The Q-branch lines of pure HD were measured at densities ranging from 1 to 7 Amagat at 304.6 K. Each profile was fitted to the well-known Rosenkranz expression to extract the size of the asymmetry due to line mixing as well as to the linewidth. Line mixing and broadening coefficients were obtained by fitting the asymmetries and widths to a straight line as a function of gas density. Apart from a single existing measurement for the Q(0) line, our mixing coefficients are the first direct measurements of the asymmetry due to line mixing in HD. Our broadening coefficients are consistent with the best earlier measurements but are an order of magnitude more precise. Agreement is found with some existing semiclassical calculations of broadening. We have fitted our HD broadening coefficients to a variety of empirical energy gap laws. Our conclusions are that none of the exponential gap law (EGL), the modified exponential gap (MEG) law, and the statistical power gap (SPG) law successfully models our broadening coefficients. We present a modified version of the EGL and the MEG laws, which are successful in reproducing the experimental results. Using the fitted parameters of the new gap law, we have calculated the relaxation matrix of HD at room temperature. With this relaxation matrix, we have simulated the Q-branch spectrum at a number of densities between 49.1 and 490 Amagat and compared the results with previous high-density measurements. At all densities and frequencies, the simulated spectral intensity was found to agree with the measured strength within about 5% of the peak of the spectrum. In addition, the comparison provides evidence of a nonlinear vibrational dephasing shift in HD. Copyright 1998 Academic Press.

中文翻译：

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304.6 K 下 HD 的 RamanQBranch 中的线混合和展宽

纯 HD 的 Q 分支线在 304.6 K 下以 1 到 7 Amagat 的密度范围进行测量。每个轮廓都适合众所周知的 Rosenkranz 表达式，以提取由于线混合以及线宽而导致的不对称大小. 通过将不对称性和宽度拟合为作为气体密度函数的直线，获得线混合和加宽系数。除了 Q(0) 线的单个现有测量外，我们的混合系数是 HD 中由于线混合引起的不对称性的第一次直接测量。我们的展宽系数与早期的最佳测量结果一致，但精度要高一个数量级。与一些现有的半经典加宽计算一致。我们已经将我们的 HD 展宽系数拟合到各种经验能隙定律。我们的结论是，指数间隙定律 (EGL)、修正指数间隙 (MEG) 定律和统计功率间隙 (SPG) 定律均无法成功模拟我们的展宽系数。我们提出了 EGL 和 MEG 定律的修改版本，它们成功地再现了实验结果。使用新间隙定律的拟合参数，我们计算了室温下 HD 的弛豫矩阵。使用这个弛豫矩阵，我们模拟了 49.1 到 490 Amagat 之间的多个密度的 Q 分支谱，并将结果与​​之前的高密度测量结果进行了比较。在所有密度和频率下，发现模拟光谱强度与光谱峰值的约 5% 内的测量强度一致。此外，该比较提供了 HD 中非线性振动移相的证据。版权所有 1998 学术出版社。