Characterization of microwave and terahertz dielectric properties of single crystal La2Ti2O7 along one single direction

New generation wireless communication systems require characterisations of dielectric permittivity and loss tangent at microwave and terahertz bands. La₂Ti₂O₇ is a candidate material for microwave application. However, all the reported microwave dielectric data are average value from different directions of a single crystal, which could not reflect its anisotropic nature due to the layered crystal structure. Its dielectric properties at the microwave and terahertz bands in a single crystallographic direction have rarely been reported. In this work, a single crystal ferroelectric La₂Ti₂O₇ was prepared by floating zone method and its dielectric properties were characterized from 1 kHz to 1 THz along one single direction. The decrease in dielectric permittivity with increasing frequency is related to dielectric relaxation from radio frequency to microwave then to terahertz band. The capability of characterizing anisotropic dielectric properties of a single crystal in this work opens the feasibility for its microwave and terahertz applications.     

Accurate segmentation of land regions in historical cadastral maps

Historical cadastral maps are valuable sources for historians to study social and economic background of changes in land uses or ownerships. In order to conduct large-scale historical research, it is essential to digitize the cadastral maps. As being established in antiquity, however, they suffer from significant noise artifacts attributed to hand-drawn cartography. In this paper, we propose a novel method of extracting land regions automatically in historical cadastral maps. First, we remove grid reference lines based on the density of the black pixel with the help of the jittering. Then, we remove land owner labels by considering morphological and geometrical characteristics of thinned image. We subsequently reconstruct land boundaries. Finally, the land regions of a user’s interest are modeled by their polygonal approximations. Our segmentation results were compared with manually segmented results and showed that the proposed method extracted the land regions accurately for assisting cadastral mapping in historical research.     

The false promises of coal exploitation: How mining affects herdsmen well-being in the grassland ecosystems of Inner Mongolia

The grasslands of Inner Mongolia are not only the source of the necessary resources for the survival and development of herdsmen, but also represent a significant green ecological barrier in North China. Coal-mining production is important in maintaining GDP growth in Inner Mongolia. However, over-exploitation has created serious problems, such as pollution of the environment and significant decreases in grassland ecosystem services, in addition to impacting the well-being of herdsmen and other humans. Based on questionnaires survey performed among 864 herdsmen addressing the relationship between coal exploitation in grasslands and human well-being in Xilinguole League in Inner Mongolia, we found that (1) coal resource exploitation in these grasslands does not benefit the herdsmen by increasing their income; (2) the rapid development of this resource has not obviously materially improved the life of the herdsmen; and (3) these activities have increased the risks that herdsman will have to endure in the future. Overall, coal resource exploitation in grasslands has more negative than positive effects on the well-being of herdsmen. We propose the conservation of coal resources and improvement of ecological compensation should be carried out without blindly pursuing economic growth, instead of focusing on economic development and structural adjustments.     

水资源优化配置的可视化决策支持系统分析平台

针对水资源优化配置的复杂性以及多目标性,从水资源、社会、经济和生态环境协调发展出发,基于已经开发并在实践推广应用的水资源多过程模拟和优化配置的复杂整体决策支持分析系统,建立水资源优化配置的可视化决策支持系统分析平台对流域水资源进行优化配置。通过淮河流域水资源与经济社会协调发展的水资源优化配置案例分析与演示,详细阐述该系统操作和分析过程。该系统有助于提高水资源优化管理与合理配置的效率,为水资源管理决策提供一种有效便利的分析平台和工具。     

Efficacy of atmospheric and pressurized carbon dioxide or air against Sitophilus zeamais Motchulsky (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in milled rice

Carbon dioxide gas was evaluated in the laboratory for control of Sitophilus zeamais Motchulsky and Tribolium castaneum (Herbst) in milled rice using a specially designed pressure chamber. Tests were conducted at atmospheric pressure with 60, 80 and 100% carbon dioxide and with 100% carbon dioxide pressurized to 4, 6 and 8 bars. LT₉₉ were ≤79, ≤78, and ≤148 h for all life stages of S. zeamais exposed to 60, 80 and 100% carbon dioxide, whereas, they were ≤59, ≤51 and ≤66 h for T. castaneum. Pure carbon dioxide controlled the adult stage, but there tended to be no significant differences of carbon dioxide concentrations on mortality of immature stages. When pure carbon dioxide was pressurized, mortalities of the two insect species were increased significantly. LT₉₉ values decreased with levels of applied pressure: ≤29, ≤9.0 and ≤4.8 h for S. zeamais and ≤15, ≤5.8 and ≤2.3 h for T. castaneum at pressures of 4, 6 and 8 bars, respectively. Sitophilus zeamais was more tolerant than T. castaneum to carbon dioxide gas. The adult was the most susceptible stage, however, immature stages responded differently to carbon dioxide gas applied at varying concentrations and pressure levels. Adult mortalities were lower when air was used in the pressure chamber instead of carbon dioxide. Pressurized carbon dioxide at relatively low pressure (4–8 bars) was found effective in controlling all live stages of S. zeamais and T. castaneum in milled rice with shorter exposure times than at atmospheric pressure using an inexpensive set of equipment as compared to high pressure carbon dioxide fumigation (20–30 bars).     

Queueing model based resource optimization for multimedia cloud

Multimedia cloud is a specific cloud computing paradigm, focusing on how cloud can effectively support multimedia services. For multimedia service providers (MSP), there are two fundamental concerns: the quality of service (QoS) and the resource cost. In this paper, we investigate these two fundamental concerns with queueing theory and optimization methods. We introduce a queueing model to characterize the service process in multimedia cloud. Based on the proposed queueing model, we study resource allocation problems in three different scenarios: single-service scenario, multi-service scenario, and priority-service scenario. In each scenario, we formulate and solve the response time minimization problem and the resource cost minimization problem, respectively. We conduct extensive simulations with practical parameters of Windows Azure. Simulation results demonstrate that the proposed resource allocation schemes can optimally allocate cloud resources for each service to achieve the minimal response time under a certain budget or guarantee the QoS provisioning at the minimal resource cost.     

Features of nanostructuring in LaMnO3 + δ (polydisperse and monodisperse structures)

The formation of polydisperse and monodisperse structures in LaMnO_3 + δ has been investigated by X-ray diffraction (XRD) analysis and transmitting electron microscopy (TEM). The sizes of LaMnO_3 + δ particles have been evaluated for different types and conditions of synthesis (solid-phase synthesis and sol–gel method) and subsequent heat treatment in the controlled atmosphere. The effect of the size distribution on the correctness in the determination of particle sizes has been analyzed.     

Caged mice mating behavior detection in surveillance videos

The purpose of this study is to develop a computer vision-based method to automatically detect the mating behavior of caged mice in surveillance videos. Previously we took advantage of our developed algorithm and analyzed the objects of mating mice in the consecutive frames, we unprecedentedly showed that, to the best of our knowledge, the mice mating behavior can be automatically detected based on video processing (Lo et al., 2009 [13]). In this paper, we proposed an improved method which monitors the distance between two mating objects and more effectively detects the mating behavior. In addition, a more detailed portrayal of the mating behavior can be further elaborated as a function of the distance patterns in the tails of two caged mice. Experimental results show that the current system can effectively detect the mice mating behavior with the highest precision rate of 96.1%, far better than that of our previously proposed method.     

Elevated temperature compressive slow strain rate properties of several directionally solidified NiAl–(Nb,Mo) alloys

Three NiAl-based alloys containing 3Nb–10Mo, 5Nb–10Mo or 13.6Nb–18Mo (at%) were directionally solidified to develop three dimensional Mo-based dendrite networks. Examination of the alloys indicated that the desired chemistry was achieved for the 3Nb–10Mo and 5Nb–10Mo versions but the composition of the highly alloyed ingot was NiAl–14.6Nb–13.2Mo. The as-grown structure for all three materials consisted of three major phases: essentially unalloyed B2 crystal structure NiAl, Laves NiAlNb phase alloyed with ∼8.5 Mo, and a bcc metallic Mo solid solution containing 27Nb–7Ni–7Al. Compressive properties were measured between 1200 to 1400 K in air under constant velocity and constant load creep conditions with strain rates ranging from ∼10⁻⁴ to ∼10⁻⁸ s⁻¹. The flow strengths of the two alloys with 10Mo were nearly identical and much weaker than those for NiAl–14.6Nb–13.2Mo under all conditions. Comparison the properties of this latter alloy with other directionally solidified NiAl-based eutectics revealed that it was the strongest material under lower temperature/fast deformation conditions, but this advantage was lost at higher temperatures and/or slower strain rates.