IBP reduction coefficients made simple

We present an efficient method to shorten the analytic integration-by-parts (IBP) reduction coefficients of multi-loop Feynman integrals. For our approach, we develop an improved version of Leinartas' multivariate partial fraction algorithm, and provide a modern implementation based on the computer algebra system Singular. Furthermore, We observe that for an integral basis with uniform transcendental (UT) weights, the denominators of IBP reduction coefficients with respect to the UT basis are either symbol letters or polynomials purely in the spacetime dimension $D$. With a UT basis, the partial fraction algorithm is more efficient both with respect to its performance and the size reduction. We show that in complicated examples with existence of a UT basis, the IBP reduction coefficients size can be reduced by a factor of as large as $\sim 100$. We observe that our algorithm also works well for settings without a UT basis.Comment: minor changes, typos correcte

A systematic study of the valence electronic structure of cyclo(Gly–Phe), cyclo(Trp–Tyr) and cyclo(Trp–Trp) dipeptides in the gas phase

The electronic energy levels of cyclo(glycine–phenylalanine), cyclo(tryptophan–tyrosine) and cyclo(tryptophan–tryptophan) dipeptides are investigated with a joint experimental and theoretical approach. Experimentally, valence photoelectron spectra in the gas phase are measured using VUV radiation. Theoretically, we first obtain low-energy conformers through an automated conformer–rotamer ensemble sampling scheme based on tight-binding simulations. Then, different first principles computational schemes are considered to simulate the spectra: Hartree–Fock (HF), density functional theory (DFT) within the B3LYP approximation, the quasi-particle GW correction, and the quantumchemistry CCSD method. Theory allows assignment of the main features of the spectra. A discussion on the role of electronic correlation is provided, by comparing computationally cheaper DFT scheme (and GW) results with the accurate CCSD method

Electron and ion spectroscopy of Azobenzene in the valence and core shells

Azobenzene is a prototype and building block of a class of molecules of extreme technological interest as molecularphoto-switches. We present a joint experimental and theoretical study of its response to irradiation with light across theUV to X-ray spectrum. The study of valence and inner shell photo-ionization and excitation processes, combined withmeasurement of valence photoelectron-photoion coincidence (PEPICO) and of mass spectra across the core thresholdsprovides a detailed insight onto the site- and state-selected photo-induced processes. Photo-ionization and excita-tion measurements are interpreted via the multi-configurational restricted active space self-consistent field (RASSCF)method corrected by second order perturbation theory (RASPT2). Using static modelling, we demonstrate that thecarbon and nitrogen K edges of Azobenzene are suitable candidates for exploring its photoinduced dynamics thanks tothe transient signals appearing in background-free regions of the NEXAFS and XP

Comorbid depressive symptoms can aggravate the functional changes of the pain matrix in patients with chronic back pain: A resting-state fMRI study

ObjectiveThe purposes of this study are to explore (1) whether comorbid depressive symptoms in patients with chronic back pain (CBP) affect the pain matrix. And (2) whether the interaction of depression and CBP exacerbates impaired brain function.MethodsThirty-two patients with CBP without comorbid depressive symptoms and thirty patients with CBP with comorbid depressive symptoms were recruited. All subjects underwent functional magnetic resonance imaging (fMRI) scans. The graph theory analysis, mediation analysis, and functional connectivity (FC) analysis were included in this study. All subjects received the detection of clinical depressive symptoms and pain-related manifestations.ResultCompared with the CBP group, subjects in the CBP with comorbid depressive symptoms (CBP-D) group had significantly increased FC in the left medial prefrontal cortex and several parietal cortical regions. The results of the graph theory analyses showed that the area under the curve of small-world property (t = −2.175, p = 0.034), gamma (t = −2.332, p = 0.023), and local efficiency (t = −2.461, p = 0.017) in the CBP-D group were significantly lower. The nodal efficiency in the ventral posterior insula (VPI) (t = −3.581, p = 0.0007), and the network efficiency values (t = −2.758, p = 0.008) in the pain matrix were significantly lower in the CBP-D group. Both the topological properties and the FC values of these brain regions were significantly correlated with self-rating depression scale (SDS) scores (all FDR corrected) but not with pain intensity. Further mediation analyses demonstrated that pain intensity had a mediating effect on the relationship between SDS scores and Pain Disability Index scores. Likewise, the SDS scores mediated the relationship between pain intensity and PDI scores.ConclusionOur study found that comorbid depressive symptoms can aggravate the impairment of pain matrix function of CBP, but this impairment cannot directly lead to the increase of pain intensity, which may be because some brain regions of the pain matrix are the common neural basis of depression and CBP

Influence of Ethical Leadership on Employees’ Innovative Behavior: The Role of Organization-Based Self-Esteem and Flexible Human Resource Management

Employees’ innovative behavior is a vital source for promoting the sustainable survival and development of enterprises. Innovation is a complicated and high-risk mental process, where in each stage employees’ innovative attitude and behavior will be affected by the varying behaviors of their direct leaders. Therefore, exploring the intricate relationship between leadership behavior and employees’ innovative behavior is necessary. Based on social exchange theory, this study builds a cross-level moderation model to investigate the impact of ethical leadership on employees’ innovative behavior and the mediating role of organization-based self-esteem and the moderating role of flexible human resource management. On the basis of a questionnaire survey of 146 supervisors and 365 subordinates in the mainland of China, the empirical results show that: (a) Ethical leadership positively affects employees’ innovative behavior significantly; (b) Organization-based self-esteem has a partial mediating relationship between ethical leadership and employees’ innovative behavior; and (c) flexible human resource management plays a positive moderating role in the relationship between organization-based self-esteem and employees’ innovative behavior, and it also positively moderates the mediating effect of organization-based self-esteem on the relationship between ethical leadership and employees’ innovative behavior. The findings reveal the internal mechanism and boundary condition of ethical leadership influencing employees’ innovative behavior, which provide a reference for enterprises to encourage employees to innovate, and have important practical significance for employees to actively pursue innovative activities in the workplace

Influence of Ethical Leadership on Employees’ Innovative Behavior: The Role of Organization-Based Self-Esteem and Flexible Human Resource Management

Employees’ innovative behavior is a vital source for promoting the sustainable survival and development of enterprises. Innovation is a complicated and high-risk mental process, where in each stage employees’ innovative attitude and behavior will be affected by the varying behaviors of their direct leaders. Therefore, exploring the intricate relationship between leadership behavior and employees’ innovative behavior is necessary. Based on social exchange theory, this study builds a cross-level moderation model to investigate the impact of ethical leadership on employees’ innovative behavior and the mediating role of organization-based self-esteem and the moderating role of flexible human resource management. On the basis of a questionnaire survey of 146 supervisors and 365 subordinates in the mainland of China, the empirical results show that: (a) Ethical leadership positively affects employees’ innovative behavior significantly; (b) Organization-based self-esteem has a partial mediating relationship between ethical leadership and employees’ innovative behavior; and (c) flexible human resource management plays a positive moderating role in the relationship between organization-based self-esteem and employees’ innovative behavior, and it also positively moderates the mediating effect of organization-based self-esteem on the relationship between ethical leadership and employees’ innovative behavior. The findings reveal the internal mechanism and boundary condition of ethical leadership influencing employees’ innovative behavior, which provide a reference for enterprises to encourage employees to innovate, and have important practical significance for employees to actively pursue innovative activities in the workplace

Analysis of Influencing Factors of Thermal Management System for LiFePO4 Lithium Battery under High Power Charging

During the high-power charging process, the heat generated by the power battery is significantly increased, resulting in a significant temperature rise, which will bring safety hazards and worsens capacity degradation. In this study, we focus on the energy storage system composed of LiFePO4 pouch battery cells whose capacity is 30Ah. The coupling calculation between the one-dimensional electro-chemical model and the 3D heat generation model is realized. The accuracy of the model is verified by charging the battery at different rates. The results show that the inlet flow rate and the cooling channel size within a certain range has a great influence on the cooling effect of the battery pack during high power charging process. Comparing the temperature distribution of the battery pack under different charging rates, the electrochemical-heating coupling model established in this study can truly reflect the heat generation of the battery. Through the calculation of the heat generation of the battery pack, the boundary conditions of the cooling system design can be found, which provides a basis for the optimal design of the conditional cooling system for battery high-power charging

Design and Analysis of Porous Elastomeric Polymer Based on Electro-Mechanical Coupling Characteristics for Flexible Pressure Sensor

Elastomeric polymers have gained significant attention in the field of flexible electronics. The investigation of the electro-mechanical response relationship between polymer structure and flexible electronics is in increasing demand. This study investigated the factors that affect the performance of flexible capacitive pressure sensors using the finite element method (FEM). The sensor employed a porous elastomeric polymer as the dielectric layer. The results indicate that the sensor’s performance was influenced by both the structural and material characteristics of the porous elastomeric polymer. In terms of structural characteristics, porosity was the primary factor influencing the performance of sensors. At a porosity of 76%, the sensitivity was 42 times higher than at a porosity of 1%. In terms of material properties, Young’s modulus played a crucial role in influencing the performance of the sensors. In particular, the influence on the sensor became more pronounced when Young’s modulus was less than 1 MPa. Furthermore, porous polydimethylsiloxane (PDMS) with porosities of 34%, 47%, 67%, and 72% was fabricated as the dielectric layer for the sensor using the thermal expansion microsphere method, followed by sensing capability testing. The results indicate that the sensor’s sensitivity was noticeably influenced within the high porosity range, aligning with the trend observed in the simulation

Predicting Current Potential Distribution and the Range Dynamics of <i>Pomacea canaliculata</i> in China under Global Climate Change

Pomacea canaliculata is one of the 100 worst invasive alien species in the world, which has significant effects and harm to native species, ecological environment, human health, and social economy. Climate change is one of the major causes of species range shifts. With recent climate change, the distribution of P. canaliculata has shifted northward. Understanding the potential distribution under current and future climate conditions will aid in the management of the risk of its invasion and spread. Here, we used species distribution modeling (SDM) methods to predict the potential distribution of P. canaliculata in China, and the jackknife test was used to assess the importance of environmental variables for modeling. Our study found that precipitation of the warmest quarter and maximum temperature in the coldest months played important roles in the distribution of P. canaliculata. With global warming, there will be a trend of expansion and northward movement in the future. This study could provide recommendations for the management and prevention of snail invasion and expansion