利用催化动力学原理测定化探样中微量碘的含量

在HAc-NaAc形成的中性缓冲溶液体系中,利用碘的催化动力学原理,使N-N-四甲基-4-4-二氨基二苯甲烷与氯胺T的氧化反应,生成蓝色络合物来测定地探样中微量碘的含量。通过实验,最佳试剂加入量为8%的HAc溶液5mL,8%的Na2CO3溶液3mL,0.1%的N-N-四甲基-4-4-二氨基二苯甲烷溶液5mL所组成的溶液体系中,在加入0.1%的氯胺T1mL显色后,其测定结果准确度、精密度高,检出限低,测定化探样中微量碘时该方法可以推广应用。     

An estimation of internal soliton forces on a pile in the ocean

Internal soliton forces on oil-platform piles in the ocean are estimated with the Morison Formula. Different from sur- face wave forces, which change only in magnitude along a pile, internal soliton forces can be distributed over the entire pile in the water and they change not only in magnitude but also in direction with depth. Our calculations show that the maximum total force caused by a soliton with its associated current of 2.1 m s-1 is nearly equal to the maximum total force exerted by a surface wave with a wavelength of 300 m and a wave-height of 18 m. The total internal soliton force is large enough to affect the operations of marine oil platforms and other facilities. Therefore, the influence of internal solitons should not be neglected in the design of oil platforms.     

Exopolysaccharide production by four cyanobacterial isolates and preliminary identification of these isolates

Four marine cyanobacterial isolates, named 104, 109, 113 and 115, from marine water off China＇s coast can release a large amount of exopolysaccharide （EPS） to medium. The effects of different components in medium on EPS production by the four isolates were investigated. Under the optimal condition, the EPS released by isolates 104,109, 113 and 115 reached 7.48 g L^-1, 8.33 g L^-1, 18.26 g L^-1, and 6.78 g L^-1 within 14 d,respectively. Based on the conventional identification methods for cyanobacteria,these isolates were assigned to genus Cyanothece.     

Nonlinear coupled analysis of a single point mooring system

Coupled effects on a single point mooring(SPM) system subjected to the combined action of wind,waves and current are studied in this paper. Due to the complicatedness of the sea state and the huge size of the vessel,physical experimental study is both time consuming and uneconomical,whereas the numerical study is cost-effective and DNV software provides powerful SESAM software in solving the issues. This paper focuses on the modeling process of the SPM system,catenary equilibrium calculation,static analysis of the vessel in three different scenarios,and dynamic response simulation of the SPM system under environmental excitations. The three scenarios in study are as follows:the SPM is under the combined function of(a) wind,waves and current,(b) wind and waves,(c) current and waves. They are so set that one can compare the contributions of different types of loads in both static and dynamic studies. Numerical study shows that wind and current are the two major factors contributing to the mooring line tension,and surge and sway are the two dominant motions of the moored vessel subjected to environmental excitations.     

环境因子对浮游甲壳动物群落功能多样性的影响

基于功能性状的生物多样性分析是当前生态学研究中的常用方法之一.浮游动物作为水生态系统食物网的重要组成成分,其功能多样性受关注的程度远不如其重要性.本文通过对14个水体浮游甲壳动物群落结构的研究,分析了环境因子对其功能多样性指数,包括功能丰富度(FRic)、功能均匀度(FEve)、功能离散度(FDiv)和功能分散度(FD...     

华南桉树人工林芒萁层片的生态筛效应

芒萁是华南退化坡地上最具代表性的先锋种、优势种和关键种,能够快速形成密集的单优种层片结构。与传统阻碍更新的观点不同,野外观察发现芒萁层片内仍有少数物种能够成功定居,被认为具有生态筛效应。文章通过设置4种芒萁层片处理（芒萁层片完全剔除-UR;仅保留地上层-AF;仅保留根毯层-AR;芒萁层片全部保留-CK）,分别在不同处理下移植目标种幼苗并结合土壤性状,探究芒萁层片生态筛效应及其潜在机理。结果发现：1）桉林芒萁根毯层中土壤有机质、全氮、碱解氮、有效磷、速效钾、交换性钠、交换性钙、交换性镁和阳离子交换量均显著高于芒萁红壤层和裸地红壤;2）多数乔木种和草本种在芒萁根毯层保留时无法存活,仅荷木、桃金娘、梅叶冬青和野牡丹等目标种幼苗在保留芒萁根毯层处理（AR和CK）下能够存活与生长。这表明芒萁层片确实具有生态筛效应,且其关键在于根毯层的作用而并非土壤养分改善作用。理论上,芒萁层片（尤其是根毯层）与生态恢复的生物阈值突破密切相关,未来需要进一步解析芒萁根毯层的结构与功能。应用上,华南地区存在大量以芒萁为单优林下植物的人工林类型（如桉林等）,在进行结构优化与林分改造时需注意芒萁的生态筛效应。     

大水沟碲矿床成矿物理化学条件研究

本文在对大水沟碲矿床各成矿阶段矿物共生分析、成矿温度、矿液成分研究的基础上,对成矿的其它物理化学条件,如pH、f_O2、f_S2、f_Te2等作了热力学计算,并结合矿床地质资料,计算与分析了成矿过程中碲的迁移形式及富集机理。     

Spherical integral transforms of second-order gravitational tensor components onto third-order gravitational tensor components

New spherical integral formulas between components of the second- and third-order gravitational tensors are formulated in this article. First, we review the nomenclature and basic properties of the second- and third-order gravitational tensors. Initial points of mathematical derivations, i.e., the second- and third-order differential operators defined in the spherical local North-oriented reference frame and the analytical solutions of the gradiometric boundary-value problem, are also summarized. Secondly, we apply the third-order differential operators to the analytical solutions of the gradiometric boundary-value problem which gives 30 new integral formulas transforming (1) vertical-vertical, (2) vertical-horizontal and (3) horizontal-horizontal second-order gravitational tensor components onto their third-order counterparts. Using spherical polar coordinates related sub-integral kernels can efficiently be decomposed into azimuthal and isotropic parts. Both spectral and closed forms of the isotropic kernels are provided and their limits are investigated. Thirdly, numerical experiments are performed to test the consistency of the new integral transforms and to investigate properties of the sub-integral kernels. The new mathematical apparatus is valid for any harmonic potential field and may be exploited, e.g., when gravitational/magnetic second- and third-order tensor components become available in the future. The new integral formulas also extend the well-known Meissl diagram and enrich the theoretical apparatus of geodesy.     

沙漠地区无人机影像连接点提取

提出了一种纹理自适应的影像连接点提取方法,有针对性地解决沙漠地区无人机影像对比度低、相似性强、纹理信息不均衡,经常会造成连接点过少甚至提取、匹配失败的突出问题。该方法利用影像金字塔进行粗匹配,建立影像之间近似单应变换关系;通过对原始影像分块计算灰度共生矩阵的熵来评估影像纹理指标,并据此实现特征点的自适应提取与匹配。实验表明,该方法能够得到数量较多、分布均匀、可靠性强的同名点。     

从NOAA卫星AVHRR资料反演中国区域地表反照率

由NOAA卫星AVHRR短波通道1、2反射率反演地表反照率需要3个反演模式,分别是窄-宽波段反射率转换模式、大气顶双向反射模式、大气订正模式.基于模式和国家卫星气象中心接收处理的NOAA-18 AVHRR1B数据,处理了2006年1月至2010年12月的中国区域地表反照率,由于云的影响,15天合成技术用来形成周期为15天的地表反照率数据文件.2006年、2010年2年的处理结果与MODIS同类产品对比,RMS为0.028～0.074、相关系数为0.76～0.93,误差较大出现在冬季,原因是两者15天合成方法不同;5年的日平均地表反照率与21个中国地面气象一级辐射站的观测测值作对比,结果是：RMS为0.053、相关系数为0.88.反演模式系统误差以及云和气溶胶影响是卫星反演地表反照率的主要误差来源.