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101.
The effects of environmental aging and accelerated aging on tensile and flexural behavior of bamboo fiber reinforced polypropylene composite (BFRP) and bamboo-glass fiber reinforced polypropylene hybrid composite (BGRP), all with a 30% (by mass) fiber content, were studied by exposing the samples in water at 25°C for up to 1600 h and at 75°C for up to 600 h. Reduction in tensile strength for BFRP and BGRP was 12.2% and 7.5%, respectively, after aging at 25°C for about 1200 h. Tensile and flexural strength of BFRP and BGRP were reduced by 32%, 11.7%, and 27%, 7.5% respectively, after aging at 75°C for 600 h. While the strengths of the bamboo fiber reinforced composites reduce with sorption time and temperature, the environmental degradation process can be delayed by adding a small amount of glass fiber. Moisture sorption and strength reduction are further suppressed by using maleic anhydride polypropylene (MAPP) as a coupling agent in both types of composite system. 相似文献
102.
The authors propose that volitional action is supported by intuitive affect regulation, defined as flexible, efficient, and nonrepressive control of own affective states. Intuitive affect regulation should be most apparent among action-oriented individuals under demanding conditions. Consistent with this, a demanding context led action-oriented individuals to down-regulate negative affect in self-reports (Study 1), in an affective Simon task (Study 2), and in a face discrimination task (Study 3). In line with the idea that intuitive affect regulation is guided by top-down self-regulation processes, intuitive affect regulation in a face discrimination task was mediated by increases in self-accessibility (Study 3). No parallel effects emerged among action-oriented participants in a nondemanding context or among state-oriented participants. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
103.
SW Tan M Singh LC Ho J Howe KT Moe XQ Chen GC Ng EH Yap 《Canadian Metallurgical Quarterly》1997,27(8):947-954
Our previous studies have shown that monoclonal antibodies (MAbs) to Blastocystis hominis react mainly with carbohydrate epitopes, while 1 MAb (1D5) reacts specifically with a protein of 30.5 kDa. In the present study, 3 monoclonal antibodies (1D5, 1E7 and 4F7) were used in immunogold localization. 1E7 and 4F7 were found to react primarily with the surface coat, while 1D5 was plasma membrane-specific. In the presence of complement, only 1D5 exhibited a cytotoxic effect on B. hominis whereas 1E7 and 4F7 did not, suggesting that the surface coat of B. hominis could serve as an immunological barrier against host antibodies. Using a recently described agar plating method, only 1D5 exhibited significant (P < 0.01) complement-independent cytotoxicity to B. hominis, inhibiting colony growth at low concentrations. Parasites that had been exposed to 1D5 were morphologically smaller than those that were not exposed to this MAb. Colonies that grew in the presence of 1D5 were isolated and grown in liquid medium containing increasing amounts of the cytotoxic MAb. Two clones that grew well in liquid medium containing 1D5 were also able to develop into colonies in soft agar. This study has shown that the 30.5 kDa protein found on the plasma membrane of B. hominis is a functionally important protein and that not all cells within a certain population would be susceptible to the cytotoxic effects of 1D5. These findings suggest that a heterogenous population exists in continuously maintained cultures of B. hominis. 相似文献
104.
Lars-Olof Kihlstrm Nils Viklund David Bridgewater 《International Journal of Satellite Communications and Networking》1990,8(6):461-490
This paper discusses the systematization effort undertaken to generate an equipment specification of an extremely detailed and new nature for DCMEs in accordance with the INTELSAT specification IESS-501. The main areas of importance addressed are additional to what has already been defined within the IESS-501. A discussion of important aspects when introducing DCME into actual network conditions is also contained and results based on simulations of performance under simulated network environments are included. 相似文献
105.
渗透汽化分离有机混合物 总被引:6,自引:1,他引:5
采用渗透汽化进行了两类有机混合物的分离,一是从C4、C5醚后混合物中脱甲醇,二是从时、间二甲苯混合物中分离对二甲苯。以一定比例的醋酸纤维素(CA)与聚丙烯酸醋共混物的表皮分离层材料,制备渗透汽化复合膜脱除C4、C5醚后混合物中的甲醇,实验考察了料液浓度、温度等操作条件对膜分离性能的影响。结果表明共混膜兼有两类膜材料的优点,当原料中甲醇质量分数为0.4%时,膜内甲醇通量为230g/m^2·h,分离因 相似文献
106.
Peter Diener Ernst Nils Dorband Erik Schnetter Manuel Tiglio 《Journal of scientific computing》2007,32(1):109-145
We construct optimized high-order finite differencing operators which satisfy summation by parts. Since these operators are
not uniquely defined, we consider several optimization criteria: minimizing the bandwidth, the truncation error on the boundary
points, the spectral radius, or a combination of these. We examine in detail a set of operators that are up to tenth order
accurate in the interior, and we surprisingly find that a combination of these optimizations can improve the operators’ spectral
radius and accuracy by orders of magnitude in certain cases. We also construct high-order dissipation operators that are compatible
with these new finite difference operators and which are semi-definite with respect to the appropriate summation by parts
scalar product. We test the stability and accuracy of these new difference and dissipation operators by evolving a three-dimensional
scalar wave equation on a spherical domain consisting of seven blocks, each discretized with a structured grid, and connected
through penalty boundary conditions. In particular, we find that the constructed dissipation operators are effective in suppressing
instabilities that are sometimes otherwise present in the restricted full norm case. 相似文献
107.
This is the second part of a paper, which is concerned with the development of a numerical algorithm for the solution of a class of differential games. The theoretical derivation is made in Part I and this part exemplifies the use of the algorithm on an atmospheric pursuit-evasion game with a nonlinear dynamic structure. The applicability and efficiency of the method is discussed in a concluding section. 相似文献
108.
Aligned eutectic composites of unstabilized ZrO2-Ta and Y2O3-stabilized ZrO2-Ta were grown by direct internal zone melting. Samples with unstabilized ZrO2 were almost completely crack-free even though the matrix had transformed from the tetragonal to the monoclinic lattice. Stabilized ZrO2-Ta composites were heavily cracked and exhibited less homogeneous fiber growth. The Ta fiber diameter in unstabilized eutectics decreased from 0.45 to 0.20 μm, as growth rates increased from 4.4 to 27 cm/h. The fracture of the composites always took place in a controlled manner. The reason is plastic deformation of the fibers and subsidiary crack formation within the twinned ZrO2 matrix. The Ta fiber ductility is caused by solute Zr which reduces the oxygen solubility of Ta considerably. 相似文献
109.
JZ Melnick PA Srere NA Elshourbagy OW Moe PA Preisig RJ Alpern 《Canadian Metallurgical Quarterly》1996,98(10):2381-2387
Chronic metabolic acidosis increases proximal tubular citrate uptake and metabolism. The present study addressed the effect of chronic metabolic acidosis on a cytosolic enzyme of citrate metabolism, ATP citrate lyase. Chronic metabolic acidosis caused hypocitraturia in rats and increased renal cortical ATP citrate lyase activity by 67% after 7 d. Renal cortical ATP citrate lyase protein abundance increased by 29% after 3 d and by 141% after 7 d of acid diet. No significant change in mRNA abundance could be detected. Hypokalemia, which causes only intracellular acidosis, caused hypocitraturia and increased renal cortical ATP citrate lyase activity by 28%. Conversely, the hypercitraturia of chronic alkali feeding was associated with no change in ATP citrate lyase activity. Inhibition of ATP citrate lyase with the competitive inhibitor, 4S-hydroxycitrate, significantly abated hypocitraturia and increased urinary citrate excretion fourfold in chronic metabolic acidosis and threefold in K+-depletion. In summary, the hypocitraturia of chronic metabolic acidosis is associated with an increase in ATP citrate lyase activity and protein abundance, and is partly reversed by inhibition of this enzyme. These results suggest an important role for ATP citrate lyase in proximal tubular citrate metabolism. 相似文献
110.
The present investigation was designed to examine the effects of sympathetic nervous system (SNS) inhibition on sexual behavior in ovariectomized, steroid-treated female rats. Clonidine, an alpha2-adrenergic agonist, guanethidine, a postganglionic noradrenergic blocker, and naphazoline, an alpha2-adrenoreceptor agonist were used to inhibit SNS activity. Intraperitoneal injections of either 33 micrograms/ml or 66 micrograms/ml clonidine significantly decreased receptive (lordosis) and proceptive (ear wiggles) behaviors and significantly increased rejection behaviors (vocalization, kicking, boxing). Either 25 mg/ml or 50 mg/ml guanethidine significantly decreased receptive and proceptive behavior and had no significant effect on rejection behaviors. Naphazoline significantly inhibited lordosis behavior at either 5 mg/ml or 10 mg/ml doses, significantly inhibited proceptive behavior at 5 mg/ml, and had no significant effect on rejection behaviors. These findings support the hypothesis that SNS inhibition decreases sexual activity in the female rat. 相似文献