AZ91D镁合金Ni-Cu-P/纳米TiO2化学镀层的抗菌性能

为了探究化学复合镀Ni-P层的抗菌性能,对AZ91D镁合金进行了Ni-Cu-P/纳米TiO2化学复合镀,制备出了具有光催化性能及优异抗菌性能的镀层.利用扫描电镜和x射线衍射技术对镀层进行了分析,并对镀层进行了紫外光照射.结果表明:TiO2粉末与复合镀层使甲基橙的脱色率均为12.5%;镀液中TiO2含量为4 g/L时抗菌性能达99.70%,其余含量时抗菌率均达到95.00%以上.     

抗菌复合镀层的组成及性能研究

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.     

镁合金Ni-Cu-P/纳米TiO2化学复合镀层性能探究

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.     

抗茵复合镀层的组成及性能研究

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：     

冷轧变形对镀Ni-Co钢带耐腐蚀性能的影响

为了获得高性能的合金镀层薄膜材料,采用电沉积法制备了Ni-Co合金镀层薄膜,对镀层的钴含量、表面形貌及冷轧变形下的耐腐蚀性能进行了研究.结果表明:当镀液中硫酸钴含量为2 g/L时,合金镀层中的钴含量约为3.89%,镀层表面光亮、结晶致密;冷轧变形量为2%～4%时,镀Ni-Co合金薄膜钢带的耐腐蚀性能得到提高,变形量超过4%后其耐腐蚀性能降低.这说明小的冷轧变形能有效地提高镀层的耐腐蚀性能.     

纳米TiO_2-Ni基镀层的电刷镀沉积行为研究

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。     

Pb-Sn-Cu合金共沉积工艺研究

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.     

脉冲电镀Zn-Ni合金工艺参数对镀层Ni含量及形貌的影响

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。     

复合电沉积法制备Ni-P-W-WC镀层及性能研究

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.     

聚丙烯塑料低温化学镀Ni-P工艺的研究

研究了Ni-P化学镀液的主要成分、pH值和温度工艺参数对化学沉积Ni-P合金镀层镀速的影响.通过选择合适的镀液成分和工艺参数,在PP塑料基体上低温化学镀Ni-P合金工艺中获得中磷含量合金镀层,探讨了镀液组分对镀层性能的影响,优化了工艺参数.利用扫描电镜测得镀层的含磷量为8.057%,所以为非晶态的镀层.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

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.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

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.……     

Optimum-Simulation von Ernteprozessen

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.     

A study of centrifugal cast high boron high speed steel

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

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 ...     

Brainstorming for ISO Strategy 2016-2020

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     

CNAS Passes APLAC's PTP Review

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.