检索结果-南通市图书馆

First-Principles Study of Magnetic Properties of TM_(13) and TM_(13)@Au_(32) Clusters(TM = Mn, Co)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第10期35卷 22-26页

作者： Yi-Bo Li Li-Jin Zeng chun-Xi＆ng zhao chun-Yao Niu International Laboratory for Quantum Fhnctional Materials of Henan School of Physics and Engineering Zhengzhou UniversityZhengzhou 450001 School of Digital Media Shenzhen Institute of Information TechnologyShenzhen 518172

The structural and magnetic properties of TM13and TM_（13）@Au32clusters（TM=Mn,Co）are studied by firstprinciples *** find that the Au32cluster can tune not only the magnetic moment but also the magnetic coupling properties between the TM atoms of the TM *** Au32cluster can increase the net magnetic moment of Mn13clusters while reducing that of *** interaction between Au and Mn atoms induces more Mn atoms to form spin parallel coupling,resulting in an increase of the total magnetic moment of Mn13clusters,while for the Co13clusters,the interaction between Au and Co atoms does not change the magnetic coupling states between the Co atoms,but reduces the magnetic moment of the Co atoms,leading to a decrease of the total magnetic moment of this *** findings indicate that the encapsulation of Au32clusters can not only raise the chemical stability of TM clusters,but also can tune their magnetic coupling properties and magnetic moment,which enables such systems to be widely applied in fields of spintronics and medical science.

关键词： net Mn Clusters Au Co

在线全文

学校读者我要写书评

暂无评论

加权加标网络的稳定与平衡

逻辑学研究 2024年第4期17卷 35-53页

作者：王轶董惠敏中山大学哲学系(珠海) 维也纳工业大学逻辑与计算研究所

经典结构平衡理论对不带权重的加标网络有较为完善的研究。Morrissette(1958)将结构平衡理论推广到加权加标网络并加以经验研究。近年来出现了基于时态逻辑CTL的结构平衡逻辑研究,但所探讨的社会网络局限于不带权重的加标网络。本文将... 详细信息

经典结构平衡理论对不带权重的加标网络有较为完善的研究。Morrissette(1958)将结构平衡理论推广到加权加标网络并加以经验研究。近年来出现了基于时态逻辑CTL的结构平衡逻辑研究,但所探讨的社会网络局限于不带权重的加标网络。本文将结构平衡逻辑推广到带权重的加标网络,引入几种适用的形式语言和语义,探讨由此得到的几个逻辑的表达能力,并给出证明系统。

关键词：加权加标网络结构平衡理论稳定性平衡性分支时间逻辑

Chalcogen heteroatoms doped nickel-nitrogen-carbon single-atom catalysts with asymmetric coordination for efficient electrochemical CO_(2)reduction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Catalysis 2024年第9期64卷 54-65页

作者： Jialin Wang Kaini zh.ng Ta Thi Thuy ng Yiqing Wang Yuchuan Shi Daixing Wei chung-Li Dong Shaohua Shen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an 710049ShaanxiChina Department of Physics Tamkang UniversityNew Taipei City 25137TaiwanChina

The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2)reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into the symmetric nickel-nitrogen-carbon(Ni-N4-C)configuration to obtain Ni-X-N3-C(X:S,Se,and Te)SACs with asymmetric coordination presented for central Ni *** these obtained Ni-X-N3-C(X:S,Se,and Te)SACs,Ni-Se-N3-C exhibited superior eCO_(2)RR activity,with CO selectivity reaching~98%at-0.70 V versus reversible hydrogen electrode(RHE).The Zn-CO_(2)battery integrated with Ni-Se-N3-C as cathode and Zn foil as anode achieved a peak power density of 1.82 mW cm-2 and maintained remarkable rechargeable stability over 20 ***-situ spectral investigations and theoretical calculations demonstrated that the chalcogen heteroatoms doped into the Ni-N4-C configuration would break coordination symmetry and trigger charge redistribution,and then regulate the intermediate behaviors and thermodynamic reaction pathways for eCO_(2)***,for Ni-Se-N3-C,the introduced Se atoms could significantly raise the d-band center of central Ni atoms and thus remarkably lower the energy barrier for the rate-determining step of*COOH formation,contributing to the promising eCO_(2)RR performance for high selectivity CO production by competing with hydrogen evolution reaction.

关键词： Electrochemical CO_(2)reduction reaction Chalcogen heteroatoms Single-atom catalysts Asymmetric coordination CO production

Syntheses,structures,and reactivity of ruthenium(Ⅱ) hydride complexes containing Klui's oxygen tripodal ligand

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2010年第10期53卷 2139-2143页

作者： ng Ho-Yuen LAI chun-Sing WILLIAMS Ian D. LEUng Wa-Hung Department of Chemistry The Hong Kong University of Science and Technology

Treatment of Ru(CO)(Cl)(H)(PPh3)3 with NaLOEt (LOEt-= [CpCo{P(O)(OEt)2}3]-) afforded the hydride complex (PPh3)(CO)-LOEtRu(H) (1), which has been characterized by X-ray crystallography. Similarly, the tricyclohexylphosphine analogue, (PCy3)(CO)LOEtRu(H) (2), was synthesized from Ru(CO)Cl(H)(PCy3)2 and NaLOEt. Treatment of complex 1 with R'SO2N3 afforded the (arylsulfonyl)amido complexes LOEtRu(CO)(PPh3)(NHSO2R) (R = 2,4,6-i-Pr3C6H2 (3), 4-t-BuC6H4 (4)). The crystal structure of complex 3 has been determined. The Ru-N distance and Ru-N-S angle in 3 are 2.076(3) and 126.14(16)°, respectively. Reactions of complex 1 with acids have been studied.

关键词： ruthenium oxygen tripodal ligand hydride complex (arylsulfonyl)amido complex

Laser and Fluorescence Properties of Organic Dye DCM Doped Sol-Gel-Derived Solid-State Materials

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1999年第6期15卷 563-566页

作者： zh.ng, QY Jiang, zh Tongji Univ Pohl Inst Solid State Phys Shanghai 200092 Peoples R China Chinese Acad Sci Shanghai Inst Opt & Fine Mech Shanghai 201800 Peoples R China

Two kinds of new Ormosil xerogels derived from GPTMS (3-glycidyl propyl trimethoxisilane) and TEOS (tetraethoxysilane) or GPTMS and Ti(OBu)4 (tetrabutoxytitanate) were synthesized viathe sol-gel method as dye laser host. Their optical properties, microstructure characteristics and sudece laser damage thresholds have been reported. The effects of dye matrix combination on the fluorescence emission, slope efficiency, photostability and tunable bandwidth were *** oscillation was easily achieved near 620 nm with a slope efficiency of 29% from DCM dopedSiO2-Ormosil pumped by a frequency-doubled radiation from a Q-switched Nd:YAG laser. The laser wavelength was tunable over 59 nm, and the laser output energy had only a 10% reduction after 2.5× 104 pulses at a pump repetition rate of 1Hz and a pump intensity of 1

关键词： GPTMS DCM EtOH

二地鳖甲煎汤联合六味地黄软胶囊治疗勃起功能障碍肾阴虚证患者的临床疗效分析

在线全文

学校读者我要写书评

暂无评论

中国现代药物应用 2024年第2期18卷 134-137页

作者：刘波钱春雷宋瑶刚宋春新溧阳市中医医院泌尿外科 213300

目的探究应用二地鳖甲煎汤联合六味地黄软胶囊治疗勃起功能障碍(ED)肾阴虚证患者的临床疗效。方法 80例勃起功能障碍肾阴虚证患者,采用计算机随机分为观察组和对照组,每组40例。观察组患者应用二地鳖甲煎汤联合六味地黄软胶囊治疗,对... 详细信息

目的探究应用二地鳖甲煎汤联合六味地黄软胶囊治疗勃起功能障碍(ED)肾阴虚证患者的临床疗效。方法 80例勃起功能障碍肾阴虚证患者,采用计算机随机分为观察组和对照组,每组40例。观察组患者应用二地鳖甲煎汤联合六味地黄软胶囊治疗,对照组患者口服安慰剂颗粒。比较两组患者治疗前后的勃起功能国际问卷(IIEF-5)评分、主要症状以及次要症状积分、血清性激素指标[促黄体生成素(LH)、催乳素(PRL)、睾酮(T)、卵泡刺激素(FSH)、雌二醇(E2)]。结果治疗8周后,观察组IIEF-5评分为(20.96±4.12)分,对照组为(15.30±3.48)分,与对照组相比,观察组IIEF-5评分显著提升(Png/dl、(38.65±4.54)ng/L、(11.04±3.47)ng/ml,对照组分别为(4.81±1.11)mIU/ml、(2.85±0.44)mIU/ml、(20.99±4.19)ng/dl、(58.79±6.16)ng/L、(11.18±3.18)ng/ml,与对照组相比,观察组FSH、LH、E2水平显著下降, T水平显著提升(P0.05)。结论应用二地鳖甲煎汤联合六味地黄软胶囊治疗勃起功能障碍肾阴虚证患者效果显著,可明显改善患者的勃起情况、主要症状以及次要症状、血清性激素指标,值得应用。

关键词：二地鳖甲煎汤六味地黄软胶囊勃起功能障碍肾阴虚证临床疗效孟河医派

Role of equal-strain assumption in unit-cell theory for consolidation with vertical drains

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2017年第12期24卷 2914-2923页

作者： lei Guo-hui XU Li-dan zh.ng Qiang ng Charles Wang Wai Key Laboratory of Geomechanics and Embankment Engineering of the Ministry of Education Geotechnical Research Institute Hohai University Department of Civil and Environmental Engineering The Hong Kong University of Science and Technology

In the development of unit-cell theory for the analytical analysis of consolidation with vertical drains, the equal-strain assumption is often made with the intention of modelling consolidation under uniform settlement conditions. In contrast, the free-strain assumption for modelling consolidation under uniform load conditions is seldom employed, mainly because of the complexities involved in the analysis. This study derives a rigorous analytical solution to the generalised governing equations of free-strain consolidation with a vertical drain subjected to an instantaneous load. Calculated results from the newly proposed solution are compared with those from three available solutions derived based on the equal-strain assumption. Surprisingly good agreement is obtained in terms of excess pore-water pressure, degree of consolidation, and settlement. Horizontal profiles of settlement were not uniform before the end of consolidation. This indicates that the uniform settlement condition is not actually reproduced by the analytical solutions derived based on the equal-strain assumption. The equal-strain assumption is a sufficient but not necessary condition for deriving an analytical solution to unit-cell consolidation theory. The assumption plays no role in modelling consolidation under uniform settlement conditions but simplifies the analytical analysis of free-strain consolidation and results in an approximate solution of high accuracy for consolidation under uniform load conditions. Moreover, drain resistance and smear effects not only retard the consolidation rate, but also importantly shape the vertical and horizontal profiles of excess pore-water pressure, respectively.

关键词： consolidation ground improvement pore pressures settlement vertical drain

在线全文

学校读者我要写书评

暂无评论

水性脱模剂对混凝土外观气泡影响的研究

四川建材 2024年第8期50卷 32-34页

作者：宋欣倪涛汪咏梅封柯 Serina ng 四川砼道科技有限公司四川成都610200 石家庄市长安育才建材有限公司河北石家庄051430

以菜籽油为基础制备了一款水性脱模剂,并通过数字图像和图像处理方法对比研究了菜籽油及其制成的水性脱模剂在不同振动时间和不同模板上对混凝土表面气孔的影响,研究发现在不同条件下,相较于油性脱模剂,水性脱模剂能够有效减少混凝土表... 详细信息

以菜籽油为基础制备了一款水性脱模剂,并通过数字图像和图像处理方法对比研究了菜籽油及其制成的水性脱模剂在不同振动时间和不同模板上对混凝土表面气孔的影响,研究发现在不同条件下,相较于油性脱模剂,水性脱模剂能够有效减少混凝土表面气孔,尤其是大尺寸气孔的数量。此外,延长振动时间、选用表面光滑的模板也能有效降低混凝土表面气孔。

关键词：水性脱模剂混凝土表面气孔振动时间模板类型

青藏高原1981-2015年暖季降水变化趋势:受控于大尺度环流型变化

在线全文

学校读者我要写书评

暂无评论

北京大学学报（自然科学版） 2024年第1期60卷 133-144页

作者：孙亚伟吴振鹏黎立页张庆红北京大学物理学院大气与海洋科学系北京100871 92154部队烟台264000 中国气象科学研究院北京100081

利用最新的高时空分辨率融合降水数据集,研究青藏高原的长期降水变化趋势。结果表明,在1981—2015年的暖季(5—9月),青藏高原降水量显著增加(格点平均趋势为0.9 mm/a),其东北部、中部和西部最为显著。采用T模态倾斜旋转主成分分析法(PC... 详细信息

利用最新的高时空分辨率融合降水数据集,研究青藏高原的长期降水变化趋势。结果表明,在1981—2015年的暖季(5—9月),青藏高原降水量显著增加(格点平均趋势为0.9 mm/a),其东北部、中部和西部最为显著。采用T模态倾斜旋转主成分分析法(PCT),将青藏高原500 hPa位势高度场分为9个典型环流型,发现第2和第4环流型(T2和T4)是暖季降水量增加的主导环流型(DT)。DT位势高度场为西低东高的“槽脊对峙”分布,青藏高原暖季降水量增加体现在DT主导降水日数和日均降水量的共同增加。除DT环流型数量的增加导致青藏高原中西部降水增加外,降水增加机制还包括降水条件的优化,即T2以“槽脊对峙”加强为驱动的动力条件优化为主导,T4以“水汽滞增”加强为驱动的热力条件优化为主导。

关键词：青藏高原(TP) 降水长期趋势大尺度环流

维普期刊数据库博看期刊