Sodium chloride methanol solution spin-coating process for bulk-heterojunction polymer solar cells

The sodium chloride methanol solution process is conducted on the conventional poly(3-hexylthiophene)(P3HT)/[6,6]-phenyl-C61-butyric acid methyl ester(PC_(61)BM) polymer bulk heterojunction solar cells. The device exhibits a power conversion efficiency of up to 3.36%, 18% higher than that of the device without the solution process. The measurements of the active layer by x-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), and ultraviolet photoelectron spectroscopy(UPS) indicate a slight phase separation in the vertical direction and a sodium chloride distributed island-like interface between the active layer and the cathode. The capacitance–voltage(C–V) and impedance spectroscopy measurements prove that the sodium chloride methanol process can reduce the electron injection barrier and improve the interfacial contact of polymer solar cells. Therefore, this one-step solution process not only optimizes the phase separation in the active layers but also forms a cathode buffer layer, which can enhance the generation, transport, and collection of photogenerated charge carriers in the device simultaneously. This work indicates that the inexpensive and non-toxic sodium chloride methanol solution process is an efficient one-step method for the low cost manufacturing of polymer solar cells.     

Quasiparticle density of states of 2H-NbSe2 single crystals revealed by low-temperature specific heat measurements according to a two-component model

Low-temperature specific heat in a dichalcogenide superconductor 2H-NbSe2 is measured in various magnetic fields. It is found that the specific heat can be described very well by a simple model concerning two components corresponding to vortex normal core and ambient superconducting region, separately. For calculating the specific heat outside the vortex core region, we use the Bardeen-Cooper Schrieffer （BCS） formalism under the assumption of a narrow distribution of the superconducting gaps. The field-dependent vortex core size in the mixed state of 2H-NbSe2, determined by using this model, can explain the nonlinear field dependence of specific heat coefficient γ（H）, which is in good agreement with the previous experimental results and more formal calculations. With the high-temperature specific heat data, we can find that, in the multi-band superconductor 2H-NbSe2, the recovered density of states （or Fermi surface） below Tc under a magnetic field seems not to be gapped again by the charge density wave （CDW） gap, which suggests that the superconducting gap and the CDW gap may open on different Fermi surface sheets.     

气相色谱法测定超临界艾叶油微胶囊的包封率

研究采用气质联用测定了超临界CO2萃取的艾叶挥发油的主要成分。实验以挥发油中含量较高的石竹烯氧化物(12.01%)为标准物,以二甲亚砜为内标,采用气相色谱程序升温的方法对艾叶油微胶囊进行石竹烯氧化物含量测定。二甲亚砜和石竹烯氧化物的出峰时间分别为4.75和14.68min,且与其它组分完全分离,空白微胶囊在两者对应出峰位置处无干扰;线性范围为1.2～19.2mg/L;精密度、重现性和回收率均符合分析的要求。艾叶油微胶囊的平均包封率为97.6%。结果表明:所建方法可靠、准确、稳定,可用于艾叶挥发油微胶囊包封率的测定来控制微胶囊质量。     

覆盖约束层阻尼的柔性机械臂抑振仿真分析

针对柔性空间机械臂容易发生振动的问题,以柔性空心圆壳机械臂为对象,在其上覆盖分段约束层阻尼、全覆盖主动约束层阻尼和全覆盖被动约束层阻尼,运用有限元软件进行动力学仿真计算分析,研究比较了三种模型的抑振效果和阻尼特性。由于分段约束层阻尼结构中切口的存在,黏弹性材料的剪切变形增大,相较于其他两种结构可有效提高结构阻尼特性,并且研究发现分段方法的适用性与阻尼层内剪切应变水平有关。     

超低频振动能量收集器中夹片弹簧结构的建模与验证

针对一类基于夹片弹簧的压电振动能量收集器,利用材料力学莫尔积分理论建立了振荡俘能结构中夹片弹簧的等效刚度模型,通过万能拉伸试验机验证了模型精度。在此基础上,讨论了夹片弹簧刚度线性简化的两种途径：拉伸曲线线性拟合和固有频率修正。研究结果表明,从夹片弹簧拉伸曲线上看,将其等效成线性弹簧具有一定的合理性;而在实际振动能量收集器结构中,若振动加速度相对较小,通过固有频率修正法对夹片弹簧刚度进行线性简化,其幅频响应特性与非线性模型的特性相近。该研究成果为压电振动能量收集器的动力学和机电耦合模型简化提供了理论支撑。     

催化剂对碳酸二甲酯与苯酚酯交换反应的影响

甲基苯基碳酸酯;碳酸二苯酯;催化剂对碳酸二甲酯与苯酚酯交换反应的影响     

一种利用实验测量和数值计算确定3m点群晶体弹性系数的方法

将实验测量与数值计算相结合确定低对称性晶体弹性系数的方法可以弥补常规方法测量时造成的弹性系数非对角元误差大的不足.本文将该方法由正交系晶体推广到了三方系3m点群晶体,在数值计算中选取了目前公认的无约束最优化方法中最稳定的两种算法-单纯形法和BFGS法,并增加了弹性系数的约束条件,提高了方法的适应性和正确性.在此基础上,本文利用3m点群晶体LiNbO3和LiTaO3的弹性劲度系数[cij]和顺服系数[sij]的实验数据对该方法进行了讨论及验证.结果表明这种方法对3m点群晶体弹性系数非对角元的计算是可行的.另外,本文还对数值计算时,初值的选取和检验结果合理性等关键性问题进行了详细的讨论.     

ADP及KDP晶体纵向压电系数d33的计算及其验证

ADP(磷酸二氢铵)和KDP(磷酸二氢钾)晶体都属于42m点群,是20世纪早期的著名压电晶体,具有易于大尺寸生长的优点。但它们在主轴坐标系中只有厚度切变压电系数(d14,d36),没有纵向压电系数(d33,k33),而这种纵向压电效应在实际应用中较多。本文通过利用坐标变换的方法,计算了这两种晶体纵向压电性能在空间的分布。通过计算,首先我们发现这两种晶体在空间存在着纵向伸缩压电效应,其次我们还得到了它们在空间的纵向压电系数的最大值和切型。ADP晶体:d33,m ax=8.66×10-12C/N,切型为(xywl)45°/50°;k33,m ax=0.07,切型为(xywl)45°/50°。KDP晶体:d33,m ax=4.54×10-12C/N,切型为(yzlw)45°/55;°k33,m ax=0.04,切型为(yzlw)45°/48°。ADP晶体的纵向压电性能略好于KDP。另外,本文还分别对上述计算结果进行了实验验证,实验结果与计算结果基本一致。对两种晶体压电器件的进一步开发和利用具有理论指导意义。     

(Ta_2O_5)_(1-x)(TiO_2)_x陶瓷结构相变研究

采用固相反应技术制备了x分别为 0 0 5、0 0 8和 0 1 1的 (Ta2 O5) 1-x(TiO2 ) x 陶瓷 ;在室温至 6 0 0℃范围内 ,测量了这些陶瓷样品的拉曼光谱随温度的变化。随着温度的升高 ,拉曼光谱中位于 35～38cm- 1的最低频移的声子模发生软化 ,并随之发生结构相变。拉曼光谱和实验结果都表明 :组分x分别为0 0 5、0 0 8和 0 1 1的 (Ta2 O5) 1-x(TiO2 ) x 陶瓷分别在 36 0、4 5 0和 5 4 0℃发生了由三斜至单斜相的结构相变。上述结论得到了 (Ta2 O5) 0 92 (TiO2 ) 0 0 8单晶热膨胀系数测量数据的支持。     

非光气法合成碳酸二甲酯

ＣｕＣｌ２，ＣｕＣｌ和ＣｕＣｌ配位催化剂用于甲醇液相氧化羰化合成碳酸二甲酯，发现ＣｕＣｌ－α－ＤＰＹ配合物催化剂具有较好的活性和选择性。