The phase transformation of galena in H_(2)SO_(4)-Fe_(2)(SO_(4))_(3) system under oxygen pressure was investigated.Results indicated that the critical conditions for the phase transformation of galena into lead jarosi...The phase transformation of galena in H_(2)SO_(4)-Fe_(2)(SO_(4))_(3) system under oxygen pressure was investigated.Results indicated that the critical conditions for the phase transformation of galena into lead jarosite(Pb-J)were 130℃,30 g/L H_(2)SO_(4),15 g/L Fe^(3+),and an oxygen partial pressure of 0.4 MPa.Furthermore,increased Fe^(3+)concentration and oxygen partial pressure did not enhance jarosite formation.Conversely,lowering the temperature and increasing the H_(2)SO_(4) concentration facilitated PbSO_(4) formation and inhibited its further conversion to Pb-J.Additionally,the effects of potassium sulfate,sodium sulfate,and high concentrations of zinc sulfate on the phase transformation of galena were examined through leaching tests,XRD,SEM-EDS,and FT-IR analyses.All three sulfates inhibited the conversion of galena to Pb-J.Among these,potassium sulfate prevented Pb-J formation and converted it more thoroughly into potassium jarosite.However,high concentrations of zinc sulfate facilitated the crystallization of both PbSO_(4) and Pb-J,which altered the morphology of the product.Zinc ions coprecipitated with Pb-J,thereby integrating into the product.展开更多
The variation of the O_(2) content in the suction gas,in the range from 7 to 30 vol.%,during the iron ore sintering process,is investigated.Miniaturized laboratory-scale sintering experiments are carried out using an ...The variation of the O_(2) content in the suction gas,in the range from 7 to 30 vol.%,during the iron ore sintering process,is investigated.Miniaturized laboratory-scale sintering experiments are carried out using an industry-like raw mixture to study the effects of O_(2) variation on the sintering process with particular emphasis on the off-gas composition,specific sintering parameters and the sinter strength as well as the chemical composition of the sinter.After the ignition at the bed surface,the gas hood is placed on the sintering column,allowing a synthetic gas mixture to be drawn through the sinter bed until the burn-through point is reached.For additional interpretation of the experimental results,the theoretical coke combustion rate as a function of the oxygen partial pressure was calculated and plotted against the experimentally measured peak temperature in the sinter bed of the respective sinter series.An increasing O_(2) content in the suction gas results in a faster flame front speed combined with a more gradual temperature rise of the heat wave and longer dwell time in the melt phase formation temperature range.Due to the more pronounced flame front,both sinter yield and strength increase,resulting in lower return rates.Below 12 vol.%O_(2),a sharp decrease in sinter yield and strength can be observed,probably due to the low extent of melt phase formation and the associated minor formation of silico ferrite of calcium and aluminum(SFCA).The carbon burnout as well as the calcination increases with increasing the O_(2) content in the suction gas,resulting in higher levels of CO_(2) in the off-gas,with more or less constant amounts of CO above 15 vol.%O_(2).The amounts of NO and SO_(2) show a similar trend with a continuous increase with increasing O_(2) supply,with the SO_(2) breakthrough starting earlier and being released over a shorter period.The chemical analysis of the sinter indicates the highest Fe(II)values in the range of 12–21 vol.%O_(2) in the suction gas.展开更多
The co-oxidation of As(Ⅲ) and Fe(Ⅱ) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150℃. It was confirmed that without Fe(Ⅱ) ions, As(Ⅲ) i...The co-oxidation of As(Ⅲ) and Fe(Ⅱ) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150℃. It was confirmed that without Fe(Ⅱ) ions, As(Ⅲ) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200℃ and an oxygen pressure up to 2.0 MPa. Fe(Ⅱ) ions in the solutions did have a catalysis effect on the oxidation of As(Ⅲ), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH ) and Fe(Ⅳ) in the oxidation process of Fe(Ⅱ). The effects of such factors as the initial molar ratio of Fe(Ⅱ)/As(Ⅲ), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(Ⅲ) and Fe(Ⅱ) were studied. It was found that the oxidation of As(Ⅲ) was limited in the co-oxidation process due to the accumulation of the As(Ⅲ) oxidation product, As(Ⅴ), in the solutions.展开更多
Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various det...Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various determination methods. The effects of leaching time,leaching temperature,leaching agent concentration,leaching L/S ratio,granularity of material,additive consumption were investigated based on the mineralogy.The results show that under the conditions of leaching time of 3-4 h, temperature of 150℃,sulfuric acid consumption of 25%?30%,ratio of liquid to solid of 1.2:1,the granularity less than 0.074 mm, additive consumption of 3%-5%,and oxygen pressure of 1.2 MPa,and the vanadium leaching rate can be more than 92%by the method of two-step pressurized acid leaching.The powdery V2O5 product with 99.52%in V2O5 content is obtained by the flowsheet of acid recovery,removing iron by reduction process,solvent extraction,precipitating vanadium with ammonium water,and pyrolysis from the stone-coal oxygen pressure acid-leaching solution.The total recovery efficiency of vanadium is above 85%,which is more than 20%higher than that obtained in the conventional process.Furthermore,the new process does not cause air pollution since no HCl or Cl2 is released by calcination of the raw material.展开更多
AIM： To study the effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome, METHODS： Garlic powder in a capsule form was given to 15 children with hepatopulmonary syndrome （confir...AIM： To study the effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome, METHODS： Garlic powder in a capsule form was given to 15 children with hepatopulmonary syndrome （confirmed by contrast echocardiography） at the dosage of 1 g/1.73 m^2 per day. Patients were evaluated clinically and by arterial blood gas every four weeks. RESULTS： The garlic capsule was administered to 15 patients with hepatopulmonary syndrome. There were 10 boys and 5 girls with a mean age of 9.4 ± 3.9 years. The underlying problems were biliary tract atresia （4 patients）, autoimmune hepatitis （4 patients）, cryptogenic cirrhosis （4 patients） and presinusoidal portal hypertension （3 patients）. Eight patients （53.3%） showed an increase of 10 mmHg in their mean arterial oxygen pressure. The baseline PaO2 was 65.6 ± 12.1 mmHg in the responder group and 47.1 ± 11.2 mmHg in nonresponder group. At the end of treatment the mean PaO2 in responders and non-responders was 92.2 ± 7.75 mmHg and 47.5 ± 11.87 mmHg, respectively （P 〈 0.01）. CONCLUSION： Garlic may increase oxygenation and improve dyspnea in children with hepatopulmonary syndrome.展开更多
N-doped ZnO films were radio frequency(RF)sputtered on glass substrates and studied as a function of oxygen partial pressure(OPP)ranging from 3.0×10-4 to 9.5×10-3 Pa.X-ray diffraction patters confirmed the p...N-doped ZnO films were radio frequency(RF)sputtered on glass substrates and studied as a function of oxygen partial pressure(OPP)ranging from 3.0×10-4 to 9.5×10-3 Pa.X-ray diffraction patters confirmed the polycrystalline nature of the deposited films.The crystalline structure is influenced by the variation of OPP.Atomic force microscopy analysis confirmed the agglomeration of the neighboring spherical grains with a sharp increase of root mean square(RMS)roughness when the OPP is increased above 1.4×10-3 Pa.X-ray photoelectron spectroscopy analysis revealed that the incorporation of N content into the film is decreased with the increase of OPP,noticeably N 1s XPS peaks are hardly identified at 9.5×10-3 Pa.The average visible transmittance(380-700 nm) is increased with the increase of OPP(from～17%to 70%),and the optical absorption edge shifts towards the shorter wavelength.The films deposited with low OPP(≤3.0×10-4 Pa)show n-type conductivity and those deposited with high OPP(≥9.0×10-4 Pa)are highly resistive(>105Ω·cm)展开更多
Zinc concentrate with high gallium content is one of the main resources of gallium.The gallium presents in the form of isomorphism in tetrahedron coordination with sulfur in sphalerite.The research was to investigate ...Zinc concentrate with high gallium content is one of the main resources of gallium.The gallium presents in the form of isomorphism in tetrahedron coordination with sulfur in sphalerite.The research was to investigate the amenability of zinc concentrate with high gallium to pressure oxygen leaching.The particle size,sulfuric acid concentration,oxygen partial pressure,additive amount,and time of reaction were studied.The extraction yields of gallium and zinc are 86%and 98%,respectively.The optimal condition is 100 g of zinc concentrate with particle size smaller than 38 lm,sulfuric acid concentration150 g L-1,leaching temperature 150℃,leaching time120 min,oxygen partial pressure 0.7 MPa,additive amount of 0.2 wt%.展开更多
The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treat...The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treatment of tetrahedrite was rarely studied,and most of silver occurred in themineral too.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Under these parameters,the result of pilot scale test showed that the leaching percentages of copper and zinc were separately as high as 98.9 wt.% and 94.9 wt.%,while lead and silver were transformed into sulfate and sulfide precipitations,respectively.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by carbonate transformation-silicofluoric acid leaching and thiourea leaching.展开更多
PolycrystaUine SnO2 thin films were deposited on sapphire substrates at 450℃ under different ambient oxygen pressures by pulsed laser deposition technique. The effect of ambient oxygen pressure on the structural, opt...PolycrystaUine SnO2 thin films were deposited on sapphire substrates at 450℃ under different ambient oxygen pressures by pulsed laser deposition technique. The effect of ambient oxygen pressure on the structural, optical and electrical properties of SnO2 thin films was studied. X-my diffraction and Hall measurements show that increasing the ambient oxygen pressure can improve crystallization of the films and decrease resistivity of the films. A violet emission peak centered at 409 nm was observed from photoluminescence measurements for SnO2 films under deposition ambient oxygen pressure above 5 Pa, which is related to the improvement of crystalline of the films.展开更多
An oxygen pressure leaching-flotation joint process was proposed to treat Jinbaoshan platinum group minerals to produce a desired concentrate.The result demonstrates that leaching parameters which include particle siz...An oxygen pressure leaching-flotation joint process was proposed to treat Jinbaoshan platinum group minerals to produce a desired concentrate.The result demonstrates that leaching parameters which include particle size,stirring speed,liquid-solid ratio,and the dosage of calcium lignosulfonate,simultaneously affect the leaching rates of base metals and the recovery of platinum group metals(PGMs).The complete dissolution of base metals sulfides leads to a reduction in the amount of flotation carrier for enriching PGMs,decreasing the recovery of PGMs.The optimum leaching conditions are determined as follows:liquid-solid ratio of 10 mL/g,73%occupancy of ore particle size below 0.043 mm,stirring speed of 400 r/min,and 0.6 g dosage of calcium lignosulfonate.Under optimal conditions,the leaching rates of Cu,Ni and Fe are 87.6%,87.6%and 90.3%,respectively.The grade of PGMs enriched in the flotation concentrate is 420 g/t through the flotation technology.展开更多
The effect of oxygen partial pressure （Po2） during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide （a-IGZO） thin film transistors （TFTs） is investigated. As Po2 increases fr...The effect of oxygen partial pressure （Po2） during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide （a-IGZO） thin film transistors （TFTs） is investigated. As Po2 increases from 10% to 30%, it is found that the device shows enhanced bias stress stability with significantly reduced threshold voltage drift under positive gate bias stress. Based on the x-ray photoelectron spectroscopy measurement, the concentration of oxygen vacancies （Or） within the a-IGZO layer is suppressed by increasing Po2. Meanwhile, the low-frequency noise analysis indicates that the average trap density near the channel/dielectric interface continuously drops with increasing Po2. Therefore, the improved interface quality with increasing Po2 during the channel layer deposition can be attributed to the reduction of interface Ov-related defects, which agrees with the enhanced bias stress stability of the a-IGZO TFTs.展开更多
A high temperature equilibration experiment was carried out to investigate the effect of oxygen partial pres- sure on the phase equilibria and liquidus in CaO-Al2O3- FeOx system with the intermediate oxygen partial pr...A high temperature equilibration experiment was carried out to investigate the effect of oxygen partial pres- sure on the phase equilibria and liquidus in CaO-Al2O3- FeOx system with the intermediate oxygen partial pressures of 10.13 Pa and 1.01 × 10^-3 Pa. The equilibrated phases and their compositions of the quenched samples were analyzed by using SEM/EPMA （Scanning Electron Microscope/Electron Probe Micro Analysis） and XRD （X Ray Diffraction）. The phase equilibrium results include two cases, the two phase coexistence and the three-phase coexistence in the high Al2O3 region with oxygen partial pressure of either 10.13 Pa or 1.01 × 10^-3 Pa. Effects of oxygen partial pressure and temperature on the liquidus along the primary phase fields of CaO · Al2O3 and CaO · 2Al2O3 were nota hle. With the decrease of oxygen partial pressure, the liquid area expands and the liquidus of CaO · Al2O3 and CaO · 2Al2O3 primary fields moves to the Al2O3-FeOx region. On the other hand, the liquid area of CaO Al2O3-FeOx sys tem extends extremely to the high Al2O3 region with the temperature increasing from 1 400 to 1 500℃, especially at lower oxygen partial pressure. The present experiment results are in good agreement with the calculated ones by FactSage.展开更多
The influence of Ce addition on the oxidation behavior of 25Cr20Ni alloy at 950 oC under low oxygen partial pressure was inves-tigated. The oxidized samples were characterized by using X-ray diffraction （XRD）, scann...The influence of Ce addition on the oxidation behavior of 25Cr20Ni alloy at 950 oC under low oxygen partial pressure was inves-tigated. The oxidized samples were characterized by using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS）, and scratch tester to obtain the oxide phases, morphology, thickness, composition and adhesion property of the oxide scales. The experiment results indicated that a small amount of Ce addition （0.02 wt.% or 0.05 wt.%） promoted oxidation resistance and inhibited the growth of the needlelike oxide. The Ce addition also decreased the formation of MnCr2O4 but promoted the SiO2 formation un-derneath the Cr2O3, which largely contributed to the improvement of oxide scale spallation resistance. For the sample with 0.3 wt.% Ce addi-tion, the oxidation rate significantly increased and the spallation resistance of the oxide scale decreased.展开更多
This paper studies the effect of oxygen partial pressure on the fabrication of YBa2Cu307-x films on （00/） LaAIO3 substrates by metalorganic deposition using trifluoroacetates （TFA-MOD）. As the oxygen partial press...This paper studies the effect of oxygen partial pressure on the fabrication of YBa2Cu307-x films on （00/） LaAIO3 substrates by metalorganic deposition using trifluoroacetates （TFA-MOD）. As the oxygen partial pressure increases to 1500 Pa, a great increase in the superconducting properties is observed at high magnetic fields parallel to the YBCO c axis. The cross-sectional transmission electron microscope images show that a high density of stacking faults in the size range of 10-15 nm may act as flux pinning centres to enhance the critical current density of the YBCO films展开更多
Based on the on-site investigation and the principle of compressible flow, the working oxygen pressure should be matched to the Mach-number at the nozzle in designing nozzle and oxygen supply schedule so that the high...Based on the on-site investigation and the principle of compressible flow, the working oxygen pressure should be matched to the Mach-number at the nozzle in designing nozzle and oxygen supply schedule so that the higher penetration depth and the more blending energy can be obtained for reducing energy loss by shock wave in the ultrasonic oxygen jet in the normal BOF steelmaking. For some special BOF blowing technologies, such as steelmaking with high phosphorus hot metal, post combustion oxygen lance, hot metal pretreatment, etc, the difference between working oxygen pressure and designed diffusion pressure which is related to Mach-number is necessary, so that the velocity of the oxygen jet will be decreased because of shock wave for expected metallurgical results.展开更多
After irradiated by & Gy 60Co γ-ray, mice were intraperitoneally injected immediately with 0.2 ml 100 % compound blood-activating soup twice a day for 10 days. The in situ ulnar bone marrow partial pressure of ox...After irradiated by & Gy 60Co γ-ray, mice were intraperitoneally injected immediately with 0.2 ml 100 % compound blood-activating soup twice a day for 10 days. The in situ ulnar bone marrow partial pressure of oxygen (PbO2) was determined in vivo before, during and after irradiation respectively. The bone marrow sections in the same part were observed. Our results showed that the normal murine ulnar PbO2 was 12.72±1. 05kpa. During irradiation, the level of PbO2 decreased to 10. 78±1. 17 kpa (P＜0. 001). And 3 days after irradiation, PbO2 decreased to 9. 75±0. 52 kpa, suggesting that the commonly used 'blood-activating and stasis-eliminating' Chinese drugs could promote the rehabilitation and proliferation of bone marrow microvessels in the acute radiation injured mice, expand their areas, increase the oxygen supply of bone marrow microenviroment, thereby leading to PbO2 much higher increase than that of control group. It is also helpful in the proliferation and rehabilitation of hematopoietic cells.展开更多
The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary coppe...The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary copper mineral of the concentrates.Most of silver also occurs in the mineral.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Pilot scale test was carried out under the parameters,and the leaching rates of copper and zinc are as high as 97.10% and 89.83% while lead and silver are transformed into sulfate and sulfide respectively and stay in leaching residue.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by chloride leaching and thiourea leaching.The extraction rate of copper achieves 96%,and the leaching rates of lead and silver reach 90% and 95%,respectively.展开更多
BACKGROUND： Moderate hypothermia is one of the effective therapeutic methods for head injury in recent years, there are many mechanisms of moderate hypothermia for brain protection, and its influence on cerebral oxyg...BACKGROUND： Moderate hypothermia is one of the effective therapeutic methods for head injury in recent years, there are many mechanisms of moderate hypothermia for brain protection, and its influence on cerebral oxygenation is also one of them. OBJECTIVE： To observe the influence of moderate hypothermia on cerebral oxygenation of animals with acute intracranial hypertension, and further investigate the protective mechanism of moderate hypothermia. DESIGN： A randomized controlled trial. SETTING： Department of Neurosurgery, Renji Hospital affiliated to the Medical College of Shanghai Jiao Tong University. MATERIALS： Twenty healthy little pigs, either male or female, weighing 4.5-5.5 kg, were used. Neurotrend-typed multiparameter monitoring system （Diametrics Company, British）; CMA/100 micro-injection pump （Carnegie Company, Sweden）. METHODS： The experiment was conducted in the Changzheng Hospital affiliated to the Second Military Medical University of Chinese PLA in November, 2001. The pigs were randomized into two groups： the normothermia group （control group, n =10） and moderate hypothermia group （n =10）. ① Bilateral femoral arteries were separated, one was connected to pressometer for monitoring mean arterial pressure （MEP）, and the other for analysis of blood gases [including peripheral blood pH value, arterial partial pressure of carbon dioxide （PaCO2）, arterial partial pressure of carbon dioxide （PaCO2）, HCO3-]. ② Rectal temperature was monitored with mercurial thermometer. ③ Intracranial pressure was monitored using Camino optic ICP probe placed in the subdural space. ④ Neurotrend multiparameter monitoring sensor was inserted into the white matter for about 4 cm to determine cerebral perfusion pressure （CPP, CPP=MAP（ICP）, brain tissue partial oxygen pressure （PO2）, partial pressure of carbon dioxide （PCO2）, HCO3- and brain temperature. The rectal temperature of animals in the moderate hypothermia group was lowered to 34 ℃ using ice bags, and the body temperature was maintained at 33-35 ℃ for 2 hours. The changes of the parameters were observed continuously, and the pigs in the normothermia group were not treated with cooling. MAIN OUTCOME MEASURES： ① MAP, ICP, rectal temperature, CCP; Indexes of cerebral oxygenation detected with Neurotrend-typed multiparameter monitoring system; ② Results of blood gases analysis in the moderate hypothermia group. RESULTS： All the 20 pigs were involved in the analysis of results. ① MAP, ICP, rectal temperature, CCP and indexes of cerebral oxygenation： In the moderate hypothermia group, the ICP after cooling was obviously lower than that before cooling [（3.31±1.19）, （5.33±0.95） kPa, P 〈 0.05], CCP was higher, brain tissue PCO2 [（12.03±1.73）, （10.59±2.01） kPa, P 〈 0.05], and brain tissue pH value was higher [（7.03± 1.63）, （9.40±1.30） kPa, P 〈 0.05], whereas the brain temperature was decreased as compared with that before cooling [（34.9±0.3）, （37.2±0.2） ℃, P 〈 0.05]. ② Results of blood gases analysis in the moderate hypothermia group： There were no significant differences in the parameters of peripheral arterial blood gases analysis before and after cooling in the moderate hypothermia group （P 〉 0.05） CONCLUSION： Moderate hypothermia will not impair the cerebral oxygenation, and it can reduce brain tissue CO2 and decrease brain tissue acidosis.展开更多
The （ 200 ） dominated Nd： LuVO4 films were fabricated successfully on polished SlOE under different ambient gases and different oxygen pressures. By XRD, it is shown that a film with good crystallization is deposit...The （ 200 ） dominated Nd： LuVO4 films were fabricated successfully on polished SlOE under different ambient gases and different oxygen pressures. By XRD, it is shown that a film with good crystallization is deposited under oxygen and the optimal pressure is 20 Pa. The surface morphology of Nd：LuVO4 films was observed by AFM, and it is found that oxygen pressure influences the surface morphology of Nd ：LuVO4 films. The ratio of content of Nd：LuVO4 films was estimated according to the yields of Lu and V by using RBS spectra, this ratio is in good agreement with the target composition. The effective index refractive of every mode is 2.0044, 1.7098, measured by prism coupler method.展开更多
Anti-coking oxide films were prepared on a 25Cr35Ni and 35Cr45Ni alloy surface under the low oxygen partialpressure atmosphere of a H2-H2O mixture. The composition and phase structure of the oxide films were analyzed ...Anti-coking oxide films were prepared on a 25Cr35Ni and 35Cr45Ni alloy surface under the low oxygen partialpressure atmosphere of a H2-H2O mixture. The composition and phase structure of the oxide films were analyzed by energydispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The anti-cokingperformance of a mini tube made of a HP40 (25Cr35Ni) alloy was evaluated on a bench scale pyrolysis and coking test unit.The results showed that the surface Fe and Ni content decreased after the oxidation of the two alloys in a low oxygen partialpressure atmosphere. The oxide films were mainly composed of MnCr_(2)O_(4) and Cr_(2)O_(3). The average mass of coke in the minitube with oxide film decreased by 87% relative to that of a tube without an oxide film when the cracking temperature was 900℃. The ethylene, propylene, and butadiene yields in the pyrolysis tests were almost the same for the mini tubes withand without an oxide film. The oxide film on the alloy surface effectively inhibited catalytic filamentous coke formation.An industrial test showed that the run length of the cracking furnace with the in-situ coating technology was significantlyextended.展开更多
基金Projects(2023AG05008,202302AB080012)supported by the Yunnan Major Scientific and Technological Program,ChinaProject(202405AC350015)supported by the Science and Technology Talent Programme of Yunnan Province,China。
文摘The phase transformation of galena in H_(2)SO_(4)-Fe_(2)(SO_(4))_(3) system under oxygen pressure was investigated.Results indicated that the critical conditions for the phase transformation of galena into lead jarosite(Pb-J)were 130℃,30 g/L H_(2)SO_(4),15 g/L Fe^(3+),and an oxygen partial pressure of 0.4 MPa.Furthermore,increased Fe^(3+)concentration and oxygen partial pressure did not enhance jarosite formation.Conversely,lowering the temperature and increasing the H_(2)SO_(4) concentration facilitated PbSO_(4) formation and inhibited its further conversion to Pb-J.Additionally,the effects of potassium sulfate,sodium sulfate,and high concentrations of zinc sulfate on the phase transformation of galena were examined through leaching tests,XRD,SEM-EDS,and FT-IR analyses.All three sulfates inhibited the conversion of galena to Pb-J.Among these,potassium sulfate prevented Pb-J formation and converted it more thoroughly into potassium jarosite.However,high concentrations of zinc sulfate facilitated the crystallization of both PbSO_(4) and Pb-J,which altered the morphology of the product.Zinc ions coprecipitated with Pb-J,thereby integrating into the product.
基金Open access funding provided by Montanuniversität Leoben.
文摘The variation of the O_(2) content in the suction gas,in the range from 7 to 30 vol.%,during the iron ore sintering process,is investigated.Miniaturized laboratory-scale sintering experiments are carried out using an industry-like raw mixture to study the effects of O_(2) variation on the sintering process with particular emphasis on the off-gas composition,specific sintering parameters and the sinter strength as well as the chemical composition of the sinter.After the ignition at the bed surface,the gas hood is placed on the sintering column,allowing a synthetic gas mixture to be drawn through the sinter bed until the burn-through point is reached.For additional interpretation of the experimental results,the theoretical coke combustion rate as a function of the oxygen partial pressure was calculated and plotted against the experimentally measured peak temperature in the sinter bed of the respective sinter series.An increasing O_(2) content in the suction gas results in a faster flame front speed combined with a more gradual temperature rise of the heat wave and longer dwell time in the melt phase formation temperature range.Due to the more pronounced flame front,both sinter yield and strength increase,resulting in lower return rates.Below 12 vol.%O_(2),a sharp decrease in sinter yield and strength can be observed,probably due to the low extent of melt phase formation and the associated minor formation of silico ferrite of calcium and aluminum(SFCA).The carbon burnout as well as the calcination increases with increasing the O_(2) content in the suction gas,resulting in higher levels of CO_(2) in the off-gas,with more or less constant amounts of CO above 15 vol.%O_(2).The amounts of NO and SO_(2) show a similar trend with a continuous increase with increasing O_(2) supply,with the SO_(2) breakthrough starting earlier and being released over a shorter period.The chemical analysis of the sinter indicates the highest Fe(II)values in the range of 12–21 vol.%O_(2) in the suction gas.
基金financially supported by the National Natural Science Foundation of China (No. 51574285)
文摘The co-oxidation of As(Ⅲ) and Fe(Ⅱ) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150℃. It was confirmed that without Fe(Ⅱ) ions, As(Ⅲ) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200℃ and an oxygen pressure up to 2.0 MPa. Fe(Ⅱ) ions in the solutions did have a catalysis effect on the oxidation of As(Ⅲ), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH ) and Fe(Ⅳ) in the oxidation process of Fe(Ⅱ). The effects of such factors as the initial molar ratio of Fe(Ⅱ)/As(Ⅲ), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(Ⅲ) and Fe(Ⅱ) were studied. It was found that the oxidation of As(Ⅲ) was limited in the co-oxidation process due to the accumulation of the As(Ⅲ) oxidation product, As(Ⅴ), in the solutions.
基金Project(2006AA06Z130)supported by the High-tech Research and Development Program of ChinaProject(50874053)supported by the National Natural Science Foundation of ChinaProject(2007GA010)supported by Science and Technology Bureau of Yunnan Province,China
文摘Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various determination methods. The effects of leaching time,leaching temperature,leaching agent concentration,leaching L/S ratio,granularity of material,additive consumption were investigated based on the mineralogy.The results show that under the conditions of leaching time of 3-4 h, temperature of 150℃,sulfuric acid consumption of 25%?30%,ratio of liquid to solid of 1.2:1,the granularity less than 0.074 mm, additive consumption of 3%-5%,and oxygen pressure of 1.2 MPa,and the vanadium leaching rate can be more than 92%by the method of two-step pressurized acid leaching.The powdery V2O5 product with 99.52%in V2O5 content is obtained by the flowsheet of acid recovery,removing iron by reduction process,solvent extraction,precipitating vanadium with ammonium water,and pyrolysis from the stone-coal oxygen pressure acid-leaching solution.The total recovery efficiency of vanadium is above 85%,which is more than 20%higher than that obtained in the conventional process.Furthermore,the new process does not cause air pollution since no HCl or Cl2 is released by calcination of the raw material.
文摘AIM： To study the effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome, METHODS： Garlic powder in a capsule form was given to 15 children with hepatopulmonary syndrome （confirmed by contrast echocardiography） at the dosage of 1 g/1.73 m^2 per day. Patients were evaluated clinically and by arterial blood gas every four weeks. RESULTS： The garlic capsule was administered to 15 patients with hepatopulmonary syndrome. There were 10 boys and 5 girls with a mean age of 9.4 ± 3.9 years. The underlying problems were biliary tract atresia （4 patients）, autoimmune hepatitis （4 patients）, cryptogenic cirrhosis （4 patients） and presinusoidal portal hypertension （3 patients）. Eight patients （53.3%） showed an increase of 10 mmHg in their mean arterial oxygen pressure. The baseline PaO2 was 65.6 ± 12.1 mmHg in the responder group and 47.1 ± 11.2 mmHg in nonresponder group. At the end of treatment the mean PaO2 in responders and non-responders was 92.2 ± 7.75 mmHg and 47.5 ± 11.87 mmHg, respectively （P 〈 0.01）. CONCLUSION： Garlic may increase oxygenation and improve dyspnea in children with hepatopulmonary syndrome.
基金the Portuguese Ministry of Science and Technology(FCT-MCTES)for offering post-doctoral fellowships through the grants SFRH/BPD/34542/2007 and SFRH/BPD/35055/2007,respectivelyfinanced by FCT-MCTES through CENIMAT-I3N
文摘N-doped ZnO films were radio frequency(RF)sputtered on glass substrates and studied as a function of oxygen partial pressure(OPP)ranging from 3.0×10-4 to 9.5×10-3 Pa.X-ray diffraction patters confirmed the polycrystalline nature of the deposited films.The crystalline structure is influenced by the variation of OPP.Atomic force microscopy analysis confirmed the agglomeration of the neighboring spherical grains with a sharp increase of root mean square(RMS)roughness when the OPP is increased above 1.4×10-3 Pa.X-ray photoelectron spectroscopy analysis revealed that the incorporation of N content into the film is decreased with the increase of OPP,noticeably N 1s XPS peaks are hardly identified at 9.5×10-3 Pa.The average visible transmittance(380-700 nm) is increased with the increase of OPP(from～17%to 70%),and the optical absorption edge shifts towards the shorter wavelength.The films deposited with low OPP(≤3.0×10-4 Pa)show n-type conductivity and those deposited with high OPP(≥9.0×10-4 Pa)are highly resistive(>105Ω·cm)
基金supported by the National Basic Research Program of China (No. 2010CB630905)
文摘Zinc concentrate with high gallium content is one of the main resources of gallium.The gallium presents in the form of isomorphism in tetrahedron coordination with sulfur in sphalerite.The research was to investigate the amenability of zinc concentrate with high gallium to pressure oxygen leaching.The particle size,sulfuric acid concentration,oxygen partial pressure,additive amount,and time of reaction were studied.The extraction yields of gallium and zinc are 86%and 98%,respectively.The optimal condition is 100 g of zinc concentrate with particle size smaller than 38 lm,sulfuric acid concentration150 g L-1,leaching temperature 150℃,leaching time120 min,oxygen partial pressure 0.7 MPa,additive amount of 0.2 wt%.
基金the 11th Five-Year Plan of National Scientific and Technological Program of China (No.2007 BAB22B01)
文摘The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treatment of tetrahedrite was rarely studied,and most of silver occurred in themineral too.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Under these parameters,the result of pilot scale test showed that the leaching percentages of copper and zinc were separately as high as 98.9 wt.% and 94.9 wt.%,while lead and silver were transformed into sulfate and sulfide precipitations,respectively.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by carbonate transformation-silicofluoric acid leaching and thiourea leaching.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50532090).
文摘PolycrystaUine SnO2 thin films were deposited on sapphire substrates at 450℃ under different ambient oxygen pressures by pulsed laser deposition technique. The effect of ambient oxygen pressure on the structural, optical and electrical properties of SnO2 thin films was studied. X-my diffraction and Hall measurements show that increasing the ambient oxygen pressure can improve crystallization of the films and decrease resistivity of the films. A violet emission peak centered at 409 nm was observed from photoluminescence measurements for SnO2 films under deposition ambient oxygen pressure above 5 Pa, which is related to the improvement of crystalline of the films.
基金Projects(51804083,51204060)supported by the National Natural Science Foundation of ChinaProject(2017B090907026)supported by Science and Technology Planning Project of Guangdong Province,ChinaProjects(2018GDASCX-0938,2018GDASCX-0939)supported by Guangdong Academy of Science Doctor Special Program,China
文摘An oxygen pressure leaching-flotation joint process was proposed to treat Jinbaoshan platinum group minerals to produce a desired concentrate.The result demonstrates that leaching parameters which include particle size,stirring speed,liquid-solid ratio,and the dosage of calcium lignosulfonate,simultaneously affect the leaching rates of base metals and the recovery of platinum group metals(PGMs).The complete dissolution of base metals sulfides leads to a reduction in the amount of flotation carrier for enriching PGMs,decreasing the recovery of PGMs.The optimum leaching conditions are determined as follows:liquid-solid ratio of 10 mL/g,73%occupancy of ore particle size below 0.043 mm,stirring speed of 400 r/min,and 0.6 g dosage of calcium lignosulfonate.Under optimal conditions,the leaching rates of Cu,Ni and Fe are 87.6%,87.6%and 90.3%,respectively.The grade of PGMs enriched in the flotation concentrate is 420 g/t through the flotation technology.
基金Supported by the National Basic Research Program of China under Grant Nos 2010CB327504,2011CB922100 and2011CB301900the National Natural Science Foundation of China under Grant Nos 11104130 and 61322112+2 种基金the Natural Science Foundation of Jiangsu Province under Grant Nos BK2011556 and BK2011050the Priority Academic Program Development of Jiangsu Higher Education Institutionsand the NUPTSF Grant Nos NY213069 and NY214028
文摘The effect of oxygen partial pressure （Po2） during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide （a-IGZO） thin film transistors （TFTs） is investigated. As Po2 increases from 10% to 30%, it is found that the device shows enhanced bias stress stability with significantly reduced threshold voltage drift under positive gate bias stress. Based on the x-ray photoelectron spectroscopy measurement, the concentration of oxygen vacancies （Or） within the a-IGZO layer is suppressed by increasing Po2. Meanwhile, the low-frequency noise analysis indicates that the average trap density near the channel/dielectric interface continuously drops with increasing Po2. Therefore, the improved interface quality with increasing Po2 during the channel layer deposition can be attributed to the reduction of interface Ov-related defects, which agrees with the enhanced bias stress stability of the a-IGZO TFTs.
基金Item Sponsored by National Natural Science Foundation of China(50974034,51074039)
文摘A high temperature equilibration experiment was carried out to investigate the effect of oxygen partial pres- sure on the phase equilibria and liquidus in CaO-Al2O3- FeOx system with the intermediate oxygen partial pressures of 10.13 Pa and 1.01 × 10^-3 Pa. The equilibrated phases and their compositions of the quenched samples were analyzed by using SEM/EPMA （Scanning Electron Microscope/Electron Probe Micro Analysis） and XRD （X Ray Diffraction）. The phase equilibrium results include two cases, the two phase coexistence and the three-phase coexistence in the high Al2O3 region with oxygen partial pressure of either 10.13 Pa or 1.01 × 10^-3 Pa. Effects of oxygen partial pressure and temperature on the liquidus along the primary phase fields of CaO · Al2O3 and CaO · 2Al2O3 were nota hle. With the decrease of oxygen partial pressure, the liquid area expands and the liquidus of CaO · Al2O3 and CaO · 2Al2O3 primary fields moves to the Al2O3-FeOx region. On the other hand, the liquid area of CaO Al2O3-FeOx sys tem extends extremely to the high Al2O3 region with the temperature increasing from 1 400 to 1 500℃, especially at lower oxygen partial pressure. The present experiment results are in good agreement with the calculated ones by FactSage.
基金supported by the Basic Research Program of the State Key Laboratory of Heavy Oil Processing (200809),China University of Petroleum, Beijing, China
文摘The influence of Ce addition on the oxidation behavior of 25Cr20Ni alloy at 950 oC under low oxygen partial pressure was inves-tigated. The oxidized samples were characterized by using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS）, and scratch tester to obtain the oxide phases, morphology, thickness, composition and adhesion property of the oxide scales. The experiment results indicated that a small amount of Ce addition （0.02 wt.% or 0.05 wt.%） promoted oxidation resistance and inhibited the growth of the needlelike oxide. The Ce addition also decreased the formation of MnCr2O4 but promoted the SiO2 formation un-derneath the Cr2O3, which largely contributed to the improvement of oxide scale spallation resistance. For the sample with 0.3 wt.% Ce addi-tion, the oxidation rate significantly increased and the spallation resistance of the oxide scale decreased.
基金supported by the National Natural Science Foundation of China (Grant No. 51002149)
文摘This paper studies the effect of oxygen partial pressure on the fabrication of YBa2Cu307-x films on （00/） LaAIO3 substrates by metalorganic deposition using trifluoroacetates （TFA-MOD）. As the oxygen partial pressure increases to 1500 Pa, a great increase in the superconducting properties is observed at high magnetic fields parallel to the YBCO c axis. The cross-sectional transmission electron microscope images show that a high density of stacking faults in the size range of 10-15 nm may act as flux pinning centres to enhance the critical current density of the YBCO films
文摘Based on the on-site investigation and the principle of compressible flow, the working oxygen pressure should be matched to the Mach-number at the nozzle in designing nozzle and oxygen supply schedule so that the higher penetration depth and the more blending energy can be obtained for reducing energy loss by shock wave in the ultrasonic oxygen jet in the normal BOF steelmaking. For some special BOF blowing technologies, such as steelmaking with high phosphorus hot metal, post combustion oxygen lance, hot metal pretreatment, etc, the difference between working oxygen pressure and designed diffusion pressure which is related to Mach-number is necessary, so that the velocity of the oxygen jet will be decreased because of shock wave for expected metallurgical results.
文摘After irradiated by & Gy 60Co γ-ray, mice were intraperitoneally injected immediately with 0.2 ml 100 % compound blood-activating soup twice a day for 10 days. The in situ ulnar bone marrow partial pressure of oxygen (PbO2) was determined in vivo before, during and after irradiation respectively. The bone marrow sections in the same part were observed. Our results showed that the normal murine ulnar PbO2 was 12.72±1. 05kpa. During irradiation, the level of PbO2 decreased to 10. 78±1. 17 kpa (P＜0. 001). And 3 days after irradiation, PbO2 decreased to 9. 75±0. 52 kpa, suggesting that the commonly used 'blood-activating and stasis-eliminating' Chinese drugs could promote the rehabilitation and proliferation of bone marrow microvessels in the acute radiation injured mice, expand their areas, increase the oxygen supply of bone marrow microenviroment, thereby leading to PbO2 much higher increase than that of control group. It is also helpful in the proliferation and rehabilitation of hematopoietic cells.
基金Project(2007BAB22B01) supported by the National Science and Technology Pillar Program during the 11th Five-year Plan Period of China
文摘The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary copper mineral of the concentrates.Most of silver also occurs in the mineral.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Pilot scale test was carried out under the parameters,and the leaching rates of copper and zinc are as high as 97.10% and 89.83% while lead and silver are transformed into sulfate and sulfide respectively and stay in leaching residue.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by chloride leaching and thiourea leaching.The extraction rate of copper achieves 96%,and the leaching rates of lead and silver reach 90% and 95%,respectively.
文摘BACKGROUND： Moderate hypothermia is one of the effective therapeutic methods for head injury in recent years, there are many mechanisms of moderate hypothermia for brain protection, and its influence on cerebral oxygenation is also one of them. OBJECTIVE： To observe the influence of moderate hypothermia on cerebral oxygenation of animals with acute intracranial hypertension, and further investigate the protective mechanism of moderate hypothermia. DESIGN： A randomized controlled trial. SETTING： Department of Neurosurgery, Renji Hospital affiliated to the Medical College of Shanghai Jiao Tong University. MATERIALS： Twenty healthy little pigs, either male or female, weighing 4.5-5.5 kg, were used. Neurotrend-typed multiparameter monitoring system （Diametrics Company, British）; CMA/100 micro-injection pump （Carnegie Company, Sweden）. METHODS： The experiment was conducted in the Changzheng Hospital affiliated to the Second Military Medical University of Chinese PLA in November, 2001. The pigs were randomized into two groups： the normothermia group （control group, n =10） and moderate hypothermia group （n =10）. ① Bilateral femoral arteries were separated, one was connected to pressometer for monitoring mean arterial pressure （MEP）, and the other for analysis of blood gases [including peripheral blood pH value, arterial partial pressure of carbon dioxide （PaCO2）, arterial partial pressure of carbon dioxide （PaCO2）, HCO3-]. ② Rectal temperature was monitored with mercurial thermometer. ③ Intracranial pressure was monitored using Camino optic ICP probe placed in the subdural space. ④ Neurotrend multiparameter monitoring sensor was inserted into the white matter for about 4 cm to determine cerebral perfusion pressure （CPP, CPP=MAP（ICP）, brain tissue partial oxygen pressure （PO2）, partial pressure of carbon dioxide （PCO2）, HCO3- and brain temperature. The rectal temperature of animals in the moderate hypothermia group was lowered to 34 ℃ using ice bags, and the body temperature was maintained at 33-35 ℃ for 2 hours. The changes of the parameters were observed continuously, and the pigs in the normothermia group were not treated with cooling. MAIN OUTCOME MEASURES： ① MAP, ICP, rectal temperature, CCP; Indexes of cerebral oxygenation detected with Neurotrend-typed multiparameter monitoring system; ② Results of blood gases analysis in the moderate hypothermia group. RESULTS： All the 20 pigs were involved in the analysis of results. ① MAP, ICP, rectal temperature, CCP and indexes of cerebral oxygenation： In the moderate hypothermia group, the ICP after cooling was obviously lower than that before cooling [（3.31±1.19）, （5.33±0.95） kPa, P 〈 0.05], CCP was higher, brain tissue PCO2 [（12.03±1.73）, （10.59±2.01） kPa, P 〈 0.05], and brain tissue pH value was higher [（7.03± 1.63）, （9.40±1.30） kPa, P 〈 0.05], whereas the brain temperature was decreased as compared with that before cooling [（34.9±0.3）, （37.2±0.2） ℃, P 〈 0.05]. ② Results of blood gases analysis in the moderate hypothermia group： There were no significant differences in the parameters of peripheral arterial blood gases analysis before and after cooling in the moderate hypothermia group （P 〉 0.05） CONCLUSION： Moderate hypothermia will not impair the cerebral oxygenation, and it can reduce brain tissue CO2 and decrease brain tissue acidosis.
文摘The （ 200 ） dominated Nd： LuVO4 films were fabricated successfully on polished SlOE under different ambient gases and different oxygen pressures. By XRD, it is shown that a film with good crystallization is deposited under oxygen and the optimal pressure is 20 Pa. The surface morphology of Nd：LuVO4 films was observed by AFM, and it is found that oxygen pressure influences the surface morphology of Nd ：LuVO4 films. The ratio of content of Nd：LuVO4 films was estimated according to the yields of Lu and V by using RBS spectra, this ratio is in good agreement with the target composition. The effective index refractive of every mode is 2.0044, 1.7098, measured by prism coupler method.
基金the scientific research project of China Petroleum&Chemical Corporation(Grant No.411048).
文摘Anti-coking oxide films were prepared on a 25Cr35Ni and 35Cr45Ni alloy surface under the low oxygen partialpressure atmosphere of a H2-H2O mixture. The composition and phase structure of the oxide films were analyzed by energydispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The anti-cokingperformance of a mini tube made of a HP40 (25Cr35Ni) alloy was evaluated on a bench scale pyrolysis and coking test unit.The results showed that the surface Fe and Ni content decreased after the oxidation of the two alloys in a low oxygen partialpressure atmosphere. The oxide films were mainly composed of MnCr_(2)O_(4) and Cr_(2)O_(3). The average mass of coke in the minitube with oxide film decreased by 87% relative to that of a tube without an oxide film when the cracking temperature was 900℃. The ethylene, propylene, and butadiene yields in the pyrolysis tests were almost the same for the mini tubes withand without an oxide film. The oxide film on the alloy surface effectively inhibited catalytic filamentous coke formation.An industrial test showed that the run length of the cracking furnace with the in-situ coating technology was significantlyextended.
