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This paper presents a type of noise-adaptive (NA) interacting multiple model (IMM) algorithm combined with an unscented Kalman filter (UKF) in order to address problems in poor filtering accuracy and filtering divergence of IMM caused by the statistical properties of noise. These properties further affect the estimation accuracy of state of charge (SOC) when IMM deals with dynamic changes in battery model parameters. Accordingly, the proposed algorithm can realize the accurate estimation of SOC when model parameters change dynamically and when the statistical properties of noise are unknown. By integrating a Sage-Husa noise estimator, NA-IMM-UKF enabled the whole UKF model set to estimate and correct noise information in real time in order for posteriori and unknown noise information to be adjusted adaptively. At the same time, a forgetting factor was introduced in order to optimize the proposed algorithm, thus improving the problem in which the Sage–Husa noise estimator converges slowly when used in conjunction with UKF. By conducting an experiment and simulation, NA-IMM-UKF was shown to carry out SOC estimation under multiple models, with an average error of only 0.4% and maximum error of only 1.08%. However, by comparing the estimated result of SOC under a single model with the Sage–Husa​ estimator minus the forgetting factor, the average error dropped by 0.15% while the maximum error decreased by 2.78%. In the final noise comparison experiment, following the addition of unknown random noise, the average error of the NA-IMM-UKF algorithm was found to be only 0.48%, while the maximum error was only 1.51%, far surpassing the estimation results of the IMM-UKF algorithm in the same state. As a result, even if the statistical properties of noise are uncertain, the proposed algorithm can still estimate SOC both accurately and effectively.

The interplay between quenched disorder and critical behavior in quantum phase transitions is conceptually fascinating and of fundamental importance for understanding phase transitions. However, it is still unclear whether or not the quenched disorder influences the universality class of quantum phase transitions. More crucially, the absence of superconducting-metal transitions under in-plane magnetic fields in 2D superconductors imposes constraints on the universality of quantum criticality. Here, we observe the thickness-tuned universality class of superconductor-metal transition by changing the disorder strength in β - W films with varying thickness. The finite-size scaling uncovers the switch of universality class: quantum Griffiths singularity to multiple quantum criticality at a critical thickness of t c ⊥ 1 ~ 8 n m and then from multiple quantum criticality to single criticality at t c ⊥ 2 ~ 16 n m . Moreover, the superconducting-metal transition is observed for the first time under in-plane magnetic fields and the universality class is changed at t c ‖ ~ 8 n m . The observation of thickness-tuned universality class under both out-of-plane and in-plane magnetic fields provides broad information for the disorder effect on superconducting-metal transitions and quantum criticality.

BACKGROUND Sarcopenia is a nutrition-related disease and has a profound effect on the long-term overall survival (OS) of patients with gastric cancer. Its diagnostic criterion is critical to clinical diagnosis and treatment. However, previous research reported widely differing sarcopenia prevalence due to different criteria. AWGS2019 and EWGSOP2 are the two latest and widely adopted criteria. AIM To compare the effects of AWGS2019 and EWGSOP2 on the long-term OS of Chinese gastric cancer patient after radical gastrectomy. METHODS An observational study was conducted from July 2014 to January 2017, which included 648 consecutive gastric cancer patients who underwent radical gastrectomy. The sarcopenia elements (skeletal muscle index, handgrip strength, and gait speed) were measured within 1 mo or 7 d before surgery. The patients were followed at fixed intervals to gain the outcomes. Multivariate Cox regression analysis was performed to determine the association between sarcopenia and the long-term OS of these patients according to the two criteria separately. The predictive performance of the models with AWGS2019 and EWGSOP2 were evaluated by the concordance index (C-index) and area under the time-dependent receiver operating characteristic curve (AUC). The Akaike information criterion (AIC) was applied to compare model fits. RESULTS The prevalence of sarcopenia was 20.5% and 11.3% according to AWGS2019 and EWGSOP2, respectively. Sarcopenia was an independent risk factor for the long-term OS no matter based on AWGS2019 or EWGSOP2, but AWGS2019-sarcopenia in multivariate model had a higher hazard ratio (HR) [2.150 (1.547-2.988)] than EWGSOP2-sarcopenia [HR 1.599 (1.092-2.339)]. Meanwhile, the model with AWGS2019-sarcopenia [C-index 0.773 (0.742-0.804); AIC 2193.7; time-dependent AUC 0.812 (0.756-0.867) for 1-year OS, 0.815 (0.778-0.852) for 3-year OS, and 0.809 (0.759-0.859) for 5-year OS] had better predictive power and model fits than the model with EWGSOP2-sarcopenia [C-index 0.762 (0.729-0.795); AIC 2215.2; time-dependent AUC 0.797 (0.741-0.854) for 1-year OS, 0.804 (0.767-0.842) for 3-year OS, and 0.799 (0.748-0.850) for 5-year OS]. CONCLUSION Sarcopenia is an independent risk factor for the long-term OS in Chinese gastric cancer patients undergoing radical gastrectomy. The prediction model with AWGS2019-sarcopenia has better predictive power and model fits than the prediction model with EWGSOP2-sarcopenia. AWGS2019 may be more appropriate for diagnosing sarcopenia in these Chinese patients than EWGSOP2.

Aging frailty is a complex geriatric syndrome that becomes more prevalent with advancing age. It constitutes a major health problem due to frequent adverse outcomes. Frailty is characterized by disruption of physiological homeostasis and progressive decline of health status. Multiple factors contribute to development of frailty with advancing age, including genome instability, DNA damage, epigenetic alternations, stem cell exhaustion, among others. These interrelated factors comprehensively result in loss of tissue homeostasis and diminished reserve capacity in frailty. Therefore, the aged organism gradually represents symptoms of frailty with decline in physiological functions of organs. Notably, the brain, cardiovascular system, skeletal muscle, and endocrine system are intrinsically interrelated to frailty. The patients with frailty may display the diminished reserves capacity of organ systems. Due to the complex pathophysiology, no specific treatments have been approved for prevention of this syndrome. At such, effective strategies for intervening in pathogenic process to improve health status of frail patients are highly needed. Recent progress in cell-based therapy has greatly contributed to the amelioration of degenerative diseases related to age. Mesenchymal stem cells (MSCs) can exert regenerative effects and possess anti-inflammatory properties. Transplantation of MSCs represents as a promising therapeutic strategy to address the pathophysiologic problems of frail syndrome. Currently, MSC therapy have undergone the phase I and II trials in human subjects that have endorsed the safety and efficacy of MSCs for aging frailty. However, despite these positive results, caution is still needed with regard to potential to form tumors, and further large-scale studies are warranted to confirm the therapeutic efficacy of MSC therapy.

The rise of two-dimensional (2D) crystalline superconductors has opened a new frontier of investigating unconventional quantum phenomena in low dimensions. However, despite the enormous advances achieved towards understanding the underlying physics, practical device applications like sensors and detectors using 2D superconductors are still lacking. Here, we demonstrate nonreciprocal antenna devices based on atomically thin NbSe2. Reversible nonreciprocal charge transport is unveiled in 2D NbSe2 through multi-reversal antisymmetric second harmonic magnetoresistance isotherms. Based on this nonreciprocity, our NbSe2 antenna devices exhibit a reversible nonreciprocal sensitivity to externally alternating current (AC) electromagnetic waves, which is attributed to the vortex flow in asymmetric pinning potentials driven by the AC driving force. More importantly, a successful control of the nonreciprocal sensitivity of the antenna devices has been achieved by applying electromagnetic waves with different frequencies and amplitudes. The device’s response increases with increasing electromagnetic wave amplitude and exhibits prominent broadband sensing from 5 to 900 MHz., Here, the authors observe reversible nonreciprocal charge transport in two-dimensional NbSe2, and demonstrate antenna devices exhibiting strong sensitivity to driving AC electromagnetic waves in the superconducting regime.

Stimulated by novel properties in topological insulators, experimentally realizing quantum phases of matter and employing control over their properties have become a central goal in condensed matte...

In terms of the dynamic changes of battery model parameters in a single-model filtering algorithm, the filter estimation accuracy can be poor, and filtering is scattered due to the different internal state parameters of lithium-ion batteries in different aging states, which affects the state of charge (SOC). In order to address these issues, an Interacting Multiple Model (IMM) algorithm was proposed in this study, which adopted an Unscented Kalman Filter (UKF) to better approximate the nonlinear characteristics of the state equation while better stabilizing the filter and having lower computational requirements. Accordingly, the IMM was used to solve the problem of the accurate estimation of the SOC under the dynamic change of model parameters. Moreover, an electrochemical impedance spectrum was used to establish the electrochemical model, after which the lithium-ion equivalent electrochemical circuit model was established, which improved the complexity problem due to its high accuracy but complicated the calculation of the multi-order equivalent circuit model. By conducting experiments and simulations, the algorithm of IMM-UKF was shown to achieve an effective estimation of the battery SOC, even when the state parameters of lithium-ion batteries were uncertain.

Aging is a complex process of systemic degeneration at multiple cellular and tissue levels that has a complex mechanism. Individuals age at different rates, and there is a high degree of aging heterogeneity. Therefore, it is inaccurate to judge an individual’s degree of aging by their chronological age. We performed transcriptome-focused multi-omics analyses (including transcriptomics, DNA methylation, proteomics, cytokine and telomere analysis, and single-cell transcriptome sequencing) on 139 healthy individuals aged 23 to 88 years. We systematically analyzed linear and non-linear changes in gene expression throughout aging. Genes with similar expression trajectories were enriched in similar biological pathways, including the PI3K-AKT signaling pathway and the inflammatory response. Through DNA methylation detection, we found that the expression of the top genes correlated with age was affected by methylation in the gene promoter region. These genes had no significant correlation with the expression of downstream proteins, but they were enriched in PI3K-AKT-associated proteins. Single-cell transcriptome sequencing showed that the expression of these genes did not significantly change in different cell subtypes, which proves that the gene expression changes were caused by internal age-related cellular changes rather than cell composition changes. We designed a transcriptome age clock and a methylation age clock using a set of 787 genes. Our models can accurately predict age with a mean absolute error (MAE) of 5.203 and 3.28, respectively, which is better than previously established aging models. The accuracy of our model was further verified by the detection of telomeres, which can identify accelerated aging of individuals.

Oral antibiotics remain the therapy of choice for severe bacterial infections; however, antibiotic use disrupts the intestinal microbiota, which increases the risk of colonization with intestinal pathogens. Currently, our understanding of antibiotic-mediated disturbances of the microbiota remains at the level of bacterial families or specific species, and little is known about the effect of antibiotics on potentially beneficial and potentially pathogenic bacteria under conditions of gut microbiota dysbiosis. Additionally, it is controversial whether the effects of antibiotics on the gut microbiota are temporary or permanent. In this study, we used 16S rRNA gene sequencing to evaluate the short-term and long-term effects of ampicillin, vancomycin, metronidazole, and neomycin on the murine intestinal microbiota by analyzing changes in the relative numbers of potentially beneficial and potentially pathogenic bacteria. We found that the changes in the intestinal microbiota reflected the antibiotics’ mechanisms of action and that dysbiosis of the intestinal microbiota led to competition between the different bacterial communities. Thus, destruction of bacteria with beneficial potential increased the abundance of bacteria with pathogenic potential. In addition, we found that these oral antibiotics had long-term negative effects on the intestinal microbiota and promoted the development of antibiotic-resistant bacterial strains. These results indicate that ampicillin, vancomycin, metronidazole, and neomycin have long-term negative effects and can cause irreversible changes in the diversity of the intestinal microbiota and the relative proportions of bacteria with beneficial potential and bacteria with pathogenic potential, thereby increasing the risk of host disease.

Two-dimensional (2D) ferromagnetic materials have been discovered with tunable magnetism and orbital-driven nodal-line features. Controlling the 2D magnetism in exfoliated nanoflakes via electric/magnetic fields enables a boosted Curie temperature (TC) or phase transitions. One of the challenges, however, is the realization of high TC 2D magnets that are tunable, robust and suitable for large scale fabrication. Here, we report molecular-beam epitaxy growth of wafer-scale Fe3+XGeTe2 films with TC above room temperature. By controlling the Fe composition in Fe3+XGeTe2, a continuously modulated TC in a broad range of 185–320 K has been achieved. This widely tunable TC is attributed to the doped interlayer Fe that provides a 40% enhancement around the optimal composition X = 2. We further fabricated magnetic tunneling junction device arrays that exhibit clear tunneling signals. Our results show an effective and reliable approach, i.e. element doping, to producing robust and tunable ferromagnetism beyond room temperature in a large-scale 2D Fe3+XGeTe2 fashion.

Mechanically exfoliated two-dimensional ferromagnetic materials (2D FMs) possess long-range ferromagnetic order and topologically nontrivial skyrmions in few layers. However, because of the dimensionality effect, such few-layer systems usually exhibit much lower Curie temperature (TC) compared to their bulk counterparts. It is therefore of great interest to explore effective approaches to enhance their TC, particularly in wafer-scale for practical applications. Here, we report an interfacial proximity-induced high-TC 2D FM Fe3GeTe2 (FGT) via A-type antiferromagnetic material CrSb (CS) which strongly couples to FGT. A superlattice structure of (FGT/CS)n, where n stands for the period of FGT/CS heterostructure, has been successfully produced with sharp interfaces by molecular-beam epitaxy on 2-inch wafers. By performing elemental specific X-ray magnetic circular dichroism (XMCD) measurements, we have unequivocally discovered that TC of 4-layer Fe3GeTe2 can be significantly enhanced from 140 K to 230 K because of the interfacial ferromagnetic coupling. Meanwhile, an inverse proximity effect occurs in the FGT/CS interface, driving the interfacial antiferromagnetic CrSb into a ferrimagnetic state as evidenced by double-switching behavior in hysteresis loops and the XMCD spectra. Density functional theory calculations show that the Fe-Te/Cr-Sb interface is strongly FM coupled and doping of the spin-polarized electrons by the interfacial Cr layer gives rise to the TC enhancement of the Fe3GeTe2 films, in accordance with our XMCD measurements. Strikingly, by introducing rich Fe in a 4-layer FGT/CS superlattice, TC can be further enhanced to near room temperature. Our results provide a feasible approach for enhancing the magnetic order of few-layer 2D FMs in wafer-scale and render opportunities for realizing realistic ultra-thin spintronic devices., Utilizing proximity effect, we realize an effective and reliable approach to accomplish near-room-temperature (286.7 K) ferromagnetic order and double switching behavior in wafer-scale 4-layer-Fe3GeTe2/1.6-nm-CrSb superlattice.

Plasmons in two-dimensional (2D) materials beyond graphene have recently gained much attention. However, the experimental investigation is limited due to the lack of suitable materials. Here, we experimentally demonstrate localized plasmons in a correlated 2D charge-density-wave (CDW) material: 2H-TaSe2. The plasmon resonance can cover a broad spectral range from the terahertz (40 {\mu}m) to the telecom (1.55 {\mu}m) region, which is further tunable by changing thickness and dielectric environments. The plasmon dispersion flattens at large wave vectors, resulted from the universal screening effect of interband transitions. More interestingly, anomalous temperature dependence of plasmon resonances associated with CDW excitations is observed. In the CDW phase, the plasmon peak close to the CDW excitation frequency becomes wider and asymmetric, mimicking two coupled oscillators. Our study not only reveals the universal role of the intrinsic screening on 2D plasmons, but also opens an avenue for tunable plasmons in 2D correlated materials., Comment: 30 pages, 5 figures

In China, energy efficiency retrofit of residential buildings is entering a new stage in which homeowners are the main subject. In order to investigate homeowners’ willingness to invest and to analyze its influencing factors, interviews and a questionnaire survey were conducted in central Tianjin, China. The results show that homeowners have a certain willingness to invest in energy efficiency retrofit but that their willingness to pay (WTP) is far from enough to cover the total cost. Among the influencing factors, the homeowner’s age, education level, and retrofit experience as well as the age and floor area of their home are significantly related to their WTP. The reasons for the impact of these factors are further discussed, including the influences of China’s previous housing policies and retrofit policies. Policy recommendations to promote investment by homeowners are suggested based on the findings.

Traditional pathological diagnoses and clinical methods are insufficient to accurately predict the prognosis of lung adenocarcinoma (LUAD). Epithelial-mesenchymal transition (EMT) process is closely related to tumor cell migration. However, the prognostic value of EMT-related genes in LUAD is still unclear. In this study, we collected bulk RNA-sequencing (RNA-seq) and microarray data of LUAD patients from public databases and identified different expressed EMT-related genes in tumor and normal tissues. Then, we used the least absolute shrinkage and selection operator Cox regression model to develop a multigene signature in the cancer genome atlas (TCGA) cohort and validated the model in the OncoSG (Singapore Oncology Data Portal) cohort as well as other datasets. Finally, we constructed a 12-gene signature to divide LUAD patients into high-risk and low-risk groups of overall survival (OS), which has a better stability and accuracy in predicating the OS of patients compared with some other published signatures of LUAD. In addition, evaluation of the risk model using the time-related receiver operating characteristic (ROC) curve confirmed the predictive ability of the model. Functional analysis showed that these genes are related to immunity. CD8 T cell and CD4 T cell types were significantly negatively correlated with the risk score in the analysis of immune infiltration. In general, our model provides useful information that may help clinicians better predict the prognosis of LUAD patients and provides potential targets for immunotherapy of LUAD. Funding Information: This work was supported by grants from the National Key Research and Development Program (2020YFC2002800), National Natural Science Foundation of China (Grant No 31671539), and Major Program of Development Fund for Shanghai Zhangjiang National Innovation Demonstration Zone. Conflict of Interest: All authors declare that no conflict of interest exists.

The motion of Abrikosov vortices is the dominant origin of dissipation in type II superconductors subjected to a magnetic field, which leads to a finite electrical resistance. It is generally believed that the increase in the magnetic field results in the aggravation of energy dissipation through the increase in vortex density. Here, we show a distinctive re-entrance of the dissipationless state in quasi-one-dimensional superconducting Ta

Stimulated by novel properties in topological insulators, experimentally realizing quantum phases of matter and employing control over their properties have become a central goal in condensed matter physics. β-silver telluride (Ag

Plasmons in two-dimensional (2D) materials beyond graphene have recently gained much attention. However, the experimental investigation is limited due to the lack of suitable materials. Here, we experimentally demonstrate localized plasmons in a correlated 2D charge-density-wave (CDW) material: 2H-TaSe2. The plasmon resonance can cover a broad spectral range from the terahertz (40 μm) to the telecom (1.55 μm) region, which is further tunable by changing thickness and dielectric environments. The plasmon dispersion flattens at large wave vectors, resulted from the universal screening effect of interband transitions. More interestingly, anomalous temperature dependence of plasmon resonances associated with CDW excitations is observed. In the CDW phase, the plasmon peak close to the CDW excitation frequency becomes wider and asymmetric, mimicking two coupled oscillators. Our study not only reveals the universal role of the intrinsic screening on 2D plasmons, but also opens an avenue for tunable plasmons in 2D correlated materials., Here, arrays of 2H-TaSe2 nanoribbons are shown to exhibit a broadband plasmonic response that can be tuned from THz to telecom range. These localized plasmons can also couple to charge density wave excitations, offering insights on the physics of plasmonic excitations in 2D correlated materials.

Licorice, the root of Glycyrrhiza glabra L. (Leguminosae), is one of the oldest known medicinal herbs. Glycyrrhizic acid (GA), a triterpenoid saponin isolated from licorice, has a variety of pharmacological activities. Previous studies indicate that GA produces neuroprotection via the modulation of anti-apoptotic and pro-apoptotic factors, primarily through the ERK signaling pathway and the suppression of inflammatory cytokine induction. However, the mechanisms of these neuroprotective effects and the effects of neuroimmunomodulation on cognition are not fully elucidated. This study investigated the effects of GA in preventing age-related immune involution and cognitive disorders as well as the relationship between immune involution and cognition and the underlying molecular mechanisms. Twelve-month-old female C57BL/6 mice were injected with GA (5mg/kg i.v. once every other day) for 6 weeks. Then, we tested the behavioral effects of GA using the Morris water maze task to evaluate spatial learning and memory. Age-related learning and memory impairments were prevented by GA treatment. This effect was accompanied by improved cerebral blood flow. Transcriptome analysis of C57BL/6 mice blood by RNA-sequencing and KEGG pathway analysis showed that GA could significantly influence hematopoietic cell lineage. The differential genes in the pathway were clustered using heat mapping, and RNA-seq results showed that GA altered gene expression. To correlate modulated gene expression and cognitive effects, we analyzed the levels of CD3e+ positive T cells, CD45R/B220+ positive B cells, and CD49b+ positive NK cells in the blood and spleen after 22 days of GA treatment. Flow cytometry showed that GA could increase T and B cells in the blood and spleen. To further investigate the relationship between neuroprotective effects of GA and effects on T and B cells, we tested behaviors after immunological reconstitution and GA treatment using a novel object recognition task in B-NDG mice. We found that, following immunological reconstitution and GA treatment, mice showed an increased preference for novel objects compared with controls as well as increased numbers of T, B, CD4, and CD8 cells. Increased neural stem cell markers accompanied these changes. Thus, our study suggests that GA may be a potential treatment for alleviating aging-associated cognitive declines and that these effects may be related to immune system modulation.

The cerebral microvasculature is essential for preservation of normal cerebral function. Age-related decreases of neurogenesis and cognitive function are accompanied by reduced blood flow and a decline in neural stem cell (NSC) number. Here, we report that metformin administered by tail vein injection enhanced cognition in aged but not young mice in a dose-dependent manner. Further, metformin restored cerebral blood flow and brain vascular density and promoted neurogenic potential of the subependymal zone/subventricular zone both in vivo and in vitro. RNA-Seq result indicated that metformin could enhance glycolysis in blood, with an increase in relative mRNA expression of the enzyme in the glycolysis pathway from hippocampal tissue of metformin-treated mice. Mechanistically, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a key enzyme in the glycolysis pathway, may contribute to angiogenic and neurogenic potentials of NSCs. Interestingly, examination of peripheral blood mononuclear cells from people of various ages showed that mRNA expression of GAPDH gradually decreased with age, while its expression level positively correlated with cognitive levels. Our results indicate that metformin represents a candidate pharmacological approach for recruitment of NSCs in aged mouse brain by enhancing glycolysis and promoting neurovascular generation, a strategy that might be of therapeutic value for anti-aging in humans.Graphical Abstract

This paper proposes a new iterative integration regularization method for robust solution of ill-posed inverse problems. The proposed method is motivated from the fact that inversion of a positive definite matrix can be expressed in an integral form. Then, the development of the proposed method is mainly twofold. Firstly, two ways—including the linear iteration and the exponential ( $$2^j$$ ) iteration—are invoked to compute the integral, of which the exponential iteration is often preferred due to its fast convergence. Secondly, after stability analysis, the proposed method is shown able to filter out the undesired effect of relatively small singular values, while preserving the desired terms of relatively large singular values, i.e., the proposed method has the guaranteed regularization effect. Numerical examples on three typical ill-posed problems are conducted with detailed comparison to some usual direct and iterative regularization methods. Final results have highlighted the proposed method: (a) due to the iterative nature, the proposed method often turns out to be more efficient than the conventional direct regularization methods including the Tikhonov regularization and the truncated singular value decomposition (TSVD), (b) the proposed method converges much faster than the Landweber method and (c) the regularization effect is guaranteed in the proposed method, while may not be in the conjugate gradient method for least squares problem (CGLS).

Residual stresses commonly arise in manufacturing, rolling, welding and heating of mechanical structures and they have a critical influence on fatigue strength, creep resistance and other properties of the structures. Therefore, identifying the residual stress distribution is crucial for quality assessment of these structures. To this end, this paper proposes a new non-destructive residual stress identification approach for thin plates using modal data. There are two key ingredients in establishing the proposed approach. The first is the parameterization of residual stress field by resorting to the Airy stress function so that residual stress identification is recast as a parameter identification problem. The second lies in the inverse identification of stress parameters through a sensitivity-based procedure. In doing so, stress parameter identification is formulated as a nonlinear optimization problem whose goal function is just least-squares of the misfit between the measured and calculated data, and then, modal sensitivity analysis and the trust-region constraint are introduced to iteratively get the solution. Numerical examples are conducted to verify the feasibility and accuracy of the proposed approach.

The search for proximity-induced superconductivity in topological materials has generated widespread interest in the condensed matter physics community. The superconducting states inheriting nontrivial topology at interfaces are expected to exhibit exotic phenomena such as topological superconductivity and Majorana zero modes, which hold promise for applications in quantum computation. However, a practical realization of such hybrid structures based on topological semimetals and superconductors has hitherto been limited. Here, we report the strong proximity-induced superconductivity in type-II Weyl semimetal WTe2, in a van der Waals hybrid structure obtained by mechanically transferring NbSe2 onto various thicknesses of WTe2. When the WTe2 thickness (tWTe2) reaches 21 nm, the superconducting transition occurs around the critical temperature (Tc) of NbSe2 with a gap amplitude (Δp) of 0.38 meV and an unexpected ultralong proximity length (lp) up to 7 μm. With the thicker 42 nm WTe2 layer, however, the proxi...

This paper investigates in a multi-level government system, how the federal government sets environmental standards for different states after communicating with state governments regarding the cost of pollution abatement to local economies. Here, the term “federal government” refers to the level of government in a federation responsible for the whole country, while “state governments” are responsible for individual states. We adopt a game-theoretical analysis under asymmetric information where state governments, which know the pollution abatement cost, report to the federal government, which is initially uninformed about the true cost level. We argue that interstate spillover of pollution causes a bias for state governments towards lax environmental standards and gives state governments an incentive to exaggerate the economic cost of pollution abatement. In equilibrium, state governments partition the set of possible costs into disjoint subsets and report the same cost to the federal government under different costs within each partition. After receiving reports, the federal government only knows the partition to which the local cost belongs and sets environmental standards that are not appropriate for the state. On the other hand, when state governments have the authority of setting local standards, the standards are inefficiently lax from a total welfare perspective. The paper compares total welfare levels of all states under the environmental standards set by the federal and state governments. The result indicates that if the degree of spillover is small, the welfare level in the centralized system is less than that in the decentralized system.

This paper presents a novel time integration algorithm for solving linear structural dynamic problems in the framework of the high-order collocation method. When two Gauss points in the integration interval are selected as collocation points, both an A-stable algorithm with third order accuracy and a non-dissipative algorithm with fourth order accuracy can be derived from a second order collocation polynomial. The only difference is that the former obtains a numerical solution at the middle point of the time interval, while the latter has a solution at the end of the interval. A new composite method is established through applying these two algorithms alternately, which combines the advantages of the numerical dissipation property of the third order algorithm and the high-order accuracy of the fourth order algorithm. The usage frequency of the two algorithms during the whole step-by-step integration procedure is an important parameter affecting the numerical dissipation, which is investigated in this study. As the algebraic equations systems solved by the two algorithms are exactly same, no extra computation effort is introduced.

Recently, layered two-dimensional ferromagnetic materials (2D FMs) have attracted a great deal of interest for developing low-dimensional magnetic and spintronic devices. Mechanically exfoliated 2D FMs were discovered to possess ferromagnetism down to monolayer. It is therefore of great importance to investigate the distinct magnetic properties at low dimensionality. Here, we report the wafer-scale growth of 2D ferromagnetic thin films of Fe3GeTe2 via molecular beam epitaxy, and their exotic magnetic properties can be manipulated via the Fe composition and the interface coupling with antiferromagnetic MnTe. A 2D layer-by-layer growth mode has been achieved by in situ reflection high-energy electron diffraction oscillations, yielding a well-defined interlayer distance of 0.82 nm along {002} surface. The magnetic easy axis is oriented along c-axis with a Curie temperature of 216.4 K. Remarkably, the Curie temperature can be enhanced when raising the Fe composition. Upon coupling with MnTe, the coercive field dramatically increases 50% from 0.65 to 0.94 Tesla. The large-scale layer-by-layer growth and controllable magnetic properties make Fe3GeTe2 a promising candidate for spintronic applications. It also opens up unprecedented opportunities to explore rich physics when coupled with other 2D superconductors and topological matters. Molecular beam epitaxy enables wafer-scale growth of Fe3GeTe2, an atomically thin ferromagnetic compound. A team led by Faxian Xiu at Fudan University demonstrated layer-by-layer growth of large-area, 8 nm-thick films of Fe3GeTe2 on sapphire and GaAs substrates in a high-vacuum molecular beam epitaxy system. The measured Curie temperature of 216.4 K was found to vary systematically with the Fe composition, indicating that Fe doping is a viable route to achieving tailored ferromagnetic ternary compounds with tunable Curie temperature. Furthermore, upon coupling Fe3GeTe2 with antiferromagnetic MnTe, the magnetic properties of the former could be enhanced owing to the exchange interaction from the ferromagnetic/antiferromagnetic superlattice interface. As a result, the coercive field increased by 50% with respect to bare Fe3GeTe2. These results highlight that Fe3GeTe2 and its heterostructures are promising candidates for spintronic devices.

We propose an efficient colocated multiple-input multiple-output radar waveform-design method based on two-step optimizations in the spatial and spectral domains. First, a minimum integrated side-lobe level strategy is adopted to obtain the desired beam pattern with spatial nulling. By recovering the hidden convexity of the resulting fractional quadratically constrained quadratic programming non-convex problem, the global optimal solution can be achieved in polynomial time through a semi-definite relaxation followed by spectral factorization. Second, with the transmit waveforms obtained via spatial optimization, a phase changing diagonal matrix is introduced and optimized via power method-like iterations. Without influencing the shape of the optimized beam pattern, the transmit waveforms are further optimized in the spectral domain, and the desired spectral nulling is formed to avoid radar interference on the overlaid licensed radiators. Finally, the superior performance of the proposed method is demonstrated via numerical results and comparisons with other approaches to waveform design.

Community or module structure is one of the most common features in complex networks. The label propagation algorithm (LPA) is a near linear time algorithm that is able to detect community structure effectively. Nevertheless, when labeling a node, the LPA adopts the label belonging to the majority of its neighbors, which means that it treats all neighbors equally in spite of their different effects on the node. Another disadvantage of LPA is that the results it generates are not unique. In this paper, we propose a modified LPA called Stepping LPA-S, in which labels are propagated by similarity. Furthermore, our algorithm divides networks using a stepping framework, and uses an evaluation function proposed in this paper to select the final unique partition. We tested this algorithm on several artificial and real-world networks. The results show that Stepping LPA-S can obtain accurate and meaningful community structure without priori information.