辐射场与二能级原子相互作用的量子逻辑功能

利用半经典理论和量子理论研究辐射场与二能级原子(量子位)的相互作用。将量子力学体系视为量子逻辑门,得到量子体系演化的幺正变换的矩阵表示,论述把量子力学体系波函数与量子逻辑门的输入输出态统一起来的方法,得出辐射场与原子相互作用能实现量子逻辑功能。结果有利于指导在实际中选取合适的遵守量子力学定律的两态系统完成量子逻辑操作。     

The influence of childhood polyvictimization on disordered eating symptoms in emerging adulthood

Children who endure multiple victimization experiences, or “polyvictims," are vulnerable to maladaptive outcomes. Yet, little research exists evaluating the relationship between childhood polyvictimization and disordered eating symptoms (DES) in emerging adulthood. The current study examines the relationship between childhood polyvictimization and DES in emerging adults. Data were collected from 288 participants across two universities using online self-report measures. Hierarchical regression analyses revealed a significant positive relationship between number of childhood victimization experiences and DES in young adulthood (ß = 0.14; p = 0.016). Female participants were more likely to demonstrate DES (ß = 0.14; p = 0.008). Further, high levels of emotion dysregulation during young adulthood were associated with more DES (ß = 0.33; p < 0.001). Findings suggest that exposure to victimization experiences in childhood increases individuals’ risk for exhibiting DES in young adulthood. Results also highlight the strong relationship between individuals’ emotion regulation abilities and the presence of DES. Findings align with the theory that children who have endured high levels of victimization often feel overwhelmed by their emotions and circumstances, demonstrate emotion regulation difficulties, and may rely on maladaptive coping strategies, including disordered eating, to manage adversities. Study results emphasize the importance of considering victimization history when working with emerging adults displaying disordered eating symptomatology.     

Nineteenth century chrome yellow and chrome deep from Winsor & NewtonTM

The Winsor & Newton^TM (W&N) nineteenth century archive database includes digitised images of hand-written instructions and workshop notes for the manufacture of their artists’ materials. For the first time, all 183 production records for yellow lead chromate pigments were studied and evaluated. They revealed that W&N produced essentially three pigment types: lemon/pale based on mixed crystals of lead chromate and lead sulphate [Pb(Cr,S)O₄]; middle on pure monoclinic lead chromate [PbCrO₄]; and deep that contains the latter admixed with basic lead chromate [Pb₂CrO₅]; accounting for 53, 22, and 21% of the production, respectively. Production records for primrose (4%) were also included since the formulation results in mixed crystals with a high percentage of lead sulphate, which, according to the literature, leaves it more prone to degradation. Each pigment type is characterised by only one or two main synthetic pathways; process variations reveal a systematic and thorough search for a high-quality durable product. A comparison of the chemical composition of pigment reconstructions with early W&N oil paint tubes showed that their records entitled ‘pale’ and ‘lemon’ correlated with the pigment in their tube labelled chrome yellow and, ‘middle’ and ‘deep’ with the label chrome deep. Lemon and middle pigment formulations were made into oil paints to assess their relative photo-stability. The degradation process was followed by colorimetry and was studied by synchrotron radiation-based techniques. Based on the X-ray absorption spectroscopy data, the possibility for creating a stability index for chrome yellows is discussed.     

De Sitter时空背景中具有整体单极的蒸发黑洞的热效应

把对动态黑洞量子热效应的研究推广到用(t,r)坐标描述的时空,采用了既不同于稳态又不同于以超前Eddington坐标描述的动态时空的乌龟坐标变换.在考虑Hawking蒸发影响的情况下,得到了De Sit-ter时空背景中具有整体单极蒸发黑洞的温度、视界位置.进一步分析表明Hawking辐射温度是坐标尺度变换下的补偿效应.     

基于现金流量法的企业外汇风险暴露度量研究

随着中国企业国际化程度的提高,由汇率波动所带来的企业价值变化的外汇风险将越来越大。因此,如何准确而简约地衡量企业外汇风险是一个亟待解决的问题。从这个角度出发,通过实证研究发现现金流量法能较好地度量中国企业的外汇风险暴露。     

基于布迪科指标的中国植被-气候关系研究

根据中国418个气象站资料，计算了布迪科（Budyko）分类系统的净辐射和辐射干燥度指数，绘制了各气候指标在中国的分布图。结合中国植被区划图，绘制了中国8个植被地带的净辐射和辐射干燥度指数的散点图，较好地表现了中国各植被类型与气候指标的关系和格局，包括寒温带针叶林，温带针阔叶混交林，暖温带落叶阔叶林，亚热带常绿阔叶林，热带季雨林、雨林区域，温带草原，温带荒漠，青藏高原高寒植被，并得到了中国各植被地带的气候指标范围及界限。通过分析可以看出，净辐射的等值线较好地反映了中国大陆的热量梯度，而辐射干燥指数则较好地反映了中国大陆的干湿梯度。综合水热指数与中国植被主要类型的对应也较好，通过KAPPA检验，结果表明净辐射和辐射干燥度指数与中国植被主要类型及其分布格局密切相关，两者结合可以进行宏观尺度上植被类型的划分。     

中国紫外辐射的空间分布特征

利用中国科学院生态系统研究网络29个生态站的2002年紫外辐射、总辐射、日照时数、相对湿度、温度等气象因子资料,采用多种方法分析紫外辐射与其他气象因子以及地理因子之间的关系,选择出最优的因子和最佳方法建立紫外辐射的计算模型.结合本课题组开发的中国陆地生态系统气象/气候要素空间化数据库的1km×1km气候要素栅格图,利用ArcMap/ArcInfo软件实现了紫外辐射的空间化.通过比较,选择出合适的紫外线指数分类方法完成了紫外线指数和紫外线辐射等级的栅格化.在空间化图像的基础上分析了年及各月中国紫外辐射的空间分布特征,并对形成这种分布的原因进行了初步探讨.     

等离子体天线轴向密度数值模拟和辐射图计算

由于电子密度分布、激励功率、气压等因素的影响，等离子体天线参数（增益、方向图等）通常难以求解。本文利用时域差分建立电磁波沿等离子体天线激励和传播的模型，得到不同参数（如激励功率、碰撞频率、等离子体迟豫时间、每个电子对所需能量）对等离子体轴向电子密度分布的影响，解释了不同激励情况下电子密度的线性和非线性分布，并解决了信号沿等离子体天线传播的波矢分布、辐射方向图的求解问题。     

论经济辐射与近代江苏经济发展

近代上海的经济辐射对江苏经济的发展产生了重要影响,而近代江苏南北在接受经济辐射方面存在的差异也直接导致了苏南与苏北经济发展的巨大差异。苏南拥有主导产业和经济功能较强的较大城市构成的接收极,因此接受辐射能力较强,从而促进了经济发展;苏北则既无主导产业,也无较大城市,难以有效地接受辐射,从而导致了经济的滞后。     

Understanding Greek Primary School Children's Comprehension of Sun Exposure

The purpose of this study was to assess Greek primary (1st to 6th grade) school children's understanding of sun exposure during summer vacation. Our results show that children know the damaging effects of long time exposure and the precautions that should be taken during sun bathing (sun glasses, hat, umbrella, sunscreen, etc). Nevertheless, they do not seem to avoid being exposed between 12.00 A.M. and 15.00 P.M., which is the most dangerous time. The socioeconomic status of father has no effect on the attitude of children towards taking protection measures when exposed to the sun, however, the educational status of the mother appears to influence children's reported knowledge and behaviour. Place of residence (urban or rural areas) and gender does not influence their knowledge on the sun's damaging effects and the precautions they should take. Finally, as children grow older they seem to gradually reduce the protective measures they take.