摘要：Rechargeable lithium-sulfur batteries have been regarded as the promising next generation energy storage system due to their overwhelming advantages in energy ***,their practical implementations are hindered by severe capacity fading and low sulfur utilization,which are caused by polysulfide shuttling and the insulating nature of ***,sulfur-embedded porous multichannel carbon nanofibers coated with mno2 nanosheets(CNFs@S/mno2)are rationally designed and fabricated as cathode for lithiumsulfur *** high conductivity of porous multichannel carbon nanofibers facilitates the kinetics of electron and ion transport in the electrodes,and the porous structure encapsulates and sequesters sulfur in its interior void space to physically retard the dissolution of high-order ***,the mno2 shell exhibits a combination of physical and chemical adsorption for high-order polysulfides,which could sequester polysulfides leaked from the carbon matrix after long-time charge/discharge cycles,resulting in enhanced cyclic *** a result,the electrode delivers a specific capacity of 1286 m A h g^-1 at 0.1 C and 728 m A h g^-1 at 3 *** the capacity could remain 774 m A h g^-1 after 600 cycles at 1 C.

摘要：Despite of considerable efforts on the mno2-based catalytic combustion,the different structural and component requirements of mno2 for gas-phase selective oxidation and complete oxidation largely remain *** comparing four types of mno2 with different crystal structures(α,β,γandδ),γ-mno2 was found to be the most efficient catalyst for both aerobic selective oxidation of ethanol and CO *** structural effect ofγ-mno2 was further investigated by doping metal ions into the framework and by comparing the catalytic performance in the gas-phase aerobic oxidation of CO and *** ten M-γ-mno2 catalysts,Zn-γ-mno2 showed the lowest temperature(160°C)for achieving 90%CO *** CO oxidation activity of the M-γ-mno2 catalysts was found to be more relevant to the surface acidity-basicity than the *** contrast,surface reducibility has been demonstrated to be more crucial in the gas-phase ethanol ***-γ-mno2 with higher reducibility and more oxygen vacancies of Mn^2+/Mn^3+species exhibited higher catalytic activity in the selective ethanol ***-γ-mno2 achieved the highest acetaldehyde yield(75%)and space-time-yield(5.4 g gcat^-1 h^-1)at 200°C,which are even comparable to the results obtained by the state-of-the-art silver and gold-containing *** results and kinetic studies further suggest that the CO oxidation follows the lattice oxygen-based Mars-van Krevelen mechanism,whereas both surface lattice oxygen and adsorbed oxygen species involve in the ethanol activation.

摘要：双氧水分解制取氧气是中学化学教学中的一个重要实验，在不同的阶段有其不同的教育功能。最新修订的义务教育教科书将该实验改为探究mno2催化作用的探究活动。在化学反应原理模块中该实验用于探究催化剂对化学反应速率的影响。[2]在不同版本的教材中实验装置的设计各有特点，有的趋向于实验设计的简约化，有的注重实验设计的趣味性，也有的教材没有给出具体的实验装置。

摘要：The pathogens of most infectious diseases invade the host through mucosal sites,and immunization with mucosal vaccines is the best means of combating these infectious *** delivery and nasal delivery are the most common methods of mucosal ***,the delivery process is inefficient,and mucosal vaccination is ineffective because the vaccine formulation is easily and rapidly removed and has difficulty in crossing the mucosal *** this paper,we investigated whether the mucosal immune response could be enhanced by ultrasound facilitation of nasal mucosal delivery of vaccine *** this purpose,we used manganese dioxide(mno2)as the vaccine carrier/adjuvant,coated with chitosan oligosaccharide(COS)to enhance mucosal adsorption,and further physically adsorbed model antigen ovalbumin(OVA)to construct a nanoparticulate vaccine formulation mno2@COS@*** treatment was found to promote antigen delivery and recruitment of dendritic cells(DCs)and macrophages as well as T-cell infiltration in nasal mucosal tissues through nasal mucosal immunization *** ultrasound assistance,mno2@COS@OVA particles promoted the maturation of DCs in vitro and in vivo and promoted the production of effector memory T cells in vivo and cytokine secretion by splenocytes in *** particular,ultrasound treatment significantly increased the levels of secretory IgA antibodies in the nasal mucosa and genital tract mucosa of experimental *** addition,the experimental data showed that the mno2@COS@OVA particles had good biocompatibility and caused no significant damage to the nasal mucosal and vital organ *** data suggest that ultrasound treatment can promote the induction of efficient immune responses to mucosal vaccines and provide new ideas for the opening and clinical translation of mucosal vaccines.

摘要：近年来,生物质碳材料由于来源广泛、化学稳定性好、比表面积高、环境友好等优点已成为备受关注的电极材料,在能源转化和能量储存领域显示出巨大的应用潜力。但是生物质碳材料的理论比电容有限,且分散性差、机械脆性等缺陷也阻碍了其性能的完全实现,进一步影响了实际比电容。当其用于超级电容器时,受低能的静电作用力驱使,生物质碳材料基超级电容器的能量密度往往较低。将赝电容活性材料mno2沉积在生物质碳材料基质上,利用生物质碳材料与mno2的协同效应,可获得电导率、循环稳定性和电化学性能优异的复合材料。在介绍mno2结构和性质的基础上,对生物质碳材料/mno2复合电极材料的制备方法展开综合述评。此外,还总结了生物质碳材料/mno2复合物作为电极材料在超级电容器上的研究进展,并指出了其在应用过程中存在的问题。最后,就生物质碳材料/mno2复合物在高性能和柔性超级电容器未来应用方面进行分析,认为对生物质碳材料基底的改性、mno2纳米结构的调控和超级电容器结构的设计优化将是今后的重点研究方向。

摘要：由氧化还原法成功合成出了mno2/石墨烯(mno2/Gh)复合材料。利用SEM、XRD、TGA等技术表征了该纳米粒子的表面形貌、晶型和热稳定性。考察了mno2/Gh非均相电-Fenton体系对亚甲基蓝的降解效果。结果表明,在非均相体系中,δ-mno2/Gh的催化效果优于γ-mno2/Gh,在最优条件下,mno2/Gh-0.8非均相电-Fenton体系对亚甲基蓝的去除率可达100%,COD的去除率可达89.61%,与传统的电催化反应相比分别提高了约40.99%和60.68%。该反应主要发生在催化剂的表面,并且循环使用5次后催化效果仅下降了6.37%,具有较高的稳定性。

摘要：研究比较了Sb(Ⅲ)在δ态、α态和β态mno2表面的吸附行为,深入探讨了pH、mno2浓度、Sb(Ⅲ)初始浓度和离子强度对mno2吸附Sb(Ⅲ)的影响。结果表明,δ态、α态mno2对Sb(Ⅲ)的吸附等温线较好地符合Langmuir吸附等温式,β态mno2对Sb(Ⅲ)的吸附等温线较好地符合Freundlich吸附等温式;Sb(Ⅲ)在δ态、α态mno2表面的吸附速率较快,吸附过程符合一级反应动力学曲线,而在β态mno2表面的吸附速率较慢,吸附过程符合二级反应动力学曲线;pH对3种形态mno2的吸附活性影响很大,适当的mno2浓度有利于对Sb(Ⅲ)的吸附,离子强度对mno2的吸附活性影响不大。

摘要：为改善吸波材料对入射电磁波的阻抗匹配性能，采用不同吸收剂设计并制备了具有阻抗渐变结构的双层吸波材料，匹配层中引入二氧化锰或炭黑为填料，吸收层采用炭黑为填料，通过改变吸收剂含量和类型首次设计了9种双层匹配方案．实验结果表明，当匹配层吸收剂为10％的二氧化锰，吸收层吸收剂为30％的炭黑时，双层复合材料的电磁波吸收性能为最佳，特别是当匹配层的厚度为2mm时，其吸收性能在8-18GHz测试频段内的16．8GHz达到-27．48dB，优于-10dB的频带达8．6GHz，具有一定的工程应用价值．

摘要：以电解法制备的mno_2粉体为原料,研制了可用于混凝土环境中的固体mno_2长效参比电极.在饱和Ca(OH)_2溶液中近一年的监测数据显示,该参比电极具有较好的电位稳定性和抗干扰能力,其电极电位的漂移<10 ***和极化曲线测试结果表明,相对于化学法合成的mno_2电极,电解法制备的mno_2参比电极具有较小的内阻、较大的交换电流密度、较强的抗极化能力和较低的温度系数(~0.68 mV·oC^(-1)).在硬化砂浆中的长期测试表明,该电极在混凝土中的电极电位基本不受Cl^-、有机胺阻锈剂的影响,能作为埋入式参比电极,满足混凝土中Cl^-浓度、pH值和钢筋半电池电位的长期监测的要求,这对于海洋混凝土工程的耐久性监测具有较高的应用价值.

摘要：酰胺类除草剂是目前使用最多、最广泛的一类芽前除草剂,而其乙基磺酸转化产物(ESA)具有更大的环境持久性,因此ESA的去除具有显著的环境意义。研究了化学合成的mno_2对ESA的吸附-氧化行为,并且考察了mno_2初始浓度、体系初始pH值以及共存金属离子等因素对ESA去除效率的影响。结果表明:ESA能被mno_2有效地去除,同时ESA的去除效率随着mno_2初始浓度的增大而增大;且酸性条件更有利于mno_2对ESA的去除,而溶液中的共存金属离子会对去除产生抑制作用,且Fe3+抑制效应最大。