In this study,we focus on the gravitational waves emitted by a stellar-mass object in a quasi-circular inspiral orbit around a central supermassive polymerized black hole in loop quantum gravity.Treating the stellar-m...In this study,we focus on the gravitational waves emitted by a stellar-mass object in a quasi-circular inspiral orbit around a central supermassive polymerized black hole in loop quantum gravity.Treating the stellar-mass object as a massive test particle,we derive its equations of motion and the corresponding radial effective potential.We find that the peak of the radial effective potential decreases with the quantum parameter k.We also examine the impact of quantum corrections on the properties of stable circular orbits(SCOs)around the polymerized black hole.We model the smaller object's trajectory as an adiabatic evolution along SCOs using a semi-relativistic approach.In this method,the motion of the object is described by relativistic geodesics,and changes in the object's energy and orbital angular momentum due to gravitational radiation are calculated using the mass quadrupole formula.The corresponding gravitational waveforms are generated using the numerical kludge method,revealing that quantum corrections cause phase advances in the gravitational waveforms.We further analyze the potential constraints on the quantum parameter k from future space-based gravitational wave observations,concluding that the constraints on k imposed by these observations will likely be stronger than those imposed by black hole shadow measurements.展开更多
采用光学显微镜(optical microscope,OM)、扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)、硬度和电导率试验仪器,研究了Cu-Ni-Fe-P合金成分设计、微观结构和性能之间的构...采用光学显微镜(optical microscope,OM)、扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)、硬度和电导率试验仪器,研究了Cu-Ni-Fe-P合金成分设计、微观结构和性能之间的构效关系。结果表明,Ni/Fe质量比对合金性能具有显著调控作用,当Ni/Fe质量比为3.00时,Cu-Ni-Fe-P合金在500℃时效0.50 h条件下维氏硬度达到峰值,为171.5,此时析出相平均尺寸为2.2 nm,随着时效时间延长至12.00 h时,析出相平均尺寸增大到5.6 nm。Fe元素的添加降低了溶质原子的固溶度,有效抑制了基体晶格畸变,提高了合金导电性,当Ni/Fe质量比为1.00时,Cu-Ni-Fe-P合金电导率在500℃/12.00 h时效条件下可达峰值63.6%IACS。其中,当Ni/Fe质量比为1.00时,500℃/6.00 h时效条件下,Cu-Ni-Fe-P合金的综合性能最好。展开更多
目的:探索腰椎疾病患者血清尿酸/肌酐比值(serum uric acid/creatinine,SUA/Cr)与骨骼肌质量指数(muscle mass index,SMI)的相关性。方法:选取2023年9月至2024年9月收治的101例腰椎疾病住院患者,收集患者临床资料及实验室检查结果,使用...目的:探索腰椎疾病患者血清尿酸/肌酐比值(serum uric acid/creatinine,SUA/Cr)与骨骼肌质量指数(muscle mass index,SMI)的相关性。方法:选取2023年9月至2024年9月收治的101例腰椎疾病住院患者,收集患者临床资料及实验室检查结果,使用双能X线吸收测定法(dual-energy X-ray absorptiometry,DXA)测量骨密度、SMI以及身体质量指数(body mass index,BMI)。并根据2019年亚洲肌肉减少症工作组(Asian Working Group for Sarcopenia,AWGS)的诊断标准,分为SMI降低组(51例)和SMI正常组(50例),比较两组的临床资料。通过Spearman相关分析研究SMI与相关变量之间的相关性,通过多因素Logistics回归分析SMI的影响因素。结果:两组经单因素分析比较,在BMI、全身骨密度(total body bone mineral density,TBMD)、血红蛋白(hemoglobin,HB)、血尿酸(uric acid,UA)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、SUA/Cr方面差异均有统计学意义(P<0.05)。将两组间比较P<0.05的指标与SMI进行Spearman相关分析,结果显示SMI降低组与正常组中SMI与BMI、TBMD、HB、UA、SUA/Cr均成正相关(P<0.05),与HDL-C成负相关,两组SMI与各指标的相关性方向一致。以是否SMI降低(SMI降低=1,SMI正常=0)为因变量,以相关性有统计学意义(P<0.05)的指标为自变量进行多重Logistic回归分析。尽管两组基线特征存在差异,但相关性分析中SMI与各指标的相关性方向一致,因此在Logistic分析中做总样本量分析(样本量=101例),采用向前回归法对回归方程进行评价,得到自变量为BMI、TBMD、HDL-C、SUA/Cr的回归模型,分析显示:BMI、TBMD、HDL-C、SUA/Cr是SMI的独立影响因素。结论:低SUA/Cr是腰椎疾病患者低SMI的危险因素。对于SUA/Cr较低的腰椎疾病患者,应注意筛查肌少症。展开更多
基金Supported by the National Key Research and Development Program of China(2021YFC2203003)the National Natural Science Foundation of China(12475056,12105126,12275238,12247101)+2 种基金the National Natural Science Foundation of Gansu Province(22JR5RA389)the‘111 Center'(B20063),the Zhejiang Provincial Natural Science Foundation of China(LR21A050001,LY20A050002)the Fundamental Research Funds for the Provincial Universities of Zhejiang in China(RF-A2019015)。
文摘In this study,we focus on the gravitational waves emitted by a stellar-mass object in a quasi-circular inspiral orbit around a central supermassive polymerized black hole in loop quantum gravity.Treating the stellar-mass object as a massive test particle,we derive its equations of motion and the corresponding radial effective potential.We find that the peak of the radial effective potential decreases with the quantum parameter k.We also examine the impact of quantum corrections on the properties of stable circular orbits(SCOs)around the polymerized black hole.We model the smaller object's trajectory as an adiabatic evolution along SCOs using a semi-relativistic approach.In this method,the motion of the object is described by relativistic geodesics,and changes in the object's energy and orbital angular momentum due to gravitational radiation are calculated using the mass quadrupole formula.The corresponding gravitational waveforms are generated using the numerical kludge method,revealing that quantum corrections cause phase advances in the gravitational waveforms.We further analyze the potential constraints on the quantum parameter k from future space-based gravitational wave observations,concluding that the constraints on k imposed by these observations will likely be stronger than those imposed by black hole shadow measurements.
文摘目的:探索腰椎疾病患者血清尿酸/肌酐比值(serum uric acid/creatinine,SUA/Cr)与骨骼肌质量指数(muscle mass index,SMI)的相关性。方法:选取2023年9月至2024年9月收治的101例腰椎疾病住院患者,收集患者临床资料及实验室检查结果,使用双能X线吸收测定法(dual-energy X-ray absorptiometry,DXA)测量骨密度、SMI以及身体质量指数(body mass index,BMI)。并根据2019年亚洲肌肉减少症工作组(Asian Working Group for Sarcopenia,AWGS)的诊断标准,分为SMI降低组(51例)和SMI正常组(50例),比较两组的临床资料。通过Spearman相关分析研究SMI与相关变量之间的相关性,通过多因素Logistics回归分析SMI的影响因素。结果:两组经单因素分析比较,在BMI、全身骨密度(total body bone mineral density,TBMD)、血红蛋白(hemoglobin,HB)、血尿酸(uric acid,UA)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、SUA/Cr方面差异均有统计学意义(P<0.05)。将两组间比较P<0.05的指标与SMI进行Spearman相关分析,结果显示SMI降低组与正常组中SMI与BMI、TBMD、HB、UA、SUA/Cr均成正相关(P<0.05),与HDL-C成负相关,两组SMI与各指标的相关性方向一致。以是否SMI降低(SMI降低=1,SMI正常=0)为因变量,以相关性有统计学意义(P<0.05)的指标为自变量进行多重Logistic回归分析。尽管两组基线特征存在差异,但相关性分析中SMI与各指标的相关性方向一致,因此在Logistic分析中做总样本量分析(样本量=101例),采用向前回归法对回归方程进行评价,得到自变量为BMI、TBMD、HDL-C、SUA/Cr的回归模型,分析显示:BMI、TBMD、HDL-C、SUA/Cr是SMI的独立影响因素。结论:低SUA/Cr是腰椎疾病患者低SMI的危险因素。对于SUA/Cr较低的腰椎疾病患者,应注意筛查肌少症。
