珍珠生长激素在合浦珠母贝育珠中的作用

以合浦珠母贝Pinctadamartensii（Dunker）作为珠母贝进行插核育珠试验,分别以其左、右边外套膜作为小片,并用珍珠生长激素浸泡小片。两个试验组用珍珠生长激素浸泡的小片各插核育珠贝200个,空白对照组用海水浸泡小片括核育珠贝207个,育珠时间为6个多月。试验结束时,实验组珍珠的正圆珠率、白色珍珠比例以及珠层厚度比空白对照组分别提高了9.28％,22．57％和52μm。     

术前处理和室内水池休养对提高珍珠产量和质量的影响

作者在近几年的珍珠生产中发现,育珠贝成活率很低,从母贝植核到收珠,育珠贝成活率不到５０％,有的仅在休养期就死亡５０％～６０％;其次,育珠贝的留核率,平均只有２５％～３５％,而所产珍珠颗粒小、珠层薄、形状差、销路不畅,造成珍珠养殖场生产效益差,在国际市场上缺乏竞争力。为此,１９９５年４月１日～１０月３１日,作者在湛江水产学院珍珠试验场进行了一系列提高珍珠产量和质量的试验工作。其中以术前处理和室内地休养效果最显著。１材料和方法１．１试验材料１．１．１试验用贝选自湛江市硇洲岛、徐闻县和安镇以及雷州市覃…     

珍珠生长激素在合浦珠母贝育珠中的作用

以合浦珠母贝Ｐｉｎｃｔａｄａ ｍａｒｔｅｎｓｉｉ （Ｄｕｎｋｅｒ）作为珠母贝进行插核育试验,分别以其左、右边外套膜作为小片,并用珍珠生长激素浸泡小片,两个试验用珍珠生长激素浸光怕小片各插核育珠贝２００个,空白对组用海水浸泡小片插核育珠贝２０７个,育珠时间为６个多月。试验结束时,实验组珍珠的正圆珠率,白色珍珠比例以及珠层厚度在比空白对照组分别提高了９．２８％,２２．５７％和５２μｍ。     

一种实用的极谱恒电位装置

近年来，极谱分析特别是催化极谱和阳极溶出伏安法，由于其灵敏度高．设备简单，在微量和超微量分析中得到普遍重视，并广泛用于各种实际工作．利用极谱方法研究水溶液体系中元素的存在形态和动力学过程的工作，亦已逐渐开展。但是，当溶液中电解质含量过低，例如在有机溶液、     

合浦珠母贝贝壳珍珠层EDTA可溶性基质蛋白对无定形碳酸钙稳定性的影响

通过红外光谱、扫描电镜、能谱等方法探讨了合浦珠母贝贝壳珍珠层EDTA可溶性基质蛋白(ESM)对无定形碳酸钙(ACC)晶型转化的影响。试验结果显示,合浦珠母贝贝壳珍珠层ESM在镁离子存在的条件下能够显著抑制ACC的转化,并减少最终诱导形成的方解石中的镁离子含量。同时,珍珠层ESM具有调节方解石晶体晶貌的作用。     

不同气氛下多孔硅中电子偶素湮没行为研究

使用正电子湮没谱学方法,在不同气氛下对电化学腐蚀法制备的多孔硅中电子偶素的湮没行为进行了系统的研究.正电子湮没寿命谱测试结果表明,样品中存在长达40 ns的电子偶素湮没成分,并且进入多孔硅膜层的正电子约有80%形成电子偶素,具有非常高的电子偶素产额;在氧气气氛下,由于气体导致o-Ps发生自旋转化猝灭是使多孔硅样品中电子偶素寿命缩短的主要原因.结合正电子寿命-动量关联谱测量结果,分析了不同气氛下多孔硅样品中电子偶素湮没寿命及动量变化关系,讨论了多孔硅中电子偶素的湮没机理以及气氛对孔径计算理论模型的影响.     

从市场角度探讨养殖有核珍珠的质量

养殖有核珍珠是指珍珠贝在人工养殖（含插核）下形成的珍珠。这类珍珠 ,大多数用于装饰品 ,只有少数供医药用。随着养殖珍珠饰品业的大发展 ,珍珠及其饰品的质量问题也凸现出来了。具体地说 ,在珍珠饰品市场上 ,一些商人为了追求眼前利益 ,把一些劣珠或下等珍珠 ,通过加工变色、抛光和修饰后流入珍珠市场 ,蒙骗顾客当作好珠或上等项链出售。一些顾客 ,买了这些项链佩戴不久 ,珍珠层很快磨损 ,色彩很快消失。这种情况发生后 ,给整个珍珠市场以极大的冲击 ,所造成的影响也是难以估量的。解决这些问题的关键是抓好珍珠质量关。要抓好珍珠质量关…     

南海深水区双峰型海浪谱特征研究

基于南海深水区波浪实测资料,对双峰型海浪谱的演化过程进行了分析,并对双峰型海浪的波高、波向、谱峰周期、出现时间和常用双峰谱模型的适用性等方面进行了研究。结果表明,双峰型海浪出现时波高普遍小于2m,其涌浪部分谱峰周期约11.37s;Ochi-Hubble谱在南海的适用性较好。研究成果可为南海深水区油气资源的开发、设计提供参考。     

X-射线荧光光谱法定量分析海山富钴结壳中MnO2与MnO的含量之比值

通过普通X-射线荧光光谱仪,结合PeakFit谱峰处理软件,对不同比例的MnO和MnO₂的混合样品的K_β谱峰参数进行了研究,用数学方法将实测的谱峰分解为各个单一的谱峰参数(峰位、峰高、半高宽、子峰面积),找出了各个谱峰参数与不同价态锰的含量之间的关系,并据此确定了中太平洋海山区大量富钴结壳样品中不同价态锰的相对含量.分析结果显示,富钴结壳中+4价锰从核心向外有增高的趋势,可以认为这与该区第三纪以来南极底流活动的增强有关.     

铜合金在海水中电化学阻抗谱特征研究

利用电化学阻抗谱(EIS)对紫铜和铜镍合金在静止、洁净海水中表面成膜的过程进行了监测，根据不同阶段的EIS特征建立不同等效电路模型进行拟合分析。获得了铜合金基体及其表面膜层对应的界面电化学信息参数，通过比较3种金属(B10，TUP，B30)表面膜层随时间变化的差异。探讨了合金成分对表面成膜过程的影响。结果表明。浸泡前期B10和TUP的耐蚀性较差，但随着海水中浸泡时间增加，三者的耐蚀能力逐渐接近。TUP的EIS显示了其表面内、外膜层信息。B10表面膜层的成长速度和稳定性均不如B30，反映出合金中镍含量的增多，增加了铜镍合金表面成膜产生钝化的效应。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance.     

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。     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

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.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations.     

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,     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.