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1.
Enthalpy-entropy compensation (EEC) is very often encountered in chemistry, biology and physics. Its origin is widely discussed since it would allow, for example, a very accurate tuning of the thermodynamic properties as a function of the reactants. However, EEC is often discarded as a statistical artefact, especially when only a limited temperature range is considered. We show that the likeliness of a statistical origin of an EEC can be established with a compensation quality factor (CQF) that depends only on the measured enthalpies and entropies and the experimental temperature range. This is directly derived from a comparison of the CQF with threshold values obtained from a large number of simulations with randomly generated Van ‘t Hoff plots. The value of CQF is furthermore a direct measure of the existence of a genuine isoequilibrium or isokinetic relationship.  相似文献   
2.
《Physics letters. A》2020,384(9):126186
The phase diagrams and magnetic properties of double perovskite Sr2CrIrO6 have been studied by using Monte Carlo simulation based on the heat bath algorithm. The ground-state diagrams of the compound Sr2CrIrO6 have been calculated for different combinations of system parameters. The diagrams obtained are very rich and they give an idea of all the most stable configurations. The effects of the exchange interactions and the crystal field on the phase diagrams and magnetic properties of the system have been examined. A number of interesting phenomena have been observed such as the compensation temperature, the first and second order phase transitions, the critical triple point and the terminal critical point.  相似文献   
3.
This work introduces the join the shortest queue policy in the retrial setting. We consider a Markovian single server retrial system with two infinite capacity orbits. An arriving job finding the server busy, it is forwarded to the least loaded orbit. Otherwise, it is forwarded to an orbit randomly. Orbiting jobs of either type retry to access the server independently. We investigate the stability condition, the stationary tail decay rate, and obtain the equilibrium distribution by using the compensation method.  相似文献   
4.
针对高超音速飞行器执行器饱和的问题,在考虑全维运动及系统不确定项的情况下,提出了一种基于执行器误差补偿的非线性反步自适应控制方法,该方法通过引入执行器误差动态补偿机制,使得当控制输入超出其自身幅值限制时,能够立刻恢复到其幅值限制范围内,且引入小波神经网络自适应律和鲁棒项确保闭环系统是最终一致有界稳定,通过仿真验证了所设计方法的有效性。  相似文献   
5.
蔡建文  黄文浩 《光子学报》2014,39(7):1243-1247
为实现三维光存储中折射率失配引起的球差补偿,建立了光学存储系统模型,获得了折射率失配引起的波前偏差函数与存储深度的表达式.采用泽尔尼克循环多项式对波前偏差函数进行补偿展开.在双光子荧光和单光子共焦荧光读出方式下,均可获得读出荧光强度与存储深度的关系:在折射率失配引起的球差未得到补偿矫正的情况下,存储深度在200 μm左右读出荧光强度基本上下降为零;当折射率失配引起的初级球差被补偿矫正后,读出荧光强度随存储深度的下降得到较好改善;当折射率失配引起的二级球差被补偿矫正后,存储深度在1 mm内存储点强度随深度基本上没有明显地变化.并且对像差补偿方法进行了具体地分析.  相似文献   
6.
郭媛  王玉田 《光子学报》2014,40(8):1186-1190
根据激光线阵CCD检测技术原理,提出一种快速、高准确度的轧辊辊型检测方法,阐述了系统组成与检测过程.针对辊型检测过程中易出现的轴线偏移现象,从垂直检测平面和平行检测平面两个方向采取补偿措施,有效地提高了系统检测准确度.同时检测系统对CCD信号进行处理时,采用浮动阈值法,有效降低噪音对CCD成像质量的影响,保证了系统的分辨率与检测准确度.实验证明,系统的检测准确度可达到实际生产过程中辊型检测的要求,为实现辊型在线检测的高速、高准确度、高自动化提供了一种新的研究方法.  相似文献   
7.
A mixed-spin Ising model on a decorated Bethe lattice is rigorously solved by combining the decoration–iteration transformation with the method of exact recursion relations. Exact results for critical lines, compensation temperatures, total and sublattice magnetizations are obtained from a precise mapping relationship with the corresponding spin-1/2 Ising model on a simple (undecorated) Bethe lattice. The effect of next-nearest-neighbour interaction and single-ion anisotropy on magnetic properties of the ferrimagnetic model is investigated in particular. It is shown that the total magnetization may exhibit multicompensation phenomenon and the critical temperature vs. the single-ion anisotropy dependence basically changes with the coordination number of the underlying Bethe lattice. The possibility of observing reentrant phase transitions is related to a high enough coordination number of the underlying Bethe lattice.  相似文献   
8.
The magnetic properties of a mixed spin-1 and spin-3/2 Heisenberg ferrimagnetic system on a square lattice are investigated by using the double-time temperature-dependent Green's function technique. In order to decouple the higher order Green's functions, Anderson and Callen's decoupling and random phase approximations have been used. The nearest- and next-nearest-neighbor interactions and the single-ion anisotropies are considered and their effects on compensation and critical temperature are studied.  相似文献   
9.
光载超宽带脉冲雷达信号传输性能研究   总被引:2,自引:1,他引:1  
姚现勋  闫娟娟 《光子学报》2012,41(5):522-527
采用双并行马赫曾德尔调制器产生高斯脉冲一阶微分和二阶微分型超宽带脉冲雷达信号和光载无线电传输技术,通过仿真研究了两种超宽带脉冲雷达信号在标准单模光纤中的传输特性.结果表明,高斯脉冲一阶微分型脉冲随着传输距离的增大而不断展宽,而高斯脉冲二阶微分型脉冲则先压缩后展宽.经100km标准单模光纤传输之后,在传输终端采用色散补偿光纤对传输信号进行不同程度的色散补偿,可获得满足美国联邦通信委员会规范要求的不同宽度高斯脉冲一阶微分和二阶微分型脉冲信号.  相似文献   
10.
Acetylcarnitine has been identified as one of several urinary biomarkers indicative of radiation exposure in adult rhesus macaque monkeys (non‐human primates, NHPs). Previous work has demonstrated an up‐regulated dose‐response profile in a balanced male/female NHP cohort. 1 As a contribution toward the development of metabolomics‐based radiation biodosimetry in human populations and other applications of acetylcarnitine screening, we have developed a quantitative, high‐throughput method for the analysis of acetylcarnitine. We employed the Sciex SelexIon DMS‐MS/MS QTRAP 5500 platform coupled to flow injection analysis (FIA), thereby allowing for fast analysis times of less than 0.5 minutes per injection with no chromatographic separation. Ethyl acetate is used as a DMS modifier to reduce matrix chemical background. We have measured NHP urinary acetylcarnitine from the male cohorts that were exposed to the following radiation levels: control, 2, 4, 6, 7, and 10 Gy. Biological variability, along with calibration accuracy of the FIA‐DMS‐MS/MS method, indicates LOQ of 20 μM, with observed biological levels on the order of 600 μM and control levels near 10 μM. There is an apparent onset of intensified response in the transition from 6 to 10 Gy. The results demonstrate that FIA‐DMS‐MS/MS is a rapid, quantitative technique that can be utilized for the analysis of urinary biomarker levels for radiation biodosimetry.  相似文献   
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