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Weather disturbances, difficult backgrounds, the shading of fruit and foliage, and other elements can significantly affect automated yield estimation and picking in small target apple orchards in natural settings. This study uses the MinneApple public dataset, which is processed to construct a dataset of 829 images with complex weather, including 232 images of fog scenarios and 236 images of rain scenarios, and proposes a lightweight detection algorithm based on the upgraded YOLOv7-tiny. In this study, a backbone network was constructed by adding skip connections to shallow features, using P2BiFPN for multi-scale feature fusion and feature reuse at the neck, and incorporating a lightweight ULSAM attention mechanism to reduce the loss of small target features, focusing on the correct target and discard redundant features, thereby improving detection accuracy. The experimental results demonstrate that the model has an mAP of 80.4% and a loss rate of 0.0316. The mAP is 5.5% higher than the original model, and the model size is reduced by 15.81%, reducing the requirement for equipment; In terms of counts, the MAE and RMSE are 2.737 and 4.220, respectively, which are 5.69% and 8.97% lower than the original model. Because of its improved performance and stronger robustness, this experimental model offers fresh perspectives on hardware deployment and orchard yield estimation.

This paper presents a study of a two-degree-of-freedom (2DOF) piezoelectric energy harvester (PEH) under concurrent aeroelastic and base excitation. The governing equations of the theoretical model under the combined excitation are developed and solved analytically using the harmonic balance method. Based on the electro-mechanical analogies, an equivalent circuit model is established. The energy harvesting performance of the 2DOF PEH under different wind speeds but the same base excitation is investigated. Voltage amplitudes of various response components with different frequencies are predicted by the analytical method and verified by the circuit simulation. The root-mean-square (RMS) voltage is used to measure the actual performance of the 2DOF PEH. Around the resonance state, the 2DOF PEH has been found to produce a larger voltage output than the conventional SDOF PEH. Moreover, several interesting phenomena, such as the quasi-periodic oscillation and the peak-to-valley transition, have been observed in the circuit simulation and explained by the analytical solution. The developed methodology in this paper can be easily adapted to analyze other similar types of multiple-degree-of-freedom (MDOF) PEHs under concurrent aeroelastic and base excitation.

The wetland resource in the wetland park is a unique natural resource, which is of great significance in maintaining regional ecological security. The ecological restoration and ecological compensation of wetland parks are related to the construction and sustainable development of the park, as well as the comprehensive ecological environment of the city. Ganjiangyuan National Wetland Park is one of the wetland parks in inland China. Discussing the ecological restoration and ecological compensation standards of the wetland park has an important guiding role in the construction of the wetland ecological protection system in Shicheng County, Jiangxi Province. Wetland ecosystem evaluation methods, ecological service value tables, and willingness to accept are used to evaluate and calculate the wetland ecosystem in Ganjiangyuan National Wetland Park. The study concluded that the wetland ecosystem evaluation result of Ganjiangyuan National Wetland Park was “excellent”. For Ganjiangyuan National Wetland Park, an ecological service value index system with regulation services as the mainstay was constructed. Based on the mathematical expectation formula of WTA and the calculation principle of reducing the value of adjustment services as the upper limit of ecological compensation, the upper and lower limits of the ecological compensation standard in the study area are calculated to be 210.49 yuan/hm²·year and 157.87 yuan/hm²·year separately. The ecological compensation mechanism has been progressing and improving. Therefore, the results of this study are only applicable to the current time period, and future development and changes will become a kind of uncertainty.

This paper proposes a softening nonlinear aeroelastic galloping energy harvester for enhanced energy harvesting from concurrent wind flow and base vibration. Traditional linear aeroelastic energy harvesters have poor performance with quasi-periodic oscillations when the base vibration frequency deviates from the aeroelastic frequency. The softening nonlinearity in the proposed harvester alters the self-excited galloping frequency and simultaneously extends the large-amplitude base-excited oscillation to a wider frequency range, achieving frequency synchronization over a remarkably broadened bandwidth with periodic oscillations for efficient energy conversion from dual sources. A fully coupled aero-electro-mechanical model is built and validated with measurements on a devised prototype. At a wind speed of 5.5 m/s and base acceleration of 0.1 g, the proposed harvester improves the performance by widening the effective bandwidth by 300% compared to the linear counterpart without sacrificing the voltage level. The influences of nonlinearity configuration, excitation magnitude, and electromechanical coupling strength on the mechanical and electrical behavior are examined. The results of this paper form a baseline for future efficiency enhancement of energy harvesting from concurrent wind and base vibration utilizing monostable stiffness nonlinearities.

Fungal terpenoids catalyzed by bifunctional terpene synthases (BFTSs) possess interesting bioactive and chemical properties. In this study, an integrated approach of genome mining, heterologous expression, and in vitro enzymatic activity assay was used, and these identified a unique BFTS sub-clade critical to the formation of a 5-15 trans-fused bicyclic sesterterpene preterpestacin I (1). The 5-15 bicyclic BFTS gene clusters were highly conserved but showed relatively wide phylogenetic distribution across several species of the diverged fungal classes Dothideomycetes and Sordariomycetes. Further genomic organization analysis of these homologous biosynthetic gene clusters from this clade revealed a glycosyltransferase from the graminaceous pathogen Bipolaris sorokiniana isolate BS11134, which was absent in other 5-15 bicyclic BFTS gene clusters. Targeted isolation guided by BFTS gene deletion led to the identification of two new sesterterpenoids (4, and 6) from BS11134. Compounds 2 and 4 showed moderate effects on LPS-induced nitrous oxide production in the murine macrophage-like cell line RAW264.7 with in vitro inhibition rates of 36.6 ± 2.4% and 24.9 ± 2.1% at 10 μM, respectively. The plausible biosynthetic pathway of these identified compounds was proposed as well. This work revealed that phytopathogenic fungi can serve as important sources of active terpenoids via systematic analysis of the genomic organization of BFTS biosynthetic gene clusters, their phylogenetic distribution in fungi, and cyclization properties of their metabolic products. KEY POINTS: • Genome mining of the first BFTS BGC harboring a glycosyltransferase. • Gene-deletion guided isolation revealed three novel 5-15 bicyclic sesterterpenoids. • Biosynthetic pathway of isolated sesterterpenoids was proposed.

This paper investigates a dynamic model and behavior of a novel double-beam piezo–magneto–elastic nonlinear wind energy harvester (DBPME-WEH). The DBPME-WEH is a double-beam structure, which contains the magnet-induced bistable nonlinearity to enhance the performance of the galloping-based vibration energy harvesting. The corresponding governing equations of motion are formulated, and the numerical results based on the equations are validated by a series of the wind tunnel experiments. Both the numerical and experimental results show that the DBPME-WEH outperforms the linear double-beam piezoelectric wind energy harvester, significantly reducing the cut-in speed. To understand the nonlinear dynamic behavior of the proposed energy harvester, this study performs the numerical investigations of the time-domain responses, phase portraits and frequency spectrums of the DBPME-WEH under selected wind speeds. The intra-well, chaotic and inter-well oscillations are discovered with respect to low, medium and high wind speeds intervals, respectively. The parametric study is performed to uncover the influences of the beams stiffness ratio, effective mass ratio and the width of the bluff body that help developing the insights of the effective design of the DBPME-WEH.

Aiming at the livelihood of fishermen under the fishing prohibition policy, quantitative research methods were used to explore the relationship between the willingness to quit fishing and livelihood capital. With reference to 609 survey data from 20 fishing grounds in 2 counties and cities of Hubei Province, this paper explores the necessity of convincing fishermen in the Yangtze River to quit fishing and evaluates the impact of livelihood mode on Honghu fishermen’s willingness to quit fishing by means of structural equation model based on the sustainable livelihood framework developed by the UK Department for International Development. The results showed the following conclusions: (1) The proportion of fishermen who are willing to participate in quitting fishing is 66.7%, indicating that fishery production is still the main source of livelihood for many fishermen. The overall willingness of fishermen to quit fishing is strong, and fishermen have realized the importance of protecting fishery resources. (2) There is a strong correlation between the indicators of livelihood capital and the willingness of fishermen to quit fishing. Among them, the human capital has the most significant impact on fishermen’s willingness to quit fishing for some compensation from public power. The research conclusion is helpful for the government to improve the fishing prohibition policy in a targeted manner and mobilize the enthusiasm of fishermen to protect fishery resources.

This Letter reports an amplitude-robust nonlinear dual-functional metastructure that combines bistable and monostable-hardening mechanisms in the local resonators for simultaneous energy harvesting and vibration suppression. The concept is verified by experiments using a primary beam with six pairs of piezoelectric cantilevered oscillators and numerical analyses using a fully coupled electromechanical model for varying base vibration acceleration and load resistance. The results show that the design offers a wide bandgap at high accelerations, attenuation of transmission peaks, and generation of power over a broad bandwidth, outperforming its linear, pure bistable, and pure monostable counterparts. The dual-functional capabilities are further quantitatively assessed by using a weighted index that reflects both the vibration and power generation behaviors. This study demonstrates opportunities in development of the smart nonlinear metastructures for simultaneous vibration suppression and energy harvesting. Published version We would like to acknowledge the financial support of the Australian Research Council under Grant No. DE210101382.

Salinization in arid or semiarid regions with water-logging limits cropland yield, threatening food security. The highest level of farmland salinization, that is, abandoned salinized farmland, is a trade-off between inadequate drainage facilities and sustainable farming. The evolution of abandoned salinized farmlands is closely related to the development of cropping systems. However, detecting abandoned salinized farmland using time-series remote sensing data has not been investigated well by previous studies. In this study, a novel approach was proposed to detect the dynamics of abandoned salinized farmland using time series multi-spectral and thermal imagery. Thirty-two years of temporal Landsat imagery (from 1988 to 2019) was used to assess the evolution of salinization in Hetao, a two-thousand-year-old irrigation district in northern China. As intermediate variables of the proposed method, the crop-specific planting area was retrieved via its unique temporal vegetation index (VI) pattern, in which the shape-model-fitting technology and the k-means cluster algorithm were used. The desert area was stripped from the clustered non-vegetative area using its distinct features in the thermal band. Subsequently, the abandoned salinized farmland was distinguished from the urban area by threshold-based saline index (SI). In addition, a regression model between electrical conductance (EC) and SI was established, and the spatial saline degree was evaluated by the SI map in uncropped and unfrozen seasons. The results show that the cropland has constantly been expanding in recent decades (from 4.7*105 ha to 7.1*105 ha), while the planting area of maize and sunflower has grown and the area of wheat has decreased. Significant desalinization progress was observed in Hetao, where both the area of salt-affected land (salt-free area increased approximately 4*105 ha) and the abandoned salinized farmland decreased (reduced from 0.45 *105 ha to 0.19 *105 ha). This could be mainly attributed to three reasons: the popularization of water-saving irrigation technology, the construction of artificial drainage facilities, and a shift in cropping patterns. The decrease in irrigation and the increase in drainage have deepened the groundwater table in Hetao, which weakens the salt collection capacity of the abandoned salinized farmland. The results demonstrated the promising possibility of reutilizing abandoned salinized farmland via a leaching campaign where the groundwater table is sufficiently deep to stop salinization.

This present study mainly focuses on the influence of low-calcium circulating fluidized bed fly ash (LCFA) on the mechanical property and microstructure of cement-based materials under different curing conditions. The mechanical properties test was conducted by changing variable parameters, such as LCFA content, the internal mixing ratio of LCFA and fly ash (FA), and dry and water curing conditions. Further, the hydration products and pore structure were analyzed using XRD, FT-IR, TG-DTG, NI, SEM, and BET micro-testing technology. The strength development law of LCFA on cement-based materials is discussed. The research results show that LCFA has a certain degree of self-hardening and can be used as a cementitious material in cement-based materials. Still, the loose and porous microstructure of LCFA leads to higher water requirements, which reduces the fluidity of cement-based pastes. Water curing is favorable for promoting the development of LCFA on the long-term compressive strength of cement-based materials. When the LCFA was added to the cement, the optimal substitution ratio was 20%, and the compressive strength at 91 days reached 101 MPa. In the case of compounding LCFA and FA, when the internal mixing ratio of LCFA/FA was 3 and the total content was 20%, the mechanical properties were the highest, and the compressive strength at 91 days was 92 MPa. The microscopic analysis result shows that the cumulative hydration heat of the samples decreased significantly with the increase of dosage of LCFA. The main hydration products of cement-based materials mixed with LCFA were AFt, C-S-H gel, and Ca(OH)2. AFt and C-S-H gels are critical to the strength development of OPC-LCFA samples. The active Al2O3 and active SiO2 in LCFA were involved in hydration reactions to promote the formation of C-A-H and C-S-H gel and effectively promote the development of the mechanical properties. Overdosages of LCFA would reduce the ettringite formation rate. FA is not conducive to AFt formation in the hydration process of OPC-FA samples.

While there has been a surge of study on nonlinear aeroelastic energy harvesting structures for enhanced wind power extraction, there is a gap in the literature on the integration of advanced power conditioning circuits with these mechanically sophisticated nonlinear structures. This article presents an investigation on the influence of different voltage processing interface circuits on the power generation performance in nonlinear galloping energy harvesting. Cubic hardening, cubic softening, and bistable configurations are studied. Their mechanical and electrical responses associated with the simple ac, standard dc, and synchronous charge extraction (SCE) circuits analyzed and compared. Results show that with the ac and standard dc circuits, the bistable and cubic hardening configurations are superior to the cubic softening configuration, generating comparably high power outputs with beneficially small displacements. The SCE circuit significantly boosts the power generation of the two monostable (cubic hardening and softening) harvester designs, but degrades the performance of the bistable design by trapping the oscillation within a single potential well over a large wind speed range. The findings form a baseline for future enhancement in the design of nonlinear aeroelastic wind power generators.

The effects of invasive species on the local community (e.g., structure and stability) are highly environmentally dependent. Invasions of amphibious species usually take place in both xeric and humid environments, yet they are relatively poorly understood. In this study, we analyzed the communities that were dominated by Alternanthera philoxeroides using ecological niche and interspecific association. A total of 66 species and 67 species were recorded in the xeric environment and humid environment, respectively. In both environments, species in family Gramineae, such as Echinochloa crusgalli and Cynodon dactylon, exhibited a higher level of importance values and greater ecological niche widths. The interspecific association and stability of the dominant species were weak and the dominant species were relatively independent of each other. In the xeric environment, A. philoxeroides was more compatible with E. crusgalli and C. dactylon in terms of ecological niche requirements and habitat suitability. In humid habitats, A. philoxeroides had a greater correlation with E. crusgalli, C. dactylon, and Persicaria lapathifolia, suggesting a higher possibility of concomitant occurrence. Overall, we suggested that during the revegetation after A. philoxeroides invasion, E. crusgalli and C. dactylon can be the alternative plants. Meanwhile, alternative control measures for A. philoxeroides invasion in agricultural fields should give more consideration to the use of plants with economic or ecological value.

Vortex-induced vibration (VIV) and wake galloping are two aeroelastic instability phenomena with similar underlying mechanisms related to vortex shedding. Inspired by this common feature, a two-degree-of-freedom (2DOF) piezoelectric aeroelastic energy harvester (PAEH) is proposed, which employs VIV and wake galloping mechanisms with their respective benefits to improve the wind energy harvesting performance in a wide wind speed range. The proposed 2DOF PAEH overcomes the limitations of conventional one-degree-of-freedom VIV and wake galloping energy harvesters, with the former being only effective in a single and narrow lock-in wind speed range and the latter failing to work at low wind speeds. The modal frequencies of the 2DOF PAEHs are easily manipulated, and the twin mechanisms improve power generation over two lock-in regions at low wind speeds by the VIV mechanism and a third power generation region at relatively higher wind speeds due to wake galloping. A coupled aero-electro-mechanical model is developed and verified by wind tunnel experiments on a prototype. The results show that the proposed harvester efficiently extracts wind energy in a wide wind speed range from 1.1 to 6 m/s. The influence of the distance between the two parallel bluff bodies, in which distance is a critical parameter, on the voltage output is experimentally investigated, revealing three distinct aerodynamic behaviors at different distances.

Increasing attention has recently been focused on complex symbiotic associations, for instance coral and its symbionts. Sea cucumber, harboring diverse fungi, has also attracted more and more attention for their functional diversity. Here, secondary metabolites produced by Chaetomium globosum associated with sea cucumber, Apostichopus japonicus, were investigated using gene mining with third-generation sequencing technology (PacBio SMRT). Nine compounds, including one new compound cytoglobosin X (1), were isolated from cultures of Chaetomium globosum. Compound 1 was identified based on NMR data, HRESIMS, and ECD, and the absolute configurations were identified as 3S, 4R, 7S, 8R, 9R, 16S, 19S, 20S, and 23S. In an antimicrobial assay, compound 4 showed moderate activity against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus with MICs of 47.3 and 94.6 μM, respectively. Our results suggest that the microbiomes associated with sea cucumber could be an important resource for biodiversity and structural novelty, and the bioactive compounds may protect the host from pathogen microbial.

© 2019 Elsevier Ltd Galloping-based piezoelectric energy harvester (GPEH) has been used in power generation from small-scale airflows for low-power devices such as Micro-Electromechanical Systems (MEMS) and wireless sensing electronics. The bluff body plays an important role for the onset of galloping. Existing literature regarding analytical and numerical analysis of GPEH has focused on designs incorporating bluff bodies with a variety of cross-sections, such as square, D-section and regular triangle. In this work, a GPEH with triangular cross-section bluff bodies with different vertex angles is investigated. The aerodynamic characteristics are determined by Computational Fluid Dynamics (CFD) and verified by experimental data. Subsequently, an aero-electro-mechanical model with piezoelectric coupling is established and numerically solved. Furthermore, a parametric study is performed to investigate the influence of electromechanical coupling on the GPEH's behavior, with a focus on the threshold wind speed, transverse displacement and power output. It is determined that with weak coupling, the obtuse angle β = 130° is the most preferred vertex angle. This is the first documented determination that an obtuse angled isosceles triangle could be used for efficient galloping energy harvesting. The findings provide a guideline for designing efficient GPEHs with triangular bluff bodies.

In the present study, a biochemical strategy for improving propionic acid production from kitchen waste acidification by bioaugmentation with Propionibacterium acidipropionici (P. acidipropionici) was investigated. When the inoculum of P. acidipropionici was 30% (w/w) of the seeding sludge, the propionic acid production increased by 79.57%. Further, bioaugmentation improved the relative abundance of Firmicute and Actinobacteria. The results of metagenomic analysis further reveal that the ATP-binding cassette (ABC) transporters and all related pathways of Propanoate metabolism (ko00640) were enriched when P. acidipropionici was added. For Propanoate metabolism, most functional genes involved in the conversion from Glycolysis / Gluconeogenesis (ko00010) to Propanoyl-CoA and conversion from Propanoyl-CoA to propionic acid were enhanced after bioaugmentation with P. acidipropionici, thereby promoting propionic acid production. As such, bioaugmentation with P. acidipropionici was effective in the anaerobic acidification of kitchen waste for propionic acid production.

Studies regarding concurrent wind-flow and base-motion energy harvesting have drawn increasing attention in recent years. However, for conventional wind energy harvesters under such dual excitations, the base-excited inertial vibration and flow-induced aeroelastic vibration supplement with each other only within a narrow range of frequency near the resonance. Within this range, aeroelastic vibration frequency is locked into the base vibration frequency where the two sources are concurrently contributing to power generation; while the concurrent feature is lost outside this range. Internal resonance in multimodal systems has been utilized in recent years for efficiency improvement in pure base vibration energy harvesters. The merit comes from the fact that energy can be pumped from other modes to the power generation bandwidth, broadening the bandwidth toward both lower and higher frequency regions. In this paper, a broadband galloping-based aeroelastic energy harvester with internal resonance is proposed for the purpose of efficiency enhancement in concurrent wind and base vibration energy harvesting. Two-to-one internal resonance is aroused by arranging two sets of magnets symmetrically at the beam connection. Numerical solutions are calculated for the fully coupled aero-electro-mechanical model. A significantly widened lock-in bandwidth with multiple power peaks is achieved for effective concurrent wind and vibration energy harvesting.

In this paper, a novel cantilever triboelectric energy harvester (TEH) working on the contact-separation mode is proposed for low-frequency vibration energy harvesting. An electro-mechanical model of TEH with non-parallel contact surfaces is derived by evaluating the total electrical energy between two surfaces. One merit of the proposed harvester is its simple design for easy implementation. The performance of TEH is investigated theoretically and experimentally, and the results show that it can harvest energy from broadband vibration sources. A peak output voltage of 25 V is achieved from the harvester under a base acceleration of 0.5 g with excitation frequency of 8 Hz. Good agreement is observed between the experimental results and analytical predictions. The performance of TEH can be improved by adjusting the gap distance between the top plate and the beam. The proposed triboelectric harvester is shown to be cost-effective to scavenge the low-frequency vibration energy from the ambient environment.

In this study, based on the lumped-parameter theory and the Lagrange approach, a novel and generalized bending-torsional-axial coupled dynamic model for analyzing the load sharing behavior in the herringbone planetary gear train (HPGT) is presented by taking into account the actual structure of herringbone gears, manufacturing errors, time-dependent meshing stiffness, bearing deflections, and gyroscopic effects. The model can be applied to the analysis of the vibration of the HPGT with any number of planets and different types of manufacturing errors in different floating forms. The HPGT equivalent meshing error is analyzed and derived for the tooth profile errors and manufacturing eccentric errors of all components in the HPGT system. By employing the variable-step Runge–Kutta approach to calculate the system dynamic response, in conjunction with the presented calculation approach of the HPGT load sharing coefficient, the relationships among manufacturing errors, component floating, and load sharing are numerically obtained. The effects of the combined errors and single error on the load sharing are, respectively, discussed. Meanwhile, the effects of the support stiffness of the main components in the HPGT system on load sharing behavior are analyzed. The results indicate that manufacturing errors, floating components, and system support stiffness largely influence the load sharing behavior of the HPGT system. The research has a vital guiding significance for the design of the HPGT system.

Fungal terpenoids catalyzed by bifunctional terpene synthases (BFTSs) possess interesting bioactive and chemical properties. In this study, an integrated approach of genome mining, heterologous expression, and in vitro enzymatic activity assay was used, and these identified a unique BFTS sub-clade critical to the formation of a 5-15 trans-fused bicyclic sesterterpene preterpestacin I (1). The 5-15 bicyclic BFTS gene clusters were highly conserved but showed relatively wide phylogenetic distribution across several species of the diverged fungal classes Dothideomycetes and Sordariomycetes. Further genomic organization analysis of these homologous biosynthetic gene clusters from this clade revealed a glycosyltransferase from the graminaceous pathogen Bipolaris sorokiniana isolate BS11134, which was absent in other 5-15 bicyclic BFTS gene clusters. Targeted isolation guided by BFTS gene deletion led to the identification of two new sesterterpenoids (4, and 6) from BS11134. Compounds 2 and 4 showed moderate effects on LPS-induced nitrous oxide production in the murine macrophage-like cell line RAW264.7 with in vitro inhibition rates of 36.6 ± 2.4% and 24.9 ± 2.1% at 10 μM, respectively. The plausible biosynthetic pathway of these identified compounds was proposed as well. This work revealed that phytopathogenic fungi can serve as important sources of active terpenoids via systematic analysis of the genomic organization of BFTS biosynthetic gene clusters, their phylogenetic distribution in fungi, and cyclization properties of their metabolic products. KEY POINTS: • Genome mining of the first BFTS BGC harboring a glycosyltransferase. • Gene-deletion guided isolation revealed three novel 5-15 bicyclic sesterterpenoids. • Biosynthetic pathway of isolated sesterterpenoids was proposed.

A compact bistable galloping oscillator is proposed for enhanced power generation from concurrent wind and base vibration. The harvester consists of a D-shaped bluff body attached to a piezoelectric cantilever. Repulsive magnetic interaction is introduced between the bluff body and a fixed windward support to bring nonlinear bistability. An aeroelectro- mechanically coupled model is established and experimentally validated. Both experimental measurements and model predictions demonstrate that the synchronization bandwidth for efficient energy harvesting from concurrent wind and base vibration can be substantially extended.

Soil organic matter (SOM) refers to all carbon-containing organic matter in soil and is one of the most important indicators of soil fertility. The hyperspectral inversion analysis of SOM traditionally relies on laboratory chemical testing methods, which have the disadvantages of being inefficient and time-consuming. In this study, 69 soil samples were collected from the Honghu farmland area and a mining area in northwest China. After pretreatment, 10 spectral indicators were obtained. Ridge regression, kernel ridge regression, Bayesian ridge regression, and AdaBoost algorithms were then used to construct the SOM hyperspectral inversion model based on the characteristic bands, and the accuracy of the models was compared. The results showed that the AdaBoost algorithm based on a grid search had the best accuracy in the different regions. For the mining area in northwest China, R p 2 = 0.91, R M S E p = 0.22, and M A E p = 0.2. For the Honghu farmland area, R p 2 = 0.86, R M S E p = 0.72, and M A E p = 0.56. The detection of SOM content using hyperspectral technology has the characteristics of a high detection precision and high speed, which will be of great significance for the rapid development of precision agriculture.

Fallows are widespread in dryland cropping systems. However, timely information about their spatial extent and location remains scarce. To overcome this lack of information, we propose to classify fractional cover data from Sentinel-2 with biased support vector machines. Fractional cover images describe the land surface in intuitive, biophysical terms, which reduces the spectral variability within the fallow class. Biased support vector machines are a type of one-class classifiers that require labelled data for the class of interest and unlabelled data for the other classes. They allow us to extrapolate in-situ observations collected during flowering to the rest of the growing season to generate large training data sets, thereby reducing the data collection requirements. We tested this approach to monitor fallows in the northern grains region of Australia and showed that the seasonal fallow extent can be mapped with >92% accuracy both during the summer and winter seasons. The summer fallow extent can be accurately mapped as early as mid-December (1–4 months before harvest). The winter fallow extent can be accurately mapped from mid-August (2–4 months before harvest). Our method also detected emergence dates successfully, indicating the near real-time accuracy of our method. We estimated that the extent of fallow fields across the northern grains region of Australia ranged between 50% in winter 2017 and 85% in winter 2019. Our method is scalable, sensor independent and economical to run. As such, it lays the foundations for reconstructing and monitoring the cropping dynamics in Australia.

Whereas a lot of efforts have been put on energy conservation in wireless sensor networks (WSNs), the limited lifetime of these systems still hampers their practical deployments. This situation is further exacerbated indoors, as conventional energy harvesting (e.g., solar) may not always work. To enable long-lived indoor sensing, we report in this article a self-sustaining sensing system that draws energy from indoor environments, adapts its duty-cycle to the harvested energy, and pays back the environment by enhancing the awareness of the indoor microclimate through an “energy-free” sensing. First of all, given the pervasive operation of heating, ventilation, and air conditioning (HVAC) systems indoors, our system harvests energy from airflow introduced by the HVAC systems to power each sensor node. Secondly, as the harvested power is tiny, an extremely low but synchronous duty-cycle has to be applied whereas the system gets no energy surplus to support existing synchronization schemes. So, we design two complementary synchronization schemes that cost virtually no energy. Finally, we exploit the feature of our harvester to sense the airflow speed in an energy-free manner. To our knowledge, this is the first indoor wireless sensing system that encapsulates energy harvesting, network operating, and sensing all together.

Salinization in arid or semiarid regions with water logging limits cropland yield, threatening food security. The highest level of farmland salinization, that is, abandoned salinized farmland, is a tradeoff between inadequate drainage facilities and sustainable farming. The evolution of abandoned salinized farmlands is closely related to the development of cropping systems. However, detecting abandoned salinized farmland using time-series remote sensing data has not been investigated well by previous studies. In this study, a novel approach was proposed to detect the dynamics of abandoned salinized farmland using time-series multispectral and thermal imagery. Thirty-two years of temporal Landsat imagery (from 1988 to 2019) was used to assess the evolution of salinization in Hetao, a two-thousand-year-old irrigation district in northern China. As intermediate variables of the proposed method, the crop-specific planting area was retrieved via its unique temporal vegetation index (VI) pattern, in which the shape-model-fitting technology and the K-means cluster algorithm were used. The desert area was stripped from the clustered non-vegetative area using its distinct features in the thermal band. Subsequently, the abandoned salinized farmland was distinguished from the urban area by the threshold-based saline index (SI). In addition, a regression model between electrical conductance (EC) and SI was established, and the spatial saline degree was evaluated by the SI map in uncropped and unfrozen seasons. The results show that the cropland has constantly been expanding in recent decades (from 4.7 × 105 ha to 7.1 × 105 ha), while the planting area of maize and sunflower has grown and the area of wheat has decreased. Significant desalinization progress was observed in Hetao, where both the area of salt-affected land (salt-free area increased approximately 4 × 105 ha) and the abandoned salinized farmland decreased (reduced from 0.45 × 105 ha to 0.19 × 105 ha). This could be mainly attributed to three reasons: the popularization of water-saving irrigation technology, the construction of artificial drainage facilities, and a shift in cropping patterns. The decrease in irrigation and the increase in drainage have deepened the groundwater table in Hetao, which weakens the salt collection capacity of the abandoned salinized farmland. The results demonstrate the promising possibility of reutilizing abandoned salinized farmland via a leaching campaign where the groundwater table is sufficiently deep to stop salinization.

We propose a compact InGaAsP/InP electro-optic ring modulator operated with coupling modulation that can circumvent the bandwidth limitation and large minimum bend radius of a ring. This device consists of frustrated total internal reflection (TIR) couplers and TIR mirrors serving as 90° waveguide bends, forming the configuration of an asymmetric rectangular Mach–Zehnder interferometer coupled to a square ring resonator (SRR). A discrete-time dynamic model and finite-difference time-domain method are used to evaluate the device performances, and the theoretical results show an operating frequency up to 60 GHz, the maximum extinction ratio of ~12 dB, the low electrical energy of ~60 fJ/bit, and a compact chip size of $\sim 18~\mu \text{m} \,\, \times 29~\mu \text{m}$ , respectively. The enabling component of the SRR represents >100-fold footprint reduction on a chip. This compact device can be potentially applied in large-scale InP-based photonic integrated circuits.

This Letter proposes a compact bistable galloping oscillator for achieving enhanced power generation from concurrent wind and base vibration. The harvester consists of a D-shaped bluff body attached to a piezoelectric cantilever, with magnetic interaction introduced between the bluff body and a fixed windward prism. Both theoretical analysis and experiment demonstrate the remarkably broadened synchronization bandwidth for concurrent energy harvesting. In the experiment, the voltage steadily increases from 26.6 V at 8.5 Hz to 40.7 V at 12 Hz, achieving a 10 times wider bandwidth than the linear galloping harvester.

Cycloaddition reactions such as intramolecular Diels–Alder (IMDA) are extremely important in constructing multicyclic scaffolds with diverse bioactivities. Using MycB as a biomarker, three new polyketides – Chaetolivacines A (1), B (3), and C (4) – with one known compound Myceliothermophin E (2) comprising of decalin and 4-hydroxy-2-pyridones were obtained from the culture of Chaetomium olivaceum SD-80A under the guidance of gene mining. The structures of these compounds were established using detailed 1D, 2D NMR, and high-resolution electron spray ionization mass spectroscopy (HRESIMS) analysis. The relative and absolute configurations of the compounds 1, 3, and 4 were elucidated by NOESY and ECD. The biosynthesis pathways of these compounds were proposed, which involves in three key genes ChaA [polyketide synthase-non-ribosomal peptide synthetases (PKS-NRPS)], ChaB, and ChaC. Compounds 1–4 were tested for their antimicrobial activities, and compounds 2 and 3 showed moderate bioactivity against Staphylococcus aureus (SA) and methicillin-resistant S. aureus (MRSA) with MIC values of 15.8 and 27.1 μM. The results showed that configuration of C-21 in 3 and 4 is important for anti-SA and anti-MRSA activities. This study reveals the significant potential of the genus Chaetomium in producing new PKS-NRPS, therefore increasing the speed in the mining for new sources of antimicrobial agents.

This paper presents an analysis of galloping-based wind energy harvesters with piezoelectric and electromagnetic transductions. The lumped parameter models of the galloping-based piezoelectric energy harvester (GPEH) and galloping-based electromagnetic energy harvester (GEMEH) are developed and the approximate analytical solutions of the equations are derived using the harmonic balance method (HBM). The accuracy of the approximate analytical solutions is validated by the numerical solutions. A parametric study is then conducted based on the validated models and solutions to understand the effects of the dimensionless load resistance, r, and electromechanical coupling strength (EMCS) on various quantities indicating the performance of the harvesters, including the dimensionless oscillating frequency, cut-in wind speed, displacement, and average power output. The results show that both r and EMCS can affect the dimensionless oscillating frequencies of the GPEH and GEMEH in a narrow frequency range around the natural frequency. A significant decrease in the displacement around r = 1 for GEPH and at a low r for GEMEH indicates the damping effect induced by the increase in EMCS. There are two optimal r to achieve the maximal power output for GPEH given strong EMCS while there is only one optimal r for GEMEH. Both GPEH and GEMEH show similar characteristics in that the optimal power outputs can reach saturation with an increase of the EMCS. The findings from the parametric study provide useful guidelines for the design of galloping-based energy harvesters with different energy conversion mechanisms.

Flow-induced vibration (FIV) energy harvesting has attracted extensive research interest in the past two decades. Remarkable research achievements and contributions from different aspects are briefly overviewed. Example applications of FIV energy harvesting techniques in the development of Internet of Things are mentioned. The challenges and difficulties in this field are summarized from two sides. First, the multi-physics coupling problem in FIV energy harvesting still cannot be well handled. There is a lack of system-level theoretical modeling that can accurately account for fluid-structure interaction, the electromechanical coupling, and complicated interface circuits. Second, the robustness of FIV energy harvesters needs to be further improved to adapt to the uncertainties in practical scenarios. To be more specific, the cut-in wind speed is expected to be further reduced and the power output to be increased. Finally, Perspectives on the future development in this direction are discussed. Machine-learning approaches, the versatility of metamaterials, and more advanced interface circuits should receive more attention from researchers, since these cutting-edge techniques may have the potential to address the multi-physics modeling problem of FIV energy harvesters and significantly improve the operation performance. In addition, in-depth collaborations between researchers from different disciplines are anticipated to promote the FIV energy harvesting technology to step out of the lab and into real applications. Published version This work was supported by the National Natural Science Foundation of China (Grant No. 51977196).

© 2017 Liya Zhao and Yaowen Yang. The concept of harvesting ambient energy as an alternative power supply for electronic systems like remote sensors to avoid replacement of depleted batteries has been enthusiastically investigated over the past few years. Wind energy is a potential power source which is ubiquitous in both indoor and outdoor environments. The increasing research interests have resulted in numerous techniques on small-scale wind energy harvesting, and a rigorous and quantitative comparison is necessary to provide the academic community a guideline. This paper reviews the recent advances on various wind power harvesting techniques ranging between cm-scaled wind turbines and windmills, harvesters based on aeroelasticities, and those based on turbulence and other types of working principles, mainly from a quantitative perspective. The merits, weaknesses, and applicability of different prototypes are discussed in detail. Also, efficiency enhancing methods are summarized from two aspects, that is, structural modification aspect and interface circuit improvement aspect. Studies on integrating wind energy harvesters with wireless sensors for potential practical uses are also reviewed. The purpose of this paper is to provide useful guidance to researchers from various disciplines interested in small-scale wind energy harvesting and help them build a quantitative understanding of this technique.

Several E3 ubiquitin ligases have been confirmed that they are related to the tumorigenesis. This study aims to find the tongue cancer‐related E3 ubiquitin ligase. The E3 ubiquitin ligase library was screened. The effect of candidate molecule on tongue cancer was validated through cell viability, cell proliferation, colony formation, invasive assay in vitro, and the xenograft model in vivo. The E3 ubiquitin ligase RNF135 significantly promoted the expression of PTEN and TP53 in SCC25 cells. The overexpression of RNF135 inhibited the viability, proliferation, and invasion of SCC25 cells. Knockdown of RNF135 had the opposite effects. Furthermore, RNF135 regulates the tumorigenesis activity of SCC25 cells in vivo. Our results demonstrated that RNF135 had the potential to affect the development of the tongue cancer in vitro. The further in vivo study is helpful to fully understand the role of it.

Regenerative shock absorber has been studied intensively for generating electricity from motion energy that would have been otherwise dissipated and wasted in the form of heat. Integration of the regenerative shock absorber with the vehicle suspension system can incorporate the interaction between the wheels and vehicle body, resulting in more accurate power output results. This paper presents the modellings of quarter, half and full vehicle suspension system models integrated with regenerative shock absorbers based on the same baseline vehicle. The time domain and frequency domain analyses enable a comprehensive comparison of all three suspension system models to be conducted in terms of the effects of vehicle speeds, position of vehicle center of gravity, road classifications (road class A, C and E) and driving speed cycles. The results suggest that the shift of vehicle center of gravity position does not affect the results of any suspension system models. All three suspension system models can respond well to road classification change and rougher road can yield higher power output. The quarter vehicle suspension system model does not present accurate power output results in the low frequency range. Moreover, it also behaves poorly with the vehicle speed variation, which limits its use to Highway Fuel Economy Test Driving Cycle. The half vehicle suspension system model resembles full vehicle suspension system model really well regardless of frequency range, vehicle speed variations and road classifications, when the transverse road profile is neglected.

© 2019 Copyright SPIE. Concurrent energy harvesting by simultaneously harvesting wind and base vibration energy has received very little attention until recently. Yet a major problem with a traditional wind energy harvester under concurrent loadings is the dramatically reduced efficiency when the base vibration frequency deviates from the resonance. This paper investigates a novel design to enhance concurrent energy harvesting from concurrent base vibrations and wind flows. A piecewiselinear aeroelastic energy harvester is integrated with a stopper which can also work as a complementary generator. In order to fast and accurately characterize the response of the harvester, exact analytical solutions are derived based on the harmonic balance analysis and method of averaging. The interaction of the two coexisting excitation frequencies as well as the impact effects between the aeroelastic energy harvester and the stopper are fully considered. Closed-form expressions for both mechanical and electrical responses are presented and validated numerically. Results show that a greatly widened bandwidth is achieved with the proposed design where both aeroelastic and base vibratory energy are effectively harnessed. The analytical solutions are essential to fully understand the characteristics of this new kind of broadband concurrent energy harvester, and serve as a guideline for efficient performance evaluation and parameter optimization.

This study evaluated surface gloss, roughness and color change of six current flowable composites after simulated toothbrushing, including four traditional flowable composites (i.e. GrandioSO Flow, Arabesk Flow, Kerr Revolution Formula 2 and Gradia Direct LoFlo), one self-adhering flowable composite (Kerr Vertise Flow) and one universal injectable composite (G-aenial Universal Flo). Forty-eight dimensionally standardized specimens (n=8/group) were made from six composites. Before and after 1 h toothbrushing simulation, surface gloss was measured with a glossmeter, and surface roughness was evaluated with a profilometer, and color was measured with a spectrophotometer. In this study, G-aenial Universal Flo, termed as universal injectable composite by the manufacturer, presented excellent surface properties after toothbrush abrasion; Gradia Direct LoFlo showed excellent color stablity after toothbrush abrasion; color alteration of composites caused by toothbrush abrasion was acceptable on the premise that 3.3∆E units were considered as acceptable threshold values.

© 2018 IEEE. In this paper, using a high frequency mechanical stopper as a complementary energy harvester is proposed to improve the performance of energy harvesting from concurrent wind flows and base vibrations. Galloping aeroelasticity of a square-sectioned bluff body is employed to achieve limit-cycle structural oscillations. The analysis demonstrates that the bandwidth for effectively harnessing both aerodynamic and base vibratory energy is substantially widened, and simultaneously, the total power amplitude is significantly enhanced as compared to the original linear galloping energy harvester. It is concluded that the proposed system is viable solution to enhance energy conversion in situations where wind flows and base vibrations are coexisting.

Background: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a promising approach for lymphomas. This study aimed to evaluate the effect of ifosfamide, cisplatin or carboplatin, and etoposide (ICE)-based regimen as a mobilization regimen on relapsed, refractory, or high-risk aggressive lymphoma. Methods: From June 2001 to May 2013, patients with lymphomas who mobilized by ICE-based regimen for ASCT were analyzed in this retrospective study. The results of the autologous peripheral blood stem cells collection, toxicity, engraftment after ICE-based mobilization regimen were analyzed in this study. Furthermore, risk factors for overall survival (OS) and progression free survival (PFS) were evaluated by univariate analysis. Results: The stem cells were mobilized using ICE-based regimen plus rituximab or ICE-based regimen alone in 12 patients and 54 patients, respectively. The results of stem cell mobilization were excellent. Ninety-seven percentages of the patients had the stem cell collection of at least 2.0 × 10 6 CD34 + cells/kg and 68% had at least 5 × 10 6 CD34 + cells/kg. Fifty-eight percentage of the patients experienced Grade 4 neutropenia, 20% developed febrile neutropenia, and only 12% had Grade 4 thrombocytopenia. At a median follow-up of 63.8 months, the 5-year PFS and OS were 64.4% and 75.3%, respectively. Conclusion: ICE is a powerful regimen for stem cell mobilization in patients with lymphomas.

This paper proposes a novel broadband energy harvester to concurrently harvest energy from base vibrations and wind flows by utilizing a mechanical stopper. A problem for a conventional wind energy harvester is that it can only effectively harness energy from two types of excitations around its resonance frequency. The proposed design consists of a D-shape-sectioned bluff body attached to a piezoelectric cantilever, and a mechanical stopper fixed at the bottom of the cantilever which introduces piecewise linearity through its impact with the bluff body. The quasi-periodic oscillations are converted to periodic vibration due to the introduction of the mechanical stopper, which forces the two excitation frequencies to lock into each other. Broadened bandwidth for effective concurrent energy harvesting is thus achieved, and at the same time, the beam deflection is slightly mitigated and fully utilized for power conversion. The experiment shows that with the stopper-bluff body distance of 19.5 mm, the output power from the proposed harvesting device increases steadily from 3.0 mW at 17.3 Hz to 3.8 mW at 19.1 Hz at a wind speed of 5.5 m/s and a base acceleration of 0.5 g. A guideline for the stopper configuration is also provided for performance enhancement of the broadband concurrent wind and vibration energy harvester.