Cd1-xMnxS稀磁半导体纳米线的制备和研究

采用多孔氧化铝模板,通过直流电化学沉积法成功制备出不同掺杂浓度的Cd1-xMnxS纳米线,用XRD、SEM、HRTEM对纳米线的成分、形貌、结构进行了系统分析,并用SQUID对样品进行了磁性测量,结果表明,制得的Cd1-xMnxS纳米线呈单晶CdS纤锌矿结构,而且沿002方向有择优取向性,没有发现其它含Mn的化合物生成。从ZFC/FC曲线看出样品的居里温度接近于室温,且在低温处存在奇异现象。45K和300K下测量的的M-H曲线显示磁滞现象,测得的矫顽力分别是300Oe和100Oe,说明样品具有铁磁性。样品的紫外-可见光反射谱显示Cd1-xMnxS纳米线的吸收边并不随掺杂浓度x单调变化,而是随着掺杂量的增大能隙先减小后增大。掺杂度在1%处能隙有最小值。     

提高显影选择性增加影像密度

通过在显影液中综合应用有机和无机添加剂,影响显影剂的活性和含潜影卤化银微晶的性质,可使医用Ｘ射线胶片和黑白胶卷已曝光和未曝光卤化银之间的催化还原速度差别增大若干倍。研究这一效应的本质表明,影像密度的提高是由于在传统显影液中不显影的小尺寸潜影中心的卤化银微晶也加入到照相显影过程之中的结果,它导致感光涂层的曝光区银量增加。根据研究结果,在医疗机构进行了应用试验,用于医用Ｘ射线胶片的加上,由于影像密度的增加,可显著降低Ｘ射线的照射剂量。     

SmCo纳米线阵的制备及其微结构

采用二次阳极氧化法,制备出高度有序的阳极氧化铝模板(AAO模板).并以AAO模板为电极,分别用交流和直流的方法从水溶液中沉积出SmCo纳米线阵列.用原子力显微镜、场发射扫描电镜对其形貌、成分进行表征,结果表明,SmCo纳米线的线壁光滑、线径一致,约为80nm和100nm;线阵中稀土Sin的含量达16.25%(质量分数).X射线衍射分析表明该SmCo纳米线为非晶结构.     

高速显影的化学控制

影片加工是包括艺术、科学和工程技术等多学科的综合技术。本文评述了当今电影洗印技术，对电影洗印技术的各个方面和未来的发展提出了独到的见解。     

水溶液体系中电沉积Sm-Co纳米线工艺的研究

以自制的AAO模板,采用交流电沉积法在添加甘氨酸的水溶液中制备了Sm-Co纳米线.利用场发射扫描电镜(FE-SEM)、能谱分析仪(EDS)和X射线衍射分析(XRD)对AA0模板和纳米线进行了表征和分析;研究了甘氧酸浓度、主盐浓度及浓度比等对纳米线中Sm含量的影响;电化学分析表明络合剂能有效正移Sm-Co共沉积的还原峰,有利于提高Sm3+的沉积效率.     

几种常用显影抑制剂性能的研究

通过实验测定了三种常用显影抑制剂──溴化钾、三氮茚、６－硝基苯并咪唑的含量与灰雾密度、反差系数、感光度的关系，分析了它们的作用原理，获得了抑制剂性能的一些结论。     

退火温度对电沉积FeNi纳米线阵列结构及磁性能的关联性研究

采用E-T和脉冲电化学沉积法,利用氧化铝（AAO）模板制备出直径200 nm,长度约为13.1μm的非晶态FeNi纳米线阵列。FeNi纳米线阵列的形貌、成分、微观结构以及磁学性能分别通过场发射扫描电子显微镜（SEM）、场发射透射电子显微镜（TEM）、X射线衍射仪（XRD）以及振动样品磁强计（VSM）进行表征。研究结果表明,FeNi纳米线排列致密,外壁平整光滑,粗细均匀,元素分布均匀。制备的纳米线表现出纯非晶结构,退火后从非晶基体中析出γ（Fe, Ni）相,且晶粒的生长具有明显的（111）择优取向。VSM结果表明在非晶纳米线中具有较强的磁各向异性,其易磁化轴为平行于长轴方向。随着退火温度的升高,矫顽力H_c和剩磁比B_r/B_s整体呈下降趋势,主要归因于纳米线内应力的释放及纳米晶间的磁交换耦合作用。     

显影抑制化合物的研究及应用

研究了几种显影抑制化合物的显影抑制性、扩散性及定时性，并探讨了其对彩色感光材料性能及影像质量的影响。     

图案化金属铜纳米线阵列的制备与表征

采用紫外线光刻技术与电化学沉积相结合的方法,成功制备了不同图案的铜纳米线阵列:一种是圆形图案;另一种是QDU图案.首先利用紫外线光刻技术在多孔阳极氧化铝模板(AAO)生成预设图案,以此作为"二次模板";再利用电化学方法将铜纳米线沉积到"二次模板"的开孔中.扫描电镜(SEM)测试结果表明,大面积、高规整的铜纳米线图案阵列各自独立地立在基底上, 同时,用电子能谱(EDS)分析了铜纳米线的化学成分.透射电镜(TEM)也探测到了铜纳米线的微结构.     

直流电沉积CdS纳米线的研究

在磷酸溶液中，采用二次铝阳极氧化法得到了多孔铝阳极氧化膜(AAO)．以AAO为模板，选用直流电沉积方法在孔内组装CdS半导体纳米线，溶去模板后，获得粗细均一、直径约为100nm、长度约为1．5μm的纳米线，与AAO模板的孔径一致．该方法在制备过程中，无需对AAO模板进行去除阻挡层、喷金或预镀金属等处理过程，而是直接在纳米孔内电沉积CdS，形成CdS半导体纳米线阵列．该方法工艺简单，操作方便，容易获得半导体CdS的一维纳米材料．TEM和XRD测试结果表明，CdS纳米线为六方晶型结构．对CdS纳米线的生长机理还进行了初步的分析和探讨．     

AgBr T颗粒的成核与成长

晶核的絮凝和聚结导致了ＡｇＢｒ孪晶的产生，从而进一步形成Ｔ颗粒，本文综述了最近在这方面的研究结果，并讨论了Ｔ颗粒形成的机理；同时还就物理成熟条件对Ｔ颗粒尺寸和形状的影响进行了讨论。     

Quantificational Etching of AAO Template

Ni nanowires were prepared by electrodeposition in porous anodized aluminum oxide （AAO） template from a composite electrolyte solution. Well-ordered Ni nanowire arrays with controllable length were then made by the partial removal of AAO using a mixture of phosphoric acid and chromic acid （6 wt pct H3PO4：1.8 wt pct H3CrO4）. The images of Ni nanowire arrays were studied by scanning electron microscopy （SEM） to determine the relationship between etching time and the length of Ni nanowire arrays. The results indicate that the length of nanowires exposed from the template can be accurately controlled by controlling etching time.     

Quantiflcational Etching of AAO Template

Ni nanowires were prepared by electrodeposition in porous anodized aluminum oxide (AAO) template from a composite electrolyte solution. Well-ordered Ni nanowire arrays with controllable length were then made by the partial removal of AAO using a mixture of phosphoric acid and chromic acid (6 wt pct H3PO4: 1.8 wt pct H3CrO4). The images of Ni nanowire arrays were studied by scanning electron microscopy (SEM) to determine the relationship between etching time and the length of Ni nanowire arrays. The results indicate that the length of nanowires exposed from the template can be accurately controlled by controlling etching time.     

用AAO模板法制备硅纳米管

先用二步阳极氧化法制备纳米孔平均孔径约为100 nm的Al/Al_2O_3(AAO)模板,再以AAO为模板用溶胶-凝胶法合成管径约为60-80 nm的硅纳米管,并用扫描电镜和透射电镜观察了硅纳米管的形貌。结果表明,AAO模板的孔径分别随着二步阳极氧化法中电解温度、氧化电压、硫酸和草酸混酸浓度的增大而增大,硅纳米管的形成与硅烷溶胶的嵌入方法、凝胶形成时间和温度有较大的关系。     

多孔氧化铝模板制备有序纳米阵列及复合体系的特殊性能

由多孔阳极氧化铝模板制备有序纳米阵列因量子化具有各种特殊性能,准一维的电子输运环境使其磁阻随磁场变化有极值出现,表面缺陷的增加使其光致发光增强,纳米线阵列对各个方向透过光的损耗不通而具有偏振性,磁性能方面具有强烈的各向异性等.简要介绍了纳米阵列复合有序多孔氧化铝的性质,并展望了多孔氧化铝制备纳米晶的应用前景.     

The Ag-based SPR effect drives effective degradation of organic pollutants by BiOCOOH/AgBr composites

The easy recombination of electron-hole pairs produced by monomeric photocatalysts under light exposure severely limits their application in wastewater treatment. Based on this, BiOCOOH/Ag/AgBr ternary photocatalysts in flower-like microspheres were controllably synthesized by precipitation photoreduction and characterized by various techniques. In addition, the effects of different molar ratio of BiOCOOH and AgBr, catalyst dose, pH and coexisting ions on the photocatalytic degradation of rhodamine B (RhB) and tetracycline (TC) were investigated. The results showed that the BOC/Ag/AgBr-0.5 composite exhibited excellent photocatalytic activity for the degradation of RhB and TC. The excellent photocatalytic activity was mainly attributed to the surface plasmon resonance (SPR) effect of metallic Ag and charge transfer mechanism between composites, thus promoting charge separation. The degradation efficiency of RhB and TC was 92.7% and 72.3% with the degradation rate constant of 0.073 and 0.023 under light irradiation of xenon lamp in 30 and 45 min, respectively, which was 6 and 2 times higher than that of BiOCOOH and AgBr. The stability studies showed that BOC/Ag/AgBr-0.5 maintained a high catalytic activity after four cycles. The results of radical capture experiments showed that h⁺ and ·O₂^– were the main reactive radicals, while ·OH played a secondary role in the photocatalytic system. Subsequently, a potential photocatalytic mechanism was proposed based on the experimental results.     

用低纯度铝制备AAO模板及其结构研究

在0.3mol/dm3草酸溶液中,通过不同纯度铝的恒电位二次阳极氧化制备了纳米孔氧化铝模板,并用场发射扫描电子显微镜(FE-SEM)和原子力显微镜(AFM)观察模板结构.实验结果表明,一次氧化除膜后低纯度铝基体表面呈现较为规则的六边形结构,这种蜂巢结构有利于二次氧化过程中获得有序度更高的纳米孔模板.低纯度铝制备的模板表面被晶界分隔为微小的区域,只是在较窄区域内才出现六边形规则排列的纳米孔.恒电位40V时所得模板经扩孔处理后,孔径由35nm增大到100nm左右,且孔径大小几乎一致.从纳米孔的有序度来看,由低纯度铝制备模板还需要进一步优化阳极氧化参数.     

Thermal conductivity and heat capacity of solid silver bromide (AgBr) under pressure

The thermal conductivity, , and the heat capacity per unit volume, c _p , have been measured for solid silver bromide (AgBr) using the transient hot-wire method. Measurements were made at temperatures in the range 100–400 K and at pressures up to 2 GPa. c _p was found to be independent of temperature and pressure over these ranges. of AgBr was found to be similar to that of AgCl, which was measured previously. For AgBr, only acoustic phonons needed to be taken into account up to 340 K, but optic phonons probably carried some heat at higher temperatures. The Leibfried-Schlömann (LS) formula could describe the ratio (AgCl)/(AgBr), but not the ratio (1 GPa)/(0) for either substance. An empirical modification of the LS formula could describe the latter ratios but not the former. Further theoretical developments are required for understanding of (P) for even such relatively simple substances as AgCl and AgBr.     

Preparation,characterization, and photocatalytic activity of novel AgBr/ZIF-8 composites for water purification

A highly efficient photocatalyst, AgBr coupled zeolitic imidazolate framework-8 (AgBr/ZIF-8) hybrid, was prepared for photocatalytic degradation of dyes under illumination of visible light. The hybrid structure of AgBr and ZIF-8 was confirmed via X-ray diffraction (XRD). Meanwhile, metal Ag was also detected via X-ray photoelectron spectroscopy (XPS), indicating that the real composition of the complex is Ag-AgBr-ZIF-8. N₂-adsorption, UV–visible diffuse reflection spectroscopy (DRS), transient photocurrent (PC), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) analyses were performed to reveal the influence of the added AgBr on the specific surface area, charge separation efficiency and optical property of ZIF-8. Results indicated that the photoabsorption performance and the specific surface area of the AgBr/ZIF-8 composite are between that of pure AgBr and ZIF-8. Nevertheless, the synergy of ZIF-8 and AgBr in separating electrons and holes was observed, which induced significantly improved efficiency in charge separation, and subsequently resulted in the enhanced photoactivity of the AgBr/ZIF-8 composite. The performance evaluation demonstrated that the optimized AgBr/ZIF-8 presented a methylene blue (MB) degradation rate of 0.0273 min⁻¹, which was 3.59 times as high as that of AgBr. Additionally, the composite also worked well in photocatalytic decomposition of methyl orange (MO) and rhodamine B(RhB) under visible light. The degradation efficiency reached to 99.5% under visible light irradiation for 60 min. This work provides a hybrid photocatalyst with high efficiency, and may shed some light on the application of MOF-based composite in photocatalytic field.     

AAO模板受热失重及发光机理的研究

为了深入理解草酸溶液中制备的阳极氧化铝(AAO)模板受热失重以及草酸根对模板发光性能的影响,利用程序升温脱附与质谱联用(TPD-MS)、热重分析(TGA)、差热分析(DTA)以及光致发光(PL)等技术对AAO模板进行了系统研究.热失重分析结果表明,当温度低于402.2℃时,发生H2O、CO以及CO2分子的脱附以及掺杂草酸的分解,其中H2O的脱附为失重的主要原因;在402.2~866.7℃范围内,主要是草酸盐分解放出CO和CO2引起失重,CO为主要产物;碳酸盐以及残余的草酸盐的剧烈分解发生在866.7~1022.9℃范围内,主要放出CO2,并且引起大量失重.由热重结果及脱附产物中CO的摩尔比得到草酸根残余量随处理温度的变化趋势.最后,对模板PL强度、草酸根含量以及氧空位缺陷(F+)浓度三者随处理温度的变化趋势进行了关联,对AAO模板发光的原因进行了分析.