弱碱性和强碱性阴离子交换树脂的离子交换平衡的比较SO_4~(2-)-Cl~--NO_3~-体系

本文详细地比较了在弱碱性和强碱性阴离子交换树脂上,SO_4~(2-)-Cl~-、NO_3~--Cl~-及NO_3~--SO_4~(2-)二元交换的等温线和修正选择系数。实验测定及理论计算了上述三种二元交换反应的标准自由能的改变量。测得了在弱碱性树脂上的SO_4~(2-)-Cl~--NO_3~-三元交换的等温线。适用于强酸性和强碱性树脂的从二元交换平衡数据推算三元交换平衡数据的方法推广应用于弱碱性树脂。     

伏安型植物组织生物微电极的研究：混合不同植物组织碳糊微电极的研究

由于香蕉组织中含有的氧化酶能够生物催化氧化多巴胺，去甲肾上腺素，Ｌ－多巴等，大大地提高了植物组织电极的灵敏度；又由于茄子组织中所含有的氧化酶在催化氧化儿茶酚的同时，能有效地抑制抗坏血酸在电极上的反应，将上述两种植物组织混合制成电极，使其更适于神经递质的测定，线性范围：２．４×１０＾－６－－９．８×１０＾－４ｍｏｌ／Ｌ；检出下限３．２×１０＾－７ｍｏｌ／Ｌ。     

硅灰石矿物发光原料中Fe2+的去除与CaSiO3∶Eu3+的光谱特性

提出了用草酸．邻菲哕啉去除硅灰石中Fe^2 的方法，研究了浸取剂的浓度、浸取时间和温度等条件对Fe^2 的去除率的影响，在最佳的浸取条件下，Fe^2 的去除率达到98．35％。在去除猝灭剂后的硅灰石矿物中，掺加适量的稀土激活剂Eu^3 ，通过高温固相法制成荧光发光材料，发光强度明显提高，接近于化学试剂合成的发光材料。     

Carbon Nanotubes Grown on Sepiolite as Catalyst Carrier

Multi-walled carbon nanotubes were synthesized by the catalytic decomposition of acetylene at 750℃ over sepiolite powder,which was treated with aqueous cobalt nitrate. It is expected that the composite with high specific area will have high capacity of hydrogen storage.     

Morphology controls of the melt blending in a novel highly crosslinked bismaleimide system

A novel bismaleimide of 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane (BMIP) with a broad working-temperature-range for the melt blending was successfully synthesized. BMIP possesses a considerably broad working-temperature-range from 75 °C to 250 °C, prior to undergoing cure reactions to form a highly crosslinked network. The morphology types of cured BMIP/clay hybrids can be controlled by varying the shearing temperatures and the contents of the clay. The conditions necessary for achieving an exfoliated or an intercalated BMIP/clay hybrid were thoroughly investigated via X-ray diffractometry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). All the uncured samples prepared at different shearing temperatures and with an adequate amount of MMT-C (above 3 phr) exhibited an intercalated form of morphology. However, the crosslinking reactions for specified samples prepared at relatively elevated shearing temperatures (above 120 °C) and with a relatively low content of clay (below 15 phr) resulted in morphology changes from the intercalated form to the exfoliated form of morphology. There exists an isotropically mechanical property for the cured matrix of the exfoliated hybrids whereas there exists an anisotropically mechanical property for the cured matrix of the intercalated hybrids.     

Spectroscopic studies on 2,3,4,5-tetraphenylpyrylium salts with and without silver (I)-bridged structures

Two novel phenylated pyrylium compounds, silver (I)-bridged 2,3,4,5-tetraphenylpyrylium perchlorate (P1) and its silver (I)-free pyrylium ligand (P2) were prepared from 1,2,3,4-tetraphenylcyclopentadiene to examine their spectroscopic behaviors. The UV/vis absorption and fluorescent emission spectra of P1 and P2, measured in three solvents (acetonitrile, dichloromethane and toluene), reveal that the photophysical behaviors are closely related to silver (I) fragment, and strongly dependent on solvent polarity. In polar acetonitrile, P1 displays longer absorption wavelength and much lower fluorescent emission intensity than P2, although they exhibit much similarity in shape. In contrast, in nonpolar toluene, while P2 shows an apparent absorption band at 338 nm, P1 displays a tail-like line without absorption band observed. All the spectra obtained indicate a better coplanarity and a stronger intra-molecular charge transfer in P1 due to the effect of silver (I) fragment. Additionally, the 1H NMR spectra of P1 and P2, which were recorded under the same conditions, indicate that the silver (I) fragment reinforces pyrylium ring's capacity to localize the formal positive charge within the heterocyclic ring.     

Pulse radiolysis of 4,4'-bipyridyl aqueous solutions at elevated temperatures: spectral changes and reaction kinetics up to 400 degrees C

The spectral changes as well as the reaction kinetics of the transient species of 4,4'-bipyridyl (4,4'-bpy) have been experimentally investigated by pulse radiolysis techniques up to 400 degrees C. The results show that the transient species such as OH adduct 4,4'-bpyOH*, monoprotonated electron adduct 4,4'-bpyH*, and doubly protonated electron adduct 4,4'-bpyH2+* have 15-20 nm blue shifts from room temperature to 400 degrees C. For a deaerated neutral solution of 4,4'-bpy in the presence of tert-butyl alcohol, ethanol, or NaCOOH, the doubly protonated electron adduct is the main transient species at room temperature. But at temperatures > 350 degrees C, a monoprotonated form, the N-hydro radical 4,4'-bpyH*, becomes predominant. Interestingly, at room temperature, CO2-* could not efficiently react with 4,4'-bpy, but the reaction was accelerated with increasing temperature; at 350 degrees C, this reaction completed within 2 mus. Using an alkaline solution (pH = 11.5) of 4,4'-bpy in the presence of tert-butyl alcohol, we studied the N-hydro radical 4,4'-bpyH* from room temperature to 400 degrees C at 25 MPa. An estimation of the temperature-dependent G(e(aq)-) at 25 MPa agrees with our previous result with methyl viologen as a scavenger.     

Absorption Spectra of 5′-carboxy-2′-hydroxychalcone and its Derivatives

Ultraviolet absorption spectra and infrared absorption spectra of 5′-carboxy-2′-hydroxychalcone and eleven derivatives substituted at side benzene nucleus are measured to elucidate the spectroscopic effects of the 5′-carboxyl group in this series of compounds.     

A NEW PROBE FOR IDENTIFYING PROPERTIES OF SUPPORTED METAL AND METAL OXIDE CATALYSTS

A novel molecular probe for identifying properties of supported transitionmetals and metal oxides catalysts was established.The catalytic mechanism oftransition metals was proposed.