A series of TiO2/Bi2O3 heterojunction microfibers have been fabricated using cotton fibers as bio-templates, and characterized by XRD, SEM and UV-Vis techniques. Results reveal that Bi2O3 in the TiO2/Bi2O3 sample is a...A series of TiO2/Bi2O3 heterojunction microfibers have been fabricated using cotton fibers as bio-templates, and characterized by XRD, SEM and UV-Vis techniques. Results reveal that Bi2O3 in the TiO2/Bi2O3 sample is assigned to monoclinic and tetragonal mix-crystal phase. Fibers lengths can reach several micrometers and diameters range from 0.5 μm to 3 μm. Compared with pure TiO2 and Bi2O3, TiO2/Bi2O3 samples display better absorption in visible light region. Photocatalytic activity was evaluated by degradation of MB under visible light irradiation. TiO2/Bi2O3 microfibers exhibite much higher activity than pure TiO2 and Bi2O3, and 22.84%TiO2/Bi2O3 can achieve the decomposition of about 95%MB, which is attributed to synergistic effects of the strong visible-light absorption of TiO2/Bi2O3 microfibers and the heterojunction formed between TiO2 and Bi2O3.展开更多
能量在果蔬保鲜及衰老过程中起着至关重要的作用,为研究O2/CO2气调对西兰花能量代谢及保鲜效果的影响,本实验以自然空气为对照(CK),研究体积分数20%O2+80%CO2、50%O2+50%CO2、80%O2+20%CO2气调环境对西兰花10℃贮藏过程中pH值和丙酮酸...能量在果蔬保鲜及衰老过程中起着至关重要的作用,为研究O2/CO2气调对西兰花能量代谢及保鲜效果的影响,本实验以自然空气为对照(CK),研究体积分数20%O2+80%CO2、50%O2+50%CO2、80%O2+20%CO2气调环境对西兰花10℃贮藏过程中pH值和丙酮酸脱氢酶(pyruvate dehydrogenase,PDH)、琥珀酸脱氢酶(succinate dehydrogenase,SDH)和细胞色素c氧化酶(cytochrome c oxidase,CCO)活力及能荷水平、色调(H值)、VC含量和水分质量分数的影响。结果表明:与50%O2+50%CO2处理组相比,过高比例的CO2(20%O2+80%CO2)处理可引起西兰花pH值的明显降低,进而造成PDH、SDH和CCO活力的下降和能荷水平的降低,最终造成贮藏期间西兰花VC含量、色调和水分质量分数的下降;过高比例的O2(80%O2+20%CO2)处理虽在贮藏前期提高了PDH、SDH和CCO活力,但在后期迅速下降,不利于建立平稳而持续的能量供应体系。适宜的O2/CO2气调如50%O2+50%CO2则可调节西兰花体内pH值和呼吸关键酶活力,建立持续稳定的能量供应体系并很好地维持西兰花贮藏品质。相关性分析表明,能荷水平与西兰花VC含量、色调和水分质量分数具有很高的正相关性,相关系数最高达0.996,因此,能荷变化可作为判断西兰花贮藏条件优劣的衡量指标。展开更多
基金V. ACKNOWLEDGEMENTS This work was supported by the Scientific Research Program Funded by Shaanxi Provincial Education Department （No.2013JK0690）, and the Shaanxi Province Natural Science Foundation （No.2013JM2013）, the National Natural Science Foundation of China （No.21203160）, and the Special Research Fund of Xianyang Normal University （No. 11XSYK204）.
文摘A series of TiO2/Bi2O3 heterojunction microfibers have been fabricated using cotton fibers as bio-templates, and characterized by XRD, SEM and UV-Vis techniques. Results reveal that Bi2O3 in the TiO2/Bi2O3 sample is assigned to monoclinic and tetragonal mix-crystal phase. Fibers lengths can reach several micrometers and diameters range from 0.5 μm to 3 μm. Compared with pure TiO2 and Bi2O3, TiO2/Bi2O3 samples display better absorption in visible light region. Photocatalytic activity was evaluated by degradation of MB under visible light irradiation. TiO2/Bi2O3 microfibers exhibite much higher activity than pure TiO2 and Bi2O3, and 22.84%TiO2/Bi2O3 can achieve the decomposition of about 95%MB, which is attributed to synergistic effects of the strong visible-light absorption of TiO2/Bi2O3 microfibers and the heterojunction formed between TiO2 and Bi2O3.
文摘能量在果蔬保鲜及衰老过程中起着至关重要的作用,为研究O2/CO2气调对西兰花能量代谢及保鲜效果的影响,本实验以自然空气为对照(CK),研究体积分数20%O2+80%CO2、50%O2+50%CO2、80%O2+20%CO2气调环境对西兰花10℃贮藏过程中pH值和丙酮酸脱氢酶(pyruvate dehydrogenase,PDH)、琥珀酸脱氢酶(succinate dehydrogenase,SDH)和细胞色素c氧化酶(cytochrome c oxidase,CCO)活力及能荷水平、色调(H值)、VC含量和水分质量分数的影响。结果表明:与50%O2+50%CO2处理组相比,过高比例的CO2(20%O2+80%CO2)处理可引起西兰花pH值的明显降低,进而造成PDH、SDH和CCO活力的下降和能荷水平的降低,最终造成贮藏期间西兰花VC含量、色调和水分质量分数的下降;过高比例的O2(80%O2+20%CO2)处理虽在贮藏前期提高了PDH、SDH和CCO活力,但在后期迅速下降,不利于建立平稳而持续的能量供应体系。适宜的O2/CO2气调如50%O2+50%CO2则可调节西兰花体内pH值和呼吸关键酶活力,建立持续稳定的能量供应体系并很好地维持西兰花贮藏品质。相关性分析表明,能荷水平与西兰花VC含量、色调和水分质量分数具有很高的正相关性,相关系数最高达0.996,因此,能荷变化可作为判断西兰花贮藏条件优劣的衡量指标。
文摘目的探讨动静脉二氧化碳分压差/氧含量差[P(v-a)CO2/C(a-v)O2]在早期重症急性胰腺炎(severe acute pancreatitis,SAP)患者中的预后评估价值.方法自2017年8月至2018年10月连续性纳入78例SAP患者,根据患者治疗后P(v-a)CO2/C(a-v)O2是否上升分为两组,研究组(上升组,n=32例)和对照组(下降组,n=46例).比较两组一般临床资料,病程中器官功能障碍并发症发生率、临床预后及氧代谢指标,并评估氧代谢指标对患者的预测价值.结果研究组病情危重度、CT评分、胰腺坏死范围及APACHEⅡ评分明显高于对照组(P<0.05);同时病程中研究组休克、急性呼吸窘迫综合征、急性肾损伤、胰腺坏死组织感染(IPN)等并发症发生率明显高于对照组(P<0.05).且与对照组比较,研究组IPN发生更早、ICU及住院天数更长、病死率更高(P<0.05).治疗前两组P(v-a)CO2/C(a-v)O2差异无统计学意义,但研究组治疗后P(v-a)CO2/C(a-v)O2(mm Hg/mL:2.51±1.37 vs.1.91±1.29,P=0.031)以及治疗前后P(v-a)CO2和乳酸明显高于对照组(P<0.05).多因素Logistics回归分析发现,治疗前患者住院死亡危险因素为P(v-a)CO2(P=0.017)及血乳酸(P=0.021),治疗后为P(v-a)CO2(P=0.009)、P(v-a)CO2/C(a-v)O2(P=0.019)及血乳酸(P=0.023).ROC曲线提示,治疗前P(v-a)CO2对SAP死亡预测价值最高,曲线下面积为0.762,最佳诊断界值为7.69 mm Hg;治疗后P(v-a)CO2/C(a-v)O2对SAP死亡预测价值最高,曲线下面积为0.840,最佳诊断界值为2.05 mm Hg/mL.结论P(v-a)CO2/C(a-v)O2在早期SAP患者预后评估中具有良好的临床应用价值,值得临床推广.
