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Erlitou (Henan province, China) is a Bronze Age site which occupies a prominent position in the study of early state and civilization of China. 359 charcoal fragments >4 mm and 40 charred fruit stones unearthed during the 2010 and 2011 excavation seasons at Erlitou have been analysed. Wood charcoals belong to 18 taxa: Platycladus, Pinus, Picea, Prunus armeniaca, Prunus persica, Quercus (deciduous oaks), Celtis, Zelkova, Broussonetia, Ziziphus, Salix, Toona, Koelreuteria, Sophora, Melia, Bambusoideae and 2 unidentified broadleaved species. In addition, 39 Prunus persica stones and 1 Ziziphus stone have been identified. The anthracological results indicate that the main types of woodland vegetation were Quercus broadleaved forest, and coniferous and broadleaved forest during the Erlitou Culture period (1750-1520 BC) including Platycladus orientalis coniferous forest and deciduous vegetation composed of oak, Zelkova, Salix, Toona and some fruit trees such as apricot, peach and Chinese date. Our study indicates a vegetation adapted to a warmer and more humid climate in phases 2 and 3 of the Erlitou Culture period (1680-1560 BC) becoming drier in phase 4 (1560-1520 BC). By the late Erligang period (1400-1300 BC) climate becomes again warmer and more humid. It also suggests that oak played an important role as firewood and possibly for wooden artefacts and as a food source. The appearance of charcoals of apricot, peach and Chinese date also suggests that fruits were consumed, while Chinese hackberries could have been used either as food or fodder.

Uncontrollable leakage has significant effects on the safety of fractured rock mass, and microbially induced carbonate precipitation (MICP) is an effective way to control the seepage. In this study, four sets of seepage experiments are conducted on transparent rock-like specimens containing MICP filled single cracks to investigate the effects of bacterial concentration, crack inclination angle, crack roughness, and crack opening on fracture permeability. The experimental results show that calcium carbonate precipitation is produced when Sporosarcina pasteurii and cementing fluid are injected into the cracks, which can seal the cracks and reduce the permeability of the cracks. Moreover, the calcium carbonate produced by Sporosarcina pasteurii increases with increasing bacterial concentration. Furthermore, the fracture permeability of the MICP filled crack increases first and then decreases with increasing inclination, roughness, and opening of cracks. The experimental results provide a better understanding of the influence of different construction conditions on fracture permeability when the MICP technology is applied in rock engineering.

Green technology innovation is an important way to solve the dilemma of economic growth and environmental protection, while the relevant policies issued by the government have an important impact on the promotion of regional green technology innovation. This paper regards the implementation of the Regional Planning of Yangtze River Delta (RPYRD) as a quasi-natural experiment, using the panel data of 274 cities in China from 2003 to 2016 to explore the green technology innovation effect of regional planning and its transmission mechanisms through the double-fixed effect model and the difference-in-difference (DID) method. The results show that (1) the implementation of the RPYRD promotes regional green technology innovation significantly and the green technology innovation effect of the policy is increasing year by year. (2) There is significant regional heterogeneity in the incentive effect of green technology innovation in regional planning. The policy effect is more obvious in cities with a larger scale, a higher level of human capital and less resource dependence. (3) The regional planning promotes green technological innovation by optimizing industrial structure, reducing FDI and increasing R&D investment.

The coordination between a ligand and a metal is a spontaneous and uncontrollable process. In this Article, we successfully observe the formation of metal coordination in a triphenylamine-functionalized salicylaldehyde Schiff base with a copper(II) ion. The ligand TPA-Py first reacts with Cu2+ in a stepwise process to afford the dynamic complex TPA-Py@Cu2+ ([ligand]:[Cu2+] = 1:1), which further reacts with an extra copper(II) ion to afford 2TPA-Py@4Cu2+ with the following stepwise (or cumulative) stability constants: K1 = 4.0694 × 103 and K2 = 1.0761 × 106, respectively. The entire metal coordination process can be visualized, and the coordination mode of the probe toward copper was further evaluated by ultraviolet-visible/fluorescence spectra, single-crystal X-ray diffraction, density functional theory calculations, high-resolution mass spectra, and nuclear magnetic resonance spectroscopic titrations. Compound TPA-Py exhibited excellent sensitivity and specificity toward copper(II) ions in THF/water media with a low limit of detection of 2.687 × 10-7 mol L-1. In addition, TPI-An-Py can be applied to the detection of Cu2+ in real samples with satisfactory recoveries in the range of 100-112% in lake water and 98-101% in tap water. This Article not only reports an excellent fluorescence probe for copper(II) ion detection but also presents an instance for more fully understanding the metal coordination process.

Trichoderma is an important and widely used plant growth-promoting fungus (PGPF). In this study, stevia residue amended with amino acids hydrolyzed from animal carcasses was used for the production of Trichoderma guizhouense NJAU 4742 by solid-state fermentation, and then its potential to promote corn plant growth was evaluated in combination with chemical fertilizer (CF) or organic fertilizer (OF). The highest spore number of 7×109 CFU g−1 fresh weight was obtained under the following optimal parameters: material ratio of 50% (stevia residue:rice bran=1:1), pH value of 3.0 (amended with 6.67% amino acids), initial moisture content of 60%, inoculum size of 10%, material thickness of 3 cm and an incubation time of 4 days. The aboveground corn plant biomass obtained with T. guizhouense applied alone and with CF treatments were slightly higher than those of no fertilizer control and CF treatments, respectively. However, T. guizhouense applied with OF significantly (P

Graphic Abstract Alkylbenzenes have a wide range of uses and are the most demanded aromatic chemicals. The finite petroleum resources compels the development of production of alkylbenzenes by non-petroleum routes. One-pass selective conversion of benzene and syngas to alkylbenzenes is a promising alternative coal chemical engineering route, yet it still faces challenge to industrialized applications owing to low conversion of benzene and syngas. Here we presented a Cu–ZnO–Al2O3/ZSM-5 bifunctional catalyst which realizes one-pass conversion of benzene and syngas to alkylbenzenes with high efficiency. This bifunctional catalyst exhibited high benzene conversion (benzene conversion of 50.7%), CO conversion (CO conversion of 55.0%) and C7&C8 aromatics total yield (C7&C8 total yield of 45.0%). Characterizations and catalytic performance evaluations revealed that ZSM-5 with well-regulated acidity, as a vital part of this Cu–ZnO–Al2O3/ZSM-5 bifunctional catalyst, substantially contributed to its performance for the alkylbenzenes one-pass synthesis from benzene and syngas due to depress methanol-to-olefins (MTO) reaction. Furthermore, matching of the mass ratio of two active components in the dual-function catalyst and the temperature of methanol synthesis with benzene alkylation reactions can effectively depress the formation of unwanted by-products and guarantee the high performance of tandem reactions. Supplementary Information The online version contains supplementary material available at 10.1007/s10562-021-03617-5.

Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells. Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells, which focuses on the Fe-N4 single-atom catalysts and the iron nitride materials (such as Fe2N and Fe3N). A hybridized catalyst having a hierarchical porous structure with regular macropores could enable the desired mass transfer efficiency in the catalytic process. In this study, we have constructed a new type of hybrid catalyst having iron and iron-nitrogen alloy nanoparticles (Fe-N austenite, termed as Fe-NA) embedded in the three-dimensional ordered macroporous N-doped carbon (3DOM Fe/Fe-NA@NC) by direct pyrolysis of single-source dicyandiamide-based iron metal-organic frameworks. The as-synthesized composites preserve the hierarchical porous carbon framework with ordered macropores and high specific surface area, incorporating the uniformly dispersed iron/iron-nitrogen austenite nanoparticles. Thereby, the striking architectural configuration embedded with highly active catalytic species delivers a superior oxygen reduction activity with a half-wave potential of 0.88 V and a subsequent superior Zn-air battery performance with high open-circuit voltage and continuous stability as compared to those using a commercial 20% Pt/C catalyst.

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is native to the Americas. It has rapidly invaded 47 African countries and 18 Asian countries since the first detection of invasion into Nigeria and Ghana in 2016. It is regarded as a super pest based on its host range (at least 353 host plants), its inherent ability to survive in a wide range of habitats, its strong migration ability, high fecundity, rapid development of resistance to insecticides/viruses and its gluttonous characteristics. The inherently superior biological characteristics of FAW contribute to its invasiveness. Integrated pest management (IPM) of FAW has relied on multiple applications of monitoring and scouting, agricultural control, chemical pesticides, viral insecticides, sex attractants, bio-control agents (parasitoids, predators and entomopathogens) and botanicals. Knowledge gaps remain to be filled to: (1) understand the invasive mechanisms of S. frugiperda; (2) understand how to prevent its further spread and (3) provide better management strategies. This review summarizes the biological characters of FAW, their association with its invasiveness and IPM strategies, which may provide further insights for future management.

First principle calculations were performed to investigate the structural, mechanical, electronic properties, and thermodynamic properties of three binary Mg–B compounds under pressure, by using the first principle method. The results implied that the structural parameters and the mechanical properties of the Mg–B compounds without pressure are well matched with the obtainable theoretically simulated values and experimental data. The obtained pressure–volume and energy–volume revealed that the three Mg–B compounds were mechanically stable, and the volume variation decreases with an increase in the boron content. The shear and volume deformation resistance indicated that the elastic constant Cij and bulk modulus B increased when the pressure increased up to 40 GPa, and that MgB7 had the strongest capacity to resist shear and volume deformation at zero pressure, which indicated the highest hardness. Meanwhile, MgB4 exhibited a ductility transformation behaviour at 30 GPa, and MgB2 and MgB7 displayed a brittle nature under all the considered pressure conditions. The anisotropy of the three Mg–B compounds under pressure were arranged as follows: MgB4 > MgB2 > MgB7. Moreover, the total density of states varied slightly and decreased with an increase in the pressure. The Debye temperature ΘD of the Mg–B compounds gradually increased with an increase in the pressure and the boron content. The temperature and pressure dependence of the heat capacity and the thermal expansion coefficient α were both obtained on the basis of Debye model under increased pressure from 0 to 40 GPa and increased temperatures. This paper brings a convenient understanding of the magnesium–boron alloys.

Low-temperature corrosion of the system and external input make it difficult to avoid the entering Fe ions in the supercritical reactor. Fe ions crystallize into particles in supercritical water and deposit on the surface of the reactor, causing safety threats and economic losses. In this paper, research on the Fe ion deposition process, from crystallization, to oxide particle formulation and to completely adhering to the wall surface, is reviewed. The literature mainly includes theoretical and experimental research on the nucleation and growth process of Fe oxide particles in a supercritical water (SCW) environment, particle movement and experimental observation methods in trans-critical turbulence, and the effects of Derjaguin-Landau-Verwey-Overbeek (DLVO) and collisions considered in the process of particle attachment. The particle deposition process involves particle formation, particle movement and surface adhesion. These three dynamic processes have cross-influencing factors that include geometric factors (the size of the particles themselves, the roughness of the wall), hydrodynamic factors (turbulence and transcritical conditions), and environmental parameters (temperature, pH). Independent research on dynamic processes is no longer suitable. The review aims to clarify the mechanism of three dynamic processes and their roles in the particle deposition process so that they can be comprehensively considered in the study of particle deposition in actual operating systems in the future.

It is difficult to recycle photocatalysts for water purification when they are in aqueous suspension. Cellulose aerogels with porous structure and biodegradability are promising carriers for photocatalysts that can be used to solve many environmental problems. In this study, a 3D recyclable g-C3N4@cellulose aerogel for photocatalytic degradation of pollutants was synthesized using a facile chemical cross-linking method. g-C3N4@cellulose aerogel (30% loading) exhibited excellent photocatalytic activity up to 99.0% degradation. In addition, the g-C3N4@cellulose aerogel exhibited high recyclability and structural stability while the photocatalytic efficiency is not significantly reduced in cycling tests. The photocatalyst was optimized using high temperature calcination, resulting in 95.35 m2 g−1 actual surface determined from Brunner–Emmet–Teller measurements. Therefore, aggregation of the photocatalyst can be avoided by the cellulose aerogel support whilst the photocatalytic property remained as efficient as its powder form. Such composites may become attractive material for practical applications.

Coal seam mining is one of the most widely participated engineering activities in China. This study examined the failure process induced by underground thin coal seam mining of Wangxia perilous rock in Chongqing, China. Numerical simulation was conducted on the stress, displacement and plastic deformation with Fast Lagrangian Analysis of Continua 3D (FLAC3D). Results show that tensile stress is dominant and it keeps increasing during coal mining. The stability failure process experiences four stages from the perspective of crack propagation. A new simplified subsidence prediction method was proposed for quick engineering applications. The relationship between mining geometric parameters and rock mass stability was established and the ultimate mining dimensions were suggested. The simplified method was demonstrated to be reliable.

The safety concern on lithium-ion batteries hampers the widely application of electric vehicles. Separator is crucial to battery safety, as its mechanical failure may trigger drastic reactions between cathode and anode. Though the separator is soaked in nonaqueous electrolyte in the state-of-the-art lithium-ion batteries, its dimensional stability, which is one of the important indications for mechanical reliability, is generally tested in a dry state. In this study, the thermal and mechanical properties of dry polyolefin separators, as well as the separators soaking with different electrolytes, are carefully investigated at elevated temperatures. The thermal shrinkage of the polyolefin separators is obviously enhanced by the solvents, and lithium salts (LiPF6, LiFSI, or LiTFSI) get the separator involved into decomposition. Significantly, the mechanical strength of the polyolefin separator declines 73.8% in the soaked state at even a relatively low operation temperature (60 °C). This work provides an instructive and supplementary approach for separator evaluation, as well as an understanding of battery failure due to the performance degradation of electrolyte-soaked separators.

Elemental carbon (EC) in wet and dry deposition is an important chain of its transportation in urban surface system. However, little was known about this key process. Based on 90 samples from 13 consecutive months of atmospheric deposition sampling at typical urban and suburban sites in Shanghai, China, this research studied EC fluxes and amounts of dry and wet deposition, the relationship between EC and polycyclic aromatic hydrocarbons (PAHs) and possible sources of deposited EC. The difference of EC in deposition from those in other typical media was also discussed. Results showed that despite of lower flux in dry deposition than wet deposition, more atmospheric EC was removed by dry deposition during sampling period. EC bulk (i.e. dry and wet mixture) deposition amount was lower than the sum of wet and dry deposition. EC had a stronger correlation with PAHs than total organic carbon (TOC) did, indicating the important role of EC in carrying PAHs. The EC-cogenerated high molecular weight PAHs revealed that traffic, coal burning and biomass burning were the main sources of EC in atmospheric deposition. Unexpectedly, EC:TOC ratio in deposition, the link between aerosols and surface soils, was significantly different from (lower than) those in the two media, which can be attributed to the attenuation of organic carbon in coarser and easy-to-deposit atmospheric particles, the stability of the EC as well as other sources to soils.

In this paper, a kind of soybean nodule-derived nitrogen-doped carbon (SNNDC) was prepared, characterized and applied to modify the assembled carbon paste electrode (CPE), to fabricate a novel chemical sensor for the detections of AA and DA. The electrochemical characteristics of SNNDC implied that it is an effective electron transfer mediator accelerating the electron transfer to CPE. The cyclic voltammetry measurements at different scan rates indicated that the electrochemical process on the electrode surface of the chemical sensor is a diffusion-controlled irreversible oxidation reaction of one-electron and one-proton for DA, and two-electron with one-proton for AA. The linear detection ranges of the chemical sensor for the detections of AA and DA were 5–3000 μM and 5–1000 μM with the detection limits of 1.90 μM and 3.18 μM, respectively, as determined by amperometric experiments. Both linear detection range and detection limit obtained are comparable or better than those of several modified electrodes reported recently. And the chemical sensor was also successfully applied to the detections of AA and DA in injection samples. This study suggested that the fabricated chemical sensor is a hopeful candidate to be used in the detection of pharmaceutical samples of AA and DA, and provides valuable reference information for the development of novel drug sensors in both clinical laboratory and food industries.

Photoreduction of carbon dioxide (CO2) provides an effective perspective for solving the energy crisis and environmental problems. Herein, two types of composite photocatalysts (TiO2/ZIF-8) based on ZIF-8 and TiO2 have been designed and synthesized with the help of the grinding method and the solid-synthesis method. Both composite photocatalysts are employed for the photocatalytic reduction of CO2. In composite photocatalysts prepared by the grinding method, ZIF-8 particles are distributed on the surface of TiO2, and provide extra available spaces for storing CO2, which is beneficial for improving their photoreduction performances. As a result, an enhanced CO formation rate of 21.74 μmol g−1 h−1 with a high selectivity of 99% is obtained for this family of composite photocatalysts via the solid–gas mode without photosensitizers and sacrificial agents. For comparison, the other family of composite photocatalysts synthesized via the solid-synthesis method possesses structures similar to ZIF-8, where TiO2 is encapsulated inside the framework of ZIF-8. This structural feature obstructs the contact between the active sites of TiO2 and CO2, and leads to lower activities. The best CO formation rate of this family is only 10.67 μmol g−1 h−1 with 90% selectivity. Both the structural features of the two families of photocatalysts are described to explain their differences in photoreduction performances. The experimental finding reveals that different synthetic approaches indeed result in diversified structures and varied photocatalytic performances. This work affords a new scalable and efficient approach for the rational design of efficient photocatalysts in the area of artificial photosynthesis.

Glycogen synthase kinase-3β (GSK-3β) is a highly conserved multifunctional serine/threonine (Ser/Thr) protein kinase widely expressed in many tissues. GSK-3β inhibitors could be used in the treatment of human key diseases, such as cancer, Alzheimer’s disease, Parkinson’s disease, inflammation, type-II diabetes, and so on, due to the multi-role of GSK-3β in the hepatic glycolysis regulation, cell signaling pathways, and phosphorylation of various proteins. Recently, sets of diverse GSK-3β inhibitors have been prepared, and biologically evaluated in vitro and in vivo in different screening models. This review summarizes the latest developments in GSK-3β inhibitors unclosed from 2015 to 2019, including their structure–activity relationship and bioactivity studies.

The availabilities of nitrogen (N) and water are two important environmental factors affecting crop growth and productivity in the dryland farming, how they affected leaf water transport capabilities, a bottleneck of whole-plant water transport, was seldom studied. So, the effects of different N and water supplies on leaf hydraulic conductance (Kleaf) in maize (Zea mays L.) were studied by a pot experiment, Kleaf, leaf gas exchange, vein traits and other physio-anatomical traits were measured. We found Kleaf was strongly coupled to leaf gas exchange (net photosynthetic rate, Pn, and stomatal conductance, gs) and whole-plant performance under varying N and water supplies. Long-term N supply had a greater impact than irrigation on Kleaf, Pn and gs due to the type and duration of stress, and the N and water treatments did not interact with these physiological parameters. Kleaf was related positively with the xylem conduit diameter of large longitudinal veins, the proportion of minor-vein length and interveinal distance of large and intermediate longitudinal veins, and negatively with the density of the major veins, and the interveinal distance of the transverse veins. The higher Kleaf under ambient N and water supply was also associated with larger leaf area, leaf mass per area and N content per leaf area and with an improved status of leaf water, which partly enhanced the vein traits responsible for the higher Kleaf. These results are helpful to understand leaf hydraulic strategy in adapting to long-term resource deficiency.

Organic photovoltaic cells (OPVs) have great potential for driving indoor electronic devices for internet of things (IoTs). Under indoor illumination, the thick active layer can produce high photocurrent due to the large light-harvesting, whereas the trap states usually dominate the charge recombination in such thick-film devices and limit the largest possible photocurrent. Herein, we adopted a strategy of insulating polymer dilution to suppress the charge trapping states in the indoor organic photovoltaic (IOPV) devices with the different active layer thickness from 140 to 1000 nm. A diluting strategy with 5% insulating polystyrene effectively reduces the trap state density, delivering an excellent fill factor of around 67% and growth of short-circuit current density with increasing the thickness to 1-micron under 2700 K light-emitting diode tube. For the diluted ultra-thick blend, the reduced trap states suppress the exciton quenching at traps, accelerate the dissociation of intra-moiety polaron pairs and improve the transport properties, enabling more photogenerated carriers and low photocurrent loss in ultra-thick devices. This work provides an effective diluting strategy of decreasing trap state density for realizing ultra-thick IOPV devices with high performance and demonstrates the key role of charge trapping in IOPV performance.

Lignin, a carbon-rich biopolymer, has great application potentials in the field of biomaterial manufacture. However, lignin produced from separation process is a heterogeneous polymer with low functionality, which largely limits its application. In this case, a simple and green approach was proposed to fractionate tetrahydrofurfuryl alcohol lignin with different acetone concentrations to produce homogeneous lignin having high antioxidant capacity. Lignin dissolved in 60% acetone solution was stirred for 1 h at room temperature and water was gradually added to precipitate and to obtain fractions with a high purity. The molecular weight distribution, structural characteristics and thermal stability of lignin before and after fractionation were extensively studied by using various methods (nuclear magnetic resonance techniques, thermogravimetric analysis, etc.). At the lowest acetone concentration, the molecular weight of lignin was 1490 g/mol, the polydispersity index was as low as 1.16, and the total phenolic hydroxyl content reached 3.3 mmol/g. Results showed that lignin samples had strong antioxidant activity as compared to commercial antioxidant butylated hydroxytoluene. This study indicated that separation with acetone/water system is meaningful approach to prepare homogeneous lignin with excellent functionality.

AIE fluorophores have been developed as bioimaging probes due to their strong brightness at high concentration and increase of the photostability to promote highly recognizable cellular signaling. However, conventional AIE fluorescent probes for bioimaging just solely lighten the cells or tissues, suffering from the limitation of satisfying the requirement of disease diagnosis. Herein, we report an AIE-active bioprobe (TPP-Tba) for linear fluorescence response and qualitative detection of hydrogen peroxide (H2O2) and viscosity with a wide detection range and a low detection limit. TPP-Tba displays an impressive ability of distinguishing normal cells and pathological cells. Furthermore, fatty liver tissue can also be efficiently distinguished from normal liver tissue, attributed to the great H2O2 and viscosity dual-response as well as the specific targeting to mitochondria by TPP-Tba. Given the high sensitivity for H2O2 and viscosity, great biocompatibility, high specificity to mitochondria, and impressive ability of distinguishing normal tissue and pathological tissue, we envisage that this novel TPP-Tba probe would open a new window for designing novel bioprobes for disease diagnosis.

A family of isostructural heterometallic MOFs based on Fe2M clusters (MOF-Fe2M; M = Fe, Co and Ni, respectively) have been synthesized and serve as potential proton conductors and photocatalysts for CO2 photoreduction, exhibiting varied proton conductivities and photocatalytic performances. Among them, MOF-Fe3 exhibits the best proton conductive performance with a value of 3.39 × 10−2 S cm−1 at 70 °C and 98% RH. Furthermore, three proton conductive membranes based on MOF-Fe3 have been prepared, and the optimum membrane shows a high proton conductivity with σ = 5.46 × 10−3 S cm−1 at 60 °C and 98% RH. Additionally, all frameworks are employed as photocatalysts for converting CO2 into CO in the solid–gas mode without sacrificial agents and photosensitizers, where MOF-Fe2Ni exhibits the highest photocatalytic activity with a CO formation rate of 15.81 μmol g−1 h−1. It should be mentioned that MOF-Fe2M represent rare MOF based photocatalysts used for reducing CO2 in the solid–gas mode. Their great performances may be attributed to the following reasons: (i) appropriate structural features promote the formation of hydrogen bond networks and the adsorption of CO2; (ii) extensive Fe2M units can adsorb visible light and provide reaction active sites for CO2 photoreduction.

This work developed a sensitive electrochemiluminescence (ECL) biosensor based on a cyclometalated iridium(III) complex ((bt)2Irbza), which was synthesized for the first time. Annihilation, reductive-oxidative, and oxidative-reductive ECL behaviors of (bt)2Irbza were investigated, respectively. The oxidative-reductive ECL intensity was the strongest compared with the other two, which showed 16.7 times relative ECL efficiency compared with commercial [Ru(bpy)3]2+ under the same experimental conditions. Therefore, an ECL biosensing system with (bt)2Irbza as the anodic luminophore was established for miRNA detection based on a closed bipolar electrode (BPE). Combined with both steric hindrance and catalytic effects induced by hemin/G-quadruplex in the cathodic reservoir of BPE that changed the Faraday current of the cathode and thus mediated the ECL intensity of (bt)2Irbza in the anode of BPE, the ECL sensor stated an ultrahigh sensitivity for microRNA (miRNA-122) analysis with a detection limit of 82 aM.

Three-dimensional covalent organic frameworks (3D-COFs) are emerging as designable porous materials because of their unique structural characteristics and porous features. However, because of the lack of 3D organic building units and the less reversible covalent bonds, the topologies of 3D-COFs to date have been limited to dia, ctn, ffc, bor, rra, srs, pts, lon, stp, acs, tbo, bcu, and fjh. Here we report a 3D-COF with the ceq topology utilizing a D3h-symmetric triangular prism vertex with a planar triangular linker. The as-synthesized COF displays a twofold-interpenetrated structure with a Brunauer-Emmett-Teller surface area of 1148.6 m2 g-1. Gas sorption measurements revealed that 3D-ceq-COF could efficiently absorb CO2, CH4, and H2 under a moderate surface area. This work provides new building units and approaches for structural and application exploration of 3D-COFs.

The interaction mechanism of a kind of natural drug helicid with typical digestive enzyme trypsin was investigated using multi-spectroscopic techniques and molecular modeling method. The fluorescen...

Poly (ADP-ribose) polymerase (PARP) plays a significant role in DNA repair responses; therefore, this enzyme is targeted by PARP inhibitors in cancer therapy. Here we have developed a number of fused tetra- or pentacyclic dihydrodiazepinoindolone derivatives with excellent PARP enzymatic and cellular PARylation inhibition activities. These efforts led to the identification of pamiparib (BGB-290, 139), which displays excellent PARP-1 and PARP-2 inhibition with IC50 of 1.3 and 0.9 nM, respectively. In a cellular PARylation assay, this compound inhibits PARP activity with IC50 = 0.2 nM. Cocrystal of pamiparib shows similar binding sites with PARP with other PARP inhibitors, but pamiparib is not a P-gp substrate and shows excellent drug metabolism and pharmacokinetics (DMPK) properties with significant brain penetration (17-19%, mice). The compound is currently being investigated in phase III clinical trials as a maintenance therapy in platinum-sensitive ovarian cancer and gastric cancer.

Metal organic frameworks (MOFs) and covalent organic frameworks (COFs) have been actively investigated as a high-profile class of versatile materials to many fields due to their permanent porosity and highly ordered structures, as well as their unique characteristic of predesigned structure and controllable synthesis. Currently, the development of MOF/COFs-based materials for lithium (ion) batteries, fuel cells and other related fields is attracting significant attention. Therefore, a review of the recent research progress in the following popular and promising fields is timely: 1) Si/SiO based anode materials, 2) lithium-sulfur batteries, 3) solid electrolytes, 4) lithium metal anodes, 5) catalysts for the oxygen reduction reaction (ORR) and 6) hydrogen storage. Furthermore, we identified the issues for the MOF/COFs-based materials from the perspective of their suitability for practical application when summarizing and demonstrating the cutting–edge development of the MOF/COFs-based materials in the abovementioned fields. Finally, we call on more “bottom-up” design studies that should be performedin the future. That is, the structure of the MOF/COFs materials should be designed and adjusted in advance according to the needs of the application to achieve maximumoptimization of the desired properties.

Commercial lithium-ion batteries still undergo safety concerns due to using perilous and flammable liquid electrolytes that are prone to fire and leakage issues. Meanwhile, the development of high energy density lithium-metal batteries with conventional liquid electrolytes has also encountered bottlenecks because of the growth of lithium-dendrites and parasitic reactions. Therefore, the use of flammable liquid electrolytes in lithium batteries is the main obstacle to be overcome, and at the same time, the contradiction between high energy density and high safety for practical applications needs to be addressed. Currently, solid polymer electrolyte has been considered as a promising solution, and hence solid polymer-based lithium batteries have attracted much attention due to their high safety compared to their counterparts. However, its low ionic conductivity, poor mechanical properties, and insufficient cycle life restrict their practical applications. At present, there are fewer comprehensive reviews available on lithium batteries based on polymer electrolyte systems, so it is substantial worthy of summarizing the existing literature and timely apprises of incessantly improving strategies of this field. This review summarizes the ion transfer mechanism and performance requirements of polymer electrolytes for lithium batteries, the classification and design of polymer electrolytes, and the essential principles and characterization for electrode/electrolyte interface construction and the research of composite electrolyte. Finally, the current status and development prospects of polymer electrolytes are briefly summarized and discussed, enabling a foundation for the wide application of solid polymer electrolyte-based batteries.

The roles of hot isostatic pressing (HIP) temperatures (490 °C/100 MPa/2 h, 510 °C/100 MPa/2 h, 530 C/100 MPa/2 h) in the microstructure and properties of AlSi7Cu2Mg alloy step castings with three types wall thicknesses were studied. The experimental results show that HIP at 490 C could effectively eliminate the internal closed porosity of the castings with a wall thickness of ≼40 mm, but for heavy castings (70 mm), even HIP at 530 C, a few loose defects remained inside the castings. Two types of incipient eutectics containing Al5Mg8Si6Cu2 and Al2Cu were observed in the samples that HIP at 530 C, which was responsible for the decrease of the tensile strength of the castings within the medium wall thickness (40 mm) compared with that HIP at 490 C. HIP could greatly reduce the difference of the tensile strength values of castings with wall thicknesses 17 mm and 70 mm from 117.93 MPa (without HIP) to 25.7 MPa (with HIP at 530 C).

In this study, servo-controlled biaxial compression tests were conducted on marble specimens to investigate their failure characteristics and fracturing process. The complete stress-strain curves were obtained, and the three-dimensional (3D) features of the failure surfaces were acquired by 3D laser scanning. Acoustic emission (AE) monitoring and moment tensor (MT) analysis were used in combination to better understand the fracturing mechanism of marble under biaxial compression. It was noted that a type of 3D stepwise cracking behaviour occurred on the fracturing surfaces of the examined specimens. The stress dropped multiple times, and a repeated fracturing mode corresponding to the repeated stress drops in the post-peak regime was observed. Three substages, i.e. stress stabilisation, stress decrease and stress increase, were identified for a single fracturing mode. Then quantitative and statistical analyses of the fracturing process at each substage were discussed. Based on the testing results, it was found that at the stress stabilisation substage, the proportion of mixed-mode fractures increased. At the stress decrease substage, the proportion of mixed-mode fractures decreased, and the tensile or shear fractures increased. At the stress increase substage, the proportion of mixed-mode or tensile fractures decreased, and the shear fractures increased. Finally, a conceptual model for the stepwise crack formation was proposed.

A new kind of tangent derivative, M-derivative, for set-valued function is introduced with help of a modified Dubovitskij-Miljutin cone. Several generalized pseudoconvex set-valued functions are introduced. When both the objective function and constraint function are M-derivative, under the assumption of near conesubconvexlikeness, by applying properties of the set of strictly efficient points and a separation theorem for convex sets, Fritz John and Kuhn-Tucker necessary optimality conditions are obtained for a point pair to be a strictly efficient element of set-valued optimization problem. Under the assumption of generalized pseudoconvexity, a Kuhn-Tucker sufficient optimality condition is obtained for a point pair to be a strictly efficient element of set-valued optimization problem.

Massive hemorrhage is a frequent cause of human death in the operating room and other emergency situations. Therefore, effective hemostatic wound dressings are essential to save lives. Here we show that, calcium functioned carboxymethylated cotton fabric (MCF-Ca) conveniently prepared by carboxymethylation of cotton fabrics followed by treatment with calcium chloride solution could serve as an effective hemostatic wound dressing. The calcium content of MCF-Ca was determined as 18.11 ± 0.44 mg/g, and the calcium ions were released into a saline solution, a process that reached near-equilibrium within about 2 min. The biocompatible MCF-Ca promoted hemostasis via forming complexes with blood cells, and it showed lower blood clotting index as well as shorter blood clotting time comparing with unmodified CF in vitro. In addition, MCF-Ca exhibited better hemostatic efficiency than CF in vivo, resulting in much shorter hemostasis time and less blood loss in rat liver injury model and femoral artery animal model. In conclusion, MCF-Ca shows good potential to be used as wound dressing for patients with uncontrolled or massive hemorrhage.

LBlock is a lightweight block cipher with Feistel-SP structure proposed by Wu and Zhang in Applied Cryptography and Network Security 2011, and a modified version LBlock-s is used later in the design of the lightweight authenticated encryption cipher LAC, one of the CAESAR candidates. The best known integral attack on LBlock is presented by Zhang and Wu which can attack 23-round LBlock based on a 16-round integral distinguisher found with division property. In Selected Areas in Cryptography 2018, Eskandari et al. further presented a 17-round integral distinguisher of LBlock with bit-based division property using SAT solver. Using their method, the authors further find some new 17-round integral distinguishers of LBlock and use one of them to present a 24-round integral attack on LBlock. Similarly, they also find some 17-round integral distinguishers of LBlock-s and select one to present a 24-round integral attack on LBlock-s. In this way, they have improved known single-key attacks on LBlock and LBlock-s by one round.

A Na-montmorillonite (Na-MMT) was activated with HNO3 (20 wt.%) solution at various temperatures and times to obtain acid-activated MMT (Acid-MMT). Zinc (4 wt.%) was supported on Acid-MMT via the impregnation method using Zn(NO3)2⋅6H2O as a precursor. The catalytic performance of the Zn/Acid-MMT for the aromatization of heptane was investigated. The amount and distribution of acidity of Acid-MMT, which could be adjusted by changing the acid activation time and temperature, significantly affected the heptane conversion and aromatics content. As a result, an efficient Zn/Acid-MMT catalyst for the aromatization reaction was obtained by optimizing the acid-treatment conditions of Na-MMT.

A flame-retardant jute/PP composite with excellent flame retarding and mechanical properties was prepared by the surface powder spraying process. The flame-retardant layer used the green and pollution-free β-cyclodextrin as a char agent. To improve the char forming ability of β-cyclodextrin, ammonium polyphosphate (APP) and melamine (MEL) were also used as acid source and a blowing agent, respectively. The results indicated that the char forming ability of β-CD could be improved by the reaction between β-CD and APP. The composite with 20% flame retardants containing β-CD, APP and MEL (1:2:1) showed the better flame-retardant properties. The LOI value of the composite increased to 27.8%, which reached the second fire resistance according to Japan's JISD 1201-77 standard, and the self-extinguishing time reached to 37 s. Compared with pure jute/PP, the PHRR value and Av-EHC value of the composites were reduced by 50% and 21%, respectively. The carbon residual at 700 °C was increased by 10.9%. The tensile strength and bending strength were increased by 5% and 19%. These results revealed that the flame retardancy, thermal stabilities and mechanical properties of composites containing β-CD/APP/MEL system were significantly improved by the surface powder spraying method.

Light-emitting diodes (LEDs) have been widely applied in the controlled environment agriculture, which are characterized by relatively narrow-band spectra and energetical efficiency. Most recently, the spectrum of Sunlike LEDs has been engineered and it closely resembles solar spectrum in the range of photosynthetic active radiation (PAR, 400–700 nm). To investigate how plant growth responses to the spectrum of Sunlike LEDs, cucumber and lettuce plants were cultivated and their responses were compared with the conventional white LEDs as well as composite of red and blue LEDs (RB, R/B ratio was 9:1). We observed that although Sunlike LEDs resulted in a longer stem in cucumber, dry weight and leaf area were similar as those under RB LEDs, and significantly higher than those under white LEDs. Moreover, cucumber leaves grown under Sunlike and white LEDs showed higher photosynthetic capacity than those grown under RB LEDs. For lettuce, plants grown under Sunlike LEDs showed larger leaf area and higher dry weight than the other two treatments. However, the leaf photosynthetic capacity of lettuce grown under Sunlike LEDs was the lowest. In this context, the spectrum induced plant functions are species-dependent. Furthermore, the three types of LEDs show distinct light spectra and they are different in many aspects. Therefore, it is difficult to attribute the different plant responses to certain specific light spectra. We conclude that plants grown under Sunlike LEDs exhibit larger leaf area, which may be due to some specific spectrum distributions (such as more far-red radiation), and consequently are favorable for light interception and therefore result in greater production.

Self-healing materials, which can autonomously repair damages like living organisms, have undergone extensive development in the last decades. The bottleneck problems for their practical applications are long healing time, inferior mechanical strength, and aging sensitivity. Here, a new class of polymeric materials rationally grafted with oligo poly(ethylene glycol) is reported. The network based on the formation of multiple weak hydrogen bonds endows the elastomers with good comprehensive performances including high stretchability (725%), high strength (4.20 MPa), and fast self-healing process (40 s). Benefiting from characteristic multiple weak hydrogen bond interactions, the fractured elastomers maintain high healing efficiency even after aging for 192 h, showing an unusual aging insensitivity. A Sudoku structural device based on the developed elastomer shows shape memory effect, providing a new avenue for fabricating novel smart devices with complicated shapes.

Triazole heterocyclic compounds have a wide range of applications in the fields of medicine, pesticide, energetic materials, etc. Introducing halogen atoms and amino groups into the triazole ring can obtain a series of important intermediates that can be further modified. 4,5-Dibromo-1-H-1,2,3-triazole (5), 3,5-dibromo-1-H-1,2,4-triazole (6), 3,5-dibromo-4-H-1,2,4-triazole (7) and 1-amino-4,5-dibromo-1,2,3-triazole (8), 2-amino-4,5-dibromo-1,2,3-triazole (9) and 1-amino-3,5-dibromo-1,2,4-triazole (10) were synthesized through the bromination and amination of 1,2,3-triazole (1), 1-amino-1,2,3-triazole (2), 1,2,4-triazole (3) and 4-amino-1,2,4-triazole (4). Their structures were characterized by IR, EI-MS, ESI-MS, 1H and13C-NMR techniques. Single crystals of these compounds were grown by evaporation solution growth technique. The cell parameters and crystal structures were determined by X-ray single crystal diffraction studies. Among these compounds, 6 and 7, 8 and 9 were isomers, respectively. Through intermolecular hydrogen bonding, 1 forms zigzag chain structure, while 4 and 5 form cyclic trimers.

The builder is an important ingredient in detergents. Sodium oxalate is a good non-phosphate detergent builder, which has good calcium-removing properties and good wash performance in detergents. However, sodium oxalate-based detergent formulations face a tricky problem of “incrustation” on fabrics due to calcium oxalate deposition. If sodium oxalate is used in commercial detergents, then “incrustation” must be solved. In this study, we examined the effect of fabric type, anionic surfactant, polymer, and temperature on incrustation and soil redeposition (“secondary” washing effect) of a sodium oxalate-based detergent. The results showed that both the anionic surfactant and polymer influenced the deposition of calcium oxalate on fabrics. Overall, the amount of calcium oxalate deposition followed the order polyamide

The CSH-bending and CH3-rocking infrared bands of CH3SH have been investigated in Fourier transform spectra recorded at 0.001 cm−1 resolution employing synchrotron radiation at the Canadian Light Source in Saskatoon. The relative band strengths and structures are quite different from those of the CH3OH methanol analogue, with the CSH bend being very weak and both the in-plane and out-of-plane CH3 rocks being strong with intensities greater than the C–S stretch. The CSH bend has parallel a-type character with no detectable b-type component. The out-of-plane CH3 rock is a purely c-type perpendicular band, whereas the in-plane rock is of mixed a/b character. Sub-bands have been assigned for A and E torsional species up to about K = 10 for each vibrational mode, providing upper-state term values from which K-reduced substate origins were determined. For the CSH bend, the origins follow the customary oscillatory torsional pattern as a function of K with a sharply reduced amplitude of 0.362 cm−1 compared to the 0.653 cm−1 for the ground state. The torsional energy curves for the out-of-plane rock are also well-behaved but have inverted ordering of the A–E torsional splitting components and a larger amplitude of 1.33 cm−1. In contrast, the substate origins for the in-plane rock are scattered over a range of about 2 cm−1 without clear oscillatory structure. Several instances of coupling among the lower modes and the ground state via resonances between accidentally near-degenerate levels have been observed and characterized. Ab initio calculations are found to give a good representation of the frequency and relative intensity patterns for the lower vibrational modes.

In this work, we have investigated the washing performance of sodium oxalate-based detergents containing different enzymes (protease, lipase and cellulase). The results show that sodium oxalate-based detergents with enzymes have a better washing performance than formulations containing the conventional builder STPP and zeolite 4A. For sodium oxalate-based with protease, the amount of sodium oxalate and protease have a significant effect on the detergency. Lipase can improve detergency of sodium oxalate-based detergents after “first washing” in the presence of different anionic surfactant (LAS, MES and AES). For cellulase, only sodium oxalate in the presence of LAS has a detergency increase.

In order to improve the management of nitrogen (N) fertilization in pear orchards, we investigated the effects of application timing on the distribution, storage, and remobilization of N in mature pear trees in a field experiment at Jingtai County, Gansu Province, China. Nine trees were selected for the experiment and each received equal aliquots of 83.33 g N in the autumn, spring, and summer, with 15N-labeled (NH4)2SO4 used in one of the aliquots each season. Results showed that the (15N H4)2SO4 applied in the autumn remained in the soil during the winter. In the following spring this N was absorbed and rapidly remobilized into each organ, especially new organs (leaves, fruit and new shoots). The 15N supplied in spring was rapidly transported to developing fruit between the young fruit and fruit enlargement stages. 15N from the summer application of fertilizer was mainly stored in the coarse roots over the winter, then was mobilized to support growth of new organs in spring. In conclusion, for pear trees we recommend that the autumn application of N-fertilizer be soon after fruit harvest in order to increase N stores in fine roots. Spring application should be between full bloom and the young fruit stages to meet the high N demands of developing fruit. Summer application of fertilizer at the fruit enlargement stage does not contemporaneously affect the growth of pears, but increases the N stored in coarse roots, and in turn the amount available for remobilization in spring.

Low-molecular-weight poly-γ-glutamic acid (LMW-γ-PGA) has attracted much attention because of its many potential applications in food, agriculture, medicine, and cosmetics. Enzymatic degradation is an efficient way for the synthesis of LMW-γ-PGA. However, the stereochemistry of γ-PGA limits the degradation of γ-PGA. This study identifies the role of γ-PGA synthase (pgsA) and glutamate racemase (racE) in the regulation of γ-PGA stereochemistry and demonstrates their combinational use for LMW-γ-PGA synthesis. First, the expression of pgsA and racE was enhanced, leading to improvements both in the molecular weight (Mw) and the d-glutamate proportion of γ-PGA. Then, an optimal combination of pgsA, racE, and γ-PGA hydrolase pgdS was constructed by exchanging the gene origins for the synthesis of LMW-γ-PGA. Finally, the Mw of γ-PGA was decreased to 6-8 kDa, which was much lower compared with the case without stereochemistry switching (20-30 kDa). This study provides a novel strategy to control the Mw of γ-PGA based on stereochemistry regulation and lays a solid foundation for synthesis of LMW-γ-PGA.

The aggregation behaviours of three primary reactive dyes in water were determined by molecular dynamics simulations. The aggregation equilibrium time period was determined by SASA analyses. The maximum aggregation sizes for the seven systems were not greater than that of a pentamer. For single dye solutions, the aggregation trend followed the order Y176 > B194 > R239. For two-colour mixed dye solutions, the aggregation compatibilities followed the order Y176-B194 > Y176-R239 > B194-R239. Overall, the three dyes had satisfactory aggregation compatibilities. The dye-dye and dye-water molecule interactions were analysed by RDG and aRDG methods. The results graphically showed the place, strength and type of the interactions. The main interactions between the dye anions were the VdW and π-π stacking interactions. Most parts of the dyes showed VdW interactions with water. The aggregation tendency may be affected by the number and the position of the water-soluble groups of the dyes, the molecular weight of the dye molecules and whether or not the configuration of the dyes was beneficial to the formation of π-π stacking interactions.

The determination of erythropoietin (EPO) isoforms by using capillary zone electrophoresis (CZE) has been a key study in the quality control of erythropoietin products. However, the current Europea...

Selective conversion of renewable sources is necessary for developing energy generation technology and protecting the environment. Herein, this work reports a one-step controllable synthesis of tri...

In this paper, the design methodology of a microstrip angular displacement sensor based on an impedance transformer with a quasi-Chebyshev frequency response is proposed. This sensor with impedance transforming function can realize the angular displacement detection by bandwidth sensing, and matching sensing simultaneously. The insertion loss in stopband achieves 24.9 dB to 32.6 dB with an average bandwidth selectivity of 2.25 MHz/degree of the sensor centered at 2.4 GHz with two poles of 1.71 GHz and 2.81 GHz. Meanwhile, the average matching level of return loss for displacement sensitivity are 0.18 dB/degree and 0.15 dB/degree, respectively. It is the first time to apply an impedance transformer into the angular displacement sensor design for both bandwidth and matching level sensing among reviewed literatures. In this design, the load-to-source impedance transformation is designed for 250-to- $50~\Omega $ , and by adding a rotated stub on the proposed microstrip transformer, the sensing function is developed with angular displacement.

To study the difference in the failures of laboratories #7 and #8 of the China Jinping Underground Laboratory Phase II (CJPL-II), different loading and unloading stress path tests were carried out under a true triaxial compression condition based on the measured in situ stress of CJPL-II. The strength, deformation and failure mechanisms of Jinping marble under different stress paths were thoroughly investigated. The results showed that under the same stress state as that at sample failure, the bearing capacity and deformation of the unloading stress path were greater than those of the loading stress path. The bearing capacity and deformation in the σ2 and σ3 directions of stress path II and stress path III were similar, and the others decreased from stress path IV to stress path V under unloading conditions. The failure mode results reflect the violence of the unloading failure. The failure features and mechanisms of different stress paths were analysed though the acoustic emission (AE) ring, cumulative energy and strain energy trend. This research may provide a reference for the excavation and support of deep underground works.

SiC/7075 aluminum matrix composites were prepared by a liquid stirring method. The role of Ti facilitating the preparation of SiC/7075 aluminum matrix were studied by means of direct-reading spectrometer, scanning electron microscope, energy dispersive spectrometer, X-ray diffraction and the sessile drop method. The results show that the SiC content in the SiC/7075 composite increases with an increase of Ti addition. The addition of Ti can significantly improve the wettability of SiC/Al system, there is a critical value of above 0.5% of Ti content in improving the wettability of the Al/SiC system at 1 173 K. The temperature of the “non wetting-wetting” transition for the (Al-2Ti)/SiC system is about 1 123 K, the contact angle decreases to 88 ° at 200 seconds and reaches a stable contact angle of 28 ° at 2 100 seconds.

Low-dimensional lead-free organic-inorganic hybrid perovskites have gained increasing attention as having low toxicity, ease of processing, and good optoelectronic properties. Seeking for lead-free and narrow band gap organic-inorganic hybrid perovskites are of great importance for the development and application of photoelectric materials. Here, we reported a Sb-based organic-inorganic hybrid perovskite (MV)[SbI3Cl2], which has one-dimensional inorganic frameworks of the I-sharing double octahedra. (MV)[SbI3Cl2] shows a narrow direct band gap of 1.5 eV, and displays obvious photoresponse for the 532 nm light with rapid response speed of trise = 0.69 s, tdecay = 0.28 s. With an illumination power of 5 mW and a 50 V bias, the responsivities (R) and external quantum efficiency (EQE) for (MV)[SbI3Cl2] photodetector under 532 nm laser are 29.75 mA/W and 6.69% respectively. This Sb-based halide double perovskite material will provide an alternative material for photodetector devices.