检索结果-南通市图书馆

Numerical investigation of pyrolysis effects on heat transfer characteristics and flow resistance of n-decane under supercritical pressure

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2018年第6期31卷 1249-1257页

作者： Zhi TAO Xizhuo HU Jianqin ZHU hongwei wu National Key Laboratory of Science and Technology on Aero-thermodynamies School of Energy and Power EngineeringBeihang University Beijing 100083 China School of Engineering and Technology University of Hertfordshire Hatfield AL10 9AB United Kingdom

Pyrolysis of hydrocarbon fuel plays an important role in the regenerative cooling process. In this article, a Two-Dimensional（2D） numerical model is proposed to investigate the pyrolysis effects on the heat transfer characteristics and flow resistance of n-decane under supercritical pressure. The one-step global pyrolytic reaction mechanism consisting of 19 species is adopted to simulate the pyrolysis process of n-decane. The thermophysical and transport properties of the fluid mixture are computed and incorporated into the numerical model for simulation. Comparisons between the current predictions and the open published experimental data are carried out and good agreement is achieved. In order to better understand the complicated physicochemical process, further investigations on the turbulent flow and heat transfer coupled with pyrolysis in a tube have been performed under various operating conditions. The results indicate that the pyrolysis intensively takes place in the high fluid temperature region. The occurrence of the heat transfer deterioration would lead to increasing n-decane conversion at the beginning of the heated section. It is found that the pyrolysis could improve the heat transfer deterioration and promote the heat transfer enhancement. Meanwhile, pyrolysis gives rise to an abrupt increase of flow resistance. The mechanisms of the physicochemical phenomena are also analyzed in a systematic manner, which would be very helpful in the development of the regenerative cooling technology.

关键词： n-Decane Convective heat transfer Flow resistance Pyrolysis Supercritical pressure

Experimental investigation on operating behaviors of loop heat pipe with thermoelectric cooler under acceleration conditions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2020年第3期33卷 852-860页

作者： Yongqi XIE Xinyu LI Sujun DONG Hongxing ZHANG hongwei wu School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China Beijing Key Laboratory of Space Thermal Control Technology China Academy of Space TechnologyBeijing 100094China School of Engineering and Computer Science University of HertfordshireHatfield AL109ABUnited Kingdom

An experimental study was carried out in this article to investigate the transient operating performance of a Dual Compensation Chamber Loop Heat Pipe(DCCLHP) with Thermoelectric Cooler(TEC) under acceleration conditions and ammonia was selected as the working *** the purpose of comparison, experimental work was conducted under terrestrial *** analysis was performed to explore the effect of several control parameters such as the heat load, acceleration magnitude and TEC assist on the startup and operating performance of the *** results indicate that the DCCLHP can get to a steady-state operation when the heat load changes from 25 W to 300 W under terrestrial *** under acceleration conditions, the DCCLHP can work at a high operating temperature or even fail to operate, which shows the acceleration effect plays a significant impact on the loop *** TEC assist with power of 10 W can improve the operating performance and reduce the operating temperature for the case of small heat load and acceleration *** the acceleration exceeds 3 g at large heat load, the effect of TEC assist on the operation at large heat load can be ignored.

关键词： Acceleration Electronic cooling Loop heat pipe Operating performance Thermoelectric cooler

Performance Design of High-Temperature Chloride Salts as Thermal Energy Storage Material

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第2期33卷 479-490页

作者： ZHAO Le WANG Jingyao CUI Liu LI Baorang DU Xiaoze wu hongwei Key Laboratory of Power Station Energy Transfer Conversion and System(North China Electric Power University) Ministry of EducationBeijing102206China School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou730050China School of Physics Engineering and Computer ScienceUniversity of HertfordshireHatfieldAL109ABUK

The chloride salts have great potential used as high-temperature thermal energy storage(TES) medium for the concentrated solar power *** this study,LiCl,KCl and CaCl_(2) were selected as energy storage materials in order to further broaden the working temperature of ternary chloride salt and improve its energy storage *** new high-temperature energy storage ternary chloride composed of LiCl,KCl,and CaCl_(2) was developed based on the phase diagram generated by *** components of LiCl-KCl-CaCl_(2) with the mass ratio of 37.85%-53.38%-8.77%,30.90%-13.82%-55.28% and 1.78%-18.61%-79.61% were developed,of which the corresponding melting temperature(T_(m)) 340.93,433.57 and 626.85℃,respectively,was obtained *** that T_(m) of the third group of salts was too high,only the first two groups of salts were *** test showed that the actual melting point was only 0.46% and 1.64% different from the melting point predicted by *** thermal properties of the two ternary chloride salts were also *** solid and liquid-specific heat of ternary salts was determined by DSC using sapphire as the standard *** vapor pressure and decomposition temperature of ternary chloride salts were *** results showed that the vapor pressure of salt 1 was almost constant below 650℃ by ***,the TG results showed that the upper working temperature of salt 1 was 650℃ under the air *** addition,the ternary chloride salts after short-term cycling still exhibited excellent thermal properties,which revealed that these good thermal properties make them have broad application prospects in high-temperature thermal energy storage systems.

关键词： chloride salts thermal energy storages thermal properties thermal stability

Recent advances in functional oxides for high energy density sodium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Materials Reports(Energy) 2021年第2期1卷 3-21页

作者： Hira Fatima Yijun Zhong hongwei wu Zongping Shao Western Australia School of Mines:Minerals Energy and Chemical Engineering(WASM-MECE)Curtin UniversityPerthWestern Australia6102Australia State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing211816PR China

The rapid development of power generation from renewable energy,such as geothermal,wind,and tidal energy,arises the need for efficient and economic electrochemical energy storage systems for integrating electric power smoothly into power *** lithium-ion battery has been successfully utilized for a variety of portable electronic devices but its application in large-scale energy storage has raised concerns about safety,availability of lithium resources,and its increasing ***,sodium-ion battery(SIB)has been in acquisition predominantly,because of the abundant sodium resources over the earth’s crust at low *** high energy density electrode materials is one of the most intensive research *** have been extensively investigated as the cathode and anode materials for high-performance and durable SIBs,owing to their various advantages including facile synthesis,versatile compositions,and easy structural *** this review,we provide an in-time thorough summary of recent advances in oxide materials for cathodes and anodes for high energy density *** energy storage mechanism,challenges,categories,and optimizations of both electrodes are *** research gaps and future perspectives are also *** review is expected to accelerate the research for developing new pathways for tuning the properties of the oxide electrodes based on different sodium storage mechanisms.

关键词： Sodium-ion battery Oxide Cathode Anode High energy density

Leakage performance of floating ring seal in cold/hot state for aero-engine

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第9期32卷 2085-2094页

作者： Guoqing LI Qian ZHANG Enliang HUANG Zhijun LEI hongwei wu Gang XU Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Research Institute of Petroleum Exploration and Development Beijing 100083China School of Engineering and Technology University of HertfordshireHatfield AL109ABUnited Kingdom

Rotating experimental investigations were carried out to study the oil sealing capability of two different floating ring seals in cold/hot state for aero-engine. High-speed Floating Ring Seal(HFRS) is a seal with the inner diameter of 83.72 mm and maximum speed of 38000 r/min, and Low-speed Floating Ring Seal(LFRS) is another seal with the inner diameter of 40.01 mm and maximum speed of 18000 r/min. In hot state, sealing air with the temperature of 371 K and oil with the temperature of 343 K was employed to model the working conditions of an aero-engine. Comparisons between floating ring seal and labyrinth seal were done to inspect the leakage *** attention was paid to the critical pressure ratio where the oil leakage began. Results show that the critical pressure ratio in cold state is obviously larger than that in hot state for both seals. An underlying sealing mechanism for floating ring seal is clarified by the fluid film, which closely associates with the dimensionless parameter of clearance over rotating diameter(2 c/Dr). Another fantastic phenomenon is that the leakage coefficient in hot state, not the leakage magnitude, is unexpectedly larger than that in cold state. Overall, the leakage performance of the floating ring seal is better than the labyrinth seal.

关键词： Aero-engine Critical pressure ratio Floating ring seal Labyrinth seal Leakage Rotating

Generation of ring-shaped human iPSC-derived functional heart microtissues in a M?bius strip configuration

在线全文

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2022年第4期5卷 687-699页

作者： Yan Xu Jingqi Qi Wenyan Zhou Xing Liu Longbo Zhang Xudong Yao hongwei wu Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine Central South UniversityChangsha 410013China Zhejiang University-University of Edinburgh Institute Haining 314400China Xiangya Hospital Central South UniversityChangsha 410008China Department of Neurosurgery School of MedicineYale UniversityNew HavenCTUSA International Institutes of Medicine The Fourth Affiliated HospitalZhejiang University School of MedicineYiwu 322000China

Although human-induced pluripotent stem cell-derived cardiomyocytes(hi PSC-CMs) have been used for disease modeling and drug discovery, clinically relevant three-dimensional(3D) functional myocardial microtissues are lacking. Here, we developed a novel ring-shaped cardiac microtissue comprised of chamber-specific tissues to achieve a geometrically non-orientable ventricular myocardial band, similar to a M?bius loop. The ring-shaped cardiac tissue was constructed of hi PSC-CMs and human cardiac fibroblasts(h CFs) through a facile cellular self-assembly approach. It exhibited basic anatomical structure,positive cardiac troponin T(c Tn T) immunostaining, regular calcium transients, and cardiac-like mechanical strength. The cardiac rings can be self-assembled and scaled up into various sizes with outstanding stability, suggesting their potential for precise therapy, pathophysiological investigation, and large-scale drug screening.

关键词： Human iPSCs Ring-shaped myocardial microtissue Ring-shaped cardiac tissue Myocardial tube

Effect of Ginkgo biloba leaf extract on cerebral cortex amino acid levels in cerebral ischemia model rats

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2018年第5期38卷 676-684页

作者： Cui Yiran wu hongwei Liu Mengting Qin Haijiao Liu Xin Yang Hongjun Beijing Hospital of Traditional Chinese Medicine Capital Medical University Institute of Chinese Materia Medica China Academy of Chinese Medical Sciences College of Science Central South University of Forestry and Technology School of Chinese Materia Medica Beijing University of Chinese Medicine

OBJECTIVE: To investigate the effect of Ginkgo biloba leaf extract on amino acid levels in the cerebral cortex of cerebral ischemia model rats induced by middle cerebral artery occlusion(MCAO).METHODS: A rat model of cerebral ischemia was established by MCAO. Male rats were divided into a negative control group(Control), a sham-operated group(Sham), an ischemic group(MCAO), and an ischemic group treated with Ginkgo biloba leaf extract(MCAO_D). All groups were divided into two subgroups with occlusion times of 12 and 24 h, respectively. The levels of 18 endogenous amino acids in the cerebral cortex were quantified by triple quadrupole-liquid chromatography-mass ***: Compared with the MCAO group, behavioral performance, neurological deficit score, and cerebral infarct volume were significantly improved in the MCAO_D group(P < 0.05, P < 0.01). Compared with the sham group, the levels of 17 amino acids in the cerebral cortex were markedly changed in the MCAO group. The levels of Alanine(Ala), Isoleucine(Ile), Glutamic acid(Glu), Serine(Ser), Valine(Val), Phenylalanine(Phe), Proline(Pro),Threonine(Thr), Lysine(Lys), Tyrosine(Tyr), Hydroxyproline(Hyp), Arginine(Arg), Leucine(Leu),Tryptophan(Trp), and Glycine(Gly) were increased(P < 0.001, P < 0.05), while levels of Gln and Tau were decreased(P < 0.001, P < 0.05). Compared with the MCAO group, Ginkgo biloba extract treatment in the MCAO_D group significantly down-regulated the levels of 11 amino acids, especially those of Arg, Thr, and Ser in 12 or 24 ***: Injection of Ginkgo biloba leaf extract has a therapeutic effect on model rats with MCAO-induced cerebral ischemia by acting on amino acids in the cerebral cortex. This effect might be associated with the regulation of amino acid metabolism in the cerebral cortex.

关键词： Cerebral ischemia Ginkgo biloba leaf extract Amino acids Metabolism

Investigation of solid-state reaction by terahertz time-domain spectroscopy

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2011年第3期22卷 139-143页

作者： LIU Xiaohong ZHAO hongwei wu Yuting LI Qingnuan ZHU Zhiyong Shanghai Institute of Applied physics Chinese Academy of Sciences Shanghai 201800 China

Terahertz time-domain spectroscopy(THz-TDS)was utilized to investigate the solid-state reaction between L(+)-Tartaric acid and sodium hydrogen *** sodium hydrogen L(+)-tartrate monohydrate was synthesized efficiently by mechanical grinding,which is particularly sustainable and environmentally *** THz absorptions were observed for pure reactants and the proposed *** reaction process could be clearly visualized by THz spectral patterns of the reaction mixtures at different grinding *** observed results were further confirmed by synchrotron radiation X-ray powder diffraction(SRXRPD)and Fourier transform infrared (FT-IR)*** study demonstrates that THz-TDS is an effective novel tool to monitor solid-state reactions in pharmaceutical industry.

关键词：太赫兹时域光谱固态反应傅里叶变换红外光谱 X射线粉末衍射碳酸氢钠可持续发展反应混合物机械研磨

Leakage performance of labyrinth seal for oil sealing of aero-engine

在线全文

学校读者我要写书评

暂无评论

Propulsion and Power Research 2019年第1期8卷 13-22页

作者： Guoqing Li Qian Zhang Zhijun Lei Enliang Huang hongwei wu Gang Xu Institute of Engineering Thermophysics.Chinese Academy of Sciences.Beijing 100190 China University of Chinese Academy of Sciences.Beijing 100190 China Research Institute of Petroleum Exploration and Development Beijing 100083China School of Engineering and Technology University of Hertfordshire.Hatfield AL109AB.United Kingdom

Experimental investigation has been done to evaluate the leakage performance of labyrinth seal for oil sealing on high-speed sealing test rig at different working and geometric *** values of pressure ratio ranging from 1.0 to 2.0 were used and the rotating speed varied from 0 to 30,000 *** Taylor number was invited to response the effect of *** was injected at the rate from 1.2 L/min to 2.8 L/min to check the sealing *** was measured at different seal configurations including sealing clearance,tooth tip thickness,pitch,teeth number,front inclined angle and oil-throwing *** from gas sealing,the application of oil-throwing tooth in oil sealing attracted much interest as an obvious alternative to the conventional labyrinth seal.A blocking ring was captured during testing,which establishes understanding of underlying flow mechanisms in the clearance and plays an important role in oil *** is a critical Taylor number at which the leakage coefficient drops *** the critical Taylor number,a parabola rule *** optimal composition of tooth tip thickness,teeth number,oil-throwing angle and front inclined angle exists where the leakage performance behaves better.

关键词： Labyrinth seal Leakage Rotating Oil sealing Aero-engine