排序方式: 共有21条查询结果,搜索用时 15 毫秒
11.
We study the sign distribution of generalized magnetic susceptibilities in the temperature-external magnetic field plane using the three-dimensional three-state Potts model. We find that the sign of odd-order susceptibility is opposite in the symmetric(disorder) and broken(order) phases, but that of the even-order one remains positive when it is far away from the phase boundary. When the critical point is approached from the crossover side, negative fourth-order magnetic susceptibility is observable. It is also demonstrated that non-monotonic behavior occurs in the temperature dependence of the generalized susceptibilities of the energy. The finite-size scaling behavior of the specific heat in this model is mainly controlled by the critical exponent of the magnetic susceptibility in the three-dimensional Ising universality class. 相似文献
12.
根据山东省1960—2018年的逐月降水量观测数据,采用标准化降水指数(SPI)作为干旱衡量指标,分析近59年来山东省冬小麦生长期的干旱时空分布特征,研究冬小麦各生长阶段干旱强度及影响范围,为山东省冬小麦的干旱防御及稳定增收提供参考.研究表明:(1)冬小麦生长期内干旱频率多集中在15%~20%之间,相对高值区集中于山东... 相似文献
13.
Based on the universal properties of a critical point in different systems and that the QCD phase transitions fall into the same universality classes as the 3-dimensional Ising, O(2) or O(4) spin models, the critical behavior of cumulants and higher cumulant ratios of the order parameter from the three kinds of spin models is studied. We found that all higher cumulant ratios change dramatically the sign near the critical temperature. The qualitative critical behavior of the same order cumulant ratio is consistent in these three models. 相似文献
14.
2013年6月3日,吉林禽业公司发生大火,300多名员工中120人遇难,是我国2000年以来死亡人数最多的一次火灾.此次火灾造成巨大伤亡的一个重要原因是厂房的6个出口只有3个可用,并且员工不知道每个出口的可用性信息.本文运用经典的地面场模型对吉林禽业火灾逃生过程进行模拟,研究了厂房各出口的重要性差异以及出口的可用性对逃生效果的影响.结果表明,如果多开一个出口,最多可挽救54.3%的遇难者,如果6个出口全部可用,76.6%的遇难者能够逃离.另外,在出口可用性信息完全掌握的情况下,遇难人数也会减少21.6%.由此可见,保证人群集聚现场出口的可用性以及信息的及时流通对于保护人民的生命财产安全至关重要. 相似文献
15.
16.
目的对多通道串联式压电微生物传感仪(MSPQC)的检测时间(FDT)给出更加准确的判定方法,并定量研究十六烷基三甲基溴化铵(CTAB)对铜绿假单胞菌(Pseudomonas aeruginosa)的影响,初步探讨抑制机理。方法用MSPQC,在线监测P.aeruginosa的生长,根据响应曲线判断CTAB对P.aeruginosa的抑制作用。依据实验结果分析了CTAB的变化。结果CTAB的浓度大于5×10^-4g/l时,细菌的生长代谢已经受到抑制,且浓度越高,抑制作用越强。CTAB浓度3.3×10^-1g/l时,Paeruginosa被杀死。结论用MsPQc检测表面活性剂的押菌作用具有实时、快速.定量、灵敏等优势。 相似文献
17.
18.
拍瓦激光系统中剩余的高阶色散导致了脉冲波形的振荡,影响了拍瓦激光的信噪比。为了进一步优化拍瓦激光的信噪比特性,满足激光加速电子、质子等粒子的效率提升需求,本文提出了一种基于双折射晶体的新型超短脉冲的三阶色散主动调控方法,用于信噪比的主动调控。通过数值分析模拟了双折射晶体引入的二阶色散、三阶色散,针对中心波长为1053 nm的拍瓦激光系统,选择适当的晶体厚度,可以通过调节双折射晶体的面内旋转角改变系统剩余三阶色散。同时,基于神光Ⅱ第九路拍瓦激光系统光参量啁啾脉冲放大(OPCPA)预压缩的信噪比测量值,对比了不同量级剩余三阶色散对脉冲信噪比的影响,得出通过改变拍瓦激光系统中剩余三阶色散量,可实现不同量级信噪比的主动调控的结论。该研究结果对于高能激光系统剩余三阶色散的补偿以及信噪比的优化具有重要意义。 相似文献
19.
Taking doubly charged particles,positive-negative charge pair production and the effects of volume fluctuations into account,the Poisson baseline of the fluctuations of net-charge is studied.Within the Poisson baseline,the cumulants of net-charge are derived.Comparing to the Skellam baseline of net-charge,we infer that doubly charged particles broaden the distributions of net-charge,while positive-negative charge pairs narrow the distributions.Using the ratios of doubly charged particles and positive-negative charge pairs from neutral resonance decays to the total positive charges from THERMINATOR 2,the first four orders of moments and the corresponding moment products are calculated in the Poisson baseline for Au + Au collisions at (s_(NN))(1/2)= 200 GeV at RHIC/STAR.We find that the standard deviation is mainly influenced by the resonance decay,while the third and fourth order moments and corresponding moment products are mainly modified and fit the data of RHIC/STAR much better after including the effects of volume fluctuations. 相似文献
20.