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Oxidation of Fe-Cr-Ni Alloys in a Low Oxygen Partial Pressure Atmosphere to Mitigate Coke Formation
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作者 Wang Hongxia Wang Guoqing +3 位作者 Zhang Lijun Wang Shenxiang Jia Jingsheng Cui Lishan 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2023年第3期49-59,共11页
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
关键词 Fe-Cr-Ni alloy low oxygen partial pressure oxide film ANTI-COKING ethylene cracking furnace in-situ coating
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Efficacy of Huangma Ding or autologous platelet-rich gel for the diabetic lower extremity arterial disease patients with foot ulcers
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作者 Xue-Qin Wang Dan-Lan Pu +8 位作者 Wei-Ling Leng Xiao-Tian Lei Jiang Juan Zou La Ding Yao Jia-Zhuang Xi Li Jian Teng Miao Qi-Nan Wu 《World Journal of Diabetes》 SCIE 2024年第5期923-934,共12页
BACKGROUND Diabetes foot is one of the most serious complications of diabetes and an important cause of death and disability,traditional treatment has poor efficacy and there is an urgent need to develop a practical t... BACKGROUND Diabetes foot is one of the most serious complications of diabetes and an important cause of death and disability,traditional treatment has poor efficacy and there is an urgent need to develop a practical treatment method.AIM To investigate whether Huangma Ding or autologous platelet-rich gel(APG)treatment would benefit diabetic lower extremity arterial disease(LEAD)patients with foot ulcers.METHODS A total of 155 diabetic LEAD patients with foot ulcers were enrolled and divided into three groups:Group A(62 patients;basal treatment),Group B(38 patients;basal treatment and APG),and Group C(55 patients;basal treatment and Huangma Ding).All patients underwent routine follow-up visits for six months.After follow-up,we calculated the changes in all variables from baseline and determined the differences between groups and the relationships between parameters.RESULTS The infection status of the three groups before treatment was the same.Procalcitonin(PCT)improved after APG and Huangma Ding treatment more than after traditional treatment and was significantly greater in Group C than in Group B.Logistic regression analysis revealed that PCT was positively correlated with total amputation,primary amputation,and minor amputation rates.The ankle-brachial pressure and the transcutaneous oxygen pressure in Groups B and C were greater than those in Group A.The major amputation rate,minor amputation rate,and total amputation times in Groups B and C were lower than those in Group A.CONCLUSION Our research indicated that diabetic foot ulcers(DFUs)lead to major amputation,minor amputation,and total amputation through local infection and poor microcirculation and macrocirculation.Huangma Ding and APG were effective attreating DFUs.The clinical efficacy of Huangma Ding was better than that of autologous platelet gel,which may be related to the better control of local infection by Huangma Ding.This finding suggested that in patients with DFUs combined with coinfection,controlling infection is as important as improving circulation. 展开更多
关键词 Diabetic foot ulcer Huangma Ding Autologous platelet-rich gel Ankle-brachial index Transcutaneous oxygen partial pressure
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Analysis of Oxygen Consumption in Lead and Zinc Metallurgy
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作者 Lun Sheng Pengpeng Zhang 《Frontiers of Metallurgical Industry》 2024年第2期5-9,共5页
This article analyzes the role of oxygen in lead zinc metallurgy,including shortening the metallurgical process,promoting energy conservation and environmental protection,improving metallurgical strength,enhancing raw... This article analyzes the role of oxygen in lead zinc metallurgy,including shortening the metallurgical process,promoting energy conservation and environmental protection,improving metallurgical strength,enhancing raw material adaptability,and enhancing comprehensive recovery efficiency.This article introduces different lead zinc metallurgical processes and their oxygen consumption characteristics,including oxygen enriched side blowing lead smelting,oxygen bottom blowing lead smelting,oxygen enriched top blowing lead smelting,flash smelting lead,oxygen pressure leaching zinc smelting,and atmospheric pressure oxygen leaching zinc smelting.It is pointed out that oxygen enhanced metallurgy is the direction for the transformation and upgrading of lead zinc metallurgy. 展开更多
关键词 lead zinc metallurgy oxygen rich smelting oxygen pressure leaching energy conservation and emission reduction
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Extracting vanadium from stone-coal by oxygen pressure acid leaching and solvent extraction 被引量:16
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作者 邓志敢 魏昶 +3 位作者 樊刚 李旻廷 李存兄 李兴彬 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第S1期118-122,共5页
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
关键词 stone-coal extracting vanadium oxygen pressure acid leaching acid recovery solvent extraction
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An investigation of oxygen pressure acid leaching of Gacun complex Cu-Pb bulk concentrate 被引量:6
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作者 Xu, Bin Zhong, Hong Jiang, Tao 《Rare Metals》 SCIE EI CAS CSCD 2012年第1期96-101,共6页
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
关键词 nonferrous metallurgy synthetic reclaiming oxygen pressure acid leaching complex Cu-Pb bulk concentrate TETRAHEDRITE
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Effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome 被引量:5
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作者 Mehri Najafi Sani Hamid Reza Kianifar +1 位作者 Abdolrazagh Kianee Gholamreza Khatami 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第15期2427-2431,共5页
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
关键词 Hepatopulmonary syndrome GARLIC Arterial oxygen pressure PEDIATRIC
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Dissolution kinetics and thermodynamic analysis of vanadium trioxide during pressure oxidation 被引量:4
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作者 Zhou, Xuejiao Wei, Chang +4 位作者 Xia, Wentang Li, Minting Li, Cunxiong Deng, Zhigan Xu, Hongsheng 《Rare Metals》 SCIE EI CAS CSCD 2012年第3期296-302,共7页
The dissolution kinetics of vanadium trioxide in sulphuric acid-oxygen medium was examined. It was determined that the concentration of sulphuric acid and stirring speed above 800 r min 1 did not significantly affect ... The dissolution kinetics of vanadium trioxide in sulphuric acid-oxygen medium was examined. It was determined that the concentration of sulphuric acid and stirring speed above 800 r min 1 did not significantly affect vanadium extraction. The dissolution rate increased with increasing temperature and oxygen partial pressure, but decreased with increasing particle size. The dissolution kinetics was controlled by the chemical reaction at the surface with the estimated activation energy of 43.46 kJ·mol-1. The leaching mechanism was confirmed by characterizing vanadium trioxide and the dissolution residue using SEM-EDS analysis. Combined with thermodynamic calculation, the pressure leaching of vanadium trioxide in the temperature range (100 to 140 ℃) studied occurs as follows: V2O3 + O2 + H2SO4 = (VO2)2SO4 + H2O. 展开更多
关键词 HYDROMETALLURGY KINETICS oxygen pressure acid leaching THERMODYNAMICS VANADIUM
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Effect of ambient oxygen pressure on structural, optical and electrical properties of SnO_2 thin films 被引量:4
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作者 ZHAO Songqing ZHOU Yueliang +2 位作者 WANG Shufang ZHAO Kun HAN Peng 《Rare Metals》 SCIE EI CAS CSCD 2006年第6期693-696,共4页
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
关键词 tin oxide pulsed laser deposition oxygen pressure PLD RESISTIVITY
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Influence of oxygen partial pressure on properties of N-doped ZnO films deposited by magnetron sputtering 被引量:5
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作者 王金忠 E.ElANGOVAN +4 位作者 N.FRANCO A.ALVESE A.REGO R.MARTINS E.FORTUNATO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第12期2326-2330,共5页
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
关键词 ZNO oxygen partial pressure magnetron sputtering TRANSMITTANCE
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Recovery of gallium from zinc concentrate by pressure oxygen leaching 被引量:4
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作者 Xue-Lan Wu Wen-Qing Qin +3 位作者 Shun-Ke Wu Xi-Hong Ma Yin-Jian Niu Cong-Ren Yang 《Rare Metals》 SCIE EI CAS CSCD 2013年第6期622-626,共5页
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
关键词 GALLIUM pressure oxygen leaching Zinc concentrate
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Oxygen pressure leaching-flotation joint process for Jinbaoshan platinum group minerals 被引量:2
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作者 Shuai RAO Zhi-qiang LIU +4 位作者 Xian-yang QIU Dong-xing WANG Hong-yang CAO WeiLI Jin-zhang TAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第5期1090-1098,共9页
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 si... 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
关键词 platinum group metals oxygen pressure leaching FLOTATION RECOVERY
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The Effect of Oxygen Partial Pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs 被引量:2
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作者 黄晓明 武辰飞 +3 位作者 陆海 任芳芳 朱洪波 王永进 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第7期171-174,共4页
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
关键词 TFT The Effect of Oxygen Partial pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs
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Influence of oxygen pressure on critical current density and magnetic flux pinning structures in YBa_2 Cu_3 O_(7-x) fabricated by chemical solution deposition
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作者 丁发柱 古宏伟 +2 位作者 张腾 戴少涛 肖立业 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第2期478-481,共4页
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
关键词 YBCO oxygen pressure stacking fault TFA-MOD
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Influence of Ambient Gas and Oxygen Pressure on Nd∶LuVO_4 Films Grown by Pulsed Laser Deposition
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作者 Wang Xiaoxia Li Hongxia +3 位作者 Zhang Huaijin Wang Jiyang Shen Mingrong Fang Liang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第4期454-454,共1页
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
关键词 pulsed laser deposition Nd LuVO4 films oxygen pressure rare earths
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Oxygen pressure acid leaching of Gacun complex Cu concentrates
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作者 XU Bin ZHONG Hong JIANG Tao 《Journal of Central South University》 SCIE EI CAS 2012年第1期71-76,共6页
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
关键词 complex Cu concentrates oxygen pressure acid leaching synthetic reclaiming TETRAHEDRITE
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Effect of Oxygen Partial Pressure on Epitaxial Growth and Properties of Laser-Ablated AZO Thin Films
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作者 王传彬 LUO Sijun +1 位作者 SHEN Qiang 张联盟 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第1期27-30,共4页
Al-doped ZnO(AZO) thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures(P_(O2)).The effect of P_(O2) on the crystal structure,preferred orientation as well a... Al-doped ZnO(AZO) thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures(P_(O2)).The effect of P_(O2) on the crystal structure,preferred orientation as well as the electrical and optical properties of the films was investigated.The structure characterizations indicated that the as-grown films were single-phased with a wurtzite ZnO structure,showing a significant c-axis orientation.The films were well crystallized and exhibited better crystallinity and denser texture when deposited at higher P_(O2).At the optimum oxygen partial pressures of 10- 15 Pa,the AZO thin films were epitaxially grown on c-sapphire substrates with the(0001) plane parallel to the substrate surface,i e,the epitaxial relationship was AZO(000 1) // A1_2O_3(000 1).With increasing P_(O2),the value of Hall carrier mobility was increased remarkably while that of carrier concentration was decreased slightly,which led to an enhancement in electrical conductivity of the AZO thin films.All the films were highly transparent with an optical transmittance higher than 85%. 展开更多
关键词 AZO thin films epitaxial growth laser ablation oxygen partial pressure electrical and optical properties
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Preparation of ultrafine rhenium powders by CVD hydrogen reduction of volatile rhenium oxides 被引量:9
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作者 白猛 刘志宏 +2 位作者 周乐君 刘智勇 张传福 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第2期538-542,共5页
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
关键词 ultrafme rhenium powders ammonium perrhenate chemical vapor decomposition oxygen partial pressure
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Oxidation behavior of C/C composites with SiC/ZrSiO_4-SiO_2 coating 被引量:3
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作者 李杨 肖鹏 +2 位作者 李专 罗威 周伟 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第2期397-405,共9页
A SiC/ZrSiO4?SiO2 (SZS) coating was successfully fabricated on the carbon/carbon (C/C) composites by pack cementation, slurry painting and sintering to improve the anti-oxidation property and thermal shock r... A SiC/ZrSiO4?SiO2 (SZS) coating was successfully fabricated on the carbon/carbon (C/C) composites by pack cementation, slurry painting and sintering to improve the anti-oxidation property and thermal shock resistance. The anti-oxidation properties under different oxygen partial pressures (OPP) and thermal shock resistance of the SZS coating were investigated. The results show that the SZS coated sample under low OPP, corresponding to the ambient air, during isothermal oxidation was 0.54% in mass gain after 111 h oxidation at 1500 ° C and less than 0.03% in mass loss after 50 h oxidation in high OPP, corresponding to the air flow rate of 36 L/h. Additionally, the residual compressive strengths (RCS) of the SZS coated samples after oxidation for 50 h in high OPP and 80 h in low OPP remain about 70% and 72.5% of those of original C/C samples, respectively. Moreover, the mass loss of SZS coated samples subjected to the thermal cycle from 1500 ° C in high OPP to boiling water for 30 times was merely 1.61%. 展开更多
关键词 C/C composite SiC/ZrSiO4-SiO2 coating oxygen partial pressure ANTI-OXIDATION thermal shock residual compressive strength
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Pentoxifylline in hepatopulmonary syndrome 被引量:4
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作者 Hamid Reza Kianifar Maryam Khalesi +1 位作者 Eftekhar Mahmoodi Monavar Afzal Aghaei 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第35期4912-4916,共5页
AIM: To determine the effects of pentoxifylline (PTX) on clinical manifestations and evaluate arterial blood gas data in hepatopulmonary syndrome (HPS) in chil- dren. METHODS: In a pilot study of 10 children wit... AIM: To determine the effects of pentoxifylline (PTX) on clinical manifestations and evaluate arterial blood gas data in hepatopulmonary syndrome (HPS) in chil- dren. METHODS: In a pilot study of 10 children with chronic liver disease, who had HPS, 20 mg/kg/d PTX was ad- ministered for 3 mo. Clinical data and arterial blood gas parameters were evaluated at baseline, the end of the treatment period, and 3 mo after drug discontinuation. RESULTS: Six patients could tolerate PTX, while four patients experienced complications, Among patients who could tolerate PTX, there was a significant increase in arterial oxygen pressure (PaO2) (P = 0,02) and oxy- gen saturation (Sa02) (P = 0.04) and alveolar-arterial oxygen gradient (P = 0.02) after 3 mo of treatment. Significant decreases in Pa02 (P = 0.02) and alveolararterial oxygen gradient (P = 0.02) were also seen after drug discontinuation. CONCLUSION: PTX may improve PaO2, Sa02 and alve- olar-arterial oxygen gradient in the early stage of HPS. 展开更多
关键词 PENTOXIFYLLINE Hepatopulmonary syndrome CHILD Arterial oxygen pressure Therapy Alveolar-arterial oxygen gradient
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Effect of early goal directed therapy on tissue perfusion in patients with septic shock 被引量:19
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作者 Yuan-hua Lu Ling Liu +3 位作者 Xiao-hua Qiu Qin Yu Yi Yang Hai-bo Qiu 《World Journal of Emergency Medicine》 CAS 2013年第2期117-122,共6页
BACKGROUND:This study aimed to observe the effect of early goal directed therapy(EGDT)on tissue perfusion,microcirculation and tissue oxygenation in patients with septic shock.METHODS:Patients with early septic shock(... BACKGROUND:This study aimed to observe the effect of early goal directed therapy(EGDT)on tissue perfusion,microcirculation and tissue oxygenation in patients with septic shock.METHODS:Patients with early septic shock(<24 hours) who had been admitted to the ICU of Zhongda Hospital Affiliated to Southeast University from September 2009 through May 2011 were enrolled(research time:12 months),and they didn't meet the criteria of EGDT.Patients who had one of the following were excluded:stroke,brain injury,other types of shock,severe heart failure,acute myocardial infarction,age below 18 years,pregnancy,end-stage disease,cardiac arrest,extensive burns,oral bleeding,difficulty in opening the mouth,and the onset of septic shock beyond 24 hours.Patients treated with the standard protocol of EGDT were included.Transcutaneous pressure of oxygen and carbon dioxide(PtcO_2,PtcCO_2) were monitored and hemodynamic measurements were obtained.Side-stream dark field(SDF) imaging device was applied to obtain sublingual microcirculation.Hemodynamics,tissue oxygen,and sublingual microcirculation were compared before and after EGDT.If the variable meets the normal distribution,Student's t test was applied.Otherwise,Wilcoxon's rank-sum test was used.Correlation between variables was analyzed with Pearson's product-moment correlation coefficient method.RESULTS:Twenty patients were involved,but one patient wasn't analyzed because he didn't meet the EGDT criteria.PtcO_2 and PtcCO_2 were monitored in 19 patients,of whom sublingual microcirculation was obtained.After EGDT,PtcO_2 increased from 62.7+24.0 mmHg to 78.0±30.9mmHg(P<0.05) and tissue oxygenation index(PtcO_2/FiO_2) was 110.7+60.4 mmHg before EGDT and 141.6±78.2 mmHg after EGDT(P<0.05).The difference between PtcCO_2 and PCO_2 decreased significantly after EGDT(P<0.05).The density of perfused small vessels(PPV) and microcirculatory flow index of small vessels(MFI) tended to increase,but there were no significant differences between them(P>0.05).PtcO_2,PtcO_2/FiO_2,and PtcCO_2 were not linearly related to central venous saturation,lactate,oxygen delivery,and oxygen consumption(P>0.05).CONCLUSION:Peripheral perfusion was improved after EGDT in patients with septic shock,and it was not exactly reflected by the index of systemic perfusion. 展开更多
关键词 Transcutaneous pressure of oxygen Transcutaneous pressure of carbon dioxide MICROCIRCULATION Septic shock EGDT Tissue perfusion Tissue oxygenation Sidestream dark field imaging
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