科研成果

Flexible electronic devices have shown increasingly promising value facilitating our daily lives. However, flexible spintronic devices remain in their infancy. Here, this research demonstrates a type of nonvolatile, low power dissipation, and programmable flexible spin logic device, which is based on the spin-orbit torque in polyimide (PI)/Ta/Pt/Co/Pt heterostructures fabricated via capillary-assisted electrochemical delamination. The magnetization switching ratio is shown to be about 50% for the flexible device and does not change after 100 cycles of bending, indicating the device has stable performance. By designing the path of pulse current, five Boolean logic gates AND, NAND, NOT, NOR, and OR can be realized in an integrated two-element device. Moreover, such peeling-off devices can be successfully transferred to almost any substrate, such as paper and human skin, and maintain high performance. The flexible PI/Ta/Pt/Co/Pt spin logic device serves as logic-in-memory architecture and can be used in wearable electronics.

China has made great efforts in industrial pollution control, but for the different industrial sectors under various development stages, it is not so clear whether there is synergistic effects among them, and how it changes with the environmental policies. This study filled this knowledge gap by comiling the China Industrial Economic and Pollutant Emission data (WatSim-CIEPE) using 1.28 million individual enterprise data. The results demonstrated a power function decreasing trend for the emission per unit output value. The load reduction at different stages had synergic effects, and coastal cities reached the inflection point earlier. There is a completely opposite pattern between pollutant emission and GIOV in spatial evolution, mainly because the chemical and metal sectors with high pollutant emissions and low GIOV migrated to western China. The year gap between the implementation of the national development strategy and the break-point of gravity center variation of GIOV indicates a hysteresis effect for the influence of development policies. There may be three risks in China's industrial pollution control: (a) NH pollution gets serious in the western regions; (b) the food sector may become a new dominant pollution source; (c) the imbalance between industrial development and pollution control may further aggravate.

Floristic regions reflect the geographic organization of floras and provide essential tools for biological studies. Previous global floristic regions are generally based on floristic endemism, lacking a phylogenetic consideration that captures floristic evolution. Moreover, the contribution of tectonic dynamics and historical and current climate to the division of floristic regions remains unknown. Here, by integrating global distributions and a phylogeny of 12,664 angiosperm genera, we update global floristic regions and explore their temporal changes. Eight floristic realms and 16 nested sub-realms are identified. The previously-defined Holarctic, Neotropical and Australian realms are recognized, but Paleotropical, Antarctic and Cape realms are not. Most realms have formed since Paleogene. Geographic isolation induced by plate tectonics dominates the formation of floristic realms, while current/historical climate has little contribution. Our study demonstrates the necessity of integrating distributions and phylogenies in regionalizing floristic realms and the interplay of macroevolutionary and paleogeographic processes in shaping regional floras.

The wastewater treatment plant (WWTP) effluent discharge affects the microorganisms in the receiving water bodies. Despite the ecological significance of microbial communities in pollutant degradation and element cycling, how the community diversity is affected by effluent remains obscure. Here, we compared the sediment bacterial communities exposed to different intensities of WWTP effluent discharge in Hangzhou Bay, China: i) a severely polluted area that receives effluent from an industrial WWTP, ii) a moderately polluted area that receives effluent from a municipal WWTP, and iii) less affected area that inner the bay. We found that the sediment bacterial diversity decreased dramatically with pollution levels of inorganic nutrients, heavy metals, and organic halogens. Microbial community assembly model analysis revealed increased environmental selection and decreased species migration rate in the severely polluted area, resulting in high phylogenetic clustering of the bacterial communities. The ecological networks were less complex in the two WWTP effluent receiving areas than in the inner bay area, as suggested by the smaller network size and lower modularity. Fewer negative network associations were detected in the severely (6.7%) and moderately (8.3%) polluted areas than in the less affected area (16.7%), indicating more collaborative inter-species behaviors are required under stressful environmental conditions. Overall, our results reveal the fundamental impacts of WWTP effluents on the ecological processes shaping coastal microbial communities and point to the potential adverse effects of diversity loss on ecosystem functions.

Sign language recognition is of great significance to connect the hearing/speech impaired and non-sign language communities. Compared to isolated word recognition, sentence recognition is more practical in real-world scenarios, but is also more complicated because continuous, high-quality sign data with distinct features must be collected and isolated signs must be identified with high accuracy. Here, we propose a wearable sign language recognition system enabled by a convolutional neural network (CNN) that integrates stretchable strain sensors and inertial measurement units attached to the body to perceive hand postures and movement trajectories. Forty-eight Chinese sign language words commonly used in daily life were collected and used to train the CNN model, and an isolated sign language word recognition accuracy of 95.85% was achieved. For sentence-level sign language recognition, we proposed a method that combines multiple sliding windows and uses correlation analysis to improve the CNN recognition performance, achieving a correct rate of 84% for 50 sign language sentence samples, showing good extendibility.

Purpose The study aims to investigate the relationship between chief executive officers' (CEOs') prenatal testosterone exposure, absorptive capacity and e-commerce adoption by small and medium-sized enterprises (SMEs). Design/methodology/approach Based on a study of 1,519 SMEs led by a male CEO in China, the impact of entrepreneur's digital ratio on e-commerce adoption is empirically analyzed through a multivariate logistic model. Findings The results show that the second-to-fourth digit ratio (2D:4D), a reverse measurement of prenatal testosterone exposure, is negatively correlated with the adoption of e-commerce by SMEs. This evidence suggests that CEOs with high prenatal testosterone exposure have a higher probability of adopting e-commerce. In addition, this research indicates a positive correlation between absorptive capacity, which is defined by market innovation, process innovation and marketing innovation, and the adoption of e-commerce by SMEs. Originality/value This research can contribute to the discussion by providing new insights into the antecedents of the adoption of e-commerce in SMEs.

In China, rangeland fragmentation leads to the problems of anticommons, in terms of livestock production and ecological conditions. As the countermeasure, rangeland use right transfer has been encouraged by the governments recently, which aims to integrate the fragmented rangelands by lease. Can transfer overcome the problems of anticommons? We addressed this question through a case study in Inner Mongolia, by comparing livelihoods and ecological conditions between the households with lease-in pastures and those without practicing transfer. We found that though transfer could make the livelihoods of lease-in households with larger rangeland better-off in weather good years, but worse-off in drought years; and the over grazing was intensified on the transferred pastures. We concluded that the transfer may not be able to fundamentally overcome the problems of anticommons. We argued that spatial anticommons and right anticommons are interrelated to each other, rather than two juxtaposed types as defined by anticommons scholars.

The massification of higher education has dramatically changed the association between credentials and jobs in advanced countries, while its impacts in transitional economies have received less academic attention. To address this research lacuna, the paper utilizes rich information from China’s national surveys of college graduates from 2003 to 2019 and multiple waves of census data to explore the temporal and spatial effects of tertiary education expansion on college graduates’ job sorting. Regression results from the fixed effects model and the two-stage least-squares model indicate that, on the temporal dimension, the higher education expansion has weakened ties between college credentials and quality jobs over the past 20 years. Recent graduates are more likely to work in informal, non-urban, and non-public sectors, and the college earnings premium has also declined. There is a persistent gap in employment outcomes between bachelor’s and associate degree holders. On the spatial dimension, the growing enrolment size leads to skill sorting towards low skilled regions. The study argues that the dynamic effects of college credentials may be explained by labour market flexibility and cohort crowding after higher education expansion. This paper calls for a critical reflection on the merit of further massification of higher education in developing economies, regarding its potential impacts on intergenerational inequality and regional inequality.