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The dissolved oxygen (DO) concentration is an important index of water quality. It has a significant impact on the biodegradation process in water and the survival of aquatic organisms. Low DO concentrations often exist and may result in a deterioration in water quality and an increase in wastewater treatment expenses. An analysis of the oxygen transfer efficiency as correlated with the flow characteristics of a falling jet could help to solve these problems. Experiments related to oxygen transfer along a falling water jet were conducted, and the effects of the flowrate ( Q ), falling height ( H ) and initial DO concentration ( c u ) were considered. The results demonstrated that a falling jet in air could be an effective way of improving the DO concentration. The results also indicated that the oxygen transfer efficiency is linearly dependent on c u and has a negative exponential relation with H . To deeply analyze the oxygen transfer process, the jet disturbance process was divided into 3 parts for the first time based on flow features: a smooth zone, turbulent zone and breakup zone. The results showed that the jet outlet velocity had a limited influence on the smooth zone height but assisted in jet breakup. Thereafter, a correlation modeling DO reaeration along the falling jet considering jet disturbance characteristics was obtained. This correlation was also applied to predict the aeration efficiency in experimental cases from the literature and showed good agreement with the reported results.

Effects of the heavy metal copper (Cu), the metalloid arsenic (As), and the antibiotic oxytetracycline (OTC) on bacterial community structure and diversity during cow and pig manure composting were investigated. Eight treatments were applied, four to each manure type, namely cow manure with: (1) no additives (control), (2) addition of heavy metal and metalloid, (3) addition of OTC and (4) addition of OTC with heavy metal and metalloid; and pig manure with: (5) no additives (control), (6) addition of heavy metal and metalloid, (7) addition of OTC and (8) addition of OTC with heavy metal and metalloid. After 35 days of composting, according to the alpha diversity indices, the combination treatment (OTC with heavy metal and metalloid) in pig manure was less harmful to microbial diversity than the control or heavy metal and metalloid treatments. In cow manure, the treatment with heavy metal and metalloid was the most harmful to the microbial community, followed by the combination and OTC treatments. The OTC and combination treatments had negative effects on the relative abundance of microbes in cow manure composts. The dominant phyla in both manure composts included Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. The microbial diversity relative abundance transformation was dependent on the composting time. Redundancy analysis (RDA) revealed that environmental parameters had the most influence on the bacterial communities. In conclusion, the composting process is the most sustainable technology for reducing heavy metal and metalloid impacts and antibiotic contamination in cow and pig manure. The physicochemical property variations in the manures had a significant effect on the microbial community during the composting process. This study provides an improved understanding of bacterial community composition and its changes during the composting process.

A novel acid-labile temperature-responsive homopolymer of poly(2-(2-(2-(2-((tetrahydrofuran-2-yl)oxy)ethoxy)ethoxy)ethoxy) ethyl methacrylate) (PTFEO4MA) combining the oligo ethylene glycol (OEG) m...

ZIF-8-induced porous α-Fe2O3/SnO2/ZnO heterostructures have been successfully fabricated via surface modification of one-dimensional (1D) rod-like Fe/Sn precursors by introducing ZIF-8 nanoparticles and subsequent annealing. The obtained composites are composed of regular and narrow size-distributed nanorods with average diameters of 90–105 nm and possessing a porous structure with a high specific surface area (197.96 m2/g). Compared with α-Fe2O3/SnO2 samples, optimal α-Fe2O3/SnO2/ZnO products exhibit higher gas response and selectivity for acetone at a lower working temperature of 240°C, with a response of 152 ppm to 100 ppm acetone that is approximately three times that of α-Fe2O3/SnO2 (~ 53.1), as well as rapid response and recovery times of 5 s and 3 s, respectively. Obviously, the decoration of ZIF-8 on the surface plays an essential role in adjusting the nucleation process of composite nanocrystals. The outstanding acetone-sensing property might be mainly attributed to the successful construction of tri-phase effective heterojunctions with abundant active sites on the surface/interface and accelerated electron migration along the 1D direction of the porous microstructures. The proposed α-Fe2O3/SnO2/ZnO heterostructures are promising sensitive materials for practical acetone detection.

Wetland is an important carbon pool, and the degradation of wetlands causes the loss of organic carbon and total nitrogen. This study aims to explore how wetland degradation succession affects soil organic carbon (SOC) and total nitrogen (TN) contents in alpine wetland. A field survey of 180 soil-sampling profiles was conducted in an alpine wetland that has been classified into three degradation succession stages. The SOC and TN contents of soil layers from 0 to 200 cm depth were studied, including their distribution characteristics and the relationship between soil water content (SWC) and microtopography. The results showed that SOC and TN of different degradation succession gradients followed the ranked order of Non Degradation (ND) > Light Degradation (LD) > Heavy Degradation (HD). SWC was positively correlated with SOC and TN (p

Pathogenic infections, particularly caused by Gram-positive bacteria (G+), pose a serious threat to human health, and therefore the fast and accurate discrimination of G+ bacteria from Gram-negative bacteria (G-) and fungi is highly desirable. Organic molecules with facile synthesis, robust photostability, good biocompatibility, and high selectivity toward pathogens are urgently needed in the clinical diagnosis and therapy. To this end, herein we report the synthesis of two naphthalimide-based bioprobes named tetraphenylethylene-naphthalimide (TPE-NIM) and triphenylamine-naphthalimide (TPA-NIM) with aggregation-induced emission (AIE) characteristic. First, the staining capacity of the designed AIEgens toward six kinds of bacteria and two kinds of fungi was evaluated. Both TPE-NIM and TPA-NIM showed a high degree of binding/imaging selectivity for G+ bacteria over G- bacteria and fungi via a wash-free protocol. Second, the two AIEgens had the ability to visualize the biofilms formed by G+ bacteria (Staphylococcus aureus) and can quickly track the G+ bacteria (Staphylococcus aureus) in red blood cell suspensions. Third, we have revealed that electrostatic attraction and hydrophobic interaction both contribute to the selective binding of the AIEgens toward G+ bacteria. In view of the high binding/imaging specificity toward G+ bacteria, low hemolysis rates, and low toxicity toward the bacterial cells, these AIEgens can be applied for the clinical detection of pathogenic infections caused by G+ bacteria and broaden the theranostic applications of AIE materials.

A α-iminol rearrangement triggered by Pd-catalyzed C-H addition of electronic-rich heteroarenes to cyclobutanone-derived O-acyl cyanohydrins was described, which provided a practical and efficient protocol for the preparation of functionalized α-amino cyclopentanones in an atom- and step-economic fashion. In addition, further synthetic transformations of products have also been demonstrated.

Bubble dissolution during the flood discharge creates high total dissolved gas (TDG) concentration zones downstream of the dams. The dissipation of supersaturated TDG is a very slow process. Thus, the elevated TDG may remain through the water body for hundreds of kilometers downstream and lead to gas bubble disease (GBD) and even mortality in fish. To improve the navigation conditions of waterways, dikes (i.e., a solid structure) of varied sizes and shapes are commonly constructed. However, this would affect the dissipation and transportation of the supersaturated TDG. It would significantly change the turbulence intensity and hydropressure of the flow, which dominates the dissipation of TDG. Therefore, TDG distribution in the waterway differs from that in the natural river. In this study, a numerical simulation of the TDG at the Yangtze River’s upper reaches (one of the inland waterways in China) was conducted with the establishment of a two-dimensional TDG dissipation model. The effect of the dikes’ size and shape was analyzed to assess the influence of the regulation structures on the dissipation and transportation of the supersaturated TDG. Meanwhile, simulation in the study area with the natural topography was also set as blank control. Based on that, impact evaluation of TDG supersaturation on fish under different simulation scenarios was made. This study can provide a scientific basis for reducing the adverse effect of supersaturated TDG in fish and the construction of ecological waterway therefore.

Uniform flower-like α-Fe2O3 architectures with self-assembled core-shell nanorods are constructed and successfully prepared via the facile process. The concentration of Fe salt plays a great significance for morphological evolution from nanorods to self-assembled microflowers. Flower-like α-Fe2O3/ZnFe2O4 consisting of α-Fe2O3 core and ZnFe2O4 shell nanorods are derived from FeOOH/ZIF-8 precursors. The detailed studies reveal that the tunable growth of ZIF-8 nanoparticles on three-dimensional FeOOH microflowers at room temperature and the availble calcination regulation are responsible for the formation of core-shell Fe2O3/ZnFe2O4 composites. The highest response value of flower-like α-Fe2O3/ZnFe2O4 architectures to 100 ppm triethylamine (TEA) has been improved to 141 at 280 °C, which is calculated to be 6.2 times compared with flower-like α-Fe2O3 architectures (22.7). The enhanced gas-sensing mechanism of α-Fe2O3/ZnFe2O4 composites can be attributed to the typical microflowers structures, the large specific surface area, the effective heterojunctions between α-Fe2O3 core and ZnFe2O4 shell, and the improved electron transfer process.

Porous MoO3/V0.13Mo0.87O2.935 heterostructures self-assembled with 2D nanosheets have been primarily prepared by a facile method for effectively detecting ethanol at room temperature. The V0.13Mo0.87O2.935 phase contributes to modified microspheres and improved surface/interface structures. The enhanced sensing mechanism benefits from the effects of MoO3–V0.13Mo0.87O2.935 heterojunctions and tunable microstructure.

Development of high efficient and stable water oxidation catalysts is essential for the realization of industrial water-splitting systems. Herein, a novel approach involving an in-situ transformation of Co(OH)2 nanosheets into NH4CoPO4•H2O nanoplates on Co foil is reported. As a 3D self-supported oxygen revolution reaction (OER) electrocatalyst, the as-prepared NH4CoPO4•H2O/Co exhibits remarkable catalytic activity and exceptional stability. Specifically, it can deliver a current density of 10 mA cm−2 at a quite low overpotential of 254 mV with a small Tafel slope of 64.4 mV dec−1 in alkaline electrolyte. Through experimental study and theoretical analysis, the excellent OER performance can be attributed to enriched exposed active sites, favorable electron/proton transfer and mass transport, and its unique asymmetric local atomic and electronic structure. Thus, this present research not only provides a practicable in-situ transformation strategy to design 3D self-supported electrocatalysts, but also enlightens a new way of developing transition-metal phosphates for efficient and stable water oxidation at atomic level.

Tumor microenvironment turn-on nanoprobes that could specifically detect the occurrence of diseases possess great potential in early diagnosis. Here, a GSH activated nanoprobe was designed for fluorescence and 19F magnetic resonance (MR) dual-modal turn-on imaging of tumors. Specifically, fluorescence AgInS2 quantum dots (QDs for fluorescence imaging) were co-encapsulated with perfluoro-15-crown-5-ether (P19FCE for19F MRI) by amphiphilic polymers and further coated with in situ formed manganese dioxide (MnO2) nanoshells, which served as efficient fluorescence and 19F MR quenchers due to energy transfer and paramagnetic relaxation effects, respectively. The over-expressed GSH in tumors would decompose the MnO2 nanoshells, resulting in remarkable enhancement of both fluorescence and 19F MRI signals of the nanoprobes, accordingly lighting up the tumor site.

Combined applications of plant residues and nitrogen (N) fertilizer in agroecosystems may increase N immobilization and reduce N loss through microbial propagation using fresh organic matter (FOM)....

Suffering from solar radiation, day–night replacement and seasonal changes, the structure will produce notable temperature behaviour, which has a vital effect on the long-term process of the health monitoring. Previous studies show that there is a significant correlation between the measuring responses and temperature from health monitoring systems. To analyse the structural state more accurately, much literature employed health monitoring methods considering temperature effects. This paper reviews technical research concerning health monitoring of civil structures under varying temperature. Firstly, the correlation researches of structural measuring responses (dynamic and static responses) and temperature are reviewed, which includes the researches of the influence mechanism and the data statistics, and the studies of the influence of non-uniform temperature on responses are also reviewed. In addition, different types of separation and forecast methods of the temperature-induced part of the structural responses data are summarized, followed by a brief summary of benefits and drawbacks of these methods. Lastly, the recently proposed process frameworks of damage assessment considering temperature effects are also introduced.

Lithium-ion-assisted ultrafast charging double-electrode smart windows with energy storage and a fluorescence display device (FTO/PB/Ru@SiO2||Ru@SiO2/WO/FTO) based on double electrochromic electrodes (cathode and anode) (FSDECEs) have been designed and fabricated. Here, Prussian blue (PB) and WOred are selected as the electrochromic cathode and anode, respectively. There is a synergistic effect and a large potential difference between the two electrodes. They could be simultaneously and rapidly bleached after being connected with each other. Also, the fluorescence intensity of Ru@SiO2 nanoparticles (NPs) could be regulated by the fluorescence resonance energy transfer effect (FRET). After discharging, the two electrochromic electrodes in the bleached state can be recharged by a Mg–O2 battery with a FeN5 single atomic catalyst to quickly recover the colored state. The double electrochromic electrodes can reversibly alter between coloring and bleaching states only by connecting and disconnecting the electrodes. The fluorescence intensity of FSDECEs can switch between quenching and emission, thus endowing the “on” and “off” functions. The system is concise, environmentally friendly, and easy to operate. The proposed FSDECEs demonstrate high fluorescence contrast, a fast response time, and long-term stability. Such an ingenious design of fluorescence switching based on the double electrochromic electrode in a single cell sheds light on next-generation transparent, portable, and self-powered electrochromic devices and electronic equipment., Inspired by the matched potential of the PB and WO, lithium-ion-assisted ultrafast charging double electrode smart windows with energy storage and fluorescence display application were put forward.

The gaseous plant hormone ethylene plays crucial roles in many aspects of plant growth, development and stress responses. Ethylene signaling is initiated upon its binding to the ethylene receptors. Since the cloning of the first ethylene receptor ETR1 from Arabidopsis, efforts have been made in elucidation of ethylene receptor organization, signaling, and receptor-interacting proteins in higher plants. However, the update information about the ethylene receptors, receptor interacting proteins and their regulatory functions and molecular mechanisms has not been well scrutinized and discussed. Critical questions regarding the confusing or contradictory responses and phenotypes have been barely answered. This article gave an overview of the current progress in the identification, regulatory functions and possible molecular mechanisms of the ethylene receptors and receptor-interacting proteins in ethylene signaling and responses. The novel findings of the crosstalk between ethylene signaling and the other plant hormones were integrated into the review article. Questions and future research directions about the key components in the regulation of ethylene signaling were also proposed and emphasized. The update message may greatly facilitate comprehensive understanding of the ethylene signaling and molecular regulations in higher plants.

A single-step method for isolation of specific cells based on multiple surface markers will have unique advantages because of its scalability, efficacy, and mildness. Herein, we developed multi-aptamer-mediated proximity ligation method on live cell membranes that leverages a multi-receptor co-recognition design for enhanced specificity, as well as a robust in situ signal amplification design for improved sensitivity of cell isolation. We demonstrated the promising efficacy of our method on differentiating tumor cell subtypes in both cell mixtures and clinical samples. Owing to its simple and fast operation with excellent cell isolation sensitivity and accuracy, this approach will have broad applications in biological science, biomedical engineering, and personalized medicine.

Honeycomb-like nitrogen-doped porous carbon (HNC) is prepared by using poly(2,6-diaminopyridine) as nitrogen-enriched precursor and silica as hard template. After carbonization and template removal, the obtained HNC possesses an interconnected 3D hierarchical porous structure and a nitrogen level up to 15.31 at.%. Owing to the hierarchical porous structure and abundant active sites in the carbon matrix, the HNC exhibits an excellent capacitive performance with a high specific capacitance of 398 F g−1 at a current density of 0.1 A g−1 and exceptional cycling stability (110.4% retention after 5000 cycles). This work provides a facile and efficient strategy for the large-scale production of nitrogen superdoped interconnected hierarchical carbon framework for high performance supercapacitors.

Aquaporins (AQPs) are a family of integral membrane proteins that have been shown to be important for osmoregulation in many vertebrates. To identify potential stress resistance-related aqp genes in salinity adaptation of the roughskin sculpin Trachidermus fasciatus, we investigated the time-course expression dynamics of seven aquaporin genes (aqpl, 4, 7, 8, 10, 11 and 12) in three osmoregulatory tissues (kidney, gill and intestine) and one metabolic tissue (liver). The fish were subjected to two different acute osmotic treatments (seawater-to-freshwater transfer respectively achieved in 1 h and 24 h, namely, E-acute and acute group). The expression profiling of the seven aqp genes were performed using quantitative real-time PCR (qRT-PCR). At the time of all sampling time points (0 h, 12 h, 24 h and 48 h), no expression of aqp4 was found in the gill, liver and intestine; no expression of aqp7 was found in the gill and liver. Significant differences of aqp expression were determined in the four target tissues, and the mRNA levels were largely variable among gene members and tissues. Similar patterns of the time-course expression were detected in most of the aqp genes in T. fasciatus between the two acute groups, except that only one gene (aqpl2) in the kidney and three genes (aqp7, aqp8 and aqp10) in the intestine revealed different expression patterns. These results suggest that the expression response of aqp genes was similar under osmotic changes with different rates.

In this work, amorphous carbon/alumina (C/Al2O3) metacomposites with tunable negative permittivity were synthesized by a facile impregnation method. We analyzed the influence of carbon content and the carbonization temperature on the microstructure and electrical properties of the metacomposites. It was found that the conductive carbon networks were formed in the composites with the higher carbon contents and carbonization temperatures, which lead to the appearance of a metal-like conduction and negative permittivity behavior. Low-frequency plasmonic state provided by plenty of free electrons in the carbon networks resulted in the negative permittivity, and its numerical values could be effectively adjusted by controlling the carbon content and carbonization temperature, which could be well explained by Drude model. This work provides a feasible way to prepare metacomposites with tunable negative permittivity, which will expand their potential applications in shielding, absorbing and novel capacitor fields.

For the intelligence of metamaterials, the -sensing mechanism and programmable reaction units are two important components for self-recognition and -determination. However, their realization still face great challenges. Here, we propose a smart sensing metasurface to achieve self-defined functions in the framework of digital coding metamaterials. A sensing unit that can simultaneously process the sensing channel and realize phase-programmable capability is designed by integrating radio frequency (RF) power detector and PIN diodes. Four sensing units distributed on the metasurface aperture can detect the microwave incidences in the x- and y-polarizations, while the other elements can modulate the reflected phase patterns under the control of a field programmable gate array (FPGA). To validate the performance, three schemes containing six coding patterns are presented and simulated, after which two of them are measured, showing good agreements with designs. We envision that this work may motivate studies on smart metamaterials with high-level recognition and manipulation.

A one-step single-spinneret electrospinning method is used to prepare tunable In2O3 hierarchical structures of one-dimensional electrospun fibers with in situ growth of octahedron-like particles, a...

Flexible optoelectronic devices have been of great significance in recent years, owing to their extensive commercial and military applications. However, the manufacturing processes of most existing flexible photodetectors are particularly complicated and expensive. Employing a facile and low cost way for constructing a high performance flexible infrared photodetector is one of the effective strategies to facilitate its practical applications. Pencil-drawing is a popular method in novel electronic and optoelectronic devices, as it is a low cost and facile fabrication process. Herein, we report a novel flexible infrared photodetector using liquid-exfoliated Bi2Se3 nanosheets as a light sensitive material, pencil-drawn graphite as the electrodes, and paper as the substrate. The as-fabricated photodetector exhibits high photocurrent, excellent responsivity and long-term stability under 1064 nm infrared light irradiation. In addition, as the pencil-drawn photodetector is made of a flexible paper substrate, it also well exhibits stability and durability under bending conditions. This work is proposed to be a route to construct a novel flexible infrared photodetector with a facile manufacturing process and low cost.

Bacterial cellulose (BC) and silk fibroin (SF) double-network hydrogel with high mechanical strength and biocompatibility was synthesized by using BC as the novel polymer substrate to absorb aqueous SF solution as the modifier. Fundamental physical characterizations were carried out by scanning electron microscopy, energy dispersive spectrometry, fourier transform infrared spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy. Thermogravimetric and differential thermal analysis was used to investigate the stability of the hydrogel. Strength and biocompatibility of the BC/SF hydrogel for cartilage tissue engineering were evaluated by tensile strength tester and cell culture experiments. Results reveal that the BC/SF double-network hydrogel was prepared successfully, and the hydrogel could be used as a cartilage repair material in clinical application.

Graphene has attracted more attention as advanced electrodes for supercapacitors due to its unique geometry structure and outstanding physicochemical property. But its low specific capacitance, especially low volumetric capacitance, has greatly restricted the practical application of graphene electrode materials. Herein, we synthesized nitrogen-containing graphene networks by using 2, 3-diaminopyridine (O-DAP) as functional agent in a facile hydrothermal route. During the hydrothermal process, not only the pyrrolic-N, but also the pyrazine-N is produced in the graphene lattice at the edge/defect site of graphene because of the double –NH2 in DAP reactant. Owing to the high nitrogen content (17.5 at%), special nitrogen configuration, and high density (1.66 g cm−3), the N-containing graphene networks present high gravimetric capacitances up to 353 F g−1 and high volumetric capacitances over 586 F cm−3 in 1 M H2SO4 electrolyte. More remarkably, the N-containing graphene electrodes exhibit exceptional rate capability with a capacitance retention of 80.6% at a high current density of 20 A g−1 and good cycling stability of 91.5% retention after 5000 cycles in a symmetrical two-electrode configuration.

The supersaturated total dissolved gas (TDG) downstream from a dam can result in an increased incidence of gas bubble disease in affected fish. With the development of cascade hydropower, the cumulative effect of cascades on TDG supersaturation is becoming increasingly prominent. This paper presents operational regulations for cascades based on the effect of TDG supersaturation on fish. Optimal regulation of the release structures and discontinuous discharge methods were proposed, and the TDG distribution for cascades in the downstream region of the Jinsha River was simulated. The results indicated that the adoption of bottom orifices rather than spillway tunnels significantly decreased the TDG oversaturation level. Moreover, a discontinuous discharge pattern instead of a continuous pattern minimized the maximum duration of the high TDG level. Based on a comparison of the simulated results of different operational scenarios for the cascades, a regulation scheme was proposed that can reduce the TDG supersaturation risk degree for fish. This paper provides a reference for eco-environmentally friendly operations of cascades to minimize the potential risks of supersaturated TDG to fish.

We present the results of the first Charged-Particle Transport Coefficient Code Comparison Workshop, which was held in Albuquerque, NM October 4-6, 2016. In this first workshop, scientists from eight institutions and four countries gathered to compare calculations of transport coefficients including thermal and electrical conduction, electron-ion coupling, inter-ion diffusion, ion viscosity, and charged particle stopping powers. Here, we give general background on Coulomb coupling and computational expense, review where some transport coefficients appear in hydrodynamic equations, and present the submitted data. Large variations are found when either the relevant Coulomb coupling parameter is large or computational expense causes difficulties. Understanding the general accuracy and uncertainty associated with such transport coefficients is important for quantifying errors in hydrodynamic simulations of inertial confinement fusion and high-energy density experiments., Comment: 45 pages, 17 figures

The rapid and accurate identification of sunflower lodging is important for the assessment of damage to sunflower crops. To develop a fast and accurate method of extraction of information on sunflower lodging, this study improves the inputs to SegNet and U-Net to render them suitable for multi-band image processing. Random forest and two improved deep learning methods are combined with RGB, RGB + NIR, RGB + red-edge, and RGB + NIR + red-edge bands of multi-spectral images captured by a UAV (unmanned aerial vehicle) to construct 12 models to extract information on sunflower lodging. These models are then combined with the method used to ignore edge-related information to predict sunflower lodging. The results of experiments show that the deep learning methods were superior to the random forest method in terms of the obtained lodging information and accuracy. The predictive accuracy of the model constructed by using a combination of SegNet and RGB + NIR had the highest overall accuracy of 88.23%. Adding NIR to RGB improved the accuracy of extraction of the lodging information whereas adding red-edge reduced it. An overlay analysis of the results for the lodging area shows that the extraction error was mainly caused by the failure of the model to recognize lodging in mixed areas and low-coverage areas. The predictive accuracy of information on sunflower lodging when edge-related information was ignored was about 2% higher than that obtained by using the direct splicing method.

Coronavirus disease 2019 (COVID-19) is an emergent infectious pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is highly contagious and pathogenic. COVID-19 has rapidly swept across the world since it was first discovered in December 2019 and has drawn significant attention worldwide. During the early stages of the outbreak in China, traditional Chinese medicines (TCMs) were involved in the whole treatment process. As an indispensable part of TCM, Chinese patent medicines (CPMs) played an irreplaceable role in the prevention and treatment of this epidemic. Their use has achieved remarkable therapeutic efficacy during the period of medical observation and clinical treatment of mild, moderate, severe, and critical cases and during convalescence. In order to better propagate and make full use of the benefits of TCM in the treatment of COVID-19, this review will summarize the potential target of SARS-CoV-2 as well as the theoretical basis and clinical efficacy of recommended 22 CPMs by the National Health Commission and the Administration of TCM and local provinces or cities in the treatment of COVID-19. Additionally, the study will further analyze the drug composition, potential active ingredients, potential targets, regulated signaling pathways, and possible mechanisms for COVID-19 through anti-inflammatory and immunoregulation, antiviral, improve lung injury, antipyretic and organ protection to provide meaningful information about the clinical application of CPMs.

Au nanoparticles (NPs) have been found to be excellent glucose oxidase mimics, while the catalytic processes have rarely been studied. Here, we reveal that the process of glucose oxidation catalyzed by Au NPs is as the same as that of natural glucose oxidase, namely, a two-step reaction including the dehydrogenation of glucose and the subsequent reduction of O2 to H2O2 by two electrons. Pt, Pd, Ru, Rh, and Ir NPs can also catalyze the dehydrogenation of glucose, except that O2 is preferably reduced to H2O. By the electron transfer feature of noble metal NPs, we overcame the limitation that H2O2 must be produced in the traditional two-step glucose assay and realize the rapid colorimetric detections of glucose. Inspired by the electron transport pathway in the catalytic process of natural enzymes, noble metal NPs have also been found to mimic various enzymatic electron transfer reactions including cytochrome c, coenzymes as well as nitrobenzene reductions., Gold nanoparticles (Au NPs) with enzyme-like activities are useful glucose oxidase mimics, but the insights into the mechanism of this reaction are limited. Here, the authors show that the process of glucose oxidation by Au NPs is analogous to the one catalysed by glucose oxidase, involving dehydrogenation and oxygen reduction to H2O2; and that other noble metal NPs also catalyse glucose dehydrogenation, but oxygen is preferably reduced to water.

The Nanpu Sag (NPS), located in northwestern Bohai Bay Basin (BBB), East China, has significant oil discoveries in recent years. The effect of intense faulting and downwraping which generated the intense subsidence of NPS in the Dongying Formation (Fm.) (Ed) (28.5–23.8 Ma) of the Late Oligocene is presented in this paper. We analyzed the geochemical characteristics of the widespread Cenozoic basalts in NPS from drill core samples. Our results show that the magma experienced negligible crustal contamination and slight fractional crystallization, and the features of remarkable positive U, Pb, Sr and Ti anomaly, low Rb/Ba and Rb/Sr values of the NPS basalts were inherited from the source region. The NPS basalts in Ed have distinctive characteristics as sub-alkaline basalts with rare earth elements (REE) patterns parallel to enriched mid-ocean ridge basalts (E-MORB), and were generated from a mixture origin of garnet-lherzolite zone with relatively high degree of partial melting (30%–50%) and garnet + spinel-lherzolite transition zone with partial melting degree ranging from 3% to 15%. In contrast, NPS basalts of other Cenozoic periods or Ed basalts of other areas in eastern China are alkaline with light REE enrichment and oceanic island basalts (OIB)-like-pattern, their magmas originated from garnet + spinel-lherzolite transition zone with partial melting degree lower than 5%. Combined with previous studies of the mantle wedge in the mantle transition zone (MTZ) beneath northeastern Asia, forming around 30 Ma, we infer that the stagnating of the Pacific slab triggered the asthenosphere upwelling and increased the degree of partial melting in mantle source, and relatively weak areas of the North China Craton (NCC) like the Tanlu Fault (TLF) where NPS located on were reactivate and susceptible to be modified. Therefore, the intense faulting and downwarping of NPS in Ed, along with the igneous activities, was a response to the Cenozoic stagnant Pacific slab more than the result of tectonic effects from the Pacific subduction like other areas in northeastern China in Paleogene.

2D Tantalum disulphide (TaS2) has been widely studied as a typical transition metal dichalcogenides (TMDCs) with excellent optical, chemical and electrochemical properties. However, there is little research on the comprehensively characterizing the interaction between light and the 2D TaS2 material. In this work, we studied the nonlinear optical response of the high quality few-layer TaS2 nanosheets and its all-optical applications. Our research shows that 2D TaS2 nanosheet has a broadband characteristic and exhibits a strong Kerr nonlinear optical response based on the spatial self-phase modulation (SSPM). More importantly, by taking advantage of the highly nonlinear optical response of the2D TaS2, typical all-optical phenomena, such as all-optical switching and nonreciprocal light propagation, have been demonstrated experimentally. This work can be viewed as an important demonstration of a TMDCs-based application prototype in nonlinear photonics, which could potentially indicate an essential step toward miscellaneous TMDCs-based passive photonic devices (all-optical diodes, all-optical switches, etc.)

In Temporal Logic (TL), a well-formed formula is generally formed by applying rules of its syntax finitely many times. However, under some circumstances, although formulas such as ones expressed by index set expressions, are constructed via applying rules of the syntax infinitely many times, they are possibly still well-formed since their equivalent concise syntax formulas can be found. With this motivation, this paper investigates the relationship between formulas specified by index set expressions and concise syntax by means of fixed-point approach. Firstly, we present two kinds of formulas, namely ⋁ i ∈ N 0 ◯ i Q and ⋁ i ∈ N 0 Q i , and prove they are indeed well-formed by proving they are equivalent to formulas ◇Q and Q ⁎ respectively. Further, we generalize ⋁ i ∈ N 0 ◯ i Q to ⋁ i ∈ N 0 P ( i ) ∧ ◯ i Q and explore the least and greatest fixed-points of an abstract equation X ≡ Q ∨ P ∧ ◯ X . Based on these, some well-formed special instances of ⋁ i ∈ N 0 P ( i ) ∧ ◯ i Q are obtained. Besides, with the index set expression technique, we equivalently represent ‘ U ’ (strong until) and ‘ W ’ (weak until) constructs of propositional Linear Temporal Logic (LTL) within Propositional Projection Temporal Logic (PPTL).

Intelligence at either the material or metamaterial level is a goal that researchers have been pursuing. From passive to active, metasurfaces have been developed to be programmable to dynamically and arbitrarily manipulate electromagnetic (EM) wavefields. However, the programmable metasurfaces require manual control to switch among different functionalities. Here, we put forth a smart metasurface that has self-adaptively reprogrammable functionalities without human participation. The smart metasurface is capable of sensing ambient environments by integrating an additional sensor(s) and can adaptively adjust its EM operational functionality through an unmanned sensing feedback system. As an illustrative example, we experimentally develop a motion-sensitive smart metasurface integrated with a three-axis gyroscope, which can adjust self-adaptively the EM radiation beams via different rotations of the metasurface. We develop an online feedback algorithm as the control software to make the smart metasurface achieve single-beam and multibeam steering and other dynamic reactions adaptively. The proposed metasurface is extendable to other physical sensors to detect the humidity, temperature, illuminating light, and so on. Our strategy will open up a new avenue for future unmanned devices that are consistent with the ambient environment., Metamaterials: Sensing surfaces that program themselves A metamaterial surface developed by researchers in China automatically adjusts its electromagnetic properties in response to changes in its environment. Metasurfaces are designed with tiny structures arranged in unique ways to manipulate electromagnetic radiation, and efforts are being made to integrate them with digital coding to produce adaptive, programmable systems. Tie Jun Cui at Southeast University in Nanjing and co-workers have designed smart metasurfaces with integrated sensors that detect features such as movement, light or temperature, linked to a microcontroller which responds by changing the configuration of a metasurface. A potential application of the system would be to help moving airplanes maintain contact with satellites; a gyroscope sensor detects changes in orientation, and the metasurface adapts its electromagnetic properties to ensure that the communication beam will always point in the satellite’s direction.

Various NiO/ZnO heterostructures have been prepared by a facile solvothermal method combined with subsequent calcination process. By adjusting the adding proportion of Ni/Zn, the superior performance in photocatalytic degradation of tetracycline (TC) can be achieved in porous NiO/ZnO flower-like microstructures consisting of interlaced nanosheet/particle framework. Compared with NiO hollow microspheres, flower-like NiO/ZnO samples exhibit the enhanced photocatalytic performance with high efficiency of 92% within 30 min as well as good photocatalytic cycle stability to TC, which is mainly ascribed to the combination of larger specific surface area (162.1 m2/g), unique surface/interface effect, faster electron/hole separation, and higher electron transmission. This work paves the way for other oxide composites applied as novel photocatalysts based on the design and construction of interlaced nanosheet/particle heterostructures.

Core-shell structural Ni(OH)2@MnO2 electrodes with widened potential window and great stability are prepared through a two-step strategy, in which freestanding Ni(OH)2 discs grow on nickel-foam as core and wrinkled MnO2 coatings are electrodeposited as shell. The MnO2 shell successfully inhibits the O2 evolution process at the high oxidation potential so that the potential window of Ni(OH)2@MnO2 electrode is up to 1 V. Besides, the Ni(OH)2@MnO2 electrode presents a high specific capacity of 642.3 C g−1 at 1 mV s−1 and a long cyclic life without capacity fading, which is a breakthrough against the poor stability of reported Ni(OH)2/MnO2 electrodes Remarkably, an asymmetric supercapacitor (ASC) constructed by Ni(OH)2@MnO2 electrode and activated carbon electrode delivers a high energy density of 66.7 Wh kg−1 at a power density of 485.7 W kg−1 under potential window of 1.7 V. Furthermore, the ASC exhibits an energy density of 17.8 Wh kg−1 at a high power density of 14571.4 W kg−1 and a capacitance retention of 101.4% after 15,000 cycles, showing great rate capability and stable cyclic performance.

In this paper, the bursting performance of triaxial woven fabric and its reinforced rubber composites are studied by the finite element method and the experimental approach, and compared with plain woven fabric and its reinforced rubber composites. The bursting morphologies and load–displacement curves of the specimens during the bursting process are obtained. The results indicate that the rubber matrix has a protective and consolidation effect on the inner fabric, significantly improving the bursting strength of the fabric. Triaxial woven fabric shows a steeper load–displacement slope, higher maximum bursting load, and smaller initial damage displacement than plain woven fabric. The bursting morphologies of the specimens indicate that the structure of triaxial woven fabric is more stable and exhibits good expansion resistance to bursting damage. The bursting process of triaxial woven fabric can be divided into four stages: yarn straightening, yarn slippage, yarn breakage, and breakage extension.

In addition to superior enzyme-mimicking abilities, nanozymes also have intrinsic physicochemical properties. Integrating the enzyme-like activities and tunable physicochemical properties into a single nanoparticle is a promising strategy for versatile nanozyme design and application. Herein, a composite nanozyme in which Au nanoparticles are encapsulated by Au nanoclusters (AuNP@AuNCs) is presented. By integrating the peroxidase-mimicking ability of fluorescent Au NCs with the glucose oxidase-like activity of Au NPs, the composite nanozyme realized cascade assay of glucose without the aid of external indicators. Compared to traditional multistep colorimetric methods, the analytical process was highly simplified by using the self-responsive nanozyme. This synthetic strategy provided valuable insights into exploring talented nanozymes for sensing diverse targets.

One-step single-spinneret electrospinning synthesis of 1D fibrous hierarchical structure can not only prevent the agglomeration or restacking of fibers or particles and enlarge surface active area but also promote the directional migration of electrons in materials and achieve effective regulation of resistances. Herein, tunable SnO2 and SnO2/ZnO fibrous hierarchical structures with in situ growth of monodisperse spherical-like particles on surface provide a new sight for adjusting component distribution, surface absorption and chemical reaction, electronic transmission path, and electron transfer efficiency. Compared with SnO2 porous fibers and SnO2 hierarchical structures, the optimal SnO2/ZnO sensors exhibit superior gas-sensing response value of 366-100 ppm ethanol at 260 °C as well as excellent gas selectivity and long-term stability, in which the enhanced gas-sensing mechanism is primarily derived from multilevel effective heterojunctions with unique interface electronic effects. Especially, these SnO2-based sensors can achieve favorable linear relationship of the response and gas concentration for sensitive trace detection in cosmetics for the first time, providing a new strategy to design composite materials for quantitative analysis of volatiles in the cosmetics evaluation process.

Particulate matter is the main air pollutant in China, especially in Xi'an in recent years. Since 2013, the WRF-SMOKE-CMAQ model system has been used to build an air quality model system for daily air quality forecasting in Xi'an. The emission inventory was built based on several anthropogenic emission inventories and open access emission datasets, and the model evaluation is presented to verify the emission inventory for particulate matter in Xi'an. Comparing the daily observed and simulated fine particulate (PM2.5) concentrations for four winters in different years (from 2014 to 2017), the model performs well in all studied time periods. The correlation coefficient of the simulated daily PM2.5 concentration data are all larger than 0.58, reaches 0.80 in 2016, and the fraction of predictions within a factor of two of observations (FAC2) are all above 66%. The differences of simulated results based on emission-unchanged system between 2014 and 2015 indicate that the slightly deteriorating air quality of 2015 is affected by the unfavorable air diffusion condition. The PM10 concentration increases from 95.9 μg/m3 to 110.3 μg/m3, and the PM2.5 from 82.4 μg/m3 to 95.4 μg/m3. According to the error analysis in model performance, the serious polluted situation of 2016 is mostly because of the sharp increased dust emissions. The emission-unchanged simulated particulate matter concentrations have little variation from 2015 to 2016, but the observation data increase obviously, that results in dramatically change of Mean Bias (MB). The absolute MB of PM10 increase from 70.3 μg/m3 to 135.2 μg/m3, and PM2.5 from 0.46 μg/m3 to 69.9 μg/m3. While the improved air quality in 2017 is attributed to both the better weather condition and the emission-reductions. The emission-unchanged simulated results decrease, and the absolute MB even have bigger decrease, that of the PM10 concentration reduce by 47μg/m3, and PM2.5 by 37μg/m3.

Tetragonal zircon BiVO4 (P-BiVO4) were grown on fluorine-doped tin oxide (FTO) glass via hydrothermal method. The cathodic photocurrent and Mott-Schottky analysis indicate that the tetragonal zircon BiVO4 is a p-type semiconductor. Inductively coupled plasma (ICP) analysis and X-ray photoelectron spectrum showed that there are Bi vacancies and interstitial oxygen exist in the crystal, which are the origin of the p-type conductivity. The flat band potential of the P-BiVO4 is about 1.33 V (vs Ag/AgCl) inferred from Mott-Schottky plots. Combining with diffuse reflection spectrum and valence band X-ray photoelectron spectrum, the calculated conduction band value of the P-BiVO4 is about 0.06 V vs RHE, slightly higher than the reduction potential of hydrogen. However, the P-BiVO4 exhibit hydrogen production activity under Xe light irradiation even though its conduction band level is not negative enough. This can be attributed to the hot carrier processes in p-type semiconductors.

A lossy-mode resonance (LMR) refractive index (RI) sensor with a few layer transition metal dichalcogenides (TMDs) is proposed. Contrasting with traditional surface plasmon resonance (SPR) sensors, the LMR sensor can support both transverse magnetic (TM) and transverse electric (TE) polarizations, while the traditional SPR sensors can only operate for TM polarization. Through theoretical calculation and simulation, we find that the proposed LMR sensor can realize higher sensitive and narrower full width half maximum (FWHM), and the most attractive character is figure-of-merit (FOM) with 1582 RIU−1, which is a significant improvement compared to the existing LMR sensors and is even 40% higher than the best graphene-based SPR sensors. We trust that the proposed LMR sensor can be extensively applied in optical sensing technology, chemical biomolecular detection, and so on.

Hierarchical WO3/ZnWO4 1D fibrous heterostructures with tunable in-situ growth of WO3 nanoparticles on surface have been fabricated by the original one-step electrospinning technology combined with subsequent calcination process. Phase composition and morphology can be transformed from bead-like WO3 fibers to hierarchical WO3/ZnWO4 1D composites with the introduction of ZIF-8 into the precursor solution, which was mainly attributed to the combination of nucleation competition and crystal planes matching mechanisms during heat treatment. Compared with pure WO3 and WO3/ZnWO4-10%, WO3/ZnWO4-5% displayed the highest specific surface area value evaluated to be 268.57, indicating the prominent enhanced absorption behavior for targeted organic species. It is found that WO3/ZnWO4-5% composites have a response about 44.5 for 5 ppm HCHO, which was almost 8 times higher than that of sensor based on pure WO3 nanofibers at the optimal operating temperature. Meanwhile, the fast response/recovery time (12/14 s) and excellent stability characteristics (recycling, long-term, and humidity stability) towards HCHO can be also observed for WO3/ZnWO4-5% samples. The enhanced gas-sensing mechanism based on WO3/ZnWO4 composites can be ascribed to the synergistic effect of effective heterojunctions, large specific surface area, multiple reaction sites, and unique surface/interface electron transmission. The design and construction of hierarchical WO3/ZnWO4 1D materials attest to the significant potential of their use as novel gas sensors for detecting low concentration HCHO.

Mid−infrared (MIR) nonlinear optical (NLO) material is critical to laser frequency−conversion technology. Although the main commercial MIR NLO crystals (AgGaS2 AgGaSe2 and ZnGeP2) are practically used, they still have some intrinsic drawbacks, so that it is of great scientific significance to discover new materials with good MIR NLO performances. Among the main systems of chalcogenides to explore MIR NLO crystals, metal thiophosphates and selenophosphates are competitive for their structural diversities and strong covalent P−Q bonds. Here, Ag4P2Se6 (P212121) was selected to evaluate the second−order harmonic generation (SHG) property. As a result, the SHG response with phase−matching ability is about 0.5 times that of AgGaS2 at 2.05 μm in the particle range of 210–270 μm, and the laser damage threshold (LDT) is larger than that of AgGaS2. Remarkably, this compound is of low melt temperature of 642 °C with a congruent melting character, also possesses excellent chemical stability, facilitating its further crystal growth and fabrication.

Potholes carved into streambeds of the Jurassic and Cretaceous sandstone and mudstone along the Sunxi River (Chongqing, China) have been carefully investigated in order to characterize the geometrical features of the potholes and to explore their implications for river incision into bedrock. The potholes formed by gyratory currents through abrasion are characterized by an average aperture aspect-ratio (a/b) of ∼1.2 and a mean diameter-to-depth ratio (D/h) of ∼1.0. The most parsimonious model for the h-D relationship over the full range of data is a linear equation in which 2 parameters (n is the slope of the line and m is the D-intercept) are essentially controlled by hydrodynamics. Data of the Sunxi River yield that n = 0.71 ± 0.18, indicating that the pothole deepening was faster than the pothole widening by a quasi-constant factor of ∼1.4 during abrasive erosion as the dominant mechanism of pothole development in bedrocks of sandstone interbedded with mudstone. The m value, which varies from 5.9 cm to 11.0 cm, apparently depends on hydrodynamics at each locality, and can be inferred as the dimensional threshold of initial depressions from which potholes grew by deepening and lateral expanding. The potholes with D/h = 1 are prone to entrap and retain coarser sediments which are more effective for pothole growth. The bedrock weakened significantly by coalescence of numerous potholes is easily broken, detached, and removed by flooding (truncation). The cyclic pothole-truncation process is particularly important for incision of bedrock channels and thus landscape evolution of mountain ranges in response to tectonic uplift and climate change.

In this paper, we focused on the hydrothermal synthesis of ZnO structures with varied morphologies by finely adjusting the ratio of water to glycol, indicating the polarity of the solution affects the growth habit of the crystal. It showed that the precise control in growth rates of different ZnO crystal faces in mixed solution is the key factor to control the morphologies of ZnO samples. Compared to pure ZnO, the response value of the hemispherical ZnO/Au to 100 ppm triethylamine (TEA) has been improved to 104.8 at the operating temperature of 260 °C, and the response and recovery time are 5 and 2 s, respectively. The enhancing mechanism of as-prepared ZnO/Au hemispheres can be ascribed to the combination of the tuning of surface electron transfer , microstructures, and the electronic and chemical sensitization of Au nanoparticles , along with the formation of Schottky junction between Au nanoparticles and ZnO hemispheres. The excellent sensing performance of ZnO/Au composite hemispheres enables them to function as promising materials for actual application in the monitoring and detecting of TEA.

A simple fluorescence biosensor for rapid and sensitive target microRNA (miRNA) quantification by branched rolling circle amplification (BRCA) is developed in this work. Target miRNA functions as primer to recognize and hybridize with a circle DNA template, initiating rolling circle amplification (RCA) by Phi29 DNA polymerase. The introduction of reverse primers complementary to the RCA products enables isothermal BRCA, in which a large amount of deoxynucleotide (dNTP) were consumed and same number of pyrophosphates (PPi) were produced. In this study, a simple and non-expensively synthesized terpyridine-based Zn(II) complex is utilized as fluorescent probe for selective detection of pyrophosphate (PPi) over dNTP. The PPi generated in this isothermal amplification process efficiently chelates to this terpyridine-Zn(II) complex, forming a highly fluorescent complex, terpyridine-Zn(II)-PPi, whose fluorescence intensity is closely related with the initial target miRNA concentration. The utilization of the isothermal BRCA amplification and direct monitoring of the DNA polymerization by-product, i.e. PPi, for non-label fluorescence detection of miRNA greatly simplify this sensor procedure. This sensor shows a linear response between the fluorescence intensity and the target miRNA concentration from 50 to 500 fM with a detection limit of 25 fM. This much-simplified sensor offers a sensitive and easy-to-use platform for miRNA quantification, and hence may significantly enhance the utilisation of miRNAs as biomarkers in drug discovery, clinical diagnosis and life science research. Ministry of Education (MOE) Financial support of this work by the Ministry of Education (R-143- 000-A14-114 and R-143-000-A14-133) is gratefully acknowledged.

Morphology-tunable C–N/SnO2-based hierarchical microspheres with good gas sensitivity for triethylamine (TEA) have been fabricated via facile electrospinning and a subsequent calcination process. The reaction temperature and modifying calcining technology played a dominant role for the morphological evolution from precursor fibers to microspherical shapes and the formation of C–N-decorated SnO2 phase composition. C–N/SnO2/ZnO composites with tunable crystallinity, microstructure, and gas-sensing performance were strictly dependent on the added amount of Zn element. Fascinatingly, the constructed C–N/SnO2/ZnO/Au composites can not only precisely regulate the crystal size, dispersion status, loading position, and content of Au nanoparticles but also display excellent gas-sensing properties with ultrasensitivity and high selectivity under various temperature detections. The response of C–N/SnO2/ZnO/Au composites can reach up to approximately 1970, calculated to be 121.6 and 23.6 times for 50 ppm TEA molecule...

The aim of mining fuzzy association rules is to find both the association and the casual relationships between the itemsets. With the arrival of dynamic data, the fuzzy association rules should be updated in real time. However, most of the existing algorithms must remine the updated database and can only be applied in classification. This paper proposes an incremental fuzzy association rule mining algorithm to solve classification and regression problems. First, the sliding window is adopted to divide the fuzzy dataset. Second, the dynamic fuzzy variable selection algorithm is adopted to select variables for reducing the search space of the fuzzy association rule mining. Finally, in each sliding window, the result of variable selection is used to incrementally mine the causal fuzzy association rules with the fuzzy Eclat algorithm. When new data are added, the process judges whether concept drift occurs, and if so, the rule set is updated; otherwise, the original rule set is still applied. The weights of the rules are calculated to find the evolving relationship. The simulation result shows that this algorithm can improve accuracy and efficiency.

Polypyrrole (PPy) composites incorporating yttrium iron garnet (YIG) particles were prepared by an in situ oxidative polymerization method. The effects of YIG particle loading level on the radio-frequency (RF) electromagnetic properties of the YIG/PPy composites were systematically investigated. A negative permittivity behaviour combined with metal-like conduction was observed in the PPy composites, which was due to the low-frequency plasmonic state of free electrons in the formed conducting PPy networks. The Drude model was used to give a good description of the dielectric response. After increasing the YIG loading, the plasma frequency, at which the real part of permittivity changed from negative to positive, shifted to a lower frequency, and the magnitude (absolute value) of negative permittivity also became smaller. In addition, the permeability of the composites showed a relaxation-type frequency dispersion, which was attributed to the combined effect of the magnetic resonance of YIG particles and diamagnetic response of PPy conducting networks. This work can pave the way for exploiting the regulation mechanism of negative permittivity, benefiting the practical applications of polymer metamaterials.