DCPTA合成新方法的研究

ＤＣＰＴＡ是近年来新发现的一种植物生长调节剂。对农作物具有明显的增产增质效果。文中就其新的合成方法进行了研究。     

一种基于自然数线性八叉树的优化构造算法

本文提出了一种基于自然数线性八叉树的优化构造算法。该算法以活动结点表为中间辅助结构，在图像输入过程中直接生成基于Ｎ码的八叉树叶结点．与常规构造算法相比，新提出的优化构造算法省去了Ｎ码的计算及合并过程，从而具有较高的时空效率．     

氨合成塔出口氨含量偏低原因分析及对策

阐述UHDE合成塔运行现状 ,分析氨净值达不到设计值的原因 ,提出相应的解决措施     

Prebiotic synthesis of sequential peptides on the Hadean beach by a molecular engine working with nitrogen oxides as energy sources

Addressing the still open question of the prebiotic origin of sequential macromolecules (peptides, nucleic acids) on the primitive Earth, we describe a molecular engine (the primary pump), which works at ambient temperature and continuously generates, elongates and complexifies sequential peptides. This new scenario is based on a cyclic reaction sequence, whose keystep is the activation of amino acids into their N‐carboxyanhydrides (NCA) through nitrosation by NOx. This process could have taken place on tidal beaches; it requires a buffered ocean, emerged land and a nitrosating atmosphere. With the help of geochemical studies and computer simulations of atmosphere photochemistry, we show that the primitive Earth during the Hadean may have satisfied all these requirements. © 2001 Society of Chemical Industry.     

A Study of AlN Films Prepared by Arc Ion Plating

Hexagonal AlN films have been obtained by arc ion plating at different negative biases ,X-ray diffraction and scanning electron microscopy results show that AlN films with smooth surfaces and (002) preferred orientation are obtained at low biases ,whereas those with coarse surfaces and (100) preferred orientation are obtained at high biases,The formation mechanism of AlN is analyzed and the experiment results are discussed,The effect of bias on adhesion strength has also been examined.     

Conducting composites of poly(N‐vinylcarbazole), polypyrrole,and polyaniline with 13X‐zeolite

N‐vinylcarbazole (NVC) was polymerized by 13X zeolite alone in melt (65°C) or in toluene (110°C) and a poly(N‐vinylcarbazole) (PNVC)‐13X composite was isolated. Composites of polypyrrole (PPY) and polyaniline(PANI) with 13X zeolite were prepared via polymerization of the respective monomers in the presence of dispersion of 13X zeolite in water (CuCl₂ oxidant) and in CHCl₃ (FeCl₃ oxidant) at an ambient temperature. The composites were characterized by Fourier transform infrared analyses. Scanning electron microscopic analyses of various composites indicated the formation of lumpy aggregates of irregular sizes distinct from the morphology of unmodified 13X zeolite. X‐ray diffraction analysis revealed some typical differences between the various composites, depending upon the nature of the polymer incorporated. Thermogravimetric analyses revealed the stability order as: 13X‐zeolite > polymer‐13X‐zeolite > polymer. PNVC‐13X composite was essentially a nonconductor, while PPY‐13X and PANI‐13X composites showed direct current conductivity in the order of 10^?4 S/cm in either system. However, the conductivity of PNVC‐ 13X composite could be improved to 10^?5 and 10^?6 S/cm by loading PPY and PANI, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 913–921, 2006     

N,N′-二(β-十八酰氧基)乙基乙二胺二乙酸钠的合成及性能研究

用 N,N′-二羟乙基乙二胺、氯乙酸钠合成了 N,N′-二羟乙基乙二胺二乙酸钠(中间体),中间体再与硬脂酰氯反应制备了一种新型 Gemini 两性表面活性剂 N,N′-二(β-十八酰氧基)乙基乙二胺二乙酸钠。对产物合成条件进行了考察,优化的反应条件为:n(硬脂酰氯):n(中间体)=2.5,溶剂 V(水):V(氯仿)=1:2,pH=9.0～10.0,反应温度15～20℃,反应时间5 h。通过红外光谱和质谱分析确定了产物结构,并测试了产物的表面性能。结果表明,在25℃时,该产物的临界胶束浓度为0.24 mmol/L,临界胶束浓度下的表面张力为35.7 mN/m;即时泡沫高度为250 mm,5 min 后泡沫高度为220 mm;乳化时间为22.48 min(甲苯-水物系)和4.65 min(正己烷-水物系),亲水-亲油平衡值为5.4,等电点为 pH 3.3～6.5。     

丙烯酸二甲氨基乙酯的合成

以丙烯酰氯与二甲氨基乙醇为原料 ,乙醚为溶剂 ,过量的二甲氨基乙醇为缚酸剂合成了丙烯酸二甲氨基乙酯。较佳实验条件为 :丙烯酰氯 /二甲氨基乙醇 /乙醚 (物质的量比 ) 1∶2 .0 5∶5 .6 ,反应温度 5℃ ,反应时间 4h ,w(吩噻嗪 ) 0 .5 0 %,产物为无色透明液体 ,相对密度 0 .943 1( 2 0℃ ) ,折光率为 1.435 2 ,收率大于 91%。     

Acidic and basic hydrolysis of poly(N‐vinylformamide)

Poly(N‐vinylformamide) (PNVF) was synthesized and hydrolyzed to poly(vinylamine) (PVAm) in both HCl and NaOH solutions. The hydrolysis kinetics and the equilibrium hydrolysis were examined experimentally at different temperatures, polymer concentrations, and acid‐ or base‐to‐amide molar ratios. The hydrolysis kinetics strongly depended on temperature, polymer, and HCl or NaOH concentrations, but showed little dependence on PNVF molecular weight. The acid hydrolysis of PNVF exhibited limited conversions because of the electrostatic repulsion among the cationic amine groups generated during hydrolysis and proton hydrates. In the basic hydrolysis, complete amide conversions were observed when the NaOH/amide molar ratios were greater than unity. The effects of temperature and PNVF concentration on the equilibrium amide conversion appeared to be negligible in both acidic and basic hydrolysis. The equilibrium conversions of base hydrolysis were higher than those of acidic hydrolysis under the same reaction conditions. At NaOH/amide ratios of less than unity, the equilibrium hydrolysis experiments revealed that one base molecule could induce the hydrolysis of more than one amide group. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3412–3419, 2002     

A polynomial factorization approach to the discrete time GI/G/1/(N) queue size distribution

The queue of a single server is considered with independent and identically distributed interarrivai and service times and an infinite (GI/G/1) or finite (GI/G/1/N) waiting room. The queue discipline is non-preemptive and independent of the service times.

A discrete time version of the system is analyzed, using a two-component state model at the arrival and departure instants of customers. The equilibrium equations are solved by a polynomial factorization method. The steady state distribution of the queue size is then represented as a linear combination of geometrical series, whose parameters are evaluated by closed formulae depending on the roots of a characteristic polynomial.

Considering modified boundary constraints, systems with finite waiting room or with an exceptional first service in each busy period are included.