Effects of an artificial reef system on demersal nekton assemblages in Xiangshan Bay, China

In 2012,an artificial reef system was deployed in Xiangshan Bay,China,to enhance its fishery resources. To determine the effect of the artificial reef system on the demersal nekton assemblages,a beforeafter-control-impact study design was applied. Comparisons of assemblages from impact and control habitats revealed that the assemblage in the impact area had a gradual response to reef deployment. The assemblages in the impact and control areas changed in different ways after reef deployment. During the study period,total biomass,species richness and average body weight in the control area remained relatively stable,whereas there were significant increases in these indicators in the impact area. Responses to the reefs differed among nekton species,inducing assemblage succession in the reefs post-deployment. Sparus macrocephalus and Cynoglossus abbreviat us benefited most from reef deployment. Conversely,smallsized shrimp Palaemon gravieri showed a progressive decrease in biomass following reef deployment. Overall,the artificial reef system diversified the demersal nekton assemblage,enhanced the total biomass,and increased the proportion of large-sized species.

Spatio-temporal distribution of net-collected phytoplankton community and its response to marine exploitation in Xiangshan Bay

To explore the spatial-temporal distribution of the phytoplankton community and evaluate the combined effects of marine resource exploitation, net-collected phytoplankton and physical-chemical parameters were investigated in the Xiangshan Bay during the four seasons of 2010. A total of eight phyla, 97 genera, and 310 species were found, including 232 diatom species, 45 dinoflageUate species and 33 other taxa. The phytoplankton abundances presented a significant （P〈0.001） seasonal difference with the average of 60.66x104 cells/m3. Diatoms （mainly consisting of Coscinodiscus jonesianus, Cerataulina pelagica, Skeletonema costatum, and genus Chaetoceros） dominated the phytoplankton assemblage in all seasons. We found great spatio-temporal variation in community composition based on the multidimensional scaling and similarity analysis. Canonical correspondence analysis show that temperature, nutrition, illumination, and salinity were the main variables associated with microalgal assemblage. Compared with the previous studies, an increase in phytoplankton abundance and change in the dominant species coincided with increased exploitation activities in this bay （e.g. operation of coastal power plants, intensive mariculture, tidal fiat reclamation, and industrial and agricultural development）. The present findings suggest that the government should exercise caution when deciding upon developmental patterns in the sea-related economy.

A numerical study on the effect of tidal flat's slope on tidal dynamics in the Xiangshan Bay, China

The Xiangshan Bay is a semi-enclosed and narrow bay, which is characterized by large scale tidal flats and has been historically utilized through coastal construction and aquaculture engineering. The hydrodynamic model using the Finite Volume Coastal Ocean Model（FVCOM） was constructed to examine the changes of tidal dynamics due to the variation of tidal flat slopes. According to the model results, a decreased slope of a tidal flat would amplify the M2 tidal amplitude and delay the M2 tidal phase in the inner harbor, due to an increased tidal prism, and vice versa. The amplitude of the main shallow-water tide M4 would be amplified/dampened in the entire bay due to the changed bottom friction, if the tidal flat＇s slope were reduced/increased at the Tie inlet. The phase was advanced. The change of a tidal flat＇s slope at the Tie inlet had greater impacts on tidal amplitude,phase and duration asymmetry, than that at the Xihu inlet. The impact of changes of the tidal flat slope at the Xihu inlet was small and was constrained locally. Changes in the tidal flats＇ slopes at the Tie and Xihu inlets changed the tidal duration asymmetry, residual current and tidal energy via modulating tides. The ebb dominance decreased when the tidal flat＇s slope at the Tie inlet was changed. Decreased/increased ebb dominance occurred when the tidal flat＇s slope was reduced/increased at the Xihu inlet. The residual current and tidal energy density was amplified/dampened and more/less tidal energy was dissipated, with reduced/increased slope at both of the inlets. The findings in this study are instructive to coastal engineering and estuarine management.

Research on changes of coastal land use intensity in bay area during past 30 years——A case study of Xiangshan Bay

Taking the coastal zone of Xiangshan Bay as a study area,based on the information of four TM images of1985,1995,2005,and2015,this study divided the land use types into8categories.Then,through calculating4kinds of index models:land-use dynamic index,conversion matrix,land use structure information entropy,and comprehensive index of land development and utilization intensity,the speed,structure,degree,and the spatial-temporal changes in the land development and utilization of Xiangshan Bay coastal zone from1985to2015are researched and analyzed.Results showed that:from1985to2015,the expansion speed of aquaculture land and salt pan of Xiangshan Bay coastal zone was the fastest,the highest dynamic degree could up to11.97%,construction land expansion rate of the second,with significant increase in the area.Intertidal zone reduced by a maximum speed,and the area of farmland decreased obviously.In that30years,the main land type change direction of Xiangshan Bay coastal zone was the farmland turn into construction land,followed by forest turn into farmland.Information entropy increased by period,the land use structure homogeneity constantly strengthened and regional development became gradually mature.The change rate of land use intensity in each period was greater than zero,and the intensity of land development and utilization in Xiangshan Bay coastal zone was enhanced continuously.

The benthic diatom community of Xiangshan Bay

The samples collected from the surface sediments in Xiangshan Bay,Zhejiang province in May and November 2005 were analyzed under a light microscope.The species composition,abundance,community structure and diversity were investigated.A total of 179 taxa belonging to 46 genera of diatom were identified.The result showed that the ecotypes of diatom were mostly eurytopic species,followed by warm water species and temperate species.The most dominant species were Cyclotella stylorum and Coscinodiscus jonesianus.The seasonal variation of diatom abundance was remarkable.The cell abundance of diatoms was higher in spring(2.974×10^3 cells/g)than that in autumn(0.071×10^3 cells/g).The number of species varies with change of season,demonstrating the adaptability of diatoms to the temperature of water.The species diversity of benthic diatom was lower in autumn than that in spring.

A Numerical Study of Tidal Asymmetry: Preferable Asymmetry of Nonlinear Mechanisms in Xiangshan Bay, East China Sea

In-situ measurements in Xiangshan Bay, the East China Sea, show that the duration of the rising tide is shorter than that of the falling tide around the bay mouth, while it becomes much longer in the inner bay. A finite volume coastal ocean model(FVCOM) with an unstructured mesh was applied to simulate the asymmetric tidal field of Xiangshan Bay. The model reproduced the observed tidal elevations and currents successfully. Several numerical experiments were conducted to clarify the roles of primary mechanisms underlying the asymmetric tidal field. According to the model results, the time-varying channel depth and nonlinear advection prefer shorter duration of the rising tide in Xiangshan Bay, while the time-varying bay width favors longer duration of the rising tide. The overtides generated by these two opposite types of nonlinear mechanisms are out of phase, resulting in smaller M4 amplitude than the sumfold of each individual contribution. Although the bottom friction as a nonlinear mechanism contributes little to the generation of overtide M4, it is regarded as a mechanism that could cause a shorter duration of the rising tide, for it can slow down the M2 phase speed much more than it slows down the M4 phase speed. The time-varying depth, nonlinear advection and bottom friction are dominating factors around the bay mouth, while the time-varying width dominates in the inner bay, causing the tidal elevation asymmetry to be inverted along the bay.

Tide-induced Lagrangian residual velocity and dynamic analysis based on field observations in the inner Xiangshan Bay,China

In the Xiangshan Bay at the east coast of China,coastal marine pollution is conspicuous and severe in recent years.As transport of the pollutants is closely related to the coastal circulation,there is a great practical significance to investigate the circulation in this area.In this work,the surface pattern and vertical profiles of Lagrangian residual velocity(LRV)were studied based on field observation data from the inner Xiangshan Bay.By tracking GPS-GPRS drifters’trajectories,the surface LRV pattern is going out in the central deep trough and flowing inwards near the shoreside.Combined with data from two mooring stations,vertical profiles of LRV is flowing out at surface and flowing in at the bottom,consistent with the gravitational circulation induced by baroclinic effects at the estuary.However,according to the diagnostic analysis,the main mechanism driving the residual current is barotropic rather than baroclinic.The LRV equation is controlled by the tidally-averaged barotropic pressure gradient force,tidal body force and tidally-averaged turbulent stress,while the tidallyaveraged baroclinic pressure gradient force is one order of magnitude less than other forces.Additionally,the tidally mean eddy viscosity coefficient which is used in the expression of tidally-averaged turbulent stress might be not adequate and requires further studies.

A Comprehensive Lagrangian Transport Study in A Long-Narrow Bay,Xiangshan Bay,China

Study on the transport and mixing in coastal waters is of great concern to the ocean resources exploitation and ecological system protection.Lagrangian methods are direct and effective of researching mass transport.Two Lagrangian tools were adopted and combined to describe water transport in a long-narrow bay,Xiangshan Bay,China.Based on the fields of tidal velocity simulated from the 3-D hydrodynamic model,Lagrangian Coherent Structures(LCSs)and synoptic Lagrangian maps(SLMs)were calculated in the study area.Through comparison of the results,the features and relation of the two tools were discussed.The results show that the LCSs act as the separatrix of the water regions with different transport characteristics and can identify the water areas with different transport time scales.The comprehensive application of the Lagrangian tools is helpful to obtain more insight into the water transport process.

Detecting and assessing Spartina invasion in coastal region of China： A case study in the Xiangshan Bay

Spartina alterniflora is one of exotic plants along the coastal region in China. It was introduced as an important engineering approach to ecological restoration in the later 1970 s. However, owing to its good adaptability and strong reproductive capacity, the introduced species is explosively spreading along the coastal region quickly and resulting in a significant impact on the health and safety of coastal wetland ecosystems. It is imperative to quantify the spatial extent and the rate of S. alterniflora sprawl in order to assess its ecological damages and economic impacts. Remote sensing techniques have been used to address these challenges but large unsuccessful due to mixed spectral properties. In this study, a hybrid method was proposed for S. alterniflora detection using medium resolution remote sensing images by integrating both spatial and spectral features of S. alterniflora. The hybrid method consists of two phases：（1） delineation of intertidal zone as the potential area of S. alterniflora distribution and（2） extraction of S. alterniflora fraction distribution with a mixture pixel analysis. The proposed method was tested at the Xiangshan Bay on the east coastal region of Zhejiang Province, China, and mapped the spatial extent of S. alterniflora with Landsat datasets in the 2003, 2009 and 2014. The results showed that, the S. alterniflora has grown exponentially over past 10 years. In 2003, the total area of S. alterniflora was about 590 hm2, but quickly reached to 1 745 hm2 in 2009, and 5 715 hm2 in 2014. With a rate of approximately 10-folds growth within a decade, the invasive species almost occupied all muddy beaches to become the most dominant coastal salt vegetation in this region. It is believed that the strong biological reproductive capacity was the primary reason for such quick spread and at the same time human reclamation activities were also believed to have facilitated the environmental conditions for S. alterniflora sprawl.

加拿大Voisey's Bay Ni-Cu-Co硫化物矿床岩浆通道成矿系统——小岩体成矿典型实例

Voisey′s Bay岩体(VBI)位于加拿大拉布拉多岛北部中元古代Nain深层岩套(NPS)中,Voisey′s Bay Ni-Cu-Co硫化物矿床的成岩成矿时代为1.34Ga。岩体主要由Western Deeps岩体和Eastern Deeps岩体组成,它们由1条隐伏的岩浆通道所连接,矿体就位于岩浆通道中,形成典型岩浆通道成矿系统。在Voisey′sBay地区同时代岩体有很多,相对于相邻的其他岩体来说,Voisey′s Bay岩体体积最小,到目前为止,只有Voisey′s Bay岩体形成了大型Ni-Cu-Co硫化物矿床,是小岩体成大矿的典型实例。

二项分布Bayes鉴定试验次数的选择与分析

讨论了二项分布的可靠性Bayes鉴定试验方案问题。在试验样本量一定的条件下,充分利用验前信息弥补现场试验信息的不足,从平均后验风险角度制定了成败型系统可靠性鉴定试验的Bayes方案。密切结合工程试验,从生产和使用双方的实际风险的角度,研究分析了Bayes可靠性鉴定试验与评估的联系与差异。最后,与传统的鉴定试验方案进行了分析比较,明确了Bayes方法的使用范围,对于工程试验方案的选择具有实际的指导意义。

估计构件疲劳极限的Bayes极小样本方法

从材料的S—N曲线与构件的S—N曲线形状相似原理出发,结合Bayes估计理论和加速寿命试验理论,提出一个估计构件疲劳极限的极小样本方法。在疲劳寿命服从对数正态函数分布的假设下,研究常幅和变幅载荷作用下由构件的疲劳寿命计算其疲劳极限的问题。两个算例表明,文中提出的方法利用以往积累的大量疲劳试验数据和现场试验数据,估计构件的疲劳极限,计算方便。计算结果与传统方法确定的疲劳极限的结果符合较好。

基于Bayesian思想的最优Copula函数选择

作为一种有效的数据建模工具,Copula在金融领域中得到了广泛应用.本文针对如何选择最优的Copula函数这一在应用中亟待解决的问题进行研究,基于Bayesian思想提出了一种选择方法.所提方法具有良好的理论基础,且应用方便.在模拟数据和原油市场数据上的实验表明,所提方法具有良好的最优Copula函数选择效果,明显优于基于K-S检验的方法.

Bayés综合征:房间传导阻滞与室上性心律失常

房间传导阻滞不仅是室上性心律失常的预测因子,也是一个独立的临床病症,目前认为其与心脏不良事件的发生相关。尽管有证据表明早期治疗房间传导阻滞可能有益,但目前还没有确切的治疗方法。现系统性回顾Bayés综合征的临床基本情况。

Petrologic composition model of the upper crust in Bohai Bay basin,China,based on Lamé impedances

Seismic attributes, such as P- and S-wave velocity, Poisson＇s ratio, and acoustic impedances, all generally can be used for distinguishing different rock types. The nonuniqueness can be largely reduced using Lame impedances instead of acoustic impedances as additional constraints. We have followed this method to constitute a petrologic composition model of the upper crust in the Bohai Bay basin, China. We briefly review the seismic parameters used for discrimination of rock types and focus our attention on the sensitivity of different combinations of parameters to determine the composition of materials. Corrections for pressure and temperature are performed in order to compare elastic wave velocities and densities measured at room temperature and surface pressure in laboratory with those for representative rock parameters. In a second step, we find the rock classes in the tested area by contrasting known data to laboratory measurements on a variety of rock samples extracted in the area. The basic field data are P-wave velocity values collected along a seismic profile conducted in the Bozhong Depression. The different rock types belonging to a particular rock class are finally constrained by the seismic velocities, Poisson＇s ratio, density, acoustic impedance, and Lame imoedance related to the topmost 10 km of the Bohai Bav crust.

Bacterial and cyanobacterial diversities determined by T-RFLP analyses in the Jiaozhou Bay

The methods of DAPI staining epifluorescence microscopy and T-RFLP analysis were used to analyze the microbial abundance and diversity in surface seawater sampled from 12 stations inside and outside of the Jiaozhou Bay during a survey on 12 and 13 September 2004. The abundance of total microbes is in the range of 10^6～ 10^7 cells/cm^3, similar to those of most semi-enclosed bays in the temperate areas in the world. The highest microbial densities occur in the northeastern part of the Jiaozhou Bay, around the mouths of Loushan and Licun Rivers and the Hongdao aquacultural farming areas, suggesting that the degree and characteristics of pollutions, along with geographical and hydrological effects, may be important determinants affecting the abundance and distribution of bacteria in the Jiaozhou Bay. Bacterial communities inside and outside of the Jiaozhou Bay can be grouped into three classes based on T-RFLP patterns and cluster analyses. Stations at the water channel of the bay mouth and outside, such as D1, D3, D5, D6 and D7, are grouped together to stand for the outside bacterial community interacting with the environment outside of the Jiaozhou Bay. Stations of the innermost side of the Jiaozhou Bay, such as A3, A5, B2 and Y1, are grouped together to stand for the residential bacteria community. Stations C1, C3 and CA are grouped together and may stand for the transitional bacterial assemblage between the residential community and the outside community. However, there is no such a defined relationship for the case of cyanobacterial diversity, indicating the fact that cyanobacteria are more flexible and adaptable to all kinds of conditions.

The Voisey's Bay Ni-Cu-Co Sulfide Deposit, Labrador, Canada: Emplacement of Silicate and Sulfide-Laden Magmas into Spaces Created within a Structural Corridor

The Voisey's Bay Ni-Cu-Co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, Canada.The Ni-Cu-Co sulfide mineralization is associated with magmatic breccias that are typically contained in weakly mineralized olivine gabbros, troctolites and ferrogabbros, but also occur as veins in adjacent paragneiss.The mineralization is associated with a dyke-like body which is termed the feeder dyke.This dyke connects the shallow differentiated Eastern Deeps chamber in the east to a deeper intrusion in the west termed the Western Deeps Intrusion.Where the conduit is connected to the Eastern Deeps Intrusion, the Eastern Deeps Deposit is developed at the entry line of the dyke along the steep north wall of the Eastern Deeps Intrusion.The Eastern Deeps Deposit is surrounded by a halo of moderately to weakly mineralized Variable-Textured Troctolite (VTT) that reaches a maximum thickness above the ENE-WSW axis of the Eastern Deeps Deposit. At depth to the west, the conduit is adjacent to the south side of the Western Deeps Intrusion, where the dyke and intrusion contain disseminated magmatic sulfide mineralization.The Reid Brook Zone plunges to the east within the dyke, and both the dyke and adjacent paragneiss are mineralized.The Ovoid Deposit comprises a bowl-shaped body of massive sulfide where the dyke widens near to the present-day surface.It is not clear whether this deposit was developed as a widened-zone within the conduit or at the entry point into a chamber that is now lost to erosion. The massive sulfides and breccia sulfides of the Eastern Deeps are petrologically and chemically different when compared to the disseminated sulfides in the VTT; there is a marked break in Ni tenor (Ni content in 100% sulfide, abbreviated to [Ni]100) and Ni/Co of sulfide between the two.The boundary of the sulfide types is often marked by strong sub-horizontal alignment of heavily digested and metamorphosed paragneiss fragments, development of barren olivine gabbro, and by a change from typically massive sulfides and breccias sulfides into more typical variable-textured troctolites with heavy to weak disseminated sulfide.Sulfides hosted in the feeder dyke tend to have low metal tenors ([Ni]100=2.5%-3.5%); sulfides in Eastern Deeps massive and breccia ores have intermediate Ni tenors ([Ni]100=3.5%-4%) and disseminated sulfides in overlying rocks have high Ni tenors ([Ni] 100=4%-8%) . Conduit-hosted mineralization and mineral zones in the paragneiss adjacent to the Reid Brook Deposit tend to have lower Ni tenor than the Ovoid and Eastern Deeps Deposits.The tenor of mineral hosted in the country rock gneisses tends to be the same as that developed in the conduit ; the injection of the sulfide into the country rocks likely occurred before formation of monosulfide solid solution.The Ovoid Deposit is characterized by coarse-grained loop-textured ores consisting of 10cm-2msized pyrrhotite crystals separated by chalcopyrite and pentlandite.A small lens of massive cubanite surrounded by more magnetite-rich sulfide assemblages represents what appears to be the product of in-situ sulfide fractionation. Detailed exploration in the area between the Reid Brook Zone and the Eastern Deeps has shown that these intrusions and ore deposits are connected by a branched dyke and chamber system in a major westeast fault zone.The Eastern Deeps chamber may be controlled by graben-like fault structures , and the marginal structures appear to have controlled dykes which connect the chambers at different levels in the crust.The geological relationships in the intrusion are consistent with emplacement of the silicate and sulfide laden magma from a deeper sub-chamber (possibly a deep eastward extension of the Western Deeps Intrusion where S-saturation was initially achieved) .The silicate and sulfide magmas were likely emplaced through this conduit into the Eastern Deeps intrusion as a number of different fragment laden pulses of sulfide-silicate melt that evolved with different R factors and in response to some variation in the degree of evolution of the parental magma.S isotope and S/Se data coupled with geological evidence point to a crustal source for the sulfur , and the site of equilibration of mafic magma and crustal S is placed at depth in a sulfidic Tasiuyak Gneiss. The structural control on emplacement of small intrusions with transported sulfide is a feature found in different nickel sulfide deposits around the world.Champagne glass-shaped openings in sub-vertical chonoliths are a common morphology for this deposit type (e.g.the Jinchuan , Huangshan , Huangshandong , Jingbulake , Limahe , Hong Qi Ling deposits in China , the Eagle deposits in the United States , and the Double Eagle deposit in Canada) .Some of the structures of the Midcontinent Rift of North America also host Ni-Cu-(PGE) deposits of this type (e.g.the Current Lake Complex in the Quetico Fault Zone in Ontario , Canada and the Tamarac mineralisation in the Great Lakes Structural Zone of the United States) .Other major nickel deposits associated with flat structures adjacent to major mantle-penetrating structures include the Noril'sk , Noril'sk II , Kharaelakh , NW Talnakh , and NE Talnakh Intrusions of the Noril'sk Region of Russia , the Kalatongke deposit in NW China , and Babel-Nebo in Western Australia.These deposits are all formed in mantle-penetrating structural conduits that link into the roots of large igneous provinces near the edges of old cratons.

Bayés syndrome and acute cardioembolic ischemic stroke

Bayés syndrome is an under-recognized clinical condition characterized by advanced interatrial block.Bayés syndrome is a subclinical disease that manifests electrocardiographically as a prolonged P wave duration>120 ms with biphasic morphology±in the inferior leads.The clinical relevance of Bayés syndrome lies in the fact that is a clear arrhythmological syndrome and has a strong association with supraventricular arrhythmias,particularly atypical atrial flutter and atrial fibrillation.Likewise,Bayés syndrome has been recently identified as a novel risk factor for non-lacunar cardioembolic ischemic stroke and vascular dementia.Advanced interatrial block can be a risk for embolic stroke due to its known sequelae of left atrial dilation,left atrial electromechanical dysfunction or atrial tachyarrhythmia(paroxysmal or persistent atrial fibrillation),conditions predisposing to thromboembolism.Bayés syndrome may be responsible for some of the unexplained ischemic strokes and shall be considered and investigated as a possible cause for cryptogenetic stroke.In summary,Bayés syndrome is a poorly recognized cardiac rhythm disorder with important cardiologic and neurologic implications.

Identification of coastal water quality by multivariate statistical techniques in two typical bays of northern Zhejiang Province,East China Sea

The Hangzhou Bay（HZB） and Xiangshan Bay（XSB）, in northern Zhejiang Province and connect to the East China Sea（ECS） were considerably affected by the consequence of water quality degradation. In this study, we analyzed physical and biogeochemical properties of water quality via multivariate statistical techniques. Hierarchical cluster analysis（HCA） grouped HZB and XSB into two subareas of different pollution sources based on similar physical and biogeochemical properties. Principal component analysis（PCA） identified three latent pollution sources in HZB and XSB respectively and emphasized the importance of terrestrial inputs, coastal industries as well as natural processes in determining the water quality of the two bays. Therefore, proper measurement for the protection of aquatic ecoenvironment in HZB and XSB were of great urgency.

Advanced interatrial block as a key marker for atrial fibrillation recurrence： Bayes＇ syndrome

It was not until 1979 that Bayes de Ltma described atrial conduction blocks and classified them as interatrial and intra- atrial.Interatrial blocks refer to conduction disorders lo- cated between the atria, while intraalxial blocks occur within the same atrium. This work motivated several authors, in- cluding Bayes himself, to further investigate atrial conduc- tion and interatrial block （IAB）.