隔声屏障-不能治理冷却塔噪声

现时中国大陆城市急速发展,做成大量环境噪声问题.某室外空调机房配备了六台冷却塔,与附近最近的居民楼距离只有15 m,测得的噪声比国标的规定高出了25 dB(A).传统的噪声治理是利用隔声屏障去阻挡冷却塔的噪声,可是效果不显着,而使用隔声罩与消声器则可能会影响冷却塔运作.此项工程最大的挑战除了要做到高消声效果外,还要解决消声器的压降与进出风短路问题.作者提供了一个整体的降噪治理和解决进出风短路的方案,最终把居民楼的噪声由75 dB(A)降至49 dB(A).此系统和产品设计非常值得讨论.     

Short-channel MOSFETs with oxynitride gate dielectrics fabricated using multiple rapid thermal processing

Short-channel MOSFETs with superior thin gate dielectrics have been successfully fabricated using multiple reactive rapid thermal processing of thermal oxides. The gate dielectrics are produced by rapid thermal nitridation (RTN) of thin thermal oxides in pure NH/sub 3/ ambient followed by rapid thermal reoxidation (RTO) in O/sub 2/ ambient. Devices fabricated with RTO/RTN gate dielectrics exhibit improved hot electron induced degradation compared to those fabricated with pure oxides. In addition, the subthreshold leakage current level of RTO/RTN devices is as good as for standard oxide devices.<>     

Study of interface state generation in thin oxynitride gate dielectrics under hot-electron stressing

The hot-electron-induced interface state generation in thin ( approximately 8.6 nm) oxynitride films prepared by rapid thermal reoxidation (RTO) of rapidly thermal nitrided (RTN) SiO/sub 2/ have been studied. Both MOS capacitors and MOSFETs were used as testing devices. For MOSFETs charge-pumping current I/sub cp/ measurement was performed to monitor the increase Delta D/sub it/ of interface state density. It is found that the optimised RTN and RTO processes could produce devices with a significantly improved resistance against the hot electron-induced interface state generation.<>     

A small OCA on a 1/spl times/0.5-mm/sup 2/ 2.45-GHz RFID Tag-design and integration based on a CMOS-compatible manufacturing technology

This letter reports, for the first time, on the design strategy and process integration for a small on-chip-antenna (OCA) with a radio-frequency identification (RFID) tag chip-area /spl sim/1/spl times/0.5 mm/sup 2/. It is designed based on a 2.45-GHz RFID tag circuit with an inductive-coupling model. A patterned Al shielding layer is used to improve the consistency of the actual performance obtained from fabricated devices and those predicated from the design. The antenna's inductor coils were fabricated based on a conventional Cu-Damascene process. To achieve the required antenna performance (e.g., Q-factor), a set of thick USG and deep-via etch processes were specifically developed. Our results demonstrate that the dc power converted by the OCA is sufficient to enable the RFID tag chip to communicate with a corresponding 2.45-GHz RFID reader with a 1-mm distance.     

Perceptions of an old female eyewitness: Is the older eyewitness believable?

Young adults rated an old female witness (82 years) to be less competent but more honest than a young female witness (28 years). The effect of age stereotyping on believability was assessed indirectly by using a variant of Loftus' misinformation paradigm. Regression analysis showed that the more competent a witness was perceived as being, the more influential was the misinformation she provided. This was true, however, only when the witness was young because the relatively lower competence of the old witness was associated with nonsignificant misinformation effects. These data suggest that negative beliefs associating incompetence with old age may compromise the believability of older eyewitnesses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

便携式和消费类电子USB应用的"非集成"方案

由于电路板空间限制,便携式电子中高集成度趋势更加明显。减少元件数量是集成带来的好处,但往往芯片组仍十分昂贵,也有其他因素驱使设计者倾向于选择分立器件。     

The impact of TiN capping Layer on NiSi, CoSi/sub 2/, and Co/sub x/Ni/sub 1-x/Si/sub 2/ FUSI metal gate work function adjustment

The impact of TiN capping layer on dual work functions of Ni, Co, and Co-Ni fully silicided (FUSI) metal gates was investigated. It was found that the TiN capping layer significantly altered the distribution of both n- and p-dopants during the FUSI process, which in turn changed the work functions of both As-doped and B-doped in the three FUSI metal gate systems. The work function tuning was found to have a linear relationship with the change of dopant level at the silicides/dielectric interface after adding TiN capping layer. The investigation of TiN capping layer on FUSI provided some insights on work function tuning mechanism in FUSI systems. This work also suggested a new methodology for optimizing the nMOS and pMOS work functions for CMOS device applications.     

Preparation of flavanol‐rich green tea extract by precipitation with AlCl3

The aim of this study was to use AlCl₃ in the extraction of green tea flavanols (GTFs) from longjing green tea and examine the factors that influence the yield of GTF extract. Dry tea leaves were soaked in hot distilled water and the infusion was obtained by filtration. To the tea infusion, varying amounts of AlCl₃ were added, causing precipitation of GTFs. After adjusting the pH to 4.0–6.5 and centrifugation, the yellow precipitate was collected. Sulphuric acid solution (40%) was then used to dissolve the GTFs from the yellow precipitate. The GTF solution was extracted using an equal volume of ethyl acetate. After the removal of ethyl acetate using a rotary evaporator, the GTF extract was redissolved in distilled water and the whole process was repeated. The resulting GTF extract was freeze‐dried. It was found that the amount of AlCl₃ used and the pH and temperature of the precipitation mixture significantly affected the yield and purity of GTF extract. A yield of 9.6 g extract per 100 g dry tea leaves with GTFs > 94% could be obtained if AlCl₃ was used in the ratio of 15 g per 100 g equivalent dry tea leaves and the pH of the precipitation mixture was adjusted to 5.5 at 30 °C. © 2001 Society of Chemical Industry     

Assembly of the epithelial Na+ channel evaluated using sucrose gradient sedimentation analysis

Three subunits, alpha, beta, and gamma, contribute to the formation of the epithelial Na+ channel. To investigate the oligomeric assembly of the channel complex, we used sucrose gradient sedimentation analysis to determine the sedimentation properties of individual subunits and heteromultimers comprised of multiple subunits. When the alpha subunit was expressed alone, it first formed an oligomeric complex with a sedimentation coefficient of 11 S, and then generated a higher order multimer of 25 S. In contrast, individual beta and gamma subunits predominately assembled into 11 S complexes. We obtained similar results with expression in cells and in vitro. When we co-expressed beta with alpha or with alpha plus gamma, the beta subunit assembled into a 25 S complex. Glycosylation of the alpha subunit was not required for assembly into a 25 S complex. We found that the alpha subunit formed intra-chain disulfide bonds. Although such bonds were not required to generate an oligomeric complex, under nonreducing conditions the alpha subunit formed a complex that migrated more homogeneously at 25 S. This suggests that intra-chain disulfide bonds may stabilize the complex. These data suggest that the epithelial Na+ channel subunits form high order oligomeric complexes and that the alpha subunit contains the information that facilitates such formation. Interestingly, the ability of the alpha, but not the beta or gamma, subunit to assemble into a 25 S homomeric complex correlates with the ability of these subunits to generate functional channels when expressed alone.