检索结果-南通市图书馆

Phylogenetic relationships and genetic divergence among sorghum mosaic virus isolates infecting sugarcane

在线全文

学校读者我要写书评

暂无评论

Phylogenetic relationships and genetic divergence among sorg...

第二十届中国作物学会学术年会

作者：许珲镁 er-qi he Zu-Li Yang 高三基 National Engineering Research Center for Sugarcane Fujian Agriculture and Forestry University

Sorghum mosaic virus(SrMV, the genus Potyvirus of the family Potyviridae) is a causal agent of common mosaic in sugarcane, threating global sugar industry. In this study, 901 sugarcane leaf samples with mosaic symptom were collected from eight provinces in China and were detected by RT-PCR using a primer pair specific to SrMV coat protein(CP). All leaf samples included 839 samples from modern cultivars(Saccharum spp. hybrids) and 62 samples from chewing cane(S. officinarum). Among these, 632 of 901(70.1%) samples were tested positive for SrMV. The incidences of SrMV infection were 72.3% and 40.3% in modern cultivars and chewing cane, respectively. Phylogenetic analysis showed that all tested SrMV isolates were clustered into three clades consisting of six phylogenetic groups based on 306 CP sequences(this study = 265 and GenBank database = 41). Ten SrMV isolates from South America(the United States and Argentina) were clustered in group D with 106 isolates from China, while other SrMV isolates from Asia(China and Vietnam) were dispersed in five groups. The group A of SrMV isolates was distributed in eight provinces, but those isolates in the group F only occurred in Yunnna province, China. Nucleotide sequence identities of all SrMV CP ranged from 69% to 100%, with high genetic variation. A potential recombination event occurred among SrMV isolates based on CP sequences. All the tested SrMV CP underwent negative selection pressure. Geographical isolation(South America vs. Asia) and host types(modern cultivars vs. chewing cane) are important factors promoting the genetic differentiation of SrMV populations. Overall, this study enriches the information of genetic evolution of SrMV worldwide and provides a reference for epidemiology and control of mosaic in sugarcane.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

神经网络在响应曲面分析中的应用

系统工程理论与实践 2001年第12期21卷 130-133页

作者：何曙光齐二石何桢天津大学管理学院天津300072

在简要介绍响应曲面方法 ( Response Surface Methodology即 RSM)基本原理的基础上 ,提出将神经网络应用于 RSM的思想。

关键词：响应曲面分析神经网络试验设计橡胶生产过程

An update on spinal cord injury research

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2013年第1期29卷 94-102页

作者： he-qi Cao er-Dan Dong Division of Neurological Disorders and Mental health Department of Health Sciences National Natural Science Foundation of China

Spinal cord injury （SCI） can have a range of debilitating effects and permanently alter the capabilities and quality of life of survivors. The first specialized centers of care for SCI were established in 1944 and since then an increasing amount of research has been carried out in this area. Despite this, the present treatment and care levels for SCI are not comparable to those in other areas of medicine. In the clinic, the aim of SCI treatment is primarily to limit secondary damage by reducing compression in trauma spots and stabilizing the spinal column. Currently, no effective strategy for functional recovery is offered. In this review, we focus on research progress on the molecular mechanisms underlying SCI, and assess the treatment outcomes of SCI in animal models, i.e., neurotrophins and stem cells are discussed as pre-clinical therapies in animal models. We also assess the resources available and national research projects carried out on SCI in China in recent years, as well as making recommendations for the future allocation of funds in this area.

关键词： spinal cord injury neurotrophins stem cell-based transplantation research funding

Grand Research Plan for Neural Circuits of Emotion and Memory-Current status of neural circuit studies in China

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2013年第1期29卷 121-124页

作者： Yuan-Gui Zhu he-qi Cao er-Dan Dong Department of health Sciences National Natural Science Foundation of China

During recent years, major advances have been made in neuroscience, i.e., asynchronous release, three-dimensional structural data sets, saliency maps, magnesium in brain research, and new functional roles of long non-coding RNAs. Especially, the development of optogenetic technology provides access to important information about relevant neural circuits by allowing the activation of specific neurons in awake mammals and directly observing the resulting behavior. The Grand Research Plan for Neural Circuits of Emotion and Memory was launched by the National Natural Science Foundation of China. It takes emotion and memory as its main objects, making the best use of cutting-edge technologies from medical science, life science and information science. In this paper, we outline the current status of neural circuit studies in China and the technologies and methodologies being applied, as well as studies related to the impairments of emotion and memory. In this phase, we are making efforts to repair the current deficiencies by making adjustments, mainly involving four aspects of core scientific issues to investigate these circuits at multiple levels. Five research directions have been taken to solve important scientific problems while the Grand Research Plan is implemented. Future research into this area will be multimodal, incorporating a range of methods and sciences into each project. Addressing these issues will ensure a bright future, major discoveries, and a higher level of treatment for all affected by debilitating brain illnesses.

关键词： neural circuits emotion and memory funding Grand Research Plan

Automatic inspection of LED indicators on automobile meters based on a seeded region growing algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第3期11卷 199-205页

作者： Hong ZHOU Hai-er XU Pei-qi he Zhi-bai SONG Chen-ge GENG Department of Instrument Science and Engineering Zhejiang University Hangzhou 310027 China haierxu0109@***

Light emitting diode (LED) indicators used on automobile meters are essential for safe driving and few errors can be tolerated. The current manual inspection approach can achieve only 95% accuracy rate in weeding out errors occurring in the production process. It is imperative to improve the accuracy of the inspection process to better achieve the goal of safe driving. This paper proposes an automatic inspection method for LED indicators for use on automobile meters. Firstly,red-green-blue (RGB) color images of LED indicators are acquired and converted into R,G,and B intensity images. A seeded region growing (SRG) algorithm,which selects seeds automatically based on Otsu's method,is then used to extract the LED indicator regions. Finally,a region matching process based on the seed and three area parameters of each region is applied to inspect the LED in-dicators one by one to locate any errors. Experiments on standard automobile meters showed that the inspection accuracy rate of this method was up to 99.52% and the inspection speed was faster compared with the manual method. Thus,the new method shows good prospects for practical application.

关键词： Automatic inspection Light emitting diode (LED) indicators Automobile meter Seeded region growing (SRG)

STUDY ON REACTION OF (μ_3-CCO_2Et)CO_2M(CO)_8(CpMe)(M=Mo,W) WITH Na_2[Fe(CO)_4].SYNTheSIS OF TWO KINDS OF The NOVEL CLUSTerS EtO_2CCFeCoM(CO)_8(CpMe)H AND (OCC)FeCoM(CO)_8(CpMe)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1996年第4期7卷 381-384页

作者： Wu, he Ping Ding, er Run Yin, Yuan qi Huano, Xiao Ying Yu, Kai Bei Lanzhou Inst. of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 Fuzhou Inst. on Structure of Matter Stn. Key Lab. of Structure Chemistry Fuzhou 350002 Chengdu Ctr. of Anal. and Msrmt. Chinese Academy of Sciences Chengdu 610041

The reactions of dusters (μ3- CCO2Et)Co2M (CO)8(MeCp)[M = Mo(2a),W(2b)], derived from the reaction of (μ3-CCO2Et)Co3(CO)9 with Na[M(CO)3(MeCp)], with Na2[Fe(CO)4] in THF at reflux not only gave the expected metal fragment exchange products (μ3-CCO2Et) FeCoM (CO)6(Me-Cp )H [M=Mo(3a), W(3b)] but also produced the unexpected compounds (μ3-CCO)FeCoM (CO)5(MeCp) [M=MO(4a), W(4b)]. It is suggested that the formation of two kinds of compounds resulted from two competitive reactions of the intermediates [(μ3-CCO2Et) FeCo M(CO)8,(MeCp)] with 11+: the one is the Protonic reaction of the intermediate giving the cluster 3a,b; the another one is the intermolecular nucleophilic substitution reaction of the intermediate under the H+ catalytic action giving the cluster 4a,b.

关键词：

Influence of masticatory fatigue on the fracture resistance of the pulpless teeth restored with quartz-fiber post-core and crown

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Oral Science 2012年第4期4卷 218-220页

作者： er-Min Nie Xia-Yun Chen Chun-Yuan Zhang Li-Li qi Ying-he Huang Department of Prosthodontics The First Affiliated HospitalSun Yat-Sen University Department of Prosthodontics The Third Affiliated HospitalSun Yat- Sen University Department of Stomatology Taishan People's Hospital

To investigate whether masticatory fatigue affects the fracture resistance and pattern of lower premolars restored with quartz-fiber post-core and full crown, 44 single rooted lower premolars recently extracted from orthodontic patients were divided into two groups of 22 each. The crowns of all teeth were removed and endodontically treated and then restored with quartz-fiber post-core and full crown. Twenty-two teeth in one group were selected randomly and circularly loaded at 45° to the long axis of the teeth of 127.4 N at a 6 Hz frequency, and the other group was not delivered to cyclic loading and considered as control. Subsequently, all teeth in two groups were continually loaded to fail at 45° to the long axis of the teeth at a crosshead speed of 1 ***-1. The mean destructive force values were （733.88±254.99） and （869.14±280.26） N for the experimental and the control group, respectively, and no statistically significant differences were found between two groups （P〉O.05）. Bevel fracture and horizontal fracture in the neck of root were the major fracture mode of the specimens. Under the circumstances of this study, it seems that cyclic loading does not affect the fracture strength and pattern of the quartz-fiber post-core-crown complex.

关键词： fracture resistance masticatory fatigue pulpless teeth quartz-fiber

Dwell Time of Particles in Tunneling Barriers of Arbitrary Shape

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1998年第12期15卷 862-864页

作者： BAI er-juan SHU qi-qing Institute of Applied Nuclear Technology Shenzhen UniversityShenzhen 518060 School of Science Shenzhen UniversityShenzhen 518060

For a one-dimensional barrier of arbitrary shape,an expression of the dwell time of tunneling particles has been obtained by subdividing it into infinitesimal rectangular barrier elements and then summing the dwell times spent by particles inside the barrier elements,and the dwell times in a parabolic potential barrier were *** results show that the dwell times are almost independent of the barrier width as it is greater than a characteristic width *** can be ascribed that in the width range beyond Wc,the tunneling probabilities through the barrier elements are very small,thus the times taken to tunnel through them make little contribution to the summation of the dwell times in all the barrier elements.

关键词： barrier tunneling beyond

Highly efficient room temperature phosphorescent liquid crystalline polymer optical waveguides for advanced optoelectronics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第10期67卷 3450-3457页

作者： Jie Li Yan Guan Wei Xia Jin-Kang Chen Jiang Huang Yi Chen qi Lin er-qiang Chen he-Lou Xie Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education and Key Laboratory of Advanced Functional Polymer Materials of CollegesUniversities of Hunan Province and College of ChemistryXiangtan UniversityXiangtan 411105China School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Active organic optical waveguide materials(OOWMs)incorporating room temperature phosphorescence(RTP)hold significant promise for diverse applications in photonic and optoelectronic *** this potential,realizing active RTP optical waveguides with large-sized ordered structures and minimal light loss remains a formidable *** address this issue,we present a groundbreaking thermoplastic active OOWM with low light loss,leveraging room temperature phosphorescent liquid crystalline polymer(LCP).This innovative material can be easily synthesized through the copolymerization of phosphorescent and liquid crystalline *** resulting RTP copolymer exhibits a nematic liquid crystal phase with a phosphorescence lifetime of approximately 0.15 ms and an afterglow duration of around 1 *** the excellent processability of LCP,we successfully produce meter-scale fibers via melt *** RTP LCP fibers,characterized by a high orientation of mesogens along the fiber axis,demonstrate superior light confinement and efficient light conduction compared to unoriented samples,resulting in a low optical loss coefficient of 0.13 dB/***,the thermal responsiveness of the RTP LCP optical waveguide enables its use as a photo *** pioneering work paves the way for the design of new OOWMs tailored for advanced photonics and optoelectronics devices.

关键词： room temperature phosphorescence liquid crystalline polymer active optical waveguide