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  • 1
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Acta Oceanologica Sinica 34 (2015):92-113, doi:10.1007/s13131-015-0650-7.
    Description: Cobalt-rich ferromanganese is an important seafloor mineral and is abundantly present in the seamount crusts. Such crusts form potential hotspots for biogeochemical activity and microbial diversity, yet our understanding of their microbial communities is lacking. In this study, we used a cultivation-independent approach to recover genomic information and derive ecological functions of the microbes in a sediment sample collected from the cobalt-rich ferromanganese crust of a seamount region in the central Pacific. A total of 78 distinct clones were obtained by fosmid library screening with a 16S rRNA based PCR method. Proteobacteria and MGI Thaumarchaeota dominated the bacterial and archaeal 16S rRNA gene sequence results in the microbial community. Nine fosmid clones were sequenced and annotated. Numerous genes encoding proteins involved in metabolic functions and heavy metal resistance were identified, suggesting alternative metabolic pathways and stress responses that are essential for microbial survival in the cobalt-rich ferromanganese crust. In addition, genes that participate in the synthesis of organic acids and exoploymers were discovered. Reconstruction of the metabolic pathways revealed that the nitrogen cycle is an important biogeochemical process in the cobalt-rich ferromanganese crust. In addition, horizontal gene transfer (HGT) events have been observed, and most of them came from bacteria, with some occurring in archaea and plants. Clone W4-93a, belonging to MGI Thaumarchaeota, contained a region of gene synteny. Comparative analyses suggested that a high frequency of HGT events as well as genomic divergence play important roles in the microbial adaption to the deep-sea environment.
    Description: China Ocean Mineral Resources R & D Association (COMRA) Special Foundation (No. DY125-15-R-03 and DY125-13-E-01); the National Natural Science Foundation of China (No. 41276173); the Zhejiang Provincial Natural Science Foundation of China (No. LQ13D060002) and the Scientific Research Fund of the Second Institute of Oceanography, SOA (No. JT1305).
    Description: 2016-04-17
    Keywords: Seamount ; Cobalt-rich ferromanganese crust ; Metagenome ; Horizontal gene transfer
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
    Format: application/vnd.ms-excel
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  • 2
    Publication Date: 2014-04-10
    Description: The liquid loading of gas well is an important issue in deep exploitation of natural gas. The technic of vortex drainage has good prospects because the tool construction and construction work is simple, the technic is environmental and efficient. Currently, the mechanism for the vortex drainage and the theory of fluid motion are still missing. Therefore, in order to further understand the downhole flow field, verify drainage mechanism and select best working conditions, based on computational fluid dynamics and mixture model of multiphase flow through Fluent, the study established a three-dimensional structural model of vortex tools and the numerical simulation has been done. By monitoring the wellhead and the radial distribution of the liquid content and observing the state of the gas-liquid flow and the path line, the study analyzed the influence on gas well flow field by vortex tool. The study revealed the working mechanism of vortex tools to facilitate understanding the nature of the vortex drainage process, guide how to select the preferred process conditions and provide theoretical basis for the application and the dynamics simulation of vortex drainage technology. Key words : The liquid loading of gas well; Vortex drainage; Multiphase flow; Numerical simulation
    Print ISSN: 1925-542X
    Electronic ISSN: 1925-5438
    Topics: Geosciences
    Published by CSCanada
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  • 3
    Publication Date: 2022-11-18
    Description: The interest in deep-sea mining increased along with the environmental concerns of these activities to the deep-sea fauna. The discovery of optimal biomarkers of deep-sea mining activities in deep-sea species is a crucial step toward the supply of important ecological information for environmental impact assessment. In this study, an in situ copper exposure experiment was performed on deep-sea scavenging amphipods. Abyssorchomene distinctus individuals were selected among all the exposed amphipods for molecular characterization. Copper concentration within the gut was assessed, followed by a tandem mass tag-based coupled with two-dimensional liquid chromatography–mass spectrometry/mass spectrometry (LC–MS/MS) applied to identify and quantify the protein expression changes after 48 h of exposure. 2937 proteins were identified and annotated, and 1918 proteins among all identified proteins were assigned by at least two nonambiguous peptides. The screening process was performed based on the differences in protein abundance and the specific correlation between the proteins and copper in previous studies. These differentially produced proteins include Na+/K+ ATPase, cuticle, chitinase, and proteins with unknown function. Their abundances showed correlation with copper and had high sensitivity to indicate the copper level, being here proposed as biomarker candidates for deep-sea mining activities in the future. This is a key step in the development of environmental impact assessment of deep-sea mining activities integrating ecotoxicological data.
    Type: Article , PeerReviewed
    Format: text
    Format: text
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  • 4
    Publication Date: 2016-06-29
    Description: “Strain engineering” has been widely used to tailor the physical properties of layered materials, like graphene, black phosphorus, and transition-metal dichalcogenides. Here, we exploit thermal strain engineering to construct two dimensional (2D) WS 2 in-plane heterojunctions. Kelvin probe force microscopy is used to investigate the surface potentials and work functions of few-layer WS 2 flakes, which are grown on SiO 2 /Si substrates by chemical vapor deposition, followed by a fast cooling process. In the interior regions of strained WS 2 flakes, work functions are found to be much larger than that of the unstrained regions. The difference in work functions, together with the variation of band gaps, endows the formation of heterojunctions in the boundaries between inner and outer domains of WS 2 flakes. This result reveals that the existence of strain offers a unique opportunity to modulate the electronic properties of 2D materials and construct 2D lateral heterojunctions.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
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  • 5
    Publication Date: 2018-02-12
    Description: Sensors, Vol. 18, Pages 548: Sensor-Oriented Path Planning for Multiregion Surveillance with a Single Lightweight UAV SAR Sensors doi: 10.3390/s18020548 Authors: Jincheng Li Jie Chen Pengbo Wang Chunsheng Li In the surveillance of interested regions by unmanned aerial vehicle (UAV), system performance relies greatly on the motion control strategy of the UAV and the operation characteristics of the onboard sensors. This paper investigates the 2D path planning problem for the lightweight UAV synthetic aperture radar (SAR) system in an environment of multiple regions of interest (ROIs), the sizes of which are comparable to the radar swath width. Taking into account the special requirements of the SAR system on the motion of the platform, we model path planning for UAV SAR as a constrained multiobjective optimization problem (MOP). Based on the fact that the UAV route can be designed in the map image, an image-based path planner is proposed in this paper. First, the neighboring ROIs are merged by the morphological operation. Then, the parts of routes for data collection of the ROIs can be located according to the geometric features of the ROIs and the observation geometry of UAV SAR. Lastly, the route segments for ROIs surveillance are connected by a path planning algorithm named the sampling-based sparse A* search (SSAS) algorithm. Simulation experiments in real scenarios demonstrate that the proposed sensor-oriented path planner can improve the reconnaissance performance of lightweight UAV SAR greatly compared with the conventional zigzag path planner.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
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  • 6
    Publication Date: 2018-06-09
    Description: Energies, Vol. 11, Pages 1498: Power Generation Expansion Optimization Model Considering Multi-Scenario Electricity Demand Constraints: A Case Study of Zhejiang Province, China Energies doi: 10.3390/en11061498 Authors: Peng Wang Chunsheng Wang Yukun Hu Liz Varga Wei Wang Reasonable and effective power planning contributes a lot to energy efficiency improvement, as well as the formulation of future economic and energy policies for a region. Since only a few provinces in China have nuclear power plants so far, nuclear power plants were not considered in many provincial-level power planning models. As an extremely important source of power generation in the future, the role of nuclear power plants can never be overlooked. In this paper, a comprehensive and detailed optimization model of provincial-level power generation expansion considering biomass and nuclear power plants is established from the perspective of electricity demand uncertainty. This model has been successfully applied to the case study of Zhejiang Province. The findings suggest that the nuclear power plants will contribute 9.56% of the total installed capacity, and it will become the second stable electricity source. The lowest total discounted cost is 1033.28 billion RMB and the fuel cost accounts for a large part of the total cost (about 69%). Different key performance indicators (KPI) differentiate electricity demand in scenarios that are used to test the model. Low electricity demand in the development mode of the comprehensive adjustment scenario (COML) produces the optimal power development path, as it provides the lowest discounted cost.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 7
    Publication Date: 2014-04-10
    Description: At present, high temperature profile control technology has become the key technology to improving recovery efficiency, management of steam channeling in thermal recovery. The particle of regular application is dosage big, poor injection and easy to cause the rigid block, Gel and foam profile control agent is poor stability, low intensity and short validity period. For the above problems, Developed a new type of high temperature resistance particle-gel complex profile control system through the theoretical analysis and the ratio optimization of indoor experiment and evaluate its performance. The formula of the system: 0.03%Coagulant + 2.2% cross-linking agent I + 1.8%cross-linking agent II + 6% modified high temperature resistance main agent + 0.7% new type inorganic particles + 0.5% suspending agent. At least 280 ℃ of heat-resistant, two-fluid process injection, injection performance is good, the plugging rate is more than 99.05%, scouring resistance and it has good thermal stability. This study provides a new direction for the thermal profile and theoretical basis for profile control construction. Key words : Thermal recovery; Steam channeling; Compound; Profile control agent; Two-fluid process
    Print ISSN: 1925-542X
    Electronic ISSN: 1925-5438
    Topics: Geosciences
    Published by CSCanada
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  • 8
    Publication Date: 2014-04-10
    Description: For high temperature steam channeling problem of the middle and later of the heavy oil reservoir, using simple variable method to optimize the ratio of the of proportion the plugging agent and Static and dynamic performance are evaluated; combined the experimental data with CMG numerical simulation software to optimize the plugging process parameters. The formula of high temperature resistant gel type plugging agent system: The first working liquid: 1.8%cross-linking agent II+ 6% modified high temperature resistant main agent; The second working liquid: 0.03% coagulant aid+2.2% cross-linking agent I. The gelling viscosity of the plugging agent more than 2 x 106 mPa·s, PH = 6-8 is applied, heat-resistant 〉 280 ℃, plugging rate 〉 96.75%; Using the double fluid method and low-pressure low-emission to inject. Optimizing the radius of profile control is 15 m, valid for 7-10 months, it has the obvious effect of increasing oil and controlling water. Key words : Steam flooding; Steam channeling; High temperature; Plugging agent; Profile control; Double fluid method
    Print ISSN: 1925-542X
    Electronic ISSN: 1925-5438
    Topics: Geosciences
    Published by CSCanada
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  • 9
    Publication Date: 2014-05-13
    Description: At present, high temperature profile control technology has become the key technology to improving recovery efficiency, management of steam channeling in thermal recovery. The particle of regular application is dosage big, poor injection and easy to cause the rigid block, Gel and foam profile control agent is poor stability, low intensity and short validity period. For the above problems, Developed a new type of high temperature resistance particle-gel complex profile control system through the theoretical analysis and the ratio optimization of indoor experiment and evaluate its performance. The formula of the system: 0.03%Coagulant + 2.2% cross-linking agent I + 1.8%cross-linking agent II + 6% modified high temperature resistance main agent + 0.7% new type inorganic particles + 0.5% suspending agent. At least 280 ℃ of heat-resistant, two-fluid process injection, injection performance is good, the plugging rate is more than 99.05%, scouring resistance and it has good thermal stability. This study provides a new direction for the thermal profile and theoretical basis for profile control construction. Key words : Thermal recovery; Steam channeling; Compound; Profile control agent; Two-fluid process
    Print ISSN: 1925-542X
    Electronic ISSN: 1925-5438
    Topics: Geosciences
    Published by CSCanada
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  • 10
    Publication Date: 2014-05-13
    Description: The liquid loading of gas well is an important issue in deep exploitation of natural gas. The technic of vortex drainage has good prospects because the tool construction and construction work is simple, the technic is environmental and efficient. Currently, the mechanism for the vortex drainage and the theory of fluid motion are still missing. Therefore, in order to further understand the downhole flow field, verify drainage mechanism and select best working conditions, based on computational fluid dynamics and mixture model of multiphase flow through Fluent, the study established a three-dimensional structural model of vortex tools and the numerical simulation has been done. By monitoring the wellhead and the radial distribution of the liquid content and observing the state of the gas-liquid flow and the path line, the study analyzed the influence on gas well flow field by vortex tool. The study revealed the working mechanism of vortex tools to facilitate understanding the nature of the vortex drainage process, guide how to select the preferred process conditions and provide theoretical basis for the application and the dynamics simulation of vortex drainage technology. Key words : The liquid loading of gas well; Vortex drainage; Multiphase flow; Numerical simulation
    Print ISSN: 1925-542X
    Electronic ISSN: 1925-5438
    Topics: Geosciences
    Published by CSCanada
    Location Call Number Limitation Availability
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