一锅法高产率合成α-羰基苯丁酸

用苯丙酸乙酯与草酸二乙酯合成α 羰基苯丁酸。采用一锅法代替文献中的两步反应 ,用稀硫酸代替文献中盐酸 -醋酸混酸水解 ,并用正交设计法对工艺条件进行优化 ,得出最佳工艺条件为 :n(苯丙酸乙酯 )∶n (草酸二乙酯 ) =1 0∶4 0 ,缩合 1 5h ,用w (H2 SO4) =2 0 %的硫酸水解15h ,产品收率由文献值的 5 7 2 %提高到 89%     

α-氰基丙烯酸酯生产新工艺

在反应器中使用甲醛水溶液与氰乙酸酯在催化剂及多功能复合助剂作用下,生成氰基丙烯酸乙酯的预聚物并使其从反应体系分离,然后置于解聚器中,使用有机溶剂(例如:苯、甲苯、二甲苯1,2-二氯乙烷1,3-二氯丙烷等)共沸脱水,脱溶剂,在高真空下解聚并精制,可获得质量好的α-氰基丙烯酸乙酯,其收率为75%以上。     

Influence of cement type on transport properties and chemical degradation: Application to nuclear waste storage

The geological repository of nuclear waste in concrete containers is a possible storage method explored by ANDRA (Agence Nationale pour la gestion des Déchets RadioActifs). The concrete must display a high confinement capacity for long periods, characterized by low transport properties and by the acido-basic buffer of hydrated cement. During service life, these properties can be endangered by chemical attack of underground water. The cement type has an important influence on the concrete's performances. Then, it is essential to establish appropriate mixtures with accurate components. In this work an ordinary Portland cement and a fly ash and blast furnace slag blended cement are compared. To determine confinement capacities, transfer properties and mortars microstructure were investigated. To predict the long term behaviour, an ammonium nitrate test has been developed to enhance decalcification and to accelerate hydrolysis of cementitious materials. Measurement of degraded depth with time regarding calcium content was carried out. Impact of decalcification on transport properties was evaluated. Fly ash and blast furnace slag provide better properties for native mortars, and more particularly diffusion properties, but not as much as necessary to limit leaching in degraded material by chemical attack.     

A Novel Instrument for the Measurement of the Thermal Conductivity of Molten Metals. Part II: Measurements

New measurements of the thermal conductivity of molten mercury, gallium, tin, and indium are reported up to 750 K. The measurements are performed in a novel transient hot-wire instrument described elsewhere. The present experimental technique overcomes problems of convection, and it is shown that it operates in an absolute way in accord with a theoretical model. The uncertainty of the thermal conductivity results is estimated to be ± 2%, which is superior to that achieved in most earlier work. The low uncertainty of the present experimental results has allowed us to test the only significant theory for the thermal conductivity of molten metals, which relates this property to the electrical conductivity. The pattern of results among the four metals indicates that further theoretical developments would be warranted.     

1-吡啶-3-[4-(苯基偶氮)苯基]-三氮烯与汞的显色反应及其应用

在Triton X-100存在下的pH 10的Na2B4O7-NaOH缓冲介质中,研究了1-吡淀-3-[4-(苯基偶氮)苯基]-三氮烯(PYPAPT)与汞离子(Hg2 )的显色反应,建立了微量汞的测定方法。Hg2 与PYPAPT形成1∶2的红色络合物,络合物最大吸收波长位于518 nm,表观摩尔吸光系数为1.42×105L.mol-1.cm-1,Hg2 质量浓度在0~0.64 mg/L范围内符合比尔定律。方法用于铅锌矿样中微量汞的测定,RSD小于2.6%,测定结果与AAS法相符。     

丁基黄原酸甲酸乙酯的合成及对黄铜矿浮选研究

考察了不同条件对丁基黄药合成丁基黄原酸甲酸乙酯(BXEF)的影响。研究结果表明,合成BXEF反应的最佳工艺参数为：反应温度25℃,反应时间200 min,n(丁基黄药)：n(氯甲酸乙酯)=1．04：1。在此条件下,BXEF的产率可以达到94．5%。对江西永平铜矿硫化物矿石的浮选试验结果表明,与丁基黄药相比,BXEF对硫化铜矿有更高的浮选回收率,而且铜精矿中铜的品位更高。对丁基黄药和BXEF的量子化学计算结果表明,BXEF比丁基黄药有更低的能量,稳定性更强。     

汞控制技术中的吸收剂喷射工艺

向烟气中喷入像粉末状活性炭之类的吸收剂，是一种最简单和最成熟的控制燃煤锅炉汞排放的方法。在4个不同的燃烟煤和次烟煤的,tY开展的第一次吸收剂喷射实验计划，证明了活性炭喷射（ACI）在控制汞排放方面的有效性。由于具有以下优点，ACI技术尤其适合现有燃煤锅炉的汞排放控制：（1）投资成本低（〈5美元／kW）；（2）改造容易且耗时短，几乎无需机组停运；（5）不论烟煤还是次烟煤均适用；（4）当使用布袋除尘器时在较低的吸收剂喷射速率下就可达到90%以上的汞去除效率。     

P(AMPS+AM)/SiO2高吸水性杂化材料的制备及性能

研究了以2-丙烯酰胺基-2-甲基丙磺酸（AMPS）和丙烯酰胺（AM）共聚物为有机相,通过正硅酸乙酯（TEOS）引入SiO2无机相,采用溶胶-凝胶法制得了P（AMPS＋AM）/SiO2高吸水性杂化材料,并着重研究了不同用量的TEOS对材料结构和性能的影响.采用傅立叶红外（FT-IR）、扫描电镜（SEM）等检测方法对材料进行了表征,同时对材料的透光性、吸液性能、热稳定性等进行了评价.结果表明,TEOS用量为5%（相对单体质量百分含量）左右制得的高吸水性杂化材料较为理想.     

气相色谱法测定茶多酚中的氯仿和乙酸乙酯残留

以正已烷为萃取剂,对茶多酚(TP)水溶液进行萃取,用气相色谱法分析了TP溶液中的残迹物氯仿和乙酸乙酯。色谱柱为2m×3mmi.d.不锈钢填充柱,固定相为10%的PEG20M,载体为ChromosorbW/WA。氯仿和乙酸乙酯的回收率分别为96.7%～104.3%和98.5%～103.6%;相对标准偏差分别为3.5%和1.7%;最低检测限分别为0.50ug/和0.36ug/g。     

甲乙酮的生产技术及消费市场

甲乙酮是一种性能优良的有机溶剂和重要的精细化工原料，应用领域十分广泛。详细介绍了甲乙酮的用途、国内外生产状况及生产工艺。分析了甲乙酮消费市场情况，展望了我国甲乙酮的生产和应用前景，并为今后发展甲乙酮生产技术提出了合理的建议。