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992.
Weigang Liang Beibei Wang Guofeng Shen Suzhen Cao Bertrand Mcswain Ning Qin Liyun Zhao Dongmei Yu Jicheng Gong Shanshan Zhao Yawei Zhang Xiaoli Duan 《Indoor air》2020,30(2):264-274
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. 相似文献
993.
994.
N. F. Goldshleger I. P. Kalashnikova Yu. G. Gorbunova A. G. Martynov V. E. Baulin A. Yu. Tsivadze 《Protection of Metals and Physical Chemistry of Surfaces》2018,54(1):33-42
Crown-containing Pc Mg[(B15C5O)8Pc], Mg[(B15C5O)4Pc], and Mg[(15C5)4Pc] are in the monomolecular state in solutions of synthetic anionic surfactants: sodium dodecylsulfate and sodium dodecylbenzenesulfonate. In micellar solutions of bile-acid salts, molecular organization of crown-substituted Pc with different methods of introduction of crown groups into the macrocycle and their different numbers changes their state from predominantly monomeric for Mg[(B15C5O)8Pc] in the presence of NaCl to the aggregated one in the case of Mg[(15C5)4Pc)]. Magnesium phthalocyaninate with annulated (15-crown-5)-fragments, Mg[(15C5)4Pc], is characterized by the highest sensitivity to the structure of the micelle-forming biocompatible surfactant. 相似文献
995.
996.
Yuanming Xie Tianda Yu Chaojun Deng Xuefei Hu 《Journal of Nuclear Science and Technology》2020,57(9):1074-1090
ABSTRACT In the lower chamber of pressurized water reactor (PWR), the flow distribution device is the core module to distribute coolant into the core. It has complex structure and numerous design parameters. Therefore, it has important theoretical and practical significance to optimize the device. The mesh independence verification, turbulence model selection, and data processing all can influence the numerical simulation results of the lower chamber, in order to research the influence, a numerical simulation method based on the original model of CNP1000 reactor lower chamber is proposed in this paper. In the method, an optimization design method of flow distribution device is established based on surrogate model. The main design variables and optimization objectives are determined based on the device’s structure and function characteristics. And then it respectively adopts Kriging algorithm and multi-objective genetic algorithm to establish a surrogate model of flow distribution device and optimize it globally. Finally, the optimal design variables are obtained. Compared with the device’s performance before optimization, the after optimization has smaller total pressure loss and more uniform flow. The effectiveness and practicability of proposed optimization design method can be verified. 相似文献
997.
相对于传统的连续激光加热方法,脉冲激光加热能够显著缩短加热时间,从而有效阻止金刚石样品腔内各组分的化学反应。基于北京同步辐射装置(Beijing synchrotron radiation facility,BSRF)高压实验站原有的连续激光加热系统,建立了可应用于高压X射线衍射实验的脉冲激光加热方法。该方法利用信号发生器对脉冲激光器、测温电荷耦合器件(Charge Coupled Device,CCD)光谱仪以及X射线探测器进行同步控制,实现了脉冲激光对样品加热,并在加热周期内完成温度谱及高压衍射数据的同步采集。利用高压条件下的Pt样品,对脉冲激光加热过程中样品的温度稳定性、重复性以及温度梯度进行了测试,并完成了原位X射线衍射实验。该脉冲激光加热系统的搭建,为在BSRF高压实验站开展原位脉冲激光加热方法研究提供了条件,也为将来在北京高能同步辐射光源上实施相关方法奠定了基础。 相似文献
998.
Jinyang Li Eunkyoung Kim Kelsey M. Gray Christina Conrad Chen‐Yu Tsao Sally P. Wang Guanghui Zong Giuliano Scarcelli Kimberly M. Stroka Lai‐Xi Wang William E. Bentley Gregory F. Payne 《Advanced functional materials》2020,30(30)
Biology uses diffusible oxidants to perform functions that range from signaling to matrix assembly, and these oxidation chemistries offer surprising selectivities. Here, it is reported that mediated electrochemistry can access the richness of such oxidation chemistries. Specifically, electrode‐imposed voltage inputs are used to locally generate oxidized mediators that can diffuse into polymer solutions and induce the formation of covalent bonds for the deposition and functionalization of hydrogels at the electrode surface. Depending on the mediator's redox potential (E0), it is possible to “gate” the voltage inputs to target specific residues (e.g., thiols or amines) and oxidation chemistries. Further, mediators of varying E0 offer different reactivities and thus allow control of reaction‐diffusion rates to modulate the hydrogel's crosslink density and mechanical properties. Importantly, this mediated oxidation can be performed under physiologically relevant conditions to preserve labile biological functionalities (e.g., cell viability and protein function). Finally, it is demonstrated that protein fusion tags can be engineered to have “targetable” amino acid residues that enable protein function to be oxidatively conjugated to electrodeposited hydrogels. In summary, mediated electrochemistry can engage orthogonal oxidation chemistries to create functionalized matrices and thus mediated electrochemistry should add important capabilities to the electrofabrication toolbox. 相似文献
999.
Endong Jin Jingkun Yu Tianpeng Wen Xinghui Hou Beiyue Ma Feixiong Mao 《Ceramics International》2018,44(6):6390-6394
High-density magnesia was fabricated using vacuum compaction molding, and effects of forming pressure and sintering temperature on bulk density, apparent porosity, diameter shrinkage ratio, volume shrinkage ratio, pore size distribution, cold compressive strength, and thermal shock resistance of the magnesia samples were investigated. There were two ranges of pore distribution in samples that were formed via conventional compaction molding, and these ranges were about 350–2058 nm and 6037–60527 nm. It was considered that the range of larger pores mainly influenced the densification of magnesia. Using vacuum compaction molding, large size pores were removed, and high-density magnesia (with a density greater than 3.40 g cm?3) was easily prepared when forming pressure was higher than 200 MPa and sintering temperature was higher than 1600 °C. Magnesia samples prepared via vacuum compaction molding showed better performance compared to that of samples prepared via conventional compaction molding. 相似文献
1000.
Yilin Zhang Ji Qi Yuhan Wang Yu Tian Junkai Zhang Tingjing Hu Maobin Wei Yanqing Liu Jinghai Yang 《Ceramics International》2018,44(6):6054-6061
Mn-doped BiFeO3 (BiFe1–xMnxO3, x = 0, 0.03, 0.05, 0.10, 0.15 and 0.20) polycrystalline multiferroic thin films were successfully synthesized using the facile sol-gel spin-coating method. The crystal structures, surface features, elements valences, and magnetic properties of as-prepared samples were systematically explored. X-ray diffraction and Raman spectroscopy studies revealed the substitutions of Mn into the Fe site and a rhombohedral-to-orthorhombic phase transition. The Field Emission Scanning Electron Microscopy showed a decrease in the average particle sizes and an improvement of surface morphology with increasing the concentration of the substitutes. Energy-dispersive X-ray spectroscopy confirmed the doping concentration of Mn2+ in the samples. X-ray photoelectron spectroscopy indicated the co-existence of Mn2+/Mn3+ ions in the doped films. The remnant magnetization value of BiFe0.90Mn0.10O3 thin film was found to be approximately six times than that of pure BiFeO3 thin film under a magnetic field of 10 kOe. The enhanced magnetic property of BiFe0.90Mn0.10O3 thin film was mainly ascribed to the structural distortion of spin cycloid and the enhancement of super-exchange interaction between the Fe3+ (Mn2+) and O2- ions. 相似文献