BEH Amide柱：使碳水化合物的分析更简单、快速、高效

碳水化合物的色谱分析对很多行业的研究来说都是非常重要的工作。例如．食品中单糖与二糖的定性定量，由于复杂糖类．糖醇、人造甜味剂与盐皆可形成复杂基质．使分析变得困难；制药行业通常使用简单或复杂的糖类或糖衍生物基质作为起始药物．通过对药物配方中的这些化合物进行分析，可以为生产提供所需要的信息；     

Electron Transfer Reactions in Pulping Systems IX. Reactions of Syringyl Alcohol with Pulping Reagents

Syringyl alcohol was heated at 135° in 1M NaOH in the presence of anthrahydroquinone, sodium hydrosulfide, and glucose. Dimerization of syringyl alcohol to disyringylmethane was suppressed by all three reagents. An analysis of the types and amounts of products formed at various times indicated (1) that the reagents reacted reversibly with intermediate quinone methides and (2) that electron transfer reactions occurred in the cases of anthrahydroquinone and glucose to give quinone methide radical anion intermediates. Sodium sulfide reacted as a nucleophile, rather than an electron transfer agent.     

Studies of the Structure and Reactivity of Soot

Vibrational spectroscopy, supplemented with other techniques, is providing a comprehensive picture of the structure and reactivity of soot. Reactions such as soot-NO₂/N₂O₄, soot-O₃, and soot-SO₂, at atmospheric and subatmospheric pressures and at different temperatures, have been studied. Determination of the kinetics and mechanisms of the formation of CO and CO₂ during the soot-O₃ reaction, and the effect of temperatures and the concentrations of soot and ozone on this reaction, have led to further insights about the soot structure. Examination of the identity and role of linkages bonding carbon layers together is underway. Application of the Elovich equation to determine initial rates for the formation of surface species in these reactions indicates that the soot-O₃ reaction is faster than the rapid soot-NO₂/ N₂O₄ reaction which, in turn, is faster than that of soot-SO₂. Oxidation of SO₂ to ionic sulfate, confirmed by isotopic substitution, occurs in the presence of soot, water vapor, and oxygen. The presence of simulated solar radiation results in the formation of both ionic and covalent sulfate species. The substrate, whether it is carbon black, cab-o-sil, or the glass walls of the reaction vessel, seems to play a role in the nonphotochemical oxidation of SO₂ to sulfate. The miscibilities of the reaction products of soot-O₃, soot-NO₂/N₂O₄, soot-SO₂, with water vary greatly and have implications for the depletion of tropospheric ozone in the presence of soot-containing particulates.     

神奇的“实时智能”

实时控制不仅仅停留在工厂层面，而是开始介入企业管理层面，使管理能够获得更大的竞争优势。虽然只有少数企业采用这种方案，但是这些企业无不具备了前所未有的办事能力。     

The effects of surface oxidation on luminescence of nano diamonds

In this work we quantify and characterise the effects of air-oxidation on nitrogen-vacancy defect luminescence in both high-temperature-high-pressure and detonation synthesized nanodiamonds using Raman and luminescence spectroscopies. We find that oxidation treatments result in an increased nitrogen-vacancy centre excited state lifetime from 13 ns to 25 ns and in 5-nm diamonds the intensity of this luminescence increases by at least 5-fold. At the same time, in 5-nm diamonds, short lived surface-defect related luminescence is reduced by 10-fold. Furthermore we find that air oxidation reduces the sp² and disordered carbon fraction of nanodiamonds by up to 5-fold in 5-nm nanodiamonds. Based on these results, the authors suggest that the disordered-carbon and graphite shell of 5-nm nanodiamonds quenches nitrogen-vacancy luminescence, and that this quenching can be partially reduced by surface oxidation. These findings provide useful insights into the role of the graphite and disordered carbon shell in quenching luminescence, and have implications for the applicability of 5-nm nanodiamonds to bio- and quantum physics applications.     

Work, Retirement, and Depression

This study investigates the relationship between depression and labor force participation by examining whether retirement induces depression or depression discourages labor force participation. The sample is drawn from newly available, nationally representative data of those 50–64 years old using the 2006 Korean Longitudinal Study of Aging. We model two possibly inter-related outcomes; depression and work. We first examine whether retirement influences depression, using the mandatory retirement provisions of the Korean labor force to identify a pathway to retirement that is not a consequence of depression. We then estimate the determinants of current work using instrumental variables for depression. We find that mandatory retirement is not associated with subsequent depression but find evidence that depression leads to reduced labor force participation, after using instrumental variables to predict the existence of depressive symptoms among respondents. We find strong evidence that depression leads to reduced labor force participation. Although retirees are often more depressed than workers, the causes that induce retirement, such as poor health, care-giving responsibilities, and inability to find a job, are also associated with depression.     

Diffraction grating scanners using polysilicon micromotors

This paper describes polysilicon micromotors with single and pyramidal diffraction grating elements fabricated on the polished surface of large-area rotors for optical scanning applications. While taking full advantage of planar processing, such scanners have high-quality scan profiles, good efficiency, meter working distances, and multiple out of plane beam diffraction orders. Chemical-mechanical polishing was used to reduce the 5-μm-thick polysilicon rotors' average surface roughness from 420 Å to below 17 Å, with less than 1500-Å film removal, improving the optical performance of the gratings as well as the definition, delineation, and side wall quality of the device features. Self-assembled monolayers (SAM) were found to improve the overall micromotor's dynamic performance. SAM-coated scanners could operate at voltages as low as 15 V and maximum operational speeds of 5200 rpm. The gratings were tested optically at 633-nm wavelength and were verified to have spatial periods of 1.80 and 3.86 μm, closely matching their design values. Stepping and continuous mode dynamic operation of the scanners was demonstrated with visible diffraction orders at meter distances away     

Carbide characterization in low-temperature tempered steels

The nature of the initial carbides formed during the early stages of the tempering of steels is still a matter of debate. Conventionally, the main transition carbide is described as epsilon carbide, with a composition of approximately Fe_2.4C. However, earlier one-dimensional atom probe (1DAP) results indicated the existence of carbon-rich regions having much lower carbon contents, with maxima of around 10 at%. There was some uncertainty about the interpretation of the 1DAP results, because of possible problems with alignment of the aperture and with trajectory aberration effects. We have therefore re-visited this topic, using the three-dimensional (3D) atom probe, and studying both a model Fe–Ni–C alloy and a well-known engineering steel (AISI4340). We demonstrate that, for both materials, low-temperature (20–150 °C) aging produces carbon-rich regions with average peak carbon contents of up to 10%. We show for the first time the three-dimensional structure of these carbon-rich regions, and demonstrate that fine-scale faulting exists within them.     

SYNTHESIS, CHARACTERIZATION, AND BIOLOGICAL PROPERTIES OF A FULLERENE TRIPHENYLPHOSPHONIUM SALT

A monofunctionalised fullerene triphenylphosphonium salt has been synthesised to investigate the potential for adaptation of fullerenes for biological application. The redox properties of fullerenes make them effective radical scavengers and consequently they are potential antioxidants in biological systems The triphenylphosphonium moiety was chosen because this lipophilic cation increases both the solubility and membrane permeability of attached compounds, and has been used as a delivery agent in biological systems in other contexts. Furthermore, the triphenylphosphonium moiety binds tightly to cognate antibodies, facilitating linkage of attached molecules to proteins. Here we report on the interaction of a triphenylphosphonium fullerene salt with biological systems and its binding of antibodies against the triphenylphosponium moiety.     

Vulnerability and resilience in women with arthritis: Test of a two-factor model.

The purpose of this study was to test a 2-factor model of affective health in women with rheumatoid arthritis (RA; n = 82) or osteoarthritis (OA; n = 88). Positive and negative social interactions and affect were assessed for 11 consecutive weeks. For each participant, Vulnerability and Resilience factors were created from factor analyses of positive and negative personal characteristics, respectively. Multilevel analyses tested the hypothesis that weekly changes in social interactions or affect would only be predicted by the factor of the same valence. The Vulnerability (and not the Resilience) factor predicted changes in negative interactions. The Resilience (and not the Vulnerability) factor predicted changes in positive interactions. The Vulnerability (and not the Resilience) factor predicted changes in current and next-week negative affect. The Resilience and Vulnerability factors each predicted changes in current and next-week positive affect, although the effects for Vulnerability were smaller than for Resilience. Finally, the Vulnerability factor interacted with pain to predict more future negative affect. The main implication is that both Vulnerability and Resilience should be considered in theory, research, and interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)