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Science China(Technological Sciences) 2011年第1期54卷 63-69页

作者： BAN Qun Martin HANKER Dietmar BORCHERT SHEN Hui institute for Solar Energy System Sun Yat-sen University Guangzhou 510006 China fraunhofer institute for Solar Energy Systems Laboratory and Service Center Gelsenkirchen 45884 Germany

A series of hydrogenated microcrystalline silicon （μc-Si：H） p-layers for back surface field in crystalline silicon solar cells were deposited on glass substrates by the developed large area （45 cm×45 cm） plasma enhanced chemical vapour deposition processor operating at 13.56 MHz and various values of source gas trimethylboron （TMB） to H2 flowratio. The influence of deposition parameters on the large area p-layer performance was intensively studied, as well as the thin film uniformity, optical, electrical and structural performances by Raman, PTIR, Ellipsometry, etc. Arrhenius and Tauc plots were used to discuss the μc-Si：H thin film＇s activation energy and the defects state distribution. When amorphous-microcrystalline transition state was obtained, the deposited p-doped μc-Si：H layers showed specific resistance of 38.3 Ω^-1cm1 at the flowratio of 0.66% and high crystallinity of 45%-50% with no further treatment. The effect of source gas flowratio, deposition rate, and source gas partial pressure on μc-Si：H thin film＇s performance was also investigated.

关键词： μc-Si:H flowratio uniformity band structure

Interferometric measurement of injection nozzles using ultra-small fiber-optical probes

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Chinese Optics Letters 2011年第7期9卷 37-40页

作者： Tilo Pfeifer Robert Schmitt Niels Knig Guilherme Francisco Mallmann fraunhofer institute for Production Technology Steinbachstr. 17 52074 Aachen Germany Laboratory for Machine Tools and Production Engineering of RWTH Aachen University

The measurement of boreholes with diameters smaller than 500 μm is a demanding task that cannot be performed using state-of-the-art production metrology. In this letter, a miniaturized fiber probe with a diameter of 80μm is presented. A probe is used for low-coherence interferometry to conduct highly precise measurements of form deviations of small boreholes. Measurements conducted in nozzles are also presented. The results prove the potential of the fiber-optical sensor for quality inspection of high-precision parts, such as injection nozzles, for common-rail diesel engines.

关键词： Charge coupled devices Fizeau interferometry Low coherence interferometry Metrology Michelson interferometers Optical fibers

Energy Disaggregation of Industrial Machinery Utilizing Artificial Neural Networks for Non-intrusive Load Monitoring

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Energy and AI 2024年第3期17卷 342-356页

作者： Philipp Pelger Johannes Steinleitner Alexander Sauer fraunhofer institute for Manufacturing Engineering and Automation IPA Stuttgart 70569Germany institute for Energy Efficiency in Production(EEP) University of StuttgartStuttgart 70569Germany

This paper explores the application of non-intrusive load monitoring techniques in the industrial sector for disaggregating the energy consumption of machinery in manufacturing processes. With an increasing focus on energy efficiency and decarbonization measures, achieving energy transparency in production becomes crucial. Utilizing non-intrusive load monitoring, energy data analysis and processing can provide valuable insights for informed decision-making on energy efficiency improvements and emission reductions. While non-intrusive load monitoring has been extensively researched in the building and residential sectors, the application in the industrial manufacturing domain needs to be further explored. This paper addresses this research gap by adapting established non-intrusive load monitoring techniques to an industrial dataset. By employing artificial neural networks for energy disaggregation, the determination of energy consumption of industrial machinery is made possible. Therefore, a generally applicable cross-energy carrier method to disaggregate the energy consumption of machinery in manufacturing processes is developed using a design science research approach and validated through a practical case study utilizing a compressed air demonstrator. The results show that the utilization of artificial neural networks is well-suited for energy disaggregation of industrial data, effectively identifying on and off states, multi-level states and continuously variable states. Non-intrusive load monitoring should be further considered in the research of emerging artificial intelligence technologies in energy consumption evaluation. It can be a viable alternative for intrusive load monitoring and is a prerequisite to installing energy meters for every machine.

关键词： Non-intrusive load monitoring Energy transparency Energy consumption evaluation Industrial manufacturing Artificial neural networks

A Reinforcement Learning approach for the continuous electricity market ofGermany: Trading from the perspective of a wind park operator

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Energy and AI 2022年第2期8卷 67-78页

作者： Malte Lehna Björn Hoppmann Christoph Scholz RenéHeinrich fraunhofer institute for Energy Economics and Energy System Technology(IEE) Königstor 5934119 KasselGermany

With the rising extension of renewable energies, the intraday electricity markets have recorded a growingpopularity amongst traders as well as electric utilities to cope with the induced volatility of the energysupply. Through their short trading horizon and continuous nature, the intraday markets offer the abilityto adjust trading decisions from the day-ahead market or reduce trading risk in a short-term notice. Producersof renewable energies utilize the intraday market to lower their forecast risk, by modifying their providedcapacities based on current forecasts. However, the market dynamics are complex due to the fact that thepower grids have to remain stable and electricity is only partly storable. Consequently, robust and intelligenttrading strategies are required that are capable to operate in the intraday market. In this work, we proposea novel autonomous trading approach based on Deep Reinforcement Learning (DRL) algorithms as a possiblesolution. For this purpose, we model the intraday trade as a Markov Decision Process (MDP) and employ theProximal Policy Optimization (PPO) algorithm as our DRL approach. A simulation framework is introducedthat enables the trading of the continuous intraday price in a resolution of one minute steps. We test ourframework in a case study from the perspective of a wind park operator. We include next to general tradeinformation both price and wind forecasts. On a test scenario of German intraday trading results from 2018,we are able to outperform multiple baselines with at least 45.24% improvement, showing the advantage of theDRL algorithm. However, we also discuss limitations and enhancements of the DRL agent, in order to increasethe performance in future works.

关键词： Deep Reinforcement Learning German intraday electricity trading Deep neural networks Markov Decision Process Proximal Policy Optimization Electricity price forecast

Absorptive Capacities for Sustainability Technologies:Perspectives from the BRICS and China

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Chinese Journal of Population,Resources and Environment 2009年第2期7卷 3-10页

作者： Rainer Walz Katrin Ostertag fraunhofer institute Systems and Innovation Research Breslauerstr.48KarlsruheGermany institute for Policy and Management CAS

For the development process in the rapidly growing economies, knowledge transfer and technology cooperation are becoming important issues. Research and technological competences are key indicators for the absorptive capacity of sustainability technologies and for the ability to export them. These issues are analyzed empirically for Brazil, Russia, India, China and South Africa (BRICS). Sustainability related research in BRICS is mostly carried out within broader, more sector oriented programmes. Specialization patterns of international patents and in foreign trade indicate various strengths and weaknesses of the BRICS countries. The differences within the countries imply that the analysis must proceed at a technology specific level. China has considerable capabilities in technologies such as photovoltaics, solar thermal or buildings. There is a strong need for strategic positioning of the countries and for coordination of the various policy fields involved.

关键词： sustainability technologies innovation absorptive capacities BRICS

Methane Production, Emission and Possible Control Measures in the Rice Agriculture

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Advances in Atmospheric Sciences 1993年第3期10卷 307-314页

作者：王明星上官行健沈壬兴 Wassmann Reiner Seiler Wolfgang institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 fraunhofer institute for Atmospheric Environmental Research F.R. Germany

In the rice field methane is produced in the soil layer with depths of 2-25 cm. The vertical profile of methane production rate in the paddy soil during the water covering period differs from that in the paddy soil in dry phase. Only a small part, about 30%. of the produced methane is emitted to the atmosphere through rice plant, air bubbles, and molecular diffusion. Therefore, the methane emission rate from the rice field depends not only on the methane production rate in the soil, but also on the transport efficiency of the rice plant, air bubble formation that in turn depends on the production rate, and molecular *** measurements show that methane emission rates from a particular rice field have very large diurnal, seasonal and interannual variations, which are related to soil characteristics, water regime, farming procedure, local climate, and rice growing activities. The relationship between the methane emission rate and the above mentioned factors is very complicated. The emission rates from different rice fields differ greatly not only in the absolute value, but also in the temporal variation *** emission rate from the rice field may be significantly reduced by scientific management of fertilizer and irrigation. While the use of SO42- containing fertilizer and fermented organic fertilizer may reduce the methane emission significantly, the most promising measure for reducing methane emission from rice field is the frequent drainage irrigation procedure.

关键词： Methane Production Emission

A CO and CO2 tolerating (La0.9Ca0.1)2(Ni0.75Cu0.25)O4+δ Ruddlesden-Popper membrane for oxygen separation

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Frontiers of Chemical Science and Engineering 2020年第3期14卷 405-414页

作者： Guoxing Chen Marc Widenmeyer Binjie Tang Louise Kaeswurm Ling Wang Armin Feldhoff Anke Weidenkaff institute of Materials Science Technische Universität Darmstadt64287 DarmstadtGermany institute of Physical Chemistry and Electrochemistry Leibniz Universität Hannover30167 HannoverGermany institute for Materials Science Universität Stuttgart70569 StuttgartGermany fraunhofer institute IWKS 63457 HanauGermany

A series of novel dense mixed conducting ceramic membranes based on K2NiF4-type(La1-xCax)2(Ni0.75Cu0.25)O4+δwas successfully prepared through a sol-gel *** chemical compatibility,oxygen permeability,CO and CO2 tolerance,and long-term CO2 resistance regarding phase composition and crystal structure at different atmospheres were *** results show that higher Ca contents in the material lead to the formation of CaCO3.A constant oxygen permeation flux of about 0.63 mL·min−1·cm−2 at 1173 K through a 0.65 mm thick membrane was measured for(La0.9Ca0.1)2(Ni0.75Cu0.25)O4+δ,using either helium or pure CO2 as sweep *** oxygen fluxes with no sign of deterioration of this membrane were observed with increasing CO2 *** membrane showed excellent chemical stability towards CO2 for more than 1360 h and phase stability in presence of CO for 4 h at high *** addition,this membrane did not deteriorate in a high-energy CO2 *** present work demonstrates that this(La0.9Ca0.1)2(Ni0.75Cu0.25)O4+δmembrane is a promising chemically robust candidate for oxygen separation applications.

关键词： K2NiF4 structure oxygen permeation membrane CO2 and CO resistances CO2 plasma resistance long-term robustness

Yield Improvement and Advanced Defect Control——Driving Forces for Modeling of Bulk Crystal Growth

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Journal of Rare Earths 2006年第Z1期24卷 200-207页

作者： Georg Mueller Jochen Friedrich Crystal Growth Laboratory University Erlangen-Nürnberg (WW6) and Fraunhofer Institute of Integrated Systems and Device Technology (IISB) Martensstrasse 7 D-91058 Erlangen Germany Crystal Growth Laboratory University Erlangen-Nürnberg (WW6) and Fraunhofer Institute of Integrated Systems and Device Technology (IISB) Martensstrasse 7 D-91058 Erlangen Germany

Yield improvement and advanced defect control can be identified as the driving forces for modeling of industrial bulk crystal growth. Yield improvement is mainly achieved by upscaling of the whole crystal growth apparatus and increased processing windows with more tolerances for parameter variations. Advanced defect control means on one hand a reduction of the number of deficient crystal defects and on the other hand the formation of beneficial crystal defects with a uniform distribution and well defined concentrations in the whole crystal. This "defect engineering" relates to the whole crystal growth process as well as the following cooling and optional annealing processes, respectively. These topics were illustrated in the paper by examples of modeling and experimental results of bulk growth of silicon (Si), gallium arsenide (GaAs), indium phosphide (InP) and calcium fluoride (CaF2). These examples also involve the state of the art of modeling of the most important melt growth techniques, crystal pulling (Czochralski methods) and vertical gradient freeze (Bridgman-type methods).

关键词： yield improvement advanced defect control crystal growth

CAD-VR geometry and meta data synchronization for design review applications

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第9期7卷 1482-1491页

作者： SCHILLING Arne KIM Seokryul WEISSMANN Daniel TANG Ziying CHOI Sangsu fraunhofer institute for Computer Graphics （IGD） Darmstadt 64283 Germany institute for Graphic Interfaces （IGI） Seou1120-750 Korea Computer Graphics Center （ZGD V） Rostock 18059 Germany

In this paper we present the MEMPHIS middleware framework for the integration of CAD geometries and assemblies with derived Virtual Reality (VR) models and its specific meta data and attributes. The goal of this work is to connect real time VR applications, especially for the Design Review, with enterprise software storing and managing CAD models (Product Data Man- agement—PDM). The preparation of VR models requires expert knowledge, is time consuming, and includes selection of required CAD data, tessellation, healing of unwanted gaps, applying materials and textures, and special surface and light effects. During the Design Review process, decisions are made concerning the choice of materials and surface forms. While materials can be switched directly on the VR model, the modification of part geometries must be made on the CAD model. Our system synchronizes modi- fications of the original CAD geometries and of attributes that are relevant for the realistic rendering using the PLM Services standard. Thus, repeated work for the VR preparation can be avoided.

关键词： Virtual Reality (VR) CAD Product Data Management (PDM) Geometry conversion

Speciation in nanosecond laser ablation of zinc in water

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Science China(Physics,Mechanics & Astronomy) 2022年第7期65卷 90-98页

作者： Stefan Reich Yannis Klügl Anna Ziefuss RenéStreubel Jorg Gottlicher Anton Plech institute for Photon Science and Synchrotron Radiation Karlsruhe Institute of TechnologyKarlsruhe D-76021Germany Department of Technical ChemistryⅠand Center for Nanointegration Duisburg-Essen University of Duisburg-EssenEssen D-45141Germany fraunhofer institute for High-Speed Dynamics Ernst-Mach-Institute(EMI)Freiburg 79104Germany

In situ experimental methods have been applied to resolve mass flow and chemical speciation in the pulsed laser ablation of zinc in water. The chemical speciation has been resolved by time-resolved μ-X-ray absorption spectroscopy and mapped onto the macroscopic mass flow during material ejection from the metallic target and bubble dynamics of evaporated water. Large particles and agglomerates have been detected via dark-field X-ray imaging with a Shack-Hartmann sensor. The characteristic of the dynamics is that the vapor bubble is nearly homogeneously filled with ablated material. This persists during bubble collapse,which means that the ablated particles are captured and retracted towards the target. Limited mass escape is indicated by the X-ray absorption signal. Importantly, the near-edge structure at the Zn-K;transition delivers information on the chemical state of the ejected material. It clearly confirms that oxidation is not present within the bubble phase and the following sub-millisecond time scale. The oxidation proceeds on Zn nanoparticles in suspension on a second to minute course. Within the first microseconds,a Zn atom phase is detected that resembles Zn vapor. The addition of either reductive NaBH;or oxidative HAuCl;to the water phase influences the quantity of the atom contribution moderately, but does not influence the initial atom phase. Such behavior must be understood in terms of the nanosecond pulse excitation. After ejected material and a plasma is formed within the pulse duration of 7 ns the laser is able to further heat the ejecta and transform it partly into vapor. Correspondingly, the coupling of energy into the ablation zone as followed by plasma intensity and bubble size follows a threshold behavior as a function of laser fluence, marking the onset of laser-plasma heating. The reaction conditions inside the bubble are probably reductive due to the concomitant formation of excess hydrogen.

关键词： laser ablation in liquids elemental speciation X-ray absorption spectroscopy oxidation zinc oxide nanoparticles

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