In this work, we have successfully fabricated hetero-structured nanofiber yarns (NFYs) with a conjugate electrospinning technique, integrating a dual-functional capability of tunable color photoluminescence and tailored superparamagnetism. These hetero-structured NFYs are comprised of [Eu(BA)3phen + Tb(BA)3phen]/polyacrylonitrile (PAN) photoluminescent nanofibers (NFs) and Fe3O4/PAN superparamagnetic NFs, which allow for the effective isolation of dark-colored Fe3O4 nanoparticles (NPs) from rare earth complexes. This design leads to enhanced photoluminescent performance for the hetero-structured NFYs. Detailed investigations into the morphologies and performances of these NFYs were conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), fluorescence spectrophotometry, and vibrating sample magnetometry (VSM). The emitting light color, ranging from red to yellow to green, can be tuned under a specific excitation wavelength (276 nm) of ultraviolet (UV) light by regulating the proportion of rare earth complexes. Furthermore, the superparamagnetism of the NFYs can be tailored by varying the amounts of Fe3O4 NPs. The designing philosophy and preparative technique can be utilized to manufacture other polyfunctional nanomaterials.

Ru-doped Co9S8 hollow porous polyhedrons (Ru-Co9S8 HPPs) derived from zeolitic-imidazolate-frameworks were synthesized through hydrothermal coprecipitation and thermal decomposition methods. The results indicate that Ru-Co9S8-500 HPPs possess a strong Ru-Co synergistic effect, large electrochemical surface area, and sufficient active sites, endowing them with excellent hydrogen evolution reaction performance.

Traction transformer is the core component of EMU traction system. It can convert high-voltage electric energy obtained from the catenary into suitable voltage level for the input of traction container. Due to abundant high order harmonics produced by the four-quadrant rectifier of the traction container, secondary windings of the traction transformer generate ferromagnetic noise which is uncomfortable to human ears. Guaranteeing traction performance and minimizing the ferromagnetic noise by traction transformer at the same time is a difficult task in EMU design. In this paper, operation principle of four-quadrant rectifier and traction transformer ferromagnetic noise generation mechanism are studied through modeling and simulation in Matlab. Noise design and suppression of EMU traction transformer are described, which provide the references and ideas for subsequent project.

Due to abundant high order harmonics produced by the four-quadrant pulse rectifier in the traction converter, secondary windings of the traction transformer generate ferromagnetic noise which is uncomfortable to human ears. How to reduce the ferromagnetic noise of the traction transformer under the premise of ensuring the performance of the traction system is a key problem to be considered in the integrated design of EMUs. This paper analyzes the operation principle of four-quadrant pulse rectifier and traction transformer ferromagnetic noise generation mechanism. Through modeling and simulation in MATLAB, it analyzes the content change of the harmonic current at the secondary side of the traction transformer under different parameter changes, and explains the noise design and noise suppression of the EMU traction transformer.

The development of highly active and stable bifunctional catalysts toward overall water splitting at large current densities through delicate control of composition and structure is a challenging work. Herein, we combined the Ru-doping of NiCo2O4 spinel (NCO) and the surface modification with Ru nanoparticles through rational design and controllable fabrication (NCRO) as a dual modification method to markedly enhance the overall water splitting. Benefiting from the structure advantages, the synergistic electronic effects and optimal binding strength of the reaction intermediates, the NCRO exhibited excellent performance for both hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The density functional theory calculations suggest that the dual modification could enhanced water dissociation ability, optimized the adsorption energy of reaction intermediates and altered the energy level of the d band center.

介绍了一种基于柴油机内燃动力包和超级电容的混合动力系统的构成和控制方法,就该混合动力系统能量管理策略、动力模式控制方法等进行了说明.通过实验,对各个工况进行了验证,试验结果证实了该混合动力系统及其控制方法的有效性.

HMU项目为采用"内电动力包+超级电容储能电源"混合动力系统的交流传动米轨动车组,文章介绍了该项目牵引辅助供电系统的组成及工作原理,详细阐述了不同运行工况和牵引设备不同状态下的供电控制设计过程,并通过地面联调试验进行验证.结果表明:牵引辅助供电系统可进行快速有效的能量转换和能量的有效利用,以及对对应设备进行保护.

Self-reconstruction of oxygen evolution reaction (OER) catalyst, especially metal (oxy)hydroxides or oxides, has attracted much attention. Herein, an in-situ self-reconstruction process for Ni, Fe, Zn ternary-metal hydroxides (NFZ-TH) involving significant morphology transformation, and self-modulated electronic structure change of Ni and Fe owing to the etching of Zn species under anodic polarization potential is revealed. NFZ-TH derived materials, undergoing in-situ self-reconstruction (NFZ-TH-SR), exhibits superior OER performance (eta = 217 mV @j = 10 mA cm(geometry)(-2)) and excellent stability over a period of similar to 48 h. Nano-pitted surface resulting from etching of Zn species improves the electrochemical surface area. Meanwhile, in NFZ-TH-SR, large amounts of defects induced defect-/corner-sited Fe and adjustability of NiOOH species are verified by Mossbauer spectra and in-situ Raman spectra respectively. Density functional theory calculations give insight that both defect-/corner sited Fe and Ni at next-nearest-neighbour defect-site have high activity. This paper helps understand that the proposed in-situ self-reconstruction strategy can improve the electrochemical performance of OER catalysts.

Transition metal oxides (TMOs) and their heterostructure hybrids have emerged as promising candidates for hydrogen evolution reaction (HER) electrocatalysts based on the recent technological breakthroughs and significant advances. Herein, Ru-Co oxides/Co3 O4 double-shelled hollow polyhedrons (RCO/Co3 O4 -350 DSHPs) with Ru-Co oxides as an outer shell and Co3 O4 as an inner shell by pyrolysis of core-shelled structured RuCo(OH)x @zeolitic-imidazolate-framework-67 derivate at 350 °C are constructed. The unique double-shelled hollow structure provides the large active surface area with rich exposure spaces for the penetration/diffusion of active species and the heterogeneous interface in Ru-Co oxides benefits the electron transfer, simultaneously accelerating the surface electrochemical reactions during HER process. The theory computation further indicates that the existence of heterointerface in RCO/Co3 O4 -350 DSHPs optimize the electronic configuration and further weaken the energy barrier in the HER process, promoting the catalytic activity. As a result, the obtained RCO/Co3 O4 -350 DSHPs exhibit outstanding HER performance with a low overpotential of 21 mV at 10 mA cm-2 , small Tafel slope of 67 mV dec-1 , and robust stability in 1.0 m KOH. This strategy opens new avenues for designing TMOs with the special structure in electrochemical applications.

Organic molecules and related nanomaterials have attracted extensive attention in the realm of electrochemiluminescence (ECL). Herein, a well-known electroluminescence (EL) dopant 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl- 1H,5H,11H-10-(2-benzothiazolyl)quinolizino[9,9a,1gh] coumarin (C545T) is selected as a new ECL illuminant, which shows a high photoluminescence quantum yield of nearly 100% and excellent ECL performance in the organic phase. For utilizing C545T to achieve ECL detection in aqueous solution, organic microrods of C545T (C545T MRs) were synthesized by a precipitation method. Cyclic voltammetry and differential pulse voltammetry of C545T and C545T MRs in acetonitrile or phosphate buffer showed one reduction and multiple oxidation peaks, suggesting that the multiple charge states of C545T could be produced by continuous electron- or hole-injection processes. The annihilated ECL emission of C545T and C545T MRs was observed using ECL transient technology. In the presence of triethanolamine (TEOA) or potassium persulfate (K2S2O8), C545T MRs can also give bright anodic and cathodic ECL emission at the GCE/water interface. The proposed ECL system not only has multichannel ECL emission but also shows intense yellow emission (569 nm) with a relative ECL efficiency of 0.81 when TEOA was used as a coreactant. Benefiting from the strong ECL emission of the C545T MRs/TEOA system and the quenching effect of dopamine (DA) on ECL, a convenient sensor for DA was developed with high selectivity and sensitivity.

In this paper, an intensive and glow-type chemiluminescence (CL) hydrogel was prepared by simultaneous incorporation of chemiluminescence reagent (luminol) and catalytic cofactor (hemin) into the scaffold of guanosine-derived hydrogel. The self-assembled hydrogel consisted of K+ stabilized hemin/G-quartet structures, showing significant enzyme-like activity to H2O2-mediated oxidation of luminol. After adding H2O2 into the hydrogel, blue light visible to naked eyes would come into being and last for over 8 h. The lasting-time CL emission of hydrogel was achieved due to a mechanism of slow-diffusion-controlled heterogeneous catalysis. Moreover, this self-assembled hydrogel performed a good response to H2O2 and the CL emission images could be recorded by smartphone. The hydrogel could remain excellent lifetime stability for months and the stable, enhanced and glow-type CL emission could improve the reliability and precision of CL detection, which has a promising application in cold light source and H2O2 detection of real biological samples.

The application of hybrid power system in EMU not only has the characteristics of low consumption and emission reduction but also can improve the reliability of power supply. The stability of the bidirectional DC/DC converter, which is connected with the energy storage device and the intermediate DC link, greatly affects the charging and discharging process of the energy storage device. In this paper, the mathematical model of the bidirectional DC/DC converter in the hybrid EMU system is studied. The modeling and transfer function analysis of Buck mode and Boost mode converters in detail are carried out by means of switching element average method. Moreover, the voltage and current double closed-loop control strategy of bidirectional DC/DC converter and the influence of DC capacitor C are introduced, which lays a foundation for further study on the stability of the whole hybrid EMU system.

Ru nanoparticles, encapsulated in ZIFs-derived porous N-doped hierarchical carbon nanofibers with excellent HER performance, were achieved.

SrRuO3 as a rare conductive perovskite ruthenate has attracted increasing attention for application in energy conversion. Here, the electrocatalytic activity for the hydrogen evolution reaction (HER) of thermally synthesized layered SrRuO3 is investigated and shows a considerable activation during cathodic polarization in alkaline solution. The analysis demonstrates the electrode activation is caused by the increased hydrophilicity of SrRuO3 surface, revealing the influence of the surface properties on HER performance. For further improving the catalytic activity of perovskite ruthenate, the RuO2 /SrRuO3 (RSRO) heterostructure is fabricated in situ by reducing the thermal decomposition temperature of 1000 °C for SrRuO3 to 600 °C. The appropriate lattice parameter of SrRuO3 ensures a good lattice match, which results in a strong interaction between SrRuO3 and RuO2 . Hence, the RSRO substantially outperforms the corresponding single-component oxides. In addition, the increased active sites induced by the rapid improvement of hydrophilicity of RSRO surface further highlight its structural advantage for catalytic hydrogen generation. The experimental and theoretical computation results consistently validate the positive synergistic effect among SrRuO3 and RuO2 in tuning the atomic and electronic configuration.

结合某型DMU动车组在运行线路上发生欠压故障后记录的相关数据,对故障发生原因进行了分析,同时为解决某型DMU动车组直流系统欠压检测回路功能缺陷提供有效的解决措施及方案,并对优化方案进行了试验验证.

分析了长株潭线路分相布置与CJ6型动车组受电弓间距匹配情况,提出了避免相间短路的重联过分相技术方案,并验证了该方案的有效性.

Ru, RuO2 and MoO3 embedded carbon nanorods (Ru-RuO2/MoO3 CNRs) were synthesized through electrospinning and low-temperature calcination. Results of comprehensive characterizations suggest that the strong interaction between Ru and Mo species, large electrochemical surface area, and high electrical conductivity (a proper ratio of RuO2 to Ru) endow Ru-RuO2/MoO3 CNRs-350 with excellent hydrogen evolution reaction (HER) performance.

针对CJ6型城际动车组长距离救援回送时需要配置供电过渡车和回送过程中空气弹簧可能处于泄气状态的问题,对辅助供电系统进行优化设计,可降低CJ6型城际动车组救援回送对设备配置和运行限制条件的要求,减少回送运输成本;对空气弹簧供风系统进行优化设计,可保证空簧处于充气抬升状态,提高运行稳定性,降低空气弹簧长时间处于泄气状态运行产生损坏的风险.

Here, we report a strategy for constructing {[Tb(BA) 3 phen + Eu(BA) 3 phen]/PAN}//[PANI/PAN] (BA = benzoic acid, phen = phenanthroline, PANI = polyaniline, PAN = polyacrylonitrile) hetero-structured microyarns simultaneously endowed with the bi-functionality of tunable luminescence colors and electrical conductivity by using a conjugate electrospinning technique. The obtained hetero-structured microyarns are composed of [Tb(BA) 3 phen + Eu(BA) 3 phen]/PAN luminescent nanofibers and PANI/PAN electrically conductive nanofibers, realizing efficient separation of dark-colored PANI from rare earth (RE) complexes, and thus the enhanced luminescent performance is obtained. Under 276-nm ultraviolet light excitation, the emitting light color of the hetero-structured microyarns can be adjusted in a broad range of green–yellow–red by changing the proportion of RE complexes. The electrical conductivity of the hetero-structured microyarns also can be modulated via tuning the percentages of PANI. These hetero-structured microyarns, by virtue of their luminescent properties and electrical performance, are expected to be applied in multifunctional applications.

A [Fe3O4/polyvinyl pyrrolidone (PVP)]//[Tb(BA)3phen/PVP] Janus nanofiber array pellicle (denoted JNAP) was successfully constructed by facile conjugate electrospinning without twisting for the first time. The JNAP offers the dual-functionality of fluorescence and magnetism. This technology entirely solves the dilemma of the magnetic spinning dope and fluorescent spinning dope being easily mixed together during the parallel electrospinning process, as it achieves complete segregation of magnetic nanoparticles and fluorescent molecules. Moreover, conjugate electrospinning without twisting has fewer requirements on the viscosity of the spinning dope compared with parallel electrospinning, in which the two spinning dopes should have the same viscosity. It was satisfactorily found that the JNAP has higher fluorescence intensity than the corresponding non-aligned Janus nanofiber pellicle. The magnetism of the JNAP could be tailored by changing the doping amount of the Fe3O4 NPs. The JNAP has potential applications in nanotechnology and biomedicine, etc., due to its enhanced green fluorescence and adjustable magnetism. In addition, this design concept and manufacturing process provide a facile way for preparing other one-dimensional Janus nanomaterials with multifunctionality.