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Effect of N_(2) partial pressure on comprehensive properties of antibacterial TiN/Cu nanocomposite coating
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作者 Hui Liu Yanhui Zhao +10 位作者 Chuanshi Sui Yi Li Muhammad Ali Siddiqui Susu Li Tong Li Shuyuan Zhang Hai Wang Tao Jin Ling Ren Ke Yang Ning Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第1期131-143,共13页
Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN... Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN/Cu nanocomposite coatings with various N_(2) partial pressures were deposited on 304 stainless steels(SS)using an arc ion plating(AIP)system,named TiN/Cu-x(x=0.5,1.0,1.5 Pa).The results of X-ray diffraction analysis,energy-dispersive X-ray spectroscopy,and scanning electron microscopy showed that the N_(2) partial pressures determined the Cu contents,surface defects,and crystallite sizes of TiN/Cu nanocomposite coatings,which further influenced the comprehensive abilities.And the hardness and wear resistances of TiN/Cu coatings were enhanced with increase of the crystallite sizes.Under the co-actions of surface defects,crystallite sizes,and Cu content,TiN/Cu-1.0 and TiN/Cu-1.5 coatings possessed excellent corrosion resistance.Besides,the biological tests proved that all the TiN/Cu coatings showed no cytotoxicity with strong antibacterial ability.Among them,TiN/Cu-1.5 coating significantly promoted the cell proliferation,which is expected to be a novel antibacterial,corrosion-resistant,and wear-resistant coating on the surfaces of medical implants. 展开更多
关键词 N_(2)partial pressure TiN/Cu coating wear resistance corrosion behavior antibacterial ability CYTOCOMpATIBILITY
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夏季东海西部表层海水中的pCO_2及海-气界面通量 被引量:34
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作者 谭燕 张龙军 +1 位作者 王凡 胡敦欣 《海洋与湖沼》 CAS CSCD 北大核心 2004年第3期239-245,共7页
根据 2 0 0 1年夏季长江口及东海西部海域表层海水pCO2 的实测数据 ,结合水文、化学和生物等要素的同步观测资料 ,对该海域pCO2 分布和变化的重要影响因素进行了探讨。结果表明 ,长江冲淡水是造成东海西部海域表层海水pCO2 分布不均匀... 根据 2 0 0 1年夏季长江口及东海西部海域表层海水pCO2 的实测数据 ,结合水文、化学和生物等要素的同步观测资料 ,对该海域pCO2 分布和变化的重要影响因素进行了探讨。结果表明 ,长江冲淡水是造成东海西部海域表层海水pCO2 分布不均匀的主要原因。利用Wan ninkhof( 1 992 )提出的通量模式计算 ,长江口口门附近海域和浙江近岸海域为CO2 的源区 ,1 2 3°E以东的调查海域表现为大气CO2 的汇 ,尤其是以 1 2 3°E ,32°N为中心 ,存在着一个极强的大气CO2 汇区。就整个东海西部海域而言 ,夏季可从大气净吸收 1 5 3× 1 0 4 tC。 展开更多
关键词 东海 二氧化碳分压(pco2) 碳通量
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Thermokinetic and conductivity analyzes of the high CO2 chemisorption on Li5AlO4 and alkaline carbonate impregnated Li5AlO4 samples:Effects produced by the use of CO2 partial pressures and oxygen addition
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作者 Pedro Sánchez-Camacho J.Francisco Gómez-García Heriberto Pfeiffer 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第5期919-926,共8页
The effect of COpartial pressure was evaluated during the COchemisorption in penta lithium aluminate(LiAlO), using different COand Opartial pressures in the presence or absence of alkaline carbonates. Results showed... The effect of COpartial pressure was evaluated during the COchemisorption in penta lithium aluminate(LiAlO), using different COand Opartial pressures in the presence or absence of alkaline carbonates. Results showed that using low PO(0.1) did not affect the kinetic and final COchemisorption process. Moreover, small additions of oxygen(PO= 0.05) into the mixture flue gas, seemed to increase the COchemisorption. Additionally, the presence of alkaline carbonates modified the COcapture temperature range. COchemisorption kinetic parameters were determined assuming a double exponential model where direct COchemisorption and COchemisorption controlled by diffusion processes are considered.Finally, ionic diffusion was analyzed by ionic conduction analysis, where all the gravimetric and ionic measurements were in good agreement showing different diffusion processes depending on temperature.Finally, the oxygen and alkaline carbonate additions have positive effects during the COchemisorption process in LiAlO, and a possible reaction mechanism is presented. 展开更多
关键词 co2 capture Thermogravimetric analysis partial pressure Ionic conduction
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Effect of N_2-Gas Partial Pressure on the Structure and Properties of Copper Nitride Films by DC Reactive Magnetron Sputtering
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作者 刘祖黎 李兴鳌 +3 位作者 左安友 袁作彬 杨建平 姚凯伦 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第2期147-151,共5页
Copper nitride thin films were deposited on glass substrates by reactive direct current (DC) magnetron sputtering at various N2-gas partial pressures and room temperature. Xray diffraction measurements showed that t... Copper nitride thin films were deposited on glass substrates by reactive direct current (DC) magnetron sputtering at various N2-gas partial pressures and room temperature. Xray diffraction measurements showed that the films were composed of Cu3N crystallites and exhibited a preferential orientation of the [111] direction at a low nitrogen gas (N2) partial pressure. The film growth preferred the [111] and the [100] direction at a high N2 partial pressure. Such preferential film growth is interpreted as being due to the variation in the Copper (Cu) nitrification rate with the N2 pressure. The N2 partial pressure affects not only the crystal structure of the film but also the deposition rate and the resistivity of the Cu3N film. In our experiment, the deposition rate of Cu3N films was 18 nm/min to 30 nm/min and increased with the N2 partial pressure. The resistivity of the Cu3N films increased sharply with the increasing N2 partial pressure. At a low N2 partial pressure, the Cu3N films showed a metallic conduction mechanism through the Cu path, and at a high N2 partial pressure, the conductivity of the Cu3N films showed a semiconductor conduction mechanism. 展开更多
关键词 Cu3N film DC magnetron sputtering N2-gas partial pressure RESISTIVITY
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FiO_2及PEEP对腹腔镜行下宫颈癌根治术全麻患者P_(a-ET)CO_2的影响 被引量:1
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作者 王瑚 曹奕 华晓君 《实用癌症杂志》 2014年第1期62-65,共4页
目的评价不同吸入氧浓度(FiO2)和呼气末正压(PEEP)对腹腔镜下行宫颈癌根治术全麻患者动脉血-呼气末二氧化碳分压差[P(a-ET)CO2]的影响。方法将108例腹腔镜下行根治术的宫颈癌患者分为4组,每组27例:第1组给予FiO2(100%的纯氧)和0 mmHg的P... 目的评价不同吸入氧浓度(FiO2)和呼气末正压(PEEP)对腹腔镜下行宫颈癌根治术全麻患者动脉血-呼气末二氧化碳分压差[P(a-ET)CO2]的影响。方法将108例腹腔镜下行根治术的宫颈癌患者分为4组,每组27例:第1组给予FiO2(100%的纯氧)和0 mmHg的PEEP;第2组给予FiO2(100%的纯氧)和7.0 mmHg的PEEP;第3组给予FiO2(50%的纯氧)和0 mmHg的PEEP;第4组给予FiO2(50%的纯氧)和7.0 mmHg的PEEP,均在即时(T1)和30 min(T2)和60 min(T3)三个时间点时分别检测动脉血二氧化碳分压(PaCO2),呼气末二氧化碳分压(P ET CO2),P(a-ET)CO2。结果不同时间点组间比较:T1时1、2、3、4组间PaCO2、和P(a-ET)CO2相互比较差异无统计学意义(P>0.05);T2和T3时,1组与2组比较、3组与4组比较、1组与3组比较、2组与4组比较PaCO2和P(a-ET)CO2差异均有统计学意义(P<0.05)。结论 FiO2浓度较高时,同时一定要相应提高PEEP,则可以有效降低P(a-ET)CO2;PEEP较低时,同时一定要降低FiO2浓度,这样可以有效降低P(a-ET)CO2。 展开更多
关键词 收入氧浓度 呼气末正压 动脉血二氧化碳分压差 气末二氧化碳分压
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Carbon dioxide partial pressure and its diffusion flux in karst surface aquatic ecosystems:a review
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作者 Xingxing Cao Qixin Wu +1 位作者 Wanfa Wang Pan Wu 《Acta Geochimica》 EI CAS CSCD 2023年第5期943-960,共18页
Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(... Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(2)partial pressure(pCO_(2))and its diffusion flux(FCO_(2))in karst surface aquatic ecosystems,mainly rivers,lakes,and reservoirs,and their influencing factors summarized the methods for monitoring CO_(2)emissions in karst aquatic ecosystems and discussed their adaptation conditions in karst areas.The pCO_(2)and FCO_(2)decreased in the order of rivers>reservoirs>lakes,and the values in karst lakes were eventually significantly lower than those in global lakes.The pCO_(2)and FCO_(2)of karst aquatic ecosystems had patterns of variation with diurnal,seasonal,water depth and hydrological cycles,and spatial and temporal hetero-geneity.The sources of CO_(2)in karst waters are influenced by both internal and external sources,and the key spatial and temporal factors affecting the CO_(2)emissions from karst rivers,lakes,and reservoirs were determined in terms of physicochemical indicators,biological factors,and bio-genic elements;additionally,the process of human activity interference on CO_(2)emissions was discussed.Finally,a conceptual model illustrating the impacts of urban devel-opment,agriculture,mining,and dam construction on the CO_(2)emissions at the karst surface aquatic ecosystem is presented.Meanwhile,based on the disadvantages existing in current research,we proposed several important research fields related to CO_(2)emissions from karst surface aquatic ecosystems. 展开更多
关键词 Karst area RIVER LAKE RESERVOIR partial pressure of CO_(2) CO_(2)diffusion flux
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Evaluation of the net CO_2 uptake in the Canada Basin in the summer of 2008 被引量:2
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作者 SUN Heng GAO Zhongyong +2 位作者 LU Peng XIU Peng CHEN Liqi 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第8期94-100,共7页
The third Chinese National Arctic Research Expedition (CHINARE) was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 (pCO2) was measured, and sea water samples were ... The third Chinese National Arctic Research Expedition (CHINARE) was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 (pCO2) was measured, and sea water samples were collected for CO2 measurement in the Canada Basin. The distribution of pCO2 in the Canada Basin was determined, the influencing factors were addressed, and the air-sea CO2 flux in the Canada Basin was evaluated. The Canada Basin was divided into three regions: the ice-free zone (south of 77°N), the partially ice-covered zone (77°-80°N), and the heavily ice-covered zone (north of 80°N). In the ice-free zone, pCO2 was high (320 to 368 patm, 1 patm=0.101 325 Pa), primarily due to rapid equilibration with atmospheric CO2 over a short time. In the partially ice-covered zone, the surface pCOs was relatively low (250 to 270 patm) due to ice-edge blooms and icemelt water dilution. In the heavily ice-covered zone, the seawater pCO2 varied between 270 and 300 laatm due to biological COs removal, the transportation of low pCOs water northward, and heavy ice cover. The surface seawater pCO2 during the survey was undersaturated with respect to the atmosphere in the Canada Basin, and it was a net sink for atmospheric CO2. The summertime net CO2 uptake of the ice-free zone, the partially ice-covered zone and the heavily ice-covered zone was (4.14±1.08), (1.79±0.19), and (0.57±0.03) Tg/a (calculated by carbon, 1 Tg=10^12 g), respectively. Overall, the net COs sink of the Canada Basin in the summer of 2008 was (6.5+1.3) Tg/a, which accounted for 4%-10% of the Arctic Ocean COs sink. 展开更多
关键词 Canada Basin net co2 uptake partial pressure of co2
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Distributions and Relationships of CO_2,O_2,and Dimethylsulfide in the Changjiang(Yangtze) Estuary and Its Adjacent Waters in Summer
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作者 WU Xi TAN Tingting +3 位作者 LIU Chunying LI Tie LIU Xiaoshou YANG Guipeng 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第2期320-334,共15页
The distributions and relationships of O_2, CO_2, and dimethylsulfide (DMS) in the Changjiang (Yangtze) Estuary and its adjacent waters were investigated in June 2014. In surface water, mean O_2 saturation level, part... The distributions and relationships of O_2, CO_2, and dimethylsulfide (DMS) in the Changjiang (Yangtze) Estuary and its adjacent waters were investigated in June 2014. In surface water, mean O_2 saturation level, partial pressure of CO_2 (pCO_2), and DMS concentrations (and ranges) were 110% (89%–167%), 374μatm (91–640 μatm), and 8.53 nmol L^(-1) (1.10–27.50 nmol L^(-1)), respectively. The sea-to-air fluxes (and ranges) of DMS and CO_2 were 8.24 μmol m^(-2)d^(-1) (0.26–62.77 μmol m^(-2)d^(-1)), and -4.7 mmol m^(-2)d^(-1) (-110.8-31.7 mmol m^(-2)d^(-1)), respectively. Dissolved O_2 was oversaturated, DMS concentrations were relatively high, and this region served as a sink of atmospheric CO_2. The pCO_2 was significantly and negatively correlated with the O_2 saturation level, while the DMS concentration showed different positive relationships with the O_2 saturation level in different water masses. In vertical profiles, a hypoxic zone existed below 20 m at a longitude of 123?E. The stratification of temperature and salinity caused by the Taiwan Warm Current suppressed seawater exchange between upper and lower layers, resulting in the formation of a hypoxic zone. Oxidative de-composition of organic detritus carried by the Changjiang River Diluted Water (CRDW) consumed abundant O_2 and produced additional CO_2. The DMS concentrations decreased because of low phytoplankton biomass in the hypoxic zone. Strong correlations ap-peared between the O_2 saturation level, pCO_2 and DMS concentrations in vertical profiles. Our results strongly suggested that CRDW played an important role in the distributions and relationships of O_2, CO_2, and DMS. 展开更多
关键词 O2 partial pressure of co2(pco2) dimethylsulfide(DMS) CHANGJIANG ESTUARY distribution relationship
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H_2S分压对油管钢CO_2/H_2S腐蚀的影响 被引量:44
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作者 张清 李全安 +1 位作者 文九巴 白真权 《腐蚀科学与防护技术》 CAS CSCD 北大核心 2004年第6期395-397,共3页
采用高温高压釜 ,辅以失重法和扫描电镜 ,对不同H2 S分压下 (1 4kPa,2 0kPa ,6 0kPa ,12 0kPa)油管钢N80、P110的CO2 /H2 S腐蚀进行了研究 .结果表明 ,在试验H2 S分压范围内 ,随着H2 S分压的升高 ,两种钢的腐蚀速率先增后降 ,且都在H2 ... 采用高温高压釜 ,辅以失重法和扫描电镜 ,对不同H2 S分压下 (1 4kPa,2 0kPa ,6 0kPa ,12 0kPa)油管钢N80、P110的CO2 /H2 S腐蚀进行了研究 .结果表明 ,在试验H2 S分压范围内 ,随着H2 S分压的升高 ,两种钢的腐蚀速率先增后降 ,且都在H2 S分压为 2 0kPa时取得最大值 . 展开更多
关键词 油管钢 co2/H2S腐蚀 失重法 腐蚀速率 高温高压 扫描电镜 分压
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CO_(2)分压对S135钢在CO_(2)/H_(2)S共存体系中腐蚀行为的影响
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作者 高科超 尚锁贵 +3 位作者 高强勇 马金鑫 张智 刘婉颖 《材料保护》 CAS CSCD 2024年第2期67-75,共9页
为了给井下油气管材的选择和腐蚀预测模型的建立提供理论依据,利用高温高压反应釜进行S135钢在CO_(2)/H_(2)S共存体系中的腐蚀模拟试验,采用失重法、恒载荷法、X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)、三维轮廓扫描仪等手段研究了CO... 为了给井下油气管材的选择和腐蚀预测模型的建立提供理论依据,利用高温高压反应釜进行S135钢在CO_(2)/H_(2)S共存体系中的腐蚀模拟试验,采用失重法、恒载荷法、X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)、三维轮廓扫描仪等手段研究了CO_(2)分压对S135钢在温度100℃、CO_(2)/H_(2)S共存体系中腐蚀行为的影响及规律。结果表明,随CO_(2)分压升高,S135钢的腐蚀速率增大,屈服强度损伤加剧,CO_(2)分压为5,10,15,20 MPa时,其屈服强度(σs)损伤率分别为1.4%、3.6%、4.5%和15.9%;抗拉强度(σb)损伤率分别为1.2%、3.4%、5.2%和15.4%。S135钢在低CO_(2)分压下发生全面腐蚀,随CO_(2)分压增大发展为以全面腐蚀为主,辅以局部腐蚀。应力腐蚀裂纹在萌生阶段以局部阳极溶解作用(点蚀)为主,随CO_(2)分压增大应力腐蚀裂纹更易生长,应力腐蚀敏感性增加,加剧了基体的腐蚀进程。 展开更多
关键词 CO_(2)分压 S135钢 CO_(2)/H_(2)S 失重腐蚀 应力腐蚀
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Clinical Study of P_(ET)CO_2 in One-lung Ventilation
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作者 张传汉 马自成 金士翱 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 1996年第3期179-182,共4页
Fourty-eight patients (ASA physical status Ⅰ - Ⅱ) undergoing selected thoracotomy and pulmonectomy were studied. They were divided into two groups according to different respiratory modes, two-lung ventilation (TLV)... Fourty-eight patients (ASA physical status Ⅰ - Ⅱ) undergoing selected thoracotomy and pulmonectomy were studied. They were divided into two groups according to different respiratory modes, two-lung ventilation (TLV) and onelung ventilation (OLV) or TLV and OLV with a Bain cyclic system for CPAP on the side of operated lung. PETCO2 and PaCO2 were measured after 30 min TLV,30 min and 60 min OLV, and repeated TLV (R-TLV) 30 min after pulmonectomy, to evaluate the difference between PETCO2 and PaCO2 in OLV and to observethe effect of abating hypoxemia and discharge of CO2 in OLV with Bain system.Our results showed that the PaCO2 and PETCO2 in different test groups were normal though the measured values in OLV were slightly higher than that in TLV (P<0. 05) , and then they were recovered after R-TLV (P>0. 05). There was nosignificant difference between group 1. and 2. in OLV (P>0. 05). There was aclose correlation between PETCO2 and PaCO2 (P<0. 05). The differences of the calculated P(a-ET)CO2 and radio of PETCO2/PaCO2 in different ventilation modes were not significant. Hypoxemia in OLV was corrected by Bain system, but the discharge of CO2 was not affected. The results showed that measurement of PET CO2 as a non-invasive procedure can be commonly used to monitor OLV. 展开更多
关键词 CO_2 partial pressure one-lung ventilation non-invasive monitoring
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倍增CO_2分压对水稻和矶子草冠层光合潜力的影响 被引量:9
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作者 孙谷畴 赵平 +1 位作者 曾小平 彭少麟 《生态学杂志》 CAS CSCD 北大核心 2003年第4期1-5,共5页
倍增CO2 分压增高水稻的光饱和光合速率、表观量子产率和光能转换效率 ,而在倍增CO2 分压下矶子草的相关光合参数降低 ,既水稻对高CO2 分压表现为正响应 ,而矶子草在高CO2 下光合作用下调。在倍增CO2 分压下 ,水稻的Rubisco羧化速率和... 倍增CO2 分压增高水稻的光饱和光合速率、表观量子产率和光能转换效率 ,而在倍增CO2 分压下矶子草的相关光合参数降低 ,既水稻对高CO2 分压表现为正响应 ,而矶子草在高CO2 下光合作用下调。在倍增CO2 分压下 ,水稻的Rubisco羧化速率和氧化速率均见增高 ,而矶子草在高CO2 分压下 ,Rubisco羧化速率降低 ,而氧化速率略见增高。倍增CO2 分压并不明显改变水稻的不包括光呼吸的CO2 补偿点Γ ,但矶子草Γ 略见增高。在高CO2 分压下可能改变矶子草Rubisco生化特性。倍增CO2 分压降低两种供试植物的光下呼吸速率。水稻在倍增CO2 分压下其Rubisco最大羧化速率 (Vcmax)和最大电子传递速率 (Jmax)分别增高 9 3%和 2 0 7% ,而矶子草在高CO2 分压下则分别降低 5 7%和 3%。在倍增CO2 分压下水稻的净光合量增高约 5 % ,而矶子草则降低 13% ,植物种的不同特性可能影响植物在倍增CO2 下的碳积累。随着全球气候变化和大气CO2 分压增高 ,将有利于发挥水稻高光合产率的优势 ,由于矶子草在高CO2 分压下碳积累减少 ,从而可能限制其生长。大气CO2 展开更多
关键词 倍增co2分压 水稻 矶子草 冠层光合潜力
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CO_2分压对油管钢腐蚀产物膜的影响 被引量:8
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作者 张清 李全安 +2 位作者 文九巴 林冠发 白真权 《石油机械》 北大核心 2004年第4期13-14,36,共3页
利用静态高压釜对 3种油管钢N80、P1 1 0和J5 5进行了CO2 腐蚀试验 ,通过扫描电镜(SEM)对比分析了腐蚀产物膜的厚度和表面晶粒尺寸的变化规律。结果表明 ,在试验条件下 ,3种钢的腐蚀产物膜均为双层结构 ;膜厚随CO2 分压变化情况比较相... 利用静态高压釜对 3种油管钢N80、P1 1 0和J5 5进行了CO2 腐蚀试验 ,通过扫描电镜(SEM)对比分析了腐蚀产物膜的厚度和表面晶粒尺寸的变化规律。结果表明 ,在试验条件下 ,3种钢的腐蚀产物膜均为双层结构 ;膜厚随CO2 分压变化情况比较相近 ,在CO2 分压为 6 90MPa时均达到最大 ,在超临界压力以上急剧减小 ;表面晶粒尺寸随CO2 分压变化出现 2峰 1谷 ,在超临界压力以上急剧减小。 展开更多
关键词 油管 腐蚀作用 co2 超临界压力 石油 天然气
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电针在术中改善CO_2气腹应激损伤的临床研究 被引量:1
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作者 张翮 王兰 +5 位作者 张敏 陈彤宇 吴晓珲 陈静 鲍丹 沈卫东 《针灸临床杂志》 2013年第8期30-35,共6页
目的:通过检测术中胃粘膜CO2分压、胃粘膜ph值、白介素-2和表皮生长因子的变化,观察电针对术中CO2气腹应激损伤的改善效果。方法:收治妇科腹腔镜手术病人60例,行随机、单盲、对照的临床试验。病人分为两组,I组30例,施以常规全身麻醉;Ⅱ... 目的:通过检测术中胃粘膜CO2分压、胃粘膜ph值、白介素-2和表皮生长因子的变化,观察电针对术中CO2气腹应激损伤的改善效果。方法:收治妇科腹腔镜手术病人60例,行随机、单盲、对照的临床试验。病人分为两组,I组30例,施以常规全身麻醉;Ⅱ组30例,在常规全身麻醉基础上,复合穴位电针,从进入手术室开始一直持续到手术结束。在不同时间点获取反映CO2气腹应激损伤的相关数据,以备评价所用。结果:胃粘膜CO2分压、胃粘膜ph值、白介素-2和表皮生长因子的组间、组内数值变化均存在显著差异(P<0.01)。结论:电针应用在全麻妇科腹腔镜手术中,能够保证胃粘膜的血氧供应,防止胃粘膜局部缺血或低灌注,维持胃黏膜屏障的生理功能,达到减轻CO2气腹对机体应激损伤的临床效果。 展开更多
关键词 电针 co2气腹 胃粘膜co2分压 胃粘膜pH值 白介素-2 表皮生长因子
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载人航天器组合体CO_2分压控制策略分析 被引量:1
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作者 靳健 陈伯翰 《系统工程与电子技术》 EI CSCD 北大核心 2018年第6期1351-1357,共7页
随着载人航天技术的发展,载人航天器由单舱段构型逐渐发展成为多舱段组合体构型,其中一个或若干个舱段在舱间通风的支持下对组合体密封舱内空气环境进行集中控制。利用多学科建模工具Ecosimpro建立了载人航天器组合体CO_2分压控制计算模... 随着载人航天技术的发展,载人航天器由单舱段构型逐渐发展成为多舱段组合体构型,其中一个或若干个舱段在舱间通风的支持下对组合体密封舱内空气环境进行集中控制。利用多学科建模工具Ecosimpro建立了载人航天器组合体CO_2分压控制计算模型,对载人航天器组合体组建过程中,各舱CO_2分压水平进行了分析。当舱段数达到3个以上,将会出现非主控舱CO_2分压超标现象。针对CO_2分压超标现象,提出了3种控制策略:提高全部舱间通风量、更改CO_2控制系统位置、提高部分舱间通风量+更改CO_2控制系统位置,并对3种控制策略的效果进行了仿真分析。结果表明,更改CO_2控制系统位置并提高部分舱间通风量是最有效的载人航天器组合体CO_2分压控制策略。 展开更多
关键词 载人航天器组合体 co2分压 舱间通风 仿真分析 控制策略
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一种新型材料固井水泥石的抗高CO_(2)分压腐蚀性能评价
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作者 刘仕康 杨威 +3 位作者 王学春 石礼岗 山永林 彭云帆 《石油化工应用》 CAS 2024年第3期39-43,共5页
井下高温、高CO_(2)含量条件使水泥环长效封固周期寿命缩短,水泥环完整性保障难度增大,由于在较高的压力环境下CO_(2)呈现低黏度、高扩散性和高压缩性的超临界特性,会加剧水泥石的腐蚀。本文与常见的6种防腐材料进行防腐性能对比测试,... 井下高温、高CO_(2)含量条件使水泥环长效封固周期寿命缩短,水泥环完整性保障难度增大,由于在较高的压力环境下CO_(2)呈现低黏度、高扩散性和高压缩性的超临界特性,会加剧水泥石的腐蚀。本文与常见的6种防腐材料进行防腐性能对比测试,研发了可用于井下高温、高CO_(2)分压环境中的一种新型防腐材料。室内实验结果表明,新型火山灰混合材料由于二次水化反应消耗Ca(OH)_(2)提高水泥石长期强度,且电镜下微观观察分析,新型火山灰混合材料水泥石渗透率更低,CO_(2)环境中养护30 d后水泥石表面仍存在CaSiO_(3),表明侵蚀仍在表层进行。新型火山灰混合材料的水泥石具有30 d腐蚀深度1.17 mm、抗压强度衰退率2.6%、渗透率变化率2.1%更好的抗CO_(2)腐蚀能力,且具有良好的综合施工性能。 展开更多
关键词 高CO_(2)分压 抗CO_(2)腐蚀性能 新型火山灰混合材料 高温高压腐蚀测试
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亚热带珊瑚礁海域枯水季pCO_(2)的分布特征及CO_(2)汇源转换机制——以深圳杨梅坑海域为例
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作者 张卓 杨波 +6 位作者 崔洲平 林子燚 谢子强 郑惠娜 廖宝林 肖宝华 朱春华 《海洋科学》 CAS CSCD 北大核心 2023年第11期45-56,共12页
由于存在极高的初级生产和高效的碳代谢速率,珊瑚礁海域二氧化碳(CO_(2))的汇/源属性仍存有争议。为明晰中国典型珊瑚礁海域CO_(2)的汇源属性及驱动因素,作者基于2022年11月(秋季)和2023年2月(冬季)在深圳杨梅坑海域的调查结果并结合室... 由于存在极高的初级生产和高效的碳代谢速率,珊瑚礁海域二氧化碳(CO_(2))的汇/源属性仍存有争议。为明晰中国典型珊瑚礁海域CO_(2)的汇源属性及驱动因素,作者基于2022年11月(秋季)和2023年2月(冬季)在深圳杨梅坑海域的调查结果并结合室内培养实验所获得的数据,探究了枯水季节典型亚热带珊瑚礁海水二氧化碳分压(pCO_(2))的分布特征及主要控制机制。结果表明,调查期间pCO_(2)的变化较大,其范围为233.3~465.3μatm。秋季表现为大气CO_(2)的汇,CO_(2)吸收通量为1.66±0.41 mmol C/(m^(2)/d);冬季表现为大气CO_(2)的弱源,其释放通量为0.36±0.17 mmol C/(m^(2)/d)。调查期间(枯水季)杨梅坑海域受淡水输入的影响较小,季节性温度影响下的生物过程是驱动pCO_(2)变化的关键因素,其贡献pCO_(2)总变化量的73.6%(表层)和66.5%(底层)。其中,浮游植物光合作用的季节差异是导致海水CO_(2)汇源转变的主要成因,而微生物呼吸作用的影响甚微。相比较,物理过程(CO_(2)海-气交换、温度和盐度变化)对pCO_(2)的影响相对较小,其作用结果远低于生物过程。此外,珊瑚的代谢活动对杨梅坑局部海域pCO_(2)分布产生一定影响,造成礁区pCO_(2)值高于非礁区。因此,海气CO_(2)通量估算中不能忽视局部海域珊瑚代谢作用的影响。 展开更多
关键词 珊瑚礁 CO_(2)分压 海气CO_(2)通量 源汇特征 杨梅坑海域
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PETCO_(2)和吸入氧浓度水平与胸腔镜肺部手术单肺通气期间脑氧饱和度的关系
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作者 王现雷 刘文超 +1 位作者 周立杰 吴振宇 《临床和实验医学杂志》 2023年第19期2123-2126,共4页
目的 探讨呼气末二氧化碳分压(PETCO_(2))和吸入氧浓度(FiO_(2))水平与胸腔镜肺部手术单肺通气期间脑氧饱和度(ScO_(2))的关系。方法 前瞻性选取2020年3月至2022年3月在秦皇岛市第一医院行胸腔镜肺部手术单肺通气患者180例,观察低脑氧... 目的 探讨呼气末二氧化碳分压(PETCO_(2))和吸入氧浓度(FiO_(2))水平与胸腔镜肺部手术单肺通气期间脑氧饱和度(ScO_(2))的关系。方法 前瞻性选取2020年3月至2022年3月在秦皇岛市第一医院行胸腔镜肺部手术单肺通气患者180例,观察低脑氧合事件发生情况。分析发生和未发生低脑氧合事件患者临床资料,如性别、年龄、体重指数、病理类型、TNM分期、手术体位、麻醉时间、单肺通气时间、手术时间、心率、平均动脉压(MAP)、体温、pH、二氧化碳分压(PaCO_(2))、氧分压(PaO_(2))、吸入氧浓度(FiO_(2))、气道峰压(Ppeak)、PETCO_(2)、肺顺应性等差异。结果 共有66例患者发生低脑氧合事件,低脑氧合事件发生率为36.67%。发生和未发生低脑氧合事件患者性别、年龄、体重指数、病理类型等比较,差异均无统计学意义(P>0.05);发生低脑氧合事件患者动脉血PaCO_(2)、FiO_(2)和Ppeak分别为(38.43±3.34)mmHg、(72.32±8.23)%和(24.54±2.54)cmH2O,明显高于未发生低脑氧合事件患者[(37.02±3.65)mmHg、(63.20±7.56)%和(21.12±2.42)cmH2O],而PETCO_(2)为(41.43±5.32)mmHg,明显低于未发生低脑氧合事件患者[(49.32±6.10)mmHg],差异均有统计学意义(P<0.05)。FiO_(2)与ScO_(2)降低幅度呈正相关(r=0.434,P<0.05),而PETCO_(2)与ScO_(2)降低幅度呈负相关(r=-0.543,P<0.05)。Logistic回归分析,结果显示:FiO_(2)和PETCO_(2)是患者发生低脑氧合事件的影响因素(P<0.05)。结论 PETCO_(2)和FiO_(2)与胸腔镜肺部手术单肺通气期间ScO_(2)降低幅度存在相关性,是患者发生低脑氧合事件的影响因素。 展开更多
关键词 呼气末二氧化碳分压 吸入氧浓度 胸腔镜肺部手术 单肺通气 脑氧饱和度
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Distributions and air-sea fluxes of CO_2 in the summer Bering Sea 被引量:2
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作者 CHEN Liqi GAO Zhongyong +2 位作者 SUN Heng CHEN Baoshan CAI Wei-jun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第6期1-8,共8页
The 3rd Chinese National Arctic Research Expedition (CHINARE-Arctic III) was carried out from July to September in 2008. The partial pressure of CO2 (pCO2) in the atmosphere and in surface seawater were determined... The 3rd Chinese National Arctic Research Expedition (CHINARE-Arctic III) was carried out from July to September in 2008. The partial pressure of CO2 (pCO2) in the atmosphere and in surface seawater were determined in the Bering Sea during luly 11-27, 2008, and a large number of seawater samples were taken for total alkalinity (TA) and total dissolved inorganic carbon (DIC) analysis. The distributions of CO2 parameters in the Bering Sea and their controlling factors were discussed. The pCO2 values in surface seawater presented a drastic variation from 148 to 563 laatm (1 μatm = 1.013 25× 10-1Pa). The lowest pCOz values were observed near the Bering Sea shelf break while the highest pCO2 existed at the western Bering Strait. The Bering Sea generally acts as a net sink for atmospheric CO2 in summer. The air-sea CO2 fluxes in the Bering Sea shelf, slope, and basin were estimated at -9.4, -16.3, and -5.1 mmol/(m2.d), respectively. The annual uptake of CO2 was about 34 Tg C in the Bering Sea. 展开更多
关键词 partial pressure of co2 co2 system air-sea co2 flux Bering Sea
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PetCO2的变化联合被动抬腿试验在脓毒性休克机械通气患者容量反应性的应用 被引量:4
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作者 张二辉 杨超 +6 位作者 王玉珍 高海波 白奎 张春民 杨柳 庄久杰 石利红 《临床肺科杂志》 2020年第10期1533-1538,共6页
目的探讨PetCO 2的变化联合被动抬腿试验在脓毒性休克机械通气患者容量反应性的临床应用价值。方法选择2017年6月至2019年03月我院ICU病房收治的脓毒性休克机械通气患者56例。分别在基线、被动抬腿试验、容量负荷试验前后监测患者PetCO ... 目的探讨PetCO 2的变化联合被动抬腿试验在脓毒性休克机械通气患者容量反应性的临床应用价值。方法选择2017年6月至2019年03月我院ICU病房收治的脓毒性休克机械通气患者56例。分别在基线、被动抬腿试验、容量负荷试验前后监测患者PetCO 2和血流动力学参数(心率HR、收缩压SBP、舒张压DBP、平均动脉压MAP、中心静脉压CVP、每搏量SV、每博变异率SVV、心指数CI)变化。以容量负荷试验△CI的值分为两组(有容量反应组和无容量反应组),以接受者操作特征曲线(ROC曲线)分析被动抬腿试验后PetCO 2的变化对容量反应性的预测价值。结果56例患者中,31例有容量反应性(有容量反应组),25例无容量反应性(无容量反应组)。PLR后有容量反应性组血流动力学参数(HR、SBP、DBP、MAP、SV、SVV、CI)和PetCO 2水平较无容量反应性组对比显著升高(P<0.05)。被动抬腿试验后,△CIPLR与△PetCO 2PLR呈正相关(r=0.685,P=0.012)。PLR后△CIPLR预测容量反应性的ROC曲线下面积为0.863±0.062(95%CI 0.761~0.964;P<0.05),以15%为临界值,敏感性为83.9%,特异性84.0%;PLR后△PetCO 2PLR预测容量反应性的ROC曲线下面积为0.828±0.055(95%CL 0.719~0.936;P<0.05),以4.5%为临界值,敏感性为66.7%,特异性92.0%。结论PLR中PetCO 2的变化能反映脓毒性性休克机械通气患者心输出量的变化,可以对容量复苏过程中容量反应性起到良好预测作用。 展开更多
关键词 脓毒性休克 呼气末二氧化碳分压 被动抬腿试验 容量反应性 容量负荷试验
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