预制装配式建筑在住宅产业化中的推广策略与挑战分析

陈大伟(Dawei Chen) ACADEMIC FRONTIERS PUBLISHING GROUP(AFP) 2024 Journal of Engineering and Technology Management ( Vol.1 No.2

预制装配式建筑是发展住宅产业化的重要方向。本文分析了预制装配式建筑在住宅产业化中的作用、推广现状,总结了完善标准规范、优化设计施工、发展产业链、加大政策支持等推广策略,也指出了观念差异、人才缺乏、配套政策不完善、实施成本高等推广面临的挑战。大力发展预制装配式建筑,对提升建筑工业化水平、推动住宅产业现代化转型具有重要意义。

Artificial neural network reconstructs core power distribution

Wenhuai Li,Peng Ding,Wenqing Xia,Shu Chen,Fengwan Yu,Chengjie Duan,Dawei Cui,Chen Chen 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.2

To effectively monitor the variety of distributions of neutron flux, fuel power or temperatures in thereactor core, usually the ex-core and in-core neutron detectors are employed. The thermocouples fortemperature measurement are installed in the coolant inlet or outlet of the respective fuel assemblies. Itis necessary to reconstruct the measurement information of the whole reactor position. However, thereading of different types of detector in the core reflects different aspects of the 3D power distribution. The feasibility of reconstruction the core three-dimension power distribution by using different combinations of in-core, ex-core and thermocouples detectors is analyzed in this paper to synthesize theuseful information of various detectors. A comparison of multilayer perceptron (MLP) network and radialbasis function (RBF) network is performed. RBF results are more extreme precision but also moresensitivity to detector failure and uncertainty, compare to MLP networks. This is because that localizedneural network could offer conservative regression in RBF. Adding random disturbance in trainingdataset is helpful to reduce the influence of detector failure and uncertainty. Some convolution neuralnetworks seem to be helpful to get more accurate results by use more spatial layout information, thoughrelative researches are still under way

Investigation lateral deformation and failure characteristics of strip coal pillar in deep mining

Chen, Shaojie,Qu, Xiao,Yin, Dawei,Liu, Xingquan,Ma, Hongfa,Wang, Huaiyuan Techno-Press 2018 Geomechanics & engineering Vol.14 No.5

In deep mining, the lateral deformation of strip coal pillar appears to be a new characteristic. In order to study the lateral deformation of coal-mass, a monitoring method and monitoring instrument were designed to investigate the lateral deformation of strip coal pillar in Tangkou Coalmine with the mining depth of over 1000 m. Because of without influence of repeated mining, the bedding sandstone roof is easy to break and the angle between maximum horizontal stress and the roadway is small, the maximum lateral deformation is only about 287 mm lower than the other pillars in the same coalmine. In deep mining, the energy accumulation and release cause a discontinuous damage in the heterogeneous coal-mass, and the lateral deformation of coal pillar shows discontinuity, step and mutation characters. These coal-masses not only show a higher plasticity but also the high brittleness at the same time, and its burst tendency is more obvious. According to the monitoring results and theoretical calculations, the yield zone of the coal pillar width is determined as 15.6 m. The monitoring results presented through this study are of great significance to the stability analysis and design of coal pillar.

Flow patterns of solid in water in oil (S/W/O) compound droplets formation in a microfluidic device with perpendicular shear

Dawei Pan,Qiang Chen,Lan Xu,Can Yang,Meifang Liu,Weixing Huang,Bo Li 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.75 No.-

Theflow patterns and corresponding breakup dynamics of solid in water in oil compound droplets underperpendicular shear force were experimentally investigated in a microfluidic device. Three typicalflowpatterns, namely double-encapsulation, plugs, and cobbles, were found and be quantitativelydistinguished by the capillary number (Cac) of continuous phase and theflow rate ratio (R) ofcontinuous phase to dispersed phase. It is found that, under all offlow regimes, the consecutive entry ofsolid particles leads d1 (the neck thickness along the center of the side channel) varying periodically. Inthe double-encapsulation regime, the neck thickness (d2) between thefirst and second particle increasesas the interface deformation recovers driven by the interfacial tension force, whereas the neck thickness(d3) between the second and third particle decreases to break off because the neck has been stretchedlong to become thin enough. As for the cobbles regime, hydrostatic pressure difference still remainsdominant, but not a shearing force. Specially, different from the W/O droplet formation, it suggests thatvarious breakup dynamics are always caused by a non-free deformation of S/W interface and the largediameter of solid particle. Finally, theflow pattern diagrams dependent on Cac and R are obtained.

Dec2 inhibits macrophage pyroptosis to promote periodontal homeostasis

Dawei He,Xiaoyan Li,Fengzhu Zhang,Chen Wang,Yi Liu,Ujjal K. Bhawal,Jiang Sun 대한치주과학회 2022 Journal of Periodontal & Implant Science Vol.52 No.1

Purpose: Macrophages play crucial roles as early responders to bacterial pathogens and promote/ or impede chronic inflammation in various tissues. Periodontal macrophageinduced pyroptosis results in physiological and pathological inflammatory responses. The transcription factor Dec2 is involved in regulating immune function and inflammatory processes. To characterize the potential unknown role of Dec2 in the innate immune system, we sought to elucidate the mechanism that may alleviate macrophage pyroptosis in periodontal inflammation. Methods: Porphyromonas gingivalis lipopolysaccharide (LPS) was used to induce pyroptosis in RAW 264.7 macrophages. Subsequently, we established an LPS-stimulated Dec2 overexpression cellular model in macrophages. Human chronic periodontitis tissues were employed to evaluate potential changes in inflammatory marker expression and pyroptosis. Finally, the effects of Dec2 deficiency on inflammation and pyroptosis were characterized in a P. gingivalis-treated experimental periodontitis Dec2-knockout mouse model. Results: Macrophages treated with LPS revealed significantly increased messenger RNA expression levels of Dec2 and interleukin (IL)-1β. Dec2 overexpression reduced IL-1β expression in macrophages treated with LPS. Overexpression of Dec2 also repressed the cleavage of gasdermin D (GSDMD), and the expression of caspase-11 was concurrently reduced in macrophages treated with LPS. Human chronic periodontitis tissues showed significantly higher gingival inflammation and pyroptosis-related protein expression than non-periodontitis tissues. In vivo, P. gingivalis-challenged mice exhibited a significant augmentation of F4/80, tumor necrosis factor-α, and IL-1β. Dec2 deficiency markedly induced GSDMD expression in the periodontal ligament of P. gingivalis-challenged mice. Conclusions: Our findings indicate that Dec2 deficiency exacerbated P. gingivalis LPS-induced periodontal inflammation and GSDMD-mediated pyroptosis. Collectively, our results present novel insights into the molecular functions of macrophage pyroptosis and document an unforeseen role of Dec2 in pyroptosis.

Investigation on millimeter-scale W1/O/W2 compound droplets generation in a co-flowing device with one-step structure

Dawei Pan,Qiang Chen,Yinjuan Zhang,Bo Li 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.84 No.-

Millimeter-scale W1/O/W2 compound droplets generation in a co-flowing microfluidic device with onestepstructure was symmetrically observed through experiments, and the formation process isdistinguished according to the variation law of thread tip velocity. Specially, under a wide range ofoperation conditions, W1/O/W2 compound droplets form accompanying with the generation of oil phasedroplet. The formation ratio of compound droplets to oil phase droplet always depends on the outerphase Capillary number, Caw2, and theflow rate ratio, R, of middle to inner phases, and thus theflowpattern diagram is obtained. Further the influences of all phasesflow rates, outer phase viscosity as wellas the interfacial tension on the formation period and geometric sizes are extensively studied. Finally, aprediction correlation for dimensionless inner and outer diameters with several dimensionless numbersis also obtained. The results could provide an experimental basis for controllably preparing monodispersecompound droplets with millimeter-scale.

Influence of oxygen vacancies on the EPIR effect in Nd0.7Sr0.3MnO3 ceramics

Dawei Shi,Shunsheng Chen,Di Liu,Lingfang Xu,Haibo Xiao,Changping Yang,Kaiying Wang 한국물리학회 2015 Current Applied Physics Vol.15 No.8

Nd0.7Sr0.3MnO3 polycrystalline ceramic samples (NSMO) were synthesized by solid state reaction with a post annealing for parts of samples under different partial pressures of oxygen at 1350 ℃ for 12 h. XRD shows that all the samples are in single phase with a perovskite structure. The electrical transport measurement implies that the oxygen concentration has an important influence on the electrical pulse induced resistance, i.e. the EPIR-effect, for NSMO samples. For the oxygen-enriched sample, which probably contains a smaller amount of oxygen vacancies, the I-V characteristic is linear with a very small resistance, and the EPIR-effect is not detectable within the experimental accuracy. However, after sintered and annealed in reducing atmospheres, an EPIR effect appears and even becomes stronger and more stable if the sintering atmosphere is more reducing than that of normal air condition. Besides, the I -V becomes nonlinear and the initial resistance increases with increasing deficiency of oxygen, which means that the oxygen vacancies and their deep level trap states play an important role for the EPIR effect of NSMO. In this manuscript, an oxygen vacancy trapped state model is put forward to explain the relation between oxygen concentration and the EPIR effect.

Study of Visual Spatial Perception Performance at Close Range in Underground Coal Mine

Ren Dawei,Liu Yang,Chen Litao 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.11

In coal mines the environment is complex, crowded with personnel and equipment, as well as lack of colors. The safety in production is influenced by visual spatial perception is whether or not accurate. The visual spatial perception precision plays a significant even crucial role in positioning. By simulating the environment in coal mines, the positioning experiment about participants’ visual spatial perception performance of different target objects in two models—from far to near and from near to far has been carried out. Experimental results showed that visual spatial perception distance was significantly shorter than target range, that visual spatial perception in deep pink was the poorest. In addition, the H has become appreciable and regular with visual spatial perception changing. The experimental results provided references for setting warning marks, safe distances and choosing colors for infrastructure in coal mines.

Dec2 inhibits macrophage pyroptosis to promote periodontal homeostasis

He, Dawei,Li, Xiaoyan,Zhang, Fengzhu,Wang, Chen,Liu, Yi,Bhawal, Ujjal K.,Sun, Jiang Korean Academy of Periodontology 2021 Journal of Periodontal & Implant Science Vol.51 No.-

Purpose: Macrophages play crucial roles as early responders to bacterial pathogens and promote/ or impede chronic inflammation in various tissues. Periodontal macrophage-induced pyroptosis results in physiological and pathological inflammatory responses. The transcription factor Dec2 is involved in regulating immune function and inflammatory processes. To characterize the potential unknown role of Dec2 in the innate immune system, we sought to elucidate the mechanism that may alleviate macrophage pyroptosis in periodontal inflammation. Methods: Porphyromonas gingivalis lipopolysaccharide (LPS) was used to induce pyroptosis in RAW 264.7 macrophages. Subsequently, we established an LPS-stimulated Dec2 overexpression cellular model in macrophages. Human chronic periodontitis tissues were employed to evaluate potential changes in inflammatory marker expression and pyroptosis. Finally, the effects of Dec2 deficiency on inflammation and pyroptosis were characterized in a P. gingivalis-treated experimental periodontitis Dec2-knockout mouse model. Results: Macrophages treated with LPS revealed significantly increased messenger RNA expression levels of Dec2 and interleukin (IL)-1β. Dec2 overexpression reduced IL-1β expression in macrophages treated with LPS. Overexpression of Dec2 also repressed the cleavage of gasdermin D (GSDMD), and the expression of caspase-11 was concurrently reduced in macrophages treated with LPS. Human chronic periodontitis tissues showed significantly higher gingival inflammation and pyroptosis-related protein expression than non-periodontitis tissues. In vivo, P. gingivalis-challenged mice exhibited a significant augmentation of F4/80, tumor necrosis factor-α, and IL-1β. Dec2 deficiency markedly induced GSDMD expression in the periodontal ligament of P. gingivalis-challenged mice. Conclusions: Our findings indicate that Dec2 deficiency exacerbated P. gingivalis LPS-induced periodontal inflammation and GSDMD-mediated pyroptosis. Collectively, our results present novel insights into the molecular functions of macrophage pyroptosis and document an unforeseen role of Dec2 in pyroptosis.

False-Negative Results of Real-Time ReverseTranscriptase Polymerase Chain Reaction for Severe Acute Respiratory Syndrome Coronavirus 2: Role of Deep-Learning-Based CT Diagnosis and Insights from Two Cases

Dasheng Li,Dawei Wang,Jianping Dong,Nana Wang,He Huang,Haiwang Xu,Chen Xia 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.4

The epidemic of 2019 novel coronavirus, later named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still gradually spreading worldwide. The nucleic acid test or genetic sequencing serves as the gold standard method for confirmation of infection, yet several recent studies have reported false-negative results of real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). Here, we report two representative false-negative cases and discuss the supplementary role of clinical data with rRT-PCR, including laboratory examination results and computed tomography features. Coinfection with SARS-COV-2 and other viruses has been discussed as well.