Over the past few years, power tower accidents often occurred, it caused serious influence to our country electric power safety, and caused great economic loss. In order to improve the efficiency of the power tower safety testing, to protect the safety of staff, some people proposed to climb the tower to replace the robot staff to detect tower. In this paper the design and selection of the robot module on the tower are compared and discussed. And draw the conclusion, find the ideal tower robot design and module model, To provide theoretical guidance for the robot to climb the tower manufacturing.
Compared to the acidic hydrogen evolution reaction (HER), the sluggish reaction rate in an alkaline electrolyte makes it a priority to develop highly efficient and cost-effective catalysts. Incorporation of Pt with transition metals to form alloy nanocrystals with different structures and atomic distributions has been reported as a promising approach to enhance HER activity and improve Pt utilization. However, whether the structural ordering of the Pt-based bimetallic alloy affects the HER activity still remains unknown. Here, we synthesized PtNi/C nanoparticles through a modified coprecipitation method and obtained their ordered and disordered phases at different annealing temperatures in a reducing atmosphere. It is contrary to our expectation that the disordered PtNi/C exhibited a superior activity toward the HER in alkaline media compared with the ordered PtNi/C. To understand this interesting phenomenon, a systematic study combining X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS) was conducted. In addition, we studied the mechanism of the HER in an alkaline electrolyte based on newly constructed models. The density functional theory (DFT) calculation demonstrated that the unexpected activity change may be attributed to the synergistic effect between the formation of Ni/Pt–OH bonds and the increased degree of disorder of Pt and Ni atoms on their surface.
Abstract The analytical solutions of the two-mode Rabi–Stark model (tmRSM) are obtained by using the Bogoliubov operators approach in su(1,1) Lie algebra space, which fit the exact numerical results well. The structure of the energy spectra is related to many fundamental physics characters such as symmetry, quantum phase transition (QPT), spectral collapse etc. In this paper, the spectral structure of tmRSM is discussed analytically. The regular energy spectra are given by the zeros of the G-function, and the poles appearing in the G-function are responsible for the exceptional solutions. The double degenerate exceptional solutions could be predicted by discussing the divergence of the coefficients in the G-function. If the numerator and denominator of Ωn vanish, the lowest double degenerate exceptional solutions for the n th energy levels would be located, including the first-order QPT point, the corresponding energy ( −Δ/U ) is independent of the coupling strength and the energy level, even independent of the Bargmann index q . While, the nondegenerate exceptional solutions can be reproduced by the nondegenerate exceptional G-functions, the results show that more nondegenerate exceptional solutions would be found in the subspace with larger q . Then, the regular solution and two kinds of exceptional Juddian solutions of tmRSM are accurately located. The spectral collapse energy are dependent on the strength of Stark coupling and the frequency of two-level system, and Stark coupling could results in the limit of E 0 pole line is higher than that of E n pole lines, which may cause more energy levels separate from the collapse energy.
Compared to the acidic hydrogen evolution reaction (HER), the sluggish reaction rate in an alkaline electrolyte makes it a priority to develop highly efficient and cost-effective catalysts. Incorporation of Pt with transition metals to form alloy nanocrystals with different structures and atomic distributions has been reported as a promising approach to enhance HER activity and improve Pt utilization. However, whether the structural ordering of the Pt-based bimetallic alloy affects the HER activity still remains unknown. Here, we synthesized PtNi/C nanoparticles through a modified coprecipitation method and obtained their ordered and disordered phases at different annealing temperatures in a reducing atmosphere. It is contrary to our expectation that the disordered PtNi/C exhibited a superior activity toward the HER in alkaline media compared with the ordered PtNi/C. To understand this interesting phenomenon, a systematic study combining X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS) was conducted. In addition, we studied the mechanism of the HER in an alkaline electrolyte based on newly constructed models. The density functional theory (DFT) calculation demonstrated that the unexpected activity change may be attributed to the synergistic effect between the formation of Ni/Pt–OH bonds and the increased degree of disorder of Pt and Ni atoms on their surface.
Abstract Carbon fiber‐reinforced cyanate ester resin matrix composites (CF/CE) are widely used in aerospace for their high‐temperature resistance and wave‐absorbing properties. However, CF/CE is prone to interlaminar delamination during the curing molding process or practical applications due to the brittleness of CE resin. In this study, we use polyether sulfone (PES) as a toughening layer through the inter‐tow toughening method to prepare PES inter‐tow toughened CF/CE (CF/CE‐P) and to investigate their thermal, mechanical, and microscopic morphology. We find that CF/CE‐P has a higher glass transition temperature ( T g ) and a lower coefficient of thermal expansion (CTE) than those of CF/CE composites. The flexural strength, flexural modulus, interlaminar shear strength (ILSS), and impact toughness of CF/CE‐P with 15 wt% PES is increased by 34%, 15%, 34%, and 45%, respectively, compared to CF/CE. In addition, the mode I interlaminar fracture toughness ( G IC ) of CF/CE‐P with 15 wt% PES is 1.86 times that of CF/CE. Highlights The inter‐tow toughening technique on a three‐dimensional scale is proposed. Model I interlaminar fracture toughness increased by 86% after inter‐tow toughness modification carbon fiber‐reinforced cyanate ester resin matrix composites. The composite material exhibits improved toughness and thermal performance. The prepreg preparation process is suitable for continuous industrial production.
If a strategy involving hydrogenation and dehydrogenation of nitrogen heterocycles is proposed, liquid organic hydrogen carrier storage will be recyclable and sustainable. In order to obtain low-cost electrocatalyst, by adhering Ni to nickel foam, a bifunctional electrode called Ni@NF is prepared. The nitrogen heterocycles including quinoline, quinoxaline and indole is hydrogenated at -1.26 V by using Ni@NF as catalytic electrode. And the yields of hydrogenation products are all above 50%. In addition, dehydrogenation potentials of 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroquinoxaline and 2,3-dihydroindole are observed and the dehydrogenation potential is just 0.4 V. The scheme in this paper is practical and meaningful because liquid organic hydrogen carrier storage becomes possible, green and recyclable.
AbstractHemoglobin Chongqing is a new slowly-moving and unstable hemoglobin variant with a high oxygen affinity, that was discovered in five members of a Chinese family in the suburb of Chongqing. Hemoglobin Harbin is another new rapidly-moving hemoglobin variant with slightly reduced stability and slightly increased oxygen affinity, found in a Chinese woman living in Harbin. The relative amounts of these two variants in the pro-positi were about 9% and 18%, respectively. Sequence analyses identified a Leu→ARG substitution at position α2(NA2) of Hb Chongqing, and a Lys→MET substitution at position α16(A14) of Hb Harbin.
Abstract With the continuous improvement of voltage level, power level and capacity level of high-voltage transmission and substation equipment, the problem of power loss and equipment failure caused by abnormal heating of electrical contact parts is becoming increasingly serious. To address this problem, graphite was exfoliated into thin layers of graphene by liquid-phase mechanical exfo-liation, ultrasonic dispersion and spray-drying techniques, and it was incorporated into polyether composites to enhance its electrical conductivity. The effect of graphene content on the electrical conductivity, high temperature resistance, wear reduction and anti-wear properties of polyether composites was investigated. The results indicated that when graphene is added at 4 wt%, the high-temperature resistance of the graphene-polyether composite (GPC) is improved to 330 °C, and the volume resistivity is reduced to 6.5×103 Ω-cm. Moreover, the contact resistance coefficient of the GPC is reduced to 0.87 and 0.73 after it is coated on the Cu rows and the Al rows, respectively, which effectively enhances the electrical conductivity of the electrical contact area. In addition, the best improvement in friction reduction and anti-wear properties was obtained for the polyether composites from this formulation. Above all, the GPC has excellent electrical conductivity, high-temperature resistance, wear reduction and anti-wear properties, which can substantially improve the quality of the electrical connection when applied to the electrical contact tips.
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