MALDI‐FT‐ICR‐MS for archaeological lipid residue analysis

Soft‐ionization methods are currently at the forefront of developing novel methods for analysing degraded archaeological organic residues. Here, we present little‐used soft ionization method of matrix assisted laser desorption/ionization‐Fourier transform‐ion cyclotron resonance‐mass spectrometry (MALDI‐FT‐ICR‐MS) for the identification of archaeological lipid residues. It is a high‐resolution and sensitive method with low limits of detection capable of identifying lipid compounds in small concentrations, thus providing a highly potential new technique for the analysis of degraded lipid components. A thorough methodology development for analysing cooked and degraded food remains from ceramic vessels was carried out, and the most efficient sample preparation protocol is described. The identified components, also controlled by independent parallel analysis by gas chromatography‐mass spectrometry (GC‐MS) and gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS), demonstrate its capability of identifying very different food residues including dairy, adipose fats as well as lipids of aquatic origin. The results obtained from experimentally cooked and original archaeological samples prove the suitability of MALDI‐FT‐ICR‐MS for analysing archaeological organic residues. Sample preparation protocol and identification of compounds provide future reference for analysing various aged and degraded lipid residues in different organic and mineral matrices.     

高效液相色谱法测定茶饮料中的黄酮类化合物

建立了茶饮料中六种黄酮类化合物的高效液相色谱检测方法。流动相采用梯度洗脱。结果表明芦丁、漆黄素、木犀草素、芹菜素在0.025~20 mg·L-1范围内呈现良好线性关系,桑色素、槲皮素在0.050~20 mg·L-1范围内呈现良好线性关系。加标回收率在84.5%~107.5%。该方法精密度良好(六种黄酮类化合物的相对标准偏差均不大于3.2%),检测限为6.2~34μg·L-1。该方法简便,灵敏、重现性好,可用于同时分析茶饮料中的黄酮化合物。     

广西航运枢纽工程建设中的极软岩研究

广西郁江桂平至上游百色规划有10个千吨级航运枢纽梯级,其中老口、鱼梁、那吉处在南宁、百色第三纪盆地。盆地内泥质岩石属软~极软泥岩,它具有低强度、对环境敏感、弱改造等特性,反映在工程设计中地基承载力不足、地基应力及变形超标,抗剪强度低、抗滑稳定问题突出等方面;在工程施工中体现在岩体工程稳定性差,施工保护要求高等。根据那吉等工程勘探试验研究成果,提出针对软岩工程地质问题评价及基础验收、建基面保护、地基处理等应注意的问题和采取的对策。     

高层建筑桩箱（筏）基础的优化设计

基于桩箱基础的工作特征，建立桩箱基础最小造价的优化设计数学模型。算例表明，优化设计具有主动改进设计的优势和明显的经济效益。     

DISCRETE MODELLING OF TWO-DIMENSIONAL LIQUID FOAMS

Liquid foam is a dense random packing of gas or liquid bubbles in a small amount of immiscible liquid containing surfactants. The liquid within the Plateau borders, although small in volume, causes considerable difficulties to the investigation of the spatial structure and physical properties of foams, and the situation becomes even more complicated as the fluid flows. To solve these problems, a discrete model of two-dimensional liquid foams on the bubble scale is proposed in this work. The bubble surface is represented with finite number of nodes, and the liquid within Plateau borders is discretized into lattice particles. The gas in bubbles is treated as ideal gas at constant temperatures. This model is tested by choosing an arbitrary shape bubble as the initial condition. This then automatically evolves into a circular shape, which indicates that the surface energy minimum routine is obeyed without calling external controlling conditions. Without inserting liquid particle among the bubble channels, periodic ordered and disordered dry foams are both simulated, and the fine foam structures are developed. Wet foams are also simulated by inserting fluid among bubble channels. The calculated coordination number, as a function of liquid fractions, agrees well with the standard values.     

Photothermally Reprogrammable Buckling of Nanocomposite Gel Sheets

Patterning deformation within the plane of thin elastic sheets represents a powerful tool for the definition of complex and stimuli‐responsive 3D buckled shapes. Previous experimental methods, however, have focused on sheets that access a limited number of shapes pre‐programmed into the sheet, restricting the degree of dynamic control. Here, we demonstrate on‐demand reconfigurable buckling of poly(N‐isopropylacrylamide‐co‐acrylic acid) (PNIPAM) hydrogel network films containing gold nanoparticles (AuNPs) by patterned photothermal deswelling. Predictable, easily controllable, and reversible transformations from a single flat gel sheet to numerous different three‐dimensional forms are shown. Importantly, the response time is limited by poroelastic mass transport, rather than photochemical switching kinetics, enabling reconfiguration of shape on timescales of several seconds, with further increases in speed possible by reducing film thickness.     

Green Precursors and Soft Templating for Printing Porous Carbon-Based Micro-supercapacitors

A combination of soft lithographic printing and soft templating has been used to fabricate high-resolution interdigitated micro-supercapacitors (MSC). Surfactant-assisted self-assembly produces high surface area ordered mesoporous carbons (490 m² g⁻¹). For the first time, such precursors have been printed by nano-imprint lithography as microdevices with a line width of only 250 nm and a spacing of only 1 μm. The devices are crack-free with low specific resistance (1.2×10⁻⁵ Ωm) and show good device capacitance up to 0.21 F cm⁻³.     

液气界面张力垂直分量引起的基底弹性变形

Young方程是毛细理论和润湿的重要方程之一．但是,该方程只描述了3个界面张力的水平分量之间的平衡与接触角的关系,而对液气界面张力垂直分量未作任何描述．现在,随着软材料的广泛应用,该垂直分量将引起基底的表面变形,并在微流体系统的制造过程中起到重要作用,这已是该研究领域的共识．综述了关于表面变形这一问题在理论分析,实验研究和数值模拟等方面取得的进展．而且,还讨论了由垂直分量引起的表面变形对液滴润湿和铺展行为、微悬臂梁的弯曲、弹性毛细现象、电弹性毛细现象等的影响．不仅对该问题的历史发展和目前的研究进展进行了简单的综述,并且也针对后续的研究提出了几点建议．     

Substrate elastic deformation due to vertical component of liquid-vapor interfacial tension

Young’s equation is a fundamental equation in capillarity and wetting,which reflects the balance of the horizontal components of the three interfacial tensions with the contact angle(CA).However,it does not consider the vertical component of the liquid-vapor interfacial tension(VCLVIT).It is now well understood that the VCLVIT causes the elastic deformation of the solid substrate,which plays a significant role in the fabrication of the microfluidic devices because of the wide use of the soft materials.In this paper,the theoretical,experimental,and numerical aspects of the problem are reviewed.The effects of the VCLVIT-induced surface deformation on the wetting and spreading,the deflection of the microcantilever,and the elasto-capillarity and electroelasto-capillarity are discussed.Besides a brief review on the historical development and the recent advances,some suggestions on the future research are also provided.     

列车荷载下海相沉积软土循环累积变形研究

以宁波轨道交通1号线②、③和④层海相沉积软土为对象,进行GDS单向振动三轴试验,研究了不同动应力幅值和频率作用下软土的动力学特性.结果表明：动力幅值越大,循环累积塑性变形越大,动应力的幅值大小对累积塑性变形有较明显的影响;在动应力为12kPa时,④层粘土的累积塑性应变比相同条件下②层和③层土的应变大;在相同动应力幅值时,②和④层土随频率增大,③层土则相反.最后,利用修正的指数模型对循环加载累积塑性应变的变化进行拟合,并得到了优化的模型参数.