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Search Results: 1 - 10 of 122104 matches for " 杜志秀 "
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酵母中性脂快速检测及积累动态分析
,,陈忠翔,匡鑫,
生物技术通报 , 2014,
Abstract: 以油红O、苏丹黑B为染料,结合酸或碱热破壁萃取,建立了通过比色快速检测酵母中性脂含量的方法。其中油红O萃取效果较好,比色结果更加准确,苏丹黑B也可以作为一种替代的中性脂含量检测的染料。并用该方法初步研究了两种中性脂肪甘油三酯代谢调控的关键基因磷脂酸磷酸酶(PAH1)和甘油三酯脂酶(triglyceridelipase,TGL)敲除突变体中性脂的变化。结果显示,前者甘油三酯显著降低,但总中性脂肪含量不变,后者甘油三酯及总中性脂肪含量均明显积累;同时,用该方法监测了酵母中性脂含量随生长周期的动态变化,表明指数生长期后有明显的积累。
春性甘蓝型油菜胚状体成苗影响因素的研究
罗玉,,唐国永?
西北农林科技大学学报(自然科学版) , 2010,
Abstract: 【目的】通过对春性甘蓝型油菜胚状体成苗影响因素的研究,以提高胚状体成苗效率,缩短dh群体构建的时间。【方法】以小孢子培养获得的5964个子叶形胚状体为材料,研究了胚状体长度、培养基分装方式、琼脂质量浓度、低温处理时间与胚状体成苗的关系。【结果】胚状体在固体培养基上的放置方式影响其形态发育;长度为3~4mm的胚状体成苗率最高,达到60.1%;分装方式ⅲ,即分装20min后封口,培养基凝固后表面没有积水的培养基出苗最好,成苗率达到65.2%;随琼脂质量浓度的增加,胚状体成苗率呈先上升后下降的趋势,琼脂质量浓度为12g/l时的成苗率最高,达到61.3%;4℃低温处理14d可使胚状体一次成苗率提高到65.5%。【结论】缺氧和低温处理影响胚状体的形态发育;胚状体发育程度影响成苗率;相对干燥的环境有利于成苗;琼脂质量浓度通过影响培养基中可利用水的分配、培养瓶内湿度以及乙烯浓度影响小孢子胚成苗率;低温可能通过影响胚状体内源激素水平起到提高成苗率的作用。
基于信任机制的水下传感器网络节点安全定位算法
张尧,,罗咏梅,
计算机应用 , 2013,
Abstract: ?为了及时检测出水下传感器网络(uwsn)定位系统中的恶意锚节点,提出一种基于信任机制的节点安全定位算法。算法结合簇结构和信任机制,根据锚节点提供的位置信息采用beta分布作出初步信任评价,并可根据需要调整信任更新权重。为了降低了水声信道的不稳定性对信任评价过程的影响,同时识别恶意锚节点的信任欺骗行为,提出信任过滤机制(tfm),对直接信任值进行差异量化,由簇头节点决定各锚节点是否可信。仿真结果表明所提算法适用于水下传感器网络,并且能够及时识别恶意锚节点,在定位系统的精确度和安全性方面都有很大提升。
微观组织对GH4720Li合金力学性能的影响
,,胡军,翁镭
- , 2017, DOI: 10.12068/j.issn.1005-3026.2017.01.010
Abstract: 摘要 对GH4720Li合金锻制棒坯进行热处理前后的微观组织观察,对一次γ′相进行能谱分析,并对其进行20,650℃拉伸力学性能检测.结果表明,合金中一次γ′相的数量由棒坯边缘向中心逐渐减少,但其尺寸逐渐增大;热处理对一次γ′相的数量和分布的影响不显著,但对二次γ′相的影响十分显著;合金强度由棒坯边缘向中心先升高再降低,其塑性则是逐渐升高,一次γ′相的数量和塑性是影响合金塑性的主要因素;一次γ′相与基体的相界是拉伸断裂的主要裂纹源;随着析出温度升高,一次γ′相的塑性增加,其Al,Ti元素含量下降,而Cr,Co,Mo和W元素含量升高.
Abstract:The microstructures of GH4720Li alloy samples which were cut from GH4720Li alloy bar including forging and heat treatment states were observed, and the phase compositions of primary γ′ was measured via energy spectrum analysis. The tensile properties of the samples through heat treatment were tested at 20 and 650℃. The results indicated that the quantity of primary γ′ of GH4720Li alloy decreases from the edge to the center of the bar while the size of primary γ′ increases gradually. The influence of heat treatment on the quantity and distribution of primary γ′ is not noticeable, but the influence of heat treatment on the quantity and distribution of secondary γ′ is noticeable. The tensile strength of GH4720Li alloy increases at the first and decreases in the end from the edge to the center of the bar, but the plasticity of alloy increases gradually. The quantity and plasticity of primary γ′ are the chief factors influencing the alloy plasticity. The phase boundary of primary γ′-γ is the crack source in the tensile tests. As the precipitation temperature rises, the plasticity of primary γ′ increase, the element contents of aluminum and titanium in the primary γ′ decrease, but the element contents of chromium, cobalt, molybdenum and tungsten in the primary γ′ increase.
春性甘蓝型油菜FCA同源基因可变剪接体的克隆及表达研究
A novel alternative splicing isoform of FCA homologue in spring rapeseed

张生萍,罗玉,,
- , 2016,
Abstract: 【目的】克隆特早熟春性甘蓝型油菜的FCA同源基因(sBnFCA)及其可变剪接体,并分析该基因的表达模式。【方法】根据拟南芥和芸薹属植物FCA基因的DNA序列和cDNA序列设计引物,用PCR和RT-PCR技术克隆特早熟春性甘蓝型油菜“86号”的FCA同源基因(sBnFCA)及其可变剪接体,对克隆基因及编码蛋白序列进行生物信息学分析,构建系统进化树,并用qR-PCR技术检测sBnFCA基因在不同发育时期根、茎、叶、茎尖中的表达量。【结果】克隆出了sBnFCA基因的全长序列(8 827 bp),得到了sBnFCA-γ可变剪接体及一个新的可变剪接体(sBnFCA-5),新的可变剪接体在GenBank中的登录号为KJ701579.1。sBnFCA-5剪接体的CDS全长1 986 bp,编码662个氨基酸残基,其推导的氨基酸序列具有2个保守的RRM结构域和1个WW结构域。生物信息学分析显示,sBnFCA-5与已报道甘蓝型油菜BnFCA-γ(AF414188.1)的相似性达99%,与拟南芥FCA-γ的相似性达87%。sBnFCA-5比sBnFCA-γ少了172个碱基序列,是一个跨外显子剪接体。sBnFCA蛋白相对分子质量和理论等电点分别为72.5 ku和9.2。基因表达模式分析显示,sBnFCA-γ和sBnFCA-5在苗期、蕾期、花期的根、茎、叶和茎尖组织中都有表达,sBnFCA-γ在蕾期茎尖和花期叶片中表达量较高,sBnFCA-5在蕾期茎尖和花期叶片中表达量极高。【结论】克隆的sBnFCA-5为甘蓝型油菜sBnFCA基因的一个新的可变剪接体,该基因在春性特早熟甘蓝型油菜开花调控中可能有着重要的调节作用。
【Objective】The research cloned the sBnFCA gene and its alternative splicing isoform,and analyze their expressions.【Method】The primers were designed according to the published FCA DNA and cDNA sequences of Arabidopsis and Brassica.The genome DNA and complete open reading frame of FCA homologue gene were cloned from an early-flowering rapeseed “No.86” strain using the method of homologues cloning and reverse transcription PCR (RT-PCR) bioinformatics analysis was conducted for cloned gene and proteins before the phylogenetic tree was constructed and the expression levels at different stages were detected using qRT-PCR.【Result】The DNA sequence of FCA from spring B.napus L.(sBnFCA) was 8 827 bp and the cDNA sequence of novel alternative splicing isoform (sBnFCA-5) was 1 986 bp,encoding a protein of 662 amino acid residues with a predicted molecular weight of 72.5 ku and a theoretical pI of 9.2.Bioinformatics analysis showed that the predicted sBnFCA-5 protein contained two RRM domains and a WW domain.It was showed that sBnFCA-5 had 99% similarity with BnFCA-γ(AF414188.1) and had 87% similarity with A.thaliana FCA-γ.The expression analysis of sBnFCA-5 using qRT-PCR showed that the sBnFCA gene was expressed in roots,stem,leaves,shoot tips and buds at seeding,bud and flowering stages.The relative expression level of sBnFCA-5 was highest in shoot tips at bud stage and in leaves at flowering stage,respectively.【Conclusion】The cloned sBnFCA-5 was a new alternative splicing isoform of sBnFCA gene and it might play an important role in flowering regulation of spring rape
Design and realization of micro-code for MPLS VPN
MPLS VPN功能的微码设计与实现*

DU Xiu-juan,JIN Zhi-gang,
,

计算机应用研究 , 2008,
Abstract: The IXP2400 network processor with powerful comuting ability made MPLS and MPLS VPN possible.The paper provided the key technology and micro-code of MPLS VPN,and achieved flexible and effcient MPLS VPN with low cost by dispatching task to micro engines and processing flexibly the data packets.The primary characteristic of the design is that it supports L2 and L3 VPN at the same time and the micro-code is very concise.The experiments show the MPLS VPN works properly and are compatible with mainstream network devices.
M2ASR: new multi-path mutual anonymous source routing protocol
M2ASR——新型多径匿名源路由协议*

DU Xiu-juan,JIN Zhi-gangb,
,刚b

计算机应用研究 , 2009,
Abstract: To solve the security and efficiency issues of mobile Ad hoc networks, this paper presented an efficient multi-path mutual anonymous source routing M2ASR which originated from the protocol DSR and provided anonymity by modifying the work flow of routing discovery of protocol DSR and adopting label switches like what used in MPLS, so multi-path anonymous routing can be used in large-scale wireless networks. Meanwhile, combined with node forwarding and multi-path, the algorithm IDA was used in the protocol for the first time so the communication efficiency of Ad hoc networks was greatly enhanced and it is showed by theoretical analysis and simulation.
基于速度闭环的自适应力位控制算法
孔民,游玮,,孙立宁
哈尔滨工业大学学报 , 2010, DOI: 10.11918/j.issn.0367-6234.2010.03.017
Abstract: 针对力觉主手力控制中接触刚度时变的特殊要求,提出了一种含有速度闭环的自适应力/位混合控制算法.通过构造系统特定的标量函数,证明可以通过选择合适的自适应参数更新律,使得在该控制律和更新律的共同作用下追踪力误差是有界的,力误差的导数是平方可积的.利用Barbalat引理证明了该控制算法具有全局渐近稳定性.给出了主手力控制系统的体系结构,并对不同频率正弦力信号进行了跟踪实验.实验结果表明:对于同样频率的力信号,所提出的方法跟踪误差小于常规阻抗控制方法,整个控制系统稳定并具有良好的控制特性.实验分析了控制律中各关键参数对控制品质的影响.
船舶振荡运动仿真的方向谱方法
赵振民,孔民,,孙立宁
哈尔滨工业大学学报 , 2010, DOI: 10.11918/j.issn.0367-6234.2010.05.015
Abstract: 为了解决船舶振荡运动时域仿真和海浪与船舶运动一致性问题,提出了一种以频谱分析方法为基础,用方向谱代替海浪谱的船舶振荡运动计算方法.对海浪谱、方向谱进行数学描述和关系分析,并选择适合用于船舶振荡分析的长峰海浪谱和ITTC方向谱,根据Gerstner模型对海浪进行分解,建立了船舶在海浪中的振荡运动计算模型.采用响应振幅算子法描述遭遇波面与船舶运动的联系,根据线性叠加假设给出了船舶振动运动的时域解和频域解.
利用rapd和scar标记鉴定草莓品种
王志刚,,李贺,,国栋,谭昌华
园艺学报 , 2007,
Abstract: 利用rapd和scar标记对32份草莓材料进行了鉴定,结果表明:8个rapd引物共扩增出85个标记,其中71个为多态性标记,多态性比率为83。5%。25份草莓材料的rapd图谱差异较大,易于区分。利用具有多态性的rapd标记,对28份草莓试材的亲缘关系进行分析,初步鉴定出同名异物和同物异名品种。两个rapd标记被转化为片段长度分别为378bp和214bp的显性scar标记,其多态性与相应rapd标记一致。利用这两个scar标记对草莓品种进行了初步鉴定。
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