We propose a new distributed algorithm for sparse variants of the network alignment problem, which occurs in a variety of data mining areas including systems biology, database matching, and computer vision. Our algorithm uses a belief propagation heuristic and provides near optimal solutions for this NP-hard combinatorial optimization problem. We show that our algorithm is faster and outperforms or ties existing algorithms on synthetic problems, a problem in bioinformatics, and a problem in ontology matching. We also provide a unified framework for studying and comparing all network alignment solvers.

Accurate harmonic state estimation (HSE) is necessary to mitigate harmonic issues in power distribution networks. However, existing HSE methods face difficulties in solution of state equation that the measured data is insufficient with limited monitors. Therefore, this study proposes a HSE algorithm for distribution networks based on multi-measurement data. Firstly, a harmonic source location method based on mutual information and distribution network partition is proposed to reduce the number of state variables and to solve the state equation. Thus, HSE with low resolution (15 min) is realized. Secondly, a HSE method with enhanced resolution is developed. This method establishes maximum entropy principle models for harmonic currents injected into buses, calculates the probability density function (PDF) of the harmonic current, and realizes optimal interpolation of the harmonic data to enhance the resolution of the HSE (3 min) according to the PDF. Finally, the applicability and effectiveness of the proposed method are verified using an IEEE-33 test system simulation and a real power system in South China.

Ubiquitous synthetic resin adhesives based on petrochemical brings environmental burdens and health concerns. Many researchers have been focused on developing biomass-derived alternatives, and reported many strong-adhesion products with high cohesive density. However, the stabilized structure-dependent adhesion contributes to greater difficulty in recycling, especially hetero-layered composites. Here, a supramolecularly connected nanoconfined network strategy is proposed for ultra-strong yet switchable biobased adhesives, where cellulose nanoconfinement phases takes up 36.5–46.3 wt%. Dependent on thermally responsive disulfide bond, resulting adhesives achieve both excellent adhesion strength (6.02 MPa) that can support a 65 kg weight with 4 cm², and instant thermo-responsive detachment with a high switching ratio over 600 (debonding adhesion ≈0 MPa, response time ≤ 10 s). Under the alternating temperature, adhesive-based composites can be disassembled into different categories and fully recycled through the destruction of dynamic crosslinked network. The full life cycle impact assessment shows this strategy is able to avoid the inherent environmental (about 7.52 * 10² PAF m³ d/kg_emitted) and health (about 2.04 * 10⁻⁴ cases/kg_emitted) burden. This work establishes a paradigm for closed-loop engineered composites by the substantive breakthrough of green intelligent adhesives, providing ways to alleviate environmental stress.

Climate-sensitive northern cryosphere inland waters emit greenhouse gases (GHGs) into the atmosphere, yet their total emissions remain poorly constrained. We present a data-driven synthesis of GHG emissions from northern cryosphere inland waters considering water body types, cryosphere zones, and seasonality. We find that annual GHG emissions are dominated by carbon dioxide ( 1149.2 1004.8 1307.5 teragrams of CO ₂ ; median Q 1 Q 3 ) and methane ( 14.2 10.1 18.5 teragrams of CH ₄ ), while the nitrous oxide emission ( 5.4 − 1.4 12.2 gigagrams of N ₂ O) is minor. The annual CO ₂ –equivalent (CO ₂ e) GHG emissions from northern cryosphere inland waters total 1.5 1.3 1.8 or 2.3 1.8 2.8 petagrams of CO ₂ e using the 100- or 20-year global warming potentials, respectively. Rivers emit 64% more CO ₂ e GHGs than lakes, despite having only one-fifth of their surface area. The continuous permafrost zone contributed half of the inland water GHG emissions. Annual CO ₂ e emissions from northern cryosphere inland waters exceed the region’s terrestrial net ecosystem exchange, highlighting the important role of inland waters in the cryospheric land-aquatic continuum under a warming climate.

Knowledge of the disturbance of the concerned bus is essential to make decisions to mitigate voltage sags. The most commonly used method is to estimate the state of voltage sag in the absence of a monitor. However, the traditional state estimation method, which is designed for rectangular voltage sags, is difficult to apply to multi-stage voltage sags (MSVSs). This study proposes an MSVS state-estimation method based on event-deduction models. First, we propose a method to identify the causes of MSVSs. Second, we present a method to calculate the matrix of relay protection trips (MRPT), which corresponds to the fault clearing time of the relay protection and a method to calculate the fault power line set to reduce the computing workload of the MRPT-based estimation method. Third, we propose a method to calculate the impedance matrix of a power system under different disturbance events, resulting in different stages of the MSVS and an event-deduction model based on this impedance matrix to deduce these events. Furthermore, we present a model to estimate the state of voltage sag for MSVS based on the event deduction result. Finally, we use the IEEE-118 system to validate the proposed method.

The existing division of system stability region does not fully consider the influence of nonlinear characteristics of the system. To address the challenge that it is difficult to inscribe the stability region of wind power grid-connected systems accurately and quantitatively, this paper proposes a nonlinear system multi-parameter practical stability region analysis method based on limit cycle amplitude tracking. Firstly, the nonlinear dynamic model of multi-machine system with doubly fed induction generator (DFIG) is established, and the bifurcation diagram of the system is obtained by nonlinear analysis of the model. Then, the limit cycle-parameter diagram is obtained by tracking the limit cycle of the Hopf bifurcation point of the system, and the problem of how the system oscillation evolves with the change of operating parameters is analyzed. Afterwards, the single parameter practical stability region of the nonlinear system is obtained by combining the system equilibrium manifold. Finally, the multi-parameter practical stability region of the nonlinear system is obtained by the three-dimensional bifurcation map with the system time delay, DFIG output active power and reactive load as the bifurcation parameters. The division of the stability region has important guiding significance for the parameter adjustment in the actual operation of the system.