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Identification of suitable reference genes for quantitative gene expression analysis in clam Cyclina sinensis under salinity stress and Vibrio infection

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Journal of Oceanology and Limnology 2023年第1期41卷 352-363页

作者： Fengjuan JIANG Qingyao WANG Jingjing DU Fu LÜ Qing NIE Weihong ZHAO college of marine and Biological engineering Yancheng Institute of TechnologyYancheng 224051China

The appropriate reference gene is a prerequisite for accurate normalization of gene expression level,and research on suitable reference genes in clam Cyclina sinensis is scarce.To improve the situation,we selected five commonly used housekeeping genes,including β-actin,Elongation factor 1-α(EF1-α),Glyceraldehyde-3-pho sphate dehydrogenase(GAPDH),40S ribosomal protein S18(RPS18),and Tubulin a(TUB-α),then evaluated their expression stability in different adult tissues and under different experimental treatments(salinity stress and Vibrio parahaemolyticus infection).Their expression stability was analyzed by three frequently used programs,geNorm,NormFinder,and BestKeeper.This analysis indicated that multiple genes should be used for normalization,and we concluded that the reference gene combination GAPDH-RPS18-β-actin,should be used for qRT-PCR analysis in different tissues of C.sinensis under normal physiological conditions.For the clams under salinity stress and Vibrio infection,EF1-α-GAPDHRPS18 was recommended as the gene combination for qRT-PCR normalization.TUB-αwas generally poorly ranked by all programs,and should not be used in future studies.This study should provide fundamental support for accurate quantitative gene expression analysis of this species.

关键词： Cyclina sinensis reference gene different tissues salinity stress Vibrio infection

Mission-oriented dynamic optimization model of carrying spares for warship redundant system

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Journal of Systems engineering and Electronics 2018年第3期29卷 539-548页

作者： RUAN Minzhi LI Hua WANG Junlong college of Naval Architecture & marine engineering Naval University of Engineering college of Weaponry engineering Naval University of Engineering

Redundancy is a common structure for warship system,and it is an effective way to improve the reliability of the system.In this paper, warship system is taken as the object of study,based on the system reliability equivalence principle, a spares demand rate calculation method for redundant system is proposed through structure transformation. According to the system analysis method, the general modeling data structure of spares support echelon and system indenture is established, and the mission success probability is taken as the optimization target to build the dynamic optimization model of carrying spares during the process of multi-phase. By introducing the Lagrange multiplier, the spares weight, volume and cost are transformed to the single target of the spares total scale, and the initial Lagrange factors and its dynamic adjustment policy is proposed. In a given example, the main influence factors of the carrying spares project are analyzed, and the study results are in accordance with the reality, which can provide a new approach to mission-oriented carrying spares optimization for the redundant system.

关键词： redundancy reliability equivalence warship carrying spares optimization

Simulation on effect of throat contraction ratio and strake stagger angle on flow field and aerodynamic performance of scrampressor

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航空动力学报 2017年第5期32卷 1183-1194页

作者： YANG Ling ZHONG Jing-jun HAN Ji-ang Marine Engineering College Dalian Maritime University

The design methods of typical supersonic aircraft intakes and shock wave compression technology have been applied to ram-rotor,an attractive compression system.A ram-rotor is of a typical structure including the compression ramp,the throat and the subsonic diffuser;a scrampressor is similar to ram-rotor,the only difference is that scrampressor has no subsonic diffuser.The work was the continuation of the preparatory work.In order to further study the effect of throat contraction ratio and strake stagger angle on the flow field and performance of a scrampressor,the flow field of a scrampressor with a three-dimensional flow path was numerically simulated with different throat contraction ratios and strake stagger angles.Simulated results indicated that the optional aerodynamic performance of a scrampressor could be achieved with an adiabatic efficiency of 0.8413atotal pressure recovery coefficient of 0.8446,a total pressure ratio of 7.14 and a static pressure ratio of 5.17for a throat contraction ratio of 0.6 and a strake stagger angle of 12°.It was therefore concluded that an appropriate decrease in throat contraction ratio and an increase in strake stagger angle could help the comprehensive improvement of a scrampressor in performance.

关键词： scrampressor flow field aerodynamic performance throat contraction ratio strake stagger angle

An improved lattice Boltzmann model for high gas and liquid density ratio in composite grids

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Theoretical & Applied Mechanics Letters 2018年第5期8卷 326-333,362页

作者： Shaojun Zhang Wanqing Wu Qinggong Zheng Marine Engineering College Dalian Maritime University college of Naval Architecture and marine engineering Shandong Jiaotong University

Lattice Boltzmann method is one of the widely used in multiphase fluid flow.However,the two main disadvantages of this method are the instability of numerical calculations due to the large density ratio of two phases and impossibility of the temperature distribution to be fed back into the velocity distribution function when the temperature is simulated.Based on the combination prescribed by Inamuro,the large density ratio two-phase flow model and thermal model makes the density ratio of the model simulation to be increased to 2778:1 by optimizing the interface distribution function of two-phase which improves the accuracy of differential format.The phase transition term is added as source term into the distribution function controlling two phase order parameters to describe the temperature effect on the gas-liquid phase transition.The latent heat generated from the phase change is also added as a source term into the temperature distribution function which simulates the movement of the flow under the common coupling of density,velocity,pressure and temperature.The density and the temperature distribution of single bubble are simulated.Comparison of the simulation results with experimental results indicates a good agreement pointing out the effectiveness of the improved model.

关键词： Lattice Boltzmann model Density ratio Composite grids Bubble motion Temperature effect

Influence of Cavity Leakage flow on Corner Separation in a Shrouded Stator Cascade

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Journal of Thermal Science 2023年第1期32卷 351-365页

作者： KONG Xiaozhi HUANG Tianshuo LIU Yuxin LU Huawei WANG Long Naval Architecture and Ocean engineering college Dalian Maritime UniversityDalian 116026China Marine Engineering College Dalian Maritime UniversityDalian 116026China

The impacts of the cavity leakage flow on the shrouded stator aerodynamic performance were investigated by modelling the annular cascade mainstream with the seal cavity flow path based on the validated numerical method.Meanwhile,the interactions between the cavity leakage and the mainstream were also determined in the current study.The development of hub corner separation under the action of leakage was discussed and the total pressure loss coefficient as well as the entropy-based loss coefficient was employed to evaluate the performance changes at different seal clearances and cavity rotational speeds.The results show that the cavity leakage flow induces a new vortex near the blade leading edge and plays an important role in the development of passage vortex and the size of concentrated shedding vortex.By increasing the seal clearance with more cavity leakage flow rate,an increase in the pitchwise extent of the separation region under 15%span is significant and the total pressure loss in the separation core increases.In addition,with the increase of cavity rotating speed,the starting point of corner separation moves backward,reducing the size and depth of the hub corner separation.The mainstream loss reduction in combination with the entropy increase in the seal cavity causes the entropy-based loss coefficient to perform a trend of decreasing first and then increasing with the cavity speed.

关键词： shrouded stator cavity leakage flow corner separation loss coefficient

Fault Diagnosis for Rolling Element Bearing in Dataset Bias Scenario

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Journal of Shanghai Jiaotong university(Science) 2023年第5期28卷 638-651页

作者：侯良生张均东 Marine Engineering College Dalian Maritime UniversityDalian 116026LiaoningChina

Recently, data-driven methods, especially deep learning, outperform other methods for rolling elementbearing (REB) fault diagnosis. Nevertheless, most research work assumes that REB dataset is unbiased. Inthe real industry applications, the dataset bias exists with REB owing to varying REB working conditions andnoise interference. Recently proposed adversarial discriminative domain adaptation (ADDA) is an increasinglypopular incarnation to solve dataset bias problem. However, it mainly devotes to realizing domain alignments, andignores class-level alignments;it can cause degradation of classification performance. In this study, we proposea new REB fault diagnosis model based on improved ADDA to address dataset bias. The proposed diagnosismodel realizes domain- and class-level alignments in dataset bias scenario;it consists of two feature extractors,a domain discriminator, and two label classifiers. The feature extractors and domain discriminator are trainedin an adversarial manner to minimize the domain difference in feature extractors. The domain discrepancy inlabel classifier is reduced by minimizing correlation alignment (CORAL) loss. We evaluate the proposed model onthe Case Western Reserve University (CWRU) bearing dataset and Paderborn University bearing dataset. Theproposed method yields better results than other methods and has good prospects for industrial applications.

关键词： rolling element bearing(REB) dataset bias adversarial discriminative domain adaptation(ADDA) correlation alignment(CORAL)loss

Effect of blade tip winglet on the performance of a highly loaded transonic compressor rotor

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Chinese Journal of Aeronautics 2016年第3期29卷 653-661页

作者： Han Shaobing Zhong Jingjun Marine Engineering College Dalian Maritime University

The tip leakage flow has an important influence on the performance of transonic com- pressor. Blade tip winglet has been proved to be an effective method to control the tip leakage flow in compressor, while the physical mechanisms of blade tip winglet have been poorly understood. A numerical study for a highly loaded transonic compressor rotor has been conducted to understand the effect of varying the location of blade tip wing]et on the performance of the rotor. Two kinds of tip winglet were designed and investigated. The effects of blade tip winglet on the compressor over- all performance, stability and tip flow structure were presented and discussed, It is found that the interaction of the tip winglet with the flow in the tip region is different when the winglet is located at suction-side or pressure-side of the blade tip. Results indicate that the suction-side winglet （SW） is ineffective to improve the performance of compressor rotor. In addition, a significant stall range extension equivalent to 33.74% with a very small penalty in efficiency can be obtained by the pressure-side winglet （PW）. An attempt has been made to explain the fundamental mechanisms of blade tip winglet in detail.

关键词： Blade tip winglet Numerical study Shock wave/tip leakage vor-tex interaction Stall range Tra,asonic compressor rotor

Assessing Dietary Consumption of Sodium and Potassium in China through Wastewater Analysis

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Biomedical and Environmental Sciences 2024年第1期37卷 127-131页

作者： TAN Dong Qin LIANG Yi GUO Ting LI Yan Ying SONG Yong Xin WANG De Gao college of Environmental Science and engineering Dalian Maritime UniversityDalian 116026LiaoningChina college of marine engineering Dalian Maritime UniversityDalian 116026LiaoningChina

A causal relationship has been reported between the average population salt(sodium chloride)intake and the increased risk of stroke and cardiovascular and cerebrovascular diseases in some epidemiological and clinical studies.The World Health Organization has recommended that a sodium intake of<2 g/day is preventive against cardiovascular disease,although the current intake is in excess in most countries.

关键词： Wastewater intake Potassium

Experimental study on combined buoyant-thermocapillary flow along with rising liquid film on the surface of a horizontal metallic mesh tube

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Frontiers in Energy 2020年第1期14卷 114-126页

作者： Manuel J.GOMES Ning MEI marine engineering Section College of EngineeringOcean University of ChinaQingdao266100China

Temperature distribution and variation with time has been considered in the analysis of the influences of the initial level of immersion of a horizontal metallic mesh tube in the liquid on combined buoyant and thermocapillary flow.The combined flow occurs along with the rising liquid film flow on the surface of a horizontal metallic mesh tube.Three different levels of immersion of the metallic mesh tube in the liquid have been tested.Experiments of 60 min in duration have been performed using a heating metallic tube with a diameter of 25 mm and a length of 110 mm,sealed outside with a metallic mesh of 178 mm by 178 mm,and distilled water.These reveal two distinct flow patterns.Thermocouples and infrared thermal imager are utilized to measure the temperature.The level of the liquid free surface relative to the lower edge of the tube is measured as angleθ.The results show that for a smallerθangle,or a low level of immersion,with a relatively low heating power,it is possible to near fully combine the upwards buoyant flow with the rising liquid film flow.In this case,the liquid is heated only in the vicinity of the tube,while the liquid away from the flow region experiences small changes in temperature and the system approaches steady conditions.For largerθangles,or higher levels of immersion,a different flow pattern is noticed on the liquid free surface and identified as the thermo-capillary(Marangoni)flow.The rising liquid film is also present.The higher levels of immersion cause a high temperature gradient in the liquid free surface region and promote thermal stratification;therefore the system could not approach steady conditions.

关键词： rising liquid film combined flow thermocapillary flow buoyant flow metallic mesh tube horizontal tube