Novel preparation of organic polymer-based monolithic column by microwave irradation

Microwave irradiation was firstly attempted for the preparation of organic-based monoliths of poly（styrene-divinylbenzene- methacrylic acid）, which single step in situ polymerization was carried out during 15 min. The colunm permeability, electrophoretic and chromatographac behaviors were comparatively evaluated using pressure-assisted CEC, GEC and low pressure-driven separation modes. The largest theoretical plates for the preparing column could be close to 18,0000 plates/m for thiourea in the mode of p-CEC. It provided a viable alternative to traditional initiation means for the perparation of monolithic capillary columns.     

丹宁纤维素富集-氢化物发生ICP-AES同时测定水中痕量锗

研究了丹宁纤维素富集10~(-11)g/ml级锗的条件,并考察了地下水中36种共存离子对磷酸介质中氢化物发生ICP-AES测定锗的干扰和消除,应用于测定地下水中的超痕量锗,结果满意,检出限为15ng/L。     

A mesoporous template route to the low-temperature preparation of efficient green light emitting Zn2SiO4:Mn phosphors

Green light emitting Zn2SiO4:Mn phosphors have been prepared via a low-temperature solid-state reaction using mesoporous silica SBA-15 template. This mesoporous silica template method features low-temperature formation of phosphors and easy doping. The structure and morphology of the phosphors were characterized by XRD, SEM, TEM, and N2 adsorption/desorption techniques, which confirmed the single crystallinity, ordered mesostructure, closed pore channels, and elongated ropelike morphology. The luminescent properties were examined by photoluminescence spectroscopy at room temperature, and the results of fluorescence decay time measurements show non-single-exponential decay behavior and a decrease of the decay time with an increase of the Mn concentration.     

MO(M=Cu和Ni)/TiO2/-Al2O3催化剂在CO+O2反应中的活性

采用X射线衍射(XRD),程序升温还原(TPR)等表征手段考察了TiO2改性对CuO(或NiO)在γ-Al2O3表面上分散以及还原性能的影响,同时检测了这些改性的催化剂在CO+O2反应中的活性.结果表明:TiO2的改性使得CuO和NiO在γ-Al2O3载体上的分散复杂化,产生了多种状态的氧化铜(氧化镍)物种.当负载量低于其在γ-Al2O3上的分散容量(0.56 mmol Ti4+/100 m2γ-Al2O3)时,TiO2的加入主要是抑制了CuO和NiO在γ-Al2O3载体上的分散;而当负载量远大于其分散容量时,出现了CuO和NiO在晶相TiO2(锐钛矿)上的分散.无论其负载量如何,TiO2的加入促进了CuO的还原.因此,在250℃的CO+O2反应中,改性的催化剂中具有更多的活性位,因而显示出更高的活性;相反,TiO2的改性则抑制了NiO的还原.因此,在350℃的CO+O2反应中,可还原的氧化镍的量明显少于未经改性的催化剂,导致改性催化剂的活性降低.     

Modeling of the relationship between electroosmotic flow and separation parameters in capillary zone electrophoresis using artificial neural networks and experimental design

The prediction of migration time of electroosmotic flow (EOF) marker was achieved by applying artificial neural networks (ANN) model based on principal component analysis (PCA) and standard normal distribution simulation to the input variables. The voltage of performance, the temperature in the capillary, the pH and the ionic strength of background electrolytes (BGE) were applied as the input variables to ANN. The range of the performance voltage studied was from 15 to 27 kV, and that of the temperature in the capillary was from 20 to 30 °C. For the pH values studied, the range was from 5.15 to 8.04. The range of the ionic strength investigated in this paper was from 0.040 to 0.097. The prediction abilities of ANN with different pre-processing procedure to the input variables were compared. Under the same performance conditions, the average prediction error of the migration time of the EOF marker was 5.46% with RSD = 1.76% according to 10 parallel runs of the optimized ANN structure by the proposed approach, and that of the 10 parallel predictions of the optimal ANN structure for the different performance conditions was 12.95% with RSD = 2.29% according to the proposed approach. The study showed that the proposed method could give better predicted results than other approaches discussed.     

纳米微晶Y_2Sn_(2-x)FexO_(7-δ)的制备及其催化选择性能研究

采用共沉淀并加法制备了Ｂ位掺杂烧绿石型稀土复合氧化物纳米微晶Ｙ２Ｓｎ２－ｘＦｅｘＯ７－δ（ｘ＝００～１０）。制备的纳米微晶属于立方晶系，Ｆｄ３ｍ，晶胞参数与掺杂量呈线性关系。通过Ｍｓｂａｕｅｒ、ＴＧＤＴＡ，气相色谱和γ射线辐照等技术研究了纳米微晶对ＣＯ的催化选择性能。结果表明，纳米微晶对ＣＯ的催化选择性明显高于一般粉料对ＣＯ的选择性；纳米微晶对ＣＯ的选择性与掺杂量有关；未辐照的纳米微晶，当掺杂量ｘ＝０６时，其对ＣＯ的选择性为最高，辐照后的纳米微晶，当掺杂量ｘ＝０４时，其对ＣＯ的选择性为最高     

Enatiomeric analysis of simendan by CE with beta-CD as chiral selector compared with CMPA-HPLC

The chiral separation of simendan enantiomers using capillary electrophoresis was studied with beta-cyclodextrin (beta-CD) as chiral selector. The influences of the concentration and pH of borate buffer solution, beta-CD concentration and methanol content in the background electrolyte were investigated. These factors were compared with those in an HPLC with beta-CD as chiral mobile phase additive (CMPA-HPLC). The quantification properties of the developed CE method were examined. A baseline separation of simendan enantiomers was achieved in the background electrolyte of 20 mmol/L borate buffer (pH 11.0) containing 12 mmol/L beta-CD-methanol (50:50 in volume ratio). The CE method is comparable with CMPA-HPLC in chiral resolution, although the optimal pH in CE (11.0) is much higher than that (6.0) in CMPA-HPLC. This chiral CE method is applicable to the quantitative ananlysis and enantiomeric excess value determination of L-simendan.     

FREE STANDING FILM OF POLYANILINE

A free standing film of polyaniline as large as 18 cm×18cm×0.002 cm can be obtained by evaporation of a solution of the chemically synthesized base in NMP. Its structure was examined by the elemental analysis, IR, U.V.-visible spectra, XPS, DSC, SEM and X-ray scattering and its conducting behavior as well as electrochemical properties were studied. Results show that the composition, structure of main chain, physical properties of the free standing film of polyanilme is similar to that of the powder. However, some differences in its electronic structure, conductivity at room temperature and potential of redox couple between the flee standing film and powder are observed, which may be due to cross-linking of the film of polyaniline.     

An unprecedented 8-fold interpenetrating diamondoid-like coordination polymer containing a Cu+(4)(RCO2)(4) cluster as connecting node

The reaction of Cu(I)(CH(3)CN)(4)BF(4) with 4-pyridylacrylic acid (4-HPYA) affords an unprecedented 8-fold interpenetrating diamondoid-like coordination polymer network [Cu(I)(3)(4-PYA)(2)(H(2)O)(BF(4)) ] (1) with a Cu(+)(4)(CO(2))(4) cluster as connecting node. The interpenetration in metal coordination polymers is the highest degree ever found within diamondoid nets containing a cluster as connecting note. Its fluorescent property was also reported.