Electrospun nanofibers of poly（vinyl pyrrolidone）/Eu^3＋ and its photoluminescence properties

Nanofibers of poly（vinyl pyrrolidone） （PVP）/Eu^3＋ with diameters of 300-900 nm were prepared by using sol-gel processing and electrospinning technique. The products were characterized by scanning electron microscope （SEM）, Fourier transform infrared spectroscopy （FT-IR）, and photoluminescence （PL）. The results indicated that, Eu^3＋ was successfully embedded in the onedimensional hybrid nanofibers, and the PVP/Eu^3＋ hybrid nanofibers had favorable photoluminescence properties.     

Cu-Mg/Al复合氧化物催化碳颗粒物燃烧性能的研究

恒定二价与三价阳离子比为3(nM2+/nM3+=3),采用共沉淀法制备不同Cu含量的系列水滑石前驱物, 800 ℃焙烧4 h形成复合氧化物(CuO质量百分数分别为0％、5％、10％、15％、20％、30％、40％)用作柴油车排放碳颗粒物燃烧的催化剂,并采用XRD、BET、TG-DSC、FT-IR、TPR等表征手段研究了Cu、Mg含量对材料前驱物物化性能的影响及对其衍生复合氧化物催化碳颗粒物燃烧性能的影响．结果表明,Cu、Mg含量对材料的热稳定性、比表面和催化氧化活性有显著的影响. Mg有助于提高催化剂的热稳定性; Cu含量增加,催化剂比表面下降,但比表面不是影响催化剂活性的主要因素. CuO含量为15％时,催化剂具有最好的催化活性和稳定性,碳颗粒物的起燃温度(T10)和半转化温度(T50)分别为336 ℃和409 ℃.在CuO含量≤30％时可以形成结构完整的水滑石前驱物, CuO含量为40％时出现Cu(OH)2杂相; CuO含量< 20％时,经高温焙烧可得到均匀的复合氧化物, CuO含量≥20％时出现CuO偏析． TPR结果表明焙烧温度和复合氧化物的组成决定了材料的可还原性能．     

Simultaneously quantifying parent drugs and screening for metabolites in plasma pharmacokinetic samples using selected reaction monitoring information-dependent acquisition on a QTrap instrument

Bioanalytical support of plasma pharmacokinetic (PK) studies for drug discovery programs primarily involves the quantitative analysis of dosed compounds using liquid chromatography/atmospheric pressure ionization tandem mass spectrometry (LC/MS/MS) operated in selected reaction monitoring (SRM) mode. However, there is a growing need for information on the metabolism of new chemical entities (NCEs), in addition to the time-concentration profiles from these studies. In this paper, we present a novel approach to not only quantify parent drugs with SRM, but also simultaneously screen for metabolites using a hybrid triple quadrupole/linear ion trap (QqQ(LIT)) instrument. This was achieved by incorporating both the conventional SRM-only acquisition of parent compounds and the SRM-triggered information-dependent acquisition (IDA) of potential metabolites within the same scan cycle during the same LC/MS/MS run. Two test compounds were used to demonstrate the applicability of this approach. Plasma samples from PK studies were processed by simple protein precipitation and the supernatant was diluted with water before injection. The fast scanning capability of the linear ion trap allowed for the information-dependent acquisition of metabolite MS/MS spectra (<1 s/scan), in addition to the collection of adequate data points for SRM-only channels. The MS/MS spectra obtained from potential metabolites in post-dose samples correlated well with the spectra of the parent compounds studied, therefore providing additional confirmatory structure information without the need for repetitive analyses. Relative quantitative time-concentration profiles of identified metabolites were also obtained. Furthermore, this articulated SRM+SRM-IDA approach generated equivalent quantitative results for parent compounds to those obtained by conventional SRM-only analysis. This approach has been successfully used to support discovery PK screening programs.     

Oxidative Methyl Esterification of Primary Alcohols with Iodine‐Mediated Poly[4‐(Diacetoxyiodo)Styrene]

An operationally simple oxidative methyl esterification of primary alcohols in good yields using an iodine‐mediated poly[4‐(diacetoxyiodo)styrene] in methanol at room temperature is described. The polymeric reagent can be regenerated and reused as an environmentally benign reagent.     

Stannous oxalate as a novel catalyst for the synthesis of polytrimethylene terephthalate

Stannous oxalate was prepared efficiently and characterized by XRD and FT-IR. It exhibited higher catalytic activity and had profitable effect than tetrabutyl titanate and stannous octoate for the synthesis of polytrimethylene terephthalate (PTT) via esterification-route. Over this catalyst, the degree of esterification of pure terephthalic acid was up to 94.4% at 260°C after 1.5 h, while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PTT polyester, polymerized at 260°C, 60 Pa for 2 h, was 0.8950 dL/g and 15 mol/t, respectively. Stannous oxalate was a promising catalyst for the synthesis of PTT polyester.     

Microdetermination of sulfite with a piezoelectric crystal detector

A piezoelectric method is proposed for the determination of sulfite in concentration range 1 × 10^–7–1 × 10^–5 mol/1. The method is based on the redox reaction of sulfite with iodine followed by measuring frequency change of the piezoelectric crystal caused by the unreacted iodine. The method is applied to the determination of sulfite in liquor.     

Solid-phase Synthesis of-Haloaldehydes from Polymer-supported 4-(Phenylseleno)morpholine

Polymer-supported reagents for organic synthesis are enjoying a renewed popularity with the emergence of combinatorial chemistry in recent years1. 4-(Arylseleno)morpholines formed in situ are useful -seleno-introducing reagents for saturated aldehydes2. -Sele- noaldehydes, as a frequently used intermediates, can be converted into -haloaldehydes by halogenating reaction3. However, organic selenium reagents always have a foul smell and are quite toxic, which is often problematic in organic sy…     

光诱导有机化合物异构化反应的研究——Ⅹ. 吲哚啉螺吡喃瞬态吸收光谱的研究

研究了1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(2-溴-4-硝基-苯并)吡喃, 1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(4-硝基-苯并)吡喃, 1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(2,4-二硝基-苯并)吡喃及1-正-辛基-3,3-二甲基-吲哚啉-2,2′螺-5′6′-(2-氯-4-硝基-苯并)吡喃在环已烷和甲苯溶液中光致开环过程的瞬态吸收光谱。观察到具有较长寿命的中间体及聚集体的存在。初步提出异构化反应过程的机制中既包含有三重态过程, 也有单重态参与。     

环糊精-六次甲基四胺超分子络合物电化学研究及应用

在0.05 mol/L KCl底液中,β-环糊精(β-CD)-六次甲基四胺超分子络合物在2.5次微分极谱仪上于-0.78V(vs.SCE)处产生吸附还原波,峰形对称且稳定,其峰电流与六次甲基四胺浓度在4.0×10-4-1.0×10～mol/L之间呈良好线性关系;检出限为1.5×10-4mol/L。应用该法测定了有机工业产品六次甲基四胺,并与传统方法进行了比较,结果令人满意。对超分子络合物电化学性质及分子识别机理进行了探讨。     

Characteristics analysis of metal-clad and absorptive dielectric waveguides by a simple and accurate perturbation method

We present a simple and accurate method for characteristic analysis of metal-clad dielectric waveguides and absorptive waveguides. The real partN of the complex modal indexN=N + iN is obtained by solving the corresponding real eigenvalue equation, and the imaginary partN is given by (n/), where= + i is the complex dielectric constant of the absorptive layer, and N/ is obtained by numerical differentiation. The method is straightforward, and the cumbersome solution of complex transcendental equations is completely eliminated. Results for simple structures are in good agreement with those obtained by exact analysis.