A row of dominoes which stand on edge will undergo a cascade when the first domino is tipped. First domino strokes the next and the wave of falling dominoes propagates. The purpose of this work is to investigate wave ...A row of dominoes which stand on edge will undergo a cascade when the first domino is tipped. First domino strokes the next and the wave of falling dominoes propagates. The purpose of this work is to investigate wave speed dependence on various domino parameters as the number of elements and the distance between dominoes and their dimensions. Theoretical examination of falling dominoes process is to create the mathematical model of the process and compare between the calculations and experimental results. An experiment with using of the speed camera was made. The dominoes of three different types of material were used. For theoretical investigation of the problem, the model [1] was used. The program for computer calculations was written. Time of a dominoes row falling was calculated without taking friction between neighbours. The calculation results show that the speed of falling dominoes reaches its constant value. This stable velocity depends on the geometric parameters of dominoes and the surface friction between dominoes but does not depend on the mass of dominoes.展开更多
电子印章在我国电子政务和电子商务领域正发挥着越来越重要的作用,基于数字签名和数字水印的电子印章解决方案还在发展完善中。该文遵循Domino—PDF—DSA这一技术路线,综合运用Lotus平台的PKI技术和PDF的数字签名技术,借助Notes C API和...电子印章在我国电子政务和电子商务领域正发挥着越来越重要的作用,基于数字签名和数字水印的电子印章解决方案还在发展完善中。该文遵循Domino—PDF—DSA这一技术路线,综合运用Lotus平台的PKI技术和PDF的数字签名技术,借助Notes C API和PDF API作二次开发,将电子印章图像作为Notes ID文件的扩展部分,在Lotus平台上实现了对PDF文档加盖电子印章的应用系统。展开更多
文摘A row of dominoes which stand on edge will undergo a cascade when the first domino is tipped. First domino strokes the next and the wave of falling dominoes propagates. The purpose of this work is to investigate wave speed dependence on various domino parameters as the number of elements and the distance between dominoes and their dimensions. Theoretical examination of falling dominoes process is to create the mathematical model of the process and compare between the calculations and experimental results. An experiment with using of the speed camera was made. The dominoes of three different types of material were used. For theoretical investigation of the problem, the model [1] was used. The program for computer calculations was written. Time of a dominoes row falling was calculated without taking friction between neighbours. The calculation results show that the speed of falling dominoes reaches its constant value. This stable velocity depends on the geometric parameters of dominoes and the surface friction between dominoes but does not depend on the mass of dominoes.
文摘电子印章在我国电子政务和电子商务领域正发挥着越来越重要的作用,基于数字签名和数字水印的电子印章解决方案还在发展完善中。该文遵循Domino—PDF—DSA这一技术路线,综合运用Lotus平台的PKI技术和PDF的数字签名技术,借助Notes C API和PDF API作二次开发,将电子印章图像作为Notes ID文件的扩展部分,在Lotus平台上实现了对PDF文档加盖电子印章的应用系统。
