纳米Fe_3O_4磁性流体的制备与测试

采用化学共沉淀法制备Fe_3O_4磁性纳米颗粒,用油酸作为分散剂制备出煤油基和二脂基磁性流体.用X射线荧光光谱仪(XRF)、X射线衍射(XRD)测试分析颗粒的组成、结构、平均粒径,表明所制备的颗粒为纯净Fe_3O_4纳米粒子,其平均粒径小于15 nm,分布均匀.用傅立叶变换红外光谱仪(FTIR)、热重法(TGA) 和导数热重量(DTG)分析法对磁性流体进行性能测试,结果表明磁性流体进行性能稳定,煤油基磁性流体工作温度应低于88.6 ℃,二脂基磁性流体的应低于236.0 ℃.     

新疆区内初中班化学教学中的难点及对策研究

九年级化学作为起始学科,在进行教学时存在许多困难,而“内初班”学生的学情与本地学生不同,教学难度更大,存在师生交流不畅、学生的理解偏差、生活习惯差异以及缺乏课外教学素材等问题。因此,需在深入了解学情和以上问题的基础上,逐一攻破知识较为抽象、语言理解困难、生活经验有差异等教学难点,通过建立深厚的师生感情、提高学生学习化学的信心、加强化学用语的练习、强调易错、易混淆知识点等方式,达到切实提高学生化学学习能力的目的。     

高师化学实验考核方法的研究与实践

本文讨论了高师化学实验课的考核方法。考核由全程考核、技能考核、书面考试及设计实验组成。应用结果表明:此方法能真实的反映学生的知识、能力、素质,是较为科学、便于实施的教学效果评价体系。     

化学危险品事故处置的程序与技术要点

根据化学危险品事故的特点及消防部队的装备配备情况 ,提出了一整套化学危险品事故抢险救援的程序 ,并介绍了处置过程中的关键技术。     

Controlling Novichoks after Salisbury: revising the Chemical Weapons Convention schedules

ABSTRACT

Novichok agents are a class of nerve agents developed by the Soviet Union during the Cold War. In light of the use of a Novichok agent in Salisbury in March 2018, two sets of proposals to amend Schedule 1 of the 1993 Chemical Weapons Convention (CWC) have been put forth, one jointly by the United States, Canada, and the Netherlands, and the other by Russia. Both sets of proposals will be discussed and voted upon at the next Conference of States Parties of the Organisation for the Prohibition of Chemical Weapons (OPCW) in November 2019. If either set of proposals is approved, it will be the first time that the list of chemicals subject to verification under the CWC will have been modified. This viewpoint will discuss these proposals, and argue that, if adopted, the joint proposal and the portions of the Russian proposal upon which consensus can be reached would significantly strengthen the CWC by considerably expanding the coverage of its Schedule 1 and bringing Novichok agents firmly within the CWC’s verification system. We also argue that, since the OPCW Technical Secretariat did not deem the fifth group of chemicals proposed by Russia to meet the criteria for inclusion in Schedule 1, Russia should withdraw this part of its proposal from consideration. The proposals have also served an important purpose in clarifying the identity of the chemical agent used in the Salisbury incident, squarely placing it within one of the two families of Novichok agents described by the Russian chemical-weapons scientist and whistleblower Vil Mirzayanov. If either proposal is approved in November, it will be important to conduct a thorough assessment of key precursors for the synthesis of Novichok agents and assess the need to amend CWC schedules and national and multinational export-control lists accordingly.     

Chemical-weapon use in Syria: atrocities,attribution, and accountability

ABSTRACT

International efforts to hold the government of President Bashar al-Assad accountable for the use of chemical weapons in the Syrian Civil War have entered a new phase. For the first time, the Organisation for the Prohibition of Chemical Weapons (OPCW), the international organization responsible for implementing the 1993 Chemical Weapons Convention, has been empowered to identify the perpetrators of chemical attacks in Syria. The Investigation and Identification Team (IIT), which was formed to conduct the OPCW’s new attribution mission, has announced its intention to investigate and identify the perpetrators of nine chemical attacks in Syria, including the April 7, 2018, attack in Douma. This article reviews recent efforts to attribute chemical attacks in Syria, describes what we know about the nine incidents to be investigated, summarizes what is known about the Syrian government officials, military commanders, and chemical-warfare scientists suspected of being responsible for these attacks, discusses what to expect during the next phase of the attribution process, and offers insights into how the international community can move beyond attribution to accountability. Accountability is necessary to provide justice for victims and to prevent future incidents by demonstrating that perpetrators of chemical attacks will be identified and punished.