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101.
Epoxidized palm oil (EPO) (0–12 wt%) was added into petrochemical-based epoxy blends (diglycidyl ether of bisphenol-A (DGEBA)/cycloaliphatic
epoxide resin/epoxy novolac resin) to develop a thermal curable bio-based epoxy system. The thermal behaviors of the EPO,
epoxy blends (EB), and bio-based epoxy blends (EB/EPO) were characterized using differential scanning calorimetry (DSC), dynamic
mechanical thermal analysis (DMT) and thermo-mechanical analysis (TM). The glass transition temperature (T
g) and storage modulus (E′) of the EB/EPO system was reduced with the increasing of the EPO loading. This is attributed to the plasticizing effect
of the EPO. It was found that epoxy blends with higher loading of EPO possessed higher coefficient of thermal expansion (CTE)
and tanδ value. This is due to the increase of the free volume and chain flexibility in the three-dimensional network of the epoxy
blends. The internal thermal stresses of the EB/EPO were decreased as the increasing loading of EPO, owing to the reduction
of crosslink density, modulus of elasticity, and T
g in the epoxy blends. 相似文献
102.
In this demonstration, a stable and wavelength-tunable erbium-doped fiber (EDF) ring laser using dual-saturable-absorber-based
(DSAB) filter inside loop cavity is proposed and experimentally investigated. The proposed DSAB filter not only can filter
the side-mode in single-frequency output, but also can obtain the flattened output power spectrum within 1 dB variation in
the effectively range of 1529 to 1563 nm. In addition, the output stabilities of wavelength and power are also measured experimentally
and discussed. 相似文献
103.
Wind-generated ambient noise in a topographically isolated basin: a pre-industrial era proxy 总被引:1,自引:0,他引:1
During the mid-1980s, calibrated measurements of ambient noise and wind speed were made in the Tongue of the Ocean in the Bahamas to quantify the spectra and statistics of wind-generated noise. This deep basin is topographically isolated from the Atlantic Ocean and, therefore, largely acoustically decoupled from the Atlantic Ocean deep sound channel. The quantitative effects of contaminating (non-surface wind-generated) noise sources within the basin were eliminated by careful measurement and robust statistical analysis methodologies. Above 500 Hz, the spectral slopes are approximately -5 dB per octave and independent of wind speed. Below 500 Hz, the ambient noise is no longer a linear function of wind speed. Below 100 Hz and for wind speeds greater than 18.5 knots (kt), the ambient noise is independent of frequency. The minimum observed ambient noise level falls 13 dB below Urick's "light shipping" level at 30 Hz and 2-5 dB below Wenz's sea state zero level through the wind-dominated portion of the spectrum. The basin's geographical isolation and the rigorous measurement and analysis methodologies employed make this two-decade-old data set a reasonable and justified proxy for pre-industrial era ocean noise levels in the 20 Hz to 20 kHz frequency band. 相似文献
104.
K. L. Chow N. K. Mak M. H. Wong X. F. Zhou Y. Liang 《Journal of nanoparticle research》2011,13(3):1007-1017
The objective of this study was to investigate antimicrobial mechanisms of a new catalytic material (charge transfer auto
oxidation–reduction type catalyst, CT catalyst) that may have great potential for application in water/wastewater treatment.
Generation of reactive oxygen species (ROS) in bacteria-free solution, induction of ROS and oxidative damage in bacteria (including
E. coli and S. aureus) were examined for the CT catalyst. The results showed that significantly higher (p < 0.05, via t-test) amount of hydroxyl radicals was generated by the CT catalyst compared with the control, particularly after 6 h of contact
time that more than twice of the amount of the control was produced. The generation of ROS in the bacteria was greater under
higher pH and temperature levels, which closely related with the oxidative damage in cells. The results indicated that CT
catalyst induced oxidative damage in the bacteria might serve as an important mechanism interpreting the anti-microbial function
of the CT catalyst. 相似文献
105.
Chow JM Córcoles AD Gambetta JM Rigetti C Johnson BR Smolin JA Rozen JR Keefe GA Rothwell MB Ketchen MB Steffen M 《Physical review letters》2011,107(8):080502
We demonstrate an all-microwave two-qubit gate on superconducting qubits which are fixed in frequency at optimal bias points. The gate requires no additional subcircuitry and is tunable via the amplitude of microwave irradiation on one qubit at the transition frequency of the other. We use the gate to generate entangled states with a maximal extracted concurrence of 0.88, and quantum process tomography reveals a gate fidelity of 81%. 相似文献
106.
Zhi-zhuang Joe 《高等学校化学研究》2011,(3):474-477
PTPRU is an MAM domain-containing receptor-like protein tyrosine phosphatase. Previous studies have demonstrated an important role of the enzyme in the maintenance of epithelial integrity and in the regulation of the Wnt/β-catenin signaling pathway. To better understand the function of PTPRU, we cloned and expressed the intracellular portion of PTPRU as a GST fusion protein in E. coli cells. We purified the protein to homogeneity and used it to immunize mice for antibody production. The resultant antibody s... 相似文献
107.
Srinivasulu Aitipamula Pui Shan Chow Reginald B. H. Tan 《Journal of chemical crystallography》2011,41(11):1604-1611
Abstract
Cocrystals of two important active pharmaceutical ingredients, carbamazepine and piracetam, with hydroquinone are reported. Cocrystal formation between the selected APIs and hydroquinone is investigated with the aid of solid-state grinding methods. Both the crystal structures belong to the triclinic, P [`1]P \bar{1} space group, with the cocrystal involving carbamazepine and hydroquinone having the unit cell parameters a = 6.9725 (14) ?, b = 8.8175 (18) ?, c = 15.083 (3) ?, α = 106.96 (3)°, β = 92.16 (3)°, γ = 103.23 (3)°, V = 858.0 (4) ?3 and Z = 2; and the cocrystal involving piracetam and hydroquinone has the unit cell parameters a = 6.4909 (13) ?, b = 6.5410 (13) ?, c = 11.612 (2) ?, α = 103.92 (3)°, β = 104.53 (3)°, γ = 91.06 (3)°, V = 461.59 (18) ?3 and Z = 2. Analysis of the cocrystals revealed that they are sustained by an alcohol–carboxamide heterosynthon. In addition, the cocrystal of carbamazepine and hydroquinone features an amide–alcohol heterosynthon and an alcohol–alcohol homosynthon. The cocrystal of piracetam and hydroquinone features an amide–amide dimer synthon. Cocrystal formation was evidenced from the shifts in the vibrational frequencies corresponding to the functional groups present on the cocrystal components. 相似文献108.
109.
C.R.A. Catlow M. Cherry K.H. Chow S.P. Cottrell S.F.J. Cox E.A. Davis K.V. Wright 《Hyperfine Interactions》1997,106(1-4):119-122
The expectation that the hydroxyl analogue state of positive muons implanted in quartz should be stabilized by a suitable
charge compensation centre is supported by preliminary data. The diamagnetic fraction correlates with aluminium content over
the narrow range investigated.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
110.
ZHANG Shujun CHENG Zhenxiang LI Guangming WANG Changqing HOU Xueyuan SUN Yuming Y. T. Chow SHAO Zongshu CHEN Huanchu 《中国光学快报(英文版)》2000,9(3)
NdxGd1-xCa4O(BO3)3 (NdGdCOB) is a new self-frequency-doubling (SFD) solid-solution crystal. The second-harmonic generation (SHG) phase-matching (PM) curves were calculated by using refractive indices. The deff of NdGdCOB crystal along different PM directions were calculated according to the sellmeier equation and dijk data in which the (θ=66.8°, φ=132.6°) PM direction has the highest deff. SFD experiments were carried out with Ti:sapphire CW laser and pulsed dye-laser. A green laser output power up to 225 mW at 530 nm was achieved from a 7×3×3 mm3 crystal sample pumped by 1560 mW CW Ti:sapphire laser. The lasing threshold of SFD was lower than 1.8 mW along the PM direction (66.8°,132.6°). The optical-optical conversion efficiency was 14.4%. The conversion efficiency was 7.7% when 10×3×3 mm3 sample was side-pumped by the pulsed dye-laser tuned to 595.4 nm with 17.5 mJ energy and the lasing threshold is 1.2 mJ. 相似文献