Urban rivers represent a unique ecosystem in which pollution occurs regularly, leading to significantly altered of chemical and biological characteristics of the surface water and sediments. However, the impact of urbanization on the diversity and structure of the river microbial community has not been well documented. As a major tributary of the Yangtze River, the Jialing River flows through many cities. Here, a comprehensive analysis of the spatial microbial distribution in the surface water and sediments in the Nanchong section of Jialing River and its two urban branches was conducted using 16S rRNA gene-based Illumina MiSeq sequencing. The results revealed distinct differences in surface water bacterial composition along the river with a differential distribution of Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes and Acidobacteria (P < 0.05). The bacterial diversity in sediments was significantly higher than their corresponding water samples. Additionally, archaeal communities showed obvious spatial variability in the surface water. The construction of the hydropower station resulted in increased Cyanobacteria abundance in the upstream (32.2%) compared to its downstream (10.3%). Several taxonomic groups of potential fecal indicator bacteria, like Flavobacteria and Bacteroidia, showed an increasing trend in the urban water. PICRUSt metabolic inference analysis revealed a growing number of genes associated with xenobiotic metabolism and nitrogen metabolism in the urban water, indicating that urban discharges might act as the dominant selective force to alter the microbial communities. Redundancy analysis suggested that the microbial community structure was influenced by several environmental factors. TP (P < 0.01) and NO3- (P < 0.05), and metals (Zn, Fe) (P < 0.05) were the most significant drivers determining the microbial community composition in the urban river. These results highlight that river microbial communities exhibit spatial variation in urban areas due to the joint influence of chemical variables associated with sewage discharging and construction of hydropower stations. (c) 2018 Elsevier B.V. All rights reserved.

对青岛仰口湾两条海滩横剖面的64个表层沉积物样品进行粒度参数特征分析,结合相关地质水文及地形观测资料,探讨了潮间带的沉积物输运趋势.结果表明:研究区存在3种沉积类型,以含砾砂(g)S为主,砾质砂gS和砂质砾sG类型零星分布,几乎没有黏土组份,或含量极低.研究区海滩表层沉积物平均粒径呈带状由陆向海变细,分选变好;偏态多数为正偏,到低潮带附近逐渐变为负偏;整体峰态较尖锐,峰态多样.波浪和风是本区沉积物输运的主要动力,海滩北部夏季受到波浪的影响最大,表现为剖面整体高程降低,沉积物较粗,分选较差,偏态值高,峰态尖锐,其次为中南部的秋、冬两季.

During the NSFC cruise in October 2010,several water samples were recovered along a typical section at the Changjiang Estuary and its adjacent area for study of suspended matters.After filtration,the materials remained were examined under Electronic Microscope and by Energy Spectrometer.Grain size analysis was carried out for the samples.In this typical section,there are four types of particles,mineral debris,bioclasts,organic particles and floc-particles.The contents of mineral debris and organic particles are higher inshore and lower offshore,whereas the bio-particles are distributed in an opposite pattern.However,floc-particles have no obvious change from DH1 to DH6.There is a good linear relationship between floc-particles and organic particles,but a negative relationship between mineral debris and bioclasts.In the suspended matters,the particles smaller than 10 microns in size account for 70%,and those smaller than 20 microns account for 90%,while the average particle size is decreasing offshore.It is believed that the types of particles are mainly controlled by the factors of continental input,biological process,flocculation and resuspension,depending upon the movement of water masses.

An international workshop on capacity building (CB) for marine research in the Asia‐Pacific region (http://www.imber.info/index.php/Science/Working‐Groups/Capacity‐Building/2012‐CB‐Workshop) was held at the East China Normal University (ECNU), in Shanghai, China. The workshop brought together about 20 marine researchers and CB experts from 14 countries to discuss CB experiences, assess regional CB needs, and consider recommendations to improve regional CB, which would be of interest to other groups and other geographical regions.

基于2010年10月在长江口海域海洋综合调查,利用多参数CTD现场调查数据、悬浮体浓度测定数据,对该区悬浮体和叶绿素的空间分布及影响因素进行系统的研究,探讨三峡工程蓄水7a以来长江口的悬浮体和叶绿素的分布特征及变化.结果表明:浊度值与悬浮体浓度存在良好的线性关系,盐度对该线性关系没有明显的影响;长江口及其邻近海域悬浮体主要分布在123°E以西的海域,表现为近岸高、离岸低,表层低、底层高,其分布主要受到水团、长江输入、上升流等的影响;叶绿素在123°E往东的海域含量较高,近岸低,在123°E～124°E之间叶绿素含量最高,其分布主要受到水团、浮游植物种类和季节变化及营养盐的共同影响.与三峡工程蓄水前对比,悬浮体高值区的界限往西移动了近半个经度,同季节的叶绿素含量的平均值降低.

The Princeton Ocean Model (POM) is a three-dimensional baroclinic ocean model based on the original equations, using a sigma coordinate in the vertical coordinate to deal with significant topographical variability, and has been widely used for estuary and coastal ocean simulation. Wetting and drying is a common and important phenomenon of the coastal ocean, and the process could not be simulated by POM using fixed boundaries. In this paper, we simulate the tides and tidal currents of Shenzhen Bay in China with POM coupling with an improved wetting and drying scheme. In order to simplify the calculation, a coordinate transformation is used to arrange the model domain. The modeled results agree well with the observed data and truly inflect the hydrodynamic characteristics of the sea, and successfully simulate the wetting and drying process of tidal flats as well. Based on the new definition of water depth, the improved wetting and drying scheme can also be used to simulate floodplain of a storm surge.

From the elastic wave equations in transversely isotropic medium with a tilted symmetry,a high-order finite difference scheme was established using a high precision operator in staggered-grid.Proposed an perfectly matched absorbing layer(PML) boundary conditions and studied its computing methods.Based on above two techniques,the forward modeling of seismic wave fields in complex anisotropic media was implemented.The numerical tests show that the method can simulate the seismic propagation accurately and can obtain high precision multi-component seismograms.

The electric prospecting is based on the rock's differentia in electromagnetic and electrochemical property,which can be used in space,land,marine and subterranean area.It is usually used to explore metal and nonmetal mineral and geology structure such as oil,gas,coalfield and so on.It can also detect hydro-geology project,city environment,construction foundation and condition of paving underground pipe.The high-density electric method is characteristic by small dot space,high density data acquisition and efficiency.It is increasingly becoming a common method in detecting pipe,finding water and investigating geology disaster.The thesis introduces the application example of use of high density electric method in finding water in Jimo.

Starting from two-way acoustic wave equation and arbitrary wide-angle acoustic wave equation respectively,the paper deduced high-order finite-difference format of seismic wave reverse-time propagation,gave the stability and boundary conditions of reverse-time migration and algorithm of imaging condition,realizing the reverse-time migration of two acoustic wave equations in 2-D isotropic medium.The migrated results of theoretical data by using above mentioned two kinds of equation showed the reverse-time migration of two-way acoustic wave equation is free from the limitation of dip,but interbed reflections may have serious influence on the quality of migrated sections;the arbitrary wide-angle acoustic wave equation can eliminate the influence of interbed reflections,getting better imaging results.

The paper studied two methods of coal fracture inversion with multiwave components seismic data.Firstly,based on forward seismograms of anisotropic media,the paper studied the polarization characteristics of P-SV wave,and then analyzed the practicability and principles of obtaining the fracture parameters underground by means of the azimuth gathering.Secondly,the paper proposed a new fracture parameters inversion technique from which the fracture azimuth is obtained by a multi-trace scan technique in common conversion point(CCP) gathering.The application of field data has proved the accuracy and reliability of these two methods.

Start from the elastic wave equations for transverse isotropic medium with a horizontal axis of symmetry,a high-order finite difference scheme is established using a high precision operator in staggered-grid.The paper also proposed a perfectly matched absorbing layer(PML) boundary condition and studied its computing methods.Based on above two techniques,the forward modeling of seismic wave fields in complex anisotropic media is implemented.The numerical tests imply that the method can simulate the seismic propagation accurately and can obtain high precision multi-component seismograms.

Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease （0.84%~1.88%） of organic carbon content from the upper reaches to the estuary. δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1 μg/dm3, or from 23.7 to 107 μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4 μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs （soil organic matter） among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream.

Shenzhen Bay (SZB) in the east Pearl River Estuary, ChinaEither NO3− or NH4+ is the dominant component of dissolved inorganic nitrogen (DIN) in most estuarine waters, but few studies focused on the mechanisms of ongoing DIN transformations under various hydrologic regimes. This analysis spans 31 years of DIN component changes and involves numerical simulations to identify the roles of various driving factors including runoff and biogeochemical actions. These new insights into DIN change mechanisms from the coupling biogeochemical and hydrodynamic processes would help to boost effective mitigation measures to deal with nitrate accumulation in estuarine waters, thereby supporting integrated land-ocean nutrient management.The dominant DIN component in the SZB was found to transition from NH4+ to NO3− between 1990 and 2020. Particularly in the -upper bay, there was an unexpected increase in the mean concentration fraction of NO3− in DIN, rising from 19.5% (1990‐2017) to 65.5% (2018‐2020). This change can be partially attributed to reduced runoff NH4+ inputs. Both runoff and tidal current can transport NH4+ and NO3−downstream, but the high background levels of NO3− in the lower bay contributed to sustaining NO3− in the upper bay through ebb and flow. Biogeochemical actions further strengthened the decline of NH4+ and the rise of NO3−. Even in scenarios without terrestrial source inputs, the simulated biogeochemical processes continued to help reduce NH4+ levels throughout the bay while increasing NO3− concentrations in the middle and lower bay.

在遥感信息反演的经验模式中,是利用离散的实测点数据与相应的影像对应像素的光谱值找出关系,建立遥感信息反演模型,从而反演出感兴趣的信息.要读出影像上对应点的灰度值,需要先找出相应影像上的对应点的像素行列值.主要介绍了用matlab实现的利用实测离散点计算遥感影像上对应像素的一种方法,实例表明配准效果良好,提取灰度简单可行.解决了计算出实测点对应影像上相应的像素这一遥感信息反演中的首要问题.

As part of a project investigating the air-water exchange of nutrients and inorganic micropollutants to the North Sea, the atmospheric deposition of nutrients and trace metals in their different compositions and via various pathways was investigated. Intensive sampling campaigns were organised on the research vessel Belgica (ns 21/98 campaign from September 28 to October 1, 1998 and ns 10/99 campaign from April 19 to 23, 1999), at a sampling station near the Belgian coast (Knokke-Heist) and at the University campus of Antwerp. Simulation work and remobilisation experiments were carried out to obtain a general view of the kinetics of solubilisation of the constituents under investigation. Sample treatment requires a leaching system with a quantitative recovery of the species of interest in the leaching solution within a reasonably short period of time (30 min).For this reason, a re-circulation leaching system was developed, tested, optimised and compared with a more accepted ultrasound leaching method.