微分多项式分担1个公共值的亚纯函数的唯一性

本文证明了非常数的亚纯函数的一类非线性微分多项式及其同次幂分担1的一个唯一性定理,该结果改进了张继龙和杨连中的相应结果。     

涉及q-差分微分多项式的亚纯函数的唯一性

本文研究亚纯函数及其q-差分算子或差分算子的1类非线性多项式的导函数分担1个非零公共值的亚纯函数的唯一性问题,这些问题涉及2009年方明亮提出的1个涉及微分多项式的亚纯函数的唯一性问题。本文结果推广了方明亮等人的有关结果。     

涉及微分多项式和差分多项式的亚纯函数的唯一性

应用差分Nevanlinna理论研究亚纯函数及其移动算子或差分算子的1类非线性微分多项式分担1个非零公共值的亚纯函数的唯一性问题。本文结果部分回答了2009年方明亮提出的1个涉及微分多项式的亚纯函数唯一性问题,推广了Lahiri[6]、杨重骏和华歆厚[7]和方明亮[8]中的相应结果。     

非线性微分多项式分担一个非零拟公共值的亚纯函数的唯一性

本文利用A.Banejee与S Mukherjee的方法证明了一类非线性微分多项式具有一个2阶拟公共值的亚纯函数的唯一性定理,改进了方彩云与方明亮,I.Lahiri与Mandal,以及A.Banerjee等人的有关结果.     

一类Painlevé差分方程与亚纯函数的唯一性

假设f是Painlevé差分方程■的有穷级非常数亚纯解,其中■和■是关于f的两个多项式,且P(f)与Q(f)互素,它们的系数{a_k},{b_j}均为f的小函数,且a_p?0和b_q?0。再设g是一个非常数的亚纯函数,如果f与g CM分担3个判别的有限值c₁,c₂和c₃,且■,那么f=g。本文主要结果涉及Ablowitz-Halburd-Herbst中的相应结果,研究了非常数的亚纯函数与有关Painlevé方程的非常数的有穷级亚纯解CM分担3个公共值的唯一性问题,并研究了有关Painlevé方程的有穷级非常数亚纯解的值分布问题。     

涉及三个分担值的一类复差分Painlevé方程亚纯解的唯一性

2007年Halburd-Korhonen研究了具有1个非常数的有穷级亚纯解的Painlevé方程(f+f)■的分类问题。在此基础上,本文研究了该类复差分Painlevé方程的1个有穷级非常数亚纯解与1个非常数的亚纯函数CM分担3个有限值的唯一性问题。本文结果是Halburd-Korhonen研究结果的补充,对于加深该类Painlevé方程的有穷级非常数亚纯解的值分布问题的理解有重要意义。     

涉及非线性微分多项式的亚纯函数的周期性

本文利用Nevanlinna理论,研究了涉及一类非线性微分多项式的超越亚纯函数的周期性问题,并举例说明本文得到的主要定理的有关条件是最佳的。所得结果改进并推广了2018年王琼和扈培础的有关结果。     

涉及差分多项式的值分布和唯一性问题

本文在条件N(r,1/f)+N(r,f)=S(r,f)下研究了超级小于1的亚纯函数f的1类非线性差分多项式的值分布问题,改进了Laine-Yang^[4]中的相应结果.本文也分别研究了具有1个非零公共值的1类非线性微分多项式和差分多项式的唯一性问题,推广了Yang-Hua^[14]和方明亮^[15]中的相应结果。     

关于超级有穷条件下角域内的亚纯函数的唯一性

研究了复平面上的亚纯函数在超级有穷条件下在角域内分担2个有限集合的唯一性问题,改进和推广了仪洪勋和林伟川,以及吴召君等人的有关结果。     

关于整函数及其k阶导数的唯一性

在亏量和等于1的条件下,证明了整函数及其k阶导数具有2个IM公共小函数的整函数的1个唯一性定理,部分回答了李平和杨重骏于2002年提出的1个问题,并改进了先前已有的结果.     

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.