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151.
用改进的三维分离变量表象(DVR3D)方法研究了基态电子态H2S和H2O的振动光谱。哈密顿形式在Jacobi坐标下给出,每个坐标都用一组DVR基函数表示.角度部分的DVR基组选择勒让德多项式形式,而径向坐标采用正弦函数形式.为了降低需要对角化的最终哈密顿矩阵的维数,采用连续对角化截断方法.用H2S和H2O振动能级的计算验证算法的正确性.  相似文献   
152.
密度泛函方法研究气相胞嘧啶的互变异构化   总被引:3,自引:0,他引:3  
分别采用7种基组、3种理论方法对胞嘧啶异构体Cyt1的结构进行优化,通过与Cyt1的实验结果进行比较,选取了适合研究胞嘧啶分子的B3LYP/6311+G方法.用该方法对胞嘧啶分子的8种异构体构型进行了充分优化,研究了其中能量较低的6种胞嘧啶异构体的互变异构化过程.对于得到的所有优化构型都进行了频率分析.对于基态构型,所有的频率都是正的;对于过渡态构型,只有一个虚频.同时,做了详尽的内禀反应坐标计算,以保证所得到的过渡态连接相应的始末异构体.所有给出的能量都已做了零点能校正.理论研究结果可以对已有的实验结果给予合理解释.  相似文献   
153.
154.
用模拟退火算法设计光学有限脉冲响应滤波器   总被引:5,自引:0,他引:5  
周瑛  吴国忠  曾广杰  余飞鸿 《光学学报》2003,23(8):000-1004
提出了利用记忆型模拟回火退火算法来进行基于晶体双折射的光学有限脉冲响应滤波器设计的新方法,用以实现任意光谱响应双通道输出。模拟退火算法模拟了固体缓慢退火从而获得最低内能的物理过程,是一种简单而有效的随机性全局优化算法。应用具有记忆功能的回火退火算法,在较少的晶体延迟片数目下,实现了较优的设计。为证明该设计方法的可行性和有效性,给出了宽波带绿色/品红(Green/Magenta,G/M)滤波器的设计实例以及实验结果。初步研究表明,所设计结果完成满足LCOS投影分合色的要求。  相似文献   
155.
Simple defect modification is a powerful means to improve material intercalation capabilities. It has received considerable interest lately as it can directly alter both the chemical and structural characteristics; techniques of note include cationic disordering, amorphization, doping, partial cation reduction, and manipulation of intrinsic defects. Defects can reduce the stress and the electrostatic repulsion between adjacent oxygen layers, which can directly alter the migration energy and diffusion barriers the alkali ion must overcome during intercalation. Complementary to experimental observations, theoretical predictions are paramount to developing a detailed understanding of material‐defect chemistry. This focus review aims to demonstrate that the optimized design of stable intercalation compounds could lead to substantial improvements in energy‐storage applications by overcoming intrinsic limitations.  相似文献   
156.
运用单光子激光诱导荧光方法 ,研究了NO2 分子在第二吸收带的光解反应动力学 .首次报道了NO2(B2 B2 态 )光解初生态产物NO自由基的v″ =1,2的转动分布 .发现了NO自由基v″ =1的明显双模式分布 .进而提出了可能有两种竞争机理控制该反应  相似文献   
157.
I.IntroductionInordcrtocfficlcntlyprcdictandcontro1thenoiseinindustria1enclosurcs,manypeoplehavestudicdmathmodclsforsoundpropagationinindustria1enclosurcs.Butsofar,thereisnosatisfactoryrcsult.Inthepast,a1mostal1studieswcrercstrictedtoidealemptyindustrialcnc1osurcs,andonlyafewofthcm['-']concerncdtheinfluenceofobstac1cswithinthemodel.Thcscmodc1strcattheobstac1eeffcctsbythemethod-ofimagesandcanonIybeusedtoregu-larhexahcdronroomswhcreobstaclcsareassumedtobedistributesuniformIy.Ondet'sartic1el'],…  相似文献   
158.
Yang L  Hua X  Xue J  Pan Q  Yu L  Li W  Xu Y  Zhao G  Liu L  Liu K  Chen J  Wu J 《Inorganic chemistry》2012,51(1):499-510
The coordination of carbohydrate to metal ions is important because it may be involved in many biochemical processes. The synthesis and characterization of several novel lanthanide-erythritol complexes (TbCl(3)·1.5C(4)H(10)O(4)·H(2)O (TbE(I)), Pr(NO(3))(3)·C(4)H(10)O(4)·2H(2)O (PrEN), Ce(NO(3))(3)·C(4)H(10)O(4)·2H(2)O (CeEN), Y(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (YEN), Gd(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (GdEN)) and Tb(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (TbEN) are reported. The structures of these complexes in the solid state have been determined by X-ray diffraction. Erythritol is used as two bidentate ligands or as three hydroxyl group donor in these complexes. FTIR spectra indicate that two kinds of structures, with water and without water involved in the coordination sphere, were observed for lanthanide nitrate-erythritol complexes. FIR and THz spectra show the formation of metal ion-erythritol complexes. Luminescence spectra of Tb-erythritol complexes have the characteristics of the Tb ion.  相似文献   
159.
In this paper several polycrystalline molecules with sulfonate groups and some of their metal complexes, including dl-homocysteic acid (DLH) and its Sr- and Cu-complexes, pyridine-3-sulphonic acid and its Co- and Ni-complexes, sulfanilic acid and l-cysteic acid were investigated using THz time-domain methods at room temperature. The results of THz absorption spectra show that the molecules have characteristic bands in the region of 0.2–2.7 THz (6–90 cm−1). THz technique can be used to distinguish different molecules with sulfonate groups and to determine the bonding of metal ions and the changes of hydrogen bond networks. In the THz region DLH has three bands: 1.61, 1.93 and 2.02 THz; and 0.85, 1.23 and 1.73 THz for Sr-DLH complex, 1.94 THz for Cu-DLH complex, respectively. The absorption bands of pyridine-3-sulphonic acid are located at 0.81, 1.66 and 2.34 THz; the bands at 0.96, 1.70 and 2.38 THz for its Co-complex, 0.76, 1.26 and 1.87 THz for its Ni-complex. Sulphanilic acid has three bands: 0.97, 1.46 and 2.05 THz; and the absorption bands of l-cysteic acid are at 0.82, 1.62, 1.87 and 2.07 THz, respectively. The THz absorption spectra after complexation are different from the ligands, which indicate the bonding of metal ions and the changes of hydrogen bond networks. M–O and other vibrations appear in the FIR region for those metal–ligand complexes. The bands in the THz region were assigned to the rocking, torsion, rotation, wagging and other modes of different groups in the molecules. Preliminary assignments of the bands were carried out using Gaussian program calculation.  相似文献   
160.
Xerogels consisting of SiO2 and TiO2 were explored for controlled release of brilliant blue FCF (BBF). Both SiO2 and SiO2–TiO2 xerogels were prepared by way of sol–gel processing, and the BBF release behavior was compared. SiO2–TiO2 xerogels with varying TiO2 content were also studied and the BBF release behavior was determined for each SiO2–TiO2 xerogel. It was found that the release of BBF from SiO2 xerogels can be increased by the addition of TiO2 content, and the amount and rate of BBF released from the SiO2–TiO2 xerogels can be changed by modifying the amount of TiO2 included during the preparation of the xerogels, where the SiO2–TiO2 xerogels with a higher content of TiO2 released a higher fraction of BBF in water media when compared to the release from SiO2–TiO2 xerogels with lower amounts of TiO2. The experimental results have to be explained by a combination of porous structure, in situ dissolution–condensation during the BBF elution and the change of surface chemistry of the xerogel network with the addition of TiO2.  相似文献   
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