State of practice and emerging application of analytical techniques of nuclear forensic analysis: highlights from the 5th Collaborative Materials Exercise of the Nuclear Forensics International Technical Working Group (ITWG)

The Nuclear Forensics International Technical Working Group (ITWG), a community of nuclear forensic practitioners who respond to incidents involving nuclear and other radioactive material out of regulatory control, completed its fifth Collaborative Materials Exercise in 2017 (CMX-5). Forensic laboratories from 19 countries and one multinational organization aimed to advance nuclear forensic science and improve international cooperation in the event of a nuclear material security incident. In all, over 30 analytical techniques were utilized to investigate the samples, many techniques applying novel methods or offering improvements in turnaround time. An objective review of the state of practice and emerging application of analytical techniques of nuclear forensic analysis based upon this exercise is provided.

     

第9届化学传感器国际会议

本届大会于2002年7月7日至10日在美国Boston市召开,由Elsevier科学公司主办。     

Oxygen isotopes of fuel pellets from the fifth collaborative materials exercise and uranium oxides reference materials determined by continuous flow laser fluorination mass spectrometry for nuclear forensic applications

Journal of Radioanalytical and Nuclear Chemistry - Uranium oxides are essential materials in the production process of nuclear fuel for civilian or military applications. As such, identifying their...     

The application of 2-(4-chlorophenyl)-sulfonylethoxycarbonyl (CPSEC) group in the synthesis of a DNA segment using the phosphotriester approach

The new base labile CPSEC group has been successfully employed for the protection of the 5′-hydroxyl function to synthesize a “universal Stop codon” DNA sequence: ^5′d(TCAATCAATCA)^3′.     

Recoupling coefficients of group SO(4) and their application to linear tetratomic molecules

The general expressions for the recoupling coefficients of group SO(4) are obtained by employing the subgroup chains (2) and (11). When considering a special case, we give results that can be used for tetratomic molecules. Using these recoupling coefficients, the matrix elements of C and M operators that are not diagonal can be given. Within the dynamic algebra framework, an effective algebraic Hamiltonian of linear tetratomic molecules is obtained. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 293–301, 2003     

Second international symposium effects of surface heterogeneity in adsorption and catalysis on solids (ISSHAC) Poland-Slovakia,September 4th–10th, 1995

Second international symposium effects of surface heterogeneity in adsorption and catalysis on solids (ISSHAC) Poland-Slovakia, September 4th–10th, 1995     

Recombination of hydrogen and oxygen in the technical gaseous waste of nuclear power plants (I)

The recombination of hydrogen and oxygen in technical gaseous waste of nuclear power plants has been studied. A highly efficient catalyst for reacting H₂ with O₂ to form water was prepared. Various operating conditions and factors affecting the recombination of H₂ and O₂ were tested and the best conditions were determined. Results show that the Pd–Al₂O₃ catalyst prepared had very good characteristics. The recombination rate of H₂ and O₂ was higher than 98.3% and 99.9%, respectively. After recombination, residual concentrations of H₂ and O₂ in waste gas were O₂<3 ppm, H₂<400 ppm. The Pd–Al₂O₃ catalyst and operating conditions determined for gaseous waste processing of nuclear power plants were satisfactory.     

Conformational energy (A-value) of the 4-phenyl-1,2,3-triazolyl group

Conformational energy (A-value) of the 4-phenyl-1,2,3- triazolyl group was estimated as 2.0 kcal mol–1 (8.5 kJ mol–1) using 1H NMR-based conformational study for a set of (4-phenyl-1,2,3-triazol-1-yl)cyclohexanes. This provides a reasonable estimation also for the conformational energy of 1,2,3-triazolyl group itself and its substituted analogues.     

Tris(pyrazolyl)borate amidoborane complexes of the group 4 metals

Treatment of the tris(pyrazolyl)borate metal triamides Tp'M(NMe(2))(3), where Tp' = (C(3)H(3)N(2))(3)BH (Tp) or (3,5-Me(2)C(3)HN(2))(3)BH (Tp*) and M = Ti, Zr and Hf, with the Br?nsted acidic Lewis adduct (C(6)F(5))(3)B·NH(3) in toluene solution leads to the formation of Tp'M(NMe(2))(2){NH(2)B(C(6)F(5))(3)} complexes. The exception to this was the attempted preparation of Tp*Ti(NMe(2))(2){NH(2)B(C(6)F(5))(3)} which was unsuccessful. Where Tp' = Tp and M = Ti and Zr and where Tp' = Tp* and M = Zr the complexes have been characterized by single crystal X-ray diffraction methods, revealing the first examples of octahedral amidoborane complexes of the group 4 metals. Attempts to drive the reactions to completion resulted in competing preferential hydrolysis of the amidoborane group, regenerating (C(6)F(5))(3)B·NH(3).     

The N-hydroxymethyl group for stereoselective conjugate addition: application to the synthesis of (-)-statine

[reaction: see text] Efficient synthesis of enantiomerically pure (-)-statine was achieved with the stereoselective intramolecular conjugate addition of the hydroxyl group tethered to the amino group of a configurationally stable N-Boc-L-leucinal derivative.     

The tert-butyl-NNO-azoxy group in the synthesis of 1,2,4-benzotriazin-3(4H)-one 1-oxides

Treatment of 2-(tert-butyl-NNO-azoxy)anilines with phosgene at 20 °C was proposed as a novel route to 1,2,4-benzotriazin-3(4H )-one 1-oxides. This method involves a new reaction, viz., an intramolecular interaction of the tert-butyl-NNO-azoxy group with a C-electrophile (leading to the formation of the N(2)—C(3) bond of the triazine ring) followed by elimination of the tert-butyl group. Complete assignment of the signals in the ¹H and ¹³C NMR spectra of the compounds obtained was performed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1507–1509, August, 2007.     

The 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc) amino-protecting group: use in the solid-phase synthesis of pyrrole-imidazole polyamides

The development of the 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc) function, a novel base-sensitive amino-protecting group, and its application to the preparation of DNA-binding polyamides are described. Pyrrole-imidazole polyamides were synthesized by an efficient solid-phase method under conditions compatible with Fmoc chemistry using two Tsc-protected amino acids, Tsc-Py-OH 1a and Tsc-Im-OH 1b.     

第14届固态传感器、传动器与微系统国际会议(Ⅱ)

分组报告续报如下: 生物微流体学组报告4个.(1)M Ikewchi等,供试管中三维组织培养用的人工毛细管网络芯片;(2)A Shastry等,输送小滴用的、微型结构的表面棘轮;(3)T Baba等,供产生双亲(亲水与亲脂)分子的阵列纳米膜用的、在附有多孔性侧壁的微通道中均匀水相栓子的积聚;(4)S H:Huang等,供混合静态或连续流动的流体用的、电渗产生的平面微涡流.