arXiv subjects

Lumeng Liu

Publications and source records attributed to Lumeng Liu.

3 recordsLinked to original sources

arXiv2026

Ecosystem service demand relationship and trade-off patterns in urban parks across China

Understanding public demand for urban ecosystem services (ES) is crucial for effective green space management, yet the intricate relationships and potential trade-offs among these diverse demands remain poorly understood. Previous studies have yielded inconsistent findings, often limited by small samples or reliance on indirect proxies. Here, we provide the first national-scale, direct assessment of the relationship among demands for nine urban park ES using a survey dataset comprising 20,075 responses across China and a point-allotment experiment that directly quantifies the trade-off patterns among service demands. We found particularly strong preferences among urban residents in China for air purification and recreation services, at the expense of other services. These preferences were further reflected in three distinct demand bundles: air purification-dominated, recreation-dominated, and balanced demands, each delineating a typical group of people with distinct representative characteristics. Socio-economic and environmental factors, such as age, environmental interest, and mean annual precipitation, significantly influence the trade-off intensity among service demands. Our study pioneers the direct, quantitative analysis of relationships among ecosystem service demands, and the results underscore the need for tailored urban park designs that address diverse service demands to sustainably enhance the quality of city life in China and beyond.

econ.GN↗

arXiv2025

Scaling approach to rigid and soft nuclear deformation through flow fluctuations in high-energy nuclear collisions

The nature of octupole deformation, whether static or vibrational, remains an open question in nuclear physics. Here, we propose a scaling approach to probe this ambiguity by triangular flow fluctuations using multi-particle cumulants, $c_{3,\varepsilon}\{4\}$, in relativistic $^{238}$U+$^{238}$U collisions. We demonstrate that both $|c_{3,\varepsilon}\{4\}|$ and the ratio $|c_{3,\varepsilon}\{4\}/c^2_{3,\varepsilon}\{2\}|$ scale linearly with the fourth-order moment of octupole deformation, $\langle \beta^4_{3,\mathrm{U}} \rangle$. Combined with the known linear relation of $c_{3,\varepsilon}\{2\}$ to $\langle \beta^2_{3,\mathrm{U}} \rangle$, this new relation provides a direct extraction of both the mean and variance of the octupole deformation fluctuations, finally discriminating between static and dynamic origins. This work establishes a new tool to probe the static and dynamic collective modes in high-energy nuclear collisions, advancing a significant step toward refining the initial conditions of quark-gluon plasma.

nucl-th↗

arXiv2025

Imprints of octupole collectivity in uranium-238 on relativistic heavy-ion flow observables

Some atomic nuclei exhibit enhanced octupole collectivity, reflected in finite reflection-asymmetric multipole correlations rather than necessarily in a rigid static pear-shaped ground state. Low-energy studies indicate finite octupole strength in uranium-238, commonly interpreted as soft or vibrational in nature, in addition to its large prolate quadrupole collectivity~\cite{MCGOWAN1994569,KIBEDI:2002wxc}, in addition to its large prolate quadrupole collectivity. Here we investigate how such octupole correlations can be encoded in the initial geometry of relativistic heavy-ion collisions and mapped to final-state flow observables. Using state-of-the-art hydrodynamic calculations, we demonstrate quantitative sensitivity to octupole-induced features encoded in the initial-state geometry and suggest a modest octupole collectivity in uranium-238, confirmed by the latest high-energy experimental measurements~\cite{STAR:2025elk}. These findings provide as a complementary probe of odd-order nuclear collectivity and help constrain quark-gluon plasma initial conditions.

nucl-th↗