Determination of elemental composition of airborne dust and dust suspended in rain

To clarify the magnitude of wash-out effect of rain on the elemental composition of airborne dust and the possible origin of the dust, the dust samples were collected with a high-volume air sampler at the JAERI-Tokai. The dust suspended in rain was also collected from rain by filtration. Up to 20 elements in both types of the dust were determined by instrumental neutron activation analysis. It was found that the elements determined could be classified into 3 groups from the elemental composition and the elemental correlation in both types of the dust samples.     

氢谱在甾醇类化合物定量和纯度分析中的应用

用^1HNMR谱可定量确定繁茂膜海绵(Hymeniacidon perleve)中分离得到的结构类似的甾醇类化合物的含量，这种方法是对鉴定分析组成复杂而性质很相近的天然甾醇化合物的新思路。     

TG-DTA/FT-IR method for analyzing thermal decomposition mechanism of polyesters

An attempt to estimate the thermal decomposition mechanism of polymers using the simultaneous TG-DTA/FT-IR system was summarized. The library search of FT-IR spectra at various temperatures and of the subtraction spectrum obtained by subtracting the spectra at different temperatures were used to determine the types of evolved gases from poly(ethylene terephthalate) and poly(butylene terephthalate) at given stages of decomposition. The quantitative analysis of evolved gases was carried out using the specific gas profiles at the specific absorption band. The kinetic parameters were estimated from both TG and spectroscopic curves measured at various heating rates.     

Thermal Decomposition Characteristics of 1,7-Diazido-2,4,6-trinitrazaheptane and its Application in Propellants

The thermal decomposition characteristics of1,7-diazido-2,4,6-trinitrazaheptane (DATH) and multi-component systems containing DATH were studied by using DSC, TG and DTG techniques. Three –NO₂ groups in the DATH molecule break away first from the main chain when DATH is heated up to 200°C. Following this process, the azido groups and the residual molecule decompose rapidly to release a great deal of heat within a short time. In the multi-component systems, DATH undergoes a strong interaction with the binder of the double-base propellant and a weak interaction with RDX. The burning rates of the two propellants were determined by using a Crawford bomb. The results showed that the burning rate rises by about 19–66% when 23.5%DATH is substituted for RDX in a minimum smoke propellant. Meanwhile, the N₂ level in the combustion gases is enhanced, which is valuable for a reduction of the signal level of the solid propellant. This revised version was published online in July 2006 with corrections to the Cover Date.     

Some radiation protection problems connected with the use of186Re-HEDP and153Sm-EDTMP for palliative therapy of bone metastases

The paper deals with the problem of the outpatient administration of¹⁸⁶Re-HEDP and¹⁵³Sm-EDTMP for palliative therapy of bone metastases. The subsequent 6 hours stay of the treated patients in a department of nuclear medicine appears to be in compliance with regulations proposed in the Czech Republic as well as with ICRP recommendations.     

Dihydrobenzoxazines and tetrahydroquinoxalines by a tandem reduction‐reductive amination reaction

A tandem reduction‐reductive amination reaction has been applied to the synthesis of 3,4‐dihydro‐2H‐1,4‐benzoxazines and 1‐acetyl‐1,2,3,4‐tetrahydroquinoxalines. The nitroketones required for the benzoxazine ring closures were prepared by (A) alkylation of the anion derived from 2‐nitrophenol with an allylic halide or (B) nucleophilic aromatic substitution of an allylic alkoxide on 2‐fluoro‐1‐nitrobenzene followed by ozonolysis. Precursors for the quinoxalines were prepared by alkylation of the anion of 2‐nitroacetanilide with an allylic halide followed by ozonolysis. Catalytic hydrogenation of the nitroketones using 5% palladium‐on‐carbon in methanol then gave the target heterocycles by a reduction‐reductive amination sequence. The N‐methyl derivatives for both ring systems were easily prepared by adding 5‐10 equivalents of aqueous formaldehyde prior to the reduction. The dihydrobenzoxazines were isolated in high yield following purification by chromatographic methods; tetrahydroquinoxalines were isolated in a similar manner and possessed differentiated functionality on the two nitrogens.