利用分子连接性指数关联CO2在吸收剂中的溶解度

初步研究了CO2在烃类、醇类、酯类、酮类、醚类等溶剂中的溶解度与分子结构的关系．结果表明：在研究范围内，碳链越长，溶剂吸收CO2的效果越好；在碳链相同或接近的情况下，羟基个数越多，吸收效果越差；羧基和醚（氧）键的个数越多，吸收效果越好．以分子连接性指数、取代基的个数、取代基的类型为参数，建立亨利常数定量模型，计算值和实验值吻合良好，线性相关系数R^2〉0．97．     

Device simulation of quasi-two-dimensional perovskite/silicon tandem solar cells towards 30%-efficiency

Perovskite/silicon (Si) tandem solar cells have been recognized as the next-generation photovoltaic technology with efficiency over 30% and low cost. However, the intrinsic instability of traditional three-dimensional (3D) hybrid perovskite seriously hinders the lifetimes of tandem devices. In this work, the quasi-two-dimensional (2D) (BA)₂(MA)_n-1Pb_nI_3n+1 (n=1, 2, 3, 4, 5) (where MA denotes methylammonium and BA represents butylammonium), with senior stability and wider bandgap, are first used as an absorber of semitransparent top perovskite solar cells (PSCs) to construct a four-terminal (4T) tandem devices with a bottom Si-heterojunction cell. The device model is established by Silvaco Atlas based on experimental parameters. Simulation results show that in the optimized tandem device, the top cell (n=4) obtains a power conversion efficiency (PCE) of 17.39% and the Si bottom cell shows a PCE of 11.44%, thus an overall PCE of 28.83%. Furthermore, by introducing a 90-nm lithium fluoride (LiF) anti-reflection layer to reduce the surface reflection loss, the current density (J_sc) of the top cell is enhanced from 15.56 mA/cm² to 17.09 mA/cm², the corresponding PCE reaches 19.05%, and the tandem PCE increases to 30.58%. Simultaneously, in the cases of n=3, 4, and 5, all the tandem PCEs exceed the limiting theoretical efficiency of Si cells. Therefore, the 4T quasi-2D perovskite/Si devices provide a more cost-effective tandem strategy and long-term stability solutions.     

2-羟肟基正壬酸对一水硬铝石的浮选脱硅性能

依据浮选药剂设计理论设计了一个捕收剂2-羟肟基正壬酸,将其应用于一水硬铝石与铝硅矿物的浮选分离。用量子化学计算方法预测其对一水硬铝石有出色的捕收性能,而后合成该捕收剂后进行单矿物的浮选。以2-羟肟基正壬酸为捕收剂应用于一水硬铝石、高岭石和伊利石的浮选分离,其浮选分离条件为:pH=7时,2-羟肟基正壬酸浓度为4×10~(-4)mol/L,抑制剂六偏磷酸钠的浓度为1.5×10~(-5)mol/L,浮选时间为4 min。     

2-乙酰氨基-4-叔丁基苯酚的合成工艺研究

本文以苯酚为初始原料,按照文献方法合成了4-叔丁基苯酚与2-硝基-4-叔丁基苯酚,用5%Pd/C作催化剂,通过催化氢化合成2-氨基-4-对叔丁基苯酚(OB酚),研究了OB酚N-乙酰化工艺条件,发现合成N-乙酰化OB酚的较佳工艺条件为:反应温度30℃,酰化剂用量为OB酚1.05个当量,反应时间8 h,介质pH 6.5;在此工艺条件下,N-乙酰化OB酚收率高达99.2%,选择性98.7%。     

溶胶凝胶模板法制备SiO2:Sm3+纳米阵列材料

采用溶胶凝胶模板法制备了不同Sm3+掺量的SiO2:Sm3+纳米阵列材料,通过SEM、EDS、FTIR等对材料的形貌和结构进行测试表征.FTIR分析表明Sm3+进入SiO2网络结构形成了Si-O-Sm键.SEM、EDS分析显示Sm3+掺量的增大促使阵列由纳米管向纳米线的转变.此外,腐蚀清洗等后处理工艺对保持纳米阵列的形貌至关重要.最后,讨论了溶胶凝胶模板法制备SiO2;Sm3+纳米阵列的机理.     

溶胶凝胶模板法制备SiO2∶Sm3+纳米阵列材料

采用溶胶凝胶模板法制备了不同Sm³⁺掺量的SiO₂∶Sm³⁺纳米阵列材料,通过SEM、EDS、FTIR等对材料的形貌和结构进行测试表征。FTIR分析表明Sm³⁺进入SiO₂网络结构形成了Si-O-Sm键。SEM、EDS分析显示Sm³⁺掺量的增大促使阵列由纳米管向纳米线的转变。此外,腐蚀清洗等后处理工艺对保持纳米阵列的形貌至关重要。最后,讨论了溶胶凝胶模板法制备SiO₂∶Sm³⁺纳米阵列的机理。     

水平轴风力机叶尖涡流动的PIV测试

在风洞开口实验段,针对不同尖速比应用PIV技术对风轮附近1/3圆周内的瞬时速度场进行测试。随着尖速比的增加,叶尖涡运动的径向位移增大,涡流诱导效应区域半径扩大,使整体尾迹半径增大;同时,尖速比增加使尾迹轴向速度亏损增大,叶尖涡运动的轴向位移减小。叶尖涡诱导效应与风轮旋转的相互作用使风轮附近形成强速度梯度区域,诱导效应延伸到风轮上游,激励叶片产生不同的振动形态,使叶片上脱落的叶尖涡结构在尾迹中出现波动,越向下游运动波动越强烈。通过叶尖涡核位置平均发现,在10°～120°方位角尾迹区域内,涡核运动轨迹与方位面交点的连线近似为直线,且该线的斜率随着尖速比的增加而增大。     

Ionization Detection of Ultracold Ground State Cesium Molecules

Photoassociation of ultracold atoms is an important method for producing stable ultracold molecules with extensive applications. Ion spectroscopy technique, which has higher sensitivity compared with trap loss spectroscopy and fragment spectroscopy, plays an important pole in the research of photoassociation spectroscopy. Based on ion spectroscopy technique, a complete experimental system is employed to produce and detect the ultracold ground state molecules, including the equipment of photoionization and time-of-fight mass spectroscopy. Ultracold ground state cesium molecules are demonstrated by the ionization detection technique. The number of the ground-state molecules produced in our MOT is measured. In addition, the relationship of the time interval of the cesium atom ion and the cesium molecular ion to the meta/grid voltage is studied for the optimization of the experimental parameters.     

用数字示波器观测拍与调幅波

介绍了拍与调幅波的原理,提出了利用数字示波器观测拍与调幅波的方法.通过实验观测,加深了对拍和调幅波原理的理解.     

ZnO原子链的结构稳定性和电子性质的第一性原理研究

本文采用基于密度泛函理论的第一性原理平面波赝势法,研究了ZnO原子链的结构稳定性和电子性质.结果表明：ZnO分子可以形成直线形结构、梯子形结构以及双梯子形结构等一维链式结构,而之字形链状结构是不能稳定存在的.计算结果也表明：这些稳定存在的一维原子链结构均表现出间接带隙的特征,而之字形结构的原子链却表现出了类似金属的能带特征. 关键词： 原子链 结构稳定性 电子结构 第一性原理计算