脉冲微波表面波PECVD在有机PET表面沉积DLC薄膜的阻隔性研究

目的 探讨使用脉冲微波表面波等离子体辅助化学气相沉积技术在聚对苯二甲酸乙二醇酯（PET）材料表面沉积类金刚石薄膜作为阻隔层的可行性。方法 以C2H2为单体,氩（Ar）为放电气体,采用脉冲微波表面波等离子体化学气相沉积（PECVD）技术在有机PET材料表面沉积类金刚石（Diamond-like Carbon, DLC）薄膜。研究工艺参数,如脉冲微波放电功率、工作气压、单体与工作气体的体积比等,对DLC薄膜沉积速率和阻隔性能的影响。通过傅里叶变换红外光谱（FT-IR）、原子力显微镜（AFM）、氧气和水蒸气透过率测试仪等对薄膜结构与性能进行表征。结果 DLC薄膜的结构和成分随着等离子体放电工艺参数的变化而改变,造成其阻隔性能也随之发生变化。PET表面沉积纳米级DLC薄膜后,氧气透过率和水蒸气透过率可以分别降至0.58 mL/(m2?d)和2.5 g/(m2?d)。结论 DLC薄膜对氧气和水蒸气都表现出良好的阻隔性,可以应用于食品、药品的阻隔包装。     

常温生长类金刚石薄膜的实验研究

利用射频等离子体增强化学气相沉积(RFPECVD)工艺在常温下实现在不锈钢、硅片、玻璃等基底上大面积沉积类金刚石(DLC)膜.薄膜表面光滑致密,与衬底的结合力较高.用Raman,FTIR,SEM,EDX研究了薄膜的形貌、结构与组分.用栓-盘摩擦磨损试验机测试了薄膜的摩擦系数.通过优化沉积参数,所沉积的DLC膜在与100Cr6钢球对磨时摩擦系数低于0.01.在摩擦过程中DLC膜的磨损机制借助SEM进行了研究.     

类金刚石碳膜的结构特性与耐磨性能

采用双离子束增强沉积（IBED）和离子束直接沉积（IBD）技术，在CHn 能量为200~550eV和3～25keV范围内沉积的类金刚石薄膜具有光滑平坦的表面和非晶结构。X光电子谱和Raman光谱分析、以及显微硬度测量的结果表明，随着轰击离子能量的降低，薄膜的金刚石特性增强；在200～550eV能量范围内制备的DLC膜具有明显的sp3键特征和很高的显微硬度。沉积在GCr15钢上的DLC膜与GCr15钢的摩擦学对比实验表明，DLC膜具有很低的摩擦系数、比磨损率和高的抗磨损指数，这证明采用上述两种方法制备的DLC膜具有优良的抗摩擦磨损性能。     

非平衡磁控溅射类金刚石碳膜的性能

用非平衡磁控溅射的方法在室温下制备了光滑、均匀、致密的类金刚石(DLC)薄膜,分析和研究了DLC膜的形貌、结构和摩擦特性.结果表明,靶工作电流对DLC膜的沉积有重要的影响.随着工作电流的增大,薄膜的沉积速率增大,薄膜中sp3键的含量增加.薄膜的摩擦系数随着工作电流的增加略有增大,在摩擦的初始阶段,摩擦系数较高,随着摩擦循环次数的增加,摩擦系数逐渐减小,并逐渐趋于稳定.     

真空弧源沉积类金刚石薄膜及其性能研究

采用真空弧源沉积技术在钛合金及Si(100)表面合成DLC薄膜．通入不同的氩气．控制DLC薄膜中的SP3／SP2比值。研究表明，薄膜硬度可达96GPa．随着氩气流量的增加，薄膜的硬度先增加．后有明显降低。随着氩气流量的增加，类金刚石薄膜中．SP2键增加，SP3键减少，而血液相容性明显提高。DLC薄膜具有优异的耐磨性，摩擦系数低，与钛合金基体结合牢固。     

NiTi合金生物医用材料表面镀类金刚石薄膜的性能研究

用脉冲电弧离子镀技术在NiTi合金生物材料表面沉积了类金刚石(DLC)薄膜.研究分析结果表明制备的DLC薄膜是四面体非晶碳薄膜;随着DLC薄膜厚度的增加,薄膜的表面粗糙度增加,薄膜中sp3的含量减少;随着sp3含量的增加,薄膜的纳米硬度升高;划痕实验表明临界载荷大于0.9 N.研究得出与NiTi合金相比,DLC薄膜能够有效地降低摩擦系数和磨损.DLC薄膜的摩擦系数主要与薄膜的硬度及薄膜中sp3的含量有关,DLC薄膜的磨损主要是轻微的磨粒磨损及疲劳磨损.     

液相法新工艺制备类金刚石膜的结构及其电学性能分析

采用液相法，在以硅片为阳极的工艺条件下沉积了一层DLC薄膜。通过Raman和FFIR光谱的分析，证实了该薄膜为含氢类金刚石薄膜（a-C：H）。并且对薄膜的交流阻抗谱（EIS）进行了测试和分析，确定该膜有非常高的阻抗值和良好的耐蚀性。     

靶电流对掺钨类金刚石膜的结构与摩擦学行为的影响EI北大核心

利用真空阴极电弧+磁控溅射+阳极层条形离子源制备了带梯度过渡层的掺钨类金刚石(DLC)膜,并研究了靶电流对掺钨DLC膜结构和性能的影响,结果表明:制备的掺钨DLC膜光滑致密,表面存在1~2μm的液滴。靶电流不大于3.5A时,随着靶电流的增加,掺钨DLC膜的钨含量逐渐增加,但sp3的含量基本不变;靶电流为5A时,制备的薄膜成分接近WC的理想化学计量比,薄膜中的sp3含量增加到48%。当靶电流不大于2A时,靶电流对掺钨DLC膜的显微硬度和摩擦系数影响较小;在高的靶电流条件下,掺钨DLC膜的显微硬度和摩擦系数随着靶电流的增加而明显增大。     

H13钢离子渗氮(PN)与类金刚石(DLC)复合处理的摩擦磨损性能研究

采用阳极层流离子源与非平衡磁控溅射结合的沉积方法在H13钢基体表面沉积出类金刚石膜(DLC),并对H13钢经不同表面预处理对后沉积的DLC膜的摩擦学性能进行了对比研究.结果表明:DLC膜结构致密,且DLC膜与梯度过渡层及基体三者之间结合牢固;H13钢经离子氮化后,梯度过渡层与氮化层间结合紧密,提高了膜与基体的承载能力;在保持相同摩擦速率的条件下,摩擦系数随着载荷的增加先增大后减小;H13钢离子渗氮处理后沉积的DLC膜其摩擦系数远小于未采用离子渗氮处理沉积的DLC薄膜.     

环境气氛对类金刚石薄膜摩擦学行为的影响

用射频等离子体化学气相沉积法(RF-PECVD)制备了含氢类金刚石薄膜(DLC).采用表面轮廓仪和纳米压痕仪分别测量膜的厚度和硬度.通过控制摩擦环境气氛对DLC薄膜和钢球对磨的摩擦系数进行了系统研究.利用光学显微镜和扫描电镜(SEM)分析了磨痕及磨斑的形貌,对DLC薄膜在不同气氛下的摩擦现象进行了表征和解释.结果表明,DLC薄膜的摩擦学行为与气氛中的O2、H2O和N2有关,其中N2的存在是DLC薄膜具有超低摩擦系数的重要原因.     

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.