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The copper pattern electroplating rate significantly impacts electronic packaging substrate preparation efficiency. The direct current (DC) electroplating technique has great potential in economy and convenience but faces challenges in improving the electroplating rate and coating properties, thus making electroplating additives the most critical parameters for controlling the electroplating process and coating properties. Convection and cathodic polarization are two essential parameters influencing the additives' interactions, but the electrolyte flow field distribution is complicated by the changed pattern size, and most electrolyte formulas cannot withstand such strong cathodic polarization. Therefore, we presented a novel electrolyte formula for ultra-high-rate DC copper pattern electroplating and employed three-dimensional flow field simulation to investigate the flow field distribution throughout the patterns. An ultra-high current density of 8 A/dm2was applied, ensuring a stable electroplating process. The pattern size-stimulated electrolyte flow rate trend was discovered by simulations. The mechanism of simultaneously achieving ultra-high-rate electroplating and coating property improvement was thoroughly investigated. An ultra-high rate of 150 μm/h and the dense, uniform copper pattern coating were achieved synchronously with weak convection and strong cathodic polarization. Utilizing the ultra-high-rate copper electroplating method offers a viable approach to expedite the production of electronic packaging substrate with enhanced efficiency.

The operational stability of radial journal bearings is the bottleneck that limits the reliability of hydraulic suspension micro-pump. Due to self-excited vibrations, the whirl amplitude of the plain journal bearing (PJB) is large at high rotational speeds, which will accelerate wear failure. It has been proven that employing herringbone grooved journal bearing (HGJB) is an effective method to reduce the whirl amplitude and improve operational stability. However, enhancing the stability of journal bearings in micro-pumps by herringbone grooved structures has rarely been studied, and its effect needs to be verified. We validated the mechanism of the stability improvement with the CFD method and compared the dynamic characteristics of HGJB and PJB by rotor dynamics evaluation and experiment. The experimental results show that under the same conditions the whirl amplitude of the HGJB decreases by 29.61% in the xdirection and by 24.09% in the ydirection compared with that of the PJB. This study reveals the effect of the herringbone grooved structure on the operational stability of bearings and may provide guidance for the reliability improvement of hydraulic suspension micro-pump.

Microseismic events must be classified to obtain effective disaster precursor information. To further improve the accuracy and efficiency of microseismic event classification, and based on the microseismic data of rockburst monitoring, combined with time–frequency analysis theory, the main factors affecting microseismic event classification were analyzed. For the first time, the rectangle histogram of oriented gradient (R-HOG) and stacking technologies were effectively combined to establish a new stacking integrated learning model (RSREL-stacking) for classifying microseismic events. Finally, the classification performances of RSREL-stacking, a deep learning model, and other models were tested. The results showed the following: 1) noisy signal interference and some events that have similar characteristics are the main factors leading to the high misjudgment rate of events; 2) RSREL-stacking can accurately distinguish the spectrum of useful signals from complex noise interference and effectively extract the contour, region, and spatial position feature information of the useful signal spectrum; and 3) through different experiments, it is confirmed that RSREL-stacking effectively combines the advantages of many independent models, can deeply recognize the subtle differences and features of similar events, and provides increased accuracy of event classification. Compared with other methods, RSREL-stacking combines the advantages of efficient and accurate classification of microseismic events, which guarantees quickly obtaining effective disaster information.

Machine learning maps the relationship between chemical formula and ionic conductivity, aiming to intelligently screen atom substitution of the solid-state electrolyte Li10GeP2S12for stabilized lithium metal batteries.

The corrosion behavior of ship steel with different microstructure in a simulated tropical marine atmosphere was systematically investigated. Results show that homogeneous martensite structure obtained by water-quenching process was much more resistant to corrosion than that of ferrite-pearlite. Furthermore, the precipitation of carbide resulting from tempering process promoted the formation of corrosive microcells within the matrix and further intensified the corrosion. Rapid cooling rate led to the enrichment of chromium, which formed protective corrosion products such as FeCr2O4and Cr(OH)3. This also facilitated the conversion of α-FeOOH and significantly enhanced the corrosion resistance.

A 1-in Cs2LiYCl6:Ce (CLYC) scintillator coupled with Photomultiplier tube (PMT) was used to detect neutrons and gamma rays simultaneously in this work. The pulses were captured by a high-speed digitizer with 1-Gsamples per second and 12-bit vertical resolution and further analyzed in real time to determine the pulse type, energy spectrum, and flux. The response of CLYC scintillators measured with three PMT models, R6231 and XP2020, were found to have better energy resolution, while R580 was found to have better pulse shape discrimination (PSD) performance. The energy resolution was optimized by adjusting the integration time window. Slight differences were found to be within the range of 2000–8000 ns for different PMT models. The fast neutron peaks from 35Cl(n, p)35S reaction were detected along with the thermal neutron peak from 6Li(n, $\alpha)^{3}\text{H}$ , and a quenching factor of 0.9 was obtained for protons. The energy resolution was 14.7% and the detection efficiency was about 0.15% for 1.5-MeV fast neutron. The discrimination performance between neutron and gamma pulses was studied using the charge comparison method. The figure-of-merit (FOM) value was found to be better than 1.90 within the energy range of 0.5–10 MeV, i.e., 2.0 for 1.5-MeV fast neutron and ~3.2 for thermal neutron. The flux of fast neutrons, thermal neutrons, and gamma rays was detected simultaneously, and the prompt gamma rays by neutron activation were also identified. It indicates that the CLYC detector can be used for multimode detection of thermal neutrons, fast neutrons, and gamma rays, and would be a suitable compact candidate for prompt gamma neutron activation (PGNAA) analysis in limited space.

Exploring the relationship between teacher support and students' learning engagement in high school information technology courses can help improve students' learning ability. The researchers took 246 high school students from a city in China as the research subjects and used structural equation modeling to explore the relationship between teacher support and learning engagement in high school information technology courses from the perspective of computer self-efficacy. The results show that teacher support, computer self-efficacy, and learning engagement are positively correlated. Teacher support has a positive effect on information technology learning engagement, and computer self-efficacy plays a partial mediating role in the relationship between teacher support and information technology learning engagement.

COVID-19 boosted online teaching and yielded a significant amount of valuable data, yet utilizing it for education is a challenge. This study employed the K-means clustering method to analyze the online teaching behavior data of 1147 courses from a local university in East China. As a result, five types of courses with distinct teaching behaviors were identified: resource preparation (4.1%), online classroom interaction (3.6%), task evaluation (9.2%), active interaction (15.5%), and inactive interaction (67.6%). By examining the relationship between these course types and academic performance, the authors discovered no significant difference in the academic performance of students in the three course groups (i.e., resource preparation, online classroom interaction, and task evaluation) and students in the inactive interaction course group. However, there was a significant disparity in academic performance between students in active interaction courses and students in inactive interaction courses. These findings can assist teachers in planning online teaching activities more effectively and improving teaching outcomes.

A novel concept based on the encapsulation of transparent phase change materials (PCMs) into the optical packaging structure of light-emitting diodes (LEDs) is presented in this article. The concept was initiated by challenges of thermal management of photoluminescent particles in high-power optical systems. LEDs, white LEDs (WLEDs), and porous/network-based photoluminescent matrices can achieve improved thermal networks by embedding PCMs. In this article, paraffin is selected as a suitable PCM encapsulant, and aside from thermal perspectives, an unexpected optical benefit with melted paraffin after surface wetting of the chip was observed. Immersing an LED chip in a melted paraffin pool showed up to an 8% increase in light extraction efficiency and a 1.5% increase in power conversion efficiency (PCE). An accurate dynamic opto-electro-thermal monitoring of studied devices was used to support the proof of concept. This viable method can be integrated into current industrial packaging processes.

The micropump is the heart of microfluidics systems. However, for mechanical micropumps, bearing wear failure has been a major obstacle to performance and reliability. Hydrodynamic suspension, which can make the rotating components levitate in liquid without any mechanical friction, is applied to break this bottleneck. In this paper, a novel kind of hydrodynamic suspension micropump (HSMP) without a grooved thrust bearing is proposed. Based on the centrifugal effect, the HSMP uses a rotating rotor to accelerate and pressurize adjacent fluid, and thus reacting forces are generated on the rotor surfaces to levitate it. The mechanisms of suspension forces formation, the centrifugal effect and the wedge effect in the liquid films near the rotor are identified using theoretical analysis and simulation. The variation in suspension forces with rotor position is investigated, revealing that the suspension bearings of the HSMP, similar to a spring damper, can self-adjust suspension forces along with a change in rotor position. Moreover, the suspension stiffness is positively correlated with the rotating speed. The HSMP prototype designed herein, whose overall size is only 34 mm × 34 mm × 31 mm, can provide a maximum output performance of 3230 mL/min and 96.3 kPa at 20000 r/min, which is manyfold greater than other micropumps. The proposed HSMP is demonstrated to be more powerful with a simple structure, high power density, and high reliability.

A new system which combined cooling, heating and power (CCHP) and based on a solid oxide fuel cell (SOFC) with a LiBr absorption chiller and water tank is investigated. The influence of the working conditions of the SOFC on its steady-state and dynamic performances are studied. Meanwhile, the effects of working conditions of the stack and absorption chillers on multi-criteria assessments are also studied. The result shows that the operating temperature and current density can greatly affect the performance of the stack and system, which can also be influenced by the working conditions of the absorption chiller simultaneously. Increasing the operating temperature can greatly increase the electrical power, and the thermal power will be reduced correspondingly. Increasing the mass flows of the cooling, chilled and hot waters increase the cooling power and coefficient of performance (COP), thereby reducing the heating power.

Electrochemical battery energy storage stations have been widely used in power grid systems and other fields. Controlling the temperature of numerous batteries in the energy storage station to be uniform and appropriate is crucial for their safe and efficient operation. Thus, effective thermal management is required. In this work, an approach for rapid and efficient design of the liquid cooling system for the stations was proposed. A hydraulic solution model for the liquid-cooling network was established based on graph theory principles, and the genetic algorithm was employed for automatic system optimization to achieve high cost-effectiveness and ideal temperature distribution. Experiments were conducted to validate the accuracy of the hydraulic model and evaluate the efficacy of the optimization strategy. The flow rate calculated from the hydraulic model agreed well with the experiments, with a discrepancy smaller than 3.5 %, and the uniformity of flow rates was improved to as high as 70 % after the optimization. Furthermore, the applicability of this approach was also confirmed across various sizes of energy storage systems.

Multicompartment micelles (MCMs) attracted much attention since they have subdivided domains that could be employed to encapsulate and transport diverse compounds simultaneously. Usually, preparation of MCMs relied on precise synthesis of block copolymers (BCPs) and elegant control of assembly kinetics, making it difficult to successively produce MCMs. Herein, we report a facile yet effective method for preparing MCMs by adjusting the hydrodynamics in microfluidic channels. It was found that well-defined MCMs were formed through hydrodynamics-dependent secondary assembly in microfluidic chips. By adjusting the flow diffusion process by varying the flow rate ratio and total flow rate, both the internal structure and size of MCMs could be effectively changed. A product diagram of micellar morphologies associated to the initial polymer concentration and flow rate ratio of water/BCPs solution was constructed. More interestingly, quantum dots (QDs) could be selectively loaded into different domains of the MCMs. Consequently, the Förster resonance energy transfer among QDs could be effectively suppressed. Thus, the emission spectrum of MCMs/QDs hybrid particles could be easily tuned by changing the ratio of QDs, showing great potential application in photonics and sensors.

As a commonly used cathode material in lithium-ion batteries, spinel LiMn2O4(LMO) suffers a significant decline in capacity during the cycling process due to pronounced Jahn-Teller distortion. To address this issue, we propose the application of c-axis compressive strain as a means to suppress the capacity decay. The results indicate that with the increase of the compressive strain, the Jahn-Teller distortion is still present but weakened a little bit. A maximum reduction of approximately 26 % in the Pugh Ratio is achieved, indicating an enhancement in the extensibility of LMO cathode, a reduced susceptibility of crack formation, and thereby increasing cycling stability. Moreover, compressive strain can also reduce the lithium-ion diffusion energy barrier, resulting in the improvement of electrochemical performance at high rates. In our study, under the strain of −3 %, a remarkable reduction of 18 % in the Li+diffusion energy barrier is observed, as it decreases from 0.401 eV to 0.328 eV. The band gap (Eg) of LMO is also reduced with compressive strain, which improves the electronic conductivity. The present study is expected to reveal the effect of applying c-axis compressive strain on LMO cathode material, and trigger the practical strain engineering applications in regulating battery performance.

•A durable and reliable TMS with superior temperature uniformity for STC was proposed.•The reliability of HSMs was proven under high-temperature vibration conditions.•The temperature of heat sources remained below 150 °C after 21 h operation.•Numerical results were validated by experiment with the relative error below 5%.•The temperature uniformity was significantly increased compared to previous works.

Narrowband mid-infrared emitters, quantified by the Q-factor, have garnered a lot of attention due to their emerging applications from chemical and biosensing to efficient thermal utilization. Previous studies reported high Q-factor emitters within several selected wavelengths, still lacking a large database of emitter structures with very high Q-factors. In this Letter, we utilized the Monte Carlo Tree Search (MCTS) algorithm under the framework of material informatics to optimize the Tamm emitters at the infrared range (from 3 to 10 µm) for achieving a high Q-factor and high emissivity simultaneously, providing a large database of high and sharp emission peaks in the infrared. Through the MCTS algorithm, the structure with a Q-factor of 508 and an emissivity peak of 0.92 at 4.225 µm is obtained, far surpassing the previous results, and the underlying mechanism is discussed by electric field simulations. The high Q-factor emitters in the database show good monochromatism and high emissivity, accelerating the selection of proper perfect emitters for desired wavelengths. This Letter also paves a feasible avenue for the emitter and absorber design with ultrahigh monochromatism.

Self-assembly of block copolymers (BCPs) in microfluidic chips is a versatile yet effective route to produce micellar aggregates with various controllable sizes and morphologies. In this study, the morphological transformation of the BCP of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) assemblies from irregular aggregates to multicompartment micelles and ultimately to ordered spherical micelles is demonstrated in microfluidic chips. Our experimental and computational simulation results indicate that the transverse diffusion of solvents plays an important role in the morphological transformation of PS-b-P4VP assemblies in the confined flow condition. We find that the mixing time (tmix) between a BCP/tetrahydrofuran (THF) solution and water affects the morphological transformation. Micellar morphologies are intended to transform from aggregates to ordered spherical structures under a relatively long mixing time (tmix). In addition, it is observed that the size of the micelles decreases with the increase of the flow velocity ratio by tuning the hydrodynamic conditions of the flows. Moreover, by adjusting the initial polymer solution concentration, temperature, and weight fraction of the introduced homopolystyrene (hPS), which can affect the viscosity of the BCP solution, the flow diffusion in the microfluidic chip and the resulted micellar structures can also be readily adjusted. The current study provides a new flow-driven method to adjust the micellar ordered structural transformation under the nonequilibrium state.

Combining phase change microcapsules and various matrix materials can construct novel composite phase change materials (CPCMs). These composite materials hold immense potential for electronics thermal management, owing to their adjustable heat storage capacity and stable shape. Most previous studies focus on enhancing the thermal conductivity of CPCMs by adding thermally conductive fillers or modifying the microcapsule shells. Nevertheless, achieving both high thermal conductivity and heat storage density simultaneously remains a challenge. In this paper, low melting point alloy (In51Bi32.5Sn16.5) was introduced as core material of the microcapsule to enhance the thermal conductivity, due to its significantly higher thermal conductivity compared to commonly used organic or inorganic phase change materials (PCMs). In51Bi32.5Sn16.5@SiO2microcapsule was synthesized through the sol-gel polymerization method. Furtherly, a form-stable CPCMs consisting of the microcapsules and silicone rubber (SR) matrix were prepared for electronics thermal management. The In51Bi32.5Sn16.5@SiO2microcapsules exhibit an impressive thermal conductivity of 13.49 Wm−1 K−1, acting as a dual-functional filler for thermal storage and thermal conduction enhancement. Hence, the CPCMs possess a significantly enhanced thermal conductivity of 0.45 Wm−1 K−1, representing a remarkable improvement of 350 % compared to that of pure SR. In addition, the phase change heat storage density of the CPCMs was as high as 71.73 J/cm3. Notable, the prepared CPCMs demonstrate exceptional heat dissipation performance, resulting in a remarkable 23 °C reduction in chip temperature when applied for thermal management. This study offers a novel perspective on the preparation of microcapsule-based CPCMs for electronics thermal management.

Thermal camouflage, which is used to conceal objects in the infrared vision for confrontation with infrared detection in civilian or military applications, has garnered increasing attraction and interest recently. Compared with conductive thermal camouflage, that is to tune heat conduction to achieve equivalent temperature fields, radiative thermal camouflage, based on emissivity engineering, is more promising and shows much superiority in the pursuit of dynamic camouflage technology when resorting to stimuli-responsive materials. In this paper, we demonstrate the emissivity-engineered radiative metasurface to realize dynamic thermal camouflage functionality via a flying laser heat source on the metal-liquid-crystal-metal (MLCM) platform. We employ a rigorous coupled-wave algorithm to calculate the surface emissivity of Au/LC/Au microstructures, where the LC-orientation angle distribution is quantified by minimizing the emitted thermal energy standard deviation throughout the whole plate. Emissivity engineering on the MCLM platform is attributed to multiple magnetic polariton resonance, and agrees well with the equivalent electric circuit analysis. Through this electrical modulation strategy, the moving hot spot in the original temperature field is erased and a uniform temperature field is observed in the infrared camera instead, demonstrating the very good dynamic thermal camouflage functionality. The present MLCM-based radiative metasurface may open avenues for high-resolution emissivity engineering to realize novel thermal functionality and develop new applications for thermal metamaterials and meta-devices.

A series of lanthanide organic complexes, namely, [Ln2PDC3(H2O)3]H2O (Ln = Eu, Tb, EuxTb2–x, H2PDC: pyridine-3,5-dicarboxylic acid), were synthesized via hydrothermal method. Eu-PDC was characterized by single-crystal X-ray diffraction. The powder X-ray diffraction, Fourier transform infrared spectra, and thermogravimetric analysis illustrate that Eu-PDC, Tb-PDC, and EuxTb2–x-PDC complexes are isostructural. All the complexes exhibit strong emission even though water molecules coordinated in the structure. Tunable emission color from green, yellow to red is realized by adjusting the Eu/Tb ratio in mixed EuxTb2–x-PDC complexes. Energy transfer from Tb3+to Eu3+is discussed in detail via fluorescence decay and time resolution spectra. The detailed energy transfer process sees that the emitting color of Eu0.15Tb1.85-PDC shifts from green to orange in a time interval of 153–790 μs. In addition, temperature-dependent emission of the Eu0.05Tb1.95-PDC complex indicates that it is a potential solid state material for a luminescence thermometer in the range of 293–333 K. The temperature resolution is less than 0.16 K. The optical properties of the EuTb-PDC complex indicate that it is a multifunctional luminescent material with promising applications in temperature sensing, time resolution imaging, lighting, and displaying.

Low carbon medium manganese steel with chromium and molybdenum addition (4MnCM), alongside a control group without these additions (4Mn), was developed. The quenching (860°C) and tempering (620°C) heat treatment process was applied to both steel groups. The influence of Cr and Mo on the microstructure evolution and mechanical properties was examined. The findings revealed that, the low−temperature impact energy values (KV2) of 4MnCM at −60 and −84°C were enhanced by 104 and 107 J, in comparison to 4Mn. The yield and tensile strength saw an increase of 100 MPa. The higher low-temperature toughness of 4MnCM is attributed, on one hand, to the addition of Cr and Mo, which inhibiting deformation twinning through enhances the stacking fault energy (SFE) of reversed austenite. On the other hand, it is due to the absence of coarse ε−martensite (ε−m) along the crack propagation path. Additionally, the phase transformation of reversed austenite occurs at the crack nucleation stage during the impact process of both steels, which helps alleviate stress concentration and increases the energy required for crack formation. The primary reason for the higher strength of 4MnCM lies in the significant enhancement of precipitation strengthening effects through the precipitation of M6C, M23C6and Nb/TiC co-precipitation with M6C.

Two-dimensional materials AB2-type and AB-type materials not only have robust electrical properties, but also have robust thermal stability, which can reduce the risk of thermal runaway of the battery. While experimental and theoretical calculations to explore the entire phase space are both very time-consuming, using machine learning combining with first principle calculations, a new material TiF that has high electronic conductivity (bandgap = 0 eV), low energy barrier (0.28 eV), high capacity (400.82 mA h/g), high thermal stability and moderate open circuit voltage (2.21 V) is screened out from 1913 materials. TiF possesses great electronic properties to be used as anode materials and its stability at high temperatures offers the feasibility of reducing the risk of thermal runaway. Besides TiF, the other 12 2D materials obtained from the screening have been used in experiments as electrodes. In addition, the screening method combining first principle calculations with new Positive and Negative Semi-supervised (PNS) machine learning model can greatly reduce the screening time and under limited samples, classification performance increases on iteration, which benefits us to complete the phase space exploration of two-dimensional AB2-type and AB-type materials.

The incorporation of microencapsulated phase change materials (MPCMs) into electronic packaging materials has demonstrated the potential to reduce the transient increase in temperature of electronic devices under thermal loading. However, because of their high specific surface area, MPCMs tend to form severe aggregates in polymer matrices, resulting in poor thermal conductivity and energy storage efficiency. Therefore, in this paper, cellulose nanofibers (CNF) were used as dispersants to effectively disperse MPCMs in the epoxy resin matrix to synthesize epoxy composites with superior thermal conductivity and thermal storage properties (referred to as EBM-C). The results demonstrated that the addition of CNF improved the dispersion of MPCMs as well as the thermal conductivity and thermal storage capacity of the composites. The thermal conductivity and energy storage efficiency of the composites with 3 wt% CNF were increased by 100 %, and 97 %, respectively, compared to those of composites without CNF. In addition, the EBM-C composites also had excellent thermal stability and mechanical properties. The experimental results conclusively demonstrate that the EBM-C composites have tremendous application potential as thermal management materials.

Recently, two Sciencepapers tackled the challenge of harvesting low-grade heat via liquid thermocells. One combines TGC and TDC to significantly enhance thermopower by an order of magnitude, and the other reveals the selectively thermosensitive crystallization/dissolution at two electrodes. These intriguing and inspiring advances in terms of materials, mechanisms, and performances are briefly introduced, and some remaining challenges and future directions are outlined for further thermopower improvement and practical implementation.

Kinetically controlled self-assembly of block copolymers (BCPs) in solution is an efficient route to fabricate complex hierarchical colloids which are of great importance for nanoencapsulation, microreactors, and biomimics. Herein, segmented wormlike micelles (SWMs) with controllable size are generated by the self-assembly of polystyrene-block-poly(4-vinyl pyridine) in microfluidic channel. Different from the assembly of BCPs off-chip at the same solution properties, it is found that the fabricated SWMs are kinetically controlled assemblies with thermodynamic metastable structures, which are formed by the orderly aggregation of preformed spherical micelles because of the fast mixing process in microfluidic channels. Moreover, by manipulating the total flow velocity of water and BCPs solution or their flow velocity ratio, both of the percentages of SWMs among the whole assemblies and their sizes can be effectively tuned. On the basis of electron microscopy and dynamic light scatting investigations, a product diagram of micellar morphologies associated to initial polymer concentration and flow velocity ratio of water/BCPs solution was constructed, which is important for the rational design and fabrication of complex hierarchical BCP colloids.

Large-area bulk oxidized cellulose nanocrystal (OCNC)/graphene nanocomposites with highly oriented structures were produced through a straightforward, cost-effective large-scale evaporation-induced self-assembly process followed by thermal curing. Well-aligned nano-sized graphene layers were evident and separated by the OCNC planar layers, which facilitate highly interconnected and continuous thermal transport parallel to the alignment. Hence, the laminated graphene-based nanocomposites possess an excellent in-plane thermal conductivity of 25.66 W/m K and a thermal conductivity enhancement (η) of 7235% with only a 4.1 vol % graphene loading. This value is the highest recorded among all laminated composite films with <70 wt % filler content reported to date. Using this design strategy, other large-area aligned composites with other functional nanomaterials, already in large-scale production, can be made for use in a wide range of applications.

Rheumatoid arthritis (RA) is a prolonged multifactorial autoimmune disease of unknown etiology. With the global population aging, the incidence of RA is increasing, highlighting the need for more effective treatments. Exercise interventions have been recognized as safe and effective for managing pain, improving function, and reducing fatigue in RA patients. However, the existing literature in this field lacks a thorough, organized, and clear line of analysis. In this study, we conducted a comprehensive analysis of the 20-year literature on exercise interventions for RA, aiming to identify hotspots and cutting-edge trends. Our objective is to provide subsequent researchers with valuable ideas and references. Using Cite Space, VOS viewer, and R-bibliometrix software for visualization and analysis, we compiled the main dataset from the web of science database, consisting of 1790 articles on exercise interventions in RA published between 2000 and 2023. Among these articles, the United States contributed the highest number of papers (433), while Karolinska Institutet ranked first institutionally with 90 papers. The study focused on the keyword’s quality of life, cardiovascular disease, aerobic exercise, social support, psychology, and multidisciplinary care. The research highlighted the importance of clinical efficacy studies that investigate different types of exercise modalities (cardiorespiratory aerobic, resistance, aquatic, and neurological) either alone or in combination, to improve pain and function and reduce cardiovascular disease risk in patients with RA. Additionally, sedentary behavior, fatigue, and multidisciplinary care were identified as potential areas for further research. Overall, this study provides a scientific perspective on exercise interventions for RA and offers valuable insights for academics, funding organizations, and policymakers.

The electronics inside the logging tools are prone to failure due to the extreme thermal environments. In this study, a hybrid thermal management system using liquid cooling and phase change material (PCM) for downhole electronics is proposed to extend the workable time. In this system, a spiral pipe and a S-shaped pipe are respectively arranged inside the PCM and the cold plates to strengthen the heat exchange. To investigate the performance of this system, the transient flow and heat transfer simulation are implemented using finite element method. The accuracy is validated by comparing with the reported experimental results, showing an error of less than 6.7 %. The results show that the hybrid thermal management system increases the operating time of the electronics from 230 min to 450 min, which is attributed to the introduction of liquid cooling. The maximum temperature difference between the electronics and PCM reduces from 30 °C to 2 °C. Moreover, the effect of flow rate, spiral pipe spacing, heating power and ambient temperature on the temperature control performance are explored. This work provides a guidance for the design and optimization of logging tools, which is significative to shorten their research and development cycle.

The red upconversion (UC) emission of Eu3+ions in Lu2O3: Yb3+/Eu3+powders was successfully enhanced by tridoping Ho3+ions in the matrix, which is due to the bridging function of Ho3+ions. The experiment data manifest that, in Yb3+/Eu3+/Ho3+tridoped system, the Ho3+ions are first populated to the green emitting level 5F4/5S2through the energy transfer (ET) processes from the excited Yb3+ions. Subsequently, the Ho3+ions at 5F4/5S2level can transfer their energy to the Eu3+ions at the ground state, resulting in the population of Eu3+5D0level. With the assistance of the bridging function of Ho3+ion, this ET process is more efficient than the cooperative sensitization process between Yb3+ion and Eu3+ion. Compared with Lu2O3: 5 mol % Yb3+/1 mol % Eu3+, the UC intensity of Eu3+5D0→7F2transition in Lu2O3: 5 mol % Yb3+/1 mol % Eu3+/0.5 mol % Ho3+is increased by a factor of 8.

The monochromaticity improvement of green upconversion (UC) in Lu2O3:Yb3+/Ho3+powders has been successfully realized by tridoping Eu3+. The integral area ratio of green emission to red emission of Ho3+increases 4.3 times with increasing Eu3+doping concentration from 0 to 20 mol %. The energy transfer (ET) mechanism in the Yb3+/Ho3+/Eu3+tridoping system has been investigated carefully by visible and near-infrared (NIR) emission spectra along with the decay curves, revealing the existence of ET from the Ho3+5F4/5S2level tothe Eu3+5D0level and ET from the Ho3+5I6level to the Eu3+7F6level. In addition, the population routes of the red-emitting Ho3+5F5level in the Yb3+/Ho3+codoped system under 980 nm wavelength excitation have also been explored. The ET process from the Yb3+2F5/2level to the Ho3+5I7level and the cross-relaxation process between two nearby Ho3+ions in the 5F4/5S2level and 5I7level, respectively, have been demonstrated to be the dominant approaches for populating the Ho3+5F5level. The multiphonon relaxation process originating from the Ho3+5F4/5S2level is useless to populate the Ho3+5F5level. As the energy level gap between the Ho3+5I7level and Ho3+5I8level matches well with that between Eu3+7F6level and Eu3+7F0level, the energy of the Ho3+5I7level can be easily transferred to the Eu3+7F6level by an approximate resonant ET process, resulting in a serious decrease in the red UC emission intensity. Since this ET process is more efficient than the ET from the Ho3+5F4/5S2level to the Eu3+5D0level as well as the ET from the Ho3+5I6level to the Eu3+7F6level, the integral area ratio of green emission to red emission of Ho3+has been improved significantly.

Lithium-ion battery temperature monitoring contributes to the higher performance of lithium batteries and reduces the risk of thermal runaway. Since the battery temperature can be approximated as a time series, this work reports a new model named convolutional transformer (Convtrans) for multi-step time series forecasting, which obtains pleasing results. To evaluate our model, we present a cross-sectional comparison of the model with the other three mainstream algorithms in multi-step time series forecasting and a vertical comparison with single-step time forecasting. On one hand, Convtrans has the minimum root mean square error with the highest prediction accuracy and can also predict the trend and shape of temperature curves compared with the other three mainstream algorithms, which means that it has the best results in multi-step time series forecasting. On the other hand, compared with single-step time series forecasting, Convtrans predicts 24 times temperature data while doesn't sacrifice much accuracy even though it costs 6 times running time. Furthermore, in the case of predicting more points, it also maintains good accuracy and can perfectly predict trends of the temperature. In all, we prove the superiority of multi-step time series forecasting over a long period. Therefore, multi-step time series forecasting based on Convtrans can sever as the battery temperature prognostic technology providing timely warnings to assist battery thermal management.

A high-temperature solid-state method was used to synthesize the Ho3+- and Yb3+-codoped cubic Lu2O3powders. The crystal structures of the as-prepared powders were characterized by X-ray diffraction. The energy-transfer (ET) phenomenon between Ho3+ions and Yb3+ions was verified by the steady-state spectra including visible and near-infrared (NIR) regions. Beyond that, the decay curves were also measured to certify the existence of the ET process. The downconversion phenomena appeared when the samples were excited by 446 nm wavelength corresponding to the transition of Ho3+: 5I8→5G6/5F1. On the basis of the analysis of the relationship between the initial transfer rate of Ho3+: 5F3level and the Yb3+doping concentration, it indicates that the ET from 5F3state of Ho3+ions to 2F5/2state of Yb3+ions is mainly through a two-step ET process, not the long-accepted cooperative ET process. In addition, a 62% ET efficiency can be achieved in Lu2O3: 1% Ho3+/30% Yb3+. Unlike the common situations in which the NIR photons are all emitted by the acceptors Yb3+, the sensitizers Ho3+also make contributions to the NIR emission upon 446 nm wavelength excitation. Meanwhile, the 5I5→5I8transition and 5F4/5S2→5I6transition of Ho3+as well as the 2F5/2→2F7/2transition of Yb3+match well with the optimal spectral response of crystalline silicon solar cells. The current research indicates that Lu2O3: Ho3+/Yb3+is a promising material to improve conversion efficiency of crystalline silicon solar cell.

Internal bases in mRNA can be subjected to modifications that influence the fate of mRNA in cells. One of the most prevalent modified bases is found at the 5′ end of mRNA, at the first encoded nucleotide adjacent to the 7-methylguanosine cap. Here we show that this nucleotide, N6,2′-O-dimethyladenosine (m6Am), is a reversible modification that influences cellular mRNA fate. Using a transcriptome-wide map of m6Amwe find that m6Am-initiated transcripts are markedly more stable than mRNAs that begin with other nucleotides. We show that the enhanced stability of m6Am-initiated transcripts is due to resistance to the mRNA-decapping enzyme DCP2. Moreover, we find that m6Amis selectively demethylated by fat mass and obesity-associated protein (FTO). FTO preferentially demethylates m6Amrather than N6-methyladenosine (m6A), and reduces the stability of m6AmmRNAs. Together, these findings show that the methylation status of m6Amin the 5′ cap is a dynamic and reversible epitranscriptomic modification that determines mRNA stability.

Jinping Underground laboratory for Nuclear Astrophysics (JUNA) will take the advantage of the ultra-low background of CJPL lab and high current accelerator based on an ECR source and a highly sensitive detector to directly study for the first time a number of crucial reactions occurring at their relevant stellar energies during the evolution of hydrostatic stars. In its first phase, JUNA aims at the direct measurements of 25Mg(p,γ)26Al, 19F(p,α)16O, 13C(α,n)16O and 12C(α,γ)16O reactions. The experimental setup, which includes an accelerator system with high stability and high intensity, a detector system, and a shielding material with low background, will be established during the above research. The current progress of JUNA will be given.

•A pump-assisted loop heat pipe with two parallel evaporators was fabricated.•Both biporous wick and impeller micropump were used to provide the driving force.•The maximum heat flux was 27.5 W/cm2and evaporator 2 performed better.•Higher pump power and lower heat sink temperature enhanced thermal performance.•The minimum thermal resistances for the two evaporators were 0.217 and 0.197 °C/W.

Filler-reinforced polymer composites are widely applied in thermal management field on account of their promising heat transport ability, superior flexibility and excellent durability. Inside these composites, thermally conductive fillers are usually uniformly distributed or unidirectionally oriented in polymer matrix to improve thermal performances. However, the ever-shrinking and spatially distributed heat sources in three-dimensional, high-density packaged electronic devices have created the localized “hotspot” problem, which raises a new challenge and stricter requirement for the composite thermal materials. Inspired by the amazing radial microstructures in ginkgo leaf, we proposed a flow field-driven self-assembly strategy to fabricate functional thermal materials with radially oriented carbon fibers (CFs). To quantitively evaluate the orientation, an orientation algorithm based on microscale image identification was developed, and an evaluation criterion was proposed. The underlying orientation mechanisms of fillers under the driving of flow field were revealed by visual simulation of vacuum filtration. Thanks to the well-oriented fillers architecture, the composites demonstrated an ultrahigh in-plane thermal conductivity of 35.5 W/(m∙K) with a thermal conductivity anisotropy of 19.8, which enables rapid and efficient heat dissipation pathways towards localized hotspots. In addition, this flow field-driven self-assembly strategy provides a promising self-design ability that is expected to solve the heat dissipation of arbitrary-shape heat sources, and shed light on other application scenarios like efficient solar-thermal-electric conversion.

Hexagonal boron nitride (hBN) platelets are widely used as the reinforcing fillers for enhancing the thermal conductivity of polymer-based composites. Since hBN platelets have high aspect ratio and show a highly anisotropic thermal property, the thermal conductivity of the hBNs-filled composites should be strongly associated with the platelets’ orientation. However, the orientation effect has been explored less frequently due to the technical difficulties in precontrol of the platelets’ orientation in the polymer matrix. In this paper, we report the use of magnetic fields to assemble the platelets into various microstructures and to study the thermal conductivities of the designed composites. The experimental results showed that thermal conductivities are dramatically different among these composites. For instance, the thermal conductivities of the composites with platelets oriented parallel and perpendicular to the heat flux direction are respectively 44.5% higher and 37.9% lower than that of unaligned composites at the volume fraction of 9.14%. The results were also analyzed by a theoretical model. The model suggests that the orientation of the hBN platelets is the main reason for the variance in the thermal conductivity.

In this study, a brightness-enhancement-film- (BEF) adaptive method is proposed to design freeform lenses for enhancing brightness performance in a direct-lit light-emitting diode (LED) backlight system. A detailed design algorithm is presented based on the analysis of the output optical properties of the BEF. By introducing a constriction factor, we can control the light intensity distribution curve at will to adapt to the characteristics of the BEF and make more light transmit through the BEF. Compared with an LED backlight system without a freeform lens, the BEF-adaptive lens method can improve axial luminance by 20.67% and output efficiency by 6.02%.

In a conventional liquid cooling garment (LCG), overcooling of the water inlet temperature shortens the working time and worsens thermal comfort. Such problems have not been well solved so far. In this study, we propose a smart cooling garment with a developed temperature regulation system, effectively reducing un-necessary loss of power consumption and hence extending the work duration. Testing on a thermal manikin was conducted to evaluate the performance of temperature-regulating LCG. The results showed that, compared to the conventional LCG, the proposed system achieved the rapid and accurate adjustment of water temperature, improved the working time by more than 37% with the total weight barely increased, and ensured the thermal comfort of the wearers. The developed LCG opens the possibility for the smart control of the temperature, fitting for the user's preferences regarding the working time and thermal comfort sensations.

Acquiring the junction temperature of light emitting diode (LED) is essential for performance evaluation. But it is hard to get in the multipleLED applications. In this paper, an engineering method is presented to estimate the junction temperatures of LEDs in multiple LED applications. This method is mainly based on an analytical model, and it can be easily applied with some simple measurements. Simulations and experiments were conducted to prove the feasibility of the method, and the deviations among the results obtained by the present method with those by simulation as well as experiments are less than 2% and 3%, respectively. In the final part of this study, the engineering method was used to analyze the thermal resistances of a street lamp. The material of leadframe was found to affect the system thermal resistance mostly, and the choice of solder material strongly depended on the material of the leadframe.

miRNAs have been shown to play essential regulatory roles in the innate immune system. They function at multiple levels to shape the innate immune response and maintain homeostasis by direct suppression of the expression of their target proteins, preferentially crucial signaling components and transcription factors. Studies in humans and in disease models have revealed that dysregulation of several miRNAs such as miR-146a and miR-155 in rheumatic diseases leads to aberrant production of and/or signaling by inflammatory cytokines and, thus, critically contributes to disease pathogenesis. In addition, the recent description of the role of certain extracellular miRNAs as innate immune agonist to induce inflammatory response would have direct relevance to rheumatic diseases.

The theoretical analysis of vibration control of multiple-degree-of-freedom structures with multi-mode vibration control systems is presented in this article. A new method of parameter optimization of the multiple-tuned mass damper system was proposed in order to obtain the best control effect, where the minimum of the dynamic magnification factor is used as the optimal objective. The numerical examples of parameter optimization indicate that optimal parameters can be obtained for the multiple-degree-of-freedom system to get satisfactory control effects. The application of the theory is used for the vibration control simulation of an offshore platform. The results indicate that reasonable control effects can be obtained by controlling the first mode and the control effects increase about 10% in average when the first two modes are controlled simultaneously.

Abstract: Optical constants, including scattering coefficient, absorption coefficient, asymmetry parameter and reduced scattering coefficient, of cerium-doped yttrium aluminium garnets (YAG:Ce) phosphor blended with SiO2 particle for white light-emitting diode (LED) packages were calculated based on Mie theory in this study. Calculation processes were presented in detail. Variations of the optical constants with the changes of phosphor weight fraction, dopant weight fraction, phosphor particle radius and SiO2 particle radius, were shown and analyzed separately. It was found that the asymmetry parameter is the intrinsic characteristic of the particles, and the increase of the phosphor weight fraction (or concentration) will lead to the increase of the optical constants. It was also discovered that the increase of the dopant weight fraction will enhance the scattering coefficient, but result in the decreases of the reduced scattering coefficient and the absorption coefficient.

Abstract: Effects of tilt angles of reflective cup structure and phosphor surface geometries on light extraction efficiency and angular color uniformity (ACU) of phosphor converted light emitting diodes (pcLED) are investigated by Monte Carlo ray-tracing simulations. It is found that tilt angles of reflective cup and phosphor surface geometries affect the light extraction efficiency and the ACU distinctly. When the tilt angle varied from 60° to 15°, the light extraction efficiency of LED can achieve the improvements of 13.87%, 18.25% and 14.79% respectively, when the phosphor surface geometry is concave, flat and convex, respectively. It is also found the variety law of phosphor concentrations with the change of tilt angles and phosphor surface geometries to maintain a fixed correlated color temperature (CCT).

The recent discovery of microRNAs (miRNAs) has revealed a new layer of gene expression regulation, affecting the immune system. Here, we identify their roles in regulating human plasmacytoid dendritic cell (PDC) activation. miRNA profiling showed the significantly differential expression of 19 miRNAs in PDCs after Toll-like receptor 7 (TLR7) stimulation, among which miR-155* and miR-155 were the most highly induced. Although they were processed from a single precursor and were both induced by TLR7 through the c-Jun N-terminal kinase pathway, miR-155* and miR-155 had opposite effects on the regulation of type I interferon production by PDC. Further study indicated that miR-155* augmented interferon-α/β expression by suppressing IRAKM, whereas miR-155 inhibited their expression by targeting TAB2. Kinetic analysis of miR-155* and miR-155 induction revealed that miR-155* was mainly induced in the early stage of stimulation, and that miR-155 was mainly induced in the later stage, suggesting their cooperative involvement in PDC activation. Finally, we demonstrated that miR-155* and miR-155 were inversely regulated by autocrine/paracrine type I interferon and TLR7-activated KHSRP at the posttranscriptional level, which led to their different dynamic induction by TLR7. Thus, our study identified and validated novel miRNA-protein networks involved in regulating PDC activation.

Abstract: Micro-electro-mechanical systems (MEMS) are being developed as a new multi-disciplinary technology, which will undoubtedly have a revolutionary impact on the future of human life. However, with the development of MEMS technology, the packaging has become the main technical obstacle to the commercialization of MEMS. An approach to MEMS packaging by high-frequency electromagnetic induction heating at wafer level is presented in terms of numerical simulation and experimental study. The structure of inductor is firstly designed and optimized. Then the heating situation of PCB board is verified. The results indicate that the heat impact on the chip during the packaging process can be effectively reduced by local induction heating packaging, therefore the thermal stress on the chip is considerably lowered. This method can effectively improve the reliability of the MEMS devices.

The optical properties of YAG:Ce phosphor were measured by a double-integrating-sphere system and calculated by Mie theory and Monte Carlo ray tracing to provide precise optical characterizations of YAG:Ce phosphor for white light-emitting diode (LED) packaging design. Measurement results showed that the phosphor presents strong absorption for blue light, high reflection for yellow light, and an isotropic emission pattern of converted light. The conversion efficiency and quantum efficiency for the saturated phosphor are around 70% and 87%, respectively. Based on the measurement results, the absorption coefficient, scattering coefficient, and anisotropy factor of the phosphor calculated by Mie theory were compared with those calculated by ray-tracing simulation to modify Mie theory to find a reasonable method that can easily obtain the optical constants of YAG:Ce phosphor. Comparisons revealed that Mie theory can predict the variation of the optical constants of phosphor, but the absorption and scattering cross sections should be multiplied with two fitting parameters. The fitting parameters have been given in this study and can be obtained by testing packaged LEDs with different phosphor concentrations.

The inversion (Li and Mn interchanging sites) of cathode material LiMn2O4(LMO) on the battery capacity is studied from the perspective of Jahn–Teller distortion (JTD) and manganese dissolution. The LMO spinel in the orthorhombic structure with anti-ferromagnetic ordering is studied using spin-polarized density functional theory calculations with anisotropic (U– J) corrections. The charge orderings and magnetic moments of the orthorhombic LMO spinel at normal, half-inverse, and full-inverse structures are connected with the battery’s properties. It is found that the magnetic moments prefer high spin states in all the cases, and the JTD is mainly due to Mn3+. The existence of Mn3+at octahedral and tetrahedral sites in normal and full-inverse LMO spinel, respectively, induces strong JTD that will reduce the battery capacity. In half-inverse LMO spinel, the cubic-like phase with degraded JTD could retard the capacity decay of lithium-ion batteries, while the existence of MnA2+at the tetrahedral sites would aggravate the manganese dissolution and exacerbate the capacity decay. In all, inversion in LMO does not always have a negative effect on battery capacity as JTD and Mn2+manganese dissolution compete with each other.

Droplet bouncing on surfaces has long been observed in nature and industry, which is rather intriguing and instructive for related technology development. Recent decades have witnessed significant progress on the mechanism exploring, device development, and application demonstrations. In this review, we focus on the recent progresses that aim at introducing the phenomena, revealing the underlying physics, and promoting the potential applications of water droplet bouncing on various solid and soft surfaces like hydrophobic/hydrophilic/heated solid surfaces and liquid film/bath/droplet. The water droplet bouncing dynamics is highly dependent on the liquid properties, surface characteristics and ambient pressure. The absence of droplet/surface contact, as the key point for droplet bouncing, can be realized by lowering the Weber number of droplet and designing hydrophobic surfaces to reduce the droplet-surface contact, actively maintaining the air/vapor film by heating the solid surface above the Leidenfrost point, vibrating the liquid bath, applying electric/magnetic/pressure fields, etc. Moreover, the comprehensive understanding of droplet bouncing has promoted the development of numerous advanced surfaces technologies, including surface self-cleaning, directional droplet transportation, heat transfer enhancement, droplet logic gate, electrical generation and so on. Finally, the future directions for research and application are outlined and discussed.