In Situ Study of Nanostructure and Electrical Resistance of Nanocluster Films Irradiated with Ion Beams

An in situ study is reported on the structural evolution in nanocluster films under He⁺ ion irradiation using an advanced helium ion microscope. The films consist of loosely interconnected nanoclusters of magnetite or iron‐magnetite (Fe‐Fe₃O₄) core‐shells. The nanostructure is observed to undergo dramatic changes under ion‐beam irradiation, featuring grain growth, phase transition, particle aggregation, and formation of nanowire‐like network and nanopores. Studies based on ion irradiation, thermal annealing and electron irradiation have indicated that the major structural evolution is activated by elastic nuclear collisions, while both electronic and thermal processes can play a significant role once the evolution starts. The electrical resistance of the Fe‐Fe₃O₄ films measured in situ exhibits a super‐exponential decay with dose. The behavior suggests that the nanocluster films possess an intrinsic merit for development of an advanced online monitor for fast neutron radiation with both high detection sensitivity and long‐term applicability, which can enhance safety measures in many nuclear operations.     

Cellulose acetate as a selective sorbent for limonin in orange juice

Cellulose acetate as flake or powder is an efficient and selective sorbent for removing the bitter principle limonin from orange juice. Treatment of orange juice serum with powder (10 g/litre) removed 44–70% of the limonin content in less than an hour, at the same time removing relatively negligible amounts of hesperidin and ascorbic acid. Similar amounts of limonin could be removed by agitating the whole juice with cellulose acetate flakes held in open mesh bags which allowed contact between the enclosed flakes and the juice. Other materials, including related carbohydrate derivatives and polymers, were tested but only cellulose acetate butyrate shared the unusual sorptive properties of cellulose acetate.     

低IQ DC/DC控制器帮助延长汽车电池运行时间

尽管开关模式电源效率很高,但是所有开关模式电源都需要一定量的功率,以在甚至没有输出负载或输出负载非常小时工作.尽管这一功率可能很低,但是在能量稀缺和多个始终保持接通电路处于体眠模式的应用中,这一功率却可能高得不可接受.为了解决这个问题,凌力尔特公司提供的LTC3857/-1双输出同步降压型控制器采用了突发模式(Burst Mode)工作,这种工作模式在DC/DC转换器轻负载时最大限度地降低了功耗     

开罪上下游企业任天堂失市场霸主地位获报应

随着任天堂公司的新游戏主机Wii在美国开卖,游戏主机市场正式进入三足鼎立时代--如今,全球游戏主机市场价值300亿美元,主要有微软Xbox360、索尼PS3和任天堂Wii参与角逐.     

10GBASE-T:基于铜质电缆的10Gb以太网指南

10GBASE-T面临着回波、近端串扰、远端串扰、Alien串扰等信道损耗带来的挑战。10Gb以太网切实可行且万事俱备自从2002年批准10Gb以太网通信标准以来,业界总是预测"明年"将会最终推出10Gb以太网。然而,自诞生以来,10Gb以太网的发展就因为其无法利用各种低速以太网标准成熟的传输方式而受到阻碍。     

Stackable nonvolatile memory with ultra thin polysilicon film and low-leakage (Ti, Dy)xOy for low processing temperature and low operating voltages

We report the fabrication process as well as material and electrical characterization of ultra thin body (UTB) thin film transistors (TFTs) for stackable nonvolatile memories by using in situ phosphorous doped low-temperature polysilicon followed by the chemical mechanical polishing (CMP) process. The resulting polysilicon film is about 13 nm thick with approximately 10¹⁹ cm⁻³ doping. Root mean square surface roughness below 1 nm is achieved. Metal nanocrystals and high-k dielectric are selected for storage nodes and tunneling barriers to achieve low operating voltages. The number density and average diameter of nanocrystals embedded in the gate stack are 7.5 × 10¹¹ cm⁻² and 5.8 nm, respectively. Furthermore, scanning transmission electron microscopy (STEM), convergent beam electron diffraction (CBED) and electron energy loss spectroscopy (EELS) are performed for material characterization. The dielectric constant of the (Ti, Dy)_xO_y film is 35, and the off-state leakage current at −1 V bias and 2.8 nm equivalent oxide thickness is 5 × 10⁻⁷ A/cm². We obtain a memory window of about 0.95 V with ±6 V program/erase voltages. Our results show that UTB TFT is a promising candidate for the three-dimensional integration in high-density nonvolatile memory applications.     

Use of Mesoscopic Host Matrix to Induce Ferrimagnetism in Antiferromagnetic Spinel Oxide

Despite the advances in the methods for fabricating nanoscale materials, critical issues remain, such as the difficulties encountered in anchoring, and the deterioration in their stability after integration with other components. These issues need to be addressed to further increase the scope of their applicability. In this study, using epitaxial mesoscopic host matrices, materials are spatially confined at the nanoscale, and are supported, anchored, and stabilized. They also exhibit properties distinct from the bulk counterparts proving their high quality nanoscale nature. ZnFe₂O₄ and SrTiO₃ are used as the model confined material and host matrix, respectively. The ZnFe₂O₄ phases are spatially confined by the SrTiO₃ mesoscopic matrix and have strongly enhanced ferrimagnetic properties as compared to bulk and plain thin films of ZnFe₂O₄, with a Curie temperature of ≈500 K. The results of a series of control experiments and characterization measurements indicate that cationic inversion, which originates from the high interface‐to‐volume ratio of the ZnFe₂O₄ phase in the ZnFe₂O₄–SrTiO₃ nanocomposite film, is responsible for the magnetization enhancement. An exchange bias is observed, owing to the coexistence of ferrimagnetic and antiferromagnetic regions in the confined ZnFe₂O₄ phase. The magnetic properties are dependent on the ZnFe₂O₄ crystallite size, which can be controlled by the growth conditions.     

阐释Sigma与机器性能的关系

生产设备的Sigma或Cpk等级非常重要,但其背后的理论很易会引起混淆.统计工艺控制(SPC)工具可以算出答案,但是假如设备一直达不到制造商声称的性能,那又如何?一些设备供应商甚至对于机器什么时候能达到最理想的重复精度6-Sigma的意见也不一致,当中的不稳定性主要来自如何诠释数据及如何运用适当的变数上限和下限.其实关键在于工艺的标准偏差,这是大家都同意的一点.     

下一代显示接口新标准--DisplayPort

随着显示技术逐渐转移到高性能的平板以及微电子技术,业界需要一种可扩充、开放产业标准的数字接口,以及可以把功能升级的解决方案。这种可升级的显示接口,应能满足企业以及一般消费者的各种需求。DisplayPort就是这种下一代的显示接口,可以为PC、监视器、显示面板、投影仪、以     

Altruism on American Television: Examining the Amount of, and Context Surrounding, Acts of Helping and Sharing

Using a representative sample of television content featuring 2,227 programs across different genres and 18 different channels, the frequency and context of altruistic actions were content analyzed. A social cognitive theory approach was taken to guide the selection of contextual variables. The results showed that 73% of the programs in the sample featured instances of helping/sharing at a rate of 2.92 incidents per hour. Further, the actions were most likely to be initiated by adult White males and many acts were depicted in a humorous, realistic, and rewarding context. In terms of channel differences, shows on children's basic cable featured not only the highest proportion of programs with one or more instances of altruism but also the highest rate per hour (4.02 acts). Differences in contextual features and channel type are discussed in terms of social cognitive theory below.