Tsinghua University
  • Beijing, China
Recent publications
Neural interfaces play an important role in vital sign monitoring [1] , clinical practice [2] , and neuroscience frontier research [3] using animal subjects, such as rodents and nonhuman primates [4] , [5] . Recently, neuroscientists have shown increasing interest in behavioral analysis of social situations with a single or multiple freely moving animals, which has been listed as a key investment by the NIH in 2023 [6] . Among those popular laboratory animals, marmosets are increasingly favored by researchers because of their small size, short sexual maturity, complex social patterns, and similarity to human beings [7] , [8] . A number of marmoset social behaviors, such as gaze following [9] , antiphonal calling [10] , and scent marking [11] , have been studied with neural signal acquisition and/or stimulation to affect the behavior of the freely moving marmoset at the same time.
Revegetation is effective in improving soil quality in ecologically fragile areas. However, little is known about the impact of diverse phytomanagement strategies of tailings on soil quality and ecological security in erosion-prone areas. We investigated the water stability, soil aggregate nutrients, and the risk of heavy metal contamination of abandoned tailings under phytomanagement and in adjacent bare land on the Loess Plateau. The results showed that phytomanagement significantly enhanced soil aggregate stability, as demonstrated by higher contents of soil organic carbon (SOC), glomalin-related soil protein (GRSP), aromatic-C, and alkene-C in macro-aggregates. The pollution load index (PLI) and ecological risk index (RI) of soil heavy metals were lower in shrub/herbaceous mixed forests than in natural grasslands and planted forests. The risk of heavy metal contamination was higher in macro-aggregates (>0.25 mm) than in micro-aggregates (<0.25 mm) and was significantly and positively correlated with the SOC and GRSP contents of the aggregates. Our study demonstrates that soil aggregate quality is closely related to the fate of heavy metals. Diversified tailing revegetation measures can improve soil quality and ensure ecological security.
While many methods have been proposed to detect driver stress with high accuracy, few studies have explored how to mitigate stress during driving effectively. This study proposed and evaluated two driver stress intervention methods, i.e., auditory Positive Comments w/o haptic Breathing guidance (BPC and PC). Sixty drivers were randomly assigned to four groups (i.e., no stress, stressful but no intervention-NI, PC, and BPC) and completed a simulated driving task with their physiological, psychological, and behavioral data collected. Driver stress was effectively induced by challenging simulated driving events. Haptic guidance provided by smart-watches efficiently regulated the breathing rate to the target. Engaging in the intervention was associated with increased RMSSD and did not worsen driving performance. Participants perceived moderate to large comfort effects. The complexity of driving scenarios should be considered for choosing interventions. Breathing intervention was less effective when complex maneuvers were required than normal driving. The findings provided implications regarding the design of in-vehicle stress intervention systems for intelligent transportation.
Hypothesis: Surfactant-free microemulsion (SFME), an emerging phenomenology that occurs in the monophasic zone of a broad category of ternary mixtures 'hydrophobe/hydrotrope/water', has attracted extensive interests due to their unique physicochemical properties. The potential of this kind of ternary fluid for solubilization and drug delivery make them promising candidates in many industrial scenarios. Experiments: Here the thermodynamic behavior of these multiscale nanodomains formed in the ternary trans-anethol/ethanol/water system over a wide range of temperatures is explored. The macroscopic physical properties of the ternary solutions are characterized, with revealing the temperature dependence of refractive index and dynamic viscosity. Findings: With increasing temperature, the ternary system shows extended areas in the monophasic zone. We demonstrate that the phase behavior and the multiscale nanodomains formed in the monophasic zone can be precisely and reversibly tuned by altering the temperature. Increasing temperature can destroy the stability of the multiscale nanodomains in equilibrium, with an exponential decay in the scattering light intensity. Nevertheless, molecular-scale aggregates and mesoscopic droplets exhibit significantly different response behaviors to temperature stimuli. The temperature-sensitive nature of the ternary SFME system provides a crucial step forward exploring and industrializing its stability.
In emerging economies, a significant amount of secondary resources are recycled by the informal sector, which can seriously harm the environment. However, some previous studies of industry management policy design ignored geographical factors. This paper introduces Geographic Information Systems into an agent-based cross-regional recycling model, and employs lead-acid batteries as an example. The model quantitatively displays the evolution of recycling markets in 31 provinces in Mainland China. Results show that: (1) High subsidies can significantly increase the number of formal enterprises in the short term, but their effectiveness decreases when the proportion of government funds in subsidies is above 80% in the long run; (2) The number of illegal recycling enterprises increases by 294% in eight inland provinces (e.g., Ningxia, Xinjiang) when all funds are invested in supervision, but this number is quite small in subsidy policy scenarios; (3) In four eastern regions, including Beijing and Tianjin, the number of illegal recycling enterprises decreases by 84% if supervision is more favored than subsidy; (4) In the optimal case where spatiotemporal factors are considered in all 31 regions, illegal recycling enterprises and waste lead emissions can be reduced by 95.59% and 45.85% nationwide. Our proposed recycling model offers a detailed simulation of multiple regions and diverse stakeholders, and serves as a useful reference for targeted recovery policies. Governments in inland regions like Ningxia and Xinjiang should implement subsidy policies, while supervision policies should be implemented in developed regions like Beijing and Tianjin.
The classical Turing morphogenesis often occurs in non‐metallic solution systems due to the sole competition of reaction and diffusion processes. Here we conceived that gallium (Ga)‐based liquid metals possess the ability to alloy, diffuse, and react with a range of solid metals and thus should display Turing instability leading to a variety of nonequilibrium spatial concentration patterns. We disclosed a general mechanism for obtaining labyrinths, stripes, and spots‐like stationary Turing patterns in the liquid‐solid metal reaction‐diffusion systems (GaX‐Y), taking the gallium indium alloy and silver substrate (GaIn‐Ag) system as a proof of concept. It is only when Ga atoms diffuse over Y much faster than X while X reacts with Y preferentially, that Turing instability occurs. In such a metallic system, Ga serves as an inhibitor and X as an activator. The dominant factors in tuning the patterning process include temperature and concentration. Intermetallic compounds contained in the Turing patterns and their competitive reactions have also been further clarified. This liquid metal Turing instability mechanism opens many opportunities for constructing micro‐structure systems utilizing condensed matter to experimentally explore the general morphogenesis process. This article is protected by copyright. All rights reserved
Gel materials are appealing due to their diverse applications in biomedicine, soft electronics, sensors and actuators. Nevertheless, the existing synthetic gels are often plagued by feeble network structures and inherent defects associated with solvents, which compromise their mechanical load‐bearing capacity and cast persistent doubts about their reliability. Herein, combined with attractive deep eutectic solvent (DES), we have presented a stepwise‐enhanced strategy to fabricate ultra‐robust eutectogels. It focuses on the continuous modulation and optimization of polymer networks through complementary annealing and solvent exchange processes, which drives a progressive increase in both quantity and mass of the interconnected polymer chains at microscopic scale, hence contributing to the evolutionary enhancement of network structure. The resultant eutectogel exhibits superb mechanical properties, including record‐breaking strength (31.8 MPa), toughness (76.0 MJ m ⁻³ ), and Young's modulus (25.6 MPa), together with exceptional resistance ability to tear and crack propagation. Moreover, this eutectogel is able to be further programmed through photolithography to in‐situ create patterned eutectogel for imparting specific functionalities. Enhanced by its broad applicability to various DES combinations, this stepwise‐enhanced strategy is poised to serve as a crucial template and methodology for the future development of robust gels. This article is protected by copyright. All rights reserved
The manufacturing and assembly of components within cells have a direct impact on the sample performance. Conventional processes restrict the shapes, dimensions, and structures of the commercially available batteries. Three‐dimensional (3D) printing, a novel manufacturing process for precision and practicality, is expected to revolutionize the lithium battery industry owing to its advantages of customization, mechanization, and intelligence. This technique can be used to effectively construct intricate 3D structures that enhance the designability, integrity, and electrochemical performance of both liquid‐ and solid‐state lithium batteries. In this study, we provide an overview of the development of 3D printing technologies and assess their suitability for comparison with conventional printing processes. Various 3D printing technologies applicable to lithium‐ion batteries have been systematically introduced, especially more practical composite printing technologies. The practicality, limitations, and optimization of 3D printing are discussed dialectically for various battery modules, including electrodes, electrolytes, and functional architectures. In addition, all‐printed batteries are emphatically introduced. Finally, the prospects and challenges of 3D printing in the battery industry were evaluated. This article is protected by copyright. All rights reserved
Chiral B/N embedded multi‐resonance (MR) emitters open a new paradigm of circularly polarized (CP) organic light‐emitting diodes (OLEDs) owing to their unique narrowband spectra. However, pure‐red CP‐MR emitters and devices remain exclusive in literature. Herein, by introducing a B‐N covalent bond to lower the electron‐withdrawing ability of the para ‐positioned B‐π‐B motif, we developed the first pair of pure‐red double hetero ‐[n]helicenes (n = 6 and 7) CP‐MR emitter peaking 617 nm with a small full‐width at half‐maximum of 38 nm and a high photoluminescence quantum yield of ∼100% in toluene. The intense mirror‐image CP light produced by the enantiomers is characterized by high photoluminescence dissymmetry factors (g PL ) of +1.40/−1.41 × 10 ⁻³ from their stable helicenes configuration. The corresponding devices using these enantiomers afford impressive CP electroluminescence dissymmetry factors (g EL ) of +1.91/−1.77 × 10 ⁻³ , maximum external quantum efficiencies of 36.6%/34.4% and Commission Internationale de I’Éclairage coordinates of (0.67, 0.33), exactly satisfying the red‐color requirement specified by National Television Standards Committee (NTSC) standard. Notably a remarkable long LT95 (operational time to 95% of the initial luminance) of approximately 400 hours at an initial brightness of 10,000 cd m ⁻² is also observed for the same device, representing the most stable CP‐OLED up to date. This article is protected by copyright. All rights reserved
Lithium iron phosphate (LiFePO 4 , LFP) batteries have been extensively used in electric vehicles and energy storage due to their good cycling stability and safety. However, the finite service life of lithium‐ion batteries has led to significant amounts of retired LFP batteries, urgently required to be recycled by environmentally friendly and effective methods. Here, we propose a direct regeneration strategy using natural and low‐cost L‐threonine as a multifunctional reductant. The hydroxyl groups and amino groups in L‐threonine act as electron donors and nitrogen sources, respectively. The reductive environment created by L‐threonine not only aids in converting the degraded FePO 4 phase back to a single LFP phase, but also facilitates the elimination of detrimental Li‐Fe anti‐site defects, thus reconstructing fast Li ⁺ diffusion channels. Meanwhile, N atoms derived from amino groups are able to dope into carbon layers, generating more active sites and enhancing the conductive properties of LFP particles. The regenerated LFP shows great electrochemical performance with a discharge capacity of 147.9 mAh g ⁻¹ at 1 C rate and a capacity retention of 86% after 500 cycles at 5 C rate. Furthermore, this approach is also feasible for LFP black mass sourced from practical industrial dismantling lines, providing considerable prospects for the large‐scale practical application of LFP recycling. This article is protected by copyright. All rights reserved
Probiotics have the potential as biotherapeutic agents for cancer management in preclinical models and human trials by secreting antineoplastic or immunoregulatory agents in the tumor microenvironment. However, current probiotics lack the ability to dynamically respond to unique TME characteristics, leading to limited therapeutic accuracy and efficacy. Although progress has been made in customizing controllable probiotics through synthetic biology, the engineering process is complex and the predictability of production is relatively low. To address this, here, for the first time, we adopted pH‐dependent peroxidase‐like (POD‐like) artificial enzymes as both an inducible “nano‐promoter” and “nano‐effector” to engineer clinically relevant probiotics to achieve switchable control of probiotic therapy. The nanozyme initially serves as an inducible “nano‐promoter”, generating trace amounts of nonlethal reactive oxygen species (ROS) stress to upregulate acidic metabolites in probiotics. Once metabolites acidify the TME to a threshold, the nanozyme switches to a “nano‐effector”, producing a great deal of lethal ROS to fight cancer. This approach shows promise in subcutaneous, orthotopic, and colitis‐associated colorectal cancer tumors, offering a new methodology for modulating probiotic metabolism in a pathological environment. This article is protected by copyright. All rights reserved
Magnesium (Mg) alloys are considered as promising bone implant materials due to their natural degradability, good biocompatibility, and good mechanical properties. Therefore, magnesium alloys have received considerable attention in the field of orthopedic implants due to their superior comprehensive properties. In this study, we analyzed the basic information of the top 100 most frequently cited articles on mg alloy orthopedic implants that met the inclusion criteria in the WoS Core Collection database, and the VosViewer software was used for web visualization and keyword analysis. Through bibliometric and visual analysis, this article systematically introduces the research status of magnesium alloy orthopedic implants, discusses the advantages of magnesium and its alloys as orthopedic implants, and explores four strategies to improve corrosion performance, including purification, alloying treatment, surface coating and Mg-based metal matrix composites (MMC). In addition, this paper revealed the future research focus in this field.
License plate recognition is an important technology in many application scenarios such as traffic monitoring and vehicle management. Due to variations of viewpoint, illumination, motion-blur, and degradation in imaging process, it is still a challenging problem to detect and recognize license plates in low quality video images. In this paper, we focus on efficient deep representation learning for license plate recognition, detection and tracking. For license plate recognition, we mainly investigate the configuration of different network structures, and propose to use a network structure with a Convolutional Neural Network (CNN) backbone, an Long Short-Term Memory (LSTM) encoder and a Transformer decoder. For license plate detection, a Transformer encoder-decoder based method is adopted. For license plate tracking, a multi-object tracking method is incorporated by using Kalman filtering and temporal matching to associate detected license plates in video frames. Experiments are carried out on the public large-scale video-based license plate dataset (LSV-LP) to validate the proposed methods.
Owing to the advancement of interdisciplinary concepts, for example, wearable electronics, bioelectronics, and intelligent sensing, during the microelectronics industrial revolution, nowadays, extensively mature wearable sensing devices have become new favorites in the noninvasive human healthcare industry. The combination of wearable sensing devices with bionics is driving frontier developments in various fields, such as personalized medical monitoring and flexible electronics, due to the superior biocompatibilities and diverse sensing mechanisms. It is noticed that the integration of desired functions into wearable device materials can be realized by grafting biomimetic intelligence. Therefore, herein, the mechanism by which biomimetic materials satisfy and further enhance system functionality is reviewed. Next, wearable artificial sensory systems that integrate biomimetic sensing into portable sensing devices are introduced, which have received significant attention from the industry owing to their novel sensing approaches and portabilities. To address the limitations encountered by important signal and data units in biomimetic wearable sensing systems, two paths forward are identified and current challenges and opportunities are presented in this field. In summary, this review provides a further comprehensive understanding of the development of biomimetic wearable sensing devices from both breadth and depth perspectives, offering valuable guidance for future research and application expansion of these devices.
The treatment of organic wastewater is of great significance. Carbon nanotube (CNT)/graphene‐based nanomaterials have great potential as absorbent materials for organic wastewater treatment owing to their high specific surface area, mesoporous structure, tunable surface properties, and high chemical stability; these attributes allow them to endure harsh wastewater conditions, such as acidic, basic, and salty conditions at high concentrations or at high temperatures. Although a substantial amount of work has been reported on the performance of CNT/graphene‐based nanomaterials in organic wastewater systems, engineering challenges still exist for their practical application. Herein, the adsorption mechanism of CNT‐ and graphene‐based nanomaterials is summarized, including the adsorption mechanism of CNTs and graphene at the atomic and molecular levels, their hydrophilic and hydrophobic surface properties, and the structure–property relationship required for adsorption to occur. Second, the structural modification and recombination methods of CNT‐ and graphene‐based adsorbents for various organic wastewater systems are introduced. Third, the engineering challenges, including the molding of macroscopically stable adsorbents, adsorption isotherm models and adsorption kinetic behaviors, and reversible adsorption performance compared to that of activated carbon (AC) are discussed. Finally, cost issues are discussed in light of scalable and practical application of these materials. The carbon nanotube (CNT)/graphene‐based nanomaterials have great potential as absorbent materials for organic wastewater treatment. The combination of new adsorption materials and traditional adsorption and desorption equipment and technologies will greatly shorten the industrialization process of new materials. Promoting the practical application of new materials will bring new vitality to the field of wastewater treatment.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
35,785 members
Jun Xu
  • Department of Chemical Engineering
Alexander Kovalev
  • Department of Engineering Mechanics
Bin Zhao
  • Department of Building Science, School of Architecture
Zheng Yao
  • Department of Electronic Engineering
Qinghua Yuan #1, 100084, Beijing, China
Head of institution
Yong Qiu