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The surge-heave-pitch coupling motions of the Φ- type vertical axis wind turbine supported by the truss Spar floating foundation

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Journal of Hydrodynamics 2019年第4期31卷 669-681页

作者： Ying Guo li-qin liu Yan li Chang-shui Xiao You-gang Tang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Tianjin 300072 China

The motions of the floating vertical axis wind turbine (VAWT) with consideration of the coupling between the aerodynamics and the hydrodynamics are calculated in this paper. The surge-heave-pitch coupling nonlinear equations of the floating VAWT are established. The aerodynamic loads are obtained by applying the double-multiple-stream tube theory with consideration of the dynamic stall and the floating foundation motion. The motion performances of a 5 MW Φ - Darrieus type floating VAWT are studied with its foundation of the Spar type with heave plates. It is shown that the amplitude of the heave motion of the floating VAWT is small when the heave plates are equipped. The effects of the wind and wave loads on the floating VAWT motions are assessed. The results show that the mean values of the surge and the pitch of the floating VAWT are mainly related to the wind loads;the standard deviations of the surge, the heave, and the pitch are mainly related to the wave loads. In the regular wave cases, the frequencies of the surge, the heave and the pitch are dominated by the wave frequencies, and the components of the 2P responses (caused by the aerodynamic loads) of the pitch are small. The 2P responses of the pitch are more significant in the irregular wave cases as compared with those in the regular wave cases.

关键词： Floating VAWT truss Spar floating foundation surge-heave-pitch motions aerodynamics regular waves irregular waves

Hydrated nickel(Ⅱ) halides mediated ring opening reaction with N-tosylaziridines

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Chinese Chemical Letters 2012年第3期23卷 285-288页

作者： Wan Xuan Zhang Wei Gang Hu li Su li qin liu Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules Hubei UniversityWuhan 430062China

An efficient and water tolerant method for the synthesis ofβ-haloamines is described utilizing hydrated nickel（Ⅱ） halides （NiX_2ⅩnH_2O X = Cl,Br,I） and aziridines as starting materials.N-Tosylaziridines reacted with NiCl_2·6H_2O or NiI_2·6H_2O givingβ-chloro -orβ-iodoamines in high yields（73-99%） within a short time,but 10 mol%of n-Bu_4NBr should be added in the reactions of N-tosylaziridines with NiBr_2·3H_2O in order to obtain the high yields of correspondingβ-*** played an important role in the *** proper solvent for the reaction of NiCl_2·6H_2O was DMF,while NiBr_2·3H_2O or NiI_2·6H_2O proceeded well in 1,4-dioxane.

关键词： N-Tosylaziridines Hydrated nickel(Ⅱ) halides Ring opening reaction β-Haloamines

Design and performance investigation of modified dual reflector parabolic trough collector with double planar mirrors

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Science China(Technological Sciences) 2024年第3期67卷 902-918页

作者： li Peijing liu TaiXiu qin YuanLong li JiChao liu QiBin School of Energy Powerand Mechanical EngineeringNorth China Electric Power University Beijing 226China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei 230027China

In a typical parabolic trough collector(PTC), sunlight is concentrated at the bottom of the absorber tube. This concentrated solar flux leads to uneven heat distribution, resulting in high local temperatures and significant thermal stress on the absorber *** limitations have restricted the application of PTCs in solar thermochemistry and other fields and have impacted their safe operation. In this study, a new PTC with dual planar mirrors(DPMS) is proposed to homogenize the circumferential solar flux distribution of the absorber tube. A design method and single-objective optimization of the new PTC with a DPMS are proposed,and an uncertainty analysis of the operational and structural parameters is performed. A coupled light-heat-structure numerical model was developed to study the heat transfer performance and structural mechanical properties. The thermodynamic properties of the PTC with DPMS under different boundary conditions were analyzed. The results show that the circumferential temperature difference of the new PTC is within 2.6 K, and the circumferential thermal deformation is within 0.9 mm under typical working conditions(the inlet velocity of the heat transfer fluid is 3 m/s, inlet temperature is 573.15 K, and the direct normal irradiance is 1000 W/m^(2)). Compared with conventional PTCs, the circumferential temperature difference is reduced by 74%–90%, and the maximum thermal deformation along the y-axis is reduced by more than 95% under all working conditions(1–5 m/s, 373.5–675.15 K, 200–1000 W/m^(2)). The new PTC maintains the uniformity of the circumferential solar flux distribution for different operating parameters(sun incident angle of 0°–3°) and installation errors(±3 mm), is suitable for solar energy applications in various fields, and has the potential for large-scale applications.

关键词： solar thermal energy parabolic trough collector secondary reflector solar flux distribution optical optimization

Engineered spidroin-derived high-performance fibers for diverse applications

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Nano Research 2024年第2期17卷 492-502页

作者： Dawen qin Jingjing li Huanrong li Hongjie Zhang Kai liu National-Local Joint Engineering Laboratory for Energy Conservation in Chemical Process Integration and Resources Utilization Tianjin Key Laboratory of Chemical Process SafetySchool of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Engineering Research Center of Advanced Rare Earth Materials Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing 100084China University of Science and Technology of China Hefei 230026China

Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and ***,the restricted production amounts from their native sources limit applications of spider *** the decades,there have been significant interests in fabricating man-made silk fibers with comparable performance to natural silks,inspiring many efforts both for biosynthesizing recombinant spider silk proteins(spidroins)in amenable heterologous hosts and biomimetic spinning of artificial spider *** strategies provide promising routes to produce high-performance and functionally optimized fibers with diverse ***,we summarize the hosts that have been applied to produce recombinant *** addition,the fabrication and mechanical properties of recombinant spidroin fibers and their composite fibers are also ***,we demonstrate the applications of recombinant spidroin-based ***,facing the challenges in biosynthesis,scalable production,and hierarchical assembly of high-performance recombinant spidroins,we give a summary and perspective on future development.

关键词： spider silk recombinant spidroin heterologous expression fiber fabrication mechanical property

Performance Enhancement of Parabolic Trough Collector by Using Homogenizer and Spiral

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Journal of Thermal Science 2024年第2期33卷 658-674页

作者： li Peijing liu Taixiu qin Yuanlong ZHENG Zhimei ZHAO Kai liu Qibin School of Energy Powerand Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Science Beijing100049China Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei230027China Research Institute of Science and Technology of China Three Gorges Group Corporation Beijing100038China

In conventional parabolic trough collectors(PTCs),sunlight is concentrated at the bottom of the absorber tube,resulting in a significant circumferential temperature gradient across the absorber tube,heat loss and thermal deformation,which affects the safety and thermal performance of *** this study,a new receiver with homogenizer and spiral(RHS) is proposed,achieving the optical and thermal synergy to ameliorate the thermal deformation of the absorber tube and enhance thermal efficiency.A plane structure homogenizer is designed to improve uniformity of the concentrated solar flux of absorber tube through second *** combination with the spiral,it improves the optical-thermal efficiency of the PTC by enhancing heat exchange between the fluid and the backlight side of the absorber *** performance of the collector is numerically studied by building a three-dimensional coupled light-thermal-structure *** results show that the thermal deformation of the RHS is reduced by more than 96% and the optical-thermal efficiency is improved by 1.2%-0.63% compared with conventional receivers(CRs) under the same inlet temperature *** proposed receiver is validated to be effective in reducing thermal deformation and improving optical-thermal efficiency.

关键词： parabolic trough collector homogenizer thermal deformation spiral

Cytokine Storm:The Novel Mechanism for Sleep Deprivation-induced Multiple Organ Dysfunction Syndrome

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Neuroscience Bulletin 2024年第7期40卷 1031-1033页

作者： liwen Wang Huimei liu li qin Lanfang li Institute of Pharmacy and Pharmacology University of South ChinaHengyang 421001China Hengyang Medical School University of South ChinaHengyang 421001China

It is well known that sleep is one of the inevitable activities of daily living and it is one of the most important factors contributing to human *** in mammals is a cyclic occurrence of two distinct states,rapid eye ... 详细信息

关键词： NREM Sleep movement

Added Benefit of the Early-Morning-Orbit Satellite Fengyun-3E on the Global Microwave Sounding of the Three-Orbit Constellation

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Advances in Atmospheric Sciences 2024年第1期41卷 39-52页

作者： Juan li Zhengkun qin Guiqing liu Jing HUANG CMA Earth System Modeling and Prediction Centre Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Joint Center for Data Assimilation Research and Applications School of Atmospheric SciencesNanjing University of Information Science&TechnologyNanjing 210044China

The three-orbit constellation can comprehensively increase the spatial coverage of polar-orbiting satellites,but the polar-orbiting satellites currently in operation are only mid-morning-orbit and afternoon-orbit ***-3E(FY-3E)was launched successfully on 5 July 2021 in *** an early-morning-orbit satellite,FY-3E can help form a complete three-orbit observation system together with the mid-morning and afternoon satellites in the current mainstream operational *** this study,we investigate the added benefit of FY-3E microwave sounding observations to the midmorning-orbit Meteorological Operational satellite-B(Met Op-B)and afternoon-orbit Fengyun-3D(FY-3D)microwave observations in the Chinese Meteorological Administration global forecast system(CMA-GFS).The results show that the additional FY-3E microwave temperature sounder-3(MWTS-3)and microwave humidity sounder-2(MWHS-2)data can increase the global coverage of microwave temperature and humidity sounding data by 14.8% and 10.6%,*** enables the CMA-GFS to achieve nearly 100% global coverage of microwave-sounding observations at each analysis ***,after effective quality control and bias correction,the global biases and standard deviations of the differences between observations and model simulations are also *** on the Advanced Microwave Sounding Unit A and the Microwave Humidity Sounder onboard Met Op-B,and the MWTS-2 and MWHS-2 onboard FY-3D,adding the microwave sounding data of FY-3E can further reduce the errors of analysis results and improve the global prediction skills of CMA-GFS,especially for the southern-hemisphere forecasts within 96 hours,all of which are significant at the 95% confidence level.

关键词： data assimilation microwave temperature sounder MWTS-3

Goaf risk prediction based on IAOA-SVM and numerical simulation:A case study

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Underground Space 2024年第2期15卷 153-175页

作者： Mingliang li Kegang li Yuedong liu Shunchuan Wu qingci qin Rui Yue Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093China Yunnan Key Laboratory of Sino-German Blue Mining and Utilization of Special Underground Space Kunming 650093China Yunnan Diqing Mining Co.Ltd. Shangrila 674400China

In regard to goaf risk prediction,due to the low accuracy and single prediction method,this study proposes a method that combines the improved arithmetic optimization algorithm(IAOA)–support vector machines(SVM)with GoCAD–FLAC^(3D)numerical ***,goaf risk is comprehensively *** the perspectives of geological and engineering conditions,eight factors that affect goaf stability and 176 sets of sample data were *** utilized eight influencing factors such as rock mass structure,geological structure,and goaf burial depth as inputs,and the goaf risk level as the ***,an IAOA–SVM goaf risk prediction model was *** 30 goaf areas of Yangla Copper Mine in Yunnan Province were selected as the research ***,the rationality of mechanical parameter values in the numerical model was verified using the parameter inversion ***,based on the GoCAD–FLAC^(3D)numerical simulation method,the goaf risk analysis in Yangla Copper Mine was ***,using numerical simulation verification,the goaf filling effect was ***,the prediction results of the IAOA–SVM model were compared with that of other intelligent *** results indicate that the numerical simulation results of the GoCAD–FLAC^(3D)model are consistent with those of IAOA–SVM and the actual results,which further verifies the effectiveness and superiority of the IAOA–SVM prediction ***,an innovative approach for goaf risk prediction is developed.

关键词： Rock mechanics Goaf risk prediction IAOA SVM Numerical simulation

A novel lightweight computerized ECG interpretation approach based on clinical 12-lead data

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Science China(Technological Sciences) 2024年第2期67卷 449-463页

作者： liu Yunqing qin ChengJin liu JinLei JIN YanRui li ZhiYuan ZHAO liQun liu Chengliang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Key Labof Artificial Intelligence(Ministryof Education) AI InstituteShanghai Jiao Tong UniversityShanghai 200240China Department of Cardiology Shanghai First Peoples Hospital Affiliated to Shanghai Jiao Tong UniversityShanghai 200080China

Although 12-lead electrocardiograms(ECGs)provide a wide range of spatiotemporal characteristics,interpreting them for arrhythmia detection is difficult due to a lack of reliable large-scale clinical ***,we proposed an innovative lightweight computerized ECG interpretation approach based on 12-lead *** model was trained,validated,and tested on 53845 standard 12-lead ECG records collected at Shanghai First People’s Hospital in affiliation with Shanghai Jiao Tong *** experiments revealed that our approach had a classification accuracy of 94.41%in the classification task of seven types of rhythms,which was markedly superior to related single-lead and 12-lead ECG classification ***,the average receiver operating characteristic area under the curve reached a value of 0.940,and the precision values for sinus tachycardia and sinus bradycardia were 0.945 and 0.91,respectively,with specificity values of 0.996 and *** employing our boosting method,we were able to improve the accuracy to 94.85%.To investigate the performance degradation of the proposed neural network in some classes,an ECG cardiologist was enlisted to review questionable ECGs;this process provides a promising direction for network performance ***,the proposed computerized ECG interpretation approach has practical significance because it could help professional physicians analyze patients’heart conditions based on real-time 12-lead ECG or grade their disease severity in advance.

关键词： computerized ECG interpretation large-scale 12-lead clinical ECG database lightweight neural network