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•The formation of Schottky barrier in MONC-3 can inhibit the backflow of electrons.•MONC-3 can convert the absorbed light energy into local high temperature.•Photodynamic and ...photothermal effects synergistically lead to bacterial death.•DFT calculation clarifies the charge transfer mechanism in Schottky heterojunction.
Developing green and highly efficient water disinfection technique is of great importance to public health. Herein, a near-infrared (NIR) light-triggerable thermo-sensitive defective molybdenum oxide-nitrogen doped carbon (MoO3-x/NCNs) composite was fabricated and applied to water disinfection. With the synergy of photodynamic and photothermal effects, the MoO3-x/NCNs achieve a rapid and effective inactivation of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared to photocatalytic treatment or thermal catalytic alone. Particularly, MONC-3 with optimal ratio can completely inactivate 7.6 log of E. coli and S. aureus within 60 min and 100 min, respectively. The MONC-3 hybrid exhibits efficient charge separation and migration ability due to the formation of Schottky heterojunction, resulting in the highly enhanced O2− (11.34 × 10−10 M) generation activity. Meanwhile, excellent NIR light absorption and photothermal conversion efficiency (52.6%) of MONC-3 can generate local high temperature to promote photocatalytic reaction rate and destruct the bacterial integrity. The monitoring of cell damage process confirmed the irreversible death of bacteria. Based on density functional theory (DFT) calculation, the antibacterial mechanism and Schottky effect were clarified. This work provides new insights for constructing a water disinfection strategy based on plasma-induced photothermal synergy catalysis.
•Spatial spillover effects of variables are considered in the curve fitting.•The influences of critical factors on the CO2 emissions are analyzed.•There exists an apparent block distribution in ...spatial structure of China's provincial CO2 emissions.•Urbanization and coal combustion are main factors on increasing CO2 emissions while the trade openness contributes to the slight decrease in CO2 emissions.
Different from previous studies which mainly focused on conventional estimation techniques, this paper examines the CO2 EKC hypothesis of China using a spatial panel data model to avoid the coefficient estimation error covering the period of 1997–2012. Furthermore, a comparative analysis of the turning points between the non-spatial panel model and spatial panel model is conducted. The results show that the relationship between economic growth and CO2 emissions shapes as an inverted-N trajectory. Spatial spillovers effects are confirmed to affect the shape of the CO2 environmental Kuznets curve. There exists an apparent block distribution in spatial structure of China's provincial CO2 emissions. Specifically, CO2 emissions have a relatively sharp increase from the eastern regions to the central and the western regions of China. It has also been found that urbanization and coal combustion are main factors on increasing CO2 emissions. While the trade openness contributes to slight decrease in CO2 emissions. The government should make targeted carbon-reduction policies for CO2 emission reduction.
Ferroelectric materials have demonstrated novel photovoltaic effect to scavenge solar energy. However, most of the ferroelectric materials with wide bandgaps (2.7–4 eV) suffer from low power ...conversion efficiency of less than 0.5% due to absorbing only 8–20% of solar spectrum. Instead of harvesting solar energy, these ferroelectric materials can be well suited for photodetector applications, especially for sensing near‐UV irradiations. Here, a ferroelectric BaTiO3 film‐based photodetector is demonstrated that can be operated without using any external power source and a fast sensing of 405 nm light illumination is enabled. As compared with photovoltaic effect, both the responsivity and the specific detectivity of the photodetector can be dramatically enhanced by larger than 260% due to the light‐induced photovoltaic–pyroelectric coupled effect. A self‐powered photodetector array system can be utilized to achieve spatially resolved light intensity detection by recording the output voltage signals as a mapping figure.
The photovoltaic–pyroelectric coupled effect is utilized to enhance the sensing performance of a self‐powered ITO/BaTiO3/Ag photodetector for realizing fast 405 nm light detection. A self‐powered photodetector array system can be utilized to achieve spatially resolved light‐intensity detection by recording the output voltage signals as a mapping figure.
With the continuous improvement of exploration degree in Bohai Bay Basin, the red beds in Jiyang Sag has become a hot exploration spot in recent years, the red beds is buried deep, and the ...distribution of favorable reservoirs has become a key factor restricting oil and gas exploration. This paper combines logging, core and seismic data, mainly introduces the sandstone reservoir characteristics of red beds in the southeast of Jiyang depression, and analyzes the influence of sedimentary environment and diagenesis on its reservoir characteristics respectively. The results showed that the red bed sandstone is mainly composed of arkose, quartz-feldspar and feldspar-quartz graywackes, with good porosity and permeability. Under the control of the original sedimentary environment, three types of reservoir sand bodies are mainly developed in the study area: proluvial fan, fan delta and beach bar deposits, among them, fan delta deposits have better storage performance. The diagenetic environment was early alkaline and late acidic, compaction and cementation greatly reduced primary pores and a large number of secondary pores are produced due to minerals dissolution. Under the combined influence of sedimentary environment and diagenesis, the red-bed reservoirs have various types of reservoir spaces, with obvious differences in porosity and permeability.
Summary
Proanthocyanidins (PAs) have antioxidant properties and are beneficial to human health. The fruit of apple (Malus × domestica Borkh.), especially the peel, is rich in various flavonoids, such ...as PAs, and thus is an important source of dietary antioxidants. Previous research on the regulation of PAs in apple has mainly focussed on the transcription level, whereas studies conducted at the post‐transcriptional level are relatively rare. In this study, we investigated the function of mdm‐miR858, a miRNA with multiple functions in plant development, in the peel of apple fruit. We showed that mdm‐miR858 negatively regulated PA accumulation by targeting MdMYB9/11/12 in the peel. During fruit development, mdm‐miR858 expression was negatively correlated with MdMYB9/11/12 expression and PA accumulation. A 5′‐RACE experiment, GUS staining assays and transient luminescent assays indicated that mdm‐miR858 cleaved and inhibited the expression of MdMYB9/11/12. Overexpression of mdm‐miR858 in apple calli, tobacco and Arabidopsis reduced the accumulation of PAs induced by overexpression of MdMYB9/11/12. Furthermore, we found that MdBBX22 bound to the mdm‐miR858 promoter and induced its expression. Overexpression of MdBBX22 induced the expression of mdm‐miR858 to inhibit the accumulation of PAs in apple calli overexpressing MdMYB9/11/12. Under light stress, MdBBX22 induced mdm‐miR858 expression to inhibit PA accumulation and thereby indirectly enhanced anthocyanin synthesis in the peel. The present results revealed that the MdBBX22–miR858–MdMYB9/11/12 module regulates PA accumulation in apple. The findings provide a reference for further studies of the regulatory mechanism of PA accumulation and the relationship between PAs and anthocyanins.
AbstractObjectiveTo examine the protective effects of appropriate personal protective equipment for frontline healthcare professionals who provided care for patients with coronavirus disease 2019 ...(covid-19).DesignCross sectional study.SettingFour hospitals in Wuhan, China.Participants420 healthcare professionals (116 doctors and 304 nurses) who were deployed to Wuhan by two affiliated hospitals of Sun Yat-sen University and Nanfang Hospital of Southern Medical University for 6-8 weeks from 24 January to 7 April 2020. These study participants were provided with appropriate personal protective equipment to deliver healthcare to patients admitted to hospital with covid-19 and were involved in aerosol generating procedures. 77 healthcare professionals with no exposure history to covid-19 and 80 patients who had recovered from covid-19 were recruited to verify the accuracy of antibody testing.Main outcome measuresCovid-19 related symptoms (fever, cough, and dyspnoea) and evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, defined as a positive test for virus specific nucleic acids in nasopharyngeal swabs, or a positive test for IgM or IgG antibodies in the serum samples.ResultsThe average age of study participants was 35.8 years and 68.1% (286/420) were women. These study participants worked 4-6 hour shifts for an average of 5.4 days a week; they worked an average of 16.2 hours each week in intensive care units. All 420 study participants had direct contact with patients with covid-19 and performed at least one aerosol generating procedure. During the deployment period in Wuhan, none of the study participants reported covid-19 related symptoms. When the participants returned home, they all tested negative for SARS-CoV-2 specific nucleic acids and IgM or IgG antibodies (95% confidence interval 0.0 to 0.7%).ConclusionBefore a safe and effective vaccine becomes available, healthcare professionals remain susceptible to covid-19. Despite being at high risk of exposure, study participants were appropriately protected and did not contract infection or develop protective immunity against SARS-CoV-2. Healthcare systems must give priority to the procurement and distribution of personal protective equipment, and provide adequate training to healthcare professionals in its use.
A
bstract
It has been shown recently that the anomalies observed in
B
¯
→
D
*
τ
ν
¯
τ
and
B
¯
→
K
¯
ℓ
+
ℓ
−
decays could be resolved with just one scalar leptoquark. Fitting to the current data on
R
...(
D
(∗)) along with acceptable
q
2
distributions in
B
¯
→
D
∗
τ
ν
¯
τ
decays, four best-fit solutions for the operator coefficients have been found. In this paper, we explore the possibilities of how to discriminate these four solutions. Firstly, we find that two of them are already excluded by the decay
B
c
−
→
τ
−
ν
¯
τ
, because the predicted decay widths have already overshot the total width Γ
B
c . It is then found that the remaining two solutions result in two effective Hamiltonians governing
b
→
c
τ
ν
¯
τ
transition, which differ by a sign and enhance the absolute value of the coefficient of
c
¯
L
γ
μ
b
L
τ
¯
L
γ
μ
ν
τ
L
operator by about 12%. However, they give nearly the same predictions as in the SM for the
D
∗
and τ longitudinal polarizations as well as the lepton forward-backward asymmetries in
B
¯
→
D
∗
τ
ν
¯
τ
decays. For the other observables like
ℬ
B
c
−
→
τ
−
ν
¯
τ
,
ℬ
B
c
−
→
γ
τ
−
ν
¯
τ
,
R
D
∗
q
2
,
d
ℬ
B
¯
→
D
∗
τ
ν
¯
τ
/
d
q
2
and
ℬ
B
c
−
→
X
3
τ
ν
¯
τ
, on the other hand, the two solutions give sizable enhancements relative to the SM predictions. With measurement of
B
c
−
→
τ
−
ν
¯
τ
at LHCb and refined measurements of observables in
B
¯
→
D
∗
τ
ν
¯
τ
at both LHCb and Belle-II, such a specific NP scenario could be further deciphered.
A hybridized nanogenerator is demonstrated, which has the structure of PVDF nanowires–PDMS composite film/indium tin oxide (ITO) electrode/polarized PVDF film/ITO electrode, and which can ...individually/simultaneously scavenge mechanical and thermal energies using piezoelectric, triboelectric, and pyroelectric effects. As compared with the individual energy harvesting unit, the hybridized nanogenerator has a much better charging performance. This work may push forward a significant step toward multienergy harvesting technology.
Graphene as a powerful inorganic material such as excellent conductivity and ideal mechanical strength has recently been extensively utilized to develop flexible strain sensors. However, ...graphene‐based strain sensors usually suffer from the deficiencies of stretchability, sensitivity, and sensing range, which can restrict their applications in wearable devices. Here, a novel strain sensor is designed by integrating graphene/ecoflex film and meandering zinc wire into the flexible base. The constructed strain sensor not only possesses high stretchability of up to 150% strain but can also self‐generates current signals from redox‐induced electricity, where the stable current and voltage signals of about 75 µA and 0.83 V can be obtained, respectively. Furthermore, the self‐powered sensor presents a broad and linear sensing range of 25% to 150% strains and a fast response time of less than 0.11 s. Attached on human body, the sensor has been utilized to realize the motion detection of knee joint.
A novel flexible self‐powered strain sensor is designed based on highly stretchable graphene film and weaved meandering zinc wire. The self‐powered sensor can deliver stable current signals form redox‐induced electricity. The sensing device shows superior stretchability, fast response time and the ability of motion detections. This work provides new opportunities for developing next generation of flexible strain sensors.
Ferroelectric materials have been a focus of much research over the last few decades for their unique piezoelectric and optoelectronic properties. Conventional solar cells have been devised based on ...the photovoltaic effect of semiconductor p–n junctions, with their photogenerated voltage being influenced by the bandgap of the semiconductors, limiting their further development. Ferroelectric photovoltaics have attracted attention for their unusual photovoltaic effect and controllability. The photogenerated voltage that is independent of bandgap along the polarization direction can be generated in ferroelectric materials, undoubtedly making up for the lack of solar cells. Ferroelectric materials have been used in a wide range of piezoelectric, storage, sensor, and optoelectronic because of their unique optical and electrical properties. However, the small photogenerated current of ferroelectric photovoltaic devices is one of the challenges that need to be overcome. Researchers have shown that the photogenerated current of ferroelectric photovoltaic devices can be significantly improved by cation doping and heterostructure construction, reigniting the enthusiasm for the investigation of ferroelectric photovoltaics. This paper reviews a variety of ferroelectric photovoltaic materials, the mechanism of ferroelectric photovoltaics, approaches for improving ferroelectric photovoltaic performance, and the applications and future prospects for ferroelectric materials.
New photovoltaic materials and devices have been a research hotspot for recent years. Ferroelectric materials with multiple effects have great potential for applications in the fields of photoelectric detection, photoelectric storage, etc. This manuscript summarizes briefly the mechanism, performance improvement and applications of ferroelectric photovoltaic materials and devices.
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