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Grain refinement of 5A06 aluminum alloy welds caused by tungsten inert gas welding arc characteristics under Ar-He alternating gas supply conditions:a coupled method of water-cooled copper plate test/numerical simulation

第十届家（柞）蚕遗传育种及良种繁育学术研讨会

作者： fangyin dai Xiaofan Liu Cun Cao Xiaoling Tong Liang Qiao Li Zhang Songzhen He Yuanhao Li Hai Hu Songyuan Wu Duan Tan Zhonghuai Xiang Cheng Lu State Key Laboratory of Silkworm Genome Biology The Key Sericultural Laboratory of Agricultural MinistrySouthwest University

The body color of insect is varied, of which the melanism is a common form. The mechanism of insect melanism has long attracted biologists and ecologists. In silkworm,Bombyx mori, black pupa（bp） is a unique pupal-stage melanic mutant. Its molecular basis,however, remains unclear. In the present study, we identified the aspartate decarboxylase gene which is responsible for bp mutant using positional cloning. In the bp mutant, a 493 bp SINE transposon was inserted 2.3 kb upstream of the transcription start site of ***, we observed the dramatic reduction of BmADC expression levels in bp mutant,resulting in the deficiency of β-alanine, NBAD and the accumulation of *** of β-alanine into bp mutant rescued its color pattern to wild-type, and knockdown of BmADC gene obtained melanic pupae in the wild-type. All the results showed that BmADC plays an important role in melanin metabolism during pupa stage in silkworm. This may contribute to a better understanding of the pigmentation mechanism of pupal cuticle in Lepidopteran.

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Journal of Iron and Steel Research International 2024年第3期31卷 767-777页

作者： Hong-bin dai Jian Miao Jia-xin Lin School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and *** the tungsten inert gas(TIG)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change *** FLUENT software was used to numerically simulate the characteristics of the TIG arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were *** with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIG arc has obvious dynamic characteristics under the condition of Ar-He alternating gas *** unique dynamic TIG arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply Grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property

Recent progress in photocatalytic NAD(P)H regeneration for photocatalytic-enzymatic-coupling system

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 1-24页

作者： Wei Lan Maodi Wang Huicong dai Qihua Yang Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Zhejiang Key Laboratory for Reactive Chemistry on Solid SurfacesInstitute of Physical ChemistryZhejiang Normal UniversityJinhua 321004China

The enzymatic redox reactions in natural photosynthesis rely much on the participation of cofactors,with reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate(NADH/NADPH)or their oxidized form(NAD+/NADP+)as an important redox *** photocatalytic regeneration of expensive and unstable NADH/NADPH in vitro is an important process in enzymatic reduction and has attracted much research *** different types of photocatalysts have been developed for photocatalytic NADH/NADPH regeneration,the efficiency is still relatively *** elucidate the key factors affecting the performance of photocatalytic NADH/NADPH regeneration is helpful to rationally design the photocatalyst and improve the photocatalytic *** this paper,we overview the recent progress in photocatalytic NADH/NADPH regeneration with the focus on the strategies to improve the visible light adsorption,the charge separation and migration efficiency,as well as the surface reaction,which jointly determine the overall photocatalytic regeneration *** potential development of photocatalytic NADH/NADPH regeneration and photocatalyticenzymatic-coupling system is prospected finally.

关键词： photocatalytic-enzymatic coupling NAD(P)H regeneration photocatalysis efficiency

Prenatal cadmium exposure impairs neural tube closure via inducing excessive apoptosis in neuroepithelium

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Journal of Environmental Sciences 2024年第4期138卷 572-584页

作者： Shiyong Zhu Xuenan Li Xueyan dai Jinlong Li College of Veterinary Medicine Northeast Agricultural UniversityHarbin 150030China Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment Northeast Agricultural UniversityHarbin 150030China Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine Northeast Agricultural UniversityHarbin 150030China

Birth defects have become a public health *** hazardous environmental factors exposure to embryos could increase the risk of birth ***,a toxic environmental factor,can cross the placental barrier during *** woman may be subjected to cadmium before taking precautionary protective ***,the link between birth defects and cadmium remains *** exposure can induce excessive apoptosis in neuroepithelium during embryonic development *** exposure activated the p53 via enhancing the adenosine 5‘-monophosphate(AMP)-activated protein kinase(AMPK)and reactive oxygen species'(ROS)*** cadmium decreases the level of Paired box 3(Pax3)and murine double minute 2(Mdm2),disrupting the process of p53 *** p53 accumulation induced excessive apoptosis in neuroepithelium during embryonic development *** apoptosis led to the failure of neural tube *** study emphasizes that environmental materials may increase the health risk for *** caused the failure of neural tube closure during early embryotic *** women may be exposed by cadmium before taking precautionary protective actions,because of cadmium concentration-containing foods and environmental tobacco *** suggests that prenatal cadmium exposure is a threatening risk factor for birth defects.

关键词： Cadmium Neural tube closure Excessive apoptosis p53 Embryogenesis

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Finite-Time Stabilization for Constrained Discrete-time Systems by Using Model Predictive Control

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1656-1666页

作者： Bing Zhu Xiaozhuoer Yuan Li dai Zhiwen Qiang IEEE the Seventh Research Division Beihang UniversityBeijing 100191China the School of Automation Beijing Institute of TechnologyBeijing 100081China

In this paper, a model predictive control(MPC)framework is proposed for finite-time stabilization of linear and nonlinear discrete-time systems subject to state and control constraints. The proposed MPC framework guarantees the finite-time convergence property by assigning the control horizon equal to the dimension of the overall system, and only penalizing the terminal cost in the optimization, where the stage costs are not penalized explicitly. A terminal inequality constraint is added to guarantee the feasibility and stability of the closed-loop *** feasibility can be improved via augmentation. The finite-time convergence of the proposed MPC is proved theoretically,and is supported by simulation examples.

关键词： Constraints deadbeat control finite-time stabilization model predictive control(MPC)

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Maximizing conditional independence for unsupervised domain adaptation

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Science China(Information Sciences) 2024年第5期67卷 136-149页

作者： Yiming ZHAI Chuanxian REN Youwei LUO Daoqing dai School of Mathematics Sun Yat-Sen University

Unsupervised domain adaptation(UDA) studies how to transfer a learner from a labeled source domain to an unlabeled target domain with different distributions. Existing methods mainly focus on matching marginal distributions of the source and target domains, which probably leads to a misalignment of samples from the same class but different domains. In this paper, we tackle this misalignment issue by achieving the class-conditioned transferring from a new perspective. Specifically, we propose a method named maximizing conditional independence(MCI) for UDA, which maximizes the conditional independence of feature and domain given class in the reproducing kernel Hilbert spaces. The optimization of conditional independence can be viewed as a surrogate for minimizing class-wise mutual information between feature and domain. An interpretable empirical estimation of the conditional dependence measure is deduced and connected with the unconditional case. Besides, we provide an upper bound on the target error by taking the class-conditional distribution into account, which provides a new theoretical insight for class-conditioned transferring. Extensive experiments on six benchmark datasets and various ablation studies validate the effectiveness of the proposed model in dealing with UDA.

关键词： conditional independence kernel method domain adaptation class-conditioned transferring

Experimental investigation on the gravity driven discharge of cohesive particles from a silo with two outlets

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Particuology 2024年第6期89卷 11-21页

作者： Li dai Zhulin Yuan Fengxian Fan Conghui Gu School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212100China

An experimental study on the gravity driven discharge of cohesive particles from a silo with two outlets was *** discharge behaviors under the conditions that a single outlet was open and two outlets were open were investigated by varying the moisture content of the particles and the filling height of the particles in the *** results show that the discharge rate of the cohesive particles increases gradually at the beginning,then almost keeps constant,and finally drops *** discharge rate in case of two openings is around 1.1–1.6 times that in case of a single *** filling height leads to lower discharge rate in case of a single opening but results in higher discharge rate in case of two ***,the avalanche dynamics in case of a single opening was examined,and the mixing behavior of the cohesive particles was *** is observed that the discharge flow is promoted by the avalanche phenomenon in the silo,generating a general trend that the normalized mass of discharge increases with the filling height at higher moisture *** case of a single opening,the transition from mass flow to funnel flow favors the particle mixing,resulting in an increasing mixing index as the moisture content *** general,a better performance of mixing can be achieved in case of a single opening compared with in case of two *** study provides vital information for fundamental understanding of the gravity driven discharge of cohesive particles from the silo with multiple outlets.

关键词： Cohesive particles Moisture content Discharge rate Avalanche Mixing

The beta-1,4-N-acetylglucosaminidase 1 gene,selected by domestication and breeding,is involved in cocoon construction of Bombyx mori

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The beta-1,4-N-acetylglucosaminidase 1 gene,selected by dome...

Aerodynamic characteristics of a pitching airfoil with leading-edge morphing

中国蚕学会2021年学术年会

作者： Chunlin Li Xiaoling Tong Weidong Zuo Hai Hu Gao Xiong Minjin Han Rui Gao Yue Luan Kunpeng Lu Tingting Gai Zhonghuai Xiang Cheng Lu fangyin dai State Key Laboratory of Silkworm Genome Biology Key Laboratory of Sericultural Biology and Genetic BreedingMinistry of Agriculture and Rural AffairsCollege of BiotechnologySouthwest University

Holometabolous insects have distinct larval,pupal,and adult *** pupal stage is typically immobile and can be subject to predation,but cocoon offers pupal protection for many insect *** cocoon provides a space in which the pupa to adult metamorphosis *** also protects the pupa from weather,predators and *** protein is a precursor of the silk used in cocoon *** used the silkworm as a model species to identify genes affecting silk protein synthesis and cocoon *** used quantitative genetic analysis to demonstrate that-1,4-N-acetylglucosaminidase 1（BmGlcNase1） is associated with synthesis of sericin,the main composite of ***1 has an expression pattern coupled with silk gland development and cocoon shell weight（CSW） variation,and CSW is an index of the ability to synthesize silk ***-regulated expression of BmGlcNase1 increased sericin content by 13.9% and 22.5% while down-regulation reduced sericin content by 41.2% and 27.3% in the cocoons of females and males,*** sequencing revealed that sequence variation upstream of the BmGlcNase1 transcriptional start site（TSS） is associated with the expression of BmGlcNase1 and *** pressure analysis showed that GlcNase1 was differentially selected in insects with and without cocoons（ω1=0.044 vs.ω2=0.154）.This indicates that this gene has a conserved function in the cocooning process of ***1 appears to be involved in sericin synthesis and silkworm cocooning.

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Chinese Journal of Aeronautics 2024年第7期37卷 81-92页

作者： Chaoyuan WEN Yuting dai Yuntao XU Chao YANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 311115China

This paper focuses on the effect of the phase offset of Leading-Edge(LE)morphing on the aerodynamic characteristics of a pitching NACA0012 *** an unstretched camber and using polynomial interpolation,an explicit expression for LE nonlinear morphing is proposed and implemented for the large pitching motion of the *** field results and aerodynamic forces are obtained by solving the unsteady Reynolds-averaged Navier-Stokes equations for both the airfoil’s pitching motion and LE ***,the index of instantaneous aerodynamic power is used to quantify the work done by the airflow in a dynamic *** to the instantaneous aerodynamic power and energy map,which denotes the energy transfer between the airfoil’s oscillation and flow field,the airfoil is subject to stall *** results show that LE morphing with an optimal phase offset of 315°reduces the energy extraction from the flow field,suppressing the stall flutter *** optimal phase offset is effective at different pitching axis positions of the *** results signify that LE morphing can suppress stall flutter by advancing the occurrence of the first LE vortex and increasing the nose-down moment during the upstroke period.

关键词： Aerodynamics Computational fluid dynamics Leading-edge morphing OpenFOAM Dynamic stall Dynamic mesh

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