A novel CVD process for the preparation of ultrafine rhenium powders was investigated using ammonium perrhenate as starting materials. In the process, volatile rhenium oxides, such as ReO4 and Re2O7, were vaporized un...A novel CVD process for the preparation of ultrafine rhenium powders was investigated using ammonium perrhenate as starting materials. In the process, volatile rhenium oxides, such as ReO4 and Re2O7, were vaporized under a controlled oxidizing atmosphere via the pyrolysis of ammonium perrhenate, and carried into reduction zone by carrier gas, and there reduced into rhenium powders by hydrogen gas. Thermodynamic calculations indicated that Re207 could be prevented from further decomposition through controlling the oxygen partial pressure higher than 10 1.248 Pa in the pyrolysis of ammonium perrhenate. This result was further validated via DSC-TGA analysis of ammonium perrhenate. The typical rhenium powders prepared by the CVD method proposed show irregular polyhedron morphology with particle size in the range of 100-800 nm and a Ds0 of 308 nm. The specific surface area and oxygen content were measured to be 4.37 m^2/g and 0.45%, respectively.展开更多
The presented results are related to the leaching of Pb-Zn-Cu-Fe sulphide concentrate, obtained from barite-sulphide ores, under the elevated temperatures and pressures in an autoclave. The leaching process was perfor...The presented results are related to the leaching of Pb-Zn-Cu-Fe sulphide concentrate, obtained from barite-sulphide ores, under the elevated temperatures and pressures in an autoclave. The leaching process was performed using the sulphur acid solution with the oxygen addition for the separation of the targeted metals from the polymetallic concentrate. In this process influences of various parameters were discussed and then correlated to the leached metals, zinc, copper and iron. Zinc, copper and iron were dissolved in a solution, while lead remained as insoluble in the leach residue. The best leaching results were determined under the temperature of 210 ℃ during the 240 min. Obtained leaching degrees were 98% zinc, 95% copper and 96% iron.展开更多
Objective: To study the effect of hyperbaric oxygen (HBO) treatment of severe brain injury. Methods: Fifty-five patients were divided into a treatment group (n=35 receiving HBO therapy) and a control group (n=20 recei...Objective: To study the effect of hyperbaric oxygen (HBO) treatment of severe brain injury. Methods: Fifty-five patients were divided into a treatment group (n=35 receiving HBO therapy) and a control group (n=20 receiving dehydrating, cortical steroid and antibiotic therapy) to observe the alteration of clinic GCS (Glasgow Coma Scale), brain electric activity mapping (BEAM), prognosis and GOS (Glasgow Outcome Scale) before and after hyperbaric oxygen treatment. Results: In the treatment group GCS,BEAM and GOS were improved obviously after 3 courses of treatment, GCS increased from 5.1 to 14.6 (P< 0.01- 0.001),the BEAM abnormal rate reduced from 94.3% to 38% (P< 0.01- 0.001),the GOS good-mild disability rate was 83.7%, and the middle-severe disability rate was 26.3% compared with the control group. There was a statistic significant difference between the two groups (P< 0.01- 0.001). Conclusions: Hyperbaric oxygen treatment could improve obviously GCS, BEAM and GOS of severe brain injury patients, and effectively reduce the mortality and morbidity. It is an effective method to treat severe brain injury.展开更多
Oxygen vacancy（VO） plays a vital role in semiconductor photocatalysis. Rutile TiO2 nanomaterials with controllable contents of VO（0–2.18%） are fabricated via an insitu solid-state chemical reduction strategy, wit...Oxygen vacancy（VO） plays a vital role in semiconductor photocatalysis. Rutile TiO2 nanomaterials with controllable contents of VO（0–2.18%） are fabricated via an insitu solid-state chemical reduction strategy, with color from white to black. The bandgap of the resultant rutile TiO2 is reduced from 3.0 to 2.56 e V, indicating the enhanced visible light absorption. The resultant rutile TiO2 with optimal contents of VO（2.07%） exhibits a high solar-driven photocatalytic hydrogen production rate of 734 μmol h-1, which is about four times as high as that of the pristine one（185 μmol h-1）. The presence of VOelevates the apparent Fermi level of rutile TiO2 and promotes the efficient electronhole separation obviously, which favor the escape of photogenerated electrons and prolong the life-time（7.6×103 ns） of photogenerated charge carriers, confirmed by scanning Kelvin probe microscopy, surface photovoltage spectroscopy and transient-state fluorescence. VO-mediated efficient photogenerated electron-hole separation strategy may provide new insight for fabricating other high-performance semiconductor oxide photocatalysts.展开更多
文摘A novel CVD process for the preparation of ultrafine rhenium powders was investigated using ammonium perrhenate as starting materials. In the process, volatile rhenium oxides, such as ReO4 and Re2O7, were vaporized under a controlled oxidizing atmosphere via the pyrolysis of ammonium perrhenate, and carried into reduction zone by carrier gas, and there reduced into rhenium powders by hydrogen gas. Thermodynamic calculations indicated that Re207 could be prevented from further decomposition through controlling the oxygen partial pressure higher than 10 1.248 Pa in the pyrolysis of ammonium perrhenate. This result was further validated via DSC-TGA analysis of ammonium perrhenate. The typical rhenium powders prepared by the CVD method proposed show irregular polyhedron morphology with particle size in the range of 100-800 nm and a Ds0 of 308 nm. The specific surface area and oxygen content were measured to be 4.37 m^2/g and 0.45%, respectively.
文摘The presented results are related to the leaching of Pb-Zn-Cu-Fe sulphide concentrate, obtained from barite-sulphide ores, under the elevated temperatures and pressures in an autoclave. The leaching process was performed using the sulphur acid solution with the oxygen addition for the separation of the targeted metals from the polymetallic concentrate. In this process influences of various parameters were discussed and then correlated to the leached metals, zinc, copper and iron. Zinc, copper and iron were dissolved in a solution, while lead remained as insoluble in the leach residue. The best leaching results were determined under the temperature of 210 ℃ during the 240 min. Obtained leaching degrees were 98% zinc, 95% copper and 96% iron.
文摘Objective: To study the effect of hyperbaric oxygen (HBO) treatment of severe brain injury. Methods: Fifty-five patients were divided into a treatment group (n=35 receiving HBO therapy) and a control group (n=20 receiving dehydrating, cortical steroid and antibiotic therapy) to observe the alteration of clinic GCS (Glasgow Coma Scale), brain electric activity mapping (BEAM), prognosis and GOS (Glasgow Outcome Scale) before and after hyperbaric oxygen treatment. Results: In the treatment group GCS,BEAM and GOS were improved obviously after 3 courses of treatment, GCS increased from 5.1 to 14.6 (P< 0.01- 0.001),the BEAM abnormal rate reduced from 94.3% to 38% (P< 0.01- 0.001),the GOS good-mild disability rate was 83.7%, and the middle-severe disability rate was 26.3% compared with the control group. There was a statistic significant difference between the two groups (P< 0.01- 0.001). Conclusions: Hyperbaric oxygen treatment could improve obviously GCS, BEAM and GOS of severe brain injury patients, and effectively reduce the mortality and morbidity. It is an effective method to treat severe brain injury.
基金supported by the Key Program Projects of the National Natural Science Foundation of China (21631004)the National Natural Science Foundation of China (51672073)
文摘Oxygen vacancy（VO） plays a vital role in semiconductor photocatalysis. Rutile TiO2 nanomaterials with controllable contents of VO（0–2.18%） are fabricated via an insitu solid-state chemical reduction strategy, with color from white to black. The bandgap of the resultant rutile TiO2 is reduced from 3.0 to 2.56 e V, indicating the enhanced visible light absorption. The resultant rutile TiO2 with optimal contents of VO（2.07%） exhibits a high solar-driven photocatalytic hydrogen production rate of 734 μmol h-1, which is about four times as high as that of the pristine one（185 μmol h-1）. The presence of VOelevates the apparent Fermi level of rutile TiO2 and promotes the efficient electronhole separation obviously, which favor the escape of photogenerated electrons and prolong the life-time（7.6×103 ns） of photogenerated charge carriers, confirmed by scanning Kelvin probe microscopy, surface photovoltage spectroscopy and transient-state fluorescence. VO-mediated efficient photogenerated electron-hole separation strategy may provide new insight for fabricating other high-performance semiconductor oxide photocatalysts.
