Local Transition Research Articles

From media campaign to local governance transition: Lessons for community‐based conservation from an Amur falcon hunting ban in Nagaland, India

AbstractMedia campaigns can spur conservation action but may alienate local communities. Transforming such action into self‐sustaining community‐based conservation involves effective governance that rapidly integrates knowledge of resource dynamics, establishes flexible institutions, and fosters multilevel networks. This study examines the emergence of community‐based conservation in response to a media campaign to protect migratory Amur falcons, illustrating shifts in governance and power dynamics that enabled local community ownership. Although conservation developed in the absence of an adequate preparation phase, external engagement, incentives, and recognition of local institutions' legitimacy were instrumental in fostering collective action. This research showcases how community‐based conservation initiatives can be triggered by external social pressure but also how the long‐term sustainability relies on effective governance that respects local institutions and employs cooperative strategies to build trust and foster ownership among local communities.

Quantum fluctuation dynamics of open quantum systems with collective operator-valued rates, and applications to Hopfield-like networks

We consider a class of open quantum many-body systems that evolves in a Markovian fashion, the dynamical generator being in GKS-Lindblad form. Here, the Hamiltonian contribution is characterized by an all-to-all coupling, and the dissipation features local transitions that depend on collective, operator-valued rates, encoding average properties of the system. These types of generators can be formally obtained by generalizing, to the quantum realm, classical (mean-field) stochastic Markov dynamics, with state-dependent transitions. Focusing on the dynamics emerging in the limit of infinitely large systems, we build on the exactness of the mean-field equations for the dynamics of average operators. In this framework, we derive the dynamics of quantum fluctuation operators, that can be used in turn to understand the fate of quantum correlations in the system. We then apply our results to quantum generalized Hopfield associative memories. Here we show that, asymptotically and at the description level of quantum fluctuations, only a very weak amount of quantum correlations, in the form of quantum discord, emerges beyond classical correlations.

Applying network-free renormalization and clustering algorithms to reveal the crack evolution laws of laterally loaded composite T-joints

Delamination or crack are standard failure patterns of composite T-joints. Most existing studies focus on pull-off loaded composite T-joint cracking but little focus on adverse conditions such as lateral loading. The mainstream composite T-joint research predicts the macroscale failure based on the composite’s microscale/mesoscale crack starting and evolution. However, the cracking process is within the microscale, mesoscale, and macroscale, making detecting its starting based on phenomena complicated. This work attempts to directly model the macroscale deformation distribution from a thermodynamic perspective to reveal the cracking/failure evolution of a laterally loaded composite T-joint. Firstly, we conducted eight laterally loaded composite T-joint tests with different molding processes. Then, network-free renormalization was applied to construct Matrices (Modes) and Hamiltonians (Characteristic parameters) that can characterize their cracking evolution process. Further, a clustering algorithm was applied to reveal the cracking starting points (phase transition loads) embedded in the macroscale deformation distribution. We can verify its rationality by comparing the composite T-joints localized and systematic phase transition loads based on Wilson’s phase transition theory. In summary, this work applies network-free renormalization and clustering algorithms from a thermodynamic perspective to reveal the cracking starting point embedded in the macroscale deformation distribution of the laterally loaded composite T-joints.

Robust Effective Ground State in a Nonintegrable Floquet Quantum Circuit.

An external periodic (Floquet) drive is believed to bring any initial state to the featureless infinite temperature state in generic nonintegrable isolated quantum many-body systems in the thermodynamic limit, irrespective of the driving frequency Ω. However, numerical or analytical evidence either proving or disproving this hypothesis is very limited and the issue has remained unsettled. Here, we study the initial state dependence of Floquet heating in a nonintegrable kicked Ising chain of length up to L=30 with an efficient quantum circuit simulator, showing a possible counterexample: the ground state of the effective Floquet Hamiltonian is exceptionally robust against heating, and could stay at finite energy density even after infinitely many Floquet cycles, if the driving period is shorter than a threshold value. This sharp energy localization transition or crossover does not happen for generic excited states. The exceptional robustness of the ground state is interpreted by (i)its isolation in the energy spectrum and (ii)the fact that those states with L-independent ℏΩ energy above the ground state energy of any generic local Hamiltonian, like the approximate Floquet Hamiltonian, are atypical and viewed as a collection of noninteracting quasiparticles. Our finding paves the way for engineering Floquet protocols with finite driving periods realizing long-lived, or possibly even perpetual, Floquet phases by initial state design.

Large-deviation analysis of rare resonances for the many-body localization transition

Large-deviation analysis of rare resonances for the many-body localization transition

A luminescent binuclear Cu(I) complex constructed by bipyridine, TD-DFT calculation, and its fluorescent sensing properties for VOCs

The design and research of materials with strong luminescence and fluorescence sensing for the detection of volatile organic compounds (VOCs) are of great significance and challenge. Herein, we report a binuclear Cu(I) complex, [Cu2(POP)2(MeCN)2(4,4′-bipy)](PF6)2 (2), which is synthesized rationally through a substitution reaction between complex [Cu(POP)(4-PBO)(MeCN)](PF6) (1) and 4,4′-bipy lignand (POP is bis[2-(diphenylphosphino)phenyl]ether, 4,4′-bipy is bipyridine, 4-PBO is 2-(4′-pyridyl)-benzoxazole). The complex 2 was characterized by single-crystal X-ray diffraction as an isolated binuclear structure constructed by a bridged 4,4′-bipy ligand. Under UV irradiation, both the powder and doped thin film of 1 and 2 exhibit broadband photoluminescence emission. The TD-DFT calculation reveals the details of the electronic transitions corresponding to the light absorption and emission of the two complexes, and also illustrates that the improved luminescence of 2 compared to 1 is due to the T1 excited state transforms from a localized transition to a charge transfer transition similar to the S1 excited state and the extremely small energy gap ΔE(S1-T1) value of 0.09 eV (2). Based on these complexes, fluorescent test strips were developed. It is gratifying to find that the test strip based 2 shows a distinguishable fluorescence response behavior to a variety of VOCs. Especially, the test strip showed a rapid quenching fluorescence response to acetophenone, and a rapid quenching followed by rapid enhancement fluorescence response to acetonitrile. Therefore, it can be used for rapid and highly selective fluorescence sensing detection of acetonitrile and acetophenone.

Analysis of localization transitions using nonparametric unsupervised learning

Analysis of localization transitions using nonparametric unsupervised learning

Energy Transition in Northern Netherlands: seeking a balance between top-down and bottom-up initiatives

This study focuses on top-down and bottom-up processes within the field of energy transition. It aims at gaining insights into the ways that a more balanced approach can be achieved, by taking into consideration the (mutual) interests, barriers and expectations of the municipality and local citizen initiatives. The theoretical framework of the study is the implementation analysis framework, distinguishing top-down and bottom-up approaches. Specifically, this qualitative (thematic analysis) research study investigates the mismatch in expectations between a number of local energy initiatives and the municipality of Groningen regarding their roles within the local energy transition context. To this end, semi-structured interviews have been conducted with members of the municipality of Groningen, Grunneger Power (a local energy intermediary), and four local energy initiatives. Need and expectation gaps have been identified and potential solutions have been explored. The main findings of the study illustrate the need of professional support for citizen initiatives, at both technical and organizational level, especially in the first phases of their development. Additionally, clear mutual communication on short and long-term planning and ambitions of the involved parties is of key importance for the alignment of the interests and the course of actions. Consequently, a clear context is needed, within which an exchange of feedback on the envisioned strategies, and the subsequent energy saving or generation interventions, can take place in an efficient and effective way. Additionally, such a context increases confidence and provides a clear understanding to the citizen initiatives regarding their role and the level and nature of support they can expect in their intended projects and activities. Based on these findings, policy implications have been drawn.

Observation of stacking engineered magnetic phase transitions within moiré supercells of twisted van der Waals magnets

Recent demonstrations of moiré magnetism, featuring exotic phases with noncollinear spin order in the twisted van der Waals (vdW) magnet chromium triiodide CrI3, have highlighted the potential of twist engineering of magnetic (vdW) materials. However, the local magnetic interactions, spin dynamics, and magnetic phase transitions within and across individual moiré supercells remain elusive. Taking advantage of a scanning single-spin magnetometry platform, here we report observation of two distinct magnetic phase transitions with separate critical temperatures within a moiré supercell of small-angle twisted double trilayer CrI3. By measuring temperature-dependent spin fluctuations at the coexisting ferromagnetic and antiferromagnetic regions in twisted CrI3, we explicitly show that the Curie temperature of the ferromagnetic state is higher than the Néel temperature of the antiferromagnetic one by ~10 K. Our mean-field calculations attribute such a spatial and thermodynamic phase separation to the stacking order modulated interlayer exchange coupling at the twisted interface of moiré superlattices.

Atomistic insights into hydrogen-enhanced strain-induced vacancy in α - iron across varied strain rates

Dynamic behavior of α-iron in the presence of hydrogen (H) under triaxial tension is investigated by molecular dynamic simulations. The process of hydrogen enhanced strain induced vacancy is directly captured at the atomic scale in a wide range of strain rates. Significant strain rate effects and H concentration dependence are observed in the hydrogen embrittlement of α-iron. When the concentration of H (CH) is substantially high, the maximum tensile stress of iron falls. More local phase transitions are observed at the aggregation sites of H atoms, which plays a crucial role in ensuring that the material does not lose its load bearing capacity immediately after reaching the maximal stress. Our study sheds light on the intricate interplay of H, strain rate, phase transition (PT) in α-iron and provides valuable insights into the complex dynamics of H embrittlement.

Does Minimally Invasive Hemilaminectomy for Intradural Extramedullary Tumor Resection Prevent Postlaminectomy Kyphosis or Lordosis Loss?

Minimally invasive hemilaminectomy is a safe and effective alternative to open laminectomy for treating intradural extramedullary tumors. There are no reports of postoperative kyphosis after this approach. This study aims to determine whether performing minimally invasive spine surgery hemilaminectomy for intradural extramedullary tumors can prevent the development of postlaminectomy kyphosis (PLK) or lordosis loss. Sixty-five patients with spinal intradural extramedullary tumors who underwent minimally invasive hemilaminectomy surgery and complete pre and postoperative radiologic imaging were included. The effect of the surgical approach on the spinal sagittal axis was assessed by comparing pre- versus postoperative segmental and local Cobb angles at different spinal levels, considering anatomical localization (cervical, thoracic, lumbar, and transition segments) and functional features (mobile, semi-rigid, and transition segments), as well as the extent of the surgical approach (1, 2, or 3 levels) and follow-up. None of the patients had an increase in thoracic kyphosis nor a loss of cervical or lumbar lordosis greater than or equal to 10° after undergoing the minimally invasive spine surgery hemilaminectomy approach.More than 5° of increase in kyphosis was detected on 7.4% and 11.1%, for the segmental and the local angles, respectively; meanwhile, for patients with loss of lordosis, this deviation was detected in 5.3%, for both angles. The occurrence of PLK was more common than that of lordosis loss, but mainly manifested in postoperative angle impairment of less than 5°. No significant differences were evidenced, considering theapproach length. Hemilaminectomy represents a promising approach for preventing PLK and postlaminectomy lordosis loss following intradural extramedullary tumor resection.

Pilot free trade zones and low-carbon innovation: Evidence from listed companies in China

The impact of pilot free trade zones (PFTZs) on companies' low-carbon innovation is not yet studied. In response, this paper considers the establishment of PFTZs as a quasi-natural experiment, using panel data on China's A-share industrial listed companies for the period 2010–2021 and utilizing the entropy balancing difference-in-differences (EB-DID) model to examine PFTZs' impact on companies' low-carbon innovation. The results show that: (1) PFTZs significantly promote companies' low-carbon innovation in pilot cities through the “promoting R&D effect” and the “environmental governance effect”; (2) Foreign capital positively moderates PFTZs' impact on companies' low-carbon innovation; (3) PFTZs' policy effect is characterized by spatial heterogeneity. The paper thus suggests that the government should improve the construction plans of PFTZs to ensure alignment with low-carbon development goals. Moreover, the government should also provide appropriate subsidies for low-carbon technology R&D to encourage innovation, implement advanced institutional systems to facilitate local companies' low-carbon transition, attract high-quality foreign investments to drive the inflow of innovation elements, and optimize the geographical distribution of PFTZs to maximize the spatial spillover effect.

In-plane distribution of huge local permittivity of KTa1-xNbxO3 estimated from local phase transition temperatures and spatially averaged permittivity.

Potassium tantalate niobate (KTa1-xNbxO3, KTN) single crystals have a very large relative permittivity εr (>104) just above the paraelectric to ferroelectric phase transition temperature (TC). The quadratic electro-optic coefficient and the electro-strictive coefficient are also very large because of their proportionality to εr2. However, the local relative permittivity can easily vary spatially due to the incongruently melting nature of KTN. In this study, we quantitatively estimated the in-plane distribution of the huge local relative permittivity of KTN. First, we measured the spatial distribution of TC using scanning nonlinear dielectric microscopy, then deposited the electrodes and measured the temperature dependence of the spatially averaged permittivity using an LCR meter. Following that, we evaluated the spatial distribution of the huge local permittivity from the combination of the spatial distribution of TC and the spatially averaged permittivity. Finally, we measured the deflection angle of light to confirm the validity of the εr estimation procedure. The maximum error for the estimated permittivity was estimated to be around 3.3%.

Unscrambling of single-particle wave functions in systems localized through disorder and monitoring

In systems undergoing localization-delocalization quantum phase transitions due to disorder or monitoring, there is a crucial need for robust methods capable of distinguishing phases and uncovering their intrinsic properties. In this paper, we develop a process of finding a Slater determinant representation of free-fermion wave functions that accurately characterizes localized particles, a procedure we dub “unscrambling.” The central idea is to minimize the overlap between envelopes of single-particle wave functions or, equivalently, to maximize the inverse participation ratio of each orbital. This numerically efficient methodology can differentiate between distinct types of wave functions: exponentially localized, power-law localized, and conformal critical, also revealing the underlying physics of these states. The method is readily extendable to systems in higher dimensions. Furthermore, we apply this approach to a more challenging problem involving disordered monitored free fermions in one dimension, where the unscrambling process unveils the presence of a conformal critical phase and a localized area-law quantum Zeno phase. Importantly, our method can also be extended to free fermion systems without particle number conservation, which we demonstrate by estimating the phase diagram of Z2-symmetric disordered monitored free fermions. Our results unlock the potential of utilizing single-particle wave functions to gain valuable insights into the localization transition properties in systems such as monitored free fermions and disordered models. Published by the American Physical Society 2024

Subsurface deformation mechanism and the interplay relationship between strength-ductility and fretting wear resistance during fretting of a high-strength titanium alloy

Fretting wear damage of high-strength titanium fasteners has caused a large number of disastrous accidents. Traditionally, it is believed that both high strength and excellent ductility can reduce fretting wear damage. However, whether strength and ductility are contradictory or not and their appropriate matching strategy under the external applied normal stress (Fw) are still confusing problems. Here, by analyzing the subsurface-microstructure deformation mechanism of several samples containing various α precipitate features, for the first time, we design strategies to improve fretting damage resistance under different matching relation between Fw and the tensile strength of materials (Rm). It is found that when Fw is greater than Rm or Fw is nearly equivalent to Rm, the deformation mechanism mainly manifests as serious grain fragmentation of β and αGB constituents. Homogeneous deformation in large areas only reduces damage to a limited extent. It is crucial to improve the strength to resist cracking and wear, but it is of little significance to improve the ductility. However, when Fw is far less than Rm, coordinated deformation ability reflected by ductility plays a more important role. The deformation mechanism mainly manifests as localized deformation of β and αGB constituents (kinking induced by twinning and spheroidizing). A unique composite structure of nano-grained/lamellar layer and localized deformation transition layer reduces fretting damage by five times compared with a single nano-grained layer. Only when the strength is great enough, improving the plasticity can reduce wear. This study can provide a principle for designing fretting damage resistant alloys.

Universal properties of single-particle excitations across the many-body localization transition

Universal properties of single-particle excitations across the many-body localization transition

Public transit and the needs of people experiencing homelessness: a directed content analysis guided by Maslow’s hierarchy of needs

ABSTRACT Transportation has rarely been a variable of interest in studying homelessness, yet its role in the lives of people experiencing homelessness (PEH), especially those in U.S. urban areas, is critical. The National Academies of Sciences, Engineering, and Medicine found transit agencies often frame riders experiencing homelessness as a problem to solve. Examining the experiences of PEH riders and appreciating the centrality of transit vehicles, properties, and personnel in the lives of PEH are critical to craft ethical solutions. Research question: How does the Dallas Area Rapid Transit system meet the daily needs of individuals experiencing homelessness? We utilized a descriptive phenomenological research design to frame the interview questions and then used Maslow’s hierarchy of needs in service of directed content analysis. We interviewed 42 PEH in Dallas, Texas, who also used the local transit system. Themes included “Transit Meets Basic Needs of Rest and Homeostasis,” “Ambivalent Safety on Transit,” “Transit and Recognition Needs,” and “Transit as a Metaphor for Being Needs.” Findings are discussed in light of previous literature and the potential for critical intervention.

The role of energy communities for thermal networks: An EU legal perspective

AbstractDecarbonising heating and cooling systems, significant contributors to the EU's (European Union) energy consumption, is a complex and urgent matter. This article discusses the potential coupling of energy communities and district heating and cooling systems, particularly fourth‐ and fifth‐generation models, in the local energy transition. The integration of new‐generation district heating and cooling systems into renewable energy generation is crucial for sustainability, circular economy practices, and community‐based solutions. An examination of the EU legal framework within the Fit‐for‐55 package elucidates how provisions from the new Energy Efficiency Directive and Renewable Energy Directive facilitate the implementation of energy communities in the heating and cooling sector. The existing enabling legislation underscores the suitability of energy communities for heating and cooling sector activities, acknowledging their transformative potential in advancing the energy transition and fostering community empowerment.

What drives energy storage deployment in local energy transitions? Stakeholders’ perspective

The global shift towards decentralised energy systems has assigned municipalities a key role in achieving national climate neutrality objectives. As the main stakeholders in the local energy transition, municipalities are responsible for the decarbonization of the local energy system through the extensive integration of renewable energy sources into existing systems. However, this integration requires new approaches and system adjustments, such as energy storage deployment, to satisfy the variable nature of renewable energy sources. The integration of novel solutions, such as energy storage, is difficult because of the diverse range of stakeholders involved, each with their own perceptions and expertise. This study uses the Fuzzy Cognitive Mapping (FCM) methodology to analyse the mental models of different stakeholders regarding their perceived importance of different factors influencing the implementation of energy storage in municipalities. The approach of this study enables a better understanding of municipal energy systems and its dynamics. The results reveal that support schemes such as subsidies and awareness campaigns are key to all stakeholders. Municipalities tend to focus on local needs and technological solutions, while energy experts prioritize technical aspects and national policies. Municipalities address challenges linearly, missing interconnections, whereas energy experts consider feedback loops and system requirements. The study highlights the need for common ground to drive effective policy and infrastructure development. The results could be used to facilitate discussions with policy makers on why energy storage is important and what policy measures should be considered to accelerate its deployment.

Intercalation-Induced Localized Conversion Reaction in h-CuSe for Ultrafast-Rechargeable and Long-Cycling Sodium Metal Battery.

Cathode materials of sodium-based batteries with high specific capacity and fast charge-discharge mode, as well as ultralong reversible cycles at wide applied temperatures, are essential for future development of advanced energy storage system. Developing transition metal selenides with intercalation features provides a new strategy for realizing the above cathode materials. Herein, this work reports a storage mechanism of sodium ion in hexagonal CuSe (h-CuSe) based on the density functional theory (DFT) guidance. This work reveals that the two-dimensional ion intercalation triggers localized redox reaction in the h-CuSe bulk phase, termed intercalation-induced localized conversion (ILC) mechanism, to stabilize the sodium storage structure by forming localized Cu7Se4 transition phase and adjusting the near-edge coordination state of the Cu sites to achieve high reversible capacity and ultra-long cycling life, while allowing rapid charge-discharge cycling over a wide temperature range.