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矿物岩石地球化学通报 2018年第6期37卷 1180-1180页

作者： D.E.Canfield S.C.Zhang A.B.Frank X.M.Wang H.J.Wang J.Su Y.T.Ye R.Frei 袁超

大气氧对生命大爆发具有重要意义。然而。前人通过Cr同位素研究表明,中元古代时期具有非常低的大气氧浓度(当今氧水平的0.1%),并不足以使得中元古代真核生物大爆发。Cr同位素是揭示大气氧化历史的一个非常有用的办法。由于Cr^3+物相发... 详细信息

大气氧对生命大爆发具有重要意义。然而。前人通过Cr同位素研究表明,中元古代时期具有非常低的大气氧浓度(当今氧水平的0.1%),并不足以使得中元古代真核生物大爆发。Cr同位素是揭示大气氧化历史的一个非常有用的办法。由于Cr^3+物相发生大陆氧化性风化作用,Cr同位素会发生分馏,重的53Cr同位素会倾向于进入氧化的镉酸盐中(Cr^4+),从而使得残留相(Cr^3+)中亏损重Cr同位素。

关键词： Cr^3+ 中元古代同位素氧浓度大气特征和分异生命大爆发

Frequency-selective Optimization of Periodic Gate Control Signals in DC/DC Converters for EMI-reduction

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Chinese Journal of Electrical Engineering 2022年第4期8卷 11-18页

作者： Caroline Krause Stephan frei On-board Systems Lab TU Dortmund UniversityDortmund 44227Germany

High-frequency switching of power transistors in power electronic systems can cause electromagnetic emissions.Simple approaches for reducing high-frequency disturbances,such as inserting an additional gate resistor,lead to increased power losses.This makes achieving both electromagnetic compatibility and power efficiency difficult.Active gate drivers help to find a trade-off between these two.Typically,only narrow-band disturbances must be reduced.Accordingly,a target signal with a spectrum notched at some frequencies can be defined.The target signal can be reached by a target-signal-oriented control of the transistor’s gate.This leads to steeper switching slopes,such that the power losses are less increased.Generating arbitrary target signals is impossible.The transistor signal exhibits some physical limitations.A constraint satisfaction problem must be solved,and the gate drive signal must be optimized by applying a residual and Newton’s method.The proposed optimization process in the frequency domain is based on the circuit simulation method named“harmonic balance”.Measurements on a DC/DC converter exhibit the benefits of this method.

关键词： Power electronics active gate driving electromagnetic compatibility Newton’s method

Coupling metal oxide nanoparticle catalysts for water oxidation to molecular light absorbers

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Journal of Energy Chemistry 2017年第2期26卷 241-249页

作者： Heinz frei Molecular Biophysics and Integrated Bioimaging Division Lawrence Berkeley National LaboratoryUniversity of CaliforniaBerkeleyCA 94720USA

Water oxidation, as a mandatory reaction of solar fuels conversion systems, requires the use of light absorbers with electronic properties that are well matched with those of the multi-electron catalyst in order to achieve high efficiency. Molecular light absorbers offer flexibility in fine tuning of orbital energetics,and metal oxide nanoparticles have emerged as robust oxygen evolving catalysts. Hence, these material choices offer a promising approach for the development of photocatalytic systems for water oxidation.However, efficient charge transfer coupling of molecular light absorbers and metal oxide nanoparticle catalysts has proven a challenge. recent new approaches toward the efficient coupling of these components based on synthetic design improvements combined with direct spectroscopic observation and kinetic evaluation of charge transfer processes are discussed.

关键词： Water oxidation catalysts Metal oxides Molecular light absorbers Artificial photosynthesis Charge transfer Electronic coupling

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自动化设备的安全问题

现代制造 2019年第30期 46-48页

作者： Markus frei 不详

对机械工程师来讲,安全问题是自动化中最复杂的问题。Stober驱动技术公司与Pilz公司合作开发了基于驱动安全技术的SE6安全模块。凭借这一多功能的驱动调节器,Stober公司为市场提供了主要用于驱动器应用的、最大额定输出电流为85A的单轴... 详细信息

对机械工程师来讲,安全问题是自动化中最复杂的问题。Stober驱动技术公司与Pilz公司合作开发了基于驱动安全技术的SE6安全模块。凭借这一多功能的驱动调节器,Stober公司为市场提供了主要用于驱动器应用的、最大额定输出电流为85A的单轴控制器。例如电子变速箱中最多32轴的同步操作或者没有叠加运动控制器的飞锯驱动控制。它可以控制、调节线性的和旋转的伺服同步电动机以及异步电动机。通过其模块化的接口方案和品种繁多的附件,使它能够准确的实现各种配置。

关键词：安全模块额定输出电流机械工程师运动控制器同步操作接口方案同步电动机驱动控制

Association mapping for root system architecture traits under two nitrogen conditions in germplasm enhancement of maize doubled haploid lines

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The Crop Journal 2020年第2期8卷 213-226页

作者： Langlang Ma Chunyan Qing Ursula frei Yaou Shen Thomas Lübberstedt Department of Agronomy Iowa State UniversityAmes 50010USA Key Laboratory of Biology and Genetic Improvement of Maize in Southwest region Maize Research InstituteSichuan Agricultural UniversityChengdu 611130China

root system architecture(rSA)contributes to nitrogen(N)uptake and utilization in maize.In this study,a germplasm enhancement of maize double haploid population of 226 lines genotyped with 61,634 SNPs was used to investigate the genetic basis of rSA under two N levels using a genome-wide association study(GWAS).GLM+PCA,FarmCPU,and MLM models were utilized to balance false positives and false negatives.In total,33 and 51 significant SNP-trait associations were detected under high and low N conditions,respectively.Under high N,SNP S9_2483543 was detected by all models.Linkage disequilibrium(LD)regions of some SNPs overlapped with the intervals of QTL for rSA and N response that were detected in previous studies.In particular,several known genes,rtcs,rtcl,rtcl,and Ms44,were located in the LD regions of S1_9992325,S9_151726472,S9_154381179,and S4_197073985,respectively.Among the candidate genes identified by this study,GrMZM2G139811,GrMZM2G314898,GrMZM2G054050,GrMZM2G173682,GrMZM2G470914,GrMZM2G462325,GrMZM2G416184,and GrMZM2G064302 were involved in seedling,seed,and root system development or N metabolism in Arabidopsis or rice.The markers identified in this study can be used for marker-assisted selection of rSA traits to improve nitrogen use efficiency in maize breeding,and the candidate genes will contribute to further understanding of the genetic basis of rSA under diverse N conditions.

关键词： germplasm breeding seedling

Editorial for Special Issue on Electromagnetic Interference and Electromagnetic Compatibility in Power Electronics System

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Chinese Journal of Electrical Engineering 2022年第3期8卷 1-1页

作者： Shuo Wang Stephan frei Hong Li University of Florida USA TU Dortmund University Germany Beijing Jiaotong University China

With the development of high and new technologies,such as 5G,big data,high-speed railway,renewable energy generation,flexible AC/DC transmission and electric vehicles,the power conversion system as the key support function is also developing rapidly in the direction of high frequency,high efficiency,high power and high-power density.The electromagnetic environment of the power and energy conversion system becomes more and more complex,which puts forward more stringent requirements for the electromagnetic compatibility design of the system,especially with the technological breakthrough and commercial use of wide bandgap semiconductor power devices represented by SiC and GaN.Electromagnetic interference(EMI)and electromagnetic compatibility(EMC)have become the important challenges to ensure the functionality,safety,reliability and performance of the system.Therefore,it is of great significance to study the EMI and EMC theory and key technologies of power electronics system.

关键词： system compatibility Electromagnetic

Improvement of rice Production under Drought Conditions in West Africa:Application of QTLs in Breeding for Drought resistance

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rice science 2022年第6期29卷 512-521页

作者： Kossi Lorimpo ADJAH Maxwell Darko ASANTE Aboubacar TOUrE Mawuli AZIADEKEY Francis Osei AMOAKO-ANDOH Michael frei Yacouba DIALLO Komi AGBOKA West African Science Service Center on Climate Change and Adapted Land Use/Climate Change and Agriculture Program IPR/IFRAP.O.Box 224KatibougouMali Council for Scientific and Industrial research-Crops research Institute P.O.Box 3785Fumesua-KumasiGhana University of Sciences Techniques and Technologies of Bamako(USTTB)P.O.Box 423BamakoMali International Crops research Institute for the Semi-Arid Tropics P.O.Box 320BamakoMali University of Lomé(UL) P.O.Box 1515LoméTogo Institute for Agronomy and Plant Breeding of Justus-Liebig-University of Giessen Giessen 35392Germany Polytechnic rural Institute of Training and Applied research(IPr/IFrA) P.O.Box 224KatibougouMali Council for Scientific and Industrial research-College of Science and Technology Department of Plant Resources DevelopmentP.O.Box 3785Fumesua-KumasiGhana

rice plays a paramount role in food and nutrition security in many West African countries.Despite the doubling of production during the last decade,rice consumption has grown faster,creating a deficit between the demand and supply.Although the West African sub-region remains the main rice-producing centre on the continent,production is severely hampered by biotic and abiotic stresses.Drought is one of the factors that most severely reduce grain yields of rice.Systems of production need to be established in order to mitigate yield loss as a result of drought.This review discusses the effects of drought on rice production in West Africa and its mitigation with an emphasis on the improvement of tolerance to drought stress.Yield stability can be achieved by developing drought-tolerant varieties through several processes encompassing profiling of known QTLs and identification of new ones,marker-assisted selection,genomic selection,and extensive multi-locational yield trials.We suggest a comprehensive strategy for breeding drought-tolerant rice varieties in West Africa.

关键词： West Africa rice drought-tolerant variety QTL high-throughput genotyping

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高增压汽油机动力总成系统的整体优化

汽车与新动力 2012年第1期44卷 11-14页

作者： Berns S Benninger K Kulzer A frei r 范明强不详

目前,降低燃油耗乃至达到法规所规定的二氧化碳排放限值是动力总成创新的主要推动力,这促使研发人员需根据不同的汽车市场和发动机等级采用不同的解决方案。除了在极度小型化的情况下,采取一些机内措施以获得可靠的燃烧过程之外,还讨论... 详细信息

目前,降低燃油耗乃至达到法规所规定的二氧化碳排放限值是动力总成创新的主要推动力,这促使研发人员需根据不同的汽车市场和发动机等级采用不同的解决方案。除了在极度小型化的情况下,采取一些机内措施以获得可靠的燃烧过程之外,还讨论了选择哪种变速箱方案及不同的混合动力结构型式。Bosch公司为汽油机动力总成系统在沟通内燃机、变速箱和电子控制3个主要领域方面起到了桥梁作用。

关键词：动力总成燃油耗二氧化碳排放模拟计算高增压汽油机变速箱电动化

提供奶嘴和软垫可以减少人工饲养仔猪的拱鼻行为吗？

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猪业科学 2020年第1期37卷 20-23页

作者：张振玲石丰运 frei Daniela 徐州生物工程职业技术学院动物工程系

研究探讨了是否可以通过提供吮吸奶嘴和拱鼻软垫等乳头和乳房仿制品来减少人工饲养仔猪的口腔行为。在一个2×2组间因子设计试验中,每个人工饲养仔猪圈内采用了4种处理方法中的一种:提供吮吸奶嘴、提供拱鼻软垫、提供吮吸奶嘴+拱鼻软垫... 详细信息

研究探讨了是否可以通过提供吮吸奶嘴和拱鼻软垫等乳头和乳房仿制品来减少人工饲养仔猪的口腔行为。在一个2×2组间因子设计试验中,每个人工饲养仔猪圈内采用了4种处理方法中的一种:提供吮吸奶嘴、提供拱鼻软垫、提供吮吸奶嘴+拱鼻软垫,不提供任何仿制品。在仔猪进入人工饲养系统后的第4天和第18天,对126头仔猪(分成21组,每组6头)进行连续集中观察,每次观察90 min,并对其行为进行评分。使用线性混合模型分析数据。在所有试验处理中,仔猪的拱鼻行为(包括拱腹或拱仔猪的其他任何部位)从第4天到第18天都在增加,但提供复合仿制品(吮吸奶嘴+拱鼻软垫)的仔猪组拱鼻行为增加幅度最小。人工饲养的仔猪将时间更多地用于拱吮吸奶嘴+拱鼻软垫组合仿制品,而不是某一单个仿制品,并且不是因为提供了仿制品而导致仔猪的拱鼻行为。所有仔猪至少有1次拱鼻行为(只有1头例外)。仔猪的休息、玩耍争斗、或其他口腔行为(非拱鼻行为),仿制品(吮吸奶嘴和拱鼻软垫),猪圈设备几乎不受不同试验处理的影响。与其他处理相比,复合仿制品(吮吸奶嘴+拱鼻软垫)处理组里的仔猪平均休息时间更长。总之,随着时间的推移,只有复合仿制品(吮吸奶嘴+拱鼻软垫)处理组里的仔猪才能在减少拱鼻行为增加方面显示现出某种效果。然而,拱鼻行为的减少非常有限,因此可以说提供奶嘴和软垫等仿制品并没有有效地防止仔猪的拱鼻行为。因此,供试仿制品(吮吸奶嘴和拱鼻软垫)未能成功地消除人工饲养仔猪的口腔重定向行为。

关键词：仔猪人工饲养拱腹行为仿制品早期断奶