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•A novel loop heat pipe module was developed for server CPU cooling.•Wicks connecting evaporator and condenser were implemented.•The 4 mm thick module dissipates 150 W with chip ...temperature below 85 °C.•Tested directions impact the heat transfer performance weakly.
The rapid development of distributed edge computing system demands urgently that the thermal management solution for server CPUs in micro-data centers have the characteristics of compact structure, high performance, maintenance-free, and energy saving. This paper focuses on a new cooling concept enabled by a compact loop heat pipe. Through removing compensation chamber, selecting a spindle-shaped evaporator structure with aid of an auxiliary gradient sintered capillary wick connecting the condenser and the evaporator, this new proposed loop heat pipe module can provide high reliability operation, meanwhile maintaining high thermal performance. Under forced air cooling, it is demonstrated that the 4 mm thick loop heat pipe module with finned tube condenser could dissipate a heat load of 150 W under a wide fan voltage range from 12 V to 24 V at tested directions when the chip junction temperature was below 85 °C, and could manage a heat load up to 275 W without dry-out. The proposed new loop heat pipe module with finned tube condenser is a potential solution to cool edge-computing server CPUs.
Summary
Viral diseases severely affect crop yield and quality, thereby threatening global food security. Genetic improvement of plant virus resistance is essential for sustainable agriculture. In the ...last decades, several modern technologies were applied in plant antiviral engineering. Here we summarized breakthroughs of the two major antiviral strategies, RNA silencing and genome editing. RNA silencing strategy has been used in antiviral breeding for more than thirty years, and many crops engineered to stably express small RNAs targeting various viruses have been approved for commercial release. Genome editing technology has emerged in the past decade, especially CRISPR/Cas, which provides new methods for genetic improvement of plant virus resistance and accelerates resistance breeding. Finally, we discuss the potential of these technologies for breeding crops, and the challenges and solutions they may face in the future.
Abstract
The process of computationally identifying and categorizing opinions expressed in a piece of text is of great importance to support better understanding and services to online users in the ...digital environment. However, accurate and fast multi-label automatic classification is still insufficient. By considering not only individual in-sentence features but also the features in the adjacent sentences and the full text of the tweet, this study adjusted the Multi-label
K
-Nearest Neighbors (MLkNN) classifier to allow iterative corrections of the multi-label emotion classification. It applies the new method to improve both the accuracy and speed of emotion classification for short texts on Twitter. By carrying out three groups of experiments on the Twitter corpus, this study compares the performance of the base classifier of MLkNN, the sample-based MLkNN (S-MLkNN), and the label-based MLkNN (L-MLkNN). The results show that the improved MLkNN algorithm can effectively improve the accuracy of emotion classification of short texts, especially when the value of
K
in the MLkNN base classifier is 8, and the value of
α
is 0.7, and the improved L-MLkNN algorithm outperforms the other methods in the overall performance and the recall rate reaches 0.8019. This study attempts to obtain an efficient classifier with smaller training samples and lower training costs for sentiment analysis. It is suggested that future studies should pay more attention to balancing the efficiency of the model with smaller training sample sizes and the completeness of the model to cover various scenarios.
Facing fast-increasing electronic documents in the Digital Media Age, the need to extract textual features of online texts for better communication is growing. Sentiment classification might be the ...key method to catch emotions of online communication, and developing corpora with annotation of emotions is the first step to achieving sentiment classification. However, the labour-intensive and costly manual annotation has resulted in the lack of corpora for emotional words. Furthermore, single-label semantic corpora could hardly meet the requirement of modern analysis of complicated user’s emotions, but tagging emotional words with multiple labels is even more difficult than usual. Improvement of the methods of automatic emotion tagging with multiple emotion labels to construct new semantic corpora is urgently needed. Taking Twitter short texts as the case, this study proposes a new semi-automatic method to annotate Internet short texts with multiple labels and form a multi-labelled corpus for further algorithm training. Each sentence is tagged with both the emotional tendency and polarity, and each tweet, which generally contains several sentences, is tagged with the first two major emotional tendencies. The semi-automatic multi-labelled annotation is achieved through the process of selecting the base corpus and emotional tags, data preprocessing, automatic annotation through word matching and weight calculation, and manual correction in case of multiple emotional tendencies are found. The experiments on the Sentiment140 published Twitter corpus demonstrate the effectiveness of the proposed approach and show consistency between the results of semi-automatic annotation and manual annotation. By applying this method, this study summarises the annotation specification and constructs a multi-labelled emotion corpus with 6500 tweets for further algorithm training.
•A 1.2mm thick miniature loop heat pipe was developed.•The mLHP can manage a wide range of heat loads at natural convection.•A minimum mLHP thermal resistance of 0.111°C/W was achieved at 11W.•The ...proposed mLHP is a promising solution for cooling mobile electronics.
In this paper, we present a miniature loop heat pipe (mLHP) employing a 1.2mm thick flat evaporator and a vapor line, liquid line and condenser with a 1.0mm thickness. The mLHP employs an internal wick structure fabricated of sintered fine copper mesh, comprised of a primary wick structure in the evaporator to provide the driving force for circulating the working fluid, and a secondary wick inside the liquid line to promote the flow of condensed working fluid back to the evaporator. All tests were conducted under air natural convection at an ambient temperature of 24±1°C. The proposed mLHP demonstrated stable start-up behavior at a low heat load of 2W in the horizontal orientation with an evaporator temperature of 43.9°C and efficiently dissipates a maximum heat load of 12W without dry-out occurring. A minimum mLHP thermal resistance of 0.111°C/W was achieved at a heat load of 11W in a gravity favorable operation mode, at which the evaporator temperature was about 97.2°C. In addition, an analytical analysis was conducted, and the devised equation could be used to evaluate the performance of the mLHP.
Accurately detecting student classroom behaviors in classroom videos is beneficial for analyzing students’ classroom performance and consequently enhancing teaching effectiveness. To address ...challenges such as object density, occlusion, and multi-scale scenarios in classroom video images, this paper introduces an improved YOLOv8 classroom detection model. Firstly, by combining modules from the Res2Net and YOLOv8 network models, a novel C2f_Res2block module is proposed. This module, along with MHSA and EMA, is integrated into the YOLOv8 model. Experimental results on a classroom detection dataset demonstrate that the improved model in this paper exhibits better detection performance compared to the original YOLOv8, with an average precision (mAP@0.5) increase of 4.2%.
Summary
Recently, CRISPR‐Cas (clustered, regularly interspaced short palindromic repeats–CRISPR‐associated proteins) system has been used to produce plants resistant to DNA virus infections. However, ...there is no RNA virus control method in plants that uses CRISPR‐Cas system to target the viral genome directly. Here, we reprogrammed the CRISPR‐Cas9 system from Francisella novicida to confer molecular immunity against RNA viruses in Nicotiana benthamiana and Arabidopsis plants. Plants expressing FnCas9 and sgRNA specific for the cucumber mosaic virus (CMV) or tobacco mosaic virus (TMV) exhibited significantly attenuated virus infection symptoms and reduced viral RNA accumulation. Furthermore, in the transgenic virus‐targeting plants, the resistance was inheritable and the progenies showed significantly less virus accumulation. These data reveal that the CRISPR/Cas9 system can be used to produce plant that stable resistant to RNA viruses, thereby broadening the use of such technology for virus control in agricultural field.
Self-assembly of ionic liquids (ILs) in solution has attracted wide attention due to their potential applications in chemical and biological investigations. In this study, the aggregation behavior of ...1-alkyl-3-methylimidazolium alkyl sulfate in aqueous solution was investigated by molecular dynamics simulations. The simulations reveal that interactions between tail groups play a dominant role in stabilizing the vesicle. The permeability of the vesicle was further studied, and the exchange rate of water molecules is determined by the thickness of membrane. Besides thickness, arrangement of alkyl chain of ILs in the vesicle structure influences the permeability. The interdigitated structure of tail groups in the C8mimC12SO4 system decreases the water exchange rate compared with the similar system of C12mimC8SO4. Furthermore, the hydrogen bonding interaction and orientation analysis indicate that the orientation of the imidazolium ring provides the empty positions for water–anion interactions and promotes the water molecules to approach the hydrophobic region. These results suggest that vesicle with excellent permeability properties could be obtained by screening the hydrophilic and hydrophobic of ILs and they might be beneficial for the application in separation and drug delivery process.
Southern rice black-streaked dwarf virus (SRBSDV), a non-enveloped icosahedral virus with a genome of 10 double-stranded RNA segments, is a novel species in the genus Fijivirus (family Reoviridae) ...first recognized in 2008. Rice plants infected with this virus exhibit symptoms similar to those caused by Rice black-streaked dwarf virus. Since 2009, the virus has rapidly spread and caused serious rice losses in East and Southeast Asia. Significant progress has been made in recent years in understanding this disease, especially about the functions of the viral genes, rice-virus-insect interactions, and epidemiology and control measures. The virus can be efficiently transmitted by the white-backed planthopper (WBPH, Sogatella furcifera) in a persistent circulative propagative manner but cannot be transmitted by the brown planthopper (Nilaparvata lugens) and small brown planthopper (Laodelphax striatellus). Rice, maize, Chinese sorghum (Coix lacryma-jobi) and other grass weeds can be infected via WBPH. However, only rice plays a major role in the virus infection cycle because of the vector's preference. In Southeast Asia, WBPH is a long-distance migratory rice pest. The disease cycle can be described as follows: SRBSDV and its WBPH vector overwinter in warm tropical or sub-tropical areas; viruliferous WBPH adults carry the virus from south to north via long-distance migration in early spring, transmit the virus to rice seedlings in the newly colonized areas, and lay eggs on the infected seedlings; the next generation of WBPHs propagate on infected seedlings, become viruliferous, disperse, and cause new disease outbreaks. Several molecular and serological methods have been developed to detect SRBSDV in plant tissues and individual insects. Control measures based on protection from WBPH, including seedbed coverage, chemical seed treatments, and chemical spraying of seedlings, have proven effective in China.
Cross-domain few-shot learning is one of the research highlights in machine learning. The difficulty lies in the accuracy drop of cross-domain network learning on a single domain due to the ...differences between the domains. To alleviate the problem, according to the idea of contour cognition and the process of human recognition, we propose a few-shot learning method based on pseudo-Siamese convolution neural network. The original image and the sketch map are respectively sent to the branch network in the pre-training and meta-learning process. While maintaining the original image features, the contour features are separately extracted as branch for training at the same time to improve the accuracy and generalization of learning. We conduct cross-domain few-shot learning experiments and good results have been achieved using mini-ImageNet as source domain, EuroSAT and ChestX as the target domains. Also, the results are qualitatively analyzed using a heatmap to verify the feasibility of our method.
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