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Heat Recuperation for the Self-Condensing CO_(2)Transcritical Power Cycle

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Journal of Thermal Science 2024年第5期33卷 1630-1641页

作者： PAN Lisheng SHI Weixiu sun yin sun Yiwei WEI Xiaolin State Key Laboratory of High-temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The supercritical CO_(2)Brayton cycle has potential to be used in electricity generation occasions with its advantages of high efficiency and compact *** on a so-called self-condensing CO_(2)transcritical power cycle,a model was established and four different layouts of heat recuperation process were analyzed,a without-recuperation cycle,a post-recuperation cycle,a pre-recuperation cycle and a re-recuperation *** results showed that the internal normal cycle's share of the whole cycle increases with increasing the cooling pressure and decreasing the final cooled *** load in the supercritical heater decreases with increasing the cooling *** perspective of performance,the re-recuperation cycle and the pre-recuperation cycle have similar thermal efficiency which is much higher than other two *** thermal efficiency and net power output have a maximum value with the cooling pressure,except in the condition with the final cooled temperature of 31℃.Considering both the complexity and the economy,the pre-recuperation cycle is more applicable than the other *** 35℃of the final cooled temperature,the thermal efficiency of the pre-recuperation cycle reaches the peak 0.34 with the cooling pressure of 8.4 MPa and the maximum net power output is 2355.24 kW at 8.2 MPa of the cooling pressure.

关键词： CO_(2)transcritical power cycle heat recuperation process self-condensing

Using the Inverse of Expected Error Variance to Determine Weights of Individual Ensemble Members： Application to Temperature Prediction

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Journal of Meteorological Research 2017年第3期31卷 502-513页

作者： Xiaogong sun Jinfang yin Yan ZHAO State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

The inverse of expected error variance is utilized to determine weights of individual ensemble members based on the THORPEX （The Observing System Research and Predictability Experiment） Interactive Grand Global Ensemble （TIGGE） forecast datasets. The weights of all ensemble members are thus calculated for summer 2012, with the NCEP final operational global analysis （FNL） data as the truth. Based on the weights of all ensemble members, the variable weighted ensemble mean （VWEM） of temperature of summer 2013 is derived and compared with that from the simple equally weighted ensemble mean. The results show that VWEM has lower root-mean-square error （RMSE） as well as absolute error, and has improved the temperature prediction accuracy. The improvements are quite notable over the Tibetan Plateau and its surrounding areas; specifically, a relative improvement rate of RMSE of more than 24% in 2-m temperature is demonstrated. Moreover, the improvement rates vary slightly with the pre- diction lead-time （24-96 h）. It is suggested that the VWEM approach be employed in operational ensemble predic- tion to provide guidance for weather forecasting and climate prediction.

关键词： ensemble forecast variable weighted ensemble mean simple equally weighted ensemble mean predic-tion accuracy

Corrosion behavior of steel rebar in coal gangue-based mortars

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第5期11卷 382-388页

作者： Ji-xiu ZHANG Heng-hu sun yin-ming sun Na ZHANG Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

Corrosion of steel rebar is the most important durability problem of reinforced concrete. The aim of this research was to investigate the corrosion behavior of steel rebar in simulated pore solutions and gangue-blended cement mortar. The simulated pore solutions were based on the pore solution composition of gangue-blended cement. The pH and Cl-concentration of simulated pore solutions had significant effects on corrosion potential. However,an increase in pH reduced the influence of Cl-concentra-tion on corrosion potential. The corrosion behavior of steel rebar in gangue-blended cement is different from that in simulated solutions. The gangue cementitious mortar surrounding steel rebar provides stable passivity environments for steel,leading to a decrease in ion diffusion coefficients. Alternating current impedance (ACI) analysis results indicated that the indicator Rc for concrete resistivity is higher for gangue mortar than for ordinary Portland cement (OPC),which improves its corrosion potential. The results from energy dispersive X-ray analysis (EDX) showed more aluminates and silicates at the rebar interface for gangue-blended cement. These aluminates improve the chloride binding capacity of hydrates in mortar,and increase the corrosion protection of steel rebar.

关键词： Steel rebar Corrosion Coal gangue Electrochemical

Uniform perfectness of the attractor of bi-Lipschitz IFS

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Science China Mathematics 2006年第4期49卷 433-438页

作者： RUAN Huojun sun Yeshun yin Yongcheng Department of Mathematics Zhejiang University Hangzhou 310027 China Department of Mathematics Zhejiang University Hangzhou 310027 China Department of Mathematics Zhejiang University Hangzhou 310027 China

In this paper, we prove that the attractor of C1,a bi-Lipschitz IFS in R is uniformly perfect if it is not a singleton. Then we construct an example to show that this does not hold for C1 bi-Lipschitz IFS in Rn.

关键词： uniform perfectness, iterated function systems.

Sufficient and Necessary Condition of Admissibility for Fractional-order Singular System

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自动化学报 2013年第12期39卷 2160-2164页

作者： YU Yao JIAO Zhuang sun Chang-yin School of Automation Electrical Engineering University of Science and Technology Beijing Beijing 100083 China Key Laboratory of Advanced Control of Iron and Steel Process Ministry of Education Beijing 100083 China Beijing Institute of Elec- tronic System Engineering Beijing 100854 China

这份报纸与顺序为部分顺序的单个系统集中于考虑条件吗？(0， 1 ) 。整齐的定义，没有推动并且考虑被给第一，然后，为部分顺序的单个系统的考虑的一个足够、必要的条件被建立。一个数字例子被包括说明建议条件。

关键词：奇异系统分数阶充要条件可容许充分必要条件

Research into tritium and helium-3 contents distributions in steel wall of spherical pressure vessel

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Science China(Technological Sciences) 2011年第6期54卷 1521-1524页

作者： LIU YuanDong yin YiHui TAN Yun sun yin MEI Jun Institute of Structural Mechanics China Academy of Engineering Physics P. O. Box 919-401 Mianyang 621900 China Committee of Science and Technology China Academy of Engineering Physics Mianyang 621900 China

The tritium quantity stored in a steel pressure vessel decreases with time because of helium-3 decay and permeation of tritium into the steel wall of the pressure ***,the tritium quantity permeating into the steel wall also decreases with time due to helium-3 decay and diffusion in and out of the wall of *** and helium-3 in the steel wall will cause hydrogen and helium embrittlement of the wall material,respectively,and thereby change the carrying capacity of the *** contemporarily both decay and permeation of tritium within the vessel and decay and diffusion of tritium having permeated into the wall into consideration,the governing equations of tritium and helium-3 contents in the wall were established and solved,and relevant formulas were *** analytical calculations,curves of tritium and helium-3 contents versus radius and time were theoretically plotted,the contents spatio-temporal distributions laws were obtained,and a law about helium-3 contents distribution in steel wall of a spherical pressure vessel was discovered which was called the law of double helium-3 content.

关键词： steel spherical pressure vessel tritium decay helium-3 diffusion law of double helium-3 content

Rapid chemical recycling of waste polyester plastics catalyzed by recyclable catalyst

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Green Chemical Engineering 2024年第2期5卷 257-265页

作者： Yu-Ji Luo Jia-yin sun Zhi Li School of Physical Science and Technology ShanghaiTech UniversityShanghai201210China

Waste plastics are serious environmental threats due to their low degradability and low recycling *** and efficient waste plastics recycling technologies are urgently demanded for a sustainable ***,we report a rapid,closed-loop,and streamlined process to convert polyesters such as poly(ethylene terephthalate)(PET)back to its purified *** trifluoromethanesulfonic acid or metal triflates as the recyclable catalyst,polyesters such as PET can be completely depolymerized by simple carboxylic acids within 1 *** coupling this acidolysis with a subsequent hydrogenolysis process,the consumed carboxylic acid was recovered and the closed-loop of PET depolymerization could be *** catalysts and depolymerization agents are fully recycled while only PET and hydrogen are consumed.

关键词： Chemical recycling Waste polyester plastics Acidolysis Recyclable catalyst

Synthesis and antibacterial activity of novel 10,11-epoxy acylide erythromycin derivatives

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Chinese Chemical Letters 2013年第3期24卷 183-185页

作者： ying Nie yin sun Qi-Dong You Experimental Center of Pharmaceutical Science China Pharmaceutical University Jiangsu Key Laboratory of Drug Design and Optimization China Pharmaceutical University

A series of novel acylide derivatives have been synthesized from clarithromyc｜n A via a tacile procedure. The C-3 modifications involved replacing the natural C-3 cladinosyl group in clarithromycin core with different aryl-piperzine sidechain via chemical synthesis, Meanwhile a distinctive intermediate with 10,11-epoxy moiety was obtained, The structure and stereochemistry of this novel structure were confirmed via NMR and X-ray crystallography. Potential anti-bacterial activities against both Grampositive and Gram-negative bacteria were reported. Because of existence of C10,11-epoxide, these derivatives can be used as intermediates for further structural modification.

关键词： Epoxide acylide erythromycin derivativesSynthesisSingle-crystal X-ray diffractionResistance antibacterial activity

Robust Attitude Decentralized Tracking Control for a 3-DOF Helicopter with Unknown Input Time-delay

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Robust Attitude Decentralized Tracking Control for a 3-DOF H...