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1.
我们重新合成了曾经报道过的反式K[Cr(C2O4)2·(H2O)2]2·3H2O三价铬配合物, 并借助先进的单晶衍射仪和更先进的解析手段得到了该配合物更加精确的结构模型,该配合物属于单斜晶系,P2/n(No. 13)空间群,晶胞相关参数为:a = 7.8827 (4) Å,b = 5.7296(3) Å,c = 13.6447(7) Å,β= 103.506(5)°,Z = 2,Dc =1.980 Mg/m3,V = 599.22(5) Å3。热重测试结果显示该配合物在357 K以前是稳定的,在410 nm最有效的紫外光光源的激发下,配合物在610 nm处有一个尖锐的发射峰。  相似文献   

2.
以牛磺酸缩5-溴水杨醛席夫碱(TBSSB)、5-溴水杨醛(BSA)、2,2''-联吡啶(bipy)为混合配体,合成了三核铜配合物[Cu3(TBSSB)2(BSA)2(bipy)2]·H2O (1),并对该化合物进行了元素分析、红外光谱、X-射线单晶衍射、光致发光光谱、固体漫反射光谱及分子轨道分析等表征。晶体结构分析表明,该化合物结晶属三斜晶系,Pī空间群,晶胞参数为a=10.031(2)Å,b=11.480(2)Å,c=12.913(3)Å,α=73.13(3)°,β=78.58(3)°,γ=75.24(3)°,V=1363.6(5)Å3,Z=1,Mr=1533.30,Dc=1.867 g/cm3,F(000)=759,μ=4.236 mm-1,S=0.921,R1=0.0488,wR2=0.0471(I > 2σ(I)),R1=0.1812,wR2=0.0546。Cu (2)离子与来自于两个TBSSB配体的两个氮原子和两个氧原子配位,形成正方形配位构型。Cu (1)离子与来自于一个2,2''-bipy的两个氮原子,TBSSB配体的一个氧原子,以及BSA的两个氧原子配位,形成四方锥形配位构型。该化合物分子通过O-H…Br分子内氢键和C-H…O分子间氢键相互连接形成三维超分子结构。研究发现该化合物能够发出蓝色荧光,它的带隙为2.19 eV。  相似文献   

3.
采用水热法合成了含混合配体的铜配合物[CuClPhen]+·[HL]-·2H2O(HL=5-硝基间苯二甲酸,Phen=1,10-菲咯啉),其结构由单晶X射线晶体学确定。标题化合物在三斜空间群P-1的晶体化合物。标题化合物的晶体数据:C32H24ClN5CuO8,Mr = 704.54,a = 10.4044(5),b = 12.3912(9),c = 12.4632(9)Å,α = 73.859(6),β = 85.036(5),γ = 78.202(5)°,V = 1510.09(17) Å3,Z = 2, T = 293(2) K,Dc = 1.549 g/cm3,μ(Mo) = 0.874 mm-1,F(000) = 720.0,R = 0.0554,wR = 0.1434,GOF = 1.098。当用作超级电容器电极材料时,所制备的配合物具有高比电容、良好的循环稳定性和优良的倍率性能。在1mol/L KOH溶液中,最大比电容可达到69 F/g。在2 A/g电流密度下,10000次循环后比电容保持率为72%。标题化合物是一种潜在的红色光致发光材料。  相似文献   

4.
通过研究硬叶兜兰(Paphiopedilum micranthum)、带叶兜兰(P.hirsutissimum)和长瓣兜兰(P.dianthum)3种兜兰属植物的光合特性,为其种质资源保育及引种栽培提供理论依据。以广西雅长兰科植物国家级自然保护区内3种兜兰属植物为试验材料,测定其叶片的光响应曲线、CO2响应曲线以及叶绿素含量,比较3种兜兰光合特性的差异。结果表明:硬叶兜兰、带叶兜兰和长瓣兜兰的最大净光合速率(Pmax)分别为2.719 μmol·m-2·s-1、1.836 μmol·m-2·s-1、2.015 μmol·m-2·s-1,光饱和点(LSP)分别为578.74 μmol·m-2·s-1 、467.72 μmol·m-2·s-1、481.25 μmol·m-2·s-1,光补偿点(LCP)均较低,分别为15.65 μmol·m-2·s-1、12.79 μmol·m-2·s-1、10.34 μmol·m-2·s-1,是典型的阴生植物。硬叶兜兰的最大净光合速率(Pmax)、CO2饱和点(CSP)、羧化效率(CE)均显著高于长瓣兜兰和带叶兜兰(P<0.05),硬叶兜兰对CO2的利用能力更强。叶片叶绿素相对含量(SPAD值)表现为硬叶兜兰(58.13)>长瓣兜兰(55.12)>带叶兜兰(51.88)。3种兜兰属植物的光合能力较弱,对光的利用范围狭窄,在引种栽培时应注意增加荫蔽度。  相似文献   

5.
采用Thermo-Calc及JMatPro软件,对GH105合金在600~1 600℃的相图进行计算,并对C,Cr,Co,Mo,Zr,Ti,Al以及微量B对GH105合金主要析出相MC,M23C6,M3B2,μ,σγ''的影响进行探究。结果表明:C的增加提高了M23C6和MC相的析出量和M23C6相的析出温度,降低了σ相的析出量和析出温度,同时μ相的析出温度明显下降;Cr的增加显著提高了σ相的析出量和析出温度;Co的增加提高了μ相和σ相的析出量和析出温度,降低了M23C6相的析出量和析出温度;Mo的增加显著提高了μ相和σ相的析出量和析出温度;Zr的增加提高了σ相的析出量和析出温度,提高了MC相的析出量,降低了M23C6相的析出量和析出温度;B的增加显著提高了M3B2相的析出量;Al,Ti和m(Al):m(Ti)的增加,提高了γ''相的析出量,其中Al和m(Al):m(Ti)相的增加还提高了γ''相的析出温度。  相似文献   

6.
为探明3种观赏性石斛属Dendrobium Sw.植物在光合生理方面的差异,为其栽培及规模化种植提供理论依据。本研究以3种观赏性石斛(叠鞘石斛D.denneanum Kerr.、流苏石斛D.fimbriatum Hook.和束花石斛D.chrysanthum Wall.ex Lindl.)为材料,测定其叶片的光响应曲线、CO2响应曲线及叶绿素相对含量(SPAD值),探究其光合特性。结果表明,叠鞘石斛、流苏石斛和束花石斛3种石斛属植物的光补偿点(LCP)分别为2.15 μmol·m-2·s-1、3.74 μmol·m-2·s-1、1.79 μmol·m-2·s-1,光饱和点(LSP)分别为995.09 μmol·m-2·s-1、679.44 μmol·m-2·s-1、712.28 μmol·m-2·s-1,LCP均低于5 μmol·m-2·s-1,LSP均低于1 000 μmol·m-2·s-1,属于典型的阴生植物,具有较强的耐阴性;3种石斛的最大净光合速率(Pmax)分别为3.54 μmol·m-2·s-1、3.86 μmol·m-2·s-1、4.03 μmol·m-2·s-1,表观量子效率(AQY)分别为0.042,0.044和0.051,束花石斛的Pmax和AQY最大,光合作用能力较强。3种石斛的CO2响应曲线中,最大净光合速率(Amax)大小依次为叠鞘石斛(11.99 μmol·m-2·s-1)、流苏石斛(10.87 μmol·m-2·s-1)、束花石斛(4.75 μmol·m-2·s-1),叠鞘石斛利用CO2进行光合作用的能力最强;3种石斛的CO2饱和点(CSP)无显著性差异,在CO2浓度不大于2 000 μmol·mol-1时均未到达饱和点;CO2补偿点(CCP)具有显著性差异,CCP分别为100.12 μmol·m-2·s-1、158.02 μmol·m-2·s-1、134.44 μmol·m-2·s-1,其中叠鞘石斛的CCP最低,对低浓度CO2的利用能力最强。3种石斛叶片的SPAD值分别为51.09,56.93和58.06,其高低与其净光合速率的大小有一定程度的相关性。在3种石斛中,束花石斛的光合作用能力最强,对弱光的利用能力较强;流苏石斛对弱光的利用能力较弱,光照适应范围狭窄;叠鞘石斛对强光的利用能力较强,光合作用适应范围较广。此外,3种石斛均具有较强的耐阴性,对CO2的耐受性也较强,在种植时应提供适当的遮阴和增加CO2浓度来提高石斛的光合作用能力。  相似文献   

7.
采用水热法合成了含混合配体的铜配合物[CuLPhen]n(HL=5-硝基间苯二甲酸,Phen=1,10-菲咯啉),其结构由单晶X射线晶体学确定。标题化合物在单斜空间群P21/c中结晶。标题化合物的晶体数据:C20H11N3CuO6,Mr=106.57,a =10.6619(3),b =12.5760(4),c =13.0550(3)Å,α =90,β=95.463(3),γ =90°,V =1742.50(9)Å3,Z =4,T=293(2)K,Dc =1.726 g/cm3,μ(MoKα)=0.301 mm-1,F(000)=51.0,R =0.0380,wR =0.07,GOF =1.026。当用作超级电容器电极材料时,所制备的配合物具有高比电容、良好的循环稳定性和优良的倍率性能。具体来说,在1 mol/L KOH溶液中,最大比电容可达到225 F/g。在5 a/g电流密度下,5000次循环后比电容保持率为67.31%。  相似文献   

8.
 运用密度泛函理论(DFT)的B3LYP方法在6-311++G**水平上,对基态CH2分子的结构进行了优化计算,得到CH2分子的稳定结构为C2v构型,电子态为X3B1,平衡核间距RCH=0.1072nm、离解能De=8.034eV,用多体项展式理论推导了基态CH2分子的解析势能函数,其等值势能图准确再现了基态CH2分子的结构特征及其势阱深度与位置.  相似文献   

9.
本文考虑了如下的一类平面四次复Lotka-Volterra系统的可线性化问题=x(1-a30x3-a21x2y-a12xy2-a03y3),=-y(5-b30x3-b21x2y-b12xy2-b03y3).该系统为四次齐次多项式扰动下的具有$1:-5$线性项的复Lotka-Volterra系统,给出了该系统可线性化的充分必要条件.  相似文献   

10.
BiB3O6 (BIBO) single crystals with sizes of 44 mm × 24 mm × 10 mm and weight of 24.7 g have been successfully grown by the top-seeded method. In this note, the preparation of seed, the growth of crystal and some problems encountered are reported. The lattice parameters of BIBO area =7.1203(7)?,b = 4.9948(7)?,c = 6.5077(7)?,β= 105.586(8) ?,V=222.93(5)?3, which were determined by BRUKER-P4 four-circle diffractometer. BIBO is biaxial crystal and the relative orientation of (X, Y, Z) with regard to (a, b, c) is:X // b, (Y, c) =47.2°, (Z, a) = 31.6°, determined by the X-ray analysis combined with polarized microscopy. The second-harmonic-generation (SHG) conversion efficiency of the sample for 1.064 μm light is up to 67.7%. We have also obtained the third harmonic generation (THG) of 1.064 μm, namely, 1.064 μm + 0.532 μm →0.355 μm. BIBO crystal is free of moisture and hygroscopy.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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