PET基纳米Ag薄膜导电及电磁屏蔽性能研究

为了研究纳米Ag薄膜厚度对导电及电磁屏蔽性能的影响,采用磁控溅射法在PET非织造布上制备了不同厚度的纳米结构Ag薄膜,用原子力显微镜（AFM）分析不同厚度纳米结构Ag薄膜形貌及粒径的变化;研究了纳米Ag薄膜厚度与薄膜导电性能及屏蔽性能之间的关系;并用网络测试仪测试了不同厚度样品的电磁屏蔽效能。实验结果表明：在100MHz～1200MHz内,100岫的PET基纳米Ag薄膜的电磁屏蔽效能在20．7dB～29．3dB之间,50nm以上的PET基纳米Ag薄膜的电磁屏蔽率均达到98％以上。     

PET基纳米Ag薄膜形貌与导电及电磁屏蔽性能的分形表征

采用磁控溅射法在PET非织造布上制备了不同厚度的纳米结构Ag薄膜,用高度相关函数法对薄膜的原子力显微镜(AFM)图像进行分形维计算,用AFM分析不同厚度纳米结构Ag薄膜形貌及粒径的变化;用网络测试仪测试了不同厚度样品的电磁屏蔽效能。结果表明,随着薄膜厚度的增加,薄膜表面质量提高,分形维增大;电磁屏蔽效能也随分形维的增大而增加。可以认为,分形维能有效地表征薄膜的表面形貌,分形维与导电及屏蔽效能存在明显的对应关系,并可以用分形维优化磁控溅射的工艺条件。     

非织造基磁控溅射纳米银薄膜导电性能的研究

在室温条件下采用射频磁控溅射在丙纶(PP)、聚乳酸(PLA)熔喷非织造布表面生长纳米银(Ag)薄膜,并且用等离子体预处理样品进行对比。采用扫描电子显微镜(SEM)对其形貌进行表征,采用四探针测试仪对所制备的纳米薄膜的导电性能进行表征。研究溅射时间、孔隙率及孔径分布和等离子处理对非织造基纳米银薄膜的导电性能的影响。实验表明:随着反应溅射时间的增加,薄膜的方块电阻值下降,导电性能增加;孔径大小也影响薄膜的导电性能,随着孔径的增大,薄膜的导电性能降低;等离子体处理对织物表面进行刻蚀,增加了纤维的比表面积,提高了纤维的润湿性能,改善了织物的导电性能。     

基底结构对纳米铜膜光电性能影响

采用射频磁控溅射法,在涤纶机织布、纺粘非织造布、针织布、纤维膜表面沉积纳米铜薄膜,并用紫外-可见分光光度计与四探针测试仪测试样品透光和导电性能,用彩色摄像机观察溅射样品的表面形貌,用毛管流动孔隙仪测试不同基底孔隙大小及分布,并对结果进行比较分析。结果表明,基底布表面结构形貌与孔隙大小对样品光透射率、导电性能均产生影响。随基底布孔隙率的增加,样品透射率提高,导电性能减弱,针织布由于其松散的线圈结构使得其表面电阻难以测知。     

非织造布表面反应溅射沉积ZnO薄膜及其结构与性能分析

实验采用低温直流磁控溅射技术，经O2和Zn在真空腔内反应、在涤纶纺粘非织造布表面沉积ZnO功能性纳米薄膜。运用能量散射X射线能谱仪（EDX）分析样品镀层前后元素组成的变化及其含量，并利用原子力显微镜（AFM）分析纳米结构表面镀层的形貌及其与直流溅射工艺参数的关系。分析表明：ZnO颗粒尺寸在一定范围内随氧氩比的增大而增大，氧氩比为20sccm：20sccm时较合适；溅射功率和镀膜厚度的增加均使ZnO颗粒尺寸增大，溅射功率过大会导致ZnO颗粒发生畸变；溅射压强增加颗粒直径则是先增大后减小，同时压强增大颗粒均匀性和取向性变差。利用织物感应式静电测试仪测试镀层前后织物的抗静电性能，发现经镀层后非织造布的抗静电性能得到了显著的改善，而且随着膜厚的增加抗静电性能提高也很明显。     

Ag反射膜厚度对PbTe热电薄膜性能的影响

采用真空蒸发法制备相同厚度的PbTe薄膜,再利用RF磁控溅射法在上面制备不同厚度的Ag反射膜,采用XRD、SEM、FTIR和四探针法分别对制备样品的物相组成、表面形貌、透射率和电阻率进行测试,结果显示,所制备的薄膜具有明显的〈100〉方向择优取向,呈多晶结构,随着反射膜厚度的增加,薄膜结晶性能先降低后增加;晶粒尺寸增加,表面粗糙程度先降低后增加;薄膜光学性能在一定膜厚范围内,随着反射膜厚度的增加透射率降低,超过一定膜厚时,透射率降为零;随着反射膜厚度的增加,电阻率呈先急剧降低后缓慢降低的趋势。     

氩等离子体预处理对纳米结构银非织造布抗菌性能的影响

采用磁控溅射技术，在丙纶非织造布（PP）基材表面沉积厚度为0．5-3nm的纳米结构银薄膜，重点研究了PP基材经氩等离子体预处理前后对纳米结构银薄膜抗菌性能的影响。采用振荡烧瓶法测试样品的抗菌性能，利用原子力显微镜（AFM）观察氩等离子处理前后PP基材表面的形态变化，同时应用EDX对纳米结构银薄膜进行元素分布及定量分析。实验结果表明：在纳米结构银薄膜厚度相同的条件下，经氩等离子预处理的丙纶非织造布具有更好的抗菌性能；AFM分析表明，经氩等离子处理后的纤维表面有明显的刻蚀痕迹，纤维表面凹凸不平，形成很多微小的空隙，溅射出的银粒子不易团聚，活性增加，抗菌性能因此提高；而EDX结果分析表明，抗菌性能提高是由于经氩等离子处理后，银离子溶出总量增加的缘故。     

离子束溅射沉积Co纳米薄膜表面特征AFM、XPS分析

采用离子束溅射沉积法，在单晶Si基片上制备了不同厚度（1nm-100nm）的Co纳米薄膜。利用原子力显微镜和X射线光电子能谱仪对不同厚度的Co纳米薄膜的表面进行了分析和研究。结果表明：当薄膜厚度为1nm～10nm时，沉积颗粒形态随着薄膜厚度的增加将由二维生长的细长胞状过渡到多个颗粒聚集成的球状；当膜厚继续增加，小颗粒球消失，集结成大颗粒球，颗粒球呈现三维生长状态；表面粗糙度随着膜厚（膜厚为1nm～10nm）的增大，呈现先增加后减小的趋势，在膜厚为3nm时出现极值。通过XPS全程宽扫描和窄扫描，薄膜表面的元素成分为Co：主要以金属Co和Co氧化物的形式存在。     

ZnO/Cu多层膜的制备及电磁屏蔽性能研究

采用磁控溅射法在涤纶水刺非织造布表面沉积纳米结构Cu单层膜和ZnO/Cu多层膜,利用原子力显微镜(AFM)对薄膜表面形貌进行分析,并利用四探针测试仪和矢量网络分析仪对样品的电学性能进行了测试。结果表明,在ZnO薄膜表面生长的Cu膜比在PET织物表面生长的Cu膜的均匀性、电学性能要好;在Cu镀膜时间相同的情况下,随着ZnO镀膜时间的增加,多层膜ZnO/Cu的电学性能先提高后降低,当ZnO镀膜时间为20min时,多层膜的电学性能达到最好;在ZnO镀膜时间相同的情况下,随着Cu镀膜时间的增加,多层膜ZnO/Cu的电学性能和织物表面颗粒均匀性经历了先提高、最后趋于稳定的过程,屏蔽效能最大平均值达到56dB。     

氩等离子体预处理对纳米结构银非织造布抗菌性能的影响

采用磁控溅射技术,在丙纶非织造布(PP)基材表面沉积厚度为0.5～3 nm的纳米结构银薄膜,重点研究了PP基材经氩等离子体预处理前后对纳米结构银薄膜抗菌性能的影响.采用振荡烧瓶法测试样品的抗菌性能,利用原子力显微镜(AFM)观察氩等离子处理前后PP基材表面的形态变化,同时应用EDX对纳米结构银薄膜进行元素分布及定量分析.实验结果表明:在纳米结构银薄膜厚度相同的条件下,经氩等离子预处理的丙纶非织造布具有更好的抗菌性能;AFM分析表明,经氩等离子处理后的纤维表面有明显的刻蚀痕迹,纤维表面凹凸不平,形成很多微小的空隙,溅射出的银粒子不易团聚,活性增加,抗菌性能因此提高;而EDX结果分析表明,抗菌性能提高是由于经氩等离子处理后,银离子溶出总量增加的缘故.     

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.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

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.……     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.