溶胶凝胶法TiO2光催化剂降解甲基橙溶液的试验研究

以钛酸四丁酯(Ti(OC4H9)4)为前驱体,采用溶胶-凝胶法制备了纳米TiO2光催化剂,并利用其对甲基橙溶液的光催化降解作用,探讨了不同配比量、热处理温度、水解抑制剂类型以及催化剂粉体添加量四个因素对催化剂光催化活性的影响.实验结果表明,原料配比、催化剂粉体添加量为显著因素,对TiO2粉体光催化活性有显著影响,热处理温度、抑制剂类型为不显著因素,对TiO2粉体光催化活性无显著影响.     

Fe~(3+)掺杂TiO_2的制备、表征与光催化性能研究

以空心玻璃微球(GMBs)为载体,钛酸四丁酯(Ti(OC4H9)4)为原料,采用浸涂法制备可漂浮附载型复合光催化剂Fe-TiO2/GMBs。样品的结构、成分、形貌和核壳厚度分别用X射线衍射仪(XRD)、X射线能谱仪(EDS)和场发射扫描电子显微镜(FESEM)进行表征。并研究样品在紫外光照射下催化降解罗丹明B(RhB)的性质。结果表明,Fe元素的存在既没有影响TiO2由锐钛矿相向金红石相转变,也没有增加新的晶相,而是使TiO2的光催化活性明显增强,本文对TiO2光催化机理也进行讨论。     

纳米TiO2光催化剂的最新发展——多孔TiO2

介绍了多孔TiO2的溶胶-凝胶制备法和模板制备法，评述了其光催化活性，并从孔径大小、比表面积、煅烧温度和煅烧时间4个方面探讨了多孔TiO2光催化活性的影响因素。孔径在介孔范围内的多孔TiO2,可以对待降解物进行吸附，反应物和生成物的扩散速度加快，光催化活性和催化速率得到提高；TiO2中适量孔的引入，增加了催化剂的比表面积，有利于催化剂与反应物的充分接触，提高光催化活性；煅烧温度过高，容易导致多孔TiO2光催化剂孔结构的坍塌，影响其光催化活性；煅烧时间太短，催化剂未形成或未完全形成锐钛矿型，催化作用减弱；煅烧时间太长，晶粒则会太大，光催化活性降低。因此以合适的制备工艺条件将TiO2制成多孔结构是提高其光催化活性的有效途径之一，具有重要的研究价值和很好的应用前景。     

光催化抗菌薄膜的制备与性能研究

采用溶胶-凝胶法,结合旋转涂膜法,制备了六种稀土掺杂光催化抗菌薄膜(Ce/TiO2,Pr/TiO2,Gd/TiO2,Dy/TiO2,Y/TiO2,Eu/TiO2),研究了影响薄膜光催化抗菌性能的因素,确定了最佳制备工艺条件.、除Ce掺杂TiO2薄膜含有极少量金红石型TiO2外,其余全部由单一锐钛矿型TiO2构成,薄膜表面均存在缺陷.RE/TiO2光催化抗菌薄膜对大肠杆菌平均杀菌率皆在90%以上,与纯TiO2的杀菌率34%相比有明显提高.稀土元素掺杂显著提高了光催化薄膜对可见光的响应.经反复使用和高温、高压、冲刷等处理,薄膜完整不脱落,始终有很高的杀菌率和稳定性.稀土掺杂TiO2具有良好的实用价值和应用前景.     

Fe^（3＋）掺杂TiO2的制备、表征与光催化性能研究

以空心玻璃微球（GMBs）为载体,钛酸四丁酯（Ti（OC4H9）4）为原料,采用浸涂法制备可漂浮附载型复合光催化剂Fe-TiO2/GMBs。样品的结构、成分、形貌和核壳厚度分别用X射线衍射仪（XRD）、X射线能谱仪（EDS）和场发射扫描电子显微镜（FESEM）进行表征。并研究样品在紫外光照射下催化降解罗丹明B（RhB）的性质。结果表明,Fe元素的存在既没有影响TiO2由锐钛矿相向金红石相转变,也没有增加新的晶相,而是使TiO2的光催化活性明显增强,本文对TiO2光催化机理也进行讨论。     

载铈纳米TiO2粉体的制备及其光催化性能

采用浸渍法制备了不同Ce4 掺杂量纳米TiO2光催化剂,并用透射电镜、X射线衍射仪和紫外-可见吸收光谱等手段对其进行了表征.以甲基橙为目标降解物,用紫外-可见吸收光谱考察了其光催化特性.结果表明:Ge4 的掺杂提高了纳米TiO2粉体的相变温度,1.2%的掺杂量可以使纳米TiO2在800 ℃煅烧后保持锐钛矿型;在汞灯照射下,90 min后对甲基橙的脱色率可达94.7%,而纯TiO2在120 min后脱色率仅仅为53.7%.     

烧结制度对稀土掺杂TiO2光催化抗菌材料抗菌性能的影响

采用溶胶-凝胶法并结合旋转涂膜法制备了稀土掺杂（Ce、Pr、Gd、Dy、Y、Eu）薄膜型光催化抗菌材料，利用TG—DSC综合热分析仪研究了烧结方式、烧结温度以及烧结时间等烧结制度对稀土掺杂TiO2光催化抗菌材料抗菌性能的影响。结果表明，各因素对材料的光催化抗菌性能均存在一最佳值，稀土元素掺杂对TiO2的晶型结构产生了一定的影响；薄膜中除Ce掺杂TiO2薄膜含有极少量金红石型TiO2外，其余全部由单一锐钛矿型TiO2构成，相比稀土掺杂TiO2薄膜对大肠杆菌的杀菌率可达93．38％，较纯TiO2（杀菌率为37．14％）杀菌效果提高了60．23％。该材料经反复使用仍具有很高的杀菌率和稳定性，极具实用价值和应用前景。     

La~(3+)/Br~-对TiO_2可见光光催化活性的影响

采用醇盐水解法制备了La3+/Br-改性的TiO2光催化剂,分别就La3+/Br-添加量以及焙烧温度对改性TiO2粉体的晶相、比表面积等对其可见光光催化活性的影响进行了研究。结果表明,La3+/Br-添加量比为0.5时,改性TiO2粉体经550℃焙烧2 h后,在波长为420 nm,照度为12μW/mm2的可见光下照射12 h后,对甲基橙的降解率可达83.58%,呈现出较好的可见光光催化活性。     

纳米光催化技术在处理室内空气污染中的应用

介绍了室内空气污染物的来源、纳米光催化技术的原理及应用方式。纳米TiO2光催化剂具有较强的光催化活性,无毒无害、成本低廉,适用于各种类型和各种场合的室内空气净化,有望在室内空气净化领域得到普遍应用。     

纳米TiO2的改性及其在废水处理中的应用

纳米TiO2的光催化技术以其反应条件温和、无污染、能耗低等特点在环境保护方面具有广泛的应用前景。介绍了纳米TiO2的光催化机理，以及改性的几种途径：金属离子的掺杂、贵金属沉淀、复合半导体、表面光敏化等。阐述了纳米TiO2光催化技术在印染废水、焦化废水、造纸废水及农药废水处理中的应用。进一步提出了纳米TiO2的改性研究领域所存在的问题并对纳米TiO2的在光催化废水处理的发展做了展望。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.