本文研究了基于第一性原理平面波赝势及虚晶近似方法的镨(Pr)元素替位掺杂SmCo5体系(PrxSm1−xCo5)的体系的电子结构和磁性。采用CASTEP软件包,基于LDA + U并进行自旋极化计算,研究了不同掺杂参数下PrxSm1−xCo5 (x = 0 − 0.2)体系的能量...本文研究了基于第一性原理平面波赝势及虚晶近似方法的镨(Pr)元素替位掺杂SmCo5体系(PrxSm1−xCo5)的体系的电子结构和磁性。采用CASTEP软件包,基于LDA + U并进行自旋极化计算,研究了不同掺杂参数下PrxSm1−xCo5 (x = 0 − 0.2)体系的能量、分态密度、波尔磁矩等性质,研究表明,PrxSm1−xCo5体系的总态密度在−40 eV附近主要由s轨道贡献,总态密度在−20 eV附近主要由p轨道贡献,d轨道主要来自于Co及Pr/Sm原子,而f轨道贡献则来自于Pr/Sm原子且其自旋向下的密度远高于其自旋向上的密度,同时,随着镨元素掺杂比例的提高,晶格常数(a, c)以及晶胞体积(V)逐步增大,同时体系总能量逐步升高,同时,随着掺杂比例的不断变化,体系的波尔磁矩结果呈现出波动变化的特点,本文的研究有助于优化钐钴永磁体的设计。In this paper, the system energy of praseodymium (Pr) elemental substitution doped SmCo5 system (PrxSm1−xCo5) based on first-principles and virtual-crystal approximation method was studied. The energy, fractional density and Bohr magnetic moment of PrxSm1−xCo5 (x = 0 − 0.2) system under different doping parameters were studied by using CASTEP software package, based on LDA + U and spin polarization calculation, and the results show that the total density of states of the PrxSm1−xCo5 system is mainly contributed by the s orbital around −40 eV, the total density of states near −20 eV is mainly contributed by the p orbital, the d orbital is mainly contributed by Co and Pr/Sm atoms, and the f orbital is contributed by Pr/Sm atoms and its spin down density is much higher than its spin up density. At the same time, the total energy of the system is gradually decreasing, indicating that the system is more stable, and with the continuous change of the doping ratio, the Bohr magnetic moment results of the system show the characteristics of fluctuating changes, and the research in this paper is helpful to optimize the design of samarium cobalt permanent magnets.展开更多
采用水热法合成了Mo-Nb2O5/C纳米片复合材料,对该材料进行形貌、结构表征和电化学性能测试。结果表明,通过钼掺杂碳复合提高了Nb2O5纳米片材料的电子电导率,从而改善了Nb2O5材料的电化学性能。3% Mo-Nb2O5/C-8复合材料具有最佳的电化学...采用水热法合成了Mo-Nb2O5/C纳米片复合材料,对该材料进行形貌、结构表征和电化学性能测试。结果表明,通过钼掺杂碳复合提高了Nb2O5纳米片材料的电子电导率,从而改善了Nb2O5材料的电化学性能。3% Mo-Nb2O5/C-8复合材料具有最佳的电化学性能,表现出优异的循环稳定性及倍率性能。在电流密度为100 mA g−1、电压范围在0.01~3.0 V的条件下,100周循环后,放电比容量为172.8 mAh g−1,容量保持率为84.9%;在500 mA g−1的高电流密度下,500周循环后,仍有119.2 mAh g−1的放电比容量,容量保持率为76.0%。展开更多
采用高纯度的Cr2O5作为原料,利用高温高压方法在不同合成条件下制备高纯度的CrO2,研究不同的合成条件对于制备CrO2晶粒尺寸和形貌的影响。结果表明:随着合成温度的降低,晶粒尺寸明显减小;合成压力的升高,晶粒尺寸明显减小,完整度有一定...采用高纯度的Cr2O5作为原料,利用高温高压方法在不同合成条件下制备高纯度的CrO2,研究不同的合成条件对于制备CrO2晶粒尺寸和形貌的影响。结果表明:随着合成温度的降低,晶粒尺寸明显减小;合成压力的升高,晶粒尺寸明显减小,完整度有一定的提高,但晶体长径比减小;合成时间的变化对晶粒尺寸和晶型完整度无明显影响。High-purity CrO2 was prepared using high-purity Cr2O5 as the raw material through a high temperature and high pressure (HTHP) method under various synthesis conditions. The influence of different synthesis conditions on the grain size and morphology of the prepared CrO2 was investigated. The results indicate that as the synthesis temperature decreases, the grain size decreases significantly. With an increase in synthesis pressure, the grain size also decreases markedly, and the crystallinity improves to some extent, although the aspect ratio of the crystals diminishes. Changes in synthesis time have no notable effect on grain size or crystallinity.展开更多
本研究专注于稀土金属Y和La掺下HfO2薄膜的铁电性。采用脉冲激光沉积技术,在(001)取向SrTiO3衬底上利用La0.7Sr0.3MnO3薄膜作为底电极,成功实现了沿(111)取向生长的外延薄膜。研究发现,掺杂下的HfO2薄膜呈现出较好的结晶性,在室温下压...本研究专注于稀土金属Y和La掺下HfO2薄膜的铁电性。采用脉冲激光沉积技术,在(001)取向SrTiO3衬底上利用La0.7Sr0.3MnO3薄膜作为底电极,成功实现了沿(111)取向生长的外延薄膜。研究发现,掺杂下的HfO2薄膜呈现出较好的结晶性,在室温下压电系数d33约为6 pm/V,畴翻转可达180˚,剩余极化强度可达到12.91 μC/cm2,表现出良好的铁电性。这些实验成果为基于HfO2薄膜的电子器件设计提供了重要的实验基础。This study focuses on the ferroelectric properties of Y and La doped HfO2 thin films. The epitaxial films grown along the (111) orientation were successfully prepared on (001)-oriented SrTiO3 substrate using La0.7Sr0.3MnO3 film as the substrate electrode by Pulsed laser deposition technique. The results show that the doped HfO2 films exhibit good crystallinity, the piezoelectric coefficient d33 is about 6 pm/V at room temperature, the domain inversion can reach 180˚, and the residual polarization strength can reach 12.91 μC/cm2, exhibit good ferroelectric properties. These experimental results provide an important experimental basis for the design of electronic devices based on HfO2 thin films.展开更多
目的:探讨腹腔镜经腹腹膜前腹股沟斜疝修补术(TAPP)中腹膜前间隙CO2与血清肿形成的关系。方法:选取2023年1月至2023年6月于青岛大学附属医院确诊腹股沟斜疝并完成TAPP治疗的101例患者,随机分为试验组(减少腹膜前CO2残余)和对照组。主要...目的:探讨腹腔镜经腹腹膜前腹股沟斜疝修补术(TAPP)中腹膜前间隙CO2与血清肿形成的关系。方法:选取2023年1月至2023年6月于青岛大学附属医院确诊腹股沟斜疝并完成TAPP治疗的101例患者,随机分为试验组(减少腹膜前CO2残余)和对照组。主要结局是比较术后14天、1个月彩色多普勒超声下的血清肿发生情况。次要结局包括术后疼痛程度,复发,感染等。结果:两组患者的年龄、疝环直径、体质量指数(BMI)、病程等基线人口学特征均无显著性差异(P均 > 0.05)。术后14天试验组血清肿体积、发生率,疼痛程度均明显低于对照组,差异有统计学意义(P均 0.05)。其余次要结局均无显著性差异(P均 > 0.05),随访期间两组未出现复发、感染等其他术后并发症。结论:腹腔镜经腹腹膜前腹股沟疝修补术(TAPP)术中减少腹膜前间隙残留CO2是一种安全有效、操作简便的方法,能显著降低血清肿发生率和体积,减轻术后疼痛。Objective: To explore the relationship between CO2 in preperitoneal space and seroma formation in laparoscopic preperitoneal inguinal hernia repair (TAPP). Methods: 101 patients with indirect inguinal hernia diagnosed in the Affiliated Hospital of Qingdao University from January 2023 to June 2023 and completed TAPP treatment were randomly divided into an experimental group (reducing the residual CO2 before peritoneum) and a control group. The main outcome was to compare the incidence of seroma under color Doppler ultrasound 14 days and 1 month after operation. Secondary outcomes included postoperative pain, recurrence and infection. Results: There was no significant difference in baseline demographic characteristics such as age, diameter of hernia ring, body mass index (BMI) and course of disease between the two groups (P > 0.05). Fourteen days after operation, the volume of serum swelling, the incidence rate and the degree of pain in the experimental group were significantly lower than those in the control group, and the difference was statistically significant (P 0.05). There was no significant difference in other secondary outcomes (P > 0.05), and there were no other postoperative complications such as recurrence and infection in the two groups during the follow-up period. Conclusion: Laparoscopic preperitoneal inguinal hernia repair (TAPP) is a safe, effective and simple method to reduce residual CO2 in preperitoneal space, which can significantly reduce the incidence and volume of seroma and relieve postoperative pain.展开更多
文摘本文研究了基于第一性原理平面波赝势及虚晶近似方法的镨(Pr)元素替位掺杂SmCo5体系(PrxSm1−xCo5)的体系的电子结构和磁性。采用CASTEP软件包,基于LDA + U并进行自旋极化计算,研究了不同掺杂参数下PrxSm1−xCo5 (x = 0 − 0.2)体系的能量、分态密度、波尔磁矩等性质,研究表明,PrxSm1−xCo5体系的总态密度在−40 eV附近主要由s轨道贡献,总态密度在−20 eV附近主要由p轨道贡献,d轨道主要来自于Co及Pr/Sm原子,而f轨道贡献则来自于Pr/Sm原子且其自旋向下的密度远高于其自旋向上的密度,同时,随着镨元素掺杂比例的提高,晶格常数(a, c)以及晶胞体积(V)逐步增大,同时体系总能量逐步升高,同时,随着掺杂比例的不断变化,体系的波尔磁矩结果呈现出波动变化的特点,本文的研究有助于优化钐钴永磁体的设计。In this paper, the system energy of praseodymium (Pr) elemental substitution doped SmCo5 system (PrxSm1−xCo5) based on first-principles and virtual-crystal approximation method was studied. The energy, fractional density and Bohr magnetic moment of PrxSm1−xCo5 (x = 0 − 0.2) system under different doping parameters were studied by using CASTEP software package, based on LDA + U and spin polarization calculation, and the results show that the total density of states of the PrxSm1−xCo5 system is mainly contributed by the s orbital around −40 eV, the total density of states near −20 eV is mainly contributed by the p orbital, the d orbital is mainly contributed by Co and Pr/Sm atoms, and the f orbital is contributed by Pr/Sm atoms and its spin down density is much higher than its spin up density. At the same time, the total energy of the system is gradually decreasing, indicating that the system is more stable, and with the continuous change of the doping ratio, the Bohr magnetic moment results of the system show the characteristics of fluctuating changes, and the research in this paper is helpful to optimize the design of samarium cobalt permanent magnets.
文摘目的:对25(OH)D3、甲状旁腺激素(PTH)与慢性心力衰竭心衰(CHF)严重程度的相关性进行系统研究。方法:选取住院CHF患者186例,其中HFpEF 96例,HFmrEF 30例,HFrEF 60例;研究同时选取同期健康人群42例作为对照组,收集一般资料、血清25(OH)D3、PTH、NT-proBNP水平、常规生化指标、心脏彩超结果等,另根据CHF组患者的不同亚型将186例CHF患者分为HFpEF组(96例患者)、HFmrEF组(30例患者)和HFrEF组(60例患者),对比HFpEF组、HFmrEF组和HFrEF组患者血清25(OH)D3和PTH表达水平差异,并进行统计分析。结果:CHF组和对照组一般资料和常规生化指标等资料对比差异无统计学意义(P > 0.05);而CHF组和对照组在25(OH)D3、PTH以及NT-proBNP等资料对比差异有统计学意义(P 3表达水平与CHF疾病的发生呈负相关(r = −0.442, P r = 0.521, P 3表达水平明显低于HFpEF组和HFmrEF组,而PTH表达水平明显高于HFpEF组和HFmrEF组(P P > 0.05)。结论:25‐羟维生素D3和PTH表达水平与心衰严重程度密切相关。25‐羟维生素D3和PTH联合检测对CHF疾病的诊断及病情严重程度评估具有重要的临床意义。
文摘采用水热法合成了Mo-Nb2O5/C纳米片复合材料,对该材料进行形貌、结构表征和电化学性能测试。结果表明,通过钼掺杂碳复合提高了Nb2O5纳米片材料的电子电导率,从而改善了Nb2O5材料的电化学性能。3% Mo-Nb2O5/C-8复合材料具有最佳的电化学性能,表现出优异的循环稳定性及倍率性能。在电流密度为100 mA g−1、电压范围在0.01~3.0 V的条件下,100周循环后,放电比容量为172.8 mAh g−1,容量保持率为84.9%;在500 mA g−1的高电流密度下,500周循环后,仍有119.2 mAh g−1的放电比容量,容量保持率为76.0%。
文摘采用高纯度的Cr2O5作为原料,利用高温高压方法在不同合成条件下制备高纯度的CrO2,研究不同的合成条件对于制备CrO2晶粒尺寸和形貌的影响。结果表明:随着合成温度的降低,晶粒尺寸明显减小;合成压力的升高,晶粒尺寸明显减小,完整度有一定的提高,但晶体长径比减小;合成时间的变化对晶粒尺寸和晶型完整度无明显影响。High-purity CrO2 was prepared using high-purity Cr2O5 as the raw material through a high temperature and high pressure (HTHP) method under various synthesis conditions. The influence of different synthesis conditions on the grain size and morphology of the prepared CrO2 was investigated. The results indicate that as the synthesis temperature decreases, the grain size decreases significantly. With an increase in synthesis pressure, the grain size also decreases markedly, and the crystallinity improves to some extent, although the aspect ratio of the crystals diminishes. Changes in synthesis time have no notable effect on grain size or crystallinity.
文摘本研究专注于稀土金属Y和La掺下HfO2薄膜的铁电性。采用脉冲激光沉积技术,在(001)取向SrTiO3衬底上利用La0.7Sr0.3MnO3薄膜作为底电极,成功实现了沿(111)取向生长的外延薄膜。研究发现,掺杂下的HfO2薄膜呈现出较好的结晶性,在室温下压电系数d33约为6 pm/V,畴翻转可达180˚,剩余极化强度可达到12.91 μC/cm2,表现出良好的铁电性。这些实验成果为基于HfO2薄膜的电子器件设计提供了重要的实验基础。This study focuses on the ferroelectric properties of Y and La doped HfO2 thin films. The epitaxial films grown along the (111) orientation were successfully prepared on (001)-oriented SrTiO3 substrate using La0.7Sr0.3MnO3 film as the substrate electrode by Pulsed laser deposition technique. The results show that the doped HfO2 films exhibit good crystallinity, the piezoelectric coefficient d33 is about 6 pm/V at room temperature, the domain inversion can reach 180˚, and the residual polarization strength can reach 12.91 μC/cm2, exhibit good ferroelectric properties. These experimental results provide an important experimental basis for the design of electronic devices based on HfO2 thin films.
文摘目的:探讨腹腔镜经腹腹膜前腹股沟斜疝修补术(TAPP)中腹膜前间隙CO2与血清肿形成的关系。方法:选取2023年1月至2023年6月于青岛大学附属医院确诊腹股沟斜疝并完成TAPP治疗的101例患者,随机分为试验组(减少腹膜前CO2残余)和对照组。主要结局是比较术后14天、1个月彩色多普勒超声下的血清肿发生情况。次要结局包括术后疼痛程度,复发,感染等。结果:两组患者的年龄、疝环直径、体质量指数(BMI)、病程等基线人口学特征均无显著性差异(P均 > 0.05)。术后14天试验组血清肿体积、发生率,疼痛程度均明显低于对照组,差异有统计学意义(P均 0.05)。其余次要结局均无显著性差异(P均 > 0.05),随访期间两组未出现复发、感染等其他术后并发症。结论:腹腔镜经腹腹膜前腹股沟疝修补术(TAPP)术中减少腹膜前间隙残留CO2是一种安全有效、操作简便的方法,能显著降低血清肿发生率和体积,减轻术后疼痛。Objective: To explore the relationship between CO2 in preperitoneal space and seroma formation in laparoscopic preperitoneal inguinal hernia repair (TAPP). Methods: 101 patients with indirect inguinal hernia diagnosed in the Affiliated Hospital of Qingdao University from January 2023 to June 2023 and completed TAPP treatment were randomly divided into an experimental group (reducing the residual CO2 before peritoneum) and a control group. The main outcome was to compare the incidence of seroma under color Doppler ultrasound 14 days and 1 month after operation. Secondary outcomes included postoperative pain, recurrence and infection. Results: There was no significant difference in baseline demographic characteristics such as age, diameter of hernia ring, body mass index (BMI) and course of disease between the two groups (P > 0.05). Fourteen days after operation, the volume of serum swelling, the incidence rate and the degree of pain in the experimental group were significantly lower than those in the control group, and the difference was statistically significant (P 0.05). There was no significant difference in other secondary outcomes (P > 0.05), and there were no other postoperative complications such as recurrence and infection in the two groups during the follow-up period. Conclusion: Laparoscopic preperitoneal inguinal hernia repair (TAPP) is a safe, effective and simple method to reduce residual CO2 in preperitoneal space, which can significantly reduce the incidence and volume of seroma and relieve postoperative pain.
