世界跳高运动发展特点及其趋势

通过对跳高运动技术变革与成绩提高过程的系统分析 ,从运动员的形态及年龄特征 ,项目的技术发展特点和训练特点中 ,揭示跳高运动发展的内在本质规律和发展趋势     

"拼命三郎"范小青

女作家范小青是个写作上的"拼命三郎",传说她十几天能写出一部20万字的长篇,一个月能写十几个中篇!她在写作时简直"不食人间烟火",只认得一个"写"字,-直就这么写、写、写…………     

民间藏书家老杜记趣

老杜75岁,一口地道的老杭州话,脸白净,眉毛很黑很粗,喜欢穿白衣黑裤,花白头发往两边梳着,看上去神清气爽。我认识他10多年了,算是忘年交,发现他有一个特点,叫"书来     

翠竹飞花映春晖

中国的竹编技艺代代相传又代代发展,如今已进入出神入化的境界,大型高精竹编便是其中的艺术结晶.竹编精品目前主要诞生在浙江省嵊州、东阳、新昌等地.从题材和内容上大致可分为大型屏风、建筑艺品、神禽灵兽和传统人物四个大类,其中最为人称道的是建筑艺品和神禽灵兽.……     

Light-inadequacy of the ultraviolet theory of ionization in the E-layer

From the reports of the CRPL, average yearly values of h′_E, h′_F1,f °_E and N_F1, for the months of January, March, June, July, September, and December of the years 1944 to 1949 were computed and plotted against the magnetic latitude. Altogether some 25,000 individual records were averaged. Seven curves were plotted. They showed that: (1) all curves are symmetrical with respect to the magnetic equator; (2) the h′_E, h′_F1, f⁰_E and the N_F, curves all swing up and down as the magnetic latitude, north and south, increases; (3) the h′_E is definitely periodic with constant period and constant amplitude; (4) the h′_E curve rises only slightly (on the average) with latitude. These results appear to be inconsistent with the ultraviolet light theory of ionization.     

Future developments in transportation

Nearly all prognostigators, from the fellow who buys a $2 ticket on Blue Boy to the financial policy-makers of government and business, base their final conclusions upon past experience. Properly tempered (and herein lies the success or failure of the prophet), this is a completely logical procedure, and is especially applicable to engineering trends, for most of our technical progress has been achieved through a process of evolution.Thus, one of the best ways to gain an insight as to the direction in which we're going is to note our present position and to review how we reached it.In the preceding discussion, I have tried to cover a few specific phases of our transportation future in just this fashion, in order to emphasize that we can expect tomorrow further applications and extensions of the things we are working with today.     

Frequency-coordinate vector diagram

From the standpoint of circuit synthesis as well as for a fundamental comprehension of circuit behavior, it is desirable to be able to visualize the response of a circuit over an extended frequency range by means of a geometrical construction. Mathematically, the response of a circuit can be expressed with the La Place transform theory as a function of the complex frequency variable, p = α + jωw, in which a is the decrement and ω is the “real” angular frequency. Physically, the nature of the real-frequency response is usually not discernible by casual inspection of the mathematical function. This paper develops a means of visualizing this frequency response readily through the construction of a vector diagram from the response function.