Metal transfer in MIG welding

The metal transfer process in MIG welding has been investigated. The heat balance of the melting process, forces acting on the wire tip and droplets, and droplet movement were examined quantitatively both under steady current and pulsed current conditions. A novel transistorised power source was employed for precision current adjustment which with the use of high speed cinephotography and careful metallographic techniques has allowed a re-assessment of current theories to be made. A new metal transfer mode designated as ’Drop Spray* has been discovered. This transfer mode is located between the well known globular and spray transfer modes and only occurs in a very narrow current range of 20A, but it has several important features. The relationship between metal transfer mode and the welding variables has been established quantitatively for the first time. It was found that the extension resistance and heat content of droplets are determined by current and hence metal transfer modes. The amount of spatter and fume was also found to be determined by transfer mode. Metal transfer under pulsed current was also investigated. It was found that the metal transfer modes under pulsed current are the same as that of steady current. It was also found that the first drop of every pulse is of drop spray mode and the subsequent droplets will be stream spray. Careful observations and measurements have been made at various stages of the current pulse to enable greater understanding of the influence of the pulse parameters. Based on the results mentioned above, a concept of controlled MIG welding was proposed, based on the control of metal transfer mode. By this concept any predetermined feature of conventional MIG welding can be achieved consistently and repeatedly. As an application of the proposed concept, drop spray transfer was reproduced over a wide current range by means of metal transfer control. A new controlled MIG process designated as ’controlled drop spray MIG' has been developed which features high efficiency, all positional ability, freedom from spatter, low fume generation and good bead appearance. The preliminary bead on plate trial shows that all the expected results have been achieved although many more trials are necessary to fully prove the process.Ph

UNDERSTANDING THE MASSIVE ONLINE REVIEWS: A NOVEL REPRESENTATIVE SUBSET EXTRACTION METHOD

Online review hasalready been recognized as an important sales assistant for consumers to make their purchase decision. However, with the rapid development of electronic commerce,overwhelming informationoverloads and review manipulation make consumers lost in ocean of reviews and face huge cognitive stress. To address this issue, different types of online review have been developed by online marketplaces. Especially, except traditional types of online reviews (positive, neutral and negative), several new types of online review (review with picture and additional review) do not only contain plain text, but also pictures. Consumers could attach additional reviews to the original reviews to further share their experience sometimes later. Few studies have focused on which types of online reviews are able to influence consumers’ decisions more efficiently. Especially, research on new types of reviews is still unanswered.Using data from Taobao.com, the biggest electronic marketplace in China,this study conducts an empirical investigation to bridge the gap. Weinvestigatethat whether and howtraditional text reviewsand new types of reviews influence consumers’ purchase decision making. The results show that under the context of information overload and review manipulation, traditional reviewsare still influential, but less effective than new types of reviews. Although review with picture and additional review don’t show valence directly, they present more reliable references towards product quality and attract consumers’ attention more efficiently.And it is more interesting that new types of online review provide an effective channel for consumers to alleviate their dissatisfaction to effect potential consumers purchase decision making. The findings of this study can provide useful implications for researchers by highlighting the roles of different types of online review in consumers’ decision making. Also, the empirical investigation in this paper will remind business vendors to focus on online reviews especially new types of online reviews and conduct targeted marketing strategies to increase competitive advantage and improve their sales performance

Coenzyme Q10 attenuates airway inflammation and oxidative stress in neonatal asthmatic rats

Purpose: To determine the therapeutic effect of coenzyme Q10 (CoQ10) on ovalbumin (OVA)-provoked asthma in neonatal rats.Methods: Asthma was induced by exposing neonatal rats to OVA. The levels of SOD, CAT, GPx, GSH, MDA and MPO were estimated using standard biochemical kits, while ELISA was used to measure the concentrations of Ig E and Th2 cytokines. Gene expressions were assayed with qRT-PCR, and protein expressions were determined with western blotting.Results: OVA treatment led to increases in levels of BALF inflammatory cells, lipid peroxidation, serum IgE and BALF Th2 cytokines, but it decreased antioxidant levels. Furthermore, the protein expression of NF-κB and mRNA expression levels of proinflammatory cytokines and inducible nitric oxide synthase (iNOS) were upregulated in the asthmatic rats (p < 0.05). However, coenzyme Q10 supplementation significantly decreased lipid peroxidation, and reduced inflammatory cells and IgE levels, while the antioxidant levels were enhanced (p < 0.05). Moreover, coenzyme Q10 reduced the levels of Th2 cytokines and downregulated the expressions of NF-κB, TNF-α, IL-6, and iNOS in the neonatal asthmatic rats (p < 0.05).Conclusion: Coenzyme Q10 attenuates airway inflammation and oxidative stress in neonatal asthmatic rats. Thus, coenzyme Q10 has promising therapeutic potential in the management of asthma. Keywords: Asthma, Neonatal, Coenzyme Q10, Th2, cytokines, Oxidative stress, Antiinflammatio

Function and clinical application of exosome—how to improve tumor immunotherapy?

In recent years, immunotherapy has been increasingly used in clinical practice to treat tumors. However, immunotherapy’s efficacy varies between tumor types and patient populations, and long-term drug resistance often occurs during treatment. Therefore, it is essential to explore the molecular mechanisms of immunotherapy to improve its efficacy. In this review, we focus on the significance of tumor-derived exosomes in the clinical treatment of tumors and how modifying these exosomes may enhance immune effectiveness. Specifically, we discuss exosome components, such as RNA, lipids, and proteins, and the role of membrane molecules on exosome surfaces. Additionally, we highlight the importance of engineered exosomes for tumor immunotherapy. Our goal is to propose new strategies to improve the efficacy of tumor immunotherapy

Spatio-Temporal Patterns and Impacts of Sediment Variations in Downstream of the Three Gorges Dam on the Yangtze River, China

Spanning the Yangtze River of China, the Three Gorges Dam (TGD) has received considerable concern worldwide with its potential impacts on the downstream side of the dam. This work investigated the spatio-temporal variations of suspended sediment concentration (SSC) at the downstream section of Yichang-to-Chenglingji from 2002 to 2015. A random forest model was developed to estimate SSC using MODIS ground reflectance products, and the spatio-temporal distributions of SSC were retrieved with this model to investigate the characteristics of water-silt variation. Our results revealed that, relatively, SSC before 2003 was evenly distributed in the downstream Yangtze River, while this spatial distribution pattern changed ce 2003 when the dam started storing water. Temporally, the SSC demonstrated a W-shaped curve of seasonal variation as one peak occurred in September and two troughs in March and November, and showed a significantly decreasing trend after three-stage impoundment. After official operation of the TGD in 2009, the SSC was reduced by over 40% than before 2003. Spatially, the most significant changes occurred in the upper Jingjiang section, where the SSC dropped by 45%. During all stages of impoundment, the water impoundment to 135 m in 2003 had the most significant impact on suspended sediment. The decreased SSC has led to emerging risks of bank failure, aggravated erosion of water front and aggressive down-cutting erosion along the downstream of the dam, as well as other ecological and environmental issues that require urgent attention by the government

Retentive Network: A Successor to Transformer for Large Language Models

In this work, we propose Retentive Network (RetNet) as a foundation architecture for large language models, simultaneously achieving training parallelism, low-cost inference, and good performance. We theoretically derive the connection between recurrence and attention. Then we propose the retention mechanism for sequence modeling, which supports three computation paradigms, i.e., parallel, recurrent, and chunkwise recurrent. Specifically, the parallel representation allows for training parallelism. The recurrent representation enables low-cost $O(1)$ inference, which improves decoding throughput, latency, and GPU memory without sacrificing performance. The chunkwise recurrent representation facilitates efficient long-sequence modeling with linear complexity, where each chunk is encoded parallelly while recurrently summarizing the chunks. Experimental results on language modeling show that RetNet achieves favorable scaling results, parallel training, low-cost deployment, and efficient inference. The intriguing properties make RetNet a strong successor to Transformer for large language models. Code will be available at https://aka.ms/retnet

Effects of LED spectrum on circadian rhythmic expression of clock genes and Aanat2 in the brain of juvenile European seabass (Dicentrarchus labrax)

The circadian rhythm is a physiological phenomenon that occurs in various organisms with a cycle of about 24 hours. Light is one of the important environmental factors affecting biological rhythm. To clarify whether a shift in light spectrum can influence the circadian expression in fish brain, a total of 175 European seabasses [body weight: 32.5 ± 0.71) g; body length: (13.78 ± 0.35) cm] were exposed to white light (WL), red light (RL), yellow light (YL), green light (GL) or blue light (BL). After 50 days of exposure, circadian expressions of four core clock genes (Clock, Bmal1, Per2, Cry1) and Aanat2 gene in brain were examined. The results showed that the temporal expression patterns of positive clock gens (Clock and Bmal1) showed increases during the scotophase and decreases during the photophase, with peaks near the middle of the darkness. Clock gene expression showed a stable circadian rhythm (R2 = 0.578-0.824, P=0.000- 0.027) in all light groups while Bmal1 showed circadian rhythm in WL, GL and RL, not in BL and YL. Daily expression patterns of the negative clock genes oscillated in the opposite phase from the positive clock genes, showing increasing mRNA levels during the light, decreases during the dark, and peaks near the shift from night to day, except Per2 in RL and Cry1 in BL. Compared with WL, the acrophases of Clock and Bmal1 were delayed under all light treatments (BL: + 3.7h, +6.73h; RL: +2.4h,+1.35h; YL: + 4.94h, 2.00h; GL: +0.05, +0.16h). Cry1 showed advanced acrophase under all light treatments (BL: -10.74 h, GL: -3.81 h, RL: -3.93 h, YL: -7.56 h) but Per2 showed delayed acrophase in all light treatments (GL: +0.86 h, RL: +10.35 h, YL: +9.62 h), except in BL (-0.43 h). The acrophase of Aanat2 was advanced by all monochromatic light, the Aanat2 level was significantly increased in RL compared with other light treatment. Therefore, the results indicate that RL may regulate the expression of Aanat2 gene by affecting the expression of clock gene in fish brain. Spectrum can affect the biological clock system of fish, and unreasonable spectrum may disturb the rhythm of gene expression of biological clock of fish. Under the irradiation of light spectrum, some clock genes still maintain obvious circadian oscillation, while the rhythm of some clock genes is not obvious and may be destroyed. Our findings suggest a primary role of light spectrum information to the fish brain circadian system

Assessment of fishery management parameters for major prey fish species in the lower reaches of the Songhua River

The stability of the ecosystem directly affects the water quality and safety, fishery production, and people’s quality of life along the route. In this study, extensive biological information on five dominant species of prey fish, including Hemiculter leucisculus (Basilewsky, 1855), Acheilognathus macropterus (Bleeker), Rhodeus sericeus (Pallas,1776), Pseudorasbora parva (Temminck & Schlegel, 1846), and Squalidus argentatus (Sauvage & Dabry de Thiersant, 1874), was collected in the lower reaches of the Songhua River, and the population parameters and variation rules of these fish were evaluated. The results showed that at present, the fish resources in the lower reaches of the Songhua River were in an overexploited state. Although the growth rate of prey fish was accelerating, their growth potential was decreasing. In addition to the homogeneous structure of the fish community, it was increasingly evident that a high proportion of small-sized fish were present in the fish community. In addition, the growth length coefficients of the five prey fish species were all greater than 0.2, indicating that the prey fish were growing at a faster rate, and the range of the growth performance indicators were 3.49 ~ 4.37. Our data also demonstrated that the exploitation rates of Hemiculter leucisculus and Squalidus argentatus were both greater than 0.5, and the exploitation rates of all species were higher than Emax except for Pseudorasbora parva. Finally, based on the above results, the mesh size of all nets should be controlled above 45 mm to ensure the size of the main prey fish populations in the lower reaches of the Songhua River. In summary, these results provided variation rules and growth of prey fish resources in the lower reaches of the Songhua River. At the same time, the distribution of major commercial or endangered baiting grounds in the lower reaches of the Songhua River was determined, which was beneficial to the balance and integrity of the ecosystem

EvoMoE: An Evolutional Mixture-of-Experts Training Framework via Dense-To-Sparse Gate

Mixture-of-experts (MoE) is becoming popular due to its success in improving the model quality, especially in Transformers. By routing tokens with a sparse gate to a few experts (i.e., a small pieces of the full model), MoE can easily increase the model parameters to a very large scale while keeping the computation cost in a constant level. Most existing works just initialize some random experts, set a fixed gating strategy (e.g., Top-k), and train the model from scratch in an ad-hoc way. We identify that these MoE models are suffering from the immature experts and unstable sparse gate, which are harmful to the convergence performance. In this paper, we propose an efficient end-to-end MoE training framework called EvoMoE. EvoMoE starts from training one single expert and gradually evolves into a large and sparse MoE structure. EvoMoE mainly contains two phases: the expert-diversify phase to train the base expert for a while and spawn multiple diverse experts from it, and the gate-sparsify phase to learn an adaptive sparse gate and activate a dynamic number of experts. EvoMoE naturally decouples the joint learning of both the experts and the sparse gate and focuses on learning the basic knowledge with a single expert at the early training stage. Then it diversifies the experts and continues to train the MoE with a novel Dense-to-Sparse gate (DTS-Gate). Specifically, instead of using a permanent sparse gate, DTS-Gate begins as a dense gate that routes tokens to all experts, then gradually and adaptively becomes sparser while routes to fewer experts. Evaluations are conducted on three popular models and tasks, including RoBERTa for masked language modeling task, GPT for language modeling task and Transformer for machine translation task. The results show that EvoMoE outperforms existing baselines, including Switch, BASE Layer, Hash Layer and StableMoE