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Evaluation of 1.2 kV SiC MOSFETs in Multilevel Cascaded h-bridge Three-phase Inverter for Medium-voltage Grid Applications

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Chinese Journal of Electrical Engineering 2019年第2期5卷 1-13页

作者： haider Mhiesan Janviere Umuhoza kenneth Mordi Chris Farnell h.Alan Mantooth Department of Electrical Engineering University of ArkansasFayettevilleARUSA Failure Analysis Engineer at Murata Power Solutions Greater BostonMAUSA Electrical Design Engineer at Benchmark Group Inc.Rogers ArkansasUSA

A study is conducted to evaluate 1.2 kV silicon-carbide(SiC)MOSFETs in a cascaded h-bridge(ChB)three-phase inverter for medium-voltage *** main purpose of this topology is to remove the need for a bulky 60 hz transformer normally used to step up the output signal of a voltage source inverter to a medium-voltage *** SiC devices(1.2-6.5 kV SiC MOSFETs)which have a high breakdown voltage,enables the system to meet and withstand the medium-voltage stress using only a minimal number of cascaded *** SiC-based power electronics when used in the presented topology considerably reduce the complexity usually encountered when Si devices are used to meet the medium-voltage level and power *** and preliminary experimental results on a low-voltage prototype verifies the nine-level ChB topology presented in this study.

关键词： SiC switching devices cascaded h-bridge inverter medium voltage AC grid energy storage

DFT研究三单原子催化剂用于一步N–C–N偶联合成尿素

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Science China Materials 2023年第6期66卷 2346-2353页

作者：陈凌唐城郑尧 kenneth Davey 焦研 School of Chemical Engineering and Advanced Materials The University of AdelaideSouth Australia 5005Australia Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

以二氧化碳(CO_(2))和氧化氮(NO_(x))为原料来电催化合成尿素的方法可以极大降低碳排放.然而,这种方法最大的挑战是缺乏有效的电催化剂.本文中,我们设计了一组C_(9)N_(4)担载的三单原子电催化剂用于尿素生产.使用DFT理论计算了反应路径... 详细信息

以二氧化碳(CO_(2))和氧化氮(NO_(x))为原料来电催化合成尿素的方法可以极大降低碳排放.然而,这种方法最大的挑战是缺乏有效的电催化剂.本文中,我们设计了一组C_(9)N_(4)担载的三单原子电催化剂用于尿素生产.使用DFT理论计算了反应路径,使用过渡态理论搜寻了多个反应能垒,结果表明三单原子催化剂Ni_(2)Zn/C_(9)N_(4)能够高效地电催化合成尿素.Ni_(2)Zn/C_(9)N_(4)的作用是多重的:它不仅可以促使CO_(2)和NO_(x)转化成耦合前驱体,更重要的是通过一步N-C-N耦合机制促进尿素的生成,从而抑制其他竞争反应.具体来讲,在这种N-C-N耦合机制中,^(*)CO插入到已经形成的h_(2)N^(*)-^(*)Nh_(2)中,与两个N原子同时结合.本工作展示了三单原子催化剂在电催化生成含多个氮/碳原子化合物过程中的重要作用.

关键词：单原子催化剂过渡态理论竞争反应碳原子反应路径电催化剂耦合机制尿素生产

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NiFeRuO_(x)nanosheets on Ni foam as an electrocatalyst for efficient overall alkaline seawater splitting

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Frontiers of Chemical Science and Engineering 2023年第11期17卷 1698-1706页

作者： Yu Liu Lin Chen Yong Wang Yuan Dong Liang Zhou Susana ICórdoba de Torresi kenneth IOzoemena Xiao-Yu Yang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing&International School of Materials Science and Engineering&School of Materials Science and Engineering&Shenzhen Research Institute&Laoshan Laboratory Wuhan University of TechnologyWuhan 430070China Instituto de Química Universidade de São Paulo05508-080 São PauloBrazil Molecular Sciences Institute School of ChemistryUniversity of the WitwatersrandJohannesburg 2050South Africa

The electrocatalyst NiFeRuO_(x)/NF,comprised of NiFeRuO_(x)nanosheets grown on Ni foam,was synthesized using a hydrothermal process followed by thermal ***_(x)/NF displays high electrocatalytic activity and stability for overall alkaline seawater splitting:98 mV@10 mA∙cm^(−2)in hydrogen evolution reaction,318 mV@50 mA∙cm^(−2)in oxygen evolution reaction,and a cell voltage of 1.53 V@10 mA∙cm^(−2),as well as 20 h of durability.A solar-driven system containing such a bifunctional NiFeRuO_(x)/NF has an almost 100%Faradaic *** NiFeRuO_(x)coating around Ni foam is an anti-corrosion layer and also a critical factor for enhancement of bifunctional performances.

关键词： NiFeRuO_(x)nanosheets Ni foam electrocatalysis overall seawater splitting solar-driven system

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Breeding for drought tolerance in perennial ryegrass(Lolium perenne L.)and tall fescue(Lolium arundinaceum[Schreb.]Darbysh.)by exploring genotype by environment by management interactions

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Grassland Research 2023年第1期2卷 22-36页

作者： Claudio C.Fernandes Filho Mario h.Murad Leite Andrade Jose A.Rodrigues Nunes Joseph Wipff Debra L.hignight Esteban F.Rios Kevin Kenworthy kenneth hignight Biology Department Institute of Natural SciencesUniversidade Federal de LavrasLavrasBrazil Agronomy Department University of FloridaGainesvilleFloridaUSA NexGen Plant Science Center LLCAlbanyOregonUSA NexGen Turf Research LLCAlbanyOregonUSA

Background:Drought‐tolerant turfgrass cultivars are becoming more important each year as landscape irrigation practices are becoming more ***:In this study,we quantified the level of drought tolerance(DT)in perennial ryegrass and tall fescue genotypes across years under different mowing(Mh)and fertility(FL)rates.A total of 48 ryegrass and 38 tall fescue genotypes were planted in 2011 at NexGen,Albany,*** trial was divided into three subtrials:(i)DT;(ii)Mh and DT;and(iii)FL and ***:The results showed that there was significant genetic variance for most of the traits in both *** genotype×year interaction was predominantly simple,indicating small changes in genotype ranking for both *** Mh improved DT in perennial ryegrass,whereas higher Mh resulted in greater DT in tall *** both species,higher Mh improved the population mean for turf *** FL inputs led to higher turf quality for both species,but it did not affect the DT ***:Using a selection index,six genotypes for perennial ryegrass and four for tall fescue were selected.

关键词： drought stress ryegrass tall fescue turf quality turfgrass breeding

Radioprotective Potencies of Allium Cepa Extract (ACE) against Radiation-Induced hepatoxicity in Wistar Rats

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2023年第3期12卷 59-83页

作者： Sylvester Kelechi kenneth Okeke Francisca Nneka Agwu kenneth Kalu Attah Okwudili Joseph Deparrtment of Radiation and Clinical Oncology University of Nigeria Teaching Hospital Enugu Nigeria Department of Physics and Astronomy University of Nigeria Nsukka Nigeria Department of Medical Radiography Faculty of Health Science University of Nigeria Enugu Campus Enugu Nigeria

Background and Purpose: All types of ionizing radiations generate ions which can lead to the formation of free radicals and reactive oxygen species (ROS). Excess production of free radicals or decrease in antioxidants level leads to oxidative stress. It is a harmful process that induces damage to cell structures, lipids, proteins, RNA and DNA which leads to a number of diseases. The aim of this study is to examine the effect of plant extract (Allium Cepa Extract (ACE)) on the kidney of wistar rats exposed to radiation using and assaying some biochemical enzymes. Material and Method: 60 wistar rats weighing 170 ± 20 g were equally divided into six groups for the study. Group 1 (control): neither received ACE nor irradiation. Group 2 (ACE): received 1000 mg/Kg *** of ACE. Group 3 (4 Gy-Irradiated): were exposed to 4 Gy TBI on day 14. Group 4 (6 Gy-Irradiated): were exposed to 6 Gy TBI on day 14. Group 5 (ACE + 4 Gy): were treated with 1000 mg/Kg *** of ACE once daily for twenty-eight days but exposed to 4 Gy TBI on day 14. Group 6 (ACE + 6 Gy): were treated with 1000 mg/Kg *** of ACE once daily for twenty-eight days but exposed to 6 Gy TBI on day 14. All the groups received distilled water and feed ad libitum during the acclimatization and experimental periods. Four animals in each group were sacrificed 24 h after irradiation and the 4 remaining animals were sacrificed on day 29 for biochemical assay and histopathological evaluation, the statistical analysis was done using one-way analysis of variance (ANOVA) on the data editor SPSS version 28. Results: From the biochemical enzymes, the level of Malondialdehyde (MDA) in group 2 when compared to group 1 was almost the same, which was not statically significant with (p > 0.05), but groups 3 and 4 show a significant increase in the level of MDA with (p hile group 5 and 6 showed no significant increase in MAD with (p > 0.05). The other enzymes like SOD, CAT, GST, and GSh followed suit. Conclusion: From the res

关键词： Allium Cepa Winstar RAT MDA SOD hepatoxicity

钩藤碱对多巴胺诱导的NT2细胞凋亡的影响(英文)

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Acta Pharmacologica Sinica 2002年第5期23卷 63-67页

作者：石京山,haglid G kenneth 遵义医学院药理学教研室歌德堡大学解剖与细胞生物学系遵义中国 563003 歌德堡大学解剖与细胞生物学系歌德堡瑞典 41390 歌德堡瑞典 41390

目的:观察钩藤碱(rhnchophylline,Rhy)对多巴胺(dopamine,DA)诱导NT2细胞凋亡的防护作用.方法:以LDh的漏出率反映细胞的生存率;用TUNEL染色法和DNA琼脂糖凝胶电泳法观察NT2神经元凋亡情况;用Western blotting法测定Bcl-2蛋白表达.结果:... 详细信息

目的:观察钩藤碱(rhnchophylline,Rhy)对多巴胺(dopamine,DA)诱导NT2细胞凋亡的防护作用.方法:以LDh的漏出率反映细胞的生存率;用TUNEL染色法和DNA琼脂糖凝胶电泳法观察NT2神经元凋亡情况;用Western blotting法测定Bcl-2蛋白表达.结果:Rhy在5和50μmol/L的浓度下能显著地抑制由DA所致的乳酸脱氢酶的漏出,以及明显地提高以PMS试剂转化为指标的生存率(Phy使DA诱导的转染bcl-2基因神经元和未转染bcl-2基因神经元的凋亡率均明显减少;Rhy能抑制DA所致的DNA降解,但Phy对NT2细胞Bcl-2蛋白表达无明显影响.结论:Rhy能对抗DA诱导的NT2细胞的损伤.

关键词：多巴胺钩藤碱 NT2细胞细胞凋亡

Photothermal controls of vegetative dormancy in Poa secunda

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Grassland Research 2022年第1期1卷 43-52页

作者： Allen A.Chen Shui-zhang Fei Andrew W.Lenssen kenneth J.Moore Department of horticulture Iowa State UniversityAmesIowaUSA Department of Agronomy Iowa State UniversityAmesIowaUSA

Background:Summer vegetative dormancy is a desirable trait in cool-season grasses when they are interplanted with annual *** bluegrass(Poa secunda ***.)shows summer dormancy,but the environmental cues that control dormancy remain ***:A controlled environment study using temperature and day length combinations of 32.2℃/15 h,26.6℃/14 h,21.1℃/13 h,and 15.5℃/12 h was conducted with *** accessions PI232347,PI639272,and PI232348,and‘Audubon’red fescue as a nondormant control to determine the optimum treatment for dormancy induction.A second study using treatments of 26.6℃/14 h,21.1℃/13 h,and 15.5℃/12 h was conducted to determine the thresholds for dormancy release.A third study used a factorial experiment with two temperatures(32.2℃ and 15.5℃)and two day lengths(15 and 12 h)to differentiate between temperature and day length effects on dormancy ***:Of the four temperature and day length combinations,all except for 15.5℃/12 h resulted in dormancy by the end of 6 weeks,with 32.2℃/15 h inducing dormancy in only 17 *** the three treatments for dormancy release,15.5℃/12 h broke dormancy the fastest in all accessions and released the most number of plants from *** variation existed between accessions for the speed of dormancy release in the 21.1℃/13 h and 26.6℃/14 h *** third study showed that temperature is the primary inducer for summer dormancy,while longer day length may promote dormancy under inductive ***:This study identified the optimum photothermal for induction and release of summer dormancy in ***,which will help future studies in elucidating the mechanism of summer dormancy.

关键词： controlled environment dormancy induction dormancy release Sandberg bluegrass summer dormancy

Agent Blue Spraying in the Mekong Delta during the Vietnam War: Fate of the Arsenic Based herbicide Weapon Used to Destroy Rice Crop and Mangrove Forests

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Open Journal of Soil Science 2022年第7期12卷 253-294页

作者： kenneth R. Olson Larry Cihacek College of Agricultural Consumer and Environmental Sciences University of Illinois Urbana Illinois USA School of Natural Resource Sciences North Dakota State University Fargo North Dakota USA

Agent Blue, a mixture of cacodylic acid (Ch3) As O2h) and sodium cacodylate (C2h6 AsNaO2), was a tactical arsenic-based herbicide used during the Vietnam War to destroy grasses and rice crops. Natural and synthetic sources of arsenic can degrade into water-soluble forms and persist in groundwater and potentially contribute to elevating As levels in drinking water. The United States Department of Defense (DOD) and United States Department of Agricultural (USDA) Operation Ranch hand records for tactical herbicides including Agent Blue sprayed in southern Vietnam during the Vietnam War (1961-1971) are very detailed, rather complete and publicly available. The same is not true for tactical herbicides sprayed by the Republic of Vietnam (RV) during the Khai Quang program which was supported by the U.S. Army, U.S. Navy and Central Intelligence Agency (CIA) in the Mekong Delta. Agent Blue was sprayed by the RV military for three years before the official start of the American-Vietnam War. Few, if any, RV military, US Army, US Navy and CIA spray records exist from 1962 to 1965. Vietnam War veterans, historians and scholars have reported the spraying of 3.2 million liters (468,008 kg As) of Agent Blue on rice paddies and mangrove forests in the Mekong Delta and Central highlands by the RV military with the support of the US Army, US Navy and CIA. The Institute of Medicine estimated that 3.2 million liters (468,000 kg As) were sprayed during the RV Khai Quang program. This was in addition to the U.S. Air Force’s Operation Ranch hand spraying of the tactical herbicide Agent Blue primarily by C-123 aircraft. The Operation Ranch hand missions maintained location and quantities of herbicides sprayed (over 4,712,000 liters (664,392 kg As) from 1961-1971. The RV military and US military (Army and Navy) spray equipment included hand and backpack sprayers, sprayers mounted on Brown Water Navy boats, on Army track vehicles and Army

关键词： Operation Ranch hand Khai Quang program Agent Blue Arsenic Cacodylic Acid North Vietnam Army Republic of Vietnam Democratic Republic of Vietnam American-Vietnam War

A Physical Origin for Quantum Entanglement and Probabilistic Behaviors

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Journal of Modern Physics 2021年第1期12卷 50-58页

作者： kenneth h. Schatten NASA/GSFC Greenbelt MD USA Now at Ai-Solutions Inc. Lanham MD USA

Quantum Mechanics’ entanglement and probabilistic behaviors are viewed in the light of Quantum Field Theory’s (QFT’s) advances made during the last century. In particular, Bohm’s version (B-EPR) of the Einstein, Podolsky, Rosen (EPR) experiment is now viewed with the aid of QFT’s modern description of electrons. In QFT, free electrons possess a bare core surrounded by a “dressing”. The dressing consists of one or more virtual particles/fields pulled from the vacuum during the bound electron’s parturition. In QFT, a bound electron’s freedom is aided by eliminating its energy losses from bremsstrahlung. The paper develops a “Shimony” numerical model using QFT’s free electron structure with the aid of a “random vector paradigm” (RVP). The RVP simply expresses QFT’s free electron as a bare core surrounded by an EM dressing. Using this RVP, we imbue newly freed electrons with a vector-like EM spin property of 1/2. From this, the Shimony Monte Carlo computer analysis provides a detailed comparison of the B-EPR experiment as described by Bell. The entanglement property can serve to provide a way to transport shared encoded information. Overall, the electron dressing can convey random elements that may provide QM with its entanglement and probabilistic behaviors.

关键词： Quantum Mechanics Entanglement Probability Einstein Electron Origin Structure