Improving the Brightness and Daylight Contrast of Organic Light‐Emitting Diodes

For most applications of displays based on organic light‐emitting diodes (LEDs), it is desirable to have good daylight contrast in combination with a high intensity of emitted light. The conventional approaches to enhance the daylight contrast, using a black cathode or circular polarizers, result in a significant loss of light emitted by the LED. A rather novel approach to enhance daylight contrast while keeping loss of emitted light to a minimum is the introduction of a chiral‐nematic film in the device. This approach leads to an increase in light efficiency by a factor of 1.8 (with respect to circular polarizers) with some loss in daylight contrast values within the reflection band of the chiral‐nematic film. Outside the reflection band, however, the contrast approaches infinity.     

Chemical Ecology of the host searching behavior in an Egg Parasitoid: are Common Chemical Cues exploited to locate hosts in Taxonomically Distant Plant Species?

Parasitoids are known to exploit volatile cues emitted by plants after herbivore attack to locate their hosts. Feeding and oviposition of a polyphagous herbivore can induce the emission of odor blends that differ among distant plant species, and parasitoids have evolved an incredible ability to discriminate them and locate their hosts relying on olfactive cues. We evaluated the host searching behavior of the egg parasitoid Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) in response to odors emitted by two taxonomically distant host plants, citrus and Johnson grass, after infestation by the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae), vector of Citrus Variegated Chlorosis. Olfactory response of female parasitoids toward plants with no herbivore damage and plants with feeding damage, oviposition damage, and parasitized eggs was tested in a Y-tube olfactometer. In addition, volatiles released by the two host plant species constitutively and under herbivore attack were characterized. Females of C. annulicornis were able to detect and significantly preferred plants with host eggs, irrespectively of plant species. However, wasps were unable to discriminate between plants with healthy eggs and those with eggs previously parasitized by conspecifics. Analysis of plant volatiles induced after sharpshooter attack showed only two common volatiles between the two plant species, indole and β-caryophyllene. Our results suggest that this parasitoid wasp uses common chemical cues released by many different plants after herbivory at long range and, once on the plant, other more specific chemical cues could trigger the final decision to oviposit.

     

裂解炉注汽法兰泄漏原因分析及对策

针对大庆石化公司480kt/a改造新增80U裂解炉注汽法兰经常泄漏的问题进行分析,找出泄漏着火的原因,并提出在600～700℃高温下法兰密封的办法,在实际使用中证实该方法经济、适用、有效。     

解放前我国学者对新疆石油地质的调查和研究

20世纪初，随着近代地质学在中国的形成和发展，一些学者开始了对新疆石油地质的调查和研究，30年代末以前，翁文灏，章鸿钊等学者利用文献和间接获得的资料，对新疆石油资源进行了宏观考察和若干重要油苗的地质研究；40年代开始，黄汲清等地质家在新疆进行实地考察，对独山子油田进行了详细研究，并在南北疆部分地区进行了路线性石油地质调查。     

新型机械密封辅助系统的研究和设计

采用新型机械密封辅助系统,将冷却液打到密封环的内径并循环使用,同时对密封的泄漏进行监测,从而改变了密封环的工作环境,延长了密封件的使用寿命,降低了装置的运行成本,提高了密封系统的安全性。     

The effect of a scattering layer on the edge output of a luminescent solar concentrator

The effect of adding white scattering layers to the bottom side of luminescent solar concentrator waveguides is evaluated. It is determined that adding a rear scatterer separated from the waveguide by an air gap results in a large increase of energy output from the waveguides, and this enhancement persists over long (>30 cm) distances, although the magnitude of the enhancement decreases with distance. An attached scatterer resulted in the greatest improvement of light output for short (∼6 cm) distances, but actually reduced edge emissions over longer distances. We provide estimates for the relative contribution of dye-emitted light and scattered light to the total waveguide emission, as well as distinguishing between the contributions of direct and indirect scattering of light to the total output as a function of dye content of the waveguides.