铯原子Λ型塞曼子能级结构中的电磁诱导透明

采用左旋和右旋圆偏振光分别作为探测光和耦合光,作用于铯原子62S1/2F=3 62P3/2F′=2简并二能级 系统,借助探测光的吸收光谱观察到了由简并二能级中Λ型塞曼子能级结构导致的电磁诱导透明(EIT)现象。同 时研究了不同耦合光的强度和失谐对电磁诱导透明的影响。由于在多普勒展宽背景下圆偏振光对塞曼子能级间 的光抽运,从而不同塞曼子能级上布居出现明显的差异,电磁诱导透明的作用程度有所不同。而且对于在扫描探 测光频率时由于存在速度选择机制使探测光通过铯气室后的吸收谱线发生的畸变作了定性分析。     

三维可视化技术在塔河油田的应用

三维地震数据体可视化是一种全三维地震资料解释方法。采用这种方法,可以在三维数据体内部直接工作,通过调整地震数据体的透明度来直接评价三维空间中地下界面的地震反射。具体作法是:首先将三维地震保幅数据体、相干数据体、波阻抗数据体等输入三维可视化软件中,再通过砂体的目标层标定,沿目标层设定种子点并自动横向追踪,刻画出砂体的分布形态。在此基础上,进行砂体顶面、底面雕刻,获得砂体的厚度变化,从而揭示碎屑岩河流相砂体以及碳酸盐岩溶洞储集体的空间展布规律。     

Crystallization behavior and optical and mechanical properties of isotactic polypropylene nucleated with rosin‐based nucleating agents

Background: Rosin‐based nucleating agents, as natural products, do not have any toxicity; hence they could be used in the industrial processing of polypropylene for the manufacture of food containers. As a result they have been the subject of considerable scientific interest in the literature. In this paper, the non‐isothermal crystallization behavior, and optical and mechanical properties of isotactic polypropylene (iPP) nucleated with rosin‐based nucleating agents are reported. Polarized optical microscopy, scanning electron microscopy and wide‐angle X‐ray diffraction were used to investigate the morphology and crystal structure of iPP with different rosin‐based nucleators. The effects of a 1:1:1 co‐crystal on the properties of iPP were also investigated. Results: The addition of rosin‐based nucleating agents led to the following changes in properties: (a) shortened crystallization half time, (b) decreased size of iPP crystals, (c) slightly increased crystallinity and (d) increased transparency, gloss, flexural modulus and tensile strength. The shrinkage of nucleated iPPs was similar to that of the blank iPP. Conclusion: Rosin‐based nucleating agents in iPP were shown to be effective for nucleating crystals, reducing their size and causing preferential growth along the b‐axis, but suppressing detectable spherulites. The 1:1:1 co‐crystal was effective at 0.2 wt%, a greater concentration giving little additional improvement. Copyright © 2007 Society of Chemical Industry     

Rheological behavior of semi‐aromatic transparent polyamide

The rheological behaviors of semi‐aromatic transparent polyamide (SATPA) melt are investigated using a capillary rheometer. The effects of shear rate, shear stress, and temperature on the apparent viscosity η_a of SATPA are discussed. A correlation of non‐Newtonian index with temperature is obtained. The results show the shear thinning of SATPA; meanwhile η_a decreases with increasing temperature and shear rate, and the viscous flow activation energy is further obtained from temperature dependence of the samples. It was concluded that the apparent viscosity η_a is sensitive to temperature at lower shear rate owing to the higher viscous flow activation energy; on the contrary, the influence of temperature effect on the apparent viscosity becomes minor at higher shear rate due to the lower viscous flow activation energy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1586–1589, 2005     

A hybrid material of graphene and poly (3,4-ethyldioxythiophene) with high conductivity, flexibility, and transparency

A novel hybrid material prepared from graphene and poly (3,4-ethyldioxythiophene) (PEDOT) shows excellent transparency, electrical conductivity, and good flexibility, together with high thermal stability and is easily processed in both water and organic solvents. Conductivities of the order of 0.2 S/cm and light transmittance of greater than 80% in the 400–1800 nm wavelength range were observed for films with thickness of tens of nm. Practical applications in a variety of optoelectronic devices are thus expected for this transparent and flexible conducting graphene-based hybrid material. Electronic Supplementary Material  Supplementary material is available in the online version of this article at http://dx.doi.org/ and is accessible free of charge.     

The realities of risk, the nature of hope, and the role of science: A response to Cook and VandeCreek.

A response is offered to the critiques of both Cook and VandeCreek. Among the points emphasized are the simple realities of risk with suicidal patients, existing empirical research with informed consent in both clinical psychology and other health care areas, as well as the persistence of common myths in clinical practice with suicidal patients. Although empirical science provides a firm foundation to much of what is proposed, it is critical for practitioners to recognize and respond to the ethical demands for openness and transparency with high-risk clients in an effort to achieve shared responsibility in care. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PC与PP透明复合膜胶粘剂的研究

通过对ＰＣ与ＰＰ透明胶粘剂配方与工艺的研究，了胶粘剂涂布量、固化温度和时间、增粘剂的种类和用量对复合膜的剥离强度的影响。     

当代艺术与建筑几个主题

作者通过媒介、波普、极少、概念、图底、透明、高技和数字化八个主题,讨论当代艺术和建筑在概念和表现上的相互影响.     

高透明高柔软度PE保鲜膜的研制

以4个碳的PE-LLD为基材，通过对不同功能改性剂的选择及用量的确定，采用三层共挤流延方法研制出了高透明、高柔软度PE保鲜膜。结果表明，25℃时，在表层添加12份（质量份数，下同）乙烯弹性体（POE）或100份超低密度聚乙烯（PE—ULLD）为增黏剂，PE保鲜膜黏性较好；在芯层添加25份PE-ULLD或15份POE或7份聚异丁烯母料为增韧剂，PE保鲜膜的透明度和柔软度较优，浅盘包装后底面黏着性好、不反弹，回缩性好；当芯层添加0．4份复合防雾剂时，PE保鲜膜的防雾效果好。这种PE保鲜膜基本上具有PVC保鲜膜的使用性能，同时还可以在微波炉中使用。     

Nesting forward-mode AD in a functional framework

We discuss the augmentation of a functional-programming language with a derivative-taking operator implemented with forward-mode automatic differentiation (AD). The primary technical difficulty in doing so lies in ensuring correctness in the face of nested invocation of that operator, due to the need to distinguish perturbations introduced by distinct invocations. We exhibit a series of implementations of a referentially-transparent forward-mode-AD derivative-taking operator, each of which uses a different non-referentially-transparent mechanism to distinguish perturbations. Even though the forward-mode-AD derivative-taking operator is itself referentially transparent, we hypothesize that one cannot correctly formulate this operator as a function definition in current pure dialects of Haskell. Supported, in part, by US NSF grant CCF-0438806, Science Foundation Ireland grant 00/PI.1/C067, and the Higher Education Authority of Ireland (An túdarás Um Ard-Oideachas). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the supporting agencies.