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以二氧化钛纳米颗粒和硫酸铜溶液为原料,在紫外线灯的照射下进行铜负载二氧化钛纳米带复合材料制备,采用扫描电子显微镜(SEM)、X-射线能谱仪(EDS)、X-射线衍射仪(XRD)、抑菌圈法、细菌比浊法等分析技术研究了所制备负载纳米带复合材料的微观结构及抗菌性能。结果表明,纳米二氧化钛粒子在水热条件下可生长成纳米带,铜均匀负载在纳米带上,从而制备出铜负载二氧化钛纳米带复合材料,负载程度可以通过更改照射时间、硫酸铜浓度等条件进行微调;该负载纳米带复合材料对革兰氏菌有很好的抗菌性能,且负载程度越高,产物抗菌性能越大。 相似文献
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在不加表面活性剂的条件下,采用微波法制备碳纳米管负载组成可控的Cu1-xNix/MWCNTs (x=0.5,0.6,0.8)纳米复合材料,其结构和形貌通过XRD,TEM,SEM,EDX,FT-IR等技术进行表征,用VSM测试了材料的磁性能.结果表明:组成可控近似球形的Cu1-xNix合金纳米粒子均匀地负载在碳纳米管表面;Cu1-xNix合金为面心立方结构,当Ni含量增加时合金的晶格常数和粒径都逐渐减小;随着铜镍合金中Ni含量的增加,Cu1-xNix/MWCNTs复合材料的饱和磁化强度(Ms)增大,矫顽力(Hc)减小.另外,探讨了纳米复合材料的形成机理. 相似文献
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通过戊二醛交联制备了细菌纤维素/壳聚糖复合材料,并采用磁控溅射技术在交联复合膜表面沉积铜(Cu)纳米颗粒。利用扫描电子显微镜观察纳米纤维膜表面形貌,采用傅里叶红外光谱仪、热重分析仪和X射线衍射仪比较交联复合前后以及镀铜前后复合膜基本化学结构、热稳定性和晶面结构的变化。通过能量色散X射线光谱对壳聚糖和铜在复合膜表面的分布情况进行表征。同时借助抗菌实验探究复合膜对金黄色葡萄球菌和大肠杆菌的抗菌能力。结果表明:壳聚糖与细菌纤维素发生了有效交联,改变了细菌纤维素的基本形貌、化学结构、晶体形态以及热学性能,并且镀铜后交联复合膜的抗菌性能得到了明显的提升(膜与细菌接触20min,对金黄色葡萄球菌和大肠杆菌的抗菌效果均达到了99.999%)。 相似文献
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对多壁碳纳米管进行纯化和功能化处理,比较了未氧化处理与经浓硝酸和浓硫酸混酸(浓硫酸与浓硝酸体积比为3∶1)处理后的不同多壁碳纳米管(MWCNTs)为载体的Pd催化剂(Pd/MWCNTs)的分散性和粒径。利用X线粉末衍射仪(XRD)、透射电镜(TEM)、X射线能谱(EDS)和傅里叶变换红外光谱仪(FT-IR)等测试手段对所得的样品进行了表征。结果表明,MWCNTs表面不修饰不利于金属Pd纳米粒子的沉积,混酸处理使MWCNTs表面有大量的含氧活性基团,能够促进负载的Pd纳米粒子均一分布,明显提高了苯甲醇氧化为苯甲醛的选择性和转化率。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa. 相似文献
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On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.…… 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill. 相似文献
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Dimiter Hadjistamov 《材料科学与工程:中英文B版...》2019,(2):56-65
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ... 相似文献
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《中国标准化(英文版)》2014,(4)
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from 相似文献
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《中国标准化(英文版)》2014,(5)
正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively. 相似文献