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Chinese Journal of Mechanical Engineering 2020年第2期33卷 152-160页

作者： Katharina Voelkel Hermann Pflaum karsten Stahl Gear Research Centre(FZG) Technical University of MunichGarchingGermany

Wet multi-plate clutches are relevant components of modern drivetrain applications,not only in terms of function but also safety and *** at the beginning of their lifetime,distinct changes of the friction behavior may occur and make the actuation of the clutch *** transcript describes the typical running-in behavior of wet multi-plate clutches and gives a general definition for running-in of ***,a new test method to systematically investigate the running-in behavior of clutches is *** test method contains a test procedure to characterize the running-in behavior on different load ***,a multi-stage procedure to evaluate and characterize the running-in behavior of clutches with mathematical approaches and new characteristic values is *** quality of the test method is demonstrated on the example of three different tribological systems from dual clutch transmissions(DCT)and automatic transmissions(AT)application using paper friction linings.

关键词： Clutch Running-in Test method Paper friction lining

Investigation of the steam-cooled blade in a steam turbine cascade

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航空动力学报 2007年第5期22卷 673-682页

作者： Dieter Bohn Jing Ren karsten Kusterer Institute of Steam and Gas Turbines RWTH Aachen UniversityTemplergraben 55 D-52056 Aachen Germany B＆B-AGEMA Gesellschaft far Energietechnische Maschinenund Anlage GmbH Jülicher Strasse 338 52070 Aachen Germany

With the increasing demand for electricity,an efficiency improvement and thereby reduced CO2 emissions of the coal-fired plants are expected in order to reach the goals set in the Kyoto *** can be achieved by a rise of the process ***,live steam pressures and temperatures up to 300 bars and 923 K are planned as the next *** circuit steam cooling of blades and vanes in modern steam turbines is a promising technology in order to establish elevated live steam temperatures in future steam turbine *** this paper,a steam-cooled test vane in a cascade with external hot steam flow is analyzed numerically with the in-house code CHTflow.A parametric analysis aiming to improve the cooling effectiveness is carried out by varying the cooling mass flow *** results from two investigated cases show that the steam cooling technique has a good application potential in the steam *** internal part of the vane is cooled homogeneously in both *** the increased cooling mass flow rate,there is a significant improvement of cooling efficiency at the leading *** results show that the increased cooling mass flow ratio can enhance the cooling effectiveness at the leading *** respect to trailing edge,there is no observable improvement of cooling effectiveness with the increased cooling mass *** implies that due to the limited dimension at the trailing edge,the thermal stress cannot be decreased by increasing the cooling mass flow ***,impingement-cooling configuration at the trailing edge might be a solution to overcome the critical thermal stress *** is also observed that the performance of the cooling effective differs on pressure side and suction *** implicates that the equilibrium of the cooling effectiveness on two sides are influenced by a coupled relationship between cooling mass flow ratio and hole *** future work,optimizing the hole geometry and cooling steam supply conditions might b

关键词：蒸汽轮机层叠蒸汽冷却调查研究翼热转移

Snapshots of a Viral RNA Polymerase Switching Gears from Transcription Initiation to Elongation

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Virologica Sinica 2013年第6期28卷 337-344页

作者： karsten Theis Westfield State University Department of Chemical and Physical Sciences

During transcription initiation,RNA polymerase binds tightly to the promoter DNA defining the start of transcription,transcribes comparatively slowly,and frequently releases short transcripts(3-8 nucleotides)in a process called abortive *** to elongation,the second phase of transcription,the polymerase dissociates from the promoter while RNA synthesis *** is characterized by higher rates of transcription and tight binding to the RNA *** RNA polymerase from enterophage T7 (T7 RNAP) has been used as a model to understand the mechanism of transcription in general,and the transition from initiation to elongation *** single-subunit enzyme undergoes dramatic conformational changes during this transition to support the changing requirements of nucleic acid interactions while continuously maintaining polymerase *** structures,available of multiple stages of the initiation complex and of the elongation complex,combined with biochemical and biophysical data,offer molecular detail of the *** of the crystal structures contain a variant of T7 RNAP where proline 266 is substituted by *** variant shows less abortive products and altered timing of transition,and is a valuable tool to study these *** structural transitions from early to late initiation are well understood and are consistent with solution *** timing of events and the structural intermediates in the transition from late initiation to elongation are less well understood,but the available data allows one to formulate testable models of the transition to guide further research.

关键词： RNA polymerase Transcription Elongation Crystal structure

Numerical Visualization of Grease Flow in a Gearbox

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Chinese Journal of Mechanical Engineering 2023年第2期36卷 220-233页

作者： Hua Liu Florian Dangl Thomas Lohner karsten Stahl School of Engineering&Design Department of Mechanical EngineeringTechnical University of MunichGear Research Center(FZG)BoltzmannstraBe1585748 Garching near MunichGermany

Lubricating greases are widely used in *** gear drives and gearboxes with difficult sealing *** efficiency and heat balance of grease-lubricated gearboxes depend strongly on the lubrication mechanisms channeling and circulating,for which the grease flow is *** computational fluid dynamics opens up the possibility to visualize and understand the grease flow in gearboxes in more *** this study,a single-stage gearbox lubricated with an NLGI 1-2 grease was modeled by the finite-volume method to numerically investigate the fluid *** show that the rotating gears influence the grease sump only locally around the *** a low grease fill volume,the rotation of the gears is widely separated from the grease *** a high grease fill volume,a pronounced geargrease interaction results in a circulating grease flow around the *** simulated grease distributions show good accordance with high-speed camera recordings.

关键词： Lubrication Grease Transmission Gearbox Computational fluid dynamics

Hydrological modelling in the anthroposphere: predicting local runoff in a heavily modified high-alpine catchment

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Journal of Mountain Science 2018年第5期15卷 921-938页

作者： Johannes WESEMANN Mathew HERRNEGGER karsten SCHULZ Institute of Water Management Hydrology and Hydraulic Engineering (IWHW) University of Natural Resources and Life Sciences Vienna (BOKU)

Hydrological models within inflow forecasting systems for high-alpine hydropower reservoirs can provide valuable information as part of a decision support system for the improvement of hydropower production or flood retention. The information, especially concerning runoff, is however rarely available for the calibration of the hydrological models used. Therefore, a method is presented to derive local runoff from secondary information for the calibration of the model parameters of the rainfallrunoff model COSERO. Changes in water levels in reservoirs, reservoir outflows, discharge measurements at water intakes and in transport lines are thereby used to derive the local, "natural" flow for a given sub-catchment. The proposed method is applied within a research study for the ?BB Infrastructure Railsystem division in the Stubache catchment in the central Austrian Alps. Here, the ?BB operates the hydropower scheme "Kraftwerksgruppe Stubachtal", which consists of 7 reservoirs and 4 hydropower stations. The hydrological model has been set up considering this human influences and the high natural heterogeneity in topography and land cover, including glaciers. Overall, the hydrological model performs mostly well for the catchment with highest NSE values of 0.78 for the calibration and0.79 for the validation period, also considering the use of homogeneous parameter fields and the uncertainty of the derived local discharge values. The derived runoff data proved to be useful information for the model calibration. Further analysis, examining the water balance and its components as well as snow cover, showed satisfactory simulation results. In conclusion, a unique runoff dataset for a small scale high-alpine catchment has been created to establish a hydrological flow prediction model which in a further step can be used for improved and sustainable hydropower management.

关键词： High alpine catchments Rainfall-runoff modelling Hydropower Ungauged basins

Recent behavior and possible future evolution of the glacieret in the cirque Golemiya Kazan in the Pirin Mountains under conditions of climate warming

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Journal of Mountain Science 2019年第1期16卷 16-29页

作者： Peter NOJAROV Emil GACHEV karsten GRUNEWALD National Institute of Geophysics Geodesy and Geography Bulgarian Academy of Sciences South-West University "Neofit Rilski" Leibniz Institute of Ecological Urban and Regional Development

This research reveals relationships between climate variables and inter-annual dynamics in the area of the glacieret located in the cirque Golemiya Kazan in the Pirin Mountains. The study period is 1993–2017. The correlations are identified using statistical methods. Also, a statistical model is constructed, including some climate variables as predictors. Despite the evident decrease of the glacieret's size in the period from the 1950 s onwards, the long-term trends for the last decades have been insignificant. The main climatic factors influencing the inter-annual dynamics in the area of the glacieret are air temperature, precipitation, zonal and meridional winds and relative humidity. With respect to the dynamics in the area of the glacieret, the important trends in the different climate variables are those of the warm period air temperatures and zonal(u) wind. They also determine to a great extent its future development by acting in two opposite directions – rising temperatures in the warm period will lead to a rapid decrease of its area by the end of the melting season, while the change of wind directionfrom west to east in the warm period will increase its area. The influence of the zonal wind in the warm period is explained mainly by the location of the glacieret in the cirque. Generally, the glacieret is tilted downwards from west to east. Thus, westerly winds facilitate blowing away the snow from the surface of the glacieret, assisting its melting in the warm period. Easterly winds do not have such an effect. The combination of the opposite effects of these two most important climate variables leads to the most likely scenario for the future development of the glacieret, according to which by the middle of this century it is expected to turn into a semi-permanent snow patch, which disappears after some summers, and by the end of the century to completely melt every year before the end of the melting season.

关键词： Climate warming Glacieret Pirin Mountains Statistical modeling Glacieret area Projection

Supporting tumor therapy by exercise:boosting T cell immunity by myokines

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Signal Transduction and Targeted Therapy 2022年第9期7卷 3177-3178页

作者： Kristina Gebhardt karsten Kruger Department of Exercise Physiology and Sports Therapy Justus-Liebig-University of GiessenGiessenGermany

In a recent study published in Cancer Cell,Kurz et *** how exercise induces inhibitory effects on tumor growth by immuno-logical processes.1The investigation of these mechanisms is particularly signifcant because life... 详细信息

关键词： immunity al. cancer.

Virtual geographic environments for water pollution control

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International Journal of Digital Earth 2018年第4期11卷 397-407页

作者： karsten Rink Cui Chen Lars Bilke Zhenliang Liao karsten Rinke Marieke Frassl Tianxiang Yue Olaf Kolditz Department of Environmental Informatics Helmholtz Centre for Environmental ResearchLeipzigGermany Faculty of Environmental Sciences Technische Universität DresdenDresdenGermany College of Environmental Science and Engineering Tongji UniversityShanghaiPeople’s Republic of China Department of Lake Research Helmholtz Centre for Environmental ResearchMagdeburgGermany Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijingPeople’s Republic of China

Due to extensive water pollution in Chinese rivers and lakes,large efforts have to be made to improve the quality of drinking water and manage the sewage water treatment *** propose a general workflow for integrating a large number of heterogeneous data sets relating to various hydrological compartments into a Virtual Geographic Environment(VGE).This allows both researchers and stakeholders to easily access complex data collections in a unified context,find interrelations or inconsistencies between data sets and evaluate simulation results with respect to other observations or simulations in the same region.A prototype of such a VGE has been set up for the region around Chao Lake,containing more than 20 spatial data sets and collections as well as first simulation *** prototype has been successfully presented to researchers and stakeholders from China and Germany.

关键词： Scientific visualisation virtual reality hydrological modelling opengeosys data explorer VISLAB

Towards intermediate-band photovoltaic absorbers:theoretical insights on the incorporation of Ti and Nb in In_(2)S_(3)

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npj Computational Materials 2020年第1期6卷 705-713页

作者： Elaheh Ghorbani Daniel Barragan-Yani karsten Albe Fachgebiet Materialmodellierung Institut für MaterialwissenschaftTU DarmstadtOtto-Berndt-Straße 3D-64287 DarmstadtGermany Physics and Materials Science Research Unit University of LuxembourgL-1511 LuxembourgLuxembourg

Creation of a partially filled intermediate band in a photovoltaic absorber material is an appealing concept for increasing the quantum efficiency of solar ***,we showed that formation of a partially filled intermediate band through doping a host semiconductor with a transition metal dopant is hindered by the strongly correlated nature of d-electrons and the antecedent Jahn–Teller distortion,as we have previously *** present work,we take a step forward and study the delocalization of a filled(valence-like)intermediate band throughout the lattice:a case study of Ti-and Nb-doped In_(2)S_(3).By means of hybrid density functional calculations,we present extensive analysis on structural properties and interactions leading to electronic characteristics of Ti-and Nb-doped In_(2)S_(3).

关键词： absorber filled intermediate

A Study of Fluid Flow in Sediments and the Effect of Tidal Pumping

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Journal of Earth Science 2017年第5期28卷 842-847页

作者： Paulo Waltrich John Whitehead Richard Hughes karsten Thompson Department of Petroleum Engineering Louisiana State University

Offshore drilling and production operations can result in spills or leaks of hydrocarbons into seabed sediments, which can potentially contaminate these sediments with oil. If this oil later mi- grates to the water surface it has the potential for negative environmental impacts. For proper contin- gency planning and to avoid larger consequences in the environment, it is essential to understand me- chanisms and rates for hydrocarbon migration from oil containing sediments to the water surface as well as how much will remain trapped in the sediments. It is believed that the amount of oil transported out of the sediment can be affected by tidal pumping, a common form of subterranean groundwater dis- charge （SGD）. However, we could find no study experimentally investigating the phenomenon of fluid flow in subsea sediments containing oil and the effects of tidal pumping. This study presents an experi- mental investigation of tidal pumping to determine if it is a possible mechanism that may contribute to the appearance of an oil sheen on the ocean surface above a sediment bed containing oil. An experimen- tal apparatus was constructed of clear PVC pipe allowing for oil migration to be monitored as it flowed out of a sand pack containing oil, while tidal pressure oscillations were applied in three different man- ners. The effect of tidal pumping was simulated via compression of air above the water （which simulated the increasing static head from tidal exchange）. Experimental results show that sustained oil release oc- curred from all tests, and tests with oscillating pressure produced for longer periods of time. Further- more, the experimental results showed that the oil migration rate was affected by grain size, oil satura- tion, and oscillation wave type. In all oscillating experiments the rate and ultimate recovery was less than the comparable static experiments. For the conditions studied, the experimental results indicate that with an oscillating pressure on top of a

关键词： tidal pumping oil migration sediments oil release rate.