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唐美娟  王延申 《物理学报》2008,57(3):1360-1364
利用量子反散射方法研究了1+1维时空中具有非对角开边界条件下的SU(2)不变Thirring模型. 于辅助空间引入独立于谱参量的规范变换,找到了适当的Fock真空态. 通过Bethe Ansatz方法得到了系统相应转移矩阵的本征值和本征态,及其谱参数所满足的Bethe Ansatz方程,并讨论了体系的边界自由度. 关键词: SU(2)不变Thirring模型')" href="#">SU(2)不变Thirring模型 非对角开边界 量子反散射方法  相似文献   

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Using nonperturbative quantum electrodynamics, we develop a scattering theory for high harmonic generation (HHG). A transition rate formula for HHG is obtained. Applying this formula, we calculate the spectra of high harmonics generated from different noble gases shined by strong laser light. We study the cutoff property of the spectra. The data show that the cutoff orders of high harmonics are greater than that predicted by the “3.17” cutoff law. As a numerical experiment, the data obtained from our repeated calculations support the newly derived theoretical expression of the cutoff law. The cutoff energy of high harmonics described by the new cutoff law, in terms of the ponderomotive energy Up and the ionization potential energy Ip, is 3.34Up+ 1.83Ip. The higher cutoff orders predicted by this theory are due to the absorption of the extra photons, which participate only the photon-mode up-conversion and do nothing in the photoionization process.  相似文献   

4.
用密度泛函理论(DFT)的杂化密度泛函B3LYP方法在6-31G*基组水平上对(XB2)2(X=Al,Be,Na,Mg)团簇各种可能的构型进行几何结构优化,预测了各团簇的最稳定结构.并对最稳定结构的电子结构、振动特性、成键特性和电荷特性等进行了理论研究.结果表明,团簇的几何结构大多是平面结构,通常是B-B键和B-X键共存,较少出现X-X键.团簇的稳定结构中通常是几个呈负电性的B原子形成一个负电中心,而其他B原子和X原子处在端位,且显正电性.  相似文献   

5.
In this work we explore the performance of CUDA in quenched lattice SU (2) simulations. CUDA, NVIDIA Compute Unified Device Architecture, is a hardware and software architecture developed by NVIDIA for computing on the GPU. We present an analysis and performance comparison between the GPU and CPU in single and double precision. Analyses with multiple GPUs and two different architectures (G200 and Fermi architectures) are also presented. In order to obtain a high performance, the code must be optimized for the GPU architecture, i.e., an implementation that exploits the memory hierarchy of the CUDA programming model.  相似文献   

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魏文叶  申佳音  吴奕暐  杨礼想  薛迅  阮自强 《物理学报》2017,66(13):130301-130301
微波背景辐射的低l极矩的各向异性可能不能用微波背景辐射静止系boost到本动参考系来解释,我们推断boost对称性在宇宙学尺度上缺失,又由于单纯结合广义相对论和物质结构的标准模型不能解释星系以上尺度的引力现象,需要引入暗物质和暗能量.而迄今为止所有寻找暗物质粒子的实验给出的都是否定结果,暗能量的本质更是一个谜.因此,我们假设洛伦兹对称性是从星系以上尺度开始部分破缺,以非常狭义相对论对称群E(2)为例,用E(2)规范理论来构造大尺度有效引力理论,并分析了此规范理论的自洽性.从这些讨论中发现,当物质源即使为普通标量物质时,contortion也一般非零,非零contortion的存在会贡献一个等效能量动量张量的分布,它可能对暗物质效应给出至少部分的贡献.我们从对称性出发修改引力,有别于其他的修改引力理论.  相似文献   

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The role of synchronization procedure is reanalysed in relation to a recent formulation of Lorentz' ether theory. While special relativity and ether theories turn out to be nonequivalent, the results of ether wind measurements from the Earth indicate that the hypothetical ether may, at most, be at rest with respect to the Sun.  相似文献   

9.
2(8-羟基喹啉)-2(苯酚)合锆薄膜的制备与性能研究   总被引:5,自引:2,他引:5  
设计合成了一种新型的有机电致发光材料2(8-羟基喹啉)-2(苯酚)合锆(Zr(OPh)2q2),制备了Zr(OPh)2q2薄膜,并利用红外光谱、差热-热重谱、扫描电镜、X射线衍射谱、UV吸收谱和荧光光谱等方法研究了其晶态、热稳定性、能带结构以及光致发光机理。结果表明,Zr(OPh)2q2的熔点为381.2 ℃,分解温度为467.1 ℃,具有非常高的热稳定性,利用真空热蒸镀方法很容易在经过净化处理的玻璃基底上形成高质量、无定形纳米级薄膜,在390 nm紫外光的激发下,Zr(OPh)2q2薄膜产生发光峰为525 nm、半峰宽度为107.6 nm的强黄绿色荧光,其粉体产生强黄色荧光,是一种性能优良的电致发光材料。  相似文献   

10.
The solvatochromic behaviour of bis-(2,2′-bipyridyl)-biscyanoiron (II) and 2,2′- bipyridyltetracyanoiron (II) in 2-ethyl-2-(hydroxymethyl)-1,3-propanediol has been established. The significance and sensitivities of the solvatochromic shifts of these charge-transfer bands are outlined for the two iron complexes above.  相似文献   

11.
采用1H-1H COSY,HMQC、HMBC等2D NMR技术对化合物(Et4N)2[Pd2(mp)2(μ-mpH)2]进行1H、13C NMR谱数据分析与归属,表明它在DMSO溶液中仍保持原有固体状态的分子结构.  相似文献   

12.
合成了一种新型的导电配位型化合物(FeCp2)0.65[Ni(C3S7)2]。通过元素分析(EA),电感耦合等离子体原子发射光谱(ICP-AES),核磁共振(1HNMR),紫外光谱(UV)对该化合物进行了表征。  相似文献   

13.
建立了一种计算Si(001)-(2×2×1):H表面O2吸附的理论模型.在周期性边界条件下,采用基于密度泛函理论广义梯度近似的超软赝势法对Si(001)-(2×2×1):H表面O2吸附进行了第一性研究.通过占位能的计算,得到了Si(001)-(2×2×1):H表面O2的最佳吸附位置.计算结果表明吸附后的反应产物应为Si=O和H2O,从理论上支持了D.Kovalev等人提出反应机制.  相似文献   

14.
Phynox is of high interest for technological applications due to its high corrosion resistance, mechanical properties and biocompatibility. In combination with these remarkable characteristics, some Phynox applications require specific surface properties that can be imparted with suitable surface functionalizations of the oxide layer. The present work aims at studying the surface-initiated atom transfer radical polymerization (ATRP) of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate (MPC) on Phynox substrates, using grafted 11-(2-bromoisobutyrate)-undecyl-1-phosphonic acid as initiator. The ability of the initiator to bind Phynox substrates and act as an initiator for ATRP of MPC is investigated. It appears that ATRP polymerization of MPC on modified Phynox substrates already takes place in aqueous media at room temperature, but the yield at 90 °C is superior.  相似文献   

15.
合成了一种新型的导电配位型化合物(FeCp2)0.65[Ni(C3S7)2]。通过EA,ICP,1H NMR,UV对该化合物进行了表征,并通过循环伏安法和变温四探针法对其电化学性质进行了研究。结果表明分子中S原子个数增多以及二茂铁阳离子(FeCp2+)的引入有利于导电性能的提高。  相似文献   

16.
采用扭曲波玻恩近似,计算了共面对称条件下低能电子碰撞Kr(4s2)的(e,2e)反应三重微分截面.与实验结果比较后发现,极化效应和后碰撞相互作用在共面对称几何条件下的~Kr(4s2)低能(e,2e)反应中起着重要的作用.  相似文献   

17.
On the basis of a charged BTZ black hole, we add an extra term in the metric function to describe the contribution from nonlinear electrodynamics. In this way we artificially construct a (2 + 1)-dimensional black hole in general relativity coupled with a nonlinear electrodynamics source. The thermodynamic quantities and Smarr formula are derived. It is found that this black hole has TS criticality like that of an RN-AdS black hole. Further modifying the metric function, we obtain a (2 + 1)-dimensional black hole possessing PV critical behaviors similar to that of van der Waals fluid. To our knowledge, this is the first example of (2 + 1)-dimensional black holes having this kind of critical behavior.  相似文献   

18.
在微波放电系统中,对NH_3-F-F_2-CF_3I体系进行研究,结果表明,向IF(X)传能的诸多媒介中,N_2(A)及N(~2D)起着主要作用,并且这一结论在经微波激发后的N_2与CF_3I的直接反应中得到了进一步证实。  相似文献   

19.
利用丝网印刷技术制备了基于Ru(bpy)23+(钌联吡啶)的印刷电极电致化学发光传感器,这种传感器具有制作简单、成本低、重现性好、对草酸盐的响应范围宽、检测限低等优点。详细研究了电极的制作方法以及发光试剂的固定化。在最优条件下,在pH 6.0的0.2 mol.L-1磷酸盐缓冲液中,利用所研制的ECL传感器测定C2O24-,线性响应范围为3.0×10-7~1.0×0-5mol.L-1,检测限为1.2×10-7mol.L-1(S/N=3)。根据同样的原理也可以用来测定其他的成分,如氨基酸,TprA(三丙胺),NAD(烟酰胺腺嘌呤二核苷酸)等物质。同时应该指出的是如果使用丝网印刷机器进行印刷的话,电极的重现性和稳定性还可以进一步提高。  相似文献   

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采用基于第一性原理的密度泛函理论研究了四角晶相二氧化铪(t-HfO2)体相及其(001)表面的原子几何与电子结构.理论计算结果表明,t-HfO2(001)表面不会产生重构现象.与体相电子结构相比, t-HfO2(001)表面态密度明显高于体相态密度.其次,表面原子的态密度更靠近费米能级(EF),价带往低能量处移动,并有表面态产生.计算结果表明了t-HfO2表面禁带宽度明显低于体相的禁带宽度. t-HfO2(001)的表面态产生以及表面禁带宽度减小是由于Hf原子与O原子的配位数减少,表面原子周围的环境发生变化而引起的.  相似文献   

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