Association of solid fuel use with risk of stunting in children living in China

Stunting adversely affects physical and mental outcomes of children. It has not been examined whether household air pollution from solid fuel combustion is a risk factor for stunting in children. In a total of 41,439 children aged 6-17 across China, height was measured using a unified protocol. Multivariable linear regression models and logistic regression models were used to assess the associations of solid fuel use for cooking/heating with stunting in children. Adjusted for covariates, cooking/heating with solid fuel was significantly associated with a lower z-score for height for age and sex (β = −0.21 [−0.32 to −0.09] and −0.17 [−0.31 to −0.03], respectively) and an increased risk of stunting with an estimated ORs of 1.34 [1.07~1.68] and 1.37 [1.02~1.83], respectively. The risk of stunting associated with solid fuel use was statistically significant in high-age children. And the effect was greater on girls than on boys, though the difference was not statistically significant. Our study suggested that Chinese children living in households using solid fuel had a significantly higher risk of stunting than those living in households using cleaner fuel.     

负压差对固体进料系统压力分布和气固两相流动规律的影响

A series of experiments on a solid feed system was performed to investigate the effects of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics. Based on the non-fluidized gas-solid two phase flow and particulate mechanics in the standpipe, a method for predicting the pressure of the air passing through the recycle chamber and the pressure drop through the loop seal slit in these systems is also presented. The predicted pressure profile along the negative pressure gradient from the proposed model exhibits a good agreement with the experimental data. The experimental data show that the gas flow in the standpipe is always upward in the negative pressure gradients, while the direction of gas cannot be changed by the drag force. The solid flow rate, the materiel bed height in the recycle chamber (Hf), the pressure drop across the slit (△Pg） decrease with an increasing negative pressure gradient. At a given negative pressure gradient, the superficial gas velocity through the recycle chamber of the loop seal does not affect the pressure drop in standpipe. It increases with an increasing negative pressure gradient.     

Effect of transition metal doping on the sintering and electrochemical properties of GDC buffer layer in SOFCs

A dense Ce_0.9Gd_0.1O_2−d (GDC) interlayer is an essential component of the SOFCs to inhibit interfacial elemental diffusion between zirconia-based electrolytes (eg YSZ) and cathodes. However, the characteristic high sintering temperature of GDC (>1400°C) makes it challenging to fabricate an effective highly dense interlayer owing to the formation of more resistive (Zr,Ce)O₂ interfacial solid solutions with YSZ at those temperatures. To fabricate a useful GDC interlayer, we studied the influence of transition metal (TM) (Co, Cu, Fe, Mn, & Zn) doping on the sintering and electrochemical properties of GDC. Dilatometry data showed dramatic drops in the necking and final sintering temperatures for the TM-doped GDCs, improving the densification of the GDC in the order of Fe > Co > Mn > Cu > Zn. However, the electrochemical impedance data showed that among various transition metal dopants, Mn doping resulted in the best electrochemical properties. Anode supported SOFCs with Mn-doped, nano, and commercial-micron GDC interlayers were compared with regard to their performance and stability levels. Although all of the SOFCs showed stable performance, the SOFC with the Mn-doped GDC interlayer showed the highest power density of 1.14 W cm⁻² at 750°C. Hence, Mn-doped GDC is suggested for application as an effective diffusion barrier layer in SOFCs.     

氮含量及固溶温度对21-6-9奥氏体不锈钢组织和硬度的影响

为了探讨氮含量及固溶温度对21-6-9不锈钢组织和硬度的影响,分别在950、1000、1050和1100 ℃对3种不同氮含量的热轧态21-6-9不锈钢进行1 h固溶处理,通过光学显微镜观察其组织结构,结合Thermo-Calc热力学计算对试验钢的微观组织进行分析,并对其进行硬度测试。结果表明,0.20%~0.28%N的21-6-9不锈钢热轧后沿轧制方向析出铁素体,且钢中铁素体经950~1100 ℃固溶处理可消除,当N含量达到0.34%时,试验钢中不再出现铁素体。随着固溶处理温度的升高,21-6-9不锈钢的晶粒组织长大,硬度降低。N含量的增加可显著提高固溶态21-6-9不锈钢的硬度,其增加程度随固溶处理温度的升高而减弱。     

Non-Flammable Liquid and Quasi-Solid Electrolytes toward Highly-Safe Alkali Metal-Based Batteries

Rechargeable alkali metal (i.e., lithium, sodium, potassium)-based batteries are considered as vital energy storage technologies in modern society. However, the traditional liquid electrolytes applied in alkali metal-based batteries mainly consist of thermally unstable salts and highly flammable organic solvents, which trigger numerous accidents related to fire, explosion, and leakage of toxic chemicals. Therefore, exploring non-flammable electrolytes is of paramount importance for achieving safe batteries. Although replacing traditional liquid electrolytes with all-solid-state electrolytes is the ultimate way to solve the above safety issues, developing non-flammable liquid electrolytes can more directly fulfill the current needs considering the low ionic conductivities and inferior interfacial properties of existing all-solid-state electrolytes. Moreover, the electrolyte leakage concern can be further resolved by gelling non-flammable liquid electrolytes to obtain quasi-solid electrolytes. Herein, a comprehensive review of the latest progress in emerging non-flammable liquid electrolytes, including non-flammable organic liquid electrolytes, aqueous electrolytes, and deep eutectic solvent-based electrolytes is provided, and systematically introduce their flame-retardant mechanisms and electrochemical behaviors in alkali metal-based batteries. Then, the gelation techniques for preparing quasi-solid electrolytes are also summarized. Finally, the remaining challenges and future perspectives are presented. It is anticipated that this review will promote a safety improvement of alkali metal-based batteries.     

Hydrogenation process in multiphase alloys of Ti-Zr-Mn-V system on the example of Ti42.75Zr27Mn20.25V10 alloy

The influence of phase composition and microstructure of Ti_42.75Zr₂₇Mn_20.25V₁₀ alloy on its hydrogenation kinetic and phase composition of hydrogenated product was studied. It is established that the process of dissociation of hydrogen molecules begins on the surface of Laves phase crystallites. The dissolution of atomic hydrogen in the material volume leads to the formation of cracks in the intermetallic crystallites, which further appear as additional centers of dissociation of hydrogen molecules and noticeably accelerate the diffusion of hydrogen into the bulk material. It was shown that the Laves phase acts as a donor of atomic hydrogen for the BCC solid solution during hydrogenation of two-phase structure, initiating intensive hydrogenation of the BCC phase at room temperature.     

Stabilizing effect of the cyclodextrins additive to spray-dried particles of curcumin/polyvinylpyrrolidone on the supersaturated state of curcumin

Although curcumin is considered to have various therapeutic effects, its use as a functional food or supplement is restricted owing to its low water solubility and bioavailability. To increase the solubility of curcumin in water, the use of polyvinylpyrrolidone (PVP) and vinylpyrrolidone-vinyl acetate copolymers with a pyrrolidone skeleton was noted to be promising. In particular, the bi-component formulations of curcumin/PVP prepared through spray drying exhibited an amorphous state in powder X-ray diffraction observations and temporally increased the apparent solubility of curcumin to over 5000 times that of untreated curcumin; nevertheless, after 24 h, the solubility decreased owing to the unstable supersaturated state of curcumin. The addition of α-cyclodextrin (α-CyD) in the bi-component curcumin/PVP formulation helped maintain the supersaturated state of curcumin, whereas the addition of β- and γ-CyD led to the collapse of the supersaturated state. The addition of α-CyD can likely help inhibit the nucleation and crystal growth of curcumin, through the interaction among the solubilized units of curcumin/PVP and α-CyD.     

亲水作用色谱-串联质谱法测定动物源运动食品中3种氨基糖苷类抗生素的残留量

该研究建立了一种亲水交互作用色谱-串联质谱（HILIC-MS/MS）法测定动物源运动食品中潮霉素B、新霉素、安普霉素3种氨基糖苷类抗生素残留量的方法。结果表明，样品经Sielc Obelisc R柱分离，采用0.1%甲酸水溶液-乙腈梯度洗脱，可以实现3种目标物组分的分离。在此条件下，3种氨基糖苷类抗生素在5～500 ng/mL的质量浓度范围内线性关系良好，相关系数R2为0.999 5～0.999 9，检出限均为15 μg/kg，定量限均为50 μg/kg，保留时间的日间和日内相对标准偏差（RSD）分别为3.5%～7.9%和3.5%～4.1%，峰面积的日间和日内RSD分别为3.6%～7.4%和3.2%～3.9%，加标回收率为85.7%～93.6%，回收率试验结果的RSD为3.1%～5.2%。该方法可以满足动物源运动食品中3种氨基糖苷类抗生素的检测需求。     

Leveraging in-situ formation of Ni–Fe nanoparticles to promote the catalytic performance of Ruddlesden-Popper based electrode for symmetrical solid oxide fuel cells

Ruddlesden?Popper layered oxide, La_0.25Sr_2.75FeNiO_7-δ (LSFN) is evaluated as a potential electrode material for symmetrical solid oxide fuel cells. The in-situ formation of Ni–Fe alloy nanoparticles on the LSFN surface in reducing atmosphere can be believed to enhance the activity towards hydrogen oxidation reaction. LSFN exhibit maximum conductivity of 221.2 S/cm and 0.206 S/cm in air and hydrogen environment. Furthermore, LSFN is mixed with GDC powder to form a composite electrode for symmetric solid oxide fuel cells (SSOFC). Results show that with the combination of GDC, the maximum power density of YSZ-based SSOFC enlarges from 232.3 mW cm^?2 to 348.5 mW cm^?2, and related polarization resistance reduces from 0.359 Ω cm² to 0.108 Ω cm². The improved performance is attributed to the enlarged triple-phase boundary with the mixing of GDC. In addition, YSZ-based SSOFC with the LSFN-GDC composite electrode shows a stable performance in intermediate-temperature SSOFCs within 200 h, which indicates that LSFN-GDC composite material is a prospective symmetrical electrode for SSOFC.     

固态发酵产酶反应中体系传热传质行为分析

固态发酵是纤维素类生物质转化的有效途径,具有用水量少、容积产率高等优点。固态发酵生产纤维素酶一般是液态发酵酶产量的近3倍,可大幅降低酶的生产成本。在固态发酵过程,微生物在缺水环境中生长,发酵底物和接种物之间存在异质性,导致发酵热量分布不均匀、发酵过程氧气与中间产物不易扩散等问题。基于此,重点对固态发酵反应中体系传热传质方式及其影响因素进行了分析,并探讨其强化方法。根据传热方式,总结了发酵罐适用的导热微分方程及传热模拟方法,并分析气泡和颗粒基质中的传质过程及其限速步骤以及解决传质限速的途径。反应体系传热传质机理研究可促进固态发酵技术产业化应用进程。该研究可为有机废弃物固态发酵技术研究及应用提供一定的理论和技术支持。