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1
Content available Selective flotation of siderite and quartz from a carbonate-containing refractory iron ore using a novel amino-acid-based collector
100%
Gu X. , Zhu Y. , Li Y. , Han Y.
Physicochemical Problems of Mineral Processing
|
2018
|
tom Vol. 54, iss. 3
803--813
EN
A novel and highly-efficient amino-acid-based collector, α-ethylenediamine lauric acid (α-EDA-LA), was studied to selectively beneficiate carbonate-containing refractory hematite ores. Single mineral and synthetic mixture flotation tests were carried out to investigate its floating performance. Zeta potential, fourier transform infrared spectroscopy (FTIR) and Density Functional Theory-based molecular simulation were used to identify the adsorption mechanism. The flotation results showed that quartz could be collected effectively at pH 11.0-12.0 in the reverse flotation. For siderite, the recovery peaked at 83.4% at pH 8.0, where siderite presented different floatability from magnetite and hematite. Exploiting such difference, the separation of siderite could be achieved. Zeta-potential measurements showed that α-EDA-LA adsorption on the surfaces of siderite and quartz decreased the corresponding zeta potentials at pH of 8.0-10.0 and 8.0-12.0, respectively. This means the adsorption overcome the electrostatic repulsion between α-EDA-LA and the mineral surfaces. The molecular simulation indicated that no chemisorption took place between α-EDA-LA and quartz. FTIR analysis suggested that α-EDA-LA was adsorbed on quartz via hydrogen bonding. The adsorption of α-EDA-LA on siderite surface was dominated by chemisorption, while further enhanced by hydrogen bonding. This study filled the gap in the research on siderite flotation reagents and its adsorption mechanism.
2
Content available The influence of ship rolling motion on take-off aerodynamic characteristics of aircraft
100%
He Z. , Sun X. , Gu X.
Polish Maritime Research
|
2018
|
tom S 2
23--29
EN
Ship motion is an important factor affecting on the safety of ski-jump take-off. The simplified frigate ship SFS1 was numerically simulated, and the results were compared with the experimental data, the feasibility of the calculation method was verified; Meshless method and WALE turbulence model were used to simulate the process of aircraft skijump take-off, aerodynamic characteristics under different rolling conditions during the aircraft ski-jump take-off process were presented. The results showed that: the influence of ship rolling motion on lift coefficient, drag coefficient and pitching moment was small, side force and rolling moment were greatly affected by rolling motion; the region of downwash with the maximum speed was about 10 m from the bow; the safety of ski-jump take-off was greatly affected when aircraft was close to the bow within 20 m.
3
The influence of ship rolling motion on take-off aerodynamic characteristics of aircraft
100%
He Z. , Sun X. , Gu X.
Polish Maritime Research
|
2018
|
tom 25
|
nr Special Issue S2
EN
Ship motion is an important factor affecting on the safety of ski-jump take-off. The simplified frigate ship SFS1 was numerically simulated, and the results were compared with the experimental data, the feasibility of the calculation method was verified; Meshless method and WALE turbulence model were used to simulate the process of aircraft skijump take-off, aerodynamic characteristics under different rolling conditions during the aircraft ski-jump take-off process were presented. The results showed that: the influence of ship rolling motion on lift coefficient, drag coefficient and pitching moment was small, side force and rolling moment were greatly affected by rolling motion; the region of downwash with the maximum speed was about 10 m from the bow; the safety of ski-jump take-off was greatly affected when aircraft was close to the bow within 20 m
4
Design and experiment of low-pressure gas supply system for dual fuel engine
100%
Gu X. , Jiang G. , Guo Z. , Ding S.
Polish Maritime Research
|
2020
|
tom 27
|
nr 2
5
Spermidine promotes starch degradation to relieve the inhibitory effect of chilling on wheat seed germination
88%
Gu X. , Wei B. , Liao Y. , Wen X. , Liu Y.
Acta Physiologiae Plantarum
|
2019
|
tom 41
|
nr 03
6
Content available Flotation behavior and separation mechanism of quartz and iron minerals in α-bromolauric acid reverse flotation system
88%
Han Y. , Guo W. , Zhu Y. , Wei Y. , Gu X.
Physicochemical Problems of Mineral Processing
|
2018
|
tom Vol. 54, iss. 3
992--1003
EN
A new type collector α-Bromolauric acid (α-BLA) had been proved to be an efficient collector for quartz flotation. However, the effects of α-BLA on the flotation behavior of iron minerals and quartz-iron separation had not been investigated. In this study, collector α-BLA was synthesized in the laboratory. The flotation behavior of quartz, hematite and magnetite under α-BLA reverse flotation system were investigated and the separation mechanism of quartz-irons was studied by contact angle, zeta-potential and infrared spectroscopy. The results showed that the optimum flotation pH was 11.5 for quartz, 6.45 for hematite and 6.97 for magnetite. The best α-BLA concentrations was 75 mg/dm3 for quartz flotation, 125 mg/dm3 for hematite and magnetite flotation. The activator CaCl2 had little effect on the flotation of hematite and magnetite, but the minimum dosage 50 mg/dm3 of activator CaCl2 was necessary for quartz flotation. On the contrary, starch had no effect on the flotation of quartz, while the recoveries of magnetite and hematite tended to be 0% as starch concentration more than 80 mg/dm3. The separation mechanism of quartz from iron minerals under α-BLA reverse flotation system was that the starch could be selectively adsorbed on the surface of hematite and magnetite in the form of strong hydrogen bond adsorption. However, the same adsorption of starch did not occur on the surface of quartz, so the α-BLA can be successfully adsorbed on the surface of activated quartz to make the quartz strongly hydrophobic, and then to be floated out.
7
Content available The improvement of a forest resource valuation system - a case study of Beijing, China
88%
Gu X. , Li M. , Dou Y. , Zhao Y. , Zhao X.
Sylwan
|
2023
|
tom 167
|
nr 09
8
Content available remote Rapid detection of trace chloroethylenes sing laser mass spectrometry
75%
Ma J. , Ding L. , Fang L. , Zheng H. , Gu X. , Zhang W.
Optica Applicata
|
2005
|
tom Vol. 35, nr 2
395-402
EN
Laser mass spectrometry is a new chemical trace analysis method with high selectivity, sensitivity and speed. The mass-resolved resonance-enhanced multiphoton ionization (REMPI) spectra of chloroethylenes-trichloroethylene and tetrachloroethylene are firstly reported in the range 305.0-325.0 nm. The mass-resolved excited spectra and laser power index of fragment ions CCl+ are presented. The experimental results indicate that 310.8 nm is the suitable ionization wavelength for detection of trichloroethylene and 322.5 nm for the detection of tetrachloroethylene in this wavelength range. The detection limits of these two chloroethylenes of concentration range expressed in ug/L are presented.
9
The molecular cloning of glial fibrillary acidic protein in Gekko japonicus and its expression changes after spinal cord transection
75%
Gao D. , Wang Y. , Liu Y. , Ding F. , Gu X. , Li Z.
Cellular and Molecular Biology Letters
|
2010
|
tom 15
|
nr 4
EN
The glial fibrillary acidic protein (GFAP) is an astrocyte-specific member of the class III intermediate filament proteins. It is generally used as a specific marker of astrocytes in the central nervous system (CNS). We isolated a GFAP cDNA from the brain and spinal cord cDNA library of Gekko japonicus, and prepared polyclonal antibodies against gecko GFAP to provide useful tools for further immunochemistry studies. Both the real-time quantitative PCR and western blot results revealed that the expression of GFAP in the spinal cord after transection increased, reaching its maximum level after 3 days, and then gradually decreased over the rest of the 2 weeks of the experiment. Immunohistochemical analyses demonstrated that the increase in GFAP-positive labeling was restricted to the white matter rather than the gray matter. In particular, a slight increase in the number of GFAP positive star-shaped astrocytes was detected in the ventral and lateral regions of the white matter. Our results indicate that reactive astrogliosis in the gecko spinal cord took place primarily in the white matter during a short time interval, suggesting that the specific astrogliosis evaluated by GFAP expression might be advantageous in spinal cord regeneration.
10
Comparative transcriptome analysis reveals the responses of winter rye to cold stress
75%
Kong Y. , Zhang T. , Guan Y. , Wang L. , Gu X. , Yang S.
Acta Physiologiae Plantarum
|
2020
|
tom 42
|
nr 05
11
Content available Dynamic test and analysis of strength of bamboo curtain plywood based on free vibration modal method
75%
Gu X. , Zhou A. , Zhang R. , Zhou Y. , Wang Z. , Adjei P.
Drewno. Prace Naukowe. Doniesienia. Komunikaty
|
2023
|
tom 66
|
nr 212
12
Mass spectral analysis of the aged 1,3,5-trimethylbenzene secondary organic aerosol in the presence of ammonium sulfate seeds
63%
Huang M. , Xu J. , Cai S. , Liu X. , Hu C. , Gu X. , Fang L. , Zhang W.
Polish Journal of Environmental Studies
|
2017
|
tom 26
|
nr 4
EN
The ammonium sulfate ((NH₄)₂SO₄) seed aerosols commonly found in the Chinese urban atmosphere could affect the formation and aging of secondary organic aerosols (SOA). Aging of aromatic SOA is performed using UV-irradiation of 1,3,5-trimethylbenzene (135-TMB)/CH₃ONO/NO/air mixtures with high concentrations (~100 μg/m³) of (NH₄)₂SO₄ seeds in the laboratory chamber in this study. The particulate products of SOA were measured using an aerosol laser time-of-flight mass spectrometer (ALTOFMS) in real-time, and fuzzy c-means (FCM) was applied to the mass spectra organic species for clusters. Experimental results indicated that methylglyxoal, 2-methyl-4-oxo-2-pentenal, 4-methyl-1H-imidazole, 4-methyl-imidazole-2-acetaldehyde, and other imidazole derivative compounds are the principal products in the aged particles. Imidazole compounds that can absorb solar radiation effectively were newly detected in the aged 135-TMB SOA with high concentrations of (NH₄)₂SO₄ seed aerosols. These would provide new information for discussing the 135-TMB SOA aging mechanism.
13
Effects of inorganic seed aerosol on the formation of nitrogen-containing organic compounds from reaction of ammonia with photooxidation products of toluene
63%
Xu J. , Huang M. , Feng Z. , Cai S. , Zhao W. , Hu C. , Gu X. , Zhang W.
Polish Journal of Environmental Studies
|
2020
|
tom 29
|
nr 1
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