鱼类双重荧光标记研究——以中华倒刺鲃幼鱼为例

为探究盐酸四环素(TCH)和茜素红S(ARS)对中华倒刺鲃(Spinibarbus sinensis Bleeker)的影响及标记效果,丰富鱼类荧光标记模式,研究使用TCH(100—500 mg/L)和ARS(100—300 mg/L)对中华倒刺鲃幼鱼进行双重浸染荧光标记,实验共设置5个处理组和1个对照组,浸染时间均为24h。结果显示,经90d的养殖实验后,标记鱼的耳石(包括矢耳石和星耳石)、倒刺、鳍条和鳍棘均能检测到双重荧光标记环,且TCH产生的黄色荧光环比ARS产生的红色荧光环更接近骨质结构内部。较高浓度处理组的矢耳石(≥300 mg/L TCH和≥150 mg/L ARS)、星耳石(≥300 mg/L TCH和≥200 mg/L ARS)和倒刺(400—500 mg/L TCH和150—300 mg/L ARS)中均能检测到明显的标记环(n≥2),但所有处理组的侧线鳞和非侧线鳞的荧光标记不明显(0≤n≤1)。经200—500 mg/L TCH和150—300 mg/L ARS处理的鳍条,及经300—500 mg/L TCH和200—300 mg/L ARS处理的鳍棘中可以同时检测到明显的TCH和ARS的标记环(n≥2)。此外,在整个实验中各处理组标记鱼与对照组相比,在生长和存活率方面均无显著性差异(P>0.05)。结果表明,使用TCH和ARS双重标记中华倒刺鲃幼鱼是可行的。双重荧光标记方法在水生生物标记回捕实验及实验性生物学研究方面具有潜在的应用前景。

Transport Properties of Ferrite Perovskite Material

Transport properties of LaFeO3 in the temperature range of 2 K 〈 T 〈 300 K have been explored for the first time using interaction potential developed by the author and found that our computed results on transport properties follow the same trend as that of available experimental values. These are scientifically and technologically important materials with orthorhombic perovskite-like structure and space group Pbnm. Lanthanum ferrite, LaFeO3 is semiconducting and antiferrom agnetically ordered at zero. The thermodynamics of perovskite-type or related materials of potential use in, e.g., solid oxide fuel cells have been studied to a rather limited extent only.

Tensor force effect on proton shell structure in neutron-rich Ca isotopes

In the framework of the Skyrme-Hartree-Fock approach with 36 sets of the TI J parameterizations,the tensor force effect on the evolution of the single-proton states in the calcium isotopes is systematically investigated.It is shown that the single-proton states with higher angular momenta are influenced significantly by the tensor force and the trend in the evolution of somesingle-particle energy differences with the mass number of the isotopes depends sensitively on a parameter βT associated with the intensity of the tensor force.To understand this phenomenon,we analyze the spin-orbit potentials and the radial wave functions of relevant single-proton orbits in detail.In addition,it is found that some TI J interactions could cause the 2s1/21d3/2 energy level inversion in 48Ca.

The effect of curing temperature on the properties of shrinkage-compensated binder

The effects of curing temperature on the expansive effectiveness, strength, hydration degree, and microstructure of shrinkagecompensated binder were studied. The results showed that under the standard curing temperature (20℃), most crystalline ettringite grows in pores, which makes less contribution to the expansion of paste than gelatinous ettringite blended with C-S-H gel. An elevated curing temperature (40℃) promotes the hydration rate of expansive agent and cement. However, quickly developing strength of paste limits its expansion. The pore structure of hardened paste under moderate curing condition is the densest one among all the pastes cured at different temperatures due to the filling effect of crystalline and gelatinous ettringite. Under a high curing temperature (60℃), the formation of massive stick-like ettringite leads to excessive expansion at early hydration age. Some ettringite decomposes at sustainable high temperature, which decreases the restricted expansion rate of paste at a late age. Appropriate volume expansion is benefit to the improvement of pore structure of hardened paste by reducing large pores.

Unconventional solution-phase epitaxial growth of organic-inorganic hybrid perovskite nanocrystals on metal sulfide nanosheets

Epitaxial heterostructures based on organicinorganic hybrid perovskites and two-dimensional materials hold great promises in optoelectronics, but they have been prepared only via solid-state methods that restricted their practical applications. Herein, we report cubic-phased MAPbBr3(MA=CH3NH3+) nanocrystals were epitaxially deposited on trigonal/hexagonal-phased MoS2 nanosheets in solution by facilely tuning the solvation conditions. In spite of the mismatched lattice symmetry between the square MAPbBr3(001) overlayer and the hexagonal MoS2(001) substrate, two different aligning directions with lattice mismatch of as small as 1% were observed based on the domainmatching epitaxy. This was realized most likely due to the flexible nature and absence of surface dangling bonds of MoS2 nanosheets. The formation of the epitaxial interface affords an effective energy transfer from MAPbBr3 to MoS2, and as a result, paper-based photodetectors facilely fabricated from these solution-dispersible heterostructures showed better performance compared to those based on MoS2 or MAPbBr3 alone. In addition to the improved energy transfer and light adsorption, the use of MoS2 nanosheets provided flexible and continuous substrates to connect the otherwise discrete MAPbBr3 nanocrystals and achieved the better film forming ability. Our work suggests that the scalable preparation of heterostructures based on organic-inorganic hybrid perovskites and 2D materials via solution-phase epitaxy may bring about more opportunities for expanding their optoelectronic applications.