共查询到19条相似文献，搜索用时 234 毫秒
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采用基于密度泛函理论的Dmol3模拟软件包对CdnSn(1≤n≤12)团簇的几何结构进行优化,并对其能量、频率以及电子性质进行了模拟分析.结果表明,当n=1～3时,团簇的最低能量结构是平面结构;当n=4～12时,团簇的最低能量结构可以看成是由Cd2S2和Cd3S3团簇的最低能量结构连接而成的三维结构.随着团簇尺寸的增大,转移的电荷逐渐增加,转移的电荷量有达到块体中电荷值的趋势.团簇的总能量二阶有限差分,平均结合能以及最高已占据轨道和最低未占据轨道的能隙都显示团簇的幻数为n=3,6和9. 相似文献
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采用密度泛函(DFT)方法,运用LSDA对不同外电场(-10.2845×109~10.2845×109 V/m)中基态NaH
分子进行理论计算,得到了它的几何参数、电荷分布、电偶极矩、最高占据轨道能级、最低空轨道能级.采用杂化
CIS-DFT方法(CIS-LSDA),在同样的外电场作用下,计算了NaH 分子的激发能、波长和振子强度.结果表明,
NaH 分子结构强烈地依赖着外电场,且变化规律对电场方向呈现非对称性,外电场改变了NaH 分子激发态出现的
顺序和电子跃迁光谱强度. 相似文献
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彭游 《安徽农业大学学报》2009,36(3)
由醇、酚或胺与中间体芳酰氯经微波光波组合干法合成了一系列新型光敏性偶氮类分子钳,其结构经1H NMR,IR,MS确证.考察了栽体、辐射时间、微波功率、催化剂对受体合成的影响. 相似文献
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严明 《厦门水产学院学报》2011,(2):149-153
采用ROHF对（BN）2C4纳米管进行构型全优化,并用密度泛函理论的DFT/ROB3LYP方法计算了（BN）2C4纳米管的电子态分布.根据其前沿分子轨道能量数据、电子态分布曲线和成键电子云密度分布图形,研究讨论了掺入硼氮对碳纳米管导电性的影响,并与BNC2纳米管作了比较.结果表明：（BN）2C4纳米管具有掺杂窄带半导体的导电性. 相似文献
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计算机配色技术在木材连缸染色中的应用研究 总被引：1，自引：0，他引：1
为了解决木材染色过程中染色废水的污染问题,实现木材连缸染色,该研究选用毛白杨单板为试材,使用6种酸性染料,通过真空加压的方法进行单拼色和多拼色的木材连缸染色实验.结果表明:利用计算机配色技术对木材进行连缸染色是可行的;在进行木材的单拼色染色时,染料是按照染液浓度的比例上染的,而多拼色染色时,各染料并不是按照染液中的比例上染的,反映出不同染料与木材的亲和能力和渗透能力之间的差异. 相似文献
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将水溶性三聚氰胺改性脲醛树脂(MUF)与红、蓝两种颜色的水溶性酸性染料、活性染料、碱性染料和直接染料共8种染料分别复配后浸渍处理杉木,考查复合染色剂的储存稳定性、上染性和染色材的颜色、色牢度等性能。筛选出适宜的染料品种、染液pH值、染料质量分数和染色助剂,从而制得MUF型木材多效染色改性剂。结果表明:以pH值为8左右的浸渍用MUF溶液为主剂,加入1%质量分数的酸性大红G染料和1%质量分数的Na_2CO_3助剂,可制得储存期长、渗透性高的MUF型复合染色剂,增强-染色复合改性杉木的上染性和色牢度良好,其密度、抗弯弹性模量和抗弯强度分别提高67.8%、43.8%和66.6%,与MUF增强改性材相当。 相似文献
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O'neil MP Niemczyk MP Svec WA Gosztola D Gaines GL Wasielewski MR 《Science (New York, N.Y.)》1992,257(5066):63-65
An electron donor-acceptor-donor molecule consisting of two porphyrin donors rigidly attached to the two-electron acceptor N,N'-diphenyl-3,4,9,10-perylenebis(dicarboximide) acts as a light intensity-dependent molecular switch on a picosecond time scale. Excitation of the porphyrins within this molecule with subpicosecond laser pulses results in single or double reduction of the acceptor depending on the light intensity. The singly and doubly reduced electron acceptors absorb light strongly at 713 and 546 nanometers, respectively. Because these absorption changes are produced solely by electron transfers, this molecular switch effectively has no moving parts and switches significantly faster than photochromic molecules that must undergo changes in molecular structure. 相似文献
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浅议天然植物染料现状及发展方向 总被引：1，自引：0，他引：1
我国染料植物资源丰富,植物染料染色技术在我国历史悠久。与化学合成染料相比,天然植物染料安全无毒,具环保效应,其中一些还兼有抗菌、防紫外线作用,适合于开发新功能型纺织品。但其生产应用还存在染料供应难、重现性及染色牢固度差等问题,需要加强研究开发,运用现代科学技术手段选育、培育出具有良好前景的染料植物并改进传统工艺,在保护植物资源前提下,推进天然植物染料生产体系的发展。 相似文献
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Yella A Lee HW Tsao HN Yi C Chandiran AK Nazeeruddin MK Diau EW Yeh CY Zakeeruddin SM Grätzel M 《Science (New York, N.Y.)》2011,334(6056):629-634
The iodide/triiodide redox shuttle has limited the efficiencies accessible in dye-sensitized solar cells. Here, we report mesoscopic solar cells that incorporate a Co((II/III))tris(bipyridyl)-based redox electrolyte in conjunction with a custom synthesized donor-π-bridge-acceptor zinc porphyrin dye as sensitizer (designated YD2-o-C8). The specific molecular design of YD2-o-C8 greatly retards the rate of interfacial back electron transfer from the conduction band of the nanocrystalline titanium dioxide film to the oxidized cobalt mediator, which enables attainment of strikingly high photovoltages approaching 1 volt. Because the YD2-o-C8 porphyrin harvests sunlight across the visible spectrum, large photocurrents are generated. Cosensitization of YD2-o-C8 with another organic dye further enhances the performance of the device, leading to a measured power conversion efficiency of 12.3% under simulated air mass 1.5 global sunlight. 相似文献
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Marder SR Cheng LT Tiemann BG Friedli AC Blanchard-Desce M Perry JW Skindhøj J 《Science (New York, N.Y.)》1994,263(5146):511-514
Conjugated organic compounds with 3-phenyl-5-isoxazolone or N,N'-diethylthiobarbituric acid acceptors have large first molecular hyperpolarizabilities (beta) in comparison with compounds with 4-nitrophenyl acceptors. For example, julolidinyl-(CH=CH)(3)-CH=N,N'- diethylthiobarbituric acid, which has 12 atoms between the donor and acceptor, has a beta(0) of 911 x 10(-30) electrostatic units, whereas (CH(3))(2)NC(6)H(4),-(CH=CH)(4)-C(6)H(4)NO(2), with 16 atoms between its donor and acceptor, has a beta(0) of 133 x 10(-30) electrostatic units. The design strategies demonstrated here have resulted in chromophores that when incorporated into poled-polymer electrooptic modulators exhibited significant enhancements in electrooptic coefficients relative to polymers containing the commonly used dye Disperse Red-1. Poled polymer devices based on these or related chromophores may ultimately lead to high-speed electrooptic switching elements with low drive-power requirements, suitable for telecommunications applications. 相似文献
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选取8株白腐菌分别与偶氮类染料刚果红和三苯甲烷类染料结晶紫共培养5d,进行脱色菌种筛选,发现白干酪菌和白耙齿菌对刚果红的脱色率均达到99%,血红密孔菌对结晶紫的脱色率达到90.62%.结合木素氧化酶系定性检测的结果,证明在相同培养条件下,漆酶活性是影响染料脱色率的主要因素;在振荡培养方式下菌种对染料的脱色率高于静置培养;利用筛选出的高效脱 色菌对简单混合染料进行脱色试验,同样达到了很好的效果,表明单一菌种的脱色效果要好于混合菌种. 相似文献