AT‐Specific DNA Binding of Binuclear Ruthenium Complexes at the Border of Threading Intercalation

The binuclear ruthenium complex [μ‐bidppz(phen)₄Ru₂]⁴⁺ has been extensively studied since the discovery of its unusual threading intercalation interaction with DNA, a binding mode with extremely slow binding and dissociation kinetics. The complex has been shown to be selective towards long stretches of alternating AT base pairs, which makes it interesting, for example, as a model compound for anti‐malaria drugs due to the high AT content of the genome of the malaria parasite P. falciparum. We have investigated the effect of bridging ligand structure on threading intercalation ability and found that length and rigidity as well as the size of the intercalated ring system are all factors that affect the rate and selectivity of the threading intercalation. In particular, we discovered a new DNA‐threading compound, [μ‐dppzip(phen)₄Ru₂]⁴⁺, which appears to be just at the border of being capable of threading intercalation and displays even greater selectivity for AT‐DNA than the parent compound, [μ‐bidppz(phen)₄Ru₂]⁴⁺.     

函数列一致收敛判别法

利用函数列和函数一致连续的有关性质,得到了函数列一致收敛新的判别法.     

极大代数上线性系统的3维最小实现的研究

研究了极大代数上线性系统的3维最小实现问题,给出了特征方程为λ<'3> c<,0>λ<'0>=c<,2>λ<'2> c<,1>λ,当c<,1>=c<'2><,2>,c<,0>=C<,1>C<,2>时,无穷序列{g<,2>}<,0><'∞>存在3维最小实现的充要条件.     

All-optical pseudorandom binary sequence generator with TOAD-based D flip-flops

An all-optical pseudo random binary sequence (PRBS) generator is designed using serially interconnected discrete Terahertz Optical Asymmetric Demultiplexer (TOAD)-based D flip-flops in a configuration exactly like the standard electronic setup. The performance of the circuit is evaluated through numerical simulation, which confirms its feasibility in terms of the choice of the critical parameters. The proposed scheme has been theoretically demonstrated for a 3-bit and 7-bit degree PRBS but can be extended to higher order by means of additional TOAD-based D flip-flops. Thus it can constitute an efficient solution for implementing all-optically a PRBS in an affordable, controllable and realistic manner.     

红外序列图像中运动弱小目标检测

为检测红外序列图像中的运动弱小目标,分析了目标在序列图像中的运动特性和概率分布特性,以及目标和噪声在序列中的能量分布特性。提出连续M帧高阶累积方法来增强运动弱目标能量,用假设检验对目标和背景进行分割,通过搜寻序列运动能量中心来实现目标的多帧关联检测。通过仿真实验证明了算法对红外弱小目标检测有效性。     

基于序列图像的几何参数测量方法研究

随着测量技术的不断发展,现代工业对物体尺寸检测的准确性及快速性要求越来越高.文中提出了一种利用序列图像来测量物体几何尺寸的方法.使用数码相机获得标定模板的序列图像,通过直接线性变换(DLT)方法来标定相机内部参数,结合透镜成像的知识,对使用数码相机采集到的物体序列图像进行处理和测量,最终计算出物体的宽度和高度.实验证明...     

Inhomogeneity-free heteronuclear iMQC

Intermolecular dipolar interactions between proton and carbon spins can be used to indirectly detect carbon spectra with high sensitivity. In this communication, we present a modified sequence that, in addition to the high sensitivity of heteronuclear intermolecular multiple quantum coherence (iMQC) experiments, retains the line narrowing capability characteristic of homonuclear zero-quantum coherences. We demonstrate that this sequence can be used to obtain high resolution (13)C spectra in the presence of magnetic field inhomogeneities, both for thermal and hyperpolarized samples, and discuss applications to water-hyperpolarized carbon imaging.     

CPMG echo amplitudes with arbitrary refocusing angle: explicit expressions, asymptotic behavior, approximations

Exact explicit analytical expression for echoes in the Carr–Purcell–Meiboom–Gill sequence with arbitrary excitation and refocusing angles and resonance offset of RF pulses was obtained, employing the generating functions formalism developed earlier by authors. Asymptotic form and analytical approximation for echoes were derived in an elegant way and analyzed in details. In particular, it was shown that depending on T₁, T₂ and parameters of the pulse sequence, oscillatory behavior of echoes can take place. Accuracy of asymptotic forms and approximations were tested by comparison with exactly calculated echo amplitudes. Besides, it was shown, that the generating function approach can be applied to the consideration of terminated pulse sequences, when after-pulses echoes are registered.