Characterization and comparison of PECVD silicon nitride and silicon oxynitride dielectric for MIM capacitors

In this letter, we report on the electrical characteristic and the comparison of the metal-insulator-metal (MIM) capacitors with PECVD silicon nitride (SiN) and silicon oxynitride (SiON). Both capacitors are found to exhibit low leakage and high breakdown field strength, as well as absence of dispersive behavior, good linearity, and comparable quality factor behaviors.     

在线近红外光谱分析仪在汽油自动调合系统中的应用

在线近红外光谱分析仪可以实时测定汽油调合组分及成品油的多种物化性质指标如烯烃、芳烃、苯及氧化物含量、辛烷值（RON、MON）、馏程、蒸气压等。文章介绍了用于汽油自动调舍工艺中的在线近红外光谱分析仪的原理、系统组成和特点，以及在国内外的汽油调合优化控制中的实际应用情况。典型的应用实例表明，将该分析仪用于汽油自动调合工艺中，可为炼油厂带来可观的经济效益和社会效益。     

Fabrication and characteristics of high-speed implant-confined index-guided lateral-current 850-nm vertical cavity surface-emitting lasers

Process technology of high-speed implant-apertured index-guide lateral-current-injection top dielectric-mirror quantum-well 850-nm vertical cavity surface-emitting lasers (VCSELs) has been developed. Oxygen and helium implantation for aperture definition and extrinsic capacitance reduction, dielectric mirror formation, p- and n-ohmic contact formation, VCSEL resistance, and thermal analysis were investigated. Employing this technology, GaAs/AlGaAs-based 850-nm VCSELs with small signal modulation bandwidths up to 11.5 Gb/s and an eye diagram generated at 12 Gb/s by a pseudorandom bit sequence of 2/sup 31/-1 were achieved. The bit-error rates were below 10/sup -13/. The threshold current is as low as 0.8 mA for 7-/spl mu/m-diameter current apertures and typical slope efficiencies of 0.45-0.5 mA/mW were obtained.     

Transmission outage models for sub-transmission network reliabilityevaluation

Methods are presented for modeling the failure and repair of transmission equipment and their impact on subtransmission system reliability. The methods account for arbitrary load variation and nonexponential downtime distribution for components. The effects of single independent outages common-mode outages and independent overlapping outages are studied. The results are used to identify conditions when nonexponentially distributed downtimes can lead to significant errors if the method of analysis does not take this factor into account     

Estimating block selectivities for physical database design

Access path deployment is a critical issue in physical database design. Access paths typically include a clustered index as the primary access path and a set of secondary indexes as auxiliary access paths. To deploy the right access paths requires an effective algorithm and accurate estimation of the parameters used by the algorithm. One parameter central to any index-selection algorithm is the block selectivity of a query. Existing methods for estimating block selectivities are limited by restrictive assumptions. Furthermore, most existing methods produce estimates useful for aiding the selection of secondary indexes only. Little research has been done in the area of estimating block selectivities for supporting the selection of the clustered index. The paper presents a set of methods that do not depend on any specific assumption, produce accurate estimates, and can be used to aid in selecting the clustered index as well as secondary indexes     

Very high-order microring resonator filters for WDM applications

High-order microring resonators having from 1 to 11 coupled cavities are demonstrated. These filters exhibit low loss, flat tops, and out-of-band rejection ratios that can exceed 80 dB. They achieve performance that is suitable for commercial applications.     

Protocol design for scalable and reliable group rekeying

We present the design and specification of a protocol for scalable and reliable group rekeying together with performance evaluation results. The protocol is based upon the use of key trees for secure groups and periodic batch rekeying. At the beginning of each rekey interval, the key server sends a rekey message to all users consisting of encrypted new keys (encryptions, in short) carried in a sequence of packets. We present a scheme for identifying keys, encryptions, and users, and a key assignment algorithm that ensures that the encryptions needed by a user are in the same packet. Our protocol provides reliable delivery of new keys to all users eventually. It also attempts to deliver new keys to all users with a high probability by the end of the rekey interval. For each rekey message, the protocol runs in two steps: a multicast step followed by a unicast step. Proactive forward error correction (FEC) multicast is used to reduce delivery latency. Our experiments show that a small FEC block size can be used to reduce encoding time at the server without increasing server bandwidth overhead. Early transition to unicast, after at most two multicast rounds, further reduces the worst-case delivery latency as well as user bandwidth requirement. The key server adaptively adjusts the proactivity factor based upon past feedback information; our experiments show that the number of NACKs after a multicast round can be effectively controlled around a target number. Throughout the protocol design, we strive to minimize processing and bandwidth requirements for both the key server and users.     

Mesoscale simulation of block copolymers in aqueous solution: parameterisation, micelle growth kinetics and the effect of temperature and concentration morphology

In this work, we utilise ‘MesoDyn’ [J Chem Phys 99 (1993) 9202; 106 (1997) 4260] density functional simulations to study the effect of temperature and concentration on the micellar morphology of polymeric surfactants. Parameterisation strategies based upon atomistic models and experimental data are discussed. Taking the temperature dependence of interaction energy into account, the change in morphology of Pluronic (PEO-PPO-PEO) block copolymer structure with temperature is well reproduced. As a function of concentration, the diameter of spherical micelles is found to increase in line with previous cryo-TEM observations [Phys Chem Chem Phys 1 (1999) 3331]. Simulations of high concentration PEO-PBO diblock systems show ordering similar to the face-centered cubic structures found experimentally [J Polym Sci B 33 (1995) 1085; Macromolecules 30 (1997) 5721; Polymer 39 (1998) 4891; Phys Chem Chem Phys 1 (1999) 2773].     

(BETS)2[RuX5NO] (X = Cl, Br): An Explanation of Different Conductive Properties Through Structural and Spectroscopic Studies

For the development of new crystal and electronic structures in molecular conductors, dimeric tetrathiafulvalene (TTF) and tetraselenafulvalenes (TSFs)1–3 linked by single or double methyl antimony bridge(s) have been prepared and their neutral crystal structures have been investigated. The donor2 (cis-2) forms a metallic cation radical salt with tetracyanoquinodimethane (TCNQ) containing one-dimensional array interactions.