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Comparisons and optimization of two absorption chiller types by considering heat transfer area,exergy and economy as single-objective functions

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Clean Energy 2024年第1期8卷 55-65页

作者： Yida Qiu Jingkun Wang Jing Han Yuzhu Chen Jun Wang Peter D.lund Management school University of LiverpoolLiverpool L693BXUK power China Huadong Engineering Corporation Limited No.201 Gaojiao RoadHangzhou 311122China Key Laboratory of solar Energy science and Technology in Jiangsu Province Southeast UniversityNo 2 Si Pai LouNanjing210096China school of science Aalto UniversityPO Box 15100FI-00076Aalto(Espoo)Finland

Absorption cooling technology is an environmentally friendly method to generate continuous chilled water making use of multiple thermal sources,such as waste heat and renewable thermal *** this study,two absorption chillers(nominal capacity of 400 kW)with series and parallel connections are *** research the ideal configuration of chillers after thermodynamic analysis,the structures of the chillers are optimized using the particle swarm optimization algorithm by considering the heat transfer area(HTA),exergy efficiency and total annual cost as single-objective *** impact of temperature differences between external and internal flows,heat exchanger efficiencies and the solution allocation ratio is *** optimized HTA,coefficient of perform-ance,exergy efficiency and total annual cost are 149.0 m^(2.,1.56,2..44%and$2.9119 for the series-connected chiller,and 146.7 m^(2.,1.59,31.45%and$2.4562.for the parallel-connected type,*** the lowest HTA condition,compared with the reference simulation results,the energy and exergy performances are improved,while the annual total cost is *** annual total cost is highest when maximizing the exergy efficiency,which is attributed to the increase in the *** operating cost accounts for 2..42.(series type)and 2..54%(parallel type)when the annual cost is the lowest.

关键词： absorption chiller series/parallel-connected temperature difference parameters solution allocation ratio

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The reconstruction and interpretations of lake status at 6 ka and 18 ka *** inland mainland Asia

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Chinese science Bulletin 1998年第14期43卷 1145-1157页

作者： QIN Boqiang 1, sHI Yafeng 1 and YU Ge 2. 3 1. Nanjing Institute of Geography & Limnology, Chinese Academy of sciences, Nanjing 2.0008, China 2. dynamic palaeoclimatology, lund university,{2., s 2.1.00, lund, sweden 3. Department of Nanjing Institute of Geography & Limnolagy Chinese Academy of Sciences Nanjing China dynamic palaeoclimatology Lund University Lund Sweden Department of Geology and Ocean sciences Nanjing University Nanjing China

By means of survey of literature through compilations of sedimentological, biogeological and geomorphologic data, the inland lake level changes in arid or semi arid mainland Asia at 6 and 18 ka B.P. have been reconstructed. The results showed that the lakes from western and northwestern Asia were characterized by very high water levels at 18 ka B.P., but low or intermediate water stands at 6 ka B.P. The high lake level in this region was associated with the southward displacement of westerlies, therefore, the extent of the high lake stand indicated the southern flank of westerlies during the glaciation. Conversely, the lakes from the eastern and southern Asia registered comparative low levels at 18 ka B.P. and significantly high one at 6 ka B.P. The lowering of lake level at 18 ka B.P. was caused by the weakened summer monsoon and the high lake level at 6 ka B.P. by the enhanced summer monsoon induced by the enlarged thermal contrast between land and ocean. The extent of high lake levels indicated the northern boundary of monsoon expansion. Between the above two regions, there is a climatic transitional zone in the Central Asia where the lake behavior was close to that in southeastern Asia at 6 ka B.P. but became similar to that in northwestern Asia at 18 ka B.P. Thus this zone became a transitional sector from the monsoon to the westerlies.

关键词： lake status inland mainland Asia westerlies monsoon.

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GraphFlow+:Exploiting Conversation Flow in Conversational Machine Comprehension with Graph Neural Networks

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Machine Intelligence Research 2024年第2期21卷 272-282页

作者： Jing Hu Lingfei Wu Yu Chen po Hu Mohammed J.Zaki school of Computer science Central China Normal UniversityWuhan 430079China Pinterest San Francisco 94016USA Meta Mountain View 94039USA Rensselaer polytechnic Institute Troy 12180USA

The conversation machine comprehension(MC)task aims to answer questions in the multi-turn conversation for a single ***,recent approaches don’t exploit information from historical conversations effectively,which results in some references and ellipsis in the current question cannot be *** addition,these methods do not consider the rich semantic relationships between words when reasoning about the passage *** this paper,we propose a novel model GraphFlow+,which constructs a context graph for each conversation turn and uses a unique recurrent graph neural network(GNN)to model the temporal dependencies between the context graphs of each ***,we exploit three different ways to construct text graphs,including the dynamic graph,static graph,and hybrid graph that combines the *** experiments on CoQA,QuAC and DoQA show that the GraphFlow+model can outperform the state-of-the-art approaches.

关键词： Conversational machine comprehension(MC) reading comprehension question answering graph neural networks(GNNs) natural language processing(NLP)

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Changes of photosynthetic capacity of some plant species under very high CO_2.concentrations in Biosphere 2

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Chinese science Bulletin 1997年第10期42卷 859-864页

作者： JIANG Gaoming and LIN Guanghui1. Ecological Research Center, Institute of Botany, Chinese Academy of sciences, Beijing 100093, China 2. Biosphere 2.Research and Education Center, Columbia university, po box 689, Oracle, Arizona 8562., UsA Ecological Research Center Institute of Botany Chinese Academy of Sciences Beijing 100093 China

THE responses of plant photosynthesis to elevated CO2.could be divided into short-term re-sponse and long-term response or *** the short-term response,photosynthesiscan be enhanced at the beginning of high CO2.treatme... 详细信息

THE responses of plant photosynthesis to elevated COsub>2./sub> could be divided into short-term re-sponse and long-term response or *** the short-term response,photosynthesiscan be enhanced at the beginning of high COsub>2./sub> treatment for most Csub>3sub> carbon fixation species,but the photosynthetic rate may decrease when the plants are exposed to that high COsub>2./sub> for

关键词： photosynthesis light compensation and saturation points apparent maximum quantum yield of CO2 fixation CO2 Biosphere 2.

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Templated synthesis of transition metal phosphide electrocatalysts for oxygen and hydrogen evolution reactions

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Journal of Energy Chemistry 2024年第2期89卷 646-669,I0014页

作者： Rose Anne Acedera Alicia Theresse Dumlao DJ Donn Matienzo Maricor Divinagracia Julie Anne del Rosario Paraggua po-Ya Abel Chuang Joey Ocon Laboratory of Electrochemical Engineering(LEE) Department of Chemical EngineeringUniversity of the PhilippinesDilimanQuezon City 1101Philippines Mechanical Engineering University of CaliforniaMercedCA 95343USA Energy Engineering Program College of EngineeringUniversity of the PhilippinesDilimanQuezon City 1101Philippines

Transition metal phosphides(TMPs)have been regarded as alternative hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts owing to their comparable activity to those of noble metal-based *** have been produced in various morphologies,including hollow and porous nanostructures,which are features deemed desirable for electrocatalytic *** synthesis routes are often responsible for such *** paper reviews the latest advances and existing challenges in the synthesis of TMP-based OER and HER catalysts through templated methods.A comprehensive review of the structure-property-performance of TMP-based HER and OER catalysts prepared using different templates is *** discussion proceeds according to application,first by HER and further divided among the types of templates used-from hard templates,sacrificial templates,and soft templates to the emerging dynamic hydrogen bubble *** catalysts are then reviewed and grouped according to their ***,prospective research directions for the synthesis of hollow and porous TMP-based catalysts,such as improvements on both activity and stability of TMPs,design of environmentally benign templates and processes,and analysis of the reaction mechanism through advanced material characterization techniques and theoretical calculations,are suggested.

关键词： OER HER Transition metal phosphide Templated synthesis Electrocatalysts

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Molecular characterization and structure basis of a malonyltransferase with both substrate promiscuity and catalytic regiospecificity from Cistanche tubulosa

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Acta Pharmaceutica sinica B 2024年第5期14卷 2333-2348页

作者： Xiao Liu Yuyu Liu Xiping Xu Wenqian Huang Yaru Yan Yingxia Wang Weisheng Tian Ting Mo Xiaoxue Cui Jun Li she-po shi Pengfei Tu Modern Research Center for Traditional Chinese Medicine Beijing Research Institute of Chinese MedicineBeijing University of Chinese MedicineBeijing 100029China Modern Research Center for Traditional Chinese Medicine School of Chinese Materia MedicaBeijing University of Chinese MedicineBeijing 100029China

Enzymatic malonylation of natural glycosides provides a promising alternative method for drug-like malonylated glycosides ***,the catalytic potential and structural basis of plant malonyltransferase are far from being fully *** work identified a new malonyltransferase CtMaT1 from Cistanche *** displayed unprecedented mono-and/or di-malonylation activity toward diverse glucosides with different aglycons.A“one-pot”system by CtMaT1 and a malonyl-CoA synthetase was established to biosynthesize nine new malonylated *** investigations revealed that CtMaT1 possesses an adequately spacious acyl-acceptor pocket capable of accommodating diverse ***,it recognizes malonyl-CoA through strong electrotactic and hydrogen ***/MM calculation revealed the H1.7-mediated sN2.reaction mechanism of CtMaT1,while dynamic simulations detected the formation of stable hydrogen bonds between the glucose-6-OH group and H1.7,resulting in its high malonylation *** energy profiles of two isomeric glycosides highlighted lower reaction energy barriers towards glucoside substrates,emphasizing CtMaT1's preference for ***,a mutant CtMaT1H36A with notably increased di-malonylation activity was *** underlying molecular mechanism was illuminated through MM/GBsA binding free energy *** study significantly advances the understanding of plant acyltransferases from both functional and protein structural perspectives,while also providing a versatile tool for enzymatic malonylation applications in pharmacology.

关键词： Plant acyltransferase Malonyltransferase Malonylated glycosides Enzymatic catalysis Enzyme promiscuity

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Large deviation principle for diffusion processes under a sublinear expectation

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science China Mathematics 2012年第11期55卷 2205-2216页

作者： CHEN ZengJing 1,2.& XIONG Jie 3,4,1 school of Mathematics,shandong university,Jinan 2.0100,China 2.Department of Financial Engineering,Ajou university,suwon 443749,Korea 3 Department of Mathematics,university of Macao,po box 3001,Macao,China 4 Department of Mathematics,university of Tennessee,Knoxville,TN 37996-1300,UsA 1. school of Mathematics Shandong University Jinan 250100 China 2. Department of Financial Engineering Ajou University Suwon 443749 Korea 3. Department of Mathematics University of Macau PO Box 3001 Macau China 4. Department of Mathematics University of Tennessee Knoxville TN 37996-1300 USA

We represent the exponential moment of the Brownian functionals under a nonlinear expectation according to the solution to a backward stochastic differential *** an application,we establish a large deviation principle of the Freidlin and Wentzell type under the corresponding nonlinear probability for diffusion processes with a small diffusion coefficient.

关键词： large deviation principle backward stochastic differential equation g-expectation ambiguity

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Modeling of elastic wave propagation on a curved free surface using an improved finite-difference algorithm

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science China(Physics,Mechanics & Astronomy) 2004年第5期47卷 633-648页

作者： WANG Xiuming1,3 & ZHANG Hailan2.1. CsIRO Petroleum, ARRC, po box 1130, Technology Park, Bentley, WA 6102. Australia 2. Institute of Acoustics, Chinese Academy of sciences, Beijing 100080, China 3. Present address: Institute of Acoustics, Chinese Academy of sciences, Beijing 100080, China 1. CsIRO Petroleum ARRC Technology Park PO BOX 1130 6102 Bentley WA Australia 2. Institute of Acoustics Chinese Academy of Sciences 100080 Beijing China

Based on existing direct and imaging methods of a staggered finite-difference scheme, an improved algorithm for staggered finite-difference is proposed to implement rugged topographic free boundary conditions. This method assumes that the free surface can be implemented with horizontal and vertical free surface segments and their corners; the free surface passes through the grid points of shear stress components, instead of the normal stress components. Imaging is carried out for stress components in both horizontal and vertical directions, thus increasing the accuracy. To update particle- velocities, imaging and updating are first performed in the horizontal direction, and then in the vertical direction. The numerical results for elastic flat horizontal free surface with the imaging method and those for flat free surfaces of various slope angles with the proposed method are compared, and are shown to be in good agreement. The advantage of the proposed method is that only the stresses are dealt with in implementing the free surface into the staggered algorithm, which improves computation efficiency.

关键词： elastic wave simulation, curved free surface, staggered finite-difference, algorithm stability.

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Al_2._3-Coated Nano-siC Particles Reinforced Al_2._3 Matrix Composites

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Journal of Materials science & Technology 2002年第6期18卷 541-543页

作者： Juxian ZHANG, Jinjun FENG and Longqiao GAOBeijing Vacuum Electronics Research Institute, po. box 749 Ext. box 33, Beijing 100016, China Beijing Vacuum Electron. Res. Inst. PO Box 749 Beijing 100016 China

Properties of Al2.3-coated nano-siC have been compared with those of as-received siC. The isoelectric point (IEP) of siC changed from pH3.4 to pH7.3 after coating with the alumina precursor, which is close to that of alumina. Because both surfaces of coated siC and AI2.3 possess higher positive charge at pH=4.5-5.0, they are uniformly dispersed in the two-phase aqueous suspensions, Then a mixed powder containing nano-siC dispersed homogeneously into the Al2.3 matrix was achieved from flocculating the two-phase suspension. Finally, Al2.3/siC nanocomposites were obtained by coating nano-siC with Al2.3, in which the majority of siC particles were located within the AI2.3 grains. The observation by transmission electron microscopy (TEM) and the analysis by the X-ray photoelectron spectroscopy (XPs) showed that cracks propagated towards the intragranular siC rather than along grain boundaries.

关键词： Coated nano-siC Colloidal processing Nanocomposites Intragranular structure Transgranular fracture

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Quantifying the effectiveness of siO_2.Au light trapping nanoshells for thin film poly-si solar cells

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science China(Technological sciences) 2010年第8期53卷 2228-2231页

作者： BAI YiMing 1 ,WANG Jun 2.,CHEN NuoFu 1,3 ,YAO JianXi 1 ,YIN ZhiGang 3 ,ZHANG Han 3 , ZHANG XingWang 3 ,HUANG TianMao 3 ,WANG Yanshuo 3 &YANG XiaoLi 3 1school of Renewable Energy Engineering,North China Electric power university,Beijing 102.06,China 2.National Engineering Research Center for Optoelectronic Devices,Institute of semiconductors, Chinese Academy of sciences,po box 912.Beijing 100083,China 3 Key Laboratory of semiconductor Materials science,Institute of semiconductors, Chinese Academy of sciences,po box 912.Beijing 100083,China 1. school of Renewable Energy Engineering North China Electric Power University Beijing 102206 China2. National Engineering Research Center for Optoelectronic Devices Institute of Semiconductors Chinese Academy of Sciences PO Box 912 Beijing 100083 China3. Key Laboratory of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of Sciences PO Box 912 Beijing 100083 China

In order to enhance light absorption of thin film poly-crystalline silicon(TF poly-si)solar cells over a broad spectral range, and quantify the effectiveness of nanoshell light trapping structure over the full solar spectrum in theory,the effective photon trapping flux(EPTF)and effective photon trapping efficiency(EPTE)were firstly proposed by considering both the external quantum efficiency of TF poly-si solar cell and scattering properties of light trapping *** EPTF,EPTE and scattering spectrum exhibit different behaviors depending on the geometric size and density of nanoshells that form the light trapping *** an optimum size and density of siO2.Au nanoshell light trapping layer,the EPTE could reach up to 40%due to the enhancement of light trapping over a broad spectral range,especially from 500 to 800 nm.

关键词： thin film poly-crystalline silicon surface plasmons siO2.Au nanoshell

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