非圆齿轮-连杆型函数发生器的机构综合

给出了非圆齿轮－连杆型函数发生器综合时必须遵循的机构学制约条件，并提出了确定连杆机构处于极限位置时的非圆齿轮角速比的基本公式。以具有等速急回特性的曲柄滑块机构型函数发生器的机构综合为例，研制了有实用价值的非圆齿轮－连杆型函数发生器机构综合CAD软件。     

Modification of visual signals by nigral stimulation

Summary Responses of the lateral geniculate neurons to light were modified by stimulation of the substantia nigra. Nigral stimulation often caused enhancement of firing in neurons responding primarily to flash, but it usually had the contrary effect on units inhibited by light.     

Potentiative effects of sulfhydryl compounds on carrageenin-induced oedema in rats and relationship to their potencies as inhibitors of angiostin-converting enzyme in vivo

Summary Carrageenin-induced oedema in rats was potentiated by oral administration of (4R)-3-[(2S)-3-mercapto-2-methylpropanoyl]-4-thiazolidinecarboxylic acid (SA291) and related sulfhydryl compounds, and the effect was closely correlated with their potencies as inhibitors of angiotensin-converting enzyme in vivo.Acknowledgment. The authors wish to thank Prof. H. Fujimura, Department of Pharmacology, Gifu University School of Medicine, for his helpful advice.     

Inhibition and enhancement of photically evoked responses by different doses ofl-DOPA

Summary Administration of small doses ofl-DOPA (10 and 20 mg/kg) resulted in reduction in amplitude of photically evoked responses in the primary visual, association, and cerebellar vermal cortices, while large doses (40 and 80 mg/kg) produced enhancement.Acknowledgment. We thank Prof.K. Kuriyama and Sr.M. McCormick for their help.     

Enhancing semiconductor device performance using ordered dopant arrays

As the size of semiconductor devices continues to shrink, the normally random distribution of the individual dopant atoms within the semiconductor becomes a critical factor in determining device performance--homogeneity can no longer be assumed. Here we report the fabrication of semiconductor devices in which both the number and position of the dopant atoms are precisely controlled. To achieve this, we make use of a recently developed single-ion implantation technique, which enables us to implant dopant ions one-by-one into a fine semiconductor region until the desired number is reached. Electrical measurements of the resulting transistors reveal that device-to-device fluctuations in the threshold voltage (Vth; the turn-on voltage of the device) are less for those structures with ordered dopant arrays than for those with conventional random doping. We also find that the devices with ordered dopant arrays exhibit a shift in Vth, relative to the undoped semiconductor, that is twice that for a random dopant distribution (- 0.4 V versus -0.2 V); we attribute this to the uniformity of electrostatic potential in the conducting channel region due to the ordered distribution of dopant atoms. Our results therefore serve to highlight the improvements in device performance that can be achieved through atomic-scale control of the doping process. Furthermore, ordered dopant arrays of this type may enhance the prospects for realizing silicon-based solid-state quantum computers.     

Grinding Characteristics Of Directionally Aligned SiC Whisker Wheel - Comparison With A12O3 Fiber Wheel

A unique SiC whisker wheel was invented, in which the whiskers were aligned normally to the grinding wheel surface. In this paper, grindabilities of the SiC whisker wheel are investigated and compared with those of other wheels of SiC grains, Al2O3 grains, as well as Al2O3 long and short fibres which were also aligned normally to the grinding wheel surface, respectively. The main research contents concern grinding characteristics of a directionally aligned SiC whisker wheel such as material-removal volume, wheel-wear rates, integrity of the ground surfaces, grinding ratios and grinding efficiency. Furthermore, grinding wheels of whiskers and fibres have a common disadvantage: they tend to load easily. The authors have proposed a simple method of loading-free grinding to overcome this propensity and investigate some related grinding characteristics under loading-free grinding conditions.     

Modification of visual signals by nigral stimulation.

Responses of the lateral geniculate neurons to light were modified by stimulation of the substantia nigra. Nigral stimulation often caused enhancement of firing in neurons responding primarily to flash, but it usually had the contrary effect on units inhibited by light.