A knowledge assimilation method for logic databases

In this paper we consider a deductive question-answering system for relational databases as a logic database system, and propose a knowledge assimilation method suitable for such a system. The concept of knowledge assimilation for deductive logic is constructed in an implementable form based on the notion of amalgamating object language and metalanguage. This concept calls for checks to be conducted on four subconcepts, provability, contradiction, redundancy, independency, and their corresponding internal database updates. We have implemented this logic database knowledge assimilation program in PROLOG, a logic programming language, and have found PROLOG suitable for knowledge assimilation implementation.     

High rate nitrogen removal by the CANON process at ambient temperature

Completely autotrophic nitrogen removal over nitrite (CANON) is a cost-effective nitrogen removal process. Implementation of the CANON process relies on the cooperation of ammonium-oxidizing and Anammox bacteria, as well as the inhibition of nitrite-oxidizing bacteria. Strict limitations on dissolved oxygen (DO) concentration in the reactor, and the addition of sufficient inorganic carbon in the influent, were adopted as the main operational strategies. The reactor was fed with synthetic inorganic wastewater composed mainly of NH(4)(+)-N, and operated for 106 days. Stable nitrogen removal rates (NRR) of around 1.4 kg N m(-3) d(-1) were obtained at ambient temperature. Morphological characteristics and analysis of bacterial community confirmed the formation of functional outer aerobic and inner anaerobic granular sludge, providing evidence of stable nitrogen removal.     

Treatment of domestic sewage by a metal membrane bioreactor

A submerged flat metal MBR (membrane bioreactor) was used to treat synthetic domestic sewage in this study. The experiment was continued for 270 days and ran under two modes as AMBR (aerobic membrane bioreactor) and A/O-MBR (anoxic/aerobic membrane bioreactor) at a permeate flux of 0.4-1 m3/(m2 d). PVA (polyvinyl alcohol) gel beads were added to the aeration tank with a volume ratio of 10% at the end of the A/O-MBR mode. The mean COD and TN removal efficiencies achieved 96.69 and 32.12% under the AMBR mode, and those were 92.17 and 72.44% under the A/O-MBR mode, respectively. SND (simultaneous nitrification and denitrification) occurred at high MLSS (mixed liquor suspended solids) concentration. The metal membranes reduced effluent COD during filtration. The system ran stably for 115 days at a permeate flux of 0.8-1 m3/(m2 d) without changing membranes under the AMBR mode, but the membrane filterability decreased gradually under high MLSS or A/O-MBR mode, and the addition of PVA worsened the membrane filterability on the contrary. PSD (particle size distribution) and sludge fractions had evident influence on membrane fouling. The main fouling mechanism was cake formation under the AMBR mode, and that was pore blocking under the A/O-MBR mode.     

Size Distribution of Gold Nanoparticles Used by Small Angle X-ray Scattering

The size distribution of gold nanoparticles was estimated based on the scattering intensity data obtained from small angle X-ray scattering (SAXS) and compared with the result of micrographs by transmission electron microscopy. The slope of the Guinier plot was used to estimate the mean size assuming a narrow particle size distribution. When the size distribution is narrow, the mean size can be easily obtained from slope of a Guinier plot of scattering data within 10% error. Additionally, assuming a lognormal size distribution, the size distribution and the mean size can be calculated using the experimental SAXS data in the fitting analysis. The histogram method, which utilizes the coefficient matrix of scattering intensity, was also applied to the estimation of the size distribution, and this method could be useful for a rough estimate of the size distribution.     

Pressure wave propagation in air-water bubbly and slug flow

Related to nuclear reactor safety problems, such as the loss of coolant accident caused by some small crevasses in nuclear reactor, choked flows after postulated breaks of hot and cold legs of pressurized water reactors and the boiling flow instability in parallel channels, the characteristics of pressure wave propagation were investigated experimentally for the air-water bubbly and slug two-phase flow in a vertical pipe. Pressure wave was generated from the small pressure disturbance by the up-and-down movement of piston in the test section. Air void fraction was up to 0.7 and superficial liquid velocity was up to 1.5 m/s as experimental conditions. The experimental results show that the pressure wave propagation velocity in bubbly flow decreases acutely with the increase of air void fraction from 0 to 0.05. In slug flow, it is constant when the air void fraction is less than 0.5 but increases gradually when the void fraction increases beyond 0.5. The attenuation coefficient of pressure wave increases with the increase of air void fraction in bubbly flow. The dependency of pressure wave propagation velocity on angle frequency ω in air-water flow shows the dispersion characteristic. The propagation velocity and attenuation coefficient increases gradually with the increase of angle frequency. However, the increase vanishes slowly as the angle frequency reaches 250 Hz in bubbly flow. The propagation of pressure wave in bubbly flow is independent of the superficial velocity of fluids in the range of experiment.     

共析钢中片层状渗碳体冷轧后的形态变化

The pearlitic transformation and the deformation behavior of lamellar cementite after cold rolling in eutectoid steels Fe-0. 76%C-0. 137%Mn (mass fraction) were studied by means of Formastor-F (Full Automatic Transformation Testing Instrument) and field emission scanning electronic microscopy (FESEM) observation. Fine and coarse pearlite were obtained in the eutectoid steels austenitized at 900℃ for 15min, then hold at 620℃ for 90 s and 690℃ for 7 h, respectively. Thedeformation behavior of cold rolled lamellar cementite could be classified as: cleavage fracture, inhomogeneous slip, fragmentation, thinning or necking, and homogeneous bending. The cementite lamellae with the thickness of more than 100 um could be deformed plastically.     

三水铝石的粉碎机械力化学效就与热特性

使用振动球磨机将三水铝石粉体进行干式微粉碎.粉碎实验条件为介质球/试样(质量比)=8.5.研究调查了不同粉碎时间处理粉碎试样的机械力化学效应(平均粒径、结晶无定形和加热特性).结果表明,长时间粉碎,达到粉碎平衡,平均粒径趋于极限值.粉碎过程中未脱水.由于粉碎,加热脱水温度、结晶相变温度降低.     

Super‐resolution of the undersampled and subpixel shifted image sequence by a neural network

Numerous approaches to super‐resolution (SR) of sequentially observed images (image sequence) of low resolution (LR) have been presented in the past two decades. However, neural network methods are almost ignored for solving SR problems. This is because the SR problem traditionally has been regarded as the optimization of an ill‐posed large set of linear equations. A designed neural network based on this has a large number of neurons, thereby requiring a long learning time. Also, the deduced cost function is overly complex. These defects limit applications of a neural network to an SR problem. We think that the underlying meaning of the SR problem should refer to super‐resolving an imaging system by image sequence observation, instead of merely improving the image sequence itself. SR can be regarded as a pattern mapping from LR to SR images. The parameters of the pattern mapping can be learned from the imaging process of the image sequence. This article presents a neural network for SR based on learning from the imaging process of the image sequence. In order to speed up the convergence, we employ vector mapping to train the neural network. A mapping vector is composed of some neighbor subpixels. Such a well‐trained neural network has powerful generalization ability so that it can be used directly to estimate the SR image of the other image sequences without learning again. Our simulations show the effectiveness of the proposed neural network. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 8–15, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20001     

The formation of graphene–titania hybrid films and their resistance change under ultraviolet irradiation

We report the fabrication of hybrid films of graphene and monolayer titania using a simple electrostatic self-assembly method. Ultraviolet (UV) responses of the hybrid films based on the graphene–titania structure were investigated. We observed that the resistance of the graphene–titania hybrid increased exponentially with UV irradiation time and decreased exponentially when UV was turned off. Time constants of the order of hundreds of seconds were identified and found to be sensitive to the gas environment of graphene. The UV response as well as the time constant is tunable by varying the number of titania layers. Our results confirmed that UV irradiation played a significant role in the resistance modulation of graphene as well as graphene–titania hybrid films.     

Conductive and flexible multi-walled carbon nanotube/polydimethylsiloxane composites made with naphthalene/toluene mixture

Conventional conductive materials face challenges when utilizing them for flexible and wearable electronics and soft robotics. Carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites are a promising alternative to the conventional hard conductors because they are light and can realize large deformation. To date, well dispersion of CNTs into PDMS to increase conductivity while maintaining flexibility remains challenging. We aimed at developing highly electrically conductive and flexible multi-walled carbon nanotube/PDMS (MWCNT/PDMS) composites. To this end, we proposed a method to enhance the dispersion of MWCNTs into PDMS using naphthalene and toluene. Our results showed that the addition of naphthalene and toluene into the composites improved dispersion of the MWCNTs and increased the direct current (DC) electrical conductivity. We also found that the morphology of primary aggregates of the MWCNTs influenced the DC electrical conductivity of the composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48167.