氧

Results show that 4-oxo-β-ionone is the major product with yield of 53.5% under the conditions as follows: reaction temperature 45℃, reaction time 24 h, the molar ratio of n: n(NaClO3): n 20: 100: 3, and pH value of solution in 1-3; on the other hand, 5,6-epoxy-β-ionone is major product with yield of 25.4% when reaction temperature is 40℃, reaction time is 24 h, the molar ratio of n: n(NaClO3): n is 20: 120: 5, and pH values of solution is 3. The excessive β-ionone can be recovered by vacuum distillation for reusing again. 4-oxo-β-ionone and 5,6-epoxy-3-ionone were purified by recrystallization and silica gel column chromatograph respectively with the purity over 98%.

研究结果表明：氯酸钠氧化β-紫罗兰酮的反应主要生成4-氧代－β-紫罗兰酮和5，6-环氧－β-紫罗兰酮，经重结晶和硅胶柱层析分离，纯度高于98%；4-氧代－β-紫罗兰酮的有利合成条件是反应温度为45℃，反应时间为24h，溶液的pH值为1~3，反应物配比n：n(NaClO3)：n为20：100：3，最佳收率为53.5%；5，6-环氧－β-紫罗兰酮有利的合成条件是反应温度为40℃，反应时间为24h，溶液的pH值为3，反应物配比n：n(NaClO3)：n为20：120：5，其收率为25.4%；未反应的β-紫罗兰酮经减压蒸馏回收后可重复使用。

This article studies the conception of safe oxygen content by theoretical and experimental researches, and discusses the simple method to decide minimum oxygen density and critical value of oxygen density by chemical calculation and graphing method, and elementarily analyses the connection between minimum oxygen density and critical value of oxygen density.

理论上分别通过化学计算法和作图法探讨了最小氧浓度和临界氧浓度的简单确定，并初步分析了最小氧浓度与临界氧浓度的关系。

Hemoglobin Saturation is percentage of Oxyhemoglobin (HbO2) capacity, compounded with oxygen, by all combinativable Hemoglobin obin (HbO2) capacity in blood. In other words, it is consistence of Oxyhemoglobin in blood. It is a very important ecological parameter for Respiratory Circulation System.

血氧饱和度是血液中，被氧结合的氧合血红蛋白(HbO2)的容量占全部可结合的血红蛋白容量的百分比，即血液中血氧的浓度，是呼吸循环系统的重要生理参数。

PECH based PUs showed higher phase separation than that of PPG base PUs owing to that the -Cl groups in PECH reduced the flexibility of molecule chain and hindered the formation of hydrogen bonds between ether groups in soft segments and -NH groups in hard segments. As a result, PECH based PUs have lower free volume content, diffusion coefficient and equilibrium adsorption of CO〓, benzene and ethanol through them than through PPG based PUs.

聚环氧氯丙烷醚聚氨酯的氯基降低了链段柔性，妨碍了软段中醚基与硬段中氨基的氢键作用，导致其相分离程度较聚环氧丙烷醚聚氨酯大，并使CO〓、苯和乙醇蒸汽在聚环氧氯丙烷醚聚氨酯中的渗透系数和扩散系数较聚环氧丙烷醚聚氨酯小，而偏离费克扩散的程度大。

The optimum conditions were reaction temperature 120°C, reaction time 20h, mole ratio of 5-chloromethyl-2-oxazolidinone and sodium phenolate 1:1. 3,5-Dimethylphenol and epichlorohydrin in sodium hydroxide were condensated to give l,2-epoxy-3-phenoxy propane, then the reation of l,2-epoxy-3-phenoxypropane and the carbamate afforded oxazolidinone in the yields of 69.0%~76.0%. The side reaction had been avoided effectively by the uses of the excessive epichlorohydrin and mixed catalysts.

用3，5-二甲基苯酚和环氧氯丙烷在氢氧化钠存在下缩合生成苯氧基环氧丙烷，然后和氨基甲酸酯反应生成噁唑烷酮，采用过量环氧氯丙烷和使用混合催化剂，有效的避免了副反应的发生，提高了噁唑烷酮的产率，产率69.0%～76.0%。

Syntheses of PPVs derivatives with alkoxyl as side-chain by the method of dehalogenating condensation reaction Those PPV derivatives, named poly (2-methoxy-5-alkoxyl) phenylene vinylene,containing alkoxyl on benzene ring, were placed on emphasis in this paper.

一。通过强碱诱导的去卤缩合法合成支链含不同烷氧基的PPV衍生物本文首先重点研究了支链中含不同链长烷氧取代基的PPV衍生物：聚(2-甲氧基-5-烷氧基)对苯乙炔。

On the basis of the photochemical energy state of oxygen ,the effect of oxygen on the photopolymerization , several methods and mechanism against the inhibition of oxygen were investigated .

介绍了光固化涂料在光固化过程中常见的空气中氧的阻聚作用，并从氧的光化学能量态着手，给出了氧在光聚合反应中的作用，并且探讨了几种抑制氧阻聚的方法及其机

The natural epoxy wax is the one or two wax within which the fatty acid and phytol chain that has one epoxide group at least naturally, while the wax made artificially is the one that has one or two fatty acid and phytol chain transformed artificially to introduce in one epoxide group at least.

天然环氧蜡为其中的该脂肪酸和醇链中的一个或两个天然地包含至少一个环氧基团的蜡。人工环氧蜡为其中的该脂肪酸和醇链中的一个或两个已人工改变以引入至少一个环氧基团。

Rubber dam laboratory model experiment: respectively measures the reaeration ability of smooth overflow surface and roughened overflow surface, then contrastively analyses the effect and reason of reaeration improving after roughened modification, and the reaeration effect between curve dam and rubber dam.

橡胶坝复氧室内模型试验：分别测量了光滑溢流面和糙化溢流面的复氧能力，对比分析了溢流面糙化后复氧增强的效果和原因，并对摘要比分析了曲线型溢流坝和橡胶坝的复氧效果。4。

A thirty-second rest period was allowed between each testing speed to reduce the effect of fatigue. Results. The SBP (85 to 172 mmHg), HR (65 to 122 beat/min), SpO23.3 to 13.7mL/(kgmin and R (0.72 to 1.04) values during concentric/eccentric exercise were all within the safe range.

结果 男女性别在股四头肌等速向心／离心运动，心跳率、血压、每分钟换气量、摄氧量、心跳而压乘积、脉搏血氧饱和度及气体交换率未有显著差异：收缩压、舒张压、心跳率、摄氧量、每分钟换气量、心跳血压乘绩、脉搏血氧饱和度和气体交换率等皆在安全范围。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。