Mesoporous High‐Surface‐Area Copper–Tin Mixed‐Oxide Nanorods: Remarkable for Carbon Monoxide Oxidation

Mesoporous, high‐surface‐area Cu–Sn mixed‐oxide nanorods were fabricated for the first time by nanocasting with the use of mesoporous KIT‐6 silica as the hard template. The Cu–Sn nanorods are significantly more active than 1 % Pd/SnO2 for the oxidation of CO and possesses long‐term durability and potent water resistance; they thus have the potential to replace noble metal catalysts for emission‐control processes.In rod we trust: Mesoporous, high‐surface‐area Cu–Sn nanorods are successfully fabricated for the first time by nanocasting with the use of KIT‐6 silica as the hard template; these nanomaterials are significantly more active than 1 % Pd/SnO2 for the oxidation of CO, and furthermore, they have the potential to replace noble metal catalysts for emission control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/1/cctc201600221.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/2/cctc201600221-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/3/cctc201600221_am.pd

Assessment Method of Wind Farm Harmonic Emission Value Based on Improved Complex Linear Regression Model

Wind turbine filter and reactive power compensation devices lead to the harmonic impedance of wind farm is not much larger than that of the utility, so the influence by the wind farm harmonic impedance can not be neglected while assessing the harmonic emission value of wind farm A method based on improved complex linear regression is proposed in this paper for assessing the harmonic emission value of wind farm. The linear regression model is established by using the harmonic current at PCC point as the explanatory variable and the harmonic voltage of the wind farm as the explanatory variable. The utility harmonic impedance is calculated by complex least squares method. For various of the topology of wind farm feeder network, an equivalent method of feeder network is proposed to calculate the wind farm harmonic impedance. Errors are analyzed by using the error marginal effect of the dispersion parameter. Simulation and measured data verify the effectiveness of the proposed metho

Assessment Method of Wind Farm Harmonic Emission Value Based on Improved Complex Linear Regression Model

Wind turbine filter and reactive power compensation devices lead to the harmonic impedance of wind farm is not much larger than that of the utility, so the influence by the wind farm harmonic impedance can not be neglected while assessing the harmonic emission value of wind farm A method based on improved complex linear regression is proposed in this paper for assessing the harmonic emission value of wind farm. The linear regression model is established by using the harmonic current at PCC point as the explanatory variable and the harmonic voltage of the wind farm as the explanatory variable. The utility harmonic impedance is calculated by complex least squares method. For various of the topology of wind farm feeder network, an equivalent method of feeder network is proposed to calculate the wind farm harmonic impedance. Errors are analyzed by using the error marginal effect of the dispersion parameter. Simulation and measured data verify the effectiveness of the proposed metho

Related factors of outcomes of pharyngeal foreign bodies in children

Objective: This study aimed to identify factors related to outcomes of the pharyngeal foreign bodies in children and to improve the management protocol of this disease. Methods: The medical records of 131 children with pharyngeal foreign bodies hospitalized in the hospital were retrospectively reviewed. Results: Significant differences were observed between the two groups (dislodgement and removal group) with respect to location of pharyngeal foreign bodies and age, while sex, time of pharyngeal foreign bodies, and nature of pharyngeal foreign bodies had no significant differences. Moreover, results suggested that location of pharyngeal foreign bodies and nature of pharyngeal foreign bodies were risk factors correlated with complications. Conclusion: Pharyngeal foreign body in children has a high rate of dislodgement (>50%). Foreign bodies in the oropharynx were more likely to dislodge compared with the foreign bodies in the laryngopharynx. Younger children were more likely to dislodge compared with older children. Although the risk of complications was very low, attention needs to be paid to the potential risks: local infection, deep abscess, and migration of foreign bodies. Because the possibility of complications caused by bone fragments and foreign bodies in the laryngopharynx increase obviously, hence, it is suggested to remove these kinds of foreign bodies as soon as possible to prevent complications

Double-shelled hollow LaNiO3 nanocage as nanoreactors with remarkable catalytic performance: Illustrating the special morphology and performance relationship

Perovskites with ABO(3) structure are the potential catalysts to replace the noble metals used in environmental catalysis, e.g. CO oxidation, volatile organic compounds (VOCs) and soot combustion. Herein, a novel double shelled porous perovskite-type LaNiO3 nanocage (assigned as LaNiO3-Cage, with dual cage or cage in cage structure) was successfully synthesized via a facile hydrothermal method for the first time. LaNiO3-Cage displayed superior activity and stability for CO oxidation. The morphology and structure properties of the samples were confirmed by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), High-angle annular dark-field scanning transmission electron microscope (HAADF-STEM), Elemental mapping, Powder Xray Diffraction (PXRD) and N-2 adsorption/desorption techniques. The inherent morphology-activity relationship was investigated through Temperature-Programmed Reduction with Hydrogen (H-2-TPR), Temperature Programmed Desorption with Oxygen and Carbon monoxide (O-2-TPD and CO-TPD), and X-ray Photoelectron Spectroscopy (XPS) methods. LaNiO3-Cage showed superior catalytic performance among all the comparison samples (with lowest Ea, highest reaction activity, rate and TOF value) which should be ascribed to its special double-shelled porous nanocage structure (main factors) as well as larger surface areas and more active surface oxygen species. It should be noted that the outstanding catalytic performance of LaNiO3-Cage is well correlated with its special morphology structure. The porous double-shelled LaNiO3 nanocage prepared in this work can be used to design other type of catalysts with the similar morphology as novel nanoreactors.</p

In Situ Embedded Pseudo Pd–Sn Solid Solution in Micropores Silica with Remarkable Catalytic Performance for CO and Propane Oxidation

Most of the industrial and environmental catalytic reactions are operated at high temperature for a long time, and the sintering of the active centers is the main factor leading to catalysts deactivation, especially for noble metal catalysts. Herein we develop a dual confinement (enhanced metal-oxide interaction and the porous shell confinement) strategy to prepare Pd–Sn pseudo solid solution and in situ embedded in microporous silica for the first time and showed superior catalytic performance for CO and propane total oxidation (two main vehicle emission gases), even stored more than 640 days

Tetragonal Rutile SnO₂ Solid Solutions for NO_<i>x</i>‑SCR by NH₃: Tailoring the Surface Mobile Oxygen and Acidic Sites by Lattice Doping

To understand the active sites requirements for NO_<i>x</i>-SCR by NH₃ and for designing better catalysts, four SnO₂-based solid solution samples with the SnO₂ lattice doped by metal cations possessing redox ability (Ce⁴⁺ and Cu²⁺) or acidity (In³⁺ and W⁶⁺) have been purposely designed. It is revealed that the metal cations have entered into the SnO₂ matrix to form a tetragonal rutile solid solution phase. Compared with individual SnO₂, all the modified catalysts possess higher surface areas, lower crystallinity, more abundant surface defects, facile oxygen, and acidic sites. Therefore, they display improved reaction performance. Both surface facile oxygen and acidic sites play vital roles, and the balance between them controls the reaction. For the catalysts modified by Ce⁴⁺ and Cu²⁺, a better balance can be generated. Therefore, they display the best performance among all the samples. NO_<i>x</i>-SCR by NH₃ on the SnO₂-based solid solutions follows a Langmuir–Hinshelwood mechanism