L-鼠李糖基(氨基)硫脲类化合物的合成

以L-鼠李糖为起始原料, 制备1-溴-2,3,4-三-O-乙酰基-β-L-吡喃型鼠李糖, 然后在甲苯中与Pb(SCN)₂作用, 得到中间体2,3,4-三-O-乙酰基-α-L-吡喃型鼠李糖基异硫氰酸酯(1). 利用2,3,4-三-O-乙酰基-α-L-吡喃型鼠李糖基异硫氰酸酯易发生亲核加成的性质, 在不同溶剂中, 与取代的苯并噻唑胺(2a～2f)、取代的苯并噻唑肼(2g～2l)、氧化和非氧化的哒嗪酮甲酰肼(2m, 2n)以及取代的嘧啶胺(2o, 2p)反应, 合成了16种新的(氨基)硫脲类化合物3a～3p. 所有化合物的结构均经IR, ¹H NMR, LC-MS和元素分析确证, 并对它们的生物活性做了初步测试.     

Micro-Gas Flow Induced Stochastic Resonance of a Nonlinear Nanomechanical Resonator

Fluidics is one of the most historic subjects that are well-established over centuries on the macroscopic scale.In recent years,fluid detection using a number of micro/nano scale devices has been achieved.However,the interaction of microfluid and solid devices on micro/nano-meter scale still lacks in-depth research.We demonstrate a practical nanomechanical detector for microfluidics via a string resonator with high Q-factor,suspended over a hole.This device is placed under a jet nozzle with several microns of diameter,and the interaction between the micro-gas flow and the resonator is observed by monitoring the variation of the fundamental frequency and the quality factor.Moreover,we manage to measure the fluctuations of the micro-gas flow on the nanomechanical resonator by means of stochastic resonance.This work manifests a potential platform for detecting dynamical fluid behaviors at microscopic scale for novel fluid physics.     

具有结构阻尼的热弹性梁耦合系统的整体解

考虑热效应对弹性梁的影响,研究了一类具有结构阻尼的热弹性梁耦合系统的整体动力行为,采用Galerkin方法证明了该系统整体弱解的存在唯一性.     

N-糖基-N＇-酰氨基硫脲及其环合产物的合成

以L-α-氨基酸为起始原料，经酯化、氨基保护、肼解制得N-对甲苯磺酰基-L—α-氨基酸酰肼2，再与糖基异硫氰酸酯3～5反应，得到9种新型N-糖基-N＇-酰氨基硫脲6～8，然后在Hg（OAc）2／EtOH条件下关环，合成了一系列新的2-对甲苯磺酰氨基烃基-5-糖氨基-1，3，4-噁二唑类化合物9～11．所有新化合物的结构均经IR，^1H NMR，MS谱和元素分析确证．     

Coherent Transfer of Excitation in a Nanomechanical Artificial Lattice

We realize a coherent transfer of mechanical excitation in a finely controlled artificial nanomechanical lattice.We also realize strong dynamic coupling between adjacent high-Q mechanical resonators,via modulated dielectric force at the frequency difference between them.An excitation transfer across a lattice consisting of 7 nanobeams is observed by applying a design sequence of switching for couplings,with the final effective population reaching 0.94.This work not only demonstrates the ability to fully control an artificial lattice but also provides an efficient platform for studying complicated dynamics in one-dimensional systems.     

N-糖基-N''''-酰氨基硫脲及其环合产物的合成

以L-α-氨基酸为起始原料,经酯化、氨基保护、肼解制得N-对甲苯磺酰基-L-α-氨基酸酰肼2,再与糖基异硫氰酸酯3～5反应,得到9种新型N-糖基-N'-酰氨基硫脲6～8,然后在Hg(OAc)2/EtOH条件下关环,合成了一系列新的2-对甲苯磺酰氨基烃基-5-糖氨基-1,3,4-噁二唑类化合物9～11.所有新化合物的结构均经IR,1H NMR,MS谱和元素分析确证.     

氯化钙/三赞胶微胶囊的制备及其对核黄素的控制释放

为实现核黄素在肠道中的可控释放，本研究利用三赞胶的pH响应性，使用滴球法制备三赞胶水凝胶微胶囊，以核黄素为负载药物，氯化钙为调控因子，研究了微胶囊的物性与释放特性。结果表明：0.3%三赞胶在0.06 mol/L盐酸固定液中可以形成稳定的凝胶结构，添加氯化钙后微胶囊的硬度增加但弹性降低。氯化钙添加量由0逐渐增加至10%,三赞胶微胶囊在十二指肠中的释放率无显著变化，空肠释放率由42.5%逐渐降低至24.1%,在氯化钙添加量2%及以上时可在回肠释放，且释放率由21.6%逐渐降低至14.9%。粘度特性与SEM图像分析表明，添加氯化钙提高三赞胶溶液的粘度，降低微胶囊的孔隙度是控制核黄素释放的主要原因。本研究通过调整三赞胶微胶囊中的氯化钙添加量，实现了核黄素在肠道中的可控释放，表明可控释三赞胶微胶囊在口服递送领域具有广阔的应用前景。