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An intercomparison of neutron personal dose equivalent measured by the Harshaw thermoluminescence neutron dosimeters (TLDs) between the National Institute of Metrology of China (NIM) and the Institute for Nuclear Science and Technology of Vietnam (INST) was performed. Three sets of TLDs (each set consisting of five TLDs) were prepared for each laboratory. Each set was then irradiated to the corresponding same nominal standard value of neutron personal dose equivalent, H p (10) n−std i , of 1.0, 2.0, and 3.0 mSv, respectively at these two laboratories. The irradiated TLDs were then read-out at the INST using the Harshaw 4500-type TLD reader to obtain neutron personal dose equivalents at the NIM, H p (10) n−NIM i and at the INST, H p (10) n−INST i , which are corresponding to different values of H p (10) n−std i . The TLDs' responses to different scattered components of neutrons in these two fields are also discussed. Comparisons between the corresponding pair values of H p (10) n−NIM i and H p (10) n−INST i show good agreements within 10% with the standard uncertainty of 12.5% (k = 1). The measured values of H p (10) n−NIM i and H p (10) n−INST i are satisfied the Trumpet curve criteria. This implies that the TLDs can be used for safety assessment of occupational neutron personal dose equivalents. This intercomparison result also confirms the capabilities of these two laboratories (i.e., NIM, INST) on deliveries of neutron personal dose equivalent standard values for calibrations. • A comparison of H p □ (10) for neutrons was performed between INST and NIM. • The H p □ (10) discrepancy is within 10% with the standard uncertainty of 12.5%. • The discrepancy is ascribed to the algorithm for different scattering components. • The algorithm is advised to be more qualified in complicated radiation fields. • INST and NIM are capable to deliver standard values of H p □ (10) for neutrons. [ABSTRACT FROM AUTHOR]

Sand dunes up to 400 m high are common in the Badain Jaran Desert in China, but how and why mega-dunes grow remains unclear. Timing is the most critical to clarify this issue. The chronological data are still limited with only a few 14 C ages from carbonate, not the direct age of the dune, and a few thermoluminescence (TL) ages whose unbleachable residual signals may result in uncertainty in age. Optically stimulated luminescence (OSL) dating uses quartz or feldspars and thus directly dates the sands. It could also be completely reset by daylight with no residual signals. We here report for the first time a batch of OSL ages, and discuss the pattern of the mega-dune growth. Field observation showed that wet sand layers could be exposed in the slope surface and could be easily seen due to its wetness and calcareous cement, causing stronger resistance to wind deflation relative to the adjacent sands. Wet sand layers are normally situated on the mega-dune windward slope, and sometimes could even be seen near the top of a mega-dune, with well-preserved original bedding layers, making them the ideal locations for collecting luminescence samples. Our four OSL samples collected from the Barunbaoritaolegai sand mountain (BSM) show that OSL ages are 4.4 ± 0.5, 5.6 ± 0.5, 11.9 ± 0.9, and 125 ± 11 ka, respectively, from top to bottom. These ages are concentrated in the early to middle Holocene and the Last Inter-glaciation (corresponding to MIS 5e). Based on field observation and OSL ages, we propose that the mega-dunes grow mostly during humid periods with water as cementing agents to build up the sands. The issues, such as the source of the water, how the water seeps into the high sand dunes, how the loose sands could build up to mega-height, etc., require further study. [ABSTRACT FROM AUTHOR]

In this paper, we studied the thermal history of a clay core sample from one leg of a bronze tripod unearthed at Daxinzhuang Site, Shandong, China. The properties of the luminescence signals of quartz depend on the maximum temperature at which the quartz was annealed in the past. We examined the feasibility of measuring the thermoluminescence (TL) sensitivity change of quartz for exploring the firing temperature of archaeological materials. The sensitization factor of the 110°C TL peak (S/S) and the ratio of the 210°C TL peak to the 110°C TL peak at different annealing temperatures were utilized to unveil the firing temperature in the clay core sample. The firing temperature of the clay core sample was approximately 700°C-800°C, proving the clay core has been fired. This result proved that the clay core has been fired by human agencies and indicated on the temperature of the clay core in drying and firing given by the foundry workers before the actual casting step. [ABSTRACT FROM AUTHOR]

Abstract: The thermoluminescence (TL) and optically stimulated luminescence (OSL) sensitivities of quartz grains from deserts and loess–red clay sequences are used to trace eolian provenances in northern China. Our results indicate that the 110°C TL peak and OSL sensitivities of quartz grains show differences among Chinese deserts, which can be subdivided into four groups according to the spatial variations of luminescence sensitivities. Such differences are related mostly to the regional difference in rock types of mountains surrounding or adjacent to the deserts. We also examine the possible provenance changes between the Quaternary loess and the Tertiary eolian red clay, and the results indicate that the luminescence sensitivity of Tertiary red clay is higher than that of Quaternary loess (L1, L15, and L33), implying source materials of the eolian deposits changed relative to those of the Quaternary. [Copyright &y& Elsevier]

Abstract: Three-dimensional thermoluminescence spectra are measured for different types of geological origin quartz from the Altay orogenic belt, northern Xinjiang, China. The results show striking differences which appear to be characteristic of their geological origin. Granitic quartz is dominated by emission bands at 420–430nm, 550–560nm, at a temperature of 170°C. Pegmatite quartz is characterized by an intense 480nm emission band at 170°C. Volcanic quartz has exclusive UV (340–360nm) and violet (410–430nm) emission bands. Hydrothermal quartz exhibits very different TL spectral characteristics because of different hydrothermal activity and mineralization. Only one TL peaks at 485nm/170°C was observed in sedimentary quartz. An intense 730nm emission band observed at 170°C considered generally to be characteristics of feldspar was observed in quartz from granite and hydrothermal Au-bearing quartz. This TL peak is probably related to the centre of [FeO4]0 on an Si site. All samples show an intense 990–1000nm emission band at 330°C. Identical types of quartz formed in different regions or different geological and tectonic settings can also exhibit striking differences in TL spectra. [Copyright &y& Elsevier]

Abstract: The single-aliquot regenerative-dose (SAR) protocol with optically stimulated luminenscence (OSL) was applied to measure the equivalent dose (ED) of ancient Chinese bricks ranging in age from 180 to 1600 years. In the protocol, sensitivity changes can be corrected by using OSL response to a fixed test dose during measurement. For comparative study between OSL and TL, thermoluminescence (TL) measurement procedures were also applied to determine the paleodose of the bricks. Both results of OSL and TL are in agreement with the known ages of the bricks, and the paleodose ratios(EDOSL/ EDTL) are between 0.96 and 1.21, mean value . The annual doses of the bricks, estimated by the paleodoses and the known ages, range from 5.07 to 6.79mGy/a, comparable with the measured annual dose values of the bricks. Therefore, it is concluded that the SAR protocol is a rapid and effective OSL technique to authenticate Chinese bricks. [Copyright &y& Elsevier]

Abstract: To determine whether the commercial foods were irradiated or not, an investigation was carried out in this study. One hundred and thirty-three commercial foods, including 33 spices, 20 dehydrated vegetables, 64 dehydrated fruits, and 16 pollens were tested by thermoluminescence (TL) method. The results showed 30 of them (22.6% of all tested samples) were proved to be irradiated. Our investigation provided a primary data for the regulation of irradiated food in China. [Copyright &y& Elsevier]