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Pressure sensors for living organisms can monitor both the movement behavior of the organism and pressure changes of the organ, and they have vast perspectives for the health management information platform and disease diagnostics/treatment through the micropressure changes of organs. Although pressure sensors have been widely integrated with e-skin or other wearable systems for health monitoring, they have not been approved for comprehensive surveillance and monitoring of living organisms due to their unsatisfied sensing performance. To solve the problem, here, we introduce a novel structural design strategy to manufacture reduced graphene oxide-polypyrrole aerogel-based microfibers with a typical coaxial heterogeneous structure, which significantly enhances the sensitivity, resolution, and stability of the derived pressure microsensors. The as-fabricated pressure microsensors exhibit ultrahigh sensitivities of 12.84, 18.27, and 4.46 kPa-1 in the pressure ranges of 0-20, 20-40, and 40-65 Pa, respectively, high resolution (0.2 Pa), and good stability in 450 cycles. Furthermore, the microsensor is applied to detect the movement behavior and organic micropressure changes for mice and serves as a platform for monitoring micropressure for the integrative diagnosis both in vivo and in vitro of organisms.

With the rapid development of information technology, different organizations cooperate with each other to share data information and make full use of data value. Not only should the integrity and privacy of data be guaranteed but also the collaborative computing should be carried out on the basis of data sharing. In this paper, in order to achieve the fairness of data security sharing and collaborative computing, a security data collaborative computing scheme based on blockchain is proposed. A data storage query model based on Bloom filter is designed to improve the efficiency of data query sharing. The MPC contract is designed according to the specific requirements. The participants are rational, and the contract encourages the participants to implement the agreement honestly to achieve fair calculation. A secure multiparty computation based on secret sharing is introduced. The problem of identity and vote privacy in electronic voting is solved. The scheme is analyzed and discussed from storage expansion, anticollusion, verifiability, and privacy.

Mechanoluminescence (ML) materials possess the mechano-optical conversion property that can produce luminescence emission upon a mechanical stimulus. This stress-luminescence responsiveness endows ML materials with application potential for optical information display. For the existing ML materials, the consecutive and overlapped trap-depth distribution in ML materials can sustain persistent afterglow noise and hinder the recognition of ML signals continually. In this study, we designed a synergistic strategy that combines defect engineering with microstructure tuning to achieve the high-contrast ML emission of Bi3+ in lithium tantalite. Non-luminous Ga3+ ions are employed as co-dopants to tune the defect trap distribution and microstructure in Bi3+-doped LiTaO3 crystals. The as-prepared Bi3+/Ga3+ codoped LiTaO3 material showed intense high-contrast ML emission with no afterglow interference under an external mechanical stimulus. Its high-contrast ML intensity increased linearly with increasing applied force (>1200 N), showing no threshold force. The composite film combined with LiTaO3:Bi/Ga particles can respond sensitively and notably to multifarious mechanical stimuli by radiating indigo blue ML light, including stretching, bending and friction. These discoveries provide a new research perspective to investigate stimuli-responsive luminophors toward various application requirements especially with optical information storage and display.

Decision conflict is a crucial issue of three-way decisions of multi-class. To overcome this limitation, there are mainly two ways. One is conflict resolution after decision-making, and the other is conflict resolution before decision-making. Considering insufficient information is a main cause of decision conflict, we propose a sequential approach to solve this problem by adding more detailed information step by step, which is conflict resolution during decision-making. Combining sequential approach with three methods to handle multi-class decision, which are converting m-class decision to m two-class decisions, based on pair-wise comparisons of m decision classes and directly making three-way decisions for each decision class of m-class simultaneously, we propose three sequential multi-class three-way decision models. At each level of three models, we define conflict region. In the sequential process of decision-making, for each model, only the objects belonging to one positive region with certain decision are assigned into corresponding decision classes, the objects in conflict region will be processed at the next level by adding more information sequentially. Finally, we compare the performance of three conflict resolutions and the performance of the proposed three models. Experimental results validate the effectiveness of the proposed three sequential multi-class three-way decision models.

Environment-friendly potassium sodium niobate-based ferroelectrics have been widely and deeply studied for their electrical properties, but there remains much potential for applications in other fi...

Establishing the dynamics of wetting film thinning and rupture during the bubbles attached on the coal surface is extremely important for flotation. However, studying the dynamics of bubble attachment from the molecular level using molecular dynamics simulation (MDS) has rarely been reported. In this work, the dynamics of bubble attachment at three different coal [low-rank coal (LRC), bituminous coal (BC), and anthracite coal (AC)] surfaces with varying degrees of coalification were studied using MDS. In the bubble attachment process, the wetting film between the bubble and coal surface gradually become thinner until it ruptures. By comparing the bubble attachment dynamics on three different coal surfaces, the results indicate that the bubble attachment rate on the surface with strong hydrophobicity is faster than that on the surface with weak hydrophobicity. Besides, the number of hydrogen bonds between the molecules of the wetting film is decreased with the attachment of bubbles; however, it is sharply decreased on the BC surface and slowly reduces on the LRC surface before the film rupture. At the same time, the radial distribution functions (RDFs) of hydrogen bonds in the wetting film at the moment of bubble attachment on the coal surface are analyzed, indicating that the peak intensity of the RDF decreases at the time of bubble attachment. The findings in this study may help to better comprehend the dynamics of bubble attachment, which is valuable for future design in practical applications.

Rational control of photoluminescence against a change in temperature is important for fundamental research and technological applications. Herein, we report an anomalous temperature dependence of ...

Given that humans and animals can learn new behaviors in a short time by observing others, the question we need to consider is how to make robots behave like humans or animals, that is, through effective demonstration, robots can quickly understand and learn a new ability. One possible solution is imitation based meta-learning, but most of the related approaches are limited in a particular network structure or a specific task. Particularly, meta-learning methods based on gradient-update are prone to overfit. In this article, we propose a generic meta-learning algorithm that divides the learning process into two independent stages ( skill cloning and skill transfer ) with a noise mechanism which is compatible with any model. The skill cloning stage enables a good understanding of the demonstration, which helps the skill transfer stage when the robot applies the learned experience into new tasks. The experimental results show that our algorithm can alleviate the phenomenon of overfitting by introducing a noise mechanism . Our method not only performs well on the regression task but is significantly better than the existing state-of-the-art one-shot imitation learning methods in the same simulation environments (i.e., simulated pushing and simulated reaching).

Photothermal conversion in the near-infrared (NIR) wavelengths, wherein light energy is converted into heat energy, has attracted great interest and developed rapidly in recent years for its wide applications in health care, flexible electronics, energy and environmental fields. However, the photothermal temperature, as one of the most important parameters in the NIR photothermal conversion, still has not been effectively studied. Herein, we successfully achieved ultrahigh photothermal temperatures in a graphene/conducting polymer system. The surface temperature of the prepared free-standing reduced graphene oxide/polypyrrole (rGO/PPy) foam can be as high as 380 °C with 808 nm NIR irradiation at 2.6 W cm−2, and the surface temperature of the rGO/PPy film on the polydimethylsiloxane (PDMS) substrate can be as high as 310 °C under the same conditions. The photothermal energy has been used for burning, thermopolymerization, alloying reactions and thermal decomposition reactions, providing new directions for photothermal conversion beyond photothermal therapy and energy utilization.

Charge/light-related advancements have greatly pushed the development of modern technology, and the relationship between charge and light is worth exploring. While research into the applications of light and charge flow (photoelectric current) is in full swing, studies on the reaction between light and electrostatic charge have made little progress on rare ways to realize photo-stimulated discharge. Herein, we link electrostatic charge and light using a bridge of intense heat, which is produced from the efficient photothermal conversion of Ti3C2Tx MXene. The in situ photothermal conversion and selective thermally stimulated discharge are successfully combined, then novel light-induced electrostatic lithography can be realized on both polymethyl methacrylate glasses and nanofilms. In this process the surface temperature of Ti3C2Tx film can be as high as 300 °C using 808 nm near-infrared irradiation at a power density of 1.7 W cm−2. The combination of light and electrostatic charge is also successfully applied to electrostatic printing and chemical reactions.

Since the beginning of the twenty-first century, people’s living standards have been continuously improved, followed by changes in diet structure and living habits. These changes have affected the body’s endocrine system, causing lesions in the pancreatic tissue. Among these pancreatic tissue diseases, pancreatic cancer is the most harmful to human health because of its inability to find and high mortality within 1 year. At present, in the diagnosis of pancreatic cancer, medical imaging and pathological puncture are the main methods of diagnosis. These methods have a high diagnostic rate for patients with advanced pancreatic cancer, but it is difficult to apply to the diagnosis of early pancreatic cancer. In response to these problems, this paper proposes a pancreatic cancer diagnosis model based on the fusion of distribution estimation algorithm and genetic algorithm. By collecting pathological data of patients with pancreatic cancer from a hospital oncology, pathological data include clinical manifestations of pancreatic cancer patients, serum tumor markers, etc., after data preprocessing, input models, and then use different machine learning classification algorithms to make pancreatic cancer for diagnosis. By evaluating the diagnosis results of each classification algorithm, an optimal classification algorithm is obtained and applied to the diagnosis model of pancreatic cancer. The results show that compared with other classification algorithms, the model using classification algorithm has the highest accuracy, recall rate and harmonic mean, and the diagnostic performance is the best. The results show that the diagnostic model constructed in this paper has a very high application value in the early auxiliary pre-diagnosis of pancreatic cancer.

Anomaly detection in videos is a challenging problem in computer vision. Most existing methods need supervised information to train their models, which limits their applications in real world scenario. Therefore, self-trained methods which do not need manually labels receive increasing attentions recently. In this paper, we propose a novel self-trained video anomaly detection method based on teacher-student model. The teacher-student architecture can significantly improve the performance of self-trained video anomaly detection by utilizing the unlabeled samples. We test our method on two surveillance datasets. Experiment results show that our method achieves better performance than state-of-the-art unsupervised methods on both datasets and achieves comparable performance as semi-supervised methods, which experimentally proves the effectiveness of our method.

Mass spectrometry-based proteomics empowers deep profiling of proteome and protein posttranslational modifications (PTMs) in Alzheimer's disease (AD). Here we review the advances and limitations in historic and recent AD proteomic research. Complementary to genetic mapping, proteomic studies not only validate canonical amyloid and tau pathways, but also uncover novel components in broad protein networks, such as RNA splicing, development, immunity, membrane transport, lipid metabolism, synaptic function, and mitochondrial activity. Meta-analysis of seven deep datasets reveals 2,698 differentially expressed (DE) proteins in the landscape of AD brain proteome (n = 12,017 proteins/genes), covering 35 reported AD genes and risk loci. The DE proteins contain cellular markers enriched in neurons, microglia, astrocytes, oligodendrocytes, and epithelial cells, supporting the involvement of diverse cell types in AD pathology. We discuss the hypothesized protective or detrimental roles of selected DE proteins, emphasizing top proteins in "amyloidome" (all biomolecules in amyloid plaques) and disease progression. Comprehensive PTM analysis represents another layer of molecular events in AD. In particular, tau PTMs are correlated with disease stages and indicate the heterogeneity of individual AD patients. Moreover, the unprecedented proteomic coverage of biofluids, such as cerebrospinal fluid and serum, procures novel putative AD biomarkers through meta-analysis. Thus, proteomics-driven systems biology presents a new frontier to link genotype, proteotype, and phenotype, accelerating the development of improved AD models and treatment strategies.

To provide stroke patients with good rehabilitation training, the rehabilitation robot should ensure that each joint of the limb of the patient does not exceed its joint range of motion. Based on the machine vision combined with an RGB-Depth (RGB-D) camera, a convenient and quick human-machine interaction method to measure the lower limb joint range of motion of the stroke patient is proposed. By analyzing the principle of the RGB-D camera, the transformation relationship between the camera coordinate system and the pixel coordinate system in the image is established. Through the markers on the human body and chair on the rehabilitation robot, an RGB-D camera is used to obtain their image data with relative position. The threshold segmentation method is used to process the image. Through the analysis of the image data with the least square method and the vector product method, the range of motion of the hip joint, knee joint in the sagittal plane, and hip joint in the coronal plane could be obtained. Finally, to verify the effectiveness of the proposed method for measuring the lower limb joint range of motion of human, the mechanical leg joint range of motion from a lower limb rehabilitation robot, which will be measured by the angular transducers and the RGB-D camera, was used as the control group and experiment group for comparison. The angle difference in the sagittal plane measured by the proposed detection method and angle sensor is relatively conservative, and the maximum measurement error is not more than 2.2 degrees. The angle difference in the coronal plane between the angle at the peak obtained by the designed detection system and the angle sensor is not more than 2.65 degrees. This paper provides an important and valuable reference for the future rehabilitation robot to set each joint range of motion limited in the safe workspace of the patient.

Epidemiology occupies a very important position in preventive medicine. Its essence is to summarize the etiology and epidemic laws by studying the distribution and possible effects of diseases, so as to promote the formation of scientific epidemic prevention measures. The purpose of this article is to help relevant personnel complete the collection, induction, and analysis of epidemiological survey data by establishing a data collection system model to improve work efficiency. This article focuses on the new coronavirus pneumonia (COVID-19), investigates the development status of epidemiological survey data collection, and analyzes the problems in the current business process, and on this basis, develops a dedicated epidemiological survey System model for data collection. From the experimental data, the optimized correction evaluation index has been increased from 8.384 to 9.067. It can be seen that the combination of data mining algorithms and backpropagation algorithms can better improve the system's ability to process information. Professional information disclosure platforms can have a good positive impression on the prevention and treatment of epidemics. The Internet-based epidemiological survey customized system model established in this article is to integrate various epidemiological data so that people can correctly understand the spread of epidemics and promote the development of preventive medicine.

Background Natural variation in protein expression is common in all organisms and contributes to phenotypic differences among individuals. While variation in gene expression at the transcript level has been extensively investigated, the genetic mechanisms underlying variation in protein expression have lagged considerably behind. Here we investigate genetic architecture of protein expression by profiling a deep mouse brain proteome of two inbred strains, C57BL/6J (B6) and DBA/2J (D2), and their reciprocal F1 hybrids using two-dimensional liquid chromatography coupled with tandem mass spectrometry (LC/LC-MS/MS) technology. Results By comparing protein expression levels in the four mouse strains, we observed 329 statistically significant differentially expressed proteins between the two parental strains and identified four common inheritance patterns, including 1,133 dominant, 980 additive, 63 over- and 62 under-dominant expression. We further applied the proteogenomic approach to detect variant peptides and define protein allele-specific expression (pASE), identifying 33 variant peptides with cis‐effects and 17 variant peptides showing trans‐effects. Comparison of regulation at transcript and protein levels show a significant divergence. Conclusions The results provide a comprehensive analysis of genetic architecture of protein expression and the contribution of cis- and trans‐acting regulatory differences to protein expression.

The (1-x) K0.5Na0.5NbO3-xNa0.5Er0.5TiO3 [(1-x)KNN-xNET] ceramics were fabricated by the traditional solid state reaction method. The effects of the NET content on their phase structure, microstructure, photochromism and photo-switching properties were systematically studied. The samples show bright green emission (530 nm, 551 nm) and red emission (660 nm) under 980 nm stimulation at room temperature. Upon visible light irradiation (407 nm), these samples change their color from the initial pale yellow to dark grey. And, luminescence emission intensity can be easily modulated by adjusting the degree of color change. In particular, the color and up-conversion emission can return its initial state by 230 °C thermal stimulation, showing excellent reversibility. These results make it potential applications in many fields such as luminescence switching and optical storage materials as a kind of multifunctional material.

For luminescent photochromic materials, the optical properties of lanthanide (Ln) ions, including emission color, excitation mode and lifetime, are extremely important in optical information storage and recording. Conventional dopants of single Ln ions generally display unicolor and unimodal emission, leading to low-level luminescence modulation and information readout. Therefore, it is urgent to develop multicolor and multimodal luminescence modulation in a single photochromic material, thus well modulating luminescent readout capability. In this study, superior multicolor emissions (red-green), multimodal properties (downshifting/upconversion) and tunable luminescent switching contrast were successfully obtained in Bi2.5Na0.5Nb2O9-based ferroelectric materials by dual-lanthanide ion doping (Pr/Er). Red/green emission ratios can be continuously tuned from red, orange and yellow to green range via controlling the excitation wavelengths and doped concentrations. Correspondingly, the luminescent switching contrast (ΔRt) gradually increases from 29% to 93% with increasing excitation wavelength upon visible irradiation (407 nm), while the ΔRt values decrease with emission wavelengths, which can be well explained by the Dexter energy transfer model. These findings offer a guide to designing tailored luminescence modulation behavior of luminescent photochromic materials for wide application in optical storage and switching devices.

In this study, Er3+-doped and Er3+/Yb3+-co-doped xLiNbO3-(1-x)(K,Na)NbO3 (xLN-(1-x)KNN) ferroelectric ceramics were synthesized by a solid state reaction process and the samples were found to exhibit tunable upconversion luminescence (UCL) under an external electric field as well as excellent optical temperature-sensing properties. By altering the polarization time, UCL intensity was effectively controlled under an external electric field. Furthermore, an optimal UCL was observed in a 0.4LN-0.6KNN:Er3+,3Yb3+ sample and its excellent optical temperature sensitivity (0.006 K−1 at 643 K) from 83 to 663 K was 131% higher than that of 0.4LN-0.6KNN:Er3+. These results suggested that xLN-(1-x)KNN ferroelectric ceramics were promising candidates for an opto-electronic integrator and optical temperature sensors with high sensitivity and broad temperature range.

Developing durable Si-based photoelectrochemical hydrogen evolution reaction in alkaline media is attracting attention in device-level water splitting, but still faces a trade-off between the alkalic corrosion resistance and light transmission for Si photocathodes. Herein, a synergetic strategy is proposed to employ an anti-reflective Co-P film cocatalyst modulated via self-assembly of protective-layer WSx onto Si photocathode. The controllable WSx thin-film efficiently ensures the excellent anti-alkali corrosion of Si semiconductors, and serves as an appropriate nucleation base to modulate the structure of Co-P cocatalyst to possess anti-reflection. The optimal Co-P/WSx/Si photocathode exhibits an onset potential of + 0.47 V vs. reversible hydrogen electrode (VRHE), a photocurrent density of − 25.1 mA cm−2 at 0 VRHE, and superior durability of up to 300 h at 0 VRHE in 1.0 M KOH electrolyte. These findings offer a facile and effective approach for the further development of durable Si-based photoelectrochemical devices.

Electrostatic capacitors based on dielectrics are ubiquitous components for applications in modern electronics and electric power systems. However, the relatively low energy density of electrostatic capacitors, which is one or two orders of magnitude lower than that of the batteries, has greatly hindered the implementation of its in energy storage devices. Here, we propose a strategy to overcome the tradeoff between high polarizability and breakdown electric field, and attain great enhancement energy storage density in the lead-free (Ba2Bi3.97Pr0.03Ti5O18/BiFeO3)N (BBPT/BFO)N multilayer ferroelectric thin films with different BFO layers through interface engineering. The interface engineering could be utilized to concurrently modify both polarization and local electric field strength caused by the synergistic effect of multiple polar structures and electric field amplifying effect. Accordingly, the discharged energy density of the optimized (BBPT/BFO)1 ferroelectric thin-film capacitors as high as ∼ 79.3 J/cm3 with discharged efficiency exceeding ∼ 75 % are achieved. Combined with its fatigue-free, favorable temperature and frequency stabilities, the multilayer ferroelectric thin films of BBPT/BFO could be a promising dielectric material for practical energy storage applications.

Objective: To compare the safety of balanced crystalloids and saline among critically ill patients in intensive care unit (ICU). Methods: The Medline, EMBASE, Web of Science, Cochrane Library databases were systematically searched from the inception dates to May 17, 2020 in order to identify randomized controlled trials which evaluated the safety of balanced crystalloids and saline in critically ill patients. The primary outcome was major adverse kidney events within 30 days (MAKE30). The second outcomes included 30-day mortality, ICU mortality, In-hospital mortality, ICU length of stay, hospital length of stay, creatinine highest before discharge (mg/dl) and needs for renal replacement therapy (RRT). Results: A total of nine randomized controlled trials involving 19,578 critical ill patients fulfilled the inclusion criteria. The outcomes of this meta-analysis showed that balanced crystalloids treatment shared the same risk of MAKE30 with saline treatment among critical ill patients [RR = 0.95; 95%CI, 0.88 to 1.01; Z = 1.64 (P = .102)]. The clinical mortality which included 30-day mortality [RR = 0.92; 95%CI, 0.85 to 1.01; Z = 1.78 (P = .075)], ICU mortality [RR = 0.92; 95%CI, 0.83 to 1.02; Z = 1.67 (P = .094)] and In-hospital mortality [RR = 0.93; 95%CI, 0.71 to 1.21; Z = 0.55 (P = .585)] were similar between balanced crystalloids treatment and saline treatment among critical ill patients. Patients who received balanced crystalloids treatment or saline treatment needed the same length of ICU stay [WMD = 0.00; 95%CI, −0.09 to 0.10; Z = 0.09 (P = .932)] and hospital stay [WMD = 0.59; 95%CI, −0.33 to 1.51; Z = 1.26 (P = .209)]. Critical ill patients who received balanced crystalloids treatment or saline treatment had the same level of creatinine highest before discharge [WMD = 0.01; 95%CI, −0.02 to 0.04; Z = 0.76 (P = .446)] and needs for RRT [RR = 1.04; 95%CI, 0.75 to 1.43; Z = 0.21 (P = .830)]. Similar results were obtained in subgroups of trials stratified according to the age of patients (children or adults). Conclusions: When compared with saline, balanced crystalloids could not reduce the risk of MAKE30, 30-day mortality, ICU mortality and in-hospital mortality, could not reduce the length of ICU stay, length of hospital stay, the level of creatinine highest before discharge and the needs for RRT among critical ill children and adults. Therefore, it was still too early for balanced crystalloids to replace normal saline among critical ill patients.

For optical temperature sensor, high luminescence intensity is as important as high temperature sensing sensitivity. In this work, research on rare-earth ions Er3+/Yb3+ codoped KY(WO4)2–K2WO4 multiphase phosphors for optical temperature sensing application was first proposed by material design. Under a 980 nm excitation, the upconversion luminescence intensity of multiphase materials was much higher than that of pure phase materials. For the 0.6KYW–0.4KW multiphase material, excellent temperature sensing property that the maximal sensitivity was 14.7 × 10− 3 K−1 at 643 K in a broad temperature range from 83 to 663 K was simultaneously obtained. These results indicate that KY(WO4)2–K2WO4 multiphase phosphors with excellent upconversion luminescence and temperature sensing properties are promising candidates for optical temperature sensors.

Trap-controlled mechanoluminescence (ML) enables the direct observation of stress concentration of load-bearing objects through imaging the ML distribution, showing numerous prospects in stress detection, bio-imaging and optical displays. However, the applications of trap-controlled ML materials universally require long-time delay to fade the noise of symbiotic persistent luminescence (PersL) in order to achieve high-contrast ML images. In view of the difficulty to solve the PersL problem through individually eliminating the PersL traps, herein we propose a novel strategy of sacrificing trap density which decreases PersL and ML traps as a whole. By employing Sr2+ substitution to decrease the trap density of Ca2Nb2O7:Pr3+, we identify a novel composition of (Ca0.5Sr0.5)2Nb2O7:Pr3+ displaying short-delay and high-contrast ML images, and evaluate its practicability through a 2-dimensional in-situ imaging experiment of dynamic stress distribution. The underlying mechanism is ascribed to the greater decrease ratio of PersL intensity than ML intensity as a result of the larger detrapping rate of traps due to stress (leading to ML) than that due to thermal energy (PersL). Furthermore, multi-spectral investigations of (Ca,Sr)2Nb2O7:Pr3+ system reveal a distinctive electron transition process co-regulated by trap levels, charge transfer state and crystal field. The proposed strategy and the associated phosphors are expected to initiate the reconstruction of PersL-type ML materials and bring important implications for real-world stress imaging.

Er3+ doped and Yb3+/Er3+ co-doped Bi3Ti1.5W0.5O9 (BTW) ferroelectric ceramics were successfully synthesized by a conventional solid-state reaction method. Their structural properties, reflectance spectra, up-conversion (UC) luminescence and temperature sensing behavior were investigated methodically. The optimal luminescent intensity was obtained in BTW:0.03Er, 0.09Yb ceramic. The UCL color coordinates of BTW:0.03Er, yYb samples indicate that the emitted light is highly saturated. In addition, by using the fluorescence intensity ratio technique, optical temperature sensing properties have been performed in the temperature range from 83 K to 483 K. The sensitivity has a large improvement of 33% by co-doping 0.09 mol Yb3+ in BTW: 0.03Er at 483 K. These results indicate that the prepared materials have a good prospect in high temperature sensor, emitting display devices and optical-electro integration applications.

As the rapid development of oxygen evolution catalysts (OECs) for photoanodes, the issue of charge transfer at the interface of OEC and semiconductor, which becomes the key challenge for the photoelectrochemical (PEC) efficiency, has been rarely addressed and should be taken seriously. Herein, a novel charge transfer system for PEC water oxidation is designed by inserting MXene nanosheets (MNs) between α-Fe2O3 and OEC. In this system, MNs act as the hole transfer mediators to efficiently suppress the interfacial charge recombination owing to the high hole mobility of MNs and the formation of built-in electric field at the MNs/α-Fe2O3 junction. Meanwhile, the OEC layers, in turn, can protect the MNs from oxidation to achieve prominent stability. The optimized photoanode of Co-Pi/MNs/α-Fe2O3 can achieve a remarkable photocurrent density, up to 3.20 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 G illumination. An impressive cathodic onset potential shift of ∼250 mV is obtained on Co-Pi/MNs/α-Fe2O3 compared with the pristine α-Fe2O3. Furthermore, this strategy is also applicable to other photoanode materials, such as BiVO4, WO3 and ZnO, verifying the versatility by utilizing the MNs as hole transfer mediators for efficient photogenerated charge separation to enhance the PEC water oxidation.

The introduction of ozonated deionized water (DIO3 water) to the silicon wafer wet cleaning process has attracted interest from the photovoltaic industry. In this work, a simple and cost-effective approach to fabricate submicron-texture multicrystalline silicon (mc-Si) wafer is presented using Ag metal-catalyzed chemical etching (MCCE) in DIO3/HF solution, where DIO3 was used as a hole injecting agent. The submicron-texture was successfully applied to fabricate efficient mc-Si PERC solar cells with an average efficiency of 20.31%, which is 0.58%abs higher than those with an acid micron-texture and exceeds those with conventional MCCE submicron-textures using H2O2 as the hole injecting agent. We demonstrated that using DIO3 as a hole injection agent in metal-catalyzed chemical etching is feasible. This novel MCCE approach is simple, low-cost, and ecofriendly, making it an attractive alternative to conventional MCCE methods for use in industrial-scale production.

In recent years, Android malware has continued to evolve against detection technologies, becoming more concealed and harmful, making it difficult for existing models to resist adversarial sample attacks. At the current stage, the detection result is no longer the only criterion for evaluating the pros and cons of the model with its algorithms, it is also vital to take the model’s defensive ability against adversarial samples into consideration. In this study, we propose a general framework named AdvAndMal, which consists of a two-layer network for adversarial training to generate adversarial samples and improve the effectiveness of the classifiers in Android malware detection and family classification. The adversarial sample generation layer is composed of a conditional generative adversarial network called pix2pix, which can generate malware variants to extend the classifiers’ training set, and the malware classification layer is trained by RGB image visualized from the sequence of system calls. To evaluate the adversarial training effect of the framework, we propose the robustness coefficient, a symmetric interval i = [−1, 1], and conduct controlled experiments on the dataset to measure the robustness of the overall framework for the adversarial training. Experimental results on 12 families with the largest number of samples in the Drebin dataset show that the accuracy of the overall framework is increased from 0.976 to 0.989, and its robustness coefficient is increased from 0.857 to 0.917, which proves the effectiveness of the adversarial training method.

In order to relieve energy crisis, more and more distributed energy systems are established and a large number of them use gas turbine as power units. For the in-depth study on the performances of steam injected gas turbine (STIG), the results and discussion show that STIG operation can increase power output and efficiency of generating unit compared with conventional gas turbine. The combined cooling heating and power (CCHP) system with STIG which can adjust the ratio of heat to power elastically and independently, has the ability of accommodating a wider range of electrical loads. The overall off-design characteristics of STIG are obtained using analytical method. For STIG cycle, each operating point is determined by the ratio of steam to air and the turbine inlet temperature calculated by monitoring the turbine outlet temperature. The results present the equal power output curve and equal quantity of heat curve that are meaningful for optimizing operation of CCHP system which works under the off-design conditions.

The CaBi2Nb2O9 materials have ultrahigh Curie temperature (T c ∼ 1216 K). Therefore, such compound as the host would make their luminescent materials have wide temperature range for application. In this work, the Er3+ doped CaBi2Nb2O9 phosphors were synthesized to investigate upconverion emission properties and their optical sensing behavior. The analyses based on photoluminescence and decay time upon the 980 nm excitation demonstrated that the phosphors had an intense green emission by two-photo process. Using the fluorescence intensity ratio technique, temperature sensing performances based on the green emission were evaluated in the wide-range 90–570 K, which fitted well with the theoretical equation. These results indicate that Er doped CaBi2Nb2O9 could be promising temperature sensor for wide range and high temperature application.

Sm-modified Na0.5Bi2.5Nb2O9 ceramics can simultaneously exhibit both visible light-driven photochromism and photoluminescence. Upon visible light irradiation, these materials change their color from green to dark gray, while exhibiting a strong red emission at 603 nm due to the 4G5/2 → 6H7/2 transition, whose emission intensity strongly depends on the irradiation wavelength, intensity, and time, and significantly decreases with increasing irradiation time and intensity. By alternating visible light or sunlight (λ > 400 nm) irradiation and thermal stimulus, both luminescence and absorption intensity can be reversibly switched without any significant degradation between the two colored and bleached states, with excellent reproducibility. On the basis of the trapped charge carrier and exponential relaxation decay models, we herein provide a detailed understanding of the photochromism and luminescence modulation mechanisms.

A novel green emitted phosphor Li2Sr1−xBaxSiO4:Eu2+ (LSBS:Eu) has been synthesized by a solid-state reaction method. Its crystal structure and grain morphology have been investigated by a powder X-ray diffractometer and a scanning electronic microscope, respectively. A green emission peak around 566 nm was observed under the excitation ranged from 225 to 500 nm, which covers the emission spectra of blue and near UV LEDs. The optimal emission intensity was obtained when the Ba content was 0.6 and Eu2+ doping level was 0.003 mol. Furthermore, the investigation of the temperature dependence of luminescence and quantum efficiency indicate that LSBS:Eu phosphors are highly thermally stable and energy saving. The lifetime decay curves and chromaticity coordinates were also obtained. The results show that Li2Sr1−xBaxSiO4:Eu2+ would be a promising green phosphor candidate for UV-chip-based multiphosphor converted white LEDs.

In this paper, we reported a new photosensitive material, Sm doped K0.5Na0.5NbO3 (KNN) ceramics, fabricated using a solid-sate reaction method, which exhibits both photochromism and luminescence switching properties. By alternating visible light irradiation (λ > 407 nm) and thermal stimulus, the samples show a reversible color change from the initial green to pale gray. Interestingly, luminescence emission intensity can be effectively tuned using photochromic reactions. Furthermore, the luminescence switching degree strongly depends on the firing temperature. These results suggest that KNN-based perovskite oxides with photochromism, luminescence switching and ferroelectric energy storage properties are particularly attractive for optical data storage applications as multi-functional materials.

Reduced graphene oxide foam (RGOF)-based pressure sensors have been fabricated through the combination of ultrasonic dispersion and freeze-drying methods. Due to the maintenance of the highly disordered structure of the ultrasonic dispersed graphene oxides before the freezing process, the RGOF sensors demonstrated an ultra-high sensitivity of 22.8 kPa−1, an ultra-low detection limit of around 0.1 Pa, and a superior separation of 0.2-Pascal-scale difference.

Luminescence modulation based on photochromic reactions is always considered to be a promising method to achieve nondestructive readout in photochromic materials. Generally speaking, two conventional strategies have been widely used to achieve this target: tuning the absorption bands and adjusting luminescent quenching mechanisms. In this paper, we found a new strategy to improve effectively luminescence readout capability in Er/Yb codoped NBN-based solid-state inorganic photochromics by using a two-photon absorption mode of luminescent centers. Upon alternating visible light irradiation (407 nm) and the thermal stimulus, the materials exhibited a high luminescence switching contrast ratio (ΔRt = 86%), excellent reversibility, and significantly improved luminescent efficiency (22 times). Most importantly, the photochromic reaction process can be efficiently read out using the two-photon absorption (or up-conversion) mode without inducing any new reactions, showing extremely low destruction on information recording (destruction degree

Luminescent switching materials upon photochromic reactions have potential applications in optical switching and high-density optical data storage in optoelectronic devices. To avoid interference and destruction of information in practical data storage applications, a nondestructive luminescence readout is essential. However, it is still unclear how to select the optimized excitation and emission bands to avoid the photochromic reaction during the “reading” process while maintaining high luminescence contrast and stability in inorganic photochromic materials. On the basis of the nonradiative energy transfer mechanism, Ho3+ ions were introduced into the Na0.5Bi2.5Nb2O9 host to obtain efficient luminescence switching due to their special excitation (451 nm) and emission (547 nm) characteristics. Under 407 nm irradiation (“writing”), the photochromic phenomenon can be effectively read out by measuring the changes in the luminescence emission intensity. The luminescence switching contrast increased up to 94%. Importantly, the excitation and emission energies did not significantly induce new photochromic reactions, causing less destruction to the material and the luminescence readout process. This outcome is superior to our previously reported results. Furthermore, the luminescence switching properties exhibit hardly any degradation after undergoing several cycles of the “writing”, “reading” and “erasing” processes, indicating excellent reversibility.

High luminescent switching contrast of photochromic materials is extremely important in improving the sensitivity and resolution of optical switches and high-density optical data storage devices. To date, conventional methods, such as tuning absorption and emission bands based on electron or resonance energy transfer mechanisms in well-known organic photochromic molecules or compounds, have routinely been adopted to tune luminescent switching behavior. However, these strategies and mechanisms are not effectively applied to luminescence switching in inorganic materials because their crystal structures differ strongly from those of organic materials. In this paper, we report a new method to significantly tune the luminescent switching contrast by modifying the excitation energy of luminescent centers in a newly synthesized photochromism material: Na0.5Bi4.5Ti4O15:Re (Re = Sm, Pr, Er). A significant enhancement of luminescence switching contrast was achieved when the luminescent centers were excited by low e...

Thermal dissipation and thermal insulation are important for maintaining the normal operation of devices, extending the service life of instruments, ensuring efficient energy utilization, and improving temperature-related human comfort. Yet it is difficult to achieve both the functions of thermal dissipation and thermal insulation in a single material with a specific thermal conductivity under specific conditions. In this work, based on the huge difference in thermal conductivity between air and reduced graphene oxide (rGO), a pressure-induced mechanism is used to regulate the amount of air inside an rGO foam, so that a periodic reversible change of thermal conductivity can be realized, achieving the dual functions of thermal dissipation and thermal insulation to meet the requirements of different application scenarios. Further fitting calculations suggest that the thermal conductivity of rGO foam is positively and negatively associated with the applied pressure and temperature, respectively, and it can be calculated for given pressure and temperature conditions. The pressure-induced reversible regulation of thermal conductivity in rGO foam provides a new design construct for smart thermal-management devices, and a new direction of application for 2D materials.

Steel strip is an important part of steel production. The defect detection for steel strip is a thriving need for steel factories. Workers must monitor the assembly line and detect the defects artificially. Automation of defect detection can save human resource and create values for industry.Nowadays, as the development of computation resources and detection algorithms, there are more and more effective defect detection solutions. In this paper, a new neural network called Inception Dual Network (IDN) is proposed to solve steel defect detection problem. IDN maximize the utilization of residual shortcut connection and concatenation connection through a dual channel structure with Google’s Inception concept. IDN combines classical feature maps to optimize the classification performance. At the same time, a steel strip dataset of 4000 kinds is collected and preprocessed in this paper for other researchers. On the dataset of this paper, IDN has achieved the best performance among some state-of-the-art structure with similar number of parameters while keeping real-time. It can not only be applied on the particular problem in this paper, but also other classical problems.

Self-powered integration is an effective way of promoting efficiency and miniaturizing in portable intelligent electronic systems. Conventional battery design focuses on the improvement of charge–discharge property, and energy storage units usually design independently from energy consumption units including sensing or transmitting device. Here, an unusual battery design in which the batteries possess the function of energy storage, sensing, and signal transducer, called all-in-one ENERGISER, is integrated for the first time, which is realized by fabricating a gallium-based liquid metal-air battery (LMAB) without any other extra electronic components. Gallium-based liquid metals (LMs) wetted on the coppered-coated carbon fibers act as anode and air electrode acts as the cathode, the chemical activity of LMs and the sensitivity of gallium oxide layer are utilized for sensing function. For the discharge performance of LMABs, the energy density of LMABs changes from 1.52 to 0.79 mWh/cm2 while the corresponding power densities range from 0.36 to 2.05 mW/cm2. Additionally, the function of sensing environmental parameters achieves selectively detecting main components of air and distinguishing liquid type. Remarkably, the physical signals, such as humidity, is converted into low and high-potential signals, and further encoded into digital signals. Eventually, the all-in-one battery strategy is validated and shows excellent energy storage capacity, marvelous sensing function, and superb signal transmitting activity. The all-in-one battery design concept may open up a new direction for the exploitation of state-of-the-art functional and highly integrated battery.

Micro-resolution range finder (MRRF) is an essential tool in various cutting-edge fields such as shooting macro, precision instrument, vibration monitoring and micro-collision-avoidance systems. Desirable MRRF requires micro-scale precision, high accuracy, rapid response, and long-term cycling stability. Yet conventional MRRFs based on optical feedback, precise machining, piezoelectric effects and magnetostriction are still limited by complicated designs, precise sequence of tasks, and cumbersome device volume. As such, for the first time, we present a new-type of micro-distance sensor consisting of reduced graphene oxide/high-oriented polypyrrole foam (rGO/HOPPyF) for MRRF. Based on the distance-resistance property of the as-prepared foam, the micro-distance sensor has shown advantages of easy operation, low cost, miniaturized device. Here, large-rate resistance change and great mechanical stability are realized in rGO/HOPPyF, thus allowing precise and accurate micro-distance detection. The micro-distance sensor demonstrates ultrahigh sensitivities of 386.7, 1260 and 546.7 m−1 within the step-length regions of 10 ~ 80, 80 ~ 290, 290 ~ 570 µm, respectively. Remarkably, both the precision and accuracy of our sensor are superior over those of the commercial micrometer and laser rangefinders, providing a new technological advance towards practical MRRF.

Bismuth layered-structure oxides in the Bi3Ti(TaxNb1−x)O9 quasi-binary system were synthesized by the conventional solid state reaction approach, and their ferroelectric and piezoelectric properties were evaluated together with the structures. The XRD analysis showed that all the ceramics were the single phase. It was found that the remnant polarization (Pr) reached a maximum of 4.2 µC/cm2 when x = 0.5 mol%. In addition, a bright up-conversional photoluminescence (UC) can be measured by partial substituting Er3+ for Bi3+. Under 980 nm radiation excitation, three emission bands located at green (534, 549 nm) and red (670 nm) wavelength regions were obtained at room temperature. These Er3+ doped Bi3Ti(Ta0.5Nb0.5)O9 based ferroelectrics could be used as a multifunctional material for a wide range of applications.

In this work, (1−x)(K0.48Na0.52)(Nb0.95Sb0.05)O3−x −xEr0.5(Na0.82K0.18)0.5ZrO3 (x = 0–0.05) ceramics were fabricated by solid-state reaction techniques. The rhombohedral–tetragonal (R–T) phase boundary of the ceramics was identified at 0.04 ≤ x, thus providing an opportunity to investigate the upconversion emission derived from the Er3+ ions at the R–T phase boundary. Under 980 nm laser excitation, the R–T phase ceramics exhibited a strong green emission. In addition, the fluorescence intensity ratios of green emissions at 530 nm and 550 nm were investigated in a temperature range of 180–510 K, and maximum sensing sensitivity was found to be 0.0037 K−1. The results indicate that Er3+-doped ceramics with R–T phase boundaries can be applied to new multifunctional electro-optical temperature sensors. Laser excitation heating effects were also observed in detail.

Er doped SrBi8Ti7O27 (SBT) ferroelectric ceramics were prepared by a solid-state reaction technique. By Er doping, the intensive green upconversion emissions were recorded under 980 nm diode laser excitation with 20 mW. The fluorescence spectrum was investigated in the temperature range of 150–580 K. By the fluorescence intensity ratio technique, the green emission band was studied as a function of temperature with a maximum sensing sensitivity of 0.0028 at 510 K. These results indicate that the Er doped SBT ferroelectric ceramics are promising multifunctional sensing materials.

For checking photoluminescence properties of BaTiO3-(Na0.5Er0.5)TiO3 lead-free piezoelectric ceramics, optical diffuse reflection spectra, visible up-conversion luminescence spectra, 1.55 μm near-infrared photoluminescence spectra, and optical temperature sensing performances under the excitation of 980 nm laser were investigated systematically. Broadband near-infrared (˜1.55 μm, FWHM˜90 nm) emission and strong visible up-conversion (˜550 nm) emission were observed under the 980 nm excitation in the ceramics at room temperature. Near-infrared emission and visible up-conversion emission became stronger with increasing (Na0.5Er0.5)TiO3 concentration below quenching point above which it will degrade. The optimal emission intensity was obtained when (Na0.5Er0.5)TiO3 content was 7 mol%. These ceramics with excellent ferro-/piezoelectric and photoluminescence properties may be useful for ultrasonic transducer, optical temperature sensor, optical amplifier, and other relative applications.

Er3+/Yb3+ co-doped MgWO4 phosphor was synthesized by a solid state reaction method and the phase, photoluminescence and temperature sensing properties were analyzed. The phosphor has shown intense visible green emission via up-conversion process on near-infrared (980 nm) excitation and down-conversion process on 379 nm excitation and thus behaves as a dual-mode phosphor. In the up-conversion and down-conversion emission, the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of the Er3+ ion portray a temperature dependent behavior and have been used for optical temperature sensor by means of the fluorescence intensity ratio method. Moreover, we compared the curves of S in the continuous temperature range (83–583 K) and the two sectional temperature ranges in up-conversion process. It is found that the phosphor can be operated over a temperature range of 83–583 K with a maximum sensitivity of about 0.0093 K−1 at 583 K. The results indicate that the Er3+/Yb3+ co-doped MgWO4 phosphor is a potential candidate to be used in display devices and optical temperature sensors.

Bi3TiNbO9 (BTN) is an important member of the Aurivillius bismuth layer-structured ferroelectric compounds, consisting of [Bi2O2]2+ layers between which [BiTiNbO7]2- layers are inserted. Ho3+ and Yb3+ co-doped Bi3TiNbO9 (BTN) ceramics were synthesized by a conventional solid state reaction method and their up-conversion (UC) luminescence and the ferroelectric properties were investigated. A strong green emission band centered at 547 nm, two weak red emission bands centered at 657 nm and 758nm were obtained under a 980 nm laser excitation at room temperature. With the increasing of Yb3+ content, the intensity of the up-conversion luminescence increased initially and then decreased due to concentration quenching. The fluorescence intensity ratio of green UC emission centered at 547 nm and red UC emission centered at 657 nm was studied as a function of temperature in a range of 123 - 573K, and the result showed a quite good linear variation of the two emissions with temperature, which indicates that Ho3+/Yb3...