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Extreme ultraviolet spectra of highly-charged rhenium ions were observed in the 1–7 nm region using two Nd:YAG lasers with pulse lengths of 150 ps and 10 ns, respectively, operating at a number of laser power densities. The maximum focused peak power density was 2.6 × 1014 W cm−2 for the former and 5.5 × 1012 W cm−2 for the latter. The Cowan suite of atomic structure codes and unresolved transition array (UTA) approach were used to calculate and interpret the emission properties of the different spectra obtained. The results show that n = 4-n = 4 and n = 4-n = 5 UTAs lead to two intense quasi-continuous emission bands in the 4.3–6.3 nm and 1.5–4.3 nm spectral regions. As a result of the different ion stage distributions in the plasmas induced by ps and ns laser irradiation the 1.5–4.3 nm UTA peak moves to shorter wavelength in the ps laser produced plasma spectra. For the ns spectrum, the most populated ion stage during the lifetime of this plasma that could be identified from the n = 4-n = 5 transitions was Re23+ while for the ps plasma the presence of significantly higher stages was demonstrated. For the n = 4-n = 4 4p64dN-4p54dN+1 + 4p64dN−14f transitions, the 4d-4f transitions contribute mainly in the most intense 4.7–5.5 nm region while the 4p-4d subgroup gives rise to a weaker feature in the 4.3–4.7 nm region. A number of previously unidentified spectral features produced by n = 4-n = 5 transitions in the spectra of Re XVI to Re XXXIX are identified.

An elliptically polarized pump-probe spectroscopy is developed. A theoretical model is derived from the rate equations of two-level system with small signal approximation to describe the experimental signal of the spectroscopy. The spectroscopy eliminates the systematic errors between theories and experimental results in present circularly polarized pump-probe spectroscopy, and is implemented easily in experiments. The initial degree of spin polarization of carriers in an excited state can be extracted by means of the spectroscopy, which is an important parameter in the investigation of spatial transport of spin polarization. The electron-spin relaxation in GaAs quantum wells is studied by using this spectroscopy.

Prior research on ERP assimilation has primarily focused on influential factors at the organizational level. In this study, the authors attempt to extend their understanding of individual level ERP assimilation from the perspective of social network theory. They designed a multi-case study to explore the relations between ERP users' social networks and their levels of ERP assimilation based on the three dimensions of the social networks. The authors gathered data through interviews with 26 ERP users at different levels in five companies. Qualitative analysis was used to understand the effects of social networks and interactive learning. They found that users' social networks play a significant role in individual level ERP assimilation through interactive learning among users. They also found five key factors that facilitate users' assimilation of ERP knowledge: homophily (age, position and rank), tie content (instrumental and expressive ties), tie strength, external ties, and centrality.