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Numerical Study of New-Type Receiver with Axially-Hollow Spiral Deflector for Parabolic Trough Direct-Steam-Generation Loop of Concentrating Solar Power System

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Journal of Thermal Science 2023年第2期32卷 597-610页

作者： shi Yaolu SUN jie WEI Jinjia School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'an 710049China Adv Energy Sci&Technol Guangdong Lab Foshan Xianhu LabXianhu Hydrogen ValleyFoshan 528200China

The thermal stress-induced deformation issue of receiver is crucial to the performance and reliability of a parabolic-trough(PT) concentrating solar power(CSP) system with the promising direct steam generation(DSG) *** objective of the present study is to propose a new-type receiver with axially-hollow spiral deflector and optimize the geometric structure to solve the above *** this end,optical-flow-thermal multi-physics coupling models have been established for the preheating,boiling and superheating sections of a typical PT-DSG *** simulation results show that our proposed new-type receiver demonstrates outstanding comprehensive *** can minimize the circumferential temperature difference through the spiral deflector while lower the flow resistance cost through the axially hollow structure at the same *** quantitatively evaluated by the temperature uniformity improvement(ε_(ΔT)) and the performance evaluation criteria(PEC),different designs are achieved based on different optimal *** ε_(ΔT)is of primary importance,the optimal design with torsional ratio of 1 is achieved,with ε_(ΔT)=25.4%,25.7%,41.5% and PEC=0.486,0.878,0.596corresponding to preheating,boiling,superheating sections,*** PEC is of primary importance,the optimal design with torsional ratio of 6-6.5 is achieved,with PEC=0.950,2.070,0.993 and ε_(ΔT)=18.2%,13.3 %,19.4% corresponding to preheating,boiling,superheating sections,respectively.

关键词： concentrating solar power parabolic though collector direct steam generation performance evaluation criteria axially-hollow spiral deflector

Array based HV/VH tree: an effective data structure for layout representation

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第3期13卷 232-237页

作者： jie REN Wei-wei PAN Yong-jun ZHENG Zheng shi Xiao-lang YAN Institute of VLSI Design Zhejiang UniversityHangzhou 310027China

We present a new data structure for the representation of an integrated circuit layout. It is a modified HV/VH tree using arrays as the primary container in bisector lists and leaf nodes. By grouping and sorting objects within these arrays together with a customized binary search algorithm, our new data structure provides excellent performance in both memory usage and region query speed. Experimental results show that in comparison with the original HV/VH tree, which has been regarded as the best layout data structure to date, the new data structure uses much less memory and can become 30% faster on region query.

关键词： Very large scale integration (VLSI) Layout representation HV/VH trees Region query

Research on the mechanical property test of a new high-strength metal bolt

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Journal of Coal Science & Engineering(China) 2011年第4期17卷 393-396页

作者： shi Jian-jun MA Nian-jie Safety Engineering College North China University of Science and Technology Beijing 101601 China School of Resources and Safety Engineering China University of Mining and Technology （Beijing） Beijing 100083 China

In order to study how to improve the overall performance of the operational metal bolt, based on the production process of an ordinary metal bolt used in understructure engineering, this paper focused on the existing problems of ordinary metal bolts identified by some survey and analysis. The results show that the structure of operational metal bolts is so unrea- sonable that the bolt tail is easily fractured by low load capacity. Furthermore, a new type of strong big-end metal bolt and its heat treatment and roughing processing technology were introduced. Through bolt tensile and metallographic tests, the property of the new big-end bolt was analyzed. The new findings indicate that after a special processing, the overall strength and plasticity of the bolt is greatly improved, and the grain of the bolt tail structure is refined, which would help build up favorable working conditions for bolt tails.

关键词： mechanical test big-end bolt processing technology microscopic test

Machine learning of mechanical properties of steels

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Science China(Technological Sciences) 2020年第7期63卷 1247-1255页

作者： XIONG jie ZHANG TongYi shi SanQiang Materials Genome Institute Shanghai UniversityShanghai 200444China Department of Mechanical Engineering the Hong Kong Polytechnic UniversityHong Kong 999077China Shenzhen Research Institute the Hong Kong Polytechnic UniversityShenzhen 518057China

Knowledge of the mechanical properties of structural materials is essential for their practical applications. In the present work,three-hundred and sixty data samples on four mechanical properties of steels—fatigue strength, tensile strength, fracture strength and hardness—were selected from the Japan National Institute of Material Science database, comprising data on carbon steels and low-alloy steels. Five machine learning algorithms were used to predict the mechanical properties of the materials represented by the three-hundred and sixty data samples, and random forest regression showed the best predictive *** selection conducted by random forest and symbolic regressions revealed the four most important features that most influence the mechanical properties of steels: the tempering temperature of steel, and the alloying elements of carbon, chromium and molybdenum. Mathematical expressions were generated via symbolic regression, and the expressions explicitly predicted how each of the four mechanical properties varied quantitatively with the four most important features. This study demonstrates the great potential of symbolic regression in the discovery of novel advanced materials.

关键词： materials informatics steel fatigue strength symbolic regression

Distributed Fiber Optic Monitoring and Stability Analysis of a Model Slope under Surcharge Loading

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Journal of Mountain Science 2014年第4期11卷 979-989页

作者： ZHU Hong-Hu shi Bin ZHANG jie YAN jun-Fan ZHANG Cheng-Cheng School of Earth Sciences and Engineering Nanjing University Department of Geotechnical Engineering Tongji University

In the discipline of geotechnical engineering, fiber optic sensor based distributed monitoring has played an increasingly important role over the past few decades. Compared with conventional sensors, fiber optic sensors have a variety of exclusive advantages, such as smaller size, higher precision, and better corrosion resistance. These innovative monitoring technologies have been successfully applied for performance monitoring of geo-structures and early warning of potential geo- hazards around the world. In order to investigate their ability to monitor slope stability problems, a medium-sized model of soil nailed slope has been constructed in laboratory. The fully distributed Brillouin optical time-domain analysis （BOTDA） sensing technology was employed to measure the horizontal strain distributions inside the model slope. During model construction, a specially designed strain sensing fiber was buried in the soil mass. Afterward, the surcharge loading was applied on the slope crest in stages using hydraulic jacks and a reaction frame. During testing, an NBX-6o5o BOTDA sensing interrogator was used to collect the fiber optic sensing data. The test results have been analyzed in detail, which shows that the fiber optic sensors can capture the progressive deformation and failure pattern of the model slope. The limit equilibrium analyses were also conducted to obtain the factors ofsafety of the slope under different surface loadings. It is found that the characteristic maximum strains can reflect the stability of the model slope and an empirical relationship was obtained, This study verified the effectiveness of the distributed BOTDA sensing technology in performance monitoring of slope.

关键词： Slope stability Geotechnical monitoring Fiber optic sensor Distributed strain sensing Brillouin optical time-domain analysis (BOTDA) Model test

Expression and significance of nuclear factor κB p65 in colon tissues of rats with TNBS-induced colitis

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World Journal of Gastroenterology 2005年第12期11卷 1759-1763页

作者： jun-HuaLi jie-PingYu Hong-GangYu Xi-MingXu Liang-LiangYu shi-QuanLiu DepartmentofGastroenterology TheRenminHospitalofWuhanUniversityWuhan430060HubeiProvinceChina

AIM: To investigate the role of NF-κB in the pathogenesis of TNBS-induced colitis in rats. METHODS: Thirty-two healthy adult Sprague-Dawley (SD) rats were randomly divided into four groups of eight each: normal, NS, model Ⅰ, model Ⅱ groups in our study. Rat colitis model was established through 2-,4-,6-trinitrobenzene sulfonic acid (TNBS) enema. At the end of four weeks, the macroscopical and histological changes of the colon were examined and mucosa myeloperoxidase (MPO) activities assayed. NF-κB p65 expression was determined by Western blot assessment in cytoplasmic and nuclear extracts of colon tissue, and the expressions of TNF-α and ICAM-1 protein in colon tissue were examined by immunohistochemistry. The relativities between expression of NF-κB p65 and other parameters were analyzed. RESULTS: TNBS enema resulted in pronounced pathological changes of colonic mucosa in model Ⅱ group (macroscopic and histological injury indices 6.25±1.39 and 6.24±1.04, respectively), which were in accordance with the significantly elevated MPO activity (1.69±0.11). And the nuclear level of NF-κB and expression of TNF-α, ICAM-1 in rats of model II group were higher than that of normal control (9.7±1.96 vs1.7±0.15, 84.09±14.52 vs 16.03±6.21, 77.69±8.09 vs 13.41±4.91 P<0.01), Linear correlation analysis revealed that there were strong correlations between the nuclear level of NF-κB and the tissue positive expression of TNF-α and ICAM-1, MPO activities, macroscopical and histological indices in TNBS-induced colitis, respectively (r= 0.8235, 0.8780, 0.8572, 0.9152, 0.8247; P<0.05). CONCLUSION: NF-κB plays a pivotal role in the pathogenesis of ulcerative colitis, which might account for the up-regulation the expression of TNF-α and ICAM-1.

关键词： NF-κB Ulcerative colitis TNBS

ENERGY SELF-SUSTAINABILITY IN 6G

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China Communications 2020年第12期17卷 6-8页

作者： Kun Yang shi Jin Nandana Rajatheva jie Hu jun Zhang the Network Convergence Laboratory (NCL) University of Essex University of Electronic Science and Technology of China (UESTC) the faculty of the National Mobile Communications Research Laboratory Southeast University the Centre for Wireless Communications (CWC) University of Oulu IEEE the School of Information and Communication Engineering University of Electronic Science and Technology of China (UESTC) the Faculty of the Jiangsu Key Laboratory of Wireless Communications College of Telecommunications and Information Engineering Nanjing University of Posts and Telecommunications the IEEE Communications Letters

With 5G being commercially deployed worldwide,research into 6G mobile communication networks has *** of the major key performance indicators for 6G is its extremely massive connectivity for small devices to enable so-called Internet of Everything (IoE),which is a scale up from Internet of Things (IoT).Most of these IoE devices will be either battery-powered or *** to prolong the lifetime of these IoE devices becomes a key *** calls for effort from two complementary aspects:1) energy efficiency to reduce IoE device’s energy consumption on one hand and 2) energy self-supply to open up new energy supply to IoE devices on the *** is envisioned that 6G will provide energy self-sustainability (ESS) to massive IoE devices.

关键词： 6G mobile communication Wireless communication Internet of Things Computer architecture Resource management Wireless sensor networks Optimization

Effect of electrical parameters and slag system on macrostructure of electroslag ingot

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China Foundry 2024年第1期21卷 44-50页

作者： Bing-jie Wang Yu Wang Meng-jun Wang Lei Zhao Li-zhong Chang Xiao-fang shi School of Metallurgy engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina

To investigate the influence of electric parameters and slag system on the solidification quality of electroslag ingot during electroslag remelting,different power supply modes,current strengths and remelting slag systems were used to conduct electroslag remelting experiments on 304L austenitic stainless steel,and the macrostructure of electroslag ingots was *** results indicate that the depth of the metal pool decreases with the reduction of remelting frequency in the low frequency power supply *** effects of different power supply modes,such as low-frequency,direct current straight polarity(DCSP),and direct current reverse polarity(DCRP),on reducing the depth of the metal pool increase in that *** reducing the remelting current strength in the same power supply mode,the depth of metal pool is *** compared to the binary slag system of 70%CaF2+30%Al2O3,the ternary slag system of 60%CaF2+20%Al2O3+20%CaO is more effective in reducing the depth of the metal pool during *** the 60%CaF2+20%Al2O3+20%CaO ternary slag system results in a shallower and flatter metal pool,with columnar crystal growth occurring closer to the axial *** effect is observed for both low frequency and direct current(DC)power supply modes.

关键词： electroslag remelting frequency slag system solidification quality

Effect of Cu loading content on the catalytic performance of Cu-USY catalysts for selective catalytic reduction of NO with NH_(3)

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Journal of Environmental Sciences 2023年第4期126卷 445-458页

作者： jie Wan Haipeng Yang Yijun shi Yanjun Liu Jin Zhang jun Zhang Gongde Wu Renxian Zhou Energy Research Institute Nanjing Institute of TechnologyNanjing 211167China Institute of Catalysis Zhejiang UniversityHangzhou 310028China

Series of Cu-USY zeolite catalyst with different Cu loading content were synthesized through simple impregnation *** obtained catalysts were subjected to selective catalytic reduction of NOxwith NH_(3)(NH_(3)-SCR) performance evaluation,structural/chemical characterizations such as X-ray diffraction (XRD),N2adsorption/desorption,H_(2)temperature-programmed reduction (H_(2)-TPR),NH_(3)temperature-programmed desorption (NH_(3)-TPD) as well as detailed in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments including CO adsorption,NH_(3)adsorption and NO+O_(2)in situ *** show that Cu-USY with proper Cu loading (in this work 5Cu-USY with5 wt.%Cu) could be promising candidates with highly efficient NH_(3)-SCR catalytic performance,relatively low byproduct formation and excellent hydrothermal stability,although its SO_(2)poisoning tolerability needs *** characterizations reveal that such catalytic advantages can be attributed to both active cu species and surface acid centers evolution modulated by Cu *** one hand,Cu species in the super cages of zeolites increases with higher Cu content and being more conducive for NH_(3)-SCR *** the other hand,higher Cu loading leads to depletion of Br?nsted acid centers and simultaneous formation of abundant Lewis acid centers,which facilitates NH_(4)NO_(3)reduction via NH_(3)adsorbed on Lewis acid centers,thus improving SCR ***,Cu over-introduction leads to formation of surface highly dispersed CuOx,causing unfavorable NH_(3)oxidation and inferior N2selectivity.

关键词： NH_(3)-SCR USY zeolite Cu species Brønsted/Lewis acid centers Diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)