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1.
为探究适合工业化生产用超疏水纳米TiO2的绿色改性工艺,以饱和脂肪酸A、硅烷B、纳米TiO2(P25)等为原料制备超疏水TiO2粉末,与环氧树脂混合后利用喷涂法制备出超疏水涂层。采用扫描电子显微镜、X射线衍射仪、傅里叶变换红外光谱仪和接触角分析仪对超疏水粉末和超疏水涂层表面的形貌和疏水性进行了表征。结果表明:超疏水TiO2粒子表面具有疏水性基团和微-纳米双重粗糙结构,粒子表面的静态水接触角为158°,滚动角为3°;当超疏水TiO2与环氧树脂的质量比在3.2~3.5时,超疏水涂层既保持超疏水性,又与基底稳固结合,同时具有自清洁性和可修复性。该工艺操作简单方便,成本低,疏水性好,无需特殊设备,工艺环保,适应工业化生产,可用来大面积制备超疏水涂层,拥有较高的商业价值。  相似文献   

2.
利用低温下的水化学生长法合成了镍钴氧化物(NiCo2O4)纳米针,因其自组装而表现出立方晶相,再用二氧化钛/炭黑(TiO2/CB)对NiCo2O4表面进行了改性,合成了TiO2/CB-NiCo2O4复合纳米材料.用X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)、能量色散X射线光谱仪(EDX)图谱对材料的形貌进行了表征,运用循环伏安法(CV)、时间-电流(i-t)曲线法考察了TiO2/CB-NiCo2O4修饰玻碳电极的电化学行为.实验发现:TiO2/CB-NiCo2O4修饰电极对葡萄糖的氧化有良好的电催化性能,其线性范围为0.001~1.780 mmol·L-1,检测限为0.53 μmol·L-1(信噪比S/N=3).将该法用于实际样品中葡萄糖的测定,结果令人满意.  相似文献   

3.
采用Ca(OH)2和Na2CO3(摩尔比1∶1)为激发剂制备碱矿渣-粉煤灰混凝土,分别研究碱当量和粉煤灰掺量对ASFC抗压强度、劈裂抗拉强度、内钢环应变、环向拉应力和抗裂性能的影响,并通过开裂系数ζt(t)和抗裂性能评价指标Acr(t)表征ASFC的抗裂性能. 研究结果表明:随着碱当量的增加,ASFC的抗压强度和劈裂抗拉强度先增大后减小;当碱当量较小时(4%和6%,除特殊说明外,文中均为质量分数),ζt(t)Acr(t)基本不变,继续增大至8%和10%时,二者明显增大,抗裂性能明显降低;随着粉煤灰掺量的增加,ASFC的抗压强度和劈裂抗拉强度先增大后减小;粉煤灰掺量为20%时,ζt(t)Acr(t)明显下降,抗裂性能提高;继续增大粉煤灰掺量至40%,ζt(t)Acr(t)变化不大,抗裂性能没有明显提升. 碱当量为6%,粉煤灰掺量为20%时,力学性能和抗裂性能最优.  相似文献   

4.
在聚甲基丙烯酸甲酯-微针(PMMA-MNs)阵列上修饰聚多巴胺(PDA)层,通过离心技术将金纳米粒子(Au NPs)组装在MNs表面,构建纳米金@聚多巴胺@聚甲基丙烯酸甲酯微针阵列(Au@PDA@MNs).Au@PDA@MNs有强表面增强拉曼散射(SERS)效应,以罗丹明6G(R6G)作为拉曼探针,在10-4~10-8 mol·L-1的范围内有良好的线性响应,检测限(LOD)可达3.1×10-10 mol·L-1.为了检测过氧化氢(H2O2),4-巯基苯硼酸(4-MPBA)被修饰在Au@PDA@MNs上以构建功能化的MNs.利用4-MPBA分子氧化生成4-羟基硫代苯酚(4-HTP)和MNs的透光性,基于1 000 cm-1和1 068 cm-1处拉曼强度比(I1 000/I1 068)的变化,完成了H2O2的拉曼定量检测,I1 000/I1 068的变化与H2O2浓度成定量关系.线性响应范围为10~2 000 μmol·L-1,LOD为0.93 μmol·L-1.MNs和SERS技术的结合为确定具有短半衰期和弱拉曼信号的疾病相关生物标志物开辟了一条新途径.  相似文献   

5.
过渡族金属基二维纳米材料作为电催化析氧反应(oxygen evolution reaction, OER)催化剂具有巨大的潜力。通过原位电沉积法,在泡沫镍基底表面制备了二维层状镍铁双氢氧化物(NiFe-LDH)和氧硫化钼Mo(OS)x纳米片异质结构。NiFe LDH/Mo(OS)x电极在1 M KOH溶液中表现出优异的OER性能和长效稳定性,在10 mA/cm2电流密度下过电势仅为220 mV。在100、500 mA/cm2的高电流密度下,也能达到253、304 mV的低过电势。研究结果表明,NiFe-LDH/Mo(OS)x电极优异的OER性能归因于Mo(OS)x和NiFe LDH的协同作用,极大地促进了Fe2+向Fe3+活性物质的转化,并促进了氧空位的形成。这种协同制备方法为合理构建和设计异质结构电催化剂,实现高效的水分解提供了帮助。  相似文献   

6.
为制备具有优异自清洁功能的耐久性水基超疏水涂层,以十二烷基三甲氧基硅烷(n-dodecyltrimethoxysilane, DTMS)为有机改性物,通过一步法在纳米TiO2表面嫁接长链烷基官能团得到超疏水TiO2/DTMS涂层。分析了TiO2涂层及TiO2/DTMS涂层的表面润湿性、形貌和化学组成,并对所得超疏水TiO2/DTMS涂层的自清洁性能、机械及化学稳定性进行了测试。结果表明:超疏水TiO2/DTMS涂层表面水接触角(water contact angle, WCA)达到159°;以亚甲基蓝粉末作模拟污染物,涂覆有超疏水TiO2/DTMS涂层的玻璃具有优异的自清洁性能;经机械磨损(10 min)、酸碱液(pH=1、3、5、7、9、11、13)浸泡、高低温(−20、30、60、90、120、150 ℃)处理后超疏水TiO2/DTMS涂层的WCA仍大于150°,表明其具有优异的机械和化学稳定性,可用于室外防污,如建筑物外墙、玻璃、太阳能电池板等。  相似文献   

7.
以钽酸锶同素异质结Sr2Ta2O7/SrTa4O11(STO)为原始材料,采用高温氨化法对原始材料做氮掺杂改性处理,得到了新型氮掺杂钽酸锶同素异质结材料Sr2Ta2O7-xNx/SrTa4O11-xNx(STO-N),并对其光电催化性能进行研究。结果显示,对比改性前的STO,STO-N具有更强的可见光吸收能力。紫外可见漫反射光谱证明,氮掺杂使得STO的吸收阈值从319 nm红移到485 nm,相应的带隙由3.97 eV减小到2.51 eV,这主要是由于N 2p和O 2p轨道的混合作用导致价带顶部上移。性能测试结果表明:STO-N20的光电催化性能提升最为显著,在施加0.7 V偏压下,STO-N20电极测得的光电流密度达到了570 nA/cm2,是STO电极的光电流密度(8.6 nA/cm2)的66倍。根据推算出的STO及STO-N20的能带结构可知,STO-N20性能提升的原因是禁带宽度变窄。  相似文献   

8.
Al/Pb-WC-ZrO2复合电极材料的电化学性能研究   总被引:1,自引:0,他引:1  
 研究了电镀液中固体微粒质量浓度及工艺条件对Al/Pb-WC-ZrO2复合电极材料的表面化学组成及稳态析氧极化曲线的影响规律,对上述工艺条件进行了优化,优化后的工艺条件如下:WC:50 g/L,ZrO2:40g/L,温度:20℃,电流密度:1.5 A/dm2,电沉积时间:2 h.所获得Al/Pb-WC-ZrO2复合电极材料的析氧动力学参数为:a=771 mV,b=140 mV,i0=3.11×10-6A·cm-2,并且电极的析氧过电位为η=1 009 mV,复合镀层中WC和ZrO2质量分数分别为10.02%和3.55%.  相似文献   

9.
采用水热法合成了含混合配体的铜配合物[CuClPhen]+·[HL]-·2H2O(HL=5-硝基间苯二甲酸,Phen=1,10-菲咯啉),其结构由单晶X射线晶体学确定。标题化合物在三斜空间群P-1的晶体化合物。标题化合物的晶体数据:C32H24ClN5CuO8,Mr = 704.54,a = 10.4044(5),b = 12.3912(9),c = 12.4632(9)Å,α = 73.859(6),β = 85.036(5),γ = 78.202(5)°,V = 1510.09(17) Å3,Z = 2, T = 293(2) K,Dc = 1.549 g/cm3,μ(Mo) = 0.874 mm-1,F(000) = 720.0,R = 0.0554,wR = 0.1434,GOF = 1.098。当用作超级电容器电极材料时,所制备的配合物具有高比电容、良好的循环稳定性和优良的倍率性能。在1mol/L KOH溶液中,最大比电容可达到69 F/g。在2 A/g电流密度下,10000次循环后比电容保持率为72%。标题化合物是一种潜在的红色光致发光材料。  相似文献   

10.
 对非相互作用磁性纳米颗粒系统的FMR线型模型进行了研究,以铁磁体从应用场中获得自由能F为例,导出磁性颗粒在较小各向异性时,共振场Hr与有效各向异性场HAeff的关系,这个结果与Raikher和Stepanou的结果一致.继而还对共振场线宽进行了分析,并与Smit和Beljers模型进行了比较,其结论说明:在超顺磁区域有效各向异性场HAeff对塞曼(Zeeman)相互作用和附加应用场H是不确定的.尤其是这种情况在HAeff较小、高温(高温区域),且HAeffH时,变得更显著.为此提出了随机颗粒阵列及参数特征对这个结果的影响机制.  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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