热致液晶乙基纤维素与尼龙－1010共混物的研究

在自制单螺杆小型挤出机上通过熔融共混的办法，制备了不同配比（５／９５—２５／７５）的ＥＣ／Ｎｙｌｏｎ—１０１０共混物．用ＷＡＸＤ、ＤＳＣ、毛细管流变仪、力学性能测试等方法对共混物进行了研究．发现共混后尼龙－１０１０的形态结构有明显改变，其强度、模量都有提高，在高剪切速率下，共混物粘度大大降低．配比为１５８５时，这些性能的改进尤为明显．     

Design and synthesis of 2-alkylbenzimidazole derivatives as novel non-peptide angiotensin Ⅱ AT1 receptor antagonists

A series of 2-alkylbenzimidazole derivatives 9a-n have been designed and synthesized as a novel class of non-peptide angiotensin Ⅱ AT1 receptor antagonists. The synthesized compounds were evaluated for their antagonism of angiotensin Ⅱ, induced contraction in the rabbit thoracic aortic ring and the results showed that compounds 9a, 9g and 9j exhibited potent antagonistic activity of AT1 receptor.     

Study of occupational health impact of atmospheric pollution on exposed workers at an iron and steel complex by using neutron activation analysis of scalp hair

The occupational health impact of atmospheric pollution on exposed workers at one iron and steel complex was studied by instrumental neutron activation analysis of workers' hair samples and medical examination. The experimental results indicate that there is a positive correlation between the high inhalation amounts of iron and other trace elements by the exposed workers and the symptom of their high blood pressure and hypoglycemia, which implies that the atmospheric environment polluted by iron and steel industry has an adverse health impact on the exposed workers. The measures to relieve and abate the occupational diseases caused by air-borne particulate matter should be taken     

Infrared Study of Solid Dispersions of β-Cyclodextrin with Naphthalene Derivitaves

The inclusion complexes of β-cyclodextrin (β-CD) with naphthalene and some of its derivatives in the solid state have been studied by infrared spectroscopy. Digital subtraction, deconvolution and curve fitting have been used to investigate the interactions between the naphthalene derivatives andβ-CD. Several preparation methods for the solid dispersions have been tested, using FTIR as an effective tool to evaluate the interactions at the molecular level. The effects of temperature and humidity on the spectra have been also analyzed. A carbonyl moiety in the guest molecule can increase the stability of the complex by establishing specific interactions with the hydroxyl groups of the CD cavity rims. The stability of the complexes is higher for 2-naphthylacetate than that for 1-naphthyl acetate, andso is the degree of association of its carbonyl groups. On the other hand, 2-acetylnaphthaleneforms very stable inclusioncomplexes although its carbonyl groups appear to be significantly less associated.     

Detailed analysis of α,ω-bis(4-hydroxybutyl) poly(dimethylsiloxane) using GPC-MALDI TOF mass spectrometry

In this study the prepolymer alpha,omega-bis(4-hydroxybutyl) poly(dimethylsiloxane), used in the formulation of oxygen permeable films, is evaluated by gel permeation chromatography (GPC) combined with matrix assisted laser desorption ionization (MALDI) time of flight (TOF) mass spectrometry (MS). Two unexpected mass distributions are observed in the mass spectra. Reaction schemes for the formation of these distributions are proposed. A solution phase trimethylsilane end group modification was performed on the prepolymer to determine whether the unexpected mass distributions occur as impurities from synthesis or as artifacts from the MS process. Evaluation of the TMS modified prepolymer indicates the unexpected mass distributions indeed occur as impurities from the synthetic procedure. Average molecular weight values are determined by traditional GPC, direct MALDI-TOF MS, and GPC-MALDI-TOF MS methods and the results are compared.     

煤的孔结构特征对水煤浆性质的影响

本文选用１７种不同变质程度的中国煤，详细研究了煤孔结构特征对煤浆性质的影响。发现煤孔体积通过影响煤在分散体系中的吸水性，从而影响煤之成浆性。但由于不同变质程度煤表面亲水性的显著差异，煤孔体积在影响煤成浆性的能力方面差别很大，这使得煤吸水性和浆体最高煤浓度与煤孔体积并不存在直接的相关性，而是取决于煤孔体积Ｖ和以煤－水接触角（θ）的余弦值表示的煤表面亲水性因子的乘积，即煤之有效孔体积：Ｖ×ｃｏｓ（θ／     

Mechanism studies of the conversion of 13C-labeled n-butane on zeolite H-ZSM-5 by using 13C magic angle spinning NMR spectroscopy and GC-MS analysis

By using 13C MAS NMR spectroscopy (MAS = magic angle spinning), the conversion of selectively 13C-labeled n-butane on zeolite H-ZSM-5 at 430-470 K has been demonstrated to proceed through two pathways: 1) scrambling of the selective 13C-label in the n-butane molecule, and 2) oligomerization-cracking and conjunct polymerization. The latter processes (2) produce isobutane and propane simultaneously with alkyl-substituted cyclopentenyl cations and condensed aromatic compounds. In situ 13C MAS NMR and complementary ex situ GC-MS data provided evidence for a monomolecular mechanism of the 13C-label scrambling, whereas both isobutane and propane are formed through intermolecular pathways. According to 13C MAS NMR kinetic measurements, both pathways proceed with nearly the same activation energies (E(a) = 75 kJ mol(-1) for the scrambling and 71 kJ mol(-1) for isobutane and propane formation). This can be rationalized by considering the intermolecular hydride transfer between a primarily initiated carbenium ion and n-butane as being the rate-determining stage of the n-butane conversion on zeolite H-ZSM-5.     

High performance organic field-effect transistors based on amphiphilic tris(phthalocyaninato) rare earth triple-decker complexes

LB films of three amphiphilic tris(phthalocyaninato) rare earth triple-decker complexes with crown-ethers as hydrophilic heads and long alkyl chains as hydrophobic tails have been prepared and found to display very well ordered layer structures, as proved by pi-A isotherms, UV-vis and polarized absorption spectra, X-ray diffraction experiments, and microscopic morphology characterization. These LB films have been fabricated into field-effect transistor (FET) devices, which show carrier mobilities as high as 0.24-0.60 cm2 V-1 s-1, among the highest mobilities achieved thus far for all LB film-based OFETs.     

An order-disorder transition in Sr2IrD5: Evidence for square pyramidal IrD5 units from powder neutron diffraction data

Neutron diffraction data have been collected on a powdered sample of Sr₂IrD₅ over a range of temperatures. The compound, which is cubic at room temperature, has been found to exhibit a gradual transformation to a tetragonal phase in the temperature range 200-140 K. As a result of the transition, deuterium atoms which randomly occupy sixfold positions in the cubic phase, become tetragonally ordered. A small fraction of the cubic phase remained untransformed at 4.2 K. Both the cubic and tetragonal structures are consistent with square pyramidal IrD₅ units with average Ir---D distances of 1.714 and 1.718 Å, respectively. Agreement factors, R₁, for the two structural analyses are 3.44 and 4.94%.     

Micro construction of poly(epsilon-caprolactone)/poly(L-lactic acid) blend film by solution casting under microwave irradiation

The micro construction of poly(epsilon-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) blend films fabricated by solution casting under microwave irradiation was investigated by selective enzymatic degradation and scanning electron microscopy (SEM). The results were totally different from the blends obtained by conventional methods. The blend was more homogeneous and the PCL continuous phase more compact as no spherulites and tiny zone separation were observed from the film surface and no PCL network was observed inside the film, and the degradation of a PCL plank by Pseudomonas lipase was significantly retarded. The distributed PLLA micro spheres were enlarged and amorphous. The thermal behavior of the blend by microwave heating revealed that PCL and PLLA underwent a melting process, which induced the variations of the PCL phase and PLLA spheres. The weight loss caused by degradation of the PCL/PLLA blend obtained by conventional methods (B50c) is greater than that of the blend obtained by microwave methods (B50m), which reflects the change in morphology from a loose PCL network (B50c) to a dense PCL plank (B50m).