Uptake of Pb(II) and Cd(II) by a new phenolformaldehyde polymer resin derived by the insertion of sulfur ligands in the form of xanthate

A new phenolformaldehyde polymer resin containing potential soft‐type donor atoms (sulfur atoms) was synthesized by the reaction of sodium salt of 2,4‐dihydroxyacetophenone formaldehyde resin with carbon disulfide. The resin was characterized by elemental analysis, IR, and ¹H‐NMR spectral studies. Because of its insolubility in aqueous media, the resin was successfully used in the removal of Pb(II) and Cd(II). Parameters such as the effect of pH, the effect of time, competitive studies, the effect of initial metal‐ion concentration, and the recyclability of the polymer resin were studied. The amount of metal removed by the resin was determined with atomic absorption spectrophotometry. The retention properties were strongly dependent on pH. The elution of metal ions was investigated in acid media. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1932–1936, 2004     

A110－1－H／A110－1型氨合成催化剂在双筐并流合成塔中的使用

在双筐并流氨合成塔中使用了Ａ１１０－１－Ｈ／Ａ１１０－１型氨合成催化剂，使用寿命达１７４０天，累计产氨４３８３７８ｔ．该催化剂组合具有低温活性好、易还原、高催化活性、高抗毒能力、良好的热稳定性与破碎强度等优点．     

Enantiospecific synthesis fromd-fructose of (2S,5R)- and (2R,5R)-2-methyl-1,6-dioxaspiro[4.5]decane [the odor bouquet minor components ofParavespula vulgaris (L.)]

The synthesis of (2S,5R)-(1) and (2R,5R)-2-methyl-1,6-dioxaspiro [4.5]decane (2) from (2RS,5R,8R,9R,10S)-8,9,10-trihydroxy-2-methyl-1, 6-dioxaspiro[4.5]decane (8), obtained in five steps fromd-fructose using Wittig's methodology, reduction, and spiroketalation, has been accomplished by a Corey dideoxygenation at C-8,9, followed by a Barton deoxygenation at C-10, of the appropriately protected derivatives.Enantiospecific synthesis of spirocetals. Part V. For Part IV, see Izquierdo et al. (1992).     

Enantiospecific synthesis of (R)-1,7-dioxaspiro [5.5]undecane [major component of olive fruit fly (Dacus Oleae) sex pheromone] from d-Fructose

The synthesis of the title compound13 has been carried out through the preparation of its precursor, (3R,4R,5S,6R)-3,4,5-trihydroxy-1,7-dioxaspiro[5.5]undecane (6), obtained fromd-fructose using Wittig's methodology, reduction, and spiroketalation. Compound6 was transformed into13 by a Barton deoxygenation at C-5 followed by a Corey dideoxygenation at C-3,4 of the appropriately protected derivatives.Enantiospecific synthesis of spiroacetals. Part II. For Part I, see Izquierdo and Plaza (1990).     

Preparation of Aluminum Nitride Powder from Aluminum Polynuclear Complexes

AIN powder was synthesized from aluminum polynuclear complexes. Basic aluminum chloride and basic aluminum lactate were used as the aluminum polynuclear complexes. These starting materials and glucose were dissolved in water and mixed homogeneously. AIN powder was obtained by calcining after drying and precalcining at 800°C under nitrogen gas flow. Then excess carbon was removed by firing in air. Nitridation in the system was investigated and compared with that in the alumina–carbon black system. It was found that in our reaction system nitridation began and proceeded at lower calcination temperatures above 1200°C than in the alumina–carbon black system. Using aluminum polynuclear complexes, AIN was synthesized through the nitridation of γ-alumina and produced in a very fine and sharp particle size distribution.     

合成气中氨含量测定方法的改进

用快速测定仪测定气体中的氨含量，采气量为50ml，可准确测出高含量氨体积百分比含量为80%-100%和低含量氨体积百分比含量为1%-20%的样气，该仪器结构简单，易于制造，测定过程简单，结果准确，一目了然。     

Enzymatic esterification of glycerol II. Lipase-catalyzed synthesis of regioisomerically pure 1(3)-rac-monoacylglycerols

Regioisomerically pure 1(3)-rac-monoacylglycerols are conveniently prepared in high yields (>75%) and in multigram quantities by enzymatic esterification of glycerol in the presence of various lipases(Chromobacterium viscosum, Rhizopus delemar, Rhizomucor miehei) with a variety of different acyl donors, such as free fatty acids, fatty acid alkyl esters, vinyl esters and triacylglycerols, as well as natural fats and oils. All reactions are carried out in aprotic organic solvents with low water content, namelyn-hexane, diethyl ether, tBuOMe or mixtures of these solvents. Essential for the success of these transformations were the following two factors. First, the creation of an artificial interphase between the solvent-immiscible hydrophilic glycerol and the hydrophobic reaction medium by its adsorption onto a solid support. Second, a facile system for the separation of the desired monoacylglycerol from the reaction mixture, coupled with the continuous recycling of acyl donor and undesirable by-products.     

改性纤维素增强丙烯酰胺水凝胶的合成与拉伸性能研究

采用水媒法制备了低取代度羧甲基纤维素,并用接枝聚合法制备了改性纤维素/丙烯酰胺水凝胶,考察了单体质量比、取代度等对水凝胶拉伸性能的影响.结果表明:对于接枝聚合反应,采用低取代度羧甲基纤维素可以提高纤维素的有效用量;当交联剂用量为180 mg/L、引发剂1 300 mg/L、低取代度羧甲基纤维素和丙烯酰胺质量比在1∶4 ～ 1∶4.5之间、单体质量分数为30%时,合成水凝胶的拉伸强度达到0.28 MPa;在此基础上,适量添加15%的淀粉可使水凝胶拉伸强度达到0.47 MPa;添加1%二氧化钛可使水凝胶拉伸强度达到0.38 MPa.     

三相电流型PWM整流器的SVPWM调制方法研究

PWM调制技术主要有:基于三角载波调制的正弦脉宽调制、基于三角载波调制的梯形波调制技术、基于空间矢量的调制技术等。其中空间矢量的调制技术与上述几种方法相比更具优越性。对三相电流型PWM整流器的空间矢量调制技术进行了研究,分析了SVPWM的多种合成模式,并通过仿真及频谱分析对不同的矢量合成方法之间的优劣进行对比,找出综合性能比较优秀的几种调制方法以满足实际需要。     

3—乙酰基—5—溴 酚酮的合成

2-乙酰基-7-甲氨基酮1与溴反应得2-乙酰基-7-甲氨基-4-溴酮2。2与氢氧化钠反应得3-乙酰基-5-溴酚酮3。化合物2和3是两种新化合物,其结构已经红外光谱、核磁共振谱及元素分析证实。