CARD资源发现架构在无线传感网络中的性能研究

(西北工业大学计算机学院,陕西西安,710072)【摘要】CARD架构适用于大规模、高查询率、每次查询的数据传输量较小的Ad-hoc网络,它的核心目标是降低网络资源发现能耗,延长网络生命周期。文章首先介绍了CARD架构的结构;然后,建立了该架构的数学模型,该模型以无线传感器网络为目标场景,并推导出CARD架构的能耗和查询成功率与各个参数之间的函数关系;最后,根据该模型对CARD架构的能耗和查询成功率进行了理论分析,为CARD架构的参数选择提供了可靠的依据,并为对架构的进一步优化打下了坚实基础。     

Sarcomere shortening and contraction nodes in stretched-restrained ovine myofibres during post mortem storage

Myofibres of muscles removed from the carcass shorten during rigor mortis. Whether myofibres of stretched and restrained muscle tissues shorten during post mortem storage was examined. Muscle strips removed from the semimembranosus muscle of sheep before rigor onset were stretched and restrained. The muscle strips were fixed separately in formalin solution from 1.5 hr to 12 days post mortem, and embedded in paraffin. Sections were stained with Mallory-azan. Some myofibres in the pre-rigor-excised and stretched-restrained muscle strips had contraction nodes at 1 day post mortem. The contraction node did not increase in frequency hereafter. Two to several successive sarcomeres shortened regularly to form the nodes parallel to the Z-line. In addition, several successive sarcomeres shortened partly and successively from one side to the other side to form the nodes oblique to the Z-line. Oblique and irregular contraction nodes appear to cause kinks or bends of myofibres. Sarcomere lengths were not always uniform in individual myofibres. Formation of contraction nodes and shortening of partial sarcomeres in the stretched-restrained myofibres indicate that the myofibres shorten individually during rigor mortis and vary in shortening states as in muscles left on the carcass.     

A generative model of article citation networks of a subject from a large-scale citation database

Scientometrics - In this paper, we analyze the structure of the article citation network of a particular subject obtained from the Web of Science (WoS) database. In specific, we modify a model...     

Pose-Invariant Facial Expression Recognition Using Variable-Intensity Templates

In this paper, we propose a method for pose-invariant facial expression recognition from monocular video sequences. The advantage of our method is that, unlike existing methods, our method uses a simple model, called the variable-intensity template, for describing different facial expressions. This makes it possible to prepare a model for each person with very little time and effort. Variable-intensity templates describe how the intensities of multiple points, defined in the vicinity of facial parts, vary with different facial expressions. By using this model in the framework of a particle filter, our method is capable of estimating facial poses and expressions simultaneously. Experiments demonstrate the effectiveness of our method. A recognition rate of over 90% is achieved for all facial orientations, horizontal, vertical, and in-plane, in the range of ±40 degrees, ±20 degrees, and ±40 degrees from the frontal view, respectively. Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users.     

Biochip with integrated pumps for plug-based sequential exchange of solutions

A novel method for exchanging solutions used in biochemical analyses and a device to carry out the exchange are proposed. An array of plugs formed using six injectors was transported in a microflow channel using a main pump located at one end of the main flow channel. The injectors and main pump were operated on the basis of the change in volume caused by the electrolysis of water. Bubbles were produced from working electrodes; these bubbles caused a diaphragm placed below the injectors to inflate and occlude the inlet of the solution reservoir. Increase in the number of bubbles caused the reservoir to inject the solution into the main flow channel in the form of a plug. Each plug was individually transported downstream to the sensing area by the main pump, which was operated in a similar manner to the injector. The device was used for the detection of a tumor marker, α-fetoprotein (AFP). Plugs of necessary solutions were individually transported to the sensing area with immobilized primary antibodies to allow antigen–antibody binding, cleaning, and detection. The fluorescence intensity from the antibodies showed clear dependence on the concentration of AFP. The immobilization of antibodies could also be carried out on-chip.     

新一代聚丙烯催化剂内给电子体的研究

综述了丙烯聚合物Z-N催化剂内给电子体的研究进展,讨论了内给电子体在丙烯聚合中的作用及机理.介绍了最新的内给电子体,通过对内给电子体在近年来发展的分析,对丙烯聚合物Z-N催化剂的发展进行了展望.     

Crystalline complex between poly(γ-methyl l-glutamate) and dimethyl phthalate

The crystalline complex between poly(γ-methyl l-glutamate) (PMLG) and dimethyl phthalate (DMP) has been formed in films cast from a solution in dichloroethane. It has the stoichiometry of 1 mol of DMP to three or four residues of PMLG and shows two definite characteristics in X-ray diffraction patterns; one is the large hexagonal unit cell with the edge of around 28 Å and another the ‘extra’ 5.07 Å meridional reflection which can not be interpreted by a PMLG α-helical conformation. The structural examination for the films with various DMP contents is carried out by X-ray, viscoelastic, and d.s.c. measurements and the following structure is proposed for the crystalline complex. Four PMLG are associated to form a group which is hexagonally packed and DMP molecules, located in the gaps between groups, form a specific favourable helical structure along PMLG chains in which the van der Waals stacking of benzene rings of DMP is significant.     

A theory of pseudo cross-link

Summary A theory of pseudo cross-link model suggests the existence of multiple links of various size composed of 116 segmental units. They possesses the heat and entropy of various magnitude giving various transition temperature, T_A for the cross-link composed of 4 segments and T_B for that of 16 segments. The glass-transition point T_g and the melting point T_m are defined by the different size of lateral multiple links. Relationships, T_m = 2 T_A and T_g = (2/3)T_m = (4/3)T_A, are derived. A wedge-type relaxation spectrum is obtained as a distribution of size of cross-links. For temperature dependence the WLF-equation is obtained.     

Web服务在电力系统DB2数据库存取中的应用

WebService是构建分布式系统的最好工具。研究了WebService的相关概念、结构以及主要支撑技术 ,并且通过微软VS Net提供的WebService实现了对电力系统DB2数据库的存取方案。实践验证 ,这种方法完成存取过程是完全可行并且有效的 ,为电力系统数据的分布处理提供有益的参考 ,使电力系统中非常庞大的数据量得到快速高效的处理 ,为电力系统安全、稳定、经济运行提供保障。