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21.
Kosuke Morita Kouji Morimoto Daiya Kaji Yu Liang Zhao Atsushi Yoshida Toshimi Suda Akira Yoneda Tetsuya Ohnishi Hiromitsu Haba Eiji Ideguchi Hu Shan Xu Tao Zheng Hisaaki Kudo Keisuke Sueki Kenji Katori Isao Tanihata 《Acta Physica Hungarica A》2004,19(1-2):53-60
A gas-filled type of recoil separator for heavy element research was installed at an experimental hall of RIKEN Linear Accelerator facility to realize getting higher intensity of primary beam and long beam time. Performance of the separator was studied using target recoils and various nuclear reactions. The results show the high performance of the separator for heave element research. As an application of the GARIS, production and identification of an isotope of the 110th element 271[110] have been performed using the 208Pb(64Ni,1n)271[110] reaction. Three decay chains coincide well both in decay times and energies with the ones reported by the group of SHIP experiment at GSI, Germany. Our results provide a confirmation of the synthesis of an isotope 271[110] of element 110. 相似文献
22.
Non-dispersive atomic fluorescence spectrometry (NDAFS) coupled with vapor generation (VG) sample introduction was applied to the determination of the concentrations of hazardous heavy metals, such as arsenic, cadmium, lead and mercury, in seawater, soils and total airborne particulate matter (PM) collected around the Xiamen area in China. Almost 100% sample introduction efficiency was achieved by using thiourea and ascorbic acid for the pre-reduction of As(V) to As(III), K3Fe(CN)6 and tartaric acid for pre-oxidation of Pb(II) to Pb(IV), and masking the interferences arising from the co-existing transition metals to As, Cd, Hg and Pb during their vapor generation process. Moreover, a novel sample pretreatment device was developed to avoid the loss of mercury, lead, cadmium and arsenic during sample pretreatment. With such methods, the detection limit (DL) of arsenic, cadmium, lead and mercury was down to 0.08, 0.03, 0.05, 0.01 ng mL(-1) (3sigma), respectively. The relative standard deviations (RSD, n = 11) for arsenic, cadmium, lead and mercury at 10 ng mL(-1) were 0.9%, 1.6%, 1.3% and 2.0%, respectively. The concentrations of hazardous heavy metals in the environmental samples collected in Xiamen, China are in the range from 0.02 +/- 0.001 ng mL(-1) in seawater to 15.3 +/- 0.2 microg g(-1) in soils. Besides flame/GF-AAS and ICP-AES/MS, VG-NDAFS should be another choice for the determination of hazardous heavy metals in environmental samples. 相似文献
23.
24.
Thiourea compounds are excellent agents of bioactive substance. A number of biological activities are associated with substituted thiourea derivatives. A survey of literature reveals that some work has been reported on benzoylthiourea, which has found plenty of applications as a facile and simple ligand in determination of trances of the transition metal and as an available starting material in preparation of a wide variety of metal complexes. In recent years,N-benzoyl-N'-(2-hydroxyethyl)-thiourea has attracted considerable attention as selective reagents for the liquid-liquid extraction and preconcentration of platinum group metals and its antifungle activity.As a part of our works in studying coordination behaviours of N-benzoyl-N'-(2-hydroxyethyl)-thiourea and its bioactivity, in view of these observations and in continuation of our previous works on it, the present work was reported on the crystal structure of N-benzoyl-N'-( 2-hydroxyethyl)-thiourea.The crystals structure in the monoclinic system and space group of P21/c of N-benzoyl-N'-(2-hydroxyethyl)- thiourea (C10H12N2O2S) was determined from single-crystal X-ray diffraction analysis, a = 17.083 (3) A, b = 4.5490 (10) A, c = 14.279 (3)A, a = 90.00°, a = 102.44(3)°, a = 90.00 °, Ⅴ = 1083.6 (4)A3, Z = 4, Dc = 1.375 Mg/m3, i (Mo Ka)= 0.280 mm-1, F(000) =472. The final R and u R are 0.0399 and 0.0881 for 783 observed reflections [Ⅰ>26(Ⅰ)].Fig. 1 shows the molecular crystal structure of N-benzoyl-N'-(2-hydroxyethyl)thiourea indicating that the carbonyl and thiocarbonyl moieties are pointing in approximate opposite directions. The six atoms in the ring structure hydrogen bonded are almost in one plane. The N(2)-H proton pendant arm extends to the carbonyl oxygen atom, forms hydrogen bond between them.The existence of hydrogen bond in benzoyl-thiourea molecular six-membered ring structure has significant implications on coordination properties, suggest the possibility of intramolecular hydrogen bond controlled coordination behaviors of these potentially bidentate ligands. In the coordination compound reported by Bourne et al.,cis-bis(N-benzoyl-N'-propylthiourea)dichloroplatinum(Ⅱ), the two ligand molecules bind to Pt(Ⅱ)via the sulfur atoms only, the carbonyl oxygen atom being locked into hydrogen bond similar to that in the free ligands. 相似文献
25.
Ming Zhao WANG Guan Liang CAI Ling XIA Jun Jian YAO Hong Yan CHEN Zhao Xing MENG Bo Li LIUDepartment of Chemistry Beijing Normal University Beijing Chemical Defense Institute PLA Beijing 《中国化学快报》2004,15(4):495-497
The crystal structures of two potential tumor imaging agents and therapeutic agents -copper(Ⅱ) complexes with salicylidene-tyrosinato Schiff base and nitrogen-donor chelating Lewis base, [Cu(sal-tyr)(bipy)] 1 and [Cu(sal-tyr)(phen)]2CH3OH 2 are presented. Our work is helpful to get deep understanding of novel 64Cu tumor imaging agents and therapeutic agents. 相似文献
26.
本文通过对大量的黄酮类化合物13C NMR图谱的分析和研究,总结了不同类型的黄酮类化合物的13C NMR图谱特征及化学位移规律.对影响黄酮类化合物结构骨架上不同位置碳原子化学位移的因素进行了分析,建立了用于黄酮类天然产物13C NMR图谱智能解析的知识库. 相似文献
27.
28.
Jie Xue Liang Chen Li Zhou Zhifeng Jia Yanping Wang Xinyuan Zhu Deyue Yan 《Journal of Polymer Science.Polymer Physics》2006,44(15):2050-2057
α‐Cyclodextrin (α‐CD) has been complexed with various poly(ethylene glycol) (PEG) derivatives in aqueous solution. It has been found that the end groups of PEG derivatives affect the complexation kinetics greatly, but have only a little influence on the thermodynamic behavior. By increasing the hydrophobicity of end groups, the complexation speeds up rapidly. On the other hand, the bulky end groups slow down the threading of polymeric guests into the cavity of CD. By changing the hydrophobicity and the size of end groups, the complexation rate can be adjusted in the range of several orders of magnitudes, which should be quite useful in the design of new supramolecular systems. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2050–2057, 2006 相似文献
29.
In this paper, we exhibit a unified treatment of the mixed initial boundary value problem for second order (in time) parabolic linear differential equations in Banach spaces, whose boundary conditions are of a dynamical nature. Results regarding existence, uniqueness, continuous dependence (on initial data) and regularity of classical and strict solutions are established. Moreover, several examples are given as samples for possible applications.
30.
A new method based on anion exchange resin separation and graphite furnace atomic absorption spectrometry (GFAAS) detection
is proposed for the determination of inorganic tin species. The result showed that Sn(IV) was quantitatively retained on the
resin when [HCl] = 9.0 mol · L−1, but Sn(II) could not be adsorbed on the resin under the same condition. Thus, a separation of Sn(II) and Sn(IV) has been
realized. When the concentration of NaOH solution was between 2.0–7.0 mol · L−1, Sn(IV) that adsorbed on the resin could be eluated from the resin completely. Meanwhile, under the atmosphere and the nitrogen
states, the translation between Sn(II) and Sn(IV) was investigated. Under the optimal conditions, the detection limit of Sn(IV)
is 0.40 μg · L−1 with RSD of 2.3% (n = 5, c = 2.0 μg · L−1). The proposed method was applied to the speciation analysis of tin in different water samples and the recovery of total
Sn was in the range of 98.7–101.7%. In order to verify the accuracy of the method, a certified reference water sample was
analyzed and the results obtained were in good agreement with the certified value. 相似文献