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energy loss of charm quarks from J/ψ production in cold nuclear matter

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Chinese Physics C 2014年第12期38卷 28-32页

作者：宋丽华苗文丹段春贵 College of Science Hebei United University Department of Physics Hebei Normal University Hebei Advanced Thin Films Laboratory

J/ψ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution,energy loss of beam proton and the finial state energy loss of color octet cc. The leading-order computations for J/ψproduction cross-section ratios RW/Be（x F） are presented and compared with the selected E866 experimental data with the cc remaining colored on its entire path in the medium. It is shown that the combination of the different nuclear effects accounts quite well for the observed J/ψ suppression in the experimental data. It is found that the J/ψ suppression on RW/Be（x F） from the initial state nuclear effects is more important than that induced by the energy loss of color octet cc in the large x F region. Whether the cc pair energy loss is linear or quadratic with the path length is not determined. The obtained cc pair energy loss per unit path length α = 2.78±0.81 Ge V/fm, which indicates that the heavy quark in cold nuclear matter can lose more energy compared to the outgoing light quark.

关键词： J/ψ production charm quark energy loss

energy loss effect of incoming gluons from J/ψ production in p-A collisions

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Chinese Physics C 2017年第2期41卷 50-54页

作者：宋丽华闫琳婉段春贵 CollegeofScience NorthChinaUniversityofScienceandTechnology DepartmentofPhysics HebeiNormalUniversity

The energy loss effect of incoming gluons from J/ψ production in p-A（or d-A） collisions is investigated by means of the E866, RHIC and LHC experimental data. The gluon mean energy loss per unit path length d E/d L = 2.18 ± 0.14 Ge V/fm is extracted by fitting the E866 experimental data for J/ψ production cross section ratios R W（Fe）/Be（x F）. The obtained result indicates that the incoming gluons lose more energy than the incident quarks. By comparing the theoretical results with E866, RHIC, and LHC experimental data, it is found that the nuclear suppression due to the incident gluon（quark） energy loss reduces（increases） with the increase of the kinematic variable x F（or y）. The energy loss effect of incoming gluons plays an important role in the suppression of J/ψ production in a wide energy range from√s = 38.7 Ge V to√s = 5.0 Te V, and the influence of incident quark energy loss can be ignored for high energies（such as at RHIC and LHC energy）.

关键词： J/ψ production gluon charm quark energy loss

energy loss optimization of run-off-road wheels applying imperialist competitive algorithm

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Information Processing in Agriculture 2014年第1期1卷 57-65页

作者： Hamid Taghavifar Aref Mardani Department of Mechanical Engineering of Agricultural Machinery Faculty of AgricultureUrmia UniversityUrmiaIran

The novel imperialist competitive algorithm(ICA)has presented outstanding fitness on various optimization *** of meta-heuristics has been a dynamic studying interest of the reliability optimization to determine idleness and reliability *** application of a meta-heuristic evolutionary optimization method,imperialist competitive algorithm(ICA),for minimization of energy loss due to wheel rolling resistance in a soil bin facility equipped with single-wheel tester is *** required data were collected thorough various designed experiments in the controlled soil bin *** and global searching of the search space proposed that the energy loss could be reduced to the minimum amount of 15.46 J at the optimized input variable configuration of wheel load at 1.2 kN,tire inflation pressure of 296 kPa and velocity of 2 m/***,genetic algorithm(GA),particle swarm optimization(PSO)and hybridized GA–PSO approaches were benchmarked among the broad spectrum of meta-heuristics to find the outperforming *** was deduced that,on account of the obtained results,ICA can achieve optimum configuration with superior accuracy in less required computational time.

关键词： Imperialist competitive algorithm Genetic algorithm Particle swarm optimization energy loss Soil bin

High-performance all-polymer solar cells with only 0.47 eV energy loss

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Science China Chemistry 2020年第10期63卷 1449-1460页

作者： Qiang Wu Wei Wang Tao Wang Rui Sun Jing Guo Yao Wu Xuechen Jiao Christoph J.Brabec Yongfang Li Jie Min The Institute for Advanced Studies Wuhan UniversityWuhan 430072China Beijing National Laboratory for Molecular Sciences Beijing 100190China Key Laboratory of Materials Processing and Mold(Ministry of Education) Zhengzhou UniversityZhengzhou 450002China Department of Materials Science and Engineering Monash UniversityAustralian SynchrotronClaytonVictoriaAustralia Institute of Materials for Electronics and energy Technology(i-MEET) Friedrich-A lexander-Universitat-Erlangen-NiirnbergErlangenGermany

The field of all-polymer solar cells(all-PSCs)has experienced rapid development during the past few years,mainly driven by the development of efficient polymer ***,the power conversion efficiencies(PCEs)of the all-PSCs are still limited by insufficient light absorption of the donor/acceptor blend and large energy loss in *** herein designed a polymer acceptor PYT1 constructed n-type molecular acceptor Y5-C20 as the key building block and blended it with a polymer donor PM6 to obtain an all-polymer photoactive *** optimized PM6:PYT1 all-PSCs achieved a record higher PCE of 13.43%with a very low energy loss of 0.47 eV and a photoresponse of up to 900 nm compared with the Y5-C20 based device with a best PCE of 9.42%.Furthermore,the PCEs of the PM6:PYT1 all-PSCs are relatively insensitive to the 1-chloronaphthalene(CN)additive contents and active layer *** results also highlight the effect of CN additive on PM6:PYT1 morphology,i.e.,charge generation,and transport find an optimized balance,and radiative and non-radiative loss is simultaneously reduced in the *** work promotes the development of high-performance polymer acceptors and heralds a brighter future of all-PSCs for commercial applications.

关键词： all-polymer solar cells polymer acceptor absorption coefficient energy loss mechanical stability

Selective fluorination on donor and acceptor for management of efficiency and energy loss in non-fullerene organic photovoltaics

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Science China Chemistry 2023年第4期66卷 1190-1200页

作者： You Chen Peng Lei Yanfang Geng Ting Meng Xiangyu Li Qingdao Zeng Qing Guo Ailing Tang Yufei Zhong Erjun Zhou CAS Center for Excellence in Nanoscience National Center for Nanoscience and TechnologyBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou 450003China School of Materials Science and Engineering Ningbo Tech UniversityNingbo 315100China

Although fluorination has been proved effective to modulate optoelectronic properties and film morphology,knowledge of managing power conversion efficiency(PCE)and energy loss(Eloss)of organic photovoltaics(OPVs)by selective fluorination on the donor and/or acceptor is *** we designed and synthesized three 1,2,3-benzotriazole(BTA)-based linear polymers(PE45,PE46 and PE47)with different numbers of fluorine atom substitution on the conjugated phenyl side *** classic non-fullerene acceptors(NFAs)Y5(without fluorination)and Y6(with fluorination)were utilized to manage the device efficiency and energy *** results revealed that increasing fluorine substitutions on polymer donor improved the OPV efficiencies when the fluorinated Y6 was used as the acceptor,whereas decreased the PCEs when the non-fluorinated Y5 was used as the *** energy loss declined with the growing fluorine substitutions on polymer donor,and Y5 systems gave the lower values in comparison with the corresponding Y6 *** turns out that PE47:Y6 achieved the highest PCE of 15.58%with an open-circuit voltage(VOC)of 0.84 V(Eloss=0.56 e V)due to the highest and balanced hole/electron mobilities,suppressed bimolecular recombination and fibril network morphology,which is the highest value in the BTA-based ***,PE47:Y5 attained an ultralow non-radiative energy loss of 0.15 e V,which is one of the lowest values among the reported *** work could not only give a direct path on how to manage the efficiency and energy loss by selective fluorination on donor and acceptor,but also show a deep understanding on charge generation,transport and collection induced by selective fluorination.

关键词： fluorination D-π-A polymer non-fullerene acceptor energy loss organic solar cells

Reducing energy loss via tuning energy levels of polymer acceptors for efficient all-polymer solar cells

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Science China Chemistry 2020年第12期63卷 1785-1792页

作者： Huiliang Sun Bin Liu Jianwei Yu Xianshao Zou Guangye Zhang Yujie Zhang Wei Zhang Mengyao Su Qunping Fan Kun Yang Jianhua Chen He Yan Feng Gao Xugang Guo Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Physics Chemistry and Biology(IFM)Linköping UniversityLinköping SE-58183Sweden eFlexPV Limited Flat/RM B12/FHang Seng Causeway Bay BLDGCauseway BayHong KongChina Division of Chemical Physics Lund University Box 12422100 LundSweden Department of Chemistry and Chemical Engineering Chalmers University of TechnologyGöteborg SE-41296Sweden School of Advanced Materials Peking University Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China School of Physics and Electronic Engineering Guangzhou UniversityGuangzhou 510006China Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration&Reconstruction The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

The open-circuit voltage(Voc) of all-polymer solar cells(all-PSCs) is typically lower than 0.9 V even for the most efficient *** energy loss is the main reason for limiting Voc and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital(LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer(CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 70% while maintaining a large Voc of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with large Voc and drives the further development of all-PSCs.

关键词： all-polymer solar cells polymer acceptors energy level modulation photovoltage energy loss

Improving current and mitigating energy loss in ternary organic photovoltaics enabled by two well-compatible small molecule acceptors

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Science China Chemistry 2021年第4期64卷 608-615页

作者： Yanna Sun Huan-Huan Gao Simin Wu Lingxian Meng Xiangjian Wan Mengyang Li Zaifei Ma Ziqi Guo Shitong Li Hongtao Zhang Chenxi Li Yongsheng Chen State Key Laboratory and Institute of Elemento-Organic Chemistry The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer MaterialsInstitute of Polymer ChemistryRenewable Energy Conversion and Storage CenterCollege of ChemistryNankai UniversityTianjin 300071China Center for Advanced Low-dimension Materials Stage Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620China

Ternary organic photovoltaic(OPV)strategy is an effective but facile approach to enhance the photovoltaic performance for single-junction ***,a series of ternary OPVs were fabricated by employing a wide bandgap donor(PBDB-TF)and two acceptor-donor-acceptor(A-D-A)-type nonfullerene small molecule acceptors(NF-SMAs,called F-2 Cl and 3 TT-OCIC).As the third component,the near-infrared SMA,3 TT-OCIC,has complementary absorption spectrum,narrow bandgap and wellcompatible crystallization property to the host acceptor(F-2 Cl)for efficient ternary *** these,the optimal ternary devices yield significantly enhanced power conversion efficiency of 15.23%,one of the very few examples with PCE higher than15%other than Y6 *** is mainly attributed to the increased short-circuit current density of 24.92 m A cm^(-2) and dramatically decreased energy loss of 0.53 e *** work presents a successful example for simultaneously improving current,minimizing energy loss and together with modifying the morphology of active layers in OPVs,which will contribute to the further construction of high performance ternary OPVs.

关键词： organic photovoltaics ternary devices small molecule acceptors film morphology energy loss

Ternary strategy: An analogue as third component reduces the energy loss and improves the efficiency of polymer solar cells

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Journal of energy Chemistry 2022年第7期31卷 67-73,I0003页

作者： Longzhu Liu Hanjian Lai Feng He School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Shenzhen Grubbs Institute and Department of Chemistry Southern University of Science and TechnologyShenzhen 518055GuangdongChina Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055GuangdongChina

Ternary strategy is a convenient and effective method to boost the performance of polymer solar cells(PSCs).Utilizing a ternary strategy to trade-off between the energy loss and the efficiency of devices however requires further ***,through the hydroxyl(-OH)and acetoxy(-OCOMe)substitution atβ-position of the IC terminal group,we developed two new synthetic acceptors,BTIC-OH-βand BTICOCOMe-β,which were designed to confine the morphology *** of an analogue as the third component provides a simple but efficient way to further balance the short current density(Jsc)and open-circuit voltage(Voc),leading to a champion efficiency based on PBDB-T:PBDB-TF:BTIC-OCOMe-β,effectively as high as 12.45%.The results were examined mainly in terms of the morphology characterization,electroluminescence external quantum efficiency(EQEEL),steady-state photoluminescence(PL)and transient *** suggested fine-tuning of the morphology by ratio modulation,reduction of the energy loss,construction of a promising pathway for charge transfer in the ternary system and enhancing the carrier *** this way,a ternary strategy with an analogue donor could provide more routes to higher-quality solar cells.

关键词： Polymer solar cell Ternary strategy energy loss Trade-off

Suppressing trap states and energy loss by optimizing vertical phase distribution through ternary strategy in organic solar cells

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Science China Chemistry 2021年第4期64卷 599-607页

作者： Pengqing Bi Shaoqing Zhang Tong Xiao Minghuan Cui Zhihao Chen Junzhen Ren Chaochao Qin Guanghao Lu Xiaotao Hao Jianhui Hou State Key Laboratory of Polymer Physics and Chemistry Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China State Key Laboratory of Crystal Materials School of PhysicsShandong UniversityJinan 250100China School of Chemistry and Biology Engineering University of Science and Technology BeijingBeijing 100083China Frontier Institute of Science and Technology State Key Laboratory of Electrical Insulation and Power EquipmentXi’an Jiaotong UniversityXi’an 710054China Department of Physics Henan Normal UniversityXinxiang 453007China

Suppressing the trap-state density and the energy loss via ternary strategy was *** vertical phase distribution with donors(acceptors)accumulated(depleted)at the interface of active layer and charge extraction layer can be obtained by introducing appropriate amount of polymer acceptor N2200 into the systems of PBDB-T:IT-M and PBDB-TF:*** addition,N2200 is gradiently distributed in the vertical direction in the ternary blend *** measurements were carried out to study the effects of N2200 on the binary *** was found that the optimized morphology especially in vertical direction can significantly decrease the trap state density of the binary blend films,which is beneficial for the charge transport and *** these features enable an obvious decrease in charge recombination in both PBDB-T:IT-M and PBDB-TF:Y6 based organic solar cells(OSCs),and power conversion efficiencies(PCEs)of 12.5%and 16.42%were obtained for the ternary OSCs,*** work indicates that it is an effective method to suppress the trap state density and thus improve the device performance through ternary strategy.

关键词： non-fullerene organic solar cells ternary strategy vertical phase distribution trap state density energy loss