scholarly journals Synthesis of Cerium Tetrafluoride and Cerium Trifluoride Nanoscale Polycrystals from Ammonium Hydrogen Difluoride

ACS Omega ◽  
2021 ◽  
Vol 6 (17) ◽  
pp. 11348-11354
Author(s):  
Yongju Sun ◽  
Xinyi Yang ◽  
Huaping Mei ◽  
Taosheng Li
Keyword(s):  
Cerium Trifluoride ◽  
Ammonium Hydrogen

Di-ammonium hydrogen phosphate for the consolidation of lime-based historic mortars – Preliminary research

2021 ◽  
Vol 48 ◽  
pp. 45-53
Author(s):  
Agnieszka Defus ◽  
Elena Possenti ◽  
Antonio Sansonetti ◽  
Cristina Tedeschi ◽  
Chiara Colombo ◽  
...  
Keyword(s):  
Hydrogen Phosphate ◽  
Ammonium Hydrogen ◽  
Historic Mortars ◽  
Ammonium Hydrogen Phosphate ◽  
Preliminary Research

High resolution 14N NMR in solids: Single crystals of ammonium hydrogen oxalate hemihydrate

1977 ◽  
Vol 66 (12) ◽  
pp. 5433-5438 ◽  
Author(s):  
E. K. Wolff ◽  
R. G. Griffin ◽  
C. Watson
Keyword(s):  
High Resolution ◽  
Single Crystals ◽  
Ammonium Hydrogen ◽  
14N Nmr

Unprecedented mechanochemical preparation of 18Crown[6] and 15Crown[5] adducts of ammonium hydrogen sulfate by grinding or kneading

CrystEngComm ◽  
2005 ◽  
Vol 7 (44) ◽  
pp. 276 ◽  
Author(s):  
Dario Braga ◽  
Marco Curzi ◽  
Matteo Lusi ◽  
Fabrizia Grepioni
Keyword(s):  
Hydrogen Sulfate ◽  
Ammonium Hydrogen ◽  
Ammonium Hydrogen Sulfate

Preparation of Silica-Supported Nickel Molybdenum Phosphides by Temperature-Programmed Reduction Technique

2007 ◽  
Vol 124-126 ◽  
pp. 1765-1768 ◽  
Author(s):  
So Yeon Lee ◽  
Yong Kul Lee ◽  
S.Ted Oyama ◽  
Seok Hee Lee ◽  
Hee Chul Woo
Keyword(s):  
Single Phase ◽  
Reduction Rate ◽  
Reduction Reaction ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
Molybdenum Oxides ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
Ammonium Hydrogen ◽  
Temperature Programmed

Silica supported nickel molybdenum phosphides (NiMoP/SiO2) were successfully prepared by temperature-programmed reduction (TPR) reaction of phosphorous-impregnated nickel molybdenum oxides (NiMoO4) precursors with hydrogen at relatively low temperatures (530 – 590 oC) and characterized by Fourier transform-Infrared spectrometry (FT-IR), X-ray diffraction (XRD), Electron probe microanalysis (EPMA) and Temperature-programmed reduction reaction (TPR). The process of solid transformation and properties of materials prepared from ammonium hydrogen phosphate (AMP)-impregnated samples were compared with those of phosphide made from phosphoric acid (PAC)-impregnated samples. Results show that the formation of a single NiMoP phase on silica significantly depends on reduction rates, phosphorous sources and phosphorous loadings. A single phase of NiMoP on SiO2 was particularly promoted at a below 5 oC/min of reduction rate and the starting molar ratio of Ni/Mo/P=1/1/1. A single phase of crystalline NiMoP on silica was produced from AMP-impregnated samples, while other phases of MoP, Ni2P, or NiMoP2 were appeared from PAC-impregnated samples with loading. The new phase of NiMoP2 was occurred with increasing phosphorous loading (above Ni/Mo/P=1/1/2.5) as a result of facilitated contact on the surface between the Ni-Mo bimetallic component and the phosphorous reagent

scholarly journals Fabrication of Dy2O3 Transparent Ceramics by Vacuum Sintering Using Precipitated Powders

2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Dianjun Hu ◽  
Xin Liu ◽  
Ziyu Liu ◽  
Xiaoying Li ◽  
Feng Tian ◽  
...  
Keyword(s):  
Near Infrared ◽  
Optical Quality ◽  
Precipitation Method ◽  
Infrared Range ◽  
Transparent Ceramics ◽  
Vacuum Sintering ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen ◽  
Liquid Precipitation ◽  
Near Infrared Range

As a kind of promising material for a Faraday isolator used in the visible and near infrared range, Dy2O3 transparent ceramics were prepared by vacuum sintering from the nano-powders synthesized by the liquid precipitation method using ammonium hydrogen carbonate as precipitant with no sintering aids. The synthesized precursor was calcinated at 950 °C–1150 °C for 4 h in air. The influences of the calcination temperature on the morphologies and phase composition of Dy2O3 powders were characterized. It is found that the Dy2O3 powder calcinated at 1000 °C for 4 h is superior for the fabrication of Dy2O3 ceramics. The Dy2O3 transparent ceramic sample prepared by vacuum sintering at 1850 °C for 10 h, and subsequently with air annealing at 1400 °C for 10 h, from the 1000 °C-calcined Dy2O3 powders, presents the best optical quality. The values of in-line transmittance of the optimal ceramic specimen with the thickness of 1.0 mm are 75.3% at 2000 nm and 67.9% at 633 nm. The Verdet constant of Dy2O3 ceramics was measured to be −325.3 ± 1.9 rad/(T·m) at 633 nm, about 2.4 times larger than that of TGG (Tb3Ga5O12) single crystals.

Accurate Determination of Total Antimony Using ICP-MS and Optimization Its Extraction Efficiency From Reference and Soil Samples

2018 ◽  
Vol 6 (1) ◽  
pp. 48-58
Author(s):  
Sameer Amereih ◽  
Thomas Meisel ◽  
Wolfhard Wegsheider
Keyword(s):  
Citric Acid ◽  
Reference Materials ◽  
Microwave Digestion ◽  
Accurate Determination ◽  
Ammonium Oxalate ◽  
Ammonium Thiocyanate ◽  
Strong Acid ◽  
Disodium Salt ◽  
Icp Ms ◽  
Ammonium Hydrogen

Two independent digestion techniques (microwave acid digestion with HF and HCl, HNO3 and Na2O2 sintering, respectively) were applied to determine the total Sb concentration in a real soil sample and in reference materials: Icelandic Basalt (BIR-1), Cody Shale (SCo-1) and (Soil-7). ICP-MS was used to determine total antimony concentrations in the digested and the extracted solutions using external calibration and isotope dilution technique. The recoveries of Sb using HF in the acids digestion mixture in closed-vessels microwave digestion system were excellent and the concentrations are in very good agreement with certified or reported concentrations of reference materials. Using closed-vessels combined with microwave heating systems probably prevents the loss of volatile Sb compounds. The use of hydrogen fluoride with other strong acid can help dissociating insoluble antimony silicates. Different extraction reagents were tested for their ability to extract antimony using an ultrasonic bath namely: EDTA disodium salt, potassium hydroxide, citric acid monohydrate, pyridine-2,6-dicarboxylic acid, ammonium acetate, ammonium oxalate, ammonium thiocyanate, ammonium persulphate and di-ammonium hydrogen citrate. A 500 mmol L-1 solution of citric acid pH 1.08 proved to be the most efficient extractant. Optimization of the extraction conditions were investigated by studying the effect of pH, concentration, temperature, time of extraction, the ratio of sample mass to the volume of extractant and the number of consecutive extractions. As a result three consecutive extractions for a total time of 45 min at 80 ˚C was the most efficient condition for Sb extraction. Using these extraction conditions 61%, 3.7% RSD and 42%, 2.2% RSD (n=6) of the total antimony in the real soil and Soil-7 samples, respectively could be extracted.

ChemInform Abstract: IONIC CONDUCTIVITY OF DOPED CERIUM TRIFLUORIDE

1977 ◽  
Vol 8 (19) ◽  
pp. no-no ◽  
Author(s):  
T. TAKAHASHI ◽  
H. IWAHARA ◽  
T. ISHIKAWA
Keyword(s):  
Ionic Conductivity ◽  
Cerium Trifluoride
Sign in / Sign up

Export Citation Format

Share Document