distribution, organic content, amount of debris, redox profiles and pH of sediment as well as temperature and salinity is given. Density, as determined by hole counts and a hole: burrow relationship derived from resin casting, generally increased with increasing water depth in the intertidal. The upper limits ranged between +10cm (Rovinj) and -20cm (Grado); densities between mean water and low water level varied strongly due to microtopography and macrophyte cover. Maximum densities in the intertidal ranged from 189 (Grado) to 2420 (Rovinj, juveniles) animals m2 . Shrimp density at the sublittoral station ranged between 80 and 230 m"2 . The zonation of the Upogebiidae and Callianassidae with respect to environmental parameters is discussed. 相似文献
4.
Abstract. Populations of the thalassinidean shrimp Upogebia pusilla were studied on tidal flats in the Northern Adriatic Sea. Biometric analysis showed a sexual dimorphism, especially in propodus size. Size frequency distributions revealed the presence of large animals during all seasons; recruitment by juveniles occurred in autumn. Moult intervals and moult increments were determined in the laboratory and used to generate growth curves which were compared with those calculated from size frequency distributions. The life span of U, pusilla is over 5 years. Ovigerous females occurred between March and September. Egg numbers were high in spring, lower in summer and increased with body size. The incubation time of embryos was 35 days; a female produces an estimated number of three egg batches during the breeding season. A total annual production of 994 kJ was estimated for a theoretical population of 100 animals; 13.5 % is spent for somatic growth, 31 % for egg production of females, and 55.2% is lost as exuviae. The population structures, growth and breeding patterns, as well as embryonic and larval development within the Upogebiidae and Callianassidae are discussed. 相似文献
5.
J. A. Colman 《新西兰海洋与淡水研究杂志》2013,47(4):693-697
The unique holotype of Arnoglossus boops Hector is compared with specimens of Arnoglossus scapha (Schneider). It is concluded that the two species are identical, and that A. boops is therefore a junior synonym of A. scapha. 相似文献
6.
北方春季时期印度次大陆和西藏高原的差异性增热吸引了印度洋的潮湿空气穿越印度大陆,产生了世界上最显著的西南印度夏季季风(ISM)体系(Webster,1987)。世界上大约25%的人口受到这种季节降雨的影响。20世纪60年代末期,印度约150万人死于连续3年的季风失常(重大灾害数据库,2005) 相似文献
7.
J. A. Colman 《新西兰海洋与淡水研究杂志》2013,47(4):575-579
A juvenile (26 mm) specimen of the New Zealand turbot Colistium nudipinnis (Waite) is figured and described. Differences between the juvenile and adult forms, and characters distinguishing juvenile C. nudipinnis from the young of other New Zealand species of flatfish, are noted. 相似文献
8.
采用周期性边界条件的密度泛函理论研究Zn(OH)42-在针铁矿(010)晶面的吸附结构和稳定性,得到了Zn(OH)42-吸附前后键长的变化规律。计算结果表明:当Zn(OH)42-通过共用O原子在针铁矿表面发生吸附时,平均ZnbridgeO键长较自由Zn(OH)42-的平均Zn-O键长有增长趋势,而平均Zn-O键长则有缩短趋势;Zn(OH)42-在针铁矿(010)晶面进行化学吸附时,双角DC2吸附方式为优势吸附物种。各吸附构型的稳定性顺序为DC2>SE1>DC1>SC1>SC2。 相似文献
9.
Laboratory experiments were conducted on the light-induced dissolution of three well defined Fe(III) (hydr)oxide phases (γ-FeOOH, α-FeOOH, and α-Fe2O3) with oxalate as reductant/ligand. Upon irradiation of an aerated γ-FeOOH suspension of pH 3, photooxidation of oxalate and photochemical formation of dissolved Fe(II) occurred according to a 1:1 stoichiometry. This was not observed with aerated α-FeOOH and α-Fe2O3 suspensions of pH 3, where photooxidation of oxalate was not accompanied by formation of appreciable concentrations of dissolved Fe(II). We hypothesize that in aerated α-FeOOH and α-Fe2O3 suspensions, oxidation of surface Fe(II) outcompetes its detachment from the crystal lattice. Also in deaerated suspensions, α-FeOOH and α-Fe2O3 behaved differently from γ-FeOOH with regard to light-induced dissolution. We interpret our results by assuming that light-induced dissolution of α-FeOOH and α-Fe2O3 in deaerated suspensions of pH 3 occurred mainly through Fe(II)-catalyzed thermal dissolution of the solid phases, where Fe(II) was initially formed by photoreductive dissolution and then predominantly via photolysis of dissolved Fe(III) oxalate complexes. With γ-FeOOH, on the other hand, dissolved Fe(II) formation occurred probably mainly through photochemical reductive dissolution under photooxidation of adsorbed oxalate. From our results we conclude that the efficiency of detachment of reduced surface iron is a key parameter of the overall kinetics of photoreductive dissolution of Fe(III) (hydr)oxides in aquatic systems, and that thermodynamically stable phases such as α-FeOOH and α-Fe2O3 are not readily dissolved in the presence of O2, even at low pH-values and in the presence of light and reductants like oxalate. We propose that redox cycling of iron at the surface of crystalline Fe(III) (hydr)oxide phases, i.e. reduction and oxidation of surface iron without transfer into solution, may be an important pathway of transformation of thermodynamically stable atmospheric Fe(III) (hydr)oxides into less stable and thus more soluble phases. 相似文献
10.
东山湾海水中Fe(II)和Fe(III)相互转化围隔实验研究 总被引：1，自引：0，他引：1
根据2008 年8 月与11 月在东山湾海域获得的调查资料对表层水中溶解态Fe(II)和Fe(III)含量、浮游植物叶绿素a、营养元素及其浓度等环境参数进行分析。结果表明, 夏、秋季海水中Fe(II)浓度及其在总溶解铁中所占比例均与浮游植物叶绿素a 呈正相关, 其相关系数分别为0.7959、0.9219。现场围隔实验表明, 海水中总溶解态Fe 含量在24 h 内有较大的变化, 最大减少量达到17.4%。DS2 站点海水中Fe(II)浓度及其在总溶解铁中所占比例随光照强度增加而增加。最高值与初始值相比较, 叶绿素a 较高的DS2 站点海水中Fe(II)浓度增加较叶绿素a 较低的DS5 号站点高0.053μg/L。Fe(II)和Fe(III)加富实验研究了溶解态的Fe(II)和Fe(III)在海水中相互转化。高浓度的Fe(II)在海水中被氧化成Fe(III),海水中浮游植物也会引发光还原作用使Fe(III)还原成Fe(II)。 相似文献
11.
通过实验室培养研究了旋链角毛藻(Chaetoceros curvisetus Cleve)和小普林藻(Prymnesium parvum Carter)生长周期内培养液中二甲基硫(DMS)和二甲巯基丙酸(DMSP)的含量。结果表明,2种微藻均能释放DMS,但小普林藻单细胞释放的DMS浓度约是旋链角毛藻的500倍。在藻类生长的不同阶段,它们释放DMS和DMSP的能力存在较大差异,但2种藻类DMS大量释放均出现在衰亡期。同时研究了盐度对2种微藻DMS释放的影响,结果表明高盐度会促进小普林藻DMS和DMSP的释放,而对旋链角毛藻DMSP的释放未有显著影响。 相似文献
12.
The interactions of Fe(II) and Fe(III) with the inorganic anions of natural waters have been examined using the specific interaction and ion pairing models. The specific interaction model as formulated by Pitzer is used to examine the interactions of the major components (Na+, Mg2+, Ca2+, K+, Sr2+, Cl−, SO4−, HCO3−, Br−, CO32−, B(OH)4−, B(OH)3 and CO2) of seawater and the ion pairing model is used to account for the strong interaction of Fe(II) and Fe(III) with major and minor ligands (Cl−, SO42−, OH−, HCO3−, CO32− and HS−) in the waters. The model can be used to estimate the activity and speciation of iron in natural waters as a function of composition (major sea salts) and ionic strength (0 to 3 M). The measured stability constants (KFeX*) of Fe(II) and Fe(III) have been used to estimate the thermodynamic constants (KFeX) and the activity coefficient of iron complexes (γFeX) with a number of inorganic ligands in NaClO4 medium at various ionic strengths: In(KFeX/γFeγX) = InKFeX − In(γFeX) The activity coefficients for free ions (γFe, γx) needed for this extrapolation have been estimated from the Pitzer equations. The activity coefficients of the ion pairs have been used to determine Pitzer parameters (BFeX, BFeX0, CFeXφ) for the iron complexes. These results make it possible to estimate the stability constants for the formation of Fe(II) and Fe(III) complexes over a wide range of ionic strengths and in different media. The model has been used to determine the solubility of Fe(III) in seawater as a function of pH. The results are in good agreement with the measurements of Byrne and Kester and Kuma et al. When the formation of Fe organic complexes is considered, the solubility of Fe(III) in seawater is increased by about 25%. 相似文献
13.
The osmolyte dimethylsulphoniopropionate (DMSP) can be enzymatically cleaved to dimethylsulphide (DMS), acrylate and a proton. The enzyme involved in this reaction is dimethylpropiothetin dethiomethylase (DMSP lyase; enzyme classification number 4.4.1.3.). Although the importance of this reaction for the global sulphur cycle, the influence of DMS on atmospheric acidity and the possible effect on climate regulation have been widely recognised, our knowledge of DMSP lyases is limited to just a few studies. Activity measurements of DMSP lyases offer an important step towards a better understanding of the conditions under which DMS is produced. In the available published data somewhat similar methods have been used before, but a critical examination of the method limitations has not been reported. To encourage further research on this enzyme, we suggest and detail two protocols for measurements of DMSP lyase activity: An in vitro assay for crude cell extracts or purified enzyme and an in vivo method for whole cells, which we recently started to use. After addition of DMSP, samples incubated in a gas tight vial may produce DMS from enzymatic cleavage under suitable conditions, and a DMS production rate can be estimated from time-series measurements of DMS in the headspace of the vial. Headspace analysis of DMS is a useful and rapid technique to estimate and compare DMSP lyase activities from different sources. The relative rates of DMS production in the liquid and of the gas transfer between liquid and headspace, determine the rate of DMS production measured via headspace analysis. If DMS production in the liquid is higher than the rate of transfer, headspace measurements will not reflect the actual amount of DMS produced in the liquid. In this case, extracts have to be diluted to a level that ensures linearity between dilution factor and reduction of enzyme activity. Additionally, incubation volumes and vials should be selected to provide a high surface-to-volume ratio to ensure maximum flux of DMS from the aqueous phase into the headspace. The methods can be adapted to further investigate species- and strain-specific activities, biogeographical distribution, cellular location and biochemical properties of various DMSP lyases. 相似文献
14.
D. Eggleston 《新西兰海洋与淡水研究杂志》2013,47(3-4):522-523
Further records of the leathery turtle, Dermochelys coriacea (Linnaeus), augment earlier records and perhaps indicate that this species may be a regular visitor. 相似文献
15.
The rates of the reduction of Cr(VI) with S(IV) were measured in deaerated NaCl solution as a function of pH, temperature and ionic strength. The rates of the reaction were found to be first order with respect to Cr(VI) and second order with respect to S(IV), in agreement with previous results obtained at concentrations two order higher than the present study. The reaction also showed a first-order dependence of the rates on the concentration of the proton and a small influence of temperature with an apparent energy of activation ΔHapp of 22.8 ± 3.4 kJ/mol. The rates were independent of ionic strength from 0.01 to 1 M. The rate of Cr(VI) reduction is described by the general expression
−d[Cr(VI)]/dt=k[Cr(VI)][S(IV)]2