Mesopic rod and S-cone interactions revealed by modulation thresholds

We analyzed mesopic rod and S-cone interactions in terms of their contributions to the blue-yellow opponent pathway. Stimuli were generated using a 4-primary colorimeter. Mixed rod and S-cone modulation thresholds (constant L-, M-cone excitation) were measured as a function of their phase difference. Modulation amplitude was equated using threshold units and contrast ratios. This study identified three interaction types: (1) A linear and antagonistic rod:S-cone interaction, (2) probability summation (3) and a previously unidentified mutual nonlinear reinforcement. Linear rod:S-cone interactions occur within the blue-yellow opponent pathway. Probability summation involves signaling by different post-receptoral pathways. The origin of the nonlinear reinforcement is possibly at the photoreceptors.

疲劳裂纹扩展机制和塑性区的研究

本文用三点弯曲试样测定15MnVN钢在淬火和200℃低温回火状态下疲劳裂纹扩展速率。试验在循环载荷比R=0.5的恒幅条件下进行,并利用金属塑性变形在光滑表面上产生浮凸的现象,用相衬显微镜测定裂纹顶端单调塑性区尺寸。在平面应力状态下垂直于裂纹面方向的单调塑性区尺寸与相应的(K_(max)/σ_s)~2成正比,其比例系数为0.21。根据Rice循环塑性区尺寸与单调塑性区尺寸关系,得到垂直裂纹面方向的循环塑性区尺寸与相应裂纹扩展速率之间为一指数关系。在裂纹扩展过程中,相对裂纹尺寸a/W约等于0.687时裂纹顶端从小范围屈服进入大范围屈服;a/W<0.687裂纹顶端的塑性变形约在θ=30—60°方向角内向两翼伸展;当a/W>0.687,不仅两翼向更大的θ角展开,而且在θ=0°附近塑性变形也有相当发展。金相和扫描电镜观察结果,具有板条状马氏体组织的15MnVN钢疲劳裂纹扩展是以穿晶型的解理开裂方式进行的,是一种再生核扩展机制。

Recueil de législation & jurisprudence coloniales / dir. P. Dareste ; dir. G. Appert

1916 (A19,T19,N1)- (A19,T19,N12).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1898 (A19).

Revue apologétique : doctrine et faits religieux

1924/05/01 (A19,T38,N432).

Revue apologétique : doctrine et faits religieux

1924/04/01 (A19,T38,N429).