Nowadays, great effort has been devoted to establishing wearable electronics with excellent stretchability, high sensitivity, good mechanical strength, and multifunctional characteristics. Herein, a ...soft conductive hydrogel is rationally designed by proportionally mixing silk fibroin, polyacrylamide, graphene oxide, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). The resultant hydrogel has considerable stretchability and compressibility, which enables it to be assembled into a strain/pressure sensor with a wide sensing range (strain, 2%–600%; pressure, 0.5–119.4 kPa) and reliable stability. Then, the corresponding sensor is capable of monitoring a series of physical signals of the human body (e.g., joint movement, facial gesture, pulse, breathing, etc.). In particular, the hydrogel-based sensor is biocompatible, with no anaphylactic reaction on human skin. More interestingly, this conductive hydrogel exhibits a positive response when it works in a triboelectric nanogenerator; consequently, it lights up 20 commericial green light-emitting diodes. Thus, this silk fibroin-based hydrogel is a kind of multifunctional material toward wearable electronics with versatile applications in health and exercise monitors, soft robots, and power sources.
An analytical model for mean wind profiles in sparse canopies (W. Wang, Boundary-Layer Meteorol 142:383–399,
2012
) has been further developed, with (1) an explicit solution being derived, and (2) a ...linear term being added to the
K
-closure scheme to improve the shear-stress parametrization when the contribution of non-local transport is significant. Results from large-eddy simulations and from laboratory experiments are used to evaluate the model and adjust model parameters, showing that the model can well simulate canopy wind and stress profiles not only for sparse-canopy scenarios, but also for dense-canopy scenarios. The analytical solution converges exactly to the standard surface-layer logarithmic wind profile in the case of zero canopy density, and tends to an exponential wind profile for a dense canopy.
The 5‐heterofunctionalized triazoles are important scaffolds in bioactive compounds, but current click reactions (CuAAC) cannot produce these core structures. A copper(I)‐catalyzed interrupted click ...reaction to access diverse 5‐functionalized triazoles is reported. Various 5‐amino‐, thio‐, and selenotriazoles were readily assembled in one step in high yields. The reaction proceeds under mild conditions with complete regioselectivity. It also features a broad substrate scope and good functional group compatibility.
A copper(I)‐catalyzed interrupted click reaction to access diverse 5‐functionalized triazoles is reported. Various 5‐amino‐, 5‐thio‐, and 5‐selenotriazoles were assembled in a single step in high yields. The reaction proceeds under mild conditions with complete regioselectivity and features a broad substrate scope and compatibility with various functional groups.
The potential of using the integrated membrane systems based on ultrafiltration (UF) coupled with nanofiltration (NF) or reverse osmosis (RO) for the treatment of phenolic wastewater from a paper ...mill was investigated. Polyethersulfone based membranes PES7000 (MWCO 7000), GR82PP (MWCO 5000), GR95PP (MWCO 2000), and SynderXT (MWCO 1000) were used for the UF treatment, and SynderXT exhibited the best results with the rejections of chemical oxygen demand (COD) and total dissolved solid (TDS) being 56.4% and 9.6%, respectively. The resulting UF permeate was further treated by NF membranes (NF99HF, NF97) or RO membrane (RO98pHt) to further remove the remaining pollutants (COD and phenol). The results showed that RO98pHt, which exhibited superior performance over NF membranes, reached rejections of 95.5% and 94.9% for COD and phenol, respectively.
•Industrial wastewater was treated by combined UF and NF/RO processes.•The permeate water from UF system was qualified to be used as the NF or RO feed water.•The hydraulic resistances of NF/RO membranes under different TMPs were determined.•The RO98pHt reached rejections of 95.5% and 94.9% for COD and phenol, respectively.
► The Scenedesmus sp. discussed in this study was cultivated in an open-pond system. ► Optimal conditions of six flocculants for harvesting Scenedesmus sp. were discussed. ► Optimal pH to each ...flocculant was found for achieving high flocculation efficiency. ► Increasing algal biomass concentration will increase the flocculant dosage needed.
The effects of culture medium pH, flocculant type (FeCl3, Al2(SO4)3, Alum, Ca(OH)2, chitosan, polyacrylamide), dosage and sedimental time on flocculation efficiency of harvesting Scenedesmus sp. cultivated in an open-pond system were investigated. Meanwhile, the relation between initial biomass concentration and the flocculant dosage needed was also investigated. The results from this work indicated that the flocculation efficiency achieved 97.4% after 10min of sedimentation when the pH was adjusted to be 11.5, without adding flocculants. FeCl3 and chitosan showed a good flocculation efficiency at dosage of 0.15 and 0.08g/L, respectively without pH adjustment. The flocculation efficiency increased from 49.74% to 90.63% when the final medium pH was adjusted to 6 after adding 0.1g/L Alum. An increment from 68.18% to 92.84% was observed after adding 0.1g/L Al2(SO4)3 followed by pH adjustment. Finally, the most suitable flocculation method was discussed in this paper.
An efficient electrophilic persulfuration reaction leading to unsymmetrical disulfides and polysulfides has been developed. Various nucleophiles, including aryl boronic acids, β-keto esters, and ...thiols, can be used as substrates. The notable features of this method include very simple and practical conditions, general scope, and inexpensive copper catalysts.
A copper(I)-catalyzed three-component CuAAC/persulfuration reaction providing rapid access to asymmetric triazole disulfides has been developed. The interrupted click reaction shows broad substrate ...scope, complete regioselectivity, and excellent functional group tolerability.
Existing analytical models for mean wind profiles within canopies are applicable only in dense canopy scenarios, where all momentum is absorbed by canopy elements and, hence, the effect of the ground ...on turbulent mixing is not important. Here, we propose a new analytical model that can simulate mean wind profiles within sparse canopies under neutral conditions. The model adopts a linearized canopy-drag parametrization and a first-order turbulence closure scheme taking into account the effects of both the ground and canopy elements on turbulent mixing. The resulting wind profile within a sparser canopy appears to be more like a logarithmic form, with the no-slip condition at the ground being satisfied. The analytical solution converges exactly to the standard surface-layer logarithmic wind profile in the case of zero canopy density (i.e., no-canopy scenario) and tends to be an exponential wind profile for a dense canopy; this feature is unique compared with existing analytical models for canopy wind profiles. Results from the new model are in good agreement with those from laboratory experiments and numerical simulations.
Mesoporous silica nanoparticles (MSNs) carrying gatekeepers that are stimuli-responsive are widely investigated for the controlled delivery of drug at target sites. In this study, thioketal (TK) ...functionalized methoxy poly(ethylene glycol) (mPEG-TK) as ROS-responsive gatekeeper is used to modify MSNs and leads to a reactive oxygen species (ROS)-responsive delivery for antibacterial drug. Vancomycin (Van) was taken as the antibacterial drug and then physically encapsulated into the surface amino functionalized MSNs (N-MSNs). Subsequently, mPEG-TK was surface immobilized. Van loaded N-MSNs with surface modification of mPEG-TK (Van-mPEG-TK-MSNs) presented approximately 21% release of Van in a physiological environment in 36 h. With H2O2 increasing in the medium, the release rate of Van from Van-mPEG-TK-MSNs was significantly up-regulated following gatekeepers' disintegration. When Van-mPEG-TK-MSNs was applied in vivo, the infected site was fully cleared after 14 days and the tissue was free of infection. On the whole, the mentioned results suggested that Van-mPEG-TK-MSNs could act as a potential antimicrobial. This study can broaden MSNs' applications and advance the development of novel antibacterial agents.
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•Thioketal-gated mesoporous silica nanoparticles were successfully developed for vancomycin encapsulation and release.•The gated nanoparticle provided a sensitive release of vancomycin dependent on the reactive oxygen species.•Vancomycin released within 6 h from the gated nanoparticles was approximately 10 times less than from no-gate nanoparticles.•Within 14 days, the gated nanoparticles with vancomycin loading, effectively cleared infection in vivo.
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