实时直接分析质谱分析中草药多糖

建立了一种机械力化学提取法和实时直接分析质谱(DART-MS)分析相结合的中草药多糖分析方法,同时测定了黄芪、银耳、百合、茯苓、鼓槌石斛、金钗石斛、铁皮石斛和党参8种中草药多糖。比较了机械力化学提取(MCE)法与传统方法的提取效果,并优化了MCE法的提取参数。通过体积排阻色谱分离中草药多糖,建立分子质量校准曲线,估算了多糖分子质量。利用DART-MS直接裂解多糖大分子,可瞬时获得m/z<350的碎片离子,不同的中草药多糖得到的特征性的质谱离子峰可用于多糖样品的有效区分。该方法具有简单、快速、高通量、无需预消化的特点,是直接从复杂多糖大分子中获取特征指纹图谱的有力工具。     

自适应环境的机器人视觉伺服控制方法

机器人和机器视觉的迅速发展,使得基于视觉的智能机器人得到更加广泛的应用。机器视觉提高了机器人控制系统对环境的适应程度,但其适应程度也受到周围环境对机器视觉算法的影响。针对这一情况,本文对机器人视觉伺服控制系统中的机器视觉算法进行了改进,提出了一种基于帧间差分法的自适应环境的机器人视觉伺服控制方法,从而提高了控制系统对环境的自适应程度,提高了对机器人控制的精确度,实验和理论分析证明,该方法具有较大的应用前景和实用价值。     

基于飞秒激光模间拍频法的大尺寸测距方法

本文基于飞秒激光模间拍频法实现多波长相位式绝对距离测量, 通过改变光频梳重复频率合成波长扩大测距量程, 并采用监测臂和双快门切换系统补偿和消除由电路产生的相位差单向漂移和大幅抖动. 实验中以20倍重复频率的拍频进行测量, 在30 min内相位测量的标准偏差为0.022°; 与双频激光干涉仪比对1125 mm行程内位移测量结果, 测距精度优于50 μm; 实验验证了合成波长方法扩大量程方案的可行性, 获得的测距重复性优于3 μm, 该系统理论上可扩展量程至7.5 km.     

等离子体激励翼型分离流动控制数值模拟

文章利用CFD软件FLUENT中的自定义函数接口, 将等离子体对中性气体的激励作用模型化为体积力引入Navier-Stokes方程, 研究了等离子体气动激励诱导的平板射流, 以及介质阻挡放电(dielectric barrier discharge, DBD)等离子体激励对NACA0015翼型大迎角分离流的控制作用.计算分析表明, 多对电极等离子体激励器可以有效控制NACA0015翼型大迎角分离流动.      

微小型组合导航系统软硬件协同设计

针对机载制导武器对组合导航系统小体积、低功耗、高实时性以及高可靠性的要求,设计了组合导航系统双CPU总体方案。基于Zynq全可定制平台搭建了组合导航系统硬件环境。在分析组合导航系统软件结构的基础上,对任务块、任务优先级以及任务间的同步机制进行了合理设计;同时基于对组合导航滤波器内数据交换的分析,通过设置消息队列实现了任务间通信,且在保证数据一致性的同时,避免了“死锁”问题的出现。     

以一种新型Gemini表面活性剂作为介孔模板剂通过转晶过程合成介孔ZSM-5分子筛

将一种新型Gemini表面活性剂,丙撑基双(十八烷基二甲基氯化铵)[C18H37(CH3)2–N+–(CH2)3–N+–(CH3)2C18H37]Cl2(C18-3-18),作为介孔模板剂用于水热法合成介孔ZSM-5分子筛.结果表明,在130 oC低温晶化即可高效合成介孔ZSM-5分子刷.C18-3-18的加入量可影响到所合成介孔ZSM-5分子筛的相对结晶度和织构性质,它的形成遵从一个转晶过程.在合成初期,凝胶中介孔模板剂C18-3-18的使用导向了介孔材料的生成;随后在TPABr的模板作用下,介孔材料慢慢转晶生成具有MFI结构的介孔ZSM-5;然后所合成的介孔ZSM-5晶粒进一步长大并聚集形成块状颗粒,同时产生晶间介孔.C18-3-18作为介孔导向剂不仅可用于合成介孔ZSM-5分子筛,也可用于其它介孔分子筛的合成中.     

Synthesis and Crystal Structure of Tianagliflozin Triacetate

The title compound tianagliflozin triacetate 1 was synthesized and its crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic system(C27H31ClO8,Mr = 518.97),space group P21 with a = 5.3913(11),b = 16.137(2),c = 15.411(3) ,β = 94.15(3)°,V = 1337.3(5) 3,Z = 2,Dc = 1.289 g/cm3,F(000) = 548,μ = 0.190 mm-1,the final R = 0.0374 and wR = 0.0809 for 3981 observed reflections(I 2σ(I)).The structure of 1,triacetate of a highly potent SGLT2 inhibitor tianagliflozin,was unambiguously determined by single-crystal X-ray diffraction,which helped to confirm the desired β configuration at the anomeric center and the position where the deoxylation occurred.The two benzene rings in the lattice are basically orthogonal to each other.There are four intermolecular hydrogen bonds in the crystal,which helps to further stabilize the crystal.     

Biodegradable thermogel as culture matrix of bone marrow mesenchymal stem cells for potential cartilage tissue engineering

Poly（lactide-co-glycolide）-poly（ethylene glycol）-poly（lactide-co-glycolide）（PLGA-PEG-PLGA） triblock copolymer was synthesized through the ring-opening polymerization of LA and GA with PEG as macroinitiator and stannous octoate as catalyst. The amphiphilic copolymer self-assembled into micelles in aqueous solutions, and formed hydrogels as the increase of temperature at relatively high concentrations（〉 15 wt%）. The favorable degradability of the hydrogel was confirmed by in vitro and in vivo degradation experiments. The good cellular and tissular compatibilities of the thermogel were demonstrated. The excellent adhesion and proliferation of bone marrow mesenchymal stem cells endowed PLGA-PEGPLGA thermogelling hydrogel with fascinating prospect for cartilage tissue engineering.     

具有优异甲醇耐受性的Rh掺杂PdCu有序金属间化合物纳米粒子增强氧还原电催化

Direct methanol fuel cells (DMFCs), as one of the important energy conversion devices, are of great interest in the fields of energy, catalysis and materials. However, the application of DMFCs is presently challenged because of the limited activity and durability of cathode catalysts as well as the poisoning issues caused by methanol permeation to the cathode during operation. Herein, we report a new class of Rh-doped PdCu nanoparticles (NPs) with ordered intermetallic structure for enhancing the activity and durability of the cathode for oxygen reduction reaction (ORR) and achieving superior methanol tolerance. The disordered Rh-doped PdCu NPs can be prepared via a simple wet-chemical method, followed by annealing to convert it to ordered phases. The results of transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), power X-ray diffraction (PXRD) analysis and high resolution TEM (HRTEM) successfully demonstrate the formation of near-spherical NPs with an average size of 6.5 ± 0.5 nm and the conversion of the phase structure. The complete phase transition temperatures of Rh-doped PdCu NPs and PdCu are 500 and 400 ℃, respectively. The molar ratio of Rh/Pd/Cu in the as-synthesized Rh-doped PdCu NPs is 5/48/47. Benefitting from Rh doping and the presence of the ordered intermetallic structure, the Rh-doped PdCu intermetallic electrocatalyst achieves the maximum ORR mass activity of 0.96 A·mg^-1 at 0.9 V versus reversible hydrogen electrode (RHE) under alkaline conditions—a 7.4-fold enhancement compared to the commercial Pt/C catalyst. For different electrocatalysts, the ORR activities follow the sequence, ordered Rh-doped PdCu intermetallics > ordered PdCu intermetallics > disordered Rh-doped PdCu NPs > disordered PdCu NPs > commercial Pt/C catalyst. In addition, the distinct structure endows the Rh-doped PdCu intermetallics with highly stable ORR durability with unaltered half-wave potential (E_1/2) and mass activity after continuous 20000 cycles, which are higher than those of other electrocatalysts. Furthermore, the E_1/2 of the Rh-doped PdCu intermetallics decreases by only 5 mV after adding 0.5 mol·L^-1 methanol to the electrolyte, while the commercial Pt/C catalyst negatively shifts by 235 mV and a distinct oxidation peak can be observed. The results indicate that the ORR activity of the Rh-doped PdCu intermetallic electrocatalyst can be well maintained even in the presence of poisoning environment. Our results have demonstrated that Rh-doped PdCu NPs with ordered intermetallic structures is a potential electrocatalyst toward the next-generation high-performance DMFCs.     

四卤化锰(Ⅱ)配合物的结构调控及力致发光性能

力致发光是一种力刺激诱导的发光现象。由于其独特的发光方式,使得力致发光材料在结构损伤检测、压力传感、显示和安全标记等方面展现出了巨大的应用价值。目前已报道的力致发光材料大多基于无机材料体系,而有机力致发光材料体系相对较少,并且人们对其发光机理的认识仍不清晰。在本文中,我们发现锰(Ⅱ)配合物[BPP]2[Mn Br4]具有力致发光特性,并在此基础上设计合成了一系列具有力致发光性质的四卤化锰(Ⅱ)配合物。改变有机阳离子配体或者卤素阴离子可对其光物理性质进行有效调控。固态下,这些锰(Ⅱ)配合物均显示出了较强的光致发光现象,同时表现出了明显的力致发光特性。晶体结构分析表明,分子内/分子间强的C―H…X (X=Br或Cl)相互作用对锰(Ⅱ)配合物的力致发光起到了至关重要的作用,它可在较大程度上降低由分子振动和旋转造成的能量损失。本工作将为力刺激响应型材料体系的拓展提供一定的参考价值。