手持技术数字化实验探究夹心式膜电池的创新改进*

借助手持技术,用阳离子交换膜代替盐桥,滤纸代替烧杯,将双液铜锌原电池改进为高效化、微型化的夹心式阳离子交换膜原电池。通过实验探究、微观分析得出阳膜电池具有电流示数大且较稳定、装置简易、操作方便、药品用量小、绿色无污染等优点。本实验不仅揭示膜电池的工作原理、还原高考膜电池实验、构建化学电源的基本模型,还贴近生活,提高学生的自主实验探究能力,培养学生宏观辨识与微观探析、科学探究与创新意识的核心素养。     

Macleayine,a new alkaloid from Macleaya cordata

Macleayine (1),a new natural occurring alkaloid with a unique spiro[furanone-piperidinedione] framework,was isolated from the aerial parts of Macleaya cordata.Its unusual structure was established by extensive spectroscopic analyses,computer-assisted structure elucidation software (ACD/Structure Elucidator),quantum chemistry calculations and ECD calculation.The result of virtual molecular docking predicted the compound can enhance the effects of insulin,and may be used to treat type II diabetes.     

Quantification of albumin in urine using preconcentration and near-infrared diffuse reflectance spectroscopy

Urinary albumin is an important diagnostic and prognostic marker for cardiorenal disease. Recent studies have shown that elevation of albumin excretion even in normal concentration range is associated with increased cardiorenal risk. Therefore, accurate measurement of urinary albumin in normal concentration range is necessary for clinical diagnosis. In this work, thiourea-functionalized silica nanoparticles are prepared and used for preconcentration of albumin in urine. The adsorbent with the analyte was then used for near-infrared diffuse reflectance spectroscopy measurement directly and partial least squares model was established for quantitative prediction. Forty samples were taken as calibration set for establishing PLS model and 17 samples were used for validation of the method. The correlation coefficient and the root mean squared error of cross validation is 0.9986 and 0.43, respectively. Residual predictive deviation value of the model is as high as 18.8. The recoveries of the 17 validation samples in the concentration range of 3.39-24.39 mg/L are between 95.9%-113.1%. Therefore, the method may provide a candidate method to quantify albumin excretion in urine.     

Bilinear form,soliton, breather,lump and hybrid solutions for a ( $$\varvec{2+1}$$ 2 + 1 )-dimensional Sawada–Kotera equation

Nonlinear Dynamics - In this paper, we investigate a ( $$2+1$$ )-dimensional Sawada–Kotera (SK) equation for the atmosphere, rivers, lakes, oceans, as well as the conformal field and...     

Ionic liquids monolithic columns for protein separation in capillary electrochromatography

A series of ionic liquids (ILs) monolithic capillary columns based on 1-vinyl-3-octylimidazolium (ViOcIm⁺) were prepared by two approaches (“one-pot” approach and “anion-exchange” approach). The effects of different anions (bromide, Br⁻; tetrafluoroborate, BF₄⁻; hexafluorophosphate, PF₆⁻; and bis-trifluoromethanesulfonylimide, NTf₂⁻) on chromatography performance of all the resulting columns were investigated systematically under capillary electrochromatography (CEC) mode. The results indicated that all these columns could generate a stable reversed electroosmotic flow (EOF) over a wide pH range from 2.0 to 12.0. For the columns prepared by “one-pot” approach, the EOF decreased in the order of ViOcIm⁺Br⁻ > ViOcIm⁺BF₄⁻ > ViOcIm⁺PF₆⁻ > ViOcIm⁺NTf₂⁻ under the same CEC conditions; the ViOcIm⁺Br⁻ based column exhibited highest column efficiencies for the test small molecules; the ViOcIm⁺NTf₂⁻ based column possessed the strongest retention for aromatic hydrocarbons; and baseline separation of four standard proteins was achieved on ViOcIm⁺NTf₂⁻ based column corresponding to the highest column efficiency of 479 000 N m⁻¹ for cytochrome c (Cyt c). These results indicated that the property of ILs based columns could be tuned successfully by changing anions, which gave these columns potential to separate both small molecules and macro biomolecules.     

纳米三氧化钨的制备、表征及对六硝基六氮杂异伍兹烷热分解的影响

采用水热法通过控制前躯体钨酸钠的加入量和反应时间制备了长方体形纳米WO₃,利用X射线粉末衍射(XRD)、透射电镜(TEM)、扫描电镜及能量散射光谱仪(SEM-EDS)对样品进行表征。并运用差示扫描量热法(DSC)研究纳米WO₃对六硝基六氮杂异伍兹烷(CL-20)热分解特性的影响。结果表明:与单组分CL-20相比,纳米WO₃的加入使复合物WO₃/CL-20的热分解峰温降低2.95℃,活化能减小7.74 kJ·mol^-1,因此纳米WO₃能够加速CL-20的热分解。     

Numerical Algorithm with Fourth-Order Spatial Accuracy for Solving the Time-Fractional Dual-Phase-Lagging Nanoscale Heat Conduction Equation

Nanoscale heat transfer cannot be described by the classical Fourier law due to the very small dimension, and therefore, analyzing heat transfer in nanoscale is of crucial importance for the design and operation of nano-devices and the optimization of thermal processing of nano-materials. Recently, time-fractional dual-phase-lagging (DPL) equations with temperature jump boundary conditions have showed promising for analyzing the heat conduction in nanoscale. This article proposes a numerical algorithm with high spatial accuracy for solving the time-fractional dual-phase-lagging nano-heat conduction equation with temperature jump boundary conditions. To this end, we first develop a fourth-order accurate and unconditionally stable compact finite difference scheme for solving this time-fractional DPL model. We then present a fast numerical solver based on the divide-and-conquer strategy for the obtained finite difference scheme in order to reduce the huge computational work and storage. Finally, the algorithm is tested by two examples to verify the accuracy of the scheme and computational speed. And we apply the numerical algorithm for predicting the temperature rise in a nano-scale silicon thin film. Numerical results confirm that the present difference scheme provides ${\rm min}\{2−α, 2−β\}$ order accuracy in time and fourth-order accuracy in space, which coincides with the theoretical analysis. Results indicate that the mentioned time-fractional DPL model could be a tool for investigating the thermal analysis in a simple nanoscale semiconductor silicon device by choosing the suitable fractional order of Caputo derivative and the parameters in the model.     

Theoretical study of UV-Vis light absorption of some impurities in alkylbenzene type liquid scintillator solvents

Special chemical impurities may greatly decrease the light transparency of liquid scintillator (LS) solvents in the wavelength region 350–450 nm, which is of great importance to the neutrino experiments. The absorption wavelengths and oscillator strengths of two types of impurities (thiocarbonyls and nitrobenzene derivatives) and some similar compounds were calculated using TD-DFT in three scintillator solvents (toluene, pseudocumene, and linear alkyl benzene). Influences of these impurity molecules on LS solvent’s optical transmission in 350–450 nm were analyzed and compared with each other.     

Photoionization of 1s Electron and Corresponding Shake-Up Process in Ground and Excited Lithium Atoms

The cross sections of the ls electron photoionization and corresponding shake-up processes for Li atoms in the ground state 1s^22s and excited states 1s^22p, 1s^23s, 1s^23p and 1s^23d are calculated using the multi-configuration Dirac-Fock method. The latest experimental photoelectron spectrum at hv= 100 eV [Cubaynes D et al. Phys. Rev. Lett. 99 （2007） 213004] has been reproduced by the present theoretical investigation excellently. The relative intensity of the shake-up satellites shows that the effects of correlation and relaxation become more important for the higher excited states of the lithium atom, which are explained very well by the spatial overlap of the initial and final state wavefunctions. In addition, strong dependence of the cross section on the atomic orbitals of the valence electrons are found, especially near the threshold.     

纳升电喷雾萃取电离质谱快速测定人参皂苷

以自行研制的纳升电喷雾萃取电离源（NanoEESI）为基础,建立了在无需色谱分离条件下快速测定人参皂苷的质谱分析方法,用NanoEESI串联质谱分析鉴定了人参中的多种人参皂苷,并将该方法用于人参、桔梗和商陆的快速鉴定。实验表明,人参中的皂苷易于在电离过程中结合钠离子,并形成[M+Na]+正离子从而被检测分析,而桔梗和商陆等样品中不含人参皂苷成份,在串联质谱中也没有相应的特征碎片离子,从而达到鉴别中药材真伪的目的。本方法简便、快速、灵敏、特征性强、重现性好,对道地中药材快速鉴定提供了思路,具有很好的实用价值。