B30铜镍合金在海水中的电化学行为

B30铜镍合金具有优良的耐海水腐蚀性能,但在海水中形成的表面膜对其自身的电化学行为有影响,过去对此研究不多.采用交流阻抗、线性极化、动电位极化、循环阳极极化等方法研究了B30铜镍合金表面在海水中形成的氧化膜对其自身腐蚀电化学行为的影响,采用原子力显微镜(AFM)对氧化膜的结构进行了分析.结果表明:B30铜镍合金在海水中浸泡72 h后,表面能够生成一层完整致密的氧化膜;表面膜使B30铜镍合金在海水中的阻抗值随浸泡时间的延长先增大后减小,而且能够降低其极化电流密度以及瞬时腐蚀速率;随着浸泡时间的延长,B30铜镍合金在海水中的点蚀倾向加重.     

纳米铜自修复添加剂摩擦学性能研究

利用T-11摩擦磨损试验机进行了纳米铜自修复添加剂摩擦磨损试验,利用光学显微镜和扫描电镜对摩擦表面进行了形貌观察,利用能谱仪进行了磨痕表面元素分析.结果表明磨痕表面形成了富含铜元素的修复膜,静止上试样的磨痕表面比运动的下试样表面形成的薄膜厚,在摩擦表面有原始微损伤(磨削沟槽)的部位边缘有不连续的铜膜沉积.分析认为摩擦使得表面金属活化,不断产生新鲜金属表面,有利于自修复添加剂中的纳米铜与金属结合形成表面膜,对磨损表面起到自修复作用.     

2-巯基-5-苯甲基-1,2,4-三氮唑/硅烷复合膜对铜耐蚀性能的影响

目前,关于三氮唑化合物/硅烷复合膜在中性氯离子溶液中对铜的防护性能研究较少。采用浸渍法在铜表面制备了2-巯基-5-苯甲基-1,2,4-三氮唑(TBT)/硅烷(PTMS)复合膜及单一的TBT膜和PTMS膜。采用扫描电镜观察膜层形貌,采用电化学阻抗谱和极化曲线研究了膜层的耐蚀性能。结果表明:单一膜层在铜表面吸附时会有裂缝、孔洞等缺陷,不能够完全阻碍腐蚀粒子与金属基体接触,TBT/PTMS复合膜不仅填补了硅烷膜表面的孔洞,同时还提高了三氮唑膜的结合力,共同起到良好的防护作用;在3.5%NaCl溶液中,铜整体电极腐蚀电流密度较大,其表面形成TBT/PTMS复合膜后的腐蚀电流密度显著降低,膜电阻和电荷转移电阻提升明显,具有较好的防腐蚀性能。     

铜表面有机镀膜及薄膜性能研究

通过有机镀膜的方法,利用一种自设计合成的三嗪硫醇化合物(TTN)在铜表面制备有机薄膜.通过循环伏安法解释了TTN在纯铜表面的反应及有机薄膜(PTT)的生长过程,并在0.05mA/cm2的电流密度下进行恒电流有机镀膜.通过电化学方法对薄膜的性能进行了评价,测试结果显示有机镀膜方法能在铜表面获得均匀致密的有机膜,为有机介电薄膜的制备提供研究基础.     

铜表面修饰硅烷膜在碱性溶液中的耐蚀性能研究

为了提高铜的耐蚀性,用自组装技术在铜表面上制备了3-巯基丙基三甲氧基硅烷(MPTS)自组装膜. 利用红外光谱和扫描电子显微镜研究了该膜的结构,运用极化曲线和交流阻抗图谱等电化学方法考察了 MPTS膜在0.5 mol/L NaOH溶液中对铜电极的缓蚀性能.结果表明,MPTS在铜表面可能以化学吸附方式强烈吸附到铜表面, 同时在表面以Si-O-Si键自我交联形成了线性低聚物, MPTS浓度越高, 其膜更致密.与裸铜电极相比,经MPTS修饰后的铜的腐蚀电位正移200 mV, 腐蚀电流降低一个数量级,其缓蚀效率为86.5%.     

电子束蒸镀快速沉积铜膜研究

利用电子束蒸镀设备沉积金属薄膜是微电子领域最常见的薄膜沉积工艺之一。然而使用普通钨坩埚电子束蒸镀铜薄膜时，沉积速度非常低。这是因为熔融的铜与钨坩埚是浸润的，当提高电子枪功率时，液态铜的表面自由能随着温度的升高而降低，液态铜会沿着坩埚壁向上铺展，消耗电子束能量。为此，对钨衬埚壁进行结构优化，阻止了电子枪功率较高时液态铜的向上铺展，将铜膜的沉积速度从2?/s提高到20?/s，并对不同沉积速率制备的铜薄膜的粗糙度、均匀性、应力进行对比，验证了该方法的可行性。     

玻璃粉对铜导体浆料烧结膜性能的影响

使用不同组成和含量的玻璃粉配制铜浆,将其印在Al_2O_3基片表面并在850℃烧结后得到铜膜,研究玻璃粉对铜膜的导电性和附着力等性能的影响。用四探针法测定铜膜方阻,使用拉力试验机测定铜膜附着力。用金相显微镜、X射线衍射仪(XRD)、扫描电子显微镜(SEM)以及热重分析仪(TGA)等手段对铜膜的显微组织、物相、形貌以及玻璃粉物理化学性质进行了表征。结果表明,组成为SiO_2-B_2O_3-ZnO的G3玻璃粉的玻璃性能良好且其转变温度合适,制备出的铜膜试样表面平整,微观组织致密,导电性好。当G3玻璃粉含量(质量分数)为4.8%时铜膜的方阻为9.5 mΩ/,与Al_2O_3基体间的附着力为24 N/mm~2。为了验证铜膜在使用过程中的可靠性,测试了G3-3铜膜的抗氧化和老化性能。结果表明,G3-3铜膜在室温氧化28 d后平均增重率为3.5%,电阻变化率的平均值为0.79%;在20℃~160℃高温老化后铜膜的电阻变化率平均值为12.63%、平均增重率为4.63%,具有良好的抗氧化性和抗老化性能。     

印刷线路板用金属表面防锈剂

一种表面处理剂，应用于印刷线路板的金属表面，形成一层防锈膜。该表面处理剂由1％～40％的乙酰基丙酸或甲氧基乙酸和0．01％～10．00％的一种或多种咪唑基化合物和苯并咪唑基化合物的水溶液组成。     

1.3 GHz高频铜腔磁控溅射镀铌工艺研究北大核心CSCD

相比于纯铌超导高频腔,铜腔内壁镀铌超导腔具有对直流磁场不敏感、热稳定性高、造价成本低等一系列优点,并且铜腔镀铌工艺是铜腔表面制备Nb3Sn、NbN以及超导-绝缘-超导(SIS)复合膜的基础。因此使用直流磁控溅射法在铜基底高频腔内壁进行铌膜沉积,以探索铜腔镀铌工艺。并借助于FIB、SEM、XRD对铌膜的内部缺陷、表面形貌、晶相结构进行表征分析。研究结果显示:通过控制镀膜真空室的洁净、降低镀膜时间和放电气压,以及控制磁环的运动方式,获得了铜腔轴向分布均匀,Tc值达9.26 K,表面连续性较好的铌膜。铜镀铌腔垂直测试结果显示,腔性能在Q0>108下达到了5 MV/m,对应峰值磁场24 mT。该结果为后续进一步改善镀铌质量,提高镀膜超导腔性能,以及尝试在铜基底上进行其他超导材料(NbN、Nb3Sn)的镀膜奠定了良好的基础。     

咪唑化合物在铜表面的成膜过程与机理

测定了几种咪唑化合物与铜(Ⅱ)所成模拟配合物的吸光度，并由此得到了模拟配合物的组成及结构；通过XPS测定了咪唑化合物在铜表面所成膜的结构，结合模拟配合物的结构得出了咪唑化合物在铜表面的成膜过程及机理。     

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.