共查询到20条相似文献,搜索用时 15 毫秒
1.
Jihao Zhu Songlin Feng Dongyu Fan Xiangqian Feng Qing Xu Huishan Quan Yueming Shen Zhenxi Zhuo Wenjiang Zhang 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(3):545-549
Chemical composition is an important information of studying the provenance character of ancient pottery and porcelain. The
ancient celadon samples produced in Later Tang (850–907 A.D.) to Former Southern Song (1127–1279 A.D.) have been analyzed
with NAA. Its provenance characteristic was compared with that of Hongzhou Kiln of Jiangxi Province and Yaozhou Kiln of Shanxi
Province in this paper. The experimental data were studied with statistic methods. The results indicated that the chemical
compositions of ancient porcelain body samples made in three kilns were different. The difference is able to be identified.
The porcelain body materials of both Silongkou Yue Kiln and Hongzhou Kiln were similar. The samples of Yaozhou kiln in north
of China existed obvious difference. 相似文献
2.
Kharfi Fayçal Boudraa Lahcen Benabdelghani Imene Bououden Mahfoud 《Journal of Radioanalytical and Nuclear Chemistry》2019,320(2):395-403
In this work, a terra-cotta brick collected from the famous archaeological Roman city Cuicul, Algeria, was successfully dated by thermoluminescence. The provenance of the fabrication material was also identified by X-ray fluorescence analysis (XRF). The results obtained show that the brick was probably made in 198 A.D. This date is in good agreement with the history of the dated site and the neighborhood Caracalla arch edified in honour to Caracalla emperor (211–217 A.D.). The XRF study demonstrates that the raw clay used for the fabrication of the brick is local and well selected by the Roman builders.
相似文献3.
M. O. A. Oladipo S. A. Adeleye F. Rehman 《Fresenius' Journal of Analytical Chemistry》1992,343(3):280-286
Summary Instrumental neutron activation analysis (INAA) has been employed to investigate the relationship between three ancient occupation sites — Samaru-west, Pantaki and Tsauni in Kaduna State, Nigeria, based on the analysis of cultural deposits at the sites. Samaru-west was found to be related with Pantaki site but not so with the Tsauni site. Elemental profiles for the pottery excavated from each site have been established. 相似文献
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Daéid NN Meier-Augenstein W Kemp HF 《Rapid communications in mass spectrometry : RCM》2011,25(13):1812-1816
The analysis of un-dyed spun cotton fibres can be challenging within a forensic science context where discrimination of one fibre from another is of importance. Conventional microscopic and chemical analysis of these fibres is generally unsuccessful because of their similar morphology. In this work we have explored the potential of isotope ratio mass spectrometry (IRMS) as a tool for spun cotton fibre analysis in an attempt to reveal any discriminatory information available. Seven different batches of un-dyed spun cotton fibre from four different countries were analysed. A combination of the hydrogen and oxygen isotopic data facilitated the correct association of the samples, demonstrating, for the first time, the applicability of IRMS to fibre analysis in this way. 相似文献
6.
利用樟脑在水-乙醇混合体系中的溶解度受温度的改变而剧烈变化的原理, 制成"结晶风暴球"。观测温度高低及其改变速度对形成晶体的数量、形状的影响。 相似文献
7.
Crozet Marielle Demeyer Séverine Lourenço Valérie Herranz Margarita Boden Sven 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(7):2967-2982
Journal of Radioanalytical and Nuclear Chemistry - INSIDER (Improved Nuclear SIte characterization for waste minimization in D&D operations under constrained EnviRonment) was a European... 相似文献
8.
G. L. Catchen 《Journal of Radioanalytical and Nuclear Chemistry》1993,171(1):125-130
I present some perspectives on teaching the subject of nuclear and radiochemistry in the form of a historical narrative. In addition, I briefly review a program, which we developed approximately seven years ago, to enchance learning in a specific course on the subject. This program involved developing illustrations, course notes, and video tutorials evaluating their effectiveness. After having used these aids extensively, I comment on their efficacy. Also, I briefly discuss the role of a nuclear science course in a nuclear engineering curriculum. 相似文献
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氢化松香与HEMA酯化物自聚与共聚研究 总被引:3,自引:0,他引:3
用氢化松香(HR)与甲基丙烯酸-2-羟乙酯(HEMA)进行酯化反应,得到了酯化物(HRH),然后对其进行了在甲苯中的自由基自聚反应、以及与甲基丙烯酸甲酯(MMA)或与苯乙烯(St)的共聚反应,制备了自聚物和共聚物,用IR和核磁共振氢谱(1HNMR)对产物进行了表征,用综合热分析仪表征了产物的热稳定性和玻璃化转变温度.结果表明:成功合成了HRH自聚物(PolyHRH)、以及共聚物[Poly(HRH-co-St)和Poly(HRH-co-MMA)].产物的热稳定性顺序为:HRH>PolyHRH>Poly(HRH-co-St)>Poly(HRH-co-MMA). 相似文献
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Pekka Pyykkö 《Theoretical chemistry accounts》1975,39(2):185-187
It is pointed out that the finite second-order hyperfine self-coupling energies, obtained by the Blinder operator, are unphysical and 102 times too large. The additional terms in the first-order matrix element are also unphysical. Therefore the Blinder operator gives no improvement over the simple delta function. The consequences on the recent calculations by Paviot and Hoarau and by Sänger and Voitländer are discussed. 相似文献
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Alpha- and beta-activities per unit volume of air due to radon (222Rn), thoron (220Rn) and their progenies were measured in the air of natural caves and ancient mines as well as inside different reference
atmospheres by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). In addition, the radon concentration
was continuously measured inside one of the studied caves by using the SSNTDs’ method and AlphaGuard counter. Equilibrium
factors between radon and its daughters and between thoron and its progeny were evaluated in the studied atmospheres. Alpha-activities
due to 218Po and 214Po short-lived radon decay products were determined in different compartments of the respiratory tract of members of the public.
The committed equivalent doses due to the 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the visitors of the considered
caves and ancient mines. Annual effective doses due to radon progeny from the inhalation of air by the visitors of the studied
caves and ancient mines were evaluated. 相似文献
15.
甜菜碱[(CH3)3N+CH2COO-],是一种季铵型水溶性生物碱,可作为甲基供体,具有促进动物蛋白质和脂肪代谢、缓和应激、调节渗透压、增进食欲、稳定维生素、参与预防球虫病 [1-3],也可作为多功能表面活性剂,广泛用于制备护发护肤用品[4-5].甜菜碱的盐酸盐可用于胃酸缺乏、动脉粥样硬化、肝脏疾病、止痛、治疗风湿病、糖尿病等[6-8].甜菜碱制备方法[9-15]有天然甜菜糖蜜提取法和化学合成法.前者由于原料来源有限而使其应用推广具有一定的局限性.传统合成方法采用氯乙酸钠和三甲胺反应,生成的氯化钠很难除去[16].近年来对此的研究如采用强阳离子交换树脂法,溶剂法或者将氢氧化钠改为氢氧化钙[17-18]等. 相似文献
16.
Radon-to-thoron ratios as well as radon and thoron activity concentrations in different underground water samples belonging to different aquifers in the Moroccan Middle Atlas area have been evaluated by LR-115 and CR-39 solid state nuclear track detectors (SSNTD) using a new calibration method. The radon isotope (222Rn) was used as a tracer for studying the water exchange between different aquifers of the area studied. The influence of the lithological and hydrogeological parameters of the aquifers on radon emanation were investigated. 相似文献
17.
Xiaoan Li Jianzhong Jia Tao Li Zefeng Zhao Haijing Liu Na Song Jin Pei 《Journal of separation science》2023,46(22):2300196
After medicinal market research, it was found that the harvest time of Ligustri Lucidi Fructus (LLF) was chaotic in practice. In order to determine the optimal harvest period of LLF to ensure its pharmacological activity, metabolomics analysis of LLF at different harvest times based on ultra-high-performance liquid chromatography-triple quadrupole-(linear ion trap)-tandem mass spectrometry was established. In this study, 166 differential metabolites (DMs) in 448 metabolites at different harvest times were screened out based on variable importance in projection value, and among them, 94 DMs with regular trends of change in relative content (59 increased and 35 decreased with the growth period) were chosen to further research. The result of the multivariate statistical analysis showed that November was the optimal harvest period of LLF. Additionally, 10-hydroxyligustroside, oleoside 11-methyl ester, and salidroside were screened out to be used as the evaluation indicators of immature LLF, while specnuezhenide, nuezhenoside G13, and neonuezhenide were the evaluation indicators of mature LLF. This study provides fundamental insight for metabolite identification and proposes the best harvest period of LLF to avoid confusion in the medicinal market. 相似文献
18.
E. A. Baryshnikova Z. A. Rotenberg V. V. Batrakov 《Russian Journal of Electrochemistry》2008,44(11):1307-1311
Intensity-modulated photocurrent (photoadmittance) and electrochemical impedance of anodicoxidized iron electrode in neutral nitrate solutions and in the presence of Ba2+, Ca2+, Cl?, and C6H5COO? (benzoate) are studied. It is shown that the ion adsorption at passive iron affects but slightly the system’s impedance; by contrast, it affects the photocurrent value significantly: when adsorbing, the anions increase the photoeffect, while the cations decrease it. These effects are associated with the potential drop redistribution in the Helmholtz layer and the film. The dissimilar changes of the generation current in the presence of similarly charged ions at their equal concentration evidence their different adsorption activity. The correlation between the generation current and surface-active ion concentration in solution is found. The photoelectrochemical spectroscopy allows evaluating qualitatively the surface-active ion adsorption at the passive iron and judging on the ion adsorption by the dependence of the generation current on the ion concentration. 相似文献
19.
Study on the recovery of hydrogen from refinery (hydrogen + methane) gas mixtures using hydrate technology 总被引:1,自引:0,他引:1
A novel technique for separating hydrogen from (H2 CH4) gas mixtures through hydrate formation/dissociation was proposed. In this work, a systematic experimental study was performed on the separation of hydrogen from (H2 CH4) feed mixtures with various hydrogen contents (mole fraction x = 40%-90%). The experimental results showed that the hydrogen content could be enriched to as high as ~94% for various feed mixtures using the proposed hydrate technology under a temperature slightly above 0℃ and a pressure below 5.0 MPa. With the addition of a small amount of suitable additives, the rate of hydrate formation could be increased significantly. Anti-agglomeration was used to disperse hydrate particles into the condensate phase. Instead of preventing hydrate growth (as in the kinetic inhibitor tests), hydrates were allowed to form, but only as small dispersed particles. Anti-agglomeration could keep hydrate particles suspended in a range of condensate types at 1℃ and 5 MPa in the water-in-oil emulsion. 相似文献