Homogeneously dispersed cobalt/iron electrocatalysts with oxygen vacancies and favorable hydrophilicity for efficient oxygen evolution reaction

Rational design of highly conductive and hydrophilic electrocatalysts are extremely important to promote their oxygen evolution reaction (OER). In this work, a homogeneously dispersed carbon-based cobalt/iron catalyst (Co/Fe–C) with abundant oxygen vacancies and favorable hydrophilicity is fabricated via a facile metal-polyphenol complexes strategy. The tannic acid (TA) and fulvic acid (FA) derived 0.3 Co/Fe–C catalysts show greatly similar morphologies, as well as the performance optimization process of electrocatalytic OER. Specifically, the TA-derived 0.3 Co/Fe–C catalyst exhibits an overpotential of 284 mV at 10 mA cm^?2 for OER in alkaline electrolyte. Combined a series of characterization techniques suggest that abundant oxygen vacancies and favorable surface hydrophilicity can improve electronic conductivity of the catalyst and accelerate reactant adsorption and charge transfer rate on the catalyst surface, thus promoting OER activity of the catalysts. This study might provide a new perspective to construct advanced electrocatalysts with oxygen vacancies and hydrophilic surface for electrocatalytic applications.     

The impact of hydrogen refueling station subsidy strategy on China's hydrogen fuel cell vehicle market diffusion

Lack of hydrogen refueling stations (HRSs) has hindered the diffusion of hydrogen fuel cell vehicles (HFCVs) in the Chinese transport market. By combining the agent-based model (ABM) and the experience weighted attraction (EWA) learning algorithm, this paper explores the impact of government subsidy strategy for HRSs on the market diffusion of HFCVs. The actions of the parties (government, HRS planning department and consumers) and their interactions are taken into account. The new model suggests dynamic subsidy mode based on EWA algorithm yields better results than static subsidy mode: HFCV purchases, HRS construction effort, total number of HRSs and expected HRS planning department profits all outperform static data by around 27%. In addition, choosing an appropriate initial subsidy strategy can increase the sales of HFCVs by nearly 40%. Early investment from government to establish initial HRSs can also increase market diffusion efficiency by more than 76.7%.     

Effects of particle sizes on performances of the multi-zone steam generator using waste heat in a bio-oil steam reforming hydrogen production system

Hydrogen production by bio-oil steam reforming is an advanced production technology. It is a good method of coupling waste heat utilization with bio-oil steam reforming to produce hydrogen, which increases the cleaning ability of the bio-oil steam reforming system. A multi-zone steam generator using waste heat has been proposed, which can produce the heat source and steam source of the hydrogen system. The DEM model of the multi-zone steam generator was set up. The model has been used to investigate the effects of particle sizes (40 mm–80 mm). With increasing particle size, the flow index and the flow uniformity gradually decrease, the vertical velocity gradient increases in the area on both side with the zone steam generator, and the vertical velocity fluctuation amplitude gradually increases. So, the hydrogen production decreases from the particle size increasing.     

产细菌素屎肠球菌SC-Y112的体外益生性及安全性评价

屎肠球菌SC-Y112是一种具有广谱抗菌性质的产细菌素乳酸菌，为更深入了解其菌株性质，本研究通过模拟胃肠液耐受实验、胆盐耐受实验、抗氧化活性测定、溶血活性测定、明胶液化实验、有害代谢物质检测、耐药性评价及肠球菌毒力基因检测对屎肠球菌SC-Y112的体外益生性质与安全性质进行分析评价。结果表明：屎肠球菌SC-Y112对模拟胃肠液耐受性强，在模拟胃液培养3 h存活率达73.66%，在0.3 g/100 mL的胆盐质量浓度下培养3 h后存活率达56.38%，其发酵24 h上清液总抗氧化能力达35.21 U/mL；此外，屎肠球菌SC-Y112不产生物胺、吲哚以及偶氮还原酶等有害代谢物质，无溶血现象，不溶解明胶，不携带常见肠球菌毒力基因，且对万古霉素敏感。研究结果可为菌株的进一步开发与应用提供科学依据。     

Exposure to environmental tobacco smoke during pregnancy and infancy increased the risk of upper respiratory tract infections in infants: A birth cohort study in Wuhan,China

We aimed to evaluate the association of the exposure to environmental tobacco smoke (ETS) during pregnancy and infancy with the risk of upper respiratory tract infections (URTI) in infants based on a Chinese birth cohort study. Among 4178 infants who constituted the final study population, 46.8% experienced URTI in their first year of life. The hazard ratios (HR) and 95% confidence intervals (CI) for the risk of URTI were assessed using Cox regression models. Compared with no ETS during pregnancy, continued ETS during pregnancy was independently associated with a higher risk of URTI (HR: 1.36, 95% CI: 1.13, 1.63) after adjustment for potential confounders and also associated with earlier occurrence of URTI (log-rank P = .002). The association remained consistent across the strata defined according to maternal age, number of siblings, sex, and breastfeeding. Exposure to ETS during infancy was associated with URTI only among infants who were breastfed for less than 12 months (P for interaction < 0.05).Furthermore, infants exposed to ETS during both pregnancy and infancy showed the highest HR of 1.46 (95% CI: 1.16, 1.85) for URTI. Efforts should be made to protect pregnant women and infants from the adverse effects of indoor and outdoor ETS.     

Failure mechanism of gently inclined shallow landslides along the soil-bedrock interface on ring shear tests

Bulletin of Engineering Geology and the Environment - There were many gently inclined shallow landslides along the soil-bedrock interface at a depth of 3–5 m in Nanjiang County, Sichuan...     

智能混凝土施工及其应用

随着时代的发展,相关从业者对智能混凝土的研究越来越深入.在实际工程推进中,智能混凝土施工的优势非常明显,可以很好地提高混凝土的性能,并根据施工的需求做好混凝土的优化控制工作,让施工单位可以结合项目的实际应用需求,有针对性地选择对应的智能混凝土施工工艺.     

Study of neutron production and moderation for sulfur neutron capture therapy

Neutron capture therapy with Sulfur-33, similar to boron neutron capture therapy with Boron-10, is effective in treating some types of tumors including ocular melanoma. The key point in sulfur neutron capture therapy is whether the neutron beam flux and the resonance capture cross section of ~(33)S(n;α)~(30) Si reaction at 13.5 keV can achieve the requirements of radiotherapy. In this research,the authors investigated the production of 13.5 keV neutron production and moderation based on an accelerator neutron source. A lithium glass detector was used to measure the neutron flux produced via near threshold~7 Li(p,n)~7 Be reaction using the time-of-flight method. Furthermore, the moderation effects of different kinds of materials were investigated using Monte Carlo simulation.     

铁矿烧结过程微细颗粒物排放行为

 采用ELPI+设备(荷电低压撞击器)对铁矿烧结过程微细颗粒物进行在线检测与采样，利用场发射扫描电子显微镜(FESEM EDS)对采集的颗粒物形貌特征进行分析，研究铁矿烧结过程中微细颗粒物的排放行为。研究结果表明，PM10大量释放集中在烧结升温段，且颗粒物质量浓度与数目浓度在粒径分布上有较大差异，其中质量浓度峰值区间为5.37～10.00 μm，数目浓度峰值区间为0.10～0.16 μm；形貌特征上，微细颗粒物呈规则的球形、方块形和片状；不同粒径物质组成差异明显，其中颗粒物中的K、Na主要以KCl和NaCl的形式存在，含量随颗粒物粒级的增大而略有降低。     

Topography‐Induced Cell Self‐Organization from Simple to Complex Aggregates

Self‐organization is a fundamental and indispensable process in a living system. To understand cell behavior in vivo such as tumorigenesis, 3D cellular aggregates, instead of 2D cellular sheets, have been employed as a vivid in vitro model for self‐organization. However, most focus on the macroscale wetting and fusion of cellular aggregates. In this study, it is reported that self‐organization of cells from simple to complex aggregates can be induced by multiscale topography through confined templates at the macroscale and cell interactions at the nanoscale. On the one hand, macroscale templates are beneficial for the organization of individual cells into simple and complex cellular aggregates with various shapes. On the other hand, the realization of these macro‐organizations also depends on cell interactions at the nanoscale, as demonstrated by the intimate contact between nanoscale pseudopodia stretched by adjacent frontier cells, much like holding hands and by the variation in the intermolecular interactions based on E‐cadherin. Therefore, these findings may be very meaningful for clarifying the organizational mechanism of tumor development, tissue engineering and regenerative medicine.