Reductive immobilization and long-term remobilization of radioactive pertechnetate using bio-macromolecules stabilized zero valent iron nanoparticles

Reductive immobilization of radioactive pertechnetate (⁹⁹TcO₄^?) in simulated groundwater was studied by prepared carboxymethyl cellulose (CMC) and starch stabilized zero valent iron nanoparticles (nZVI), and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic conditions. The stabilized nZVI can effectively reduce soluble ⁹⁹Tc(VII) to insoluble ⁹⁹Tc(IV), and they can be easily delivered into a contaminated groundwater zone and facilitate in situ remediation. In this study, CMC-stabilized nZVI showed higher reactivity than that using starch as the stabilizer. Batch experiments indicated that more than 99% of ⁹⁹Tc(VII) (C₀ = 12 mg/mL) was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2% (w/w) at a broad pH of 5–8. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses further confirmed that ⁹⁹Tc(VII)O₄^? transformed into ⁹⁹Tc(IV)O₂ (s). The presence of bicarbonate exhibited insignificant effect on Tc immobilization, while humic acid (HA) inhibited reaction mainly due to retardation on electron transfer and formation of Tc(IV)-HA complexes. More interesting, the immobilized Tc(IV) remained insoluble even after 120 d under anoxic condition, while only ～21% was remobilized when exposed to air. Therefore, bio-macromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.     

单调混合变分不等式的若干新的迭代算法

In this paper,some new iterative algorithms for monotone mixed variational inequalities and the convergence in real Hilbert spaces are studied.     

分析化学发展中的几个问题

分析化学在迅速发展中出现了一些令人关注的问题。它们是：如何确定现代分析化学煌范围，如何给字以明确的定义；对分析化学煌前沿的预测；当今分析化学在化学中的地位；对分析介的批评意见的反思；分析化学应注意克有孤自身的弱点；如何培养高水平的分析化学专业人材等。本文就这些问题介绍国内外同行的一些看法发表本人的浅见。     

近10年中国作者在Journal of Chemical Education发表论文概述

对2007-2016年中国作者在美国Journal of Chemical Education上发表论文的数量、作者人数、发文地区、作者单位及合作情况、论文内容等进行了统计与分析,揭示了近年来我国化学教育研究成果的特点,旨在为我国化学化工人才培养工作提供一些参考,并促进中国化学教育的国际交流。     

A surprising permanence of old motivations (a not-so-rigid story)

This is not a survey article. Rather it is a personal statement written for a lifelong friend and collaborator. Still, it is an ambition of this article to survey some of the key moments of our development in the past 40 years. In doing so perhaps some evidence has arisen which otherwise seems to be obscured by the hectic day-to-day academic life. Hence the title.     

The role of innovations in secondary school performance – Evidence from a conditional efficiency model

This paper studies the influence of educational innovations on school performance. We apply a tailored, fully nonparametric conditional efficiency model to study secondary school efficiency in the Netherlands. The application uses official school data and a self-collected questionnaire on recent innovations in schools. In the nonparametric model, it is assumed that schools aim to maximize educational attainments of students under a budget constraint. The results suggest that innovations are positively related to efficiency. We find that profiling, pedagogic, process and education chain innovations are significantly related to school efficiency, whereas innovations in the professionalization of teachers are insignificantly related to school efficiency. Furthermore, the number of locations per school and the number of schools per governing body are negatively and significantly related to school efficiency. School type and region significantly influence school efficiency, whereas share of disadvantaged students, degree of urbanization and student/teacher ratio do not have significant influence.     

Operations research practice on logistics management in Taiwan: An academic view

The opinions of logistics educators in Taiwan on OR practices in the domestic logistics industry are explored in this research. In this study, questionnaires were given to 42 pre-screened educators at 10 logistics departments and graduate institutes. According to the 37 valid returned questionnaires, 70% of the responding educators believe the major source of OR techniques in Taiwan’s logistics industry originates from individual employee training, while 92% believe OR is not widely used primarily because companies are unfamiliar with OR techniques. OR techniques were considered helpful in solving problems by 73%. Generally speaking, familiarity with OR techniques is not associated with implementation of OR techniques by educators. Additionally, logistics educators express concern about insufficient training for logistics students in Taiwan. However, they are optimistic about the logistics industry’s willingness to more actively adopt OR techniques in Taiwan in the next two years.