scholarly journals Determination of [CH3NC]/[H2C═C═NH] Abundance Ratios from N + CH3CN Solid Phase Reaction in the Temperature Range from 10 to 40 K: Application to the Complex Chemistry in Star-Forming Regions

2019 ◽  
Vol 3 (6) ◽  
pp. 973-979 ◽  
Author(s):  
Lahouari Krim ◽  
Alejandro Mencos
Keyword(s):  
Solid Phase ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Star Forming ◽  
Temperature Range ◽  
Star Forming Regions ◽  
Complex Chemistry

Effect of Sr Doping on Piezoelectric Properties of Pb(Mn1/3Nb2/3)O3-Pb(Zr,Ti)O3 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 201-204
Author(s):  
Bao Shan Li ◽  
Guo Rong Li ◽  
Zhi Gang Zhu ◽  
Wang Zhong Zhang ◽  
Qing Rui Yin ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Oxygen Vacancies ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Solid Phase ◽  
Coupling Factor ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Pzt Ceramics

This paper aims at the determination of the effects of strontium addition on the microstructural evolution and the piezoelectric properties for Pb(Mn1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMnN-PZT) ceramics. The Sr content was chosen in the range of 2-8 mol%. These materials were prepared by the solid phase reaction of the oxides. It was found, from the experimental results, the tetragonality of the PMnN-PZT lattice and the Curie temperature decreased with Sr content; in the meantime, dielectric constant increased greatly. Dielectric constant (er) and planar coupling factor (Kp) was proven to be dependent on sintering temperature. P-E curves of PMnN-PZT system exhibited some “pinched” shape instead of the normal square-like P-E loops, illustrating presence of the oxygen vacancies by reason of the preferable substitution of the B-sites ion.

PREPARATION AND CHARACTERIZATION OF MnSi1.7 THIN FILMS

2002 ◽  
Vol 16 (15n16) ◽  
pp. 583-588 ◽  
Author(s):  
ZHIMIN WANG ◽  
QINGRUN HOU ◽  
YUANJIN HE
Keyword(s):  
Solid Phase ◽  
Annealing Process ◽  
Silicon Substrates ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Thermal Annealing Process

MnSi 1.7 films were prepared by Solid Phase Reaction on Si(100) substrates under UHV conditions. Auger Electron Spectroscopy (AES) and X-ray diffraction (XRD) were used to study the composition and the structure of the MnSi x films. Compared with the reactive-deposited MnSi 1.7 films on silicon substrates, severe diffusion of manganese atoms into the silicon substrate during the thermal annealing process was observed. If the annealing process was not long enough, the phenomenon of coexistence of manganese-rich and silicon-rich silicides was found. The electrical resistivity of MnSi 1.7 films was measured in the temperature range of 30°C to 450°C. The resistivity increases gradually with temperature in the temperature range measured.

scholarly journals Fe3O4@C Nanoparticles Synthesized by In Situ Solid-Phase Method for Removal of Methylene Blue

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Solid Phase ◽  
Raw Materials ◽  
Phase Method ◽  
Maximum Adsorption Capacity ◽  
High Catalytic Activity ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
High Concentrations

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.

Microstructure and Mechanical Properties of ZrB2/h-BN Multiphase Ceramics by Low-Temperature Reactive Sintering

2016 ◽  
Vol 697 ◽  
pp. 510-514 ◽  
Author(s):  
Feng Rui Zhai ◽  
Ke Shan ◽  
Ruo Meng Xu ◽  
Min Lu ◽  
Zhong Zhou Yi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Fracture Strength ◽  
Solid Phase ◽  
Raw Materials ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Microstructure And Mechanical Properties ◽  
Multiphase Ceramics ◽  
Strength And Toughness

In the present paper, the ZrB2/h-BN multiphase ceramics were fabricated by SPS (spark plasma sintering) technology at lower sintering temperature using h-BN, ZrO2, AlN and Si as raw materials and B2O3 as a sintering aid. The phase constitution and microstructure of specimens were analyzed by XRD and SEM. Moreover, the effects of different sintering pressures on the densification, microstructure and mechanical properties of ZrB2/h-BN multiphase ceramics were also systematically investigated. The results show that the ZrB2 was obtained through solid phase reaction at different sintering pressures, and increasing sintering pressure could accelerate the formation of ZrB2 phase. As the sintering pressure increasing, the fracture strength and toughness of the sintered samples had a similar increasing tendency as the relative density. The better comprehensive properties were obtained at given sintering pressure of 50MPa, and the relative density, fracture strength and toughness reached about 93.4%, 321MPa and 3.3MPa·m1/2, respectively. The SEM analysis shows that the h-BN grains were fine and uniform, and the effect of sintering pressure on grain size was inconspicuous. The distribution of grain is random cross array, and the fracture texture was more obvious with the increase of sintering pressure. The fracture mode of sintered samples remained intergranular fracture mechanism as sintering pressure changed, and the grain refinement, grain pullout and crack deflection helped to increase the mechanical properties.

AMBIPOLAR DIFFUSION AND TURBULENT MAGNETIC FIELDS IN MOLECULAR CLOUDS

2011 ◽  
Vol 26 (04) ◽  
pp. 235-249 ◽  
Author(s):  
MARTIN HOUDE ◽  
TALAYEH HEZAREH ◽  
HUA-BAI LI ◽  
THOMAS G. PHILLIPS
Keyword(s):  
Magnetic Fields ◽  
Molecular Clouds ◽  
Ambipolar Diffusion ◽  
Star Forming ◽  
Star Forming Regions ◽  
Spin Interactions ◽  
Line Narrowing ◽  
Weakly Ionized ◽  
Novel Method

We review the introduction and development of a novel method for the characterization of magnetic fields in star-forming regions. The technique is based on the comparison of spectral line profiles from coexistent neutral and ion molecular species commonly detected in molecular clouds, sites of star formation. Unlike other methods used to study magnetic fields in the cold interstellar medium, this ion/neutral technique is not based on spin interactions with the field. Instead, it relies on and takes advantage of the strong cyclotron coupling between the ions and magnetic fields, thus exposing what is probably the clearest observational manifestation of magnetic fields in the cold, weakly ionized gas that characterizes the interior of molecular clouds. We will show how recent development and modeling of the ensuing ion line narrowing effect leads to a determination of the ambipolar diffusion scale involving the turbulent component of magnetic fields in star-forming regions, as well as the strength of the ordered component of the magnetic field.

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