Three heat sinks with porous-coated parallel microchannels were fabricated by using a solid-state sintering method. The enhanced flow boiling of anhydrous ethanol in the porous-coated microchannels ...was systematically studied and compared to that of bare microchannels. The changes in pressure drop, flow boiling instability and flow boiling heat transfer performances caused by the introducing of porous coatings were discussed. The effect of particle size on pressure drop and heat transfer performance was also studied. The porous-coated microchannels showed significant mitigation of flow boiling instability, which was explained by the changes in bubble dynamics. Dramatic enhancement of flow boiling heat transfer in the porous-coated microchannels was obtained. The enhancement from porous coatings showed dependence on particle size and diminished with the increase of vapor quality.
•The enhanced flow boiling in porous-coated parallel microchannels was studied.•The pressure drop and flow boiling instability performances were discussed.•A size-dependant heat transfer enhancement from porous coatings was recorded.•The mitigation of flow boiling instability by the porous coatings was observed.
•A 3D VC with an integrated structure for LED automotive headlamps was fabricated.•The thermal performance of the 3D VC under different conditions was tested.•The lowest measured thermal resistance ...is 0.125 °C/W at 50 W.
This paper proposes a three-dimensional vapor chamber (3D VC) to solve heat dissipation of LED (light-emitting diode) automotive headlamps, which can be installed in a very limited setup space and a high heating load. The proposed 3D VC can be regarded as a combination of a flattened heat pipe and a circular vapor chamber. A test system was implemented to study the effects of different heating modes on thermal performance, power distribution characteristics, the temperature distribution and thermal resistance of the 3D VC. The experimental results show that the thermal performance of the 3D VC by both-sides heating is better than that of the one-side heating under the same total heating load. The 3D VC exhibits a favorable temperature uniformity, and the minimum thermal resistance of the 3D VC is 0.125 °C/W at a 50 W heating load.
This paper considers how an online food delivery platform can improve last-mile delivery services’ performance using multi-source data. The delivery time is one critical but uncertain factor for ...online platforms that also regarded as the main challenges in order assignment and routing service. To tackle this challenge, we propose a data-driven optimization approach that combines machine learning techniques with capacitated vehicle routing optimization. Machine learning methods can provide more accurate predictions and have received increasing attention in the operations research field. However, different from the traditional predict-then-optimize paradigm, we use a new smart predict-then-optimize framework, whose prediction objective is constructed by decision error instead of prediction error when implementing machine learning. Using this type of prediction, we can obtain a more accurate decision in the following optimization step. Efficient mini-batching gradient and heuristic algorithms are designed to solve the joint order assignment and routing problem of last-mile delivery service. Besides, this paper considers the mutual effect between routing decision and delivery time, and provides the corresponding solution algorithm. In addition, this paper conducts a computational study and finds that the proposed method’s performance has an approximate 5% improvement compared with other methods.
Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a chronic inflammatory disease in the lower gastrointestinal tract. Mounting evidence suggests that the ...predominance of the classically activated (M1) macrophages versus the alternatively activated (M2) macrophages plays a role in the progression of IBD. Thus, agents able to shift pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages may be beneficial to IBD. The pentacyclic triterpene Lup-20(29)-en-3β-ol (Lupeol), a potent anti-inflammatory natural product, has been shown to inhibit pro-inflammatory cytokine production, suggesting it is potentially able to modulate macrophage polarization, thereby beneficial to IBD.
CD4+ monocytes were differentiated to M1 or M2 macrophages, which were cocultured with epithelial cell lines, T84 and Caco-2, in the absence or presence of Lupeol (10μM). Experimental colitis was induced with dextran sodium sulfate (DSS), with or without oral administration of Lupeol (50mg/kg, q.d.). Cytokines were measured with Luminex kits. M1/M2 genes were measured with real-time polymerase chain reaction. Macrophage phenotypes were defined by measuring M1 and M2 markers with confocal microscopy. Proteins were measured with Western blotting, while cell surface markers were measured with confocal microscopy or flow cytometry. Histology was evaluated with H&E staining.
Treatment of M1 macrophages with Lupeol resulted in a marked decrease in the production of pro-inflammatory cytokines, including IL-12, IL6, IL-1β and TNFα, and a marked increase in the production of IL-10, an anti-inflammatory cytokine. This was associated with a down-regulation of CD86, a typical marker of M1 macrophages, and an up-regulation of CD206, a typical M2 macrophage marker. IRF5, a transcription factor that is critically involved in M1 polarization, was down-regulated in M1 macrophages after being incubated with Lupeol, associated with a marked decrease in the phosphorylation of p38 mitogen activated protein kinase. Coculture of epithelial cells with M1 macrophages resulted in down-regulation of the tight junction protein ZO-1 and disruption of epithelial integrity, which were blocked by Lupeol treatment of the M1 macrophages. Moreover, oral administration of Lupeol to dextran sulfate sodium (DSS)-induced colitis mice resulted in mitigated intestinal inflammation and increased survival from lethal colitis, associated with decreased expression of M1-related genes and increased expression of M2-related genes.
Lupeol ameliorates experimental inflammatory bowel disease through, at least in part, inhibiting M1 and promoting M2 macrophages.
•The pentacyclic triterpene Lup-20(29)-en-3β-ol (Lupeol), a potent anti-inflammatory natural product, was able to switch macrophages from M1 to M2 phenotype.•Moreover, oral administration of Lupeol to dextran sulfate sodium (DSS)-induced colitis mice resulted in mitigated intestinal inflammation and increased survival from lethal colitis, associated with decreased expression of M1-related genes and increased expression of M2-related genes in the lesion.•Our data suggest Lupeol ameliorates experimental IBD through, at least in part, inhibiting M1 and promoting M2 macrophages.•Considering the very low toxicity of Lupeol, we believe that these findings are significant.
The electrowetting display (EWD) is a kind of reflective paper-like display. Flicker and grayscale distortion are caused by oil backflow, which is one of the important factors restricting the wide ...application of EWDs. The charge embedding caused by the electric field force in the dielectric layer is the cause of oil backflow. To suppress oil backflow, a separated reset waveform based on the study of oil movement is proposed in this paper. The driving waveform is divided into two parts: a reset waveform and a grayscale waveform. The reset waveform generated by a reset circuit can be used to output various voltages. The grayscale waveform is set as a traditional PWM waveform. The reset waveform is composed of a charge-releasing stage and oil-moving back stage. Two phases are contained in the charge releasing stage. The overdriving voltage is used during the first phase to reverse the voltage of all pixels. The trapped charges can then be released from the dielectric layer during the second phase. A higher voltage is used during the oil-moving back stage to drive the oil faster in the pixel. By comparing the experimental data, the oil backflow time is extended 761 times by the reset waveform. The four grayscales can be maintained by the reset waveform after driving for 300 s.
As a reflective display technology, electrowetting displays (EWDs) have the advantages of paper-like display, low power consumption, fast response, and full color, but the aperture ratio of EWDs is ...seriously affected by oil dispersion and charge trapping. In order to improve the aperture ratio and optimize the display performance of EWDs, a combined pulse driving waveform with rising gradient design was proposed. First, an initial driving voltage was established by the threshold voltage of oil film rupture (V
th
). And then, a rising gradient was designed to prevent oil from dispersing. At last, the oil splitting and movement were controlled to achieve the target aperture combined with the pulse waveform. Experimental results showed that the oil dispersion of EWDs can be effectively improved by using the proposed driving waveform, the aperture ratio of EWDs was increased by 3.16%, and the stability was increased by 71.43%.
Programmed cell death (PCD) plays critical roles in plant immunity but must be regulated to prevent excessive damage. The E3 ubiquitin ligase SPL11 negatively regulates PCD and immunity in plants. We ...show that SPL11 cell-death suppressor 2 (SDS2), an S-domain receptor-like kinase, positively regulates PCD and immunity in rice by engaging and regulating SPL11 and related kinases controlling defense responses. An sds2 mutant shows reduced immune responses and enhanced susceptibility to the blast fungus Magnaporthe oryzae. Conversely, SDS2 over-expression induces constitutive PCD accompanied by elevated immune responses and enhanced resistance to M. oryzae. SDS2 interacts with and phosphorylates SPL11, which in turn ubiquitinates SDS2, leading to its degradation. In addition, SDS2 interacts with related receptor-like cytoplasmic kinases, OsRLCK118/176, that positively regulate immunity by phosphorylating the NADPH oxidase OsRbohB to stimulate ROS production. Thus, a plasma membrane-resident protein complex consisting of SDS2, SPL11, and OsRLCK118/176 controls PCD and immunity in rice.
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•The RLK SDS2 positively regulates plant cell death and immunity in rice•SDS2 phosphorylates E3 ligase SPL11, which in turn ubiquitinates SDS2 for degradation•SDS2 phosphorylates receptor-like cytoplasmic kinases RLCK118•RLCK118 interacts with and phosphorylates the NADPH oxidase OsRbohB
Plant cell death and immunity must be strictly controlled. Fan et al. show that the monocot-specific RLK SDS2 phosphorylates the E3 ligase SPL11 to positively regulate cell death and immunity. SDS2 also interacts with the receptor-like cytoplasmic kinases RLCK118 and RLCK176 to regulate immunity via the NADPH oxidase OsRbohB.
The suddenness, complexity, and devastation of major geological disasters make it necessary to improve the efficiency of disaster rescue. At present, the dispatch of geological disaster rescue ...equipment represented by landslide and debris flow has some shortcomings, such as low efficiency, low matching degree and low utilization rate. Rescue equipment is an important guarantee for the rescue work. Predicting the demand for rescue equipment is conducive to optimizing the equipment scheduling decision, so as to improve the rescue ability of geological disasters. Based on the idea of "disaster scenario—rescue mission—rescue equipment—demand forecast", this study analyzes 87 representative geological disaster rescue cases in China from 2004 to 2019, and summarizes the matching relationship of "scenario—task—equipment". On this basis, The scenarios affecting the demand for various kinds of equipment were introduced as influencing factors, and the prediction models of rescue equipment demand based on different "scenario-tasks" were constructed; Finally, taking the rescue operation of "7–23" massive landslide in Shuicheng, Guizhou province in 2019 as an example, the demand prediction of rescue equipment was realized by adjusting parameter values, and the results were compared with the actual data of the case to verify the effectiveness and feasibility of the model.
Geological disaster rescue presents features such as multi-stage, multi-sector, multi-subject, and multi-target. However, due to the shortage of professional rescue technicians, it is necessary to ...consider the matching, fairness, and efficiency of rescue tasks and rescue subjects. This study takes "disaster scenario-rescue task-rescue subject-demand prediction-subject deployment" as the main line in major geological disasters such as landslides and mudslides. By collecting data on 87 rescue operations in China from 2004 to 2019, we screened 18 representative cases of rescue operations and sorted out different types of rescue force function positioning, divisions of responsibility, and collaboration modes, summarizing them into five major rescue tasks and five major rescue subjects. A rescue subject demand prediction model was developed based on different scenarios according to the influence of rescue tasks on the demand of rescue subjects. Considering the urgency of the rescue tasks, a rescue subject deployment model based on different tasks and the NSGA-II algorithm can be built up. We tested the Zhejiang Yongjia weir breach rescue operation case (2019) in China for empirical analysis to verify the effectiveness and practicality of the model and algorithm.
Data augmentation diversifies the information in the dataset. For class imbalance, the copy‐paste augmentation generates new class information to alleviate the impact of this problem. However, these ...methods rely excessively on human intuition. Over‐fitting or under‐fitting can occur while adding the class information, which is inappropriate. The authors propose a self‐adaptive data augmentation: the copy‐paste with self‐adaptation (CPA) algorithm, which improves the phenomenon of over‐fitting and under‐fitting. For the CPA, the evaluation results of a model are taken as an important adjustment basis. The evaluation results are combined with the information of class imbalance to generate a set of class weights. Different number of class information will be replenished according to class weights. Finally, the generated images will be inserted into the training dataset and the model will start formal training. The experimental results show that CPA can alleviate class imbalance. For TT100 K dataset, YOLOv3 is trained with the optimised dataset and its AP is increased by 2% for VOC2007 dataset, the mAP of RetinaNet on optimised dataset is 78.46, which is 1.2% higher than original dataset. For COCO2017 dataset, SSD300 is trained with the optimised dataset and its AP is increased by 1.3%.
CPA extracts the evaluation results of the model from pre‐training. Then, the evaluation results are combined with class imbalance to replenish the class information. Finally, the generated images will be inserted into the training dataset and the model will start the formal training.
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