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Atomic-scale simulation of nano-grains:structure and diffusion properties

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原子与分子物理学报 2003年第2期20卷 149-152页

作者： WEN Yu-hua CHEN zheng-zheng WANG Chong-yu zhu Ru-zeng Department of Physics Tsinghua UniversityBeijing100084P.R.of China LNM Institute of MechanicsAcademia SinicaBeijing 100080P.R.of China

Nanograins are characterized by a typical grain size from 1 to 100 nm. Molecular dynamics simulations have been carried out for the nanograin sphere with the diameters from 1.45 to 10.12 nm. We study the influence of grain size on structure and diffusion properties of the nanograins. The results reveal that as the grain size is reduced, the fraction of grain surface increases significantly, and the surface width is approximately constant; the mean atomic energy of the surface increases distinctly, but that of the grain interior varies insignificantly; the diffusion coefficient is increased sharply, and the relation of the diffusion coefficient and the grain size is close to exponential relation below 10 nm.

关键词： Nano grain Structure Diffustion property Molecular dynamics simulation

Probes of axial and nonaxial hexadecapole deformation effects in nuclei around^(230)U

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Communications in Theoretical Physics 2023年第2期75卷 133-143页

作者： zhuo Song hua-Lei Wang zhen-zhen Zhang Min-Liang Liu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The structure properties for even–even nuclei around^(230)U,located on the hexadecapoledeformation island,are investigated using the potential-energy-surface calculation within the framework of the macroscopic-microscopic *** impact of different deformation degrees of freedom(including axial and nonaxial quadrupole and hexadecapole deformations)on total energy,shell,and pairing contributions is analyzed,based on the projected energy maps and *** single-particle structure is presented and briefly *** a large extent,a much better agreement with experimental data and other theoretical results is obtained if the hexadecapole deformations,especially the axial one,are taken into *** results could provide useful insights into understanding the effects of different quadrupole and hexadecapole deformations.

关键词： hexadecapole deformation triaxial deformation even-even nuclei potential-energysurface calculation macroscopic−microscopic model

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制造企业绿色生产过程实施体系

计算机集成制造系统 2010年第1期16卷 70-75页

作者：吴小珍张华武汉科技大学汽车与交通工程学院湖北武汉430081

现有的绿色制造理论在我国制造企业的生产过程中难以实施,缺乏能够应用于生产车间的切实可行的绿色制造实施体系。为此,在对制造企业生产过程绿色特性研究的基础上,构建了一种面向绿色制造的车间生产过程实施体系,包括绿色生产过程的技... 详细信息

现有的绿色制造理论在我国制造企业的生产过程中难以实施,缺乏能够应用于生产车间的切实可行的绿色制造实施体系。为此,在对制造企业生产过程绿色特性研究的基础上,构建了一种面向绿色制造的车间生产过程实施体系,包括绿色生产过程的技术基础、研究内容、软件支撑和目标;对资源环境数据中的模糊数据采用模糊实体-关系方法建模,实现了绿色生产过程数据库系统的模糊化设计,在一定程度上解决了生产过程中具有不确定性的资源环境数据在数据库中的管理问题;并基于产品数据管理提出了一种车间级绿色制造的信息集成模式,为相关软件工具的开发奠定了基础。

关键词：绿色制造生产过程实施体系模糊数据库制造企业

Magnetic impurity in hybrid and type-Ⅱ nodal line semimetals

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Chinese Physics B 2021年第6期30卷 490-497页

作者： Xiao-Rong Yang zhen-zhen huang Wan-Sheng Wang Jin-hua Sun Department of Physics Ningbo UniversityNingbo 315211China

We study the Kondo screening of a spin-1/2 magnetic impurity in the hybrid nodal line semimetals(NLSMs) and the type-Ⅱ NLSMs by using the variational method. We mainly study the binding energy and the spin–spin correlation between magnetic impurity and conduction electrons. We find that in both the hybrid and type-Ⅱ cases, the density of states(DOS) is always finite, so the impurity and the conduction electrons always form bound states, and the bound state is more easily formed when the DOS is large. Meanwhile, due to the unique dispersion relation and the spin–orbit couplings in the NLSMs, the spatial spin–spin correlation components show very interesting features. Most saliently, various components of the spatial spin–spin correlation function decay with 1/r^(2) in the hybrid NLSMs, while they follow 1/r^(3) decay in the type-Ⅱ NLSMs. This property is mainly caused by the special band structures in the NLSMs, and it can work as a fingerprint to distinguish the two types of NLSMs.

关键词： hybrid nodal line semimetals type-Ⅱnodal line semimetals Anderson impurity Kondo screening

Does Liuzijue Qigong affect anxiety in patients with chronic obstructive pulmonary disease,even during the COVID-19 outbreak?a randomized,controlled trial

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Traditional Medicine Research 2020年第4期5卷 216-228页

作者： Yu-Xuan Zhang Ying Quan Ming-Hu Chen Duo Zhang Ying Zhang zhen-Gang zhu First Teaching Hospital of Tianjin University of Traditional Chinese Medicine Tianjin 300381China Tianjin University of Traditional Chinese Medicine Tianjin 301617China Australian National University Canberra 2601Australia

Background:Anxiety is a common comorbidity associated with chronic obstructive pulmonary disease(COPD),but no well-recognized method can provide effective *** Qigong(LQG)is a traditional Chinese fitness method,based on breath *** study aimed to examine the efficacy of LQG to relieve anxiety in COPD patients and to explore the factors that influence anxiety,including whether LQG is effective during the coronavirus disease 2019(COVID-19)***:We conducted an open-label,randomized,controlled,clinical trial.A total of 60 patients with stable COPD were randomly assigned to two *** groups were given routine medical treatment,and the patients in the pulmonary rehabilitation(PR)group were given an extra intervention in the form of LQG,performed for 30 minutes each day for 12 *** collection was performed at baseline and 12 weeks(during the COVID-19 epidemic).The primary outcomes were the self-rating anxiety scale(SAS)scores,and the secondary outcomes were relevant information during the epidemic and analyses of the related factors that influenced SAS scores during the COVID-19 ***:Compared with baseline,patients in both groups demonstrated varying degrees of improvements in their SAS scores(all P<0.01).An analysis of covariance,adjusted for baseline scores,indicated that the SAS scores improved more dramatically in the PR group than in the control group(F=9.539,P=0.004).During the outbreak,the SAS scores for sleep disorder were higher than all other factors,reaching 1.38±0.67,and the scores for“I can breathe in and out easily”for the PR group were lower than the scores for the control group(Z=−2.108,P=0.035).Significant differences were identified between the two groups for the categories“How much has the outbreak affected your life”,“Do you practice LQG during the epidemic”and“Do you practice other exercises during the epidemic”(all P<0.05).Compared with current reports,LQG had a relatively high adherence rat

关键词： Chronic obstructive pulmonary disease Anxiety Self-rating anxiety scale scores Liuzijue Qigong Pulmonary rehabilitation Coronavirus disease 2019

Microstructure,properties and first principles calculation of titanium alloy/steel by Nd: YAG laser self-fluxing welding

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China Welding 2018年第3期27卷 1-10页

作者： Zhang Yifu Zhang hua zhu zhengqiang Pan Jiluan Key Laboratory for Robot ＆ Welding Automation of Jiangxi Province School of Mechanical ＆ Electrical EngineeringNanchang UniversityNanchang 330031China School of Mechanics ＆ Materials Engineering Jiujiang UniversityJiujiang 332005China

The experiment of Nd： YAG pulsed laser self-fluxing welding for 304 stainless steel/Ti6Al4V titanium alloy dissimilar metal was carried out. The microstructure properties of welded joint were analyzed by SEM, EDS and XRD. The equilibrium lattice constants, enthalpies of formation, cohesive energies, mechanical properties, Debye temperatures and valence electron structures of Ti-Fe intermetallic compounds （IMCs） were calculated by the first principle pseudopotential plane wave method based on density functional theory （DFT）. According to the thermodynamic data of Ti-Fe-Cr compounds, the Gibbs free energy per mole of compound at different temperatures was calculated and their thermal stability was compared. The results show that there are no macroscopic cracks in the welded joints, and the IMCs distributed evenly along the welding interface exhibits 3 distinct layers of microstructure with different colors. The welds interface generates IMCs of TiFe, TiFe 2 and a small amount of Ti 5Cr 7Fe 17 IMCs. Ti-Fe IMCs with high thermodynamic stability and easy alloying formation. The results of Gibbs free energies show that the sequence of precipitates in the interface is Ti 5Cr 7Fe 17 , TiFe 2 and TiFe in high temperature during the metallurgical reaction. The G/B values of Ti-Fe IMCs are greater than the critical value of 0.5, indicating that it is an intrinsic brittleness.

关键词： Nd:YAG pulsed laser self-fluxing welding titanium alloy stainless steel first-principle calculation

Single-atom cobalt nanozymes promote spinal cord injury recovery by anti-oxidation and neuroprotection

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Nano Research 2023年第7期16卷 9752-9759页

作者： Yuxing Jiang Hongtao Rong Yifan Wang Shange Liu Peng Xu zhen Luo Lamei Guo Tao zhu(✉) Hongpan Rong Dingsheng Wang Jiatao Zhang Yu Yi Hao Wang Tianjin Medical University General Hospital Tianjin 300052China CAS Center for Excellence in Nanoscience CAS Key Laboratory for Biomedical Effects of Nanomaterials and NanosafetyNational Center for Nanoscience and TechnologyBeijing 100190China Beijing Key Laboratory of Construction-Tailorable Advanced Functional Materials and Green Applications Key Laboratory of Medical Molecule Science and Pharmaceutics EngineeringMinistry of Industry and Information TechnologySchool of Materials Science&EngineeringSchool of Chemistry and Chemical EngineeringInstitute of Engineering MedicineBeijing Institute of TechnologyBeijing 100081China Department of Chemistry Tsinghua UniversityBeijing 100084China University of Chinese Academy of Sciences Beijing 100049China

Oxidative stress and inflammation are central pathophysiological processes in a traumatic spinal cord injury(SCI).Antioxidant therapies that reduce the reactive oxygen and nitrogen species(RONS)overgeneration and inflammation are proved promising for improving the ***,efficient and long-lasting antioxidant therapy to eliminate multiple RONS with effective neuroprotection remains ***,a single-atom cobalt nanozyme(Co-SAzyme)with a hollow structure was reported to reduce the RONS and inflammation in the secondary injury of *** SAzymes featuring different single metal-N sites(e.g.,Mn,Fe,Co,Ni,and Cu),this Co-SAzyme showed a versatile property to eliminate hydrogen peroxide(H_(2)O_(2)),superoxide anion(O_(2)·^(-)),hydroxyl radical(·OH),nitric oxide(·NO),and peroxynitrite(ONOO^(-))that overexpressed in the early stage of *** porous hollow structure also allowed the encapsulation and sustained release of minocycline for neuroprotection in *** vitro results showed that the Co-SAzyme reduced the apoptosis and pro-inflammatory cytokine levels of microglial cells under oxidative *** addition,the Co-SAzyme combined with minocycline achieved remarkable improved functional recovery and neural repairs in the SCI-rat model.

关键词： single-atom catalysis spinal cord injury reactive oxygen and nitrogen species anti-inflammation neuroprotection

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正丁醇萃取磷酸的微分散过程与传质系数研究

高校化学工程学报 2015年第2期29卷 292-297页

作者：白洁祝杰叶世超刘振华四川大学化学工程学院四川成都610065

采用受力分析的方法建立了微分散液滴直径计算模型,以正丁醇/磷酸/水为实验体系,研究了微分散法萃取磷酸的传质特性,依据传质理论计算出了各实验条件下的传质系数及传质速率。研究结果表明:在微分散条件下,液滴直径随分散相流量的增大... 详细信息

采用受力分析的方法建立了微分散液滴直径计算模型,以正丁醇/磷酸/水为实验体系,研究了微分散法萃取磷酸的传质特性,依据传质理论计算出了各实验条件下的传质系数及传质速率。研究结果表明:在微分散条件下,液滴直径随分散相流量的增大而减小;直接影响传质系数的因素主要是进口酸浓度、物性、相比、液滴直径、两相流量;采用准数关联出传质系数关联式为:Sh=9.01×10-8Sc1.612Re0.6876p1.027,计算值与实验值相对误差小于10%,为微分散萃取磷酸技术的深入研究提供了理论基础。

关键词：萃取磷酸正丁醇模型

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应力吸收层沥青混合料压实特性研究

建材世界 2024年第2期45卷 63-68页

作者：李君述李鹏飞李想袁恒林振华磨炼同湖北楚天智能交通股份有限公司武汉430000 河南省豫南高速投资有限公司信阳465550 武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070

为了解应力吸收层沥青混合料的压实特性,保证施工和易性,采用旋转压实仪成型试件,利用压实度与旋转次数的关系研究油石比、压实温度和矿料级配对压实特性的影响。结果表明:压实能量指数、压实速率、95%和99%压实度对应的压实次数均可作... 详细信息

为了解应力吸收层沥青混合料的压实特性,保证施工和易性,采用旋转压实仪成型试件,利用压实度与旋转次数的关系研究油石比、压实温度和矿料级配对压实特性的影响。结果表明:压实能量指数、压实速率、95%和99%压实度对应的压实次数均可作压实参数,压实速率对应力吸收层沥青混合料适用性不强,95%和99%压实度对应的合理压实次数为10次和35次,其可用于确定最佳油石比,提出了应力吸收层沥青混合料关键筛孔1.18 mm和2.36 mm合理通过率范围分别为45%~50%和65%~75%。

关键词：应力吸收层旋转压实压实特性压实温度级配控制