No abstract available

[en] We derive an envelope solitary-wave solution for the following generalized nonlinear Schroedinger equation U_t+ia₂U_xx+a₃U_xxx=ib mod U mod ²U+b₁(mod U mod ²U)_x by gauge transformation. (author)

No abstract available

[en] A method for determination of trace Zr in U₃O₈ by ICP-MS after TTA-xylene extraction is reported. The sample is converted to UO₂(NO₃)₂ with HNO₃ and the Zr is separated from matrix element uranium by TTA/xylene in 4 mol/L HNO₃. Then Zr is back extracted by 8 mol/L HNO₃ after lowering the concentration 10 times of organic phase and is determined by ICP-MS directly after lowering the concentration of aqueous phase 10 times again. The analytical results of uranium standard substance agree with recommendatory value

[en] Radioisotope source excited X-ray fluorescence (XRF) has been widely used for determination trace elements in hair. The source excited XRF was once established in China Institute of Atomic Energy, it was used to analyze hair sample, the detection limit of Pb is about 10 μg This project took the ever work as the basis, by amending the parameters the background signal intensity was reduced, the sensitivity was improved especially for Pb, the detection limits of Ca, Fe, Cu, Zn, Pb are 19, 1.2, 1.1, 0.62, 1.1 μg respectively. Taking V as inner-standard and sample mass is 0.5 g, instrument short-term stability relative standard deviation (RSD) is 0.38%, long-term stability RSD is 0.98%. (authors)

[en] The influence of matrix elements that usually exist in spent nuclear fuel reprocessing, such as Na, Al, Ru, Cs, Pd, Nd, Fe, Ce, Sr, Y, Mo, and Zr, on the determination of uranium by highly oriented pyrolytic graphite (HOPG) pre-diffraction EDXRF is studied. The results show that the influence of matrix elements Na, Fe, Al, Ru, Cs, Pd, Nd, and Ce is negligibly small when their mass concentrations are lower than 1 000 mg/L. The influence of matrix elements Sr, Y, Mo and Zr is somewhat greater, and can be corrected to some degree by correction with scattered line of the silver target if their mass concentrations are lower than 1 000 mg/L. For higher mass concentration of these elements, their influence can be corrected by extrapolation of their mass fraction to zero by using the linear relationship between the logarithm of the uranium line intensity and the mass fraction of these elements. (authors)

[en] A quantitative method for determination of U and Ce in simulative MOX fuel samples by binary intensity ratio and X-ray fluorescence spectrometry is studied. Pressed powder pellet sample preparation is adopted. The pretreatment of the sample is fast and simple. The mutual interference of the two elements is eliminated efficiently by intensity ratio technique. The relative standard deviation (s_r) of U and Ce is 0.2% and 1.8%, respectively. (authors)

[en] By independent research L_Ⅲ--absorption edge densimeter, an analytical method for uranium sample with the concentration from 20 g/L to 200 g/L was developed. The fitting area for uranium measurement was determined through experiment. The left fitting area was 1659-1856 channel, and the right one was 2063-2280 channel. The uranium L_Ⅲ--absorption edge was at 1995 channel. The results show that the influence of HNO_3 concentration lower than 9 mol/L, Al and Fe concentration lower than 10 g/L was negligibly small. The uranium measurement precision is better than 0.5%, and the instrument stability is good. Some samples in bench test of uranium recovery were determined. The results are satisfactory. (authors)

No abstract available

[en] An analytical instrument which can measure the concentration of technetium is developed. The Ag Cold Cathode which can excitated L series X-ray fluorescence of Tc is taken as excitation source. The X-Ray fluorescence is measured by Si-Pin detector. In order to determine high toxic and radio sample, a specific designation is adopted for sealing the sample cell in glove box. The X ray tube and detector are isolated with the sample by special windows. Such arrangement can provide convenience for measurement of high radioactive sample, as well as maintenance of the instrument. The basic performance of the instrument is tested. The linearity range of working curve for technetium is from 20 μg mL"-"1 to 200 μg/mL"-"1. The determination precision (RSD) of technetium with the concentration of 40 μg/mL"-"1 is l.2%. (authors)