Excess-noise dependence on intracavity aperture shape

In lasers with nonorthogonal eigenmodes the excess-noise factor K can be large, especially in unstable-cavity lasers with hard-edged intracavity apertures. To the best of our knowledge, we report the first detailed study of the dependence of K on aperture shape. Calculations and measurements of K for unstable-cavity lasers with variable-size apertures of triangular, square, pentagonal, hexagonal, octagonal, and rhomboid symmetries are summarized. It is shown that both the magnitude of K and its resonant behavior strongly depend on aperture shape and that many aspects of this dependence can be explained in terms of one-dimensional resonance lengths.     

Listening to caregiving sons: misunderstood realities

In-depth interviews with 30 sons actively involved in caring for a parent with dementia expand the understanding of sons' caregiving experiences. The within-group analysis revealed common themes that emerged from the narratives--duty, acceptance, taking charge, common emotions, and work flexibility--as well as common issues--loss, sibling relationships, role reversal, coping strategies, and positive outcomes. The interviews also generated a typology of son caregivers that included such types as the dutiful son, the son who goes the extra mile, the strategic planner, and the son who shares the care.     

Hematocrit values in weight-selected and relaxed lines of White Rock chickens

Hematocrits (PCV) were measured at 29 and 106 d of age (PCV1 and PCV2, respectively) in male and female White Plymouth Rocks. Four lines were used, two of which had undergone 40 generations of divergent selection for 8-wk BW (HWS, LWS), and two respective sublines (HWR, LWR), in which selection had been relaxed for five generations. At both ages, males and females did not differ for PCV in lines HWR, LWR, and LWS. For line HWS there was an age by sex interaction that resulted from an age effect for males but not for females, and from a sex effect at each age. At both ages, PCV was higher for the HW than the LW lines. Initially, there was no difference between the selected and their respective relaxed lines, but by 106 d, HWR chickens had a higher PCV than HWS chickens. In lines HWR and LWR, PCV increased with age. There was a negative correlation in HWS males for PCV1 with 28 and 56 d BW. The HWR males also had a negative correlation for PCV1 with BW at 28 d, but not between PCV2 and BW. The correlation for PCV1 with PCV2 was high and positive for HWR males and females.     

循环冷却水的处理与利用

为实现工业企业的节约用水，采用反渗透技术处理循环冷却水系统的排污水，使之用作脱盐水的补充。     

高效结晶器长寿命技术

介绍应用结晶器铜管新技术，能显提高结晶器铜管的使用寿命，提高生产效率，降低生产成本。     

UHMWPE混炼接枝马来酸酐研究

讨论了超高相对分子质量聚乙烯(UHMWPE)混炼接枝马来酸酐(MAH)过程中，单体MAH用量、引发剂DCP用量、交联抑制剂己内酰胺(CAILA)用量、流动改性剂硬脂酸钙(CaSt2)用量及混炼温度、时间等工艺条件对UHMWPE接枝率和凝胶含量的影响。用红外光谱表征了接枝物的存在。并用滴定分析法和重量分析法测定了接枝物UHMWPE～g～MAH的接枝率和凝胶含量。实验表明，MAH用量为5份、DCP为0．15份、CALA为0．1份、CaSt2为1份时。混炼温度175∽180℃。混炼时间14min时，可得到接枝率0．75％、凝胶含量1．48%的UHMWPE接枝物。     

强化单螺杆挤出机内层流混合的方法

综述了单螺杆挤出机内聚合物熔体层流混合机理的研究进展，对提高混合的措施进行了分析总结，指出了进一步强化混合效果的方法。     

The DNA extruded by rat spleen cells in culture

1. Part of the DNA extruded by cultured rat spleen cells occurs in the form of a low density lipid complex. 2. The present work indicates that this complex is also associated with protein but not with RNA and its elementary properties have been studied. 3. For example, it is destroyed by freezing and thawing or by deoxycholate treatment and small quantities of copper salts added to the medium may either inhibit or stimulate its release depending on the conditions.