Advances of microwave plasma-enhanced chemical vapor deposition in fabrication of carbon nanotubes: a review

Journal of Materials Science - Microwave plasma chemical vapor deposition (MPCVD) has received tremendous research interest in fabrication of carbon nanotubes (CNTs) due to its unique advantages of...     

Microwave‐Assisted Continuous‐Flow Reactor Based on a Ridged Waveguide

Microwave‐assisted continuous‐flow reactors (MCFRs) are a valuable alternative to conventional reactors for accelerating chemical reactions. However, despite several interesting applications, only little quantitative research has been conducted on the temperature uniformity of the heating load. With water as a common inorganic solvent, a novel MCFR type based on a special ridged waveguide for heating water is studied by optimizing some parameters of micropipes in order to achieve better temperature uniformity. Compared to the original reactor, the standard deviation of the electric field decreased significantly when using the optimized reactor under the same heating conditions while the average electric field density increased. The optimized results were verified by experiments.     

高灵敏度溶液介电常数测量探头

文中提出一种适用于溶液介电常数测量的高灵敏探头。采用时域有限差分(FDID)分析其电磁场分布及测量端口反射系数与溶液介电常数的关系。通过实验测量证明该探头对溶液的介电常数变化敏感，经数值计算反演介电常数与Debye公式计算结果相吻合。     

电磁波对微小生物体呼吸作用的影响

生物呼吸包含一系列生物化学反应过程。本文用实验证实了电磁波对生物呼吸过程的影响。用单位时间的相对耗氧摩尔数来反应呼吸速率的快慢，而用呼吸商来反应呼吸过程中代谢燃料的分解途径。实验结果表明电磁波可对新陈代谢产生干扰．这种干扰不仅可以改变呼吸速率，更为重要的是干扰还可以改变分解代谢的途径。     

Frequency‐selected microwave heating: Its mathematical physics basis and characteristics

Microwave energy is widely used for heating, however, it usually causes nonuniformity temperatures. In this study, systematical mathematic derivations as well as the theory of electromagnetic wave propagation in a multimode cavity is used to demonstrate the mathematical physics basis of frequency‐selected microwave heating, moreover, the characteristics including the dependence of frequency selecting criteria and the shape of heated samples on heating performance are further analyzed. Finally, numerical computation based on finite element method is used to verify the correctness of the conclusions. This study can help us make better use of microwave energy.     

Corrosion Resistance of Zinc Coatings Obtained in High-Temperature Baths

We present the results of investigation of the technology of application of coatings in zinc baths at temperatures different from the standard temperatures of the process of galvanization. The corrosion resistance of the coatings is determined under the action of neutral salt mist and sulfur dioxide in the case of condensation of moisture. With the help of galvanization at elevated temperatures of 540–560°C, it is possible to obtain coatings of constant thickness with improved structure and higher corrosion resistance as compared with the coatings obtained at standard temperatures.     

Electrochemical reactivity of magnesium hydride toward lithium: New synthesis route of nano-particles suitable for hydrogen storage

Electrochemical conversion reaction of MgH₂ with Li ion enables the production of in-situ nanometric Mg and MgH₂ particles so-called (nano-Mg) _INSITU and [(nano-MgH₂)_INSITU] showing interesting hydrogen sorption properties with hydrogen absorption at 100 °C under 10 bars of hydrogen pressure (PH₂) and desorption at 200 °C under primary vacuum, respectively. Differential Scanning Calorimetry (DSC) measurements of MgH₂ electrochemically prepared confirmed a decrease in the desorption temperature from 416 °C to 295 °C and in the heat of formation from −74 kJ mole mol⁻¹ (H₂)⁻¹ to −56 kJ mol⁻¹ (H₂)⁻¹ for commercial (particle size diameter: 10 μm–100 μm) and as prepared MgH₂ hydride (particle size: 10 nm–40 nm), respectively.     

Seismic performance of moment resisting steel frame subjected to earthquake excitations

This study presents static and dynamic assessments on the steel structures. Pushover analysis (POA) and incremental dynamic analysis (IDA) were run on moment resisting steel frames. The IDA study involves successive scaling and application of each accelerogram followed by assessment of the maximum response. Steel frames are subjected to nonlinear inelastic time history analysis for 14 different scaled ground motions, 7 near field and 7 far field. The results obtained from POA on the 3, 6 and 9 storey steel frames show consistent results for both uniform and triangular lateral loading. Uniform loading shows that the steel frames exhibits higher base shear than the triangular loading. The IDA results show that the far field ground motions has caused all steel frame design within the research to collapse while near field ground motion only caused some steel frames to collapse. The POA can be used to estimate the performance-based-seismic-design (PBSD) limit states of the steel frames with consistency while the IDA seems to be quite inconsistent. It is concluded that the POA can be consistently used to estimate the limit states of steel frames while limit state estimations from IDA requires carefully selected ground motions with considerations of important parameters.