SEPARATION AND PURIFICATION TECHNOLOGY
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2020
·
IF 5.774
Lu Ye,Yangcheng Lu
With the depletion of rich fluorite ore, flotation process suitable for fine-grained fluorite is of great necessity. In this study, such method was preliminarily developed with a combination of in-situ surface modification and gas-liquid microdispersion. By introducing additives into ball-milling, the interaction between reagents and particles was improved. Through exploitation of selective sedimentation of undesired minerals via pH adjustment, the flotation of fine-grained fluorite was achieved with little or even no depressant in this study. Using a well-designed membrane dispersion device, effective interaction between the particles and bubbles was achieved, with massive expansion of the surface area in a limited space, enabling continuous flotation in a miniaturized device. Satisfactory product grade and recovery were obtained while reducing the use of additives, along with significantly decreased costs related to energy consumption, wastewater and flue gas treatment, and facility investments. The mechanism of this flotation separation strategy was summarized on the basis of empirical data. The strategy was effectively and flexibly applied to fluorite ores with different particle sizes and surface properties.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2020
·
IF 3.004
Yanshuxian Liu,Yilei Fan,Zhongping Huang,Huijun Liu,Lili Wang,Zhenlu Shen,Ichi Watanabe
A rapid and sensitive method utilizing flash evaporation-gas chromatography/mass spectrometry (FE-GC/MS) has been developed. The method is applicable to determine ketamine (KET), methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA) in human hair. Cut and weighted hair (0.30 mg) was heated at the flash evaporation temperature of 350 °C. KET, MAMP and MDMA were released into a capillary column for GC/MS analysis and produced fragment ions in SIM mode. Validation of the method included evaluation of linearity, sensitivity, accuracy, precision and repeatability. Linearity ranged from 2 to 300 ng/mg for KET in hair and 2 to 200 ng/mg for MAMP and MDMA in hair with the correlation coefficients all greater than 0.998. Limits of detection were 0.7 ng/mg and limits of quantification were 2.0 ng/mg of hair for KET, MAMP and MDMA. The precision ranged from 1.57% to 7.75% for KET, 1.49% to 7.10% for MAMP and 1.84% to 8.31% for MDMA. The recovery ranged from 102.1% to 110.9% for KET, 99.3% to 108.0% for MAMP and 89.5% to 112.6% for MDMA. Six authentic hair samples from known drug abusers and three drug-free hair samples from volunteers who had never used drugs were successfully analyzed. Compared with traditional time-consuming and hair-comsuming pretreatment method, FE-GC/MS was a faster, simpler and low sample consumption method for the determination of KET, MAMP and MDMA in human hair.
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PubMed
高影响因子
FUEL
·
2020
·
IF 5.578
Yun-Fei Wang,Ling-Ban Wang,Yang Li,Jin-Xiang Gu,Chang-Yu Sun,Guang-Jin Chen,Xiao-Hui Wang,Qing Yuan,Nan Li
Methane hydrate exploitation via depressurization for a reservoir with a bottom gas-rich zone was simulated using a large-sized three-dimensional hydrate simulator. A single vertical well system and a system with a combination of vertical and horizontal wells were employed to elucidate the different effects of horizontal and vertical wells on the exploitation process. The results showed that effect of promoting gas production using a horizontal well is not obvious for a high permeability reservoir. A large exploitation temperature drop may lead to ice blockage in the pipelines, and fracturing technology was introduced to solve this blockage problem. Experiments performed above and below the freezing point inferred that the decomposition of the hydrate in different areas of the reactor was not simultaneous, according to analysis of the temperature distribution of the entire reactor during the exploitation process. For exploitation above the freezing point, temperatures in the bottom of the reactor tend to maintain a low level and work against hydrate decomposition. However, for exploitation below the freezing point, the low-temperature area in the bottom of the reactor preferentially converts to ice. Heat release and salt precipitation promoted hydrate decomposition, and the decomposition rate was significantly accelerated.
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Food Science & Nutrition
·
2020
·Vol. 8
·期 6
·2882-2894
·
IF 1.797
Changyuan Wang,Yuchao Feng,Shu Zhang,Tianxin Fu,Yanan Sheng,Yiwei Zhang,Yingjun Jiang,Miao Yu,Liyuan Zhang,Dongjie Zhang
Metabolomic studies were carried out using gas chromatography and mass spectrometry (GC-MS) on Daohuaxiang variety rice ( Oryza sativa L.) from the Wuchang Geographical Indication Rice Protection Area in Heilongjiang Province, to investigate the effects of storage on brown rice metabolism. The data were subjected to principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and cluster analysis using software such as SIMCA. Analysis of the samples led to the identification of a total of 160 metabolites. No significant differences were found in the amount of metabolites before and after storage. A total of 31 differential metabolites were screened, and the changes in metabolite content showed a “reverse change” overall. Storage significantly changed the content of various metabolites in rice, with fatty acids impacted most significantly. Metabolic pathway analysis revealed that fatty acid biosynthesis is a key metabolic pathway in rice storage. The degradation of brown rice quality caused by storage is closely related to the composition and content of its metabolites, and that change in lipid content significantly affects brown rice quality during storage.
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PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
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IF 4.598
Hongwei Gao,Wenkai Cao,Jinmei He,Yongping Bai
Poly(ethylene terephthalate) (PET) reinforced with hydrogen bonding is prepared by incorporating 4 mol% amide units formed by 1,12-dodecanediamine and terephthalic acid. Structurally modified PET (PETA) containing amide units is extruded and biaxially stretched to make biaxially oriented (BO) PETA films with high performance. The formation of hydrogen bonds in BOPETA is detected, and the effect of the incorporated amide units on the performance is discussed. Attractive interchain forces are increased through the hydrogen bonds formed in BOPETA, and its crystallinity and mechanical properties are improved. The fabricated BOPETA film exhibits lower water and oxygen permeabilities than that of BOPET because the free volume was reduced. The optical properties of the BOPETA film remain good after incorporating amide units into the PET backbone, and its light transmittance reaches 88.8%. Moreover, BOPETA with 4 mol% amide units absorbs somewhat ultraviolet (UV) light and exhibits slight anti-UV performance. A facile approach for the preparation of PET films with good mechanical strength, high transparency, and improved gas barrier properties for packaging is discussed in this work.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Kaiqiang Shi,Yi Wang,Anlin Xu,Xiezhen Zhou,Hongwei Zhu,Kajia Wei,Xiaodong Liu,Jinyou Shen,Weiqing Han
Gas-diffusion electrodes (GDEs) are the efficient generator for the hydrogen peroxide, which plays an important role in the degradation of refractory organic contaminants by electro-Fenton processes. In this work, the microtubular gas-diffusion electrodes (MGDEs) were fabricated with the carbon nanotubes (CNTs) hollow fiber base by wet-spinning technology and then employed as gas-diffusion electrodes (GDEs). Characterized by FESEM, TEM, BET, XPS, the MGDEs were proved to be relatively compact and intact without fracture on the hollow fiber surface. Cyclic voltammetry test in three electrodes system was carried out to prove the catalysis effect of the surface functional groups in the electrochemical reactions. The time-course of H 2 O 2 production rate in the range of the different current density (10 ~ 25 mA cm −2 ), pH value (3.0 ~ 9.0) and electrolyte concentration (0.01 ~ 0.1 M Na 2 SO 4 ) were conducted to evaluated the electrochemical performance of MGDEs and explorer the optimal condition. The stability of electrocatalytic was also tested by repeated runs. Furthermore, several parallel-degradation process of the simulated wastewater with the 1.0 ~ 10.0 mg L -1 IBP were carried out in electro-Fenton system. Under the optimal conditions, the removal rate of IBP could reach 90.2% in 120 min with the pseudo first-order degradation rate constant of 0.01415 min −1 . It shows the potential of this system to degrade NSAIDs.
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JOURNAL OF POWER SOURCES
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2021
·
IF 9.127
Yuan Zhou,Yang Yang,Xun Zhu,Ding-ding Ye,Rong Chen,Qiang Liao
The power generation property of direct liquid fuel cells at high current densities is plagued by gas bubbles generation. Herein, we propose a bubble-trap layer to help mitigate the problem and improve the power generation stability performance. A novel chip-based liquid fuel cell with the bubble-trap layer is fabricated as a facile visualization and fast test platform, validating that most of CO 2 bubble releases from the bubble-trap layer in situ rather than at the microchannel outlet. The dynamic behaviors of gas bubbles are visualized and their impact on the power generation performance is discussed. It suggests the fuel cell equipped with the bubble-trap layer has superior power generation stability, power density (29 mW cm −2 ) and current density (163 mA cm −2 ), which are 10% and 27% higher than that without the bubble-trap layer. And a maximum power density of 35 mW cm −2 is achieved. The bubble growth and gas emission mechanisms are analyzed according to the mechanical model, providing a guidance for the channel design and operation condition determination of cells. These results demonstrate the viability of applying the bubble-trap layer for stabilizing power generation and cast new light on the structure design of direct liquid fuel cells.
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高影响因子
CHEMICAL PHYSICS LETTERS
·
2021
·
IF 2.328
Hao Liu,Yayun Zhao,Chen Zhou,Bin Mu,Liang Chen
A reliable strategy of Zr-based metal–organic framework (Zr-fum-fcu-MOF) was successfully achieved by microwave-assisted synthesis. Well-shaped and octahedral Zr-fum-fcu-MOF particles were obtained at 100 °C for 1.0 h with 150 equivalents of FA per ZrOCl 2 ·8H 2 O. A clear difference for the adsorption behavior of iso -C 4 H 10 (1.11 mmol/g) and n-C 4 H 10 (3.56 mmol/g) was observed at 25 °C and 1.0 bar. Moreover, 3.16 mmol/g CO 2 uptake was also obtained at 0 °C and 1.0 bar while the adsorption capacity of CH 4 and N 2 is 0.85 mmol/g and 0.21 mmol/g, respectively. This indicates that Zr-fum-fcu-MOF is a promising candidate for CO 2 capture.
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SENSORS AND ACTUATORS B-CHEMICAL
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2021
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IF 7.46
Chaozhu Huang,Jingwei Zhao,Fengdong Qu,Jiacheng Wang,Minghui Yang
Hydrogen sulfide (H 2 S) is considered a highly hazardous toxic gas. H 2 S sensors are therefore of paramount significance for real-time leak detection. However, existing solutions do not meet the strict performance targets set by stakeholders, while deactivation due to surface area of sensing materials decrease and contamination is a widely unsolved problem. Presented here is a new support material, mesoporous niobium nitride (NbN), which improve the long-term stability largely via enhancing the interaction between metal and support. Simultaneously, sensor devices using NbN as support show enlarged sensitivity, enhanced limit of detection and well repeatability when compared with these sensors using traditional carbon black support. In a wider perspective, our work suggests strategies for enhancing long-stability of next-generation chemical gas sensors by optimizing metal-support interaction.
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Advanced Materials Interfaces
·
2021
·Vol. 8
·期 22
·2101178
·
IF 6.147
Zijian Dai,Shravan Pradeep,Jie Zhu,Wenyi Xie,Heather F. Barton,Yang Si,Bin Ding,Jianyong Yu,Gregory N. Parsons
Metal organic framework (MOF)-based adsorptive membranes are attractive materials in high flux separation and/or in abatement of hazardous materials. However, fabrication of continuous MOF membrane with ultra-high loading and anti-solvent property is a challenging task. Here, the authors report a coordination replication synthetic approach via a morphological replacement procedure that employs pre-shaped Al 2 O 3 microfiltration membrane to produce freestanding MOF multifunctional membrane (FMMMs). The authors achieve precise control of crystal size, morphology, and orientation on the FMMMs. Moreover, the intrinsic porous structure inherited from Al 2 O 3 pre-fabricated membrane and newly introduced MOF active sites synergistically contribute to a great rejection (99%) of organic dyes from organic solvent with a permeability over 175 L m −2 h −1 bar −1 . Furthermore, the as-synthesized FMMMs enable heterogeneous HCHO catalytic oxidation and extremely rapid 2-chloroethyl ethyl sulfide (CEES) detoxification. This work opens the way to design high-performance FMMMs from pre-shaped membranes for various applications.
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高影响因子
AICHE JOURNAL
·
2019
·Vol. 66
·期 1
·e16779
·
IF 3.463
Guiling Shi,Hongqin Zhao,Kaihong Chen,Wenjun Lin,Haoran Li,Congmin Wang
For an ideal absorbent for CO 2 capture from flue gas, there are some key features including easy preparation, high stability, low absorption enthalpy, high capacity at high temperature and excellent reversibility. Herein, several polyamine-functionalized ionic liquids (ILs) were easily prepared from cheap polyamines and lithium salts, which exhibited significantly improved stability due to the presence of multisite coordinating interactions. The viscosity was reduced by introducing polyalcohol-based ILs, leading to polyamine-based hybrid ILs. Interestingly, these polyamine-based hybrid ILs exhibited high CO 2 capacity (4.09 mmol/g, 0.1 bar) at high temperature (80°C) and excellent reversibility in the presence of H 2 O and O 2 , which is superior to many other good absorbents. Moreover, these ILs also showed good performance for CO 2 capture from stimulated air (2.10 mmol/g, 380 ppm). We believe that this method with easy preparation, low cost, high efficiency and excellent reversibility has a great potential in the industrial capture of CO 2 from flue gas.
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高影响因子
Journal of CO2 Utilization
·
2019
·
IF 5.189
Jing Chang,Chengming Hou,Donghai Wan,Xiuli Zhang,Bin Xu,Hongjing Tian,Xia Wang,Qingjie Guo
An alcoholamine, 2-[2-(dimethylamino)ethoxy]ethanol (DMAEE), was co-tethered with pentaethylenehexamine (PEHA) on the surfaces of the flue gas desulfurized gypsum (FGDG) carriers to synthesize a solid bi-amine adsorbent. The effects of temperature, loading of the blended amines, mass ratio of DMAEE to PEHA, CO 2 partial pressure on the CO 2 adsorption performance were discussed. The water of hydration contained in the FGDG carriers promoted the CO 2 adsorption capacity of the bi-amine adsorbent. Both the breakthrough time and the saturation adsorption capacity of the bi-amine adsorbent were distinctly higher than the DMAEE or PEHA singly tethered adsorbents. The adsorption capacity of the bi-amine adsorbent decreased by only 1.86% over twelve cycles. The isosteric heat of adsorption Q s t and the mean free energy of adsorption E f e was determined and both the values indicated that the adsorption was primarily chemisorption. In the kinetics analysis, Avrami model fitted best with the measured adsorption capacity. With the aid of the 13 C–NMR quantitative analysis results, the CO 2 adsorption mechanism of the bi-amine adsorbent in the presence of the water of hydration was revealed. For the bi-amine adsorbents supported on some porous carriers, FGDG particles were testified to replace up to 7 wt.% of montmorillonite clay or 7 wt.% of MCM–41 zeolite or 10.5 wt.% of ZSM–5 zeolite without any decrease in the CO 2 adsorption capacity.
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