Electromagnetic wave-absorbing materials play a crucial role in modern electronics,particularly in stealth and communication technologies.Carbon-based materials demonstrate considerable potential for the development a...Electromagnetic wave-absorbing materials play a crucial role in modern electronics,particularly in stealth and communication technologies.Carbon-based materials demonstrate considerable potential for the development and use of effective wave-absorbing substances,attributed to their complex structure,lightweight nature,excellent corrosion resistance,and affordability.Notably,nitrogen-doped carbon-based two-dimensional(2D)materials exhibit a more pronounced depletion effect on electromagnetic waves owing to their increased specific surface area and numerous polarization states.This article presents the successful synthesis of nitrogen-doped carbon(NC)2D flakes using a hydrothermal method.In addition,single Fe atoms were successfully incorporated onto their surfaces,forming Fe@NC.The wave-absorbing capabilities of the Fe@NC samples were considerably improved,achieving a minimum reflection loss(RLmin)of−69.22 dB at 11.48 GHz and an effective absorption bandwidth of 5.79 GHz.The enhancement in electromagnetic wave absorption is attributed to the synergistic effects of magnetic loss,relaxation processes,dipole polarization,and electrical conduction loss.The successful synthesis of Fe@NC opens up new avenues for the development of atomically dispersed wave-absorbing materials.展开更多
在双核系统模型(Dinuclear System Model,DNS)的框架下,深入讨论了不同核质量模型对计算超重核存活概率的影响,并进一步考察了它如何影响DNS预测超重新元素合成截面。不同核质量模型输出的核质量表具有较大差异,尤其对于未知核区。原子...在双核系统模型(Dinuclear System Model,DNS)的框架下,深入讨论了不同核质量模型对计算超重核存活概率的影响,并进一步考察了它如何影响DNS预测超重新元素合成截面。不同核质量模型输出的核质量表具有较大差异,尤其对于未知核区。原子核质量作为DNS的核心输入量,它们在结合能、四极形变以及外推能力等方面的微小差异,都能对DNS的计算结果产生直接影响。此外发现,原子核质量是影响熔合概率和存活概率计算数值的关键因素。具体来说,不同核质量表提供的粒子分离能对超重核通过发射中子、质子、α粒子的衰变概率计算具有直接的影响。仔细分析超重核^(291)Mc的存活概率,我们发现随着蒸发中子数的增加,不同核质量表计算出的存活概率差异也会逐渐累积。值得注意的是,使用不同的核质量表进行超重核合成截面计算,其结果与实验数据相吻合,分布范围在一个数量级之内,这进一步验证了DNS预测的准确性。最后,讨论了五种核质量表对预测119、120号超重新元素合成截面的影响,误差范围在一个数量级之内。展开更多
OBJECTIVE:To summarize the evidence from Traditional Chinese Medicine(TCM)practice in the treatment of acute primary headache and provide clinical practice guidance.METHODS:The guidelines were developed in accordance ...OBJECTIVE:To summarize the evidence from Traditional Chinese Medicine(TCM)practice in the treatment of acute primary headache and provide clinical practice guidance.METHODS:The guidelines were developed in accordance with the World Health Organization guideline development manual.After the establishment of steering committee,panel and the registration and protocol formulation,the evidence on TCM for acute primary headache from published guidelines,clinical evidence,and expert experience and consensus were collected.The grading of recommendations assessment,development and evaluation method was used to grade the evidence and make the recommendations.RESULTS:Based on the available evidence,the guidelines recommended three TCM herbal decoctions,six Chinese patent medicines,and two kinds of external application of Chinese herbal medicines.Diagnostic recommendations based on the expert experience and consensus were also included in the guidelines.CONCLUSION:TCM diagnosis and treatment of decoction,Chinese patent medicine and external application for treating acute primary headache were recommended.We hope these guidelines will be helpful in standardize the TCM acute treatment of primary headache.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2021XD-A04-2)the National Natural Science Foundation of China(Grant Nos.61874014 and 61874013)+1 种基金the Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications,China)BUPT Excellent Ph.D.Students Foundation(Grant No.CX2022237).
文摘Electromagnetic wave-absorbing materials play a crucial role in modern electronics,particularly in stealth and communication technologies.Carbon-based materials demonstrate considerable potential for the development and use of effective wave-absorbing substances,attributed to their complex structure,lightweight nature,excellent corrosion resistance,and affordability.Notably,nitrogen-doped carbon-based two-dimensional(2D)materials exhibit a more pronounced depletion effect on electromagnetic waves owing to their increased specific surface area and numerous polarization states.This article presents the successful synthesis of nitrogen-doped carbon(NC)2D flakes using a hydrothermal method.In addition,single Fe atoms were successfully incorporated onto their surfaces,forming Fe@NC.The wave-absorbing capabilities of the Fe@NC samples were considerably improved,achieving a minimum reflection loss(RLmin)of−69.22 dB at 11.48 GHz and an effective absorption bandwidth of 5.79 GHz.The enhancement in electromagnetic wave absorption is attributed to the synergistic effects of magnetic loss,relaxation processes,dipole polarization,and electrical conduction loss.The successful synthesis of Fe@NC opens up new avenues for the development of atomically dispersed wave-absorbing materials.
文摘在双核系统模型(Dinuclear System Model,DNS)的框架下,深入讨论了不同核质量模型对计算超重核存活概率的影响,并进一步考察了它如何影响DNS预测超重新元素合成截面。不同核质量模型输出的核质量表具有较大差异,尤其对于未知核区。原子核质量作为DNS的核心输入量,它们在结合能、四极形变以及外推能力等方面的微小差异,都能对DNS的计算结果产生直接影响。此外发现,原子核质量是影响熔合概率和存活概率计算数值的关键因素。具体来说,不同核质量表提供的粒子分离能对超重核通过发射中子、质子、α粒子的衰变概率计算具有直接的影响。仔细分析超重核^(291)Mc的存活概率,我们发现随着蒸发中子数的增加,不同核质量表计算出的存活概率差异也会逐渐累积。值得注意的是,使用不同的核质量表进行超重核合成截面计算,其结果与实验数据相吻合,分布范围在一个数量级之内,这进一步验证了DNS预测的准确性。最后,讨论了五种核质量表对预测119、120号超重新元素合成截面的影响,误差范围在一个数量级之内。
基金National Key Research and Development Program of China:Research on the Development and Evaluation of International Standards of Traditional Chinese Medicine(No.2019YFC1712000)。
文摘OBJECTIVE:To summarize the evidence from Traditional Chinese Medicine(TCM)practice in the treatment of acute primary headache and provide clinical practice guidance.METHODS:The guidelines were developed in accordance with the World Health Organization guideline development manual.After the establishment of steering committee,panel and the registration and protocol formulation,the evidence on TCM for acute primary headache from published guidelines,clinical evidence,and expert experience and consensus were collected.The grading of recommendations assessment,development and evaluation method was used to grade the evidence and make the recommendations.RESULTS:Based on the available evidence,the guidelines recommended three TCM herbal decoctions,six Chinese patent medicines,and two kinds of external application of Chinese herbal medicines.Diagnostic recommendations based on the expert experience and consensus were also included in the guidelines.CONCLUSION:TCM diagnosis and treatment of decoction,Chinese patent medicine and external application for treating acute primary headache were recommended.We hope these guidelines will be helpful in standardize the TCM acute treatment of primary headache.
