磷钨酸催化合成丁酮乙二醇缩酮

以磷钨酸H3 PW12 O40 为催化剂 ,通过丁酮和乙二醇反应合成丁酮乙二醇缩酮。探讨了H3 PW12 O40 对缩酮反应的催化活性 ,较系统地研究了酮醇物质的量比、催化剂用量、反应时间等因素对产品收率的影响。实验表明 :H3 PW12 O40 是合成丁酮乙二醇缩酮的良好催化剂 ,在n(酮 )∶n(醇 ) =1∶1.75 ,催化剂用量为反应物料总质量的 1.2 5 % ,环己烷为带水剂 ,反应时间 2 .0h ,反应温度 72～ 96℃的优化条件下 ,丁酮乙二醇缩酮的收率可达 5 9.5 %。     

分子筛MCM-48负载硅钨酸催化合成丁酮-1,2-丙二醇缩酮

报道了以分子筛MCM-48负载硅钨酸H4SiW12O40/MCM-48为催化剂,通过丁酮和1,2-丙二醇反应合成了丁酮-1,2-丙二醇缩酮。探讨了H4SiW12O40/MCM-48对缩酮反应的催化活性,较系统地研究了酮醇物质的量比、催化剂用量、反应时间诸因素对产品收率的影响。实验表明:H4SiW12O40/MCM-48是合成丁酮-1,2-丙二醇缩酮的良好催化剂,在n(丁酮)∶n(1,2-丙二醇)=1∶1.6,催化剂用量为反应物料总质量的0.6%,环己烷为带水剂,反应时间45 min的优化条件下,丁酮-1,2-丙二醇缩酮的收率可达91.9%。     

H3PW12O40／TiO2催化合成环己酮乙二醇缩酮

制备了H3PW12O40/TiO2复合催化剂,并利用该催化剂催化合成了环己酮乙二醇缩酮,探讨了H3PW12O40/TiO2对缩酮反应的催化活性,较系统地研究了酮醇物质的量比,催化剂用量,反应时间诸因素对产品收率的影响。实验表明,H3PW12O40/TiO2是合成环己酮乙二醇缩酮的良好催化剂,在n(环己酮)∶n(乙二醇)=1∶1·5,催化剂用量为反应物料总质量的0·5%,环己烷为带水剂,反应时间1·0h的优化条件下,环己酮乙二醇缩酮的收率可达87·9%。     

H3PW12O40/SiO2催化合成环己酮乙二醇缩酮

采用溶胶-凝胶法制备了二氧化硅负载磷钨酸H3PW12O40/SiO2催化剂,并通过FTIR、XRD对其进行了表征。以环己酮和乙二醇为原料,合成了环己酮乙二醇缩酮,探讨了H3PW12O40/SiO2对缩酮反应的催化活性,考察了酮醇摩尔比、催化剂用量、带水剂用量、反应时间对产物收率的影响。结果表明,在n(环己酮)∶n(乙二醇)=1∶1.3,催化剂用量占反应物料总质量的1.2%,带水剂环己烷用量3 mL,反应时间45 min的最佳条件下,环己酮乙二醇缩酮收率可达89.7%。     

TiSiW12O40/TiO2微波催化合成丁酮乙二醇缩酮

以TiSiW12O40/TiO2为固相催化剂,通过微波催化丁酮和乙二醇反应快速合成丁酮乙二醇缩酮,较系统地研究了酮醇物质的量比,催化剂TiSiW12O40/TiO2的用量,反应功率和反应时间等诸因素对产品产率的影响。实验表明:TiSiW12O40/TiO2是合成丁酮乙二醇缩酮的良好催化剂,在环己烷为带水剂n(酮)∶n(醇)=1∶1.25,催化剂的用量为反应物总质量的0.5%,反应功率为480 W,反应时间为35 min的优化条件下,丁酮乙二醇缩酮的收率可达87.16%。     

硅钨钼酸掺杂聚苯胺催化合成丁酮乙二醇缩酮

以H4SiW6Mo6O40（硅钨钼酸）/PAn（聚苯胺）为催化剂,通过丁酮和乙二醇反应合成了丁酮乙二醇缩酮。探讨了H4SiW6Mo6O40/PAn对缩酮反应的催化活性,较系统地研究了酮醇物质的量比、催化剂用量和反应时间诸因素对产品收率的影响。实验表明：在n（丁酮）∶n（乙二醇）=1∶1.9、催化剂用量为反应物料总质量的0.8%、带水剂环己烷的用量为6mL和反应时间1.0h的优化条件下,丁酮乙二醇缩酮的收率可达61.5%.     

二氧化钛负载磷钨钼酸催化合成环己酮乙二醇缩酮

首次采用回流法制备了二氧化钛负载磷钨钼杂多酸催化剂H3PW6Mo6O40/TiO2,该催化剂的适宜制备条件为：原料质量比m（TiO2）∶m（H3PW6Mo6O40）=1∶2.0,水用量30mL,回流反应时间2.0h,活化温度150℃。以H3PW6Mo6O40/TiO2为催化剂,对以环己酮与乙二醇为原料合成环己酮乙二醇缩酮的反应条件进行了研究,较系统地研究了酮醇物质的量比、催化剂用量、反应时间对收率的影响。实验结果表明,在n（环己酮）∶n（乙二醇）=1.0∶1.5、催化剂用量占反应物料总质量的0.8%、反应时间1.0h的条件下,环己酮乙二醇缩酮的收率为86.3%。     

硅钨酸掺杂聚苯胺催化剂催化合成丁酮乙二醇缩酮

报道了以H4SiW12O40(硅钨酸)／PAn(聚苯胺)为催化剂,通过丁酮和乙二醇反应合成了丁酮乙二醇缩酮,探讨了H4SiW12O40／PAn对缩酮反应的催化活性,较系统地研究了酮醇物质的量比,催化剂用量,反应时间诸因素对产品收率的影响。实验表明：在n酮：n醇=1：1．5,催化剂用量为反应物料总质量的0．60％,环己烷为带水剂,反应时间2．0h的优化条件下,丁酮乙二醇缩酮的收率可达70．1％。     

二氧化钛负载磷钨杂多酸催化合成丁酮乙二醇缩酮

以二氧化钛负载磷钨杂多酸H_3PW_(12)O_(40)/TiO_2为多相催化剂,以丁酮和乙二醇为原料,合成了丁酮乙二醇缩酮。探讨了H_3PW_(12)O_(40)/TiO_2对缩酮反应的催化活性。研究了酮醇物质的量比、催化剂用量、反应时间诸因素对产品收率的影响。实验表明,H_3PW_(12)O_(40)/TiO_2是合成丁酮乙二醇缩酮的良好催化剂;在n(酮):n(醇)=1:1．5,催化剂用量为反应物料总质量的1．6%(亦即质量分数),环己烷为带水剂,反应时间1．0 h的最佳条件下,丁酮乙二醇缩酮的收率可达60．3%。     

H_3PW_6Mo_6O_(40)/TiO_2-MoO_3催化合成环己酮乙二醇缩酮

探讨以H3PW6Mo6O40/TiO2-MoO3为催化剂,以环己酮、乙二醇为原料催化合成环己酮乙二醇缩酮反应的催化活性,较系统地研究了酮醇物质量比,催化剂用量,带水剂用量及反应时间等因素对产物收率的影响。实验表明:固定环己酮的用量为0.2 mol时,在n(环己酮)∶n(乙二醇)=1.0∶1.4,催化剂用量为反应物料总质量的1.0%,带水剂环己烷为6 mL,反应时间为60 min的优化条件下,环己酮乙二醇缩酮的收率可达78.9%。     

(Ba_(1-α)Sr_α)_(4.8)(Sm_(0.7)La_(0.3))_(8.8)Ti_(18)O_(54)陶瓷的微波介电性能

采用固相合成法制备了(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54(α=0.1～0.5)系陶瓷,表征了该陶瓷的相组成和显微结构,测试了微波介电性能.结果表明:α=0.3时,(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54系陶瓷为单相的新钨青铜结构固溶体.α>0.3时,相继出现了第二相BaLa2Ti4O12和La0.66TiO2.993.随α的增加,(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54系陶瓷的相对介电常数(εr)先增大后有所波动,品质因数(Qf)先增大后减小,谐振频率温度系数(τf)单调减小.α=0.3时,在1 350℃烧结的陶瓷的微波介电性能最佳:εr=98.77,Qf=5184GHz,τf=10.9×10-6/℃,优于不掺杂的BaO-Sm2O3-TiO2陶瓷的.     

Fe~(3 )、Zn~(2 )、Mn~(2 )、Cu~(2 )、Ca~(2 )、Mg~(2 )等离子共存体系中Ca~(2 )、Mg~(2 )的测定

叙述了Fe3 、Zn2 、Mn2 、Cu2 、Ca2 、Mg2 等离子共存体系中采用六次甲基四胺 -铜试剂沉淀除去Fe3 、Zn2 、Mn2 、Cu2 等干扰离子 ,用EDTA滴定钙镁的方法 ,该方法钙的回收率在 99.7%～ 10 0 .3 % ;镁的回收率在 10 0 .0 %～ 10 0 .4% ,标准偏差为 0 .0 2 2。     

Ternary Complexes of cis-(NH(3))(2)PtCl(2) (cis-DDP) With Guanosine (guo), Cytidine (cyd) and the Aminoacids Glycine (gly), L-Alanine (ala), L-2-Aminobutyric Acid (2-aba), L-Norvaline (nval) and L-Norleucine (nleu)

The ternary complexes of formulae cis-[(NH(3))(2)Pt(nucl)(amac)]NO(3), where nucl = guo and cyd (guanosine and cytidine) and amac = the deprotonated aminoacids glycine (gly), L-alanine (ala), L-2-aminobutyric acid (2-aba), L-norvaline (nval) and L-norleucine (nleu), were prepared from the reactions of the binary chelated ones cis-[(NH(3))(2)Pt(nucl)(amac)]NO(3) with the nucleosides.They were characterized by (1)H, (13)C and (195)Pt NMR and IR spectra, together with elemental analysis and conductivity measurements. The aminoacids coordinate with Pt(II) in the ternary complexes with their terminal -NH(2) groups, guo through N(7) and cyd through N(3). Ligand-ligand hydrophobic interactions were also observed in the ternary complexes and were stronger with longer aliphatic chains of the aminoacids. The (3)E sugar conformation increased by 5-7% in the ternary systems, as compared to the free nucleosides, while the percentage of the gg conformation remained almost constant and the one of the anti conformation of the sugar increased also slightly. Finally, the h conformer around the C(alpha)-C(beta) bonds of the aminoacids reached a maximum in the binary systems and decreased again considerably in the ternary ones.     

(K_(0.485)Na_(0.485)Li_(0.03))NbO_3-Pb(Zr_(0.53)Ti_(0.47))O_3压电陶瓷的压电性能与微观结构

采用传统电子陶瓷制备技术和工业原料制备了新型(1-x)(K0.485Na0.485>Li0.03)NbO3-Pb(Zr0.53Ti0.47)O3少铅压电陶瓷,研究了该体系陶瓷的压电性能及微观结构.X射线衍射分析表明:在1250℃烧结3h的条件下,所有陶瓷样品都具有纯的钙钛矿结构和高致密性,并且在室温下形成了正交相和四方相共存的结构.x=0.75时,陶瓷的压电性能达到最佳:压电常数d33=363 pC/N,机电耦合系数kp=63%,相对介电常数εr=1 590,介质损耗tanδ=1.70%.     

Adhesion of calcium phosphate coatings on polyethylene (PE), polystyrene (PS), poly(tetrafluoroethylene) (PTFE), poly(dimethylsiloxane) (PDMS) and poly-L-lactic acid (PLLA)

Calcium phosphate (CaP) coatings can be applied to improve the biological performance of polymeric medical implants. For clinical applications, a strong adhesion of the coating to the polymeric substrate is important. Therefore, the adhesion of rf magnetron-sputter-deposited CaP coatings on five polymers was studied: polyethylene (PE), polystyrene (PS), poly(tetrafluoroethylene) (PTFE), poly-L-lactic acid (PLLA) and poly(dimethylsiloxane) (PDMS). To influence the adhesion, the interface was varied in six different ways, e. g. by a plasma or ion-beam pretreatment, or by using a Ti interlayer. The adhesion was determined by using scratch, tensile and 180^° bend tests. Especially the polymers PE and PS needed a bombardment by energetic particles prior to or during coating deposition, to enable the formation of chemical bonds between the coating and the polymer, which gave adhesion. On PLLA and PDMS, being oxygen containing polymers, it was easier to establish a strong interface. An overtreatment of the polymeric substrates gave worse adhesion, probably due to the formation of weak low molecular weight (LMW) layers on the polymer. On PTFE, the use of a Ti interlayer was necessary to prevent the PTFE from UV degradation during coating deposition, as this caused cohesive failure within the PTFE. The results showed that each polymer requires a different approach for obtaining optimal adhesion. The observed adhesion could often be explained in the terms of processes occurred during the pretreatment of the polymers or the deposition of the coating.     

La掺杂(Na_(0.5)Bi_(0.5))_(0.82)(K_(0.5)Bi_(0.5))_(0.18)TiO_3系统无铅压电陶瓷的制备工艺探讨

采用传统陶瓷工艺,研究了制备[(Na0.5Bi0.5)0.82(K0.5Bi0.5)0.18]1-xLaxTiO3(x=0.00,0.01,0.03,0.05,0.10)无铅压电陶瓷的工艺条件对陶瓷的物相组成、显微结构和压电性能的影响。利用XRD、SEM等技术分析结果表明,合成温度的提高有利于主晶相的形成,且此系统烧成温度范围较窄,故需控制在合适的烧成温度下才能得到高致密度的陶瓷。同时,研究了极化工艺条件对材料压电性能的影响,结果表明,提高极化电场强度、控制适当的极化温度有利于提高材料的压电性能。