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纳米TiO2已证明具有良好的抗菌性能,本研究采用化学复合镀的方法在钢铁基体上形成Ni-P-TiO2复合镀层,运用SEM、AES和XPS对镀层的表面形貌和组成进行了分析,并对其抗大肠杆菌和金黄色葡萄球菌的性能进行了定量测试.结果显示,Ni-P-TiO2镀层均匀、光亮;其相对原子百分数为74.51%Ni,13.37%P,3.02%Ti,6.81%O和1.38?,镀层对大肠杆菌的杀菌率为97.86%,对金黄色葡萄球菌的杀菌率为96.23%,显示出Ni-P-TiO2对上述两种细菌具有良好的抑制作用. 相似文献
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镁合金Ni-Cu-P/纳米TiO2化学复合镀层性能探究 总被引:1,自引:0,他引:1
对镁合金表面化学镀Ni-Cu-P进行改进,在其镀液中加入纳米粒子TiO2,在镁合金AZ91D上获得耐磨耐蚀性能优良且兼具有抗菌性能的化学复合镀层.对此镀层表面形貌、组织结构、抗菌、耐磨、耐蚀性能进行了分析,结果表明:该镀层均匀、致密,结合力优良;Ni-Cu-P/纳米TiO2化学复合镀层磨料磨损最佳耐磨性是基材的1.69倍,粘着磨损最佳耐磨性是基材的1.63倍;耐氯化钠和醋酸溶液腐蚀结果均显示该镀层具有较好的耐蚀性;抗菌性能中最佳杀菌率为99.7%,达到了理想的效果. 相似文献
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纳米TiO2已证明具有良好的抗菌性能,本研究采用化学复合镀的方法在钢铁基体上形成Ni—P—TiO2复合镀层,运用SEM、AES和XPS对镀层的表面形貌和组成进行了分析,并对其抗大肠杆菌和金黄色葡萄球菌的性能进行了定量测试。结果显示,Ni—P—TiO2镀层均匀、光亮;其相对原子百分数为74.51%Ni,13.37%P,3、02%Ti,6.81%O和1.38%Fe,镀层对大肠杆菌的杀菌率为97.86%,对金黄色葡萄球菌的杀菌率为96.23%,显示出Ni—P—TiO2对上述两种细菌具有良好的抑制作用: 相似文献
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为了使纳米颗粒均匀地悬浮在镀液中从而获得纳米颗粒均匀分布的复合镀层,研究了不同表面活性剂对纳米TiO2在镀液中的分散行为的影响,采用电刷镀方法制备纳米TiO2-Ni基复合镀层,并运用SEM、EDS和XRD研究了纳米TiO2-Ni基镀层的表面形貌和成分特点。结果表明,阳离子型表面活性剂十六烷基三甲基氯化铵(CTAB)对纳米TiO2颗粒的分散效果最好,沉降时间超过40min;CTAB分散的纳米TiO2-Ni基镀层显微硬度比不加表面活性剂的提高50%左右,镀层结合性较好,孔隙率显著降低;CTAB分散的纳米TiO2-Ni基镀层均匀细致、晶粒细小,纳米TiO2被生长着的镍晶粒夹持嵌埋,分布于镍基间隙中,镀层由纳米TiO2颗粒和镍基组成。纳米粉末与镍共沉积符合迁移、吸附、嵌埋的过程。 相似文献
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为了改善内燃机滑动轴承镀层的减摩性能,采用在合金基体上镀覆三元合金的工艺,在氟硼酸盐镀液体系中实现了Pb-Sn-Cu三元合金表面电镀.研究了镀液体系中镀液成分及工艺参数对Pb-Sn-Cu三元合金镀层成分及含量的影响.结果表明,镀液成分及电镀工艺参数对镀层成分及含量有较大的影响.镀液成分及电镀工艺参数的试验结果表明,镀液的最佳组成及工艺参数为:200 g/L Pb2+,25 g/L Sn2+,2.5 g/LCu2+,4g/L对苯二酚,2.5 g/L蛋白胨,100 g/L游离HBF4,30 g/L H3803,温度为25℃,电流密度6.0A/dm2. 相似文献
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脉冲电镀Zn-Ni合金工艺参数对镀层Ni含量及形貌的影响 总被引:1,自引:0,他引:1
为了优化Zn-Ni合金制备工艺,在硫酸盐型Zn-Ni合金镀液中脉冲电镀Zn-Ni合金层。分别采用扫描电镜和X射线成分分析镀层形貌和成分,通过中性盐雾试验测试镀层耐蚀性。研究了脉冲参数、工艺条件对Zn-Ni合金镀层Ni含量与形貌的影响。结果表明:镀液温度、平均电流密度、频率、逆向脉冲系数及占空比对镀层性能和形貌均有较大影响;最佳工艺参数为温度60℃,平均电流密度70 m A/cm2,脉冲频率200 Hz,逆向脉冲系数0.4,占空比0.7,此时Zn-Ni合金镀层晶粒细小,表面平整光亮,呈银白色,镀层Ni含量为13%,耐蚀性优良。 相似文献
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运用电沉积法制备Ni-P-W-WC复合镀层,着重研究了制备工艺和镀层性能.以镀层中碳化钨含量、镀速和镀层外观为指标,探讨了电流密度、电沉积时间、镀液中WC含量、镀液中钨酸钠含量、镀液pH等因素影响规律,确定了复合镀层的最佳工艺条件为:以Ni为阳极、电沉积时间为40 min、镀液中WC含量为14 g/L、镀液中钨酸钠含量为120 g/L、镀液pH为4.0、电流密度是4A/dm2.并用扫描电镜、X-衍射分析仪、阳极极化曲线等手段表征了复合镀层的形貌、结构、耐蚀性、抗氧化性等性能,结果表明,与Ni-P-W复合镀层相比,Ni-P-W-WC复合镀层有良好的综合性能. 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