Atlas of Mineral Deposits Distribution in China (2020)

This open access book includes instruction of national mineral database 2020 and atlas of national mineral deposits distribution derived from national mineral database 2020. National mineral database 2020 is based on data from National Geological Archives China(NGAC). Moreover, it introduces the construction method and updates maintenance mechanism of the mineral deposits database and proposes the concept of updating data based on collected archives. The construction guideline on national mineral deposits database provides guiding framework for the future development on geological database

Upper ocean biogeochemistry of the oligotrophic North Pacific Subtropical Gyre : from nutrient sources to carbon export

Subtropical gyres cover 26–29% of the world’s surface ocean and are conventionally regarded as ocean deserts due to their permanent stratification, depleted surface nutrients, and low biological productivity. Despite tremendous advances over the past three decades, particularly through the Hawaii Ocean Time-series and the Bermuda Atlantic Time-series Study, which have revolutionized our understanding of the biogeochemistry in oligotrophic marine ecosystems, the gyres remain understudied. We review current understanding of upper ocean biogeochemistry in the North Pacific Subtropical Gyre, considering other subtropical gyres for comparison. We focus our synthesis on spatial variability, which shows larger than expected dynamic ranges of properties such as nutrient concentrations, rates of N2 fixation, and biological production. This review provides new insights into how nutrient sources drive community structure and export in upper subtropical gyres. We examine the euphotic zone in subtropical gyres as a two-layered vertically structured system: a nutrient-depleted layer above the top of the nutricline in the well-lit upper ocean and a nutrient-replete layer below in the dimly lit waters. These layers vary in nutrient supply and stoichiometries and physical forcing, promoting differences in community structure and food webs, with direct impacts on the magnitude and composition of export production. We evaluate long-term variations in key biogeochemical parameters in both of these euphotic zone layers. Finally, we identify major knowledge gaps and research challenges in these vast and unique systems that offer opportunities for future studies

Using the High-Level Based Program Interface to Facilitate the Large Scale Scientific Computing

This paper is to make further research on facilitating the large-scale scientific computing on the grid and the desktop grid platform. The related issues include the programming method, the overhead of the high-level program interface based middleware, and the data anticipate migration. The block based Gauss Jordan algorithm as a real example of large-scale scientific computing is used to evaluate those issues presented above. The results show that the high-level based program interface makes the complex scientific applications on large-scale scientific platform easier, though a little overhead is unavoidable. Also, the data anticipation migration mechanism can improve the efficiency of the platform which needs to process big data based scientific applications

Adsorption of 17α-Ethinyl Estradiol and Bisphenol A to Graphene-Based Materials: Effects of Configuration of Adsorbates and the Presence of Cationic Surfactant

Endocrine-disrupting chemicals (EDCs) have attracted much attention in recent years. Graphene-based materials (GMs) have been deemed as excellent adsorbents for the removal of EDCs. The objective of the present study was to understand how the cationic surfactants (CTAB; cetyltrimethylammonium nitrate) affect the adsorption of EDCs (17α-ethinyl estradiol (EE2) and bisphenol A (BPA)) on graphene oxide (GO), reduced graphene oxides (RGOs), and the few-layered commercial graphene (CG). It was observed that the presence of CTAB showed different effects on the adsorption of EDCs to different GMs. The adsorption of EDCs on GO was enhanced because of the enhanced hydrophobicity of GMs after the adsorption of CTAB and the newly formed hemimicelles by the adsorbed CTAB, which could serve as the partition phase for EDCs. Moreover, the electron donor-acceptor interaction and cation bridging effect of the –NH4+ group of the adsorbed CTAB between EDCs and GMs could also enhance the adsorption of EDCs to GMs. With the increase of the extent of GM reduction, the adsorption enhancement by the presence of CTAB weakened. This could be attributed to the competition and pore blockage effect caused by the adsorbed CTAB. It is worth noting that the enhancement of CTAB on the adsorption of BPA to GMs was more profound than that of EE2. This is likely because the pore blockage effect plays a less important role in the adsorption of BPA due to its smaller molecular diameter and deformable structure

Effects of Magnetic Minerals Exposure and Microbial Responses in Surface Sediment across the Bohai Sea

Extensive production and application of magnetic minerals introduces significant amounts of magnetic wastes into the environment. Exposure to magnetic minerals could affect microbial community composition and geographic distribution. Here, we report that magnetic susceptibility is involved in determining bacterial alpha-diversity and community composition in surface sediment across the Bohai Sea by high-throughput sequencing analysis of the 16S rRNA gene. The results showed that environmental factors (explained 9.80%) played a larger role than spatial variables (explained 6.72%) in conditioning the bacterial community composition. Exposure to a magnetite center may shape the geographical distribution of five dissimilatory iron reducing bacteria. The microbial iron reduction ability and electroactive activity in sediment close to a magnetite center are stronger than those far away. Our study provides a novel understanding for the response of DIRB and electroactive bacteria to magnetic minerals exposure

Effect of charging operating conditions on open zeolite/water vapor sorption thermal energy storage system

Sorption thermal energy storage (STES) is one of the most promising solutions to realize inter-seasonal thermal energy storage for building heating. However, the analysis of charging operation parameters on the thermal energy storage performance of STES system is insufficient. In this paper, a STES experimental bench using zeolite 4A/water vapor as the sorption working pairs was built, and the charging/discharging experiments were conducted. The thermal energy chain during the full charging-discharging process was analyzed. The experimental results indicated that approximately 60% of the thermal energy provided by the heater was directly lost through the reactor outlet in the charging process, which seriously hindered the improvement of the thermal energy storage performance of the STES system, such as the coefficient of performance (COP). In addition, the influence of charging conditions on the thermal energy storage performance of the system was also investigated. Both the improvement of charging temperature and the reduction of charging air humidity are beneficial to enhancing the thermal energy storage performance of the STES system. When the charging temperature was 150 °C, the energy storage density of zeolite reached a maximum of 251 kWh/m3. The COP of system reduced by 28% when the relative humidity of charging air rose from 20% to 70%. The effect of the volume flow rate of charging air on the thermal energy storage performance of the system is insignificant. The COP of system maintained around 0.212 at different charging air volume flow rates

Enrichment culture of electroactive microorganisms with high magnetic susceptibility enhances the performance of microbial fuel cells

Many electroactive microorganisms (EAMs) are known as dissimilatory iron-reducing bacteria (DIRB) which can access iron as an electron acceptor to transfer electrons during the process of respiration. Previous research has shown that magnetic susceptibility (chi lf) could be used as an indicator of DIRB activities. However, the relationship between chi lf and electroactivity of EAMs is still unclear. Here, we report that after sediments of the Sha River enriched with amorphous iron, the chi lf of enrichment cultures increased dramatically. The reactor inoculated with higher chi lf enrichment cultures started earlier and had a higher peak voltage (0.228 V), higher power density (310.14 mW m(-2)) and higher coulombic efficiency (10.16%) than lower chi lf cultures. Sequencing of bacterial 16S rRNA gene amplicons and chi lf measurement revealed that relative abundance of dominant phyla Proteobacteria increased with chi lf values in sediments. Further analysis of cyclic voltammetry curves and bacterial terminal-restriction fragment length polymorphism (T-RFLP) of bacterial rRNA genes indicated that the improved performance of the MFCs might be due to a highly electroactive microbial community that the 162 bp terminal restriction fragments (TRFs) originated from. Our results suggested a potential correlation between chi lf and presence of EAM indicating a promising route for fast screening in complex environments. (C) 2018 Elsevier B.V. All rights reserved

Effects of Zr^(4+) codoping on the Lu_(0.8)Sc_(0.2)BO_3:Ce scintillation materials

Both Zr-codoped Lu_(0.8)Sc_(0.2)BO_3:Ce polycrystalline powders and single crystals were obtained by solid-state reaction and Czochralski method, respectively. The effects of Zr codoping on the optical absorption, Ce^(3+)/Ce^(4+) ratio, scintillation efficiency, decay time and point defect in Lu_(0.8)Sc_(0.2)BO_3:Ce materials were examined systematically. Our results show that there is no positive contribution of Zr^(4+) ion codoping to the scintillation efficiency. And the reasons for the deterioration of scintillation efficiency by codoping Zr^(4+) were revealed

Atlas of Mineral Deposits Distribution in China (2020)

This open access book includes instruction of national mineral database 2020 and atlas of national mineral deposits distribution derived from national mineral database 2020. National mineral database 2020 is based on data from National Geological Archives China(NGAC). Moreover, it introduces the construction method and updates maintenance mechanism of the mineral deposits database and proposes the concept of updating data based on collected archives. The construction guideline on national mineral deposits database provides guiding framework for the future development on geological database