Characterizing the dynamics of auditory perception

After listening to a sound that is presented repeatedly, subjects report hearing different transforms of the original sound. The frequency of reported transforms is a sensitive index of some speech disorders as well as cognitive flexibility in aging. In this paper, we propose and investigate quantitative measures that characterize the dynamics of this phenomenon, known as the verbal transformation effect. In particular, we show that the distribution of the dwell time, the time spent perceiving a string of a given phonemic form before switching to another form, obeys a power law for normal subjects with an exponent valued between 1 and 2. This result suggests that within this paradigm there is no characteristic time scale for the perceptual process. Additionally, we analyze the correlation properties of the transforms. We suggest that the complexity measures and techniques introduced here might be useful diagnostic tools for a number of speech and cognitive disorders. (c) 1995 American Institute of Physics.     

The projection method for computing multidimensional absolutely continuous invariant measures

We present an algorithm for numerically computing an absolutely continuous invariant measure associated with a piecewiseC ² expanding mappingS: on a bounded region R ^N. The method is based on the Galerkin projection principle for solving an operator equation in a Banach space. With the help of the modern notion of functions of bounded variation in multidimension, we prove the convergence of the algorithm.     

稀土肥料在日光温室栽培草莓上的应用研究

探讨了不同浓度的稀土肥料,分别用于日光温室栽培草莓（Ｆｒａｇａｒｉａａｎａｎａｓｓａ）的浸根及根外追肥,结果表明：定植时用２００－３００ｍｇ／ｋｇ浓度浸根;生长旺盛期、初花期、盛花期用３００－４００ｍｇ／ｋｇ浓度喷施,对草莓具有显著的增产效果。     

Chronology of environmental events over East Asia during the past 130 ka

In the transitional region between the Loess Plateau and deserts, 4 sections located respectively at Yuling, Hengshan, Dingbian and Huining of China are studied. The high-resolution paleoclimatic records obtained show that environmental events on varying time scales have happened over East Asia. These events are dated with the time scales established using the recently-developed approach of Automatic Orbital Tuning. This leads to the establishment of the chronology of the environmental events.     

Shear-wave splitting and anisotropy in crust of Dabieshan orogenic belt

The shear-wave splitting was analyzed on the deep seismic sounding profile crossing the Dabieshan area. The direction difference between Sg and SmS fast wave polarization indicates that the modem regional tectonic stress field in the Dabieshan area exists only in uppcr crust, while the crack alignment caused by the Triassic collision between the North China and the Yangtze blocks had been preserved in mid-lower curst.     

1,3—二氯—2—丙醇氧化反应的研究

对１,３－二氯－２－丙醇的氧化反应进行了系统的研究,将８４％的硫酸溶液慢慢滴加到包含有１,３－二氯－２丙醇和重铬酸钠水溶液的反应容器中去,将体系保持在２４℃～２６℃拦反应６ｈ,反应完成后,过滤回收１,３－二氯丙酮粗品,粗品用冰水洗涤,然后通过蒸馏经可获得８０．４％的收率的１,３－二氯丙酮,这是一种合成１,３－二氯丙酮较好的工艺,这种工艺与同类文献介绍的方法比较目标产物收率提高１０％,而反应时间缩短     

老年牙周炎患者外周血NK细胞活性的研究

测定老年牙周炎患者外周血ＮＫ细胞活性。采用ＭＴＴ法测定,并与成年和青少年牙周炎患者进行比较。发现老年牙周炎患者外周血ＮＫ细胞活性低于成年牙周炎患者（Ｐ＜０．０１）,也低于青少年牙周炎患者（Ｐ＜０．０５）。老年牙周炎患者ＮＫ细胞活性低下可能是老年人牙周病发病率高,组织破坏重的原因之一。