113 research outputs found
Rapeseed Oil Monoester of Ethylene Glycol Monomethyl Ether as a New Biodiesel
A novel biodiesel named rapeseed oil monoester of ethylene glycol monomethyl ether is developed. This fuel has one more ester group than the traditional biodiesel. The fuel was synthesized and structurally identified through FT-IR and P1PH NMR analyses. Engine test results show that when a tested diesel engine is fueled with this biodiesel in place of 0# diesel fuel, engine-out smoke emissions can be decreased by 25.0%–75.0%, CO emissions can be reduced by 50.0%, and unburned HC emissions are lessened significantly. However, NOx emissions generally do not change noticeably. In the area of combustion performance, both engine in-cylinder pressure and its changing rate with crankshaft angle are increased to some extent. Rapeseed oil monoester of ethylene glycol monomethyl ether has a much higher cetane number and shorter ignition delay, leading to autoignition 1.1°CA earlier than diesel fuel during engine operation. Because of certain amount of oxygen contained in the new biodiesel, the engine thermal efficiency is improved 13.5%–20.4% when fueled with the biodiesel compared with diesel fuel
Training strategy for a lightweight countermeasure model for automatic speaker verification
The countermeasure (CM) model is developed to protect Automatic Speaker
Verification (ASV) systems from spoof attacks and prevent resulting personal
information leakage. Based on practicality and security considerations, the CM
model is usually deployed on edge devices, which have more limited computing
resources and storage space than cloud-based systems. This work proposes
training strategies for a lightweight CM model for ASV, using generalized
end-to-end (GE2E) pre-training and adversarial fine-tuning to improve
performance, and applying knowledge distillation (KD) to reduce the size of the
CM model. In the evaluation phase of the ASVspoof 2021 Logical Access task, the
lightweight ResNetSE model reaches min t-DCF 0.2695 and EER 3.54%. Compared to
the teacher model, the lightweight student model only uses 22.5% of parameters
and 21.1% of multiply and accumulate operands of the teacher model.Comment: ASVspoof202
Multimodal Transformer Distillation for Audio-Visual Synchronization
Audio-visual synchronization aims to determine whether the mouth movements
and speech in the video are synchronized. VocaLiST reaches state-of-the-art
performance by incorporating multimodal Transformers to model audio-visual
interact information. However, it requires high computing resources, making it
impractical for real-world applications. This paper proposed an MTDVocaLiST
model, which is trained by our proposed multimodal Transformer distillation
(MTD) loss. MTD loss enables MTDVocaLiST model to deeply mimic the
cross-attention distribution and value-relation in the Transformer of VocaLiST.
Our proposed method is effective in two aspects: From the distillation method
perspective, MTD loss outperforms other strong distillation baselines. From the
distilled model's performance perspective: 1) MTDVocaLiST outperforms
similar-size SOTA models, SyncNet, and PM models by 15.69% and 3.39%; 2)
MTDVocaLiST reduces the model size of VocaLiST by 83.52%, yet still maintaining
similar performance.Comment: Submitted to ICASSP 202
Low Concentrations of Caffeine and Its Analogs Extend the Lifespan of Caenorhabditis elegans by Modulating IGF-1-Like Pathway
Caffeine has been reported to delay aging and protect aging-associated disorders in Caenorhabditis elegans. However, the effects of low concentration of caffeine and its analogs on lifespan are currently missing. Herein, we report that at much lower concentrations (as low as 10 μg/ml), caffeine extended the lifespan of C. elegans without affecting food intake and reproduction. The effect of caffeine was dependent on IGF-1-like pathway, although the insulin receptor homolog, daf-2 allele, e1371, was dispensable. Four caffeine analogs, 1-methylxanthine, 7-methylxanthine, 1,3-dimethylxanthine, and 1,7-dimethylxanthine, also extended lifespan, whereas 3-methylxanthine and 3,7-dimethylxanthine did not exhibit lifespan-extending activity
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The Output Cost of Gender Discrimination: A Model-based Macroeconomics Estimate
We use a growth model in which saving, fertility and labour market participation are endogenous, to quantify the cost that barriers to female labour force participation impose in terms of an economy’s output. The model is calibrated to mimic the U.S. economy’s behavior in the long-run. We find that a 50 percent increase in the gender wage gap leads to a 35 percent decrease in income per capita in steady-state. Using independent estimates of the female to male earnings ratio for a wide cross-section of countries, we construct an economy with parameters similar to those calibrated for the U.S. economy, except for the degree of gender barriers.
Higher discrimination decreases steady-state output per capita for two distinct reasons: a direct effect due to the decrease in female labour market participation, and an indirect effect working through an increase in fertility. For several countries, a large fraction of the difference between
the country’s output and U.S. output can be ascribed to differences in gender discrimination. In addition, we find that close to half of the overall decrease in output per capita is due to the effect of gender discrimination in fertility.This paper has benefited from the financial support from Egide and Nova Forum at Universidade Nova de Lisboa, from the Funda¸cao para Ciencia e Tecnologia (FCT) and POCTI through FEDER, and from the Conselho Nacional de Desenvolvimento Cientıfico e Tecnologico (CNPq-Brazil)
NaBiS2 as a Novel Indirect Bandgap Full Spectrum Photocatalyst: Synthesis and Application
Photocatalysts with a superior activity range, from ultraviolet (UV) to near-infrared (NIR) light, are attractive for solar utilization. From this perspective, sulfides are promising due to their narrower bandgap than oxides. In this report, NaBiS2 was synthesized hydrothermally under mild conditions by adjusting the alkaline amount. The rough NaBiS2 nanosheets possessed various surface atomic configurations on their surfaces, including amorphous clusters and amorphous nano-domains, revealed by HRTEM. A theoretical investigation of the band structure employing the density functional theory (DFT) method for the first time indicated that NaBiS2 is an indirect bandgap semiconductor with a narrow bandgap of 1.02 eV. Experimentally, it showed excellent photocatalytic activity for the degradation of methyl blue under UV, visible light and NIR light due to its experimental bandgap width of 1.32 eV. A degradation rate of 99.6% was reached after 80 min under full spectrum irradiation
Rational Construction of a Mitochondria-Targeted Reversible Fluorescent Probe with Intramolecular FRET for Ratiometric Monitoring Sulfur Dioxide and Formaldehyde
Sulfur dioxide (SO2) and formaldehyde (FA) are important species that maintain redox homeostasis in life and are closely related to many physiological and pathological processes. Therefore, it is of great significance to realize the reversible monitoring of them at the intracellular level. Here, we synthesized a reversible ratiometric fluorescent probe through a reasonable design, which can sensitively monitor SO2 derivatives and FA, and the detection limit can reach 0.16 μM. The probe can specifically target mitochondria and successfully monitor the fluctuations of SO2 and FA in living cells. It also works well in the detection of SO2 and FA in zebrafish. This high-performance probe is expected to find broad in vitro and in vivo applications
The CEV
The constant elasticity of variance (CEV) model is used to describe the price of the risky asset. Maximizing the expected utility relating to the Hamilton-Jacobi-Bellman (HJB) equation which describes the optimal investment strategies, we obtain a partial differential equation. Applying the Legendre transform, we transform the equation into a dual problem and obtain an approximation solution and an optimal investment strategies for the exponential utility function
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