膨润土对废水中Cu~（2＋）的吸附性能研究

研究了钙基膨润土和钠基膨润土对废水中铜离子的吸附特性。结果表明,钠基膨润土和钙基膨润土的吸附行为都依赖于溶液的pH值,初始离子浓度和吸附剂用量。在低pH值时主要是H＋与Cu2＋竞争吸附位。pH值在3到7时基本的吸附机制是离子交换的过程。在高pH值（〉8.3）时,在膨润土颗粒表面形成氢氧化铜的吸附或沉淀。随初始金属离子浓度的增加去除率降低,而吸附剂的单位吸附量迅速增加。Cu2＋浓度为40mg/L时,钠基膨润土和钙基膨润土的去除率分别达98.4%和81.2%。钠基膨润土和钙基膨润土的最大吸附容量分别为26mg/g和12mg/g。     

硅基固体胺吸附剂捕集空气中CO2的研究进展

人类活动导致的CO₂过量排放,是造成全球气候变暖的主要原因,因此亟需一种能够有效控制CO₂浓度增长的方法。直接空气捕获技术是目前唯一能够大规模实现碳排放负增长的技术。固体胺吸附剂,特别是硅载体固体胺吸附剂,因其具有高吸附能力、抗腐蚀、低能耗等优点,被广泛研究并用于环境空气中捕获CO₂。将硅基固体胺吸附剂按照负载方式进行分类,并归纳了不同硅基载体对吸附剂性能的影响;提出粉末状固体胺吸附剂在工业应用中遇到的难题,整理并分析了固体胺吸附剂当前的成型方法;指出了开发高吸附量、高稳定性的成型固体胺吸附剂是CO₂吸附剂工业化的未来趋势。     

邯郸膨润土吸附含镍废水的实验研究

研究了邯郸钙基膨润土及其钠化改性土对模拟废水中Ni2 的吸附行为,探索了膨润土用量、吸附时间、pH值、初始离子浓度和温度等因素对Ni2 吸附效果的影响。结果表明,实验所用两种膨润土对Ni2 的吸附在15min时基本达到吸附平衡,吸附率随溶液pH值的增大、吸附剂用量的增加、搅拌时间的延长而增大;钠化土的吸附效果明显优于钙基土,Ni2 的去除率可达96%以上;经钠化土处理后废水中的Ni2 浓度为0.825mg/L,低于国家排放标准1mg/L。     

膨润土对废水中Cu2+的吸附性能研究

研究了钙基膨润土和钠基膨润土对废水中铜离子的吸附特性.结果表明,钠基膨润土和钙基膨润土的吸附行为都依赖于溶液的pH值,初始离子浓度和吸附剂用量.在低pH值时主要是H+与Cu2+竞争吸附位.pH值在3到7时基本的吸附机制是离子交换的过程.在高pH值(＞8.3)时,在膨润土颗粒表面形成氢氧化铜的吸附或沉淀.随初始金属离子浓...     

邯郸膨润土吸附含镍废水的实验研究

研究了邯郸钙基膨润土及其钠化改性土对模拟废水中Ni^2＋的吸附行为，探索了膨润土用量、吸附时间、pH值、初始离子浓度和温度等因素对Ni^2＋吸附效果的影响。结果表明，实验所用两种膨润土对Ni^2＋的吸附在15min时基本达到吸附平衡，吸附率随溶液pH值的增大、吸附剂用量的增加、搅拌时间的延长而增大；钠化土的吸附效果明显优于钙基土，Ni^2＋的去除率可达96％以上；经钠化土处理后废水中的Ni^2＋浓度为0．825mg/L，低于国家排放标准1mg／L。     

石膏与硅灰对钢渣水泥基胶凝材料复合改性效应

以钢渣和水泥为主要原料,加入少量石膏(CaSO4·2H2O)与硅灰,制备钢渣水泥基胶凝材料。探讨了CaSO4·2H2O与硅灰掺量对钢渣水泥基胶凝材料强度的影响,并通过XRD、SEM表征,研究钢渣水泥基胶凝材料的水化性能。结果表明：复掺1% CaSO4·2H2O和4% 硅灰的钢渣水泥基胶凝材料3 d抗压强度较未掺CaSO4·2H2O与硅灰提高了59.0%,28 d抗压强度提高了32.4%;CaSO4·2H2O与硅灰的加入不会影响钢渣水泥基胶凝材料水化产物种类;相同龄期内,加入CaSO4·2H2O与硅灰的钢渣水泥基胶凝材料中水化硅酸钙(C-S-H)凝胶和钙矾石(AFt)含量增多,Ca(OH)2晶体含量、晶体尺寸有所减小。     

膨润土对底泥重金属的抑制效果及机制探讨

采用底泥原地稳定化处理技术中的帽封方法,考察膨润土对苏州河底泥中Cu2＋、Pb2＋和Zn2＋3种重金属离子释放的抑制效果。结果表明：钙基膨润土对Cu2＋、Pb2＋和Zn2＋的最大吸附容量分别为273.4 mg.g-1、473.6mg.g-1和263 mg.g-1;均具有较强的吸附性能;且在溶液pH值升高时,其对Cu2＋、Pb2＋和Zn2＋的吸附效果增强。在Zn-Pb混合体系下,钙基膨润土对Pb2＋吸附效果增强,Zn2＋的吸附效果不明显;而在Zn-Cu混合体系下,钙基膨润土对Cu2＋效果增强,对Zn2＋的吸附效果减弱。     

石墨烯基吸附剂的制备及其在农药残留萃取中的应用研究进展

食品中农药残留问题日趋严重,为了保证食品安全,需要对食品中的农药残留进行准确测定,而从食品基质中有效地萃取农药残留是影响测定的关键步骤。石墨烯基材料作为一种有潜力的新型吸附剂,具有大的比表面积、大的离域π电子体系、优异的机械性能和热稳定性等优点,已被应用于农药残留的萃取中。综述了近5年来石墨烯及其复合材料作为吸附剂在食品农药残留萃取中的应用,以及石墨烯基吸附剂的种类、制备方法和萃取方式,探讨了石墨烯基吸附剂对农药残留的萃取机制,并对将来的发展趋势进行了展望。     

电厂燃煤锅炉干法催化脱硫技术

技术名称:电厂燃煤锅炉干法催化脱硫技术原理:在炉内喷钙的基础上提高脱硫率另一方法是改进吸收剂的性能来提高吸收剂对SO2 的吸收率,以提高脱硫率。在喷钙脱硫过程中,引入催化技术,在钙基脱硫剂中加入少量的碱金属化合物来提高CaO的空隙率,使其变得膨松、有利于SOx扩散到CaO内部,提高固硫率。在钙基脱硫剂中加入微量重金属化合物,可起到催化及氧化作用,使SO2 转化为更容易被CaO吸收的SO3,以提高固硫率。工艺特点:不需增加大的附加设备(如吸收塔)和加大占地面积,对现有锅炉不用改造,具有工艺简单、一次性投资少、运行费用低、操作方便…     

天然高分子吸附剂吸附水中的 Cu2+和Ni2+

为了更有效地去除水中的Cu2+和Ni2+,采用壳聚糖、泥炭和海藻3种吸附剂对Cu2+和Ni2+进行吸附性能研究。考察了溶液pH、吸附时间、吸附剂的质量浓度和金属离子的质量浓度对Cu2+和Ni2+吸附率的影响。结果表明,采用壳聚糖作为吸附剂,pH为6,吸附剂的质量浓度为3 g/L,吸附时间120 min的条件下,对Cu2+的吸附效果最好,吸附率可达98%。采用泥炭为吸附剂在pH为6,吸附剂的质量浓度为1 g/L,吸附时间为120 min时,对Ni2+的吸附效果最好,吸附率达80%。     

Nonselective etching of GaN/AlGaN heterostructures by Cl<Subscript>2</Subscript>/Ar/BCl<Subscript>3</Subscript> inductively coupled plasmas

A systematic study of the nonselective and smooth etching of GaN/AlGaN heterostructures was performed using Cl₂/Ar/BCl₃ inductively coupled plasmas (ICP). Nonselective etching can be realized by adjusting the BCl₃ ratio in the Cl₂/Ar/BCl₃ mixture (20%–60%), increasing the ICP power and dc bias, and decreasing the chamber pressure. Surface morphology of the etched heterostructures strongly depends on the gas chemistry and the chamber pressure. Specifically, with the addition of 20% BCl₃ to Cl₂/Ar (4∶1) gas mixture, nonselective etching of GaN/Al_0.28Ga_0.72N heterostructures at high etch rate is maintained and the surface root-mean-square (rms) roughness is reduced from 10.622 to 0.495 nm, which is smoother than the as-grown sample. Auger electron spectroscopy (AES) analysis shows that the effective removal of residual oxygen from the surface of AlGaN during the etching process is crucial to the nonselective and smooth etching of GaN/AlGaN herterostructures at high etch rate.     

Combustion Synthesis of TiB2 Ceramics Powder from B2O3-TiO2-Mg System in Air Atmosphere

TiB2 ceramics powder was syuthesized from B2O3 - TiO2 - Mg system. The effects of TiB2 addition as diluent on the conbustion synthesis process were investigated. The results of thermodynanmic calculation and experiments stow that the increase of TiBz content ranging from 0 to 20wt% can reduce the adiabatic temperature Tad from 3100 Kto 2896 K and combustion temperature T,. from 2139 K to 1621 K respectively. The particle size and half width of the particle distributhm are also increased with the addition of TiB2 increasing from 0 to 20wt% . The combustion product is a mixture of TiB2 , MgO , and other intermediate phases. The leached produet contains mairdy TiBz, TiOz and TiN, and its oxygen content is 7.77wt% .     

Structure and electrochemical properties of LiMn<Subscript>2</Subscript>O<Subscript>4</Subscript>−<Emphasis Type="Italic">x</Emphasis>F<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>

LiMn₂O₄−_xF_x prepared by the sol-gel method has a perfect crystal formation. The crystal particle size of the material was medium and distributed uniformly. The substitution of F for O increased the specific capacity of the material at the cost of the cycleability. The explanation of this results is that the F decreases the valence of Mn, that is, more Mn³⁺ and less Mn⁴⁺ exist in the material. The increase of Mn³⁺ will improve the initial specific capacity and Mn³⁺ is the original reason for Jahn-Teller effect that caused the poor cycleability of the cathode material by the micro-distortion of the crystal structure. In addition, the expanded measurement of the crystal lattice is also the reason for the poor cycleability. Therefore, the results of F-substitution and cation-substitution are opposite. If the two methods are combined, they can compensate the inability each other and the satisfactory results may be obtained. XIA Jun-lei: Born in 1977 Funded by the National Natural Science Foundation of China (No. 59972026)     

Synthesis and performance of LiMnO<Subscript>2</Subscript> as cathodes for Li-ion batteries

Two structure types of LiMnO₂ were synthesized by sol-gel method and ion-exchange method respectively. The results indicate that orthorhombic phase LiMnO₂ is more stable than layered LiMnO₂, o-LiMnO₂ can be synthesized directly by sol-gel methods followed by heat-treated in argon, but layered LiMnO₂ was obtained only by indirect methods such as ion-exchange method. In this paper, we first synthesized layered NaMnO₂ by the sol-gel method, and then obtained layered LiMnO₂ by the ion-exchange method. The phase, constitution, chemical composition, and images of the products were tested by XRD, AAS (atomic absorption spectroscopy) and SEM. The electrochemical performances of the two structural types of LiMnO₂ are obviously different during the initial few cycles, but later they both have a good capacity-retaining ability. The capacity of layered structure LiMnO₂ is higher than that of o-LiMnO₂. ZHAO Shi-xi: Born in 1966 Funded by the National Natural Science Foundation of China (No.59972026)     

Self-Propagating High-Temperature Reduetive Synthesis of TiB2-Al2O3 Composite Powders

TiB2-Al2O3 composite powders were produced by self-propagating high-temperature synthesis（SHS） method with reductive process from B2O3-TiO2-AI system. X-ray diffraction（XRD） and scanning electron microscopy（SEM） analyses show the presence of TiB2 and Al2O3 only in the composite powders produced by SHS. The powders are uniform and free-agglomerate. Transmission electron microscopy （TEM） and high resolution electron microscopy （HREM） observation of microstructure of the composite powders indicate that the interfaces of the TiB2-Al2O3 bond well, without any interfacial reaction products. It is proposed that the good interfacial bonding of the composite powders can be resulted from the TiB2 particles crystallizing and growing on the Al2O3 particles surface with surface defects acting as nucleation centers.     

Synthesis and electrochemical properties of Cr-doped Li<Subscript>3</Subscript>V<Subscript>2</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript> cathode materials for lithium-ion batteries

Cr-doped Li₃V₂(PO₄)₃ cathode materials Li₃V_2−x Cr _x (PO₄)₃ were prepared by a carbothermal reduction(CTR) process. The properties of the Cr-doped Li₃V₂(PO₄)₃ were investigated by X-ray diffraction (XRD), scanning electron microscopic (SEM), and electrochemical measurements. Results show that the Cr-doped Li₃V₂(PO₄)₃ has the same monoclinic structure as the undoped Li₃V₂(PO₄)₃, and the particle size of Cr-doped Li₃V₂(PO₄)₃ is smaller than that of the undoped Li₃V₂(PO₄)₃ and the smallest particle size is only about 1 μm. The Cr-doped Li₃V₂(PO₄)₃ samples were investigated on the Li extraction/insertion performances through charge/discharge, cyclic voltammogram (CV), and electrochemical impedance spectra(EIS). The optimal doping content of Cr was that x=0.04 in the Li₃V_2−x Cr _x (PO₄)₃ samples to achieve high discharge capacity and good cyclic stability. The electrode reaction reversibility was enhanced, and the charge transfer resistance was decreased through the Cr-doping. The improved electrochemical performances of the Cr-doped Li₃V₂(PO₄)₃ cathode materials are attributed to the addition of Cr³⁺ ion by stabilizing the monoclinic structure. Funded by the Guangxi Natural Science Foundation(No. 0832259) and the National Basic Research Program of China (No. 2007CB613607)     

功能型离子液体制备及应用的试验研究

综述了离子液体的制备方法及辅助合成手段的研究进展,包括一步合成法、两步合成法、微波合成法、超声波合成法,并介绍了其在CO_2,SO_2,NO_x及重金属Hg等多种污染物联合脱除技术中的应用.     

N掺杂Co3O4纳米片的制备以及活化过一硫酸盐的性能研究

采用牺牲模板法合成N掺杂Co₃O₄纳米片（N-Co NS）,通过透射电子显微镜（TEM）、原子力显微镜（AFM）和光电子能谱（XPS）对制备材料的形貌结构、化学组成进行分析,并通过催化活化过一硫酸盐（PMS）降解水中双酚A （BPA）来探究催化剂的催化性能.实验结果表明与Co₃O₄纳米颗粒（Co NP）、Co₃O₄纳米片（Co NS）相比,N-Co NS表现出了较高的催化性能.在PMS浓度为2 mmol·L^-1、BPA初始质量浓度为50 mg·L^-1的反应条件下,N-Co NS在10 min内完全降解水中的BPA,表明N掺杂和二维纳米片结构有利于催化剂性能的提升.通过pH及离子影响实验证实N-Co NS在复杂水化学环境中仍具有较高的活性.此外结合自由基捕获实验和电子顺磁共振（EPR）测试证实反应体系中产生了高氧化活性的羟基自由基和硫酸根自由基.     

Dielectric Properties of B2O3 Doped MgTiO3-CaTiO3 System Ceramics

The dielectric ceramics with a main crystal phase of MGTiO3 and additional crystal phase of CaTiO3 were prepared by the conventional electronic ceramics technology .the strucures of MgTiO3 are ilmenitetype,and belong to hexagonal syngony.the ratio of MgTiO3 to Ca TiO3 doping on the dielectric properties of MGTiO3-CaTiO3(MCT)ceranics were inrestigated.the addition of B2O3 decreases the sintering temperatnre and results in rapid desification without obrious negative effect on the Q values of the system(Q=1/tan ).B2O3 exists as liquid phase in the sintering process,promoting the reactions as a singering agent.     

Electrochemical behaviors of Zn-Fe alloy and Zn-Fe-TiO2 composite electrodeposition

Electrochemical behaviors of Zn-Fe alloy and Zn-Fe-TiO₂ composite electrodeposition in alkaline zincate solutions were studied respectively by the methods of linear potential sweep and cyclic voltammetry. From the results it can be concluded that Zn shows under potential deposition, Zn-Fe alloy codeposition is anomalous codeposition and Zn-Fe alloy cathode polarization is increased with the introduction of additive. From the view point of electrochemistry, the reasons that the content of Fe in the Zn-Fe coating changes with the composition of the electrolyte and the process conditions altering and the relationship between the content of Fe and the appearance of the coating are interpreted. The cathode polarization of Zn-Fe alloy codeposition is enhanced obviously with addition of additive. In the course of composite electrodeposition, TiO₂ has less promotion to electrodeposition of zinc ions than to iron ions, while the electrodeposition of iron ions improves the content of TiO₂ in composite coating, which is in agreement with the results of process experiments.