氧浓度对瓦斯检定器示值的影响

阐述了氧气浓度变化对光干涉型和催化燃烧型瓦斯检定器检测示值的影响范围及原因．并有针对性地提出了防范对策。     

BOF-LF-VD冶炼非调质N80钢工艺

对鞍钢采用氧气顶吹转炉(BOF)冶炼、非调质工艺开发的N80级油井管用钢进行了系统的工艺设计、实验室研究、工业实验及工业生产研究.提出了V、N微合金化取代常规淬火和回火工艺,设计了非调质N80的化学成分,确定了符合鞍钢氧气转炉大规模生产非调质N80的冶炼工艺以及各工序的工艺控制要点,特别是确定了实际工况下氧气转炉终点碳、氧、温度的回归公式以及VD底吹增氮动力学模型等关键工艺要点.连续生产的实测数据分析结果表明:非调质N80冶炼工艺稳定可行,化学成分、冶炼工艺设计合理,力学性能和使用性能均满足API Spec 5CT及油井管生产的特殊要求.     

食品活性包装

包装类型是影响包装食品货架期的重要因素之一．活性包装可以降低外部因素对包装内部食品的影响．笔者综述了食品的活性包装及其应用，以及食品活性包装的发展方向．     

鸟类后气囊O2和CO2的来源

分析了鸟类后气囊CO_2比前气囊低、比吸入气体高,O_2比前气囊高、比吸入气体低的原因,实验表明气囊壁的气体交换和腹支气管气体的再循环对后气囊O_2和CO_2成分影响很小,后气囊残气同吸入气的混合、无效腔气体的再吸入以及新肺三级支气管的气体交换是主要的影响因素。     

Programmed cell death features in apple suspension cells under low oxygen culture

Suspension-cultured apple fruit cells (Malus pumila Mill. cv. Braeburn) were exposed to a low oxygen atmosphere to test whether programmed cell death (PCD) has a role in cell dysfunction and death under hypoxic conditions. Protoplasts were prepared at various times after low oxygen conditions were established, and viability tested by triple staining with fluorescein diacetate (FDA), propidium iodide (PI) and Hoechst33342 (HO342). DNA breakdown and phosphatidylserine exposure on the plasma membrane were observed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and annexin V binding. About 30% of protoplasts from cells after 48 h under low oxygen showed an increased accumulation of HO342, indicating increased membrane permeability. Positive TUNEL and annexin V results were also only obtained with protoplasts from cells under low oxygen. The results suggest that apple celi death under low oxygen is at least partially PCD mediated, and may explain tissue breakdown under controlled atmosphere (low oxygen) conditions in apple fruit.     

Kinetics of C2(a3Πu) radical reactions with NO, N2O, O2, H2 and NH3

Pulsed laser photolysis/laser-induced fluorescence (LP-LIF) is utilized to measure rate constants for C₂(a³Π_u) reactions with NO, N₂O, O₂, H₂ and NH₃. Multiphoton dissociation of C₂Cl₄ at 266 nm is employed for the generation of C₂(a³Π_u) radicals. The C₂(a³Π_u) concentration is monitored by the fluorescence of the (0, 0) band of the (d³Π_g&#8596;a³Π_u) transition at 516.5 nm. C₂(a³Π_u) removal rate constants for the reactions are determined as k_NO = (5.46 ± 0.10) × 10^-11 cm³ molecule^-1 s^-1 , k_N2O = (1.63 ± 0.20) × 10^-13 cm³ molecule^-1 s^-1 , k_N2O = (1.58 ± 0.16) × 10^-11 cm³ molecule^-1 s^-1, k_O2 = (5.92 ± 1.00) × 10^-14 cm³ molecule^-1 s^-1, k_H2< 1.0× 10^-14 cm³ molecule^-1 s^-1. Based on the data analysis and theoretical calculation, we suggest that the C₂(a³Π_u) reactions with H₂ and NH₃ proceed via the hydrogen abstraction mechanism, barriers exist at the entrance channel of the reactions of C₂(a³Π_u) with H₂ and NH₃.     

一种催化氧气氧化乙二醛制备乙醛酸的新方法

提出了氧化氮(NOn,n=1,2) 催化氧气氧化乙二醛制乙醛酸的方法,讨论了反应机理.当催化剂用量在0.13～0.15 mol(每1 mol乙二醛),原料乙二醛的质量分数为25%,酸性介质使用Lewis酸0.11～0.13 mol(每1 mol乙二醛),反应温度40～50 ℃,氧气压力为0.5 MPa时,乙二醛转化率达到98.7%,氧化选择性79%,产率78%.这种方法与硝酸氧化法相比,较为安全、经济且具有环境污染小的特点,有工业化应用的前景.     

SiH3+O2(3∑g)反应路径的理论研究

采用密度泛函B3LYP／6—311G^＊＊和高级电子相关耦合簇CCSD（T）／6-311G^＊＊。方法计算并研究了SiH3与O2（^3∑g）反应的机理，全参数优化了反应势能面上各驻点的几何构型，并用频率分析方法和内禀反应坐标（IRC）进行了计算，对过渡态进行了验证．结果表明：SiH3＋O2（^3∑g）反应可经多条路径和多个步骤，经缔合、氢转移和离解得到SiH3O2，SiH2O2＋H，SiH2O＋OH，SiH3O＋O，SiHO2＋H2等产物．     

Elementary reaction allyl radical with oxygen

The elementary reaction between allyl radical with oxygen molecule was experimentally investigated. The allyl radical was produced via laser photolysis of C3H5Br in gaseous phase. Nascent vibrational excited products HCO, CO2, CH3CHO and HCOOH were recorded by the timeresolved Fourier transform infrared spectroscopy. The product channels of C2H5 CO2, CH3CHO HCO, and HCOOH C2H3 have been identified. The vibrational populations of product CO2 are obtained by spectral simulation. A mechanism forming a series of three-membered ring-struc-ture intermediates is suggested.     

O2在Cu—A1—MCM—41上NO选择性还原反应中的作用

考察了O2对Cu-A1-MCM-41催化剂上NO选择性还原反应和吸附性能的影响．结果表明，O2在反应中有相反两方面的作用：一方面为NO氧化及催化剂活性中心的氧化还原循环提供氧物种；另一方面，直接完全氧化C3H6，引起还原剂的耗尽．