Using hydrogen peroxide to mediate through a one-step hydrothermal method for the fast and green synthesis of N-CDs

RSC Advances ◽  
2015 ◽  
Vol 5 (116) ◽  
pp. 95744-95749 ◽  
Author(s):  
Jiangling He ◽  
Bingfu Lei ◽  
Haoran Zhang ◽  
Mingtao Zheng ◽  
Hanwu Dong ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
High Pressure ◽  
High Temperature ◽  
Green Synthesis ◽  
Hydrothermal Method ◽  
Formation Mechanism ◽  
Formation Process ◽  
Top Down ◽  
Bottom Up ◽  
One Step

The strategy for the formation mechanism of N-CDs under high temperature and high pressure can be summarized as consisting of two parts including top-down and bottom-up. It can serve as an efficient way to express the detailed formation process of N-CDs.

Study of high-pressure air jet controlled compression ignition with compound thermodynamic cycle for combustion and emission formation process

2020 ◽  
pp. 146808742096933
Author(s):  
Xiangyu Meng ◽  
Sicheng Liu ◽  
Jingchen Cui ◽  
Jiangping Tian ◽  
Wuqiang Long ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Low Temperature ◽  
Formation Process ◽  
Combustion Process ◽  
Thermodynamic Cycle ◽  
Compression Ignition ◽  
Temperature Reaction ◽  
Air Jet ◽  
High Temperature Reaction

A novel method called high-pressure air (HPA) jet controlled compression ignition (JCCI) based on the compound thermodynamic cycle was investigated in this work. The combustion process of premixed mixture can be controlled flexibly by the high-pressure air jet compression, and it characterizes the intensified low-temperature reaction and two-stage high-temperature reaction. The three-dimensional (3D) computational fluid dynamics (CFD) numerical simulation was employed to study the emission formation process and mechanism, and the effects of high-pressure air jet temperature and duration on emissions were also investigated. The simulation results showed that the NOx formation is mainly affected by the first-stage high-temperature reaction due to the higher reaction temperature. Overall, this combustion mode can obtain ultra-low NOx emission. The second-stage high-temperature reaction plays an important role in the CO and THC formation caused by the mixing effect of the high-pressure air and original in-cylinder mixture. The increasing air jet temperature leads to a larger high-temperature in-cylinder region and more fuel in the first-stage reaction, and therefore resulting in higher NOx emission. However, the increasing air jet temperature can significantly reduce the CO and THC emissions. For the air jet duration comparisons, both too short and too long air jet durations could induce higher NOx emission. A higher air jet duration would result in higher CO emission due to the more high-pressure air jet with relatively low temperature.

scholarly journals Solar-to-hydrogen peroxide energy conversion on resorcinol–formaldehyde resin photocatalysts prepared by acid-catalysed polycondensation

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Yasuhiro Shiraishi ◽  
Takumi Hagi ◽  
Masako Matsumoto ◽  
Shunsuke Tanaka ◽  
Satoshi Ichikawa ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
High Temperature ◽  
Hydrothermal Method ◽  
Liquid Fuel ◽  
Artificial Photosynthesis ◽  
Chemical Conversion ◽  
Formaldehyde Resin ◽  
Resorcinol Formaldehyde ◽  
Donor Acceptor ◽  
Acidic Conditions

AbstractThe photocatalytic generation of hydrogen peroxide from water and dioxygen (H2O + 1/2O2 → H2O2, ΔG° = +117 kJ mol–1) under sunlight is a promising strategy for the artificial photosynthesis of a liquid fuel. We had previously found that resorcinol–formaldehyde (RF) resin powders prepared by the base-catalysed high-temperature hydrothermal method act as semiconductor photocatalysts for H2O2 generation. Herein, we report that RF resins prepared by the acid-catalysed high-temperature hydrothermal method (~523 K) using common acids at pH < 4 exhibit enhanced photocatalytic activity. The base- and acid-catalysed methods both produce methylene- and methine-bridged resins consisting of π-conjugated and π-stacked benzenoid–quinoid donor–acceptor resorcinol units. The acidic conditions result in the resins with a lower bandgap (1.7 eV) and higher conductivity because the lower-degree of crosslinking creates a strongly π-stacked architecture. The irradiation of the RF-acid resins with simulated sunlight in water with atmospheric-pressure O2 generates H2O2 at a solar-to-chemical conversion efficiency of 0.7%, which is the highest efficiency ever reported for powder catalysts used in artificial photosynthesis.

Gradation Process by Imbibition in WC-Co for Mining Tools Application

2009 ◽  
Vol 83-86 ◽  
pp. 810-817
Author(s):  
Elodie Lefort-Sorlier ◽  
Christophe Colin ◽  
Alfazazi Dourfaye
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
High Temperature ◽  
Thermal Processing ◽  
Temperature Step ◽  
High Pressure High Temperature ◽  
One Step ◽  
Shock Resistance ◽  
Composition Gradients ◽  
Mining Tools

Continuous composition gradients of several millimetres were generated in commercial WC-Co cutters to improve their shock resistance. This important gradation was obtained in one-step by using the imbibition process. The effects of this thermal processing were analysed in terms of microhardness, cobalt concentration and WC grain size. A gradient of a 300 HV amplitude is measured in the 8 mm-height sample treated by the imbibition process in association with a boron-rich coating. This gradient was preserved after the HPHT (high pressure – high temperature) step used for the diamond table deposition on the WC-Co cutter. To our knowledge, such gradients have never before been reported and should certainly increase cutter service life.

Green synthesis of sheet-like cellulose nanocrystal–zinc oxide nanohybrids with multifunctional performance through one-step hydrothermal method

Cellulose ◽  
2018 ◽  
Vol 25 (11) ◽  
pp. 6433-6446 ◽  
Author(s):  
Somia Yassin Hussain Abdalkarim ◽  
Hou-Yong Yu ◽  
Chuang Wang ◽  
Lin-Xi Huang ◽  
Juming Yao
Keyword(s):  
Zinc Oxide ◽  
Green Synthesis ◽  
Hydrothermal Method ◽  
Cellulose Nanocrystal ◽  
One Step

High-temperature, high-pressure hydrothermal synthesis, crystal structure and photoluminescent properties, of K3[Gd1−xTbxGe3O8(OH)2] (x = 0, 0.3, 0.1, 1)

RSC Advances ◽  
2014 ◽  
Vol 4 (51) ◽  
pp. 26951-26955 ◽  
Author(s):  
Wei Liu ◽  
Min Yang ◽  
Ying Ji ◽  
Fuyang Liu ◽  
Ying Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Hydrothermal Synthesis ◽  
Single Crystal ◽  
Hydrothermal Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature High Pressure

A family of new lanthanide germanates K3LnGe3O8(OH)2 have been synthesized by a high-temperature, high-pressure hydrothermal method and characterized by single-crystal X-ray diffraction.

One step towards the 1T/2H-MoS2 mixed phase: a journey from synthesis to application

2021 ◽  
Author(s):  
Sarmistha Das ◽  
Gayatri Swain ◽  
Kulamani Parida
Keyword(s):  
Energy Storage ◽  
Mixed Phase ◽  
Energy Storage And Conversion ◽  
Pollutant Degradation ◽  
Top Down ◽  
Bottom Up ◽  
One Step

The mixed phase 1T/2H-MoS2, synthesized by top-down and bottom-up approaches reveals intriguing properties due to the semiconducting 2H with metallic 1T phase and exhibits various applications including pollutant degradation, energy storage and conversion.

One-step electrocatalytic synthesis of ammonia and acetone from nitrogen and isopropanol in an ionic liquid

2021 ◽  
Author(s):  
Qikun Zhang ◽  
Ya'nan Zhao ◽  
Liping Yu ◽  
Xiaoyang Zhang ◽  
Yiling Bei ◽  
...  
Keyword(s):  
High Pressure ◽  
Ionic Liquid ◽  
High Temperature ◽  
Synthesis Method ◽  
Environmentally Friendly ◽  
Ambient Conditions ◽  
One Step ◽  
The One

Electrocatalysis is an environmentally friendly synthesis method that overcomes thermodynamic limitations and enables some reactions usually requiring high temperature and high pressure to be realized under ambient conditions. The one-step...

One-Step Synthesis of Lemonile from Citral by Liquid Phase Catalytic Ammoxidation

2013 ◽  
Vol 641-642 ◽  
pp. 959-961
Author(s):  
Ye Wang ◽  
Shao Feng Pi ◽  
Jin Hua Zhou ◽  
Hai Li Gao ◽  
Ji Lie Li ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Phase ◽  
Green Synthesis ◽  
New Technology ◽  
Reaction System ◽  
Experimental Results ◽  
Optimal Conditions ◽  
One Step

Lemonile is a new kind of spice. The new technology for synthesis of lemonile from citral by catalytic ammoxidation has been investigated. Experimental results showed the optimal synthetic conditions are as follows. The molar material ratio n(H2O2):n(Citral) is 3:1, solvent for the reaction is isopropanol, dosage of the catalyst CuCl is 3% (wt, calculated by citral), the drop-feeding temperature and time for hydrogen peroxide are 10 °C-14 °C and 3 hrs, respectively; after hydrogen peroxide being drop-fed into the reaction system, the reaction should be continued for 4 hrs. Lemonile yield is 91.2% and purity is 98.5% (detected by GC) under the optimal conditions. This new one-step liquid phase catalytic ammoxidation technology is a green synthesis way for lemonile. The structure of the product has been confirmed by GC-MS.

scholarly journals Enhancement of Solvent Resistance of Polyimide Electrospun Mat via the UV-Assisted Electrospinning and Photosensitive Varnish

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2055 ◽  
Author(s):  
Lin Qi ◽  
Chen-Yu Guo ◽  
Meng-Ge Huang Fu ◽  
Yan Zhang ◽  
Lu-meng Yin ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Uv Irradiation ◽  
Starting Material ◽  
Current Work ◽  
Mercury Lamp ◽  
Solvent Resistance ◽  
One Step ◽  
The One

A new methodology for enhancing the solvent resistance of electrospun polyimide (PI) ultrafine fibrous mat (UFM) was investigated in the current work. For this purpose, a negative intrinsically photosensitive polyimide (PSPI) resin was prepared by the one-step high- temperature polycondensation procedure from 3,3’,4,4’-benzophenonetetracarboxylic dianhydride (BTDA) and α,α-bis(4-amino-3,5-dimethylphenyl)phenylmethane (PTMDA). The PI varnish, by dissolving the derived PI (BTDA-PTMDA) resin in N,N-dimethylacetamide (DMAc) at a solid of 20 wt %, was used as the starting material for the standard electrospinning (ES) and ultraviolet-assisted ES (UVAES) fabrications, respectively. The 365 nm wavelength of the high-pressure mercury lamp ultraviolet (UV) irradiation induced the photocrosslinking reaction in the PSPI mat. Solubility tests indicated that the PI UFM fabricated by standard ES procedure showed poor DMAc resistance, while the one by UVAES (PI-UV) exhibited excellent resistance to DMAc.

scholarly journals An Eclectic Phraseological Research on the Formation and Degrammaticalization of Phraseological Units

2016 ◽  
Vol 6 (4) ◽  
pp. 1
Author(s):  
Ai Inoue
Keyword(s):  
Formation Process ◽  
Communicative Competence ◽  
Word Formation ◽  
Top Down ◽  
Function Words ◽  
Bottom Up ◽  
Word Combination

<p>This paper reveals new features of certain phraseological units (PUs) through bottom-up and top-down examination. Previous phraseological research has tended to focus on the PUs characteristically observed in a genre or context or how PUs semantically and syntactically behave to improve communicative competence. However, previous phraseological research has failed to give systematic explanations as to the formation of PUs and the process and conditions necessary for a word-combination to become a PU. By applying existing word-formation rules to various PUs, this study clarifies the formation and formation process for PUs and the four conditions required for a word combination to become a PU. It was found that although the word-formation rules are used, PUs generally arise in an unformed manner. Further, word-combinations are used as PUs only if they undergo a formation process and abide by the four conditions. PU features were found to be function words from a degrammaticalization standpoint. It has been widely accepted that degrammaticalization occurs in words. However, no research to date has dealt with the application of degrammaticalization to PUs. It was found that semantic degrammaticalization occurs in PUs arising from function words.</p>

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