Wyniki wyszukiwania - Biblioteka Nauki

1

Characteristic studies of micron zinc particle hydrolysis in a fixed bed reactor

100%

Lv M. , Liu H. , Nie X. , Ashraf M. A.

Polish Maritime Research

|

2015

|

tom S 1

112--120

EN

Zinc fuel is considered as a kind of promising energy sources for marine propeller. As one of the key steps for zinc marine energy power system, zinc hydrolysis process had been studied experimentally in a fixed bed reactor. In this study, we focus on the characteristics of micron zinc particle hydrolysis. The experimental results suggested that the steam inner diffusion is the controlling step of accumulative zinc particles hydrolysis reaction at a relative lower temperature and a relative higher water partial pressure. In other conditions, the chemical reaction kinetics was the controlling step. And two kinds of chemical reaction kinetics appeared in experiments: the surface reaction and the gas-gas reaction. The latter one occurs usually for larger zinc particles and high reaction temperature. Temperature seems to be one of the most important parameters for the dividing of different reaction mechanisms. Several parameters of the hydrolysis process including heating rate, water partial pressure, the particle size and temperature were also studied in this paper. Results show that the initial reaction temperature of zinc hydrolysis in fixed bed is about 410 oC. And the initial reaction temperature increases as the heating rate increases and as the water partial pressure decreases. The total hydrogen yield increases as the heating rate decreases, as the water partial pressure increases, as the zinc particle size decreases, and as the reaction temperature increases. A hydrogen yield of more than 81.5% was obtained in the fixed bed experiments.

2

Characteristic studies of micron zinc particle hydrolysis in a fixed bed reactor

100%

Lv M. , Liu H. , Nie X. , Ashraf M. A.

Polish Maritime Research

|

2015

|

tom 22

|

nr Special Issue S1

EN

Zinc fuel is considered as a kind of promising energy sources for marine propeller. As one of the key steps for zinc marine energy power system, zinc hydrolysis process had been studied experimentally in a fixed bed reactor. In this study, we focus on the characteristics of micron zinc particle hydrolysis. The experimental results suggested that the steam inner diffusion is the controlling step of accumulative zinc particles hydrolysis reaction at a relative lower temperature and a relative higher water partial pressure. In other conditions, the chemical reaction kinetics was the controlling step. And two kinds of chemical reaction kinetics appeared in experiments: the surface reaction and the gas-gas reaction. The latter one occurs usually for larger zinc particles and high reaction temperature. Temperature seems to be one of the most important parameters for the dividing of different reaction mechanisms. Several parameters of the hydrolysis process including heating rate, water partial pressure, the particle size and temperature were also studied in this paper. Results show that the initial reaction temperature of zinc hydrolysis in fixed bed is about 410 oC. And the initial reaction temperature increases as the heating rate increases and as the water partial pressure decreases. The total hydrogen yield increases as the heating rate decreases, as the water partial pressure increases, as the zinc particle size decreases, and as the reaction temperature increases. A hydrogen yield of more than 81.5% was obtained in the fixed bed experiments

3

Human neutrophil peptide 3 could be functionally expressed in Rhodobacter sphaeroides

88%

Nie X. , Zhang L. , Hu Z. , Liu Y. , Zhao Z.

|

2015

|

tom 62

|

nr 2

4

Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

88%

Li X. , Jiang G. , Nie X. , Ma P. , Gao Z.

Autex Research Journal

|

2015

|

tom Vol. 15, no. 3

191--197

EN

This paper introduces a knitting technique for making innovative curved three-dimensional (3D) spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction) were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns), and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

5

Generating Porosity Spectrum of Carbonate Reservoirs using Ultrasonic Imaging Log

75%

Zhang J. , Nie X. , Xiao S. , Zhang C. , Zhang C. , Zhang Z.

Acta Geophysica

|

2018

|

tom Vol. 66, no. 2

191--201

EN

Imaging logging tools can provide us the borehole wall image. The micro-resistivity imaging logging has been used to obtain borehole porosity spectrum. However, the resistivity imaging logging cannot cover the whole borehole wall. In this paper, we propose a method to calculate the porosity spectrum using ultrasonic imaging logging data. Based on the amplitude attenuation equation, we analyze the factors affecting the propagation of wave in drilling fluid and formation and based on the bulk-volume rock model, Wyllie equation and Raymer equation, we establish various conversion models between the reflection coefficient β and porosity φ. Then we use the ultrasonic imaging logging and conventional wireline logging data to calculate the near-borehole formation porosity distribution spectrum. The porosity spectrum result obtained from ultrasonic imaging data is compared with the one from the microresistivity imaging data, and they turn out to be similar, but with discrepancy, which is caused by the borehole coverage and data input difference. We separate the porosity types by performing threshold value segmentation and generate porosity-depth distribution curves by counting with equal depth spacing on the porosity image. The practice result is good and reveals the efficiency of our method.

6

High - grade mutant OmpF induces decreased bacterial survival rate

75%

Zhao Z. , Liu T. , Zhang L. , Luo M. , Nie X. , Li Z. , Pan Y.

|

2014

|

tom 61

|

nr 2

EN

OmpF plays very important roles in the influx of antibiotics and bacterial survival in the presence of antibiotics. However, high-grade mutant OmpF and its function in decreasing bacterial survival rate have not been reported to date. In the present study, we cloned a high-grade mutant OmpF (mOmpF) and sequence analysis suggested that over 45 percent of the DNA sequence was significantly mutated, leading to dramatic changes in over 55 percent of the amino acid sequence. mOmpF protein was successfully expressed. When grown in the presence of antibiotic, the bacterial survival rate decreased and the antibiotic inhibition zone became larger with the increase of the mOmpF. It was concluded that concentration of high-grade mutant mOmpF dramatically influenced the bacterial survival rate. The study presented here may provide insights into better understanding of the relationships between structure and function of OmpF.

7

Interactive effect of radioactive and heavy-metal contamination on soil enzyme activity in a former uranium mine

63%

Yang G. , Dong F. , Liu M. , Nie X. , Zong M. , Peng C. , Chen H. , Wei H. , Wang P. , Zhang W.

|

nr 3

EN

Radioactivity and heavy metal toxicity of multi-metal deposits coexisting with the element uranium (U) could have long-term adverse impacts on soil biological processes and the health of soil ecosystems. Soil enzyme activities are considered bioindicators for assessing soil health. An experiment was designed to investigate invertase and ß-glucosidase activity in multi-metal deposits. Radioactivity and heavy metals were also investigated during this study. Our results showed that the invertase and ß-glucosidase activities were significantly lower in the core mining area than the control area (p<0.05). Activities of the two enzymes decreased with increasing metal concentrations and radioactivity. Cu and Zn showed significant negative effects on ß-glucosidase and invertase activities in a multi-metal deposit at the study site. A significant nonlinear relationship was recorded between soil enzyme activities, radiation dose (R² = 0.71, 0.63; p<0.05), Zn (R² = 0.34, 0.41; p<0.05) and Cu concentrations (R² = 0.46, 0.45; p<0.05). There were turning points at 1 μGy h⁻¹, 250 μg g⁻¹, and 30 μg g⁻¹ for radiation dose, Zn and Cu contents, respectively. The findings could provide more information regarding the toxic effects of radiation and heavy metals on the soil health of multi-metal deposits, which can more precisely guide environmental protection.

8

Reduction and enrichment of uranium after biosorption on inactivated Saccharomyces cerevisiae

63%

Zhang W. , Dong F. , Liu M. , Song H. , Nie X. , Huo T. , Zhao Y. , Wang P. , Qin Y. , Zhou L.

Polish Journal of Environmental Studies

|

2020

|

tom 29

|

nr 2