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Horticulture Research 2023年第7期10卷 152-164页

作者： Weizong Yang Ziwei Xin Lihang Xie Yuhui Zhai Yanlong Zhang Lixin Niu Qingyu Zhang College of Landscape Architecture and Arts Northwest A&F UniversityYangling 712100ShaanxiChina Academy of Medical Sciences Zhengzhou UniversityZhengzhou 450000China

Tree peony(Paeonia rockii)is an excellent woody oilseed crop,known for its highα-linolenic acid(ALA,∼45%)content,which is of great value for human health.However,the mechanisms underlying this high-level ALA accumulation in tree peony seeds are poorly understood.In this study,we evaluated the dynamic changes in the lipidomic profile of P.rockii seeds during development.A total of 760 lipid molecules were identified in P.rockii seeds;triacylglycerol(TAG)lipid molecules showed the highest abundance and diversity,both increasing during seed development.Particularly,ALA was the predominant fatty acid at the TAG sn-3 position.We further characterized two diacylglycerol acyltransferase(DGAT)genes and three phospholipid:diacylglycerol acyltransferase(PDAT)genes involved in the transfer of fatty acids to the TAG sn-3 position.Gene expression and subcellular localization analyses suggested that PrDGATs and PrPDATs may function as endoplasmic reticulum-localized proteins in seed TAG biosynthesis.In vitro functional complementation analysis showed different substrate specificities,with PrPDAT2 having a specific preference for ALA.Multiple biological assays demonstrated that PrDGAT1,PrDGAT2,PrPDAT1-2,and PrPDAT2 promote oil synthesis.Specifically,PrPDAT2 leads to preferential ALA in the oil.Our findings provide novel functional evidence of the roles of PrDGAT1 and PrPDAT2,which are potential targets for increasing the ALA yield in tree peony and other oilseed crops.

关键词： synthesis. finding predominant

A petunia transcription factor, PhOBF1, regulates flower senescence by modulating gibberellin biosynthesis

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Horticulture Research 2023年第4期10卷 38-52页

作者： Xiaotong Ji Ziwei Xin Yanping Yuan Meiling Wang Xinyi Lu Jiaqi Li Yanlong Zhang Lixin Niu Cai-Zhong Jiang Daoyang Sun College of Landscape Architecture and Arts Northwest A&F UniversityYanglingShaanxi 712100China Department of Plant Sciences University of CaliforniaDavisDavisCA 95616USA Crops Pathology and Genetics Research Unit USDA-ARSDavisCA 95616USA

Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence remain elusive.In this study,we characterized one up-regulated gene PhOBF1,belonging to the basic leucine zipper transcription factor family,in senescing petals of petunia(Petunia hybrida).Exogenous treatments with ethylene and GA3 provoked a dramatic increase in PhOBF1 transcripts.Compared with wild-type plants,PhOBF1-RNAi transgenic petunia plants exhibited shortened f lower longevity,while overexpression of PhOBF1 resulted in delayed flower senescence.Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants.Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways,as well as accumulation levels of bioactive GAs GA1 and GA3.Application of GA3 restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines,and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1,PhACS1,and PhACS2.Moreover,PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif.Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence.Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated f lower senescence by modulating the GA production.

关键词： senescence pet flower

RECENT PROGRESS IN MULTIFOCAL MULTIPHOTON MICROSCOPY

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Journal of Innovative Optical Health Sciences 2012年第3期5卷 41-48页

作者： JUNLE QU lixin LIU YONGHONG SHAO HANBEN niu BRUCE Z.GAO College of Optoelectronic Engineering Shenzhen University Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceShenzhen 518060P.R.China School of Technical Physics Xidian University Xi'an 710071P.R.China Department of Bioengineering and COMSET Clemson University Clemson SC 29634USA

Multifocal multiphoton microscopy(MMM)has recently become an important tool in biomedicine for performing three-dimensional fastfluorescence imaging.Using various beamsplitting techniques,MMM splits the near-infrared laser beam into multiple beamlets and produces a multifocal array on the sample for parallel multiphoton excitation and then recordsfluorescence signal from all foci simultaneously with an area array detector,which significantly improves the imaging speed of multiphoton microscopy and allows for high efficiency in use of the excitation light.In this paper,we discuss the features of several MMM setups using different beamsplitting devices,including a Nipkow spinning disk,a microlens array,a set of beamsplitting mirrors,or a diffractive optical element(DOE).In particular,we present our recent work on the development of an MMM using a spatial light modulator(SLM).

关键词： Multifocal multiphoton microscopy(MMM) microlens array beamsplitter diffractive optical element(DOE) spatial light modulator(SLM)

Integrating full-length transcriptomics and metabolomics reveals the regulatory mechanisms underlying yellow pigmentation in tree peony(Paeonia suffruticosa Andr.)flowers

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Horticulture Research 2021年第1期8卷 3242-3256页

作者： Xiaoning Luo Daoyang Sun Shu Wang Sha Luo Yaqi Fu Lixin Niu Qianqian Shi Yanlong Zhang College of Landscape Architecture and Art Northwest A&F UniversityYanglingChina

Tree peony(Paeonia suffruticosa Andr.)is a popular ornamental plant in China due to its showy and colorful flowers.However,yellow-colored flowers are rare in both wild species and domesticated cultivars.The molecular mechanisms underlying yellow pigmentation remain poorly understood.Here,petal tissues of two tree peony cultivars,“High Noon”(yellow flowers)and“Roufurong”(purple–red flowers),were sampled at five developmental stages(S1–S5)from early flower buds to full blooms.Five petal color indices(brightness,redness,yellowness,chroma,and hue angle)and the contents of ten different flavonoids were determined.Compared to“Roufurong,”which accumulated abundant anthocyanins at S3–S5,the yellow-colored“High Noon”displayed relatively higher contents of tetrahydroxychalcone(THC),flavones,and flavonols but no anthocyanin production.The contents of THC,flavones,and flavonols in“High Noon”peaked at S3 and dropped gradually as the flower bloomed,consistent with the color index patterns.Furthermore,RNA-seq analyses at S3 showed that structural genes such as PsC4Hs,PsDFRs,and PsUFGTs in the flavonoid biosynthesis pathway were downregulated in“High Noon,”whereas most PsFLSs,PsF3Hs,and PsF3’Hs were upregulated.Five transcription factor(TF)genes related to flavonoid biosynthesis were also upregulated in“High Noon.”One of these TFs,PsMYB111,was overexpressed in tobacco,which led to increased flavonols but decreased anthocyanins.Dual-luciferase assays further confirmed that PsMYB111 upregulated PsFLS.These results improve our understanding of yellow pigmentation in tree peony and provide a guide for future molecular-assisted breeding experiments in tree peony with novel flower colors.

关键词： yellow flowers tree

含齿面剥落缺陷影响的共轴对转轮系振动特性分析

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振动与冲击 2022年第19期41卷 254-265页

作者：杜正柱许立新牛坤重庆大学机械与运载工程学院重庆400044 重庆大学机械传动国家重点实验室重庆400044 航空工业直升机设计研究所天津333001

针对某型无人直升机共轴对转主减齿轮箱设计,采用集中参数法建立该齿轮箱中多级斜齿轮传动系统25自由度动力学模型,模型中考虑了时变啮合刚度、轴承支承刚度、传动轴扭转刚度以及啮合误差的影响。分析了输入转速和高速级齿轮齿面剥落缺... 详细信息

针对某型无人直升机共轴对转主减齿轮箱设计,采用集中参数法建立该齿轮箱中多级斜齿轮传动系统25自由度动力学模型,模型中考虑了时变啮合刚度、轴承支承刚度、传动轴扭转刚度以及啮合误差的影响。分析了输入转速和高速级齿轮齿面剥落缺陷尺度、位置对传动系统动态特性的影响规律。研究表明,上下旋翼轴齿轮副动态啮合力波动较大,上旋翼轴齿轮副动态啮合力波动幅度是下旋翼齿轮副的1.7倍;随着转速增大,各级齿轮副动态响应中的2倍输入级啮合频率的幅值提升最显著;当高速级齿轮齿面出现剥落缺陷,啮合频率附近会出现边频带,振动冲击随着缺陷尺寸的增大而增大;在不同的缺陷位置中,位于双齿啮合区与三齿啮合区交界位置,缺陷产生的振动冲击幅值最大。研究结论为无人直升机共轴对转主减齿轮箱的减振降噪,故障诊断提供了理论参考。

关键词：共轴对转齿轮传动集中参数法剥落缺陷动力学

Investigation of the sliding friction behaviors of locust on slippery plates

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Chinese Science Bulletin 2009年第24期54卷 4549-4554页

作者： WANG lixin ZHOU Qiang Xu ShuYan niu HuLi Department of Mechatronic Engineering China Agricultural University Beijing 100083 China

The slippery trapping plate in swarm locust control is a method of realizing resource utilization of locust and avoiding pesticide residues in the entironment. Some slippery plates with different material composition or surface characteristic were investigated through the sliding tests of locust on slippery plates, and sliding rubbing behaviors of locusts on the plate were observed by means of CCD video monitoring system. Poor sliding character of silicate glass to locust was verified, which is in accordance with the adhesive effect generated by secretion of locust feet pads on the smooth surface. And also, PVC plastic plate presents a poor sliding character to locusts, because the soft surface of PVC can permit claws of locust feet to engender mechanical interlock on the surface. The zinc plate shows a considerable slippery ratio for locusts because of the appropriate surface characteristic and material property. Photoelectric stimulation for resting locust can promote the movement of locust. Accordingly, the contact form of locust feet and abdomen on slippery plates is changed and contact area is reduced severely, so the sliding effect of locust on slippery plates is strengthened effectively. These results supply a suitable theoretical foundation for manufacturing locust slippery trapping plates and trapping units, and indicate the important role of photoelectric stimulating factors in biotribology.

关键词：摩擦行为蝗虫滑片滑动 PVC塑料板表面特性视频监控系统硅酸盐玻璃

Influence of epitaxial layer structure and cell structure on electrical performance of 6.5 kV SiC MOSFET

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Journal of Semiconductors 2022年第8期43卷 71-77页

作者： lixin Tian Zechen Du Rui Liu Xiping niu Wenting Zhang Yunlai An Zhanwei Shen Fei Yang Xiaoguang Wei State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute Co.Ltd.Beijing 102209China Key Laboratory of Semiconductor Material Sciences Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Silicon carbide(SiC)material features a wide bandgap and high critical breakdown field intensity.It also plays an important role in the high efficiency and miniaturization of power electronic equipment.It is an ideal choice for new power electronic devices,especially in smart grids and high-speed trains.In the medium and high voltage fields,SiC devices with a blocking voltage of more than 6.5 kV will have a wide range of applications.In this paper,we study the influence of epitaxial material properties on the static characteristics of 6.5 kV SiC MOSFET.6.5 kV SiC MOSFETs with different channel lengths and JFET region widths are manufactured on three wafers and analyzed.The FN tunneling of gate oxide,HTGB and HTRB tests are performed and provide data support for the industrialization process for medium/high voltage SiC MOSFETs.

关键词： silicon carbide epitaxial layer channel length JFET region width FN tunneling HTGB

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磁窑沟矿11~#煤层回采巷道支护设计优化

水力采煤与管道运输 2019年第1期 30-31,34页

作者：钮利新山西省晋神能源有限公司山西河曲036500

为了选取合理的巷道支护体系和安全经济的维护巷道工程,结合工作面工程地质条件,通过经验公式确定顶板、两帮的支护参数,并在实施过程中,根据现场经验,对顶板锚索规格、间排距、帮锚杆的间排距等参数进行优化。应用实践表明,锚杆、锚索... 详细信息

为了选取合理的巷道支护体系和安全经济的维护巷道工程,结合工作面工程地质条件,通过经验公式确定顶板、两帮的支护参数,并在实施过程中,根据现场经验,对顶板锚索规格、间排距、帮锚杆的间排距等参数进行优化。应用实践表明,锚杆、锚索的预紧力得到了加强,间排距更加合理,支护体系发挥出支护效果,确保了巷道围岩的稳定。

关键词：煤矿巷道锚杆支护优化设计参数

Identification of microsatellites in cattle unigenes

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Journal of Genetics and Genomics 2008年第5期35卷 261-266页

作者： Qiuliang Yan Yinghan Zhang Hongbin Li Caihong Wei Lili niu Shan Guan Shangang Li lixin Du College of Animal Science and Technology NorthwestA ＆ F University Yangling 712100 China National Center for Molecular Genetics and Breeding of Animal Institute of Animal Sciences Chinese Academy of Agricultural Sciences Beijing 100094 China Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 China

To identify EST-SSR molecular markers, 41,986 cattle UniGene sequences from NCBI were mined for analyzing SSRs. A total of 1,831 SSRs were identified from 1,666 ESTs, which represented an average density of 19.88 kb per SSR. The frequency of EST-SSRs was 4.0%. The dinucleotide repeat motif was the most abundant SSR, accounting for 54%, followed by 22%, 13%, 7% and 4%, respectively, for tri-, hexa-, penta- and tetra-nucleotide repeats. Depending upon the length of the repeat unit, the length of microsatellites varied from 14 to 86 bp. Among the di- and tri-nucleotide repeats, AC/TG （57%） and AGC （12%） were the most abundant type. Annotation of EST-SSRs was also carried out. Three hundred primer pairs were randomly designed using Prime Premier 5.0 program and Oligo 5.0 for further experimental validation.

关键词： cattle microsatellite expressed sequence tags EST-SSR

高强稳定型锚网索耦合支护在大断面硐室中的应用研究

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煤矿现代化 2017年第1期26卷 25-26,29页

作者：钮利新晋神能源沙坪煤业有限公司山西忻州034000

针对硐室围岩岩性差、原有支护设计不合理、无控制底板措施、高地应力作用下硐室围岩发生局部变形破坏。采取在原有一次锚网支护的基础上,采取二次锚网支护加固技术,并针对支护承载结构的薄弱部位,采用锚索对锚网支护形成的承载结构进... 详细信息

针对硐室围岩岩性差、原有支护设计不合理、无控制底板措施、高地应力作用下硐室围岩发生局部变形破坏。采取在原有一次锚网支护的基础上,采取二次锚网支护加固技术,并针对支护承载结构的薄弱部位,采用锚索对锚网支护形成的承载结构进行结构补偿的支护方式,有效的控制了硐室围岩变形,锚杆失效和载荷分布不均造成的支架承载能力降低。

关键词：硐室围岩控制变形破坏二次支护