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In this experimental study, we use a data-driven machine learning framework based on genetic programing (GP) to discover model-free control laws (individuals) for suppressing self-excited thermoacoustic oscillations in a prototypical laminar combustor. This GP framework relies on an evolutionary algorithm to make decisions based on natural selection. Starting from an initial generation of individuals, we rank their performance based on a cost function that accounts for the trade-off between the state cost (thermoacoustic amplitude) and the input cost (actuator power). We then breed subsequent generations of individuals via a tournament in which the direct forwarding of elite individuals occurs alongside genetic operations such as mutation, replication, and crossover. We implement this GP control framework in both closed-loop and open-loop forms, followed by benchmarking against conventional open-loop control based on time-periodic forcing. We find that while all three control strategies can achieve similarly large reductions in thermoacoustic amplitude, GP closed-loop control consumes the least actuator power, making it the most efficient. It achieves this efficiency by learning an actuation mechanism that exploits the strong heat-release-rate amplification of the open flame at its preferred mode, even though the GP algorithm has never seen the open flame itself. This study demonstrates the feasibility of using GP to discover new and more efficient model-free individuals for suppressing self-excited thermoacoustic oscillations, providing a promising approach to data-driven feedback control of combustion devices. [ABSTRACT FROM AUTHOR]

This paper investigates the complete regularity of the weak solutions, the existence of the strong (X,X2α)$$ \left(X,{X}_{2\alpha}\right) $$‐global and exponential attractors, and their stability on dissipative index α$$ \alpha $$ for the structurally damped Kirchhoff wave equation: utt−M(‖∇u‖2)Δu+(−Δ)αut+f(u)=g(x)$$ {u}_{tt}-M\left({\left\Vert \nabla u\right\Vert}^2\right)\Delta u+{\left(-\Delta \right)}^{\alpha }{u}_t+f(u)=g(x) $$, together with the Dirichlet boundary condition, where the perturbed parameter α∈(1/2,1)$$ \alpha \in \left(1/2,1\right) $$ is called a dissipative index, X$$ X $$ is energy space, and X2α$$ {X}_{2\alpha } $$ is strong solution space. We show that when the nonlinearity f(u)$$ f(u) $$ is of supercritical growth: p∗=N+2N−2≤p

The paper is concerned with the exponential attractors for the viscoelastic wave model in Ω ⊂ R 3 : u tt - h t (0) Δ u - ∫ 0 ∞ ∂ s h t (s) Δ u (t - s) d s + f (u) = g , with time-dependent memory kernel h t (·) which is used to model aging phenomena of the material. Conti et al. (Am J Math 140(2):349–389, 2018a; Am J Math 140(6):1687–1729, 2018b) recently provided the correct mathematical setting for the model and a well-posedness result within the novel theory of dynamical systems acting on time-dependent spaces, recently established by Conti et al. (J Differ Equ 255:1254–1277, 2013), and proved the existence and the regularity of the time-dependent global attractor. In this work, we further study the existence of the time-dependent exponential attractors as well as their regularity. We establish an abstract existence criterion via quasi-stability method introduced originally by Chueshov and Lasiecka (J Dyn Differ Equ 16:469–512, 2004), and on the basis of the theory and technique developed in Conti et al. (2018a, b) we further provide a new method to overcome the difficulty of the lack of further regularity to show the existence of the time-dependent exponential attractor. And these techniques can be used to tackle other hyperbolic models. [ABSTRACT FROM AUTHOR]

In this study, calibrated hot box and finite element simulation methods were used to study the influence of a slotted web on the thermal performance of a lightweight steel stud composite wall. By comparing the results from the simulations and experiments, the accuracy of the finite element method was verified; this method was then used for parameter analyses. The results showed that the wall's thermal transfer coefficient is inversely proportional to increases in the length of the slot and height of the stud web, leading to improvements in the thermal insulation effect; vice versa, the wall thermal transfer coefficient increases when the slot transverse spacing and stud thickness increase, and the insulation effect correspondingly worsens. The stud spacing influences the insulation performance of the wall by changing the proportion of studs within a certain wall. The greater the proportion of studs, the greater the stud thermal bridging, the faster the thermal loss, and the worse the insulation effect of the wall. In practice, the height of the stud web can be set as required. Preferably, for practical applications, the number of rows of slots is 5–7, the length of the slots is 70–80 mm, the transverse distance of the slots is 6–8 mm, the thickness of each stud is 1 or 1.2 mm, and the distance of each stud is 600 mm. [ABSTRACT FROM AUTHOR]

The paper investigates the well-posedness and the regularity of the solutions, the existence and the continuity of the strong attractors for the structurally damped Kirchhoff wave models with subcritical-critical nonlinearities: u tt - (1 + ϵ ‖ ∇ u ‖ 2 ) Δ u + (- Δ) α u t + h (u t) + g (u) = f (x) , where ϵ ∈ [ 0 , 1 ] is a perturbed extensibility parameter, α ∈ [ 1 / 2 , 1) is a dissipative index. We show that when the nonlinearity g(u) is of either critical growth as α ∈ (1 / 2 , 1) or subcritical growth as α = 1 / 2 , while h (u t) is of critical growth depending on α , the model is well-posed and its weak solution is exactly the strong one; the related solution semigroup S ϵ (t) has a strong (X, Y)-global attractor and a strong (X, Y)-exponential attractor, which are also the standard global and exponential attractor of optimal regularity of S ϵ (t) in X, respectively, where X is the energy space and Y is the strong solution space; these global attractors are upper semicontinuous and these exponential attractors are Hölder continuous with respect to perturbed parameter ϵ in the sense of Y-topology, respectively. [ABSTRACT FROM AUTHOR]

Sweet potato (Ipomoea batatas [L.] Lam) is an important food crop, an excellent fodder crop, and a new type of industrial raw material crop. The lack of genomic resources could affect the process of industrialization of sweet potato. Few detailed reports have been completed on the mitochondrial genome of sweet potato. In this research, we sequenced and assembled the mitochondrial genome of sweet potato and investigated its substructure. The mitochondrial genome of sweet potato is 270,304 bp with 23 unique core genes and 12 variable genes. We detected 279 pairs of repeat sequences and found that three pairs of direct repeats could mediate the homologous recombination into four independent circular molecules. We identified 70 SSRs in the whole mitochondrial genome of sweet potato. The longest dispersed repeat in mitochondrial genome was a palindromic repeat with a length of 915 bp. The homologous fragments between the chloroplast and mitochondrial genome account for 7.35% of the mitochondrial genome. We also predicted 597 RNA editing sites and found that the rps3 gene was edited 54 times, which occurred most frequently. This study further demonstrates the existence of multiple conformations in sweet potato mitochondrial genomes and provides a theoretical basis for the evolution of higher plants and cytoplasmic male sterility breeding. [ABSTRACT FROM AUTHOR]

Sweet potato (Ipomoea batatas [L.] Lam) is an important food crop, an excellent fodder crop, and a new type of industrial raw material crop. The lack of genomic resources could affect the process of industrialization of sweet potato. Few detailed reports have been completed on the mitochondrial genome of sweet potato. In this research, we sequenced and assembled the mitochondrial genome of sweet potato and investigated its substructure. The mitochondrial genome of sweet potato is 270,304 bp with 23 unique core genes and 12 variable genes. We detected 279 pairs of repeat sequences and found that three pairs of direct repeats could mediate the homologous recombination into four independent circular molecules. We identified 70 SSRs in the whole mitochondrial genome of sweet potato. The longest dispersed repeat in mitochondrial genome was a palindromic repeat with a length of 915 bp. The homologous fragments between the chloroplast and mitochondrial genome account for 7.35% of the mitochondrial genome. We also predicted 597 RNA editing sites and found that the rps3 gene was edited 54 times, which occurred most frequently. This study further demonstrates the existence of multiple conformations in sweet potato mitochondrial genomes and provides a theoretical basis for the evolution of higher plants and cytoplasmic male sterility breeding. [ABSTRACT FROM AUTHOR]

Background: SARS-CoV-2, the causal agent of COVID-19, enters human cells using the ACE2 (angiotensin-converting enzyme 2) protein as a receptor. ACE2 is thus key to the infection and treatment of the coronavirus. ACE2 is highly expressed in the heart and respiratory and gastrointestinal tracts, playing important regulatory roles in the cardiovascular and other biological systems. However, the genetic basis of the ACE2 protein levels is not well understood. Methods: We have conducted the largest genome-wide association meta-analysis of plasma ACE2 levels in >28 000 individuals of the SCALLOP Consortium (Systematic and Combined Analysis of Olink Proteins). We summarize the cross-sectional epidemiological correlates of circulating ACE2. Using the summary statistics–based high-definition likelihood method, we estimate relevant genetic correlations with cardiometabolic phenotypes, COVID-19, and other human complex traits and diseases. We perform causal inference of soluble ACE2 on vascular disease outcomes and COVID-19 severity using mendelian randomization. We also perform in silico functional analysis by integrating with other types of omics data. Results: We identified 10 loci, including 8 novel, capturing 30% of the heritability of the protein. We detected that plasma ACE2 was genetically correlated with vascular diseases, severe COVID-19, and a wide range of human complex diseases and medications. An X-chromosome cis–protein quantitative trait loci–based mendelian randomization analysis suggested a causal effect of elevated ACE2 levels on COVID-19 severity (odds ratio, 1.63 [95% CI, 1.10–2.42]; P =0.01), hospitalization (odds ratio, 1.52 [95% CI, 1.05–2.21]; P =0.03), and infection (odds ratio, 1.60 [95% CI, 1.08–2.37]; P =0.02). Tissue- and cell type–specific transcriptomic and epigenomic analysis revealed that the ACE2 regulatory variants were enriched for DNA methylation sites in blood immune cells. Conclusions: Human plasma ACE2 shares a genetic basis with cardiovascular disease, COVID-19, and other related diseases. The genetic architecture of the ACE2 protein is mapped, providing a useful resource for further biological and clinical studies on this coronavirus receptor. [ABSTRACT FROM AUTHOR]

Harmonic injection method is widely used in the suppression of current harmonic and torque ripple in field-oriented control (FOC) permanent magnet synchronous motor (PMSM) servo system. However, under some working conditions of FOC PMSM, the harmonic injection method fails to suppress the current harmonics and causes oscillation. To analyze the cause of oscillation, the transfer mechanism of injected voltage harmonic is analyzed in this article, and the relation between injected voltage harmonic and current harmonic is derived. The theoretical analysis results show that the relation between harmonics will change with motor speed and parameters of FOC PMSM. When the relation between harmonics is reversed, the existing harmonic injection method will fail and cause harmonic oscillation. To solve this problem, a simple improvement of the harmonic injection method is proposed in this article based on the proposed close-loop model. The correctness of the mathematical derivation and the effectiveness of the proposed method is evaluated by experiment and simulation. [ABSTRACT FROM AUTHOR]

The paper investigates the robustness of pullback attractors and pullback exponential attractors of the non-autonomous Kirchhoff wave models with strong nonlinear damping: u tt - (1 + ϵ ‖ ∇ u ‖ 2 ) Δ u - σ (‖ ∇ u ‖ 2) Δ u t + f (u) = g (x , t) , where ϵ ∈ [ 0 , 1 ] is an extensibility parameter. It shows that when the growth exponent p of the nonlinearity f(u) is up to the supercritical range: 1 ≤ p < p ∗ ∗ ≡ N + 4 (N - 4) + , (i) the related process has a pullback attractor A ϵ in natural energy space H = (H 0 1 ∩ L p + 1) × L 2 for each ϵ , and it is upper semicontinuous on the perturbation ϵ ; (ii) the related process has a partially strong pullback exponential attractor M ϵ for each ϵ , and it is Hölder continuous on ϵ ∈ [ 0 , 1 ] . These results deepen and extend those in recent literatures (Chueshov in J Diff Equ 252:1229–1262, 2012; Ding et al. in Appl Math Lett 76:40–45, 2018; Wang and Zhong in Discrete Contin Dyn Syst 7:3189–3209, 2013). The main novelty of this paper is that it provides a new method to investigate the upper semicontinuity of pullback attractors and the stability of pullback exponential attractors in supercritical nonlinearity case. [ABSTRACT FROM AUTHOR]

In this paper, we prove the upper semicontinuity of the strong global attractors 𝒜θ on the dissipative index θ in the topology of the stronger space for the Kirchhoff wave model with structural nonlinear damping: utt−ϕ(‖∇u‖2)△u+σ(‖∇u‖2)(−Δ)θut+f(u)=g(x), with θ ∈ [1/2, 1). It is continuation of the research in recent literatures1,2 where the upper semicontinuity of the strong attractor 𝒜θ on θ in the topology of natural energy space is obtained. This result improves and deepens those in recent literatures (Li and Yang in J Differ Equat. 2020; 268: 7741‐7743; Li, Yang and Ding in Appl. Math. Lett. 2020; 104:106258). [ABSTRACT FROM AUTHOR]

Torque ripple degrades the performance of a permanent magnet synchronous motor (PMSM). Harmonic injection method can minimize torque ripple well by suppressing the speed harmonic. But its performance under transient conditions is not satisfactory. Moreover, too much computation and complex parameter adjustment limit its application in multiharmonic suppression of speed. Therefore, this article proposes an order-domain-based harmonic injection (OHI) method for multiple speed harmonics suppression under both steady-state and transient conditions. In the OHI method, speed harmonics are extracted as feedback signals and suppressed by a speed harmonic controller. The speed harmonic controller is designed based on real and imaginary parts. The relations among the voltage, current, and speed harmonics are derived. According to these relations, speed harmonics are adjusted directly by voltage harmonics. For faster harmonic extraction, the real-time angular-domain Fourier transform (AFT) is proposed by improving an AFT algorithm. The OHI method has less calculation and simpler parameter adjustment compared with existing methods. So, it is more suitable for multiharmonic suppression of speed. Due to the extremely fast respond of speed harmonic control loop, the OHI method is effective even under transient conditions. The OHI method is simulated and experimentally evaluated in PMSM servosystem. [ABSTRACT FROM AUTHOR]

The Fusarium wilt disease caused by Fusarium oxysporum f. sp. batatas (Fob) is one of the devastating diseases of sweetpotato. However, the molecular mechanisms of sweetpotato response to Fob is poorly understood. In the present study, comparative quantitative proteomic analysis was conducted to investigate the defense mechanisms involved. Two sweetpotato cultivars with differential Fob infection responses were inoculated with Fob spore suspensions and quantitatively analyzed by Tandem Mass Tags (TMT). 2267 proteins were identified and 1897 of them were quantified. There were 817 proteins with quantitative ratios of 1.2-fold change between Fob-inoculated and mock-treated samples. Further, nine differentially expressed proteins were validated by Parallel Reaction Monitoring (PRM). According to Gene Ontology (GO) annotation information, the proteins functioned in molecular metabolism, cellular component formation, and biological processes. Interestingly, the results showed that sweetpotato resistant response to Fob infection included many proteins associated with signaling transduction, plant resistance, chitinase and subtilisin-like protease. The functions and possible roles of those proteins were discussed. The results provides first insight into molecular mechanisms involved in sweetpotato defense responses to Fob. [ABSTRACT FROM AUTHOR]

Four prestressed high-strength concrete pile- (PHC pile-) pile cap connections under low-cycle loading were tested to study the test phenomena, failure modes, hysteretic performance, ductility, and bearing capacity. The PHC piles were reinforced with steel fiber and deformed bars and CFRP. The tests results showed that the connections were damaged by bending. The concrete of the caps were squeezed to be crushed. The concrete of connection was crushed and formed a hinge joint that resulted in the connection rotating unrestricted, and the rotation capacity of connection increased. The PHC pile reinforced with steel fiber and deformed bars can improve the displacement ductility of the connections. The finite element software ABAQUS was used to simulate the nonlinear behavior of pile-cap connections. The prediction agreed relatively well with the experimental results. The stress and strain of specimens were studied. The connections should be designed with enough rotating capacity and make sure the cap will not be damaged by squeezing or prying due to the rotation of pile end. [ABSTRACT FROM AUTHOR]

The paper investigates the well-posedness and longtime dynamics of the Kirchhoff wave model with structural nonlinear damping: u t t − ϕ (‖ ∇ u ‖ 2) Δ u + σ (‖ ∇ u ‖ 2) (− Δ) θ u t + f (u) = g (x) , with θ ∈ [ 1 / 2 , 1). We find a new critical exponent p ⁎ ≡ N + 2 N − 2 (> p θ ≡ N + 2 θ N − 2 , N ≥ 3) and show that when the growth exponent p of the nonlinearity f (u) is up to the range: 1 ≤ p < p ⁎ : (i) the IBVP of the equation is well-posed and its solution is of additionally global regularity when t > 0 ; (ii) for each θ ∈ [ 1 / 2 , 1) , the related solution semigroup has in natural energy space H an optimal global attractor A θ whose compactness and attractiveness are in the regularized space H 1 + θ where A θ lies, and an optimal exponential attractor E θ ⁎ whose compactness, boundedness of the fractional dimension and the exponential attractiveness are in H 1 + θ where E θ ⁎ lies, respectively; (iii) the family of global attractors { A θ } θ ∈ [ 1 / 2 , 1) is upper semi-continuous at each point θ 0 ∈ [ 1 / 2 , 1). The paper breaks though the longstanding existed growth restriction: 1 ≤ p ≤ p θ for p θ had been considered a uniqueness index, deepens and extends the results in literature [6,25,27]. [ABSTRACT FROM AUTHOR]

Previous dismal clinical studies have stated that colorectal cancer with unresectable liver metastases is an absolute contraindication for liver transplantation (LT). During recent decades, it has been shown that patients with colorectal cancer with liver metastasis benefited from LT, but 100% recurrence was inevitable in progressive colorectal cancer with liver metastasis. A 61-year-old man was found at the first visit to be suffering from unresectable liver metastases of colorectal cancer. This patient underwent colorectal radical surgery and palliative treatment after the operation. During a 2-year follow-up, we found that CEA and CA199 rebounded sharply to high levels, and liver metastasis lesions increased significantly, so we made the decision to perform LT 2 years after the first surgery. Chemotherapy and sirolimus were given post-LT. Slow-growing pulmonary metastases after transplantation were found 4 months post-LT. This patient survived the next 4 months tumor-free and by now has survived 34 months free of liver tumors. Here, we review the literature on LT for progressive liver metastasis of colorectal cancer and summarize our experience from this successful case. This case provides vital evidence that LT is an option and can provide curative therapy for patients with advanced unresectable liver metastasis. Careful selection of patients, postoperative comprehensive treatments, and rational application of immunosuppressive agents are vital factors for favorable prognosis. • A patient with simultaneous colon and rectal colon liver metastasis, received liver transplantation and has been tumor-free for 34 months up to now. • Perioperative chemotherapy and mTOR immunosuppressive agents are key factors to reduce recurrence, but not tumor loading. • We present a summary of our center experience in comprehensive management of liver transplantation in patients with NRCLM. [ABSTRACT FROM AUTHOR]

Self-healing polymeric materials have attracted considerable interests due to the capability of healing the cracks generated in functional materials autonomously, resulting in improved reliability and life cycle. This paper is intended to develop a self-healing polymeric binder for energetic composites by incorporation of reversible covalent bonds into polyurethane. A novel polyurethane was synthesized from NCO-terminated prepolymer with furfuryl amine, and cross-linked with bismaleimide via Diels-Alder (DA) reaction. The chemical structures of the intermediates and products of Diels-Alder polyurethane (DAPU) were firstly confirmed by nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Then, the thermal reversibility and the self-healing performances of DAPU based energetic composites were systematically studied by DSC, polarizing optical microscopy (POM) and tensile testing. All the results showed that the as-prepared DAPU had high self-healing efficiency and remarkable mechanical performance, providing potential applications as a promising self-healing material in repairing the cracks generated in energetic composites. • Self-healing polymeric binder with Diels-Alder bonds can be easily synthesized. • The as-prepared Diels-Alder polyurethane has perfect self-healing properties. • The self-healing polyurethane has stronger mechanical properties than commercial polyurethane. • Energetic composites contained self-healing polyurethane exhibit evidently high self-healing capability. • The self-healing energetic composites present remarkable mechanical performance. [ABSTRACT FROM AUTHOR]

With the emergence and commercialization of graphene, new opportunities have emerged for toughening polymer‐based functional energetic composites (e.g., polymer‐bonded explosives [PBX]) using nano‐graphene without sacrificing strength and glass transition temperature, as compared with conventional elastomeric tougheners. In this work, inorganic nano‐graphene is used to study the toughness enhancing effects and mechanical properties of 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (HMX)‐based PBX. Fabrication procedures of HMX‐based PBX with different content of graphene are presented, and well‐dispersion for graphene in binder matrix is obtained by ultrasonic processing. Experimental results indicated the addition of nano‐graphene can greatly increase the toughness, with the fracture energy enhanced from 32.5 to 64.9 J m−3 compared with normal HMX‐based PBX. Such improvement was obtained at a low graphene concentration (0.2–0.4 wt%). Strong interaction of the graphene and the binder matrix, combined with the inherent properties of well‐dispersed graphene are the decisive factors with respect to the outstanding toughening effect. POLYM. COMPOS., 40:E1151–E1161, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Research shows that the viscosity greatly reduction of viscous crude oil can improve the exploitation and promote the fluidity. We studied the effects and the mechanism of viscosity reduction of viscous crude oil emulsion after introducing the ternary compound of sulfonate-straight chain alcohol-alkaline as the viscosity reducer. Results showed that the best emulsifying performance can be achieved using 5% 1-pentanol. 0.2% of Na2CO3 and DEA shows the strongest emulsification ability of the O/W emulsion. The use of AOS, straight chain alcohol and petroleum carboxylate resolves diffusion on the oil-water interface, which can form a dense surfactant of single molecular layer to reduce the interfacial tension and prevent the phase change of the emulsification. When the mass fraction of AOS, Na2CO3, DEA and 1-pentanol were 0.2%, 0.25%, 0.2% and 5% respectively, the viscous crude oil would achieve the best effect of viscosity reduction. [ABSTRACT FROM AUTHOR]

Abstract The paper investigates longtime dynamics of the Kirchhoff wave equation with strong damping and critical nonlinearities: u t t − (1 + ϵ ‖ ∇ u ‖ 2) Δ u − Δ u t + h (u t) + g (u) = f (x) , with ϵ ∈ [ 0 , 1 ]. The well-posedness and the existence of global and exponential attractors are established, and the stability of the attractors on the perturbation parameter ϵ is proved for the IBVP of the equation provided that both nonlinearities h (s) and g (s) are of critical growth. [ABSTRACT FROM AUTHOR]

The paper investigates the stability of exponential attractors for a family of semilinear wave equations with gentle dissipation: u t t − Δ u + γ ( − Δ ) α u t + f ( u ) = g ( x ) , with α ∈ ( 0 , 1 / 2 ) . (i) We propose a new criterion on the existence and stability of a family of exponential attractors depending on the perturbation parameters. (ii) By applying this criterion to the equations, we construct a family of exponential attractors A e x p α and show their stability on the dissipative exponent α . [ABSTRACT FROM AUTHOR]

The paper investigates the existence of global attractor of the quasi-linear wave equation with strong damping u t t − γ Δ u t − Δ u + f ( u ) = ∇ ⋅ ϕ ′ ( ∇ u ) + g . It proves that the energy solution of the equation is stable and the related dynamical system possesses a (strong) global attractor in natural energy space (rather than a weak one as known before). These results improve the recent ones in [13] . [ABSTRACT FROM AUTHOR]

The paper investigates the existence of global attractor of Kirchhoff type equations with strong nonlinear damping: u t t − σ ( ‖ ∇ u ‖ 2 ) Δ u t − ϕ ( ‖ ∇ u ‖ 2 ) Δ u + f ( u ) = h ( x ) . It proves that when the growth exponent p of the nonlinearity f ( u ) is up to the supercritical range: N + 2 N − 2 ≡ p ∗ < p < p ∗ ∗ ≡ N + 4 ( N − 4 ) + ( N ≥ 3 ) , the related solution semigroup still has a global attractor (rather than a partially strong one as known before) in natural energy space. [ABSTRACT FROM AUTHOR]

The paper investigates the well-posedness and longtime dynamics of Boussinesq type equations with fractional damping: u t t + Δ 2 u + ( − Δ ) α u t − Δ f ( u ) = g ( x ) , with α ∈ ( 1 , 2 ) . The main results focus on the relations among the dissipative exponent α , the growth exponent p of nonlinearity f ( u ) and the well-posedness and the longtime dynamics of the equations. We find a new critical exponent p α ≡ N + 2 ( 2 α − 1 ) ( N − 2 ( 2 α − 1 ) ) + rather than p ∗ ≡ N + 2 N − 2 ( N ≥ 3 ) as known before and show that when 1 ≤ p < p α : (i) The equations are like parabolic, that is, not only the IBVP of the equations are well-posedness, but also their weak solutions are of higher global regularity as t > 0 . (ii) The related solution semigroup has a global attractor A α in natural energy space, and also has an exponential attractor A e x p α in the sense of partially strong topology. In particular, when 1 ≤ p < p α ′ ≡ N + 2 α ( N − 2 α ) + ( < p α ) , the partially strong topology becomes the strong one. (iii) For any α 0 ∈ [ 1 , 2 ) , the family of global attractors A α is upper semicontinuous at the point α 0 . [ABSTRACT FROM AUTHOR]

Introduction: Femur head necrosis (FHN) is a challenging clinical disease with unclear underlying mechanism, which pathologically is associated with disordered metabolism. However, the disordered metabolism in cancellous bone of FHN was never analyzed by gas chromatography-mass spectrometry (GC-MS). Objectives: To elucidate altered metabolism pathways in FHN and identify putative biomarkers for the detection of FHN. Methods: We recruited 26 patients with femur head necrosis and 22 patients with femur neck fracture in this study. Cancellous bone tissues from the femoral heads were collected after the surgery and were analyzed by GC-MS based untargeted metabolomics approach. The resulting data were analyzed via uni- and multivariate statistical approaches. The changed metabolites were used for the pathway analysis and potential biomarker identification. Results: Thirty-seven metabolites distinctly changed in FHN group were identified. Among them, 32 metabolites were upregulated and 5 were downregulated in FHN. The pathway analysis showed that linoleic acid metabolism were the most relevant to FHN pathology. On the basis of metabolites network, L-lysine, L-glutamine and L-serine were deemed as the junctions of the whole metabolites. Finally, 9,12-octadecadienoic acid, inosine, L-proline and octadecanoic acid were considered as the potential biomarkers of FHN. Conclusion: This study provides a new insight into the pathogenesis of FHN and confirms linoleic acid metabolism as the core. [ABSTRACT FROM AUTHOR]

Background: Most of Camellia oleifera forests have low fruit yield and poor oil quality that are largely associated with soil fertility. Soil physical and chemical properties interact with each other affecting soil fertility and C. oleifera growing under different soil conditions produced different yield and oil composition. Three main soil types were studied, and redundancy, correlation, and double-screening stepwise regression analysis were used for exploring the relationships between C. oleifera nutrients uptake and soil physical and chemical properties, shedding light on the transport law of nutrient elements from root, leaves, and kernel, and affecting the regulation of fruit yield and oil composition. Results: In the present study, available soil elements content of C. oleifera forest were mainly regulated by water content, pH value, and total N, P and Fe contents. Seven elements (N, P, K, Mg, Cu, Mn and C) were key for kernel's growth and development, with N, P, K, Cu and Mn contents determining 74.0% the yield traits. The transport characteristics of these nutrients from root, leaves to the kernel had synergistic and antagonistic effects. Increasing oil production and unsaturated fatty acid content can be accomplished in two ways: one through increasing N, P, Mg, and Zn contents of leaves by applying corresponding N, P, Mg, Zn foliar fertilizers, while the other through maintaining proper soil moisture content by applying Zn fertilizer in the surface layer and Mg and Ca fertilizer in deep gully. Conclusion: Soil type controlled nutrient absorption by soil pH, water content and total N, P and Fe content. There were synergistic and antagonistic effects on the inter-organ transport of nutrient elements, ultimately affecting N, P, K, Cu and Mn contents in kernel, which determined the yield and oil composition of C. oleifera. [ABSTRACT FROM AUTHOR]

The paper investigates the upper semicontinuity of global attractors A α of a family of semilinear wave equations with gentle dissipation: u t t − △ u + γ ( − △ ) α u t + f ( u ) = g ( x ) , with α ∈ ( 0 , 1 ∕ 2 ) . It is a continuation of researches in Yang et al. (2016), where the existence of global attractors of the equations has been established. We further show that for any neighborhood U of A α 0 , α 0 ∈ ( 0 , 1 ∕ 2 ) , A α ⊂ U when 0 < α − α 0 ≪ 1 . [ABSTRACT FROM AUTHOR]

The development of a facile method for improvement of interface interaction between rigid particles and coating polymer is of great importance for energetic composite materials, especially for military purpose. In this paper, energetic composites with spherical morphology, toughness property and low sensitivity are firstly fabricated by using Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) as core material and thermoplastic polyester-ether elastomer (TPEE) as shell material via an emulsion solvent evaporation (ESV) method. From the morphology and structure characteristic of as-prepared energetic microspheres, it is found that the HMX@TPEE energetic microspheres have uniform spherical morphologies, narrow size distribution and honeycomb coating structure under the circumstance of compound emulsifiers and appropriate core-shell ratio. The good toughness of HMX@TPEE microspheres in Brazilian test and dynamic mechanical analysis (DMA) demonstrates a new route to enhance interface interaction between HMX particles and TPEE matrix. Moreover, because of the favorable energy-decentralizing property of this exotic honeycomb structure, the sensitivity of HMX@TPEE microspheres measured by BAM impact sensitivity instrument can be markedly decreased and the impact energy ( E li ) can be improved from 3.5 J to 8.0 J at the HMX/TPEE ratio of 5/1. This fabrication of HMX@TPEE microspheres with adjustable coating content via a facile ESV process might provide a promising approach for HMX based energetic composites to enhance the safety and toughness properties when used in advanced weapon system. [ABSTRACT FROM AUTHOR]

ABSTRACT A compact broadband horizontally/vertically polarized omnidirectional antenna with high isolations is presented for indoor distributed antenna systems. The antenna is a combination of a horizontally polarized (HP) element and a vertically polarized (VP) element, which are connected by four broadside parallel strips (BPSs). Its HP and VP elements consist of four horizontal and vertical elliptical printed dipoles respectively. The vertical dipoles locate between adjacent horizontal dipoles, which makes the antenna compact in structure. The dual-polarized antenna obtains a bandwidth of 45.5% from 1.7 to 2.7 GHz, and the port isolations are better than 30 dB without introducing large distance between vertical dipoles and horizontal dipoles. The HP and VP gains are higher than 1.7 and 2 dBi respectively. For both horizontal and vertical elements, the radiation patterns in the horizontal plane are omnidirectional with ripples <2.5 dB, and the cross-polarization levels are also below −25 dB in the horizontal plane. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:176-180, 2017 [ABSTRACT FROM AUTHOR]

The paper studies the existence of an exponential attractor for the wave equation with structural damping and supercritical nonlinearity . By constructing a bounded absorbing set with higher global regularity (rather than the long-standing partial regularity) and by using the weak quasi-stability estimates (rather than the strong ones as usual), we establish the existence of an exponential attractor in the natural energy space. [ABSTRACT FROM AUTHOR]

The paper investigates the global well-posedness and the longtime dynamics of the Kirchhoff equations with fractional damping and supercritical nonlinearity: u t t − M ( ‖ ∇ u ‖ 2 ) Δ u + ( − Δ ) α u t + f ( u ) = g ( x ) , with α ∈ ( 1 2 , 1 ) . The main results are focussed on the relationships among the growth exponent p of the nonlinearity f ( u ) , the global well-posedness and the longtime dynamics of the equations. We show that (i) even if p is up to the supercritical range, that is, 1 ≤ p < N + 4 α ( N − 4 α ) + , the well-posedness and the longtime behavior of the solutions of the equation are of the characters of the parabolic equation; (ii) when N + 4 α ( N − 4 α ) + ≤ p < N + 4 ( N − 4 ) + , the corresponding subclass G of the limit solutions exists and possesses a weak global attractor. [ABSTRACT FROM AUTHOR]

The two-dimensional (2D) graphene nanoplatelets (GNPs) were adopted to enhance the thermal conductivity of PBX. The results indicated that, the thermal conductivity of PBX was only slightly improved with very low GNP loading (0.05 wt% and 0.15 wt%). However, a remarkable enhanced effect was observed at a relatively high GNP loading (0.5 wt% and 1 wt%). The thermal conductivity of PBX had a nonlinear dependence on the GNPs loading. The nonlinear dependence of the thermal conductivity on GNPs content was fitted by an analytical model which incorporated all the effects. And the thermal conduction mechanism of GNPs based composite could change from series thermal structure to parallel thermal structure with the GNP loading increasing. Additionally, the calculated thermal shock resistance and thermal stress distribution of PBX was both enhanced with the GNP loading. Finally, the sensitivity of sensitive hexanitrohexaazaisowurtzitane (CL-20) based PBX composition could be improved by GNPs due to enhanced thermal conductivity. [ABSTRACT FROM AUTHOR]

The paper studies the longtime dynamics of the Kirchhoff equation with strong damping and critical nonlinearity on R N : u t t − Δ u t − M ( ‖ ∇ u ‖ 2 ) Δ u + u t + g ( x , u ) = f ( x ) . We establish the well-posedness, the existence of the global and exponential attractors in natural energy space H = H 1 ( R N ) × L 2 ( R N ) in critical nonlinearity case. These results improve not only the recent ones achieved by Yang (2007) [32] , but also ones achieved by Conti, Pata and Squassina (2005) [9] to some extent. [ABSTRACT FROM AUTHOR]

We study the existence of exponential attractor for the Kirchhoff equations with strong nonlinear damping and supercritical nonlinearity u t t − σ ( ‖ ∇ u ‖ 2 ) Δ u t − ϕ ( ‖ ∇ u ‖ 2 ) Δ u + f ( u ) = h ( x ) . The main result is that the nonlinearity f ( u ) is of supercritical growth. In this case we establish an exponential attractor in natural energy space by using a new method based on the weak quasi-stability estimates (rather than the strong one as usual). [ABSTRACT FROM AUTHOR]

This work is focused on the long-time behavior of solutions to the singularly perturbed damped Boussinesq equation in a 3D case [ABSTRACT FROM AUTHOR]

Melamine–formaldehyde resins (MF resins) were selected for the fabrication of three typical nitramine explosives (cyclotrimethylenetrinitramine, RDX; cyclotetramethylenetetranitramine, HMX; and hexanitrohexaazaisowurtzitane, CL-20) based microcapsules, the polymer coating shell could be prepared via a facile in situ polymerization of melamine and formaldehyde on the surface of explosive crystals. Structural characterizations and thermal properties of the core–shell composites were systematically studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), fourier-transform infrared (FT-IR) spectra and differential scanning calorimeter (DSC). The SEM and XPS results indicated that these three energetic cores were mostly well coated. XRD and FTIR analyses showed the combined characteristics of explosives and MF resins, and revealing that the polymorph of CL-20 maintained the optimal ε form during the whole preparing process. After coating, the endothermic polymorphic phase transition as well as the exothermic thermal decomposition temperature of the explosives was visibly increased, attributing to the outstanding heat resistance of MF resin shell. The impact sensitivity of the resultant microcapsules could be reduced from 2 to 3 times, depending on energetic material, after coating by 3 wt% MF resins. [ABSTRACT FROM AUTHOR]

The paper studies the existence of global attractor for the generalized double dispersion equation arising in elastic waveguide model u t t − Δ u − Δ u t t + Δ 2 u − Δ u t − Δ g ( u ) = f ( x ) . The main result is concerned with nonlinearities g ( u ) with supercritical growth. In that case we construct a subclass G of the limit solutions and show that it has a weak global attractor. Especially, in non-supercritical case, the weak topology becomes strong, the further regularity of the global attractor is obtained and the exponential attractor is established in natural energy space. [ABSTRACT FROM AUTHOR]

Six pile-cap connections were tested to evaluate performance of prestressed high-strength concrete piles (PHC pile)-cap connection under cyclic loading. The failure modes, hysteretic performance, ductility and bearing capacity were observed and analyzed. In addition, the seismic performance of pile-cap connection with different connections and cutting-off pile was studied. The test results showed that the connections appear to be bending damage. The two flexural modes were tensile rupturing of prestressed bar and yielding of anchor bars. The connections were severely damaged because of the yielding of anchor bars and appearing of the plastic hinge. The bond slippage failure of anchor bars was not observed in the cap, and the length of anchor bars meet requirements. It shows that the bearing capacity and energy dissipation capacity increased with the rotation capacity of pile connection. Nonlinear finite element models were established to analyze the mechanical properties of these connections using ABAQUS. The moment-displacement curves obtained from the numerical analysis compared well with the experimental results. The effects of parameters on the behavior of the connections were conducted based on the numerical model. [ABSTRACT FROM AUTHOR]

This paper investigates the well-posedness, the existence and the regularity of the time-dependent global attractor for a viscoelastic equation in Ω ⊂ R 3 : | ∂ t u | ρ ∂ t t u − ∂ t t Δ u − h t (0) Δ u − ∫ 0 ∞ ∂ s h t (s) Δ u (t − s) d s + f (u) = h with time-dependent memory kernel which is used to model aging phenomena of the material. By using the novel theory framework recently developed in literature (Conti et al., 2018 [12,13]) and establishing some delicate integration estimates along the trajectory of the solutions in the time-dependent phase space, we show that when ρ ∈ (1 , 4 ] , the growth exponent p of f (u) is up to the critical range 1 ≤ p ≤ 5 , and the time-dependent memory kernel satisfies the same conditions as in Conti et al., (2018) [12,13], the model is well-posed. Especially, when ρ ∈ (1 , 4) and 1 ≤ p < 5 , the related process has an invariant time-dependent global attractor which has optimal regularity. [ABSTRACT FROM AUTHOR]

We will introduce four new geometric constants closely related to the James constant J (X) , which have symmetric structure, along with a discussion on the relationships among them and some other well-known geometric constants via several inequalities, together with the calculation of several values on some specific spaces. In addition, we will characterize geometric properties of J 1 (X) , such as uniform non-squareness and uniformly normal structure. [ABSTRACT FROM AUTHOR]

We will introduce some new geometric constants based on the constant H (X) proposed by Gao and the constant A 2 (X) proposed by M. Baronti et al. We first provide a study of a new constant M 1 (X) closely related to the midlines of equilateral triangles, including a discussion of some of its properties and the connections with other parameters of the sphere. Next, we focus on a new constant M 2 (X) and its generalized form M 2 (X , p , q) , along with some of their basic properties. Finally, we concentrate on a new constant M 3 (X) and discuss some of its properties. [ABSTRACT FROM AUTHOR]

Abstract: The paper studies the existence of global strong attractor for the Kirchhoff type equations with strong nonlinear damping and supercritical nonlinearity . It proves that in strictly positive stiffness factors and supercritical nonlinearity case, there exists a global finite-dimensional attractor in the natural energy space endowed with strong topology (rather than partially strong topology). The result extends the recent one achieved by Chueshov (2012). [Copyright &y& Elsevier]

Abstract: In this paper, we study the longtime dynamics to a strongly damped wave equation. First, in the critical case, we prove by the l-trajectories method that the related solution semigroup has the exponential attractor. Second, in the subcritical case, we give an explicit upper bound of the fractal dimension of the exponential attractor in terms of the data of the equation. [Copyright &y& Elsevier]

Abstract: The paper studies the global existence, stability and the longtime dynamics of solutions to the initial boundary value problem (IBVP) of an extensible beam equation with nonlinear damping and source terms: . It proves that (i) the IBVP is global well posed provided that either the growth exponent p of the source term is non-supercritical, that is, and if or p is supercritical but is dominated by the growth exponent q of the nonlinear damping , i.e. if ; (ii) the related solution semigroup has in phase space X a finite-dimensional global attractor , which has -regularity, and also an exponential attractor provided either or if ; (iii) especially, when the space dimension , all the above mentioned conclusions hold without any restriction on p and q, that is, . [Copyright &y& Elsevier]

Abstract: The paper studies the longtime dynamics of the damped Boussinesq equation . First, the existence of global solutions to the initial boundary value problem of the equation is obtained provided that the growth exponent of , say , is either non-supercritical (subcritical and critical) or supercritical, especially, the stability of solutions is established when is non-supercritical. Second, the existence of a global attractor and an exponential attractor for the related solution semigroup are respectively established in the non-supercritical case. [Copyright &y& Elsevier]

Abstract: This paper studies the longtime behavior of solutions to the elastic waveguide model in . It proves that when the space dimension , under rather mild conditions on and the related solution semigroup possesses in phase space with low regularity , with , a global attractor which is connected. [Copyright &y& Elsevier]