[en] As part of the development of electric and hybrid vehicles, energy management in the battery pack is a major issue. Car manufacturers need a numerical model to represent the dynamic behavior of batteries. The objective of this work is to develop, on the one hand, a characterization method of the dynamic behavior of battery cells and their assemblies, and on the other hand the combined numerical models which are simple, fast, robust and with the best accuracy/simplicity compromise. The first part of the work is dedicated to develop a new experimental characterization method with an equivalent circuit model, which can be applied easily to different battery cells and allows calibrating the complexity of the model (number of the RC circuits) according to the measurement duration of the resting phase after a solicitation. Therefore, the generated model is able to follow the rapid and slow voltage change of the battery cell, which improves voltage and state of charge estimation for the BMS (Battery Management System) applications. The validation tests on different battery cells show that the generated model allows accurate prediction of the battery cell's dynamic behavior. The second part of the work studies the cell assemblies with cells connected in series. It begins with an energy definition of the cell assembly. Then modelling of the assembly with the developed characterization method is discussed. The validation tests were carried out on different assemblies and show that the dynamic behavior of the assembly can be also well represented with the identified models. (author)

[en] In order to give the uncertainty of activity concentration of radio xenon which leaked into air after nuclear fission happened, it was supposed that the radio xenon leakage was instantaneous, and the radio xenon leaked into a confined space, the distribution was uniform. After decay correction and in principle that the theoretical value of the average activity is consistent with the measuring values, the mathematical model of the airborne radio xenon monitoring was derived. By analyzing the sources of uncertainty, the uncertainty components evaluation, synthesis, and the mathematics model was evaluated under the certain condition. In the sources of uncertainty, radio xenon peak net count rate and efficiency value are the main sources, the concentration, volume of xenon in air and gamma-ray emission rate of radio xenon are smaller, the decay constant and time measurement are the least. (authors)

[en] In order to explore the influence of sieving meshes and hot air drying on the determination of carbon and nitrogen isotope ratio in vegetables, and the effects of sieving meshes (20, 40, 60, 80, 100 and 200 mesh), green killing (105℃, 30 min) and no-green killing treatment, drying temperature (45, 60 and 75℃) on the reliability of element analysis isotope ratio mass spectrometry (EA-IRMS) based on CO₂ dilution were studied. The results of δ¹³C and δ¹⁵N in six vegetables (spinach, cowpea, leek, lotus root, eggplant and potato) were compared. The results showed that the standard deviation of δ¹³C and δ¹⁵N values measured by EA-IRMS with 89% CO₂ dilution ratio could meet the requirements of detection accuracy; when the number of sieving mesh exceeded 80 mesh, the determination results of δ¹³C and δ¹⁵N in the six types of vegetable samples tended to be stable and reached the requirements of determination accuracy. The δ¹³C and δ¹⁵N values measured by vacuum freeze-drying process were used as reference. Treatment using different hot air drying temperatures (45, 60 and 75℃) showed no significant change for the δ¹³C and δ¹⁵N values of eggplant, spinach, lotus root and Chinese chive. However, the δ¹³C and δ¹⁵N values of Chinese chive after 45℃ hot air drying were significantly different from the reference values, and the cowpea (δ¹³C and δ¹⁵N values) and potato (δ¹³C values) after hot air drying were also different from the reference values. Conclusion, it is feasible to simultaneously determine δ¹³C and δ¹⁵N values in vegetables by EA-IRMS with 89%CO₂ dilution ratio. Vegetable samples should be sieved with no less than 80 mesh before carbon and nitrogen isotope determination. The samples of eggplant, spinach, lotus root, and leek can be prepared by hot air drying and Chinese chive shall to be treated with green killing first. Cowpea and potato are recommended to be vacuum freeze-dried. This study provides a reference for the sample preparation of the simultaneous determination of carbon and nitrogen isotopes in vegetable samples and. (authors)

[en] The membrane fouling is an important problem for FO applied to the radioactive wastewater treatment. The FO fouling characteristics for simulated radioactive wastewater treatment was investigated. On-line cleaning by deionized (DI) water and external cleaning by ultrasound and HCl were applied for the fouled membrane. The effectiveness and foulant removing amount by each-step cleaning were evaluated. The membrane fouling was divided into three stages. Co(II), Sr(II), Cs(I), Na(I) were all found deposited on both active and support layers of the membrane surface, resulting in membrane surface became rougher and more hydrophobic, which increased membrane resistance. On-line cleaning by DI water recovered the water flux to 69%. HCl removed more foulants than ultrasound.

[en] A method has been developed to detect irradiated beef by GC analysis of differences of the types and contents of hydrocarbons between unirradiated and irradiated beef. Six hydrocarbons in irradiated beef were qualitatively and quantitively determined by procedures of extraction by hexane, separation by Florisil cloumn and GC analysis. The results shows that no 1, 7-C16: 2(1, 7-hexadecadiene) has been found in unirradiated beef, while it is significantly detectable in the irradiated sample. Therefore, 1, 7-C16: 2 is the best probe to determin whether beef is treated by irradiation or not. (authors)

[en] The magnetocaloric effect (MEC) in Gd_1-xDy_x (x=0.13,0.20,0.27,0.34,0.40) alloys is investigated using commercial elements with purity of up to 99.80% for Gd and Dy. These alloys are prepared by arc melting in stoichiometric proportions on a water-cooled copper crucible under high pure argon atmosphere. As a result, when x was changed from 0 to 40at%, the adiabatic temperature change (ΔT) increases from 1.6 K to 3.1 K, the Curie temperature decreased from 288 K to 245.5 K. Gd₇₃Dy₂₇ exhibits the largest ΔT_max value of 3.1 K at the T_C value of 260 K among the alloys investigated up to 1.2 T (tesla) applied field, it is almost same as the ΔT of high pure unitary Gd (99.99%) and is clearly superior to commercial unitary Gd (99.80%). The T_C of Gd₇₃Dy₂₇ alloy is minor to high pure unitary Gd (99.99%) and commercially unitary Gd (99.80%). But this alloy prepared by commercial elements with low cost has better MEC to be a promising candidate for magnetic working substances for room temperature magnetic refrigeration. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

[en] Highlights: • A core-shell structure photocatalysts of Ag₃PO₄@TCNQ was prepared successfully. • TCNQ greatly increased visible light response for Ag₃PO₄. • The close contact makes the conjugated π bond system of TCNQ interact with Ag₃PO₄. • The photocatalysts exhibited higher activity for the degradation organic pollutant. - Abstract: We report a composite photocatalyst with a core-shell structure of Ag₃PO₄@TCNQ (7,7,8,8-Tetracyanoquinodimethane). TCNQ nano-sheet with a conjugated structure was coated on Ag₃PO₄ particles to enhanced photocatalysis and the stability of Ag₃PO₄. This composite catalyst can improve the contact area between semiconductors, promote the separation efficiency of electron and hole, and improve photocatalytic activity and stability. Ag₃PO₄@TCNQ exhibited a high degradation of phenol under visible light. The degradation rate of Ag₃PO₄@TCNQ (0.3 wt.%) to degradation phenol achieved almost 100% in 12 min, which was about 23% higher than that of pure Ag₃PO₄. In addition, TCNQ wrapped on Ag₃PO₄ surface, as the core’s protective layer, can effectively improve its stability. After five cycles, the degradation rate still reached 90%, but monomer stability retained only 43%. TCNQ, as a good electron acceptor, can transfer electrons from Ag₃PO₄ surface well, reduce the reduction of Ag⁺, and improve the separation efficiency of photogenerated charge, greatly improving the activity and stability of catalyst. TCNQ has a positive position of its energy band relative to Ag₃PO₄, and the electrons on the Ag₃PO₄ conduction band can easily transform to the Lowest Unoccupied Molecular Orbital (LUMO) level of TCNQ to realize the efficient separation of charge, which effectively improve quantum efficiency, thus improving activity and stability of catalyst.

[en] The double membrane activated charcoal method measuring ²²⁰Rn and its progeny concentrations in ambient air simultaneously was established. According to the temporary equilibrium theory, the theoretical formula of ²²⁰Rn and its progeny in the air was derived in this method. Aiming at the half-life characteristics of ²²⁰Rn and its progeny, classical theory model was modified and simplified, and several key time points was identified. For ²²⁰Rn progeny collection, the waiting time should be greater than 21.4 minutes after sampling, and the sum of waiting time and measuring time should be less than 7.41 hours. For ²²⁰Rn gas adsorption, the waiting time should be greater than 6.17 minutes. The radioactivity levels of ²²⁰Rn and its progeny in a laboratory and in a tunnel was studied by the method. It is provided a new technical support for ²²⁰Rn and its progeny dose assessment by the active membrane activated charcoal method. (authors)

[en] Objective: To compare the results of three different registration methods in the kilovolt CBCT guided IMRT for nasopharyngeal cancer (NPC). Methods: Total 560 CBCT images of 24 NPC patients who received kilovolt CBCT guided IMRT were analyzed off line. Three registration methods were used for alignment between CBCT and planning CT, including translational and rotational errors for bone and grey (Bone_{T + R}, Grey_{T + R}), only translational errors for grey (Grey_T). The registration results were analyzed by mean paired t-test respectively. Results: With method Bone_{T + R}, the translational errors on x, y and z axes were (-0.11 ± 1.35) mm, (0.40 ± 2.09) mm and (0.95 ± 1.56) mm and the rotational errors were 1.06° ± 0.67°, 0.01° ± 1.280° and 0. 92° ± 1.00° respectively. With Grey_{T + R}, the translational errors on x, y and z axes were (-0.02 ± 1.06) mm, (0.68 ± 1.92) mm and (0.81 ± 1.46) mm and the rotational errors were 0.85° ± 0.610, -0.05° ± 1.32° and 0.910 ± 0.720 respectively, With Grey_T, the translational errors on x, y and z axes were (0.58 ± 1.02), (0.52 ± 1.89) and (0.44 ± 1.43 ) mm. The results of compared mean t-test for different registration methods groups have significant difference (P = 0.00-0.01) except for the rotational errors on y and z axes between Bone_{T + R} and Grey_{T + R} (P = 0.05, 0.62). Conclusions: There have different alignment errors when different registration methods used for NPC kilovolt CBCT guided radiotherapy. If there have correct methods for rotation errors, Grey_{T + R} registration method may be a better choice. In opposite, Grey_{T + R} registration method would be used firstly to verify whether the rotational error > 2°or 3°. If the rotational error > 2° or 3°, the patient should be re-setup. If not, according to these alignment results, the Grey_T method, manual method would be used to compensate the translational errors. (authors)

[en] In active adsorption of activated charcoal, it is uneven distribution of "2"2"2Rn in the collector in different adsorption time, which makes impact on efficiency calibration by HPGe γ spectrometry. By the adsorption experiment of active double membrane activated charcoal in the standard radon chamber, the relationship between detection efficiencies of different energy characteristics of the γ-ray and counting relative deviation of "2"2"2Rn from import and export side of the double-membrane activated charcoal collector by HPGe γ spectrometer in different adsorption time was obtained, which is linear. The absolute value of relative deviation of adsorption capacity for "2"2"2Rn is less than 5% between calculated and measured, which is to verify the correctness and reliability of the method of active double membrane activated charcoal. (authors)