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转向细胞数为2的链状四角系统的Randi(c)指标
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作者 柯小玲 《三明学院学报》 2011年第2期17-22,共6页
一个图(分子图)G的Randi(c)指标定义为图G的所有边uν上的权(d(u)d(ν))-12之和,其中(d(u)和d(ν))分别表示顶点u和ν的度.Randi(c)指标是化学图论中常见且重要的一个拓扑指标。本文给出了转向细胞数为2的链状四角系统的Randi(c)指标。
关键词 链状四角系统 randi(c)指标 转向细胞
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维生素C含量测定本科教学实验设计与实践
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作者 熊庆 蒲雪梅 +2 位作者 宋红杰 郭彩红 赵燕 《实验室科学》 2023年第2期26-28,35,共4页
在仪器分析实验教学中,以“当被测物质具有酸性或碱性基团时,溶剂的p H值对光谱影响较大”知识为实验的切入点,由低年级本科生来探索研究维生素C在中性和不同浓度的酸性介质环境中紫外吸收光谱特性和稳定性,建立用紫外吸收分光光度法稳... 在仪器分析实验教学中,以“当被测物质具有酸性或碱性基团时,溶剂的p H值对光谱影响较大”知识为实验的切入点,由低年级本科生来探索研究维生素C在中性和不同浓度的酸性介质环境中紫外吸收光谱特性和稳定性,建立用紫外吸收分光光度法稳定、快速测定维生素C含量的方法。通过合理的教学实验设计,将理论与实验教学相融合,使理论知识点在实验中可视化,直观且容易理解,提高了学生的学习热情,锻炼了本科生理论知识联系实际运用能力。 展开更多
关键词 仪器分析实验 紫外光谱 维生素c 酸性环境
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Emission spectra of microwave plasma and MPCVD transparent diamond film 被引量:1
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作者 周健 何伟 +2 位作者 袁润章 姜德生 汪建华 《中国有色金属学会会刊:英文版》 EI CSCD 2000年第4期502-504,共3页
The emission spectra of microwave plasma was in line measured in visible light wave band using a self made optical fiber spectrometer, the change rule of the atomic hydrogen ( H ) and double carbon radical( C 2) was g... The emission spectra of microwave plasma was in line measured in visible light wave band using a self made optical fiber spectrometer, the change rule of the atomic hydrogen ( H ) and double carbon radical( C 2) was given under different CH 4/H 2 ratios of volume flow. The effect of atomic hydrogen ( H ) on CVD diamond, deposited high quality and transparent diamond film by microwave plasma CVD (MPCVD) was analyzed according to the measured results by scanning electron microscopy(SEM), laser Raman spectrometry(Raman), and Fourier transform infrared spectrometry(FTIR). The results showed that the diamond film consisted of (220) orientation and it was homogeneous, compact, low defective, high quality film, its infrared transmissibility was about 70%, approached theoretical transmissibility of diamond. It was key conditions that a large number of atomic hydrogen ( H γ ) and double carbon radical( C 2) exist in the course of high quality diamond film growth. The research provided a rapid method for technology exploration of microwawe plasma CVD, and a reliable basis for research on growth mechanism of diamond film. 展开更多
关键词 EMISSION spectra H γ c 2 MPcVD tansparent DIAMOND FILM
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Theoretical Study on the Structures and Electronic Spectra of the Derivatives of C_(60)-P-2,4,6-Triphenyl Borazinc 被引量:3
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作者 JIANG Qi-Jun 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第10期1140-1144,共5页
The structures and electronic spectra of the derivatives of C60-P-2,4,6-triphenyl borazinc have been studied by using AM 1 method. The calculated results indicate that this kind of compounds has a lower energy differe... The structures and electronic spectra of the derivatives of C60-P-2,4,6-triphenyl borazinc have been studied by using AM 1 method. The calculated results indicate that this kind of compounds has a lower energy difference between HOMO and LUMO. It is found that the electron cloud on unoccupied frontier orbital mainly comes from the contribution of C60, while that on occupied frontier orbital mainly concentrates on the side chain. A long-lived charge-separated state may occur in the objective compounds. 展开更多
关键词 derivatives of c60-P-2 4 6-triphenyl borazinc electronic spectra charge-separated state AM1
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Stabilities and Electronic Spectra for C_(78)O_2 Isomers 被引量:1
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作者 TENG Qi-Wen WU Shi 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第8期925-929,共5页
Structures and stabilities of 22 possible isomers for C78O2 based on C78(C2v) were studied by INDO series of methods. The most stable geometry is that two oxygen atoms are added to 1,2-bond crossed by the shortest z... Structures and stabilities of 22 possible isomers for C78O2 based on C78(C2v) were studied by INDO series of methods. The most stable geometry is that two oxygen atoms are added to 1,2-bond crossed by the shortest z axis and 32,35-bond near the longest x axis in C78(C2v),in agreement with the experiment of adducts for C78(C2v). 1,2,32,35-C78O2 is more stable than 1,2,19,22-C78O2 by 0.12 kcal/mol and epoxide structures are formed in each isomer. Electronic spectra for C78O2 were investigated with INDO/CIS method. The reason of the blue-shift for UV absorptions of 1,2,32,35-C78O2 compared with that of C78(C2v) was discussed and electronic transition was theoretically assigned. 展开更多
关键词 c78O2 electronic spectra INDO
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A Study on the Characteristics of Carbon-Related Spectral Lines from a Laser-Induced Fly Ash Plasma 被引量:3
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作者 潘刚 陆继东 +3 位作者 董美蓉 姚顺春 谢子鑫 樊炬 《Plasma Science and Technology》 SCIE EI CAS CSCD 2015年第8期625-631,共7页
A 1064 nm Nd:YAG laser was used to of the spectral lines measured from the laserablated ablate fly ash samples. The characteristics fly ash plasmas are presented with special attention to atomic and molecular carbon ... A 1064 nm Nd:YAG laser was used to of the spectral lines measured from the laserablated ablate fly ash samples. The characteristics fly ash plasmas are presented with special attention to atomic and molecular carbon emission. It is shown that the intensity of the atomic line C I 192.9 nm is weak and the shot-to-shot intensity is fluctuant. The carbon atomic line C I 247.7 nm is relatively intensive and stable, however it is seriously interfered with by Fe I 247.8 nm. The intensity of the CN molecular line is close to that of C I 247.7 nm and the CN line is stable and less interfered with. The comparison of molecular CN emission under different conditions (air, Ar and N2) shows that the CN lines detected from the plasmas formed in an atmospheric environment are correlated with the reaction of carbon atoms in the plasma with the nitrogen in air, which indicates that the CN line is also important in pulsed laser ablation fly ash plasmas and this information can be incorporated in the detection of unburned carbon content in fly ash. Finally, a calibration curve is established with a correlation coefficient R2 of 0.999, using C I 247.7 nm and the CN molecular line as associated variables. In addition, accuracy is improved to a certain extent. 展开更多
关键词 cHARAcTERISTIcS fly ash LIBS c-related spectra
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单壁开口碳纳米管的Randic指数
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作者 王广富 郭秀清 王洪伟 《保山师专学报》 2008年第2期4-6,共3页
针对单壁开口碳纳米管的规则性,当给定纳米管的周长(或直径)和长度时,得出了常见的锯齿型开口纳米管和扶手椅型开口纳米管的Randi'c指数的计算公式。并比较出具有相同直径和长度的纳米管,扶手椅型的Randi'c指数较小。
关键词 randi c指数 单壁开口碳纳米管 锯齿型开口纳米管 扶手椅型开口纳米管
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空间风化对C型小行星的光谱影响研究概述
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作者 周婷 唐红 +5 位作者 缪秉魁 曾小家 夏志鹏 于雯 周传娇 贺恩成 《空间科学学报》 CAS CSCD 北大核心 2023年第4期647-660,共14页
C型小行星主要由硅酸盐矿物和含碳有机质组成,保存了太阳系形成初期的原始物质,是认识太阳系形成初期的重要物质,对研究水和生命起源与演化具有重要科学意义。目前对小行星物质组成的认识主要基于光谱特征分析,但长期的空间风化作用会... C型小行星主要由硅酸盐矿物和含碳有机质组成,保存了太阳系形成初期的原始物质,是认识太阳系形成初期的重要物质,对研究水和生命起源与演化具有重要科学意义。目前对小行星物质组成的认识主要基于光谱特征分析,但长期的空间风化作用会改变小行星表面物质的光谱特征,所以认识小行星的物质组成需要准确厘清空间风化对光谱的影响。随着中国小行星探测工程的推进,迫切需要深入认识C型小行星的光谱特征及对空间风化的响应规律。为此,分析了C型小行星的反射率、水和有机质吸收等光谱特征以及空间风化的影响,提出研究存在的主要问题,进而指出了该研究方向的未来发展趋势和研究重点。 展开更多
关键词 c型小行星 光谱 碳质球粒陨石 空间风化
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Studies on the Electronic Structures and Spectra of C_(78)(CH_2)_3
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作者 TENG Qi-Wen WU Shi CHEN Si-Cong 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第3期314-320,共7页
The structures and spectra of 20 possible isomers of C78(CH2)3 have been studied by using AMI, INDO/CIS and DFT methods. The results show that the most stable isomer is 1,2,3,4,5,6-C78(CH2)3 (A) with annulene st... The structures and spectra of 20 possible isomers of C78(CH2)3 have been studied by using AMI, INDO/CIS and DFT methods. The results show that the most stable isomer is 1,2,3,4,5,6-C78(CH2)3 (A) with annulene structures, where three -CH2 groups are added to the 6/6 bonds located at the same hexagon passed by the shortest axis of C78 (C2v). Compared with that of C78 (C2v), the first absorption in the electronic spectrum of C78(CH2)3 (A) iS blue-shifted because of its wider LUMO-HOMO energy gap. While the IR frequencies of the C-C bonds on the carbon cage are red-shifted owing to the formation of annulene structures and the extension of the conjugated system. The chemical shifts of the carbon atoms in 13C NMR spectra are moved upfield upon the addition. 展开更多
关键词 c78(cH2)3 DFT electronic spectra IR spectra NMR spectra
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Absorption Spectra Calculation of Torus-type C_(120) and Its Nitrogen Doped Derivatives
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作者 范广 周彩华 谢茹玉 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第3期434-438,共5页
The absorption spectra of torus-type C_(120) and its derivatives doped by nitrogen(C_(119)N, C_(118)N_2, C_(115)N_5) have been investigated based on the density functional theory. The longest absorption band of torus-... The absorption spectra of torus-type C_(120) and its derivatives doped by nitrogen(C_(119)N, C_(118)N_2, C_(115)N_5) have been investigated based on the density functional theory. The longest absorption band of torus-type C_(120) can arrive at the near IR fields. For three derivatives doped by nitrogen, doped nitrogen atoms can induce the longer absorption band, and the more numbers of nitrogen atoms are doped in torus-type C_(120), the longer absorption band can be induced. 展开更多
关键词 torus-type c120 photodynamic therapy ABSORPTION spectra
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Investigation on Electronic Structures and Spectra for the Substituted Fullerene C_(77)B^-
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作者 WU Shi TENG Qi-Wen 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第6期694-698,共5页
The structures and stabilities of all the 21 possible isomers for C77B^- based on C78 (C2v) were studied by the INDO series of methods. The most two stable geometries are C77B^-(10) and C77B^-(7), where B(10) ... The structures and stabilities of all the 21 possible isomers for C77B^- based on C78 (C2v) were studied by the INDO series of methods. The most two stable geometries are C77B^-(10) and C77B^-(7), where B(10) and B(7) are located at the apexes among two hexagons and a pentagon near the shortest axis of C78 (C2v), and the former is more stable than the latter by 0.1902 eV. Based on the optimized geometries, the electronic spectra of the C77B^- isomers were investigated with the INDO/CIS method and the electronic transitions were assigned. The reason for the red-shift of the first absorption peaks for C77B^- compared with that of C78 (C2v) was discussed. 展开更多
关键词 c77B^- electronic spectra INDO
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All Fiber-optic Fluorescent Spectral Measurement and Analysis on Alga Chla/c Characteristics
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作者 ZHANG Shu-qing (School of Electr. Eng., Yanshan University,Qinhuangdao 066004,CHN) 《Semiconductor Photonics and Technology》 CAS 2001年第2期120-124,共5页
The fluorescent principle used for measuring alga characteristic parameters and the optimum structure design of the instrument are discussed. The fluorescent spectrum of Chla/c and the time-resolved different spectrum... The fluorescent principle used for measuring alga characteristic parameters and the optimum structure design of the instrument are discussed. The fluorescent spectrum of Chla/c and the time-resolved different spectrum ΔA(λ,t) are given. The research provides an effective method for considering the density and the classification of algae, which will be helpful to monitor sea pollution. 展开更多
关键词 荧光测量 光纤传输 特征光谱
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STUDY ON THE SEQUENCE STRUCTURE OF SBR BY ^(13)C—NMR METHOD Ⅰ. ASSIGNMENT FOR UNSATURAT CARBONS SPECTRA
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作者 焦书科 陈晓农 +1 位作者 胡力平 严宝珍 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第1期17-24,共8页
The sequence structures of emulsion-processed SBR and solution-processed (by lithium catalyst) SBR were investigated by ^(13)C-NMR spectroscopy. Seventeen peaks within unsaturated carbon region were recorded under the... The sequence structures of emulsion-processed SBR and solution-processed (by lithium catalyst) SBR were investigated by ^(13)C-NMR spectroscopy. Seventeen peaks within unsaturated carbon region were recorded under the adopted experimental conditions. Assignments for these peaks were made by empirical-parameter-evaluation method. 展开更多
关键词 Sequence distribution ^(13)c-NMR spectra of SBR Peak assignment for olefinic car- bon atoms.
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C_(120)NH的电子光谱和结构的理论研究 被引量:5
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作者 田维全 封继康 +4 位作者 任爱民 葛茂发 黄旭日 李志儒 孙家锺 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 1998年第10期1627-1631,共5页
用INDO系列方法对双笼化合物C120NH进行了理论研究,并预测C120NH的形成缓解了C60NH中亚胺基三元环处的角张力,从而较稳定;两碳笼直接键连使其相互间有较弱的相互作用,N仍具有较强的捕获质子能力,且有一定选... 用INDO系列方法对双笼化合物C120NH进行了理论研究,并预测C120NH的形成缓解了C60NH中亚胺基三元环处的角张力,从而较稳定;两碳笼直接键连使其相互间有较弱的相互作用,N仍具有较强的捕获质子能力,且有一定选择性;C120NH的电子光谱与母体C60及C120O和C120CH2相似. 展开更多
关键词 c120NH 电子光谱 结构 双笼化合物 碳60衍生物
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不同浓度维生素C对DNA紫外损伤的影响 被引量:7
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作者 周殿凤 柯惟中 +1 位作者 陈年凤 籍康 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2005年第12期2012-2015,共4页
分别检测了DNA与不同浓度维生素C的混合物经10和30 min紫外辐射的拉曼光谱,紫外线的辐 射照度为18.68W·m-2。实验表明,维生素C对DNA损伤的影响与其浓度密切相关。低于0.35 mmol·L-1 的维生素C对紫外线诱发的DNA损伤具有明... 分别检测了DNA与不同浓度维生素C的混合物经10和30 min紫外辐射的拉曼光谱,紫外线的辐 射照度为18.68W·m-2。实验表明,维生素C对DNA损伤的影响与其浓度密切相关。低于0.35 mmol·L-1 的维生素C对紫外线诱发的DNA损伤具有明显的保护作用,且保护效果随着其浓度的增大越来越好,0.35 mmol·L-1时保护效果最佳。当维生素C的浓度高于0.35 mmol·L-1时,在10 min的紫外辐射中,维生素C 不仅没有保护DNA,反而促进了DNA的损伤,DNA被损伤的程度随着维生素C浓度的增加而增加;但在 30 min的紫外辐射中,相对于不加VC的紫外辐射,维生素C对DNA仍起保护作用。 展开更多
关键词 拉曼光谱 DNA 维生素c 紫外辐射
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C_(59)O的结构、电子光谱及NMR谱的理论预测 被引量:3
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作者 任爱民 封继康 +2 位作者 田维全 孙秀云 孙家钟 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 1998年第2期288-291,共4页
用INDO系列方法对C60的取代产物C59O进行几何构型优化,得到Cs对称性的稳定构型,以此构型为基础,计算并预测了C59O的电子光谱和NMR谱.最后与C59O的等电子分子体C2-60及C60O进行了比较.
关键词 c59O 电子光谱 碳笼 碳60衍生物 富勒烯
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C_(76)及C_(76)~n离子的电子结构和单态的电子光谱 被引量:8
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作者 滕启文 吴师 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2001年第6期1019-1021,共3页
The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there a... The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there are not Jahn Teller distortion in C n 76, which is different from C n 60 and C n 70. Furthermore, the C n 76 ions are less stable than C 76. Based on the optimized geometries, the electronic spectra were calculated by INDO/SCI method. It was shown that the NIR absorptions for C n 76 singlet will appear beyond \{1 000\} nm. Electronic transition was assigned theoretically and the reason of red shift for absorption peaks of C n 76 compared with those of C 76 was discussed. 展开更多
关键词 电子光谱 INDO 碳76 单态离子 电子结构 红移 电子跃迁
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C_(60)-TTF及其衍生物的结构与光谱的理论研究 被引量:6
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作者 张锁秦 封继康 +2 位作者 任爱民 付伟 李耀先 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2001年第6期987-990,共4页
采用 ZINDO系列方法优化了环状桥联的 C60 -TTF分子及其 7个衍生物的几何构型 ,研究了各分子的电子结构 ;以稳定构型为基础 ,计算了各分子的电子光谱 ,理论计算值与实验值符合得较好 .对电子光谱的本质在理论上进行了指认 。
关键词 分子结构 电子光谱 ZINDO 几何构型 衍生物 碳60 富勒烯 环状桥联 四硫富瓦烯
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C_(60)O_3的结构和电子光谱的理论研究 被引量:4
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作者 田维全 封继康 +4 位作者 葛茂发 任爱民 李志儒 黄旭日 孙家锺 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 1998年第3期446-450,共5页
用INDO系列方法对C60O3的可能构型进行研究,结果表明:环氧结构邻近的6-6键易发生进一步的加成反应.其中3个氧原子加在同一个六元环的6-6边上,形成环氧结构最稳定的C3v构型,第3个氧原子加在2个环氧结构相邻的... 用INDO系列方法对C60O3的可能构型进行研究,结果表明:环氧结构邻近的6-6键易发生进一步的加成反应.其中3个氧原子加在同一个六元环的6-6边上,形成环氧结构最稳定的C3v构型,第3个氧原子加在2个环氧结构相邻的六元环的6-6边上的C2、Cs构型也相当稳定,C2、Cs构型的部分13CNMR谱与实验吻合.C60O3可能有较好的反应活性,其电子光谱属于理论预测. 展开更多
关键词 c60O3 环氧结构 电子光谱 结构 碳60氧化物
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烷基苯基五元杂环基锡化合物的^(13)C—NMR研究 被引量:4
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作者 杨振云 王世华 +1 位作者 刘秀梅 阎圣刚 《波谱学杂志》 CAS CSCD 1989年第4期489-494,共6页
本文测定了18个含有各种烷基、苯基、烯丙基、五元杂环及其它极性基团的有机锡化合物的^(13)C—NMR谱。对全部谱线进行了归属。讨论了烷基锡、苯基锡中Sn—C键的性质和极性取代基对C—1δ值的影响。考察了各类C-Sn偶合常数大小顺序,以及... 本文测定了18个含有各种烷基、苯基、烯丙基、五元杂环及其它极性基团的有机锡化合物的^(13)C—NMR谱。对全部谱线进行了归属。讨论了烷基锡、苯基锡中Sn—C键的性质和极性取代基对C—1δ值的影响。考察了各类C-Sn偶合常数大小顺序,以及~1J_(C-)^(119)Sn与~1J_(C-)^(117)Sn的关系。 展开更多
关键词 烷基 苯基 五元杂环基 有机锡 NMR
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