In , the notion of homogeneous perfect sets as a generalization of Cantor type sets is introduced and their Hausdorff
and lower box-counting dimensions are studied. In this paper, we determine their exact packing and upper box-counting dimensions
based on the length of their fundamental intervals and the gaps between them. Some known results concerning the dimensions
of Cantor type sets are generalized.
A study of the immobilization for226Ra waste has been carried out. Cement-based concrete was used as a matrix for the solidification of radium waste. The experimental results show that the cement mixture with water/cement between 0.46–0.54 has higher strengh (above 20 MPa), and the compressive strength was not reduced by addition of 1% barite or the radium waste (RaSO4) into the concrete solid.
A detail study of distribution, host range, and seasonal pattern of western flower thrips (WFT),
(Pergande), in Yunnan Province was conducted in 2004–2006. The pest is distributed throughout the province and was found in 22 out of 25 widely spaced locations surveyed. WFT was found feeding on 45 species of vegetables, ornamentals, and weeds in the province. Seasonal pattern of WFT on vegetables planted in open field and inside greenhouses was similar and, with exception of minor local differences, did not differ from information generated elsewhere. These findings may provide some useful data for the management of this and possibly other thrips pests in Yunnan.
Authors:Y. Pan, X. Guan, Z. Feng, Y. Wu, and X. Li
A new method was proposed for determining the most probable mechanism function of a solid phase reaction. According to Coats-Redfern's
integral equation Eβ→0 was calculated by extrapolating β to zero using a series of TG curves with different heating rates. Similarly, Eα→0 was calculated according to Ozawa's equation. The most probable mechanism function of the solid phase dehydration of manganese(II)
oxalate dihydrate was confirmed to be G(α)=(1-α)1/2 by comparing Eα→0 with Eβ→0.
Authors:X. Wang, X. Yin, X. Zhang, Z. Li, J. Tian, M. Wu, and X. Sheng
A radioactive multitracer solution obtained from the nuclear reaction of selenium with 25 MeV/nucleon40Ar ions was applied to the investigation of the trace elements behavior in feces and urine of mouse. The excretion rates of
23 elements, Na, K, Rb, Mg, Ca, Sr, Ga, As, Sc, V, Cr, Mn, Co, Fe, Zn, Y, Zr, Mo, Nb, Tc, Ru, Ag and In were simultaneously
detected under strictly identical experimental conditions, in order to clarify the excretion behavior of the elements in mice.
Fecal and urinary excretion rates of the elements in mice reached the highest value separately at 48 and 24 hours. The total
excretion of Mo, Tc and Co within 96 hours were all larger, more than 60%. Accumulative excretion rates of Ca, Nb, Mg, Sr,
V, Sc, Na, Cr, Fe, Ag, Mn and Zr were 60-30%. The total rates of Ru, K, As, Zn, Rb, Y, Ga and In were less than 30%, and low
excretion. The main excretion pathway of Mo, Co, Mg, Fe and Ag was through urine, and Na, K, As and Rb were eliminated from
the body also in urine. But fecal excretion of Tc, Nb, Sr, Y, Ru, and In were larger than urinary excretion, and Ca, Sc, Mn,
Zr, Zn were eliminated from the body in feces.
An Al2(WO4)3 target bombarded with a proton beam (28.5 MeV, 20 A) for 1 hour was completely dissolved in about 5 ml of hot 2N NaOH and the clear solution was neutralized with 2N HCl. The resulted white precipitate of Al2(WO4)3 can be separated from the solution by centrifugation and decantation. The supematant containing radioactive Re as ReO
was loaded onto a column (1 cm×10 cm) of activated alumina (100–200 mesh). Eluted with 10 ml of saline, the carrier-free ReO
was collected, while the small amount of Al2(WO4)3 in the supematant was adsorbed on the column. The total yield of ReO
was 94.7% and the breakthrough of WO
, only 1.0·10–6 M. The whole separation process can be accomplished within 30 minutes. This rapid and efficient Re/W separation protocol is applicable to the preparation of carrier-free186Re, when an enrichel Al2(186WO4)3 target is used.
A total reflection X-ray fluorescence (TXRF) analyzer with a special structure is described. Its short X-ray path (about 15 cm) resulted in a high sensitivity, low power consumption and small volume. The structure with double total reflection path is suitable for easy change of exciting source to cover a large element range. The minimum detection limit (MDL) of 6 pg for Co under Cu exciting source and 22 pg for Sr under Mo tube. Some significant works were done, such as the detemination of sulfur content in fuel oils, the non-destructive analysis of an ancient bronze utensil and the regular analysis of tap water.
Authors:S. Lahiri, X. Wu, Yang Weifan, Xu Yanbing, and Yuan Shuanggui
Liquid liquid extraction of 46Sc was studied with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP). It has been found that PMBP extracts almost quantitatively scandium from 10-3 to 10-2M HCl solutions. Tributyl phosphate (TBP) has a pronounced antagonistic effect on the extraction process.
Authors:Y. Wen, S. Lahiri, Z. Qin, X. Wu, and W. Liu
An attempt has been made to develop a radiochemical methodology for the decontamination of a trace amount of radioactive cesium from a bulk amount of natural NaCl by liquid-liquid extraction (LLX). Open chain crown ethers, of amide type, namely, N,N,N",N"-tetraphenyl-3,6-dioxaoctanediamide (TDD), N,N,N",N"-tetraphenyl-3,6,9-trioxaundecanediamide and N,N"-dinaphthyl-N,N"-diphenyl-3,6-dioxaoctanediamide (DDD) have been chosen for this purpose. The separation factor between Cs and Na is the highest when 10-4M TDD dissolved in nitrobenzene is used as extractant and 0.4M picric acid at pH 5.0 is used as aqueous phase. About 60% Cs is extracted in this condition in a single run.
Multitracers were prepared by 80 MeV/A 12 C irradiation on thick gold foil at Heavy Ion Research Facility, Institute of Modern Physics, Lanzhou, China. The bulk gold was removed quantitatively from the multitracer solutions with a MIBK-HCl solution.