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Abstract Early prediction of acute kidney injury (AKI) may provide a crucial opportunity for AKI prevention. To date, no prediction model targeting AKI among general hospitalized patients in developing countries has been published. Here we show a simple, real-time, interpretable AKI prediction model for general hospitalized patients developed from a large tertiary hospital in China, which has been validated across five independent, geographically distinct, different tiered hospitals. The model containing 20 readily available variables demonstrates consistent, high levels of predictive discrimination in validation cohort, with AUCs for serum creatinine-based AKI and severe AKI within 48 h ranging from 0.74–0.85 and 0.83–0.90 for transported models and from 0.81–0.90 and 0.88–0.95 for refitted models, respectively. With optimal probability cutoffs, the refitted model could predict AKI at a median of 72 (24–198) hours in advance in internal validation, and 54–90 h in advance in external validation. Broad application of the model in the future may provide an effective, convenient and cost-effective approach for AKI prevention.

In southern China, co-incorporating winter green manure and rice straw has proven to be a practical and economically viable strategy that enhances soil carbon (C) sequestration and agricultural productivity in rice paddies. However, the issue of how to control the greenhouse gas (GHG) emissions in paddy fields owing to the incorporation of substantial organic matter remains a bottleneck. A 2-year field experiment was conducted, which included five treatments: conventional water management with no residue (CK) and with co-incorporation of green manure and rice straw (GM+Rs), delayed flooding by 5, 10, and 15 days after the co-incorporation of green manure and rice straw (GM+Rs-DW5, GM+Rs-DW10, and GM+Rs-DW15) before transplanting rice seedlings. The delayed flooding treatments reduced the 2-year average CH4 emissions by 40.9%–60.8% compared with GM+Rs. The delayed flooding inhibited the growth of methanogens and CH4 emissions, which was linked to a reduction of dissolved organic carbon (DOC) concentration in surface water. The lowest C footprint (4.05 t CO2-eq ha−1) as well as the yield-scaled C footprint (0.6 kg CO2-eq kg−1) were observed in the GM+Rs-DW10 treatment, both even lower than those in CK (15.11 t CO2-eq ha−1and 2.1 kg CO2-eq kg−1). Moreover, the GM+Rs-DW10 treatment led to an increase in net ecosystem economic benefit (NEEB) of 3750 and 2870 CNY ha−1 than CK and GM+Rs over a 2-year period. Collectively, delayed flooding with green manure and rice straw incorporation is conducive to achieving high NEEB and low risk of GHG emissions. This finding provides important and novel insights for eco-efficient rice production.

Abstract Fe-modified biochar (FB) and co-using Chinese milk vetch and rice straw (MR) are two effective ways for mitigating the cadmium (Cd) contamination in paddy fields in southern China. Nevertheless, the effects of FB combined with MR on Cd passivation mechanism remain unclear. In the current study, the strengthening effects of FB induced by MR were found and the mechanisms of the extracted dissolved organic matter (DOM) from the co-decomposition of MR on Cd alleviation were investigated through pot experiment and adsorption experiment. Pot experiment demonstrated that co-incorporating FB and MR decreased available Cd by 23.1% and increased iron plaque concentration by 11.8%, resulting in a 34.7% reduction in Cd concentrations in brown rice compared with addition of FB. Furthermore, co-using FB and MR improved available nutrients in the soil. The molecular characteristics of DOM derived from the decomposition of MR (DOM-MR) were analyzed by fluorescence excitation emission matrix spectroscopy-parallel factor analysis (EEM-PARAFAC) and Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). Results showed that lignin/carboxylic-rich alicyclic molecules and protein/amino sugar were the main compounds, potentially involved in the Cd binding. Adsorption experiments revealed that the addition of DOM-MR improved the functional groups, specific surface area, and negative charges of FB, inducing the strengthening of both physisorption and chemisorption of Cd(II). The maximum adsorption capacity of Fe-modified biochar after adding DOM-MR was 634 mg g−1, 1.30 times that without the addition of DOM-MR. This study suggested that co-incorporating MR, and FB could serve as an innovative practice for simultaneous Cd remediation and soil fertilization in Cd-polluted paddy fields. It also provided valuable insights and basis that DOM-MR could optimize the performances of Fe-modified biochar and enhance its potential for Cd immobilization. Graphical Abstract

This paper considers the event-triggered distributed fixed-time consensus control problem of leader-following multi-agent systems with nonlinear dynamics and inherent disturbances. First, an event-triggered distributed strategy, that is used to decide when to update states by agents, is proposed. Under the proposed strategy, each agent receives its neighbors’ state to make decisions only if the measurement error exceeds a certain threshold. Second, we design a nonsingular terminal sliding mode consensus protocol so that all followers reach the leader’s state in a fixed-time. Particularly, the gain in the consensus protocol is determined by the settling time, which makes devising and tuning the gain conveniently. Simulation examples are worked out to demonstrate the effectiveness of our theoretical results.

In2O3 based materials are one of the most promising high-temperature thermoelectric materials for application. Herein, Sm doped In2O3 samples were prepared by mechanical alloying, high-temperature calcination, and discharge plasma sintering, and the influence mechanism of rare earth element doping on the thermoelectric properties of In2O3 based semiconductors was studied. The results indicate that the electrical conductivity increased significantly. Due to the introduction of Sm impurity levels, the density of states near the Fermi level significantly increases. The bandgap widens, and the mobility first decreases and then increases. Due to the increase in carrier concentration, the absolute value of the Seebeck coefficient decreases, but the gain effect caused by the increase in conductivity is greater than the debuff caused by the decrease in the absolute value of the Seebeck coefficient. The power factor increases after Sm doping.The thermal conductivity decreases due to the decrease in Young's modulus, enhanced heterogeneous scattering, and enhanced heavy element scattering. The ZT value was raised to ∼0.327 at 973 K, obtained by Sm doped In2O3 sample with x = 0.060, which is ∼6 times as that of the pristine In2O3 sample.

Abstract This paper studies the iterative learning control (ILC) for a class of second‐order nonlinear hyperbolic impulsive partial differential systems. Firstly, to follow the discontinuous desired output, a P‐type learning law is adopted, and sufficient conditions for the convergence of the tracking error is established under identified initial state value. The rigorous analysis is also given using the impulsive Gronwall inequality. Secondly, the tracking error of output trajectory is considered in systems with state initial values shifting based on an initial learning algorithm. These results of this paper show that the tracking error on the finite time interval can uniform converge to 0 as the iteration index goes to infinity if impulse number of the systems is only a finite numbers. Finally, two numerical simulation examples are given to verify the effectiveness of the theoretical results.

Optical bistability and multistability are numerically investigated based on periodic superconducting photonic multilayers with graphene in cryogenic environments. Bandgap edge resonances are sensitive to circumstance temperature and can localize the electric field greatly, which is utilized to enhance the nonlinearity of graphene. Consequently, low threshold optical bistability and double-bistability are realized. Optical multistability subsequently arises by increasing the value of circumstance temperature as well. The thresholds of bistability and multistability lower further by decreasing the chemical potential of graphene or promoting the period number of photonic multilayers. The thresholds can be decreased as low as several hundred MW/cm2. The complex structure has a great potential for the development of two- and multiple-valued all-optical switches in low-temperature condition.

Abstract Biological nitrogen (N) fixation (BNF) via diazotrophs is an important ecological process for the conversion of atmospheric N to biologically available N. Although soil diazotrophs play a dominant role in BNF and arbuscular mycorrhizal fungi (AMF) serve as helpers to favor BNF, the response of soil BNF and diazotrophic communities to different long‐term fertilizations and the role of AMF in diazotrophs‐driven BNF are poorly understood. Herein, a 33‐year fertilization experiment in a wheat–maize intercropping system was conducted to investigate the changes in soil BNF rates, diazotrophic and AMF communities, and their interactions after long‐term representative fertilization (chemical fertilizer, cow manure, wheat straw, and green manure). We found a remarkable increase in soil BNF rates after more than three decades of fertilization compared with nonfertilized soil, and the green manure treatment rendered the highest enhancement. The functionality strengthening was mainly associated with the increase in the absolute abundance of diazotrophs and AMF and the relative abundance of the key ecological cluster of Module #0 (gained from the co‐occurrence network of diazotrophic and AMF species) with dominant diazotrophs such as Skermanella and Azospirillum. Furthermore, although the positive correlations between diazotrophs and AMF were reduced under long‐term organic fertilization regimes, green manuring could reverse the decline within Module #0, and this had a positive relationship with the BNF rate. This study suggests that long‐term fertilization could promote N fixation and select specific groups of N fixers and their helpers in certain areas. Our work provides solid evidence that N fixation and certain groups of diazotrophic and AMF taxa and their interspecies relationship will be largely favored after the fertilized strategy of green manure.

Programming the patterned magnetization profile on the magnetic elastomer can enable the magnetic soft robot to produce controlled deformation. But the magnetization profiles are usually unchangeable, which leads to the single function of magnetic soft robot. This paper presents a reprogrammable mangetic elastomer based on liquid-metal/NdFeB/Silicone composites. Liquid-metal/NdFeB functional groups wrapped in silicone matrix can realize repeated magnetization through thermal-assisted magnetic programming. By using several liquid metals (melting points

Solanum nigrum L. (S. nigrum) and microbial agents are often used for the remediation of cadmium (Cd)-contaminated soil; however, no studies to date have examined the efficacy of using various microbial agents for enhancing the remediation efficiency of Cd-contaminated soil by S. nigrum. Here, we conducted greenhouse pot experiments to evaluate the efficacy of applying Bacillus megaterium (BM) along with citric acid (BM + CA), Glomus mosseae (BM + GM), and Piriformospora indica (BM + PI) on the ability of S. nigrum to remediate Cd-contaminated soil. The results showed that BM + GM significantly increased the Cd accumulation of each pot of S. nigrum by 104% compared with the control. Application of microbial agents changed the soil microbial communities. Redundancy analysis showed that the activities of Catalase (CAT) and urease (UE), soil organic matter, available N and total Cd were the main influencing factors. By constructing the microbial co-occurrence networks, the soil microbe was divided into four main Modules. BM + GM and BM + PI significantly increased the relative abundance of Module#1 and Module#3, respectively, when compared with the control. Additionally, Module#1 showed a significant positive correlation with translocation factor (TF), which could be regarded as the key microbial taxa. Further research found that Ascomycota, Glomeromycota, Proteobacteria, and Actinobacteria within Module#1 were also significantly correlated with TF, and these key species enriched in BM + GM. Overall, our findings indicate that the BM + GM treatment was the most effective for the remediation of Cd pollution. This treatment method may further affect the rhizosphere microbial community by affecting soil indicators, which might drive the formation of Module#1, thus greatly enhancing the Cd remediation capacity of S. nigrum.

Fertilizer application practices are one of the major challenges facing agroecology. The agrobenefits of combined application of green manure and chemical fertilizers, and the potential of green manure to replace chemical fertilizers are now well documented. However, little is known about the impact of fertilization practices on microbial communities and tice yield. In this study, the diversity of bacterial and fungal communities, symbiotic networks and their relationship with soil function were analyzed in five fertilization treatments (N: 100% nitrogen fertilizer alone; M: green manure alone; MN60: green manure couple with 60% nitrogen fertilizer, MN80: green manure couple with 80% nitrogen fertilizer; and MN100: green manure couple with 100% nitrogen fertilizer). First, early rice yield was significantly higher by 12.6% in MN100 treatment in 2021 compared with N. Secondly, soil bacterial diversity showed an increasing trend with increasing N fertilizer application after green manure input, however, the opposite was true for fungal diversity. Microbial interaction analysis showed that different fertilizer applications changed soil microbial network complexity and fertilizer-induced changes in soil microbial interactions were closely related to soil environmental changes. Random forest models further predicted the importance of soil environment, microorganisms and rice yield. Overall, nitrogen fertilizer green manure altered rice yield due to its effects on soil environment and microbial communities. In the case of combined green manure and N fertilizer application, bacteria and fungi showed different responses to fertilization method, and the full amount of N fertilizer in combination with green manure reduced the complexity of soil microbial network. In contrast, for more ecologically sensitive karst areas, we recommend fertilization practices with reduced N by 20–40% for rice production.Graphical Abstract

Magnetic soft robots (MSRs) can achieve controllable shape-morphing by magnetic programming to the magnetic elastomer. However, the magnetization profile is usually implemented on a continuous region and is unchangeable. The deformation and function design of MSR hence is limited. This study presents a programmable magnetic pixel soft robot (MPSR). By encapsulating liquid-metal/NdFeB composites into a Silicone shell, the thermal-magnetic response functional film with lattice-structure is fabricated, with the highest pixel resolution of 1 × 1 mm2. A piece of laser-assisted magnetic programming equipment is developed to implement magnetic encoding on discrete regions of the film. Therefore, a mathematical model is proposed to help calculate the magnetic codes according to the preset end shape. At last, several pixel-structure MPSRs are prepared and tested. Experimental results show that using the magnetic encoding technique, we can reconfigure the deformations and functions of the robot. This study provides a basis for the programmed shape regulation and motion design of the soft robot.

Coherent perfect absorption laser points (CPA-LPs) are investigated in the Thue-Morse (Th-M) PT-symmetric photonic crystals. CPA-LPs are induced as incident light impinges perpendicularly upon the structure. The operating wavelengths of the CPA-LPs are dependent on the Th-M sequence number, the incident angle and the gain-loss factor of materials. Especially, two CPA-LPs may be achieved with the same value of incident angle for a specific gain-loss factor. Double-wavelength laser consequently is supported in this structure and the corresponding transmittance of the CPA-LPs is optional. An abrupt jump in the calculated reflection coefficient phase could be found at the CPA-LPs as well. This study may be helpful in potential applications for lasers and highly sensitive sensors.

Doping is an important method to modulate the physical and chemical properties of two-dimensional materials. By substitutional doping, different group IV–VI atoms are doped in GeSe monolayers to compose the doped models, of which the effects are investigated using first-principles calculations. The results show that local deformations of geometrical structure can be observed around the doping atoms. According to the analysis of the formation energy and the cohesive energy, all the doped models have a strongly bonded network, and GeSe_N possesses the most stable structure. Only the bandgap of Ge_As is direct, while those of other doped models are indirect. Thus, direct and indirect bandgaps are alternative by doping different atoms. The structural and electronic properties, especially for the bond lengths variation around doping atoms, are explained by the charge density difference. Finally, the scanning tunnel microscope images of the doped models are analyzed for further experimental investigations. Our work provides a stimulating account by atom doping which could trigger the developments and applications of new two-dimensional materials for manufacturing microelectronic and optoelectronic devices.

Abstract The transmittance, conductivity, and flexibility are the crucial properties for the development of next-generation flexible electrodes. Achieving a good trade-off between transmittance and conductivity of flexible electrodes has been a challenge because the two properties are inversely proportional. Herein, we reveal a good trade-off between transmittance and conductivity of gold nanomesh (AuNM) can be achieved through appropriately increasing the AuNM thickness no more than 40 nm, the mean free path of electrons in Au metal. The further flexibility investigation indicates that the AuNM electrodes with mesh structure show higher tolerance than the Au bulk film, and the AuNM electrodes with smaller inter-aperture wire width can accommodate more tensile strains than a counterpart with bigger inter-aperture wire width. The simulated results based on finite element analysis (FEA) show good agreement with experimental results, which indicates the fabrication method of versatile nanosphere lithography (NSL) is reliable. These results established a promising approach toward next-generation large-scale flexible transparent AuNM electrodes for flexible electronics.

To ensure the photovoltaic (PV) arrays under partial shading condition(PSC) could still output maximum power quickly and efficiently, this work presents a modified hybrid maximum power point tracking (MPPT) method, which applies artificial neural network (ANN) to the modified perturb and observe (MP&O). Instead of using expensive illumination intensity sensors directly, the illumination intensity on each module in the PV array can be obtained indirectly by sampling the specific points of their own cheaper voltage-current sensors. ANN uses indirect illumination intensity to predict the optimal voltage areas of the global maximum power point (GMPP). Based on the areas, MP&O adopts a adaptive step size strategy to obtain GMPP. By modeling and simulation in Matlab/Simulink, it is shown that the tracking time and efficiency of the proposed method in this work can reach 0.026s and 99.87% respectively. Compared with other methods, the method has faster speed, higher efficiency, smaller fluctuation and lower complexity.

The centre of the potential well of the quantum-behaviour particle swarm optimization (QPSO) is restricted to the super rectangle which is made up of the local optimal position and the global optimal position. The information sharing mechanism among particles is single, and the algorithm has the problems of premature convergence and low optimization efficiency. To solve this problem, an improved QPSO algorithm is proposed, which integrates social learning and Lévy flights (LSL-QPSO). Firstly, the social learning strategy is used to update the non-optimal particle and improve the global search ability. Then, the Lévy flights strategy is introduced to overcome the shortcoming of the low efficiency of the optimal particle in the social learning mechanism, and further improve the convergence accuracy and search efficiency of the algorithm. Finally, four typical Benchmark functions are tested. The results show that the convergence accuracy, search efficiency and universality of the LSL-QPSO algorithm are ahead of QPSO and other similar QPSO improved algorithms.

Object detection in remote sensing images plays an important role in both military and civilian remote sensing applications. Objects in remote sensing images are different from those in natural images. They have the characteristics of scale diversity, arbitrary directivity, and dense arrangement, which causes difficulties in object detection. For objects with a large aspect ratio and that are oblique and densely arranged, using an oriented bounding box can help to avoid deleting some correct detection bounding boxes by mistake. The classic rotational region convolutional neural network (R2CNN) has advantages for text detection. However, R2CNN has poor performance in the detection of slender objects with arbitrary directivity in remote sensing images, and its fault tolerance rate is low. In order to solve this problem, this paper proposes an improved R2CNN based on a double detection head structure and a three-point regression method, namely, TPR-R2CNN. The proposed network modifies the original R2CNN network structure by applying a double fully connected (2-fc) detection head and classification fusion. One detection head is for classification and horizontal bounding box regression, the other is for classification and oriented bounding box regression. The three-point regression method (TPR) is proposed for oriented bounding box regression, which determines the positions of the oriented bounding box by regressing the coordinates of the center point and the first two vertices. The proposed network was validated on the DOTA-v1.5 and HRSC2016 datasets, and it achieved a mean average precision (mAP) of 3.90% and 15.27%, respectively, from feature pyramid network (FPN) baselines with a ResNet-50 backbone.

Cultivation of green manure crops is important strategy for improving soil fertility in South China. Therefore, it is important to obtain plant varieties that can better accumulate nutrients during the green manuring phase. The present study evaluated the phosphorus (P) and potassium (K) uptake efficiencies of various winter leguminous species at two different sites. Varieties tested included six Chinese milk vetch cultivars (i.e., Minzi No.6, Ningbodaqiao, Wanzi No.1, Xiangzi No.1, Yijiangzi, and Yujiangdaye), as well as hairy vetch and common vetch, while ryegrass was planted as a control. All leguminous species showed higher ability for P and K absorption in the two sites compared to the ryegrass. Hairy vetch and common vetch performed better than all six Chinese milk vetch cultivars, and the highest biomass and P and K uptake capacities were observed in hairy vetch. Green manuring had different effects on soil enzymes. Phosphatase (87.0%) and leucine-aminopeptidase (163.8%) were increased by hairy vetch. β-glucosidase (143.4%) and N-acetyl-glucosaminidase (283.3%) were increased by Yijiangzi and Yujiangdaye, respectively, in Guangxi compared to the control. Xiangzi No.1 increased N-acetyl-glucosaminidase (352.6%), leucine-aminopeptidase (477.5%), phosphatase (591%), and β-glucosidase (786.0%) in Hunan compared to the ryegrass. Enzyme activities increased nutrient availability at both experimental sites. P and K uptake efficiencies significantly related with soil enzymes in Guangxi. It is suggested that hairy vetch has the largest capability for P and K uptake and might be a potential choice for improving P and K management in sustainable agriculture.

The stable operation of charging pile is related to the entire operation efficiency of the charging network of electric vehicles so the prediction of charging pile operation abnormality rate can help the operational department to make operational decisions in advance. This paper uses the electric vehicle charging network operating date in the north of Hebei province, based on the feature of the anomalies records of charging pile, to combine the generalized AR(q) model and the regression model and to predict the abnormality rate of electric vehicle charging network in the north of Hebei province. It is predicted that the average absolute error is 0.0044 and the acceptable prediction effect can be obtained.

The fluctuations of wind power impact the stable operation of a power system as its penetration grows high. Energy storage may be a potential solution to suppress these fluctuations and has drawn much attention in recent years. As the time scale of wind power fluctuations is in a range of seconds to hours, multi-type energy storage with complementary characteristics, such as the combination of energy-type storage devices (ESD) and power-type storage device (PSD), may be technically and economically feasible to suppress multi-time-scale wind power fluctuations. Therefore, system control is very important when the power allocation among each of the energy storage units is considered. In this paper, a novel coordinated control strategy based on model predictive control (MPC) was proposed for wind power fluctuation suppression, which employs MPC for the total power required for the whole energy storage system and then allocates it between ESD and PSD with the low-pass filter algorithm (LFA) method. Due to the predictive feature of MPC, the power requirement of the energy storage system can be obtained with little time delay, which means less energy is needed. The effectiveness of the proposed control strategy was verified in a time-domain simulation system. The influence of wind speed conditions and LFA time constant on the wind/storage system were further discussed.

This paper is concerned with the stability analysis and control of a new smooth Chua's system. Firstly, the chaotic characteristic of the system is confirmed with the aid of the Lyapunov exponents. Secondly, it is proved that the system has globally exponential attractive set and positive invariant set. For the three unstable equilibrium points of the system, a linear controller is designed to globally exponentially stabilize the equilibrium points. Then, a linear controller and an adaptive controller are, respectively, proposed so that two similar types of smooth Chua's systems are globally synchronized, and the estimation errors of the uncertain parameters converge to zero as t tends to infinity. Finally, the numerical simulations are also presented.

This work concerns the stability of impulsive Cohen-Grossberg neural networks with time-varying delays and reaction-diffusion terms as well as Dirichlet boundary condition. By means of Poincaré inequality and Gronwall-Bellman-type impulsive integral inequality, we summarize some new and concise sufficient conditions ensuring the global exponential stability of equilibrium point. The proposed criteria are relevant to the diffusion coefficients and the smallest positive eigenvalue of corresponding Dirichlet Laplacian. In conclusion, two examples are illustrated to demonstrate the effectiveness of our obtained results.