排序方式: 共有10条查询结果,搜索用时 15 毫秒
1
1.
冠心病患者尽管接受了标准的氯吡格雷治疗,但仍有一部分患者对氯吡咯雷表现为低反应甚至无反应,称为氯吡格雷抵抗。导致这种抵抗现象的可能原因包括患者个体的基因多态性和药物之间的相互作用等。临床处理的主要对策有提高氯吡格雷的给药剂量和采用新型药物等。笔者就现有的临床研究证据对氯吡格雷抵抗的定义、发生机制及临床干预策略进行了综述。 相似文献
2.
3.
4.
Near-optimal control of a stochastic rumor spreading model with Holling II functional response function and imprecise parameters 下载免费PDF全文
Liang'an Huo 《中国物理 B》2021,30(12):120205-120205
In recent years, rumor spreading has caused widespread public panic and affected the whole social harmony and stability. Consequently, how to control the rumor spreading effectively and reduce its negative influence urgently needs people to pay much attention. In this paper, we mainly study the near-optimal control of a stochastic rumor spreading model with Holling II functional response function and imprecise parameters. Firstly, the science knowledge propagation and the refutation mechanism as the control strategies are introduced into a stochastic rumor spreading model. Then, some sufficient and necessary conditions for the near-optimal control of the stochastic rumor spreading model are discussed respectively. Finally, through some numerical simulations, the validity and availability of theoretical analysis is verified. Meanwhile, it shows the significance and effectiveness of the proposed control strategies on controlling rumor spreading, and demonstrates the influence of stochastic disturbance and imprecise parameters on the process of rumor spreading. 相似文献
5.
Dynamical behavior and optimal impulse control analysis of a stochastic rumor spreading model 下载免费PDF全文
Liang'an Huo 《中国物理 B》2022,31(11):110204-110204
The Internet era has brought great convenience to our life and communication. Meanwhile, it also makes a bunch of rumors propagate faster and causes even more harm to human life. Therefore, it is necessary to perform effective control mechanisms to minimize the negative social impact from rumors. Thereout, firstly, we formulate a rumor spreading model considering psychological factors and thinking time, then, we add white noise (i.e., stochastic interference) and two pulse control strategies which denote education mechanism and refutation mechanism into the model. Secondly, we obtain the global positive solutions and demonstrate the global exponential stability of the unique positive periodic rumor-free solution. Thirdly, we discuss the extinction and persistence of rumor. Moreover, we use Pontriagin's minimum principle to explore the optimal impulse control. Finally, several numerical simulations are carried out to verify the effectiveness and availability of the theoretical analysis. We conclude that the pulse control strategies have a great influence on controlling rumor spreading, and different control strategies should be adopted under different transmission scenarios. 相似文献
6.
时域有限差分法对双原子分子振动光谱计算的应用 总被引:9,自引:1,他引:8
描述了将时域有限差分法应用于双原子分子振动能级的量子力学计算的 方法。推导了含时Schrdinger方程的离散化公式,提出了对含时Schrdinger方程作数值求解的边界截断处理方法。在此基础上,利用HF分子的势能函数,对HF分子的振动能级进行 了数值计算。结果表明,将时域有限差分法应用于双原子分子振动能级的量子力学计算是方 便可行的。计算结果令人满意。 相似文献
7.
8.
冠心病患者PCI前后生活质量的变化 总被引:1,自引:0,他引:1
应用普适性量表-医学结局研究简短量表和冠心病专用量表-西雅图心绞痛调查问卷评价经皮冠状动脉介入治疗对冠心病患者生活质量的影响.以PCI治疗成功病例171例和同期接受单纯药物治疗的冠心病病人198例为对象,采用回顾性问卷调查的方式调查患者在入院前1 d、出院后第1天以及病人出院后6个月的生活质量.PCI治疗组患者的生活质量为出院后6个月>出院前>入院前(P<0.05);药物治疗组患者的生活质量为出院后6个月>出院前>入院前(P<0.05);PCI治疗组患者生活质量变化幅度高于药物治疗组患者的生活质量变化幅度;PCI手术可以显著提高冠心病患者的住院期间和出院后近期的生活质量. 相似文献
9.
蔬菜中不同价态铬元素分析检测能对蔬菜中铬的营养与安全做出正确的评价。为了准确的了解蔬菜中铬的含量及危害,本研究利用高效液相色谱仪-电感耦合等离子体质谱仪(HPLC-ICP-MS)联用技术,以姜、番薯、莲藕等3种蔬菜作为主要研究对象,优化合理有效的提取方式,分离技术以及采集方法,建立测定蔬菜中三价铬和六价铬含量的铬形态分析方法。研究结果表明,以10 mmol/L EDTA-硝酸铵溶液作为提取溶剂,在50 ℃温度下提取络合15 min,该提取方式既保证三价铬完全络合,又能减少六价铬的转化;以 pH值为7.0,50 mmol/L硝酸铵溶液作为流动相,选择52Cr作为铬的质量数,采用氦气碰撞模式进行采集分析,可以在5 min内完成三价铬与六价铬的有效分离和测定;该方法的线性范围为5~200 μg/L,相关系数均大于 0.9999,三价铬与六价铬的方法检出限分别为 0.010 mg/kg 和 0.015mg/kg,精密度RSD分别为0.93% 和1.32%,加标回收结果良好,各技术指标表明该方法能满足测定的需求;本研究所建立的方法前处理操作简单且合理有效、检出限低、准确性和重复性好,可实现对蔬菜中铬形态的快速准确分析。 相似文献
10.
1