Temperature distribution in semiconductor wafers heated in ahot-wall-type rapid diffusion furnace

Transient temperature distribution was calculated for wafers heated in a new hot-wall-type rapid diffusion furnace. Two-dimensional radiative heat transfer was combined with unsteady conduction in wafers and the furnace. The furnace is composed of parallel plate heaters, and heats wafers to a temperature of about 1000°C. The heaters are divided into four zones and their heating powers are PID-controlled. Two wafers on a holder are inserted vertically from the bottom of the furnace, and heated for three minutes. The calculated results show the wafer temperature approached the desired heating temperature about one minute after insertion, agreeing with experimental results. The average temperature distribution in the wafers during heating is found to be within ±1°C at 1000°C, when the heating power (temperature) of the four zones is properly controlled. The effects of heater temperature, insertion speed, and holder thickness on the temperature distribution in wafers were calculated. The new hot-wall-type rapid diffusion furnace can be used to manufacture future VLSI     

Formulation of a nonlinear model of chromatic adaptation for a light-gray background

The nonlinear model of chromatic adaptation of Nayatani, Takahama, and Sobagaki^1–3 is extended to apply to an adapting field with a light-gray background. Its formulation and computational procedure are described in detail. Using the extended formulation, the following adaptation effects are predicted for a background reflectance of 50%: )1( the chromatic-adaptation effect between standard illuminants D₆₅ and A, )2( the change of colorfulness of colored samples )the Hunt effect(, )3( the change of bright and dark contrast of nonselective samples )the Stevens effect(, and )4( the color perception of nonselective samples under a colored adapting illumination )the Helson-Judd effect(. Effects )2( and )3( are observed by changing the adapting luminance. The effect of changing the background reflectance from 0.20 to 0.50 is discussed with respect to prediction of the above four effects. This change is especially significant in the Helson-Judd effect but less so in the others.     

Photoinduction of arginine decarboxylase activity in leaves of Pharbitis nil

The activity of arginine decarboxylase (ADC) in leaves of Pharbitis nil was induced by light. The ADC activity increased to a maximum 1 h after illumination, followed by a gradual decrease. This suggested light either induced synthesis of ADC protein de novo or was involved in its activation. Cycloheximide inhibited the photoinduction of ADC activity, and the half life of ADC in leaves was 30-40 min. The temperature and relative humidity in darkness before illumination had no effect on the photoinduction of ADC activity, contrary to the photoresponse of S-adenosylmethionine decarboxylase (SAMDC) activity where the conditions of darkness before lights-on have a marked effect. The light response of the polyamine (PA)-biosynthetic enzyme activity produced transient accumulation of PA. The level of spermidine increased in leaves in which activities of both SAMDC and ADC increased after illumination, while the level of putrescine increased in leaves in which the activity of ADC increased but that of SAMDC did not.     

Learning Petri network and its application to nonlinear systemcontrol

According to recent knowledge of brain science it is suggested that there exists functions distribution, which means that specific parts exist in the brain for realizing specific functions. This paper introduces a new brain-like model called Learning Petri Network (LPN) that has the capability of functions distribution and learning. The idea is to use Petri net to realize the functions distribution and to incorporate the learning and representing ability of neural network into the Petri net. The obtained LPN can be used in the same way as a neural network to model and control dynamic systems, while it is distinctive to a neural network in that it has the capability of functions distribution. An application of the LPN to nonlinear crane control systems is discussed. It is shown via numerical simulations that the proposed LPN controller has superior performance to the commonly-used neural network one.     

Analysis of a cavity-backed annular slot antenna with one pointshorted

Analysis of a cavity-backed annular slot antenna with one point shorted is performed experimentally and theoretically. Resonance frequencies, bandwidths, and radiation patterns are studied with respect to slot width, cavity depth, and slot shorting position. In the theoretical analysis, the method of moments is applied to find the magnet current on the slot, and the Green's function for the field inside the cavity has been newly derived. By selecting a slot shorting position, circular polarization, and a bandwidth of more than 10%, the voltage standing-wave ratio (VSWR) ⩽2 for the input impedance is obtained     

Nitrosymmetallochelates—I. Mechanism of FeNO—EDTA complex formation and its oxidation

A nitrosyliron(II) complex with EDTA was produced by reaction of the Fe(II)—EDTA complex and nitrous acid in citric acid—phosphate buffer solution. The experimental results pointed out that nitrous acid is reduced to nitrous oxide by Fe(II)—EDTA complex followed by the formation reaction of nitrosyliron(II) EDTA complex. The composition of this complex was determined to be Fe(II) (NO)₂EDTA by both electrochemical and spectroscopic methods.A mechanism of the oxidation of Fe(II) (NO)₂EDTA was proposed in which nitrous oxide breaks away from the iron ion. The photoeffect on this reaction is discussed.     

A proposal of new standard deviate observers

The method of singular-value decomposition analysis of matrices is used to analyze the 20 color-matching functions of Stiles's observers. It is confirmed that the 20 color-matching functions are well reconstituted by the first three decomposed components. A new deviate observer is derived from the first decomposed component. It is shown that the new deviate observer can be used well in the computation of observer-metamerism indices. Furthermore, an optimized deviate observer is developed by modifying the color-matching functions of the new deviate observer slightly. Both the new and the optimized deviate observer give a basis for the further study of the evaluation of observer metamerism.     

Asymmetric Aldol Reaction of Dichloroacetaldehyde Catalyzed by Diarylprolinol

The asymmetric cross‐aldol reaction of dichloroacetaldehyde with aldehyde pronucleophiles proceeds in the presence of a trifluoromethyl‐substituted diarylprolinol to afford γ,γ‐dichloro‐β‐hydroxy aldehydes in good yield with excellent enantioselectivity. The obtained products are useful synthetic intermediates; they were successfully converted to form chiral alkynes and dichloroalkenes.