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The binding energy parameter for common envelope evolution

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Research in Astronomy and Astrophysics 2016年第8期16卷 71-78页

作者： Chen Wang Kun Jia xiang-dong li Department of Astronomy Nanjing University Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of Education

Abstract The binding energy parameter A plays a vital role in common envelope evolution. Though it is well known that A takes different values for stars with different masses and varies during stellar evolution, it has been erroneously adopted as a constant in most population synthesis calculations. We have system- atically calculated the values of A for stars of masses 1 - 60 M by use of an updated stellar evolution code, taking into account the contribution from both gravitational energy and internal energy to the binding energy of the envelope. We adopt the criterion for the core-envelope boundary advocated by Ivanova. A new kind of A with an enthalpy prescription is also investigated. We present fitting formulae for the calculated values of various kinds of A, which can be used in future population synthesis studies.

关键词： binaries: general -- stars: evolution -- stars: mass-loss

Fallback Disk-Involved Spin-Down of Young Radio Pulsars

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Chinese Journal of Astronomy and Astrophysics 2005年第5期5卷 487-494页

作者： Zi-Bo Jiang xiang-dong li Department of Astronomy Nanjing University Nanjing 210093

Disks originating from supernova fallback have been suggested to surround young neutron stars. Interaction between the disk and the magnetic field of the neutron star may considerably influence the evolution of the star through the so called propeller effect. There are many controversies about the efficiency of the propeller mechanism proposed in the literature. We investigate the faUback diskinvolved spin-down of young pulsars. By comparing the simulated and measured results of pulsar evolution, we present some possible constraints on the propeller torques exerted by the disks on neutron stars.

关键词： stars: magnetic fields - stars: neutron - pulsars: individual: PSRs B0532+21 B0833+45 B0540-69 B1509-58

Rapid Finite Element Analysis of Bulk Metal Forming Process Based on Deformation Theory

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Journal of Iron and Steel Research International 2009年第5期16卷 23-28,42页

作者： WANG Peng dong xiang-huai FU li-jun Department of Plasticity Technology Shanghai Jiao Tong University Shanghai 200030 China

The one-step finite element method （FEM）, based on plastic deformation theory, has been widely used to simulate sheet metal forming processes, but its application in bulk metal forming simulation has been seldom investigated, because of the complexity involved. Thus, a bulk metal forming process was analyzed using a rapid FEM based on deformation theory. The material was assumed to be rigid-plastic and strain-hardened. The constitutive relationship between stress and total strain was adopted, whereas the incompressible condition was enforced by penalty function. The geometrical non-linearity in large plastic deformation was taken into consideration. Furthermore, the force boundary condition was treated by a simplified equivalent approach, considering the contact history. Based on constraint variational principle, the deformation FEM was proposed. The one-step forward simulation of axisymmettic upsetting process was performed using this method. The results were compared with those obtained by the traditional incremental FEM to verify the feasibility of the proposed method.

关键词： bulk metal forming finite element method (FEM) deformation theory rapid simulation

On the magnetic fields of ultraluminous X-ray pulsars

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Research in Astronomy and Astrophysics 2021年第8期21卷 124-134页

作者： Shi-Jie Gao xiang-dong li School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modem Astronomy and Astrophysics Nanjing UniversityMinistry of EducationNanjing 210023China

So far quite a few ultraluminous X-ray(ULX) pulsars have been *** this work,we construct a super-Eddington,magnetic accretion disk model to estimate the dipole magnetic field of eight ULX pulsars based on their observed spin-up variations and *** obtain two branches of dipole magnetic field *** are distributed in the range of B-(0.156-64.5) × 10^(10) G and-(0.275-79.0) × 10^(13) G corresponding to the low-and high-B solutions *** low magnetic field solutions correspond to the state that the neutron stars are far away from the spin equilibrium,and the high magnetic field solutions are close to the spin *** ultra-strong magnetic fields derived in Be-type ULX pulsars imply that the accretion mode in Be-type ULX pulsars could be more complicated than in the persistent ULX pulsars and may not be accounted for by the magnetized accretion disk *** suggest that the transition between the accretor and the propeller regimes may be used to distinguish between the low-and high-B magnetic field solutions in addition to the detection of the cyclotron resonance scattering features.

关键词： accretion accretion disks X-rays:binaries stars:neutron pulsars:individual(M82 X-2 NGC5907 ULX-1 M51 ULX-7 NGC7793 P13 NGC300 ULX-1 SMC X-3 NGC2403 ULX and Swift J0234.6+6124)

急性缺血性脑卒中伴发下肢深静脉血栓应用低分子肝素钙治疗的效果评估

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中国实用医药 2024年第11期19卷 100-103页

作者：席富强常昕董向力包头医学院第一附属医院神经内一科 014010 包头医学院第一附属医院蒙医骨伤科 014010 包头医学院 014010

目的讨论在急性缺血性脑卒中伴发下肢深静脉血栓患者中使用低分子肝素钙治疗的效果,并评估其安全性。方法选取50例急性缺血性脑卒中伴发下肢深静脉血栓患者,按随机数字表法分为对照组与治疗组,每组25例。对照组给予脑卒中常规治疗,治... 详细信息

目的讨论在急性缺血性脑卒中伴发下肢深静脉血栓患者中使用低分子肝素钙治疗的效果,并评估其安全性。方法选取50例急性缺血性脑卒中伴发下肢深静脉血栓患者,按随机数字表法分为对照组与治疗组,每组25例。对照组给予脑卒中常规治疗,治疗组给予脑卒中常规治疗联合低分子肝素钙治疗。比较两组临床疗效、临床预后[美国国立卫生研究院卒中量表(NIHSS)评分]、静脉血栓栓塞(VTE)风险[无手术患者静脉血栓栓塞风险评分表(Padua)评分]、不良反应(血小板减少、注射部位皮肤变化、肝肾功能异常、出血)发生率。结果治疗组总有效率为80%,对照组总有效率为52%,治疗组高于对照组,差异有统计学意义(P0.05)。结论低分子肝素钙可以促进急性缺血性脑卒中伴发下肢深静脉血栓患者肢体功能恢复,减少不良反应发生,在急性缺血性脑卒中伴发下肢深静脉血栓的治疗中取得理想效果。

关键词：急性缺血性脑卒中下肢深静脉血栓低分子肝素钙

Preparation of Dendritic Carbosilane-supported Palladium Catalyst and Its Catalytic Activity in Hydrogenation of Organic Compounds

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Chinese Chemical Letters 2005年第10期16卷 1389-1392页

作者： Chun Fang li dong xiang li Zhi Jie ZHANG Sheng Yu FENG School of Chemistry and Chemical Engineering Shandong University Jinan 250100 School of Chemistry Chemical Engineering and Materials Shandong Normal University Jinan 250014 Institute of Chemistry Chinese Academy of Sciences Beijing 100080

The preparation of palladium complex from PdCl2·2H2O and carbosilane dendrimers with pelripheral aminopropyl groups was described. The compound obtained was characterized by IR, H NMR, X-ray photoelectron spectroscopy （XPS） and inductively coupled plasma atomic emission spectrometric （ICP-AES） spectroscopy respectively. The metal complex was employed as catalyst in hydrogenation of organic compounds. The high activity of the complex was probably due to the formation of the coordinatively unsaturated palladium.

关键词： Dendrimer complex catalysis.

Fabrication of micro-nano patterned materials mimicking the topological structure of extracellular matrix for biomedical applications

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Nano Research 2024年第5期17卷 4244-4258页

作者： Yifeng Nie dong Han xiang li CAS Center for Excellence in Nanoscience National Center for Nanoscience and TechnologyBeijing 100190China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China

With the advent of tissue engineering and biomedicine,the creation of extracellular matrix(ECM)biomaterials for in vitro applications has become a prominent and promising *** ECM materials provide physical,biochemical,and mechanical properties that guide cellular behaviors,such as proliferation,differentiation,migration,and *** micro-and nano-patterned materials have a unique surface topology and low energy replication process that directly affect cellular biological behaviors at the interface,the fabrication of micro-nano pattern biomaterials and the regulation of surface physical and chemical properties are of great significance in the fields of cell regulation,tissue engineering,and regenerative ***,we provide a comprehensive review of the progress in the fabrication and application of patterned materials based on the coupling of mechanical action at the micro-and nano-meter scale,including photolithography,micro-contact printing,electron beam lithography,electrospinning,and 3D printing ***,a summary of the fabrication process,underlying principles,as well as the advantages and disadvantages of various technologies are *** also discuss the influence of material properties on the fabrication of micro-and nano-patterns.

关键词： micro/nano hybrid materials patterning fabrication techniques extracellular matrix substrate-cell interaction biomedical engineering

Are There Magnetars in High-mass X-Ray Binaries?

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Research in Astronomy and Astrophysics 2022年第1期22卷 46-59页

作者： Kun Xu xiang-dong li Zhe Cui Qiao-Chu li Yong Shao Xilong liang Jifeng liu School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Astronomy Nanjing UniversityNanjing 210023China Key Laboratory of Modem Astronomy and Astrophysics Nanjing UniversityMinistry of EducationNanjing 210023China WHU-NAOC Joint Center for Astronomy Wuhan UniversityWuhanChina

Magnetars form a special population of neutron stars with strong magnetic fields and long spin periods. About 30 magnetars and magnetar candidates known currently are probably isolated, but the possibility that magnetars are in binaries has not been excluded. In this work, we perform spin evolution of neutron stars with different magnetic fields in wind-fed high-mass X-ray binaries and compare the spin period distribution with observations, aiming to find magnetars in binaries. Our simulation shows that some of the neutron stars, which have long spin periods or are in widely-separated systems, need strong magnetic fields to explain their spin evolution. This implies that there are probably magnetars in high-mass X-ray binaries. Moreover, this can further provide a theoretical basis for some unclear astronomical phenomena, such as the possible origin of periodic fast radio bursts from magnetars in binary systems.

关键词： stars:magnetars stars:neutron stars:rotation (stars:)supergiants accretion accretion disks X-rays:binaries

From Zn-Al layered double hydroxide to ZnO nanostructure:Gradually etching by sodium hydroxide

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Chinese Chemical Letters 2012年第12期23卷 1415-1418页

作者： Gang Qiang Wan dong xiang li Chun Fang li Jie Xu Wan Guo Hou State Key Laboratory Base of Eco-chemical Engineering Lab of Colloids and Functional NanostructuresCollege of Chemistry and Molecular EngineeringQingdao University of Science and Technology Key Laboratory of Colloid and Interface Chemistry of Ministry of Education Shandong University

Zn-Al layered double hydroxide （LDH） was used as precursor to produce ZnO nanostructures through dissolution of aluminum hydroxide in caustic soda. The Zn-Al LDH could transform into different nanostructures of ZnO on LDH nanosheets and even pure ZnO nanorods under various NaOH concentration. The formed ZnO nanorods vertically aligned on both LDH sides. UV-vis diverse reflectance spectra show that the obtained ZnO nanorods have a band gap of approximately 3.05 eV. Such ZnO/LDH nanostructures might be used as photocatalyst in the organic pollutant decomposition.

关键词： Layered double hydroxide (LDH) ZnO Nanostructure