This article focuses on the electronic structure of the poly(3-hexylthiophene):phenyl-6,6-C61 butyric acid methyl ester (P3HT:PCBM) blend, widely used in bulk heterojunction (BHJ) solar cells. Given ...the fact that the surface of the blend film is a nearly pure P3HT wetting layer, we use a lift-off method to access the originally buried surface, which is rich in both P3HT and PCBM and thus representative of the BHJ. The combination of direct and inverse photoemission spectroscopy on this surface leads to a determination of the energy gap between the lowest unoccupied molecular orbital (LUMO) of the acceptor and the highest occupied molecular orbital (HOMO) of the donor. The gap is ∼1.4
eV, which implies a 0.5–0.6
eV interface dipole barrier between the two materials. The energy gap is found to be stable versus
in situ annealing up to 100
°C.
Abstract
In order to solve the problem of quantitative traceability of detection devices for fire emergency lighting and evacuation indication systems. Method analysis and research were conducted on ...parameters such as emergency switching time, emergency working time, DC charging voltage, DC discharge voltage, DC charging current, DC discharge current, environmental test temperature, and environmental test humidity. We searched for appropriate calibration methods for the technical characteristics of each parameter and designed a set of calibration devices for fire emergency lighting detectors. The test results show that the technical indicators of the calibration device can meet the traceability requirements of the fire emergency lighting and evacuation indication system.
Although tropical forest soils contributed substantially global soil methane uptake, observations on soil methane fluxes in tropical forests are still sparse, especially in Southeast Asia, leading to ...large uncertainty in the estimation of global soil methane uptake. Here, we conducted two-year (from Sep, 2016 to Sep, 2018) measurements of soil methane fluxes in a lowland tropical forest site in Hainan island, China. At this tropical forest site, soils were substantial methane sink, and average annual soil methane uptake was estimated at 2.00 kg CH
-C ha
yr
. The seasonality of soil methane uptake showed strong methane uptake in the dry season (-1.00 nmol m
s
) and almost neutral or weak soil methane uptake in the wet season (-0.24 nmol m
s
). The peak soil methane uptake rate was observed as -1.43 nmol m
s
in February, 2018, the driest and coolest month during the past 24 months. Soil moisture was the dominant controller of methane fluxes, and could explain 94% seasonal variation of soil methane fluxes. Soil temperature could not enhance the explanation of seasonal variation of soil methane fluxes on the top of soil moisture. A positive relationship between soil methane uptake and soil respiration was also detected, which might indicate co-variation in activities of methanotroph and roots and/or microbes for soil heterotrophic respiration. Our study highlights that tropical forests in this region acted as a methane sink.
As the first-line drug to treat ulcerative colitis (UC), long-term use of glucocorticoids (GCs) produces severe toxic and side effects. Local administration as enema can increase the local GCs ...concentrations and reduce systemic exposure to high oral doses by directly delivering GCs to the inflammation site in the distal colorectum. However, UC patients are often accompanied by diarrhea, leading to the short colonic residence time of GCs and failure to exert their function fully.
A kind of mucoadhesive nanoparticles (NPs) loading different dexamethasone derivatives (DDs) were developed, which could attach to the positively charged inflammatory colonic mucosa through electrostatic adsorption after administered by enema, thereby improving the local concentration and achieving effective targeted therapy for UC.
Two DDs, dexamethasone hemisuccinate and dexamethasone phosphate, were synthesized. In NPs preparation, The core PEI-DDs NPs were built by the electrostatic adsorption of DDs and the cationic polymer polyethyleneimine (PEI). Then, the natural polyanionic polysaccharide sodium alginate (SA) was electronically coated around NPs to construct the final SA-PEI-DDs NPs, followed by the in vitro stability and release tests, in vitro and in vivo colonic mucosal adhesion tests. In the in vivo anti-UC test, the experimental colitis mice were induced by 2,4,6-trinitrobenzenesulfonic acid. The body weight and disease activity index changes were measured, and the myeloperoxidase activity, pro-inflammatory cytokines concentration, and hematoxylin and eosin staining were also investigated to evaluate the therapeutic effect of NPs.
The structures of two DDs were demonstrated by
H-NMR and MS. Both NPs were negatively charged and achieved high loading efficiency of DDs, while their particle sizes were significantly different. NPs showed good stability and sustained release properties in the simulated colonic environment. Moreover, the negative charge on the of NPs surface made them easier to adhere to the positively charged inflammatory colonic mucosa, thereby enhancing the enrichment and retention of DDS in the colitis site. Furthermore, the NPs exhibited better therapeutic effects than free Dex on the experimental colitis mice induced by TNBS through the enema rectal.
These results indicated the mucoadhesive NPs as a kind of novel nano-enema showed great potential to achieve efficient treatment on UC.
In this work, effective and novel heterogeneous catalysts of Metal–organic framework MIL-101(Fe) doped with cobalt (Co
2+
) or copper (Cu
2+
) have been synthesized by post-synthesis method, namely ...Co–MIL-101(Fe) and Cu–MIL-101(Fe). The initial and metal-doped samples were tested to activate persulfate (PS) for removal of Acid Orange 7 (AO7) in water. The surface of samples were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, N
2
adsorption, scanning electron microscopy and transmission electron microscopy. The addition of Cu
2+
and Co
2+
could alter structure characteristics of MIL-101(Fe) in crystal structure and morphology. The unusual octahedron morphology of MIL-101(Fe) turned to be irregular, disorder and a rod-like morphology was shaped. What is more, Co doping caused greater changes in structure characteristics in comparison with Cu doping. The alteration was reflected in the catalytic capacity of PS activation. An interesting note was that, whether Co or Cu doping, metal-doped MIL-101(Fe) greatly improved the PS activation as compared to unmodified MIL-101(Fe). The removal rate of AO7 was about 66, 92, 98% in MIL-101(Fe)/PS, 6%wtCu–MIL-101(Fe)/PS and 6%wtCo–MIL-101(Fe)/PS system, respectively. Some results also suggested the performance of Co–MIL-101(Fe) was superior to that of Cu–MIL-101(Fe). Additionally, a series of parameters were designed to achieve maximum capacity of PS activation. Such an enhancement in activity may be attributed to the main reasons: the new active sites created by metal additives; an increase in number of active Fe sites produced by Co and Cu doping which results in alteration of morphology and structure of catalysts.
•A new calculating route was recommended for tropical forest gs.•gs jointly controlled by radiation and water deficit.•A updated value of 24.8 ± 13.8 mm s−1 was suggested for tropical forest gsmax.
...Tropical forests are responsible for the evaporation and transpiration of large quantities of water into the atmosphere annually. Surface conductance (gs) is a poorly understood phenomenon that plays a central role in regulating this evapotranspiration. We studied the calculations, variations, and environmental factors controlling gs based on eddy flux measurements from 10 tropical forest sites that covered a wide range of water gradients across continents. We found that boundary layer conductance (gb) is comparable with aerodynamic conductance for momentum (gaM) and thus, it should not be ignored in estimations of total aerodynamic conductance for water vapor (gaV). Based on the findings, we have made some recommendations for gaM estimation both with and without measurements of turbulence. The seasonal variation of gs is low in humid sites but large in sites with a dry season. A value of 24.8 ± 13.8 mm s−1 was suggested for maximum surface conductance (gsmax) for tropical forests. Both water vapor deficit (D) and radiation (Q) play an important role in controlling gs. The model driven by both D and Q could capture the diurnal variations of gs well and could be implemented in large-scale models in future. We believe the findings of this study could contribute substantially to our understanding of tropical forest gs.
We aimed to characterize the clinical significance of epigenetic loss of death-associated protein kinase (DAPK) gene function through promoter methylation in the development and prognosis of ...lymphoma. PubMed, Web of Science and ProQuest databases were searched for relevant studies. Twelve studies involving 709 patients with lymphoma were identified. The prognostic value of DAPK methylation was expressed as risk ratio (RR) and its corresponding 95% confidence interval (CI), while the associations between DAPK methylation and the clinical characteristics of patients with lymphoma were expressed as odd ratios (ORs) and their corresponding 95% CIs. Meta-analysis showed that the 5-year survival rate was significantly lower in lymphoma patients with hypermethylated DAPK (RR = 0.85, 95% CI (0.73, 0.98), P = 0.025). Sensitivity analysis demonstrated consistent result. However, no associations were found between DAPK methylation and clinicopathological features of lymphoma, in relation to gender (OR = 1.07, 95% CI (0.72, 1.59), P = 0.751), age (OR = 1.01, 95% CI (0.66, 1.55), P = 0.974), international prognostic index (OR = 1.20, 95% CI (0.63, 2.27), P = 0.575), B symptoms (OR = 0.76, 95% CI (0.38, 1.51), P = 0.452), serum lactate dehydrogenase (OR = 1.13, 95% CI (0.62, 2.05), P = 0.683), and BCL-2 expression (OR = 1.55, 95% CI (0.91, 2.66), P = 0.106). Lymphoma patients with hypermethylated DAPK are at risk for poorer 5-year survival rate. DAPK methylation may serve as a negative prognostic biomarker among lymphoma patients, although it may not be associated with the progression of lymphoma.
As a unique type of ecosystem, tropical coastal sandy vegetation lies in the transition zone extending from coastal beaches to further inland and provides important ecosystem services such as ...windproofing, tourism, and agriculture. However, the energy and matter fluxes of these tropical coastal ecosystems have been rarely studied. We reported one-year eddy flux observations in a tropical sandy coastal ecosystem and specifically focused on the carbon and water exchanges between the atmosphere and the ecosystem. The studied ecosystem was a carbon sink (approximately –560 gC m−2 yr−1) and approximately 1000 mm of water evaporated from the ecosystem into the atmosphere during the study year. The highest levels of vegetation photosynthesis occurred in April, shortly before the wet season. This can be attributed to an endogenous self-adjustment of the ecosystem to improve the water- and carbon-use efficiency during the wet season. This study is expected to not only fill the data gap with respect to the gas exchange between tropical sandy coastal plains and the atmosphere but also provide knowledge about the function and ecological service of these specific ecosystems.
The high-cycle fatigue (HCF) behavior is significantly affected by surface roughness, especially for high strength metal FV520B-I. However, with surface roughness effect, neither the fatigue ...property, nor the high-cycle fatigue life model about FV520B-I with surface roughness has been reported. In this paper, designed fatigue experiment using the specimen with different surface roughness is presented to study the effectiveness of the roughness to the fatigue. The observations of the fatigue crack initiation sites and the crack propagation. Then the high cycle fatigue behavior of FV520B-I affected by surface roughness is analyzed. The existing very-high-cycle fatigue life model is not well-fit for high-cycle fatigue model of FV520B-I. A NEW high-cycle fatigue life prediction model of FV520B-I, taking surface roughness as a main effective variable is proposed. The model is built up by a comprehensive use of experimental data and the traditional fatigue modeling theory. The new finding between the fatigue strength coefficient and stress amplitude, with surface roughness, is adopted, leading to a NEW modified life prediction model. Study on fatigue model of FV520B-I with surface roughness is a very beneficial effort in fatigue theory and fatigue engineering development.
Lithium iron phosphate (LiFePO
4
) was prepared and applied in the heterogeneous activation of persulfate (PS) for Orange G (OG) degradation in water. Scanning electron microscopy, X-ray diffraction, ...Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the properties of the material before and after activation. The effects of several parameters on its catalytic activity were also investigated. It was found that the catalyst presented ultrafast activity for OG and other organic dye degradations. The results from XPS further suggested that the highly catalytic efficiency possibly involved the activation of PS to sulfate radicals as main radical meditated by the redox pair of Fe(
ii
)/Fe(
iii
) of LiFePO
4
/FePO
4
.
LiFePO
4
was synthesized and successfully applied for activation of persulfate to produce sulfate radicals for dye degradation.
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