主动网络中一致执行环境的研究

执行环境的结构组成直接影响主动节点对主动信包的处理性能，本文试图给出一种新型的执行环境实现方案．在分析了当前执行环境存在弊端的基础上，运用组件思想提出了一种一致性执行环境的框架模型．其核心思想是：使得接口与实现相分离，实现语言无关性以及利用组件构建执行环境和主动应用．该模型能够较好的克服当前执行环境EE存在的弊端，提高主动网络的整体性能．     

压电类智能结构在船体振动控制方面的应用研究

振动是存在于舰船结构中一个普遍的现象,它所带来的危害一直为人们所关注.根据振动主动控制原理,建立了以PZT为执行器的振动主动控制模型,研究通过控制甲板的边界条件,从而达到减振效果的方法.利用ANSYS软件对建立的实验模型进行了数值仿真研究,搭建物理实验平台,开发了单输入多输出的振动自适应主动控制系统,进行物理实验研究.最后,将实验值与仿真值进行比较分析,验证了该方法的有效性,为船体振动的主动控制提供了一条新的途径.     

风力发电机主动磁悬浮轴灰色PID控制研究

径向主动轴磁悬浮轴系统是一个典型的非线性迟滞系统,应用现有的建模理论来建立精确的数学模型很难。应用传统的PID控制器调节可以达到的最佳控制效果也并不理想。在此,针对风力发电机主动磁悬浮轴系统设计出了灰色PID控制器,它结合了灰色控制提前预判、超调小、鲁棒性好和PID控制快速、精度高的优点;前级灰色预判能够使PID控制器具有更好地跟踪给定值的能力和更好地抗外界干扰的能力。通过MatIab对磁悬浮系统进行了仿真,仿真结果表明灰色PID控制器明显地减小了系统的超调,增强了系统的抗干扰能力和跟踪能力,具有很强的鲁棒性。     

主动磁悬浮轴承支承旋转机械的减振性能研究

针对旋转机械的振动噪声问题,在对轴承工作特性及系统振动传递特性进行理论分析的基础上,提出了采用新型主动磁悬浮轴承取代传统机械轴承以实现整机减振降噪的设想.以某工程试验样机为研究对象,利用有限元软件考察了轴承的刚度变化对该样机轴承座机脚振动不平衡响应的影响,进而开展了专门的振动对比实验来对主动磁悬浮轴承的减振性能进行实际评估.结果表明:减小轴承刚度的思路对于降低旋转机械的机脚振动确实可行;相比于机械轴承,采用主动磁悬浮轴承支承对于减小整机振动水平具有显著实际效果.相关结论可为拓展主动磁悬浮轴承技术的应用领域和场合提供重要思路及数据支持,同时也为其今后的工程化实用奠定研究基础.     

土钉墙分步开挖中挡土机理分析

土钉墙和由它派生出的复合支护方式在实际工程中广泛应用,但在理论上对它的挡土机理研究还不够。本文对均质土中的土钉墙,采用数值分析方法,探讨开挖过程中土钉、面层、土体三者的受力变化及土钉墙的稳定机理,得到了面层受到的总土压力是主动土压力的0．05倍等一些结论。     

Thiogenistein—Antioxidant Chemistry,Antitumor Activity,and Structure Elucidation of New Oxidation Products

Isoflavonoids such as genistein (GE) are well known antioxidants. The predictive biological activity of structurally new compounds such as thiogenistein (TGE)–a new analogue of GE–becomes an interesting way to design new drug candidates with promising properties. Two oxidation strategies were used to characterize TGE oxidation products: the first in solution and the second on the 2D surface of the Au electrode as a self-assembling TGE monolayer. The structure elucidation of products generated by different oxidation strategies was performed. The electrospray ionization mass spectrometry (ESI-MS) was used for identifying the product of electrochemical and hydrogen peroxide oxidation in the solution. Fourier transform infrared spectroscopy (FT-IR) with the ATR mode was used to identify a product after hydrogen peroxide treatment of TGE on the 2D surface. The density functional theory was used to support the experimental results for the estimation of antioxidant activity of TGE as well as for the molecular modeling of oxidation products. The biological studies were performed simultaneously to assess the suitability of TGE for antioxidant and antitumor properties. It was found that TGE was characterized by a high cytotoxic activity toward human breast cancer cells. The research was also carried out on mice macrophages, disclosing that TGE neutralized the production of the LPS-induced reactive oxygen species (ROS) and exhibits ABTS (2,2′-azino-bis-3-(ethylbenzothiazoline-6-sulphonic acid) radical scavenging ability. In the presented study, we identified the main oxidation products of TGE generated under different environmental conditions. The electroactive centers of TGE were identified and its oxidation mechanisms were proposed. TGE redox properties can be related to its various pharmacological activities. Our new thiolated analogue of genistein neutralizes the LPS-induced ROS production better than GE. Additionally, TGE shows a high cytotoxic activity against human breast cancer cells. The viability of MCF-7 (estrogen-positive cells) drops two times after a 72-h incubation with 12.5 μM TGE (viability 53.86%) compared to genistein (viability 94.46%).     

DiffServ模型中主动队列管理研究

区分服务模型是现代大规模网络保证IP QoS的主要模型,该模型是当前互联网通讯性能方面研究的热点问题。在改进RIO-C算法的基础上,提出了一种适合于区分服务模型的主动队列管理算法-PFRIO（RIO based on Priority and Fair）。该算法提高了带宽分配的公平性,增强了网络对突发数据流的处理能力,有效改善了区分服务模型的总体性能。     

The Skeptical Explorer: A Multiple-Hypothesis Approach to Visual Modeling and Exploration

The primary intent of this work is to present a method for sequentially associating three-dimensional surface measurements acquired by an autonomous exploration agent with models that describe those surfaces. Traditional multiple-viewpoint registration approaches are concerned only with finding the transformation that maps data points to a chosen global frame. Given a parts-based object representation, and assuming that the view correspondence can be found, the problem of associating the registered data with the correct part models still needs to be solved. While traditional approaches are content to group segmented data sets that geometrically overlap one another with the same part, there are cases where this causes ambiguous situations. This paper addresses the model-data association problem as it applies to three-dimensional dynamic object modeling. By tracking the state of part models across subsequent views, we wish to identify possible events that explain model-data association ambiguities and represent them in a Bayesian framework. The model-data association problem is therefore relaxed to allow multiple interpretations of the object's structure, each being assigned a probability. Rather than making a decision at every iteration about an ambiguous mapping, we look to the future for the information needed to disambiguate it. Experimental results are presented to illustrate the effectiveness of the approach.     

MAX274/275有源滤波器的应用研究

介绍MAX274/275有源滤波器的特性及电路参数的设计和测控应用实例。     

Realization of reconfigurable filtering horn antennas using active frequency selective surfaces for GSM and LTE signal filtering

Herein, it is aimed to design an Active Frequency Selective Surface (AFSS) based high performance reconfigurable filtering antenna (Filtenna). The proposed AFSS unit element is consist of a single PIN diode with a simple microstrip patch design which performance characteristics are varies with the state of the diodes. The proposed unit elements have been used to form an array that is placed at the aperture of a double ridge horn antenna. With the variation in state of diodes, the antenna acts as a Filtenna module to filtering the incoming electromagnetic waves in frequency band of 1.8 to 2.8 GHz. From the experimental results, it is shown that the proposed Filtenna achieves a signal attenuation of 7.3 dBi at 2.1 GHz.