Distribution dependent stochastic differential equations

Due to their intrinsic link with nonlinear Fokker-Planck equations and many other applications, distribution dependent stochastic differential equations (DDSDEs) have been intensively investigated. In this paper, we summarize some recent progresses in the study of DDSDEs, which include the correspondence of weak solutions and nonlinear Fokker-Planck equations, the well-posedness, regularity estimates, exponential ergodicity, long time large deviations, and comparison theorems.     

矿物药炉甘石煅制前后锌、铅元素的赋存形态及分布特征研究

采用X射线衍射(XRD)技术和电子探针微区分析(EPMA)技术针对中药炉甘石煅制前后锌、铅元素的赋存形态及分布特征进行了研究，探明了煅制对炉甘石中锌、铅元素赋存状态及分布的改变，为后续水飞减除铅元素的机理研究提供了理论依据。测试结果显示：21批次炉甘石(生品)中的锌元素以主矿物水锌矿[Zn₅(CO₃)₂(OH)₆]和杂质矿物异极矿[Zn₄(OH)₂(H₂O)(Si₂O₇)]为主要赋存形态，偶见菱锌矿(ZnCO₃)；炉甘石(生品)的背散射电子图谱及元素分布数据显示：Zn和Pb元素同时分布的区域为水锌矿，Zn和Si元素同时分布的区域为异极矿，Ca和Mg元素同时分布的区域为白云石，Ca元素单独分布区域为方解石。在炉甘石(生品)中，Pb主要分布于水锌矿中且分布相对均匀，Pb元素的分布与水锌矿中的Zn元素密切相关。大量水锌矿的微区点位的电子探针定量分析结果显示：各不同点位中的ZnO/PbO含量的比值趋于定值，Pb在水锌矿中呈统计式均匀分布，说明Pb在水锌矿中主要以类质同象混入物的形式存在。但是炉甘石(生品)中的异极矿、方解石及白云石等杂质矿物中铅元素含量极低甚至检测不到。炉甘石煅烧后水锌矿晶格中的Zn和Pb分别生成了ZnO和PbO。Zn元素在炉甘石煅制品中主要以氧化锌(ZnO)形式存在，少部分以杂质矿物硅酸锌(Zn₂SiO₄)形式存在，呈较连续状态分布。Pb元素在炉甘石煅制品中主要以氧化铅(PbO)的形式存在，呈星点状分布，与Zn元素的分布未呈现相关性，说明Pb在炉甘石煅制品中是以独立矿物形式存在的。煅烧破坏了水锌矿的晶格结构，在改变锌、铅化合物形态的同时，更改变了锌、铅的分布特征，打破了炉甘石中锌、铅的共生状态，使水飞减除铅元素成为可能。     

影视节目中酸碱指示剂的应用与评价

将影视节目中酸碱指示剂的应用引入到化学教学中，让学生在娱乐中学习化学知识，创造一个有趣的学习情境，提高学生的学习兴趣。     

"地小氢"和"月小氢"

Hydrogen is the most abundant chemical element in the Universe and is tightly related to human life. This article personifies hydrogen, bringing a close interaction between the hydrogen on the moon and the hydrogen on the Earth. Through lively and interesting dialogues, the history of hydrogen discovery and the properties are introduced, and the application of hydrogen in different aspects of the future is prospected.     

环氧乙烷亲核开环的区域选择性规则在有机化学教学中的应用

环氧乙烷亲核开环的区域选择性规则是有机化学中典型脂肪三元杂环亲核性开环的选择性规则,具有普遍性。本文以非对称环氧乙烷的亲核性开环为核心,从开环反应过渡态稳定性的角度讨论了决定环氧乙烷亲核开环区域选择性的原因。介绍了该区域选择性规则在经过三元杂环正离子中间体的非对称烯烃亲电加成反应区域选择性教学中的应用。加强学生对不同反应的机理和选择性的联系,起到教学中融会贯通的作用,可以提高教学效率和效果。     

Decorating Single-Atomic Mn Sites with FeMn Clusters to Boost Oxygen Reduction Reaction

The regulation of electron distribution of single-atomic metal sites by atomic clusters is an effective strategy to boost their intrinsic activity of oxygen reduction reaction (ORR). Herein we report the construction of single-atomic Mn sites decorated with atomic clusters by an innovative combination of post-adsorption and secondary pyrolysis. The X-ray absorption spectroscopy confirms the formation of Mn sites via Mn-N₄ coordination bonding to FeMn atomic clusters (FeMn_ac/Mn-N₄C), which has been demonstrated theoretically to be conducive to the adsorption of molecular O₂ and the break of O−O bond during the ORR process. Benefiting from the structural features above, the FeMn_ac/Mn-N₄C catalyst exhibits excellent ORR activity with half-wave potential of 0.79 V in 0.5 M H₂SO₄ and 0.90 V in 0.1 M KOH as well as preeminent Zn-air battery performance. Such synthetic strategy may open up a route to construct highly active catalysts with tunable atomic structures for diverse applications.     

Tuning Local Charge Distribution in Multicomponent Covalent Organic Frameworks for Dramatically Enhanced Photocatalytic Uranium Extraction

Optimizing the electronic structure of covalent organic framework (COF) photocatalysts is essential for maximizing photocatalytic activity. Herein, we report an isoreticular family of multivariate COFs containing chromenoquinoline rings in the COF structure and electron-donating or withdrawing groups in the pores. Intramolecular donor-acceptor (D-A) interactions in the COFs allowed tuning of local charge distributions and charge carrier separation under visible light irradiation, resulting in enhanced photocatalytic performance. By optimizing the optoelectronic properties of the COFs, a photocatalytic uranium extraction efficiency of 8.02 mg/g/day was achieved using a nitro-functionalized multicomponent COF in natural seawater, exceeding the performance of all COFs reported to date. Results demonstrate an effective design strategy towards high-activity COF photocatalysts with intramolecular D-A structures not easily accessible using traditional synthetic approaches.     

石墨烯非共价功能化及其应用

石墨烯的湿法化学修饰,主要包括共价及非共价两种,是目前广泛采用的宏量功能化策略,亦是有效避免其团聚而充分发挥其优异纳米性能的重要修饰方法。非共价功能化因可同时保持原有及引入物质的物化性质,并可充分发挥协同作用,近年来已受到比共价修饰更多的研究关注,并已在生物科学与技术、可持续能源储存及转化、医疗和复合材料等诸多领域得到了广泛应用。本文综述了以应用为导向的石墨烯非共价功能化的构建策略,期望文中涉及的湿法组装策略能为进一步构建性能提升的新材料提供参考。     

松香胺类衍生物在非表面活性剂方面的应用研究

综述了近年来国内外松香胺类衍生物在非表面活性剂方面的应用研究进展,主要包括催化特定氧化反应、手性反应及手性拆分、Maillard反应、抗菌活性、离子识别、施胶、废水处理、缓释、缓蚀、助焊剂等方面。     

Elution profiles of lanthanides with α‐hydroxyisobutyric acid by ion exchange chromatography using fine resin

Experiments were carried out using a strong acid cation exchange resin with a particle size of 75–150 μm, termed as “fine resin” in hydrogen ion form for the elution of individual lanthanides Sm, Eu, Gd, Tb, and Dy that are produced as fission products in the spent nuclear fuel and generated in the effluent during reprocessing of spent nuclear fuel. Batch experiments were carried out to study the effect of concentration of nitric acid on distribution coefficient. The distribution coefficient values for these individual lanthanides were determined in nitric acid medium in the concentration range of 0.01–4.0 N. Uptake of each individual lanthanide by resin was increased with increased nitric acid concentration from 0.01 to 0.5 N and remained similar from 0.5 to 1.0 N and decreased thereafter up to 4.0 N. Column experiments were also carried out using the same resin to study the parameters like pH of the eluent, flow rate, and resin bed height under isocratic elution conditions for eluting lanthanide elements using α‐hydroxyisobutyric acid as eluent. The results of this study have indicated the possibility for the elution of individual lanthanides.