[en] Short Communication

[en] The paper introduced the development and process of CN-101 "6"0Co sealed source for industrial irradiation, including the structure design, prototype test, underwater disassembly of cobalt bundles, underwater activity measurement of cobalt rods, cutting of cobalt rods, encapsulation and welding of capsules, leakage test, surface contamination test, outside dimension measurement, and activity measurement of the finished sources. The products passed through certification test in February 2011, and the results show that all technical parameters reach the advanced world level. The successful development of CN-101 sealed source fills the vacancy of domestic fields and breaks with the monopoly of foreign products. Annual fabrication capacity can reach to 2.035 × l0"1"7 Bq. (authors)

[en] Electrophoretic deposition has always been an attractive method to deposit nanoparticles on conductive materials, while most fiber-based materials have poor conductivity which limits the application of electrophoretic deposition in assembling nanoparticles onto fiber-based materials. A new approach to assemble graphene oxide (GO) nanosheets on nonconductive nonwovens via the synergistic effect of electrophoresis and fiber interception was reported in this study. To improve surface wettability, polypropylene (PP) nonwovens were modified by acrylic acid and subsequent N_2 plasma treatment. Then GO nanosheets were anchored onto modified nonwovens by electrophoresis process and nonwoven interception. The results of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) manifested that etching and grafting simultaneously occurred on the surface of modified PP nonwovens, resulting in a great improvement of nonwoven hydrophily, which corresponded to the results of water contact angle. Furthermore, the results of X-ray diffraction, energy dispersive X-ray, SEM, and FTIR indicated that different amounts of GO nanosheets were successfully assembled onto modified PP nonwovens. This method provides a new avenue for incorporating carbon nanoparticles with nonconductive fiber-based materials, and modified PP nonwovens assembled with GO nanosheets show good air filtration performance for sodium chloride aerosol with a filtration efficiency of 87.9 % and a pressure drop of 36.4 mmH_2O, and the reduced GO/PP composite nonwovens exhibit enhanced conductivity

[en] The Zhantang andesites, which erupted in the Late Cretaceous Huichang Basin of SE China interior, were associated the the Late Mesozoic lithospheric extension and basaltic underplating. They are high-Na(6.59-8.46 wt% Na₂O), high-Al trondhjemitic rocks with high Sr and Ba, low Y and HREE, and high Sr/Y and La/Yb ratios, similar to modern adakites. However, they are much higher in Na₂O but lower in CaO than adakites. Their εNd(T) values of -2.3 to -3.8 and initial ⁸⁷Sr/⁸⁶Sr ratios of 0.707 to 0.708 are also significantly different from those of adakites with MORB-like isotopic compositions. These chemical and isotopic features, along with the tectonic setting, suggest that they were not produced by partial melting of subducting slab. The Zhantang adakite-like magmas may be derived from underplated basaltic lower crust, but require a compositionally peculiar basaltic protolith to account for their extremely high-Na and low-Ca feature. They are compositionally comparable to the experimentally produced partial melts of alkali-rich basalt. We therefore interpret them as the products of melting of an alkali-rich basaltic rock. (author)

[en] Graphical abstract: Our analytical protocol compared with traditional methods. Highlights: ► Sr and Nd from the same filament loading were sequentially measured without venting using TIMS. ► This protocol shows a great improvement in the analytical efficiency. ► Experimental costs and labour intensity are significantly cut down. - Abstract: Thermal ionization mass spectrometry (TIMS) offers the excellent precision and accuracy of the Sr and Nd isotopic ratio analysis for geological samples, but this method is labour intensive, expensive and time-consuming. In this study, a new analytical protocol by TIMS is presented that aims at improving analytical efficiency and cutting down experimental cost. Using the single-step cation exchange resin technique, mixed Sr and rare earth elements (REEs) fractions were separated from matrix and evaporated to dryness. Afterwards, mixed Sr + REEs fractions were dissolved and loaded onto the same Re filament using 1 μL of 2 M HCl. Then, Sr and Nd were sequentially measured without venting using TIMS. In contrast to conventional TIMS methods, the merits of this analytical protocol are its cost- and time-saving adaptations. The applicability of our method is evaluated by replicated measurements of ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd for nine international silicate rock reference materials, spanning a wide range of bulk compositions. The typical internal precision in this study is ca. 0.001% (RSE) for ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd; the analytical results obtained for these standard rocks show a good agreement with reported values, indicating the effectiveness of the proposed method.

[en] Graphical abstract: Distribution curve of all eluting fractions for a BCR-2 (1-2-3.5-7 mg) on LN column using HCl and HF as eluting reagent. Highlights: → This analytical protocol affords a simple and rapid analysis for Sm and Nd isotope in minor rock samples. → The single-step separation method exhibits satisfactory separation effect for complex silicate samples. → Corrected ¹⁴³Nd/¹⁴⁴Nd data show excellent accuracy even if the ¹⁴⁰Ce¹⁶O⁺/¹⁴⁴Nd¹⁶O⁺ ratio reached to 0.03. - Abstract: A single-step separation scheme is presented for Sm-Nd radiogenic isotope system on very small samples (1-3 mg) of silicate rock. This method is based on Eichrom LN Spec chromatographic material and affords a straightforward separation of Sm-Nd from complex matrix with good purity and satisfactory blank levels, suitable for thermal ionization mass spectrometry (TIMS). This technique, characterized by high efficiency (single-step Sm-Nd separation) and high sensitivity (TIMS on NdO⁺ ion beam), is able to process rapidly (3-4 h), with low procedure blanks (<10 pg) and very small sample (1-3 mg). Replicate measurements by TIMS on ¹⁴³Nd/¹⁴⁴Nd ratios and Sm-Nd concentrations are presented for eleven international silicate rock reference materials, spanning a wide range of Sm-Nd contents and bulk compositions. The analytical results show a good agreement with recommended values within ±0.004% for the ¹⁴³Nd/¹⁴⁴Nd isotopic ratio and ±2% for Sm-Nd quantification at the 95% confidence level. It is noted that the uncertainty of this method is about 3 times larger than typical precision achievable with two-stage full separation followed by state-of-the-art conventional TIMS using Nd⁺ ion beams which require much larger amounts of Nd. Hence, our single-step separation followed by NdO⁺ ion beam technique is preferred to the analysis for microsamples.