NiCoB超细非晶合金的化学制备和热稳定性研究

用化学还原法制备了Ni－B、Co－B及不同含量的Ni－Co－B超细非晶态微粒．电感耦合等离子光谱（ICP）测定合金的组成表明：微粒中Ni与Co的含量可通过调节反应溶液中Ni与Co离子浓度来控制．X衍射（XRD）、透射电镜（TEM）及电子衍射证实合金是粒径约为20nm的非晶相球状颗粒．用示差量热法（DSC）考察了制备条件对非晶态合金热稳定性的影响．发现相同组成不同含量及不同条件下制得的样品其热稳定性均有差异．初步解释了引起这种差别的原因．从而揭示了非晶态合金结构的复杂性．     

Comparative evaluation of the possibilities of INAA, ED-XRF, ICP-AES and AAS in the analysis of plants

The usefulness of INAA, radionuclide ED-XRF, ICP-AES and AAS are comparatively evaluated for the determination of nutrients, essential and trace elements in various plant matrices. The comparison is performed by analysis of the following reference materials: NIST-SRM-1573, NIST-SRM-1575, NIES-1, NIES-3, NIES-6, IAEA-V-10 and Bowen's kale. The detection limits, accuracy and precision of the methods are discussed and a combination of INAA and GFAAS is recommended for analysis of plants for monitoring purposes.     

大气中HSO-3异构体的“量子化学后”研究

在量子化学计算的基础上，用统计热力学方法，计算了亚硫酸氢根离子的两种异构体HOSO^-₂(C_S)和HSO^-₃(C₃V)的热力学性质及它们相互转化的平衡常数(相对稳定性随温度的变化)等。通过计算数据的回归分析，给出了摩尔熵、摩尔热容等随温度变化的表达式。     

A molecular dynamics simulation of the adsorption of water molecules surrounding an Au nanoparticle

This study uses molecular dynamics simulations performed in a parallel computing environment to investigate the adsorption of water molecules surrounding Au nanoparticles of various sizes. An observation of the oxygen and hydrogen atom distributions reveals that the adsorption of the water molecules creates two shell-like formations of water in close vicinity to the Au nanoparticle surface. These shell-like formations are found to be more pronounced around smaller Au nanoparticles. The rearrangement of water molecules in this region reduces the local hydrogen bond strength to below that which is observed in the bulk region. Finally, the simulation results indicate that the absolute value of the interaction energy between the water molecules and the Au nanoparticle is reduced when the water molecules surround a nanoparticle of larger diameter. This observation implies that a stronger adsorption effect exists between smaller Au nanoparticles and water molecules. Hence, the value of the adsorption constant increases for smaller Au nanoparticles.     

Synthesis of novel C2-C3'N-linked macrocyclic taxoids by means of highly regioselective Heck macrocyclization

[reaction: see text] Novel C2-C3'N-linked macrocyclic taxoids are synthesized using intramolecular Heck reaction in the key step. Macrocyclization proceeds with high regioselectivity in good yield. Taxoids bearing an olefin moiety at C2 and an iodide at C3'N give exo-products exclusively. However, the endo-products are formed with up to 100% regioselectivity just by switching the positions of the olefin and the iodide moieties. Some of these macrocyclic taxoids are significantly cytotoxic.     

含有偶氮染料侧基的聚氨酯（脲）的研究

用扩链法合成了一系列含有偶氮染料的侧基聚氨酯和聚脲。ＴＦ－ＩＲ、ＤＳＣ、ＤＭＡ的研究表明，聚合物有良好的力学性能，样品中软硬段的含量决定材料的物理性能。通过ＵＶ的测定，计算出样品均有较高的三阶非线性光学（ＮＬＯ）系数。     

Syntheses and Structures of Zinc(II) Co‐Ordination Polymers Bridged by Flexible Bidentate Nitrogen Ligands

The reaction of Zn(NO₃)₂·6H₂O and bpp (bpp = 1,3‐Bis(4‐pyridyl)pronpane) in CH₃OH afforded the complex [Zn(bpp)(NO₃)₂]_n, 1 . The IR has been recorded and the structure has been determined. Crystal data for 1: Space group P2(1)/n, a = 11.749(1), b = 11.413(1), c = 11.942(1) Å, β = 96.06(6)°. V = 1592.5(3) ų, Z = 4 with final residuals R1 = 0.0484 and wR2 = 0.0984. The complexes show supramolecular structure in the solid state by intermolecular hydrogen bonding interaction.     

A Novel Substrate for in situ Synthesis of Oligonucleotides： Hydrolyzed Microporous Polyamide-6 Membrane

A novel substrate for in situ synthesis of oligonucleotide was prepared by hydrolyzing microporous polyamide-6 membranes in a 0.01mol/L NaOH/(H2O-CH3OH) mixture medium. The formation of amines (NH2) on the surface was proved by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The treated membrane was applied for in situ synthesis of oligonucleotide and a single step coupling efficiency determined by ultraviolet (UV) spectra was above 98%.     

高变质福建无烟煤连续流化床混合气催化气化

连续流化床（内径123mm、高1．2m）中，采用工业纯碱（碳酸钠）为催化剂进行了高变质程度无烟煤一福建永安煤（低挥发分k=5．47％、高灰Aad=29．45％）混合气（空气／水蒸气）催化气化的研究，考察了催化剂质量分数、气化温度、水汽比等操作参数的影响。实验结果表明，工业纯碱作为催化剂添加5％可使碳转化率增加3倍，实现了煤的高效转化；气化温度有明显催化气化促进作用，超过900℃时，流化床内易结渣。从同时满足高产气率及高煤气热值两个指标出发，在适宜操作条件（碳酸钠质量分数5％、850℃～880℃、适宜水汽比）下，产气率提高2倍，从无催化剂时的2．13m^3／kg～2．15m^3／kg提高到4．2m^3／kg～5．1m^3／kg；煤气热值提高5倍，从1．0MJ／m^3左右提高到5．0MJ／m^3；表明工业纯碱进行高变质福建无烟煤流化床混合气催化气化具有重要的工业应用价值和现实的开发意义。     

烯烃配位活性聚合研究的新进展

从活性聚合的特征、催化剂的结构和特点、聚合单体的种类、以及控制工艺条件的重要性4个方面．评述了近年来烯烃配位活性聚合研究的进展状况。