A Dual-Mode Terahertz Filter Based on a Metallic Resonator Design

We present a metallic resonator fabricated on silicon capable of dual-mode operation at terahertz frequencies. The resonator exhibits a notch plus stop band filter response or a notch filter response depending on the orientation of the incident electric field with respect to the structure. The former results in two resonance features: one at 0.69 THz with a Q-factor of 3.7 and the other at 0.91 THz. The latter results in a resonance feature at 0.63 THz with a Q-factor of 5.7. Using 3D finite-difference time-domain simulations, the resonator is designed to operate between 0.1 and 1.4 THz. Experimental verification is performed using a free space terahertz time-domain spectroscopy system, and agreement with our simulations is realized.     

The Relationship Between R&D Investment and Firm Profitability Under a Three-Stage Sigmoid Curve Model: Evidence From an Emerging Economy

The relationship between investment in research and development (R&D) and firm performance has been the subject of numerous academic investigations, but the findings of these investigations have varied greatly, with research revealing a number of different patterns in the R&D–performance relationship. This inconsistency may be partly attributable to the failure of the commonly used linear modeling method to capture the full dynamics of the R&D–performance relationship. Based on the sigmoid (S) curve paradigm, as well as on other economic foundations, this study proposes the use of a three-stage S-curve model to help reconcile the disparities in the literature. This S-curve model shows that the relationship between R&D intensity and firm profitability is nonlinear, with the slope negative at low levels (stage 1), positive at medium levels (stage 2), and negative again at high levels of R&D investment (stage 3). Empirical evidence from a sample of 377 publicly listed Taiwanese high-tech manufacturing firms and 179 nonhigh-tech firms, examined during the period between 2000 and 2007, confirmed our proposed model. This study not only establishes a relationship pattern that differs from that shown in past studies, but also has important managerial implications for R&D managers and important policy implications for governments.      

业务财务一体化需求分析思路与方法研究

首先介绍电信运营商实施业务财务一体化的外部驱动力及意义,然后介绍3种实施业务财务一体化的需求分析思路与方法,最后给出电信运营商业务财务一体化实施方法建议及对实施难点的探讨。     

Fibrillar Starch in Ultrathin Sections of Potato

Ultrathin sections of raw potato embedded in Spurr's “low viscosity” resin show radial splitting of the starch grains into long bands, presumably evoked when the resin is expanded by hydrocarbon vapor after sectioning. There are no concentric lamellae of starch in these sections, and no evidence of tangentially extended layers of refolded molecules was found. Thus, the principal units of organization in the starch grain are radially extended starch molecules and/or radial fibrillar clusters of these molecules.     

Windows映像劫持的分析与防范

本文首先介绍了windows映像劫持的原理,对映像劫持进行了分析.同时根据笔者的日常工作经验总结除了一套比较完善的映像劫持防护方法,具有较强的针对性和实际意义.     

Phase characterisation of metalenses

Metalenses have emerged as a new optical element or system in recent years, showing superior performance and abundant applications. However, the phase distribut...     

混凝土喷射机出料管防粘结措施研究

利用有限元分析软件ANSYS对湿式混凝土喷射机关键零件出料管进行了结构动力学分析,计算了出料管的固有频率及振型,通过对结果的分析提出了出料管防粘结方法和措施,对实际中解决出料管粘料问题具有一定的理论研究和参考价值.     

Betaine Alleviates High-Fat Diet-Induced Disruption of Hepatic Lipid and Iron Homeostasis in Mice

Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive fat deposition in the liver, which is often associated with disrupted iron homeostasis. Betaine has been reported to be hepatoprotective, yet whether and how betaine ameliorates high-fat diet-induced disruption of hepatic lipid and iron homeostasis remains elusive. In this study, mice were fed either standard (CON) or high-fat diet (HFD) for 9 weeks to establish a NAFLD model. Mice raised on HF diet were then assigned randomly to HF and HFB groups, HFB group being supplemented with 1% (w/v) of betaine in the drinking water for 13 weeks. Betaine supplementation significantly alleviated excessive hepatic lipid deposition and restored hepatic iron content. Betaine partly yet significantly reversed HFD-induced dysregulation of lipogenic genes such as PRARγ and CD36, as well as the iron-metabolic genes including FPN and HAMP that encodes hepcidin. Similar mitigation effects of betaine were observed for BMP2 and BMP6, the up-stream regulators of hepcidin expression. Betaine significantly rectified disrupted expression of methyl transfer gene, including BHMT, GNMT and DNMT1. Moreover, HFD-modified CpG methylation on the promoter of PRARγ and HAMP genes was significantly reversed by betaine supplementation. These results indicate that betaine alleviates HFD-induced disruption of hepatic lipid and iron metabolism, which is associated with modification of CpG methylation on promoter of lipogenic and iron-metabolic genes.     

Gelatination Temperatures of Starch,as Influenced by Polyhydric and Monohydric Alcohols,Phenols, Carboxylic Acids and some other Additives

The effect of polyhydric and monohydric alcohols, of phenols, of carboxylic acids and their anions, of halide anions, of alkalimetalions and of some other compounds on the gelatination temperature of potato starch granules in aqueous solutions were studied. Polyhydric alcohols and methanol raise the gelatination temperature, whereas ethanol, propanol, butanol, p-dioxane, carboxylic acids, phenols, urea and hydrogen peroxide cause a decrease in the gelatination temperature. The effect of polyhydric alcohols may be attributed to the lessened tendency of the medium to rupture hydrogen bonds. Carboxylic acids, phenols, urea and hydrogen peroxide may act in a opposite way. The lowering effect of the monohydric alcohols, dioxane, and other non-polar substances may be due to structural and kinetic alterations of the aqueous medium, induced by the non-polar groups. At higher concentrations of ethanol, propanol, p-dioxane, acetic, propionic and butyric acid the gelatination temperature tends to increase. This is to be attributed to the association of solute molecules.     

安藤忠雄的几何方法论

安藤以其执着的信念,具有标识性的几何手法,抵达了“纯粹空间”的彼岸,成功营造了人类精神的乌托邦.就安藤如何将几何学提升为方法论,使其作品具有一种超越国界、超越时间的魅力,结合最新实例做出简要分析.