PMMA掺杂对P3HT/P(VDF-TrFE)复合薄膜阻变性能影响研究

Organic semiconducting/ferroelectric blend films attracted much attention due to their elec-trical bistability and rectification properties and thereof the potential in resistive memory devices. Blend films were usually deposited from solution, during which phase separation oc-curred, resulting in discrete semiconducting phase whose electrical property was modulated by surrounding ferroelectric phase. However, phase separation resulted in rough surface and thus large leakage current. To further improve electrical properties of such blend films, poly(methyl metacrylate) (PMMA) was introduced as additive into P3HT/P(VDF-TrFE) semiconducting/ferroelectric blend films in this work. It indicated that small amount of PMMA addition could effectively enhance the electrical stability to both large electrical stress and electrical fatigue and further improve retention performance. Overmuch PMMA addition tended to result in the loss of resistive switching property. A model on the con-figuration of three components was also put forward to well understand our experimental observations.     

六角相硼碳氮化合物的合成研究

 以三聚氰胺和氧化硼为原料,利用真空热处理和高温高压技术,对BCN化合物的形成及结构进行了研究。在真空条件下,原料经1 100 K热处理得到非晶BCN的前驱物,将前驱物在5.0 GPa、1 500 K条件下高温高压热处理30 min,合成出了单相的六角BCN晶体。采用Materials Studio软件的Reflex模块对样品的X射线衍射图谱进行分析,结果表明,得到的样品为纯的六角相,晶格常数为a=0.250 5 nm,c=0.665 9 nm。对样品进行了透射电镜（TEM）分析,得到了样品的形貌和电子衍射,同样证实了样品为六角BCN晶体,晶粒尺寸约200 nm。对样品进行了XPS表征,确定了样品中存在C—C、C—N、C—B、N—B键,表明B、C、N三元素之间达到了原子级化合,样品的组分含量通过EDX进行标定。     

冬虫夏草中8种矿物元素含量分析

利用火焰原子吸收光谱法(FAAS),测定了冬虫夏草中Cu,Zn,Fe,Mn,Mg,Ca,Co以及Cd等8种矿物元素的含量,测定了各元素的加标回收率在98.9%~109.3%之间,相对标准偏差(RSD)小于1.2%,具有良好的准确度和精确度。结果表明,冬虫夏草中含有丰富的Cu,Zn,Fe,Mn,Mg,Ca,Co等多种矿物元素,不含有毒金属元素Cd。     

纤维素酶降解纤维素机理的研究

纤维素是自然界中含量最多的一类碳水化合物,同时它也是地球上数量最大的可再生资源。纤维素酶是一种高活性生物催化剂,在纤维素类资源的利用方面发挥重要的作用。本文综述了纤维素、纤维素酶的分子结构和纤维素酶对纤维素的降解机理,影响酶解的主要因素以及提高酶解效率的主要措施,并对纤维素酶研究存在的问题以及今后的发展作了进一步展望。     

pH对十二烷基二甲基氧化胺与DNA相互作用的影响

pH对十二烷基二甲基氧化胺与DNA相互作用的影响;DNA;十二烷基二甲基氧化胺;相互作用     

Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.     

一类人体内寄生虫传染的数学模型

研究了一类人体内寄生虫传染的数学模型,分析了人体内健康细胞、受传染细胞和寄生虫的变化规律,对模型进行了定性和稳定性分析,讨论了模型无病平衡点和地方病平衡点的存在条件,得到了各个平衡点渐近稳定的充分条件.结合实际钩虫病感染数据,对模型进行数值模拟,并绘制出模型的变化趋势图.     

二级6—8型大腔体装置的高压发生效率机理研究

利用自行设计与集成的二级6—8型大腔体静高压装置,研究了影响八面体压腔高压发生效率的主要因素及机理,并提出了一种八面体压腔密封的简化力学模型.针对于10/4（八面体传压介质边长为10 mm,二级WC立方体增压块截角边长为4 mm）组装的实验结果发现：预密封边尺寸会显著影响八面体压腔的压力产生效率;在腔体压力为12 GPa左右时,高压发生效率随八面体MgO传压介质初始密度的增加而提高;在15 GPa以上时,影响压力产生效率的主要因素是WC增压立方块本身的强度以及加压过程中所形成密封边的尺寸及材料. 关键词： 6—8型大腔体静高压装置 压力产生效率     

磁偶极相互作用下玻色-爱因斯坦凝聚体中出现的奇特涡旋晶格结构

文章简要地介绍了玻色-爱因斯坦凝聚体中出现的涡旋和铬原子玻色-爱因斯坦凝聚体的实验研究进展，还介绍了文章作者的一项最新的理论工作。研究指出，由于铬原子磁偶极相互作用的影响，凝聚体中将出现奇特的各向异性的涡旋晶格结构。