Successful recovery of limonite from iron fines was achieved by using flocculation-high intensity magnetic separation (FIMS) and adding hydrolyzed and causticized flocculants according to the characteristic of iron fi...Successful recovery of limonite from iron fines was achieved by using flocculation-high intensity magnetic separation (FIMS) and adding hydrolyzed and causticized flocculants according to the characteristic of iron fines. The separation results of the three iron samples are as follows: iron grade 66.77%67.98% and the recovery of iron 69.26% 70.70%by the FIMS process with flocculants. The comparative results show that under the same separation conditions the FIMS process can effectively increase the recovery of iron by 10.97%15.73%. The flowsheet results confirm the reliability of the process in a SHP high intensity magnetic separator. The concentrate product can be used as raw materials for direct reduction iron-smelting. The hydrolyzed and causticized flocculants can selectively flocculate fine feebly-magnetic iron mineral particles to increase their apparent separation sizes. The larger the separation size, the stronger the magnetic force. By comparing the separation results of the three samples it is found that amongthe three samples the higher the limonite content, the better the separation result. This means that the separation result relates closely to the flocculation process and the adding pattern of the flocculant.展开更多
Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent p...Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is a common cancer in women. HIFU therapy, in combination with other therapies, has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Currently, HIFU therapy is not commonly used in breast cancer treatment, and efforts to promote the application of HIFU is expected. In this article, we compare different image-guided models for HIFU and reviewed the status, drawbacks, and potential of HIFU therapy for breast cancer.展开更多
The effects of separation time and magnetic induction intensity on the separation efficiency of alumina particles with diameters varying from 30 to 200 μm in aluminum melt were investigated. The experimental results ...The effects of separation time and magnetic induction intensity on the separation efficiency of alumina particles with diameters varying from 30 to 200 μm in aluminum melt were investigated. The experimental results show that the particle-accumulated layer is formed in the periphery of the solidified specimen when the diameter of the separated molten metal, the magnetic induction intensity and the separation time are 10 mm, 0.04 T and 1 s, respectively. When the separation time is 2 s, the particle-accumulated layer can be observed obviously and the separation efficiency is about 80%. There are few alumina particles in the inner of the solidified specimen when the separation time is 3 s. The separation efficiency higher than 85% can be achieved when the separation time is longer than 3 s. When the magnetic induction intensity is 0.06 T, the visible particle-accumulated layer can be formed in 1 s and the separation efficiency is higher than 95%. The experimental results were compared with the calculated results at last.展开更多
The removal of phosphate from municipal sewage by high gradient magnetic separation using aluminium sulphate as precipitating agent and Fe3O4 as seeding material was studied. The effects of aluminium sulphate, Fe3O4, ...The removal of phosphate from municipal sewage by high gradient magnetic separation using aluminium sulphate as precipitating agent and Fe3O4 as seeding material was studied. The effects of aluminium sulphate, Fe3O4, magnetic field intensity, pH value and flow-rate of sewage on phosphorus removal rate were investigated. The results show that addition of 200 mg/L Al2(SO4)3·18H2O and 300 mg/L Fe3O4, magnetic field intensity of 200 kA/m, pH value of 4.57.0 and flow-rate of 6.15 cm/s are both efficient and economic technical parameters for removal of phosphate. The pH value has a tremendous effect on the removal of phosphate. In the pH range of (4.5)7.0, more than 95% phosphate can be removed. Theoretical analysis indicates that the solubility of AlPO4 is minimum at pH 4.07.0 and the electrostatic attractive force between AlPO4 and Fe3O4 is maximum at pH 4.5(6.5.)展开更多
AIM: To use magnetic resonance-guided high intensity focused ultrasound(MRg-HIFU), magnetic resonance imaging(MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue. ME...AIM: To use magnetic resonance-guided high intensity focused ultrasound(MRg-HIFU), magnetic resonance imaging(MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue. METHODS: Six anesthetized/mechanically-ventilated pigs underwent single/double renal sonication(n = 24) using a 3T-MRg-HIFU(1.1 MHz frequency and 3000J-4400 J energies). T2-weighted fast spin echo(T2-W), perfusion saturation recovery gradient echo and contrast enhanced(CE) T1-weighted(T1-W) sequences were used for treatment planning, temperature monitoring, lesion visualization, characterization and quantification, respectively. Histopathology was conducted in excised kidneys to quantify and characterize cellular and vascular changes. Paired Student's t-test was used and a P-value < 0.05 was considered statistically significant.RESULTS: Ablated renal parenchyma could not be differentiated from normal parenchyma on T2-W or nonCE T1-W sequences. Ablated renal lesions were visible as hypoenhanced regions on perfusion and CE T1-W MRI sequences, suggesting perfusion deficits and necrosis. Volumes of ablated parenchyma on CE T1-W images invivo(0.12-0.36 cm3 for single sonication 3000 J, 0.50-0.84 cm3, for double 3000 J, 0.75-0.78 cm3 for single 4400 J and 0.12-2.65 cm3 for double 4400J) and at postmortem(0.23-0.52 cm3, 0.25-0.82 cm3, 0.45-0.68 cm3 and 0.29-1.80 cm3, respectively) were comparable. The ablated volumes on 3000 J and 4400 J double sonication were significantly larger than single(P < 0.01), thus, the volume and depth of ablated tissue depends on the applied energy and number of sonication. Macroscopic and microscopic examinations confirmed the locations and presence of coagulation necrosis, vascular damage and interstitial hemorrhage, respectively.CONCLUSION: Contrast enhanced MRI provides assessment of MRg-HIFU renal ablation. Histopathology demonstrated coagulation necrosis, vascular damage and confirmed the volume of damage seen on MRI.展开更多
A new method-dry High Gradient Magnetic Separation (HGMS)-to remove iron from ultrafine kaolin powder is described. A new kind of disperser, which breaks down the particle clusters in the powder by high speed gas fl...A new method-dry High Gradient Magnetic Separation (HGMS)-to remove iron from ultrafine kaolin powder is described. A new kind of disperser, which breaks down the particle clusters in the powder by high speed gas flow from an air compressor, is used to completely disperse the powders. The dispersed particles are passed through vibrating HGMS by a vacuum pump to remove the iron. The magnetic and nonmagnetic fractions are separately collected by cloth collectors. Dry HGMS laboratory experiments are carried out. A product containing 0.90% Fe<sub>2</sub>O<sub>3</sub> was obtained, and the recovery was 70%.展开更多
The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotech...The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotechnical sector. This technique has some advantages especially for the recycling of immobilized enzymes. A new magnetic filter with sight glasses was constructed and produced to study the performance of high-gradient magnetic separation at varied parameters. By optical analysis the buildup of a clogging was identified as the major parameter which affected the separation performance. For the cleaning procedure, a two-phase flow of water with highly dispersed air bubbles was tested which led to a nearly complete cleaning of the filter chamber.展开更多
The introduction of functionalized magnetizable particles for the purification of enzymes or for the multi-use of pre-immobilized biocatalysts offers a great potential for time and cost savings in biotechnological pro...The introduction of functionalized magnetizable particles for the purification of enzymes or for the multi-use of pre-immobilized biocatalysts offers a great potential for time and cost savings in biotechnological process design. The selective separation of the magnetizable particles is performed for example by a high-gradient magnetic separator. In this study FEM and CFD simulations of the magnetic field and the fluid flow field within a filter chamber of a magnetic separator were carried out, to find an optimal separator design. The motion of virtual magnetizable particles was calculated with a one-way coupled Lagrangian approach in order to test many geometric and parametric variations in reduced time. It was found that a flow homogenisator smoothed the fluid flow, so that the linear velocity became nearly equal over the cross section in the direction of flow. Furthermore the retention of magnetizable particles increases with a high total edge length within the filter matrix.展开更多
To achieve the utilization of the abandoned ultrafine ilmenite(-20 μm) produced in the titanium magnetite processing plant in Panzhihua,the superconducting high-gradient magnetic separation(SMS) technology was propos...To achieve the utilization of the abandoned ultrafine ilmenite(-20 μm) produced in the titanium magnetite processing plant in Panzhihua,the superconducting high-gradient magnetic separation(SMS) technology was proposed in this study.After optimizing the conditions of magnetic intensity,feeding and pulsation,an SMS concentrate with TiO_(2) grade of 16.03% and TiO_(2) recovery of 66.39% was obtained through one roughing-one cleaning pre-concentration flowsheet.The specific magnetic force and magnetic force were calculated and analysed to illustrate the pre-concentration mechanism,and the results revealed that the combination of high magnetic field and strong pulsating resulted in the effective preconcentration of the ultrafine ilmenite in the SMS process.In addition,the magnetic force analysis indicated that the high magnetic intensity and high magnetic gradient are the key factors of the SMS technology.Furthermore,the EDS-Mapping detection certified that the ultrafine ilmenite was concentrated from the gangue minerals using SMS technology.展开更多
A new permanent magnetic separator was introduced to treat the ores with the characteristics of weak magnetic iron minerals and in a fine size range. The new machine was applied to the iron removal from potash feldspa...A new permanent magnetic separator was introduced to treat the ores with the characteristics of weak magnetic iron minerals and in a fine size range. The new machine was applied to the iron removal from potash feldspar. The effects of the magnetic field intensity, pulp density and grinding fineness on the iron removal were investigated. The optimized operation parameters were achieved and listed as follows: the -0.074 mm content is 85%, the pulp density is 45% and the magnetic field strength is 2T. A close test of middles regrinding was also carried out to improve concentrate yield. The data show that the grade of TFe(total iron) in potash feldspar product decreased from 1.31% to 0.21% and the concentrate yield reached 85.32%. All the results indicated that the traditonal high-intensity electromagnetic separators can be betterly substituted by the new permanent magnetic separator. This study may provide the theoretical evidence for iron removal from potash feldspar.展开更多
After interface layer was simulated by the magnetic nano-particles in the egg white phantom, high intensity focused ultrasound (HIFU) at the same dosage was introduced to radiate the phantom in different depths to blo...After interface layer was simulated by the magnetic nano-particles in the egg white phantom, high intensity focused ultrasound (HIFU) at the same dosage was introduced to radiate the phantom in different depths to blow the acoustic interface layer to mimic "point" exposure. The results showed that the volumes of biological focal region (BFR) were enlarged when the acoustic focal region (AFR) is close with interface layer. This meant that the magnetic nano-particles enhanced the therapeutic efficiency of HIFU. When the distance of the AFR from the interface layer was 10 mm, the size and shape of the BFR were similar with those of the control group, but a larger lesion at the interface, which was harmful for treatment, was observed. When the distance of the AFR to the interface layer increased to 30 mm, the size and shape of the BFR were also similar to those of the control group. When the thickness of the interface layer diminished, the utility of enhancement decreased. Continuous increase of the safe area for treatment and decrease of the utility of enhancement were observed along with the abatement of the thickness of the interface展开更多
The section shape of an assembled magnetic medium is the most important structural parameter of a high gradient magnetic separator, which directly affects the induction distribution and magnetic field gradient of the ...The section shape of an assembled magnetic medium is the most important structural parameter of a high gradient magnetic separator, which directly affects the induction distribution and magnetic field gradient of the magnetic separator. In this study, equilateral triangle, square, hexagonal, octagon, dodecagon, and round shape sections of the assembled magnetic medium are chosen to study their influence on magnetic field distribution characteristics using the ANSYS analysis. This paper utilizes a single assembled magnetic medium to understand the relationship between the geometry of the assembled magnetic medium and its magnetic field distribution characteristics. The results show that high magnetic field,regional field, magnetic field gradient, and magnetic force formed by the different sections of the assembled magnetic medium in the same background magnetic field reduce in turn based on the triangle,square, hexagonal, octagon, dodecagon, and round. Based on the magnetic field characteristics analytic results, the magnetic separation tests of the ilmenite are carried out. The results indicate that the section shape of the toothed plate compared with the section shape of cylinder can improve the recovery of ilmenite up to 45% in the same magnetizing current condition of 2A, which is consistent with magnetic field characteristics analysis of different assembled magnetic medium section shapes.展开更多
Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) has become an established part of neuroimaging and is used to diagnose and characterize several neurologic disorders. Intracerebral Haemorrhage (ICH) is a severe ...Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) has become an established part of neuroimaging and is used to diagnose and characterize several neurologic disorders. Intracerebral Haemorrhage (ICH) is a severe medical condition, which may develop quickly into a life-threatening situation, and thereby requires prompt medical attention. Early and reliable identification of the age of haemorrhage is essential when choosing the correct treatment, and estimating patient’s diagnosis and outcome. Diffusion Weighted (DW) images presents a variation in the image signal intensity characteristics relative to the different stages of ICH. In the present paper, an effort is made to document the variation in the image signal intensity characteristics of ICH at evolving stages, for 30 subjects, using High Frequency Power (HFP) parameter. Results showed that the difference in the HFP values on DW images for the subjects with ICH com- pared to their contralateral normal hemisphere, were highly significant (p 14 days). There was a negative correlation (r = ?0.81) observed between the RHFP values and the evolving stages of ICH. The results indicate that the quantitative changes in the RHFP values can be assessed to derive information about the stage of ICH, and their adoption in clinical diagnosis and treatment could be helpful and informative.展开更多
Scandium (Sc) concentration from the rare earth ore by high gradient magnetic separation (HGMS) was determined on the basis of Sc content, geophysical parameter determination and the magnetic analyses of the ore. Base...Scandium (Sc) concentration from the rare earth ore by high gradient magnetic separation (HGMS) was determined on the basis of Sc content, geophysical parameter determination and the magnetic analyses of the ore. Based on the condition experiments, expanding experiments were carried out. The results showed that the ore had a Sc grade of 48.90 g/t, and after removing iron by low-intensity magnetic separation, a Sc concentrate of 314.89 g/t grade and with 77.53% recovery was obtained by one-stage roughing-one...展开更多
文摘Successful recovery of limonite from iron fines was achieved by using flocculation-high intensity magnetic separation (FIMS) and adding hydrolyzed and causticized flocculants according to the characteristic of iron fines. The separation results of the three iron samples are as follows: iron grade 66.77%67.98% and the recovery of iron 69.26% 70.70%by the FIMS process with flocculants. The comparative results show that under the same separation conditions the FIMS process can effectively increase the recovery of iron by 10.97%15.73%. The flowsheet results confirm the reliability of the process in a SHP high intensity magnetic separator. The concentrate product can be used as raw materials for direct reduction iron-smelting. The hydrolyzed and causticized flocculants can selectively flocculate fine feebly-magnetic iron mineral particles to increase their apparent separation sizes. The larger the separation size, the stronger the magnetic force. By comparing the separation results of the three samples it is found that amongthe three samples the higher the limonite content, the better the separation result. This means that the separation result relates closely to the flocculation process and the adding pattern of the flocculant.
文摘Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is a common cancer in women. HIFU therapy, in combination with other therapies, has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Currently, HIFU therapy is not commonly used in breast cancer treatment, and efforts to promote the application of HIFU is expected. In this article, we compare different image-guided models for HIFU and reviewed the status, drawbacks, and potential of HIFU therapy for breast cancer.
基金Projects(50474055, 50274018) supported by the National Natural Science Foundation of ChinaProject (20052176) supported by the Natural Science Foundation of Liaoning Province, China
文摘The effects of separation time and magnetic induction intensity on the separation efficiency of alumina particles with diameters varying from 30 to 200 μm in aluminum melt were investigated. The experimental results show that the particle-accumulated layer is formed in the periphery of the solidified specimen when the diameter of the separated molten metal, the magnetic induction intensity and the separation time are 10 mm, 0.04 T and 1 s, respectively. When the separation time is 2 s, the particle-accumulated layer can be observed obviously and the separation efficiency is about 80%. There are few alumina particles in the inner of the solidified specimen when the separation time is 3 s. The separation efficiency higher than 85% can be achieved when the separation time is longer than 3 s. When the magnetic induction intensity is 0.06 T, the visible particle-accumulated layer can be formed in 1 s and the separation efficiency is higher than 95%. The experimental results were compared with the calculated results at last.
文摘The removal of phosphate from municipal sewage by high gradient magnetic separation using aluminium sulphate as precipitating agent and Fe3O4 as seeding material was studied. The effects of aluminium sulphate, Fe3O4, magnetic field intensity, pH value and flow-rate of sewage on phosphorus removal rate were investigated. The results show that addition of 200 mg/L Al2(SO4)3·18H2O and 300 mg/L Fe3O4, magnetic field intensity of 200 kA/m, pH value of 4.57.0 and flow-rate of 6.15 cm/s are both efficient and economic technical parameters for removal of phosphate. The pH value has a tremendous effect on the removal of phosphate. In the pH range of (4.5)7.0, more than 95% phosphate can be removed. Theoretical analysis indicates that the solubility of AlPO4 is minimum at pH 4.07.0 and the electrostatic attractive force between AlPO4 and Fe3O4 is maximum at pH 4.5(6.5.)
文摘AIM: To use magnetic resonance-guided high intensity focused ultrasound(MRg-HIFU), magnetic resonance imaging(MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue. METHODS: Six anesthetized/mechanically-ventilated pigs underwent single/double renal sonication(n = 24) using a 3T-MRg-HIFU(1.1 MHz frequency and 3000J-4400 J energies). T2-weighted fast spin echo(T2-W), perfusion saturation recovery gradient echo and contrast enhanced(CE) T1-weighted(T1-W) sequences were used for treatment planning, temperature monitoring, lesion visualization, characterization and quantification, respectively. Histopathology was conducted in excised kidneys to quantify and characterize cellular and vascular changes. Paired Student's t-test was used and a P-value < 0.05 was considered statistically significant.RESULTS: Ablated renal parenchyma could not be differentiated from normal parenchyma on T2-W or nonCE T1-W sequences. Ablated renal lesions were visible as hypoenhanced regions on perfusion and CE T1-W MRI sequences, suggesting perfusion deficits and necrosis. Volumes of ablated parenchyma on CE T1-W images invivo(0.12-0.36 cm3 for single sonication 3000 J, 0.50-0.84 cm3, for double 3000 J, 0.75-0.78 cm3 for single 4400 J and 0.12-2.65 cm3 for double 4400J) and at postmortem(0.23-0.52 cm3, 0.25-0.82 cm3, 0.45-0.68 cm3 and 0.29-1.80 cm3, respectively) were comparable. The ablated volumes on 3000 J and 4400 J double sonication were significantly larger than single(P < 0.01), thus, the volume and depth of ablated tissue depends on the applied energy and number of sonication. Macroscopic and microscopic examinations confirmed the locations and presence of coagulation necrosis, vascular damage and interstitial hemorrhage, respectively.CONCLUSION: Contrast enhanced MRI provides assessment of MRg-HIFU renal ablation. Histopathology demonstrated coagulation necrosis, vascular damage and confirmed the volume of damage seen on MRI.
基金The project was financially supported by China National Science and Technology Committee
文摘A new method-dry High Gradient Magnetic Separation (HGMS)-to remove iron from ultrafine kaolin powder is described. A new kind of disperser, which breaks down the particle clusters in the powder by high speed gas flow from an air compressor, is used to completely disperse the powders. The dispersed particles are passed through vibrating HGMS by a vacuum pump to remove the iron. The magnetic and nonmagnetic fractions are separately collected by cloth collectors. Dry HGMS laboratory experiments are carried out. A product containing 0.90% Fe<sub>2</sub>O<sub>3</sub> was obtained, and the recovery was 70%.
文摘The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotechnical sector. This technique has some advantages especially for the recycling of immobilized enzymes. A new magnetic filter with sight glasses was constructed and produced to study the performance of high-gradient magnetic separation at varied parameters. By optical analysis the buildup of a clogging was identified as the major parameter which affected the separation performance. For the cleaning procedure, a two-phase flow of water with highly dispersed air bubbles was tested which led to a nearly complete cleaning of the filter chamber.
文摘The introduction of functionalized magnetizable particles for the purification of enzymes or for the multi-use of pre-immobilized biocatalysts offers a great potential for time and cost savings in biotechnological process design. The selective separation of the magnetizable particles is performed for example by a high-gradient magnetic separator. In this study FEM and CFD simulations of the magnetic field and the fluid flow field within a filter chamber of a magnetic separator were carried out, to find an optimal separator design. The motion of virtual magnetizable particles was calculated with a one-way coupled Lagrangian approach in order to test many geometric and parametric variations in reduced time. It was found that a flow homogenisator smoothed the fluid flow, so that the linear velocity became nearly equal over the cross section in the direction of flow. Furthermore the retention of magnetizable particles increases with a high total edge length within the filter matrix.
基金financial support from the Joint Fund (Key program U2067201) for Nuclear Technology Innovation Sponsored by the National Natural Science Foundation of China and the China National Nuclear CorporationNational key research and development program (2019YFC1907702) Sponsored by MOSTthe Fundamental Research Funds for the Central Universities (N2001013) for supporting this research。
文摘To achieve the utilization of the abandoned ultrafine ilmenite(-20 μm) produced in the titanium magnetite processing plant in Panzhihua,the superconducting high-gradient magnetic separation(SMS) technology was proposed in this study.After optimizing the conditions of magnetic intensity,feeding and pulsation,an SMS concentrate with TiO_(2) grade of 16.03% and TiO_(2) recovery of 66.39% was obtained through one roughing-one cleaning pre-concentration flowsheet.The specific magnetic force and magnetic force were calculated and analysed to illustrate the pre-concentration mechanism,and the results revealed that the combination of high magnetic field and strong pulsating resulted in the effective preconcentration of the ultrafine ilmenite in the SMS process.In addition,the magnetic force analysis indicated that the high magnetic intensity and high magnetic gradient are the key factors of the SMS technology.Furthermore,the EDS-Mapping detection certified that the ultrafine ilmenite was concentrated from the gangue minerals using SMS technology.
基金Funded by the National High-tech R&D Program of China(No.2007AA06Z123)the Hubei Provincial Key Laboratory of Pollutant Analysis and Recycling Project(KY2010G19)the Independent Innovation Research Fund of Wuhan University of Technology(2010-YB-16)
文摘A new permanent magnetic separator was introduced to treat the ores with the characteristics of weak magnetic iron minerals and in a fine size range. The new machine was applied to the iron removal from potash feldspar. The effects of the magnetic field intensity, pulp density and grinding fineness on the iron removal were investigated. The optimized operation parameters were achieved and listed as follows: the -0.074 mm content is 85%, the pulp density is 45% and the magnetic field strength is 2T. A close test of middles regrinding was also carried out to improve concentrate yield. The data show that the grade of TFe(total iron) in potash feldspar product decreased from 1.31% to 0.21% and the concentrate yield reached 85.32%. All the results indicated that the traditonal high-intensity electromagnetic separators can be betterly substituted by the new permanent magnetic separator. This study may provide the theoretical evidence for iron removal from potash feldspar.
基金the Development Plan for Innovation Teams of Ministry of Education (2005-33)the National Natural Science Foundation of China (30471653)the Natural Science Foundation of Chongqing (2006BA5020)
文摘After interface layer was simulated by the magnetic nano-particles in the egg white phantom, high intensity focused ultrasound (HIFU) at the same dosage was introduced to radiate the phantom in different depths to blow the acoustic interface layer to mimic "point" exposure. The results showed that the volumes of biological focal region (BFR) were enlarged when the acoustic focal region (AFR) is close with interface layer. This meant that the magnetic nano-particles enhanced the therapeutic efficiency of HIFU. When the distance of the AFR from the interface layer was 10 mm, the size and shape of the BFR were similar with those of the control group, but a larger lesion at the interface, which was harmful for treatment, was observed. When the distance of the AFR to the interface layer increased to 30 mm, the size and shape of the BFR were also similar to those of the control group. When the thickness of the interface layer diminished, the utility of enhancement decreased. Continuous increase of the safe area for treatment and decrease of the utility of enhancement were observed along with the abatement of the thickness of the interface
基金provided by the Postdoctoral Science Foundation of China(No.2013M542076)the self-determined and innovative research funds of WUT(No.2014-IV-069)the Ministry of Science and Technology of China(No.2011BAB05B01)
文摘The section shape of an assembled magnetic medium is the most important structural parameter of a high gradient magnetic separator, which directly affects the induction distribution and magnetic field gradient of the magnetic separator. In this study, equilateral triangle, square, hexagonal, octagon, dodecagon, and round shape sections of the assembled magnetic medium are chosen to study their influence on magnetic field distribution characteristics using the ANSYS analysis. This paper utilizes a single assembled magnetic medium to understand the relationship between the geometry of the assembled magnetic medium and its magnetic field distribution characteristics. The results show that high magnetic field,regional field, magnetic field gradient, and magnetic force formed by the different sections of the assembled magnetic medium in the same background magnetic field reduce in turn based on the triangle,square, hexagonal, octagon, dodecagon, and round. Based on the magnetic field characteristics analytic results, the magnetic separation tests of the ilmenite are carried out. The results indicate that the section shape of the toothed plate compared with the section shape of cylinder can improve the recovery of ilmenite up to 45% in the same magnetizing current condition of 2A, which is consistent with magnetic field characteristics analysis of different assembled magnetic medium section shapes.
文摘Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) has become an established part of neuroimaging and is used to diagnose and characterize several neurologic disorders. Intracerebral Haemorrhage (ICH) is a severe medical condition, which may develop quickly into a life-threatening situation, and thereby requires prompt medical attention. Early and reliable identification of the age of haemorrhage is essential when choosing the correct treatment, and estimating patient’s diagnosis and outcome. Diffusion Weighted (DW) images presents a variation in the image signal intensity characteristics relative to the different stages of ICH. In the present paper, an effort is made to document the variation in the image signal intensity characteristics of ICH at evolving stages, for 30 subjects, using High Frequency Power (HFP) parameter. Results showed that the difference in the HFP values on DW images for the subjects with ICH com- pared to their contralateral normal hemisphere, were highly significant (p 14 days). There was a negative correlation (r = ?0.81) observed between the RHFP values and the evolving stages of ICH. The results indicate that the quantitative changes in the RHFP values can be assessed to derive information about the stage of ICH, and their adoption in clinical diagnosis and treatment could be helpful and informative.
文摘Scandium (Sc) concentration from the rare earth ore by high gradient magnetic separation (HGMS) was determined on the basis of Sc content, geophysical parameter determination and the magnetic analyses of the ore. Based on the condition experiments, expanding experiments were carried out. The results showed that the ore had a Sc grade of 48.90 g/t, and after removing iron by low-intensity magnetic separation, a Sc concentrate of 314.89 g/t grade and with 77.53% recovery was obtained by one-stage roughing-one...