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21.
Co/SiO2, Mg-Co/SiO2, and Co-Mg/SiO2 catalysts were prepared from nitrate precursors to get more insight into the effect of magnesium promotion on the cobalt catalyst. The desorption characteristics and reactivity of the catalysts towards synthesis gas were evaluated in a pulse micro reactor connected to an on-line quadrupole mass spectrometer. The presence of MgO both decreased the extent of reduction and increased the dispersion of cobalt. The reactivity results suggested that MgO promotion created new types of active sites, probably at the edge sites of cobalt and magnesium. The highest activity per metallic site available was obtained with a Mg: Co molar ratio of 1/2, i.e. with a high amount of edge sites. In accordance with previous results the formation of CO2 was clearly suppressed in the presence of MgO, and methanol was formed in trace amounts.  相似文献   
22.
It is widely acknowledged that users of Spoken Language Systems (SLS) want the ability to truncate system prompts by using a barge-in capability (e.g., Basson et al., 1995; Yankelovich et al., 1995). However, little has been published on how barge-in is used or if it adversely affects Automatic Speech Recognition (ASR) and the interface usability. Typically, user requests for barge-in are assumed to be based on the desire to make system interactions faster and therefore more similar to interactions with touch-tone systems. We believe that requests for a barge-in capability are rooted in the notion of discourse as a turn-taking event. Viewed in this way, we believe SLS can be enhanced to develop speech interfaces that are deemed more natural by users, as well as to increase system performance. This study addressed several issues. We found that users new to the system did not need to be informed about the barge-in capability before they attempted barge-in, that they used barge-in during almost half of their interactions with the system, and that they had identifiable patterns of barge-in use consistent with the turn-taking model. Results are presented and consequences for speech interface design as well as algorithm enhancement are discussed.  相似文献   
23.
Describes a treatment program for males suffering from hypoactive sexual desire disorder. Treatment focused on developing the emotional aspects of the client, on increasing his sexual repertoire, and on improving his attitude and response to these sexual experiences in the context of each client's relationship. These aims were addressed by the use of communication exercises, sensate focus exercises, and guided fantasies. 15 men and their partners were so treated. While there was a decrease in the level of performance anxiety and sexual anxiety, Ss still experienced difficulty in level of sexual interest and in initiating sexual activity. At the 3- and 6-mo follow-up, the level of communication, sexual satisfaction, sexual arousal, and satisfaction with the relationship was still high. A case study is included. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
24.
Particulate matter in the atmosphere is known to affect Earth’s climate and to be harmful to human health. Accurately measuring particles from emission sources is important, as the results are used to inform policies and climate models. This study compares the results of two ELPI?+?devices, two PM10 cascade impactors and an eFilter, in combustion emission measurements. The comparison of the instruments in a realistic setting shows what types of challenges arise from measuring an emission aerosol with unknown particle morphologies and densities, different particle concentrations and high temperature. Our results show that the PM10 cascade impactors have very good intercorrelation when the collected mass is greater than 150?µg, but below that, the uncertainty of the results increases with decreasing mass. The raw signals of two ELPI?+?devices were nearly identical in most samples, as well as the particle number concentrations and size distributions calculated from raw signals; however, transforming the current distributions into mass distributions showed variation in the mass concentration of particles larger than 1?µm. The real-time time signal measured by eFilter was similar to the total current measured by ELPI+. The eFilter and PM10 cascade impactors showed similar particle mass concentrations, whereas ELPI?+?showed clearly higher ones in most cases. We concluded that the difference is at least partially due to volatile components being measured by ELPI+, but not by the mass collection measurements.

Copyright © 2019 American Association for Aerosol Research  相似文献   

25.
Cell wall cross‐linking can have a substantial effect on the properties of the wall. To estimate cross‐linking (between arabinoxylans) in cereal fibres, dehydrodiferulate levels were measured in soluble and insoluble dietary fibre (SDF and IDF) isolated from whole grains of maize (Zea mays L), wheat (Triticum aestivum L), spelt (Triticum spelta L), rice (Oryza sativa L), wild rice (Zizania aquatica L), barley (Hordeum vulgare L), rye (Secale cereale L), oat (Avena sativa L) and millet (Panicum miliaceum L). After saponification of the cereal fibres the extracts were investigated for dehydrodimers of ferulic acid using GLC–MS and GLC–FID. From most cereal IDF the whole spectrum of dehydrodiferulic acids (DFAs) (8‐5′‐, 8‐8′‐, 5‐5′‐, 8‐O‐4′‐ and 4‐O‐5′‐coupled) could be identified. The absolute contents of total DFAs ranged between 2.4 and 12.6 mg g?1. With the exception of 4‐O‐5′‐coupled DFA, the whole range of DFAs was also detected from cereal SDF but only in amounts of 40–230 µg g?1. It was estimated that arabinoxylans of cereal IDF contain 8–39 times more diferulates than arabinoxylans of cereal SDF (where measurement of DFA levels in SDF was possible). In cereal IDF, 8‐5′‐coupled dimers dominated, whereas in cereal SDF, 8‐8′‐coupled dimers were relatively enhanced and often became the major dimers. © 2001 Society of Chemical Industry  相似文献   
26.
The effect of suspension ageing time during the catalyst precipitation process on the performance of co-precipitated Cu/ZnO/ZrO2 catalysts in methanol synthesis from CO2 and H2 has been studied. The ageing time influenced greatly the physical and chemical characteristics of the catalysts as well as their activity in the methanol synthesis. Prolonged ageing was advantageous, mainly due to both lower sodium contents and enhanced crystallinity of the catalysts.  相似文献   
27.
We review in this paper the work performed by our group to develop multifunctional bioabsorbable ciprofloxacin releasing bone implants. Poly lactide-co-glycolide (PLGA 80/20 and polylactide (P(L/DL)LA 70/30) were used. Ciprofloxacin (CF) and bioactive glass (BaG) 13-93 were added. The mixture was then extruded and self-reinforced. CF release, mechanical strength, and the effect on S. epidermidis attachment and biofilm formation were evaluated. In rabbits, tissue reactions were assessed. Pull out strength was evaluated in cadaver bones. CF was released over 44 weeks (P(L/DL)LA) and 23–26 weeks (PLGA). Initial shear strength of the CF screws was 152 MPa (P(L/DL)LA) and 172 MPa (PLGA). Strength was retained for 12 weeks (P(L/DL)LA) and 9 weeks (PLGA). Histologically, CF releasing implants did not show much difference from control plain PLGA screws except for increased giant cells. CF miniscrews had lower pullout strength than the controls, but CF tacks had better values than controls. BaG led to a drop in pullout strength properties. Bacterial growth, attachment and biofilm formation on CF implants was significantly reduced when compared to controls. Accordingly, bioabsorbable multifunctional implants with appropriate CF release, mechanical, and biocompatibility properties are possible to develop and are considered appropriate to apply clinically.  相似文献   
28.
The repressor activator protein 1 (RAP1) plays a role in telomere structure and function inS. cerevisiae. Here, the RAP1 homologue was identified and cloned from the budding yeast Saccharomyces castellii (scasRAP1). The scasRAP1 gene encodes a protein of 826 amino acids and shares an overall high degree of similarity with the S. cerevisiae RAP1 (scerRAP1). We demonstrate that the scasRAP1 is able to complement scerRAP1 in temperature-sensitive S. cerevisiae strains and is able to function as a regulator to maintain the original telomere lengths. Binding analyses of the E. coli-expressed scasRAP1 protein demonstrate that it needs two consecutive telomeric repeats in order to bind the S. castellii telomeric DNA sequences, and that it binds adjacent sites having a 16 bp centre-to-centre spacing. The binding affinity to telomeric DNA of several other yeasts is similar to that of scerRap1p. However, in contrast to scerRap1p, scasRap1p was found to bind the human telomeric sequence. Moreover, the scasRap1p was found to incorporate a variant repeat in its binding to the otherwise homogeneous telomeric DNA of S. castellii. This ability to bind various sites differing in DNA sequence indicates a high degree of adjustability in the binding of scasRap1p to DNA.  相似文献   
29.
Ubimedia is a concept where media files are embedded in everyday objects and the environment. We propose an approach where the user can read and write these files with his/her personal mobile phone simply by touching the physical objects. This facilitates easy access and storage of, e.g. video and audio files related to the physical object in question. This paper describes our work in developing a technical solution for ubimedia and studying user acceptance of forthcoming ubimedia services. Our technical development of the ubimedia concept has been focused on a mobile phone platform with a tag reader/writer, memory tags with large storage capacity, and the communication between the phone and the tags. Currently, the technical design is in test and evaluation phase. The preliminary results show that the concept works and it can be implemented technically. In parallel with the technical development, we have studied usage possibilities for ubimedia and user acceptance of future ubimedia services. User acceptance has been studied in a web survey and in user evaluations of proofs-of-concept. In addition, an ethical assessment has been carried out. The users appreciated especially the simplicity, speed, low cost and reliability of ubimedia. Ethical concerns were related to control over the download with regard to viruses and other unwanted content.  相似文献   
30.
A corporate workplace model for ergonomic assessments and improvements   总被引:1,自引:0,他引:1  
Several companies have developed their own company-specific models for ergonomic improvements. This study aims to describe and identify factors supporting and hindering the implementation and application of one such corporate model for ergonomic assessment and improvement. The model has been developed by Volvo Car Corporation and implemented at an assembly plant in G?teborg, Sweden. The model is unique as it is intended to be used by production engineers and safety representatives in cooperation. The process for assessment of musculoskeletal risks is standardised and participatory, which also supports identification of solutions. Interviews, questionnaires, observation and document studies were used to evaluate the use of the model. The model was found to improve participation and collaboration among stakeholders; provide a more effective ergonomic improvement process; visually represent the ergonomics situation in the company; and give legitimacy to and awareness of ergonomics. However, the model was found to be rather resource demanding and dependent on support from management and unions. In particular, a substantial training programme and regular use of the model are needed.  相似文献   
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