Wetting and interfacial reactions in liquid Au-Ti alloys / ZrO2 system

This study investigates wetting of zirconia by Au-Ti alloys containing 0.6–4 wt% Ti in view of brazing zirconia to titanium with pure gold for biomedical applications. Experiments were carried out using sessile and dispensed drop methods under high vacuum at 1040–1250 °C. Bulk drops and Au-Ti / ZrO₂ interfaces were characterized by SEM and FEG-SEM with EDXS analysis. While Au does not wet zirconia, the contact angle θ being ∼ 120°, the addition of Ti in Au leads to a significant improvement of wetting due to the formation of a wettable oxide layer at Au-Ti / ZrO₂ interface. The nature of this oxide was determined by X-ray diffraction of the reaction layer after the detachment of the droplet from the substrate or after the dissolution of the droplet. The mechanism of formation and growth of the oxide layer and its growth kinetics were determined based on fine analysis of the Au-Ti / oxide layer / ZrO₂ interfacial system.     

Enhancement reactivity of Bombyx mori silk fibroins via genipin-mediated grafting of a tyrosine-rich polypeptide

Bombyx mori silk fibroin has potential applications in the biomedical field owing to its satisfactory biocompatibility. In the present work, a tyrosine-rich polypeptide (P) with the sequence of GKGYGGYGK was grafted onto fibroin molecules using a natural cross-linking agent of genipin (GP), aiming at improving the reactivity of the fibroin-based materials. Incubation of the polypeptide-grafted fibroin membrane was subsequently carried out, with a mushroom tyrosinase (MT) and a model functional macromolecule of ε-poly-l-lysine (ε-PL). The changes in the structure and composition of the silk fibroin before and after polypeptide grafting were examined by means of size exclusion chromatography and amino acid analysis. The results indicated that the polypeptide was covalently bonded to fibroin chains and evidently promoted the succeeding enzymatic coupling of ε-PL with fibroins, resulting in a higher content of ε-PL compared to the control. The obtained antibacterial activities against S. aureus and E. coli for the fibroin membrane treated with GP/P and MT/ε-PL was more satisfactory than others. Cytotoxicity testing reveals that polypeptide grafting did less impact on the biocompatibility of silk fibroins. The present work provides a novel method to improve the reactivity of silk fibroins and it can be utilized for bio-functionalization of silk fibroin.     

硫杂质对焦反应性的影响及其机理(英文)

采用以低杂质沥青焦模拟石油焦和外掺杂的方式,研究硫杂质元素对焦反应性的影响,并通过XRD、SEM和EDS等检测手段探讨其作用机理。结果表明:在无其他杂质元素干扰的情况下,硫实际上是一种对焦的空气和CO2反应性都具有明显催化性的杂质元素。其催化作用可能是通过在焦的空气和CO2反应过程中分别引发有机硫→H2S→SO2→COS和单质硫(S x)→SO2和有机硫→H2S→COS→S x→C2S→COS两组可部分循环并具有增加碳耗和增大焦比表面积作用的反应体系来实现的。     

煤超分子结构及研究方法进展

为了进一步理解煤的超分子结构研究对于煤清洁和高效利用具有的理论价值和实际意义,对煤超分子结构及研究方法进行了综述。首先对煤超分子的概念及超分子结构之间的相互作用进行了介绍;然后阐述了煤超分子结构模型的研究方法及研究进展;最后对煤超分子结构和反应性能之间的关系进行了探讨,旨在为煤超分子结构的构建与反应性之间关系的研究提供参考,为进一步研究工作起到指导作用。     

Calculational Methods of Control Rod Worth for High Conversion Light Water Reactor

By making use of the isotope approximation; neglecting squares of relative mass differences among the isotopes, the authors derived analytically approximations to ordinary diffusion coefficients in a 3- and 4- component isotope mixture. Moreover, approximations to multi-component diffusion coefficients were given on the analogy of those to the 3- and 4-component coefficients, and these approximations were verified to satisfy constrains on the exact ordinary diffusion coefficients.

For 4-component mixture of uranium hexafluoride isotopes, ²³⁴UF_6- ²³⁵UF_6- ²³⁶UF_6- ²³⁸UF₆, composition dependences of the approximation were equal to those of the exact diffusion coefficients. In addition, relative errors between the exact and the approximations were less than 0.2% for 5-component mixture of krypton 80–82-83-84-86 isotopes.     

Correction to Buehler and Welsh (2009).

Reports an error in "A process model of adolescents' triangulation into parents' marital conflict: The role of emotional reactivity" by Cheryl Buehler and Deborah P. Welsh (Journal of Family Psychology, 2009[Apr], Vol 23[2], 167-180). In the article “A Process Model of Adolescents’ Triangulation Into Parents’ Marital Conflict: The Role of Emotional Reactivity” by Cheryl Buehler and Deborah P. Welsh (Journal of Family Psychology, 2009, Vol. 23, No. 2, pp. 167–180), the abstract contains an error. The sample size for the study was 416 rather than 426. (The following abstract of the original article appeared in record 2009-04780-005.) This study examined adolescents' emotional reactivity to parents' marital conflict as a mediator of the association between triangulation and adolescents' internalizing problems in a sample of 2-parent families (N = 426). Four waves of annual, multiple-informant data were analyzed (youth ages 11–15 years). The authors used structural equation modeling and found that triangulation was associated with increases in adolescents' internalizing problems, controlling for marital hostility and adolescent externalizing problems. There also was an indirect pathway from triangulation to internalizing problems across time through youths' emotional reactivity. Moderating analyses indicated that the 2nd half of the pathway, the association between emotional reactivity and increased internalizing problems, characterized youth with lower levels of hopefulness and attachment to parents. The findings help detail why triangulation is a risk factor for adolescents' development and which youth will profit most from interventions focused on emotional regulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response Rate Choice for Reactivity Meters

Simulation has been used to estimate the error in reactivity measurement in relation to the response rate in an instrument which integrates the input signal or by a converter with a constant measurement time without integration.     

Ethanol Palatability and Consumption by High Ethanol-Drinking Rats: Manipulation of the Opioid System With Naltrexone.

Three experiments examined the effect of acute naltrexone treatment on both taste reactivity and consumption of ethanol in high ethanol-preferring rat lines: Alko Alcohol-Accepting (AA) rats (Experiments 1 and 2) and Alcohol-Preferring (P) rats (Experiment 3). A 3.0 mg/kg naltrexone dose was ineffective at altering ethanol palatability for either line, whereas 7.5 mg/kg was effective at reducing palatability of 10% ethanol for AA, but not P, rats, as reflected by both a decrease in ingestive responding and an increase in aversive responding. The effects of naltrexone on ethanol consumption were quite consistent: At both dosages, acute naltrexone treatment significantly decreased consumption of 10% ethanol. Termination of naltrexone resulted in an immediate increase in ethanol consumption to control levels. Results show that ethanol palatability and consumption can be dissociated in the rat and that the organization of opioidergic mechanisms that mediate ethanol responses may vary between rat lines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reactivity to ecological momentary assessment: An example using undergraduate problem drinkers.

A. A. Stone and S. Shiffman (1994) defined ecological momentary assessment (EMA) as monitoring or sampling strategies that assess phenomena at the moment they occur in natural settings, thus maximi7ing ecological validity while avoiding retrospective recall. To address the extent to which EMA affects the behavior and cognitions under observation, the authors examined behavioral and motivational reactivity to EMA among male and female undergraduate problem drinkers (n = 33). Participants completed a 2-week monitoring protocol using palmtop computers as well as pre- and postmonitoring measures of their drinking behavior and motivation for change. The findings suggest that the magnitude of reactivity to EMA is small. Suggestions for future research Are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)