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High-spin configuration of asymmetric CoN_(1)C_(2)coordination for boosting d-p orbital hybridization in Fenton-like reactions
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作者 Qian Bai Juanjuan Qi +8 位作者 Rongzhe Zhang Zhiyuan Chen Zihao Wei Zhiyi Sun Ziwei Deng Xudong Yang Qiangwei Li Wenxing Chen Lidong Wang 《Chinese Journal of Catalysis》 2025年第6期334-346,共13页
Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains un... Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications. 展开更多
关键词 Asymmetric coordination C_(2)N high-spin configuration d-p orbital hybridization Fenton-like reaction
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Theoretical Design of High-spin Organic Molecules with Heterocycles as Ferromagnetic Coupling Units
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作者 WANG Li-min ZHANG Jing-ping WANG Rong-shun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2003年第4期508-511,共4页
Novel stable high spin molecules possessing three different arranged fashions are designed with - · N-N< as a spin-containing(SC) fragment, phenylene as an end group and various aromatic molecules, such as ben... Novel stable high spin molecules possessing three different arranged fashions are designed with - · N-N< as a spin-containing(SC) fragment, phenylene as an end group and various aromatic molecules, such as benzene(1), 2,6-pyridine(2), 3,5-pyridine(3), pyridazine(4), 4,6-pyrimidine(5), 2,6-pyrimidine(6), pyrazine(7) and triazine(8), as a ferromagnetic coupling(FC) unit. The effects of the different coupling units on the spin multiplicities of the ground states and their stabilities were investigated by means of AM1-CI approach. It has been found that the spin densities on the two atoms of the SC fragment are different from delocalization results in the specific stability of - · N-N<. In these molecules, the stabilities of the triplet states decrease when the distance between the atoms of central SC(-N-) increases. It is shown that the heterocycles as the coupling units have influence on the stabilities of the high-spin ground states. That the heteroatom lying in m -phenyl can improve ferromagnetic coupling, while the heteroatom lying in o -phenyl or p -phenyl is not in favor of the ferromagnetic coupling. 展开更多
关键词 HETEROCYCLE Coupling unit BIRADICAL high-spin AM1-CI B3LYP
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Theoretical Design of High-spin Organic Molecules with —~*N—S— as a Spin-containing Fragment and Heterocycle as End Groups
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作者 WANG Li-min CHU De-qing +1 位作者 ZHANG Jing-ping WANG Rong-shun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第5期631-634,共4页
Novel stable high-spin molecules possessing three different arranging fashions were designed with —^*N—S— as a spin-containing (SC) fragment, an aromatic group, such as benzene ( 1 ), pyridine (2), pyridazi... Novel stable high-spin molecules possessing three different arranging fashions were designed with —^*N—S— as a spin-containing (SC) fragment, an aromatic group, such as benzene ( 1 ), pyridine (2), pyridazine (3) , pyrimidine (4), pyrazine (5) or triazine (6) as end groups (EG), and phenyl as a ferromagnetic coupling (FC) unit. The effects of different EG on the spin multiplicities of the ground states and their stabilities were investigated by means of the AM1-CI approach. All the investigated molecules corresponded to the FC and possessed high-spin ground states. The spin on the two atoms of the SC fragment was not in agreement with the delocalization results in the specific stability of —^*N—S—. In those molecules, the stabilities of the triplet states decreased when the distance between the atoms of central SC fragments (—N—) increased. The stabilities of the triplet states of compounds 1a-n, 1b-n and 1c-n, with heterocycles as EG were higher than those of the triplet states of those compounds with phenyl as EG. Furthermore, the stahilities of the triplet states of the compounds with pyrimidine and triazine as EG were higher than those with pyridine, pyridazine or pyrasine as EG. 展开更多
关键词 HETEROCYCLE End group BIRADICAL high-spin AM1-CI
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Regulating the intrinsic electronic structure of carbon nanofibers with high-spin state Ni for sodium storage with high-power density
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作者 Zhijia Zhang Gang Xie +6 位作者 Yuefang Chen Yanhao Wei Mengmeng Zhang Shulei Chou Yunxiao Wang Yifang Zhang Yong Jiang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第4期16-23,共8页
Carbon nanofibers(CNFs)with high specific surface area show great potential for sodium storage as a hard carbon material.Herein,CNFs anchored with Ni nanoparticles(CNFs/Ni)were prepared through chemical vapor depositi... Carbon nanofibers(CNFs)with high specific surface area show great potential for sodium storage as a hard carbon material.Herein,CNFs anchored with Ni nanoparticles(CNFs/Ni)were prepared through chemical vapor deposition and impregnation reduction methods,in situ growing on the three-dimensional porous copper current collector(3DP-Cu).The coupling effect of high-spin state Ni nanopar-ticles leads to the increase of defect density and the expansion of lattice spacing of CNFs.Meanwhile,the 3DP-Cu ensures a high loading capacity of CNFs and short ion/electron transport channels.As an integral binder-free anode,the 3DP-Cu/CNFs/Ni exhibits excellent electrochemical performance,which demon-strates a high specific capacity with 298.5 mAh g^(-1)at 1000 mA g^(-1)after 1500 cycles,and a high power density with 200 mAh g^(-1)over 1000 cycles at 5000 mA g^(-1).Density functional theory calculation re-sults show that the high-spin state Ni regulates the electronic structure of CNFs,which significantly reduces the adsorption energy for Na^(+)(-2.7 Ev)and thus enables high-rate capability.The regulation of the electronic structure of carbon materials by high-spin state metal provides a new strategy for developing high-power carbonaceous anode materials for sodium-ion batteries. 展开更多
关键词 Carbon nanofibers Ni nanoparticles high-spin state Sodium-ion batteries Anode materials Density functional theory calculation
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Formalism of rotating-wave approximation in high-spin system with quadrupole interaction
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作者 丁文魁 王晓光 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期72-78,共7页
We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions.The conventional way to apply... We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions.The conventional way to apply the rotating wave approximation in a driven high-spin system is to assume the dynamics being restricted in the reduced Hilbert space.However,when the driving strength is relatively strong or the driving is off resonant,the leakage from the target resonance subspace cannot be neglected for a multi-level quantum system.We propose the correct formalism to apply the rotating wave approximation in the full Hilbert space by taking this leakage into account.By estimating the operator fidelity of the time propagator,our formalism applied in the full Hilbert space unambiguously manifests great advantages over the conventional method applied in the reduced Hilbert space. 展开更多
关键词 rotating wave approximation quadrupole interaction high-spin system
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A Microscopic Investigation of High-Spin States for ^(162)Hf and ^(164)Hf Isotopes
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作者 Yang Bang-jun (Department of Physics,Guizhou University,Guiyang 550025)Sang Jian-ping (Department of Physics,Wuhan University,Wuhan 430072)Liu Yong (Institute of Particle Physics,Hua zhong Normal University,Wuhan 430070) 《Chinese journal of nuclear physics》 1995年第1期36-39,共4页
A truncated shell model approach is applied to the description of high-spinstates for <sup>162</sup>Hf and <sup>164</sup>Hf isotopes.The backbends of the moment of inertia are repro-duced well ... A truncated shell model approach is applied to the description of high-spinstates for <sup>162</sup>Hf and <sup>164</sup>Hf isotopes.The backbends of the moment of inertia are repro-duced well by the calculation.The results show that the approach is able to investigatethe yrast states of nuclei in rare earth region. 展开更多
关键词 A TRUNCATED shell model approach 162 164Hf ISOTOPES high-spin states
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High-Spin States in ^(141)Pm
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作者 朱胜江 顾龙 +12 位作者 王建国 肖志刚 杨韵颐 张明 刘宇 丁怀博 竺礼华 吴晓光 贺创业 李广生 王烈林 郑云 张彪 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第6期496-498,共3页
The high-spin states of 141pro nucleus have been studied by using in-beam v-ray spectroscopy technology through the126Te(19F, 4n) reaction at a beam energy of 90 MeV. The previous level scheme has been extended with... The high-spin states of 141pro nucleus have been studied by using in-beam v-ray spectroscopy technology through the126Te(19F, 4n) reaction at a beam energy of 90 MeV. The previous level scheme has been extended with spin up to 49/2 h. Many new levels and transitions are identified. Five collective band structures are observed. Based on systematic comparison with the neighboring nuclei, two bands with strong AI = 1 M1 transitions inside the bands are proposed as the oblate bands with γ--60°, and three bands with large signature splitting have been suggested as the oblate-triaxial deformation with γ--90°. The characteristics for these bands have been discussed. 展开更多
关键词 nuclear structure high spin states oblate band oblate-triaxial band
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Tilted-axis-cranking covariant density functional theory for high-spin spectroscopy of^(69)Ga
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作者 Y.P.Wang Y.K.Wang P.W.Zhao 《Chinese Physics C》 2026年第1期279-283,共5页
The tilted-axis-cranking covariant density functional theory is applied to investigate the three newly-observed positive-parity bands SI,SII,and SIII in^(69)Ga.The energy spectra and angular momenta are calculated,and... The tilted-axis-cranking covariant density functional theory is applied to investigate the three newly-observed positive-parity bands SI,SII,and SIII in^(69)Ga.The energy spectra and angular momenta are calculated,and they agree closely with experimental data.For band SI,pairing correlations are crucial for the states with spin I≤23/2h.Bands SII and SIII are suggested to be signature partner bands with positive and negative signatures,respectively.By analyzing the angular momentum alignments,we reveal that the g9/2 protons and neutrons are crucial in the collective structures of^(69)Ga.The transition probabilitiesB(E2)for these bands are predicted,awaiting further experimental verification. 展开更多
关键词 high-spin spectroscopy collective structure cranking covariant density functional theory
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熔融纺高强度聚酰胺纤维及其凝聚态结构调控研究进展
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作者 梁程耀 黄威蕾 +6 位作者 高宇 俞森龙 相恒学 朱丽萍 胡泽旭 成艳华 朱美芳 《高分子学报》 北大核心 2026年第1期79-94,共16页
聚酰胺纤维是世界上最早实现工业化生产的合成纤维,也是当今产量第二大的合成纤维,因其具有拉伸断裂强度高、断裂伸长率大、回弹性优等特性,而被广泛应用到纺织服装、工业丝、家纺和特殊防护等领域.随着工业技术的发展革新,常规的聚酰... 聚酰胺纤维是世界上最早实现工业化生产的合成纤维,也是当今产量第二大的合成纤维,因其具有拉伸断裂强度高、断裂伸长率大、回弹性优等特性,而被广泛应用到纺织服装、工业丝、家纺和特殊防护等领域.随着工业技术的发展革新,常规的聚酰胺纤维由于断裂强度较低已难以满足某些特殊应用场景的性能需求.聚酰胺相邻分子链间的酰胺键间极易形成氢键,致使分子链间的相互作用力较强,难以通过高倍牵伸获得高取向结构从而限制了其强度的提高.为突破现有纺丝体系下聚酰胺纤维力学性能的瓶颈,需要深入了解工艺-结构-性能三元关系,精准调控聚酰胺纤维的多层次结构,进而实现聚酰胺纤维的高强化.本文就纺丝阶段的三个重要阶段(熔融挤出、牵伸和热定型)讨论了纤维在成形过程中的多尺度结构演变以及纺丝参数对其结构-性能的调控机制,有望为高强聚酰胺纤维工艺设计提供理论指导. 展开更多
关键词 聚酰胺纤维 凝聚态结构 高性能 熔融纺丝
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氧化铝纤维的制备及其应用研究进展
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作者 曹雪华 魏亮 +3 位作者 孙润军 董洁 范星宇 冯燕 《棉纺织技术》 2026年第1期84-91,共8页
总结了氧化铝纤维的制备及应用研究进展。介绍了氧化铝陶瓷纤维的制备方法,包括如离心纺丝法、熔融纺丝法、浸渍法和静电纺丝法,并分析了各种制备方法的优缺点。综述了氧化铝纤维在高温隔热领域、吸附过滤领域、工业催化领域、储能领域... 总结了氧化铝纤维的制备及应用研究进展。介绍了氧化铝陶瓷纤维的制备方法,包括如离心纺丝法、熔融纺丝法、浸渍法和静电纺丝法,并分析了各种制备方法的优缺点。综述了氧化铝纤维在高温隔热领域、吸附过滤领域、工业催化领域、储能领域和纤维增强材料中的研究进展。未来氧化铝纤维的发展应着重于新型纺丝技术的研究,新型轻质柔性耐高温纤维材料的开发以及新应用领域的拓展。 展开更多
关键词 氧化铝陶瓷纤维 静电纺丝 高温隔热 吸附过滤 储能材料
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Structure change of ^(156)Yb at high-spin states
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作者 华辉 李忠宇 +28 位作者 王守宇 孟杰 李智焕 李湘庆 许甫荣 刘红亮 张双全 周善贵 叶沿林 江栋兴 郑涛 竺礼华 吴晓光 李广生 贺创业 马立英 卢飞 范凤英 韩丽英 王赫 肖军 李雪琴 陈东 方晓 楼建玲 刘颖 郝昕 潘波 李立华 《Chinese Physics C》 SCIE CAS CSCD 2009年第S1期148-150,共3页
High-spin states of 156Yb have been studied via the 144Sm(16O,4n)156Yb fusion-evaporation reaction at beam energy 102 MeV. The positive-parity yrast band and negative-parity cascade have been extended up to higher-spi... High-spin states of 156Yb have been studied via the 144Sm(16O,4n)156Yb fusion-evaporation reaction at beam energy 102 MeV. The positive-parity yrast band and negative-parity cascade have been extended up to higher-spin states, respectively. The characteristics of the negative-parity sequence above the 25-state may related to the excitation from the nucleon in the Z =64, N =82 core. The E-GOS curve for the positiveparity yrast sequence in 156Yb indicate that this nucleus may undergo an evolution from quasivibrational to quasirotational structure with increasing angular momentum. The Cranked Woods-Saxon-Strutinsky calculations by means of Total-Routhian-Surface (TRS) methods has been made to understand this structure change. 展开更多
关键词 high-spin states 156Yb structure change ALIGNMENT fusion-evaporation
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Theoretical Design of High-spin Organic Molecules with -·N-N- as a Spin-containing Fragment and Heterocycles as an End Group
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作者 储德清 王立敏 +1 位作者 张景萍 王荣顺 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2006年第11期1648-1652,共5页
Novel stable high spin molecules possessing three different arranged fashions are designed with -·N-N〈 as a spin-containing (SC) fragment, various aromatic, such as benzene (1), pyridine (2), pyridazine (... Novel stable high spin molecules possessing three different arranged fashions are designed with -·N-N〈 as a spin-containing (SC) fragment, various aromatic, such as benzene (1), pyridine (2), pyridazine (3), pyrimidine (4), pyrazine (5), triazine (6) as end groups (EG) and phenyl as a ferromagnetic coupling (FC) unit. The effects of a different end groups on the spin multiplicities of the ground states and their stabilities were investigated by means of AM1-CI approach. It has been found that the spin densities on the two atoms of the SC fragment are different from delocalization resulting in the specific stability of -·N-N〈. In these molecules, the stabilities of the triplet states decrease when the distance between the atoms of central SC (-N-) increases. The orders of the stability of triplet states for 1an, 1bn, 1cn [They are isomers in which SC is connected with FC in different way (1an, N1NNN1; 1bn, N1N N1N; 1cn, NN1N1N) and six heterocycles are EG] show that the stability of triplet states with heterocycles as end groups is higher than that with phenyl as end groups, and in the order: triazine (EG) 〉 pyrimidine, pyrazine 〉 pyridine, pyridazine. 展开更多
关键词 HETEROCYCLE end group BIRADICAL high-spin AM1-CI
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New Ni(Ⅱ)Cu(Ⅱ)Ni(Ⅱ) trinuclear complexes with an S=3/2 high-spin ground state
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作者 MIAO, Ming-Ming LIAO, Dai-Zheng JIANG, Zong-Hui CHENG, Peng WANG, Geng-LinDepartment of Chemistry, Nankai University, Tianjin 300071,China 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1996年第4期326-330,共5页
Four new heterotrinuclear complexes have been synthesized and characterized, namely {[Ni(L)2]2[Cu(opba)]}(ClO4)2, where opba denotes o-phenylenebis(oxamato) and L stands for 1,10-phenanthroline(phen) (1), 5-nitro-1,10... Four new heterotrinuclear complexes have been synthesized and characterized, namely {[Ni(L)2]2[Cu(opba)]}(ClO4)2, where opba denotes o-phenylenebis(oxamato) and L stands for 1,10-phenanthroline(phen) (1), 5-nitro-1,10-phenanthroline(NO2-phen) (2), 2,2'-bipyridyl(bpy) (3) and 4,4'-dimethyl-2,2'-bipyridyl(Me2bpy) (4). The temperature dependence of the magnetic susceptibility of {[Ni(phen)2]2[Cu(opba)]}(ClO4)2.3H2O has been studied in the 4-300 K range, giving the exchange integral J=-109 cm-1. The MT vs. T plot exhibits a minimum at about 100 K, characteristic of this kind of coupled polymetallic complex with an irregular spin-state structure. 展开更多
关键词 Ni(Ⅱ)Cu(Ⅱ)Ni(Ⅱ) complexes irregular spin state structure high-spin ground state
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Monopole effects and high-spin levels in neutron-rich ^(132)Te
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作者 王韩奎 Amir Jalili +1 位作者 李歌星 王友宝 《Chinese Physics C》 SCIE CAS CSCD 2023年第7期96-101,共6页
The neutron-rich nuclei near doubly magic132^(Sn)have attracted considerable interest in both nuclear physics and nuclear astrophysics.For the particle-hole nuclei in this region,the low-lying and high core excitation... The neutron-rich nuclei near doubly magic132^(Sn)have attracted considerable interest in both nuclear physics and nuclear astrophysics.For the particle-hole nuclei in this region,the low-lying and high core excitations have been well described by shell model calculations using the extended pairing plus multipole-multipole force model.However,there is a significant difference between experiment and theory in the high-spin level 17+of^(132)Te.We intend to illustrate this difference through monopole interactions.For this purpose,the monopole corrections betweenπ(ν)0g_(7/2),ν1d_(5/2)andπ(ν)0h_(11/2)are investigated in^(132-134)Te,^(131-133)Sb,and^(130)Sn.Some theoretical levels are connected to the(17^(+))state of^(132)Te with the monopole correction(Mc)of Mc(νd_(5/2),νh_(11/2))and the quadruple-quadruple force between the proton and neutron,i.e.,levels 3^(-)(8^(-))in^(130)Sn,level 14^(-)in^(132)Te,and level 23/2^(-)in^(131)Sb.Their observations at lower energies can confirm the datum of level(17^(+))in^(132)Te with an illustration of monopole effects and quadruple-quadruple force. 展开更多
关键词 monopole effects high-spin levels quadruple-quadruple force
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高强钢内筋筒体对轮主动旋压塑性变形行为
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作者 陈开达 赵升吨 +4 位作者 邵旭山 李帆 朱文宇 孙浩然 黄晓鹏 《精密成形工程》 北大核心 2026年第1期224-235,共12页
目的针对固体火箭领域中超高强度钢带筋筒体生产制造成本高、生产周期长、比强度不高的问题,提出一种超高强度钢内筋薄壁筒体对轮主动旋压成形方法,并通过数值模拟和实验验证其可行性。方法建立了D406A超高强度钢内筋对轮主动强旋塑性... 目的针对固体火箭领域中超高强度钢带筋筒体生产制造成本高、生产周期长、比强度不高的问题,提出一种超高强度钢内筋薄壁筒体对轮主动旋压成形方法,并通过数值模拟和实验验证其可行性。方法建立了D406A超高强度钢内筋对轮主动强旋塑性变形过程的有限元模型,通过正交实验分析了旋轮进给率、旋轮圆角半径、旋轮工作角等工艺参数对内筋成形精度的影响。通过旋压机对直径720 mm的筒体进行成形实验,验证了内筋旋压成形的可行性。结果在内筋对轮主动旋压成形过程中,旋轮工作角对壁厚精度影响最大,旋轮圆角半径次之,旋轮进给率影响最小,最佳工艺参数如下:旋轮进给率为0.5 mm/r,旋轮圆角半径为8 mm,旋轮工作角为25°。结论通过有限元模拟和实验,确定了影响内筋对轮主动旋压成形质量的主要工艺参数及最佳工艺参数组合,并验证了新成形工艺的可行性。 展开更多
关键词 高强钢 内筋筒体 对轮旋压 塑性变形 数值模拟
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压力调控的双态转换材料
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作者 陈恩 温婷 +1 位作者 林传龙 王永刚 《物理学报》 北大核心 2026年第3期2-21,共20页
双态转换材料可在两稳定状态间可逆切换,是下一代信息存储、光电器件与量子调控的核心载体.高压因其通用性与可控性,可用于调控晶体结构、晶体场与电子结构,是实现多种物理性质双态转换的有效外场手段.本文综述了利用高压技术实现材料... 双态转换材料可在两稳定状态间可逆切换,是下一代信息存储、光电器件与量子调控的核心载体.高压因其通用性与可控性,可用于调控晶体结构、晶体场与电子结构,是实现多种物理性质双态转换的有效外场手段.本文综述了利用高压技术实现材料光、电等双态转换现象的研究进展,包括压致倍频转换、发光/变色转换、绝缘体-金属相变,半导体载流子类型的n-p转换和自旋交叉的调控,并重点讨论其中的构效关系研究以及原位表征方法.此外,部分体系还可在更复杂能量势面上表现出多态转换特征,可视作双态调控的延伸,为实现多进制信息编码与高密度数据存储提供新的可能.最后针对该领域目前在低压化与器件化和相变的可逆性等方向面临的困难,提出发展金刚石对顶砧集成微纳电极、光纤耦合及片上高压腔、降低转换压力到实用范围等潜在方向,以推动双态材料在超低功耗存储与可重构光电器件中的工程化应用. 展开更多
关键词 高压 双态转换 物性调控 构效关系 自旋交叉
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High-spin states in ^(128)I
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作者 郑云 竺礼华 +10 位作者 吴晓光 李广生 郝昕 王烈林 贺创业 刘颖 李雪琴 潘波 汪雷 李忠宇 丁怀博 《Chinese Physics C》 SCIE CAS CSCD 2009年第S1期179-181,共3页
The high-spin states in 128I have been studied by using in-beam γ-ray spectroscopy with the 124Sn(7Li,3n)128I reaction at beam energies of 25, 28 and 42 MeV. A new level scheme including 20 new levels and 27 new γ-t... The high-spin states in 128I have been studied by using in-beam γ-ray spectroscopy with the 124Sn(7Li,3n)128I reaction at beam energies of 25, 28 and 42 MeV. A new level scheme including 20 new levels and 27 new γ-transitions for 128I has been established preliminarily. 展开更多
关键词 high spin state level scheme doubly odd nucleus
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热亚胺化中应力对聚酰亚胺纤维结构和性能的影响 被引量:1
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作者 王彪 李源 +1 位作者 董杰 张清华 《纺织学报》 北大核心 2025年第3期1-8,共8页
为提高聚酰亚胺(PI)前驱体环化纤维的力学性能,并优化其微结构,通过红外光谱、X射线衍射、力学性能及热稳定性测试,研究了在热亚胺化过程中施加一定应力对PI纤维结构和性能的影响。结果表明:施加应力加快了热亚胺化反应的进程,300℃保温... 为提高聚酰亚胺(PI)前驱体环化纤维的力学性能,并优化其微结构,通过红外光谱、X射线衍射、力学性能及热稳定性测试,研究了在热亚胺化过程中施加一定应力对PI纤维结构和性能的影响。结果表明:施加应力加快了热亚胺化反应的进程,300℃保温120 s,纤维亚胺化程度达到90%,相比于松弛状态下提升了17%,这有利于纤维性能的提升;在纤维聚集态结构方面,应力作用下,纤维轴向晶面间距增大,取向度和结晶度提高;相较于松弛状态下,经400℃应力热亚胺化反应,纤维内部(004)晶面的取向度由0.63提升至0.80,结晶度由14.20%提升至16.73%,表明纤维内部形成更加完善的晶体结构,纤维径向分子链有序度增加,但大部分仍为非晶结构;得益于热亚胺化过程中分子链取向度的提高,纤维的强度和模量显著提升,断裂伸长率下降,且在应力作用下,经400℃热亚胺化处理纤维的5%和10%热失重温度分别达到529℃和565℃。 展开更多
关键词 高性能纤维 聚酰亚胺纤维 干喷湿纺 热亚胺化 应力 聚集态结构
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硅烷交联UHMWPE纤维的在线制备及抗蠕变性能研究 被引量:2
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作者 陶德昌 文鑫 +3 位作者 严坤 杨晨光 王雯雯 王栋 《化工新型材料》 北大核心 2025年第5期83-89,共7页
通过凝胶纺丝工艺制备硅烷偶联剂KH-590交联的超高分子量聚乙烯(UHMWPE)复合纤维,研究了UHMWPE纤维改性前后的结晶行为、力学性能、抗蠕变性能和微观形貌的变化,系统探究了硅烷偶联剂对复合纤维抗蠕变性能的作用关系。结果表明:当KH-59... 通过凝胶纺丝工艺制备硅烷偶联剂KH-590交联的超高分子量聚乙烯(UHMWPE)复合纤维,研究了UHMWPE纤维改性前后的结晶行为、力学性能、抗蠕变性能和微观形貌的变化,系统探究了硅烷偶联剂对复合纤维抗蠕变性能的作用关系。结果表明:当KH-590含量为2%时,UHMWPE纤维的凝胶率基本达到饱和。KH-590交联后样品的抗蠕变性能显著提高,当KH-590含量为2%时,UHMWPE的抗蠕变性能最佳。随着分子量的增加以及偶联剂含量的增加,UHMWPE纤维的结晶度、热稳定性能、凝胶含量均得到显著增强。这为UHMWPE纤维的抗蠕变性能改性方法提供了一定的实验依据,有望为制备高抗蠕变UHMWPE复合纤维提供参考。 展开更多
关键词 超高分子量聚乙烯纤维 凝胶纺丝 交联改性 蠕变性能
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多毛羽纱线的高品质再造成纱技术及应用
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作者 夏治刚 《纺织高校基础科学学报》 2025年第1期22-24,共3页
短纤纱成形的本质是将散纤维加工成按纵向有序排列的线性集合体。短纤纱成形方法主要有开放端和握持端纺纱^([1])。开放端纺纱以转杯纺、涡流纺为代表,共同点在于:纤维须条在非握持状态下加捻成纱,加捻、卷绕位置分开,实现高速成纱;开... 短纤纱成形的本质是将散纤维加工成按纵向有序排列的线性集合体。短纤纱成形方法主要有开放端和握持端纺纱^([1])。开放端纺纱以转杯纺、涡流纺为代表,共同点在于:纤维须条在非握持状态下加捻成纱,加捻、卷绕位置分开,实现高速成纱;开放端纺纱以纤维缠绕结构为主,其中转杯纺以纤维搭接加捻缠绕方式成形,纱体呈内紧外松式层状包缠结构^([2]);涡流纺以前纤维尾端连续包缠后纤维头端的方式包缠成纱,纱体纤维呈螺旋直径递增的单螺旋包缠结构^([3]),纱表面光洁度、紧密度高,对应织物抗起球等级高。但包缠成纱结构决定了纱体纤维内外转移不足、抱合力差^([4]),纱强低、纱表摩擦易解缠,严重制约纱线高强稳固的高品质成形。 展开更多
关键词 多毛羽纱线 短纤纱 高品质成纱技术 转杯纺 涡流纺 环锭纺
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