Temperature variations on the Tibetan Plateau over the last two millennia

The paleoclimate data recovered from ice cores,tree rings and lake sediments indicate regional features of cfimatic change on the Tibeta n Plateau (TP) during the last 2000 years. The composite temperature reconstructions in-dicate that several main climatic episodes, such as the “LittleIce Age“ between 1400 and 1900, the “Medieval Warm Pe-riod“ in 1150-1400, a less warm period in 800-1100, and an earlier cold period between the 3rd and 5th centuries,occurred in the TP. In addition, temperature varied from region to region. The period from AD 800 to 1100, which waswarm in northeastern TP, was contemporaneous with cool-ing in the western and southern TP. The southern TP ex-perienced warming between 1150 and 1400. For western TP,the δ^18O records of the Guliya ice core indicate that the pe-Hod 1250-1500 witnessed a clear warming. Large-scaletrends in the temperature history from northeastern TP aremore similar to those in eastern China than are the trendsfrom the Guliya ice cap far to the west and southern TP. The most prominent similarities between the temperature varia-tions of the TP and eastern China are such cold phases as 1100-1150, 1500-1550, 1650-1700 and 1800-1850, andthe latter three cold events match with three widespreadg lacial advances which occurred on the TP during the Little Ice A2e.     

Time-division phase modulated single-photon interference in a Sagnac interferometer

We introduce a stable, long-distance singlephoton Sagnac interferometer, which has a balanced configuration to efficiently compensate phase drift caused by change of the fiber-optic path. By using time-division phase modulation, single-photon interference was realized at 1550nm in a 5-km-long as well as 27-km-long Sagnac fiber loops,with a fringe visibility higher than 90% and long-term stability. The stable performance of the single-photon interference indicated that the time-division phase-modulated Sagnac interferometer might readily lead to practical applications in single-photon routing and quantum cryptography.     

Expression of human clotting factor Ⅸ mediated by recom- binant lentiviral vector in cultured cells and hemophilia B mice

To explore the expression of human clotting factor Ⅸ (hFⅨ) cDNA in vitro and the feasibility of gene therapy for hemophilia B mice mediated by recombinant lentiviral vector, a recombinant hFⅨ lentiviral vector driven by ubiquitin-C promoter, FUXW, and by ABP liver specific promoter, FAXW, was constructed respectively. Recombinant lentivirus was harvested from 293T cells by calcium phosphate-mediated transient cotransfection of three plasmids (transgene vector, CMV腞8.2, VSV-G). hFⅨ expression was detected in supernatant of 293T, BHK and L-02 cells infected with FUXW virus, whereas higher expression of hFⅨ levels (630 ng/106 cells/48 h) was detected only in L-02 cells infected with FAXW virus. Serum hFⅨ antigen was detected in all hemophilia B mice treated with FAXW virus by tail vein injection, an efficiency level of hFⅨ was observed (45 ng/mL, approximately 1% of normal human levels), the expression lasted for more than 60 d. The results indicated that HIV-based lentiviral vectors offer a promising approach to the gene therapy of hemophilia B.     

基于数学形态学的图像处理方法

从图像的描述方法出发，在二值形态变换的基础上，通过引入图像的阀集合和本影，导出了多值形态学基本形态变换建立的方法．并揭示了二值形态学与多值形态学在结构算法上的相互联系．在图像处理的形态学方法上，提出了基于形态变换的图像边缘提取、多种形态梯度、形态骨架表示方法，以及具有去噪和形态平滑功能的开、闭形态变换在图像分析中的应用．     

生态遗传算法在模糊系统辨识中的应用

给出一类模糊系统的模糊神经网络模型 .提出一种实用的生态算子 ,构建的生态遗传新算法有效解决了基本遗传算法的“早熟”问题 .采用新算法实现模糊神经网络模型的辨识 ,提高了辨识精度 .实例仿真结果验证了新算法在模糊系统辨识中的有效性     

带有油膜轴承的裂纹轴转子系统故障特征分析

通过大量仿真计算，对于带有油膜轴承的裂纹轴转子系统的故障特征进行了较为全面的论证．这些特征是通过三维频谱、转速-振幅特性和周期分岔特性来表达的．除了分析裂纹轴转子系统的基本故障特征外，还重点分析了作为故障特征的一个重要方面的非线性行为．为诊断转子系统裂纹故障提供了理论依据．     

描述石灰石分解的分数维收缩核模型及模拟

基于分形理论中颗粒表面积与颗粒当量半径以及表面积与体积之间的关系式，考虑固体颗粒表面形貌的不规则性，建立了化学反应起控制作用的固体颗粒分解的分数维收缩核模型，并将其用来模拟石灰石颗粒的缎烧分解过程，取得了较为满意的模拟结果．同时，将其模拟结果与收缩核模型的模拟结果进行了比较．     

弯掠翼叶轮内流二次涡系的计算机数值仿真

采用非交错网格下的曲率时间尺度K-ε湍流模型和纳维斯托克斯方程线求解，对宇宙航空用弯掠叶轮和基准叶轮叶道内部三维粘性速度场进行了数值仿真，分析了叶轮流道内部通道涡等复杂二次涡系结构的流谱特性及其对气动性能特别是旋转失速的作用机理．研究表明：弯掠叶轮流道内通道涡、刮擦涡有效卷吸翼顶边界层低能流体，抑制了翼顶部的流动分离和旋转失速，有利于失速裕度的扩大．数值仿真结果为弯掠叶轮的计算机辅助设计提供了改进指导信息．     

Butterflies and ants: The communicative domain

Associations with ants, termed myrmecophily, are widespread in the butterfly family Lycaenidae and range from mere co-existence to more or less specific mutualistic or even parasitic interactions. Secretions of specialized epidermal glands are crucial for mediating the interactions. Transfer of nutrients (carbohydrates, amino acids) from butterfly larvae to ants plays a major role, but manipulative communication with the help of odour signals is also involved. By means of myrmecophily, lycaenid butterflies largely escape ant predation, and certain species gain protection through attendant ants or achieve developmental benefits from ant-attendance. Benefits to the ants range from minimal to substantial food rewards. While most lycaenid species maintain facultative relationships with a variety of ant genera, highly specific and obligatory associations have convergently evolved in a number of butterfly lineages. As a corollary, communication systems are largely unspecific in the former, but may be highly specialized in the latter. The sophisticated communication between obligate myrmecophiles and their host ants is tightly connected with the evolutionary rise of specialized life-cycles and thus is a source of augmenting diversity within the butterflies.