MABP: an optimal resource allocation approach in data center networks

In data center networks, resource allocation based on workload is an effective way to allocate the infrastructure resources to diverse cloud applications and satisfy the quality of service for the users, which refers to mapping a large number of workloads provided by cloud users/tenants to substrate network provided by cloud providers. Although the existing heuristic approaches are able to find a feasible solution, the quality of the solution is not guaranteed. Concerning this issue, based on the minimum mapping cost, this paper solves the resource allocation problem by modeling it as a distributed constraint optimization problem. Then an efficient approach is proposed to solve the resource allocation problem, aiming to find a feasible solution and ensuring the optimality of the solution. Finally, theoretical analysis and extensive experiments have demonstrated the effectiveness and efficiency of our proposed approach.     

分离压对不同基底上含活性剂液滴铺展特征的影响

针对不同基底结构上含不溶性活性剂液滴的铺展过程,引入受活性剂浓度影响的分离压模型,应用润滑理论建立了液滴厚度和活性剂浓度演化方程组,通过数值计算得到了分离压作用下含活性剂液滴过程的演化特征。研究表明不考虑分离压时,最小液膜高度贴近壁面,诱发去润湿现象发生,基底不平整度增加加剧液膜变形;分离压作用下最小液膜高度显著上升,铺展前沿处衍生出的子波结构明显减少,铺展更加稳定;分离压具有抑制液膜表面变形促进液滴铺展的作用。     

基于GaAs电感模型的微波功率放大器

基于0.15μm砷化镓(GaAs)工艺建立一种电感模型,并用高频结构模拟器(High Frequency Structure Simulator,HFSS)仿真验证,并在此基础上设计一种微波功率放大器,并用高级系统设计软件(Advanced Design System,ADS)进行仿真。仿真结果显示在8¹2GHz频率范围内,饱和输出功率大于21.9dBm,1dB压缩点输出功率大于20dBm,功率增益大于26dB,功率附加效率大于34%,稳定系数大于1。     

Evaluating the role of composition and local structure on alkali out-diffusion in glasses for thin-film solar cells

The presence of alkali ions has reportedly improved the performance of CIGS/CZTS–based thin-film solar cells. The out-diffusion of the alkali ion, in particular, Na, from the glass substrate offers a facile scalable route of supplying the alkali ions during the growth of the absorber layer. In this work, we demonstrate the diffusion of different alkali ions (Li/Na/K) from composition tuned glasses with intentionally incorporated excess alkali ions into a thin Mo film, typically used as a bottom electrode in solar cells. We also evaluate the physical, mechanical, and thermal properties of the glasses for suitability as a substrate in thin-film deposition. The out-diffusion of alkali ions to the overlayer is found to be critically influenced by the composition and the local structure of the glasses. The Na ions exhibit the highest extent of diffusion among the alkali ions present in glass substrates, while that for the K-ions is the lowest. For the glasses with mixed alkali ions, the presence of Li facilitated the out-diffusion of Na, whereas K ions appear to inhibit the same. Differently with the existing reports, we show that the activation energy and the presence of Ca ions as additional modifiers play a crucial role in the transport mechanism of the ions. In addition, the synthesized glasses exhibit hardness of the order 5-7 GPa, density ~2.55 g cm^-3. The glass transition temperature lies between 535 and 580°C and the coefficient of thermal expansion 8.5-10 ppm/K, which is highly suitable for use as substrates in thin-film solar cells.     

Indentation method for fracture resistance determination of metal/ceramic interfaces in thick TBCs

The indentation technique has been used to measure the adhesion of plasma- sprayed ceramic coatings on metals intended for thick thermal barrier coating ( TTBC) applications. This approach provides the adhesion value as the critical strain energy release rate,Gc, of the interface, which also takes into account any residual stresses. The theoretical background of the method is outlined, and specific examples are reported with respect to the effect of substrate temperature on the metal/ceramic adhesion of thick TBCs.     

热处理对两种铜膜结合强度的影响

采用PVD和CVD技术制备Cu/TiN/PI试样，研究表明，TiN薄膜可以有效地阻挡Cu向PI基板内部扩散，CVD工艺制备的Cu膜内部残余应力很小，Cu膜有相对高的结合强度；而PVD制备的Cu膜，在有TiN阻挡层存在的情况下，Cu膜内存在拉应力，拉应力降低了Cu膜结合强度，300℃退火可以消除膜内残余应力，结合强度提高。     

INTERFACIAL REACTIONS OF METAL FILMS WITH AlN SUBSTRATE

ＩＮＴＥＲＦＡＣＩＡＬＲＥＡＣＴＩＯＮＳＯＦＭＥＴＡＬＦＩＬＭＳＷＩＴＨＡｌＮＳＵＢＳＴＲＡＴＥＨｅＸｉａｎｇｊｕｎ；ＴａｏＫｕｎ；ＦａｎＹｕｄｉａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎｇ，Ｔｓｉｎｇｈ...     

New attachment for controlling gas flow in the HVOF process

During the decade, the high-velocity oxyfuel (HVOF) process proved to be a technological alternative to the many conventional thermal spray processes. It would be very advantageous to design a nozzle that provides improved performance in the areas of deposition efficiency, particle in-flight oxidation, and flexibility to allow deposition of ceramic coatings. Based on a numerical analysis, a new attachment to a standard HVOF torch was modeled, designed, tested, and used to produce thermal spray coatings according to the industrial needs mentioned above. Performance of the attachment was investigated by spraying several coating materials including metal and ceramic powders. Particle conditions and spatial distribution, as well as gas phase composition, corresponding to the new attachment and the standard HVOF gun, were compared. The attachment provides better particle spatial distribution, combined with higher particle velocity and temperature. The original version of this article was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Science and Applying the Technology, International Thermal Spray Conference (Orlando, FL), 5–8 May, 2003, Basil R. Marple and Christian Moreau, Ed., ASM International, 2003.     

Au-Ni-Kovar合金系统基底元素表面偏聚的SAM和XPS研究SCIEI

本文采用SAM和XPS对实用Au-Ni-Kovar合金系统热处理样品(250—350℃,0.5—1.5h)进行了基底元素穿透Au层的表面偏聚研究,给出了这一复杂系统中Ni,Co表面偏聚机理的直观证据,即Ni,Co主要是通过晶界扩散穿透Au层而后以表面扩散覆盖镀Au表面的;表面偏聚元素化学态的研究则不仅表明,氧的吸附和氧化反应是Ni,Co表面偏聚的驱动力,而且发现,上述偏聚会引起样品表面吸水的现象。     

Quenching stress in plasma sprayed coatings and its correlation with the deposit microstructure

Quenching stress arises within a thermally sprayed splat as its thermal contraction after solidification is constrained by the underlying solid. Dependence of the quenching stress in plasma-sprayed deposits of Ni-20Cr alloy and alumina on the substrate temperature during spraying was discussed in conjunction with the change in the nature of the interlamellar contact between splats. It was found by mercury intrusion porosimetry and observation of cross sections of impregnated deposits that the interlamellar contact is improved significantly by raising the substrate temperature during deposition from 200 to 600 °C. The positive dependence of the quenching stress on the substrate temperature in this temperature range was attributed to a stronger constraint against thermal contraction of sprayed splats after solidification due to the improved contact.