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Chemiluminescence information is of great significance for characterization of flame structure and combustion characteristics. An atmospheric low swirl burner was developed to investigate the chemiluminescence characteristics of OH* and CH* in low swirl flames, with the equivalence ratio varying from 0.8 to 1.2 and the swirl number from 0.2 to 0.6. The chemiluminescence images were captured via ICCD cameras coupled with narrow-bandpass filters, and an Abel inversion method was introduced to transform the line-of-sight-integrated image into two-dimensional radial distributions. The results show that the distribution of CH* is smaller than that of OH* and concentrated more upstream of the flame near the burner. The equivalence ratio has a relatively more direct influence on chemical reactions, while the swirl number has a more evident effect on the flame structure. As the equivalence ratio increases, the peak value of OH* and CH* increases and the peak position moves downstream of the flame, suggesting that the chemical reactions become more intense. In contrast, the height and width of chemiluminescence distribution increase linearly with increasing swirl number. Moreover, it is found that the equivalence ratio and swirl number can be feasibly estimated based on chemiluminescence measurement results, using the correlation between them derived from this study.

According to the energy conversion relationship during the lightning strike, a lightning damage analysis model based on coupled electrical-thermal simulation for composites was established. The variation of electrical conductivity of the composite with pyrolysis was considered in the model. By means of the model, the lightning ablation damage of the composite material with multiple changes of conductivity was compared in three directions. The results show that under the same lightning current parameters, the electrical conductivity changes of composite materials in different directions have different effects on the ablation damage caused by lightning strikes. When the electrical conductivity along the fiber direction increases, both the apparent damage area and the damage depth decreased. While the electrical conductivity perpendicular to the fiber direction increases, the apparent damage area increased and the damage depth decreased. When the electrical conductivity along the thickness increases, the apparent damage area increased and the damage depth increased. When the conductivity along any of the three directions increases , the total damage volume of the composite decreased. When the conductivity of each direction increases by 1, 2, 3 orders of magnitude, the greatest changes in damage volume are observed along the fiber direction, which are decreased by 47.83 %, 75.08 % and 97.82 % respectively, followed by changes along the thickness direction, which are decreased by 36.25 %, 53.44 % and 65.54 %, and the least changes are perpendicular to the fiber direction, which are reduced by 8.72. %, 12.58 % and 24.76 %. The increase of the conductivity of the composite material play a significant role in lightning strike protection. A comprehensive assessment of the lightning protection effect requires a combination of two-dimensional damage and three-dimensional damage.

In order to study the lightning protection effect of copper wire mesh on composite materials, two different lightning current waveforms were used to simulate the lightning current impact test on composite specimens with and without copper wire mesh in different sizes. Through visual damage observation, optical microscope amplification and ultrasonic damage scanning, the lightning damage degree and characteristics of composite materials were compared and analyzed. The experimental results show that when the lightning current waveform is 1 and peak currents are 50 kA and 80 kA, the lightning strike damage area and depth of the Type1 specimen without copper wire mesh are 1785 mm2, 0.63 mm and 3041 mm2, 0.96 mm respectively, while the test specimens with copper wire mesh in the same type are basically scatheless. When the lightning current waveform is 2 and the peak current is 40 KA, the lightning strike damage area and depth of the Type2 specimen without copper wire mesh are 2156.75 mm2, 0.36 mm, while the damage area of the test specimen with copper wire mesh in the same type is less than 100 mm2, and the inner layer has not been damaged. There exists a threshold value for the maximum lightning current strength of the 0.25 mm copper wire mesh, which can be expressed by the action integral. The lightning protection effect is independent of the specimen size, and is only related to the action integral, the corresponding threshold value of which is about 85218 A2·s.

Speech recognition accuracy is severely reduced by the variability caused by stress. Considering the fact that speech under stress is caused by the physiological changes of the vocal folds in the physiological system whose vibration behavior is reflected by glottal flow, this paper presents a method of study on speech under stress based on a physical speech production model and characteristics of glottal flow. The physical model is used to model glottal aerodynamics in the vocal system to represent speech production. The relationship between physical parameters and glottal flow parameters is explored based on the physical model, and the glottal source and physical model are linked. Through studying on the glottal and physical parameters for the neutral and for the speech under stress, features for speech under stress characterizing the vocal folds, vortex-flow interaction, and shape of glottal flow are compared with those of neutral speech. The relations between the proposed parameters and stress-speech production mechanism are discussed. Experiments show that physical parameters representing the stiffness and viscosity of vocal folds, subglottal pressure, and laryngeal ventricle strongly influence the glottal flow. The relations for physical parameters, glottal parameters, and stress production are revealed, and theoretical and experimental bases are provided for stress detection and classification in speech recognition system.

In order to study the moisture absorption characteristics of BA9916-Ⅱ/CCF300 composite stiffeners, Carrying out the moisture absorption experiment in 70℃/85%RH hot and humid environment. Fick moisture absorption model Mt=???63???vi[GiM∞i+M0i(1-Gi)] based on thethickness partition is put forward.The mass diffusion model is used for moisture absorption behavior of the finite element simulation.The result show that: Moisture absorption model is put forward based on the thickness of fick moisture absorption model can better describe the moisture absorption behavior of the structure of the type,the analysis is of the high precision; But as a result of composite stiffened plate's staging phenomenon of moisture absorption. There is a certain deviation of Fick moisture absorption model on the structure hygroscopic behavior later described;The Hygroscopic power curve and water concentration distribution results of the finite element simulation is verified the rationality of the hygroscopic model based on thickness division,better expressing the real process of moisture absorption and moisture distribution.

DNA repair is related to many physiological and pathological processes, including pigmentation. Little is known about the role of the transcriptional cofactor Mediator complex in DNA repair and pigmentation. Here, we demonstrate that Mediator MED23 plays an important role in coupling UV-induced DNA repair to pigmentation. The loss of Med23 specifically impairs the pigmentation process in melanocyte-lineage cells and in zebrafish. Med23 deficiency leads to enhanced nucleotide excision repair (NER) and less DNA damage following UV radiation because of the enhanced expression and recruitment of NER factors to chromatin for genomic stability. Integrative analyses of melanoma cells reveal that MED23 controls the expression of a melanocyte master regulator, Mitf, by modulating its distal enhancer activity, leading to opposing effects on pigmentation and DNA repair. Collectively, the Mediator MED23/MITF axis connects DNA repair to pigmentation, thus providing molecular insights into the DNA damage response and skin-related diseases.

Oily sludge is a hazardous waste containing emulsified petroleum hydrocarbons, water, heavy metals, and solid particles. The objective of this work is to employ solidification/stabilization (S/S) techniques to utilize oily sludge as a roadbed material with ordinary Portland cement (OPC), fly ash (FA), and silica fume (SF) as binders and phosphogypsum (PG) as a stabilizer. The efficacy of the S/S process is assessed mainly through an unconfined compressive strength (UCS) test and a toxicity leaching test. Road performance, including water stability, freeze-thaw resistance, and volume stability, is also tested on the solidified samples. The mineralogical compositions, microstructures, and pore structure are characterized through X-ray diffractometry (XRD), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP). The results show that the addition of 20% binders (OPC : FA : SF = 1 : 0.7 : 0.8) in combination with phosphogypsum to the oily sludge not only increases the 28-day compressive strength of the solidified samples and remarkably decreases the release of heavy metals but also refines the pore structure and compacts the microstructure. The solidified body had sufficient strength and good water stability performance, freeze-thaw resistance, and volumetric stability. This solidification/stabilization (S/S) process, which combines oily sludge treatment and phosphogypsum resource utilization, significantly enhances environmental protection and renders the solidified product economically profitable.

The poor workability and the risk of alkali-silica reaction (ASR) caused by alkaline activators restrict the wide range of applications of alkali-activated slag (AAS) cement. This paper presents a study on the effect of fly ash microsphere (FAM) on mitigating the rheological properties and ASR of AAS mortars for the first time. For comparison, the ordinary Portland cement (OPC) mortars blended with FAM are also prepared and investigated. The FAM addition is effective in decreasing the viscosity and meanwhile increasing the fluidity of the AAS pastes and mortars due to its ‘ball-bearings’ effect. According to the results obtained from the accelerated mortar bar test, the addition of more than 10% FAM reduces the ASR expansion effectively in both of the AAS and OPC mortars. Mineralogical studies demonstrate that for the AAS mortars, FAM promotes the formation of C-A-S-H gel phases with a better alkali binding capacity to mitigate ASR. The pozzolanic reaction of FAM consumes Ca(OH) _2 in the OPC mortars, which is essential to the ASR development. In addition, minor ASR products are observed in the AAS or OPC mortars modified with FAM, and meanwhile there is a more strong bonding between the interface of aggregate-paste.

With the increase of English teaching courses, the specific vocal characteristics of teachers in English teaching are studied and used as the basic data for the design of teachers’ spatial acoustics. In order to study this problem, three different English voice materials were read in a anechoic room under three sound intensity levels: large, medium and small, respectively, so as to analyse the equivalent continuous sound pressure level (SPL) and frequency characteristic curves of male and female teachers at 0.3m. In the low frequency band, the SPL increases as the frequency increases. In the mid-frequency band, the SPL reaches the first peak, then decreases briefly as the frequency increases, then increases again to the second peak, and then decreases again briefly as the frequency increases. Then increase again to the third peak. In the high frequency band, the SPL decreases as the frequency increases.

The transcription factor Runx2 regulates osteoblast differentiation of mesenchymal stem cells. In this manuscript, the authors, using a specific conditional knock-out mouse model and molecular studies, demonstrate that the mediator subunit MED23 binds to Runx2 and is essential for driving mesenchymal stem cells toward an osteoblast fate.

According to reports, since 2012, there have been 12 terrorist attacks in France. At the same time, the number of visitors of Louvre reached a peak of 8.1 million in 2017. Therefore, making an efficient evacuation plan in Louvre is particularly important. In our paper, we assume that the process of evacuation contains two main parts: the path from the starting point to the exit, and the location where the congestion may occur, such as stairs and exits. For the first part, we use the ant colony optimization algorithm to find the optimal path and get how many flows arrive at each exit. For the second part, as we already know the number of flows, we can use queuing theory to determine whether it is congested or not and calculate the corresponding congestion time. Finally, the optimal evacuation path and the corresponding time are obtained. In addition, associated with the application "Affluences" used in Louvre, some devices are designed to measure the average speed of the crowd movement. If the average speed is below a threshold value, an emergency exit will be opened to improve the evacuation process.

In order to solve the problems of dust, low mixing efficiency, and poor quality stability in dry mixing and continuous mixing, this study combined the flocculation extrusion technology with continuous mixing technology of carbon black/additives/natural rubber composites. The flocculation of latex was achieved by carbon black itself and the shearing of the twin screw. The continuous mixing was carried out in a double-rotor continuous mixer, which was composed of functional elements such as the exhaust section and extrusion section. The results showed that the technology promoted the formation of the filler-rubber network, the sensitivity of viscosity to temperature was weakened, and the rubber was closer to a Newtonian fluid, with less extrusion swell phenomenon and no obvious spiral distortion. Compared with the dry mixing, the tensile strength, rebound rate, and abrasion resistance of the rubber composites prepared by this technology were increased by 11%, 31%, and 9%, respectively, providing theoretical and technical guidance for the green production and continuous production of high-performance natural rubber composites. Highlights * The process is achieved by a twin-screw extruder and a twin-rotor continuous mixer. * The process promotes the formation of the filler-rubber network. * The sensitivity of viscosity to temperature is weakened, with no spiral distortion. * The tensile strength, rebound rate, and abrasion resistance are increased by 11%, 31%, and 9%. KEYWORDS biocomposite, extrusion, particle-reinforcement, rheological properties, 1 | INTRODUCTION The mixing process is the core part of rubber processing, which determines the processing performance of rubber and affects the subsequent molding process, the properties, and the [...]