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An effective method to determine bedding system insulation based on measured data

Building Simulation 2023年第1期16卷 121-132页

作者： nan Zhang Bin cao Yingxin Zhu Department of Building Science School of ArchitectureTsinghua UniversityBeijing 100084China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(Tsinghua University) Beijing 100084China Key Laboratory of Eco Planning&Green Building Ministry of Education(Tsinghua University)Beijing 100084China

The thermal environment is an essential factor that affects sleep quality.In many circumstances,the bed microenvironment is more important than the ambient environment because of the large covered area of the human body and the close contact between the bedding system and the human body.The main objective of this research is to establish an effective method to determine bedding system insulation.A thermal manikin was used in the measurement of bedding system insulation.Three different types of quilts,which were filled with cotton,polyester and duvet respectively,were chosen to be tested.In total ten different quilts with different materials and weights were involved in the test.Four regular arrangements of covers were chosen with coverage rates of 94.1%,85.9%,70.6%,and 54.4%to test.A total of 64 bedding systems were tested to build an effective method to determine the bedding system insulation.On the basis of test data,the change of bedding system insulation with coverage was found to be nonlinear.Exponential fitting was applied to establish an insulation evaluation method for bedding system insulation.In addition,the effects of quilt cover and sleepwear on bedding system insulation were discussed and thermal insulation increment caused by quilt cover and sleepwear were estimated.The relationships between neutral indoor temperature and weight per unit area of the quilt for different coverage rates have been quantified based on existing subject experiments.This research provides an effective method to determine bedding system insulation,which can be widely used in thermal comfort research and HVAC system design.

关键词： sleep environment bedding system thermal insulation thermal comfort

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Reliability-based selective maintenance for redundant systems with dependent performance characteristics of components

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Journal of Systems Engineering and Electronics 2023年第3期34卷 804-814页

作者： cao Hui DUAN Fuhai DUAN Yu’nan School of Mechanical Engineering Dalian University of TechnologyDalian 116024China

The reliability-based selective maintenance(RSM)decision problem of systems with components that have multiple dependent performance characteristics(PCs)reflecting degradation states is addressed in this paper.A vine-Copulabased reliability evaluation method is proposed to estimate the reliability of system components with multiple PCs.Specifically,the marginal degradation reliability of each PC is built by using the Wiener stochastic process based on the PC’s degradation mechanism.The joint degradation reliability of the component with multiple PCs is established by connecting the marginal reliability of PCs using D-vine.In addition,two RSM decision models are developed to ensure the system accomplishes the next mission.The genetic algorithm(GA)is used to solve the constraint optimization problem of the models.A numerical example illustrates the application of the proposed RSM method.

关键词： D-vine genetic algorithm(GA) reliability-based selective maintenance(RSM) redundant system Wiener stochastic process

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曹楠:数学、人工智能及计算机技能应被注入设计核心能力

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设计 2023年第6期36卷 34-39页

作者：李杰李叶曹楠不详同济大学设计创意学院

《设计》曹楠《设计》:从学术背景上看,您一直深耕于计算机、大数据、AI等智能科技领域,是什么契机使您跨界到了设计创意领域?曹楠:我从来没有想过有一天会成为设计学院的教授。从13岁起我就有一个从事计算机领域工作的梦想,那一年父亲... 详细信息

《设计》曹楠《设计》:从学术背景上看,您一直深耕于计算机、大数据、AI等智能科技领域,是什么契机使您跨界到了设计创意领域?曹楠:我从来没有想过有一天会成为设计学院的教授。从13岁起我就有一个从事计算机领域工作的梦想,那一年父亲送给我一台配置有Intel 80286 CPU芯片及1MB内存的二手个人电脑。

关键词：计算机技能个人电脑智能科技人工智能大数据 CPU芯片设计创意计算机领域

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Effect of rotor-mounted protrusion on sealing performance and flow structure in rotor-stator cavity

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Chinese Journal of Aeronautics 2018年第11期31卷 2057-2072页

作者： Nan Cao Xiang LUO Zeyu WU Jie WEN National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics School of Energy and Power EngineeringBeihang UniversityBeijing 100083China Collaborative Innovation Center for Advanced Aero-Engine Beijing 100083China

This paper presents an experimental investigation on the effect of protrusion radial position and height on the sealing performance and flow structure in the rotor-stator cavity. The rotormounted protrusions are assembled at three radial positions and are set to three heights. The cavity is equipped with three rim seals: a radial seal, an axial seal and a seal with double fins on the stator.The annulus Reynolds number is set at 4:39 ×10;and the rotational Reynolds number ranges from 7:51×10;to 1:20×10;. Heat and mass transfer analogy is applied. Pressure and CO;concentration are measured. The experimental results show that in cavities with different rim seals, radial distributions of the sealing efficiency, pressure and swirl ratio are basically the same. The sealing performance is improved by protrusions compared with the cavity without protrusion and improves with the increase of protrusion radial position and height. The effect of protrusion increases with the increase of the rotational Reynolds number. The windage loss and the flow resistance introduced by protrusions are investigated. It is found that induced windage loss and flow resistance decrease with the increase of protrusion radial position but increase with the protrusion height.

关键词： Height Protrusion Radial position Rim seal Sealing performance

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Effect of protrusion amount on gas ingestion of radial rim seal

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Chinese Journal of Aeronautics 2020年第3期33卷 893-901页

作者： Zeyu WU Xiang LUO Nan Cao Xue LI Hang CHEN School of Energy and Power Engineering Beihang UniversityBeijing 100083China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijing 100083China

In this paper, the effect of different amount of protrusion on various parameters in rotor–stator system was experimentally studied by measuring CO_2 concentration and pressure, in order to obtain the optimal protrusion amount.The parameters of different dimensionless sealing flow were measured under the condition that the annulus Reynolds number was 4.39 × 10~5 and the rotating Reynolds number was 1.05 × 10~6.The results show that the change of the amount of protrusions has little effect on the static pressure in the cavity, and the static pressure change near the sealing ring is almost negligible.But the total pressure and sealing efficiency increase first and then decrease with the increase of the amount of protrusion.The variation of power consumption is the same.A complex vortex structure will appear at the high radius region when the protrusion is installed.On the other hand, the protrusion can effectively reduce the minimum sealing flow of the rotor–stator cavity.Furthermore, considering the sealing efficiency and power consumption,the best range of the protrusion amount is about 36.The ratio near this range can optimally balance the alleviation of the gas ingestion and the reduction of the power consumption.

关键词： Gas ingestion Protrusion amount Radial seal Rotor–stator cavity Sealing efficiency Turbine

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A novel strategy for loading metal cocatalysts onto hollow nano-TiO_(2)inner surface with highly enhanced H_(2)production activity

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Green Energy & Environment 2023年第2期8卷 509-518页

作者： nan Chen Yu Zhou Songtao cao Ruixin Wang Weizhou Jiao School of Chemical Engineering and Technology North University of ChinaTaiyuanShanxi030051China

The loading strategy of cocatalysts affects its activity exerting and atom utilization.Here,a novel strategy for loading precious metal(Pt)cocatalysts by means of ultrathin N-doped carbon layer is reported.The strategy is based on a pyrolysis process of predesigned N-containing polymers and Pt complexes on hard-template surface,during which Pt can be reduced by carbon from pyrolysis at high temperatures.Finally,the hollow TiO_(2)composite with stable and dispersed Pt on its inner surface was prepared.It shows an ultrahigh photocatalytic H_(2)production activity as high as 25.7 mmol h^(-1)g^(-1)with methanol as sacrificial regent,and displays an apparent quantum yield as 13.2%.The improved photocatalytic activity and stability can be attributed to the highly dispersed and ultrafine Pt nanoparticles,enhanced interaction between Pt-species and carbon support,fast photo-excited electron transport from the high graphitization degree of NC layers,ample oxygen vacancies/defects,as well as the manipulated local charge distribution of Pt/NC-layer configuration.Additionally,the universality of the proposed strategy was demonstrated by replacing metal sources(such as,Ru and Pd).This work presented a promising strategy for the design and development of novel photocatalysts,which shows a broad application prospect.

关键词： Ultrathin carbon layer Ultrafine Pt nanoparticles Loading Hollow photocatalyst Photocatalytic hydrogen production

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Protecting-Group-Free One-Step Palladium-Catalyzed Coupling on C25 of Cucurbitacin B Expands Chemical Diversity with Improved Cytotoxicity against A549 Cells

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Chinese Journal of Chemistry 2022年第14期40卷 1662-1666,I0002页

作者： Ning Zhuo Jie Ma Lei cao Linhai Chen Fajun nan University of Chinese Academy of Sciences No.19A Yuquan RoadBejing 100049China State Key Laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China School of Chinese Materia Medica Nanjing University of Chinese MedicineNanjingJiangsu 210046China Drug Discovery Shandong Laboratory Bohai Rim Advanced Research Institute for Drug DiscoveryYantaiShandong 264117China

The natural product cucurbitacin B has been widely studied because of its multiple biological activities,especially its potent antitumor effects.However,modifications of cucurbitacin B are mainly focused on the C2 and C16 site,studies on the C25 acetoxy group are still limited.We successfully developed a palladium-catalyzed allylic coupling of cucurbitacin B with boronic acids,providing a one-step approach to expand the chemical diversity of the C25 position.Our method was protecting-group-free,showing a good functional group tolerance and a wide substrate scope under mild reaction conditions.A library of 29 derivatives was prepared,compounds 2q and 2u showed higher cytotoxicity against A549 cells than cucurbitacin B,compounds 2n and 2o maintained potency,and the introduced hydroxyl and amino groups could be further derived.

关键词： Natural products Cucurbitacin B Palladium-catalyzed coupling Divergent synthesis Structure-activity relationships

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Distribution of per-and polyfluoroalkyl substances in blood,serum,and urine of patients with liver cancer and associations with liver function biomarkers

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Journal of Environmental Sciences 2024年第5期139卷 418-427页

作者： cao Dai Lin Peng Yanjie Li Zhendong Li Da Chen Fei Wang nan Lin Department of Hepatobiliary Surgery The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510630China School of Environment Guangdong Key Laboratory of Environmental Pollution and HealthJinan UniversityGuangzhou 510632China State Key Laboratory of Environmental and Biological Analysis Department of ChemistryHong Kong Baptist UniversityHong Kong 999077China South China Institute of Environmental Sciences MEEGuangzhou 510655China

Studies have shown that per-and polyfluoroalkyl substances(PFASs)may be hepatotoxic in animals or humans.However,data on clinical epidemiology are very limited.In this study,21PFASs were determined in patients with liver diseases,with the highest median concentrations detected in the serum sample(26.7 ng/mL),followed by blood(10.7 ng/mL)and urine(5.02 ng/mL).Higher total PFAS concentrations were found in hepatocellular carcinoma(HCC)patients compared to non-HCC patients,with significant discrepancies in serum and blood samples.Besides,significant correlations were also found among PFAS concentrations and age,gender,body mass index(BMI),and liver function biomarkers levels.For example,PFAS concentrations are significantly higher in males than in females;Several serum PFASs concentrations increase with age and BMI,while the serum perfluorohexane sulfonic acid(PFHxS)concentrations are negatively correlated with age.In addition,multiple regression models adjusted for age,gender and BMI found that increased serum perfluorobutane sulfonic acid(PFBS),perfluoroheptane sulfonic acid(PFHpS)and perfluorohexylphosphonic acid(PFHxPA)conentrations are correlated with elevated alkaline phosphatase(ALP),aspartate aminotransferase(AST),and alpha-fetoprotein(AFP)(p<0.05).Our results provide epidemiological support for the future study on the potential clinical hepatotoxicity of PFAS.

关键词： Per-and polyfluoroalkyl substances(PFASs) Liver cancer Serum Blood Urine Liver function biomarkers

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Optimal design of extractive dividing-wall column using an efficient equation-oriented approach

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Frontiers of Chemical Science and Engineering 2021年第1期15卷 72-89页

作者： Yingjie Ma nan Zhang Jie Li Cuiwen cao Centre for Process Integration Department of Chemical Engineering and Analytical ScienceSchool of EngineeringThe University of ManchesterManchester M139PLUK Key Laboratory of Advanced Control and Optimization for Chemical Processes(Ministry of Education) East China University of Science and TechnologyShanghai 200237China

The extractive dividing-wall column(EDWC)is one of the most efficient technologies for separation of azeotropic or close boiling-point mixtures,but its design is fairly challenging.In this paper we extend the hybrid feasible path optimisation algorithm(Ma Y,McLaughlan M,Zhang N,Li J.Computers&Chemical Engineering,2020,143:107058)for such optimal design.The tolerances-relaxation integration method is refined to allow for long enough integration time that can ensure the solution of the pseudo-transient continuation simulation close to the steady state before the required tolerance is used.To ensure the gradient and Jacobian information available for optimisation,we allow a relaxed tolerance for the simulation in the sensitivity analysis mode when the simulation diverges under small tolerance.In addition,valid lower bounds on purity of the recycled entrainer and the vapour flow rate in column sections are imposed to improve computational efficiency.The computational results demonstrate that the extended hybrid algorithm can achieve better design of the EDWC compared to those in literature.The energy consumption can be reduced by more than 20%compared with existing literature report.In addition,the optimal design of the heat pump assisted EDWC is achieved using the improved hybrid algorithm for the first time.

关键词： design extractive dividing-wall column equation-oriented optimisation pseudo-transient continuation model hybrid algorithm

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Multi-Level Feature-Based Ensemble Model for Target-Related Stance Detection

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Computers, Materials & Continua 2020年第10期65卷 777-788页

作者： Shi Li Xinyan cao Yiting nan School of Information Engineering Northeast Forestry UniversityHarbinChina Petabase LLC Washington DC20001USA

Stance detection is the task of attitude identification toward a standpoint.Previous work of stance detection has focused on feature extraction but ignored the fact that irrelevant features exist as noise during higher-level abstracting.Moreover,because the target is not always mentioned in the text,most methods have ignored target information.In order to solve these problems,we propose a neural network ensemble method that combines the timing dependence bases on long short-term memory(LSTM)and the excellent extracting performance of convolutional neural networks(CNNs).The method can obtain multi-level features that consider both local and global features.We also introduce attention mechanisms to magnify target information-related features.Furthermore,we employ sparse coding to remove noise to obtain characteristic features.Performance was improved by using sparse coding on the basis of attention employment and feature extraction.We evaluate our approach on the SemEval-2016Task 6-A public dataset,achieving a performance that exceeds the benchmark and those of participating teams.

关键词： Attention sparse coding multi-level features ensemble model

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