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This work presents a Finite Element approach to model the in-plane mechanical behavior of C/C-SiC fabrics at the lamina level, including the non-linear response of diverse lay-ups and the bending-to-tensile strength ratio at failure. The material model employs a decomposition into two idealized phases, which can be exploited to capture matrix- and fiber-dominated responses at a high level of abstraction. The constitutive law of the matrix phase adopts a Continuum Damage approach driven by two Tsai-Wu surfaces, while a quasi-brittle behavior is attributed to the fibers phase. This decomposition effectively represents the influence of matrix degradation on the response and failure of the laminates. Moreover, simulations reveal that a statistical distribution of the strength is required to represent some of the experimental outcomes. The correlation with experimental data that was achieved points out that the technique is a promising tool for supporting the early design phase of CMC structures. [ABSTRACT FROM AUTHOR]

The carbon sink in pantropical biomes play a crucial role in modulating the inter‐annual variations of global terrestrial carbon balance and is threatened by extreme climate events. However, it has not been carefully examined whether an increase in tropical gross primary productivity (GPP) can compensate the decrease during precipitation anomalies. Using the asymmetry index (AI) and multiple GPP products, we assessed responses of pantropical GPP to precipitation anomalies during 2001–2022. Positive AI indicates that GPP increases are greater than GPP decreases during precipitation anomalies, and vice versa. Our results showed an average negative pantropical GPP asymmetry, that is, GPP decreases exceeded the GPP increases during precipitation anomalies. In addition, a positive AI was found in tropical hyper‐arid and arid regions, which is opposite to the negative AI observed in tropical semi‐arid, sub‐humid, and humid regions. This suggest that tropical GPP asymmetry changes from positive to negative as the moisture increases. Notably, a significant decreasing trend of negative AI was observed over the entire tropical region, indicating that the negative effect of inter‐annual precipitation variations on pantropical vegetation productivity has enhanced. Considering the model predicted increasing climate variability and extremes, the negative impact of precipitation variability on tropical carbon cycle may continue to intensify. Lastly, the divergence in AI estimates among multiple GPP products highlight the need to further improve our understanding of the response of tropical carbon cycle to climate changes, especially for the tropical humid regions. Plain Language Summary: Tropical biomes play an essential role in controlling the global carbon balance but has been threatened by extreme climate events recently. Whether the increase in tropical GPP can compensate the GPP decrease during precipitation anomalies is still poorly known. In this study, we found an average negative asymmetric GPP response to precipitation anomalies over the entire tropics during 2001–2022, that is, GPP decreases exceeded the GPP increases during precipitation anomalies. Meanwhile, we found that the tropical GPP was shifted from positive asymmetry to negative asymmetry as the moisture increases. Besides, a significantly decreasing trend of GPP asymmetry was observed over the study period, suggesting that the negative effect of inter‐annual precipitation variations on pantropical GPP has intensified. Key Points: We find the tropical GPP shows a negative asymmetric response to precipitation anomalies over the past two decadesAn overall decreasing trend of the GPP asymmetry was observed over the entire tropical regionAnisohydric biomes have a stronger positive asymmetric response of GPP to precipitation anomalies than isohydric biomes [ABSTRACT FROM AUTHOR]

The use of herbicides on crops often results in unintentional, low-dose exposure of non-target organisms, such as insects. While these exposures are increasingly known to alter the survival and physiology of insects, it remains unclear whether these effects can vary between populations and modify other fitness-related traits, such as behaviour and immunity. Here, we addressed these questions by testing the effects of sublethal exposure to a glyphosate-based herbicide (GBH) on the behaviour and immunity of European earwig males from six natural populations. We exposed each male to a dose of a common GBH (Roundup©) that was either recommended for crops, five times lower than that recommended for crops, or to a control solution. Twenty-four hours later, we measured the activity, boldness, and aggregation of each male. We then exposed them to an entomopathogenic fungus, monitored their survival for 6 weeks, and measured the immune response of the survivors. We found a condition-dependent effect of GBH exposure on male activity. Exposure to low doses induced a positive association between activity and weight, which was not observed in the high-dose and control groups. However, GBH had no effect on any of the other measured traits. All these results were consistent across the six populations tested, although we did find population-specific differences in almost all measurements on males. Further research is now needed to better understand the dose–response to GBH on male activity and its biological impact, as well as to evaluate the effectiveness of detoxification processes in this species. Overall, these results emphasise the importance of investigating the effects of herbicides on insects to expand our general understanding of the use and potential risks of plant protection products in integrated pest management programs. [ABSTRACT FROM AUTHOR]

Abstract The carbon sink in pantropical biomes play a crucial role in modulating the inter‐annual variations of global terrestrial carbon balance and is threatened by extreme climate events. However, it has not been carefully examined whether an increase in tropical gross primary productivity (GPP) can compensate the decrease during precipitation anomalies. Using the asymmetry index (AI) and multiple GPP products, we assessed responses of pantropical GPP to precipitation anomalies during 2001–2022. Positive AI indicates that GPP increases are greater than GPP decreases during precipitation anomalies, and vice versa. Our results showed an average negative pantropical GPP asymmetry, that is, GPP decreases exceeded the GPP increases during precipitation anomalies. In addition, a positive AI was found in tropical hyper‐arid and arid regions, which is opposite to the negative AI observed in tropical semi‐arid, sub‐humid, and humid regions. This suggest that tropical GPP asymmetry changes from positive to negative as the moisture increases. Notably, a significant decreasing trend of negative AI was observed over the entire tropical region, indicating that the negative effect of inter‐annual precipitation variations on pantropical vegetation productivity has enhanced. Considering the model predicted increasing climate variability and extremes, the negative impact of precipitation variability on tropical carbon cycle may continue to intensify. Lastly, the divergence in AI estimates among multiple GPP products highlight the need to further improve our understanding of the response of tropical carbon cycle to climate changes, especially for the tropical humid regions.

The paper analyses the behavior of a rigid passive pile embedded in a soil profile consisting of a stable layer underlying an unstable layer subjected to a uniform soil displacement. Pile-soil interaction is considered by modeling the soil by a series of elastic–plastic springs along the pile shaft. The modulus of horizontal subgrade reaction is assumed to linearly increase with depth in the unstable layer and constant in the stable one. The ultimate soil resistance is assumed increasing with depth in both layers. The results of analysis are presented in dimensionless form in terms of shear force developed at the slip surface as a function of the pile embedment into the stable layer and the distribution of soil characteristics over depth. The method allows capturing pile response not only at the soil ultimate state but also at the intermediate states. Specifically, the governing equations for the elastic, elastic–plastic and plastic cases are discussed and, whenever possible, a set of closed-form expressions is provided to estimate the maximum bending moment along the shaft and the pile head deflection, so that for an assigned value of the required stabilizing force both ultimate and serviceability limit state of the pile can be checked. A numerical example is given to illustrate the application of the proposed procedure. [ABSTRACT FROM AUTHOR]

The study of the dynamic response mechanism of the charge during the process of projectile penetration into concrete targets was carried out to address the issue of projectile charge safety. Combined with the typical characteristics of the actual projectile structure, a theoretical model of the charge non-linear response of the structure with clearance was established, and the local response amplification of the structure under different clearances or different loading frequencies was revealed through theoretical analysis and calculation. Finite element numerical simulations were used to verify the correctness of the theoretical calculation results. Shaker tests were designed to further verify the realism of the theoretical and simulation results. Through a combination of theory, numerical simulations and experiments, the intrinsic mechanism of charge ignition and detonation phenomena under low intensity loads was investigated. The results show that when the projectile penetrates the multi-layer concrete target layer by layer, the vibration generated by the projectile structure has a great influence on the mechanical response of the projectile and the stability of the charge, and there is a certain amplification of the vibration response of the projectile structure. [ABSTRACT FROM AUTHOR]

The rapid development of the social economy and the continuous change in land use have greatly altered the ecological risk of the regional landscape. This study focused on the Yangtze River Basin in China and aimed to examine the temporal and spatial variation characteristics of landscape ecological risk (LER) over a period of 34 years (1982–2015), after determining the optimal sub-watershed scale. Based on the conditional probability framework, the non-linear response of NPP to LER was revealed. Finally, the primary driving factors of LER were explored, and additional potential causes for changes in NPP were discussed. The study findings indicated that the mean annual LER of the Yangtze River Basin exhibited a spatial distribution characterized by high values observed in the western regions and low values in the eastern regions at the optimal sub-basin scale. Specifically, 30.56 and 22.22% of the sub-basins demonstrated a significant upward and downward trend in annual LER, respectively (P < 0.05). The spatial distribution pattern of the mean annual NPP demonstrated high values in the middle region and low values in the western area, with annual NPP significantly increasing in 94.44% of the sub-basins (P < 0.05). The relationship between annual NPP and annual LER was found to be non-linear, indicating that higher annual LER results in a higher probability of median and high values of annual NPP from the perspective of watershed average. Furthermore, climate factors emerged as the main influencing factor of the NPP. Based on these discoveries, upcoming endeavors should concentrate on optimizing landscape formations and executing a judicious distribution of plant species.

In the process of penetrating a multi-layer target, the local response of charge components is often amplified under relatively low loads. Such response amplification phenomenon may have some influences on the pre-ignition or pre-explosion of the projectile. In this paper, a configuration structure reflecting the basic connection characteristics of the simulated charge and shell is constructed. A theoretical model of the non-linear response for the charge with clearance structure is established based on the configuration characteristics. The phenomenon of local response amplification is discussed from the perspective of structural dynamics. In order to further verify the phenomenon of local response amplification, simulation and test verification of the response amplification for the simulated projectile were carried out by combining finite element numerical simulation and shaking table test. The results show that the projectile's vibration during the penetration of a multi-layer target may be an important factor in the local response amplification of the charge. The influence of the vibration characteristics for the projectile's itself needs to be considered in the impact penetration analysis. This study has a strong reference value for understanding the problem of early unintended ignition during the projectile penetration process. [ABSTRACT FROM AUTHOR]

Abstract: While resistors with memory, sometimes called memristive elements (such as ReRAM cells), are often studied under conditions of periodic driving, little attention has been paid to the Fourier features of their memory response (hysteresis). Here we demonstrate experimentally that the hysteresis of memristive systems can be unambiguously distinguished from the linear or non-linear response of systems without hysteresis by the values of certain Fourier series coefficients. We also show that the Fourier series convergence depends on driving conditions, and introduce a measure of hysteresis. These results may be used to quantify the memory content of resistive memories, and tune their Fourier spectrum according to the excitation signal.

Increasing aridity can sharply reduce vegetation productivity in drylands, but elevated CO _2 and warming can enhance vegetation growth. However, the extent to which these positive effects counteract the negative effects of heightened aridity on vegetation productivity remains uncertain. Here, we used space-for-time substitution to assess the responses of 15 ecosystem variables to aridity in China’s drylands and predicted vegetation productivity under future aridity, temperature, precipitation, nitrogen deposition, and CO _2 . The results showed that vegetation productivity decreased abruptly as aridity (1-precipitation/potential evapotranspiration) increased to the threshold of 0.7, which corresponds to the vegetation decline stage in the dryland ecosystem’s response to increasing aridity. Future projections suggest that 12.8% of China’s drylands will cross aridity thresholds (0.7, 0.8, and 0.95) by 2100, in which vegetation productivity will significantly increase by 40.0%. Elevated CO _2 will stimulate vegetation growth, but continuously rising temperature and CO _2 by 2100 will have adverse effects, particularly in regions with limited nitrogen and water. This study suggests that effective adaptation and mitigation actions should be developed for regions crossing aridity thresholds, to ensure that drylands maintain the capacity to provide essential ecosystem services required to support the increasing population.

This paper presented a novel bond-slip model to better reveal the mechanical behavior of the bolt-grout interface for fully-grouted rockbolts under tensile loads by considering the non-linear response in the softening stage. The exponential decay function is adopted for describing the non-linear response in the softening stage. Based on the improved bond-slip model, the corresponding analytical solutions for the interfacial shear stress and the axial force of the bolt under different loading stages are solved. Then, the validity of this proposed model was verified by comparing with the experimental results. The results show that compared with the linear softening model, the proposed model is more suitable for predicting the mechanical performance of fully-grouted rockbolts. Finally, a series of parametric studies are conducted to explore the effect of model parameters on the mechanical properties of fully-grouted rockbolts. The results indicate that compared with the anchor length, the bolt diameter and the bond strength of the bolt-grout interface have a significance influence on the ultimate load of bolt, especially for the elastic and softening stage. Moreover, it can be found that using the linear softening model maybe overestimates the supporting performance of grouted bolt, resulting in an unsafe design for bolt.

A modified Depleted P-Channel Field Effect Transistor (DEPFET) is the key feature of the DEPFET Sensor with Signal Compression (DSSC), a 1 Mpixel X-ray camera aiming at ultra-fast imaging of soft X-rays at the European XFEL. Operation of large-area devices with a large number of DSSC-type DEPFET pixels requires the accurate knowledge of the sensitivity of the response to the relevant DEPFET parameters. The paper presents the experimental qualification of the response of DSSC-type DEPFET pixels in the space of 4 relevant parameters: drain current, source voltage, drain voltage and back side voltage. The obtained results allow estimation of the impact of the inevitable parameter fluctuations in large monolithic sensors and of the actual trimming range of the shape of signal compression in view of the pixelwise calibration of the 1 Mpixel DSSC camera. [ABSTRACT FROM AUTHOR]

We consider the problem of diffusion with stochastic resetting in a population of random walks where the diffusion coefficient is not constant, but behaves as a power-law of the average resetting rate of the population. Resetting occurs only beyond a threshold distance from the origin. This problem is motivated by physical realizations like soft matter under shear, where diffusion of a walk is induced by resetting events of other walks. We first reformulate in the broader context of diffusion with stochastic resetting the so-called HĂ©braudâ€"Lequeux model for plasticity in dense soft matter, in which diffusivity is proportional to the average resetting rate. Depending on parameter values, the response to a weak external field may be either linear, or non-linear with a non-zero average position for a vanishing applied field, and the transition between these two regimes may be interpreted as a continuous phase transition. Extending the model by considering a general power-law relation between diffusivity and average resetting rate, we notably find a discontinuous phase transition between a finite diffusivity and a vanishing diffusivity in the small field limit. [ABSTRACT FROM AUTHOR]

A new real-time two-point non-uniformity correction method is proposed to solve the problems of detector response nonlinearity and detector response shift with time. It can make up for the deficiency that the two-point correction method can not be used for on-line real-time correction, and restrain the influence of the drastic change of working environment on the detector non-uniformity. The correction process of the new method is simulated and theoretically demonstrated for the infrared focal plane detection system in aerodynamic thermal environment. The results show that this method can basically satisfy the actual non-uniformity correction situation in theory, and can be applied to the complex and changeable detector working environment.

A new model for laterally loaded piles is proposed, consisting of a linear part and a non-linear iterative part. The linear part is based on the Green's function method, which strictly satisfies the displacement and stress continuity conditions at the pile-soil interface and leads to a rigorous solution. The non-linear iterative part assumes that the shear modulus of the soil around the pile decreases with the average strain of the soil layer. Only two soil parameters need to be calibrated, including the initial shear modulus of the soil and the reference shear strain at half the initial modulus. Compared to the finite element model, the advantage of this model is that it converges quickly while maintaining accuracy, which greatly improves computational efficiency. The advantage of this model over the p-y curve model is that it does not have the difficulty of selecting p-y spring parameters, especially for monopiles. The accuracy of this model is verified by comparison with three-dimensional finite element models and nine existing studies, including numerical models, field tests and centrifuge tests. These cases cover various piles with diameters of D∼0.273–10 m and aspect ratios of L/D∼3–40, installed in sand or clay by driving, jacking or vibration. • A new model for laterally loaded piles is proposed. • Only two soil parameters need to be calibrated in the model. • The model is suitable for piles of any aspect ratio in both clay and sandy soils. • The accuracy of the model is similar to that of the FEM model. • The computation time is comparable to the p-y curve model. [ABSTRACT FROM AUTHOR]

In this paper, we develop and extend the work of Jia and Qin on sexually transmitted disease models with a novel class of non-linear incidence. Awareness plays a central role both in the susceptible and the infectious classes. The Existence, uniqueness, boundedness, and positivity of solutions are systematically established. Concavity arguments and the occurrence of a vertical asymptote are essential in the proof of the existence of a unique endemic equilibrium. Conditions for the stability of all steady states are investigated. In particular, numerical simulations are performed in order to capture the asymptotic behavior of solutions.AMS Classification: 92D30, 34D23.

• A method coupled wavelet transformation for identifying non-linear periodic of eco-hydrological was established. • The characteristics of different hydrological oscillation period and its impact on river algal blooms was found. • The law of weakened interannual hydrological oscillation increased the frequency of river algal blooms was revealed. The evolution of riverine aquatic ecosystems typically exhibits notable characteristic with cumulative, enduring, and hysteresis. Exploring the non-linear response of riverine ecology to long-term hydrological fluctuations become a major challenge in contemporary interdisciplinary research. In response to the critical issue of frequent river algal blooms in the lower Han River, which is impacted by Asian largest inter-basin water diversion project. We identified the non-linear response of eco-hydrology across various time scales through the integration of Continuous Wavelet Transform (CWT) and Inverse Wavelet Transform (IWT). Our study revealed that: 1) Over the past half century, the hydrological regime in the lower Han river showed a significant downward trend, and existed three significant hydrological oscillation periods (HOPs), including the short-scale Intra-AC (180 days), the medium-scale AC (365 days, the first major period), and the long-scale Inter-AC (2500 days), the variation of Inter-AC changed most dramatically. 2) We further found that the Inter-AC variation of hydrology is more closely related to the formation of river algal blooms in the Han River, and when the hydrological Inter-AC shows steady state or downward trend, the frequency of algal blooms in the lower Han River increases significantly. 3) The river algal blooms in the lower Han River is a cumulative consequence to the long-term hydrological influences. Weakened hydrological Inter-AC is more likely to increase the frequency of river algal blooms, and 10-years Inter-AC cumulation increased the frequency by 60%. Therefore, the weaken of long-scale HOP will significantly increase the frequency of river algal blooms in the future. This study received a critical scientific insight and aimed at provide guidance for the optimization of ecological management within the framework of national large-scale water conservation. [ABSTRACT FROM AUTHOR]

In recent years, the need for portable, low-cost, and eco-friendly devices for testing and monitoring has arisen. Paper-based devices have emerged as a response to these needs due to the properties induced by capillarity, flexibility, disposability, and biodegradability. In this work, the authors explored the possibility of tuning the hygro-mechanical response of paper-based cantilever beams using glycerol. A lumped-parameter model with non-linear stiffness is used to describe the dynamic response of the beams using three parameters. An experimental method based on resonance frequency tests is used to study the influence of glycerol on the dynamic response of four different beam configurations. The obtained results demonstrate that the resonance frequency of paper-based mechanical systems can be easily tuned by the imbibition of a glycerol–water solution. This study could lead to the development of tunable paper-based mechanical systems for specific applications such as energy harvesters and hygro-mechanical-based sensors. [ABSTRACT FROM AUTHOR]

Cross arms are mainly made up of wood (conventional) and pultruded glass fiber reinforced polymer composite (modern) installed in suspension tower. However, the creep response of both materials has not been fully covered in many literatures to explain the long-term durability of the current cross arm design. Thus, it is necessary to find the creep trends and models to evaluate the behavior in the tropical outdoor environment. The creep properties of Balau wood and pultruded composite at load of 10, 20 and 30 % of ultimate flexural stress were evaluated from quasi-static flexural test results. Using several creep numerical models, the creep properties of wood and composite cross arms were modelled. The results showed that the GFRP had a significant value of flexural strength, while Balau wood performed better in flexural modulus. In terms of creep properties, GFRP specimen exhibited high creep resistance with greater stability during transition from elastic to viscoelastic phase. From numerical modelling perspective, the simulated creep trends from Burger and Norton models were deviated from the experimental data. Subsequently, the most suitable creep model to forecast the creep behavior for wood and composite specimens was Findley model. All in all, pultruded composite is the most appropriate durable material to be applied in cross arms, while Findley model is a suitable model to represent creep performance of anisotropic materials. [ABSTRACT FROM AUTHOR]

Global warming has a known impact on ecosystems but there is a lack of understanding about its impact on ecosystem processes. Net ecosystem productivity (NEP) and its components play a key part in the global carbon cycle. Analysing the impact of global warming on NEP will improve our understanding of how warming affects ecosystems. In our study, conducted in 2018, five warming treatments were manipulated (0 W, 500 W, 1000 W, 1500 W, and 3000 W) using three repetitions of far infrared open warming over a paddy field in Northeast China. NEP and its two related components, gross primary productivity (GPP) and ecosystem respiration (ER), were measured using the static chamber-infrared gas analyser method to explore the effects of different warming magnitudes on NEP. Results showed that measurement dates, warming treatments, and their interactions significantly affected NEP, ER, and GPP. Warming significantly increased NEP and its components but they showed a non-linear response to different warming magnitudes. The maximum increases in NEP and its components occurred at 1500 W warming. NEP is closely related to its components and the non-linear response of NEP may have primarily resulted from that of GPP. Gradient warming non-linearly increased GPP in the paddy field studied in Northeast China, resulting in the non-linear response of NEP. This study provides a basis for predicting the responses of carbon cycles in future climate events.

Dynamic response characteristics of a hollow steel single-pile and three-pile group are investigated under coupled vibration. Forced coupled vibration tests are conducted on the piles for static loads of 12 kN and 14 kN under different eccentric moments. The time-acceleration responses are measured for different frequencies for both horizontal and rocking modes and finally the frequency-amplitude responses are determined for horizontal and rocking components separately. The dynamic frequency-amplitude responses of piles are analysed by continuum approach method with two different soil-pile models: (i) a linear visco-elastic composed medium with the consideration of reduced shear modulus and (ii) a boundary zone model with non-reflective interface of shear modulus with parabolic variation. The variation of stiffness and damping of the soil-pile system are also determined. The analytical results are compared with the dynamic test results to verify the applicability of those soil models for predicting the non-linear response of soil-pile system under coupled vibration. It is observed from the comparison curves that the results obtained from the first soil model are found reasonably close to the dynamic test data. However in the case of second soil model, the resonant amplitude values are found much higher than the test data. Based on the analytical results, the boundary zone parameters like modulus reduction ratio, thickness ratio, weak zone soil damping and separation lengths of pile under different eccentric moments are predicted in present field condition. The variations of group efficiency ratio of the pile group with frequency are also determined form the analysis. [ABSTRACT FROM AUTHOR]

Background and Aims Coastal wetlands have evolved to withstand stressful abiotic conditions through the maintenance of hydrologic feedbacks between vegetation production and flooding. However, disruption of these feedbacks can lead to ecosystem collapse, or a regime shift from vegetated wetland to open water. To prevent the loss of critical coastal wetland habitat, we must improve understanding of the abiotic–biotic linkages among flooding and wetland stability. The aim of this research was to identify characteristic landscape patterns and thresholds of wetland degradation that can be used to identify areas of vulnerability, reduce flooding threats and improve habitat quality. Methods We measured local- and landscape-scale responses of coastal wetland vegetation to flooding stress in healthy and degrading coastal wetlands. We hypothesized that conversion of Spartina patens wetlands to open water could be defined by a distinct change in landscape configuration pattern, and that this change would occur at a discrete elevation threshold. Key Results Despite similarities in total land and water cover, we observed differences in the landscape configuration of vegetated and open water pixels in healthy and degrading wetlands. Healthy wetlands were more aggregated, and degrading wetlands were more fragmented. Generally, greater aggregation was associated with higher wetland elevation and better drainage, compared with fragmented wetlands, which had lower elevation and poor drainage. The relationship between vegetation cover and elevation was non-linear, and the conversion from vegetated wetland to open water occurred beyond an elevation threshold of hydrologic stress. Conclusions The elevation threshold defined a transition zone where healthy, aggregated, wetland converted to a degrading, fragmented, wetland beyond an elevation threshold of 0.09 m [1988 North American Vertical Datum (NAVD88)] [0.27 m mean sea level (MSL)], and complete conversion to open water occurred beyond 0.03 m NAVD88 (0.21 m MSL). This work illustrates that changes in landscape configuration can be used as an indicator of wetland loss. Furthermore, in conjunction with specific elevation thresholds, these data can inform restoration and conservation planning to maximize wetland stability in anticipation of flooding threats. [ABSTRACT FROM AUTHOR]

• Doping with Al and Ga substituting one of the B atoms of the B 12 N 12 and B 12 P 12 nanocages increases the reactivity of the cage. • THF/F adsorbed complexes show the highest adsorption energy for Al-doped nanocages. • For a given nanocage, THF molecule is adsorbed strongly than F. • B 12 P 12 complexes show higher optical responses compared to its B 12 N 12 counterparts. Removing pollutants like furan (F) and tetrahydrofuran (THF) from the environment is challenging, and adsorption can efficiently remove pollutants. Fullerene like inorganic nanocages B 12 N 12 and B 12 P 12 are known for their efficient adsorption capability. To address these concerns, we report here the adsorption of the F and THF on the pristine and Al and Ga-doped B 12 N 12 and B 12 P 12 nanocages and consequently the change in the electronic structure, property and optical responses. Doping Al and Ga at the nanocage diminishes the HOMO-LUMO energy gap by 2.9 to 0.4 eV compared to the pristine cage, making the doped cage surface more reactive. The doped surface of nanocage adsorbs F (F@AlB 11 N 12 (-130.1 kJ/mole) and THF (THF@AlB 11 N 12 (-202.3 kJ/mole) more effectively compared to pristine ones (F@B 12 N 12 -28.7 kJ/mole, THF@B 12 N 12 (-98.3 kJ/mole) at ωB97XD/6–31+ G (d,p) level. For a given cage, THF is more strongly adsorbed (THF@B 12 N 12 (-98.3 kJ/mole)) on the cage surface than F (F@B 12 N 12 -28.7 kJ/mole). Interestingly, Al-doped cages exhibit the highest adsorption energy value ranging from -68.5 kJ/mole to -202.3 kJ/mole. Natural bonding orbital analysis, global reactivity descriptor, molecular electrostatic potential, frontier molecular orbital, etc. have been employed to comprehend the distinctive patterns of adsorption. The optical response properties of the studied complexes show that the complexes of B 12 P 12 nanocages exhibit higher polarizability and second hyperpolarizability value (1.51 × 105 to 1.62 × 105 au) compared to its analogous B 12 N 12 complex (3.62 × 104 to 4.15 × 104 au) at ωB97XD/6–311+ G (d,p) level. Our theoretical results further demonstrate the capability of AlB 11 N 12 and AlB 11 P 12 as promising adsorbents of the toxic organic pollutants F and THF, and the computed higher second hyperpolarizability value of the B 12 P 12 complexes indicates these nanomaterials could be used as potential optoelectronic materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Finite disarrangements of important (vital) physiological agents and nutrients can induce plethora of beneficial effects, exceeding mere attenuation of the specific stress. Such response to disrupted homeostasis appears to be universally conserved among species. The underlying mechanism of improved fitness and longevity, when physiological agents act outside their normal range is similar to hormesis, a phenomenon whereby toxins elicit beneficial effects at low doses. Due to similarity with such non-linear response to toxins described with J-shaped curve, we have coined a new term “mirror J-shaped curves” for non-linear response to finite disarrangement of physiological agents. Examples from the clinical trials and basic research are provided, along with the unifying mechanisms that tie classical non-linear response to toxins with the non-linear response to physiological agents (glucose, oxygen, osmolarity, thermal energy, calcium, body mass, calorie intake and exercise). Reactive oxygen species and cytosolic calcium seem to be common triggers of signaling pathways that result in these beneficial effects. Awareness of such phenomena and exploring underlying mechanisms can help physicians in their everyday practice. It can also benefit researchers when designing studies and interpreting growing number of scientific data showing non-linear responses to physiological agents.

Plastic scintillators are widely used in detecting nuclear radiation due to their low construction cost, the ability to be produced in nearly any shape and size and relatively fast time response, among which NE102A (or its equivalents, BC400 and EJ-212) is one of the most famous and widely used scintillators in the focal plane of the particle magnetic spectrometers. In this study, the response of a large NE102A scintillator to 3He ions was investigated in the energy range of 55–87 MeV. The experimental data were collected from the measurements carried out at the accelerator center of University of Groningen, the Netherlands (KVI-CART). The results of this research, acceptably consistent with previous published experimental data, confirmed that the response of the NE102A scintillator to 3He ions with energies more than 10 MeV is approximately linear. [ABSTRACT FROM AUTHOR]

In recent decades, terrestrial vegetation in the northern hemisphere (NH) has been exposed to warming and more extremely high temperatures. However, the consequences of these changes for terrestrial vegetation growth remain poorly quantified and understood. By examining a satellite-based vegetation index, tree-ring measurements and land-surface model simulations, we discovered a consistent convex pattern in the responses of vegetation growth to temperature exposure (TE) for forest, shrub and grass in both the temperate (30°−50° N) and boreal (50°−70° N) NH during the period of 1982−2012. The response of vegetation growth to TE for the three vegetation types in both the temperate and boreal NH increased convergently with increasing temperature, until vegetation type-dependent temperature thresholds were reached. A TE beyond these temperature thresholds resulted in disproportionately weak positive or even strong negative responses. Vegetation growth in the boreal NH was more vulnerable to extremely high-temperature events than vegetation growth in the temporal NH. The non-linear responses discovered here provide new insights into the dynamics of northern terrestrial ecosystems in a warmer world. [ABSTRACT FROM AUTHOR]

Abstract Global estimates of soil nitrate leaching of applied nitrogen (N) in agricultural production systems are not imprecise; however, the results of some field experiments have suggested that nitrate leaching responds exponentially rather than linearly to increasing N inputs. In this study, we compiled field data on nitrate leaching for 324 site-year combinations extracted from 86 peer-reviewed articles to test the hypothesis that in response to N fertilizer addition, soil nitrate leaching emission factors (EF) do not remain constant, but rather increase rapidly with increasing rates of N application. The averaged overall results showed that the proportional change in the EF response to increasing N input (ΔEF, %) was 0.042. Because this value was positive and significantly different from zero, our results demonstrate that EF is not constant, but rather increases with N addition. We compared our ΔEF response pattern with other constant EF patterns, and found that the 30% EF estimate of the Intergovernmental Panel on Climate Change and the 19% EF used in another published model were too high. A global estimate of soil nitrate leaching in arable uplands calculated with our ΔEF pattern was substantially lower than other estimates calculated with other procedures. In conclusion, our ΔEF pattern provided a globally applicable procedure for more accurate estimation of leaching loss and potential environmental costs incurred by various N application gradients. Graphical abstract Unlabelled Image Highlights • The estimation using constant EF covered the effect of excessive fertilization on nitrate leaching. • Fertilizer-induced EFs of nitrate leaching are not constant but increase with N additions. • ∆EF model provided a more accurate empirical model for nitrate leaching worldwide. [ABSTRACT FROM AUTHOR]

Abstract The United States Environmental Protection Agency (US EPA) has recently proposed changes to strengthen the transparency of its pivotal regulatory science policy and procedures. In this context, the US EPA aims to enhance the transparency of dose-response data and models, proposing to consider for the first time non-linear biphasic dose-response models. While the proposed changes have the potential to lead to markedly improved ecological risk assessment compared to past and current approaches, we believe there remain open issues for improving the quality of ecological risk assessment, such as the consideration of adaptive, dynamic and interactive effects. Improved risk assessment including adaptive and dynamic non-linear models (beyond classic threshold models) can enhance the quality of regulatory decisions and the protection of ecological health. We suggest that other countries consider adopting a similar scientific-regulatory posture with respect to dose-response modeling via the inclusion of non-linear biphasic models, that incorporate the dynamic potential of biological systems to adapt (i.e., enhancing positive biological endpoints) or maladapt to low levels of stressor agents. Graphical abstract Image 1 Highlights • The US EPA proposed changes in its regulatory science. • The EPA is proposing to consider a wide range of dose-response models beyond threshold and linear. • Such a change offers a perspective for increasing the protection of ecological health. • Other countries should consider following this part of the proposal of EPA. EPA proposed changes in its regulatory science that can improve ecological risk assessment and increase protection of ecological health. [ABSTRACT FROM AUTHOR]

Highlights • This work analyzes the non-linear response of periodic elastic lattice structures using moderate-rotation theory. • The periodicity of the structure is accounted for through a unit cell and a RVE. • We find that the choice of RVE size is important to capture the non-linear response. • The method is illustrated through several geometries and boundary conditions. Abstract Periodic elastic lattice materials are a class of cellular materials with unique properties that cannot be achieved with fully uniform solids. In this work we employ moderate-rotation theory, which is an expansion of linear elasticity that takes into account moderate displacements and rotations, to derive a fundamental multi-scale model that captures the non-linear response of infinitely periodic elastic lattice materials and allows the imposition of local constraints on lattice junctions. We begin by modeling the response of a single strut. Next, an infinitely periodic lattice structure is considered. The periodicity of the structure is accounted for through a unit cell (UC) and periodic lattice directions. A representative volume element (RVE) comprising one or more UCs is then defined. It is assumed that the RVE experiences the macroscopic displacement gradient. To determine the stress, we employ the principle of virtual work and homogenization methods. To illustrate the predictions of the model, we analyze two infinitely periodic lattice materials - a diamond lattice and a triangular lattice with rigid junctions. To validate our predictions, we compute the response for RVEs of several sizes until convergence is reached. [ABSTRACT FROM AUTHOR]

Normal-phase high-performance liquid chromatography (HPLC) is widely used in combination with evaporative light scattering detection (ELSD) for separating and detecting lipids in various food samples. ELSD responses of different lipids were evaluated to elucidate the possibilities and challenges associated with quantification by means of HPLC-ELSD. Not only the number and type of polar functional groups but also the chain length and degree of unsaturation of (free or esterified) fatty acids (FAs) had a significant effect on ELSD responses. Tripalmitin and trilinolein yielded notably different ELSD responses, even if their constituting free FAs produced identical responses. How FA structure impacts ELSD responses of free FAs is thus not predictive for those of triacylglycerols and presumably other lipids containing esterified FAs. Because ELSD responses of lipids depend on the identity of the (esterified) FA(s) which they contain, fully accurate lipid quantification with HPLC-ELSD is challenging and time-consuming. Nonetheless, HPLC-ELSD is a good and fast technique to semi-quantitatively compare the levels of different lipid classes between samples of comparable FA composition. In this way, lipid profiles of different flours from near-isogenic wheat lines could be compared.

The paper falls within the framework of dynamic control of existing structures exhibiting non-linear behaviour. On the basis of some previous research developed by the authors, it specifically focuses on the analytical setup and development of a control algorithm for mitigating in an improved way the response of non-linear spatial structures, made of masonry. The presented setup does not involve the gross simplifications of the structural model behaviour that are usually adopted in these cases; on the contrary it proposes a more appropriate full mathematical formulation, which is, nevertheless, made still manageable for numerical purposes and significantly more reliable than alternative approaches. [ABSTRACT FROM AUTHOR]

Floor location of adjacent buildings may be different in terms of height elevation, and thus, the slab may hit on the columns of adjacent insufficiently separated buildings during severe ground motions. Such impacts, often referred to as midcolumn pounding, can be catastrophic. Substantial pounding damage or even total collapse of structures was often observed in large amount of adjacent low rise buildings. The research on the mid-column pounding between low rise buildings is in urgency need. In present study, the responses of two adjacent low rise buildings with unequal heights and different dynamic properties have been analyzed. Parametric studies have also been conducted to assess the influence of story height difference, gap distance and input direction of ground motion on the effect of structural pounding response. Another emphasis of this study is to analyze the near-fault effect, which is important for the structures located in the near-fault area. The analysis results show that collisions exhibit significant influence on the local shear force response of the column suffering impact. Because of asymmetric configuration of systems, the structural seismic behavior is distinct by varying the incident directions of the ground motions. Results also show that near-fault earthquakes induced ground motions can cause more significant effect on the pounding responses. [ABSTRACT FROM AUTHOR]

The term “spatial variability of seismic ground motions” denotes the differences in the amplitude and phase content of seismic motions. The effect of such spatial variability on the structural response is still an open issue. In-situ experiments may be helpful in order to answer the questions regarding both the quantification of the spatial variability of the ground motion within the dimensions of a structure as well as the effect on its dynamic response. The goal of the present study is to quantify the variability of the seismic ground motion accelerations in the shallow sedimentary basin of Argostoli, Greece, and thereafter to identify its effect on the linear and non-linear elasto-plastic response of a single degree of freedom system in terms of spectral displacements. Around 400 earthquakes are used, recorded by the 21-element very dense seismological array deployed in Argostoli with inter-station spacing ranging from 5 to 160 meters. The seismic motion variability, evaluated in terms of spectral accelerations, is found to be significant and to increase with inter-station distance and frequency. Thereafter, the amplitude variability in terms of spectral displacements, which is indeed the linear response of a single degree of freedom (SDOF) system with various fundamental periods, is compared with the amplitude variability of a SDOF with non-linear elasto-plastic response. The variability of the maximum top displacement of the linear single degree of freedom system is estimated to be on average 12% with larger variabilities to be observed within two narrow frequency ranges (between 1.5 and 1.7 Hz and between 3 and 4 Hz). Such high variabilities are caused by locally edge-generated diffracted surface waves. The non-linear perfectly elasto-platic structural response of the SDOF system shows that although the variability has the same trends as in the case of linear response, it is almost constantly increased by 5%. [ABSTRACT FROM AUTHOR]

Summary: In the paper, the response of a typical 3‐D masonry building subject to dynamic disturbance is considered, with the purpose to identify control strategies able to mitigate the effects of the excitation. The structure is made of vertical planar elements (the walls) firmly jointed at the wall crosses and horizontally connected by rigid floors. The structural control of the building is realized through the introduction of a suitable dissipative action, which is operated through active, semi‐active, or even passive devices. The control action is ruled by suitable algorithms that are optimally designed with the purpose to optimize the balance between the reduction of the oscillations of the floors, and consequently of the ductility demand to the walls on one side, and the intensity of the control force on the other side. The system behaves in dependency of the single‐wall shear displacement in‐plane constitutive law that can be identified on the basis of the no‐tension model with shear friction strain modes. The behaviour of the whole is ruled by the relevant non‐linear history‐dependent equations. The control strategy is developed for non‐linear systems and then specialized and tested for the presented application to seismic protection of masonry buildings. [ABSTRACT FROM AUTHOR]

Excessive nitrogen (N) fertilizers are often used in China, and a large proportion of the N can be lost as ammonia (NH 3 ). However, quantifying the NH 3 emission from paddy fields is always affected by large uncertainties due to different measuring methods and other factors such as climate. In this study, using a standardized method, we measured the NH 3 emissions in three typical annual rice cropping systems: single rice, double rice and rotation with other crops. The measurements were conducted for 2 years with a total of 3131 observations across China. Results showed that NH 3 emissions accounted for 17.7% (14.4–21.0%) of the N applied under current farm practice, which was 33.1% (10.6–52.6%) higher than previous estimates. Nitrogen application rate was the dominant factor influencing NH 3 emission rate, which exponentially increased with the N fertilizer rate ( p  < . 001 ). Total NH 3 emissions from paddy fields were estimated at 1.7 Tg N yr −1 in 2013 in China, several times the amount of N lost through leaching or runoff. This suggests that mitigation measures for non-point source pollution from cropland should take into account not only the N lost to water, but also to air, thereby improving air quality. [ABSTRACT FROM AUTHOR]

Thermoacoustic phenomena generated inadvertently during combustion, and those produced by heating and cooling material to generate a temperature gradient, have mostly been studied independently. Indeed, researchers of one phenomenon are seldom familiar with the literature on the other. This paper seeks to remedy this by reviewing the two subjects alongside one another, by comparing and contrasting them where possible. There is a brief account of the historically important papers in the development of both subjects, followed by a description of the nature of the phenomena. A selective number of papers is called upon to illustrate these principles. Techniques for handling the pure acoustics in the two subjects are addressed, before an outline is given of the modelling of the two thermoacoustic systems. Non-linear phenomena in the two systems are then explored. Finally, methods of ‘control’, of changing the system characteristics, are briefly discussed. [ABSTRACT FROM AUTHOR]

This paper deals with a high-sensitivity method for the assessment of damage in high-strength fibres exposed to UV radiation. A recently developed experimental testing machine, based on an optical measurement system and electro-magnetic driving force, was used to characterize fibre materials. Stiffness, damping, and non-linearity were measured on several Kevlar® fibre samples previously exposed to UV light for different lengths of time. The results show that UV radiation increases the material non-linearity by amounts which can be clearly observed even at low vibration amplitudes. On the contrary, uncertainties affecting the determination of stiffness and damping with the adopted approach don’t seem to allow a similarly unambiguous UV damage assessment. Result confirm our initial hypothesis that non-linearity may be a valuable index of damage, at least in case of UV exposure, for applications in the Structural Health Monitoring (SHM) field. [ABSTRACT FROM AUTHOR]

We study the linear and nonlinear viscoelastic properties of two tire tread compounds. We discuss the difference in nonlinear response between the oscillatory tensile and shear modes. We also analyze strain relaxation (creep) data for the same systems. We discuss what type of measurements are most suitable for obtaining the viscoelastic modulus used in rubber friction calculations.

Recently, a considerable literature has grown up around the theme of seismic protection of rigid blocks, with a special focus on strategies to reduce the overturning vulnerability due to rocking motion. The present paper investigates a semi-active control method for rocking blocks and compares different strategies for its implementation. In more detail, a feedback control algorithm was developed to adjust the stiffness of the restraints placed at the two lower corners of the block. The utility of the proposed control was quantified through “ad hoc” indices derived from overturning spectra. The performance of a feedback strategy was numerically investigated and specific simulations were performed to quantify the control method degradation when implemented for a real-world application. Finally, the stability of the block controlled with the proposed strategy is compared with the stability of the block whose anchorage is set according to different control strategies. [ABSTRACT FROM AUTHOR]

The non-linear seismic response of in-plan asymmetric systems has been extensively studied since the 1980s. Nevertheless, most of the research effort has been devoted to the study of specific asymmetric buildings and, even though relevant progresses have been achieved in the understanding of the complex translational-to-torsional coupled response of such systems, a complete understanding of the seismic behaviour of in-plan asymmetric buildings is still missing. In this paper a systematic study of the seismic response of linear and non-linear one-storey asymmetric structures is presented. A mixed analytical-numerical approach, the so-called 'alpha' method, is used to investigate the non-linear seismic response of a wide range of in-plan asymmetric structures with the aim of providing general trends of behavior. [ABSTRACT FROM AUTHOR]