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排序方式: 共有1083条查询结果,搜索用时 15 毫秒
981.
Summary
A series of PET/expandable fluorine mica (ME) nanocomposites with different proportions of compatibilizer, 10-[3,5-bis(methoxycarbonyl)phenoxy]decyltriphenylphosphonium bromide (IP10TP) were prepared by in situ polymerization process. The crystallite
size, nucleation and the effect of content of compatibilizer on the dispersibility of ME in PET matrix were investigated by
XRD and DSC techniques. The XRD results showed a decrease in the crystallite size of ME giving rise to partially exfoliated
structure and the crystallite size of PET reduced considerably as compared to pure PET at low content of IP10TP. The DSC results
revealed a dramatic increase in crystallization temperature (T
c) and also showed enhancement in glass transition (T
g) and melting point (T
m) at low content of IP10TP. These various findings have been explained based on the miscibility of IP10TP/ME with PET.
Received: 17 May 2002 / Accepted: 12 July 2002 相似文献
982.
The sintering processes of Ni-TiC powder mixtures with the addition of a third alloying element, Mo, Ta or Co, were studied by differential thermal analysis and optical microscopy at room temperature and high temperature. The TiC content was varied between 5 and 90 wt%, and Mo, Ta and Co contents were varied between 0 and 20 wt%. The mean TiC powder and metal powder sizes were 1 and 2m, respectively. The initiation of a endothermic reaction was observed by thermal analysis of the Ni-TiC system. The structural change corresponding to the reaction was confirmed by optical microscopy. 相似文献
983.
M Ikeda CS Moon ZW Zhang H Iguchi T Watanabe O Iwami Y Imai S Shimbo 《Canadian Metallurgical Quarterly》1995,70(1):35-46
Possible cadmium (Cd) exposure-associated changes in urinary levels of low-molecular-weight proteins were studied in nonsmoking and non-drinking female members of the general Japanese population (378 subjects with no known occupational heavy metal exposure) who lived at 19 study sites (all without any known environmental heavy metal pollution) in 13 prefectures throughout Japan. The external Cd dose was evaluated in terms of daily Cd intake via food (Cd-F), whereas Cd levels in blood (Cd-B) and urine (Cd-U) were taken as internal dose indicators. When the subjects were classified according to Cd-F into three groups with "low" (20.4 micrograms/day as a geometric mean of 97 women), "middle" (35.0 micrograms/day, 120 women) and "high" (67.0 micrograms/day, 66 women) exposure, both Cd-B and Cd-U increased in parallel with the changes in Cd-F. However, there were no dose-dependent changes in beta2-microglobulin or retinol-binding protein levels in urine, alpha1-microglobulin levels appeared to increase, but the distribution of the cases above the two cutoff levels of 9.6 and 15.8 micrograms/mg creatinine among the three Cd-F groups did not show any bias. Overall, it was concluded that there was no apparent Cd exposure-associated elevation in urinary low-molecular-weight protein levels in the study population. 相似文献
984.
In designing and developing a gesture recognition system, it is crucial to know the characteristics of a gesture selected to control, for example, an end effector of a robot arm. We conducted an experiment to collect a set of user-defined gestures and investigate characteristics of the gestures for controlling primitive motions of an end effector in human–robot collaboration. We recorded 152 gestures from 19 volunteers by presenting virtual robotic arm movements to the participants, and then asked the participants to think about and perform gestures that would cause the motions. It was found that the hands were the parts of the body used most often for gesture articulation even when the participants were holding tools and objects with both hands: a number of participants used one- and two-handed gestures interchangeably, gestures were consistently performed by the participants across all pairs of reversible gestures, and the participants expected better recognition performance for gestures that were easy to think of and perform. These findings are expected to be useful as guidelines in creating a gesture set for controlling robotic arms according to natural user behaviors. 相似文献
985.
Yasuhiro Yoshida Shinji Nakagawa Akiko Yoshida Kazuyoshi Yoshiyama Hiroyuki Furukawa Shigeki Imai 《Journal of the Society for Information Display》2011,19(11):771-780
Abstract— In this paper, the resolution characteristics of multi‐primary‐color (MPC) display systems are analyzed. That four‐primary‐color (4PC) displays can increase the effective resolution for achromatic images in the luminance domain by a factor of two as compared to conventional RGB‐based displays with MPC‐specialized subpixel rendering, which is proposed in this paper, is demonstrated. Five‐ and six‐primary‐color (5PC and 6PC) display systems can reproduce denser luminance data than conventional RGB‐based display systems and solve a problem of MPC displays, viz. an increase of production costs and a decrease in the aperture ratio caused by increasing the number of subpixels in one pixel. This is an essential advantage of MPC display systems, which is related to the combination of the proposed color‐filter architecture and image processing. Thus, a completely new advantage of MPC display systems, in addition to their well‐known capabilities of color reproduction and power saving, is proposed. 相似文献
986.
This paper presents iPlumber, a user-oriented management system for ubiquitous computing environments. Different from previous low-benefit “zero-configuration” systems or high cognitive-cost “end user programming” tools, our work attempts to attain a better balance between user benefits and cost by exploring the meta-design approach. A set of typical management activities in ubicomp environments are supported, from basic-level software sharing, foraging, and low-cost software configuration to advanced-level cooperative software co-design and error handling. These activities are elaborated through a smart home control scenario. The usability of our system is validated through an initial user study with a total of 33 subjects to test the management activities from an open exhibition environment and a controlled university environment. 相似文献
987.
OPEN is an ontology-based programming framework for rapid prototyping, sharing, and personalization of context-aware applications.
Unlike previous systems that provide programming support for single group of users, OPEN provides different programming support
for users with diverse technical skills. According to the programming requirements of different users, several cooperation
patterns are identified, and the mechanisms to facilitate resource sharing and reuse are built into the framework. Three corresponding
programming modes are elaborated by showing how a context-aware game has been developed with the support of the OPEN framework,
and the usability of our system is validated through an initial user study. 相似文献
988.
Summary This paper is concerned with an experimental investigation on the transverse variation of the velocity and bed shear stress in hydraulic jumps in a rectangular open channel. The velocity is measured by means of a Pitot tube and small propeller-type flowmeter, while the bed shear stress is determined by the Preston's method. The experimental parameter is the supercritical Froude number
, whereU
0 is the supercritical velocity,g the acceleration due to the gravity andz
0 the supercritical water depth.It is found that hydraulic jumps can be divided into two groups broadly at the supercritical Froude number Fr2.5. In case of the first group, no surface roller is formed and only a little amount of air is entrained into the jump. A series of swelling-depression sequences are formed on the surface along the channel axis, and thus the bed shear stress experiences a sinusoidal variation. On the other hand, in case of the second group a definite roller is formed in the jump region and a considerable amount of air is entrained into the roller. The surface height increases rapidly from the toe line to end line. As the result, the bed shear stress decreases rapidly with increasing the distance from the toe line, but the decay rate is decreased with increasing the supercritical Froude number.It is concluded that in hydraulic jumps the surface height, velocity and bed shear stress are dependent on all of the three spatial coordinates. For example, the bed shear stress is greatly decreased with increasing the transverse distance from the channel axis. 相似文献
989.
Yoshida T. Kimura S. Kimura H. Kumozaki K. Imai T. 《Lightwave Technology, Journal of》2006,24(2):786-796
This paper proposes a new single-fiber 10-Gb/s optical loopback method for wavelength-division-multiplexing (WDM) optical access networks. The proposed method improves the tolerance of backreflection that causes interferometric crosstalk with the loopback method on a single fiber. Furthermore, bit synchronization is used to avoid the problem of wavelength dispersion caused in optical access networks. The authors simulated the available distance, received eye patterns at 10 Gb/s, and confirmed the excellent eye opening. 10-Gb/s back-to-back experiments show that the proposed method provides a 17-dB improvement in backreflection tolerance compared with the direct method. The paper reports the first successful results for 10- and 20-km transmission experiments using a standard single-mode optical fiber. The measured eye patterns agreed well with the simulation results. The paper also shows measured bit-error rates (BERs) equivalent to those of a back-to-back configuration. 相似文献
990.
T Motohiro K Nagai T Yamada S Oki T Yamada Y Yoshinaga N Tsumura K Oda Y Sakata H Kato S Imai J Morita Y Matsuo S Ikezawa K Takahgashi T Fukuda Y Yamashita M Aramaki M Hayashi R Yamakawa Ono-E Y Tananari T Tsutsumi A Hoshuyama K Aida 《Canadian Metallurgical Quarterly》1998,51(6):413-431
A drug susceptibility test of the combination drug TAZ/PIPC, which consists of a newly developed beta-lactamase inhibitor, tazobactam (TAZ), and one of penicillin antibiotics, piperacillin (PIPC), with combination ratio of 1:4 in potency, was conducted with stock strains and clinical isolates. The clinical efficacy and safety of its injection was also evaluated in children with a variety of infectious diseases. The results were as follows: 1. In susceptibility test, 114 strains from 4 species of stock strains were treated with 8 drugs, that is, TAZ/PIPC, PIPC, penicillin G (PCG), ampicillin (ABPC), cefotiam (CTM), cefotaxime (CTX), ceftazidime (CAZ), and sulbactam/cefoperazone (SBT/CPZ). Of three clinically isolated species from patients, Staphylococcus aureus (S. aureus) was treated with TAZ/PIPC, PIPC, methicillin (DMPPC), CTM, CTX, and SBT/CPZ, and the others were treated with the same drugs except for DMPPC. The MICs were measured for these bacterial strains inoculated at the concentration of 10(6) CFU/ml. The MIC90 values of TAZ/PIPC against 45 strains of Streptococcus pyogenes (S. pyogenes), one of the stock cultures of Gram-positive cocci, were 0.05 microgram/ml and similar to those of PIPC, CTM, CAZ, and SBT/CPZ. The MICs of TAZ/PIPC for 28 strains of Streptococcus agalactiae (S. agalactiae) were 0.39 microgram/ml and similar to those of PIPC, CTM, CAZ, and SBT/CPZ. As for Gram-negative bacilli, the MIC90 of TAZ/PIPC against 10 strains of Bordetella pertussis (B. pertussis) were 0.10 microgram/ml and similar to those of PIPC. The MIC90 of TAZ/PIPC against 31 strains of Haemophilus influenzae (H. influenzae) were 0.05 microgram/ml and similar to those of PIPC, CTX, and SBT/CPZ. Regarding Gram-positive cocci isolated from patients received this combination drug, the MIC90 of TAZ/PIPC against 2 strains of S. aureus, a non beta-lactamase producing strain and a low-beta-lactamase producing strain, were 0.78 microgram/ml and 3.1 micrograms/ml, respectively; the former value was similar to those of PIPC, DMPPC, CTM, and CTX, and the latter was similar to those of PIPC, DMPPC, CTX, and SBT/CPZ. Of 4 strains of Streptococcus pneumoniae, 2 strains were inhibited at 0.05 microgram/ml, and the others at 1.56 micrograms/ml; both values were similar to those of PIPC, SBT/CPZ. As for Gram-negative bacilli, 6 of 7 strains of H. influenzae did not produce beta-lactamase and 1 strain was a high producer. The MICs of TAZ/PIPC against beta-lactamase nonproducing strains were < or = 0.025 microgram/ml in 5 strains and 0.39 microgram/ml in 1 strain, and the values were similar to those of PIPC and SBT/CPZ. While the MIC of TAZ/PIPC against the high beta-lactamase producing strain was 0.78 microgram/ml; similar to that of SBT/CPZ and smaller than that of PIPC. 2. The results of clinical effects on 7 diseases in 33 cases were as follows: TAZ/PIPC was clinically judged "excellent" in 17 (51.5%); good in 14 (42.4%); fair in 2 (6.1%). No case with no response was seen in this study, and the total efficacy rate of "excellent" and "good" was 93.9%. 3. Bacteriological effects were evaluated in 17 strains of 4 species, and all of them were eradicated. 4. Adverse reactions were judged in 35, which consisted of 33 in which the clinical effects were evaluated and 2 dropped from this study. Of these cases, diarrhea was observed in 4 (11.4%). 5. Laboratory tests revealed an increase in platelets in 1 of 32 cases (3.1%), and eosinophilia in 2 of 29 cases (6.9%). Biochemical profile showed an increase in GPT alone and abnormal increases in both GOT and GPT in 1 each out of 21 cases. 相似文献