[en] The pseudobinary alloy Hf_0.82Ta_0.18Fe₂ was prepared by arc melting and annealing technique. X-ray powder diffraction indicated a C14-type Laves phase structure with the crystal parameters a=4.92133(3) Angstrom and c=8.0488(1) Angstrom. The Moessbauer spectra were measured at different temperatures between 20 K and 380 K, and showed two magnetic phase transitions, one from paramagnefic state to antiferromagnetic state at about 330 K and the other from antiferromagnetic state to ferromagnetic state at about 180 K. The latter transition indicated a spin-reorientation for 6h site Fe atoms, thus, the Fe atom spin at 6h turn to ab plane from c axis. However, the Fe atoms at 2a also showed a magnetic moment in ferromagnetic state. (authors)

[en] Moessbauer effect has become a necessary tool in the study of hyperfine interactions since it was discovered. But the application of this technique was restricted by several factors such as the recoil-free factor and the lifetime of the Moessbauer precursor isotope. With the development of the radioactive nuclear beam techniques, dozens of short life Moessbauer precursor isotopes were discovered. After educed from the Isotope Separator On-Line (ISOL) facility, the Moessbauer precursor isotopes were implanted into the samples, and then the Moessbauer spectra were recorded on-line. The on-line Moessbauer spectrometers have been established on many ISOL-type radioactive facilities (such as CERN, RIKEN) all over the world. In this paper a test bench of on-line Moessauber spectrometer is introduced. (authors)

[en] A mini-transducer for Moessbauer is described in this paper. The mini-transducer uses SmCo₅ magnets instead of AlNiCo₅. The mini-transducer is featured by its weight (1360 g) and size (Φ67.5 mm x 113.5 mm). The ratio between error signal value and the velocity signal(peak-to-peak) is lower than 0.4%. At room temperature, the average Moessbauer line width of the inner lines of a 25 μm α-Fe foil is less than 0.23 mm/s. The transducer can be used to measure Moessbauer spectrum with long-time stability. (authors)

[en] TS-d is a rough polysaccharide obtained form polyporaceae JB-2, 615, Kunming mice and rabbit and S180, MA737 tumors were used to study the effects of TS-d. Preliminary results indicated that TS-d is an effective radioprotective and antineoplastic drug with low toxicity and few side effects. Injecting TS-d i.p. to mice at a dosage of 400 mg/kg 60 min before 8.5 Gy γ-irradiation, the survival rate of mice was increased by 43% (P<0.05) as compared with control. Injecting 400 mg/kg of TS-d i.p. into mice 60 min before 7.0 Gy γ-irradiation, the number of WBC, BMC and CFU-S were significantly increased (P<0.01-0.001) as compared with control. The inhibitory rates of TS-d on S180 and MA737 were 46-77% (P<0.05 and P<0.001) and 37-46% (P<0.05 and P<0.05), respectively. TS-d showed significant protective effects on the hematopoietic tissues of rabbits exposed to-γ-irradiation. The LD50_(7d) values of TS-d given i.p. in Kunming mice were 4027.6 +- 434.9 in male and 5115.6 +- 453.5 mg/kg in female, and the LD50_(7d) values of TS-d given i.v. in JB-2 mice were 1389.6 +- 240.8 and 1361.5 +- 208.3 mg/kg, respectively. TS-d had no effect on the growth of mice at the age of four weeks, and neither on the production rate of micronucleus

[en] Highlights: • A green process for AuNPs synthesis was achieved by fungus Aspergillus. • Uniform spherical AuNPs with well dispersity and stability were biosynthesized. • The biogenic AuNPs possessed remarkable catalytic activities for 4-NP reduction. - Abstract: A facile one-pot eco-friendly process for synthesis of gold nanoparticles (AuNPs) with high catalytic activity was achieved using cell-free extracts of Aspergillus sp. WL-Au as reducing, capping and stabilizing agents. The surface plasmon resonance band of UV–vis spectrum at 532 nm confirmed the presence of AuNPs. Transmission electron microscopy images showed that quite uniform spherical AuNPs were synthesized and the average size of nanoparticles increased from 4 nm to 29 nm with reaction time. X-ray diffraction analysis verified the formation of nano-crystalline gold particles. Fourier transform infrared spectra showed the presence of functional groups on the surface of biosynthesized AuNPs, such as O−H, N−H, C=O, C−H, C−OH and C−O−C groups, which increased the stability of AuNPs. The biogenic AuNPs could serve as a highly efficient catalyst for 4-nitrophenol reduction. The reaction rate constant was linearly correlated with the concentration of AuNPs, which increased from 0.59 min"−"1 to 1.51 min"−"1 with the amount of AuNPs increasing form 1.46 × 10"−"6 to 17.47 × 10"−"6 mmol. Moreover, the as-synthesized AuNPs exhibited a remarkable normalized catalytic activity (4.04 × 10"5 min"−"1 mol"−"1), which was much higher than that observed for AuNPs synthesized by other biological and conventional chemical methods.

[en] The STI stress effect is investigated based on the 0.13 μm SOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences (IMECAS). It shows that the threshold voltage and mobility are all affected by the STI stress. The absolute value of the threshold voltage of NMOS and PMOS increased by about 10%, the saturation current of NMOS decreases by about 20%, while the saturation current of PMOS increases by about 20%. It is also found that the lower temperature enhances the STI stress and then influences the device performance further. Then a macro model for this effect is proposed and is well verified. (semiconductor devices)

[en] The rainwater samples were collected from Beijing, China, from May 2006 to November 2007 and measured by a hybrid neutron activation analysis (NAA) method combining with gas chromatography (GC) for the concentrations and distribution of extractable persistent organic halogens (EPOX=EPOCl+EPOBr+EPOI), polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs). The average concentrations of EPOCl, EPOBr and EPOI in all the samples were 102, 0.18, and 0.31 μg/L, respectively. The relative proportions of the known organochlorines (84 PCB congeners+10 OCPs) to total EPOCl were 0.03- 1.44%, which implied that most of EPOCl measured in rainwater were unidentified. Significant correlations between the logarithms of the concentrations of EPOCl and EPOBr (r = 0.65, p < 0.0001) or EPOI (r = 0.72, p < 0.0001) and between the concentrations of EPOBr and EPOI (r = 0.79, p < 0.0001) were observed, which suggested that EPOCl, EPOBr and EPOI in rainwater might mainly come from the similar sources. There were no clear seasonal trends for the concentrations of EPOX. PCBs in rainwater were dominated by tetra-CB and tri-CB. The homologue was consistent with the technical PCB products in China, which indicated that PCBs in the environment mainly came from the historical usage of technical PCB products. (orig.)

[en] In this paper, Moessbauer spectra were used to research thermal decomposing process and the occupation of Fe ions in iron rich palygorskite, which is collected from Longwangshan, Xuyi, Jiangsu Province. It is indicated that Fe ions are in ferric and occupy both M1 and M2 of octahedral ribbon with a ratio close to 3:1. (authors)

[en] Highlights: • A hierarchical structure of a community integrated energy system is proposed. • A tri-level game model is proposed to design distributed transaction mechanism. • Vertical trading is formulated as a dual-Stackelberg game. • Horizontal bidding among the energy hubs is modeled as a non-cooperative game. • Game equilibrium is proven to exist and solved by the distributed algorithm. As the energy market shifts from vertically integrated structures to interactive competitive structures, the transaction mechanism for resident users faces significant challenges because of its large numbers and small size. This paper proposes a distributed coordinative transaction mechanism of a community integrated energy system utilizing a tri-level game model. The vertical trading aspect is formulated as a dual-Stackelberg game, wherein the load aggregators serve as an intermediary between the energy hubs and resident users. Horizontal bidding among the energy hubs is modeled as a non-cooperative game, wherein each stakeholder pursues the optimal benefit. The equilibrium of this tri-level game is proven to exist and is solved by means of a distributed algorithm. The tri-level model is initially transformed into a bi-level problem through the Karush–Kuhn–Tucker condition and convexification, and is then solved using the distributed iterative algorithm. Finally, the effectiveness of the proposed tri-level game model and distributed solution algorithm was verified by case study, which confirmed that all stakeholders could benefit from the proposed transaction mechanism.

[en] Moessbauer spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to study trace iron-bearing mineral combination in uranium field, alteration rock and surrounding rock at 338 uranium deposit of Xiazhuang granite-type uranium ore field, Guangdong, China. The results show that the main iron-beating mineral in ore-vein is pyrite. The alternation belt contains mainly chlorite and a little lepidocrocite, with less content of pyrite than in ore-vein. There are more original minerals in surrounding rock (diabase of weak alternation) than other belts. The pyrite content decreases with increasing distance of the sampling point to the ore belt. And the chlorite content is the highest in alternation belt. The ore-vein of uraninite, alternation belt and diabase vein of weak alternation can be distinguished, and the range of alternation belt is confirmed with Moessbauer spectroscopy, XRD and FT-IR. (authors)