Molybdenum trioxide impregnated carbon aerogel for gaseous elemental mercury removal

Yang Ling,Xiaokun Man,Wenbo Zhang,Daolei Wang,Jiang Wu,Qizhen Liu,Mingyan Gu,Yuyu Lin,Ping He,Tao Jia 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.4

A novel gaseous elemental mercury (Hg0) removal agent was successfully synthesized via impregnation method, by using molybdenum trioxide (MoO3) as the active component and carbon aerogel (CA) as the carrier. The as-prepared samples maintained a large specific surface area and excellent pore structure of the pure carbon aerogel, so that MoO3 was better dispersed to obtain enhanced Hg0 removal performance. The maximum efficiency of elemental mercury removal was about 74%, achieved by Mo/C500 sample at 300 oC, while it still had good ability (nearly 60%) in the range of 500-700 oC. The mechanism of mercury oxidation removal was also verified by DFT calculation. This work should help in developing suitable materials for thermocatalytic oxidation of elemental mercury, and also provide some theoretical basis and data support for full-scale application of heavy metal mercury pollution control in coalfired power plants.

Accuracy analysis for machine tool spindles considering full parallel connections and form errors based on skin model shapes

Xiaokun Hu,Qiangqiang Zhao,Yitao Yang,Shaoke Wan,Yanhui Sun,Jun Hong 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.5

The rotation accuracy of a machine tool spindle is essential for ensuring the machining precision. Due to the existence of manufacturing and assembly errors, the rotation accuracy of the spindle will be inevitably impacted and degraded. Therefore, to reduce the influence of the errors and improve the work performance, this paper focuses on accuracy analysis for the spindle and a novel optimization-oriented skin model shape method to tackle this highly complex problem. First, a structural analysis of the spindle is carried out to elaborate the intractable full parallel collections in the assembly. Then, based on the iterative closest point method, the deviation propagation of the spindle considering complex full parallel collections is transformed into an optimization problem, in which the skin model shapes and small displacement torsor are utilized to represent the form and pose errors of the part, respectively. By solving the optimization problem, assembly accuracy analysis for the spindle in terms of full parallel connections and form errors is accordingly achieved. On this basis, the tolerance analysis model of the spindle is also comprehensively established by employing the corresponding error simulation. Finally, measurement experiments are conducted to validate the effectiveness of the proposed method. The experiments show the predicted rotation runout and tolerance magnitude are close to the testing results, therefore indicating the proposed method can provide effective accuracy analysis for spindles.

Expression of Human FGF18 by Fusion with Oleosin in Arabidopsis thaliana Seeds

Chao Jiang,Xiaokun Li,Feng Zhai,Nuo Xu,Jing Yang,Yunpeng Wang,Libo Jin,Haiyan Li 한국식물학회 2018 Journal of Plant Biology Vol.61 No.3

Expression of recombinant human fibroblast growthfactor 18 (hFGF18) in mammalian cells and Escherichia colihas been extensively used for fundamental research andclinical applications, but they are difficult, expensive. Theexpression of recombinant proteins fused to oleosin proteinhave distinct advantages, such as safety, ease, low cost. Sowe have expressed hFGF18 fused to oleosin protein in the oilbodies of Arabidopsis thaliana (A. thaliana) and screen theproliferation effect of NIH3T3 cells. The vector of oleosinhFGF18fusion gene was constructed and transformed intowild A. thaliana. Transformed A. thaliana lines were obtainedby the floral dip method and confirmed using polymerasechain reaction (PCR). The PCR results indicated that theoleosin-hFGF18 fusion gene was integrated into the A. thaliana genome. The oil bodies expression of oleosin-hFGF18was confirmed by sodium dodecyl sulfate polyacrylamidegel electrophoresis and western blotting. The biologicalactivity showed that oil bodies expressing oleosin-hFGF18could stimulate the proliferation of NIH3T3 cells.

One-Step Construction of Ni/Co-Doped C–N Nanotube Composites as Excellent Cathode Catalysts for Neutral Zinc–Air Battery

Liang Yu,Qingfeng Yi,Xiaokun Yang,Xiulin Zhou 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

Development of a neutral Zn–air battery is of much significance due to the high stability of zinc in a neutral electrolyte. Here, Ni/Co-doped C–N nanotube composites (C–N, Ni/C–N, Co/C–N, and Ni–Co/C–N) as efficient oxygen reduction reaction (ORR) electrocatalysts in a neutral medium have been prepared by direct pyrolysis of Ni/Co salt, dicyandiamide (DCD) and glucose. Among the synthesized catalysts, Ni–Co/C–N presents a high ORR current density of 8.5mA · cm -2 in a 0.5 mol · L -1 KNO3 solution. The ORR electron transfer number of the catalyst Ni–Co/C–N is 3.8, indicating that O2 is almost completely reduced to H2O. A neutral zinc–air battery utilizing a 0.5 mol · L -1 KNO3 solution has been assembled by using the prepared composite catalyst coated on carbon paper as an air cathode, and Zn plate as an anode. The battery with the cathode catalyst Ni–Co/C–N delivers the open-circuit voltage of 1.13 V and the maximum power density of 65mW · cm -2. The constant discharge current density of 50mA · cm -2, 100 mA · cm -2 and 150mA · cm -2 can last 202 h, 93 h and 11 h, respectively. A stable voltage plateau appears at various discharge current densities. The neutral zinc–air battery can be repeatedly discharged after replacing the zinc anode. Results indicate that the synthesized Ni–Co/C–N catalyst is an excellent cathode material applied to a neutral zinc–air battery, showing broad application prospects as a mobile power source.

Mechanical behavior test and analysis of HEH sandwich external wall panel

Wu, Xiangguo,Zhang, Xuesen,Tao, Xiaokun,Yang, Ming,Yu, Qun,Qiu, Faqiang Techno-Press 2022 Advances in concrete construction Vol.13 No.2

Prefabricated exterior wall panel is the main non-load-bearing component of assembly building, which affects the comprehensive performance of thermal insulation and durability of the building. It is of great significance to develop new prefabricated exterior wall panel with durable and lightweight characteristics for the development of energy-saving and assembly building. In the prefabricated sandwich insulation hanging wall panel, the selection of material for the outer layer and the arrangement of the connector of the inner and outer wall layers affect the mechanical performance and durability of the wall panels. In this paper, high performance cement-based composites (HPFRC) are used in the outer layer of the new type wall panel. FRP bars are used as the interface connector. Through experiments and analysis, the influence of the arrangement of connectors on the mechanical behaviors of thin-walled composite wall panel and the panel with window openings under two working conditions are investigated. The failure modes and the role of connectors of thin-walled composite wallboard are analyzed. The influence of the thickness of the wall layer and their combination on the strain growth of the control section, the initial crack resistance, the ultimate bearing capacity and the deformation of the wall panels are analyzed. The research work provides a technical reference for the engineering design of the light-weight thin-walled and durable composite sandwich wall panel.

Behavior of UHPC-RW-RC wall panel under various temperature and humidity conditions

Wu, Xiangguo,Yu, Shiyuan,Tao, Xiaokun,Chen, Baochun,Liu, Hui,Yang, Ming,Kang, Thomas H.K. Techno-Press 2020 Advances in concrete construction Vol.9 No.5

Mechanical and thermal properties of composite sandwich wall panels are affected by changes in their external environment. Humidity and temperature changes induce stress on wall panels and their core connectors. Under the action of ambient temperature, temperature on the outer layer of the wall panel changes greatly, while that on the inner layer only changes slightly. As a result, stress concentration exists at the intersection of the connector and the wall blade. In this paper, temperature field and stress field distribution of UHPC-RW-RC (Ultra-High Performance Concrete - Rock Wool - Reinforced Concrete) wall panel under high temperature-sprinkling and heating-freezing conditions were investigated by using the general finite element software ABAQUS. Additionally, design of the connection between the wall panel and the main structure is proposed. Findings may serve as a scientific reference for design of high performance composite sandwich wall panels.