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周环反应的立体选律
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作者 汪帆 《曲靖师范学院学报》 1998年第Z3期75-78,共4页
本文介绍一种从π电子数与前线轨道(FMO)的HOMO(最高占有轨道)、LUMO(最低空轨道)的能级及对称性和反应条件三者的关系中得出的表示方法,用这种方法可以使学生易于理解和掌握周环反应的反应规律。
关键词 π电子数 前线轨道 对称性 周环反应 选律
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协同反应选律的一种简便推导
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作者 杨季冬 《长江师范学院学报》 1997年第3期88-96,共9页
本文依据FMO的吼对称性关系对电环化反应、环加成反应、a一键迁移应等三种类型的协同反应选律作了一种简便推导,直截了当,方便教学。
关键词 协同反应 选律 简便推导
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选沙相似律对模型沙波相似性影响的试验研究 被引量:2
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作者 徐敏 陈立 +1 位作者 何俊 李东锋 《水科学进展》 EI CAS CSCD 北大核心 2017年第5期712-719,共8页
为了弄清选沙相似律对动床模型沙波相似性的影响,开展基于起动相似等3种不同相似律选择模型沙的沙波水槽试验。基于试验观测的沙波波高、波长以及沙波不同部位的水深、流速,对比分析了沙波尺度及其随水流强度变化过程的相似性。结果表明... 为了弄清选沙相似律对动床模型沙波相似性的影响,开展基于起动相似等3种不同相似律选择模型沙的沙波水槽试验。基于试验观测的沙波波高、波长以及沙波不同部位的水深、流速,对比分析了沙波尺度及其随水流强度变化过程的相似性。结果表明:当模型沙重率、形状与原型沙相同时,满足起动相似的模型沙沙波尺度与原型相似性最高,满足悬浮相似模型沙的沙波整体偏高、偏长,兼顾起动与悬浮相似的模型沙介于两者之间;不同选沙相似律不影响沙波波高、波长随相对水流强度的变化规律,满足不同相似律的模型沙沙波波高均在相同的相对水流强度达到最大值,波长随相对水流强度增大而增大。说明偏离起动相似越少,沙波相似程度越高。 展开更多
关键词 沙相似 波高 波长 相似性
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戈载佚著《词律订》考论 被引量:2
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作者 刘宏辉 《南阳师范学院学报》 CAS 2016年第10期36-41,共6页
《词律订》是戈载的论律之作,惜已散佚。《词律订》一书是否完成在清代即存有不少争议。秦巘《词系》引录不少《词律订》内容,依据《词系凡例》推断《词律订》业已完成。《词律订》以订定万树《词律》为主要内容,间论及韵,与《词林正韵... 《词律订》是戈载的论律之作,惜已散佚。《词律订》一书是否完成在清代即存有不少争议。秦巘《词系》引录不少《词律订》内容,依据《词系凡例》推断《词律订》业已完成。《词律订》以订定万树《词律》为主要内容,间论及韵,与《词林正韵》可参互考订。《宋七家词选》是戈载撰写《词律订》过程中编订的,两书可互为补充。对戈载校定《词律》之评价应避免偏颇,既要认识到其贡献,也要察觉其不足。 展开更多
关键词 《词订》 戈载 《词系》 《宋七家词 《词校勘记》
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论模式思维
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作者 凌立坤 《求是学刊》 1986年第1期9-15,21,共8页
关键词 模式思维 弹动 辩证思维 模糊思维 选律 客观对象 认识对象 思维模型 灵感思维 构成模式
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转向架构架的试验
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作者 裴士英 《电力机车与城轨车辆》 1981年第1期25-32,共8页
一、试验的必要性转向架构架是铁路机车车辆的主要部件,机车车辆通过转向架传递牵引力和制动力而进行运转。其强度在很大程度上决定转向架的寿命,因而,在批量生产前,制造者和用户必须进行试验。二、转向架的作用就转向架的作用来看,它... 一、试验的必要性转向架构架是铁路机车车辆的主要部件,机车车辆通过转向架传递牵引力和制动力而进行运转。其强度在很大程度上决定转向架的寿命,因而,在批量生产前,制造者和用户必须进行试验。二、转向架的作用就转向架的作用来看,它好象是一个十分简单的部件,但从表面上是不能了解实质的。 1。 展开更多
关键词 转向架 转向装置 选律
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大学分析化学教材中紫外-可见吸收光谱产生条件的讨论
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作者 王中慧 任列香 +2 位作者 周慧 刘红云 晋卫军 《化学教育(中英文)》 CAS 北大核心 2024年第16期108-112,共5页
在分析化学教材中简要介绍电子跃迁光选律的相关内容,是对选择性吸收知识点的有益补充,有助于学生更全面地理解电子吸收光谱产生的原理,符合当前分析化学发展趋势,也符合以选拔培养基础学科拔尖创新人才为目标的国家强基计划所需。考虑... 在分析化学教材中简要介绍电子跃迁光选律的相关内容,是对选择性吸收知识点的有益补充,有助于学生更全面地理解电子吸收光谱产生的原理,符合当前分析化学发展趋势,也符合以选拔培养基础学科拔尖创新人才为目标的国家强基计划所需。考虑到本科生一或二年级的数理水平,以及鉴于部分学生此后可能不再接触到电子吸收光谱的基本理论方面的知识,建议在化学分析和仪器分析课程中分层次引入电子吸收光谱光选律的内容。并建议只作定性的、非数学化描述,同时提供更深入的阅读资料,以便于学习的可持续性。 展开更多
关键词 紫外-可见吸收光谱 选律 跃迁偶极矩 分析化学
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明“大臣专擅选官”律研究
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作者 高露露 《长江文明》 2020年第4期58-64,共7页
明初太祖设"大臣专擅选官"律,以防止大臣结党营私,实为集权。在实际案件的处理中,该律的使用可以分为常规程序和比拟程序。但由于此律含义模糊,范围广泛,对"大臣"缺乏明确界定,因而在实际运用中其威慑意义大于现实... 明初太祖设"大臣专擅选官"律,以防止大臣结党营私,实为集权。在实际案件的处理中,该律的使用可以分为常规程序和比拟程序。但由于此律含义模糊,范围广泛,对"大臣"缺乏明确界定,因而在实际运用中其威慑意义大于现实操作,且逐渐成为党争间相互倾轧的手段。据此,此律的法律意义和作用让位于政治需要。至明后期,大臣"卖官"和以权谋私的现象严重,从而加强了该律的实际落实作用,法律意义再次回升。至清代虽仍保有此律,但对其的重视和运用较少,形同虚设。清末,此条律文被删除。 展开更多
关键词 大臣专擅 威慑作用 党争工具 意义
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How does the Civil Code Process the Civil and Commercial Relations According to the Insurance Law
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作者 WANG Rong 《International English Education Research》 2015年第12期68-73,共6页
The relationship between the civil law and commercial law is a long-standing issue of controversy in the area of private law, and it is also an issue of unavoidably legislative selection during the codification the ci... The relationship between the civil law and commercial law is a long-standing issue of controversy in the area of private law, and it is also an issue of unavoidably legislative selection during the codification the civil code in almost every country. Since the founding of the People Republic of China, China has carried out the codification of civil code for four times, and since the part^s eighteen plenary session officially proposed the 'codification of civil code', the issue of the civil and conmaercial relation draws the attention again, either unification or division of civil and commercial law directly affects the system and content of the civil code, and affects how to process the relationship between the civil law and commercial law during the codification of the civil code as well. The codification of the civil code should not only consider the legislative tradition of the civil and commercial legislation and the current legal system, but also pursue characteristics of the commercial law, in a system of combining civil and commercial law, through adding commercial law into the general principle of civil law; the existing commercial law should be separately retained. 展开更多
关键词 The civil code unification of civil and commercial law division of civil and commercial law commercial custom
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Influence of Oscillation Frequency of a Sieve on the Screening Process for a Conical Sieve with Oscillatory Circular Motion
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作者 Gh. Voicu D. Stoica N. Ungureanu 《Journal of Agricultural Science and Technology(B)》 2011年第8期1224-1231,共8页
Removal of foreign bodies from seed mixtures, or their calibration for use as planting material, as well as fraction classification of granular materials requires screening surfaces with vibratory motion. This paper p... Removal of foreign bodies from seed mixtures, or their calibration for use as planting material, as well as fraction classification of granular materials requires screening surfaces with vibratory motion. This paper presents some aspects on the working process of a sieve, made of perforated sheet and having an outer conical surface with oscillatory circular motion (alternative) on the horizontal. Results are presented for some experimental researches on the movement of material on the sieve, for various kinematical parameters of the sieve (amplitude and oscillation frequency). A conical sieve, suspended at the upper and lower in three points, was tested for screening of rapeseeds in order to estimate the influence of oscillation frequency on the screening process. Curves were drawn for separation intensity on the sieve generating line, and by regression analysis with normal distribution law were determined the equation coefficients and the correlation with experimental data. Movement of material on the sieve and its working process, in general, was appreciated by means of the peak position of distribution curve depending on the oscillation frequency of the sieve, considering that the normal distribution law correlates very well the data obtained by experiments. 展开更多
关键词 Grain sieving conical sieve oscillatory circular motion oscillation frequency normal distribution law.
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Yb3+/Li+共掺Y2O3纳米颗粒的1μm光致发光机制 被引量:1
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作者 樊婷 吕健滔 李娜 《光学学报》 EI CAS CSCD 北大核心 2013年第F06期237-240,共4页
通过甘氨酸燃烧法制备了Yb3+/Li+共掺的YzO。纳米颗粒,研究了940nm半导体激光器激发下的Yb3+ 1μm附近的光致发光光谱,结果表明1pm附近的荧光峰在共掺Li+的摩尔分数为5%时达到最强,比不掺杂Li+离子时增强了大约12倍。分析了X... 通过甘氨酸燃烧法制备了Yb3+/Li+共掺的YzO。纳米颗粒,研究了940nm半导体激光器激发下的Yb3+ 1μm附近的光致发光光谱,结果表明1pm附近的荧光峰在共掺Li+的摩尔分数为5%时达到最强,比不掺杂Li+离子时增强了大约12倍。分析了X射线主衍射峰的移动,结果表明Li+离子的掺杂改变了Yb3+离子的晶体场环境。求解了稳态速率方程,结果表明荧光增强的主要原因是掺杂的Li+离子扰乱了发光中心Yb3+离子在Y2O3晶格中的环境,打破了发光跃迁选律,致使4f组态内电偶极跃迁增强,电偶极跃迁振子强度增大,从而导致基态吸收截面的增大。 展开更多
关键词 材料 稀土离子 光致发光 跃迁选律 速率方程
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二维材料的拉曼光谱研究进展 被引量:10
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作者 吴娟霞 谢黎明 《科学通报》 EI CAS CSCD 北大核心 2018年第35期3727-3746,共20页
二维材料因其独特的结构与性质引起了科学家们的广泛关注.拉曼光谱是一种特征性强、快速、无损的材料结构表征方法,其在低维材料的结构表征方面具有独特的优势.本文主要综述了拉曼光谱在二维材料结构表征方面的研究进展.首先,系统介绍... 二维材料因其独特的结构与性质引起了科学家们的广泛关注.拉曼光谱是一种特征性强、快速、无损的材料结构表征方法,其在低维材料的结构表征方面具有独特的优势.本文主要综述了拉曼光谱在二维材料结构表征方面的研究进展.首先,系统介绍了二维材料结构和拉曼选律基础知识,并分析了二维材料的典型拉曼特征;其次,通过对二维材料的典型拉曼特征峰的峰位和峰强的分析,讨论了拉曼光谱测定二维材料的层数、边缘手性/晶格取向、合金成分等;然后,介绍了缺陷、掺杂、外界应力以及热效应对二维材料拉曼散射的影响;最后,结合二维电荷密度波材料相变过程中的结构和拉曼特征的变化,讨论了拉曼光谱在相变性质研究中的应用. 展开更多
关键词 二维材料 拉曼光谱 结构表征 拉曼选律
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A preliminary discussion on rules of clinical acupoint selection of acupuncture for the treatment of chemotherapy-induced nausea and vomiting 被引量:8
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作者 安琪 陈波 +2 位作者 郭义 潘兴芳 郭永明 《World Journal of Acupuncture-Moxibustion》 CSCD 2015年第2期39-44,66,共7页
Objective To preliminarily investigate the rules of acupoint selection of acupuncture and moxibustion for the treatment of chemotherapy-induced nausea and vomiting by retrospecting pertinent literature from 1986 to 20... Objective To preliminarily investigate the rules of acupoint selection of acupuncture and moxibustion for the treatment of chemotherapy-induced nausea and vomiting by retrospecting pertinent literature from 1986 to 2013. Methods Literature of clinical studies on acupuncture and moxibustion for the treatment of chemotherapy-induced nausea and vomiting published from 1986 to 2013 in CNKI, Wanfang and VlP databases and in PubMed database were retrieved. Data were analyzed statistically via Excel. Results One hundred and nineteen articles retrieved were related to the study. Based on the current literature analysis, meridians selected for acupuncture and moxibustion on chemotherapy-induced nausea and vomiting were mainly the stomach meridian, the pericardium meridian, the conception vessel, the spleen meridian and bladder meridian; point combination was applied more in prescription, accounting for 73.11%, while single point was applied less, only accounting for 26.89%. There were numerous methods for point combinations, but proximal and distal point combination was the most widely used method, accounting for 20.93%. Meanwhile, main acupoints selected were mostly Zusanli (足三里 ST 36), Neiguan (内关 PC 6), Zhongwan (中脘CV12), Gongsun (公孙SP 4) and Taichong (太冲 LR 3) and point combinations were mainly Shenmen (神门 HT 7), Geshu (膈俞 BL 17), PishB (脾俞 BL 20), Weishu (胃俞 BL 21) and Jianli (建里 CV 11). Conclusion Acupoints selection on acupuncture and moxibustion for chemotherapy-induced nausea and vomiting shows a certain rules that the meridians selected are mainly stomach meridian, pericardium meridian and conception vessel and acupuncture points selected are normally ST 36, PC 6 and CV 12, proximal and distal point combination is applied more, while single point applied less. 展开更多
关键词 ACUPUNCTURE chemotherapy-induced nausea and vomiting rulesof acupoints selection
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Therapy of auricular subcutaneous penetration needling combined with row acupuncture at the meridian sinew in 103 cases of prolapse of lumbar intervertebral disc
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作者 侯献兵 刘英莉 +3 位作者 王利春 卢威威 宋书昌 贾春生 《World Journal of Acupuncture-Moxibustion》 CSCD 2015年第2期63-66,共4页
Objective To observe the clinical efficacy of auricular subcutaneous penetration needling combining with row acupuncture at meridian sinew on prolapse of lumbar intervertebral disc. Methods One hundred and three patie... Objective To observe the clinical efficacy of auricular subcutaneous penetration needling combining with row acupuncture at meridian sinew on prolapse of lumbar intervertebral disc. Methods One hundred and three patients with prolapse of lumbar intervertebral disc were treated with a combined treatment of auricular subcutaneous penetration needling and row acupuncture at meridian sinew. Results Of 103 patients, 46 cases were cured, 33 were markedly effective, 21 effective and 3 ineffective. The total effective rate was 97.1% (100/103). Conclusion The combined treatment of auricular subcutaneous penetration needling and row acupuncture at meridian sinew has a significant efficacy for the treatment of prolapse of lumbar intervertebral disc. 展开更多
关键词 prolapse of lumbar intervertebral disc auricular subcutaneouspenetration needling row acupuncture at meridian sinew
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Half-lives of double β^+-decay with two neutrinos
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作者 REN YueJiao REN ZhongZhou 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第1期38-41,共4页
Nuclear double β^--decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys Rev C, 2014, 89: 06... Nuclear double β^--decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys Rev C, 2014, 89: 064603]. However, double β^+ -decay (β^+β^+) with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we pcrform a systematic analysis on the candidates of double β^+-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double β^+-decay and their half-lives are predicted according to the generalization of the systematic law to double β^+-decay. As far as we know, there is no theoretical result on double β^+-decay of nucleus ^154Dy and our result is the first prediction on this nucleus. This is also the first complete research on eight double β^+-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double β^+-decay in this article will be useful for future experimental search of double β^+-decay. 展开更多
关键词 double β^+-decay with two neutrinos HALF-LIVES systematic law weak interaction.
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Controlling Thermal Conduction by Graded Materials 被引量:1
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作者 Qin Ji Ji-Ping Huang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2018年第4期434-440,共7页
Manipulating thermal conductivities are fundamentally important for controlling the conduction of heat at will. Thermal cloaks and concentrators, which have been extensively studied recently, are actually graded mater... Manipulating thermal conductivities are fundamentally important for controlling the conduction of heat at will. Thermal cloaks and concentrators, which have been extensively studied recently, are actually graded materials designed according to coordinate transformation approaches, and their effective thermal conductivity is equal to that of the host medium outside the cloak or concentrator. Here we attempt to investigate a more general problem: what is the effective thermal conductivity of graded materials? In particular, we perform a first-principles approach to the analytic exact results of effective thermal conductivities of materials possessing either power-law or linear gradation profiles. On the other hand, by solving Laplace's equation, we derive a differential equation for calculating the effective thermal conductivity of a material whose thermal conductivity varies along the radius with arbitrary gradation profiles.The two methods agree with each other for both external and internal heat sources, as confirmed by simulation and experiment. This work provides different methods for designing new thermal metamaterials(including thermal cloaks and concentrators), in order to control or manipulate the transfer of heat. 展开更多
关键词 thermal metamaterials graded materials effective thermal conductivity
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The Legal Regulation of Irrational Elements in the Operations of Boards of Directors 被引量:1
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作者 Zhu Yikun 《Social Sciences in China》 2017年第2期95-113,共19页
The operating processes of boards of directors are delicate and complex, so corporate legislation cannot simply equate board structure law with board governance law. It is therefore necessary to start from China's ac... The operating processes of boards of directors are delicate and complex, so corporate legislation cannot simply equate board structure law with board governance law. It is therefore necessary to start from China's actual conditions and grasp the operating processes of Chinese boards with a sober appreciation of the irrational elements in their operating mechanisms. Board governance has entered a new stage of institutionalization, and the law should shift from its emphasis on structure to give equal attention to structure and process in optimizing institutional structure. In the construction of board operating mechanisms, we should treat differently such "living laws" as customs, experiences and traditions, give full play to the functionality of boards' strategic choices, and provide legal regulation of irrational elements, so as to distinguish between different roles, develop consensus, select strong points and improve efficiency. We should build control over board operational procedures, improve the system of functional allocation, correct assessment mechanisms, develop a mechanism for judicial scrutiny of the affective relationships in society and curb such behavioral tendencies as relational identity, structural bias and group polarization, with a view to controlling such "living laws" within the framework of the basic values and principles of board governance. 展开更多
关键词 board governance group decision-making strategic choices irrational elements
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