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Performance Improvement of Two-Phase Steam Ejector based on CFD Techniques,Response Surface Methodology and Genetic Algorithm

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Journal of Thermal Science 2024年第2期33卷 675-695页

作者： ZHANG hao Zhao hongxia ZHANG Xiuao ZENG Hongxuan DENG Jianqiang School of Energy and Power Engineering Shandong UniversityJi’nan250061China School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an710049China

The steam ejector is a crucial component in the waste heat recovery system.Its performance determines the amount of recovered heat and system efficiency.However,poor ejector performance has always been the main bottleneck for system applications.Therefore,this study proposes an optimization methodology to improve the steam ejector's performance by utilizing computational fluid dynamics(CFD) techniques,response surface methodology(RSM),and genetic algorithm(GA).Firstly,a homogeneous equilibrium model(HEM) was established to simulate the two-phase flow in the steam ejector.Then,the orthogonal test was presented to the screening of the key decision variables that have a significant impact on the entrainment ratio(ER).Next,the RSM was used to fit a response surface regression model(RSRM).Meanwhile,the effect of the interaction of geometric parameters on the performance of the steam ejector was revealed.Finally,GA was employed to solve the RSRM's global optimal ER value.The results show that the RSRM exhibits a good fit for ER(R^(2)=0.997).After RSM and GA optimization,the maximum ejector efficiency is 27.94%,which is 48.38% higher than the initial ejector of 18.83%.Furthermore,the optimized ejector efficiency is increased by 46.4% on average under off-design conditions.Overall,the results reveal that the combination of CFD,RSM,and GA presents excellent reliability and feasibility in the optimization design of a two-phase steam ejector.

关键词： two-phase steam ejector optimization methodology CFD techniques response surface methodology genetic algorithm homogeneous equilibrium model

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One-Dimensional Modulational Instability of Broad Optical Beams In Photorefractive Crystals with Both Linear and Quadratic Electro-Optic Effects

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激光与光电子学进展 2024年第5期61卷 397-403页

作者： hao Lili Wang Zhen Tang hongxia Zhang Xiaoyang Yang Qi Wang Qiang Department of Physics College of physics and Electronic EngineeringNortheast Petroleum UniversityDaqing 163318HeilongjiangChina Department of Physics College of Electrical EngineeringSuihua UniversitySuihua 152000HeilongjiangChina

We present a theoretical study of the one-dimensional modulational instability of a broad optical beam propagating in a biased photorefractive crystal with both linear and quadratic electro-optic effects(Kerr effect)under steadystate conditions.One-dimensional modulational instability growth rates are obtained by treating the space-charge field equation globally and locally.Both theoretical reasoning and numerical simulation show that both the global and local modulational instability gains are governed simultaneously by the strength and the polarity of external bias field and by the ratio of the intensity of the broad beam to that of the dark irradiance.Under a strong bias field,the results obtained using these two methods are in good agreement in the low spatial frequency regime.Moreover,the instability growth rate increases with the bias field,and the maximum instability growth occurs when ratio of light intensity to dark irradiance is 0.88.

关键词： nonlinear optics photorefractive effects spatial soliton modulational instability

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Development of an Integrated Disposable Device for SARSCoV-2 Nucleic Acid Extraction and Detection

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Biomedical and Environmental Sciences 2024年第6期37卷 639-646页

作者： Jing Ma Yanzhe hao Meiling Hou Xiaoshan Zhang Jingduan Liu haodi Meng Jiangbo Chang Xuejun Ma Jihua Liu Qingjie Ying Xianhua Wang hongxia Li Yuxi Cao Xiaoguang Zhang National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China Beijing Runbio Biotechnology Development Co. LtdBeijing 100106China Beijing Beta Technology Co. LtdBeijing 101318China Jiangsu Qitian Gene Biotechnology Co. LtdWuxi 214135JiangsuChina

Objective To develop a highly sensitive and rapid nucleic acid detection method for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods We designed,developed,and manufactured an integrated disposable device for SARS-CoV-2 nucleic acid extraction and detection.The precision of the liquid transfer and temperature control was tested.A comparison between our device and a commercial kit for SARS-Cov-2 nucleic acid extraction was performed using real-time fluorescence reverse transcription polymerase chain reaction(RT-PCR).The entire process,from SARS-CoV-2 nucleic acid extraction to amplification,was evaluated.Results The precision of the syringe transfer volume was 19.2±1.9μL(set value was 20),32.2±1.6(set value was 30),and 57.2±3.5(set value was 60).Temperature control in the amplification tube was measured at 60.0±0.0°C(set value was 60)and 95.1±0.2°C(set value was 95)respectively.SARS-Cov-2 nucleic acid extraction yield through the device was 7.10×10^(6) copies/mL,while a commercial kit yielded 2.98×10^(6) copies/mL.The mean time to complete the entire assay,from SARS-CoV-2 nucleic acid extraction to amplification detection,was 36 min and 45 s.The detection limit for SARS-CoV-2 nucleic acid was 250 copies/mL.Conclusion The integrated disposable devices may be used for SARS-CoV-2 Point-of-Care test(POCT).

关键词： An integrated disposable device SARS-Cov-2 Nucleic acid detection

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Study on Sealing Characteristics of Sliding Seal Assembly of Aircraft Hydraulic Actuator

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Instrumentation 2024年第1期11卷 18-29页

作者： Weinan Li Saixin Shi hongxia Tang Liang Chen Jiawei Zhang hao Tang Jianhua Zhao Shijiazhuang Haishan Industrial Development Corporation Shijiazhuang 050200 China Heavy Machinery Fluid Power Transmission and Control Laboratory Yanshan UniversityQinhuangdao 066004China

The hydraulic actuator,known as the"muscle"of military aircraft,is responsible for flight attitude adjustment,trajectory control,braking turn,landing gear retracting and other actions,which directly affect its flight efficiency and safety.However,the sealing assembly often has the situation of over-aberrant aperture fit clearance or critical over-aberrant clearance,which increases the failure probability and degree of movable seal failure,and directly affects the flight efficiency and safety of military aircraft.In this paper,the simulation model of hydraulic actuator seal combination is established by ANSYS software,and the sealing principle is described.The change curve of contact width and contact pressure of combination seal under the action of high-pressure fluid is drawn.The effects of different oil pressure,fit clearance and other parameters on the sealing performance are analyzed.Finally,the accelerated life test of sliding seal components is carried out on the hydraulic actuator accelerated life test rig,and the surface morphology is compared and analyzed.The research shows that the O-ring is the main sealing element and the role of the check ring is to protect and support the O-ring to prevent damage caused by squeezing into the fit clearance,so the check ring bears a large load and is prone to shear failure.Excessive fit clearance is the main factor affecting the damage of the check ring,and the damage parts are mainly concentrated at the edge of the sealing surface.This paper provides a theoretical basis for the design of hydraulic actuator and the improvement of sealing performance.

关键词： hydraulic actuator contact stress sealing characteristics maximum shear stress

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Test for Heteroscedasticity in Partially Linear Regression Models

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Journal of Systems Science & Complexity 2019年第4期32卷 1194-1210页

作者： KHALED Waled LIN Jinguan HAN Zhongcheng Zhao Yanyong hao hongxia School of Mathematics Southeast UniversityNanjing 210096China Department of Applied Statistics Faculty of EconomicsDamascus UniversitySyria School of Statistics and Mathematics Nanjing Audit UniversityNanjing 211815China

Testing heteroscedasticity determines whether the regression model can predict the dependent variable consistently across all values of the explanatory variables.Since the proposed tests could not detect heteroscedasticity in all cases,more precisely in heavy-tailed distributions,the authors established new comprehensive test statistic based on Levene’s test.The authors built the asymptotic normality of the test statistic under the null hypothesis of homoscedasticity based on the recent theory of analysis of variance for the infinite factors level.The proposed test uses the residuals from a regression model fit of the mean function with Levene’s test to assess homogeneity of variance.Simulation studies show that our test yields better than other methods in almost all cases even if the variance is a nonlinear function.Finally,the proposed method is implemented through a real data-set.

关键词： ANOVA heteroscedastic errors hypothesis testing partially linear regression model

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Design and implementation of the monochromator shielding for the cold neutron spectrometers XINGZHI and BOYA

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Chinese Physics B 2024年第5期33卷 96-102页

作者：汪晋辰刘娟娟徐大业 Florian Grünauer 郝丽杰刘蕴韬张红霞程鹏鲍威 Laboratory for Neutron Scattering and Beijing Key Laboratory of Optoelectronic Functional Materials and MicroNano Devices Department of PhysicsRenmin University of ChinaBeijing 100872China Physics Consulting Zorneding 85604Germany China Institute of Atomic Energy Beijing 102413China Department of Physics City University of Hong KongKowloon 999077China Center for Neutron Scattering City University of Hong KongKowloon 999077China

An innovative monochromator shielding is designed and implemented for the cold neutron spectrometers XINGZHI and BOYA operated by Renmin University of China at China Advanced Research Reactor.Via Monte Carlo simulations and careful mechanical designs,a shielding configuration has been successfully developed to satisfy safety requirements of below 3μSv/h dose rate at its exterior,meanwhile fulfilling space,floor load and nonmagnetic requirements.Composite materials are utilized to form the sandwich-type shielding walls:the inner layer of boron carbide rubber,the middle layer of steel-encased lead and the outer layer of borated polyethylene.Special-shaped liftable shielding blocks are incorporated to facilitate a continuous adjustment of the neutron energy while preventing radiation leakage.Our work has demonstrated that by utilizing composite shielding materials,along with the sandwich structure and liftable shielding blocks,a compact and lightweight shielding solution can be achieved.This enables the realization of advanced neutron scattering instruments that provide expanded space of measurement,larger energy and momentum coverage,and higher flux on the sample.This shielding represents the first of its kind in neutron scattering instruments in China.Following its successful operation,it has been subsequently employed by other neutron instruments across the country.

关键词： neutron scattering cold neutron spectrometer monochromator shielding sandwich shielding structure

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风电机组用滑动轴承研究现状与发展趋势

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太阳能学报 2024年第5期45卷 77-85页

作者：李浩朱才朝谭建军孙章栋王红霞重庆大学高端装备机械传动全国重点实验室重庆400044 湖北汽车工业学院机械工程学院十堰442002

首先,分析滚动轴承在风电传动系统中应用的局限性,探讨滑动轴承“以滑代滚”的可行性。然后,从风电机组用滑动轴承结构设计、轴承材料、性能分析及优化、试验测试及应用4个关键环节,综述滑动轴承风电应用的现有技术手段和面临的困难。最... 详细信息

首先,分析滚动轴承在风电传动系统中应用的局限性,探讨滑动轴承“以滑代滚”的可行性。然后,从风电机组用滑动轴承结构设计、轴承材料、性能分析及优化、试验测试及应用4个关键环节,综述滑动轴承风电应用的现有技术手段和面临的困难。最后,对风电机组滑动轴承的材料改性、一体化设计、延寿技术发展趋势做出展望。

关键词：滑动轴承风电机组滚动轴承齿轮箱

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基于Weibull分布的镁水泥涂层钢筋混凝土耐温性可靠度评价

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应用基础与工程科学学报 2024年第2期32卷 587-600页

作者：杨天霞乔宏霞王鹏辉李金鹏薛豪兰州理工大学土木工程学院西部土木工程防灾减灾教育部工程研究中心甘肃兰州730050 中国科学院青海盐湖研究所青海西宁810000 青海民族大学土木与交通工程学院青海西宁810000

针对西部盐湖地区建筑结构在恶劣气候环境下工作寿命缩短的现象,提出采用耐盐、耐卤的镁水泥涂层钢筋混凝土(CRMOCC)延长其服役时间.通过对防护层厚度为45mm的试件进行高低温交变湿热加速试验,定期无损检测并结合微观手段进行机理分析,... 详细信息

针对西部盐湖地区建筑结构在恶劣气候环境下工作寿命缩短的现象,提出采用耐盐、耐卤的镁水泥涂层钢筋混凝土(CRMOCC)延长其服役时间.通过对防护层厚度为45mm的试件进行高低温交变湿热加速试验,定期无损检测并结合微观手段进行机理分析,最后选用Weibull分布函数进行可靠性建模,使用最小二乘法、中位秩法、极大似然法3种方法估计可靠度的形状参数和尺度参数.结果表明,加速试验条件除了针棒状水化产物还有纤维絮状的腐蚀产物,随着加速时间增长,内部产物体积膨胀顺着界面过渡区发展,造成部件局部开裂;3种不同参数估计方法估计可靠性存在一定差异:最小二乘法的形状参数值m最小;中位秩法的尺度参数η较大;极大似然法受二分迭代次数影响,形状参数m最大,尺度参数η最小,概率密度函数较大,失效时间越短,失效率越大.

关键词：镁水泥涂层钢筋混凝土(CRMOCC) Weibull分布函数参数估计方法可靠度最小二乘法中位秩极大似然法

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带有时变杠杆效应的随机波动率模型参数估计及其应用

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应用概率统计 2024年第2期40卷 264-276页

作者：郝红霞胡红倩韩忠成林金官南京审计大学统计与数据科学学院南京211815

为了更好地捕捉金融时间序列中杠杆效应的时变非对称性,本文基于线性样条思想,提出一种带有时变杠杆效应的半参数随机波动率模型,并利用贝叶斯MCMC方法对所提模型中的参数进行了估计.模拟研究表明贝叶斯MCMC方法在所提模型的参数估计方... 详细信息

为了更好地捕捉金融时间序列中杠杆效应的时变非对称性,本文基于线性样条思想,提出一种带有时变杠杆效应的半参数随机波动率模型,并利用贝叶斯MCMC方法对所提模型中的参数进行了估计.模拟研究表明贝叶斯MCMC方法在所提模型的参数估计方面有着良好的有限样本表现.最后利用本文所提出的带有时变杠杆效应的半参数随机波动率模型对2000年1月4日至2020年8月18日的上证综合指数和深证成份指数日收益数据进行了实证分析,结果表明利用本文所提出的模型拟合这两组实例数据是合理的.

关键词：半参数随机波动率模型线性样条时变杠杆效应贝叶斯MCMC方法

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武都地区初榨橄榄油酚类和脂肪酸组成对油脂氧化稳定性研究

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林产化学与工业 2024年第1期44卷 111-119页

作者：唐凤霞李川周昊陈虹霞张昌伟王成章中国林业科学研究院林产化学工业研究所江苏省生物质能源与材料重点实验室国家林业和草原局林产化学工程重点实验室林木生物质低碳高效利用国家工程研究中心江苏省林业资源高效加工利用协同创新中心江苏南京210042

对武都地区的白橄榄(U)、恩帕特雷(E)、奇迹(K)、阿斯(As)、中山24(Z)、云台14(Y)、皮瓜尔(P)、豆果(Arbe)、小苹果(M)、鄂植8(Ez)、阿尔伯萨拉(Arbo)、科拉蒂(C)、莱星(L)、佛奥(F)这14个品种初榨橄榄油的脂肪酸、酚类成分及油脂氧化... 详细信息

对武都地区的白橄榄(U)、恩帕特雷(E)、奇迹(K)、阿斯(As)、中山24(Z)、云台14(Y)、皮瓜尔(P)、豆果(Arbe)、小苹果(M)、鄂植8(Ez)、阿尔伯萨拉(Arbo)、科拉蒂(C)、莱星(L)、佛奥(F)这14个品种初榨橄榄油的脂肪酸、酚类成分及油脂氧化稳定性进行检测和分析,单因素方差分析表明:品种间多酚和脂肪酸含量及油脂氧化稳定性存在显著性差异(p<0.05)。所有分析样品的脂肪酸组成均符合欧盟特级初榨橄榄油标准,初榨橄榄油中油酸质量分数在(56.12±0.24)%(豆果)和(71.45±0.42)%(科拉蒂)之间,亚油酸质量分数在(5.73±0.06)%(皮瓜尔)和(15.80±0.05)%(阿斯)之间,棕榈酸质量分数在(12.67±0.12)%(科拉蒂)和(18.76±0.04)%(豆果)之间。裂环烯醚萜类是主要的酚类成分,总酚质量分数最高为奇迹,为(471.35±29.34)mg/kg,最低为豆果,仅(165.65±8.08)mg/kg。主成分分析表明:富含橄榄苦苷苷元、女贞子苷元、橄榄裂环烯醚萜、油酸、芹菜素的品种氧化稳定性越高,而富含棕榈酸、亚油酸、酪醇、羟基酪醇、刺激醛的品种氧化稳定性越低。基于芹菜素、橄榄裂环烯醚萜、木犀草素和亚油酸建立的多元线性逐步回归模型可以预测90.70%的油脂氧化稳定性变化(p<0.001)。

关键词：油橄榄裂环烯醚萜类脂肪酸主成分分析多元线性逐步回归分析

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