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How to get high-efficiency lead chalcogenide quantum dot solar cells?

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Science China(Physics,Mechanics & Astronomy) 2023年第1期66卷 34-59页

作者： Chao Ding Qing Shen Faculty of Informatics and Engineering The University of Electro-CommunicationsTokyo 182-8585Japan

Lead chalcogenide colloidal quantum dots(CQDs)are regarded as attractive absorption materials for novel solar cells(SCs).The cost of lead chalcogenide CQD has been decreased to a commercialization target of$5/g due to the direct production of CQD ***,the photoelectric conversion efficiency(PCE)of lead chalcogenide CQDSCs is presently close to 14%,well below the commercialization target(20%),which is only 41%of the theoretical Shockley-Queisser limit *** this study,the different losses of open-circuit voltage(V_(oc)),fill factor(FF),and short circuit current density(J_(sc))for current CQDSCs are systematically discussed,as well as the percentage and likely causes of each *** the primary reasons for the CQDSCs’performance constraints are *** that,we focus on the CQDSCs interfaces(i.e.,CQD/CQD,CQD/HTL,and ETL/CQD)and explore viable ways to reduce device performance ***,based on the discussion above,we propose many enhancements to significantly solve numerous major obstacles impeding device performance to boost the PCE of CQDSCs for future commercialization significantly.

关键词： lead chalcogenide colloidal quantum dots solar cell interface engineering non-radiative carrier recombination charge carrier transport losses

Tuning of textural properties of germanosilicate zeolites ITH and IWW by acidic leaching

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Journal of Energy Chemistry 2016年第2期25卷 316-324页

作者： Valeryia I.Kasneryk Mariya V.Shamzhy Maksym V.Opanasenko Jirí Cejka J. Heyrovsky Institute of Physical Chemistry Academy of Sciences of Czech Republic v.v.i. Dolejgkova 3 182 23 Prague 8 Czech Republic Centre of Research Excellence in Petroleum Refining and Petrochemicals King Fahd University of Petroleum & Minerals Dhahran 31261 Saudi Arabia

The possibility to adjust textural properties of ITH and IWW zeolites by the variation of conditions（***, p H, duration） of acidic leaching was shown. While the growth of the temperature of acid treatment caused the increasing amount of leached Ge atoms and enhancing volumes of both micro and mesopores at 80 ℃, the mesopore volume in ITH（Si/Ge = 3.4 and 5.8） and IWW（Si/Ge = 3.3） zeolites changed with the duration of the treatment（p H = 2; T = 80 ℃） as follows： 96 h 〈 1 h 〈 24 h. Independently on the chemical composition and zeolite topology, the treatment of germanosilicate zeolites at p H = 2–7 resulted in development of both micro and mesoporosity accompanied by the extraction of substantial amount of Ge atoms, while the increasing acidity up to p H = 0 resulted in some reduction of Ge extraction and in the development of mesopores at maintained value of micropore volume when compared with initial germanosilicates. The higher activity（i.e. number of reactant molecules converted per active site） of germanosilicate with modified micro-mesoporous channel system in comparison with parent IWW zeolite in esterification of levulinic acid was attributed to enhanced accessibility of active sites.

关键词： Textural properties ITH IWW Degermanation

FINITE ELEMENT APPROXIMATION OF EIGENVALUE PROBLEM FOR A COUPLED VIBRATION BETWEEN ACOUSTIC FIELD AND PLATE

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Journal of Computational Mathematics 1997年第3期15卷 265-278页

作者： L. Deng T. Kako(Department of Computer Science and information Mathematics, The University of Electro-Communications, Japan) UNIV ELECTROCOMMUN DEPT COMP SCI & INFORMAT MATHCHOFUTOKYO 182JAPAN

We formulate a coupled vibration between plate and acoustic field in mathematically rigorous fashion. It leads to a non-standard eigenvalue problem. A finite element approximation is considered in an abstract way, and the approximate eigenvalue problem is written in an operator form by means of some Ritz projections. The order of convergence is proved based on the result of Babugka and Osborn. Some numerical example is shown for the problem for which the exact analytical solutions are calculated. The results shows that the convergence order is consistent with the one by the numerical analysis.

关键词： FINITE ELEMENT APPROXIMATION OF EIGENVALUE PROBLEM FOR A COUPLED VIBRATION BETWEEN ACOUSTIC FIELD AND PLATE

Secondary Flow Effects in Relatively Narrow Channels

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Journal of Thermal Science 2003年第3期12卷 209-213,238页

作者： Rudolf Dvo■ák Institute of Thermomechanics Academy of Sciences of the Czech Republic 182 00 Prague The Czech Republic

Secondary flow effects were discussed in numerous papers at the past ISAIF Symposia, mainly in connection with turbine or compressor cascades. This paper will complement these papers by looking at the problem from the channel (or blade passages) geometry point of view. If we describe as secondary flows any flows in planes perpendicular to the main flow direction, then there are at least three kinds of secondary flows in a typical turbine rotor cascade:-secondary flows of the 1st kind, generated by centrifugal forces in closed curved channels,-secondary flows of the 2nd kind, generated by interacting boundary layers, mainly in corners (this will include even the horseshoe vortices),-secondary flows due to mass inflow through the tip clearance.Quite often all the secondary flow vortices merge downstream into a passage vortex with a non-negligible contribution to the channel (cascade) losses, and it is worth investigating the individual contributions to these losses to take them into account in the design procedure.

关键词： channel flows secondary flows flow separation.

Haptic interface using tendon electrical stimulation with consideration of multimodal presentation

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Virtual Reality & Intelligent Hardware 2019年第2期1卷 163-175页

作者： Akifumi TAKAHASHI Kenta TANABE Hiroyuki KAJIMOTO Department of Informatics University of Electro-CommunicationsChofuTokyo 182-8585Japan

Background Our previous studies have shown that electrical stimulation from the skin surface to the tendon region(Tendon Electrical Stimulation:TES)can elicit a force sensation,and adjusting the current parameters can control the amount of the *** is thought to present a proprioceptive force sensation by stimulating receptors or sensory nerves responsible for recognizing the magnitude of the muscle contraction existing inside the tendon,so it can be a proprioceptive module of a small-size,low-cost force feedback *** there is also suspect that TES presents only strong,noisy skin *** previous study,it was found that TES has some limitation on varying *** In this study,in addition to characterizing the proprioceptive sensation induced by TES,we constructed a multimodal presentation system reproducing a situation in which force is applied to the hand was offered,so as to investigate whether TES contributed to the reproduction of haptics cooperating with other modalities,rather than disturbing ***,we used vibration to present a cutaneous sensation and a visual head mounted display(HMD)system to present simultaneous *** this system,we also evaluated the efficacy of TES itself and that of the multimodal system involving *** We found that TES,along with visual and vibration stimulation,contributed to the perception of a certain *** Thus,TES appears to be an effective component of multimodal force sense presentation systems.

关键词： Tendon Electrical Stimulation Proprioception Multimodal Force sensation

Recrystallization behaviour of fine-grained magnesium alloy after hot deformation

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中国有色金属学会会刊：英文版 2007年第6期17卷 1139-1142页

作者：杨续跃 H. Miura T. Sakai School of Materials Science and Engineering Central South University Department of Mechanical Engineering and Intell igent Systems UEC Tokyo Tokyo 182-8585 Japan Department of Mechanical Engineering and Intell igent Systems UEC Tokyo Tokyo 182-8585 JapanYANGXu-yue

Annealing behaviors of hot-deformed magnesium alloy AZ31 were studied at temperatures from 300 to 673 K by optical and SEM/EBSD metallographic observation. Temperature dependence of the average grain size(D) is categorized into three temperature regions, i.e. an incubation period for grain growth, rapid grain coarsening, and normal grain growth. The number of fine grains per unit area, however, is reduced remarkably even in incubation period. This leads to grain coarsening taking place continuously in the whole temperature regions. In contrast, the deformation texture scarcely changes even after full annealing at high temperatures. It is concluded that the annealing processes operating in hot-deformed magnesium alloy with continuous dynamic recrystallized grain structures can be mainly controlled by grain coarsening accompanied with no texture change, that is, continuous static recrystallization.

关键词：镁合金退火连续再结晶晶体生长纹理

Design on hopping locomotion mechanism

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光学精密工程 2005年第5期13卷 548-553页

作者： LU Yong-kui WU Yuc-hua YANG Jie Hisayuki AOYAMA Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei 230027 China Tokyo Japan 182-8585

A new type of locomotion mechanism is introduced in this paper. With vibrating motors used in controling the movement of the hopping locomotion mechanism, the simple hopping locomotion mechanism had two motors, when the current went through the vertical motor, the vertical motor would vibrate to cause the mechanism to go forward, and when the current went through the horizontal motor, the mechanism will go around itself. A spring was added to the mechanism to change the natural frequency of the mechanism, when the frequency of the motor was equal to the natural frequency of the mechanism, the mechanism would hop resonantly. With the resonant hopping, the load of the mechanism was greatly enlarged, and some sensors could be added to the mechanism. Optical sensors were used to detect the infrared source, the current that went through the sensors related to the distance between the infrared light. Three optical sensors was put on the left, right and the front the mechanism, when the mechanism detect the special infrared source, it would turn itself to the light, and go forward to the light. The experiments of the mechanism shown that the mechanism could work well on different surfaces freely, and the resonant hopping locomotion mechanism with infrared sensors could move to the special light by automatic regulation. Experimental results and theoretical studies demonstrate that the innovative design for hopping locomotion mechanism is superior.

关键词：电动机机械装置机器人传感器

News on the physics potential of the reaction e^+e^-→ Zγ

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Science China(Physics,Mechanics & Astronomy) 2021年第2期64卷 27-28页

作者： Philipp Roloff CERN CH-1211Geneva 23Switzerland

The next large project in particle physics is widely expected to be a high-energy electron-positron *** a facility could be realised as a circular collider,like the Circular Electron Positron Collider(CEPC)and the Future e^+e^-Circular Collider(FCC-ee)[1],or as a linear collider,like the International Linear Collider(ILC)and the Compact Linear Collider(CLIC)[2].

关键词： circular positron potential

Application of CCD Cameras to Investigations of Mixing on Boundaries of a Thermal Plasma Jet

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Plasma Science and Technology 2007年第6期9卷 743-746页

作者： J.HLINA J.SONSKY J.SLECHTA Institute of Thermomechanics Academy of Sciences of the Czech RepublicDolejskova 5182 00 Praha 8Czech Republic

Mixing of a thermal plasma jet with the surrounding atmosphere was studied using two CCD cameras （PCO SensiCam） situated detecting simultaneously the radiation of argon and nitrogen. The evaluation of image differences between two records showed that the location of regions on plasma jet boundaries characterised by stronger nitrogen radiation changes with the plasma flow rate. Close-to-laminar flow results in a small mixing rate and consequently low nitrogen optical emission on plasma jet boundaries. The increase of the flow rate leads to the formation of a relatively thick and stable layer on the boundaries characterised by strong nitrogen radiation. Further enhancement of the flow rate results in the formation of unstable regions of excited nitrogen molecules moving along the jet.

关键词： thermal plasma jet mixing CCD camera