A desulphurization experimental study under the effects of compounding physical force fields has been described for 〈 0.5 mm fine particles of high sulfur coal. A statistical test using the Box-Behnken Design of expe...A desulphurization experimental study under the effects of compounding physical force fields has been described for 〈 0.5 mm fine particles of high sulfur coal. A statistical test using the Box-Behnken Design of experiments was conducted to evaluate the effects of individual operating variables and their interactions on desulfurization of fine coal using an enhanced centrifugal gravity separator. A model describing the relation between desulphurization efficiency of pyrite sulfur and different operating variables has been designed. The interactions between different factors on the pyrite sulfur desulphurization efficiency have been analysed. The optimal test conditions for desulfarization are extracted from the Design-Expert 6.0 software. Finally, the pointed out. advantage of centrifugal gravity separation for fine coal is pointed out.展开更多
In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite ad...In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite adsorbents loaded with silver nitrate was studied.The test results indicated that the bentonite adsorbents loaded with Ag + ions were effective for adsorbing the alkyl dibenzothiophenes.The crystal structure of bentonite adsorbents was characterized by X-ray diffraction (XRD) and their acidity was measured by Fourier transform infrared (FT-IR) spectroscopy.Several factors influencing the desulfurization capability,including the Ag + loading,the baking temperature,as well as the reaction temperature,were investigated.The desulfurization efficiency was enhanced by increasing the Ag + loading and the best result was obtained at a silver loading of 7 m%.It was found that the adsorption capacity of the alkyl dibenzothiophenes on bentonite loaded with Ag + ions increased with a decreasing temperature.Baking of the adsorbent could also improve the desulfurization capacity,and the optimum baking temperature was 423 K.展开更多
Objective： To evaluate the biomechanicai effect and clinical results of hook screw fixation after direct repair of lumbar spondylous defects in the pars interarticularis. Methods ： L2-L6 spines of 8 fresh-frozen an...Objective： To evaluate the biomechanicai effect and clinical results of hook screw fixation after direct repair of lumbar spondylous defects in the pars interarticularis. Methods ： L2-L6 spines of 8 fresh-frozen and thawed calf cadavers were used for mechanical testing. Bilateral spondylous defects were created in the L4 vertebra. The intervertebrai rotation ranges between L4 and Ls were scanned and computerized in various states of motion, such as flexion/extension, lateral bending and torsional ioadings applied on the intact spine and the spondyious spine when the spondylous spine was fixed with modified Scott＇ s fixation, hook screw fixation and Buck ＇ s fixation sequentially and respectively. Between July 2002 and February 2004, 14 young male patients （aged 15-31 years） suffering from symptomatic lumbar spondyiolysis were treated with TSRH hook screw fixation after direct repair of the defects. MacNab criteria were used to assess their preand post-operative status. Results： Each fixation technique could significantly increase the intervertebral rotational stiffness and made the stiffness return to nearly the intact level. Hook screw technique provided more rotational stability than the others. Hook screw and Buck＇ s techniques provided more flexion/extension stability than modified Scott＇ s technique. Neither complication nor instrumental failure was observed in this study. The mean follow-up period was 21 months. All the patients except one acquired union during the follow-up period. Thirteen patients had a ＂ good ＂ or ＂excellent＂ result according to MacNab criteria. Conclusions ： Hook screw fixation shows biomechanicai advantages and is safe and effective for young patients with lumbar spondyiolysis.展开更多
文摘A desulphurization experimental study under the effects of compounding physical force fields has been described for 〈 0.5 mm fine particles of high sulfur coal. A statistical test using the Box-Behnken Design of experiments was conducted to evaluate the effects of individual operating variables and their interactions on desulfurization of fine coal using an enhanced centrifugal gravity separator. A model describing the relation between desulphurization efficiency of pyrite sulfur and different operating variables has been designed. The interactions between different factors on the pyrite sulfur desulphurization efficiency have been analysed. The optimal test conditions for desulfarization are extracted from the Design-Expert 6.0 software. Finally, the pointed out. advantage of centrifugal gravity separation for fine coal is pointed out.
文摘In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite adsorbents loaded with silver nitrate was studied.The test results indicated that the bentonite adsorbents loaded with Ag + ions were effective for adsorbing the alkyl dibenzothiophenes.The crystal structure of bentonite adsorbents was characterized by X-ray diffraction (XRD) and their acidity was measured by Fourier transform infrared (FT-IR) spectroscopy.Several factors influencing the desulfurization capability,including the Ag + loading,the baking temperature,as well as the reaction temperature,were investigated.The desulfurization efficiency was enhanced by increasing the Ag + loading and the best result was obtained at a silver loading of 7 m%.It was found that the adsorption capacity of the alkyl dibenzothiophenes on bentonite loaded with Ag + ions increased with a decreasing temperature.Baking of the adsorbent could also improve the desulfurization capacity,and the optimum baking temperature was 423 K.
文摘Objective： To evaluate the biomechanicai effect and clinical results of hook screw fixation after direct repair of lumbar spondylous defects in the pars interarticularis. Methods ： L2-L6 spines of 8 fresh-frozen and thawed calf cadavers were used for mechanical testing. Bilateral spondylous defects were created in the L4 vertebra. The intervertebrai rotation ranges between L4 and Ls were scanned and computerized in various states of motion, such as flexion/extension, lateral bending and torsional ioadings applied on the intact spine and the spondyious spine when the spondylous spine was fixed with modified Scott＇ s fixation, hook screw fixation and Buck ＇ s fixation sequentially and respectively. Between July 2002 and February 2004, 14 young male patients （aged 15-31 years） suffering from symptomatic lumbar spondyiolysis were treated with TSRH hook screw fixation after direct repair of the defects. MacNab criteria were used to assess their preand post-operative status. Results： Each fixation technique could significantly increase the intervertebral rotational stiffness and made the stiffness return to nearly the intact level. Hook screw technique provided more rotational stability than the others. Hook screw and Buck＇ s techniques provided more flexion/extension stability than modified Scott＇ s technique. Neither complication nor instrumental failure was observed in this study. The mean follow-up period was 21 months. All the patients except one acquired union during the follow-up period. Thirteen patients had a ＂ good ＂ or ＂excellent＂ result according to MacNab criteria. Conclusions ： Hook screw fixation shows biomechanicai advantages and is safe and effective for young patients with lumbar spondyiolysis.
