用CdSe/ZnS量子点提高体异质结有机太阳电池的效率

通过掺杂吸收光谱在可见光波段的量子点可提高聚合物对可见光的吸收,因此掺杂CdSe/ZnS核-壳结构量子点(CQDs)能提高聚(3-己基噻吩):[6,6]-苯基-C61-丁酸甲酯(P3HT:PCBM)体异质结太阳电池的能量转换效率.本文研究了CdSe/ZnS量子点在P3HT:PCBM中的不同掺杂比例及其表面配体对太阳电池光伏性能的影响,优化器件ITO(氧化铟锡)/PEDOT:PSS(聚(3,4-乙撑二氧噻吩:聚苯乙烯磺酸)/P3HT:PCBM:(CdSe/ZnS)/Al的能量转换效率达到了3.99%,与相同条件下没有掺杂量子点的参考器件ITO/PEDOT:PSS/P3HT:PCBM/Al相比,其能量转换效率提高了45.1%.     

Nondestructive damage assessment in fiber reinforced composites with the pulsed ultrasonic polar scan

This study investigates the use of both amplitude and time-of-flight based pulsed ultrasonic polar scan (P-UPS) as a sophisticated non-destructive damage sensor for fiber reinforced composites. Focus is put on stiffness related damage phenomena, which are in general difficult to monitor nondestructively, and their associated signature in the P-UPS image. Various composite samples, with different damage states, have been inspected at multiple material spots with the P-UPS technique. The results demonstrate the capability of the P-UPS method to obtain a unique signature of the local material damage characteristics. Several indicators in the acquired P-UPS images have been identified from which the type and level of material degradation can be obtained. The P-UPS extracted characteristics are fully supported by simulations, conventional tests as well as visual inspection.     

Simple power supply for power load controlled isoelectric focusing

The power supply for IEF based on features of the Cockcroft‐Walton voltage multiplier (CW VM) is described in this work. The article describes a design of the IEF power supply, its electric characteristics, and testing by IEF analysis. A circuit diagram of the power supply included two opposite charged branches (each consisting of four voltage doublers). The designed CW VM was powered by 230 V/50 Hz alternate current and it generated up to 5 kV and 90 mW at the output. Voltage and current characteristics of the power supply were measured by known load resistances in the range from 10 kΩ to 1 GΩ, which is a common resistance range for IEF strip geometry. Further, the power supply was tested by a separation of a model mixture of colored pI markers using a 175 × 3 × 0.5 mm focusing bed. Automatically limited power load enabled analysis of samples without previous optimization of the focusing voltage or electric current time courses according to sample composition. Moreover, the developed power supply did not produce any intrinsic heat and was easy to set up with cheap and commonly available parts.     

玉米粕蛋白质提取工艺的响应面法分析

探讨提取玉米粕蛋白质的最佳工艺条件。在单因素试验的基础上,选取料液比(g·mL-1)、温度、NaoH浓度为响应因子,玉米粕蛋白质的提取率为响应值,实施3因素3水平的响应面分析,建立数学模型,得出最佳工艺条件。试验结果表明,玉米粕蛋白质的最佳提取条件为:料液比1:6.89(g·mL-1)、温度44.92℃、NaoH浓度0.078mol·L-1,在此工艺条件下玉米粕蛋白质的提取率可达到40.57%。     

Power‐to‐Gas

The power‐to‐gas concept is a promising technology to chemically store energy and therefore a feasible approach to mitigate the challenges of energy transition. Heterogeneous catalysis plays a crucial role in CO₂ conversion to methane using nickel based catalysts. A thorough catalyst characterization facilitates the synthesis of optimized catalyst systems. The determination of reaction kinetics is fundamental for industrial reactor design.     

Ultrasonic Spectrometry of Aqueous Solutions of Alkyl Maltosides: Kinetics of Micelle Formation and Head‐Group Isomerization

At frequencies between 100 kHz and 400 MHz, ultrasonic attenuation spectra are measured at 25 °C for aqueous solutions of hexyl‐, heptyl‐, octyl‐, nonyl‐, and decyl‐β‐D ‐maltopyranoside as well as of decyl‐α‐D ‐maltopyranoside. The spectra with surfactant concentration c above the relevant critical micelle concentration (cmc) display three relaxation terms with discrete relaxation times. That with a relaxation time between 0.1 and 1.2 μs is due to exchange of monomers between micelles and the suspending phase. It is discussed in the light of the Teubner–Kahlweit–Aniansson–Wall model of the formation/decay kinetics of systems with Gaussian size distribution of micelles. The relaxation parameters are compared to those for solutions of other non‐ionic surfactants, such as alkyl monoglycosides and poly(ethylene glycol) monoalkyl ethers. At c<cmc this low‐frequency relaxation term is missing and at c≈cmc it is broadened, as is characteristic of solutions of oligomeric molecular structures rather than proper micelles. The relaxation terms with relaxation times between 6 and 15 ns and 0.7 and 2.3 ns reveal head‐group rotations around glycosidic angles and isomerization of the exocyclic hydroxymethyl group, respectively. These unimolecular reactions are also examined with a view to solutions of alkyl monoglycosides as well as of glucose and maltose.     

Symmetric AC fuzzy power flow model

Power flow calculations are one of the most important computational tools for planning and operating electric power systems. After the stabilization of the deterministic power flow calculation methods, the need to capture uncertainty in load definition lead first to the development of probabilistic models, and later to fuzzy approaches able to deal with qualitative declarations and other non-probabilistic information about the value of the loads. Present fuzzy power flow (FPF) calculations use typically incremental techniques, in order to obtain a good approximation of the fuzzy state variables. However, these models and procedures are not entirely satisfactory for the evaluation of the adequacy of the electric transmission system, since they are not completely symmetric. In this paper, we show how to perform the detailed calculation of the state variables of the FPF problem in an exact and symmetrical way, by means of solving multiple optimization problems. The procedure is illustrated using the IEEE 118 test system.     

生物质快速热解油水相溶液超声乳化特性

使用生物油水相溶液与0# 柴油乳化,筛选了四种常用乳化剂和一种助乳化剂进行复配乳化实验,考察了复配乳化剂型号、乳化剂用量、超声作用时间对乳化效果的影响。结果表明,六种乳化液超过30d不破乳,与0# 柴油相比,密度和热值相差不大,含水量3%以下,黏度增大约40%,pH值降低一半。因素分析法表明,水相溶液与柴油质量比和不同的水相溶液对乳化效果影响较大。探讨了乳化机理,认为生物油水相溶液中水、醛、酸、酮等极性组分化合物稳定地被乳化剂包裹在W/O型乳化液液滴中,生物油水相溶液中少量的乙酸乙酯、芳香类化合物等则增溶于非离子乳化剂胶束中。热力学分析表明,超声乳化作用比静置作用具有更大的熵增,乳化液更趋于稳定平衡状态。     

Strong NP-hardness of AC power flows feasibility

We prove that testing feasibility for an AC power flow system is a strongly NP-hard problem.     

高效液相色谱法测定胶粘剂中的游离甲醛

建立了胶粘剂中游离甲醛的高效液相色谱检测方法,对提取方法、衍生化条件及色谱条件进行了研究。结果表明,采用超声波萃取法代替经典的水蒸气蒸馏法能更快速、高效地提取目标物。液相色谱法对甲醛的检出限为0．024μg／mL,在0．1～12μg／mL范围内,线性相关系数R^2=0．9995,在1、2、8μg／mL三个添加水平下,回收率在98．73％～101．68％之间。五个实验室间的相对标准偏差为2．6％。对某白乳胶样品的测定结果表明,本法在定性检测、抗干扰能力及稳定性上都高于常用的乙酰丙酮比色法。