无机化学工业中的企业会计档案应用提升策略——评《现代化工企业管理》

在当代社会,无机化学工业的发现十分重要,无论是各种企业能源的利用方面,还是在国家重要资源的开采工作中,都离不开化学工厂企业,因此,做好企业的管理工作十分重要。其中会计档案工作的有效平稳运行成为影响企业运行状态的重要环节之一,在实际工作中,相关工作人员需要根据企业的发现需求和政策的变化,随时调整企业会计档案管理工作的流程和重点,以便于更好地顺应变化,同时也可以达到有效提高档案管理工作质量的目的,为化学工厂企业的发展创造更加有利的环境和条件。     

加强实验教学环境内涵建设 提高环境育人质量

在实验室里的实验教学过程涉及到教书育人、管理育人、服务育人和环境育人。一个良好的实验环境不仅能够对学生起到潜移默化的教育作用,而且对教书育人、管理育人和服务育人工作的开展和实施也能起到推动和促进作用。本文主要介绍厦门大学化学国家级实验教学示范中心"以学生为中心",在强化实验教学环境内涵建设、提高实验环境育人质量方面的一些做法和体会,以期更好地为实验教学"思政"提供可复制、可推广的建设方案。     

石墨烯负载的氧配位钴单原子稳定金属锂负极

Lithium (Li)-based batteries are the dominant energy source for consumer electronics, grid storage, and electrified transportation. However, the development of batteries based on graphite anodes is hindered by their limited energy density. With its ultrahigh theoretical capacity (3860 mAh∙g⁻¹), low redox potential (−3.04 V), and satisfactorily low density (0.54 g∙cm⁻³), Li metal is the most promising anode for next-generation high-energy-density batteries. Unfortunately, the limited cycling life and safety issues raised by dendrite growth, unstable solid electrolyte interphase, and dead Li have inhibited their practical use. An effective strategy is to develop a suitable lithiophilic matrix for regulating initial Li nucleation behavior and controlling subsequent Li growth. Herein, single-atom cobalt coordinated to oxygen sites on graphene (Co-O-G SA) is demonstrated as a Li plating substrate to efficiently regulate Li metal nucleation and growth. Owing to its dense and more uniform lithiophilic sites than single-atom cobalt coordinated to nitrogen sites on graphene (Co-N-G SA), high electronic conductivity, and high specific surface area (519 m²∙g⁻¹), Co-O-G SA could significantly reduce the local current density and promote the reversibility of Li plating and stripping. As a result, the Co-O-G SA based Li anodes exhibited a high Coulombic efficiency of 99.9% at a current density of 1 mA∙cm⁻² with a capacity of 1 mAh∙cm⁻², and excellent rate capability (high current density of 8 mA∙cm⁻²). Even at a high plating capacity of 6 mAh∙cm⁻², the Co-O-G SA electrode could stably cycle for an ultralong lifespan of 1300 h. In the symmetric battery, the Co-O-G SA based Li anode (Co-O-G SA/Li) possessed a stable voltage profile of 18 mV for 780 h at 1 mA∙cm⁻², and even at a high current density of 3 mA∙cm⁻², its overpotential maintained a small hysteresis of approximately 24 mV for > 550 h. Density functional theory calculations showed that the surface of Co-O-G SA had a stronger interaction with Li atoms with a larger binding energy, −3.1 eV, than that of Co-N-G SA (−2.5 eV), leading to a uniform distribution of metallic Li on the Co-O-G SA surface. More importantly, when matched with a sulfur cathode, the resulting Co-O-G SA/lithium sulfur full batteries exhibited a high capacity of 1002 mAh∙g⁻¹, improved kinetics with a small polarization of 191 mV, and an ultralow capacity decay rate of 0.036% per cycle for 1000 cycles at 0.5C (1C = 1675 mA∙g⁻¹) with a steady Coulombic efficiency of nearly 100%. Therefore, this work provides novel insights into the coordination environment of single atoms for the chemistry of Li metal anodes for high-energy-density batteries.     

新型样品前处理材料在环境污染物分析检测中的研究进展

针对复杂样品的分析和痕量目标物的检测,样品前处理是必不可少的,高效的样品前处理技术不仅可以去除或减小样品基质干扰而且能够实现分析物的富集,提高分析检测的准确性和灵敏度.近年来,固相萃取、磁分散固相萃取、枪头固相萃取、搅拌棒萃取、固相微萃取等高效的样品前处理技术已在环境污染物分析检测中获得广泛关注,萃取效率主要取决于萃取...     

荧光法直接测定环境水中十二烷基苯磺酸钠

在我国,十二烷基苯磺酸钠(SDBS)是使用量最大的洗涤剂之一,也是环境水中的一种污染物。检测SDBS常用的方法有:吸光光度法显色后一般需用有毒的有机溶剂萃取,操作繁琐;导数吸光光度法是采用四阶导数进行处理的测定方法,过程较复杂。本文用荧光分光光度法直接测定环境水中的SDBS含量,此法不需萃取和显色,通过控制溶液的pH值来进行测定,波长为λ_(ex)╱λ_(em)=230/290nm,干扰物少。     

应正确阐述结构、构造、构型和构象等基本概念

通过对构造、构型与构象概念之间的联系与区别，以及差向异构体定义问题的讨论，针对现行教材中存在的不足，从概念的严密性上进行了比较深入的分析，指出了规范有机化学中的基本概念的必要性和可行性。     

痕量苯胺的单扫描极谱法测定

１引言环境水样中痕量苯胺的测定多采用偶氮化色法，利用苯胺偶氮盐与羟基化合物偶合生成的偶氮化合物的吸附波间接测定苯胺的方法已有报道。作者观察到，在氨水－氯化铵介质中，８－羟基喹啉与苯胺重氮盐偶合生成的偶氮化合物在滴汞电极上于－０．７４Ｖ（ｖｓ．ＳＣＥ）处产生－灵敏的导数极谱波，苯胺浓度在０．００８～１．４０ｍｇ／Ｌ范围内与波高呈良好的线性关系，可用于痕量苯胺的测定，方法用于污水中痕量苯胺的测定，结果令人满意。２实验部分２．１仪器与试剂ＪＰ－２型示波极谱仪；三电极体系导数档；苯胺标准溶液：１００与１…     

环境元素与健康

通过一些分析数据，说明了环境元素与健康的关系。     

环境微量元素与大骨节病

通过对两个自然村的大骨节病的流行病学调查结果表明，患病率在１７．２％，从Ｘ线检查病变部位都在干骺端，说明致病因素的持续作用仍在发展中，所采水样中微量元素低于国家饮水标准，在今后疾病的防治中，应根据营养条件，生态环境，元素比例，农作物的病害，制作相关的防治措施。     

从自然科学基金资助项目看我国环境化学进展和趋势

本文通过对近年来国家自然科学基金中环境化学学科资助项目的介绍和评述, 分析了我国环境化学基础性研究的进展, 对环境化学学科发展趋势作出了展望, 并对部分相关前沿领域的研究提出了建议。