Preparation of Y-H3PW12O40/TiO2 and La-H3PW12O40/TiO2 by hydrothermal method and its photocatalytic activity for dinitrotoluene decomposition

A series of mesoporous materials （H3PW12O40/TiO2, Y-H3PW12O40/TiO2 and La-H3PW12O40/TiO2） were prepared by a modified sol-gel-hydrothermal route, which realized the load and modification of H3PW12O40 at the same time. The prepared samples were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR）, nitrogen adsorption-desorption analysis, ultraviolet-visible absorption spectrum （UV-Vis） and scanning electron microscopy （SEM）. The XRD and FT-IR results displayed that the catalysts had uniform anatase phase and the primary Keggin structure of H3PW12O40 remain intact. Nitrogen ad-sorption-desorption analysis suggested that suitable doping of rare earth elements could increase the specific surface area from 177.9 m2/g （H3PW12O40/TiO2） to 229.5 （1 wt.%Y-H3PW12O40/TiO2） or 236.1 m2/g （1 wt.%La-H3PW12O40/TiO2）. Results of UV-Vis spectra showed that the band of the 1 wt.%Y-H3PW12O40/TiO2 and 1 wt.%La-H3PW12O40/TiO2 have an obvious redshift compared with the H3PW12O40/TiO2. Additionally, the composites were used as heterogeneous photocatalysts to the degradation of dinitrotoluene （DNT）. It is the first time that polyoxometalate （POM） is applied in the degradation of explosive wastewater.     

Synthesis and antitumor activities of rare earth substituted phosphotungstates containing 5-fluorouracil

Two novel rare earth substituted phosphotungstates containing 5-fluorouracil,K 9(C 4 H 4 FN 2 O 2) 2 Nd(PW 11 O 39) 2 ·25H 2 O(FNdPW) and K 9(C 4 H 4 FN 2 O 2) 2 Ce(PW 11 O 39) 2 ·23H 2 O(FCePW),were synthesized and characterized by elementary analysis,FT-IR spectra,X-ray powder diffraction and 1 H NMR.The thermal analysis showed that FNdPW decomposed at 210 and 493 oC,and FCePW decomposed at 223 and 471 oC,both of which had good thermal stabilities.MTT tests were performed to study the antitumor activities against HeLa cells and HepG-2 cells of FNdPW,FCePW,5-fluorouracil,C 4 H 4 FN 2 O 2 H 2 PW 12 O 40 ·8H 2 O and K 11 Ln(PW 11 O 39) 2 ·xH 2 O(Ln=Nd,Ce),and their cytotoxicities against HEK 293 cells.The results showed that FNdPW and FCePW possessed higher antitumor activities and lower cytotoxicities than those of 5-fluorouracil and C 4 H 4 FN 2 O 2 H 2 PW 12 O 40 ·8H 2 O,of which FNdPW exhibited the highest antitumor activates against HeLa cells(EC 50 =3.41×10-6 mol/L) and HepG-2 cells(EC 50 =6.24×10-6 mol/L).Thus the introduction of rare earth elements and 5-fluorouracil could significantly enhance antitumor effect of polyoxometalates.     

Synthesis, characterization and antitumor activity of rare earth （Y, La） substituted phosphotungstates containing 5-fluorouracil

Two rare earth substituted Keggin-type phosphotungstates containing 5-fluorouracil,K10C4H4FN2O2Y(PW11O39)2·10H2O(FYPW) and K9(C4H4FN2O2)2La(PW11O39)2·18H2O(FLaPW)were synthesized in aqueous solution,and the structures were characterized by Fourier transform infrared spectroscopy(FT-IR),element analysis,inductively coupled plasma spectrometry(ICP),X-ray powder diffraction(XRD) and 1 H nuclear magnetic resonance(NMR).Thermal analysis showed that the decomposition processes of the two compounds could be divided into three steps,the loss of crystal water,the decomposition of 5-fluorouracil unit and the decomposition of Keggin-type polyanions. The in vitro cytotoxicities against HEK 293,HeLa and HepG-2 cells were studied by methyl thiazolyl tetrazolium(MTT)assay.The results showed that FYPW and FLaPW had higher antitumor activities than 5-fluorouracil,C4H4FN2O2H2PW12O40·8H2O and rare earth substituted polyoxometalates K11Ln(PW11O39)2·nH2O(Ln=Y,La).It was concluded that introducing 5-fluorouracil and rare earth(Y or La)into its structure was a considerable way to enhance antitumor activities of polyoxometalates.     

Preparation and Photocatalytic Behaviors of Nanoporous Polyoxotungstate-Anatase TiO2 Composites

Nanoporous anatase TiO2 crystalline particles coupled with Keggin or Wells-Dawson unit, H3PW12O40/TiO2 or H6P2W18O62/TiO2, were prepared at a low temperature （200℃ ） using sol-gel method combined with hydrothermal treatment at programmed temperature. The as-prepared composites have uniform anatase phase, and they exhibit both micrand mesoporosities with pore sizes of 0.6 and 4.0 nm, respectively, and their average size is lower than 10 nm. Photocatalytic tests show the composites exhibit relatively higher photocatalytic activities to decompose the organocholorine pesticide hexachlorobenzene（HCB） than anatase TiO2, the starting polyoxotungstates, and EuEOa/TiO2 prepared by using sol-gel method, and this was attributed to （ 1 ） the synergistic effect of photoactive anatase TiO2 with the polyoxotungstate, and （2） the fascinating physical and chemical properties of the porous materials.     

H_3PW_6Mo_6O_(40)·nH_2O催化过氧化氢清洁氧化环己酮合成己二酸

以自制H3PW6Mo6O40.nH2O为催化剂,在无有机溶剂、相转移催化剂的情况下,用过氧化氢氧化环己酮合成己二酸。探讨了催化剂用量、过氧化氢用量、反应时间、反应温度对反应的影响。确定了最佳反应条件为n(环己酮)∶(n磷钼钨杂多酸)∶(n过氧化氢)=100∶0.15∶400,在90℃反应5h,己二酸的分离收率达75.8%。     

钼铁冶炼收尘灰制备钼酸盐的实验研究

利用钼铁冶炼收尘灰制备钼酸盐。固液比1∶40,在80℃时用稀H2SO4浸出3 h;浸出液以N235作为萃取剂,相比W/O=2∶1,进行2级萃取;有机相用0.27 mol/L NH3.H2O反萃;硝酸调节pH=1.5~2.0得到钼酸盐产品,晶体组成为(NH4)3PO4(MoO3)12.4H2O,纯度95.5%。     

稀土镧改性磷钨杂多酸盐催化油酸与甲醇酯化反应合成生物柴油活性研究

以H ₃PW ₁₂O ₄₀和La(NO ₃) ₃为原料,通过离子交换法制备一种稀土镧改性磷钨杂多酸盐催化剂.通过扫描电镜、红外光谱和X射线粉末衍射等表征方法,对合成的催化剂的物理及化学性能进行分析,进而通过以油酸和甲醇为反应物的酯化反应,对其催化活性进行研究.结果表明:稀土镧已经导入磷钨杂多酸的骨架结构,并与杂原子P形成配位键,有效提高磷钨杂多酸的比表面积和孔径;合成的催化剂具有完整的Keggin型结构;当反应温度为62 ℃,油酸与甲醇摩尔比为1∶6,反应时间为4.5 h,催化剂用量为反应物质量的2.5 %,油酸的转化率可达88.0 %.      

硅钨酸/TiO_2复合光催化材料光解水催化性能研究

采用浸渍法制备了复合杂多酸H4SiW12O40/TiO2光催化材料,并用XRD、FT-IR和UV-Vis-DRS研究了其结构形态,同时考察了H4SiW12O40/TiO2光催化剂对光解水制氧的应用研究。结果表明,H4SiW12O40/TiO2仍然保留Keggin结构,TiO2均匀固载在H4SiW12O40中,H4SiW12O40与TiO2之间仅仅是简单的物理吸附。在紫外光辐射下光催化分解水制氧的实验中,H4SiW12O40/TiO2的光催化析氧速率高达231.37μmol/(L.h),为纯H4SiW12O40的1.37倍。     

共沉淀法制备稀土石榴石Ln3Al5O12(Ln=Y, Ce, Yb)

以Y2O3、Yb2O3、Al(NO3)3.9H2O和Ce(NO3)3.6H2O为原料,NH4HCO3、NH3.H2O做复合沉淀剂,用共沉淀法制备纳米稀土石榴石Ln3Al5O12(LnAG,Ln=Y,Ce,Yb)粉体。用TG/DTA、XRD、SEM、TEM等手段对LnAG前驱体及煅烧后的粉体进行表征。结果表明,用上述方法在1 000℃煅烧3h可得到分散性好、形状规则且粒径为50nm左右的Y3Al5O12、Yb3Al5O12、Y2.9Ce0.1Al5O12石榴石粉体,但不能得到Ce3Al5O12石榴石,合成石榴石粉体的最佳煅烧温度为1 050℃以上。     

Catalytic Partial Oxidation of Methane over Ni/CeO2-ZrO2-Al2O3

Nickel catalysts supported on CeO2-ZrO2-CeO2,ZrO2-Al2O3 and Al2O3 were prepared and characterized by means of X-ray diffraction（XRD）,BET areas,H2 temperature-programmed reduction（H2-TPR）,and X-ray photoelectron spectroscopy（XPS）.Through the test of catalytic partial oxidation of methane（CPOM）,Ni/CeO2-ZrO2-Al2O3 displayed the highest activity,which resulted from its largest BET area and best NiO dispersion.Furthermore,Ni/CeO2-ZrO2-Al2O3 maintained a long-time stability in CPOM,which was attributed to its best coking resistance among all the prepared catalysts.     

甘氨酸硝酸盐法制备超细Mo-Cu粉末及烧结

以四水合钼酸铵（（NH4）6Mo7O24·4H2O）、硝酸铜（Cu（NO3）2·3H2O）、甘氨酸和乙二胺为原料采用甘氨酸硝酸盐法（GNP）制备前驱体粉末,经过700℃氢气还原2 h得到Mo-Cu 复合粉末,经压制后进行真空烧结,研究不同烧结温度对Mo-Cu 烧结体性能的影响.结果表明：甘氨酸-硝酸盐法（GNP）制备的超细Mo-Cu 复合粉末形状规则、大小均匀、钼铜两相弥散分布,颗粒大小平均为50~80 nm.在950~1250℃范围内,随着烧结温度的升高,烧结体的硬度增大,致密度、电导率和热导率在1150℃达到最大值.     

掺钕氧化钪激光透明陶瓷纳米粉体的合成及研究

研究了化学共沉淀法合成Nd:Sc2O3纳米粉的工艺.以Sc2O3为基质材料,掺杂0.5％(原子分数)的Nd3+,添加适量聚乙二醇(PEG)和(NH4)2SO,作为分散剂,以氨水(NH3·H2O)和碳酸氢铵(NH4HCO3)混合溶液作复合沉淀剂,采用化学共沉淀法获得了碱式稀土碳酸盐前躯体,在1100℃下煅烧该前躯体4h,制备出性能良好的Nd:Sc2O3纳米粉.采用热重-差热分析仪(TG/DSC)、红外光谱分析仪(IR)、X射线衍射仪(XRD)、透射电子显微镜(TEM)等测试手段对Nd:Sc2O3前躯体和煅烧后的粉体进行表征.实验结果表明:在室温下,用氨水和碳酸氧铵混合溶液作为复合沉淀剂合成出的前躯体为碱式稀土碳酸盐.通过XRD和EDS能谱分析,Nd3+完全固溶于Sc2O3的立方晶格中,这将有利于制备激光透明陶瓷.在1100℃的温度下煅烧此前躯体得到的Nd:Sc2O3纳米粉具有颗粒粒度小(约50 nm)、分散性好、团聚程度轻、结晶良好的性能.因此,采用此工艺合成的粉体将有可能制备出的Nd:Sc2O3透明陶瓷.     

撞击流-活性炭吸附法制备氧化钇超细粉体

以Y( NO3)3·6H2O和碳酸氢铵为原料,在撞击流反应器中制备碳酸钇,经焙烧得到超细氧化钇粉体.考察了分散剂加入量、反应物摩尔比n( NH4HCO3)/n(Y(NO3)3)、活性碳用量、反应温度、反应时间、搅拌速度以及碳酸钇的焙烧温度和焙烧时间等因素对Y2O3粒径的影响,并用WJL激光粒度仪、TG、XRD和SEM等表征手段对产品进行表征,从而获得制备超细氧化钇的优化工艺条件为:PEG4000的质量为硝酸钇的3％,活性炭用量为0.025 mol·L-1,反应物摩尔比n( NH4HCO3):n(Y( NO3)3)为8:1,反应温度50℃,反应40 min,螺旋桨转速1000 r·min-1,800℃下焙烧1.5h,在此条件下制得球形氧化钇超细粉体,表观粒径小于0.5μm.     

Ni/Y_2O3-Al2O3 catalysts for hydrogen production from steam reforming of ethanol at low temperature

Y2O3-Al2O3 with different mole ratios of Y:Al were prepared by co-precipitation method. Catalysts Ni/Y2O3, Ni/Al2O3 and Ni/ Y2O3-Al2O3 were prepared by impregnation method. The result of BET showed that Al2O3 with relative high surface area was in favor of Ni distribution, whilst the TPR test demonstrated that composite support had appropriate synergistic effect between active constituent and sup-port, and NiO could be reduced more easily than loaded on the single support. H2-TPD test indicated that the catalyst NYA11 had lots of ac-tivity sites where H could be desorbed easily, which led to hydrogen-rich production over the catalyst. Composite support catalysts exhibited high activity for ethanol steam reforming (SRE), and the supported catalyst with composite of 1:1 mole ratio of Y:Al exhibited the optimum catalytic properties for SRE. Ethanol could be completely converted over catalyst NYA11 even at 450 °C, and there had no inactivation after 60 h continuous reaction, hydrogen yield appeared maximum 35.9% at 400 °C, and tended to increase with increasing H2O/EtOH molar ratio and feed flow rate.     

Synthesis, Characterization and Inhibition Effects of Vanadium Substituted Dawson-type Heteropoly Acids(Mo, P)

Four new vanadium substituted Dawson-type heteropoly acids H<,7>[P<,2>Mo<,17>VO<,62>]·39H<,2>O(1), H8[P2Mo16V2O62]·41H2O(2) H9[P2Mo15V3o62]·51H2O(3)and H8[P2Mo14V4O62H2]·45H2O(4)were prepared respectively. Their structures were determined by IR and ICE. The inhibition effects of vanadium substituted Dawson-type heteropoly acids(Mo, P) on free radical polymerization of methyl methacrylate(MMA) were investigated by dilato- metry. The results show that the rate of the polymerization of MMA decreases and the inhibition effects of the four heteropoly acids reach the inhibitor performance of hydroquinone at a certain ratio.     

Comparison of body composition by dual energy X-ray absorptiometry to other estimates of body composition during weight loss in obese patients with rheumatoid arthritis

Body composition was determined by dual energy X-ray absorptiometry (DXA) scanning and classical reference methods (40K, 3H2O, and a combination of these in a four-compartment model) in 19 overweight patients with rheumatoid arthritis who underwent a 12-week weight-reducing regimen. The aim of the study was to investigate whether DXA provides a valid estimate of body composition. The results showed that weight as determined by DXA was highly significantly correlated to weight determined by scales. Furthermore, significant correlations were found in the body components (fat-free mass, fat mass) determined by DXA, 40K, 3H2O and the four-compartment model. Mean values differed slightly but significantly. With respect to changes in body composition, no significant correlations were found between any of the methods, except for the weight loss recorded by DXA and scales, and loss of fat mass (and fat free mass) estimated by 3H2O and the four-compartment model. The sparseness of correlations reflected the small changes in fat-free mass and fat mass (2.6 and 1.7 kg respectively), and the fact that changes were comparable to measurement errors of the various methods. We suggest that DXA scanning is a valid supplement for determination of body composition. Validation of DXA scanning requires new experimental in vitro investigations, which, incidentally, also applies to the classical reference methods.     

Synthesis of neodymium modified CeO2-ZrO2-Al2O3 support materials and their application in Pd-only three-way catalysts

Ce-Zr-Al-Nd2O3 (CZAN) support materials were prepared by co-precipitation and impregnation methods, respectively. They were characterized by X-ray diffraction (XRD), low temperature nitrogen adsorption-desorption, oxygen pulsing technique, H2-temperature pro-grammed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The Pd-only three-way catalysts (Pd-TWC) supported on these materials were prepared by incipient wetness method and studied by activity tests. The results demonstrated that the CZAN supports obtained by the two methods showed better structural, textural and redox properties than the CZA without Nd2O3, and the addition of Nd2O3 improved the catalytic activity of TWC. Especially, the CZAN-i support prepared by impregnation method had better thermal stability and redox prop-erty. Meanwhile, the Pd/CZAN-i catalyst exhibited the best catalytic performance. XPS measurements indicated that the Nd-modified sam-ples possessed more Ce3+ and oxygen vacancies on the surface of samples, which led to a better redox property. The excellent redox property of support materials helped to improve the catalytic activity of TWC.     

Anti-diabetic drugs as a cause of hypoglycaemia among acute medical admissions in Hong Kong and Singapore--relationship to the prescribing patterns in diabetic patients

By a reaction of salicylaldehyde (Scl) with the corresponding amino acids and by the next complexation reaction of the formed Schiff bases with Cu2+ ions in an aqueous-alcoholic medium, aqua (N-salicylideneaminoalkanoato)copper(II) complex chelates of the composition Cu(Scl-DL-Asp(2-)) (H2O)2, Ip and Cu(Scl-L-Asn(2-)(H2O), In were prepared. The monodiazole complexes with pyrazole IIp and IIn (as monohydrate) as well as with 3,5-dimethylpyrazole IIIp a IIIn were prepared by replacing the molecule of H2O in the parent aquacomplexes with the diazoles under the same reaction conditions. Using a routine dilution micromethod, the antimicrobial activity of the prepared complexes and free diazoles was tested against Staphylococcus aureus, Escherichia coli and Candida albicans. Only a significant antistaphylococcus activity was found (highest for the complex IIn; MIC = 39 micrograms/cm3). All chelates (Ip,n-IIIp,n) were more effective (MIC = 39-156 micrograms/cm3) than both pyrazole (312 micrograms/cm3)and 3,5-dimethylpyrazole (625 micrograms/cm3) alone. The relationship between the coordination-chemical properties and the biological effects of the complexes studied is discussed.     

不同锂源对尖晶石锰酸锂性能的影响

采用溶胶凝胶法,以氢氧化锂、醋酸锂、硝酸锂为锂源制备锂离子电池正极材料尖晶石LiMn2O4,分别用XRD和SEM对产物的结构和微观形貌进行表征,并对其电化学性能进行了测试。结果表明,用硝酸锂制备的LiMn2O4有较好的的微观形貌及较高的初始比容量,用氢氧化锂制备的LiMn2O4有较好的循环性能。     

Synthesis and Characterization of Lanthanide Complexes Involving Cyclopentadienyl and Benzohydroximic Acid Ligand

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