Lagrangian coherent structure analysis on transport of Acetes chinensis along coast of Lianyungang,China

Spatial heterogeneity or“patchiness”of plankton distributions in the ocean has always been an attractive and challenging scientific issue to oceanographers.We focused on the accumulation and dynamic mechanism of the Acetes chinensis in the Lianyungang nearshore licensed fishing area.The Lagrangian frame approaches including the Lagrangian coherent structures theory,Lagrangian residual current,and Lagrangian particle-tracking model were applied to find the transport pathways and aggregation characteristics of Acetes chinensis.There exist some material transport pathways for Acetes chinensis passing through the licensed fishing area,and Acetes chinensis is easy to accumulate in the licensed fishing area.The main mechanism forming this distribution pattern is the local circulation induced by the nonlinear interaction of topography and tidal flow.Both the Lagrangian coherent structure analysis and the particle trajectory tracking indicate that Acetes chinensis in the licensed fishing area come from the nearshore estuary.This work contributed to the adjustment of licensed fishing area and the efficient utilization of fishery resources.

Analysis of a simplification strategy in a nonhydrostatic model for surface and internal wave problems

This paper examines the simplification strategy of retaining only the nonhydrostatic effect of local acceleration in a three-dimensional fully nonhydrostatic model regarding the submesoscale wave phenomenon in the ocean.Elaborate scale analysis of the vertical component of the Reynold-averaged Navier-Stokes(RANS)equation was performed,confirming the rationalization of this simplification.Then,the simplification was implemented in a RANS equation-based nonhydrostatic model NHWAVE(nonhydrostatic WAVE)to make a simplified nonhydrostatic model.Numerical examples were taken to test its performance,including surface sinusoidal waves propagating on an idealized East China Sea topography,tidally induced internal lee waves and small-scale solitary waves.The results show that in a considerably wide range of nonlinear strengths,the simplified nonhydrostatic model can obtain similar results as those in the fully nonhydrostatic model,even for smaller-scale solitary waves.Nonlinearity influences the applicability of the simplification.The stronger the nonlinearity is,the worse the simplified model describes the nonhydrostatic phenomenon.In general,the simplified nonhydrostatic model can simulate surface waves better than internal waves.Improvement of computational efficiency in the simplified nonhydrostatic model is reasonable,reducing the central processing unit time duration in the fully nonhydrostatic model by 16.4%–20.6%.The specially designed algorithm based on the simplified nonhydrostatic equation can remarkably reduce the computational time.

海州湾及毗邻海域潮不对称性研究

外海潮波传播到近海河口海湾过程中,由于地形作用而发生变形,表现为潮汐潮流涨落潮的不对称。本文利用海州湾附近18天连续高频观测资料,分析了潮汐和潮流的不对称性,潮波向海州湾传播过程中,潮波变形较小,潮流变形较大,4个站位均为涨潮占优,本研究可为海州湾的泥沙输运、污染物迁移等研究提供参考。

Posterior quadrantic disconnection maintains the activity of isolated temporal-parietal-occipital nerve tissue: neuroprotective measures in the surgical treatment of epilepsy

Extensive lesions involving the posterior quadrant of the cerebral hemisphere(temporal,parietal,and occipital lobes)induce intractable epilepsy.These patients are potential candidates for surgical treatment[1].Maintenance of isolated nerve tissue activity after surgery plays a crucial role in the neuroprotective effects of neurosurgery treatment.Disconnection surgery of the posterior quadrant is used to completely isolate nerve fibers,while blood supply at the isolated lobes is maintained.Subsequently,cavities caused by

A Study on Nanoscale Infrared Absorbent Working in Waveband Range of 1300-400 cm^(-1)

Nanoscale powder of SiO_2/Al_2O_3/TiO_2 composite was prepared by sol-gel method.Microstructure and mor- phology of the obtained samples were characterized by infrared(IR),X-ray diffraction(XRD)analysis and transmission electron microscopy(TEM).It is proved that infrared absorbing peaks of the samples are in waveband range of 1300-400 cm^(-1),and the peak shape changes with their component.Mechanism of the in- frared peak's positions and shapes which changes with the size and morphology of the prepared nano-particles has been tentatively discussed.

The effect of large reservoirs impoundment to the spatial and temporal variations of regional crustal deformation in Hubei Province, China

The total capacity of Three Gorges Reservoir(TGR) and Danjiangkou Reservoir(DJR) is large and has significant seasonal fluctuations, which give rise to crustal instability. In this research, we focus on studying the temporal and spatial variation of crustal deformation in Hubei Province caused by reservoir impoundment of TGR and DJR.The Digital Elevation Model, historical hydrological information, GPS monitoring data and load-induced deformation model are combined to monitor the crustal deformation. The modeled results indicate that in the trapezoidal area between the TGR and DJR, the average vertical deformations at different latitudes have different variation tendencies. The vertical deformation modulus and fluctuation amplitude are larger at the latitude of 33 N/32.5 N from 2003 to 2006 and at the latitude of 31 N/32.5 N from 2008 to 2014, while the latter are much larger than the former. Moreover, from2008 to 2014, the frequency and the intensity of seismic activities are all enhanced significantly in this region. The modeled results at the GPS sites are consistent with the vertical displacement of GPS monitoring results in trends and the waveform. It can be inferred that the seasonal deformation is elastic. The horizontal deformation components have the same variation trends with that at each GPS monitoring station,which demonstrates that the whole region is moving toward the southeast. The spatial variation of crustal deformation demonstrates that the impoundment of TGR in2003 causes significant vertical displacements, with the maximum modulus of 32 mm downward located in Xiangjiang River's estuary. When the water storage increases, the maximum value will become larger, and the location will move toward the upstream.Besides, the earthquakes occurred more frequently in the region with maximum deformation modulus.

Impact of typhoon Lekima(2019)on material transport in Laizhou Bay using Lagrangian coherent structures

Typhoon has an impact on an estuary and coastal environment.However,the present research lacks the detailed description of material transport processes during typhoon passage,such as the transport channels and barriers in the course of material transport and material accumulation area,etc.Therefore,Lagrangian coherent structures(a method developed for describing the transport structure of fluids in recent years)was introduced to investigate and predict the floating material and debris transport process in the Laizhou Bay,Bohai Sea,during typhoon Lekima in 2019.Results show that the Lagrangian coherent structure could well explain the complex flow phenomena in the bay.During the typhoon,the general direction of floating material transport in the Laizhou Bay was anticlockwise.There was a channel for material transport in the northwest and south of the bay,and there are transportation obstacles in the northeast-southwest direction in the middle of the bay.Therefore,the typhoon might worsen the water quality.These results provide references for precise countermeasures to control the formulation of pollution in the Laizhou Bay.

Erratum to:Impact of typhoon Lekima(2019)on material transport in Laizhou Bay using Lagrangian coherent structures

Erratum to:https://doi.org/10.1007/s00343-021-0384-7 The authors’affiliations of this article contain a few mistakes.The correct ones are given below:1 College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China 2 Key Laboratory of Marine Environment and Ecology,Ministry of Education of China,Ocean University of China,Qingdao 266100,China The online version of the original articles can be found at:https://doi.org/10.1007/s00343-021-0384-7.

Research progress on the lignans from the genus Schisandra and their biological activities

The plants of the genus Schisandra belong to the Schisandraceae family.As one of the main active components of genus Schisandra,lignans have rich biological activities,including anti-inflammatory,anti-tumor,anti-HIV and PAF antagonism.This article summarizes and classifies the types and activities of lignans isolated from the genus Schisandra in the past ten years.

Multiple isotopes reveal the driving mechanism of high NO_(3)^(-) level and key processes of nitrogen cycling in the lower reaches of Yellow River

The continuous increase of nitrate(NO_(3)^(-))level in rivers is a hot issue in the world.However,the driving mechanism of high NO_(3)^(-)level in large rivers is still lacking,which has limited the use of river water and increased the cost of water treatment.In this study,multiple isotopes and source resolution models are applied to identify the driving mechanism of high NO_(3)^(-)level and key processes of nitrogen cycling in the lower reaches of the Yellow River(LRYR).The major sources of NO_(3)^(-)were sewage and manure(SAM)in the low-flow season and soil nitrogen(SN)and chemical fertilizer(CF)in the high-flow season.Nitrification was the most key process of nitrogen cycling in the LRYR.However,in the biological removal processes,denitrification may not occur significantly.The temporal variation of contributions of NO_(3)^(-)sources were estimated by a source resolution model in the LRYR.The proportional contributions of SAM and CF to NO_(3)^(-)in the low-flow and high-flow season were 32.5%-52.3%,44.2%-46.2%and 36.0%-40.8%,54.9%-56.9%,respectively.The driving mechanisms of high NO_(3)^(-)level were unreasonable sewage discharge,intensity rainfall runoff,nitrification and lack of nitrate removal capacity.To control the NO_(3)^(-)concentration,targeted measures should be implemented to improve the capacity of sewage and wastewater treatment,increase the utilization efficiency of nitrogen fertilizer and construct ecological engineering.This study deepens the understanding of the driving mechanism of high nitrate level and provides a vital reference for nitrogen pollution control in rivers to other area of the world.

Epidemiologic survey and analysis of mild cognitive impairment amongst community senior citizens of Changsha City

Objective:The purpose of the current study was to conduct a mild cognitive impairment(MCI)prevalence survey among the community senior citizens of Changsha City and analyze possible relevant factors so as to perform early screening and intervention for MCI patients,and delay or prevent MCI from developing into Alzheimer’s disease(AD).Methods:Between April and September 2012,a total of 1764 community senior citizens in Changsha City were selected through multi-stage and random cluster sampling as study subjects.The following tables were used during the investigation to perform preliminary MCI screening for the subjects of this study:a general information survey;Mini-Mental State examination(MMSe);Montreal Cognitive Assessment(MoCA);Beijing version;global Deteriorate Scale(gDS);Clinical Dementia Rating(CDR)scale;and Activities of Daily Living(ADL)scale.Then,neurology specialists made diagnoses according to the actual status of subjects,survey findings,and clinical MCI diagnostic standards.The prevalence of MCI was calculated and the rates concerning senior citizens with different demographic characteristics were compared.Logistic regression analysis was used to analyze relevant factors that led to MCI,and comparing findings with those of other cities was conducted.Results:The MCI prevalence among senior citizens in Changsha City was 16.27%(287/1764).The MCI prevalence increased with age[for the 60,70,and 80 age groups,the prevalence was 9.79%(84/858),20.14%(149/740),and 32.53%(54/166),respectively,P<0.05].The more education received,the less the likelihood of developing MCI[the prevalence of illiteracy,those who went to pri-mary school,junior high school,senior high school,or technical secondary school,college,and un-dergraduates and above was 32.10%(26/81),18.40%(90/489),13.97%(70/501),15.29%(61/399),14.39%(19/132),and 12.96%(21/162),respectively,P<0.05].Bluecollar workers’chances of developing MCI was higher than white-collar workers[19.12%(187/978)and 12.72%(100/786),respectively,P<0.05].Living alone increased the likelihood of developing MCI than not living alone[21.59%(65/301)and 15.17%(222/1463),P<0.05].The logistic regression analysis showed that age,educational background,and marital status were in the regression(P<0.05).The MCI prevalence of Changsha did not differ from that Portugal,Singapore,Beijing,and Urumchi(P>0.05),but lower than Shanghai[35.78%(161/450)]and higher than Chengdu[2.35%(92/3910)](P<0.05).Conclusion:The prevalence of MCI among the community senior citizens of Changsha City is highly related to factors like age,educational background,and marital status.Prevention against these highrisk factors shall be carried out to delay cognitive decline for senior citizens.