Extending the response spectrum of organic photodetectors by quaternary active layer method with complementary absorption spectra

In this work, we report a new method for extending the response spectra of organic photodetectors (OPDs) by incorporating PBDT-TT-C and PBDT-TT-F in the P3HT:PC₆₁BM. The effects of PBDT-TT-C and PBDT-TT-F incorporation on the optical and electrical properties of OPDs were investigated, It was found that when the mass ratio of P3HT:PBDT-TT-F:PBDT-TT-C:PC₆₁BM was 12:2:2:8, the response spectrum of the active layer was extended to 780 nm. The responsivity (R) and external quantum efficiency (EQE) of the OPDs reached 340, 376, 315 mA/W and 67%, 88%, 85% under 630, 530, and 460 nm illumination and −1 V bias, respectively, and the detectivity (D*) reached 10¹² Jones. The results show that the inclusion of an appropriate amount of donor material with similar chemical structure and complementary absorption spectrum can reduce the influence of the doping material on the micro-morphology of the original film while improving the absorption of the spectrum. The interaction between the donor materials promotes the generation of photogenerated carriers and increases the photocurrent of the OPDs. In addition, the incorporation of the different component promotes crystallization of the film, resulting in a reduction in dark current of the OPDs.     

火焰原子吸收和发射光谱法测定盐湖卤水中的钙

在波长422.7nm下,用火焰原子吸收和发射光谱法测定了盐湖卤水中钙的含量,考察了酸度及共存离子对测定结果的影响,并对两种方法的优缺点进行了比较.结果表明,原子吸收光谱法受酸度及共存离子的影响较小,火焰发射光谱法测定钙的灵敏度比原子吸收光谱法高,两种方法的RSD均小于2%,加标回收率介于103.7%-107.2%.     

新型卟啉吡啶季铵盐对铜(Ⅱ)显色反应的研究

研究了在不使用表面活性剂的情况下,新型卟啉吡啶季铵盐溴化5-[4-N-(甲氧基)苄铵基吡啶基]-10,15,20-三(4-N-吡啶基)卟啉对铜(I)的显色反应.结果表明,在pH=1.2时卟啉与Cu2 形成了稳定的配合物,其最大吸收波长为423nm,试剂与Cu2 络合比为1:1,表观摩尔吸光系数为3.24×105L·mol-1·cm-1,铜含量在0-0.8μg/10mL范围内符合比耳定律,该方法应用于环境水样中铜的测定,结果令人满意.     

新水溶性卟啉季铵盐的合成及与锌的显色反应研究

合成了-种新型水溶性卟啶卟啉季铵盐即溴化5-[(4-N-芐基)吡啶基]10,15,20-(4-N-吡啶基)卟啉,研究了该试剂与锌的显色反应.在pH2.5的邻苯二甲酸氢钾-盐酸缓冲溶液中,形成了配位比为1:1的配合物,基最大吸收波长λ=424nm,表现摩尔吸光系数ε=2.03×105L·mol-1·cm-1.在0-1.2μg/10mL范围内吸光度与锌质量浓度关系符合比耳定律,该法灵敏度高、选择性好.本法应用于环境水试样中痕量锌离子的分析,结果令人满意.     

Effect of high intensity ultrasound on gelation properties of silver carp surimi with different salt contents

Surimi from silver carp with different salt contents (0–5%) was obtained treated by high intensity ultrasound (HIU, 100 kHz 91 W·cm⁻²). The gelation properties of samples were evaluated by puncture properties, microstructures, water-holding capacity, dynamic rheological properties and intermolecular interactions. As the salt content increased from 0 to 5%, gel properties of surimi without HIU significantly improved. For samples with low-salt (0–2% NaCl) content, HIU induced obvious enhancement in breaking force and deformation. HIU promoted the protein aggregation linked by SS bonds, hydrophobic interactions and non-disulfide covalent bonds in surimi gels with low-salt content. Moreover, microstructures of HIU surimi gels with low-salt content were more compact than those of the corresponding control samples. HIU also improved the gelation properties of surimi with 3% NaCl to an extent. However, for high-salt (4–5% NaCl) samples, HIU decreased the breaking force and deformation of surimi gels due to the degradation of proteins suggested by increased TCA-soluble peptides. In conclusion, HIU effectively improved the gelation properties of surimi with low-salt content (0–2% NaCl), but was harmful for high-salt (4–5% NaCl) surimi. This might provide the theoretical basis for the production of low-salt surimi gels.     

基于光谱学分析的聚氨酯弹性体/聚磷酸铵/氢氧化铝复合材料阻燃机理研究

采用熔融共混技术,将聚磷酸铵(APP)和氢氧化铝(ATH)引入到聚氨酯弹性体(TPU)中,制备了一系列热塑性聚氨酯/聚磷酸铵/氢氧化铝(TPU/APP/ATH)复合材料。采用傅里叶红外光谱(FTIR)、X-射线光电子能谱(XPS)、扫描电镜(SEM)、激光拉曼光谱研究了TPU和阻燃TPU(FR-TPU)复合材料燃烧后炭渣的微观形貌、表面结构、元素组成、键合状态和石墨化程度,结合阻燃性能测试,揭示APP和ATH的协同阻燃机制。SEM分析表明相较于APP与ATH单独使用,TPU/APP/ATH炭层的空洞结构更少,炭渣的致密性更高。XPS分析表明FR-TPU的炭渣中C元素含量相比于纯TPU有所降低,O元素的含量有所上升,其中TPU/APP10/ATH10的C元素含量从88.2%降至69.24%,O元素的含量从8.07%升至17.78%,P和Al元素含量相较于单独添加分别从11.74%和16.36%下降至3.91%和3.31%。在此基础上,通过对C元素的分峰拟合发现TPU炭渣中C—C/C—H,C—O/C—N和CO/CN含量分别为61.05%,35.65%和3.30%;TPU/APP10/ATH10炭渣中三种结构含量分别为45.38%,45.00%和9.63%,说明ATH和APP复配使用有利于C元素形成酯、醚、羰基、羧酸（盐）、酯基等结构。通过对O元素的分峰拟合发现,TPU炭渣中O₂/H₂O,—O—,O三种结构含量分别为28.75%,44.36%和26.89%;TPU/APP10/ATH10炭渣中O₂/H₂O,—O—,O三种结构含量分别为44.33%,32.78%和22.89%,说明APP和ATH的加入有利于炭渣中O元素形成O₂/H₂O结构。通过对N元素的分峰拟合发现,TPU炭渣中—NH—,N结构的N元素含量分别为40.93%和59.07%;TPU/APP10/ATH10中—NH—,N结构的N元素含量分别47.17%和52.83%,说明ATH与APP复配使用促进了—NH—结构的形成。拉曼测试表明,相比于单独使用,APP和ATH复配使用,炭层的石墨化程度更好,致密性更高。以上分析结合阻燃测试可以得出TPU/APP/ATH复合材料阻燃机制：ATH受热分解生成氧化铝,吸收热量并释放大量水蒸气,有效促进APP降解,生成不燃性的氨气和聚磷酸,氨气和水蒸气稀释可燃性气体的浓度。随着温度继续升高,氧化铝可继续与聚磷酸反应生成偏磷酸铝[Al(PO₃)₃],同步催化聚氨酯基体成炭,形成高度石墨化炭层,石墨化炭层与偏磷酸铝一起覆盖在基体表面,有效抑制燃烧区域物质以及能量的输运,从而达到阻燃目的。     

15N-Labelled Ammonium and Nitrate Uptake by the Grass Calamagrostis villosa

Abstract

Calamagrostis villosa dominates the understory vegetation in declining spruce forests at higher elevations of the Central European mountain areas which show symptoms of needle yellowing and associated magnesium (Mg) deficiency. It was hypothesized that grasses would preferentially take up nitrate-nitrogen (NO₃-N) over ammonium-nitrogen (NH₄-N) which would support the cation balance in Mg deficient soils. In order to test this hypothesis, growth experiments were carried out in the greenhouse using plants which were cultivated in sand for nine weeks with full nutrient solution containing 0.2 or 2 mmol of N with different NH₄ ⁺ to NO₃ ^? ratios (1:0, 0.5:0.5, 0:1). In a short term experiment with labelled ¹⁵NH₄ ⁺ and ¹⁵NO₃ ^?, uptake of NH₄ ⁺ and NO₃ ^? was measured. When NO₃ ^? was the only N source it was taken up at similar rate per g dry mass as in the experiment in which NH₄ ⁺ was the only N source. However, at high supply pure NO₃ ^? nutrition resulted in higher biomass. In contrast, supply of only NH₄ ⁺ caused accumulation of N in the roots but growth remained restricted. If NH₄ ⁺ and NO₃ ^? were supplied at equal amounts, NH₄ ⁺ was the preferred form for N uptake. Biomass of the plants with mixed supply did not differ from the plants with pure NO₃ ^? nutrition.

The results point to an interesting interaction of carbon and nitrogen relation, but they do not support the initial hypothesis that grasses may prefer NO₃ ^? over NH₄ ⁺.     

A novel technique for scaffold fabrication: SLUP (salt leaching using powder)

In this study, we proposed a novel salt-leaching method using PCL and NaCl powders, known as the SLUP (salt leaching using powder) technique, which has several advantages: this technique does not require solvent, pressure, or unnecessary expensive devices. First, PCL powder (100–180 μm size) and NaCl powder (350–400 μm size) were prepared. Second, the PCL and NaCl powders were mixed at a certain ratio, and then the mixed powder was poured into a mold. Afterward, the mold was heated to melt the PCL powder in an oven at 80 °C for 15 min. Subsequently, after the PCL/NaCl mixture was separated from the mold, the PCL/NaCl mixture was soaked in D.I. water for 24 h to leach out the NaCl particles. Consequently, the remaining PCL structure was porous and could be used as a scaffold. To analyze the compressive modulus of the fabricated scaffold, a uniaxial compression test was performed using a UTM (universal testing machine), and the surface characteristics of the scaffold were observed using an SEM (scanning electron microscope). Additionally, cell-culture experiments were performed using hMSCs (human mesenchymal stem cells), and the cell-culture characteristics were assessed and compared with the characteristics from a conventional salt-leaching scaffold.     

基于高阶残差量化的光谱二值编码新方法

光谱二值和多值编码技术能够实现目标光谱的快速匹配、识别和分类等应用,但这类量化编码方法会损失大量的光谱细节信息,且不能解码出与原始光谱近似的重构光谱,应用有限。为了解决上述问题,提出一种高阶残差量化的光谱编码新方法HOBC(high-order binary coding)。首先,对光谱向量进行去均值的规范化处理,得到值域为(-1, 1)的光谱序列;然后,求解规范化光谱的±1编码、编码系数和残差（即一阶残差）;基于一阶残差,逐阶解算2至K阶残差的±1编码及其系数;最后得到K个编码序列及其系数,即为HOBC的编码结果。选择典型波谱库数据集,对比光谱0/1二值编码BC01(binary coding with 0 and 1)、光谱分析编码SPAM(spectral analysis manager)、二值/四值混合编码SDFC(spectral derivative feature coding)和DNA四值编码等4种方法,进行了光谱量化编码和解码重构实验,分别统计了光谱形状特征和斜率特征编码的信息熵和存储量、光谱形状特征编码与原始光谱之间的光谱矢量距离SVD (spectral vector distance)、谱间Pearson相关系数SCC (spectral correlation coefficient)和光谱角SAM (spectral angle mapping)。结果表明,在编码存储量上,HOBC的1～4阶编码分别与以上4种编码相等;在编码信息熵上,HOBC的1～2阶编码分别与BC01和SPAM相等,而HOBC的3～4阶编码分别高于SDFC和DNA编码;在SCC上,HOBC1阶编码与BC01相等,而2～4阶编码均分别优于SPAM,SDFC和DNA编码;在SAM方面,HOBC 1～4阶编码均分别明显优于4种对比方法;4种对比方法不能明确解码重构,而HOBC可简便重构出与原始光谱近似的解码序列,且SVD逐阶递减。进一步,基于临泽草地试验站公开光谱数据集,进行了10类地物目标的光谱编码和监督分类实验,实验结果表明,在Kappa系数,总体分类精度和平均分类精度等3种性能评价指标上,HOBC均明显优于4种对比方法,尤其是,HOBC 4阶编码优于原始光谱的分类性能;对样本数量较少且类间相似性较高的难分类地物,HOBC亦具有优于其他算法的鲁棒性。说明HOBC编码在大幅压缩数据量的同时,其编码序列能保留较高的信息量,且具有较高的光谱可分性,可用于光谱高精度快速识别和分类;其解码重构序列与原始光谱序列具有较高的相似性,理论上可适用于目标识别和分类等应用。     

Thermodynamic description of the viscosity of liquid solder alloys with minor Co impurities

Because of the increasing complexity and cost of experiments carried out, the data for the multi-component alloy systems have frequently been obtained by numerical modelling. It is clear that the related calculations require reliable data dealing with the pure components and binary alloy systems. Selecting the reliable data concerning the pure components from the literature, the viscosities for the SAC and (SAC)_1?x Co_x solder alloys have been calculated using different viscosity models (geometric and physical). The viscosity decreases as the amount of tin content increases in the SAC387 alloy while the addition of the cobalt to SAC387 solder results in the increasing of the viscosity. Moreover, by computing the root mean square values between theoretical and experimental viscosities, it can be concluded that the lowest value among all models is that of obtained by Kaptay equation.