Gravitational waves (GWs) from the compact binary coalescences can be used as standard sirens to explore the cosmic expansion history. In the next decades, it is anticipated that we could obtain the multi-band GW standard siren data (from nanohertz to a few hundred hertz), which are expected to play an important role in cosmological parameter estimation. In this work, we give for the first time the joint constraints on cosmological parameters using the future multi-band GW standard siren observations. We simulate the multi-band GW standard sirens based on the SKA-era pulsar timing array (PTA), the Taiji observatory, and the Cosmic Explorer (CE) to perform cosmological analysis. In the ΛCDM model, we find that the joint PTA+Taiji+CE data could provide a tight constraint on the Hubble constant with a 0.5% precision. Moreover, PTA+Taiji+CE could break the cosmological parameter degeneracies generated by CMB, especially in the dynamical dark energy models. When combining the PTA+Taiji+CE data with the CMB data, the constraint precisions of Ω m and 𝐻 0 are 1.0% and 0.3%, meeting the standard of precision cosmology. The joint CMB+PTA+Taiji+CE data give 𝜎(𝑤) = 0.028 in the 𝑤CDM model and 𝜎(𝑤 0 ) = 0.11 and 𝜎(𝑤 𝑎 ) = 0.32 in the 𝑤 0 𝑤 𝑎 CDM model, which are comparable with or close to the latest constraint results by the CMB+BAO+SN. In conclusion, it is worth expecting to use the future multi-band GW observations to explore the nature of dark energy and measure the Hubble constant.

Objective Venous leg ulceration (VLU) is one of the complications of lower extremity venous reflux and reflux disorder of severe diseases, with many adverse effects on patient’s work and life. Nowadays, more and more patients with VLU accept wound care in community setting. Clinical nurses generally take care of the patients based on their own experiences. Healing in VLU is an incredibly complex process, which puzzles even experts. The majority of general nurses do not have this level of expertise, especially those nurses serving in community. Function is the basis of nursing activities. Patients always show different clinical manifestations and self-care abilities due to various function states, which cannot be reflected completely by the existing nursing practice. How to describe nursing practice standardized in order to demonstrate the effectiveness of interventions and facilitate interdisciplinary communication is another urgent problem. Therefore, the aim of this project is to develop an accurate nursing program based on function in chronic venous leg ulcers, which can both satisfy the needs of patients and promote nursing revolution. Methods This study will use International Classification of Functioning Disability and Health as a framework to choose suitable functions and to filter function classification standards of chronic venous leg ulcers through evidence-based systematic research. Nursing interventions related to VLU are selected based on Nursing Interventions Classification, adding other nursing activities by methods of evidence-based systematic review and clinical observation. Then, nursing interventions and function status are matched through steering committee. Finally, the Delphi survey method is adopted to make nursing program native and scientific. Conclusions This study is expected to be very significant and meaningful in using standardized nursing terminology. The nursing program established could better meet the needs of both patients with chronic venous leg ulcers and clinical nurses, promoting the development of wound specialist and standardized nursing language.