Extremum-seeking with variable gain control for intensifying biogas production in anaerobic fermentation.

A state-dependent variable-gain control system is implemented to follow the characteristics of a laboratory-scale up-flow anaerobic fixed-bed reactor dynamically. The transition from one state to another is determined on an hourly basis, depending on difference between the setpoint of the reactor pH and its true value. Considerable improvement of the process stability--reduction of oscillation in both the reactor pH and biogas production rate during high-rate operation, has been achieved, although the control structure is simple and intuitive.     

The origination and optimization of Si/SiO/sub 2/ interface roughness and its effect on CMOS performance

As CMOS device dimensions scale down to 100 nm and beyond, the interface roughness between Si and SiO/sub 2/ has become critical to device performance and reliability. Si/SiO/sub 2/ interface roughness degrades channel mobility decreasing drive currents. The authors have used atomic force microscopy to study surface roughness in the processing of 0.16 /spl mu/m CMOS integrated circuits. All of the process steps that could potentially affect the interface roughness have been studied. The results show that oxidation is the major contributor to the interface roughness. The rms roughness is found to be linearly dependent on oxide thickness. Transistors with Si/SiO/sub 2/ interface rms roughness that has been reduced from 1.6 to 1.1 /spl Aring/ by reducing oxide thicknesses show improved device drive currents. This technique for interfacial smoothing and device performance improvement has the advantage of being easily implemented in today's technology.     

Efficient particle filter-based processing algorithm for clutter suppression and IR point targets enhancement

A novel soft decision-based median subtraction filter is presented for clutter suppression and infrared (IR) point targets enhancement. The decision is made based on a jump Markov model and its state and parameter estimation using a particle filter. The scheme is compared with other conventional clutter background removal techniques and good results are obtained.     

锆(Ⅳ)-3,5-diBr-PADAP-安替比林三元配合物的分光光度研究与应用

本文提出在安替比林存在下,以3,5-diBr-PADAP为显色剂,分光光度测定微量锆的新方法。在pH1～2的HCl介质中,锆(W)与试剂和安替比林形成配合比为1:1:1的红色三元配合物,最大吸收值在615nm波长处,摩尔吸光系数ε=1.35×10~5。锆(Ⅳ)量在0～25μg/25ml范围内,遵守比尔定律。方法简单、快速、准确。若采用钽试剂—苯萃取法分离共存离子,可适用于钽铌矿和合金中痕量锆的测定。     

贵冶动力中心二期反渗透系统改造

本文阐述对贵冶动力车间二期反渗透进行改造的成功实践 ,主要从反渗透系统设计、反渗透系统中容易出现的问题及解决方法等进行介绍。     

天津德景住宅与商业

因：用地为东西向长达470m的长条形，其北侧紧邻城市干道。     

CFD Simulation of Liquid Film Flow on Inclined Plates

A two‐phase flow CFD model using the volume of fluid (VOF) method is presented for predicting the hydrodynamics of falling film flow on inclined plates, corresponding to the surface texture of structured packing. Using the proposed CFD model the influence of the solid surface microstructure, liquid properties and gas flow rate on the flow behavior was investigated. From the simulated results it was shown that under the condition of no gas flow the liquid flow patterns are dependent on the microstructure of the plates, and proper microstructuring of the solid surface will improve the formation of a continuous liquid film. It was also found that liquid properties, especially surface tension, play an important role in determining the thin‐film pattern. However, there are very different liquid film patterns under the action of gas flow. Thinner liquid films break easily, but thicker liquid films can remain continuous even at higher gas flow rates, which demonstrates that all factors affecting the liquid film thickness will affect the liquid film patterns under conditions of counter‐current two‐phase flow.     

Development of an end-point detector for parylene deposition process

Parylene is an emerging material for MEMS. It is an organic material that is grown by using the chemical vapor deposition method at room temperature. The deposition thickness is commonly controlled by the amount of solid-phase dimer loaded in a sublimation chamber. In a conventional deposition machine, the end point of the process is designated by the moment the dimer is exhausted. However, this end-of-process criterion does not offer precise, repeatable control of film thickness. We present the results of the development of an in situ end-point detector for a Parylene chemical vapor deposition process. The detector is based on the thermal transfer principle and can be implemented on commercial parylene deposition systems with minimal system modification. Such a sensor enables a user to stop the deposition when a targeted thickness is reached. The end point detector is very simple to implement on existing parylene deposition systems. A series of such sensors with different target deposition thickness would allow extraction of the actual deposition rate within a deposition run.