超导芯截面形状对Bi-2223/Ag带Jc的影响

磁光图像显示Ｂｉ－２２２３／Ａｇ带材中单根超导芯的宽面两侧边缘分布有较大的超导电流密度，Ｂｉ－２２２３单根超导芯的横截面是纺锤形的，单位宽度上的横截面面积之比与电流密度在横截面上不同部分的分布之比相当，高的电流密度在单根超导芯两则的分布可能是由单芯横截面的形状引起的。     

Optimal control for a population dynamics with age-dependent and diffusion in a periodic environment

Here we consider the optimal harvesting problem for a periodic age-dependent population dynamics with diffusion. Namely, we investigate the model with periodic vital rates and a periodic forcing term that sustains oscillations. By using Mazur’s theorem, we demonstrate existence of solutions of the optimal control problem and by the conception of normal cone, we also obtain the first order necessary conditions of optimality for the problem. Our results extend some known criteria.     

A new luminol derivative as a fluorescent probe for trace analysis of copper(II)

Microchimica Acta - A new luminol derivative has been synthesized and its fluorescence has been studied. The luminol derivative emits at 460 nm in pH 10.0 phosphate buffer which is...     

Preparation and optical properties of silver chromate self-assembly necklace structures

The silver chromate self-assembly necklace structures were synthesized using high-active acrylicamide template. The whole length of the necklace structure was between 1.2 and 1.5 μm. The product was composed of single crystalline nanorods with diameters of about 40 nm and lengths of 300 nm. The synthetic mechanism and product’s optical properties were also studied.     

Determination of the limit of photon mass and cosmic magnetic vector with rotating torsion balance

A rotating torsion balance method to detect the product of the photon mass squared and the ambient cosmic vector potential is proposed. This modulation method is efficacious whether the vector potential is fortuitously aligned with Earth's rotation axis or not, and the experimental precision of the modulation method can be improved by at least an order of magnitude compared to the statistical method.     

Disentangling proton connectivity networks in highly overlapped 1H-NMR spectra of polynuclear aromatics using 1D-HOHAHA

One-dimensional ( 1D ) variants of two-dimensional ( 2D ) nmr techniques can frequently provide the required information in a much shorter period of time than the 2D experiment from which they were derived. Application of the 1D homonuclear Hartmann-Hahn (1D-HOHAHA) experiment to establish proton-proton connectivity networks in highly overlapped four-spin systems in the proton nmr spectra of polynuclear aromatics is described. Selective subspectra are contrasted to the data obtained in a COSY experiment on the same molecule, benzo[f][l]benzothieno [2,3 -c]quinoline. Results from the 1D-HOHAHA technique are especially useful when component resonances from several spin systems are heavily overlapped. Relayed 1D-HOHAHA provides the means of exploiting small, long range coupling pathways of polynuclear aromatics.     

Diffraction integral for misaligned systems and interference effects of optical arrays

Summary In the present paper, a diffraction integral formula for a misaligned optical system is derived. The interference effects of opticalelement arrays are studied by means of such a formula. The possibility of eliminating interference fringes is discussed. The conclusion is that the interference fringes could be eliminated when the αβγδ condition for arrays is satisfied. The synthetical aberration is simultaneously eliminated. However, in this case, the synthetical image coincides with the individual images. For some special application, the synthetical image does not coincide with the individual images and the αβγδ condition is not fulfilled. But the interference fringes may disappear in some special cases.

---

Riassunto La formula di Collins, che esprime il cammino ottico fra un punto del piano oggetto e un punto del piano immagine nel caso di un sistema ottico centrato, è generalizzata al caso di un sistema ottico disallineato. La formula cosí ottenuta è applicata allo studio del fenomeno d’interferenza che ha luogo nel piano della cosiddetta ?immagine sintetica? fra i vari fasci emergenti da una cortina di elementi ottici. Si discutono infine le condizioni in cui non si hanno frange d’interferenza sull’immagine sintetica.

     

一个带阻尼项Josephson振动的半经典模型

在双势阱模型的基础上考虑了Josephson流与凝聚体的相互作用而引起的阻尼效应,得出相对粒子数Z(t)的表达式,并用一个简单的碰撞模型得出Josephson振动的振幅和能量及随时间呈指数衰减,以及凝聚体的质量越大,衰减越慢。     

Analytical solution of the linear fractional differential equation by Adomian decomposition method

In this paper, we consider the n-term linear fractional-order differential equation with constant coefficients and obtain the solution of this kind of fractional differential equations by Adomian decomposition method. With the equivalent transmutation, we show that the solution by Adomian decomposition method is the same as the solution by the Green's function. Finally, we illustrate our result with some examples.     

Low temperature fabrication of efficient porous carbon counter electrode for dye-sensitized solar cells

Porous carbon counter electrodes have been fabricated at low temperature by coating an organic binder free carbon slurry onto F-doped tin oxide conducting glass. The carbon slurry is prepared by ball-milling a dispersion of activated carbon in aqueous SnCl₄ solution. During ball-milling, SnCl₄ hydrolyzes and transforms into stannic acid gel, which acts as an inorganic “glue” to connect the carbon particles during film preparation. Dye-sensitized solar cells employing this carbon electrode achieve efficiency as high as 6.1% which is comparable to that of the cells using sputtering Pt as counter electrode.