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991.
《Analytical letters》2012,45(4):649-661
Abstract Trans‐resveratrol is a metabolite involved in resistance of plants during biotic and abiotic stress. Here we report the optimization of a rapid solvent extraction protocol and its application to different parts of grapevines. We also demonstrate the influence of sample pretreatment with liquid nitrogen on trans‐resveratrol stability, which results as the key step in avoiding oxygen degradation during solvent extraction. Up to 94% of trans‐resveratrol was recovered using this procedure. Berries and leaves from healthy and symptomatic, esca proper–affected vines collected at two different phenological growth stages were analyzed. Trans‐resveratrol was determined in berry and leaf samples; symptomatic vines always showed a significantly higher amount with respect to healthy vines. The mean concentration of trans‐resveratrol in berries was 0.93 µg/gdm and 1.92 µg/gdm at veraison and 1.49 µg/gdm and 2.72 µg/gdm at harvest from healthy and symptomatic vines, respectively. 相似文献
992.
Wen Wen Chen 《Molecular physics》2013,111(20):2213-2220
Two modified Mayer-sampling methods are described based on Transition Matrix Monte Carlo (TMMC) and overlap sampling for calculating the integrated diagrams appearing in the coefficients of the bridge function; bn (r) constructed in terms of the total correlation function h(r) for a hard-sphere system. Calculations are performed using prescribed h(r) for reduced densities at 0.2, 0.5 and 0.8 up to the third-order expansion in density. The results from these methods compared with the generic Monte Carlo Mayer-sampling are analysed in detail. It was found that the TMMC Mayer-sampling approach shows better precision over core and tail regions of b 2(r) and b 3(r), and the overlap sampling method shows overall improvement in the precision of the bridge coefficients. Both methods can be straightforwardly applied to calculate higher order bridge function coefficients and to any model systems with relatively simple modifications. 相似文献
993.
An optical transfer matrix (OTM) is introduced and proposed to analyze the performance of optical polarization imaging systems. This 4 × 4 OTM describes the frequency transfer characteristics of the optical system for each Stokes parameter. It includes the transfer functions and the crosstalk functions. The transfer functions can be used to analyze the imaging quality of the system for each polarization component, while crosstalk functions indicate the polarization errors. We calculate the modulation transfer matrix as an example and numerically simulate the Stokes vector imaging for a polarization imaging system with a singlet and rotating polarization elements. The simulated imaging results show conformance with the analysis. 相似文献
994.
Chicken breast is not preferred in Japan because it is not juicy. In this study, the effect of combined high pressure and sodium hydrogen carbonate (NaHCO3) treatment on the texture and palatability of chicken breast was investigated. The sample used was broiler chicken breast. Meat samples were soaked in.0–.4 M NaHCO3 solution and then pressurized at 100–400 MPa. After pressurization, the samples were heated for 30 min at 80°C and cooled down in ice-cold water. High pressure and NaHCO3 treatment of broiler chicken breast resulted in increased water content, and decreased weight reduction and rupture stress. Moreover, meat exposed to 200 MPa pressurization and.3 M NaHCO3 treatment was judged tender, juicy and of good taste by sensory evaluation. The combination of high pressure and NaHCO3 treatment can be effectively used for broiler chicken breast production. 相似文献
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风力机叶片21%相对厚度翼型粗糙敏感性研究 总被引:4,自引:0,他引:4
基于变速变桨水平轴风力机,依据动量叶素理论和风力机实例,分析得出了叶片外侧翼型(包括21%相对厚度翼型)在低于额定风速变速运行阶段的粗糙敏感性评价指标为升力系数和升阻比的下降率;提出了根据升、阻力系数对输出功率的作用大小来确定两粗糙敏感性评价指标权重系数的方法,并用实例演示了21%相对厚度翼型粗糙敏感性评判基准的获得;另外,通过正交设计、XFOIL软件几何造型与气动计算和方差分析得出了翼型各几何参数在不同雷诺数下对粗糙敏感性不同评价指标的影响程度和最优组合是不一样的。本文结论可为不同风况下风力机翼型的设计和粗糙敏感性评价提供参考。 相似文献
999.
In this paper, we propose a modified fitness evaluation mechanism, which integrates the environmental factors into the focal player’s fitness calculation, to investigate the evolution of cooperative behaviors in the prisoner’s dilemma game. Here, the fitness of a player is computed by combining the individual raw payoff and the highest payoff within the neighborhood, which is regulated by a single parameter termed as trust level η. We show, compared to the traditional version (η=0), that the cooperation level can be highly enhanced for η>0. Meanwhile, we illustrate the dynamical evolution of cooperators on the square lattice, and for different defection parameters b the FC−K curves are utilized to investigate the impact of noise during the strategy updates. Likely, the role of pursuing the highest payoff within the neighborhood also favors the survival of cooperators in the spatial snowdrift game. In addition, the sensibility of knowing the external factors is often not identical for all individuals and we consider the distributed trust level in which η is a distributed parameter, and the results indicate that pursuing the highest payoff in the neighborhood is also inspiring as a consequence of its positive effect on cooperation. The current results are highly instructive for us to further understand the maintenance and emergence of cooperation under the framework of evolutionary game theory. 相似文献
1000.
Guided plate wave scattering at vertical stiffeners and its effect on source location 总被引:1,自引:0,他引:1
This paper examines guided wave transmission characteristics of plate stiffeners and their influence on the performance of acoustic noise source location. The motivation for this work is the detection of air leaks in manned spacecraft. The leaking air is turbulent and generates noise that can be detected by a contact-coupled acoustic array to perform source location and find the air leak. Transmission characteristics of individual integral stiffeners are measured across a frequency range of 50-400 kHz for both high and low aspect-ratio rectangular stiffeners, and comparisons are made to model predictions which display generally good agreement. It is demonstrated that operating in frequency ranges of high plate wave stiffener transmission significantly improves the reliability of noise source location in the plate. A protocol is presented to enable the selection of an optimal frequency range for leak location. 相似文献