This paper summarizes the transmission chain of "digital finance-financing constraint-firm innovation" at the theoretical and practical levels, incorporates digital finance into the empirical ...analysis framework of firm innovation, selects the data of Chinese GEM(Growth Enterprise Market)-listed companies from 2011 to 2020, and matches the data of the digital inclusive finance index. The paper empirically examines the incentive effect and impact mechanism of digital finance on SME innovation through the two-way fixed-effects model and mediated-effects model by matching the data of China GEM-listed companies from 2011 to 2020 with the digital financial inclusion index data. The findings show that the digital development and promotion of digital finance play a significantly positive impact in helping SMEs innovate and stimulate innovation. The effect is realized by alleviating corporate financing constraints. Further, digital finance has different incentive effects on enterprises with varying rights of property nature, as well as on other regions.
Reverse water gas shift（RWGS） reaction can be served as a pivotal stage of transitioning the abundant CO2 resource into chemicals or hydrocarbon fuels, which is attractive for the CO2 utilization and ...of eventually significance in enabling a rebuilt ecological system for unconventional fuels. This concept is appealing when the process is considered as a solution for the storage of renewable energy, which may also find a variety of potential end uses for the outer space exploration. However, a big challenge to this issue is the rational design of high temperature endurable RWGS catalysts with desirable CO product selectivity. In this work, we present a comprehensive overview of recent publications on this research topic,mainly focusing on the catalytic performance of RWGS reaction over three major kinds of heterogeneous catalysts, including supported metal catalysts, mixed oxide catalysts and transition metal carbides. The reaction thermodynamic analysis, kinetics and mechanisms are also described in detail. The present review attempts to provide a general guideline about the construction of well-performed heterogeneous catalysts for the RWGS reaction, as well as discussing the challenges and further prospects of this process.
Earthquakes act as a dominant trigger for failure of slopes in seismic active regions. In this study, a seismic stability analysis of a three-dimensional (3D) rock slope in Hoek–Brown media is ...conducted based on the limit analysis method. The energy balance equation is derived by equating the external work rate by rock mass weight and seismic forces to the internal energy dissipation rate, and an optimization code is then programmed to capture the optimized factor of safety (FoS) of a 3D rock slope based on the strength reduction technique. The validity of the equivalent Mohr–Coulomb parameters method and generalized tangent technique in conjunction with the limit analysis method to estimate FoS of a 3D rock slope is investigated. Subsequently, a quasi-static method is used to explore the effect of seismic forces on stability of a 3D rock slope. The results of the parametric analysis indicate that the seismic force exhibits significant negative effects on the stability of a 3D slope and that a significant difference exists between a 3D FoS solution and a solution obtained under two-dimensional (2D) plane strain. A stability chart analysis is performed to produce a set of seismic stability charts for preliminary design purposes. Finally, a case study is performed to apply stability charts in practical situations.
An extended guided crowd dynamics model is proposed to investigate the guide optimization during emergency evacuation. The initial assignment scheme for guides based on clustering algorithm, taking ...the numbers of both informed and uninformed pedestrians into consideration, is studied. The guide choice method for informed followers based on an exponent model, considering the distance to the guide and the follower quantity, is further investigated. On the basis of the modeling method of this paper, evacuation behavior dynamics under guides is explored, from which the leading role of guides can be clearly observed. The effects of guide quantity, parameter in the guide choice method and the size of visual field on evacuations are analyzed. Simulation results indicate that the evacuation efficiency gradually increases with the increase of guide quantity until it reaches a certain level, and the optimal number of guides is closely related to the initial distribution of pedestrians. The combination of density factor and distance factor with a reasonable proportion when determining which guide is very necessary. Pedestrians have stronger evacuation ability within a certain period of time when continuously increasing their visual radii. The study can provide theoretical suggestions for guiding pedestrian evacuation under emergencies.
Mn2+-doped ZnSe nanocrystals (Mn:ZnSe d-dots) with high optical qualityhigh dopant emission quantum yield with monoexponential dopant-emission decay dynamicsenable systematic and quantitative ...studies of temperature- and Mn2+ concentration-dependent optical properties of the dopant emission, especially its relationship with magnetic coupling. While temperature-dependent steady-state and transient dopant emission of d-dots with dilute Mn2+ concentrations originated from isolated Mn2+ ions, and can be quantitatively treated as a result of exciton–phonon coupling of isolated paramagnetic emission centers. Dopant emission of d-dots with high Mn2+ concentrations (up to 50% of Zn2+ ions being replaced by Mn2+ ions in the core nanocrystals) are found solely related to magnetically coupled Mn2+ emission. Magnetic coupling effects on steady-state dopant emission of d-dots with high Mn2+ concentrations are much stronger than those observed for doped bulk semiconductors, which is found to follow a strong and universe shell-thickness dependence for the epitaxial ZnSe and/or ZnS shells of the d-dots. By exciting the magnetically coupled Mn2+ ions directly, dopant-emission of d-dots with high Mn2+ concentrations exhibit monoexponential decay dynamics. In addition to this emission channel, a minor channel with slightly longer decay lifetime appears when the host nanocrystals with high Mn2+ concentrations are excited, which is barely visible at room temperature and increases its fraction by decreasing temperature.
The activity of Fischer–Tropsch synthesis (FTS) can be promoted by the reducible oxides, while their role remains elusive. Here, the authors reveal that, by varying the reduction condition to ...regulate the TiO x overlayer on Ru nanocatalysts, the TiOx overlayer participate in the C–O bond dissociation.
Abstract
The activity of Fischer–Tropsch synthesis (FTS) on metal-based nanocatalysts can be greatly promoted by the support of reducible oxides, while the role of support remains elusive. Herein, by ...varying the reduction condition to regulate the TiO
x
overlayer on Ru nanocatalysts, the reactivity of Ru/TiO
2
nanocatalysts can be differentially modulated. The activity in FTS shows a volcano-like trend with increasing reduction temperature from 200 to 600 °C. Such a variation of activity is characterized to be related to the activation of CO on the TiO
x
overlayer at Ru/TiO
2
interfaces. Further theoretical calculations suggest that the formation of reduced TiO
x
occurs facilely on the Ru surface, and it involves in the catalytic mechanism of FTS to facilitate the CO bond cleavage kinetically. This study provides a deep insight on the mechanism of TiO
x
overlayer in FTS, and offers an effective approach to tuning catalytic reactivity of metal nanocatalysts on reducible oxides.
Polycystic ovary syndrome (PCOS) represents an endocrine disorder, which is closely related with gut microbiota. Inulin, a kind of probiotics, has been proven to alleviate gut microbiota dysbiosis. ...Metformin, a biguanide agent, shows beneficial effects on chronic metabolic diseases. Our objective was to assess the effects and associated mechanisms of inulin and metforin on attenuation of PCOS in mice. Mice were divided into 4 groups: control group (CON), model group (MOD), inulin group (INU), metformin group (MET). The last three groups were fed 6 mg of dehydroepiandrosterone (DHEA) per 100 g body weight and 60% high-fat diet to generate mice model. After 21 days of intervention, mice were euthanized and associated indications were investigated. Body weight (BW) and testosterone (T) levels were significantly decreased, but estradiol (E2) levels were increased in INU or MET group, respectively. Ovary HE staining demonstrated that inulin or metformin ameliorated PCOS morphology. Inflammatory indicators from plasma and ovary including TNF-α, IL-6, and IL-17A were decreased in INU or MET group. Moreover, IL-10 in ovary of INU or MET group was increased. Sequencing and analysis of gut microbiota showed that compared to MOD group, Bifidobacterium was increased, but Proteobacteria, Helicobacter and Parasutterella were decreased in INU group. Helicobacter was decreased in MET group. Correlation analysis showed that gut microbiota was correlated with inflammatory factors. Our results revealed that inulin and metformin alleviated PCOS via anti-inflammation and modulating gut microbiota, which may contribute to potential clinical therapy for the disease.
How human activities have altered hydrological droughts (streamflow deficits) in China during the past five decades (1961–2016) is investigated using the latest version (v2.0) of PCR‐GLOBWB model at ...high spatial resolution (~10 km). Although both human activities and climate variability have significant effects on river flows over China, there are large regional north‐south contrasts. Over northern China, human activities generally intensify hydrological droughts. We find that human activities exacerbated drought deficit by about 70–200% from 2004 to 2015. In contrast, droughts over southern China are generally alleviated by human activities. For instance, irrigation and water management (such as reservoir operation and water ion) increase drought StDef (standardized drought deficit volume) by about 80% in the Yellow River (north) but reduce it by about 20% in the Yangtze River (south). Human activities slightly reduce drought deficit in the Yangtze River due to the combination of large reservoir storage and low ratio of agriculture consumption to ed irrigation water. In contrast, hydrological drought is aggravated in the semiarid Yellow River basin because of high water consumption from agricultural sectors. This study suggests that human activities have contrasting influences on hydrological drought characteristics in the northern (intensification) and southern (mitigation) parts of China. Therefore, it is critical to consider the variable roles of human activities on hydrological drought in China when developing mitigation and adaptation strategies.
Plain Language Summary
China faces unprecedented challenges for water resources management under a changing climate, which is expected to lead to more frequent and severe droughts in the future. Of particular importance is streamflow drought, which jeopardizes regional water supply and local ecosystem services. On one hand, human activities through reservoir operation can effectively alleviate drought by releasing water during the low flow period. But on the other hand, water ion to meet sectoral water demand (such as irrigation) could exacerbate the streamflow deficit. To what extent such human activities differ across regions is not clear. In this study, we use a physically based hydrological and water resources model to investigate how human activities have altered streamflow droughts in China during the past five decades (1961–2016). We find that human activities generally alleviate streamflow droughts in the southern region (e.g., Yangtze River) but intensify them in the northern part of China (e.g., Yellow River). Our research highlights the contrasting geographical differences of human influences on hydrological drought across China, which can be useful for making more effective drought adaptation strategies.
Key Points
We used the PCR‐GLOBWB model at high spatial resolution to investigate the effects of human activities on hydrological drought over China
Influences of human activities on hydrological drought characteristics have a strong and contrasting north‐south gradient
Reservoir operation, water ion, and irrigation increase drought deficit in the Yellow River but reduce it in the Yangtze River
With the proposal of the Belt and Road Initiative, Hainan has witnessed a great development opportunity. This article analyzes the importance of Hainan in the Belt and Road Initiative from the ...perspectives of history, location and culture. Based on the prop position of tourism industry in Hainan’s economy, it puts forward that trade in tourism service should be considered as an important joint point for the construction of “One Belt, One Road”. Countermeasures and suggestions for the development of trade in tourism service in Hainan are put forward combined with the strategic background of “One Belt, One Road”.
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