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Effective and robust electrocatalysts are mainly based on innovative materials and unique structures. Herein, we designed a flakelike cobalt phosphide-based catalyst supporting on NiCo2O4 nanorods array, which in-situ grew on the nickel foam (NF) current collector, referring as N–Co2P/NiCo2O4/NF electrode. By optimizing the microstructure and electronic structure through 3D hierarchy fabrication and nitrogen doping, the catalyst features with abundant electrochemical surface area, favorable surface wettability, excellent electron transport, as well as tailored d band center. Consequently, the as-prepared N–Co2P/NiCo2O4/NF electrode exhibits an impressive HER activity with a low overpotentials of 58 mV at 10 mA cm−2, a Tafel slop of 75 mV dec−1, as well as superior durability in alkaline medium. This work may provide a new pathway to effectively improve the hydrogen evolution performance of transition metal phosphides and to develop promising electrodes for practical electrocatalysis.

The renewable energy-powered electroreduction of carbon dioxide or monoxide (CO) has been emerging as an attractive means to decarbonize the emission-intensive chemical manufacturing, which heavily relies on fossil fuels nowadays. One potential approach to promote the activity of electrocatalysts is to construct hybrid interface that can increase the stability of intermediates on electrode surfaces. Herein we developed a copper nanoparticle/polypyrrole (Cu-Ppy) nanowire composite as an efficient electrocatalyst for electrochemical CO reduction reaction. Compared to pure Cu nanoparticles, the Cu-Ppy composite exhibited a dramatically enhanced Faradaic efficiency of converting CO to ethylene (C2H4) from 34% to 69% at −0.78 V vs. reversible hydrogen electrode (RHE) in KOH electrolyte, and an excellent C2H4 partial current density of 276 mA·cm−2 at −1.18 V vs. RHE. Density functional theory calculations showed that the Cu-Ppy composite could bind CO more strongly as compared to pure Cu. As the Ppy coating allowed to stabilize OCCO*, a key intermediate in the C2H4 formation, both the activity and selectivity of Cu-Ppy for CO-to-C2H4 were increased. Our work suggests that constructing rationally designed hybrid interface can tune the local environment of catalyst surface toward enhanced activity and product selectivity.

High-efficiency chemiluminescence (CL) resonance energy transfer (CRET) can be obtained by shortening the donor-acceptor distance and/or improving the luminescence efficiency of CRET acceptors. However, careful design and stringent experimental conditions are usually required for the ordered assembly of CRET acceptors on support materials to avoid aggregation-caused quenching problems. In this work, an aggregation-induced emission (AIE)-active fluorophore was disorderly adsorbed on the surface of layered double hydroxides (LDHs), which could exhibit high-efficiency luminescence. On the other hand, the positively charged LDHs can further adsorb peroxynitrite (ONOO-) on the surface of LDHs. Therefore, the LDH-supported AIE fluorophore could dramatically amplify weak CL signals from ONOO- donors as a result of ultra-high CRET efficiency by coupling the shorter donor-acceptor distance with efficient CRET acceptors. The proposed CL system has been successfully applied for the detection of NaNO2 in the concentration range from 1.0 to 100 μM with a detection limit as low as 0.5 μM. Satisfactory recoveries (98-106%) and good accuracy were achieved for sausage samples. Our success will open new avenues for the convenient design of high-efficiency CRET systems.

The redox field generated by electrically conductive minerals is one of the main constituents of self-potentials. It can be explained by electrochemical reactions in which conductors participate. The location and outline of seafloor hydrothermal ore deposits can be detected using marine self-potential anomalies that can be approximated through a marine geobattery model. The numerical modeling of marine self-potentials could be the foundation of corresponding data inversion and interpretation and improving the application effect of the self-potential method in detecting seafloor hydrothermal ore deposits. In this study, the inert electrode model and the on-land geobattery model are introduced to build the marine geobattery model, and the finite-infinite element coupling method is derived to deal with the truncated boundary problem effectively. Also, two tests are conducted to study the effect of model parameters on ground self-potential anomalies. A seafloor sulfide deposit model is built to study the self-potential characteristics. The numerical modeling results suggest that the precision and efficiency of the coupled method are superior to that of the traditional finite element method. Self-potential anomalies are greatly affected by medium resistivity, complex terrain, and amplitudes of embedded redox fields. Gradient changes in embedded redox fields do not cause significant self-potential anomalies but lead to mutations of current sources. The self-potential anomaly from the sulfide deposit model shows that the self-potential method can be effectively used to explore seafloor hydrothermal deposits that accompany negative self-potential anomalies above the ore bodies. The coupled method is quite suitable for multi-source models such as self-potential models.

ZIF-67@NH2–SiO2 composites were prepared by loading the metal-organic frameworks ZIF-67 on amino modified SiO2 gel particles (NH2–SiO2, 80–100 mesh) through layer-by-layer self-assembly method. Systematic investigation on the effects of ZIF-67 loading amounts on NH2–SiO2 packed stainless steel chromatographic column (specification 1.0 m×2.0 mm I.D.), the flow rate of He as carrier gas and the injection amount of mixed gas (H2/D2) on the hydrogen isotope H2/D2 separation performance at liquid nitrogen temperature, unraveled the optimal conditions for H2/D2 isotope separation. The results showed that the optimal stationary phase materials under the optimized conditions can effectively separate H2 and D2 with separation resolution R = 1.52 and the separation time t = 10.15 min. The superior performance of the ZIF-67 is tentatively thought to be due to kinetic quantum sieving (pore size 3.3 A) effect and chemical affinity sieving effect of Co ion in ZIF-67.

Levoglucosan has been widely used to quantitatively assess biomass burning's contribution to ambient aerosols, but previous such assessments have not accounted for levoglucosan's degradation in the atmosphere. We develop the first global simulation of atmospheric levoglucosan, explicitly accounting for its chemical degradation, to evaluate the impacts on levoglucosan's use in quantitative aerosol source apportionment. Levoglucosan is emitted into the atmosphere from the burning of plant matter in open fires (1.7 Tg yr-1) and as biofuels (2.1 Tg yr-1). Sinks of atmospheric levoglucosan include aqueous-phase oxidation (2.9 Tg yr-1), heterogeneous oxidation (0.16 Tg yr-1), gas-phase oxidation (1.4 × 10-4 Tg yr-1), and dry and wet deposition (0.27 and 0.43 Tg yr -1). The global atmospheric burden of levoglucosan is 19 Gg with a lifetime of 1.8 days. Observations show a sharp decline in levoglucosan's concentrations and its relative abundance to organic carbon aerosol (OC) and particulate K+ from near-source to remote sites. We show that such features can only be reproduced when levoglucosan's chemical degradation is included in the model. Using model results, we develop statistical parametrizations to account for the atmospheric degradation in levoglucosan measurements, improving their use for quantitative aerosol source apportionment.

Electrochemical CO2 reduction can produce valuable products with high energy densities but the process is plagued by poor selectivities and low yields. Propanol represents a challenging product to obtain due to the complicated C3 forming mechanism that requires both stabilization of *C2 intermediates and subsequent C1–C2 coupling. Herein, density function theory calculations revealed that double sulfur vacancies formed on hexagonal copper sulfide can feature as efficient electrocatalytic centers for stabilizing both CO* and OCCO* dimer, and further CO–OCCO coupling to form C3 species, which cannot be realized on CuS with single or no sulfur vacancies. The double sulfur vacancies were then experimentally synthesized by an electrochemical lithium tuning strategy, during which the density of sulfur vacancies was well-tuned by the charge/discharge cycle number. The double sulfur vacancy-rich CuS catalyst exhibited a Faradaic efficiency toward n-propanol of 15.4 ± 1% at −1.05 V versus reversible hydrogen electrode in H-cells, and a high partial current density of 9.9 mA cm−2 at −0.85 V in flow-cells, comparable to the best reported electrochemical CO2 reduction toward n-propanol. Our work suggests an attractive approach to create anion vacancy pairs as catalytic centers for multi-carbon-products. Electrochemical CO2 reduction to the valuable n-propanol is challenging due to the complicated C3 forming mechanism. Here, authors demonstrate double sulfur vacancies formed on hexagonal copper sulfide can serve as efficient electrocatalytic centers.

Biomass chars are a major component of the soil environmental black carbon pool and prepared forms are a potentially useful tool in remediation. A function critical to the roles of both environmental and prepared chars is sorption of organic compounds. Char properties known to control sorption include surface area, porosity, functional group composition, and percent aromatic carbon. Here, we show that sorption affinity (but not maximum capacity) of organic compounds is directly related to the degree of condensation of the aromatic fraction. The Dubinin-Ashtakov characteristic sorption energy (EDA, kJ mol-1) of 22 compounds on a thermoseries of bamboo chars correlates strongly with the DP/MAS-13C NMR-determined bridgehead aromatic carbon fraction (χb), which relates to the mean ring cluster size. Density functional theory-computed binding energy (Ebd) for five of the compounds on a representative series of polybenzenoid hydrocarbon open-face sheets also correlates positively with χb, leveling off for rings larger than ∼C55. The Ebd, in turn, correlates strongly with EDA. An increase in Ebd with cluster size is also found for sorption, both monolayer and bilayer, between parallel sheets representing slit micropores. The increasing sorption energy with cluster size is shown to be due to increasing cluster polarizability, which strengthens dispersion forces with the sorbate. The findings underscore a previously overlooked explicit role of aromatic condensation in sorption energy, and illustrate the utility of EDA-Ebd comparison for predicting sorption.

Chromium is recognized as one of the most harmful heavy metal pollutants. Facile and efficient Cr(VI) removal technology is an urgent need, but still a challenge. Here, a novel core–shell magnetic mesoporous polydopamine nanocomposite adsorbent (Fe3O4@mesoPDA) was prepared by in situ polymerization of dopamine on the surface of Fe3O4 nanoparticles. The adsorption of Cr(VI) was highly pH-dependent, and optimal Cr(VI) adsorption occurred at pH = 1.5 with a maximum adsorption capacity of 574.71 mg g−1. The adsorption kinetics results showed that the large-sized mesoporous polydopamine shell layers of Fe3O4@mesoPDA significantly increased the adsorption sites and removal rate of Cr(VI), and its inner core Fe3O4 nanoparticles could also accelerate Cr(VI) removal. The adsorption mechanisms of Fe3O4@mesoPDA were primarily redox reactions and also involved electrostatic interactions and coordination. Cr(VI) was mainly reduced to Cr(III) by catechol and imino groups of PDA shell layers, but the pathway of the superoxide radical reduction of Cr(VI) mediated by iron ions on the surface of Fe3O4 nanoparticles could promote the electron transfer between PDA shell layers and Cr(VI) and greatly improve the adsorption performance of Fe3O4@mesoPDA, especially under weak acid conditions. Meanwhile, newly generated Cr(III) was further immobilized onto Fe3O4@mesoPDA through coordination with N and O functional groups and recovered by magnetic separation in favor of decreasing the environmental hazard of heavy metal Cr. Overall, this work can provide new insights into the interaction mechanisms between PDA-based adsorbents and Cr(VI), and also offers a significant reference for the subsequent preparation of Cr(VI) adsorbents.

In this study, perfluorosulfonic acid (PFSA) was firstly grafted on multi-walled carbon nanotubes (MWCNTs) to obtain PFSA-g-MWCNT nanocomposites. The combination of MWCNTs with PFSA effectively prevents the interactions among them, so that the dispersion of PFSA-g-MWCNTs in N,N-dimethylacetamide (DMAc) was greatly improved. Then, polyethersulfone (PES)/PFSA-g-MWCNT ultrafiltration (UF) membranes were prepared via a non-solvent induced phase separation (NIPS) method using different contents of PFSA-g-MWCNT nanocomposites as additives. The nanocomposites and membranes were characterized using techniques including Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy (SEM). The SEM images show that the PFSA-g-MWCNTs no longer agglomerate and entangle, and exist as individual nanotubes in the PES/PFSA-g-MWCNT membrane. The mechanical and thermal properties of the composite membranes were enhanced with the increasing PFSA-g-MWCNT nanocomposite content. The performance of the UF membrane was evaluated using bovine serum albumin (BSA) as a model system. The results show that the permeation and antifouling performances of the PES/PFSA-g-MWCNT membranes were enhanced. For example, the pure water flux, BSA rejection and pure water flux recovery rate of the PES (M0) membrane were 80.49 L m−2 h−1, 86.29%, and 70.96%, respectively, while for the PES/PFSA-g-MWCNT (M6) membrane, they were 447.83 L m−2 h−1, 87.47%, and 92.10%, respectively. Long-term stability experiments show that the PES/PFSA-g-MWCNT membrane still maintains a high pure water flux.

Artificial visual memories (AVMs) are crucial to many technologies, including artificial intelligence, humanoid robots, and visual prostheses. Most studies used a thick polycrystalline film as the AVM active layer to achieve a continuous channel for charge collection. However, because of the inherent interlayer shielding effect in thick films, both photogating and electrical gating are inefficient and the photoresponse of these AVMs is extremely low. Herein, the obstacle of the interlayer shielding effect in thick films is overcome by using molecularly thin two-dimensional molecular crystals (2DMCs). Because of the highly efficient photogating and electrical gating effects of 2D channels, the developed AVMs based on few-layered 2DMCs show record-high photoresponse. The AVMs also exhibited multilevel non-volatile memory functionality, with long retention time and excellent write–erase stability, by exploiting the persistent photoconductivity effect.

In this work, we demonstrated a facile approach for the formation of Ag octopods via pseudomorphic transformation of Ag2O by using histidine as a shape-directing agent. In this approach, Ag2O octopods were firstly formed via precipitation of AgNO3 in basic solutions, and their size increased with the increased concentration of histidine introduced into the solutions. After reduction of the Ag2O octopods by hydroxylamine, the resulting Ag particles well kept the shape and size of the Ag2O ones. Such pseudomorphic transformation allowed the formation of Ag octopods with tunable size (161–260 nm) and localized surface plasmon resonance (750–1380 nm), dependent on the concentration of histidine used in the reactions. Attributed to the well-defined size and morphology, the resulting Ag octopods showed well reproducible surface-enhanced Raman scattering (SERS) signals with a relative standard derivation lower than 5%, qualified as substrates in quantitative SERS detection.

The development of three-dimensional (3D) single-cell imaging and protein quantitative methods can provide more comprehensive information for diagnoses. We report the design and synthesis of a multisignal nanoprobe (AuGdNC@BSA-CV) for single-cell 3D imaging and quantifying the integrin αIIbβ3 using correlated synchrotron radiation soft X-ray tomography microscopy and an iterative tomographic algorithm termed equally sloped tomography for the first time. Moreover, on the basis of the Au or Gd content of our nanoprobe, the number of integrin αIIbβ3 on a single cell also can be accurately quantified (1.5 × 107 per cell) via inductively coupled plasma mass spectrometry.

The electrochemical reduction of carbon dioxide and nitrite ions into value-added chemicals represents one of the most promising approaches to relieve the greenhouse gases, while a critical challenge is to search for a highly effective catalyst with low energy input and high conversion selectivity. In this work, we demonstrated low-valence Cu doped, oxygen vacancy-rich anatase TiO2 (Cu-TiO2) nanotubes as a synergetic catalyst for electrochemical co-reduction of both CO2 and NO2–. The incorporation of Cu dopants in anatase TiO2 facilitated to form abundant oxygen vacancies and bi-Ti3+ defect sites, which allowed for efficient nitrite adsorption and activation. The low-valence Cu dopants also served as effective catalytic centers to reduce CO2 into CO* adsorbate. The close proximity of CO* and NH2* intermediates was beneficial for the subsequent cooperative tandem reaction to form urea via the C N coupling. This oxygen vacancy-rich Cu-TiO2 electrocatalyst enabled excellent urea production rate (20.8 μmol⋅h−1) and corresponding Faradaic efficiency (43.1%) at a low overpotential of –0.4 V versus reversible hydrogen electrode, substantially superior than those of undoped TiO2, thus suggesting an exciting approach for cooperative CO2 and nitrogen fixation.

The streaming potential in porous media is one of the main constituents of the self-potential. It has attracted special attention in environmental and engineering geophysics. Forward modeling of streaming potentials could be the foundation of corresponding data inversion and interpretation, and improving the application effect of the self-potential method. The traditional finite element method has a large subdivision area and computational quantity, and the artificial boundary condition is not suitable for complex models. The Helmholtz-Smoluchowski equation is introduced for evaluating the streaming potential. Then three new shape functions of the multidirectional mapping infinite elements are proposed and the finite-infinite element coupling method is deduced for reducing the subdivision scale and improving both the calculation efficiency and accuracy. The correctness and validity of the new coupled method are verified by a resistive model in homogeneous half-space. Besides, a seepage model with complex terrain and a landfill model with dynamic leakages are modeled using the improved coupled method. The results show that the accuracy of the improved coupled method is superior to the unimproved coupled method, and is better than the finite element method. Also, the coupled method has better adaptability to complex models and is suitable for the accurate simulation of dynamic multi-source seepage models.

Due to the unpredictable nature of a battlefield environment, in the simultaneous degradation of sulfur mustard and nerve agents it is preferable to use just one decontaminant. Herein, the new composite HPVMo@MOF-808 (HPVMo = H5PV2Mo10O40) was deliberately synthesized via a simple impregnation method and thoroughly characterized. The results showed that the decontamination rate of the composites (30-40 mg) with optimal HPVMo loadings for HD (4 μL) and GD (4 μL) under ambient conditions was 97.2% (within 120 min) and 90.8% (within 30 min), respectively. Due to the combinational/synergistic effect of MOF-808 and encapsulated homogeneously dispersed HPVMo, the composite can very efficiently oxidize HD to nontoxic products in a single system, while retaining the inherent excellence of MOF-808 in hydrolytically degrading GD. The decontamination process was found to follow first-order reaction kinetics, and the rate constant and half-life of the composite for HD and GD were 0.0231 min-1, 30.13 min and 0.0795 min-1, 8.72 min, respectively. In addition, experimental results in guinea pigs and Kunming mice used as animal models showed that the composite provided effective skin protection against HD and GD, showing great potential for application in skin decontamination and protection.

To improve the high-value application of corn stalk, phosphorus-containing stalk cellulose (PFC) was prepared, characterized, and utilized for the adsorption of sulfamethoxazole (SMZ) and sulfadiazine (SD), with maximum adsorption capacities of 1.385 and 2.527 mg/g at pH 7. As expected, the adsorption efficiency of PFC was strongly affected by pH, and the preferential adsorption order of SMZ− (SD0) > SMZ0 (SD−) > SMZ+ (SD+) was obtained from the experimental results and due to the charges of PFC and the SMZ and SD species. Furthermore, these results were qualitatively linked to the adsorption mechanism, e.g., π+-π electron donor-acceptor (EDA), anion-π bond electrostatic, and hydrophobic interactions. In particular, the adsorption mechanism was further characterized in terms of structure and analyzed systematically using density functional theory (DFT), frontier orbital theory (FOT), and molecular dynamics (MD) simulation, with the aim to explain the theoretical calculation and experimental results. As a result, the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) orbitals revealed the key role of the rings and functional groups of PFC and SMZ (or SD) and validated the optimized structures of PFC+ sulfonamides (SAs)+, PFC− SAs0, and PFC− SAs−, in which their binding energy values, energy gaps, and relevant molecular lengths determined their stability. Additionally, the van der Waals (vdW) energy confirmed the effect of various interactions on adsorption.

The multishell-structured NaYF4:Yb,Tm,Nd@NaYF4:Yb,Nd@SiO2@ZnO nanospheres were synthesized for the first time by combining active-core/active-shell structured upconversion nanoparticles (UCNPs) wit...

A hierarchical multiporous ternary composite HPW@HKUST-1/γ-Al2O3 (HPW = phosphotungstic acid) is prepared, in which the nanosized HPW@HKUST-1 is formed on both the external and internal surface of mesoporous γ-Al2O3 beads due to the confinement effect of internal pores/channels of the γ-Al2O3 beads. The composite not only possesses excellent adsorptive desulfurization capacity (e.g. 65.3 mg S/g MOF for dibenzothiophene; the adsorption capacities decreased in the order of dibenzothiophene > benzothiophene > 3-methylthiophene > 4,6-dimethyldibenzothiophene) superior to HKUST-1/γ-Al2O3 beads due to the significant role of the favorable acid-base interaction between acidic HPW and slightly basic sulfur-containing compounds, but also exhibits super acid catalytic activity for hydrolysis of ethyl acetate (325.6 mmol molacid −1 min−1) and for synthesis of ethyl acetate (75.4 mol molacid −1 min−1) and n-butyl acetate (13.2 mol molacid −1 min−1) with selectivity of 100%, due to high dispersion and free access of the HPW in the composite which features high surface area and more easily accessible active sites of HPW and HKUST-1. Besides, the composite features remarkable mechanical strength, chemical/thermal stability, being friendly to the environment, and low cost, can easily be regenerated and reused many times for both acid catalysis reactions and adsorptive desulfurization without observable HPW leaching or material dissolution/decomposition.

To determine the role of pyruvate dehydrogenase complex (PDHC) in Klebsiella pneumoniae, the growth and metabolism of PDHC-deficient mutant in glycerol-based medium were analyzed and compared with those of other strains. Under aerobic conditions, the PDHC activity was fourfold higher than that of pyruvate formate lyase (PFL), and blocking of PDHC caused severe growth defect and pyruvate accumulation, indicating that the carbon flux through pyruvate to acetyl coenzyme A mainly depended on PDHC. Under anaerobic conditions, although the PDHC activity was only 50% of that of PFL, blocking of PDHC resulted in more growth defect than blocking of PFL. Subsequently, combined with the requirement of CO2 and intracellular redox status, it was presumed that the critical role of PDHC was to provide NADH for the anaerobic growth of K. pneumoniae. This presumption was confirmed in the PDHC-deficient mutant by further blocking one of the formate dehydrogenases, FdnGHI. Besides, based on our data, it can also be suggested that an improvement in the carbon flux in the PFL-deficient mutant could be an effective strategy to construct highyielding 1,3-propanediol-producing K. pneumoniae strain.

Knowing the phase relations of carbon-bearing phases at high-pressure (HP) and high-temperature (HT) condition is essential for understanding the deep carbon cycle in the subduction zones. In particular, the phase relation of carbon-bearing phases is also strongly influenced by redox condition of subduction zones, which is poorly explored. Here we summarized the phase relations of carbon-bearing phases (calcite, aragonite, dolomite, magnesite, graphite, hydrocarbon) in HP metamorphic rocks (marble, metapelite, eclogite) from the Western Tianshan subduction zone and high-pressure experiments. During prograde progress of subduction, carbonates in altered oceanic crust change from Ca-carbonate (calcite) to Ca,Mg-carbonate (dolomite), then finally to Mg-carbonate (magnesite) via Mg–Ca cation exchange reaction between silicate and carbonate, while calcite in sedimentary calcareous ooze on oceanic crust directly transfers to high-pressure aragonite in marble or amorphous CaCO3 in subduction zones. Redox evolution also plays a significant effect on the carbon speciation in the Western Tianshan subduction zone. The prograde oxygen fugacity of the Western Tianshan subduction zone was constrained by mineral assemblage of garnet-omphacite from FMQ − 1.9 to FMQ − 2.5 ​at its metamorphic peak (maximum P-T) conditions. In comparison with redox conditions of other subduction zones, Western Tianshan has the lowest oxygen fugacity. Graphite and light hydrocarbon inclusions were ubiqutously identified in Western Tianshan HP metamorphic rocks and speculated to be formed from reduction of Fe-carbonate at low redox condition, which is also confirmed by high-pressure experimental simulation. Based on petrological observation and high-pressure simulation, a polarized redox model of reducing slab but oxidizing mantle wedge in subduction zone is proposed, and its effect on deep carbon cycle in subduction zones is further discussed. Keywords: Oxygen fugacity, Western Tianshan, Subduction zone, Deep carbon cycle, Polarized redox model

Glyphosate-tolerant soybean is the most widely planted genetically modified crop worldwide. However, soybean remains recalcitrant to routine transformation because of the low infection efficiency of Agrobacterium to soybean and lack of useful selectable markers. In this study, several Agrobacterium strains and cell densities were compared by transient expression of the GUS gene. The results showed that Agrobacterium strain Ag10 at cell densities of OD600 of 0.6–0.9 yielded the highest infection efficiency in Agrobacterium-mediated soybean cotyledonary node transformation system. Meanwhile, a simple and rapid method was developed for identification of glyphosate tolerance in putative T0 transgenic plants, consisting of spotting plantlets with 1 µL Roundup®. The whole cycle of genetic transformation could be shortened to about 3 mon by highly efficient selection with glyphosate during the transformation process and application of the spot assay in putative T0 transgenic plantlets. The transformation frequency ranged from 2.9 to 5.6%. This study provides an improved protocol for development and identification of glyphosate-tolerant transgenic soybeans.

In order to understand the influence of porphyrin substituents on the nonlinear optical properties of organic–inorganic hybrids composed of an anionic metal–oxygen cluster and a porphyrin cation, p...

Polystyrene crosslinked microspheres were prepared by soap-free emulsion polymerization using styrene (St) and divinylbenzene (DVB) as monomers; then, the microporous structure was knitted by the Friedel-Crafts alkylation reaction, and the Au nanoparticles (AuNPs) were loaded into the pores through thermal reduction, to obtain AuNPs/hyper-crosslinked microporous polymer composite microspheres. SEM and particle-size test results show that the microspheres show good monodispersity. The micropore analysis indicates that the specific surface area and the pore volume of the microporous polymer microspheres decrease with increasing DVB content, and when the DVB content is 0.1%, the specific surface area reaches a maximum of 1 174.6 m2/g. After loading AuNPs, the specific surface area and the amount of micropores of the composite microspheres decrease obviously. The results of XRD and XPS analyses suggest that HAuCl4 is reduced to AuNPs. The composite microspheres show a good catalytic performance for the reduction catalyst of 4-nitrophenol.

The effects of human activities on climate change are a significant area of research in the field of global environmental change. Land use and land cover change (LUCC) has a greater effect on climate than greenhouse gases, and the effect of farmland expansion on regional drought is particularly important. From the 1910s to the 2010s, cultivated land in Songnen Plain increased by 2.67 times, the area of cultivated land increased from 4.92×104 km2 to 13.14·104 km2, and its percentage of all land increased from 25% to 70%. This provides an opportunity to study the effects of the conversion of natural grassland to farmland on climate. In this study, the drought indices in Songnen Plain were evaluated from the 1910s to the 2010s, and the effect of farmland expansion on drought was investigated using statistical methods and the Weather Research and Forecasting Model based on UK’s Climatic Research Unit data. The resulting dryness index, Palmer drought severity index, and standardized precipitation index values indicated a significant drying trend in the study area from 1981 to 2010. This trend can be attributed to increases in maximum temperature and diurnal temperature range, which increased the degree of drought. Based on statistical analysis and simulation, the maximum temperature, diurnal temperature range, and sensible heat flux increased during the growing season in Songnen Plain over the past 100 years, while the minimum temperature and latent heat flux decreased. The findings indicate that farmland expansion caused a drying trend in Songnen Plain during the study period.

To understand the unexpected and puzzling long-term stability of nanoscale gas bubbles, it is crucial to probe their nature and intrinsic properties. We report herein synchrotron-based scanning transmission X-ray microscopy (STXM) evidence of highly condensed oxygen gas molecules trapped as surface nanobubbles. Remarkably, the analysis of absorption spectra of a single nanobubble revealed that the oxygen density inside was 1-2 orders of magnitude higher than that in atmospheric pressure, and these bubbles were found in a highly saturated liquid environment with the estimated oxygen concentration to be hundreds of times higher than the known oxygen solubility in equilibrium. Molecular dynamics simulations were performed to investigate the stability of surface nanobubbles on a heterogeneous substrate in gas-oversaturated water. These results indicated that gas molecules within confinement such as the nanobubbles could maintain a dense state instead of the ideal gas state, as long as their surrounding liquid is supersaturated. Our findings should help explain the surprisingly long lifetime of the nanobubbles and shed light on nanoscale gas aggregation behaviors.

Vibration is a very common process in nature, industry, biology, etc. Thus, whether vibration could induce the formation of nanoscale bubbles in water or not is very important for some chemical or biological reactions. In this paper, we designed a control experiment to simulate the vibration process to explore the production and stability of bulk nanobubbles. Experimental results showed that the vibration could indeed induce the formation of a certain number of bulk nanobubbles in water. In addition, the formation of bulk nanobubbles depended on the frequency and time of vibration. The existence of gas-liquid interface played an important role for the bulk nanobubbles formation because that external air is a possible important gas source. Our findings would be helpful to explore the mystical behavior of nanobubbles in natural processes.

It is known that the main-group metals and their related materials show poor catalytic activity due to a broadened single resonance derived from the interaction of valence orbitals of adsorbates with the broad sp-band of main-group metals. However, Mg cofactors existing in enzymes are extremely active in biochemical reactions. Our density function theory calculations reveal that the catalytic activity of the main-group metals (Mg, Al and Ca) in oxygen reduction reaction is severely hampered by the tight-bonding of active centers with hydroxyl group intermediate, while the Mg atom coordinated to two nitrogen atoms has the near-optimal adsorption strength with intermediate oxygen species by the rise of p-band center position compared to other coordination environments. We experimentally demonstrate that the atomically dispersed Mg cofactors incorporated within graphene framework exhibits a strikingly high half-wave potential of 910 mV in alkaline media, turning a s/p-band metal into a highly active electrocatalyst., Although magnesium-based cofactors are highly active in biochemical reactions, magnesium-based materials generally exhibit poor catalytic activity for oxygen reduction. Here the authors enhance electrocatalytic activity of magnesium through atomic dispersion with a graphene framework.

Using household level and plot level survey data spanning over 10 years, this study examines the effects of climatic factors on the frequency of punctual on-demand deliveries of groundwater for irrigation at the farm level in the North China Plain. Data show that for the past few decades, farmers have experienced a decline in the frequency of punctual on-demand deliveries of groundwater for irrigation, which is measured by the proportion of the number of groundwater irrigations whose delivery timing matched the requests of farmers. Econometric estimation results show that both long-term climate conditions (mean temperature and total precipitation) and short-term weather conditions during the growing seasons have statistically significant effects on the frequency of punctual on-demand deliveries of groundwater for irrigation. However, these effects can show opposite results. The frequency of punctual on-demand deliveries of groundwater for irrigation is negatively associated with an increase in the long-term average temperature but is positively associated with a short-term temperature rise. The effects, moreover, may also differ in magnitude. Although the frequency of punctual on-demand deliveries of groundwater for irrigation is positively associated with higher precipitation levels in both the short-term and the long-term, the latter exerts a larger influence.

Tuning the anionic redox chemistry (O2− → O2n−) activity and reversibility by crystal and/or electronic modulation is essential for Li-rich oxide cathode materials. Herein, we report a facile strategy to improve the activity and reversibility of both anionic and cationic redox by integrating oxygen vacancies and the spinel phase. The initial specific capacity (216.1 mA h g−1vs. 316.3 mA h g−1), coulombic efficiency (80% vs. 94.8%), long-term cycling stability (1000 cycles at 5C) and voltage decay have all been greatly improved due to the largely suppressed irreversible oxygen release. The underlying modulation mechanism has been unraveled. Firstly, the introduction of oxygen vacancies decreases the covalency of TM–O and the density of states of the O 2p band, which mitigates the irreversible oxygen release during oxygen redox. Secondly, the spinel phase integration induced by oxygen vacancies not only improves the Li-ion conductivity and the rate capability due to its 3D Li+ channel and the expanded Li layer but also enhances the structural stability. Thirdly, the first-principles calculations indicate that the increase of delocalized electrons around the transition metal also intensifies the MnO6 octahedral distortion and the inactive Mn-ions are partially activated during the first cycle and participate in the charge compensation. This study sheds some new light on designing high-performance Li-rich layered oxide cathode materials by regulating the anionic and cationic redox with the incorporation of oxygen vacancies and the spinel phase.

Purpose Small lung metastases change their location with respiration, making difficult to localize, therefore, increasing the number of punctures. Accurate puncture can reduce trauma to lung tissue and accelerate patient’s recovery. The aim of the study was to present our experience with the technique of using local anesthesia 5-ml syringe as a guide for computerized tomography-guided iodine-125 seed implantation (CT-ISI). Material and methods This was a retrospective study, including patients with small metastatic tumors in the lung, treated with CT-ISI between December 2013 and March 2018 at the Affiliated Hospital of the University. The patients were divided according to whether a 5-ml syringe was used as a guide during CT-ISI or not. The final follow-up was on March 31st, 2018. Implantation success and complications were examined. Results Nineteen patients were included. A total of 840 seeds were used, with 44.2 ±33.6 (range, 10-160) seeds per patient. The mean D90 for CT-ISI was 134.5 ±7.5 Gy. Treatment intervention for eleven patients was performed using a 5-ml syringe as a guide during CT-ISI. There were no differences in total dose and number of implanted seeds between the two groups, but the number of punctures per lesion was lower in the syringe group than in the no-syringe group (1.9 ±0.5 vs. 2.9 ±0.6, p < 0.001), suggesting a higher puncture accuracy. The total number of SMTIL was 50 (median, 2; range, 1-10), and the median size was 1.9 cm (range, 0.8-2.4 cm). All SMTIL were well-controlled at 6-months follow-up (response rate [RR] = 100%). One patient in the no-syringe group experienced grade 2 chest tightness, chest pain, intraoperative needle tract bleeding, and post-operative blood in sputum. Conclusions Puncture with a 5-ml syringe as a guide during CT-ISI seems to be a more accurate option for patients with small (< 2.5 cm) lung metastasis.

Using the WRF-Chem model, we simulated the surface PM2.5 concentrations on the North China Plain (NCP) during a severe winter haze episode (December 6–10, 2015) with the goal of assessing the effectiveness of the implemented emergency response measures (ERMs) in alleviating the pollution. We estimated that the ERMs decreased the anthropogenic pollutant emissions, with the exception of NH3, by 8–48% during this event. Inputting these reduced emission estimates, our simulations reproduced the observed PM2.5 concentrations and compositions. Stagnant regional meteorological conditions increased the lifetime of the PM2.5 in the NCP boundary layer from 1 day during the clean period to 5 days during the haze episode. Additionally, local emissions accounted for approximately only 20% of the surface PM2.5 in Beijing but more than 62% over the rest of the NCP. We found that the ERMs achieved a modest reduction in the mean surface PM2.5 concentrations during the event, decreasing them by 7% and 4% in Beijing and across the rest of the NCP, respectively. The limited effect was due to the duration of the ERMs being much shorter than the lifetime of the PM2.5, which prevented the concentrations of the latter from fully reflecting the reduction in emissions. We conclude that anthropogenic emissions on the NCP during severe winter haze episodes must be reduced by a much larger percentage to substantially abate the PM2.5 concentrations.

Purpose To evaluate the clinical efficacy and safety of computed tomography (CT)-guided iodine-125 (125I) seed implantation (ISI) for hepatocellular carcinoma (HCC) or cholangiocellular carcinoma (CCC) lesions in challenging locations after transcatheter arterial chemoembolization (TACE). Material and methods A retrospective single-center review of 24 patients with HCC or CCC tumors in challenging locations (hepatic dome or close to the heart/diaphragm/hepatic hilum) was conducted. Patients who underwent CT-guided 125I implantation from May 2014 to January 2019 were recruited. Patients' demographics and details including technical success, treatment response, patient survival, and complication rate were also evaluated. Results Treated tumors were located in the hepatic dome (n = 10; 41.7%), subcapsularly (n = 6; 25%), close to the heart (n = 3; 12.5%), and in the liver hilum (n = 5; 20.8%). The mean maximum diameter of tumors in challenging locations was 40.08 ±11.34 mm (range, 25-68 mm). TACE (2 ±1, 1-4 times) was applied before ISI. There were 27 ISI treatments administered (3 patients also received supplemental ISI). The total number of implanted seeds was 1,160, with mean 48 ±16 seed per patient (range, 30-90 seeds). The mean D90 value for ISI was 125 Gy. Technical success rate was 100%, while a complete response + partial response (CR + PR) was documented in 70.83%, 79.17%, 83.33%, and 79.17% of patients at 3, 6, 12, and 24 months post-ISI, respectively. There were no major complications, although 2 cases experienced 125I seed transfer to the diaphragm, and 1 case experienced transfer to the heart cavity. Conclusions CT-guided ISI for HCC or CCC lesions in challenging locations after TACE is both highly effective and safe.

Electrochemical N2 reduction (N2RR) in aqueous solutions under ambient conditions is extremely challenging; thus, a rational design of electrocatalytic centers is required to effectively adsorb and activate N2. Herein, we report Ru cluster-doped, oxygen vacancy-rich CeO2 (Ru/CeO2-VO) nanorods as an efficient N2 reduction electrocatalyst. The high-density oxygen vacancies inside CeO2 are beneficial for the adsorption of N2, and the unsaturated, low-valence Ru nanoclusters provide active sites for N2 activation and subsequent electron transfer for N2 reduction. The Ru/CeO2-VO catalyst exhibits a high ammonia production rate of 9.87 × 10−8 mmol s−1 cm−2 and a partial current density of 32 μA cm−2 at −0.25 V versus reversible hydrogen electrode in 0.05 M H2SO4 solution, corresponding to a faradaic efficiency of 11.7%. Our work suggests that the synergistic effects between Ru nanoclusters and oxygen vacancies in CeO2 for efficient N2 fixation.

The science linking thermochemical conversion of large-scale industry oily sludge with applied materials has been improved in the last ten years. However, with the traditional converting methods it is hard to precisely control the composition and structure of oily sludge-based products during pyrolysis due to the complexity of the composition of the oily sludge. Here, a chlorinating calcination method using sodium chloride (NaCl) as a chlorinating salt and template was first developed to prepare porous Fe–N–C materials (FCN-500) through pyrolysis of oily sludge containing iron-bearing minerals and pyridine. The formation mechanism of FCN-500 was proposed, where iron ions (Fe3+) from the inorganic component (anorthite) in the sludge were rapidly dissociated with the assistance of NaCl, followed by coordination with the organic component (pyridine nitrogen) in the oily sludge to form the pyridine nitrogen–iron ((C5H6N)n–Fe) complex, and then carbonization. As-obtained FCN-500 exhibited higher specific capacitance (286.3 F g−1 at a current density of 0.5 A g−1), enhanced energy density (33.5 W h kg−1 at a power density of 606.1 W kg−1) and more excellent stability and durability (more than 80.1% capacitance retention after 10 000 cycles) compared with two other electrodes. The reasonably better performance of the obtained FCN-500 in supercapacitors (SCs) is attributed to its large surface area, hierarchically porous channels, high conductivity, and unique Fe–N–C structure. Therefore, this work not only provides a feasible way to solve the bottleneck problem in sludge pyrolysis, but also provides a method to design large scale porous Fe–N–C materials for practical applications.

Summary Highly efficient inorganic light absorbers combined with highly specific biocatalysts, i.e., chemolithoautotrophic microbes, have recently been proposed for solar-powered biomanufacturing to pave the way in artificial photosynthesis. In this work, we studied the global protein and metabolite changes of a Moorella thermoacetica-CdS (cadmium sulfide quantum dots) hybrid system during light harvesting. The Wood-Ljungdahl pathway (WLP) that has been considered as the main approach for CO2 fixation was found to be highly activated by CdS. Targeted metabolite quantification revealed that energy-metabolism-associated glycolysis and the tricarboxylic acid (TCA) cycle were also activated. Therefore, we propose an energy-conservation scheme to the M. thermoacetica-CdS hybrid system, i.e., glycolysis and the TCA cycle along with the oxidation of acetyl-coenzyme A (CoA) and NADH, in addition to the well-documented chemiosmotic proton gradient-driven ATP production by ATPase. We expect that the study can be helpful to guide the design of effective and biocompatible photo-biocatalytic systems in the future.

Asymmetric-electrolyte metal-air batteries (AMABs) with high operating voltage and energy density are highly appealing, but some challenges remain. In the April 7, 2021 issue of Matter, Jung-Ho Lee and co-workers first reported a novel separator and an atomically dispersed catalyst to achieve high voltage and long stability of AMABs.

The crystal phase plays an important role in controlling the properties of a nanomaterial; however, it is a great challenge to obtain a nanomaterial with high purity of the metastable phase. For instance, the large-scale synthesis of the metallic phase MoS2 (1T-MoS2 ) is important for enhancing electrocatalytic reaction, but it can only be obtained under harsh conditions. Herein, a spatially confined template method is proposed to synthesize high phase-purity MoS2 with a 1T content of 83 %. Moreover, both the confined space and the structure of template will affect the purity of 1T-MoS2 ; in this case, this approach was extended to other similar spatially confined templates to obtain the high-purity material. The obtained ultrathin nanosheets exhibit good electrocatalytic activity and excellent stability in the hydrogen evolution reaction.

Single-grain GdBaCuO (GdBCO) superconducting rings have been fabricated by the Gd 2 O 3 +BaCuO 2 (Gd+011) bottom-seeded infiltration and growth (BSIG) process without obvious shrinkage. It is found that first small, thick single-grain GdBCO rings have been fabricated successfully; second, the growth sections on the top surface of the GdBCO ring can be observed and controlled; third, the maximum levitation force of the GdBCO ring with a height of 7.1 mm is 69.3 N (Bpm = 0.50 T, T = 77 K), and the trapped field of the ring with a height of 10.0 mm is 0.32 T at 77 K; fourth, the single-grain GdBCO ring with a height of 10.0 mm shows a good magnetic shielding property, and the limit induction B lim is 0.37 T at 77 K; finally, the critical temperature (T c ) and critical current density (J c ) are decent. Overall, the Gd+011 BSIG process provides a convenient way to fabricate single-grain REBaCuO (REBCO, RE is a rare earth element, such as Y, Gd, or Dy) superconducting rings directly.

Synoptic meteorology is a branch of meteorology that uses synoptic weather observations and charts for the diagnosis, study, and forecasting of weather. Weather refers to the specific state of the atmosphere near the Earth’s surface during a short period of time. The spatial distribution of meteorological elements in the atmosphere can be represented by a variety of transient weather phenomena, which are caused by weather systems of different spatial and temporal scales. Weather is closely related to people’s life, and its development and evolution have always been the focus of atmospheric scientific research and operation. The development of synoptic meteorology is closely related to the development of observation systems, dynamical theories and numerical models. In China, observation networks have been built since the early 1950s. Up to now, a comprehensive meteorological observation system based on ground, air and space has been established. In particular, the development of a new generation of dense radar networks, the development of the Fengyun satellite series and the implementation of a series of large field experiments have brought our understanding of weather from large-scale environment to thermal dynamics, cloud microphysical structure and evolution characteristics of meso and micro-scale weather systems. The development of observation has also promoted the development of theory, numerical model and simulation. In the early days, China mainly used foreign numerical models. Lately, China has developed numerical model systems with independent intellectual property rights. Based on the results of high-resolution numerical simulations, in-depth understanding of the initiation and evolution mechanism and predictability of weather at different scales has been obtained. Synoptic meteorology has gradually changed from an initially independent development to a multidisciplinary approach, and the interaction between weather and the change of climate and environment has become a hot and frontier topic in atmospheric science. This paper reviews the important scientific and technological achievements made in China over the past 70 years in the fields of synoptic meteorology based on the literatures in China and abroad, from six aspects respectively including atmospheric dynamics, synoptic-scale weather, typhoon and tropical weather, severe convective weather, numerical weather prediction and data assimilation, weather and climate, atmospheric physics and atmospheric environment.

This study introduced multistage pH-responsive nanohybrids (MSN-hyd-MOP) based on mesoporous silica nanoparticles (MSNs) modified with polymers with charge-reversal property via an acid-labile hydrazone linker, which were applied as a drug delivery system loaded anticancer drugs. In this study, MSN-hyd-MOP nanohybrids were completely investigated for their synthesis, pH response, drug release behavior, cytotoxicity capability and endocytic behavior. Responding to the acidic extracellular microenvironment of solid tumor (pH 6.5), MSN-hyd-MOP nanohybrids exhibited surface charge-reversal characteristic from negative (−10.2 mV, pH 7.4) to positive (16.6 mV, pH 6.5). The model drug doxorubicin (Dox) was efficiently loaded within the channels of MSN-hyd-MOP (encapsulation efficiency about 87%). The increased acidity in endo-/lysosome promote Dox-loaded MSN-hyd-MOP (MSN-hyd-MOP@Dox) release Dox quickly. In vitro study revealed the drug delivery system had good biocompatibility and could deliver the payload to tumor cells. Overall, the described nanohybrids can be used as a potential anticancer drug delivery system.

The ladybird beetle Propylea japonica is an important natural enemy in agro-ecological systems. Studies on the strong tolerance of P. japonica to high temperatures and insecticides, and its population and phenotype diversity have recently increased. However, abundant genome resources for obtaining insights into stress-resistance mechanisms and genetic intra-species diversity for P. japonica are lacking. Here, we constructed the P. japonica genome maps using Pacific Bioscience (PacBio) and Illumina sequencing technologies. The genome size was 850.90 Mb with a contig N50 of 813.13 kb. The Hi-C sequence data were used to upgrade draft genome assemblies; 4,777 contigs were assembled to 10 chromosomes; and the final draft genome assembly was 803.93 Mb with a contig N50 of 813.98 kb and a scaffold N50 of 100.34 Mb. Approximately 495.38 Mb of repeated sequences was annotated. The 18,018 protein-coding genes were predicted, of which 95.78% were functionally annotated, and 1,407 genes were species-specific. The phylogenetic analysis showed that P. japonica diverged from the ancestor of Anoplophora glabripennis and Tribolium castaneum ~ 236.21 million years ago. We detected that some important gene families involved in detoxification of pesticides and tolerance to heat stress were expanded in P. japonica, especially cytochrome P450 and Hsp70 genes. Overall, the high-quality draft genome sequence of P. japonica will provide invaluable resource for understanding the molecular mechanisms of stress resistance and will facilitate the research on population genetics, evolution and phylogeny of Coccinellidae. This genome will also provide new avenues for conserving the diversity of predator insects.

The semi-pilot scale bioleaching of electroplating sludge by the moderately thermophilic acidophilic consortium was carried out for the first time. During the microbial cultivation, Leptospirillum ferriphilum CS13, Acidithiobacillus caldus S2, and Sulfobacillus acidophilus CS5 could grow rapidly in a 300 L aeration packed reactor, in which the total suspended cell concentration could fluctuate around 3 × 108 cells/mL and the community structure remained relatively stable. During the bioleaching process, the microbial stock solution could effectively leach heavy metals from electroplating sludge in a stirred reactor within a few hours. Meanwhile, the effects of pH, temperature, the quantity of active culture, and liquid-solid ratio on the bioleaching behavior were also investigated. The optimal conditions for electroplating sludge bioleaching were pH 1.5, temperature 45 °C, bacterial liquid ratio 40%, liquid-solid ratio 4:1 L kg−1, and leaching time 5 h. The total removal rate of various heavy metals in electroplating sludge was over 99%. The bioleaching residue was successfully passed the TCLP test, and the total contents of heavy metals in the residue were also well below the regulatory criteria. In addition, the XRD analysis of the bioleaching residue was also confirmed that the moderately thermophilic consortium bioleaching provided a cleaner process than chemical leaching on the removal of the residual fraction metals, which was feasible and attractive for industrial treatment of electroplating sludge.

A combination method of ultra-performance liquid chromatography (UPLC) coupled with diode array detection has been developed for quality evaluation of Qinma prescription (QMP), based on chromatographic fingerprint technology with the similarity analysis (SA) and the quantitative analysis of 12 components by hierarchical cluster analysis (HCA). The established method has been validated by linearity, precision, repeatability, stability and recovery tests. The UPLC fingerprints with 17 common peaks of 5 QMP samples prepared by different extraction methods including water decoction extraction, water extraction-ethanol precipitation method, ethanol reflux extraction, ethanol extraction-water precipitation method and methanol ultrasonic extraction were obtained, and the SA results indicated that similarity index was greatly influenced by the large peak. The similarity index ranged from 0.816 to 0.999 basing on 17 peaks, which has been decreased to 0.683–0.999 basing on 16 peaks without the large peak of baicalin (BA). The results of simultaneous quantification of 12 components in these 5 QMP samples proved that BA, gallic acid (GA), wogonoside (WOG) and gentiopicroside (GEN) were the major ingredients in QMP with high contents >1.44 (mg/g), indicating that ethanol reflux was the most effective extraction method. Integrating fingerprint analysis, simultaneous determination and HCA, the established method is rapid, sensitive, accurate and readily applicable. All the results indicated that the combination method can control the quality of QMP and its related traditional Chinese medicinal compounds more comprehensively and scientifically.

In this work, the solubilities of (R)- and (R,S)-crizotinib in six solvents including methanol, ethanol, 1-propanol, 1-butanol, ethyl acetate, and n-hexane were first measured by a static method in...

In this study, a novel adsorbent was synthesized through the entrapment of KMnO4 modified biochar (MB) in poly(vinyl alcohol)/sodium alginate hydrogel bead (PSMB) and then tested to determine its capacity for removal of Cu(II) from aqueous solutions. The maximum Cu(II) adsorption capacity estimated with Langmuir isotherm modeling was 87.07 mg/g of PSMB, which was higher than that of previously reported adsorbents. PSMB had a good selectivity towards Cu(II) as well as high anti-interference ability. The main species for Cu(II) adsorption likely were the inner-sphere Cu-O complexes, as indicated by the results of spectral analyses. The PSMB was easily collected and exhibited a minimal loss of adsorption capacity after 10 adsorption/regeneration cycles. The effective removal of Cu(II) from environmental water samples with relative low treatment cost indicated a possibility for practical application.

Chiral fluorescent materials with fluorescent nanoparticles assembled into a chiral structure represent a grand challenge. Here, we report self-assembled emissive needle-like nanostructures through decorating cellulose nanocrystals (CNCs) with carbon quantum dots (CQDs). This assembly is facilitated by the heterogeneous amphiphilic interactions between natural and synthetic components. These emissive nanostructures can self-organize into chiral nematic solid-state materials with enhanced mechanical performance. The chiral CQD/CNC films demonstrate an intense iridescent appearance superimposed with enhanced luminescence that is significantly higher than that for CQD films and other reported CQD/CNC films. A characteristic fluorescent fingerprint signature is observed in the CQD/CNC film, proving the well-defined chiral organization of fluorescent nanostructures. The chiral organization of CQDs enables the solid CQD/CNC film to form a right-hand chiral fluorescence with an asymmetric factor of -0.2. Additionally, we developed chemical 2D printing and soft lithography patterning techniques to fabricate the freestanding chiral fluorescent patterns that combines mechanical intergrity and chiral nematic structure with light diffraction and emission.

Ascorbic acid (AA) is an essential vitamin and plays an irreplaceable role in humans’ daily life. Therefore, it is of profound significance to develop effective strategies for AA sensing. Herein, a novel bi-functional sensing strategy was developed by using carbon dots (CDs) and MnO2 nanosheet as the fluorometric/magnetic signal source. When AA was absence, the fluorescence of CDs was quenched by MnO2 nanosheet due to the inner filter effect. Neither the fluorescence nor magnetic signal of the nanoprobe can be detected. In the presence of AA, a redox reaction occurred between MnO2 nanosheet and AA resulting in the generation of magnetic resonance imaging (MRI) response Mn2+ and decomposing of MnO2 nanosheet structure, thus leading to the recovery of CDs fluorescence. The detection limit of the AA was determined to be 2.89 μM with a linear range of 0–80 μM in fluorescence mode, and detection limit of 0.776 μM with a linear range of 0–80 μM in MRI mode when used transverse relaxation rate as signal. Furthermore, the developed fluorometric/magnetic bi-functional nanoprobe showed good biocompatibility, high response rate, high selectivity towards AA and could be used to analyses AA in real samples. Moreover, in vivo imaging of AA in mice was achieved in magnetic mode. The fluorometric/magnetic bi-function sensor for AA detection was introduced, which provided a novel strategy for sensor design based on CDs.

In this work, polypyrrole-coated ZnFe2O4 (ZnFe2O4@PPy) nanocomposites were successfully synthesized via a simple in-situ polymerization process, then evaluated as electromagnetic wave (EMW) absorbers over the 2–40 GHz frequency range. The ZnFe2O4@PPy nanocomposites exhibited excellent EMW absorption properties, including very low reflection losses (−42.31 dB at 30.24 GHz and a thickness of 2.5 mm) and a broad absorption bandwidth of 28.20 GHz (from 9.66 to 37.86 GHz). The EMW absorption properties of the ZnFe2O4@PPy nanocomposites could be adjusted by changing the PPy shell thickness and also the thickness of the absorber (1–2.5 mm). The excellent microwave absorption performance of the ZnFe2O4@PPy nanocomposites is attributable to the synergistic effects of magnetic losses (ZnFe2O4 nanoparticles), dielectric losses (ZnFe2O4 and PPy) and interfacial relaxation losses at ZnFe2O4-PPy interfaces.

Alkali metal-sulfur/selenium batteries have attracted much attention because they offer promising high energy density. However, the shuttle effect of the polysulfide dissolutions, poor electrical conductivity, and relatively large volume variations greatly hinder their potential applications. Herein, a novel organic carbon/selenium sulfide (OC/SeS2) composite has been prepared by a one-step in situ method by heating the mixture of commercial polyacrylonitrile (PAN) with selenium sulfide powder in vacuum. The carbonized PAN matrix with an N-doped carbon ring structure could effectively confine SeS2 in the form of small molecules and regulate its electronic structure. The superior sodium/potassium storage performance of the OC/SeS2 composite electrodes stems from their rational chemical structure design, including high electrical conductivity of the N-doped organic carbon network and chemical binding with SeS2 molecules. As a result, the OC/SeS2 cathode delivers a reversible capacity of 416 mAh g-1 after 700 cycles for sodium-ion batteries and 216 mAh g-1 after 500 cycles for potassium-ion batteries at 0.5 A g-1, respectively. These findings could open a new window to develop selenium sulfide cathode for metal-sulfur/selenium batteries.