JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2019
·Vol. 34
·期 11
·2229-2235
·
IF 3.646
Lei Tang,Wenting Bu,Xuemei Liu,Sheng Hu
The accurate determination of ultra-trace amounts of 99Tc is still a challenge due to its long half-life and the lack of a commercially available isotopic tracer. Negative thermal ionization mass spectrometry (N-TIMS) has been proven to be a powerful method for the analysis of isotopes with relatively high ionization potentials. In this work, we established a novel method based on N-TIMS for the measurement of Tc isotopes. By using Pt filaments and Ba(OH)2 as the ionization activator, the ionization efficiency of Tc was significantly improved to be more than 10%. The oxygen isotopic compositions were measured with a 99Tc standard solution and the obtained coefficients can be applied directly for the correction of interferences from oxygen isotopes. We used this method for the measurement of the isotopic abundance and concentration of the 97Tc tracer produced in our laboratory. Due to the high ionization efficiency of this method and the calibration of the 97Tc tracer, ultra-trace determination of 99Tc in radioactive wastes and environmental samples is now possible.
研究领域:
分析化学
·
环境科学
·
放射化学
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2023
·Vol. 9
·期 43
·
IF 13.6
Wei Zhao,Yiwei Zheng,Meng Jiang,Tingting Sun,Aibin Huang,Lianjun Wang,Wan Jiang,Qihao Zhang
Ionic liquid–based ionogels emerge as promising candidates for efficient ionic thermoelectric conversion due to their quasi-solid state, giant thermopower, high flexibility, and good stability. P-type ionogels have shown impressive performance; however, the development of n-type ionogels lags behind. Here, an n-type ionogel consisting of polyethylene oxide (PEO), lithium salt, and ionic liquid is developed. Strong coordination of lithium ion with ether oxygen and the anion-rich clusters generated by ion-preferential association promote rapid transport of the anions and boost Eastman entropy change, resulting in a huge negative ionic Seebeck coefficient (−15 millivolts per kelvin) and a high electrical conductivity (1.86 millisiemens per centimeter) at 50% relative humidity. Moreover, dynamic and reversible interactions among the ternary mixtures endow the ionogel with fast autonomous self-healing capability and green recyclability. All PEO-based ionic thermoelectric modules are fabricated, which exhibits outstanding thermal responses (−80 millivolts per kelvin for three p-n pairs), demonstrating great potential for low-grade energy harvesting and ultrasensitive thermal sensing.
研究领域:
材料科学
·
能源转换
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Siqi Zhu,Xuefang Lu,Lu Cheng,Lemin Jia,Wei Zheng
Cubic boride crystals with pure boron isotopes have attracted great attention in recent years. Here, high-quality cubic boron phosphide single crystals with isotopic 10B and a maximum width reaching 1.5 mm are grown via the high-temperature molten salt method. An interesting phenomenon that there are many discrete sharp lines in the low-temperature (4–80 K) photoluminescence spectra is observed. Besides, as temperature increases, the luminescence intensity of these sharp lines shows a nonmonotonic decay with two different trends exhibited. Based on analyses, the sharp-line emission originates from phonon-assisted donor–acceptor pair radiative recombination. The nonmonotonic decay is affected by the number of assisting phonons and the degree of thermal ionization under the effect of temperature, and the different decay trends are attributed to the effect of thermal ionization dependent on the distance between the donor and acceptor. Results obtained in this research are expected to enrich the knowledge concerning cubic boride crystals in the aspect of physical properties.
研究领域:
材料科学
·
固体物理
·
光学材料
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·
IF 27.4
Ya-Hsin Pai,Chen Xu,Renyang Zhu,Xinyi Ding,Shengqiang Bai,Ziqi Liang,Lidong Chen
A paradigm ionogel consisting of ionic liquid (IL) and PVDF−HFP composites is made, which inherently possesses dual-function ionic thermoelectric (iTE) and piezoelectric (PE) attributes. This study investigates an innovative “PE-enhanced iTEs” effect, wherein the ionic thermopower exhibits a 58% enhancement while the ionic conductivity arises more than 2× within a PE-induced internal electric field. By harnessing these multifaceted features, fully self-powered, multimodal sensors demonstrate their superior energy conversion capabilities, which possessed minimum sensitivities of 0.13 mV kPa −1 and 0.96 mV K −1 in pressure and temperature alterations, respectively. The PE augmentation of iTEs is maximized by ≈3× under rising water pressure. Their swift and sophisticated responses to various in vivo vital signs simultaneously in a hemorrhagic shock scenario, indicative of good prospects in the clinical medicine field are showcased.
研究领域:
材料科学
·
生物医学工程
·
临床医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2025
·
IF 3.1
Jin-Hua Liu,Xiao-Dong Deng,Jian-Wei Li,Lan-Ping Feng,Thomas J. Algeo
The rhenium–osmium (Re–Os) isotopic system has emerged as a widely utilized tool in cosmochemistry and high-temperature geochemical studies. A critical prerequisite for high-precision Os isotope analysis via Negative Thermal Ionization Mass Spectrometry (N-TIMS) involves achieving complete isotopic equilibrium between the sample and spike through the isotope dilution technique. In this study, we present an innovative technique to address valence state disparities in Os species within mixed solutions, thereby enabling effective isotopic equilibration through a chemical reducing reaction with a strong reductant under ambient conditions. Experimental results demonstrate that a solution containing 0.05 mol L−1 hydroxylamine hydrochloride (NH2OH·HCl) coupled with 0.01 mol L−1 HBr effectively stabilizes a nanogram-level Os mass. Systematic optimization of reductant concentration and sample-to-reductant ratio yielded a mean 190Os/188Os value of 1.2280 ± 0.0006 (2s, n = 18) for a mixed Os spike solution, closely aligned with the recommended value of 1.2278 ± 0.0003 (2s, n = 12) obtained through the conventional Carius tube method. Controlled comparative experiments revealed critical considerations for method implementation: (1) a freshly prepared reductant must be employed immediately to ensure reagent efficacy, and (2) precise absolute volume control of the reductant solution is essential to mitigate potential losses of volatile OsO4 linked to extended decomposition times. This novel approach successfully achieves isotopic equilibration between sample–spike and inter-spike components under ambient conditions, offering significant analytical advantages over traditional methods. The validity of the proposed approach was demonstrated by analyzing reference material WMS-1a yielding a 187Os/188Os value of 0.1665 ± 0.0006 (2s, n = 5), which agrees within uncertainty with the established value of 0.1664 ± 0.0003 (2s, n = 5) obtained via the Carius tube method. The protocol enhances operational efficiency by reducing equilibration time and explosive risk, and decreases procedural Os blanks via reducing material and reagent consumption. The combined improvements in precision, cost-effectiveness, and methodological flexibility position this technique as a valuable advancement in Os isotope geochemistry.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Shen Zhang,Wencai Cheng,Congcong Ding,Ze Qiu,Junwen Tan,Xirui Lu,Jun Wen,Hao Li
Developing an efficient uranium enrichment process for large-scale eluates from marine-tested fibers is crucial for filling the gap in the downstream of seawater uranium extraction. Alkaline elution of 10 kg real marine-tested fibers yielded 33 L of clear eluate after pretreatment, where uranium existed mainly as [UO 2 (CO 3 ) 2 ] 2− , [UO 2 (CO 3 ) 3 ] 4− , and [UO 2 (O 2 )(CO 3 ) 2 ] 4− species with a concentration of 11.98 mg/L, while magnesium concentration was up to 352.48 mg/L.MIP analysis selected D201 resin with more and larger pores, which showed better uranium adsorption due to a maximum electrostatic potential of 114.93 kcal/mol via simulation. 1 kg of D201 resin was used in a self-developed ion exchange equipment (maximum 100 L eluate per run) for concentration and purification. After 5 days of enrichment, 3 L of uranium concentrate was obtained, with uranium concentration increased to 121.48 mg/L and magnesium reduced to 14.9 mg/L. Ammonia water was added to the concentrate for precipitation, collecting 1112.45 mg of uranium product. The uranium precipitation rate was 99.27 %, and that of magnesium was only 31.1 %. The overall enrichment efficiency reached 93.13 % for uranium. ICP results showed the uranium mass fraction in the product was 33.1 %. TI-MS results indicated the U-235 abundance (≈0.72 %) was consistent with natural levels, and U-234 abundance (0.0064 %) was, slightly higher than natural, but still qualified it as natural uranium. This study provides an innovative enrichment process and theoretical support for efficient downstream uranium recovery in seawater uranium extraction.
研究领域:
核工程
·
环境化学
·
材料科学
·
化学工程
·
海洋科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）