检索结果-南通市图书馆

Solid-state transformer-based new traction drive system and control

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2018年第3期13卷 411-426页

作者： Jianghua FENG Jing SHANG Zhixue ZHANG Huadong LIU zihao huang CRRC Zhuzhou Institute Co. Ltd. Zhuzhou 412001 China

A new type of traction drive system consisting of solid-state traction transformer （SSTT）, inverter unit, auxiliary inverter, traction motor and other key components is built in order to suit the demand of developing the next-generation electric traction system which will be efficient and lightweight, with high power density. For the purpose of reducing system volume and weight and improving efficiency and grid-side power quality, an efficient SSTT optimized topology combining highvoltage cascaded rectifiers with high-power high-frequency LLC resonant converter is proposed. On this basis, an integrated control strategy built upon synchronous rotating reference frame is presented to achieve unified control over fundamental active, reactive and harmonic components. The cartier-interleaving phase shift modulation strategy is proposed to improve the harmonic performance of cascaded rectifiers. In view of the secondary pulsating existing in a single-phase system, the mathematical model of secondary power transfer is built, and the mechanism of pulsating voltage resulting in beat frequency of LLC resonant converter is revealed, so as to design optimum matching of system parameters. Simulation and experimental results have verified that the traction system and control scheme mentioned in this paper are reasonable and superior and that they meet the future application requirements for rail transit.

关键词： solid-state traction transformer high-voltage cascaded rectifier LLC resonant converter synchronous rotating reference frame carrier-interleaving phase shift control secondary pulsating voltage beat frequency

Dechlorination of Crude Oil by Phase Transfer Catalyst via Nucleophilic Substitution Reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2021年第4期23卷 18-28页

作者： Gu Jin Han Xin Liu Jichang huang zihao Xing Biao State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237 Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan School of Chemistry and Chemical EngineeringShihezi UniversityShihezi 832003

Dechlorination of crude oil is an effective way to alleviate corrosion in refinery units,and the critical process is the removal of organochlorine which can be efficiently removed through nucleophilic substitution reaction catalyzed by phase ***,seven typical chlorinated alkanes were selected as model compounds to study the mechanism of dechlorination of crude oil by phase transfer catalyst in the nucleophilic substitution method,and a new dechlorination reagent using hexamethyl quaternary ammonium hydroxide(HMQAH)with two quaternary ammonium groups as phase transfer catalyst,ethylenediamine as nucleophile and ethanol as solvent was *** results show that the dechlorinating performance of the dechlorination reagent on the model compounds decreases in the following order:epichlorohydrin>1,2-dichlorobutane>1,2-dichloroethane>1,3-dichloropropane>2-chloropropane>1-chlorobutane>*** the results of the reaction kinetics show that epichlorohydrin with epoxy structure has the lowest activation energy in the process of nucleophilic substitution reaction by the phase transfer catalyst which makes it easier to be removed by the dechlorination *** removal rate of epichlorohydrin can reach up to 99.4%.The optimal dechlorination reagent used ethylenediamine as nucleophile,ethanol as solvent and HMQAH as phase transfer *** dechlorinating rate of the Iranian crude oil reached 71.6%under conditions covering a reaction temperature of 95℃,a reaction time of 90 minutes,a dechlorination reagent dosage of 1000μg/g,and a phase transfer reagent/nucleophile molar ratio of 6:*** addition,the mechanism of phase transfer in nucleophilic substitution reaction of chloroalkanes was investigated in the paper.

关键词： model compounds phase transfer nucleophilic substitution dechlorination Iranian crude oil

A review of the amino acid metabolism in placental function response to fetal loss and low birth weight in pigs

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2022年第4期13卷 987-998页

作者： Chengquan Tan zihao huang Wenyu Xiong Hongxuan Ye Jinping Deng Yulong Yin Guangdong Provincial Key Laboratory of Animal Nutrition Control National Engineering Research Center for Breeding Swine IndustryInstitute of Subtropical Animal Nutrition and FeedCollege of Animal ScienceSouth China Agricultural UniversityGuangzhou 510642GuangdongChina National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production Institute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125HunanChina

The fertility of sows mainly depends on the embryo losses during gestation and the survival rate of the postfarrowing *** selection of highly-prolific sows has been mainly focused on the selection of genotypes with high ovulatory ***,in the early-and post-implantation stages,the rate of embryo losses was increased with the increase of *** the various factors,placental growth and development is the vital determinant for fetal survival,growth,and *** the potential survival of fetuses with deficient placental development,their life-conditions and growth can be damaged by a process termed intrauterine growth retardation(IUGR).The newborn piglets affected by IUGR are prone to increased morbidity and mortality rates;meanwhile,the growth,health and welfare of the surviving piglets will remain hampered by these conditions,with a tendency to exacerbate with *** amino acids such as glycine,proline,and arginine continue to increase with the development of placenta,which are not only essential to placental growth(including vascular growth)and development,but can also be used as substrates for the production of glutathione,polyamines and nitric oxide to benefit placental function in many ***,the exact regulation mechanism of these amino acids in placental function has not yet been *** this review,we provide evidence from literature and our own work for the role and mechanism of dietary functional amino acids during pregnancy in regulating the placental functional response to fetal loss and birth weight of *** review will provide novel insights into the response of nutritionally nonessential amino acids(glycine and proline)to placental development as well as feasible strategies to enhance the fertility of sows.

关键词： Amino acids Birth weight Fetal loss Pigs Placenta

Spin-flop transition and Zeeman effect of defect-localized bound states in the antiferromagnetic topological insulator MnBi_(2)Te_(4)

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第1期16卷 1101-1106页

作者： Guojian Qian Mengzhu Shi Hui Chen Shiyu Zhu Jiawei Hu zihao huang Yuan huang Xian-Hui Chen Hong-Jun Gao Institute of Physics Chinese Academy of Sciences and University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics and Chinese Academy of Sciences Key Laboratory of Strongly-Coupled Quantum Matter PhysicsUniversity of Science and Technology of ChinaHefei 230026China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China

The correlation of surface impurity states with the antiferromagnetic ground states is crucial for understanding the formation of the topological surface state in the antiferromagnetic topological insulators MnBi_(2)Te_(4).By using low-temperature scanning tunneling microscopy and spectroscopy,we observed a localized bound state around the Mn-Bi antisite defect at the Teterminated surface of the antiferromagnetic topological insulator MnBi_(2)Te_(4).When applying a magnetic field perpendicular to the surface(Bz)from–1.5 to 3.0 T,the bound state shifts linearly to a lower energy with increasing Bz,which is attributed to the Zeeman ***,when applying a large range of Bz from–8.0 to 8.0 T,the magnetic field induced reorientation of surface magnetic moments results in an abrupt jump in the local density of states(LDOS),which is characterized by LDOSchange-ratio■***,two asymmetric critical field,–2.0 and 4.0 T determined by the two peaks in■are observed,which is consistent with simulated results according to a Mills-model,describing a surface spin flop transition(SSF).Our results provide a new flatform for studying the interplay between magnetic order and topological phases in magnetic topological materials.

关键词： antiferromagnetic topological insulators MnBi_(2)Te_(4) scanning tunneling microscope Mills model surface spin flop transition

Maternal supply of cysteamine alleviates oxidative stress and enhances angiogenesis in porcine placenta

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2022年第1期13卷 181-196页

作者： Shuangbo huang Zifang Wu zihao huang Xiangyu Hao Longmiao Zhang Chengjun Hu Jianfu Wei Jinping Deng Chengquan Tan Guangdong Provincial Key Laboratory of Animal Nutrition Control National Engineering Research Center for Breeding Swine IndustryInstitute of Subtropical Animal Nutrition and FeedCollege of Animal ScienceSouth China Agricultural UniversityGuangzhou 510642GuangdongChina Guangzhou DaBeiNong Agri-animal Huabandry Science and Technology Co. Ltd.Guangzhou 510642GuangdongChina Guangdong Laboratory for Lingnan Modern Agriculture South China Agricultural UniversityGuangzhou 510642GuangdongChina

Background:Oxidative stress in placenta is associated with the occurrence of adverse pregnancy outcomes in sow,but there are few satisfactory treatment strategies for these *** study investigated the potential of cysteamine(CS)as an antioxidant protectant for regulating the reproductive performance,redox status,and placental angiogenesis of ***:The placental oxidative stress status and vascular density of piglets with different birth weights:<1.0 kg(low birth weight,LBW)and 1.4–1.6 kg(normal birth weight,NBW)were evaluated,followed by allotting 84 sows to four treatments(n=21)and feeding them with a basal diet supplemented with 0,100,300,or 500 mg/kg of CS from d 85 of gestation to d 21 of lactation,***,serum,and colostrum samples of sows or piglets were collected,and the characteristics of sows and piglets were ***,the in vivo results were validated using porcine vascular endothelial cells(PVECs).Results:Compared with the NBW placentae,the LBW placentae showed increased oxidative damage and were vulnerable to angiogenesis ***,H2O2-induced oxidative stress prompted intracellular reactive oxygen species generation and inhibited the tube formation and migration of PVECs as well as the expression of vascular endothelial growth factor-A(VEGF-A)in ***,dietary CS supplementation can alleviate oxidative stress and improve the reproductive performance of ***,compared with the control group,dietary 100 mg/kg CS could(1)decrease the stillbirth and invalid rates,and increase both the piglet birth weight in the low yield sows and the placental efficiency;(2)increase glutathione and reduce malondialdehyde in both the serum and the colostrum of sows;(3)increase the levels of total antioxidant capacity and glutathione in LBW placentae;(4)increase the vascular density,the mRNA level of VEGF-A,and the immune-staining intensity of platelet endothelial cell adhesion molecule-1 in the LB

关键词： Angiogenesis Cysteamine Oxidative stress Placenta Sow

Special Termination of Minimal Model Program

在线全文

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2024年第11期12卷 3897-3901页

作者： zihao huang Mathematical Sciences Research Center (MSRC) Chongqing University of Technology Chongqing China

This paper presents a self-contained proof of Special Termination of MMP (Minimal Model Program). By refining the assumptions and simplifying the argument, it offers a more accessible approach compared to the original... 详细信息

关键词： Special Termination Minimal Model Program Birational Geometry Algebraic Geometry

Robustness of the unidirectional stripe order in the kagome superconductor CsV_(3)Sb_(5)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第5期31卷 15-20页

作者： Bin Hu Yuhan Ye zihao huang Xianghe Han Zhen Zhao Haitao Yang Hui Chen Hong-Jun Gao Institute of Physics and University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100190China CAS Center for Excellence in Topological Quantum Computation Beijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

V-based kagome materials AV_(3)Sb_(5)(A=K,Rb,Cs)have attracted much attention due to their novel properties such as unconventional superconductivity,giant anomalous Hall effect,charge density wave(CDW)and pair density *** for the 2a_(0)×2a_(0)CDW(charge density wave with in-plane 2×2 superlattice modulation)in AV_(3)Sb_(5),an additional 1×4(4a_(0))unidirectional stripe order has been observed at the Sb surface of Rb V3 Sb5 and CsV_(3)Sb_(5).However,the stability and electronic nature of the 4a_(0) stripe order remain controversial and ***,by using low-temperature scanning tunneling microscopy/spectroscopy(STM/S),we systematically study the 4a_(0) stripe order on the Sb-terminated surface of CsV_(3)Sb_(5).We find that the 4a_(0) stripe order is visible in a large energy *** STM images with positive and negative bias show contrast inversion,which is the hallmark for the Peierls-type *** addition,below the critical temperature about 60 K,the 4a_(0)stripe order keeps unaffected against the topmost Cs atoms,point defects,step edges and magnetic field up to 8 *** results provide experimental evidences on the existence of unidirectional CDW in CsV_(3)Sb_(5).

关键词： CsV_(3)Sb_(5) 4_(a0)stripe charge order scanning tunneling microscopy/spectroscopy charge density wave

Remarkable mechanochromism and force-induced thermally activated delayed fluorescence enhancement from white-light-emitting organic luminogens with aggregation-induced emission

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第10期33卷 4536-4540页

作者： Yitao Zheng Lingqi Zuo Letian Zhang zihao huang Shufeng Li Zhan Yang Zhu Mao Suilian Luo Cong Liu Fengqiang Sun Guang Shi Zhenguo Chi Bingjia Xu Key Laboratory of Theoretical Chemistry of Environment Ministry of Education/School of ChemistrySouth China Normal UniversityGuangzhou 510006China State Key Laboratory of Optoelectronic Materials and Technologies(Sun Yat-sen University) Guangzhou 510275China School of Chemistry Sun Yat-sen UniversityGuangzhou 510275China Shenzhen Institute of Advanced Electronic Materials Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

The development of organic materials with white-light emission and thermally activated delayed fluorescence(TADF)properties in the solid state remain a ***,a series of white-light-emitting organic luminogens have been developed and are found to show aggregation-induced delayed fluorescence(AIDF)*** AIDF emitters present dual-emission consisted of prompt fluorescence and TADF in the crystalline *** white-light emissions can be easily tuned by altering the chemical structure and connecting position of the heterocyclic aromatic *** the stimuli of mechanical force and solvent vapor,the compounds exhibit remarkable and reversible mechanochromism,in which their emission colors are switchable between white and *** grinding,they also display linearly tunable luminescence colors,as well as force-induced TADF enhancement,which may be associated with the more compact molecular packing and the restriction of intramolecular *** results from time-resolved emission scanning and theoretical calculation suggest that the dual-emission of the AIDF luminogens likely results from the twisted intramolecular charge transfer transitions of the molecules,and the reversible mechanochromism properties probably stem from the interconversion of the quasi-axial and the quasi-equatorial conformations.

关键词： White-light emission Thermally activated delayed fluorescence Aggregation-induced delayed fluorescence mechanochromism Force-induced emission enhancement

Two-photon nanolithography of micrometer scale diffractive neural network with cubical diffraction neurons at the visible wavelength

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第10期22卷 93-99页

作者： Qi Wang Haoyi Yu zihao huang Min Gu Qiming Zhang Institute of Photonic Chips University of Shanghai for Science and TechnologyShanghai 200093China Centre for Artificial-Intelligence Nanophotonics School of Optical-Electrical and Computer EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China

Free-space diffractive neural networks(DNNs)have been an intense research topic in machine learning for image recognition and encryption due to their high speed,lower power consumption,and high neuron *** advances in DNNs have highlighted the need for smaller device footprints and the shift toward visible ***,DNNs fabricated by electron beam lithography,are not suitable for microscopic imaging applications due to their large sizes,and DNNs fabricated by two-photon nanolithography with cylindrical neurons are not optimal for visible wavelengths,as the highorder diffraction could induce low diffraction *** this paper,we demonstrate that cubical diffraction neurons are more efficient diffraction elements for DNNs compared with cylindrical *** on the theoretical analysis of the relationship between the detector area sizes and classification accuracy,we reduced the size of DNNs operating at the wavelength of 532 nm for handwritten digit classification to micrometer scale by two-photon *** DNNs with cubical neurons demonstrated an experimental classification accuracy(89.3%)for single-layer DNN,and 83.3%for two-layer DNN with device sizes similar to that of biological cells(about 100μm×100μm).Our results paved the pathway to integrate 3D micrometer-scale DNNs with microscopic imaging systems for biological imaging and cell recognition.

关键词： optical neural networks diffractive neural networks two-photon nanolithography