水热法合成羟基磷灰石的结构和形貌

羟基磷灰石是一种微溶于水的弱碱性磷酸钙盐 (Ｃａ10 (ＰＯ4 ) 6 (ＯＨ) 2 ,ＨＡ) [1] ,多用于人体硬组织(骨、牙 )的修复替换[2 ] 。与人类骨骼相比 ,致密羟基磷灰石仍然表现出较低的力学性能[3] 。由于针棒状的晶体具有较低的位错密度 ,较高的抗拉性能[4 ] 。近年来 ,针状或棒状羟基磷灰石的合成已引起广泛关注。合成ＨＡ的方法有固态反应法[5] 、液相沉淀法[6 ] 、溶胶 凝胶法[7,8] 及溅射法[9] 等 ,但只有少数几种方法能够对产物的形貌进行控制。虽然采用水热法在 2 0 0℃和 2ＭＰａ下合成了羟基磷灰石晶须[10 ] ,但实验步骤较为复杂 ,…     

微波法固相合成二茂铁基α、β-不饱和酮

由于二茂铁具有芳香性,氧化还原可逆性,稳定性高,亲电性,毒性低等特点,其衍生物在材料学、电化学、生物学、医学等方面有广泛的应用[1,2]。本文报道以负载于氧化铝上的氟化钾为固体碱催化剂,使用微波法合成了一系列二茂铁基α、β 不饱和酮,并研究了芳香醛上取代基对反应的影响。Ａｒ:ａ,Ｃ6Ｈ5 ;ｂ,4 ＭｅＯＣ6Ｈ4;ｃ,2 Ｆｕｒｙｌｄ,4 Ｍｅ2ＮＣ6Ｈ4;ｅ,Ｆｅｒｒｏｃｅｎｙｌ;ｆ4 ＮＯ2 Ｃ6Ｈ4.1　实验部分1 1　试剂和仪器所用药品均为国产ＡＲ或ＣＰ级试剂。ＸＰＣ 1显微熔点测定仪(温度计未校正)(四川大学科仪厂);Ｃａｒｌｏ Ｅｒｂ…     

氨基膦酸树脂吸附镨的研究

氨基膦酸树脂 (简称ＡＰＡＲ)是一类性能优良的螯合树脂 ,功能基为 ＣＨ2 ＮＨＣＨ2 Ｐ(Ｏ) (ＯＨ) 2 ,由于功能基上同时含有Ｎ和Ｏ等配位原子 ,它能与多种金属离子形成比较稳定的配合物。近年来有关含磷的螯合树脂吸附金属离子的各种研究比较活跃[1～ 4] 。本文就氨基膦酸树脂在ＨＡｃ ＮａＡｃ体系中对镨 (Ⅲ )的吸附行为进行了研究。获得了诸多基本参数 ,为氨基膦酸树脂在湿法冶金中对镨离子的富集、提取等方面的应用提供了理论依据。1　实验部分1 1　试剂及仪器72 1型分光光度计 ,ＳＨＡ Ｃ水浴恒温振荡器(± 0 .1℃ ) ,ｐＨＳ 3ｃ型…     

氢氧化铝镁正电溶胶稳定性研究

氢氧化铝镁正电溶胶 (以下简称溶胶 )是近几年研制开发的一种新型正电溶胶 ,在油田、化妆品、涂料、污水处理等领域具有广阔的应用前景 .我们曾对溶胶制备、组成、结构[1～ 4] 及其在油田钻井液中的应用做了大量研究工作[5 ,6] ,但关于溶胶的稳定性研究尚少 .本文从恒表面电荷密度模型出发 ,对溶胶进行了近似处理 ,得到了势能曲线 ,并采取动态法研究了无机电解质对溶胶的聚沉规律 .1　实验部分1 .1　氢氧化铝镁正电溶胶的合成　按文献 [1 ]非稳态共沉淀法制备 ,ＡｌＣｌ3·6Ｈ2 Ｏ与ＭｇＣｌ2 ·6Ｈ2 Ｏ的物质的量比为 1∶1 .1 .2　组成和电…     

相转移催化合成对甲氧基肉桂酸-2-乙基己酯的研究

对甲氧基肉桂酸 2 乙基己酯是一种有效的ＵＶＢ防晒剂[1 ,2 ] ,一般采用Ｃｌａｉｓｅｎ Ｓｃｈｍｉｄｔ缩合反应制得[3] ,但由于催化剂ＫＯＨ处于水相 ,对反应物不能充分起到催化作用导致产率较低[4] 。我们利用乙二醇 (ＰＥＧ)为相转移催化剂合成立体专一的反式对甲氧基肉桂酸 2 乙基己酯 ,产率提高到 72 .5 %。合成路线如下 :1　实验部分1 .1　仪器与试剂ＢＩＯ ＲＡＰＦＴ45 0红外光谱仪 ,用液膜法测试 ;Ｂｒｕｒｅｒ ＡＭ 30 0超导核磁共振仪 (溶剂ＤＣ Ｃｌ3) ;ＭＡＴ/44Ｓ ,ＧＣ ＭＳ型色质联用谱仪 ;试剂均为分析纯 ,上海化学试剂…     

配合物Co〔S_2P(O-i-C_3H_7)_2〕_3的合成和晶体结构

过渡金属硫配合物可作为加氢脱硫 (ＨＤＳ)和加氢脱氮 (ＨＤＮ)过程的有效催化剂而倍受人们关注[1 - 3] 。这类配合物的催化活性、选择性和抗毒性与过渡金属的种类、配合物本身的立体结构和电子分布密切相关[4- 5] 。其中 ,钴的硫化物在ＨＤＳ和ＨＤＮ过程中有很好的催化活性。本文由二元金属羰合物Ｃｏ2 (ＣＯ) 8和双 (硫代磷酸二异丙基酯 )二硫化物 (Ａ) ,合成标题配合物Ｃｏ〔Ｓ2 Ｐ(Ｏ -ｉ-Ｃ3Ｈ7) 2 〕3(Ｂ) ,对配合物Ｂ进行ＸＲＤ表征 ,并对反应机理进行初步探讨。反应式如下 :1　实验部分1 1　试剂与仪器苯和石油醚 (ｍ .ｐ .60～ 9…     

聚丙烯酸钠对钛表面仿生生长磷灰石涂层的调制

1　前言羟基磷灰石 (Ｃａ10 (ＯＨ) 2 (ＰＯ4 ) 6,ｈｙｄｒｏｘｙａｐａｔｉｔｅ ,ＨＡ)作为人体硬组织的主要无机成分具有良好的生物活性。钛表面等离子喷涂ＨＡ综合了钛的力学性能和ＨＡ的生物活性 ,得到了广泛应用[1] 。但喷涂技术具有视线效应的缺点 ,同时涂层与基体界面的长期可靠性也是广泛关注的问题。为此发展的各种涂层方法中仿生化学法制备磷灰石涂层是极为活跃的前沿领域[2 ] 之一。仿生法基于异相成核原理[3 ] :将基体预先功能化后浸入磷酸钙过饱和溶液 ,在溶液过饱和度低于均相沉淀的条件下在基体表面发生磷灰石异相成核并自发…     

两种N-烷基内酰胺铀酰配合物的合成

作为目前国际上常用的铀的萃取剂 ,磷酸三丁酯 (ＴＢＰ)对铀有较强的萃取能力 ,但其耐辐射能力较差 ,于是人们开始寻找ＴＢＰ的替代品[1～ 4] 。酰胺类萃取剂对铀、钍元素的萃取规律和分配比类似于ＴＢＰ ,它们对锆、铌的萃取能力比ＴＢＰ低 ,它们的耐辐照能力比ＴＢＰ强 ,比ＴＢＰ更有利于去污 ,因而倍受关注[5～ 7] 。本文合成了Ｎ 丁基十二内酰胺 (ＣＨ2 ) 11ＣＯＮＣ4Ｈ9和Ｎ 辛基丁内酰胺(ＣＨ2 )3ＣＯＮＣ8Ｈ17及其铀酰配合物 ,研究了它们的部分性质 ,并分别与同化学式的Ｎ 烷基己内酰胺铀酰配合物[3] 作了比较 ,为选择萃取铀酰离子的…     

β-环糊精衍生物的金属配合物模拟酶催化测定葡萄糖含量

葡萄糖含量常用生物酶法[1 ] 间接测定 ,但酶试剂较贵 ,且多数对酸、碱、热不稳定 ,反应条件苛刻、易失去活性。模拟生物酶测定一直是分析化学领域研究的热点之一[2 ] 。 (本文利用双 [6-氧- (丁烯二酸 - 1 ,4-单酯 - 4) ]β -ＣＤ·Ｆｅ3+·Ｈ2 Ｏ2同时模拟葡萄糖氧化酶 (ＧＯＤ)和过氧化物酶(ＰＯＤ) ,Ｈ2 Ｏ2 与邻甲苯胺生成的氧化型产物在波长 365ｎｍ处有较强的吸收[3] ,通过测定 365ｎｍ处吸光度的变化对葡萄糖进行定量分析。该模拟酶具有制备简便、费用低廉、寿命长、不易失活等优点。该法检测下限可达 1 5ｍｇ·Ｌ- 1 。模拟酶制备…     

常压气相氧化羰基化合成碳酸二乙酯

碳酸二乙酯是一种重要的有机化工原料,可广泛用于合成农药如脱叶灵,医药如喹啉酮衍生物,中间体3-氧硫代羧酸酯,还可用于电子管阴极的镀层[1-3]。生产碳酸二乙酯的传统方法为:无水乙醇与光气反应生成氯甲酸乙酯,氯甲酸乙酯继续与乙醇反应生成碳酸二乙酯后经水洗蒸馏制成。使用光气为原料对设备的要求较高。我们在常压下气相羰基化合成碳酸二乙酯[4]:2ＮＯ+Ｃ2Ｈ5ＯＨ+0.5Ｏ2→2Ｃ2Ｈ5ＯＮＯ+Ｈ2Ｏ(1)ＣＯ+2Ｃ2Ｈ5ＯＮＯ→(Ｃ2Ｈ5Ｏ)2ＣＯ+2ＮＯ(2)产生的一氧化氮可与氧气和乙醇进行反应再生为亚硝酸乙酯,符合原子经济反应且几乎不放出对…     

On the escape process during phase inversion of an emulsion

This paper deals with a phenomenon which plays an important role in the phase inversion process of emulsions. This process is governed by the interplay of coalescence of droplets, often leading to double emulsions, and the escape of those internal droplets. The latter process retards the inversion process. Coalescence has been the subject of many studies, contrary to the escape event. This paper addresses the escape process both theoretically and experimentally. The model developed analyses the rate of the escape of internal droplets from the mother droplet via a coalescence process, where the internal flow, as generated by the external flow, generates the viscous force for coalescence. Incomplete mixing in the droplet has been assumed. Experimental data on the escape rate of oil droplets from O/W/O emulsions have been analysed using a Computational Fluid Dynamics approach, where the model as indicated above has been incorporated. Experimental data and simulations compare very well. Data have been compared on varying the size of the inner droplets and the rotational speed of the vessel where the double emulsion has been formed and where the escape took place.     

热化学循环分解水制氢研究进展

热化学循环分解水制氢是利用核能或太阳能进行大规模、无污染制氢的有前景的方法 ,已经提出了多种流程.本文对热化学制氢流程及其评价标准进行了综述,重点介绍了碘硫循环、UT-3循环和Westinghouse循环等先进流程的研究进展.     

反应和分离过程的结合

本文简要介绍了近年来反应和分离过程结合的现状和发展趋势。     

镁离子存在下乙醇-水混合溶液中碳酸钙结晶行为的研究

通过对不同反应体系中合成样品的物相及镁含量变化规律的分析, 认为水溶液中碳酸钙的结晶遵循溶解重结晶机理, 乙醇-水溶液中则以聚集重构为主, 碳酸根阴离子的溶剂化作用对碳酸钙的沉积产生显著影响. 采用XRD, IR等手段对醇水混合溶液中合成的碳酸钙样品进行分析, 认为形成了含镁方解石及具有类白云石结构的过渡相同时存在的混合物相, 醇水溶液中含镁方解石趋于白云石化.     

The protonation of three-membered ring molecules Theab initio SCF versus the electrostatic picture of the proton approach

The protonation processes for eight three-membered ring molecules have been investigated using the SCF LCAO MO method with Gaussian basis sets and the results are compared with those obtained at the first order approximation, i.e. the electrostatic approximation. The electrostatic results are linearly connected with the SCF ones and are sufficient to get an ordering of the protonation energies in different chemical sites and to obtain reliable representations of the proton approaching paths.     

Comparison of the water change characteristics between the formation and dissociation of methane hydrate and the freezing and thawing of ice in sand

Hydrate formation and dissociation processes are always accompanied by water migration in porous media, which is similar to the ice. In our study, a novel pF-meter sensor which could detect the changes of water content inside sand was first applied to hydrate formation and dissociation processes. It also can study the water change characteristics in the core scale of a partially saturated silica sand sample and compare the differences of water changes between the processes of formation and dissociation of methane hydrate and freezing and thawing of ice. The experimental results showed that the water changes in the processes of formation and dissociation of methane hydrate were basically similar to that of the freezing and thawing of ice in sand. When methane hydrate or ice was formed, water changes showed the decrease in water content on the whole and the pF values rose following the formation processes. However, there were very obvious differences between the ice thawing and hydrate dissociation.     

Comparative study of the properties of post-consumption high density polyethylene used in the injection process

The high-density polyethylene, thermoplastic widely-used in the production of industrial domestic utilities, was collected in two situations: virgin high-density polyethylene (JV 060) and post-consumption high-density polyethylene (with features of low-density polyethylene). After collecting the samples, they were submitted to natural aging with the quantification of the incident solar radiation for 180 days. The samples were characterized by melt flow index, differential scanning calorimetry, tensile strength, rupture load, elongation at break and infrared. The results showed that after 180 days of exposure the virgin high-density polyethylene presented physical properties similar to the post-consumption polyethylene. This revised version was published online in August 2006 with corrections to the Cover Date.     

环丙沙星的合成工艺改进

对环丙沙星(1)的合成工艺进行了改进。在2,4-二氯-5-氟苯乙酮和碳酸二甲酯的缩合反应中,用甲醇钠代替氢化钠;在乙氧亚甲基化反应中,用N,N-二甲基甲酰胺二甲缩醛代替价格昂贵的原甲酸三乙酯;在哌嗪取代反应中,采用硼络合物的方法,提高了取代反应的选择性。1及其中间体的结构经1H NMR确证。缩合反应收率80.6%,亚甲基化和胺化的总收率70.8%,哌嗪取代收率90.8%。     

Fractal Characterization of Silica Sol Prepared by the Sol-Gel Method: From the Sol Formation to the Flocculation Process

The fractal characterization of silica particles prepared by the sol-gel method was obtained; from the beginning of the sol-gel synthesis to the aggregation process of these particles by adding metal ions in solution, the fractal dimension was determined. At the beginning of the sol-gel process, unstable structures were formed due, essentially, to the auto-catalytic nature of the sol-gel condensation reactions; these particles are fractal structures with a fractal exponent corresponding to a reaction limited aggregation regime. As the time proceeds, the reactants are consumed approaching the system to equilibrium, stabilizing the size of the silica particles. The silica sol can be flocculated by adding metal ions in solution. The fractal exponent for the aggregation process was determined, obtaining a value corresponding to a diffusion limited aggregation regime.     

2,3,6,7,10,11-六甲氧基苯并菲的合成工艺改进

以1,2-二甲氧基苯(1)为原料,二氯乙烷为溶剂,氯化铁为催化剂,合成了2,3,6,7,10,11-六甲氧基苯(2)。在142 mmol,n(FeC l3)∶n(1)=4∶1,50℃反应2 h的最佳反应条件下,2的收率达81.48%。