Regional variations in trace element concentrations in tissues of black tiger shrimp Penaeus monodon (Decapoda: Penaeidae) from South Vietnam     

Tu NP  Ha NN  Ikemoto T  Tuyen BC  Tanabe S  Takeuchi I 《Marine pollution bulletin》2008,57(6-12):858-866

The goal of the present study was to examine the specific bioaccumulation of 22 trace elements in muscle, exoskeleton and hepatopancreas of black tiger shrimp Penaeus monodon from the Mekong River Delta (MRD), and the South Key Economic Zone (SKEZ), South Vietnam. The general tendency in most trace element concentrations among different tissues were hepatopancreas>exoskeleton>muscle. Comparisons of trace element levels in tissues between the two regions showed that concentrations of Se in muscle and As in all three tissues were higher in SKEZ; whereas in MRD, the higher concentrations of most elements such as Mn, Cu, Cd, Ba, Hg, were observed in tissues. These geographical variations in trace element levels may reflect the differences in human activities between the two regions of South Vietnam. The target hazard quotient (THQ) values for trace elements (<1) indicate that local residents are not exposed to potential health risks via the consumption of shrimp.  相似文献   

Regional variations in trace element concentrations in tissues of black tiger shrimp Penaeus monodon (Decapoda: Penaeidae) from South Vietnam     

Nguyen Phuc Cam Tu  Nguyen Ngoc Ha  Tokutaka Ikemoto  Bui Cach Tuyen  Shinsuke Tanabe  Ichiro Takeuchi   《Marine pollution bulletin》2008,57(6-12):858

The goal of the present study was to examine the specific bioaccumulation of 22 trace elements in muscle, exoskeleton and hepatopancreas of black tiger shrimp Penaeus monodon from the Mekong River Delta (MRD), and the South Key Economic Zone (SKEZ), South Vietnam. The general tendency in most trace element concentrations among different tissues were hepatopancreas > exoskeleton > muscle. Comparisons of trace element levels in tissues between the two regions showed that concentrations of Se in muscle and As in all three tissues were higher in SKEZ; whereas in MRD, the higher concentrations of most elements such as Mn, Cu, Cd, Ba, Hg, were observed in tissues. These geographical variations in trace element levels may reflect the differences in human activities between the two regions of South Vietnam. The target hazard quotient (THQ) values for trace elements (<1) indicate that local residents are not exposed to potential health risks via the consumption of shrimp.  相似文献   

Mixed‐Mode Remediation of Cadmium and Arsenate Ions Using Graphene‐Based Materials          下载免费PDF全文

Supriya Lath  Divina Navarro  Diana Tran  Anu Kumar  Dusan Losic  Michael J. McLaughlin 《洁净——土壤、空气、水》2018,46(9)

  相似文献   

Sediment transport trends and cross-sectional stability of a lagoonal tidal inlet on the Central Coast of Vietnam     

Do Minh Duc  Tran Thanh Tung  Patrick McLaren  Tran Ngoc Anh  Dinh Thi Quynh 《国际泥沙研究》2019,34(4):322-334

Lagoonal tidal inlets are a typical morphology of the Central Coast of Vietnam. Recently, navigation channels in these inlets have become increasingly threatened by siltation. This study analyses the relations between sediment distribution and transport trends (using the technique of Sediment Trend Analysis-STA■) in the lagoonal system of the De Gi inlet and then proposes appropriate countermeasures against sand deposition in the navigation channel. The STA identified three types of transport trends in the De Gi inlet, namely dynamic equilibrium, net accretion, and net erosion. Processes associated with the tidal prism have resulted in trends of sediment transport and deposition across the flood and ebb tidal shoals, which maintain a present cross-sectional area of about 1000m^2. However, longshore sediment transport from north to south resulting from northeast waves cause additional sand deposition in the channel. In addition, the effects of refraction associated with a nearby headland and jetty also increase sedimentation. These processes provide the main reasons for sediment deposition in the De Gi inlet. Short term and regular dredging helps to maintain the navigation channel. A system comprised of three jetties (north, south, and weir) is necessary to ensure the longterm cross-sectional stability of the navigation channel.  相似文献   

Estimation of Blast-Induced Air Overpressure in Quarry Mines Using Cubist-Based Genetic Algorithm     

Fang  Qiancheng  Nguyen  Hoang  Bui  Xuan-Nam  Tran  Quang-Hieu 《Natural Resources Research》2020,29(2):593-607

In the present work, blast-induced air overpressure is estimated by an innovative intelligence system based on the cubist algorithm (CA) and genetic algorithm (GA) with high accuracy, called GA–CA model. Herein, CA initialization model was developed first and the hyper-parameters of the CA model were selected randomly. Subsequently, the GA procedure was applied to perform a global search for the optimized values of the hyper-factors of the CA model. Root-mean-square error (RMSE) is utilized as a compatibility function to determine the optimal CA model with the lowest RMSE. Gaussian process (GP), conditional inference tree (CIT), principal component analysis (PCA), hybrid neural fuzzy inference system (HYFIS) and k-nearest neighbor (k-NN) models are also developed as the benchmark models in order to compare and analyze the quality of the proposed GA–CA algorithm; 164 blasting works were investigated at a quarry mine of Vietnam for this aim. The results revealed that GA significantly improved the performance of the CA model. Based on the statistical indices used for model assessment, the proposed GA–CA model was confirmed as the most superior model as compared to the other models (i.e., GP, CIT, HYFIS, PCA, k-NN). It can be applied as a robust soft computing tool for estimating blast-induced air overpressure.

  相似文献   

Influences of diel and tidal cycles on fish assemblage in eelgrass (Zostera marina) bed of southern Korea during autumn     

KWAK Seok Nam  PARK Joo Myun  IM Seong Oh  JAWAD Laith A. 《海洋学报(英文版)》2018,37(4):40-47

Short-term tidal and diel variations of autumn fish assemblage in a Zostera marina bed were investigated using 3 h interval samplings for 24 h in both spring and neap tide using a small beam trawl. A total of 1 346 fishes belonging to 19 species were collected at spring tide, whereas 1 115 fishes belonging to 17 species were at neap tide. The common fish species were Nuchequula nuchalis, Acanthogobius flavimanus, Takifugu niphobles, Acentrogobius pflaumii, and Pholis nebulosa with the former three species dominating at spring tide, while the latter two species being abundant at neap tide. Diel variation in abundance was significant with higher abundance at night than day, but there were no significant differences between spring and neap tides, and between ebb and flood tides (three-way ANOVAs). Diel variation in the abundance of fishes may be influenced by tidal range and cycle, and day-night differences of food availability and behaviors of fishes indirectly. Non-metric multidimensional scaling (nMDS) ordination and analysis of similarity (ANOSIM) results revealed significant differences in species compositions both between day and night, and between spring and neap tide. Eelgrass beds are highly productive marine ecosystem, and thus, our results will contribute to conservation of seagrass ecosystem in the study area.  相似文献   

Introduction to the China-Vietnam Cooperation Project: A Comparative Study of the Holocene Sedimentary Evolution of the Yangtze and Red River Deltas     

Ping Yin  Van Phach Phung  Dinh Lan Tran  Huy Cuong Do  Van Vuong Bui  Xiaoyong Duan 《中国海洋大学学报(英文版)》2018,17(6):1269-1271

Both China and Vietnam confront the challenges of natural geohazards and environmental changes in their deltas and coastal zones due to rapid urbanization, economic development, and the impacts of global climate change. China and Vietnam initiated a comparative study of the Holocene sedimentary evolution of the Yangtze River Delta(YRD) and Red River Delta(RRD) for the period 2015–2018 in order to improve the understanding of the two delta evolution histories in the Holocene. Previous investigative data of the two rivers, onshore delta plains, and offshore subaqueous deltas have been explored and reinterpreted. New data gleaned from boreholes, piston cores, shallow seismic and hydrodynamic sources have been collected from the offshore YRD and the East China Sea inner shelf, and surface sediments and short cores have been collected from the RRD near-shore areas. Six focal areas of the joint project have been defined for comparative studies of the two deltas, including morphological development, sequential stratigraphy, coastline shifting, sedimentary characteristics, sedimentary dynamics, and correlation with anthropogenic global climate change. The results of these study areas are presented herein. The joint project also includes cooperative capacity building; exchanges of young scientists have been organized during the project period, and hands-on training in laboratory geochemical analysis, numerical modeling, and seismic data processing and interpretation have been provided by China and its Vietnamese geoscientist partners. Joint field excursions were organized to the upstream of the Yangtze and Red Rivers in Yunan Province, China, all the way downstream along the Vietnamese portion of the Red River. These joint studies have, over the past three years, improved understanding of the evolutionary history of these two major rivers and their mechanisms of source to sink. Joint project results of these two major deltas are not limited to the geosciences; the cooperative mechanical and operational experiences have been helpful for future cooperation in the field of marine geoscience between China and Vietnam, as well for cooperative activities with other ASEAN member countries.  相似文献   

The Mid-IR view of interacting galaxies     

V. Charmandaris  O. Laurent  I.F. Mirabel  P. Gallais  M. Sauvage  L. Vigroux  C. Cesarsky  D. Tran 《Astrophysics and Space Science》1999,266(1-2):99-104

In this paper, we present ISOCAM mid-IR broad band images and spectraof three well known interacting galaxies. These are the prototypicalultraluminous IR galaxy Arp 220, and NGC 6240, which are classifiedas major mergers resulting from a collision of two disk galaxies ofapproximately equal mass, and the prime example of collisional ringgalaxies, the Cartwheel. Our observations provide a new powerful tooland shed some more light to the properties of the hot dust and starformation in interacting galaxies.  相似文献   

Precambrian crustal evolution in Rangrim Massif , Korean Peninsula   总被引：2，自引：0，他引：2       下载免费PDF全文

LYANG To Jun  LIU Yongjiang  YANG Jong Hyok  KIM Hon  HAN Ryong Yon  KIM Jong Nam 《世界地质(英文版)》2009,12(2):57-63

Petrological, chronological and geotectonic geological analysis of Precambrian metamorphic rock in Korean Peninsula shows that the remnants ( > 314 Ga) of continental nuclei crust were formed in the Paleo-archean in the Rangrim Massif. In the massif, the main formation ages of continental crust range from 3.2 Ga to 2.5 Ga, its important growing period was 2.8 - 2.5 Ga. The subsequent expansion period of the Rangrim Massif was 2.4 - 2.2 Ga. The division events occurred in 1.85 Ga and in the Late Paleoproterozoic－Early Mesoproterozoic, respectively. Since then the massif was relatively stable. However, the last division of the Rangrim Massif occurred at 793 Ma.  相似文献   

Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes     

Ngo Xuan Quang  Ann Vanreusel  Nic Smol  Nguyen Ngoc Chau 《Ocean Science Journal》2010,45(4):213-224

Meiobenthos assemblages in eight estuaries of the Mekong river system were investigated in August 2008 (from the Cua Tieu estuary to the Tran De estuary). In each estuary, one sampling station was established for meiobenthos sampling. Twelve major taxa of meiobenthos were recorded in this estuarine system, including Nematoda, Copepoda, Turbellaria, Polychaeta, Oligochaeta, Tardigrada, Bivalvia, Ostracoda, Amphipoda, Cumacea, Gastrotricha, Gastropoda, and Crustacean Nauplii larvae. The densities of the meiobenthos range from 581 to 3168 inds/10 cm². Nematodes always occupy the highest numbers with a percentage ranging from 64–99%. There are 135 nematode genera recorded in this study with the following as dominant genera Desmodora, Leptolaimus, Halalaimus, Thalassomonhystera, Theristus, Daptonema, Rhynchonema, Parodontophora, and Oncholaimus. Although the biodiversity of the meiobenthos at higher taxa level is not high compared to other marine environments, the estimates of nematode biodiversity at the genus level indicates high values. The increase in number of genera with increasing sampling intensity illustrate that the diversity is underestimated and would have been higher if the authors had considered a larger number of individuals, more replicates per station, and more sampling stations.  相似文献