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A growing body of literature has attempted to understand the social integration of rural migrants in Chinese cities, and specifically patterns and determinants of migrant settlement intention. However, few studies have directly investigated the role of housing access in migrant settlement in cities. Based on a 12-city migrant survey conducted in 2009, this paper adopts the structural equation modelling approach to delineate the causal relationship between housing access and migrant settlement intention.We found a positive correlation between access to formal housing and stronger settlement intention, but such relationship was more attributed to a sorting process in which rural migrants who are more willing to settle down strive to expand their access to formal housing. Meanwhile, controlling for sociodemographic variables, sociocultural attachment factors are more significant predictors of migrant settlement intention than economic opportunities and achievements. These findings imply the necessity of a combination of affordable housing policy and other social policy measures if the government hopes to achieve the goal of boosting permanent settlement of rural migrants in cities and towns.

Infrared polarization-sensitive photodetectors have attracted considerable interest for night vision, remote sensing and imaging applications. Traditional bulk infrared photodetectors suffer from integration challenges and high-power consumption induced by the cryogenic cooling requirement. Here, we demonstrate a tunneling-dominant triple-junction broadband polarization-sensitive photodetector based on a van der Waals heterostructure, operating from the near-infrared (NIR) to the long-wave infrared (LWIR) band. The device exhibits low noise current, low power consumption and high detectivity. Benefiting from the photogating-assisted tunneling, it reaches a responsivity of ~ 8 × 10 4  A/W and a response speed of 590 ns under NIR illumination. Apparent blackbody response and high photoresponse up to 10.6 μm is achieved with a room temperature responsivity and detectivity of 0.47 A/W and over 10 9 Jones. Remarkably, bias-tunable polarization detection capability and high polarization ratios are observed from NIR to LWIR, which further boost target detection and imaging capabilities. Our results offer a promising approach for multidimensional imaging applications and device miniaturization. Conventional bulk infrared detectors usually operate at cryogenic temperatures, leading to high power consumption. Here, the authors report high-performance polarization-sensitive photodetectors based on MoSe 2 /PdSe 2 heterostructures, operating from the near- to the long-wave infrared band at room temperature.

Background Social isolation and loneliness have detrimental impacts on health, especially for older adults. During the COVID-19 pandemic, physical access to third places (e.g., coffee shops, libraries) decreased due to the closure of non-essential destinations and personal risk assessments. Older adults reported adopting information and communication technology (ICT) during pandemic lockdowns. ICT-mediated socializing may have different impacts on loneliness than in-person equivalents. Understanding access to social connection and their distinct relationships to the built environment and health for older Chinese migrants is critical to supporting equitable, healthy aging in a post-COVID world. Methods Using a survey of older Chinese migrants in the Greater Toronto Area (GTA) during the extended COVID-19 lockdown, we investigate how community mobility and ICT use, two mechanisms of socializing, relate to the built environment and influence loneliness (De Jong Gierveld 6-item scale), as well as mental and physical health (SF-12). Specifically, we use a structural equation model to test a theoretical framework of older adult social isolation. Results Our model demonstrates the importance of community mobility for reducing feelings of loneliness, while ICT use is significantly related to better physical health. Both community mobility and ICT use have significant, although opposite, relationships to transit density. Conclusions Results indicate that ICT use might have limited ability to reduce loneliness and support mental health when mobility is limited. Addressing older migrants’ barriers to community mobility is critical to reducing feelings of loneliness.

Polarization is an important attribute of light and can be artificially modulated as a versatile information carrier. Conventional polarization-sensitive photodetection relies on a combination of polarizing optical elements and standard photodetectors, which requires a substantial amount of space and manufacturing expenses. Although on-chip polarized photodetectors have been realized in recent years based on two-dimensional (2D) materials with low-symmetry crystal structures, they are limited by the intrinsic anisotropic property and thus the optional range of materials, the operation wavelength, and more importantly, the low anisotropic ratio, hindering their practical applications. In this work, we construct a versatile platform that transcends the constraints of material anisotropy, by integrating WSe 2 -based photodetector with MoS 2 -based field-effect transistor, delivering high-performance broadband polarization detection capability with orders of magnitude improvement in anisotropic ratio and on/off ratio. The polarization arises from hot electron injection caused by the plasmonic metal electrode and is amplified by the transistor to raise the anisotropic ratio from 2 to an impressive value over 60 in the infrared (IR) band, reaching the level of existing applications. Meanwhile, the system achieves a significant improvement in photosensitivity, with an on/off ratio of over 10 3 in the IR band. Based on the above performance optimization, we demonstrated its polarization-modulated IR optical communication ability and polarized artificial vision applications with a high image recognition accuracy of ~99%. The proposed platform provides a promising route for the development of the long-sought minimized, high-performance, multifunctional optoelectronic systems. A versatile polarization detection platform that surpasses the limitation of material anisotropy is demonstrated for optical communication and artificial vision with a high polarization ratio.

Neuromorphic computing vision is the most promising technological solution to overcome the arithmetic bottleneck in machine vision applications. All-in-one neuromorphic sensors have been attracting increased attention because they can integrate visual perception, processing, and memory functionalities into one single device. However, the limited responsivity and data retention time of all-in-one neuromorphic sensors usually hinder their potential in multispectral machine vision, especially in the near-infrared (NIR) band which contains critical information for pattern recognition. Here, we demonstrate physisorption-assistant optoelectronic synaptic transistors based on Ta 2 NiSe 5 /SnS 2 heterojunction, which present tunable synaptic functionality in broadband (375–1310 nm). We propose a strategy about the physisorption-assistant persistent photoconductivity (PAPPC) effect to effectively solve the problem in detecting and storing the NIR light information. Under this strategy, the responsivity and data retention time of our devices were significantly enhanced and prolonged in broadband from 375 to 1310 nm. Further, the devices realize multilevel non-volatile optoelectronic memory through the modulation of several optical and back-gate signals to simulate emotion-controlled learning and memory processes, optical writing-electric erasing, and associative learning. Moreover, we developed a simplified human visual system to simulate color-cognitive perception and memory functions. Our approach offers a route for creating advanced all-in-one neuromorphic sensors and developing neuromorphic computing vision.

The inoculation method of grain refinement is widely used in research and industry. Because of its commercial and engineering importance, extensive research on the mechanisms/theories of grain refinement and development of effective grain refiners for diverse cast metals/alloys has been conducted. In 1999, Easton and St. John reviewed the mechanisms of grain refinement of cast Al alloys. Since then, grain refinement in alloys of Al, Mg, Fe, Ti, Cu, and Zn has evolved a lot. However, there is still no full consensus on the mechanisms/theories of grain refinement. Moreover, some new grain refiners developed based on the theories do not ensure efficient grain refinement. Thus, the factors that contribute to grain refinement are still not fully understood. Clarification of the prerequisite issues that occur in grain refinement is required using recent theories. This review covers multiple metals/alloys and developments in grain refinement from the last twenty years. The characteristics of effective grain refiners are considered from four perspectives: effective particle/matrix wetting configuration, sufficiently powerful segregating elements, preferential crystallographic matching, and geometrical features of effective nucleants. Then, recent mechanisms/theories on the grain refinement of cast metals/alloys are reviewed, including the peritectic-related, hypernucleation, inert nucleant, and constitutional supercooling-driven theories. Further, developments of deterministic and probabilistic modeling and nucleation crystallography in the grain refinement of cast metals are reviewed. Finally, the latest progress in the grain refinement of cast Zn and its alloys is described, and future work on grain refinement is summarized.

A scalable ultrasound-assisted direct-chill casting technique was used to manufacture ultra-large 2219 Al alloy ingots (1250 mm in diameter; 2700 mm in net length). Following industrial ultrasonic casting experiments, three fundamental aspects of the resulting alloy were investigated: the microstructural refinement, the macro- and microsegregation mediation at different length scales, and the modification of eutectic skeletons and intermetallic compounds. This work presents new insights regarding the manufacture of ultra-large metallic ingots for special industrial applications.Graphical Abstract

Path following and obstacle avoidances are used in heading control and path replanning for unmanned surface vessels (USVs), which have attracted the interest of many researchers over the years. This paper investigates the path-following and obstacle avoidance problems for USVs. First, on the basis of the current position and desired path, an adaptive line-of-sight (ALOS) algorithm is used to obtain the desired heading angle, and the sideslip angle compensation is considered. Then, to ensure that the USV follows the desired path. Model predictive control (MPC) is used to reduce the lateral error. The event-triggered mechanism (ETM) strategy is utilized to reduce the computational cost of MPC. Moreover, to obtain accurate state quantities in real time, a linear extended state observer (LESO) is used to counteract the effects of external disturbances and the nonlinear term of the model. Furthermore, an improved obstacle avoidance algorithm based on the geometric relationship is proposed. This method can better ensure USV navigation safety and reduce consumption and computation. Lastly, multiple simulation experiments illustrate that the algorithm improves the path-following capability and security and ensures smooth input changes by setting input constraints. Therefore, the designed controller has better feasibility and robustness.

Background: Mycoplasma pneumoniae pneumonia (MPP) is a common community-acquired pneumonia in children. Increasing drug resistance highlights the need for more effective treatments with fewer side effects. The Qingfei Tongluo Jiedu formula (QTJD) has demonstrated clinical efficacy against MPP; however, its underlying mechanisms remain unclear. This study aimed to explore the mechanism of QTJD on MPP using network pharmacology and in vitro experiments. Methods: Network pharmacology was used to identify the active compounds and signaling pathways of QTJD in MPP. QTJD-containing serum was prepared, and primary mouse lung and bone marrow cells were isolated to examine the effects of QTJD on macrophage polarization through butyric acid. Cell viability assays, flow cytometry, and quantitative reverse transcription-polymerase chain reaction were performed. GPR109−/− cells were used to confirm the receptor mediating butyric acid’s action, and Western blotting was employed to assess the MAPK signaling pathway. Results: QTJD promoted macrophage polarization and alleviated the inflammatory response caused by Mycoplasma pneumoniae. High-performance liquid chromatography-electrospray ionization mass spectrometry combined with network pharmacology identified 20 active compounds. Protein-protein interaction analysis revealed 10 core target, including JUN and Tumor Necrosis Factor (TNF), while enrichment analysis highlighted pathways such as Mitogen-Activated Protein Kinase (MAPK) and Phosphoinositide 3-Kinase-Protein Kinase B. Experimental validation demonstrated that QTJD reduced M1 markers (CD86, CXCL10) by increasing butyrate levels (p < 0.01) and enhanced M2 markers (CD206, Arg-1, MRC-1), promoting M2 polarization. QTJD inhibited ERK1/2, p38, and JNK1/2 (p < 0.01). In GPR109A−/− mice macrophages, QTJD suppressed p38 and JNK1/2 (p < 0.01) but showed no effect on ERK1/2 (p > 0.05), confirming involvement of the butyrate-GPR109A-MAPK pathway. Conclusions: QTJD effectively alleviates MPP by regulating macrophage polarization through the butyrate-GPR109A-MAPK pathway. Future studies should explore how QTJD modulates pulmonary immunity through gut microbiota and butyrate production and elucidate its immunoregulatory mechanisms along the gut-lung axis using multi-omics approaches.

Organic-inorganic hybrid metal halide perovskites (MHPs) have attracted tremendous attention for optoelectronic applications. The long photocarrier lifetime and moderate carrier mobility have been proposed as results of the large polaron formation in MHPs. However, it is challenging to measure the effective mass and carrier scattering parameters of the photogenerated large polarons in the ultrafast carrier recombination dynamics. Here, we show, in a one-step spectroscopic method, that the optical-pump and terahertz-electromagnetic probe (OPTP) technique allows us to access the nature of interplay of photoexcited unbound charge carriers and optical phonons in polycrystalline CH3NH3PbI3 (MAPbI3) of about 10 μm grain size. Firstly, we demonstrate a direct spectral evidence of the large polarons in polycrystalline MAPbI3. Using the Drude–Smith–Lorentz model along with the Frӧhlich-type electron-phonon (e-ph) coupling, we determine the effective mass and scattering parameters of photogenerated polaronic carriers. We discover that the resulting moderate polaronic carrier mobility is mainly influenced by the enhanced carrier scattering, rather than the polaron mass enhancement. While, the formation of large polarons in MAPbI3 polycrystalline grains results in a long charge carrier lifetime at room temperature. Our results provide crucial information about the photo-physics of MAPbI3 and are indispensable for optoelectronic device development with better performance.Ultrafast terahertz conductivity spectroscopy reveals the formation of large polarons in CH3NH3PbI3, which protects the charge carriers from scattering with polycrystalline grain boundaries or defects and explains the long lifetime.