硒锌氨基酸治疗儿童锌缺乏症疗效分析

为观察硒锌氨基酸治疗儿童锌缺乏的疗效,将98例锌缺乏儿童随机分为硒锌氨基酸治疗组及对照组,测定治疗前后血锌增加值,并比较治疗效果。结果表明,治疗组血锌平均增加值为(16.37±4.89)μmol/L,对照组为(12.39±5.01)μmol/L,P<0.01,差异有高度显著性;治疗组50例中,显效36例,有效10例,无效4例,对照组48例中显效24例,有效12例,无效12例,χ2=4.12,P<0.05,差异有显著性。可见硒锌氨基酸治疗儿童锌缺乏症取得显著疗效。     

碱土金属掺杂纳米TiO2催化剂的制备与光催化活性的评价

The nanometer TiO₂ were prepared by the hydrolyze-gel method and fellowed by doping alkaline-earth metals (Mg, Ca, Sr, Ba). XRD, SEM, diffuse reflection spectra were used to investigate their characteristices. The result indicates that the average particles size of the TiO₂ is about 80 nm and keep uniformity in distributing. The product was mainly anatase in 300～400 ℃ calcinations, the einstein shift of absorption spectrum was observed after doping the alkaline-earth metals. The best mole percentages of Mg, Ca, Sr and Ba are 0.5%, 1.0%, 1.5%, 1.5% respectively. Under the same reaction conditions, it is more effective to the UV-catalyed degradation reaction that the catalysts containing Mg and Ca were calcined at 300 ℃ for 1h or containing Sr and Ba were calcined at 400 ℃ for 1 h. The photocatalystic activity is considerably depondent on pH and the concentration of the oxidant. Using the sunlight to do the degradation experimental, the result also show that the doping catalysts has higher degradation efficiency than that of pure TiO₂.     

Highly Enantioselective Phenylacetylene Addition to Benzaldehyde Catalyzed by Chiral Tridentate Ligand

Development of new or improved methods for the asymmetric preparation of chiral propargylic alcohols has gained considerable significance during the past years because they are useful building blocks for the synthesis of many biologically active compounds and natural products.[1] A series of chiral tridentate ligands were conveniently synthesized from amino acids with good yields (Scheme 1).[2] A preliminary study of the enantioselective alkynylation of benzaldehyde catalyzed by this chiral tridentate ligand was carried out and up to 83% ee of chiral propargyl alcohols was obtained (Table 1 ). A further investigation of the tridentate ligand is currently underway.     

Synthesis and Crystal Structure of 〔P(CH_2Ph)Ph_3〕〔PdWS_4(S_2CNC_4H_8)〕

1INTRoDUCTIoNThiomolybdate(thiotungstate)isafundamentalunitoPsomemolybdenumen-zymesandplaysanimportantroleincoordinationchemistryasaligandforothermet-alstoformanalogouscompoundsofmetalloproteinst'3.Recentlyinterestingnonlinearoptical(NLO)propertieshavebeendiscoveredforthetypeofMo(W)-Cu(Ag)-Sclusterst2.33.Bythevarioussyntheticmethodsseveralhundredmixedmetalclustersandcomplexes,Mo(W)-M-S(M=transitionmetal),havebeensynthesizedt'i.AmongthesecompoundsthecasesofMbeingCu,Ag,Feareusualwhile…     

新型聚醚的合成与表征

用高活性催化剂催化环氧丙烷开环聚合得到一类新型高质量聚醚。对产物进行IR和NMR表征和分析,并探讨了合成工艺条件。结果表明,调节单体与调节剂的比例,控制反应温度在100 5℃,压力在0.15 ~ 0.25 MPa ,可得到不饱和度低、相对分子质量可控、相对分子质量分布窄的聚醚产品。     

Synthesis, crystal structure and magnetic properties of a novel manganese(II)-nitronyl nitroxide-azido(μ_(1,1) and μ_(1,3)) one-dimensional complex

A novel one-dimensional manganese(Ⅱ) complex containing nitronyl nitroxide radical [Mn2(IM2-py)2(Ac)2((μ1.1-N3)(μ1,3-N3) . EtOH]n was synthesized and characterized structurally and magnetically. It crystallizes in the monoclinic space group p21/n. Each Mn(Ⅱ) ion is six-coordinated in a distorted octahedral environment. The two N atoms of the nitronyl nitroxide radical and the two O atoms of acetate ligands are in the equatorial plane, whereas the two different azido bridging ligands are in trans axial position. Mn(Ⅱ) ions are linked by nitrogen atom of μ1,1-azido and oxygen atoms of two carboxy groups to form a Mn-Mn unit. Mn-Mn units are linked by azido ligands through u1,3 bridging style to form a one-dimensional chain. The compound is connected by the coordination bonds,π-π interactions and hydrogen bonds as a three-dimensional structure. Magnetic susceptibility data support that there are stronger antiferromagnetic interactions between the radical and Mn(Ⅱ) ion, weak antiferromagnetic inter     

CRYSTALLIZATION AND MELTING OF NYLON 610

Differential scanning calorimetry was used to study the crystallization andmelting of nylon 610. For nylon 610 crystallized from the melt state (260℃), the overall rateof bulk crystallization can be described by a simple Avrami equation with Avrami exponentn ≈ 2, independent of crystallization temperature. With the experimentally obtainedT_m~0 (235℃ ～ 255℃) of nylon 610, the fold surface free energy σ_e was determined to be35 ～38 erg/cm~2. The effects of annealing temperature and time on the melting of quenchednylon 610 were also investigated. For nylon 610 quenched at room temperature there isonly one DSC endotherm peak DSC scans on annealed samples exhibited an endothermpeak at approximately 10℃ above the annealing temperature. The size and position of theendothermic peak is strongly related to annealing temperature and time. An additionalthird melting was observed when quenched nylon 610 was annealed at high temperaturefor a sufficiently long residence time. The existence of the third melting peak suggests thatmore than one kind of distribution of lamella thickness may occur when quenched nylon610 is annealed. The implications of these results in terms of crystal thickening mechanismwere discussed.     

平行光栅对在刻线不平行时的色散研究

 利用三维空间光线追迹法，分析了啁啾脉冲放大系统中的压缩光栅对，在刻线不平行而光栅面平行时光的衍射特性。导出了此时光通过光栅对的群延时，数值计算了系统2阶和3阶色散量，以及这些色散量在光栅对严格平行时的相对误差。得出了中心波长光的接收位置相对于光栅对严格平行时的偏移量，并且分析了它与入射角的变化关系。     

新型添加剂全氟辛酸铵对提高锂离子电池安全性能的研究

报导可显著提高锂离子电池安全性的新型电解液添加剂全氟辛酸铵(APC). UL 94 可燃性试验显示添加0.70 wt% APC能使有机电解液的火焰传播速率下降33%. 差示扫描量热法(DSC)测试表明APC显著减弱了嵌锂碳电极和电解液之间的放热反应, 并将其热不稳定温度由138.0 ℃提高到167.5 ℃. 交流阻抗检测显示APC的加入明显降低了碳材料电极的界面阻抗, 并且提高了在储存过程中其固态电解质界面(SEI)层的稳定性. 添加APC还能有效地提高Li/MCMB电池充放电循环性能和库仑效率.     

恒定磁场(0.4T)对聚苯胺微观取向结构的影响

在恒定磁场(0.4 T)条件下, 采用乳液聚合法合成了十二烷基苯磺酸掺杂聚苯胺(PAn), 并通过透射电子显微镜(TEM)、X射线衍射(XRD)、傅立叶红外光谱(FT-IR)、电导率、产物复合膜电阻率的各向异性, 以及产物间甲酚(m-cresol)溶液的电导率在外电场作用下变化的分析与表征, 系统研究了磁场对PAn的微观取向结构及其性能的影响. 实验结果表明, 与无磁场条件下制备的聚苯胺(PAn_-O)相比, 磁场条件下制备的聚苯胺(PAn_-M)具有更高的结晶度和明显的微观取向结构, 其微粒有序排列和堆砌成了许多具有一定长/径比的条状聚集体; PAn_-M/PVA(聚乙烯醇)复合膜经磁化成膜, 可以表现出明显的导电性能的各向异性; PAn_-M/m-cresol溶液的电导率, 在有、无外场(电场)作用下存在明显的突变. 分析认为: 由于磁场条件下制备的PAn粉末存在着微观取向和显著的抗磁磁化率的各向异性, 在外磁场作用下其堆砌方式会进一步演变成宏观的取向, 随之表现出物理性能上的各向异性.