Stability and stabilization for the coupling permanent magnet synchronous motors system with input delay

Nonlinear Dynamics - This paper studied the problem of stability and stabilization for a coupling permanent magnet synchronous motors (CPMSMs) system with input delay. Input delays caused by...     

基于侧链不对称喹喔啉聚合物的高效非富勒烯太阳电池

喹喔啉衍生物由于合成简单,易功能化,成本较低等特点在众多领域都有广泛应用。其自身具有平面刚性结构,也是构建光电聚合物的重要单体。基于喹喔啉单元的有机分子化学结构和电子结构可修饰性强,通过骨架、侧链和取代基等修饰,易于调控分子的能级和吸光光谱,因此,当使用喹喔啉体系的共轭给体与球形富勒烯受体(如PCBM)及弱结晶性非富勒烯受体(如ITIC)均可表现出优异的光伏性能。在本工作中,基于结晶性较强的非富勒烯受体(o-IDTBR),我们首次制备出侧链不对称喹喔啉(简称：不对称喹喔啉)基聚合物(TPQ-1)与之匹配。相比于侧链对称性喹喔啉(简称：对称喹喔啉)(HFQx-T)与o-IDTBR组合,“弱结晶给体-强结晶受体”组合能表现出更佳均匀的相分离尺度,从而获得更高的短路电流及能量转换效率。TPQ-1与o-IDTBR共混后器件效率为8.6%,加入15%的TB7-Th后,器件效率达到9.6%。     

低温气液两相流数值计算

低温工质两相流动在很多场合都存在,研究深冷剂在两相流动时参数的分布有着很重要的作用.文中采用一维均相流模型对液氮循环流动过程进行稳态数值模拟,得到了循环流动过程中液氮含汽率、压力和温度沿管程方向的分布情况,并对由于不同回路条件引起的不同结果进行了分析.     

Immunoassay for netrin 1 via a glassy carbon electrode modified with multi-walled carbon nanotubes,thionine and gold nanoparticles

We describe a nanostructured immunosensor for the cardiovascular biomarker netrin 1. A glassy carbon electrode was consecutively modified with multi-walled carbon nanotubes (MWCNTs), nafion (to retain the MWCNTs), thionine-coated gold nanoparticles (Thi@AuNPs), and monoclonal antibodies against netrin 1. The modified electrode was characterized by transmission electron microscopy, cyclic voltammetry, differential pulse voltammetry, UV-visible spectrophotometry and X-ray diffraction. The presence of Thi@AuNPs warrants direct and convenient immobilization of the antibody. This immunoelectrode enables netrin 1 to be determined, best at a voltage of −300 mV (vs. SCE), with a limit of detection of 30 fg mL⁻¹ (at an S/N ratio of 3) after a 50 min incubation time. The detection range extends from 0.09 to 1800 pg∙mL⁻¹. The method is simple, sensitive, specific and reproducible. We presume this stable and reproducible biosensor to be useful for the early detection of cardiovascular diseases.

A high sensitivity immunoassay was developed for the detection of netrin 1 based on multi-walled carbon nanotubes, thionine and gold nanoparticles. Its excellent performance is ascribed to the good conductivity of MWCNTs and the combination of materials.

     

Side-chain fluorination on the pyrido[3,4-<Emphasis Type="Italic">b</Emphasis>]pyrazine unit towards efficient photovoltaic polymers

A series of new polymer donors (PT-PP, PT-2fPP and PT-4fPP) were synthesized based on alkylthiophene substituted benzodithiophene (BDT-T) and pyrido[3,4-b]pyrazine (PP) building blocks and the effects of fluorination on the polymer properties were explored. Photophysical properties, charge mobilities and morphologies of the three polymers have been intensively investigated. The results indicated that the introduction of the fluorine atom at meta-positions of phenyl substituted PP unit hardly affected their highest occupied molecular orbital (HOMO) level. More importantly, controlling the degree of side-chain fluorination in the polymers is crucial for optimizing the blend morphology. Three polymers showed different photovoltaic properties. The polymer solar cell (PSC) based on the single layer device structure of ITO/PEDOT:PSS/PT-4fPP:PC₇₁BM (1:1, w:w)/ZrAcac/Al demonstrates a high power conversion efficiency (PCE) of 7.61% under the illumination of AM 1.5G, 100 mW cm^?2, which is the highest value for PP-based PSCs.     

Side-chain fluorination on the pyrido[3,4-b]pyrazine unit towards efficient photovoltaic polymers

A series of new polymer donors (PT-PP, PT-2fPP and PT-4fPP) were synthesized based on alkylthiophene substituted benzodithiophene (BDT-T) and pyrido[3,4-b]pyrazine (PP) building blocks and the effects of fluorination on the polymer properties were explored. Photophysical properties, charge mobilities and morphologies of the three polymers have been intensively investigated. The results indicated that the introduction of the fluorine atom at meta-positions of phenyl substituted PP unit hardly affected their highest occupied molecular orbital (HOMO) level. More importantly, controlling the degree of side-chain fluorination in the polymers is crucial for optimizing the blend morphology. Three polymers showed different photovoltaic properties. The polymer solar cell (PSC) based on the single layer device structure of ITO/PEDOT:PSS/PT-4fPP:PC71BM (1:1, w:w)/ZrAcac/Al demonstrates a high power conversion efficiency (PCE) of 7.61% under the illumination of AM 1.5G,100 mW cm-2, which is the highest value for PP-based PSCs.     

基于非操作系统车载记录仪数据管理系统的设计

为解决在无操作系统的环境下车载记录仪文件管理存在的问题,提出一种适合于专用性强的车载记录仪的文件管理系统,容量可达到160 G且易于扩展;车载大容量记录仪主要由控制模块、存储模块、电源模块和各种采集接口组成,并通过建立索引、存储数据、获取索引、获取历史数据等流程对文件进行有效管理,该大容量车载记录仪通过温度循环试验、高温老练试验、电磁兼容试验、振动试验等,性能稳定,数据的存取速度快,存储容量大,已用于工程实践中。     

Composite mechanics and energy method based stiffness prediction model for composite leaf springs

Predicting the stiffness of composite leaf spring accurately is the key to improve vehicles' performance. In this paper, a stiffness prediction model which is based on composite mechanics and energy method is proposed. Influence of un-coincident between neutral layer and middle of the thickness of each rectangular cross-section is considered. Calculation based on finite element method, existing theoretical method and bench test are carried out. Compared with these results, the model proposed in this paper can predict stiffness accurately. Besides, influences parameters are analyzed. The proposed model has a certain guiding significance for the lightweight of vehicles.

Communicated by Corina Sandu.     

聚合马来松香乙二醇酯Ca(Ⅱ)、Ni(Ⅱ)配合物固定化淀粉酶研究

将松香改性合成聚合马来松香乙二醇酯(简称MEEP),使之分别与CaCl2、NiCl2、MgCl2和CuCl2反应,制备聚合马来松香乙二醇酯Ca(Ⅱ)、Ni(Ⅱ)、Mg(Ⅱ)和Cu(Ⅱ)配合物,再对淀粉酶进行固定化,比较了固定化酶和游离酶的性能.实验结果表明,4种聚合马来松香乙二醇酯配合物固定化酶使用5次后,固定化酶保留活力均在50%以上,其中MEEPCa(Ⅱ)和MEEPNi(Ⅱ)固定化酶的效果较好,固定化酶保留活力均在70%以上;固定化酶最适温度50℃,较游离酶高10℃;聚合马来松香乙二醇酯Ca(Ⅱ)、Ni(Ⅱ)固定化酶的最适pH值分别为5.24、6.86,米氏常数分别为1.47×10-4kg/L和2.64×10-4kg/L,游离酶为2.69×10-5kg/L.     

Second-law thermodynamic analysis on non-premixed counterflow methane flames with hydrogen addition

Journal of Thermal Analysis and Calorimetry - Natural gas is an attractive alternative fuel because of its environment-friendly nature, and hydrogen addition is considered as an efficient method to...