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991.
Microbiome modulators such as probiotics are known to modulate oral diseases. Very few probiotics are commercially available for use in the oral cavity. In this context, we selected human-origin Lactobacillus salivarius AR809 as a promising oropharyngeal probiotic and characterized its functional and immunomodulatory properties. Results demonstrated that AR809 could efficiently adhere to pharyngeal epithelial FaDu cells, antagonize Staphylococcus aureus, adapt to the oral environment, and modulate host innate immunity by inducing potentially protective effects. Particularly, AR809 diminished proinflammatory activity by enhancing the production of IL10 and inhibiting the expression of tumor necrosis factor-α, IL1B, inducible nitric oxide synthase, and RELA. Finally, we observed that AR809 grew efficiently when cultured in milk, suggesting that the preparation of a fermented milk product containing AR809 could be a practical way to administer this probiotic to humans. In conclusion, AR809 has high potential to adhere to the pharyngeal mucosa and could be applied in novel milk-based probiotic fermented food products.  相似文献   
992.
993.
为保障LNG接收站的安全运行,有效控制泄漏风险,通过泄漏检测及修复工作的开展,对天然气泄漏模式进行了分析。结果表明LNG接收站泄漏部位以法兰、引压管接头为主,占总泄漏部位的92.9%,在泄漏量上,占总泄漏量的98.1%。引压管管接头的泄漏原因以结构失效为主,占82.4%,法兰的泄漏原因以压紧力不足为主,占65.7%。最后根据泄漏修复经验,提出了防泄漏控制措施,为防泄漏工作提供了支持。  相似文献   
994.
The most prominent challenge associated with offshore horizontal drilling is wellbore stability. In this paper, simulation of in-situ stresses around the wellbore is conducted to study the effects of transient pore pressure on the stability of horizontal wells. The rock mechanical analysis based on finite element technique lead to investigate a unique behavior found in subsea horizontal wells known as transient pore pressure behavior and near wellbore pressure gradients. The results demonstrate that near wellbore pore pressure gradient is only active in rock formations which possess transient pore pressure behavior; therefore, simulated solutions require adjustment to achieve accurate results.  相似文献   
995.
Jia  Dedong  Zheng  Kun  Song  Ming  Tan  Hua  Zhang  Aitang  Wang  Lihua  Yue  Lijun  Li  Da  Li  Chenwei  Liu  Jingquan 《Nano Research》2020,13(1):215-224

Aqueous Zinc-ion batteries (ZIBs), using zinc negative electrode and aqueous electrolyte, have attracted great attention in energy storage field due to the reliable safety and low-cost. A composite material comprised of VO2·0.2H2O nanocuboids anchored on graphene sheets (VOG) is synthesized through a facile and efficient microwave-assisted solvothermal strategy and is used as aqueous ZIBs cathode material. Owing to the synergistic effects between the high conductivity of graphene sheets and the desirable structural features of VO2·0.2H2O nanocuboids, the VOG electrode has excellent electronic and ionic transport ability, resulting in superior Zn ions storage performance. The Zn/VOG system delivers ultrahigh specific capacity of 423 mAh·g−1 at 0.25 A·g−1 and exhibits good cycling stability of up to 1,000 cycles at 8 A·g−1 with 87% capacity retention. Systematical structural and elemental characterizations confirm that the interlayer space of VO2·0.2H2O nanocuboids can adapt to the reversible Zn ions insertion/extraction. The as-prepared VOG composite is a promising cathode material with remarkable electrochemical performance for low-cost and safe aqueous rechargeable ZIBs.

  相似文献   
996.
997.
贾永生 《同煤科技》2016,(4):9-12,16
针对大同矿区石炭系巷道具有煤层厚度大、断面大、火成岩侵入等,在开采过程中普遍存在采场压力大,矿压显现剧烈;区段煤柱宽,煤炭损失严重;煤巷支护困难等突出问题,本文基于多尺度全方位均压耦合支护理论,采用物理相似模拟实验和数值模拟的方法,对无支护、棚架支护和锚网支护情况下呈现出支护效果进行了对比分析,结果表明以锚网为主体的支护形式能较好地实现均压耦合支护,可有效阻止围岩松动圈的扩展,并在塔山矿5105巷得到了应用。  相似文献   
998.
999.
1000.
Internal stress and stress-related defects are considered as the major obstacles that significantly hinder the growth of high-quality ZnO-based crystals. In this work, high-crystalline-quality ZnO:Zn bulk crystals were successfully grown by carbon-assisted chemical vapor transport (CVT). Internal stress in the crystal was directly measured by a neutron beam from a reactor, and stress distributions along the radial direction at different depths were obtained. The stress, temperature, and flow fields in the growth system were simulated by the finite element (FE) method, and the results agreed with the neutron stress analysis. The etch pit density (EPD), Hall properties, and optical transmittances of different crystal regions were studied in detail, and the distribution trend of the crystal properties was consistent with that of internal stress and stress-related defects in the crystal. It is found that the unique temperature filed in the growth system causes the crystal to bend to a slightly convex toward the growth direction and gives rise to a driving force for structural defect formation. The + c and –c faces of the crystal are subjected to tensile and compressive stress, respectively. The maximum stress values are about 280 MPa and -291 MPa near the central regions of ±c faces, while the crystal periphery is basically free of internal stress. The region near the center of +c face has an EPD of 7.5 × 103 cm-2 and a transmittance of 79.2% at 800 nm wavelength, while the corresponding carrier concentration and mobility are 2.27 × 1017 cm?3 and 159 cm2/V·s, respectively. By comparison, the crystal periphery has an EPD of 102 cm-2 with an 80.5% transmittance at 800 nm, while the carrier concentration and mobility are 1.85 × 1017 cm?3 and 184 cm2/V·s, respectively.  相似文献   
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