摘要：背景:磁性微粒作为一种磁性载体在固定化酶、免疫检测、靶向载药治疗及细胞分离等生物医学领域得到了广泛的应用。目的:制备分散稳定性好,相对磁性强的纳米级fe3o4微粒。方法:以氯化亚铁、氯化铁、氢氧化钠为主要原料,采用化学共沉淀法合成fe3o4磁性粒子。结果与结论:用正交设计法优化了fe3o4微粒的合成工艺条件,得到制备fe3o4粒子的最佳实验条件为fe2+/fe3+的物质的量之比为2∶1、共沉淀时的pH值为11、熟化温度为90℃、表面活性剂聚乙二醇的用量为40mL,此时制得的fe3o4粒子粒径最小,为78nm,fe3o4溶液的分散稳定性最好,相对磁性最强。从fe3o4的扫描电镜图可以看出,fe3o4微粒晶体颗粒为纳米级。

摘要：重金属离子污染严重影响着人类的生活环境和身体健康,因此准确检测重金属离子的含量已成为当今环境保护及检测领域亟待解决的问题。针对重金属离子痕量分析困难及传统磁性固相萃取技术存在的萃取容量小、对重金属离子选择萃取性差等缺点,以溶剂热法制备的fe_(3)o_(4)磁性纳米颗粒为磁核,并配合多巴胺改性及具有丰富端基的聚酰胺-胺树状大分子(PAMAM)接枝设计,制备出具有核壳结构的磁性固相萃取剂fe_(3)o_(4)/PDA/PAMAM-NH2,用于重金属离子Pb^(2+)和Cd^(2+)的检测。利用包括电感耦合等离子体发射光谱仪(ICP-oES)在内的多种技术手段分别对材料的微观结构、磁性能以及对重金属离子的吸附性能进行表征,研究结果表明:fe_(3)o_(4)/PAMAM-NH2对水体中Pb^(2+)和Cd^(2+)离子均具有较高的富集因子(100),对Pb^(2+)和Cd^(2+)检出限分别达到0.68ng3;mL^(-1)和0.13ng3;mL^(-1),显著降低了ICP-oES的仪器检出限1~2个数量级。

摘要：采用溶剂热法制备表面修饰柠檬酸的磁性fe_3o_4纳米粒子和磁性fe_3o_4纳米粒子,并对其粒径大小、晶体结构和磁性能进行表征,并考察其用于DNA提取分离的效果。结果表明,两产物均为立方晶系的fe_3o_4纳米颗粒。磁性fe_3o_4纳米粒子和表面修饰柠檬酸的磁性fe_3o_4纳米粒子的平均粒径为411.1nm和586.3nm。当全血体积200μL、磁性纳米粒子用量2.0mg时,提取的DNA浓度最高分别为270.6ng/μL(fe_3o_4)和466.4ng/μL(fe_3o_4@柠檬酸)。

摘要：fe3o4 is a promising high-capacity anode material for lithium ion batteries, but challenges including short cycle life and low rate capability hinder its widespread implementation. In this work, a well-defined tubular structure constructed by carbon-coated fe3o4 has been successfully fabricated with hierarchically porous structure, high surface area, and suitable thickness of carbon layer. Such purposely designed hybrid nanostructures have an enhanced electronic/ionic conductivity, stable electrode/electrolyte interface, and physical buffering effect arising from the nanoscale combination of carbon with fe3o4, as well as the hollow, aligned and hierarchically porous architectures. When used as an anode material for a lithium-ion half cell, the carbon-coated hierarchical fe3o4 nanotubes showed excellent cycling performance with a specific capacity of 1,020 mAh.g^-1 at 200 mA.g^-1 after 150 cycles, a capacity retention of ca. 103%. Even at a higher current density of 1,000 mA3;g^-1, a capacity of 840 mAh3;g^-1 is retained after 300 cycles with no capacity loss. In particular, a superior rate capability can be obtained with a stable capacity of 355 mAh.g^-1 at 8,000 mA3;g^-1. The encouraging results indicate that hierarchically tubular hybrid nanostructures can have important implications for the development of high-rate electrodes for future rechargeable lithium ion batteries （LIBs）.

摘要：叙述了磁流变流体的磁变效应 (MagnetorhelogicalEffect,简称MRE) ,以及fe3o4磁流变流体的粘度特性实验。以实验为例 ,对磁流变流体的粘度特性进行研究。介绍有关实验的细节及结果。

摘要：利用正硅酸乙酯(TEoS)、3-氨基丙基三乙氧基硅烷(APTES)对fe_3o_4磁性纳米粒子进行改性,合成fe_3o_4@Sio_2-NH_2,再以戊二醛为交联剂接枝壳聚糖制备fe_3o_4@Sio_2-CS。利用XRD、红外光谱(FⅡR)、透射电镜(TEM)对fe_3o_4@Sio_2-CS进行表征。考察温度、时间、Pb(Ⅱ)初始浓度和pH值等不同因素的影响下,fe_3o_4@Sio_2-CS对Pb(Ⅱ)的吸附机理及其再生性能。研究表明,fe_3o_4@Sio_2-CS对Pb(Ⅱ)的吸附动力学过程符合Lagergren准二级动力学方程,属于化学吸附;同时,此吸附过程符合Langmuir等温吸附模型的条件,属单分子层吸附。此反应过程为吸热反应,升温有利于吸附持续进行。

摘要：介绍了一种氯化苯生产废水制备fe3o4的方法,通过实验得出最佳反应条件,并在此基础上进行工业化设计及应用,解决了氯化苯生产废水处理难度大的问题,废物得到资源化利用,大大降低了环境污染,为氯化苯生产废水处理开辟了一种新的途径。

摘要：Li-ion hybrid supercapacitors （Li-HECs） facilitate effective combination of the advantages of supercapacitors and Li-ion batteries （LIBs）. However, challenges remain in designing and preparing suitable anode and cathode materials, which often require tedious and expensive procedures. Herein, we demonstrated that hollow N-doped carbon capsules （HNC） with and without a fe304 nanoparticle core can respectively function as the anode and the cathode in very-high-performance Li-HECs. The fe3oa@NC anode exhibited a high reversible specific capacity exceeding 1530 mA h g^-1 at 100 mA g^-1 and excellent rate capability （45% capacity retention from 0.1 to 5 A g^-1） and cycle stability （〉97% retention after 100 cycles）. Moreover, high rate performance was achieved in a full-cell using the HNC cathode. By combining the respective structural advantages of the components, the hybrid device with fe3oa@NC//HN C exhibited a remark- able energy density of 185 W h kg^-1 at a power density of 39 W kg^-1. The hybrid device furnished a battery-inaccessible power density of 28 kW kg^-1 with rapid charging/discharging within 9 s at an energy density of 95 W h kg^-1.

摘要：Lithium-ion capacitors(LICs)could combine the virtues of high power capability of conventional supercapacitors and high energy density of lithium-ion ***,the lack of high-performance electrode materials and the kinetic imbalance between the positive and negative electrodes are the major *** this study,fe3o4 nanoparticles encapsulated in nitrogen-rich carbon(fe3o4@NC)were prepared through a self-assembly of the colloidal fe ooH with polyaniline(PANI)followed by *** to the well-designed nanostructure,conductive nitrogen-rich carbon shells,abundant micropores and high specific surface area,fe3o4@NC-700 delivers a high capacity,high rate capability and long cycling *** analyses of the redox reactions reveal the pseudocapacitive mechanism and the feasibility as negative material in LIC devices.A novel LIC was constructed with fe3o4@NC-700 as the negative electrode and expanded graphene(EGN)as the positive *** wellmatched two electrodes effectively alleviate the kinetic imbalance between the positive and negative *** a result,fe3o4@NC-700//EGN LIC exhibits a wide operating voltage window,and thus achieves an ultrahigh energy density of 137.5 W h kg^-*** results provide fundamental insights into the design of pseudocapacitive electrode and show future research directions towards the next generation energy storage devices.

摘要：一、问题的提出背景铁与水蒸气反应的实验是高中化学必修1(人教版)的科学探究实验(50页),做实验时有一个产物检验环节,原有实验教学设计关注的重点是H2的检验,很少关注另一种产物fe3o4。在学习铁的性质之前学生已经学习了钠和镁的性质,了解了活泼金属与水反应的产物是氢氧化物.