When images matter: Internet child pornography, forms of observation and an ethics of the virtual

The arrest of Pete Townshend, lead guitarist for The Who, for downloading and possessing Internet child pornography and the publicity surrounding the case provides an initial point of discussion concerning the emergence of an ethics of the image that is not predicated on the actual evidential status of that image but on more virtual forms of observation. The discussion in this article focuses on three substantive aspects of this event - legislation in the UK and the US, expert psychological discourse, and public discussion in the UK press - in order to present a particular and situated rendering of forms of virtual observation. The context to this discussion concerns the notion that digital imaging technology presages a need for new legislation, law enforcement and social analytical frameworks for understanding and tackling the production, distribution and consumption of images of child sexual abuse.     

基于投影的fMRI时间序列图像配准方法研究

利用投影技术,针对功能磁共振时间序列图像,介绍了一种新的自动图像配准方法。该方法将序列图像二值化后沿着水平方向或垂直方向进行投影,根据投影向量元素的位置和大小,快速地计算出图像的旋转、平移运动的变化参数。仿真实验和实际的功能磁共振应用证实了该方法的有效性。     

耐热日用陶瓷坯体及其低热膨胀性

阐明了高档锂质耐热日用陶瓷研究的目的和意义,通过实验研究获得了具有良好抗热震性能的锂质耐热陶瓷材料,对材料的显微结构和主要物理性能分别进行了分析和测定,并对其低热膨胀性进行了深入研究.     

快速循环热处理对(Co_(0.35)Fe_(0.65))_(99)O_1薄膜磁性能的影响

针对(Co0.35Fe0.65)99O1薄膜,研究了两种不同热处理工艺对其磁性能的影响。结果表明:快速循环热处理可以改善高磁矩(Co0.35Fe0.65)99O1薄膜磁性能,在450°C几个快速循环热处理后,沉积薄膜的矫顽力从105下降到3Oe,电阻率下降到70%,a-Fe(Co)相晶粒尺寸可以减小到15～35nm,该处理方法较以往的热处理更能改善软磁薄膜的性能。     

星载合成孔径雷达多普勒参数的估计

主要分析了星载合成孔径雷达(SAR)多普勒参数的估计误差对成像质量的影响,提出了利用自聚焦同时估计多普勒质心和多普勒调频率的方法;该方法使得两个多普勒参数的估计在准均匀和非均匀场景下能同时具有较高的精度,而且使估计的运算量也大为减少;最后通过星载 SEASAT-A海洋卫星原始数据成像试验,证明了该方法的优越性。     

Why does onlyAthalia Japonica enter summer diapause among three sympatricAthalia sawflies feeding on crucifers?

Summary This report assesses the primary factor for the evolution of summer diapause of the three species of sawfly,Athalia japonica, A. rosae andA. infumata that feed on cruciferous plants and coexist in the same area.A. japonica has two discrete spring and autumn generations, butA. rosae andA. infumata 5–6 generations. OnlyA. japonica enters summer diapause in response to the long daylengths in spring. Although these three sawflies usually feed on the same cultivated crucifers, they differ markedly in the utilization of wild crucifers. They oviposit only on young leaves.A. japonica mainly usesCardamine plants which sprout in spring and autumn.A. rosae andA. infumata primarily use hosts with new leaves all the year round, i.e. cultivated crucifers andRorippa indica, respectively. The thermal threshold for development is lower inA. japonica than in the other two species. The low heat tolerance ofA. japonica is adapted only to cool shady habitats whereCardamine grows. Presumably, summer diapause ofA. japonica is adaptation to the deterioration of the primary host plants rather than unfavorable climatic conditions. This interpretation is supported by the movement patterns of the threeAthalia sawflies, alternative means to escape from deteriorated habitat conditions.     

Efficient Algorithms for Determining 3-D Bi-Plane Imaging Geometry

Biplane projection imaging is one of the primary methods for imaging and visualizing the cardiovascular system in medicine. A key problem in such a technique is to determine the imaging geometry (i.e., the relative rotation and translation) of two projections so that the 3-D structure can be accurately reconstructed. Based on interesting observations and efficient geometric techniques, we present in this paper new algorithmic solutions for this problem. Comparing with existing optimization-based approaches, our techniques yield better accuracy and have bounded execution time, thus is more suitable for on-line applications. Our techniques can easily detect outliers to further improve the accuracy.This research was supported in part by NIH under USPHS grant numbers HL52567.     

液体中热晕的矩阵分析及有关新现象

对液体中热晕现象从新的角度，即矩阵光学的方法进行了处理，以热透镜为模型，建立了热晕效应的等效焦距形成发展过程的数学表达式。同时进行了部分实验以验证理论结果。成功地观察到了热晕形成发展的全部动态过程，得到了与理论计算基本一致的实验数据。在实验中，同时观测到了一些周期性的跳动现象，给出了定性的物理解释。     

保温层的临界热绝缘直径

通过对传热速率随保温层直径增加而变化的讨论,得出结论,保温层直径必须大于保温层的临界热绝缘直径,才能降低热损失。     

预氧化对多孔碳化硅陶瓷抗氧化及抗热震性的影响

考察了多孔碳化硅陶瓷的抗氧化性及抗热震性,探讨了不同制造工艺对多孔碳化硅陶瓷抗氧化性及抗热震性的影响。研究了SiC陶瓷在热处理过程中SiC颗粒表面氧化形成的SiO_2在不同热处理温度的状态变化及其对试样抗热震性的影响。