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Lithium-ion battery is an efficient and environmentally friendly energy storage device. Electrochemical reaction, heat generation, and aging formation in battery cells interplay with each other, which is currently insufficiently considered and studied under various conditions. A dynamic electrochemical–thermal–aging coupling model was developed to study the effects of ambient temperature and charge/discharge rate on a lithium-ion cell under natural convection condition. Evolution of heat generation power and cell temperature and dynamic distribution of electrochemical and aging parameters during charge/discharge were studied. If charge/discharge rate increases or ambient temperature decreases, the polarization effect or internal resistance of the lithium-ion cell increases to increase the polarization heat and ohmic heat; however, the reversible heat changes little. Peaks of current density and lithium-ion concentration difference of electrode particles caused by potential plateaus of the negative electrode were discovered. The main reasons for lithium-ion cell aging are high total strain energy density in electrode particle, solid electrolyte interface (SEI) film, and lithium metal deposition (lithium plating). The low ambient temperature can cause the total strain energy density peak of electrode particle at the beginning of charge or discharge, and the potential plateaus of negative electrode also cause the total strain energy density peaks. SEI film mainly forms during charge; the increase of ambient temperature or charge rate increases SEI reaction rate to accelerate the SEI film growth. Kinetics difficulty of lithium-ion intercalation on the negative electrode is increased by the decrease of ambient temperature or increase of charge rate, which causes the lithium plating overpotential less than 0 V to appear earlier to accelerate the deposited lithium metal growth.

Serverless computing has revolutionized online service development and deployment with ease-to-use operations, auto-scaling, fine-grained resource allocation, and pay-as-you-go pricing. However, a gap remains in configuring serverless functions—the actual resource consumption may vary due to function types, dependencies, and input data sizes, thus mismatching the static resource configuration by users. Dynamic resource consumption against static configuration may lead to either poor function execution performance or low utilization. This paper proposes Freyr$^+$+, a novel resource manager (RM) that dynamically harvests idle resources from over-provisioned functions to accelerate under-provisioned functions for serverless platforms. Freyr$^+$+ monitors each function's resource utilization in real-time and detects the mismatches between user configuration and actual resource consumption. We design deep reinforcement learning (DRL) algorithms with attention-enhanced embedding, incremental learning, and safeguard mechanism for Freyr$^+$+ to harvest idle resources safely and accelerate functions efficiently. We have implemented and deployed a Freyr$^+$+ prototype in a 13-node Apache OpenWhisk cluster using AWS EC2. Freyr$^+$+ is evaluated on both large-scale simulation and real-world testbed. Experimental results show that Freyr$^+$+ harvests 38% of function invocations’ idle resources and accelerates 39% of invocations using harvested resources. Freyr$^+$+ reduces the 99th-percentile function response latency by 26% compared to the baseline RMs.

Microdroplet chemistry is now well-known to be able to remarkably accelerate otherwise slow reactions and trigger otherwise impossible reactions. The uniqueness of the microdroplet is attributable to either the air–water interface or solid–liquid interface, depending on the medium that the microdroplet is in contact with. To date, the importance of the solid–liquid interface might have been confirmed, but the contribution from the air–water interface seems to be elusive due to the lack of method for generating contactless microdroplets. In this study, we used a droplet atomization method with acoustic levitation. Upon manipulation of the acoustic field, the levitated parent droplet can be further atomized into progeny microdroplets. With this method, only the air–water interface was present, and a large variety of reactions were successfully tested. We anticipate that this study can be an advance toward the understanding of the air–water interfacial processes of microdroplet chemistry.

C3-functionalized dihydroquinolinones represent a class of important biologically active compounds. Although methods for synthesizing C2/4-functionalized dihydroquinolinones have been extensively reported, research on the synthesis of C3-functionalized dihydroquinolinone is extremely rare. Herein, we report for the first time a method for C3-alkenylated dihydroquinolinones via iron(III)-catalyzed amine-release triple condensation of enaminones. These reactions exhibit broad substrate scope and offer operationally simple, low-cost catalyzed procedures in a single step. Subsequent intramolecular and intermolecular additions to the alkene moiety provide diverse C3-functionalized dihydroquinolinone derivatives.

Within the context of the Belt and Road Initiative (BRI) and the China-Myanmar Economic Corridor (CMEC), the Dulong-Irrawaddy (Ayeyarwady) River, an international river among China, India and Myanmar, plays a significant role as both a valuable hydro-power resource and an essential ecological passageway. However, the water resources and security exhibit a high degree of vulnerability to climate change impacts. This research evaluates climate impacts on the hydrology of the Dulong-Irrawaddy River Basin (DIRB) by using a physical-based hydrologic model. We crafted future climate scenarios using the three latest global climate models (GCMs) from Coupled Model Intercomparison Project 6 (CMIP6) under two shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5) for the near (2025–2049), mid (2050–2074), and far future (2075–2099). The regional model using MIKE SHE based on historical hydrologic processes was developed to further project future streamflow, demonstrating reliable performance in streamflow simulations with a validation Nash-Sutcliffe Efficiency (NSE) of 0.72. Results showed that climate change projections showed increases in the annual precipitation and potential evapotranspiration (PET), with precipitation increasing by 11.3% and 26.1%, and PET increasing by 3.2% and 4.9%, respectively, by the end of the century under SSP2-4.5 and SSP5-8.5. These changes are projected to result in increased annual streamflow at all stations, notably at the basin’s outlet (Pyay station) compared to the baseline period (with an increase of 16.1% and 37.0% at the end of the 21st century under SSP2-4.5 and SSP5-8.5, respectively). Seasonal analysis for Pyay station forecasts an increase in dry-season streamflow by 31.3%–48.9% and 22.5%–76.3% under SSP2-4.5 and SSP5-8.5, respectively, and an increase in wet-season streamflow by 5.8%–12.6% and 2.8%–33.3%, respectively. Moreover, the magnitude and frequency of flood events are predicted to escalate, potentially impacting hydropower production and food security significantly. This research outlines the hydrological response to future climate change during the 21st century and offers a scientific basis for the water resource management strategies by decision-makers.

The incidence of type 2 diabetes is high, and the existing metformin hydrochloride (MH) tablets of 250 mg cannot meet the demands of the Chinese drug market. This study aimed to evaluate the bioequivalence and safety of generic formulations of MH tablets (test formulation [T], 250 mg/tablet) and innovative products (reference formulation [R], 250 mg/tablet) under fasting conditions. This was an open‐label, single‐dose, 2‐period, 2‐sequence crossover, single‐center, randomized phase I clinical trial. T and R were considered bioequivalent if the adjusted geometric mean ratios (GMRs) and 90% confidence intervals of the area under the curve (AUC) and maximum concentration (Cmax) were within the range of 0.8‐1.25. Thirty‐five participants completed the trial. The T/R adjusted GMRs (95.7% for Cmax, 98.7% for AUC0→t, 98.8% for AUC0→∞) were within the acceptable bioequivalence range of 80%‐125%. No serious adverse events or suspected or unexpected serious adverse reactions occurred during this trial. The study findings confirmed that generic MH is a well‐tolerated and bioequivalent alternative to innovative products under fasting conditions in healthy Chinese participants. (www.chinadrugtrials.org.cn; registration no. CTR20190356)

Few-shot semantic segmentation (FSS), which can perform segmentation using only a limited number of annotated examples, is a promising technique that has been embedded in many electronic products. Existing approaches usually achieve segmentation for the query image by computing the similarity between the support and query images. However, when segmenting a new query image, the model prediction may be interfered with by distinct classes with similar semantic information, leading to unsatisfactory results. This may greatly weaken the generalization of FSS in real-world scenarios. In response to this challenge, we propose a few-shot semantic segmentation model based on inter-class relation mining named IRMNet. Firstly, we devise a class filter module that accurately selects useful semantic information by mining the class relations between the query and support images. Then, we use a class generation module that applies a diffusion model to generate rough segmentation masks for query images to augment supervision signals. Finally, we conduct extensive experiments on the PASCAL- $5^{i}$ and FSS-1000 datasets. The evaluation results show that IRMNet can achieve superior performance compared to other baselines. The advancement of FSS in this work can contribute to enhancing visual intelligence in real-world consumer electronics.

Price discrimination has been empirically exposed where e-commercial platforms aim to gain additional profits by charging customers with different prices for the same product/service. This situation becomes even worse in nowadays’ Big Data era, giving the chance for service providers to leverage artificial intelligence technologies to have the deep analysis of personalized patterns, urgently calling for solutions to prevent such discriminated behaviors to protect customers’ rights. This article aims to defend against price discrimination by developing a secure and privacy-preserving solution, provable for e-commerce fairness. Using a newly designed cryptographic accumulator and public bulletin board, our system, called FairECom, allows an auditor (i.e., a customer or third-party auditor) to verify if customers are experiencing price discrimination. In particular, FairECom enables a customer to check if his payment to a product/service is identical to other customers through a privacy-preserving challenge-response protocol, for implementing the price transparency against discrimination. We implement a prototype using an Ethereum-based public bulletin board to conduct the system evaluation. Our evaluation indicates that FairECom can integrate with existing APIs provided by Ethereum and incur acceptable costs when deploying to the e-commercial systems.

If a control input signal constructed by backstepping is used to generate an event-triggered control signal, then not only the real control input is discontinuous, but all the virtual control signals that make up the control signal are also discontinuous and have the same triggering instants with the control input. This fact makes the control design and stability analysis more difficult and complex via backstepping. This article focuses on this problem and works at coming up a new backstepping design procedure of event-triggered fuzzy adaptive control for nonlinear strict feedback systems. A concurrent event-triggered mechanism is proposed to ensure that the real control input and the virtual control signals have the same triggering instants. Then, a systemic backstepping design procedure is developed to construct event-triggered fuzzy adaptive controller. The Lyapunov technique for nonlinear impulsive system is employed to provide the closed-loop stability analysis. It is shown that the derived event-triggered fuzzy adaptive controller ensures that the closed-loop system output well follows the desired tracking trajectory and the other closed-loop signals remain bounded. Eventually, two examples are provided to further verify the applicability and reliability of the presented control scheme.

Catalytic cleavage of C=C double bonds in alkenes is highly important to convert feedstocks into high-value compounds. However, these approaches are mainly limited to oxidative cleavage of alkenes with excess oxidants and redox-neutral alkene metathesis. In contrast, reductive C=C double bond cleavage and functionalization have not been reported. Herein, we report a novel visible-light photoredox-catalyzed carboxylation of styrenes with CO2viareductive C=C double bond cleavage. The use of dicyclohexylmethylamine as scission reagent is the key to the success. Different from previous homologation reactions with CO2, this protocol enabled exchange of the carbon of styrenes with CO2, affording important aryl acetic acids viaC=C double bond cleavage. Moreover, preliminary mechanistic investigation and DFT calculations shed light on the reaction mechanism, disclosing aminomethyl-carboxylation intermediate, benzylic radicals and carbanions as key intermediates in the reaction.

In this study, we achieved high‐resolution pixelated QLED device with 500 pixels per inch (ppi) through electrohydrodynamic printing (EHD) technology. We optimize the EHD printing process by controlling ink viscosity and printing speed to obtain a uniform and flat emission layer film. Then, we prepared high‐resolution pixelated bottom‐emission and top‐emission PMQLED with maximum current efficiencies of 13.6 cd/A and 16.4 cd/A, respectively. Finally, we fabricated a 500 ppi red and green (R/G) dual‐color bottom‐emission QLED device using the EHD printing method. The successful preparation of these 500 ppi QLED devices with high efficiency indicated that the EHD printing method can provides a technical basis for developing the high‐resolution QLED display technology in the future.

Even though it is still an emerging field, the application of a high external electric field (EEF) as a green and efficient catalyst in synthetic chemistry has recently received significant attention for the ability to deliver remarkable control of reaction selectivity and acceleration of reaction rates. Here, we extend the application of the EEF to Menshutkin reactions by taking advantage of the spontaneous high electric field at the air–water interfaces of sprayed water microdroplets. Experimentally, a series of Menshutkin reactions were accelerated by 7 orders of magnitude. Theoretically, both density functional theory calculations and ab initiomolecular dynamics simulations predict that the reaction barrier decreases significantly in the presence of oriented external electric fields, thereby supporting the notion that the electric fields in the water droplets are responsible for the catalysis. In addition, the ordered solvent and reactant molecules oriented by the electric field alleviate the steric effect of solvents and increase the successful collision rates, thus facilitating faster nucleophilic attack. The success of Menshutkin reactions in this study showcases the great potential of microdroplet chemistry for green synthesis.

In Pakistan, five continuous extreme precipitation events in the summer (July‒August) of 2022 caused disastrous floods, depriving thousands of people's lives and ruining millions of hometowns. This tremendous disaster in Pakistan also happened in 2010 but with three concentrated extreme precipitation events in the middle of summer. The amount of Pakistan heavy daily precipitation in 2022 surpasses that in 2010 record, making it the strongest precipitation event ever recorded. To comprehensively understand the causes of extreme precipitation in Pakistan, this study investigated the anomalies in atmospheric circulation and moisture contribution of 2010/2022 extreme precipitation and compared their differences. The results show that an atmospheric blocking over northern Europe in both 2022 and 2010 enhanced convection in Pakistan by transporting cold‒dry air from the high-latitude region and benefiting warm‒wet monsoonal air marching to Pakistan. By employing a moisture track model, the main moisture sources for summer precipitation in Pakistan were identified. It is found that moisture contributions except from Eurasia were enhanced, causing extreme precipitation. In particular, enhanced moisture contribution from the southern Indian Ocean and the northern Indian continent in 2022 are more prominent than that in 2010. The increased moisture contribution in 2010 was due to increased evaporation induced by warming sea surface in the Indian Ocean, while much richer moisture transport in 2022 was attributed to the enhanced cross‒equatorial flow induced by the anomalous subtropical high in the Southern Hemisphere. Therefore, attention should be paid to the role of subtropical high in the Southern Hemisphere in addition to those in Northern Hemisphere in understanding disastrous extreme precipitation events in Pakistan.

The use of external electric fields as green and efficient catalysts in synthetic chemistry has recently received significant attention for their ability to deliver remarkable control of reaction selectivity and acceleration of reaction rates. Technically, methods of generating high electric fields in the range of 1–10 V/nm are limited, as in-vacuo techniques have obvious scalability issues. The spontaneous high fields at various interfaces promise to solve this problem. In this study, we take advantage of the spontaneous high electric field at the air–water interface of sprayed water microdroplets in the reactions of several halogen bond systems: Nu:--X–X, where Nu: is pyridine or quinuclidine and X is bromine or iodine. The field facilitates ultrafast electron transfer from Nu:, yielding a Nu–X covalent bond and causing the X–X bond to cleave. This reaction occurs in microseconds in microdroplets but takes days to weeks in bulk solution. Density functional theory calculations predict that the reaction becomes barrier-free in the presence of oriented external electric fields, supporting the notion that the electric fields in the water droplets are responsible for the catalysis. We anticipate that microdroplet chemistry will be an avenue rich in opportunities in the reactions facilitated by high electric fields and provides an alternative way to tackle the scalability problem.

The proliferation of IoT devices, with various capabilities in sensing, monitoring, and controlling, has prompted diverse emerging applications, highly relying on effective delivery of sensitive information gathered at edge devices to remote controllers for timely responses. To effectively deliver such information/status updates, this paper undertakes a holistic study of AoI in multi-hop networks by considering the relevant and realistic factors, aiming for optimizing information freshness by rapidly shipping sensitive updates captured at a source to its destination. In particular, we consider the multi-channel with OFDM (orthogonal frequency-division multiplexing) spectrum access in multi-hop networks and develop a rigorous mathematical model to optimize AoI at destination nodes. Real-world factors, including orthogonal channel access, wireless interference, and queuing model, are taken into account for the very first time to explore their impacts on the AoI. To this end, we propose two effective algorithms where the first one approximates the optimal solution as closely as we desire while the second one has polynomial time complexity, with a guaranteed performance gap to the optimal solution. The developed model and algorithms enable in-depth studies on AoI optimization problems in OFDM-based multi-hop wireless networks. Numerical results demonstrate that our solutions enjoy better AoI performance and that AoI is affected markedly by those realistic factors taken into our consideration.

Herein, we demonstrate the successful utilization of copper catalysis and oxygen oxidation for consecutive C(sp3)–C(sp3) bond cleavage in alkyl cyclic ethers. A key step involves a copper–oxygen autoxidation process, generating in situalkoxy radicals and triggering sequential C–C bond cleavage. This β-oxidative cleavage strategy enables the use of cyclic ethers as valuable C1 building blocks for the synthesis of bridged methylene dimers. This reaction holds promise for inspiring alternative methods targeting inert C(sp3)–C(sp3) bond cleavage.

It is known that a controller designed via backstepping contains all virtual control signals constructed at the previous design steps. When this controller is used to generate an event-triggered control signal which is discontinuous, those virtual control signals are simultaneously triggered and the corresponding triggered virtual signals are utilized for the real control operation, they are also discontinuous. This fact results in the noncontinuity of the virtual error dynamics. This problem is ignored in the existing backstepping-based event-triggered control schemes, in which control design and stability analysis are implemented according to the continuous virtual error dynamics, namely, all the virtual control signals are required to be continuous. Based on this observation, this article focuses on the backstepping-based event-triggered fuzzy adaptive control for nonlinear strict-feedback systems with unavailable states. To do so, a concurrent event generator is first introduced, furthermore, the backstepping-based output feedback control design is given according to the discontinuous virtual error dynamics. Then, the Lyapunov approach for nonlinear impulsive systems is used to provide the closed-loop performance analysis. The results show that with the event-based fuzzy adaptive controller, all the closed-loop signals meet bounded requirements and the Zeno phenomenon is prevented. Ultimately, the proposed theoretical results are supported by two simulation examples.

Water is considered as an inert environment for the dispersion of many chemical systems. However, by simply spraying bulk water into microsized droplets, the water microdroplets have been shown to possess a large plethora of unique properties, including the ability to accelerate chemical reactions by several orders of magnitude compared to the same reactions in bulk water, and/or to trigger spontaneous reactions that cannot occur in bulk water. A high electric field (∼109V/m) at the air–water interface of microdroplets has been postulated to be the probable cause of the unique chemistries. This high field can even oxidize electrons out of hydroxide ions or other closed-shell molecules dissolved in water, forming radicals and electrons. Subsequently, the electrons can trigger further reduction processes. In this Perspective, by showing a large number of such electron-mediated redox reactions, and by studying the kinetics of these reactions, we opine that the redox reactions on sprayed water microdroplets are essentially processes using electrons as the charge carriers. The potential impacts of the redox capability of microdroplets are also discussed in a larger context of synthetic chemistry and atmospheric chemistry.

In this paper, we obtained the optimal structure of QLED top‐emission spin‐coating device. Meanwhile, we also have successfully developed quantum dots and ZnO ink materials with high stability. With the top‐emission device structure and stable ink materials, we optimize the morphology of every film by controlling the drying process after ink‐jet printing. The emission area of united devices prepared by using the optimized ink‐jet printing process is equal to the designed area of pixels, with clear boundaries, uniform electroluminescent morphologies within a single sub‐pixel, and no significant difference in luminescence between pixels. Finally, we assembled and fabricated a 55‐in. 8K AMQLED display with a color gamut of 116% NTSC. The device structure of top‐emission and high stable ink materials are applied to the IJP device. The morphology of every film is achieved by using the optimized ink‐jet printing process. A 55‐in. 8K AMQLED display with a high resolution and wide color gamut is fabricated.

A new and efficient output-feedback adaptive backstepping control strategy is developed to realize a finite-time output tracking control task for nonlinear output-constrained systems. The main characteristic of this strategy is to construct an asymmetric barrier Lyapunov function based on the performance functions and error variable to achieve finite-time tracking control. Because the system states are unknown, fuzzy state observer is set up to reconstruct the system states. Consequently, an observer-based fuzzy adaptive output-feedback controller is presented. The proposed control strategy ensures that the output tracking error meets the preassigned precision level throughout a pre-given time period, meanwhile, the output variable complies with time-varying restrictions for all time and other closed-loop signals are bounded. Lastly, two examples are employed for numerical simulation research to reveal the feasibility and availability of the developed control strategy.

Microdroplet chemistry has been an emerging new field for its large plethora of unique properties, among which an especially intriguing one is the strong oxidizing and reducing powers. The hydroxide ion in water microdroplets is considered to split into a hydroxyl radical and an electron at the air–water interface, and the former is responsible for the oxidizing capability while the latter is responsible for the reducing power, making a unity of opposites. However, to date there are only two examples showing that oxidation and reduction occur simultaneously to the same substrates, which might be a result of the redox properties of the substrate per se. In this study, we carefully chose a group of ο-quinone compounds as the substrates in water microdroplets and discovered that they can be both oxidized by the hydroxyl radical and reduced by the electron. These results keep pushing the limit of the unique redox properties of microdroplet chemistry.

In this study, three sampling points located in the Nanchong section of the Jialing River were selected as research objects, and the temporal distribution characteristics and influencing factors of water pollutants in the Nanchong section of the Jialing River mainstream were discussed through monthly sampling analysis of nine monitoring indicators from 2017 to 2021. Gray correlation analysis, Mann– Kendall test, Spearman’s correlation analysis, and multivariate statistical analysis were used to analyze the variation trend, time distribution, and differences in water pollutants in different periods. Results show that the water quality in the Nanchong section of the Jialing River mainstream was lightly polluted, and total nitrogen (TN) was the main water pollutant. Except for the concentrations of NH3–N and TN, the concentrations of pollutants (TP and CODMn) in the Nanchong section of the Jialing River mainstream decreased. The water quality of the Jialing River was different in time, and the water quality in the rainy season (May–November) was better than that in the dry season (December–April). The concentrations of CODMn, NH3–N, TP, and TN in water were lower in the rainy season than in the dry season. The contents of organic matter, nitrogen, and phosphorus nutrients in water in the Jialing River were affected by climate change, rainfall dilution, and other environmental factors. The main sources of pollution were agricultural and rural nonpoint source pollution.

Multi-view clustering can cluster signal samples from multiple views into groups. Currently, multi-view clustering fuses the information of different views into a low-dimensional space for clustering. However, the direct reduction of high-dimensional information to a very low-dimensional space leads to the loss of a lot of sample semantic information, while a higher dimension after dimensionality reduction may blur the clustering structure of samples. To tackle these problems, we propose a novel framework called Mining Multi-view Clustering Space with Interpretable Space Search Constraint to explore the clustering structure while preserving the low-dimensional space semantic information. Our method maps samples from the raw space to a low-dimensional space separated into consensus and private features. This allows us to explore the interpretability of samples in the low-dimensional space to achieve representative representations. After assembling these representations, guided fusion is carried out and a search constraint is imposed to achieve a more reasonable clustering structure. Finally, by dynamically screening positive and negative samples, the clustering performance of the clustering space is maximized by contrastive learning. Extensive experiments on public datasets demonstrate that our method achieves state-of-the-art clustering effectiveness.

This article aims at this problem of adaptive neural tracking control for state-constrained systems. A general fixed-time stability criterion is first presented, by which an adaptive neural control algorithm is developed. Under the action of the proposed adaptive neural tracking controller, the tracking error converges into a small neighborhood around the origin in fixed time; meanwhile, all system states abide by the corresponding state constraints for all the time. The main difference between the present research and the previous control schemes for state-constrained systems is that this article proposes a novel and feasible approach to ensure that the constructed virtual control signals satisfy the state constraints on the corresponding states viewed as the virtual control inputs. Such an approach guarantees theoretically that all the system states cannot violate their constrained requirements at any time. Finally, two simulation examples provide support to the proposed results.

Data deduplication is of critical importance to reduce the storage cost for clients and to relieve the unnecessary storage pressure for cloud servers. While various techniques have been proposed for secure deduplication of identical files/blocks, the effective and secure deduplication solutions on fuzzy similar data (image, video, and others) which occupy a large portion in the real world across wide applications, remain open. In this article, we propose a novel deduplication system, named Fuzzy Deduplication (FuzzyDedup), to implement the secure deduplication of similar data (i.e., similar files, chunks, or blocks). In particular, we leverage the similarity-preserving hash, a fuzzy extractor based on error-correcting codes, and the encryption with customized design to construct a fuzzy-style deduplication encryption scheme (FuzzyMLE), achieving the ciphertext-based deduplication for similar data. Besides, to defend against data ownership cheating attack and duplicate-faking attack, a fuzzy-style proof of ownership scheme (FuzzyPoW) is designed for the cloud server to securely verify a client in possession of the similar data. To further enhance security and efficiency, we also propose both server-aided and random-tag FuzzyMLE to make FuzzyDedup robust against off-line brute-force attack and to support tag randomization, respectively. Then, we design Hamming distance reduction and tag cutting optimization algorithms to improve the tag query efficiency of FuzzyDedup. In the end, we formally prove the security of our solution and conduct experiments on real-world datasets for performance evaluation. Experimental results exhibit the efficiency of FuzzyDedup in terms of computation cost and communication overhead.

Graphical Abstract:

While Deep Reinforcement Learning (DRL) has achieved outstanding performance in extensive applications, exploiting its vulnerability with adversarial attacks is essential towards building robust DRL systems. In this work, we aim to propose a novel Decoupled Adversarial Policy (DAP) for attacking the DRL mechanism, whereas the adversarial agent can decompose the adversarial policy into two separate sub-policies: 1) the switch policy which determines if an attacker should launch the attack, and 2) the lure policy which determines the action an attacker induces the victim to take. If the adversarial agent samples an injection action from the switch policy, the attacker can query the pre-constructed database for universal perturbation in the real-time manner, misleading the victim to take the induced action sampled from the lure policy. To train the adversarial agent to learn DAP, we utilize those samples wherein both of the sub-actions from DAP are not restricted by each other or by the external constraint, but can actually affect the attacker’s behaviors. Therefore, we propose trajectory clipping and padding in data pruning, and Decoupled Proximal Policy Optimization (DPPO) in optimizing. Extensive experiments on different Atari games demonstrate the effectiveness of our proposed method. In addition, it can simultaneously implement the real-time and few-steps attack, which outperforms the existing counterparts.

High-speed centrifugal pumps are crucial in aerospace and petrochemical industries due to their high speed and head. To enhance cavitation performance, the inducer and impeller, which are critical flow components, need specialized design and optimization. In this paper, the ANSYS CFX 2021 software is used to perform cavitation flow calculations for a high-speed centrifugal pump. The calculations are well considered, and the SST k-ω model is used. Analyzing the void volume fraction in the inducer and impeller flow passages under various effective cavitation allowances reveals that as the allowance decreases, void volume increases, and the hump position shifts backward. The study also correlates the static pressure distribution on the inducer blade surface with cavitation states, finding that a decrease in the cavitation allowance leads to an expansion of the low-pressure area on the blade surface, aligning with the cavitation distribution area. This finding is vital for assessing the inducer's power capacity. Observations of the impeller blade's pressure distribution show that the low-pressure area is concentrated at the inlet of the suction surface, expanding toward the impeller outlet. The bubble volume distribution area matches the low-pressure region. As cavitation progresses, the static pressure in the impeller passage decreases, impacting the impeller's normal operation and performance. Comparing the interference between the cavitation zone and the high-speed zone in the flow channels of the inducer and impeller, it is evident that cavitation increases the low-speed zone area on the velocity contour surface. This results in the appearance of a velocity vector in the low-speed zone, affecting the pump's performance. As cavitation worsens, bubbles adhere to the entire flow channel, causing a significant drop in the pump head and impacting the pump's working efficiency. This paper provides valuable insights into the cavitation flow and high-speed vortex interference mechanisms in high-speed inducer centrifugal pumps, offering significant guidance for their design and operation.

The multiphase oxidation of SO2to sulfate in aerosol particles is a key process in atmospheric chemistry. However, there is a large gap between the observed and simulated sulfate concentrations during severe haze events. To fill in the gaps in understanding SO2oxidation chemistry, a combination of experiments and theoretical calculations provided evidence for the direct, spin-forbidden excitation of SO2to its triplet states using UVA photons at an air–water interface, followed by reactions with water and O2that facilitate the rapid formation of sulfate. The estimated reaction energy for the whole process, 3SO2+ H2O + 1/2O2→ HSO4–+ H+(298 K, 1 M), was ΔGr= −107.8 kcal·mol–1. Moreover, calculations revealed that this was a multistep reaction involving submerged, small energy barriers (∼10 kcal·mol–1). These results indicate that photochemical oxidation of SO2at the air–water interface with solar actinic light may be an important unaccounted source of sulfate aerosols under polluted haze conditions.

The purpose of this article is to present a novel backstepping-based adaptive neural tracking control design procedure for nonlinear systems with time-varying state constraints. The designed adaptive neural tracking controller is expected to have the following characters: under its action: 1) the designed virtual control signals meet the constraints on the corresponding virtual control states in order to realize the backstepping design ideal and 2) the output tracking error tends to a sufficiently small neighborhood of the origin with the prescribed finite time and accuracy level. By combining the barrier Lyapunov function approach with the adaptive neural backstepping technique, a novel adaptive neural tracking controller is proposed. It is shown that the constructed controller makes sure that the output tracking error converges to a small neighborhood of the origin with the prespecified tracking accuracy and settling time. Finally, the proposed control scheme is further tested by simulation examples. [ABSTRACT FROM AUTHOR]

Herein, we report an elemental sulfur-promoted switchable redox condensation reaction that can selectively prepare 2-aminofurans and 2-aminothiophenes from the corresponding enaminones and methylene nitriles, respectively. Mechanistic studies demonstrated that the enaminones, as dual nucleophiles, reacted with nitrile acetate to produce 2-aminofurans via 3,5-annulation under promotion by elemental sulfur. These reactions used readily available starting materials, transition metal-free, eco-friendly procedures, gram-scale syntheses, and wide functional group tolerance. The methodology may be useful for the construction of 2-aminofuran and 2-aminothiophene derivatives with potential biological activity.

Oxidative C–H/N–H cross-coupling has emerged as an atom-economical method for the construction of C–N bonds. Conventional oxidative C–H/N–H coupling requires at least one of the following: high temperatures, strong oxidizers, transition metal catalysts, organic solvents, light, and electrochemical cells. In this study, by merely spraying the water solutions of the substrates into microdroplets at room temperature, we show a series of oxidative C–H/N–H coupling products that are strikingly produced in a spontaneous and ultrafast manner. The reactions are accelerated by six orders of magnitude compared to the same reactions in the bulk. It has been previously proposed by fluorescence microscopy and theory that the spontaneously generated electric field at the microdroplets peripheries can be in the ∼109V/m range. Based on mass spectrometric analysis of key radical intermediates, we opine that the ultrahigh electric field catalytically oxidizes the substrates by removing an electron, which further promotes C/N coupling. Taken together, we anticipate that microdroplet chemistry will be an avenue rich in green opportunities of constructing C-heteroatom bonds.

Herein, we report a green cascade approach to prepare a variety of diastereoselective polysubstituted cyclopentene derivatives through metal-free oxidative [2 + 1 + 1 + 1] annulation of aldehydes and methylene nitriles. Mechanistic studies demonstrated that the reaction underwent a four-step cascade reaction including air oxidation and Michael addition to obtain the final product. This reaction features readily available starting materials, transition metal-free, eco-friendly operations, gram-scale syntheses, and wide functional group tolerance. The methodology may be useful for the construction of polysubstituted cyano-cyclopentene heterocycles with potential biological activity.

In this study, we obtained the optimal the structure of QLED topemission spin‐coating device. We use the device structure for inkjet printing, and optimize the morphology and thickness of each layer by controlling the drying process. The red, green and blue devices prepared by using the optimized inkjet printing process show that the electroluminescence area is equal to the designed area of pixels, with clear boundaries, uniform electroluminescent morphologies within a single sub‐pixel, and no significant difference in luminescence between pixels. Finally, we assembled and fabricated a 55‐inch 8K AMQLED display.

In this study, the monitoring data of 23 parameters in 25 monitoring sections of the first-level tributaries of Jialing River in Nanchong City during the 13th Five-Year Plan period (2016–2020) were taken as the research object to analyze water environment quality. Results showed that the water quality is gradually improving in this area, and the main pollutant indexes are chemical oxygen demand, total phosphorus, ammonia nitrogen, permanganate index, 5-day biochemical oxygen demand, and dissolved oxygen. Cluster analysis divided the 12 months into two periods and the 25 monitoring sites into three groups based on similarity of water quality characteristics. The water quality of rainy seasons (July–December) was better than that of dry seasons (January–June). Groups 1, 2, and 3 were mainly located in the urban–rural fringe area, mountain area, and urban industrial park, respectively, representing moderate pollution, low pollution, and high pollution areas. Discriminant analysis (DA) presented good results with great discriminatory ability for both temporal and spatial analyses and provided an important data reduction. DA only used nine parameters for temporal analysis, affording approximately 91.7% correct assignations, and 18 parameters for spatial analysis, affording 96% correct assignations. Multivariate statistical analysis showed that the four major pollution sources in the basin are industrial wastewater, agricultural runoff, domestic sewage, and livestock pollution. The research results are relevant to the prevention and control of water pollution in the Jialing River Basin of the Yangtze River Economic Belt. The achievement of Nanchong City and the summary of the experience of winning the battle of pollution prevention and control in China take the lead in implementing the municipal river chief system in Sichuan Province.

Water serves as an inert environment for the dispersion and application of many kinds of herbicides. Viologen compounds, a type of widely used but highly toxic herbicide, are stable in bulk water, whose half-life can be up to 23 weeks in natural water, imposing a severe health risk to mammals. In this study, we present the striking results of the spontaneous and ultrafast reduction-induced degradation of three viologen compounds in water microdroplets and provide the concentration, time, temperature dependence, mechanism, and scale-up of the reactions. We postulate that the electrons existing at the air–water interface of the microdroplets due to the unique redox potential therein initiate the reduction, from which further degradation occurs. The host–guest complexation between cucurbit[7]uril and viologens only slightly changes the redox potential of viologens in the bulk but completely inhibits the reactions in microdroplets, adding to the uniqueness of the redox potentials at the air–water interfaces of microdroplets. Taken together, microdroplets might have been functioning as naturally occurring ubiquitous tiny electrochemical cells for a plethora of unique redox reactions that were thought to be impossible in the bulk water.

To better understand the temporal and spatial variation characteristics of water quality of the Jialing River and its main influencing factors, this work adopted the methods of cluster analysis and discriminant analysis of multivariate statistical analysis and collected the monitoring data of five main sections (Liduzhen, Xiaodukou, Wencheng, Shaxi, Caihongqiao) of the Nanchong section of the Jialing River from 2011 to 2019. The results showed that the overall water quality of Jialing River Basin is clearly demarcated before and after 2017. pH, dissolved oxygen, chemical oxygen demand permanganate index, and ammonia nitrogen (NH3–N) are the main influencing factors that distinguish the water quality in different periods. After 2017, the water quality of the Langzhong section of the Jialing River is generally in good condition, and the content of reducing pollutants and nitrogen-containing pollutants in the water body is showing a downward trend. Taking 2015 as the boundary, the main water quality influencing factors of Xichong River after 2015 (Caihongqiao monitoring point), a tributary of Jialing River, are pH and NH3–N. However, the current trend of water pollution in the Nanchong section of the Jialing River still exists. According to the water quality analysis results of the Nanchong section of the Jialing River Basin (Xiaodukou and Liduzhen monitoring points), the concentration of NH3–N in the water body increased after 2017, indicating that the Nanchong section of the Jialing River will be more affected by nitrogen pollutants after 2017.

A metal-free dual C(sp3)–H bond functionalization of saturated cyclic ethers via photooxidative singlet oxygen-mediated ring opening and ring closing has been developed, providing a method for generating hydrobenzofurans/pyrans/dioxins. Mechanistic studies have confirmed that ring-opening intermediates were effectively generated by singlet oxygen-mediated C(sp3)–H activation and efficiently reacted with aldehydes and activated methylene compounds to form a wide array of products with high diastereoselectivities (up to >95:5 dr). This study is a rare example of α,β-dual C(sp3)–H bond functionalization of ethers.

The current paper addresses the fuzzy adaptive tracking control via output feedback for single-input single-output (SISO) nonlinear systems in strict-feedback form. Under the situation of system states being unavailable, the system output is used to set up the state observer to estimate the real system states. Furthermore, the estimation states are employed to design controller. During the control design process, fuzzy logic systems (FLSs) are used to model the unknown nonlinearities. A novel observer-based finite-time tracking control scheme is proposed via fuzzy adaptive backstepping and barrier Lyapunov function approach. The suggested fuzzy adaptive output feedback controller can force the output tracking error to meet the pre-specified accuracy in a fixed time. Meanwhile, all the closed-loop variables are bounded. Compared to some existing finite-time output feedback control schemes, the developed control strategy guarantees that the settling time and the error accuracy are independent of the uncertainties and can be specified by the designer. At last, the effectiveness and feasibility of the proposed control scheme are demonstrated by two simulation examples. [ABSTRACT FROM AUTHOR]

Carboxylic acids, including amino acids (AAs), have been widely used as reagents for decarboxylative couplings. In contrast to previous decarboxylative couplings that release CO2as a waste byproduct, herein we report a novel strategy with simultaneous utilization of both the alkyl and carboxyl components from carboxylic acids. Under this unique strategy, carboxylic acids act as bifunctional reagents in the redox-neutral carbocarboxylation of alkenes. Diverse, inexpensive, and readily available α-AAs take part in such difunctionalizations of activated alkenes via visible-light photoredox catalysis, affording a variety of valuable but otherwise difficult to access γ-aminobutyric acid derivatives (GABAs). Additionally, a series of dipeptides and tripeptides also participate in this photocatalytic carbocarboxylation. Although several challenges exist in this system due to the low concentration and quantitative amount of CO2, as well as unproductive side reactions such as hydrodecarboxylation of the carboxylic acids and hydroalkylation of the alkenes, excellent regioselectivity and moderate to high chemoselectivity are achieved. This process features low catalyst loading, mild reaction conditions, high step and atom economy, and good functional group tolerance, and it is readily scalable. The resulting products are subject to efficient derivations, and the overall process is amenable to applications in the late-stage modification of complex compounds. Mechanistic studies indicate that a carbanion is generated catalytically and it acts as the key intermediate to react with CO2, which is also generated catalytically in situand thus remains in low concentration. The overall transformation represents an efficient and sustainable system for organic synthesis, pharmaceutics, and biochemistry.

Herein, we describe a Cu-catalyzed approach to directly accessing aromatic heterocyclic amines from cyclic amides. The most-reported methods for cyclic amide conversions to aromatic heterocyclic amines use an activating group, such as a halogen atom or a trifluoromethane sulfonyl group. However, subsequent elimination of activating groups during the amination process results in significant waste. This copper-catalyzed direct amination of cyclic amides in DMF forms aromatic heterocyclic amines with environmental friendliness and readily available reagents. A plausible radical mechanism has been proposed for the reaction. Meanwhile, the coordinating effect of the N1atom is key to the success of this reaction, which provides assistance to the copper ions for the activation and amination of C–O bonds.

We report an effective strategy to in situ construct the oxime-Ni2+complex unit on polymeric carbon nitride (PCN) as a molecular catalyst for the highly efficient hydrogen evolution reaction (HER). The PCN was functionalized with oxime groups that allowed for immobilizing Ni2+to form oxime-Ni2+complex units on the PCN surface with uniform distribution. The electrochemical characterizations reveal that these oxime-Ni2+units can effectively capture photogenerated electrons from PCN and serve as active catalytic sites for proton reduction. Notably, the oxime-Ni2+enriched PCN showed even higher activities for photocatalytic hydrogen evolution than the Pt-loaded PCN. This work provides a new way to synthesize low-cost photocatalysts with surface grafting of noble-metal-free molecular HER catalysts for efficient light-driven hydrogen generation.

In 2022, the Pakistan witnessed the hottest spring and wettest summer in history. And devastating floods inundated a large portion of Pakistan and caused enormous damages. However, the primary water source and its contributions to these unprecedented floods remain unclear. Based on the reservoir inflow measurements, Multi-Source Weighted-Ensemble Precipitation (MSWEP), the fifth generation ECMWF atmospheric reanalysis (ERA5) products, this study quantified the contributions of monsoon precipitation, antecedent snowmelts, and orographic precipitation enhancement to floods in Pakistan. We found that the Indus experienced at least four inflow uprushes, which was mainly supplied by precipitation and snowmelt; In upper Indus, abnormally high temperature continued to influence the whole summer and lead to large amounts of snowmelts which not only was a key water supply to the flood but also provided favorable soil moisture conditions for the latter precipitation. Before July, the snowmelt has higher contributions than the precipitation to the streamflow of Indus River, with contribution value of more than 60%. Moreover, the snowmelt could still supply 20%–40% water to the lower Indus in July and August; The leading driver of 2022 mega-floods over the southern Pakistan in July and August was dominated by the precipitation, where terrain disturbance induced precipitation account to approximately 33% over the southern Pakistan. The results help to understand the mechanisms of flood formation, and to better predict future flood risks over complex terrain regions.

Herein, we report the first visible-light photoredox-catalyzed carboxylation of aryl epoxides with CO2to synthesize hydroxy acid derivatives. A variety of valuable β-, γ-, δ-, ε-hydroxy acid derivatives are obtained in moderate to high yields under mild conditions. This protocol shows noteworthy functional-group compatibility, high chemo- and regioselectivities under transition-metal-free conditions with an inexpensive organo-dye as photosensitizer. Mechanistic studies indicate that the benzylic carbanion is generated as an intermediate via the sequential single electron transfer (SSET) process.

The catalytic asymmetric functionalization of readily available 1,3-dienes is highly important, but current examples are mostly limited to the construction of tertiary chiral centers. The asymmetric generation of acyclic products containing all-carbon quaternary stereocenters from substituted 1,3-dienes represents a more challenging, but highly desirable, synthetic process for which there are very few examples. Herein, we report the highly selective copper-catalyzed generation of chiral all-carbon acyclic quaternary stereocenters via functionalization of 1,3-dienes with CO2. A variety of readily available 1,1-disubstituted 1,3-dienes, as well as a 1,3,5-triene, undergo reductive hydroxymethylation with high chemo-, regio-, E/Z-, and enantioselectivities. The reported method features good functional group tolerance, is readily scaled up to at least 5 mmol of starting diene, and generates chiral products that are useful building blocks for further derivatization. Systemic mechanistic investigations using density functional theory calculations were performed and provided the first theoretical investigation for an asymmetric transformation involving CO2. These computational results indicate that the 1,2-hydrocupration of 1,3-diene proceeds with high π-facial selectivity to generate an (S)-allylcopper intermediate, which further induces the chirality of the quaternary carbon center in the final product. The 1,4-addition of an internal allylcopper complex, which differs from previous reports involving terminal allylmetallic intermediates, to CO2kinetically determines the E/Z- and regioselectivity. The rapid reduction of a copper carboxylate intermediate to the corresponding silyl-ether in the presence of Me(MeO)2SiH provides the exergonic impetus and leads to chemoselective hydroxymethylation rather than carboxylation. These results provide new insights for guiding further development of asymmetric C–C bond formations with CO2.

This paper investigates a technical problem, that is, how to apply the backstepping to obtain an event-triggered controller for multiple-input multiple-output (MIMO) nonlinear systems. If the controller is set to be triggered, then all virtual controls are also forcibly triggered synchronously since this controller incorporates all virtual controls. That indicates the virtual controls applied to the control operation are event-triggered and discontinuous. As a result, the control design and performance analysis may become more complicated for such event-triggered systems. Therefore, this paper presents a prescribed-time fuzzy adaptive event-triggered control strategy for MIMO nonlinear systems. A new event-triggered mechanism is constructed for updating the actual controller and all virtual controls, and the nonlinear impulsive dynamics approach is employed for tackling the difficulties arising from the discontinuity of the virtual controls. Moreover, the Lyapunov stability analysis approach for nonlinear impulsive system is utilized to determine the performance of the controlled system. The good tracking performance is accomplished by selecting the proper design parameters. Ultimately, the feasibility and validity of the developed control strategy is supported by simulation. [ABSTRACT FROM AUTHOR]

To test the neural electrophysiological basis of acupuncture treatment on attention deficit of insomnia patients.

This article describes how with the rapid increasing of multimedia content on the Internet, the need for effective cross-modal retrieval has attracted much attention recently. Many related works ignore the latent semantic correlations of modalities in the non-linear space and the extraction of high-level modality features, which only focuses on the semantic mapping of modalities in linear space and the use of low-level artificial features as modality feature representation. To solve these issues, the authors first utilizes convolutional neural networks and topic modal to obtain a high-level semantic feature of various modalities. Sequentially, they propose a supervised learning algorithm based on a kernel with partial least squares that can capture semantic correlations across modalities. Finally, the joint model of different modalities is learnt by the training set. Extensive experiments are conducted on three benchmark datasets that include Wikipedia, Pascal and MIRFlickr. The results show that the proposed approach achieves better retrieval performance over several state-of-the-art approaches.

AbstractSupply-demand matching is crucial to optimize resource utilization and form long-term partnership. This study will contribute to the current supply-demand matching research by (1)generalizing the broker dominant supply-demand matching problem (B-SDMP); (2) proposing the B-SDMP multi-objective decision approach including (a) the mathematical model considering the satisfaction of important suppliers and buyers determined by the broker; (b) a weighted linearization method to solve the model; and (3) application the B-SDMP in practice. The results are the optimum matching decision solutions which can help the buyers to find the appropriate suppliers on one commodity. It could promote the formulation of long-term partnership of the three parties (suppliers, buyers, and the broker) as a stable supply chain. To demonstrate the effectiveness of the approach on a practical level, a seaborne coal transaction project is used. The matching solutions obtained from B-SDMP analysis are practically feasible.

Pre-existing (multiple) shear bands were introduced into the ductile Zr36Co28Al16and Zr65Ni16Cu15Al10bulk metallic glasses (BMGs) through the lateral-deformation, respectively. It was found that the pre-exiting shear bands can further enhance the compressive plasticity of ductile BMGs. According to the serration analysis on the plastic deformation of the as-cast and the pre-deformed samples, the serration events in the stress-strain curves during deformation display a self-organized critical (SOC) behavior. Compared with the as-cast BMGs, a larger power-law scaling exponent calculated based on serrated flow behaviors becomes larger for the pre-deformed BMGs, implying that the shear banding stability of BMGs is effectively enhanced. This should be caused by the pronounced interactions of shear bands during plastic deformation for the pre-deformed BMGs. However, by introducing a large amount of multiple shear bands into the glassy matrix, it also becomes easier for shear bands to propagate along the pre-existing shear bands, leading to a lower cut-off elastic energy density for the pre-deformed BMGs. More multiple shear bands with stronger interactions for the pre-deformed BMGs could provide a larger chance to activate the shear-band cracking but less local elastic energies are remained for the subsequent crack-linking.