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少年科普世界(快乐数学4-6年级版) 2025年第3期 36-37,40,F0003页

作者：马鲁克不详

境之探险队在时空隧道中突然消失,随后又离奇地出现在了充满神秘色彩的奇幻π世界。在城门前,他们看到了这个异世界发布的任务,只要挑战成功,就能返回到现实世界。快来和他们一起探索吧!

关键词：时空隧道神秘色彩奇幻 π 世界

A new digital pulse processing method for 2πa and 2πb emitter measurement

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Nuclear Science and Techniques 2016年第6期27卷 137-143页

作者： Zheng Tu Ke-Zhu Song Ming Zhang Zhi-Jie Yang Zhi-Guo Ding Hong-Wei Yu Jun-Cheng Liang Hao-Ran Liu State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China National Institute of Metrology 18 North Third Ring EastRd.Beijing 100029China

Digital pulse processing has developed rapidly during recent ***,it has been widely applied in many *** this study,we introduce a digital pulse processing method for 2πa and 2πb emitter *** digital pulse processing method for 2πa and 2πb emitter measurement is comprised of a field-programmable gate-array-based acquisition card and a pulse-height analysis *** established two channels(one for the a emitter and one for the b emitter) on an acquisition board using an analog-to-digital converter with a 16-bit resolution at a speed of 100 million samples per *** this study,we used captured and stored data to analyze emission rate counts and *** method we established takes into account noise cancelation,dead-time correction,background subtraction,and zero-energy *** carefully designed control procedures in order to simplify pulse-width fitting and threshold-level *** transmitted data and commands through a universal serial bus between the acquisition board and the *** results of our tests prove that our method performs well in pulse reconstruction fidelity and amplitude measurement *** with the current standard method for measuring 2πa and 2πb emission rates,our system demonstrates excellent precision in emission rate counting.

关键词：脉冲处理测量性能发射器顺序控制程序 π 数据采集卡测量精度模数转换器

Theoretical studies on cation-π interactions (I)——Density-functional theory investigation on the configurations and interaction for ammonium cation-benzene complex

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Science China Chemistry 1998年第5期41卷 535-542页

作者：蒋华良朱维良谭小健顾健德陈建忠林茂伟陈凯先嵇汝运 1. State Key Laboratory of Drug Research Shanghai Institute of Materia Medica 200031 Shanghai China

Density\|functional theory (DFT) approach of B3LYP/6\|31G\+* has been employed to calculate the six possible configurations of ammonium cation\|benzene complex (NH\++\-4\|C\-6H\-6). The calculation result released that the asymmetrical configuration of this complex with two hydrogen atoms pointing to the benzene ring was the most stable structure. Structural characteristics, molecular interaction fashion and thermodynamic parameters indicated that NH\++\-4 was bound to benzene through hydrogen bonding interaction.

关键词： cation π interaction hydrogen bond ammonium cation\|benzene complex quantum chemistry densi\| ty\|functional theory (DFT).

The Simplest General Formula of Approximate Calculationfor Total π- Bond Energies of Randomly Fused Polycyclic Aromatic Hydrocarbons

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Chinese Science Bulletin 1994年第18期39卷 1516-1519页

作者：梁吉春 Department of Chemistry Hubei Institute for Nationalities Enshi 445000 PRC

The total π-bond energy shows a quantum-chemical characteristic of the conjugated molecules. Based on HMO methods, a lot of people try to search for the simple general formulas of an approximated calculation for a wi... 详细信息

关键词： polycyclic aromatic hydrocarbons total π bond energy approximate calculation the simplest general formula.

Study on Laccase-Catalyzed Oxidation of Disubstituted Ferrocene and π-arene-π- cyclopentadienyliron Derivatives

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Wuhan University Journal of Natural Sciences 2000年第3期5卷 351-356页

作者： Ji Li-cai1, Hu Pei-zhi2, Jin Chang-hua3 , Ding Zi-rong2 1. College of Adult Education, Wuhan University, Wuhan 430072, China 2. Col lege of Chemistry and Environment Science, Wuhan University, Wuhan 430072, C hina 3,Yiping Plant of Chemistry and Industry at Zhong Qing City, Zhong Qing 631323, China College of Adult Education Wuhan University Wuhan China College of Chemistry and Environment Science Wuhan University Wuhan China Yiping Plant of Chemistry and Industry at Zhong Qing City Zhong Qing China

It is studied that Rhus vernicifera laccase catalyzed oxidation of 26 disubstituted ferrocene and its metal complexes, π-arene-π-cyclopentadienyliron derivatives and metal meso-(tetra-4-sulfanatophenyl)porphyrin in the diethylene glycol monobutyl ether (DGBE)/phosphate buffer (V/V, 1/5). It is found that 1,1′-bishydroxylmethyl ferrocene etc 16 compounds are new substrates of laccase. The relation of structure and function of substrates is discussed. The affective factors of laccase-catalyzed oxidation of 1,1′-bishydroxyl-methyl ferrocene—pH, temperature, substrate concentration, laccase quantity and surfactant were investigated further.

关键词： Key words Rhus vernicifera laccase disubstituted ferrocene catalytic oxidation π arene π cyclopentadienyliron

Random Bragg-gratings-based narrow linewidth random fiber laser with a π-phase-shifted FBG

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Chinese Optics Letters 2019年第9期17卷 33-37页

作者： Shuaijie Miao Wentao Zhang Ying Song School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China Optoelectrorzic System Laboratory Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

A new structure of short-cavity random fiber laser(RFL) with narrow linewidth lasing is proposed. Aπ-phase-shifted fiber Bragg grating(FBG) loop mirror was used in the RFL for spectral filtering and to suppress multi-mode oscillation due to the narrow transmission window. The random feedback of the RFL was implemented by a randomly dispersed weak reflection FBG array. The high gain of the erbium-doped fiber and a half-open cavity design results in a low lasing threshold. The linewidth of the laser was 225 Hz with58 d B side-mode-suppression ratio. The laser threshold was 4.5 mW, and the optical signal-to-noise ratio was up to 63 dB.

关键词： random Random FBG optical mirror π was loop

手征Su(3)夸克模型研究低能Nπ散射相移(英文)

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高能物理与核物理 2005年第10期29卷 948-953页

作者：黄飞张宗烨余友文中国科学院高能物理研究所

在手征SU(3)夸克模型中,通过求解共振群方程动力学地研究了同位旋I=1/2和I=3/2道Nπ的S波和P波低能弹性散射相移.所用的模型参数由基态八重态和十重态重子的能量定出,并能给出不同分波的KN散射相移.除了有明显共振态的道以外,计算得到... 详细信息

在手征SU(3)夸克模型中,通过求解共振群方程动力学地研究了同位旋I=1/2和I=3/2道Nπ的S波和P波低能弹性散射相移.所用的模型参数由基态八重态和十重态重子的能量定出,并能给出不同分波的KN散射相移.除了有明显共振态的道以外,计算得到的各个分波的Nπ散射相移和实验值定性一致.

关键词： Nπ散射相移夸克模型手征对称性手征SU(3)夸克模型弹性散射相移低能 π 模型参数共振态

CP VIOLATION IN Ks → 3π

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Chinese Physics C 2016年第10期40卷 709-710页

作者： T. Nakada L. Wolfenstein Paul Scherrer Institute Carnegie-Mellon University

The possible final states for the decay K^0→ π＋π-π^0 have isospinI = 0, 1, 2, and 3. TheI= 0 andI= 2states have CP = ＋1 and Ks can decay into them without violating CP symmetry, but they are expected to be strongly suppressed by centrifugal barrier effects. The I = 1 and I = 3 states, which have no centrifugal barrier, have CP = -1 so that the Ks decay to these requires CP violation.

关键词： CP破坏 π 对称性衰变状态势垒离心

亲疏水一体化策略构筑π共轭光诊疗纳米材料的研究进展

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高分子学报 2024年第12期55卷 1622-1647页

作者：侯胜鑫曲松楠田雷蕾澳门大学应用物理及材料工程研究院中国澳门特别行政区999067 南方科技大学材料科学与工程系深圳518055

有机光诊疗π共轭分子由于明确的分子结构、丰富的激发态性质、大的摩尔吸光系数以及优异的生物安全性,在生物成像和肿瘤治疗方面展示出巨大的应用潜力.然而,π共轭分子的强疏水性严重制约了它在生物体内的实际应用.目前的研究致力于利... 详细信息

有机光诊疗π共轭分子由于明确的分子结构、丰富的激发态性质、大的摩尔吸光系数以及优异的生物安全性,在生物成像和肿瘤治疗方面展示出巨大的应用潜力.然而,π共轭分子的强疏水性严重制约了它在生物体内的实际应用.目前的研究致力于利用两亲性的聚合物载体包裹疏水分子以达到在水中分散的目的,这可能会导致不可控的分子泄露并造成严重的肝脾富集.合成π共轭双亲聚合物构建一体化胶束是增强生物安全性,实现体内光诊疗应用的理想手段.本文首先介绍了光诊疗π共轭分子的种类和分子结构设计,及其光物理化学性质.其次,详细探讨了一体化胶束的构建方法,主要包括聚合物直接接枝(graft to)和π共轭分子参与聚合(graft from)2种方式.同时,对一体化胶束构建过程中使用亲水性高分子种类及功能进行了分类探讨,主要包括非生物大分子聚乙二醇和聚两性离子以及生物大分子核酸、多肽、多糖等.最后,讨论了一体化胶束的独特性质及其在调控分子组装结构、调节生物体代谢性质、细胞和活体成像以及肿瘤治疗等方面的应用.并对一体化的有机光诊疗纳米胶束在生物医学领域的研究进展进行了总结和展望.

关键词：光诊疗 π 共轭分子水溶性高分子一体化胶束

从ψ’→J/ψπ^+π^-衰变中抽取ππ相移(英文)

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高能物理与核物理 2005年第9期29卷 852-855页

作者：郭奉坤沈彭年姜焕清中国科学院高能物理研究所

ψ’→J/ψπ+π-提供了一个抽取低于0.59GeV的ππS波相移的新途径.基于在树图衰变振幅中忽略D波的近似,给出了从ψ’→J/ψπ+π-的ππ不变质量谱中得到ππS波相移的公式.

关键词： ππ S波相移 ψ'→J/ψ π^+π^- 衰变振幅 J/ψ 相移抽取 π 不变质量谱