The geometric phase has become a fundamental concept in many fields of physics since it was revealed. Recently, the study of the geometric phase has attracted considerable attention in the context of quantum phase tra...The geometric phase has become a fundamental concept in many fields of physics since it was revealed. Recently, the study of the geometric phase has attracted considerable attention in the context of quantum phase transition, where the ground state properties of the system experience a dramatic change induced by a variation of an external parameter. In this work, we experimentally measure the ground-state geometric phase of the three-spin XY model by utilizing the nuclear magnetic resonance technique. The experimental results indicate that the geometric phase could be used as a fingerprint of the ground-state quantum phase transition of many-body systems.展开更多
Quantum discord, as a kind of measurement of quantum correlation, has received much attention since it was introduced. This paper focuses on studying quantum discord in three-spin XXZ chain with three-spin interaction...Quantum discord, as a kind of measurement of quantum correlation, has received much attention since it was introduced. This paper focuses on studying quantum discord in three-spin XXZ chain with three-spin interaction. The effects of all kinds of pa- rameters on quantum discord in the ferromagnetic region J=-I are studied. The three-spin interaction may increase the value of quantum discord between two spins, while the anisotropy may decrease the value. In addition, the regrowth of quantum discord with temperature is found in the model. For zero temperature, quantum phase transition is existent.展开更多
目的探讨磁共振三维动脉自旋标记(3D-ASL)灌注成像和血清非对称性二甲基精氨酸(ADMA)、CXC趋化因子配体12(CXCL12)水平与急性脑梗死(ACI)患者静脉溶栓(IVT)治疗反应性的关系及其对神经康复效果的预测价值。方法选取ACI患者206例,IVT治...目的探讨磁共振三维动脉自旋标记(3D-ASL)灌注成像和血清非对称性二甲基精氨酸(ADMA)、CXC趋化因子配体12(CXCL12)水平与急性脑梗死(ACI)患者静脉溶栓(IVT)治疗反应性的关系及其对神经康复效果的预测价值。方法选取ACI患者206例,IVT治疗前及治疗24 h采用美国国立卫生研究院卒中量表(NIHSS)评分评估治疗反应性,其中IVT治疗无应答61例(无应答组)、有应答145例(有应答组),计算IVT治疗24 h NIHSS评分下降率。IVT治疗前,接受磁共振3D-ASL序列扫描,测量缺血半暗带(IP)脑血容量(CBF);入院当日,采集空腹外周静脉血,离心留取血清,采用双抗体夹心ELISA法检测血清ADMA、CXCL12。比较两组IVT治疗24 h NIHSS评分下降率、CBF及血清ADMA、CXCL12水平。分析ACI患者血清ADMA、CXCL12水平及CBF与IVT治疗24 h NIHSS评分下降率的关系。IVT治疗3个月,采用改良Rankin量表评分评估神经康复情况。采用多因素Logistic回归模型分析ACI患者神经康复效果的影响因素。采用ROC曲线分析血清ADMA、CXCL12水平及CBF对ACI患者神经康复效果的预测价值。结果无应答组IVT治疗24 h NIHSS评分下降率、CBF均显著低于有应答组(P均<0.05),血清ADMA、CXCL12水平均显著高于有应答组(P均<0.05)。Pearson相关分析显示,ACI患者血清ADMA、CXCL12水平与IVT治疗24 h NIHSS评分下降率呈负相关(r分别为-0.769、-0.698,P均<0.05),CBF与IVT治疗24 h NIHSS评分下降率呈正相关(r=0.718,P<0.05)。IVT治疗3个月,ACI患者转归不良45例、转归良好161例。ACI患者转归不良者血清ADMA、CXCL12水平显著高于转归良好者(P均<0.05),CBF显著低于转归良好者(P<0.05)。多因素Logistic回归分析发现,CBF降低及血清ADMA、CXCL12水平升高为ACI患者转归不良的独立危险因素(P均<0.05)。ROC曲线分析发现,CBF及血清ADMA、CXCL12水平单独及联合预测ACI患者转归不良的AUC分别为0.777、0.793、0.788、0.915,血清ADMA、CXCL12水平联合CBF预测ACI患者转归不良的AUC高于三者单独(Z分别为2.904、2.697、2.897,P均<0.05)。结论磁共振3D-ASL灌注成像及血清ADMA、CXCL12水平与ACI患者IVT治疗反应性有一定相关性,三者对ACI患者IVT治疗后神经康复效果均有一定预测价值,三者联合预测价值更高。展开更多
基金Supported by the National Key Basic Research Program under Grant Nos 2013CB921800 and 2014CB848700the National Science Fund for Distinguished Young Scholars under Grant No 11425523+4 种基金the National Natural Science Foundation of China under Grant Nos 11375167,11227901,91021005 and 11575173the Strategic Priority Research Program(B)of the Chinese Academy of Sciences under Grant No XDB01030400the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20113402110044the China Postdoctoral Science Foundationthe Fundamental Research Funds for the Central Universities
文摘The geometric phase has become a fundamental concept in many fields of physics since it was revealed. Recently, the study of the geometric phase has attracted considerable attention in the context of quantum phase transition, where the ground state properties of the system experience a dramatic change induced by a variation of an external parameter. In this work, we experimentally measure the ground-state geometric phase of the three-spin XY model by utilizing the nuclear magnetic resonance technique. The experimental results indicate that the geometric phase could be used as a fingerprint of the ground-state quantum phase transition of many-body systems.
基金supported by the ‘211’ Innovative Talents Cultivation Project of Inner Mongolia Universitythe National Natural Science Foundation of China (Grant No. 10847005)the Inner Mongolia Talent Development Foundation and Chinese Universities Scientific Fund (Grant No.BUPT2011RC0706)
文摘Quantum discord, as a kind of measurement of quantum correlation, has received much attention since it was introduced. This paper focuses on studying quantum discord in three-spin XXZ chain with three-spin interaction. The effects of all kinds of pa- rameters on quantum discord in the ferromagnetic region J=-I are studied. The three-spin interaction may increase the value of quantum discord between two spins, while the anisotropy may decrease the value. In addition, the regrowth of quantum discord with temperature is found in the model. For zero temperature, quantum phase transition is existent.
文摘目的探讨磁共振三维动脉自旋标记(3D-ASL)灌注成像和血清非对称性二甲基精氨酸(ADMA)、CXC趋化因子配体12(CXCL12)水平与急性脑梗死(ACI)患者静脉溶栓(IVT)治疗反应性的关系及其对神经康复效果的预测价值。方法选取ACI患者206例,IVT治疗前及治疗24 h采用美国国立卫生研究院卒中量表(NIHSS)评分评估治疗反应性,其中IVT治疗无应答61例(无应答组)、有应答145例(有应答组),计算IVT治疗24 h NIHSS评分下降率。IVT治疗前,接受磁共振3D-ASL序列扫描,测量缺血半暗带(IP)脑血容量(CBF);入院当日,采集空腹外周静脉血,离心留取血清,采用双抗体夹心ELISA法检测血清ADMA、CXCL12。比较两组IVT治疗24 h NIHSS评分下降率、CBF及血清ADMA、CXCL12水平。分析ACI患者血清ADMA、CXCL12水平及CBF与IVT治疗24 h NIHSS评分下降率的关系。IVT治疗3个月,采用改良Rankin量表评分评估神经康复情况。采用多因素Logistic回归模型分析ACI患者神经康复效果的影响因素。采用ROC曲线分析血清ADMA、CXCL12水平及CBF对ACI患者神经康复效果的预测价值。结果无应答组IVT治疗24 h NIHSS评分下降率、CBF均显著低于有应答组(P均<0.05),血清ADMA、CXCL12水平均显著高于有应答组(P均<0.05)。Pearson相关分析显示,ACI患者血清ADMA、CXCL12水平与IVT治疗24 h NIHSS评分下降率呈负相关(r分别为-0.769、-0.698,P均<0.05),CBF与IVT治疗24 h NIHSS评分下降率呈正相关(r=0.718,P<0.05)。IVT治疗3个月,ACI患者转归不良45例、转归良好161例。ACI患者转归不良者血清ADMA、CXCL12水平显著高于转归良好者(P均<0.05),CBF显著低于转归良好者(P<0.05)。多因素Logistic回归分析发现,CBF降低及血清ADMA、CXCL12水平升高为ACI患者转归不良的独立危险因素(P均<0.05)。ROC曲线分析发现,CBF及血清ADMA、CXCL12水平单独及联合预测ACI患者转归不良的AUC分别为0.777、0.793、0.788、0.915,血清ADMA、CXCL12水平联合CBF预测ACI患者转归不良的AUC高于三者单独(Z分别为2.904、2.697、2.897,P均<0.05)。结论磁共振3D-ASL灌注成像及血清ADMA、CXCL12水平与ACI患者IVT治疗反应性有一定相关性,三者对ACI患者IVT治疗后神经康复效果均有一定预测价值,三者联合预测价值更高。
