抑制型离子色谱法测定白酒中的F~-、CI~-、NO_2~-、H_2PO_4~-、NO_3~-

用抑制型离子色谱法测定白酒中的F~-、cl~-、NO_2~-、H_2PO_4~-、NO_3~-。流动相为4mmoL/L Na_2CO_3-3mmoL/L NaHCO_3混合溶液,流速为1.5mL/min,进样量为0.5mL,在最佳色谱条件下,5种无机阴离子10min内实现基线分离。F~-、cl~-、NO_2~-、H_2PO_4~-、NO_3~-的检出限分别为0.008、0.012、0.030、0.068、0.077mg/L。测定结果的相对标准偏差分别为1.86％、1.30％、2.06％、1.82％、1.50％,回收率分别为108.0％、94.0％、101.0％、98.7％、94.4％。     

Quantitative determination of zinc in milkvetch by anodic stripping voltammetry with bismuth film electrodes

Bismuth film electrode (BiFE) was shown to be an attractive alternative to common mercury film electrode (MFE) for anodic stripping voltammetric measurements. In this study, bismuth film, that was in situ deposited onto glassy carbon electrode, was used to detect zinc content of milkvetch, used in traditional Chinese medicine. Variables affecting the response have been evaluated and optimized. Experimental results showed a high response, with a good linearity (between 0.5 × 10⁻⁶ mol L⁻¹ and 3 × 10⁻⁶ mol L⁻¹) a good precision (R.S.D. = 3.58%) and a low detection limit (9.6 × 10⁻⁹ mol L⁻¹ with a 120 s anodic). The anodic stripping performance makes the bismuth film electrode very desirable for measurements of trace nutritive element zinc in milkvetch and should impart possible restrictions on the use of mercury electrode.     

三价铬丙二酸配合物[Cr(C3H2O4)(H2O)4][Cr(C3H2O4)2(H2O)2]·4H2O的合成、晶体结构及性质研究

在三重桥氧三核铬羧酸配合物的系列研究中,采用与铬的一元羧酸配合物类似的实验条件,以丙二酸为配体合成了不同构型的配合物[Cr(C₃H₂O₄)(H₂O)₄)][Cr(C₃H₂O₄)₂(H₂O)₂]·4H₂O,通过X射线衍射测定了其单晶结构,并对-COO的配位方式作了讨论,还研究了配合物的红外光谱、拉曼光谱、紫外可见光谱、质谱、磁化率等性质,探讨了性质与结构的关系,并由此论证了二元羧酸和铬形成的双齿螯合构型化合物的稳定性.     

基于干涉原理精确对中折衍混合器件的技术研究

在折衍混合光学系统的加工和装配过程中,折、衍器件间的对中精度严重影响混合器件的质量和性能,但是由于衍射器件与传统折射器件的显着差异,传统的对中手段已不再适用,如何简便实现二者的精确对中是混合光学系统实用化过程中亟待解决的问题之一.本文提出利用干涉原理简便地实现衍射器件与折射器件的高精度对中,理论分析和实验结果表明该对中装校方法是有效可行的,可以满足光学系统的对中要求。     

天花粉蛋白的化学—拉曼光谱法研究其溶液构象

本文用拉曼光谱法测定了天花粉蛋白在pH为1.9～11.5范围内二级结构的变化。结果表明,随pH值的增加,α-螺旋略有减少,β-折叠略有增加,而无序结构没有明显变化。     

Proapoptotic Peptide Brush Polymer Nanoparticles via Photoinitiated Polymerization-Induced Self-Assembly

Herein, we report the photoinitiated polymerization-induced self-assembly (photo-PISA) of spherical micelles consisting of proapoptotic peptide–polymer amphiphiles. The one-pot synthetic approach yielded micellar nanoparticles at high concentrations and at scale (150 mg mL⁻¹) with tunable peptide loadings up to 48 wt. %. The size of the micellar nanoparticles was tuned by varying the lengths of hydrophobic and hydrophilic building blocks. Critically, the peptide-functionalized nanoparticles imbued the proapoptotic “KLA” peptides (amino acid sequence: KLAKLAKKLAKLAK) with two key properties otherwise not inherent to the sequence: 1) proteolytic resistance compared to the oligopeptide alone; 2) significantly enhanced cell uptake by multivalent display of KLA peptide brushes. The result was demonstrated improved apoptosis efficiency in HeLa cells. These results highlight the potential of photo-PISA in the large-scale synthesis of functional, proteolytically resistant peptide–polymer conjugates for intracellular delivery.     

压电声透通信的研究进展*

由于电磁屏蔽效应,传统的无线通信技术受限于金属障碍物的遮挡而无法应用。压电声透通信能够克服电磁无线通信方式的这一缺陷,在不破坏金属障碍物物理结构的前提下,通过声波穿透障碍物实现通信。本文在介绍金属隔物通信的基本原理和实现方式的基础上,总结阐述了压电声透通信目前国内外的研究进展,包括传输系统模型的建立、参数的设计、系统的搭建以及该技术中独特的能量传输方式,最后对影响压电声透通信系统性能的因素进行了分析。     

Biomass‐derived Nitrogen and Phosphorus Co‐doped Hierarchical Micro/mesoporous Carbon Materials for High‐performance Non‐enzymatic H2O2 Sensing

Nitrogen and phosphorus co‐doped hierarchical micro/mesoporous carbon (N,P‐MMC) was prepared by simple thermal treatment of freeze‐dried okra in the absence of any other additives. The 0.96 wt % of N and 1.47 wt % of P were simultaneously introduced into the graphitic framework of N,P‐MMC, which also possesses hierarchical porous structure with mesopores centered at 3.6 nm and micropores centered at 0.79 nm. Most importantly, N,P‐MMC carbon exhibits excellent catalytic activity for electrocatalytic reduction of H₂O₂, resulting in a new strategy to construct non‐enzymatic H₂O₂ sensor. The N,P‐MMC‐based H₂O₂ sensor displays two linear detection range about 0.1 mM–10 mM (R²=0.9993) and 20 mM–200 mM (R²=0.9989), respectively. The detection limit is estimated to be 6.8 μM at a signal‐to‐noise ratio of 3. These findings provide insights into synthesizing functional heteroatoms doped porous carbon materials for biosensing applications.     

Ultrasonic Wireless Communication Through Metal Barriers

Ultrasound can be used as a carrier to realize wireless communication to and from a metal-enclosed space, which has the characteristics such as immunity to the electromagnetic shielding effect and non-destructive penetration of metal obstacles. This paper firstly reviews the previous studies in the field of ultrasonic wireless communication through metal barriers, and summarizes their achievements and the existing problems. Secondly, an overview of the research methods involved in studying the characteristic of acoustic-electric channel is presented, and the principles are introduced for the actual measurement method, equivalent circuit method, ABCD parameter method, finite element analysis method and time-domain finite difference method. Then, an overview of the communication algorithms are presented such as orthogonal frequency division multiplexing (OFDM), single-carrier frequency domain equalization and multiple input multiple output OFDM. Finally, the potential future study are proposed in light of the trend of development and unsolved problems.     

声载波无线电能传输的自适应负载匹配

该文提出了一种可以实现动态阻抗匹配的交直流转换电路及自适应阻抗调节算法,通过可调电容矩阵和可调电感的共振作用实现阻抗匹配,并利用改进的梯度下降算法实现了元器件参数的动态调整,提高了声载波无线电能传输系统在实际应用中的驱动效果和适应能力.研究对提出的电路结构和算法进行了模型仿真,并分析了不同负载接入时系统阻抗的变化及其动...