Positional distribution of fatty acids on the glycerol backbone during the biosynthesis of glycerolipids in Ectocarpus fasciculatus

The biosynthesis of glycolipids in E. fasciculatus was studied by ¹⁴C label and chase. The fatty acids in sulphoquinovosyl diacylglycerol (SQDG) were almost 16-car- bon and 18-carbon ones. In addition to the two fatty acids, monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG) contained 8.5 mol% and 31.0 mol% of eicosapentaenoic acid (20∶5), respectively, and this fatty acid was usually distributed in the sn-1 position of the glycerol backbone. When plants were incubated with [2-¹⁴C] acetate, differences existed in the positional distribution of the labeled fatty acids in sn-1 and sn-2 among the three glycerolipids. In SQDG, ¹⁴C-labeled fatty acids were distributed uniformly in the sn-1 and sn-2 positions. In DGDG, ¹⁴C-labeled fatty acids were mainly distributed in the sn-2 position. In MGDG, the radioactivity of fatty acids in sn-1 position was far greater than that in sn-2 position after a 30 min pulse label, and the difference in radioactivity between the two positions decreased rapidly. The above results indicated that differences in the positional distribution of ¹⁴C-labeled fatty acids between sn-1 and sn-2 positions might be related to 20∶5 and the biosynthesis of DGDG. Our results also suggested that E. fasciculatus had the same DGDG biosynthetic pathway as that in higher plants and galactosyl transferase was selective for MGDG.     

MCAI课件在大学理科教学中的应用

MCAI课件应用于大学理科教学中的课堂教学、自学和辅导、复习总结和单元测验以及教学中的数据处理。MCAI课件要求教师改变教育观念，改造知识结构，研究新的教育方法；要求学生的学习转向创造性的思维训练；要求教学经验丰富的教师来设计课件的思路和编写脚本；要求建设的投资力度进一步加强。     

Protection of phosphatidylcholine to photosystem Ⅱ membrane during heat treatment

Photosystem Ⅱ membrane was reconstituted with phosphatidylcholine (PC) with different kinds of fatty acyl chains and the protection of PC to photosystem Ⅱ (PS Ⅱ)membrane during heat treatment was investigated using oxygen electrode, variable fluorescence and circular dichroism (CD) spectroscopy. Heat treatment decreased the oxygen evolution rate and the F′v/Fm′ ratio of PS Ⅱ membrane and influenced CD spectra of PS Ⅱ membrane, but PC inhibited the effect of heat treatment on the oxygen evolution rate, the F′v/F′m ratio and CD spectra of PS Ⅱ membrane. The results indicate that PC can protect PS Ⅱ membrane against heat treatment and the alterations in the unsaturated fatty acid extent in PC can cause the changes of the protection ability.     

胶州湾潮滩整治工程对潮流泥沙影响及冲淤预测分析

潮滩开挖后回淤问题一直困扰航道建设和港口发展的突出问题,为探究胶州湾北部海湾整治工程在不同开挖方案下潮流场分布情况,本研究通过对胶州湾北部海域进行潮流数值模拟,基于二维平面不可压缩雷诺平均纳维埃-斯托克斯（Navier-Stokes）浅水方程,对比分析两种潮滩开挖方案对航道水动力条件及冲淤变形影响。研究结果表明,工程疏浚后,开挖区及附近海域涨潮流作用明显增强,落潮流深槽流速降低,产生进水加速,出水缓慢的效应,方案二涨潮流作用增强而落潮流减小效应大于方案一。工程完成以后,开挖区有所淤积,方案一潮滩开挖区年平均淤强约15.6cm/a, 方案二约为19.0cm/a,淤积强度由深水区向浅水区逐渐增加,工程疏浚产生的涨潮流增强、落潮流减弱的效应将使淤积加速。     

基于双向长短期记忆神经网络的配网电压异常数据检测

受自然环境、计量仪器等影响,量测数据会出现异常,导致调度人员错误决策,威胁电力系统安全稳定运行。为保障电力系统安全稳定运行,提出了一种基于双向长短期记忆(bidirectional long short-term memory, Bi-LSTM)神经网络的配网电压无监督异常数据检测方法。利用Bi-LSTM神经网络处理时序数据的双向特性,建立时序预测模型,通过对比预测值和实际值的误差检测异常数据。最后,基于某实际配网电压数据进行仿真验证,仿真结果表明:所提方法在准确率、F1分数等指标方面均优于决策树、K近邻、支持向量机、长短期记忆(long short-term memory, LSTM)神经网络。     

WSN跟踪应用中一种新的目标恢复机制研究

无线传感器网络（WSN）跟踪应用中,当目标丢失时需要研究目标跟踪恢复方案。用于唤醒跟踪区域节点,以重新寻找到目标。为减少唤醒无关睡眠节点的数量,本文提出了一种新的逐层节点唤醒目标恢复机制,在不丢失目标的前提下,逐级唤醒相关区域睡眠节点,降低节点能量消耗,延长了WSN生命周期。     

SPR生物传感系统研究

对自行研制的SPR生物传感系统各部分给出了详细描述.系统采用独特的角向会聚光路代替传统的角度机械扫描方式,采用CCD作为光电检测器件,避免了机械扫描可能带来的误差,可一次完成样品响应曲线的采集分析,提高了检测精度和速度.此外,利用M ATLAB软件对信号进行了F IR滤波分析处理,提高了信噪比.测试表明,系统的分辨率为3.59×1-0 5R IU,灵敏度为98.61度/R IU,检测范围为1.00~1.47 R IU.     

大体积混凝土结构无缝施工技术的应用研究

根据已有的关于大体积混凝土裂缝控制的理论与工程经验,结合武汉国际会展中心地下室超长混凝土结构的具体特点,提出了一些关于超长混凝土结构无缝施工中有利于控制大体积混凝土裂缝开展的措施,工程实践证明,效果良好．     

基于军事规则的无人坦克集群协同作战仿真

现代战争逐渐向无人化、信息化、智能化方向发展,无人坦克作为未来陆战中的主要装备,在机动性、安全性和经济性方面具有很大的优势。单无人坦克在大规模的陆战中能力有限,很多复杂的任务需要无人坦克集群合作完成。围绕无人坦克集群协同作战应用,建立了动力学控制、单机决策、武器装甲等单无人坦克系统模型。结合无人坦克自身状态和融合态势信息,设计了无人坦克集群的协同感知模型,基于现有的目标分配、避敌和编队自修复等军事规则,提出一种新型无人坦克集群协同作战模型。搭建仿真系统,对所设计的模型算法进行了测试,探索验证了无人坦克协同作战的可行性和有效性。     

测量参数估值和误差分析的最大最小准则法

本文建议一种平差方法.与最小二乘平差不同,它除了利用观测值以外,还使用我们对观测质量的评价即测量误差范围(可以根据所采用的观测方法的精度以及测量仪器的特性来确定).应用线性规划理论的单纯形法,该方法是以所估参数的最大可能误差最小为目标,最后可得未知参数的最佳估值及其最大可能的误差.