表面和界面效应对铁电薄膜极化分布的影响

运用铁电的Thomas和Landau理论,研究了外延铁电膜中极化分布受表面和界面的影响.结果表明:由于膜中存在表面和界面效应的竞争,对于超薄膜,表面效应占优,界面处极化强度(极化)变小;反之对于厚膜,界面效应占优,界面处极化变大.外推长度δ大于零、正比于膜中电偶极子间的关联长度η,δ/η与偶极子倔强系数的大小有关、与温度无关.     

碳酸盐热稳定性的定量探讨

探讨了碳酸盐热稳定性与离子极化作用之间的定量关系，并应用中心原子稳定势预测其分解温度。     

极化电荷体密度和极化强度关系的一种简明推导

利用电偶极子的电荷密度的表达式,并借助δ函数导出极化电荷体密度和极化强度关系。     

药物不良反应与药源性疾病

药物在防治疾病的同时也会产生对机体有害的作用和不期望产生的作用，即药物不良反应。药源性疾病是由药物引起的机体功能或结构的损害并有临床过程的疾病，是药物不良反应的结果。常见的药物不良反应有副作用，毒性作用，变态反应，特异质反应等。     

Tunable polarization of high numerical-aperture objective with phase plate

The intensity distribution of depolarized field in the focal region of a high numerical-aperture optical system was investigated and found that the depolarization effect is tunable by the plate. The depolarization effect gains with the increase of the inner convergence angle of the phase plate, goes through a dramatic descent when the angle is larger than 30° and begins to come back when the angle reaches a threshold of respectively 60°and 65° for the orthogonal diffractive field and the longitudinal diffractive fields. This reveals two convergence points where the depolarization effect is the strongest and weakest, respectively, suggesting that the pure phase plate can be a promising method for altering depolarization diffractive fields and constructing optical instruments.     

钙钛矿型铁电体的宏观效应及其应用

简要综述了铁电体的基本物理特性，并重点论述了钙铁矿型氧化物铁电体的介电响应、压电效应和热电效应，以及这些宏观功能效应使其作为相应的材料在电子、国防、医疗、航天等领域的应用。     

Design of S-band circularly polarized double-layer microstrip antenna

This paper proposes a compact polarization microstrip antenna based on double-layer structure.The bandwidth of the whole antenna is widened by expanding the top and bottom layers respectively.After the design of antenna structure and adjustment of size,the proposed antenna can achieve both the left-and right-hand circular polarizations in 2.33 GHz-2.97 GHz.Measurement results indicate that the effective bandwidth is 640 MHz in S-band and the relative bandwidth can achieve 24% with 11 S less than 15 dB.     

“Pick and choose” opinion climate: How browsing of political messages shapes public opinion perceptions and attitudes

ABSTRACT

High-choice media environments allow people to cocoon themselves with like-minded messages (confirmation bias), which could shape both individual attitudes and perceived prevalence of opinions. This study builds on motivated cognition and spiral of silence theory to disentangle how browsing political messages (both selective exposure as viewing full articles and incidental exposure as encountering leads only) shapes perceived public opinion and subsequently attitudes. Participants (N?=?115) browsed online articles on controversial topics; related attitudes and public opinion perceptions were captured before and after. Multi-level modeling demonstrated a confirmation bias. Both selective and incidental exposure affected attitudes per message stance, with stronger impacts for selective exposure. Opinion climate perceptions mediated selective exposure impacts on attitudes.     

贫富悬殊背景下对社会分配原则的思考

改革开放以来,我国施行的是"效率优先,兼顾公平"的社会分配原则。对效率的价值目标追求,使得我国经济实现了持续快速增长,但对公平的价值目标仅为"兼顾"也造成了贫富差距的悬殊。中国特色的社会主义奋斗目标决定了贫富悬殊解决的必需性。面临这样一项复杂而艰苦的系统工程,首先必须从行动的纲领入手,制定和实施"效率与公平并重"的社会分配原则。     

从情感视角分析小说中的人物形象

通过对小说中人物性格的剖析,加深学生对人物的理解,使其更好地把握小说的主旨。