Erratum to:Tuning the coordination environment of single-atom catalyst M-N-C towards selective hydrogenation of functionalized nitroarenes

Erratum to Nano Research https://doi.org/10.1007/s 12274-021-3511-z The affiliation of the author“Jianzhong Yin”was unfortunately mistakenly marked.This error did not affect any of the content and conclusions from the published paper.     

Controlling stage in the transfer of carbon in the system carbon steel/liquid sodium/chromium-nickel steel

The mechanism of transfer of carbon in sodium was studied. On the basis of experimental data the activation energy for carburizing type 18/8 steel was calculated. The activation energy for transfer of carbon in sodium calculated from experimental results agreed with published data. It was concluded that the main controlling stage in the transfer of carbon in the system studied is the diffusion of carbon in type 18/8 steel.     

Reduced wear damage of carbon brushes via transfer layer upon W/Cu composite

An ultrafine (～100?nm) W particle-reinforced Cu matrix composite was fabricated by spark plasma sintering. The tribological properties of the fabricated W/Cu composite were tested by pin-on-disc sliding experiments and compared with those of brass alloy. The wear rate of the carbon brush when sliding against the W/Cu composite (0.102?mm?³s^?1) was much lower than that with brass (4.83?mm³?s^?1). Simultaneously, the W/Cu composite possessed higher conductivities and greater surface hardness than brass. The surface roughness of the W/Cu composite was found to play a critical role in improving the robustness of the tribofilm and reducing the volume loss of the carbon brush. The W/Cu composite has promising engineering applications for the long-term wear protection of self-lubricating materials.     

Multi-walled carbon nanotube supported aminomethylphosphine-Ru(II) complexes: Optical behavior and catalytic properties in transfer hydrogenation of acetophenone derivatives

The novel multi-walled carbon nanotube (MWCNT) supported bis(diphenylphosphinomethyl)amine [MWCNT@CHO-NHArN(CH₂PPh₂)₂ type] ligands and their Ru(II) complexes have been synthesized and characterized with Fourier Transform Infrared Spectrometry (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), Transmission Electron Microscopy (TEM), Ultraviolet-Visible Spectrometry, X-Ray Diffraction Spectrometry (XRD), and Thermal analysis (TG/DTA) techniques. In addition, MWCNT@CHO-NHArN(CH₂PPh₂)₂Ru(p-cymene)Cl₂ type complexes were tried as catalysts in the catalytic transfer hydrogenation reactions of acetophenone derivatives. The crystallite size and lattice strain of the MWCNT-based compounds were calculated by the Scherrer's equation. The optical parameters of the MWCNT-based structures were analyzed and the band gap enhanced from 4.42 eV to 4.98 eV. It was confirmed that the reduction of bromo and chloro acetophenone derivatives using all the catalysts, the conversions were high. The results showed that MWCNT-supported Ru(II) complexes were efficient catalysts in the reduction of bromo and chloro acetophenone derivatives with 99% efficiency in K₂CO₃ media at 80 ^°C.     

Synthesis of individual ultra-long carbon nanotubes and transfer to other substrates

In this article, we report the synthesis of ultra-long carbon nanotubes (CNTs) by thermal chemical vapour deposition method. Ultra-long, individual and aligned CNTs were directly grown on a flat silicon substrate. The orientation of the nanotubes was found parallel to the gas flow direction. The ultra-long CNTs were grown with different transition metallic salts, such as nickel chloride, iron (III) chloride, cobalt acetate and ruthenium acetate, as the catalysts. The influence of the growth conditions, such as growth temperature, reactive gas flow on the length and alignment of the CNTs was studied in detail. By using different catalysts, ultra-long single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) were successfully grown. These ultra-long CNTs were transferred to other substrates by two methods. (1) The first method is to use polydimethylsiloxane as a stamp. (2) The second method is to use KOH as an etching agent. The diameter and length of the CNTs were characterised by transmission electron microscope, scanning electron microscope, atomic force microscope and Raman spectroscopy. The results indicate that the length of the CNTs can reach up to 4?mm. The diameter of the SWCNTs is in the range of 0.7–2.1?nm and the diameter of the MWCNTs is approximately 150?nm.     

Determination of near coincident site lattice orientations in MgO/Cu composite

Orientation relations between MgO precipitates and Cu matrix have been characterized by electron diffraction. Four orientation relations were newly found to be coincident with 41 [110], 13 [111], 29 [100] and 35 [112] near coincidence-site orientations. The possible dislocation network for these orientation relations was analyzed using O-lattice theory. The size of MgO precipitates with these orientations are in a range of 0.5–1 micron. Frequently appearance of these special orientation relations implies that they may be the favorable orientations for precipitation and coarsening of MgO particles to some extent.     

Exciton energy transfer in pairs of single-walled carbon nanotubes

We studied the exciton energy transfer in pairs of semiconducting nanotubes using high-resolution optical microscopy and spectroscopy on the nanoscale. Photoluminescence from large band gap nanotubes within bundles is observed with spatially varying intensities due to distance-dependent internanotube transfer. The range of efficient energy transfer is found to be limited to a few nanometers because of competing fast nonradiative relaxation responsible for low photoluminescence quantum yield.     

Investigation of micro-structural transition through disproportionation and recombination during hydrogenation and dehydrogenation in Mg/Cu super-laminates

Micro/nano-structures and hydrogen storage properties of Mg/Cu super-laminates were investigated. Mg/Cu super-laminates showed reversible hydrogenation and dehydrogenation at 473 K. In order to clarify the process of hydrogenation and dehydrogenation at 473 K, we performed TEM observations of micro/nano-structures of the Mg/Cu super-laminates and Mg₂Cu powder prepared by conventional casting method. TEM observations revealed that the as-rolled Mg/Cu super-laminates had laminated structures in size of sub-micrometer thickness composed of Mg and Cu layers with dense lattice defects. The super-laminates after initial activation kept laminated structures and had uniformly distributed pores with a sub-micrometer diameter. On the other hand, the cast Mg₂Cu powder after initial activation had pores only beneath the surface oxide layers. It is considered that these micro/nano-structures of Mg/Cu super-laminates lead to lower dehydrogenation temperature and better kinetics, which would contribute to achieve high-performance hydrogen storage materials.     

Heat transfer in a multistage apparatus of fluidized-bed type

Results are given on the heat transfer between the gas and the granular material in a multistage apparatus, and comparison is made with calculations.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 19, No. 4, pp. 682–688, October, 1970.     

Al/Cu键合系统中金属间化合物的形成规律及防止方法

Al/Cu键合界面金属间化合物的形成是导致微电子器件失效的重要因素之一,总结了微电子器件生产和使用过程中Al/Cu键合界面金属间化合物的生长规律,分析了Al/Cu键合系统的失效机制。热超声键合过程中,Al焊盘上氧化铝层的破裂使金属间化合物的形成成为可能,键合及器件使用过程中,金属间化合物和柯肯德尔空洞的形成和长大最终导致键合失效。采用在Al焊盘上镀覆Ti过渡层的方法,可有效降低键合系统中Cu原子的扩散速度,抑制金属间化合物的生长,从而提高电子元器件的可靠性。     

Direct spectroscopic evidence of energy transfer from photo-excited semiconducting polymers to single-walled carbon nanotubes

Single-walled carbon nanotubes have been efficiently dispersed in an organic solvent using the semiconducting polymers MEHPPV and PFO. It has been found that energy is transferred to the carbon nanotubes when the polymer is photo-excited across its minimum energy gap. This is shown using photoluminescence excitation mapping in the range of both the polymer's and the nanotube's optical absorbance. Possible mechanisms for the energy transfer are discussed.     

Study by a modified scanning electron microscope fractography of hydrogenation process in vapour grown carbon fibres

The present paper intends to study the microstructure of vapour grown carbon fibres (VGCF), whose fracture depends on the breaking mode, as it was stated. Before being examined, transversal sections of fibres were etched, using an argon ion beam, aiming to remove a thin surfacial layer, then seriously altered by the failure process. After that, based upon the results of the scanning electron microscopy (SEM) examination, it can be established that the inner core of as-grown VGCF is constituted by a Rowland's structure. Although differentiated crystals do not exist in the cortical phase, the boundary between the core and the latter phase is clearly observable. After that, an overhydrogenation process took place as a result of an annealing of the fibres in a hydrogen atmosphere.The microstructure had been, by then, slightly modified. In the inner core, not only the gap width between crystals had been modified but the boundary between catalytical and pyrolytical phases had vanished as well. As a consequence of such modifications, the fibres Young's modulus increases and their failure strain diminishes, in a similar manner as the mechanical properties of current ex-polyacrylonitrile (PAN) carbon fibres are altered by graphitization, during a graphitizing process. © 1998 Chapman & Hall     

Prediction of simultaneous adsorption of Cu(II) and Pb(II) onto activated carbon by conventional Langmuir type equations

Removal of Cu(II) and Pb(II) by adsorption onto activated carbon was examined in single- and binary-component aqueous solutions representative of contaminated solutions containing heavy metals. Reversibility of adsorption of the heavy metals on the activated carbon was evaluated by desorption experiments. The number of the maximum adsorption sites and adsorption equilibrium constants of Cu(II) and Pb(II) were estimated by the results of single-component systems assuming the Langmuir adsorption model. The adsorption sites per gram of activated carbon resulted in similar values for Cu(II) and Pb(II) from the isotherms. The adsorption constant for Pb(II) was nearly 1.8 times greater than that of Cu(II). Rate constants of adsorption and desorption were also estimated from the kinetic analysis. Using the single set of common parameters obtained from the single-component systems, the experimental results for a binary-component system were quantitatively predicted. Competitive adsorption of Cu(II) and Pb(II) on the same adsorption sites was confirmed by both experimental and predicted results of adsorption in the binary mixture.     

Temperature dependence of electron-to-lattice energy transfer in single-wall carbon nanotube bundles

The electron-phonon coupling strength in single-wall carbon nanotube (SWNT) bundles has been studied directly in the time domain by femtosecond time-resolved photoelectron spectroscopy. We have measured the dependence of H(Te, Tl), the rate of energy transfer between the electronic system and the lattice as a function of electron and lattice temperatures Te and Tl. The experiments are consistent with a T5 dependence of H on the electron and lattice temperatures, respectively. The results can be related to the e-ph mass enhancement parameter lambda. The experimentally obtained value of for lambda/[symbol: see text] D2, where [symbol: see text] D is the Debye temperature, suggests that e-ph scattering times at the Fermi level of SWNT bundles can be exceptionally long, exceeding 1.5 ps at room temperature.     

超临界二氧化碳微细管内冷却换热研究

对超临界二氧化碳在微细竖直圆管内冷却条件下的对流换热进行了数值模拟研究,分析了不同管径、进口雷诺数及不同的热流率对超临界二氧化碳对流换热的影响,考察管内局部流体温度、湍动能、湍流雷诺数的变化。湍流模型采用低雷诺数YS模型。研究表明,在临界温度区域比较大的截面,超临界二氧化碳局部传热系数达到最大值,同时管内传热受湍流雷诺数影响较大。     

Radiative-convective heat transfer of a spherically shaped space vehicle in carbon dioxide

A system of equations of motion of viscous, heat-conducting, chemically nonequilibrium, and selectively radiating and absorbing gas is used for solving the problem of radiative-convective heat transfer of a space vehicle of the simplest (spherical) shape in carbon dioxide used for simulating the Mars atmosphere. Comparison is made of the convective and radiative heating of the entire surface of the space vehicle (from forward to rear stagnation point) for the typical conditions of entry of space vehicles into the Mars atmosphere, in particular, for individual points of the Pathfinder trajectory. It is demonstrated that, in some regions of space vehicle entry into the atmosphere, the radiative thermal heating of some elements of space vehicle surface may exceed the convective thermal heating. There is also demonstrated the need for analysis of the level of radiation heat fluxes on the entire surface of the Mars-bound space vehicle rather than on its frontal surface alone.     

The stress transfer efficiency of a single-walled carbon nanotube in epoxy matrix

This paper investigates the effects of tube length and diameter on the distributions of tensile stress and interfacial shear stress of a single-walled carbon nanotube in epoxy matrix. It was shown that a smaller tube diameter has a more effective reinforcement and there exists an optimal tube length at which reinforcement is maximized. It was also found that a carbon nanotube has a greater stress transfer efficiency than a solid fibre, providing flexibility for toughness and tensile strength optimization.     

Effect of substitution at the barium site in YBa2Cu3O7-δ

The oxygen content in YBa₂Cu₃O_7-δ has been varied by substitution at Ba site with Sr or K and its influence on the structural and superconducting properties has been studied. These properties are compared with that of unsubstituted YBa₂Cu₃O_7-δ prepared by quenching. The increase inδ value of YBa₂Cu₃O_7-δ decreases theT _c drastically, whereas in YBa_2-χK_χCu₃O_7-δ system increase in theδ value (as high as 0·92) does not affect the superconducting transition temperature, which remains above 77 K. In the YBa_2-χSr_χCu₃O_7-δ system, as Sr content increases there is marginal decrease in the oxygen content as well as in the superconducting transition temperature.     

聚苯乙烯催化加氢制备聚环己烷基乙烯的研究进展

聚苯乙烯是五大通用塑料之一,经催化加氢后可制得物理性能更为优越的聚环己烷基乙烯。综述了国内外聚苯乙烯催化加氢制备聚环己烷基乙烯的研究,主要包括改善加氢催化剂和改进加氢工艺两个方面,并对聚苯乙烯催化加氢的研究方向进行了展望。     

Anomalous transfer phenomenon of carbon nanotube in the blend of polyethylene and polycarbonate

A contradict interphase transfer of multi-walled carbon nanotubes (MWCNT) is detected in the immiscible polymer pair of polyethylene (PE) and polycarbonate (PC). When laminated sheets composed of PE with MWCNTs and PC are annealed in the molten state of both polymers, MWCNTs are found to move from PE to PC. This transfer phenomenon is originated from the difference in the interfacial tension with the aid of Brownian motion. On the contrary, MWCNTs prefer to reside in the PE phase in the blend of PE, PC and MWCNTs, even when MWCNTs are first dispersed in PC. This result indicates that MWCNTs transfer from PC to PE. The opposite direction of the transfer is attributed to the PE molecules being adsorbed on the surface of MWCNTs, which are generated during mixing.