CALL-IN系统在新闻直播节目中的应用

现今,大众广泛接触的媒体主要有网络媒体、电视媒体、报纸杂志媒体等,在这三类媒体中,网络媒体由于其广泛的受众和开放自由互动等优越条件日益受到新一代年轻人群的青睐,甚至有人预言在不久的将来网络会取代电视,报纸杂志等传统媒体.那么如何在电视这种传统的单向信息传播媒体中增加互动性成为广大电视制作人员关注的重点.基于E P G电子节目指南的数字电视以及短信互动与电话互动在娱乐节目中的应用都旨在提高电视节目的互动性,增加收视率.但在传统的新闻节目中是否可以增加互动环节以更好地吸引观众呢?回答是肯定的.     

Radial stereo imaging system for three-dimensional reconstruction

In this paper, we propose a radial stereo imaging system for three-dimensional reconstruction of an object. This system uses a novel optical device which consists of a camera and two reflected mirrors. It can reconstruct three-dimensional model of an object by capturing one image. Depending on the reflection of the mirrors, each world point in the scene has a pair of points which sit in the inner and outer of the captured image, respectively. We firstly analyze the imaging constraint of the proposed system, and then derive the geometrical relationship between world point and image point pair to calculate the three-dimensional coordinate values of an arbitrary point on the object, which means that the three-dimensional model of the object can be recovered. Experiments are carried out to prove our design, and the results show that our radial stereo imaging system is convenient and effective for the three-dimensional reconstruction of an object. This system can be used in variety of applications, such as virtual reality and commodity show.     

Structures,microstructures, physical and chemical properties of different rice grains

Herein, we demonstrated a well-rounded exploration of the universal structures, microstructures and physical properties of different rice grains. We show that these rice grains are nanocrystalline in nature, have the standard pattern of type A rice crystalline, and can be attributed to the hexagonal crystal structure with space group of P6. These rice grains have uneven surfaces, clusters of the granules, or schistose structure. Carbon, nitrogen and oxygen elements are presented in the rice grains. No significant difference is observed in FTIR spectra in these rice grains, indicating the fundamental chemical structures of these rice grains are analogical. Their microstructural and physical properties were investigated in detail. Moreover, chemical properties (e.g. thermal stability) of the rice grains were explored. This research provides an in-depth understanding on the physical and structural properties on the atomic and molecular level, as well as guidance for food and industry applications.     

无线技术的新领域--WUSB

无线USB(WUSB)技术是一个全新的无线传输标准.实现USB(通用串行总线)无线化以后,既可以保持有线USB的高速传输等优点,又可以去掉电缆的羁绊,给各种设备带来更大的便捷和移动性.文中首先介绍了WUSB技术的由来--UWB技术规范的标准化难以确定,然后对WUSB技术的规范标准进行了阐述,最后概述了WUSB技术的发展现状及目前和今后的技术研发重点,并对WUSB的发展前景进行了展望.     

Five New Polyoxypregnane Glycosides from the Vines of Aspidopterys obcordata and Their Antinephrolithiasis Activity

From the dried vines of Aspidopterys obcordata Hemsl, five new polyoxypregnane glycosides, named obcordatas J–N (1–5), were obtained. Their structures were fully elucidated and characterized by HRESIMS and extensive spectroscopic data. In addition, all of the new compounds were screened for their antinephrolithiasis activity in vitro. The results showed that compounds 1–3 have prominent protective effects on calcium oxalate crystal-induced human kidney 2 (HK-2) cells, with EC₅₀ values ranging from 6.72 to 14.00 μM, which is consistent with the application value of A. obcordata in folk medicine for kidney stones.     

Phenolic resin as a carbon source for the synthesis of monometallic Mo and bimetallic CoMo carbides via carbothermal reduction route

It was the first time that phenolic resin (PR) was used as a carbon source for the synthesis of nanostructured monometallic Mo and bimetallic CoMo carbides via carbothermal reduction route. The results showed that phase-pure β-Mo₂C can be formed under an Ar atmosphere at 900°C or a H₂ atmosphere above 700°C. However, almost pure CoMo carbides (Co₃Mo₃C and Co₆Mo₆C) can be obtained only under a H₂ atmosphere at a low temperature of 630°C for 24 and 48 h, respectively. The role of PR in the preparation process has been investigated and a detailed formation mechanism was proposed based on the experimental results.     

磷杂菲改性腰果酚多元醇的合成及阻燃聚氨酯硬泡性能

采用生物质原料腰果酚和9,10-二氢-9-氧杂-10-膦杂菲-10-氧化物(DOPO)为原料, 合成了一种磷杂菲改性腰果酚多元醇(P-Cardanol-Polyol), 并利用核磁共振氢谱和磷谱对其结构进行了表征. 利用P-Cardanol-Polyol对聚氨酯硬泡(RPUF)进行阻燃改性, 得到一系列阻燃聚氨酯硬泡. 考察了P-Cardanol-Polyol的用量对阻燃聚氨酯硬泡的形貌、 密度、 热导率、 压缩性能、 热稳定性以及阻燃性能的影响. 研究结果表明, P-Cardanol-Polyol对聚氨酯硬泡的密度影响可以忽略不计; 随着P-Cardanol-Polyol的加入, 阻燃聚氨酯硬泡的平均孔径逐渐减小, 热导率也逐渐降低. 未改性聚氨酯硬泡的最大热释放速率和总放热量分别为390 kW/m²和31.9 MJ/m², 阻燃聚氨酯硬泡则降低至340 kW/m²和24.6 MJ/m². 此外, 阻燃聚氨酯硬泡的压缩强度比未改性聚氨酯硬泡提升了约13%. 炭层分析结果表明, P-Cardanol-Polyol能够促进聚氨酯硬泡形成连续致密且具有良好抗热氧化性能的炭层, 有利于减少燃烧过程中可燃性气体的逸出, 从而提升阻燃性能.     

基础化学实验教学的新理念——再议实验教学之本质

最近20年以来,国内高校的本科基础化学实验教学从理念、内容、标准,到组织机构和评价方法,都经历了一系列变化和改革。立足于新的历史机遇和时代,有必要深刻理解和厘清本科阶段基础化学实验教学的本质和角色,既不轻视和简慢其地位、也不夸大和拔高其效用;须还基础实验教学以其本来面目,着重深挖其在传播"第三类知识"(Knowhow)以及培养"元认知"能力当中的不可替代作用,才能在化学实验教学改革大潮中不懈怠、不迷惘。     

Sulfur Precursor Reactivity Affecting the Crystal Phase and Morphology of Cu2−xS Nanoparticles

For plasmonic copper-deficient Cu_2−xS nanoparticles (NPs), accurate control of the crystal phase and morphology is highly desirable as both of which are known to determine the localized surface plasmon resonance (LSPR) wavelength and amplitude. Here, how the sulfur precursor reactivity in the synthesis of Cu_2−xS NPs affects the resulting crystal phase and morphology is examined. Djurleite Cu_1.94S, roxbyite Cu_1.8S, digenite Cu_1.8S as well as covellite CuS nanodisks were synthesized by using 1-dodecanethiol, N,N-dibutylthiourea, and crystal sulfur 1-octadecene/oleylamine solutions and their crystal phase dependent LSPR properties were exhaustively discussed. In addition, crystal phase interconversion between covellite CuS and djurleite/roxbyite Cu_2−xS was realized in the presence of the above sulfur precursors. On the other hand, djurleite Cu_1.94S nanorods rather than nanodisks were prepared by replacing 1-dodecanethiol with more reactive tert-dodecanethiol. The structural and morphological Cu_2−xS NPs here holds great promise in the application of photothermal therapy, photocatalysis, surface-enhanced Raman scattering (SERS), and many others.