In situ Investigation on Layer-by-Layer Deposition of Polyelectrolytes by Quartz Crystal Microbalance

The effect of salt concentration on layer-by-layer deposition of poly（sodium 4-styrene sulfonate） （PSSS）/poly（vinylbenzyl trimethylammonium chloride） （PVTC） was investigated by use of quartz crystal microbalance with dissipation （QCM-D）. The changes in frequency and dissipation demonstrate that the addition of NaC1 leads the thickness of PSSS/PVTC multilayer to increase. The deposition of PSSS/PVTC is dominated by surface charge overcompensation level at lower salt concentrations. However, it is mainly determined by the interpenetration of polyelectrolytes at a higher salt concentration, as reflected in the oscillation of dissipation change.

Predicting the Growth of Ash Deposits in Drop Tube Furnace Using Dynamic Mesh Technique

Modeling and experiments of the growth of ash deposits during the combustion in a drop tube furnace are presented in this paper.An existing deposition model for ash deposit was used,which involves relationship among the force of gravity,elastic rebound and adhesion forces acting at the moment of ash particle impaction.Important parameters of this model were determined by the experimental data.The influence of particle size and velocity on deposit geometry was investigated.The growth of ash deposits involving various inlet velocities,tube diameters and tube arrangements were simulated with dynamic mesh technique in Fluent.The simulation results show that particle normal impacted velocity plays an important role due to elastic bounce force term.Deposited geometry was influenced by side velocity(velocity of inlet⁃2),and large velocity has an obvious effect to change the shape of deposition and postpone the steady time.

基于layer-by-layer技术构建胆碱检测生物传感器酶电极的研究

基于层层累积自组装法将PDDA高分子材料和胆碱氧化酶逐层固定在高分子聚合膜PVS／PDDA修饰的电极表面，制备了电流型胆碱检测生物传感器。利用石英晶体微天平（QCM）分别分析了PDDA和胆碱氧化酶的固定过程，结果表明酶的固定量可以得到有效控制。探讨了自组装膜层数、pH值、温度对传感器电流响应的影响。制备的生物传感器在胆碱浓度为5×10^-7～1×10^-4mol／L的范围内对胆碱有良好的线性响应，响应时间为10s，检出限为5×10^-7mol／L。传感器的稳定性好，30天时的响应值仍保持90％。

Visual investigation of slagging characteristics in a pilot-scale facility:Influence of deposition surface

Slagging is a major problem in boilers,especially the low-rank coal applied in boilers.In this study,the influence of heat transfer surface on the slagging characteristics of a pilot-scale furnace was investigated.Ni coatings were applied in modifying the deposition surface to control slagging.The growth characteristics of the slag were studied using an online digital image technique.Scanning electron microscopy linked with energy-dispersive X-ray analysis and X-ray diffraction(XRD)were applied to investigate the microstructure,semi-quantitative chemical composition,and mineralogy of slag samples.Ni coating demonstrated a positive effect on the mitigation of slagging.Results revealed that the thicknesses of the slag initially increased with experimental time and then inclined toward stable values for both cases(Case 1:substrate material;Case 2:modified surface).The stable thicknesses for Cases 1 and 2 were 4.91 mm and 3.95 mm,respectively.The heat transfer efficiency was improved by approximately 18.2%with the application of Ni coating for probe surface modification.The mechanism of the mitigation of slagging was investigated in this study.XRD results revealed that the content of alkali reduced when the surface was coated with Ni.The alkali significantly affected the adhesion behavior of the deposition.Hence,Ni coating showed potential in reducing slagging and increasing the efficiency of boilers.The overall study makes a contribution to a deep understanding of the effect of Ni coating on the growth characteristics of the slag.

Controlled Growth of Well-Aligned Carbon Nanotubes, Electrochemical Modification and Electrodeposition of Multiple Shapes of Gold Nanostructures

An efficient method has been developed to synthesize well-aligned multi-walled carbon nanotubes (MWCNTs) on a conductive Ta substrate by chemical vapour deposition (CVD). Free-standing MWCNTs arrays were functionalized through electrochemical oxidation with the formation of hydroxyl and carboxyl functional groups. Using a new oven drying technique, we demonstrate that the unidirectionally aligned and laterally spaced geometry of the CNT arrays can be retained after being subjected to each step of electrochemical modification. Samples were analyzed by using a field emission scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transformed infrared (FTIR) and Raman spectroscopy. Useful electrochemical methods for the synthesis of various gold nanostructures onto the aligned MWCNTs were then presented for the first time. The results demonstrated that flowerlike nanoparticle arrays, nanosheets and nanoflowers were obtained on the aligned CNTs under different experimental conditions. These kinds of aligned-CNT/Au nanostructures hybrid materials introduced by these efficient and simple electrochemical methods could lead to development of a new generation device for ultrasensitive catalytic and biological application.

压水堆一回路注锌的热力学与动力学特性

堆芯腐蚀产物沉积会引起垢致功率偏移和垢致局部腐蚀,威胁反应堆的安全性和经济性。根据反应堆运行经验,注锌能有效缓解堆芯腐蚀产物沉积,但锌在一回路中热力学平衡、动力学置换和质量平衡理论尚不清晰。基于此,本文从理论机理和数值计算分析的角度分析一回路中锌的平衡与热力学动力学行为。理论分析表明,锌在冷却剂水化学条件下主要以氢氧化锌形式存在,锌对反尖晶石中二价离子的置换能力可以结合锌浓度与水解化学平衡进行求解。数值分析表明,模型预测值与核电站观测值有良好的吻合度,逐步降低注锌量是维持锌浓度在特定最优化范围内的有效手段,注锌有效缓解腐蚀释放的程度可达约50%,注锌后的污垢厚度约为注锌前的42%。本文研究结果能为核反应堆采取最优化注锌技术提供理论支撑。

MR mDxion-Quant技术评价早期糖尿病肾病大鼠肾脏脂质沉积的实验研究

目的 探讨MR mDxion-Quant技术评价早期糖尿病肾病(DN)大鼠肾脏脂质沉积的价值。方法 选取6周龄健康清洁级(SPF级)雄性SD大鼠70只,分为实验组(50只)和对照组(20只)。实验组用高脂饮食配合链脲佐菌素建立2型糖尿病模型。于成模后第4、8、12、16周末分批行肾脏MR扫描得到肾脏脂肪分数(FF)。随后行血脂及肾脏病理检查。计算肾脏细胞内脂滴累计光密度值/细胞总面积值(IOD/TAC)。根据病理结果将实验组中病理分级为Ⅰ、Ⅱ级的大鼠纳入早期DN组(n=15),将对照组中肾脏未见异常的大鼠纳入正常对照组(n=13)。共28只大鼠纳入研究。比较早期DN组与正常对照组之间各指标的差异,分析肾脏FF值与其余指标的相关性。结果 早期DN组大鼠肾脏FF值、细胞内脂滴IOD/TAC、TC、TG、LDL较正常对照组升高,HDL含量降低(均P<0.001),FF值与IOD/TAC、TC、TG、LDL及糖尿病病程呈正相关(r分别为0.85、0.66、0.71、0.76、0.85,均P<0.01),与HDL呈负相关(r=-0.71,P<0.01)。结论 mDxion-Quant技术可无创性定量评估早期DN大鼠肾脏脂质沉积。早期DN大鼠肾脏脂肪含量较正常对照组增加,且与糖尿病病程、血脂水平相关。

地震频率谐振技术在内蒙古额尔古纳东珺银铅锌矿区勘查中的应用

内蒙古自治区额尔古纳市东珺银铅锌矿床属于浅成低温热液型矿床,浅部已控制的陡脉状与缓倾斜银、铅、锌矿体资源储量已达到大型规模。对浅部数据的处理解译并结合成矿地质条件分析认为,缓倾斜矿体赋存于一套波阻抗值相对较低的层间破碎带内,在其下部存在含矿构造带。为探获与成矿相关的热液上升通道,在矿区内应用地震频率谐振技术进行剖面性勘查工作,探测陡倾角断裂的结构和位置信息,以实现深部更大的资源量突破。通过地震频率谐振勘探所获得的波阻抗特征和已有钻孔及新钻孔等地质资料,证实了矿区深部的确存在与构造有关的厚大矿体的认识。地震频率谐振勘探的高精度视波阻抗勘查成果为本区深部探测提供了明确的目标和靶点。

基于地震波方法的矿床探测技术研究

本研究的重点在于探讨地震波方法在矿床探测中的原理和技术,以及其在勘探过程中的应用和挑战。通过地震波方法,可获取地下矿体的位置、规模和性质,为矿床勘探提供重要的地质信息。同时,地震波方法还可以帮助识别地下构造和地质灾害风险,为工程建设提供可靠的地质评估。

不同参数电沉积混凝土抗微生物腐蚀性能研究

针对污水管道混凝土结构受微生物腐蚀问题,利用电化学技术将铜复合物沉积到混凝土表面,赋予其抗腐蚀性;通过电沉积试验、微生物抑制试验,使用平板菌落计数法,分析沉积时间和电流密度对复合铜膜沉积效果和混凝土抑菌性能的影响。结果表明,混凝土经过电沉积技术处理具有良好的杀菌能力,样本抑菌率均超过70%。抑菌效果随沉积时间及电流密度的增加而提升,当电流密度为5 A/m^(2)、沉积时间为5 d时试件的抑菌率可达89.5%。

Application of a ^(137)Cs fingerprinting technique for interpreting responses of sediment deposition of a karst depression to deforestation in the Guizhou Plateau,China

Deforestation to reclaim land often triggers severe soil erosion in the Guizhou Karst Plateau. 137Cs dating of the deposited sediments in the karst depression bottom was used to estimate soil losses by surface erosion since deforestation started in 1979 on hillslopes in the Shirenzhai catchment, Puding County, Guizhou Province. The catchment has a drainage area of 0.054 km2. The average 137Cs contents of the top and peak layers in five cores of the depression bottom (with an area of 2652 m2), collected in 2009, were 2.35 and 7.25 Bq kg-1, respectively. The medium depths in the depression (which ranged between 84 cm and 113.5 cm with a mean value of 92.1 cm) showed the presence of sediments deposited in 1979. The total volume and weight of the deposited sediments since 1979 were estimated to be 1965 m3 and 2496 t, respectively. The depression bottom can be treated as a temporary impoundment and its sediment trapping efficiency was estimated to be 0.7. The relevant average soil erosion rate on the hillslopes was 2315 t km-2 yr-1 since 1979. The mean 137Cs inventory of the five cores was 7693 Bq m-2, which was ~10 times the local reference inventory of 782 Bq m-2. The total 137Cs activity of the sediments in the bottom was 20.4×106 Bq, and the relevant 137Cs inventory loss from the hillslopes was 358 Bq m-2 (since 1954), which accounted for 45.8% of the reference inventory. As soil erosion was not severe before and after the period of deforestation and following cultivation in 1979-1990, the erosion rates on the hillslopes could potentially reach 7000 t km-2 yr-1.

Boron-Doped Diamond Films Deposited on Silicon Substrates by MPCVD

High quality, good adhesion and p-type diamond films are obtained by microwave plasma chelincal vapordeposition. The area of the films is 20 x 20 nun. The structural morphologies, bonding mechanism and surfacemol'Phology are characterized by X-ray diffraction (XRD), Raman scattering and scanning Electron microscopy(SEM) respectively. The resistance, Hall coefficient, mobility, etc. are also measured. Tile factors related tonucleation and other properties of diamond films are discussed.

Electrochemical deposition of uranium oxide with an electrocatalytically active electrode using double potential step technique

The development of effective uranium-removal techniques is of great significance to the environment and human health.In this work,a double potential step technique(DPST)was applied to remove U(VI)from uranium-containing wastewater using a carbon felt electrode modified by graphene oxide/phytic acid composite(GO-PA@CF).The application of DPST can inhibit water splitting and prevent GO-PA from adsorbing other interfering ions in wastewater.The GO-PA composite can effectively accelerate the electrochemical reduction rate of U(VI),which significantly improved the electrochemical deposition rate of uranium oxide.As a result,the maximum removal efficiency and maximum removal capacity of GOPA@CF electrode reached 98.7%and 1149.3 mg/g,respectively.The removal efficiency remained 97.2%after five cycles of reuse.Moreover,the removal efficiency of GO-PA@CF electrode can reach more than 70%in simulated wastewater.

Improvement of thickness uniformity and elements distribution homogeneity for multicomponent films prepared by coaxial scanning pulsed laser deposition technique

In conventional pulsed laser deposition （PLD） technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products. We present a novel method based on PLD for depositing large CIGS films with uni- form thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam, the laser＇s focus is scanned across the rotating target surface. This arrangement maintains a constant re- flectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated. This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness uniformity exceeding ±3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.

金川岩浆镍钴硫化物矿床深部找矿勘查技术研究

岩浆镍钴硫化物矿床是中国镍钴资源的主要来源,金川矿床在其占有绝对位置。但随着新兴产业的快速发展和低碳时代的来临,中国镍钴资源供给对外依赖程度不断攀升,镍钴战略性矿产资源安全受到严重威胁,深部找矿是实现镍钴资源增储上产的唯一途径。笔者在金川岩浆镍钴硫化物矿床的成矿地质特征、矿体分布规律系统研究的基础上,利用重磁电等地球物理异常信息与含矿岩体耦合关系,搭建地质-地球物理三维模型和深部找矿勘查技术有效性组合,梳理总结综合找矿标志及岩体含矿性评价指标,精确快速定位隐伏矿体可能的赋存空间,支撑服务金川岩浆镍钴硫化物矿床深部找矿实践,不断提升中国镍钴资源自我保障能力。

河南省某铁矿区隐伏铁矿体深部找矿研究

河南省某铁矿区主要地质面貌为平原和丘陵,已发现并且开采的铁矿有近20条,已探明储量高达6.7亿t,属于全国铁矿产量前十的矿区之一。通过高精度磁法勘探技术进行找矿勘探并圈定异常点,再通过可控源音频大地电磁法勘探技术对异常点进行找矿勘探,圈定找矿靶区和预测钻探深度,最后通过实际工程勘探,对预测结果进行了验证。研究表明:(1)区内共有6个异常点,其中M2、M6异常可能是地下存在铁矿石所引起的磁场异常;(2)区内圈定找矿靶区两处,分别为C1勘测线45^(#)~47^(#)监测点(1^(#)靶区)和C2勘测线11^(#)~21^(#)监测点(2^(#)靶区),经过地质信息分析获得1^(#)、2^(#)靶区的钻探深度均为1000m。(3)通过实际工程勘探,验证了所圈定的靶区深部存在隐伏铁矿体。

油水分离陶瓷膜表面疏水改性方法研究进展

陶瓷膜具有优异的化学稳定性、热稳定性和耐污染性,机械强度高、易清洗、寿命长,在油水分离领域引起了研究人员的广泛关注.分离油包水乳液常选用疏水陶瓷膜,对陶瓷膜进行疏水改性可赋予其特殊润湿性能,增强油水分离能力.本文根据近年来陶瓷膜疏水表面制备及改性方法的研究,综述了陶瓷膜表面疏水改性的策略及效果,重点介绍了浸渍法、溶胶-凝胶法、化学气相沉积法的改性原理及研究成果,对3种方法的特点进行了比较,对陶瓷膜疏水改性的发展前景及研究方向进行了展望.

Application of ^(137)Cs fingerprinting technique to interpreting sediment production records from reservoir deposits in a small catchment of the Hilly Loess Plateau,China

According to variations of 137Cs and clay contents, 44 flood couplets were identified in a profile of res- ervoir deposit with a vertical length of 28.12 m in the Yuntaishan Gully. Couplet 27 at the middle of the profile had the highest average 137Cs content of 12.65 Bq·kg?1, which indicated the 1963s' deposits, then 137Cs content decreased both downward and upward in the profile. The second top and bottom couplets had average 137Cs contents of 2.15 Bq·kg?1 and 0.92 Bq·kg?1, respectively. By integrated analysis of reservoir construction and management history, variations of 137Cs contents over the profile, sediment yields of flood couplets and rainfall data during the period of 1958-1970, individual storms related to the flood couplets were identified. 44 floods with a total sediment yield of 2.36×104 m3 occurred and flood events in a year varied between 1 and 10 times during the period of 1960-1970. 7-10 flood events occurred during the wet period of 1961-1964 with very wet autumn, while only 1-2 events during the dry period of 1965-1969. Average annual specific sediment yield was 1.29×104 t·km?2·a?1 for the Yuntaishan Gully during the period of 1960-1970, which was slightly higher than 1.11 ×104 t·km?2·a?1 for the Upper Yanhe River Basin above the Ganguyi Hydrological Station and slightly lower than 1.40 ×104 t·km?2·a?1 for the nearby Zhifang Gully during the same period. Annual specific sediment yields for the Yuntaishan Gully were correlated to the wet season's rainfalls well.

基于成分数据分析及S—A分形的地电提取法在川西容须卡地区寻找隐伏锂矿预测研究

川西容须卡地区以高寒地貌景观为主,由于自然条件恶劣给找矿工作带来较大困难。为实现该区的找矿突破,开展地电提取法测量、分析与锂成矿密切相关的Li、Be、Rb、Cs、U、Th等6种元素。其结果表明原始数据存在明显的闭合效应,给地球化学异常圈定带来一定的干扰;同时,研究区地球化学背景存在较大差异,可能会漏掉有意义的弱异常。为进一步确定各元素之间的关系,明确找矿指示意义,采用成分数据分析方法打开数据之间的闭合效应,对原始数据、对数变换、ilr变换等3种不同数据处理结果进行对比,得出3点结论:①经过对数及ilr变换后的数据比原始数据更接近正态分布;②ilr变换明显消除数据的闭合效应,其中Li、Rb、Cs、U、Th等成矿元素组合对第一主因子PC1正载荷存在较大贡献;③通过S—A异常分解,有效消除研究区背景值的差异,强化低背景区的弱异常,为矿区找矿提供新线索。最后,结合研究区地质成矿规律、元素组合及异常空间分布特征,圈定出4个找矿靶区。