黄金香柳的组织培养与快速繁殖

以黄金香柳(Melaleuca bracteata cv.)为材料,研究基本培养基中不同浓度6-BA和NAA对黄金香柳试管苗增殖的影响。试验结果表明,温度为(25±1)℃、光照时间12 h·d-1、光照强度2000 LX的培养条件下,在13种培养基处理中,适宜黄金香柳试管苗快速增殖的培养基是MS+6-BA 0.1 mg·L-1+NAA 0.05 mg·L-1+琼脂6.2 g·L-1+蔗糖30 g·L-1,该培养基配比的每瓶试管苗平均增殖倍数可达16.17倍。丛生芽在1/2MS+琼脂6.2 g·L-1+蔗糖30 g·L-1的培养基上易生根,可以获得健壮完整的小苗。     

发动机活塞拍击动力学分析及活塞表面磨损预测

针对活塞在缸内的拍击直接导致了活塞和气缸套摩擦磨损的问题,提出在多体动力学分析软件AVL-EXCITE中建立包括活塞、气缸套、活塞环组、活塞销以及连杆的模型,输入发动机相关结构参数和工况条件,进行了活塞拍击动力学仿真,利用模拟结果数据预测活塞表面磨损趋势和分析了活塞型线的变化.结果表明:活塞拍击运动参数随活塞和气缸套之间的间隙变大而增大,本来有中凸型线的活塞变成倾斜圆筒活塞.模拟结果跟实际观察结果相对比,二者有比较好的一致性.     

基于Lingo的铁氧化物还原反应热力学数据的最优拟合

根据铁氧化物还原反应热力学计算模型,以广泛引用的纯物质热力学数据为基础参数,计算出精确的标准反应吉布斯自由能和平衡还原势热力学散点数值.以数学建模软件Lingo11为平台,并结合Baur-GlaessnerDiagram的热力学限制性条件,进行了还原热力学数据的约束性最优化拟合,得出铁氧化物还原过程的16个G-T近似公式和8个298K下的反应焓变.实验研究表明,自由能近似公式能完全满足热力学限制条件,拟合后的CO和H2还原铁氧化物的三相共析温度为576℃,此时平衡还原势分别为5070%和7583%,CO和H2还原能力大小的转换温度点为819℃.     

基于历史特征的FAST TCP公平性改进算法

新建和已存在的旧FAST TCP连接估测的传播延时不同,它们无法公平地分配瓶颈链路的带宽。为了解决新旧FAST TCP连接的公平性,提出了一种改进估测FAST TCP传播延时的算法。在各连接无法通信的情况下,该改进算法利用新连接建立时,旧连接会表现RTT逐步增大和拥塞窗口逐步减小的特征。当旧连接发现这一特征出现时,就同步计算新的“传播延时”,从而使新旧连接具有相同的“排队延时”,公平地分配瓶颈链路带宽。NS-2仿真实例验证了该改进算法的有效性。     

一类网络蠕虫传播模型的建立与研究

基于传染病动力学和网络蠕虫传播机制,建立了一类网络蠕虫传播模型,研究其边界平衡态与正平衡态的全局渐进稳定性.利用MATLAB R2009a仿真,分析和揭示网络蠕虫病毒后期的动态传播规律,提高对网络蠕虫病毒的认识;用安装杀毒软件、打系统漏洞补丁、断开网络、阻断任意网络连接的防火墙等方法来降低蠕虫病毒感染率,从而有效遏制蠕虫的传播.通过仿真分析验证了所得结果的有效性,为网络安全研究提供指导.     

青蒿离体快繁技术研究

为建立青蒿（Artemisia annua L．）快速繁殖技术体系,以青蒿带腋芽茎段作为外植体,以MS、1／2MS为基本培养基,附加不同种类、不同浓度的植物激素进行青蒿离体快繁培养研究．结果表明：外植体在MS＋6-BA1．0mg／L＋NAA0．5mg／L培养基上诱导丛生芽效果最好;1／2MS＋NAA0．5mg／L诱导生根效果最佳,可达90％．     

Characterstics of seasonal variations of leaf n-alkanes and n-alkenes in modern higher plants in Qingjiang, Hubei Province, China

On the basis of GC and GC-MS analyses, the seasonal variation of leaf lipids is observed in five plant species in Qingjiang in Hubei Province. The CPI values （carbon preference index） of n-alkanes decrease gradually from May to November, though the carbon number distributions and the predominant carbon number in an individual species keep unchanged. The declined CPI values might be caused by the leaf fading, which is further supported by a comparison of the defoliated leaves with the fresh leaves. This observation infers the CPI values of n-alkanes in Quaternary sediments can be used as a tool to index the humification, and thus the climatic and the environmental conditions. The plants analyzed here show a remarkable difference in n-alkanes abundance, suggesting their differential contribution to the n-alkanes identified in sediments. The abundance and the compound species of the n-alkenes detected in the plant leaves change greatly with the seasons due to the influence of temperature, with the least compounds being identified in August.     

Inter-hemispheric comparison of climate change in the last millennium based on the ECHO-G simulation

The commonality and difference in the variations of temperature and precipitation between the Northern Hemisphere （NH） and Southern Hemispheres （SH） in the last millennium are investigated by analysis of the millennium simulation with the ECHO-G coupled climate model. The NH mean temperature variations are generally consistent with those of the SH counterpart on the interannual, decadal and centennial time scales. But, the transition times between the medieval warm period （MWP）, the little ice age （LIA）, and the present-day warm period （PWP） in the NH leads that in the SH; and the anomaly amplitude in the NH is significantly larger than the SH counterpart. For the precipitation variations, the NH mean precipitation varies in-phase with the SH mean precipitation on decadal and centennial scales （mainly in the mid-high latitudes） but out-of-phase on the interannual scale （mainly in the low latitudes）. During the MWP the warming has comparable amplitude in the NH and SH; however, during the PWP the NH warming is considerably stronger than the SH warming. Further, the present-day temperature rises in the NH high latitudes but decreases in the SH high latitudes, which is very different from the warming pattern during the MWP. Since during the MWP the greenhouse gases （GHG） concentration stayed at a low level, we infer that the present-day opposite temperature tendency in the high latitudes between the two hemispheres may be related to the increase of the GHG concentration.     

凤仙花的组织培养与离体快繁

以凤仙的带芽茎段、茎尖、幼叶为外植体,在附加不同种类及浓度的植物激素的MS培养基上进行快速繁殖,诱导芽的最适培养基为MS 0.5 mg·L-1 BA 0.01 mg·L-1 IAA 0.01 mg·L-1 GA3,芽的增殖培养基为MS 1.0 mg·L-1 BA 0.01 mg·L-1 IAA 0.01 mg·L-1 GA3;增殖系数为6～8倍.根诱导最佳培养基为MS 0.1～0.5 mg·L-1 BA 0.005 mg·L-1 IAA.     

高性能混凝土高温微观结构演化研究

通过热重分析、电镜扫描和汞压力测孔等方法,对高温过程中高性能混凝土材料的物理化学变化以及由此造成的微观结果变化进行了分析.相关试验和分析表明:造成升温过程中材料质量损失的主要原因是脱水和各种分解反应.在400℃之前,材料孔隙结构的变化主要来自材料内部水分的散失;400~500℃之间,由于材料发生分解反应,氢氧化钙的分解将提供大量的孔隙.这些结论将为进一步解释爆裂现象提供更为本质的试验支持,同时也为进一步建立高温情况下材料微观结构演化模型提供了试验基础.