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A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.

The common cutworm, Spodoptera litura, is a polyandrous moth with high reproductive ability. Sexual reproduction is a unique strategy for survival and reproduction of population in this species. However, to date available information about its reproductive genes is rare. Here, we combined transcriptomics, genomics and proteomics approaches to characterize reproductive-related proteins in S. litura. Illumina sequencing in parallel with the reference genome led to the yields of 12,161 reproductive genes, representing 47.83% of genes annotated in the genome. Further, 524 genes of 19 specific gene families annotated in the genome were detected in reproductive tissues of both sexes, some of which exhibited sex-biased and/or tissue-enriched expression. Of these, manual efforts together with the transcriptome analyses re-annotated 54 odorant binding proteins (OBPs) and 23 chemosensory proteins (CSPs) with an increase of 18 OBPs and one CSP compared to those previously annotated in the genome. Interestingly, at least 35 OBPs and 22 CSPs were transcribed in at least one reproductive tissue, suggestive of their involvement in reproduction. Further proteomic analysis revealed 2381 common proteins between virgin and mated female reproductive systems, 79 of which were differentially expressed. More importantly, 74 proteins exclusive to mated females were identified as transferred relatives, coupled with their specific or high expression in male reproductive systems. Of the transferred proteins, several conserved protein classes across insects were observed including OBPs, serpins, trypsins and juvenile hormone-binding proteins. Our current study has extensively surveyed reproductive genes in S. litura with an emphasis on the roles of OBPs and CSPs in reproduction, and identifies potentially transferred proteins serving as modulators of female post-mating behaviors.

Begonia shenzhenensis D.K.Tian & X.Yun Wang, sp. nov., a new species in Begonia sect. Platycentrum of Begoniaceae from Shenzhen of Guangdong province, China, is described and illustrated. Morphologically, it is primarily similar to B. coelocentroides in the same section but differs by its denser hairs on leaf, petiole, and pedicel, abtuse anther apex, hairy ovary, and narrower adaxial fruit wing. Based on only one small population found to date, its conservation status is assigned to Critical Endangered according to the IUCN Red List Categories and Criteria.

Seismic waves passing through partially saturated porous rocks produce pressure gradients in the fluid phase, and, hence, the resulting fluid flow is accompanied by various length scales. The major mechanism responsible for seismic attenuation and dispersion is arguably known as wave‐induced fluid flow between inhomogeneities of microscopic, mesoscopic and macroscopic scales. Previous studies have revealed that differentiating the influence of heterogeneities at various scales on wave attenuation within seismic exploration and sonic frequencies, nevertheless, is very difficult. This is because wave attenuation mechanisms due to different heterogeneities are practically impossible to be unrelated. Therefore, it is important for a more quantitative interpretation of the relative contribution of inter‐dependent energy loss mechanisms through improved understanding of the combined influences associated to the microscopic squirt flow and mesoscopic fluid flow. We introduce a scaled poroelastic model to evaluate frequency‐dependent attenuation and velocity dispersion characteristics by considering the combined presence of microscopic and mesoscopic heterogeneities. To do so, the capillarity effects are incorporated into the poroelastic model with random distributions of the sizes of mesoscopic‐scale heterogeneities. A range of pertinent scenarios are calculated, and the acoustic properties indicate wave attenuation decreases whereas the phase velocity increases corresponding to additional capillary forces. Meanwhile, numerical results of the proposed model were compared with experimental measurements of a tight sandstone to examine its validity. Results of numerical simulations suggest that seismic reflections produce more complicated signatures in the presence of an interbedded structure of a reservoir exhibiting velocity dispersion. Therefore, the proposed procedure can help in assessing the sensitivities of frequency‐dependent seismic signatures to reservoir fluid mobility and patch heterogeneities.

SUMMARY Elastic moduli and velocities of tight sandstones are strongly influenced by rock-frame heterogeneity, pore microstructure and fluid in addition to pressure and probing-wave frequency. The effects of pressure and frequency on the elastic moduli and velocities are different from those of conventional sandstones with high porosity and high permeability due to complexity of pore microstructure. To investigate these effects, we measured two tight sandstone samples for their velocities in the dry and fluid saturation conditions using the ultrasonic transmission technique and the low-frequency stress–strain method. The variations in the ultrasonic velocities with pressure see a transition from non-linear to linear increase for the dry samples, in contrast to a gradual increase for the fluid-saturated samples. The low frequency velocities of the saturated sample T1 and T2 directly show significant dispersion in a wide range of frequencies (1–100 Hz), and the magnitudes of the dispersion are suppressed by the pressure. The low-frequency velocities also increase with pressure, showing increasing trends bounded by the ultrasonic velocity–pressure curves for the dry and fluid saturation conditions. An elaborate rock physics model, considering a discrete aspect ratio spectrum and the simple squirt flow model, was constructed to account for the pressure and frequency dependence of the velocities. The predictions from the modified squirt flow model can fit well the measured velocities at varying pressures, both in the low-frequency range and the ultrasonic frequency range. The real measurements and the modelling results suggest that the pressure- and frequency-dependence cannot be modelled without considering such aspect ratio spectra. The effects of pressure and frequency are coupled in that they are interconnected by the microstructure of the pores. Changes in the pressure and fluid saturation (and thus wave frequency) both contribute to stiffening of the rock frame, and they both strongly depend on the presence of microcracks in the rock. Therefore, this rock physics model could be applied in extraction of pore microstructure and fluid properties provided elastic moduli or velocities can be estimated accurately.

Olivine is a ubiquitous mineral in mafic-ultramafic rocks and has been widely used as a mineral marker in various geological processes. However, its development of trace elements is limited. Here we present newly-obtained trace element data 7Li, 27Al, 29Si, 31P, 43Ca, 45Sc, 49Ti, 51V, 53Cr, 55Mn, 59Co, 60Ni, and 66Zn of olivine in typical mantle xenoliths, mantle peridotites in ophiolites, and plutonic rocks from layered and Alaskan-type intrusions to develop trace element proxies for the petrogenesis, mineralization and discrimination of various mafic-ultramafic rocks. Residual olivine grains in mantle xenoliths and ophiolitic peridotites, which represent residues of mantle melting, have higher Ni/Co (>20) and Ni/Mn (>2) ratios than magmatic olivine (Ni/Co < 20, Ni/Mn < 2), which are consistent with the compatibilities of these elements during partial melting and magma differentiation. Lower Ni content, and lower Ni/Co and Ni/Mn ratios at a given Fo content can distinguish olivine in Alaskan-type intrusions from layered intrusions, reflecting the nature of their mantle sources. The V and Sc contents and V/Sc ratios in olivine can distinguish mantle xenoliths (V > 2 ppm, V/Sc > 0.5) from ophiolitic peridotites (V < 2 ppm, V/Sc < 0.5), indicating a more reduced state of continental lithospheric mantle compared to the oceanic lithospheric mantle. As a consequence, the four occurrences of mafic-ultramafic rocks can be distinguished by olivine with (Sc × 10)-(Ti × 2)-Zn and V/Sc-(Co/Ni × 2)-(Zn/Mn × 5) ternary diagrams. In addition, Li, Ti and P contents in olivine are good tracers of melt/fluid metasomatism, whereas Ni/Co, Ni/Mn and Mn/Zn ratios are indicators of chromite mineralization. Therefore, trace elements in olivine can be used as chemical proxies to distinguish the origin of various mafic-ultramafic rocks, as well as the processes by which they evolved.

We show how to map Grothendieck's dessins d'enfants to algebraic curves as Seiberg-Witten curves, then use the mirror map and the AGT map to obtain the corresponding 4d $\mathcal{N}=2$ supersymmetric instanton partition functions and 2d Virasoro conformal blocks. We explicitly demonstrate the 6 trivalent dessins with 4 punctures on the sphere. We find that the parametrizations obtained from a dessin should be related by certain duality for gauge theories. Then we will discuss that some dessins could correspond to conformal blocks satisfying certain rules in different minimal models., 55 pages; dedicated to the memory of Prof. Omar Foda; v3: minor corrections

Hydroxy-γ-sanshool was prepared with 19.5% overall yield through eight steps. Wittig reactions of ylides with ethyl 4-oxobut-2-enoate as well as (2E,4E)-hex-2,4-dienal were key steps to construct a carbon skeleton. The 2E,4Z-isomer in ethyl 8-hydroxyocta-2,4-dienoate can be isomerized to the desired 2E,4E-isomer with iodine as a catalyst, and free tetradeca-2,4,8,10,12-pentaenoic acid can be purified through crystallization in 1% ethyl acetate in n-hexane. The impurities in other intermediates can be easily removed, the synthetic process can avoid the synthesis or use of 4-bromobutyraldehyde which comes from the oxidation of unstable 4-bromobutan-1-ol, and the work-ups were simple.

Qudit entanglement is an indispensable resource for quantum information processing since increasing dimensionality provides a pathway to higher capacity and increased noise resilience in quantum communications, and cluster-state quantum computations. In continuous-variable time–frequency entanglement, encoding multiple qubits per photon is only limited by the frequency correlation bandwidth and detection timing jitter. Here, we focus on the discrete-variable time–frequency entanglement in a biphoton frequency comb (BFC), generating by filtering the signal and idler outputs with a fiber Fabry–Pérot cavity with 45.32 GHz free-spectral range (FSR) and 1.56 GHz full-width-at-half-maximum (FWHM) from a continuous-wave (cw)-pumped type-II spontaneous parametric downconverter (SPDC). We generate a BFC whose time-binned/frequency-binned Hilbert space dimensionality is at least 324, based on the assumption of a pure state. Such BFC’s dimensionality doubles up to 648, after combining with its post-selected polarization entanglement, indicating a potential 6.28 bits/photon classical-information capacity. The BFC exhibits recurring Hong–Ou–Mandel (HOM) dips over 61 time bins with a maximum visibility of 98.4% without correction for accidental coincidences. In a post-selected measurement, it violates the Clauser–Horne–Shimony–Holt (CHSH) inequality for polarization entanglement by up to 18.5 standard deviations with an S-parameter of up to 2.771. It has Franson interference recurrences in 16 time bins with a maximum visibility of 96.1% without correction for accidental coincidences. From the zeroth- to the third-order Franson interference, we infer an entanglement of formation (Eof) up to 1.89 ± 0.03 ebits—where 2 ebits is the maximal entanglement for a 4 × 4 dimensional biphoton—as a lower bound on the 61 time-bin BFC’s high-dimensional entanglement. To further characterize time-binned/frequency-binned BFCs we obtain Schmidt mode decompositions of BFCs generated using cavities with 45.32, 15.15, and 5.03 GHz FSRs. These decompositions confirm the time–frequency scaling from Fourier-transform duality. Moreover, we present the theory of conjugate Franson interferometry—because it is characterized by the state’s joint-temporal intensity (JTI)—which can further help to distinguish between pure-state BFC and mixed state entangled frequency pairs, although the experimental implementation is challenging and not yet available. In summary, our BFC serves as a platform for high-dimensional quantum information processing and high-dimensional quantum key distribution (QKD).

Lepidoptera (moths and butterflies) and Trichoptera (caddisflies), belonging to the superorder Amphiesmenoptera, are the most diverse insect orders as representatives of the terrestrial and aquatic insects, respectively. The insects of the two orders possess different biological and behavioral characteristics, especially their larvae, presumably resulting in the differences of the ionotropic receptor (IR) genes in numbers, sequence characteristics or gene structure. Here, we employed genomics, transcriptomics, bioinformatics, phylogenetics and molecular biology strategies to characterize the IR gene repertoire in Lepidoptera and Trichoptera. Genome and transcriptome analyses with exhaustive homology-based searches and manual efforts, in 32 lepidopterans and five trichopterans, led to the identification of 1449 genes encoding IRs with 1170 full-length sequences, representing the most comprehensive set of chemoreceptor superfamilies across the Amphiesmenoptera. Analysis of gene gains and losses in orthologous groups implied that some IRs were lost in related species, and multiple gene copies occurred mainly in divergent IRs (D-IRs) by gene duplications. Phylogenetic analysis of 2442 IR proteins from 67 species revealed that Lepidoptera and Trichoptera IRs could be classified into three subfamilies, i.e., 14 antennal IRs (A-IRs), five Lepidoptera-specific IRs (LS-IRs) and four D-IRs. Of the three subfamilies, A-IRs and LS-IRs members within orthologous groups exhibited high conservation of gene structure, but D-IRs shared extremely low amino acid identities (below 30%). Expression profiles revealed functional diversities of IRs from Bombyx mori and Papilio xuthus involving smell, taste or reproduction, in which some genes displayed sex-biased expression in antennae associated with specific chemosensory behaviors of female or male adults. Our current study has provided insights into the evolution, conservation and divergence of IRs between/within Lepidoptera and Trichoptera, and allows for further experiments to investigate IR functions.

To better understand the role and extent of inter-mineral diffusion during subsolidus processes, we investigated the iron and magnesium isotopic compositions of olivine, orthopyroxene, and chromite separates from the Peridotite Zone of the Stillwater Complex. Olivine and orthopyroxene show limited Mg isotopic variations, with δ26Mg values ranging from −0.40 to −0.26‰ and from −0.29 to −0.22‰, respectively. In contrast, chromite displays extremely large Mg isotopic variations, with δ26Mg values ranging from −0.05 to +0.84‰. The δ56Fe values of olivine and orthopyroxene range from 0.00 to +0.17‰ and −0.04 to +0.06‰, respectively, whereas those of chromite range from −0.09 to +0.13‰. Most olivine-orthopyroxene pairs in our samples show no clear Fe-Mg isotopic differences, whereas silicate and coexisting chromite pairs plot away from theoretically predicted equilibrium lines, indicating disequilibrium inter-mineral fractionation. Higher δ56Fe values in silicates than in chromite and significantly higher δ26Mg values in chromite than in silicates indicate that subsolidus re-equilibration is responsible for the observed disequilibrium Fe-Mg isotope fractionation. We develop a quantitative model based on the investigated olivine and chromite to reproduce the observed kinetic Fe-Mg isotope fractionations. Our model results indicate a systematic difference between the Fe and Mg isotope fractionation factors, β, of olivine (βFe ≈ 0.27 and βMg ≈ 0.16) and chromite (0.03

Arbuscular mycorrhizal fungi (AMF) can benefit many plants, but their effects on walnuts are not yet known. The present study aimed to analyze the effect of five AMF species, namely, Acaulospora scrobiculata, Diversispora spurca, Glomus etunicatum, G. mosseae and G. versiforme on biomass production, chlorophyll contents, sugar fraction contents, and mineral element contents of walnut (Juglans regia L.) seedlings. The five AMF species colonized roots of walnut, established mycorrhizas in roots and hyphae in soil, and released easily extractable glomalin-related soil protein into soil, whilst D. spurca exhibited the best effect. All the AMF inoculations, except A. scrobiculata, stimulated shoot and root biomass production. Mycorrhizal fungal inoculations collectively increased leaf chlorophyll a, chlorophyll b, and total chlorophyll a+b concentrations, and thus promoted leaf sucrose accumulation, which provides an important mycorrhiza-carbon source to roots. AMF inoculations conferred a positive effect on leaf N, P, K, Mg, Fe, B, Zn and Cu contents, while they reduced leaf Mn contents. These results concluded that AMF were beneficial to the growth and physiological activities of walnut, which gives the support for the AMF application in walnut.

Although the involvement of hydrous fluids has been widely invoked in formation of podiform chromitites in ophiolites, there is lack of natural evidence to signify the role and mechanism of fluids. In this study, a new model for the genesis of podiform chromitite is proposed on basis of revisits of comprehensive petrological, mineralogical and geochemical results of the well-preserved Kizildag ophiolite and the well-characterized Luobusa chromite deposit. In this model, ascending magmas intruding oceanic lithospheric mantle would presumably form a series of small magma chambers continuously connected by conduits. Tiny chromite nuclei would collect fluids dispersed in such magmas to form nascent droplets. They tend to float upward in the magma chamber and would be easily transported upward by flowing magmas. Chromite-rich droplets would be enlarged via coalescence of dispersed droplets during mingling and circulation in the magma chamber and/or transport in magma conduits. Crystallization of the chromite-rich liquid droplets would proceed from the margin of the droplet inward, leaving liquid entrapped within grains as precursor of mineral inclusions. With preferential upward transportation, immiscible chromite-rich liquids would coalesce to a large pool in a magma chamber. Large volumes of chromite would crystallize in situ , forming podiform chromitite and resulting in fluid enrichment in the chamber. The fluids would penetrate and compositionally modify ambient dunite and harzburgite, leading to significant fractionations of elemental and isotopic compositions between melts and fluids from which dunite and chromitite respectively formed. Therefore, fluid immiscibility during basaltic magma ascent plays a vital role in chromitite formation.

Reasonable design and fabrication of core/shell heterojunction has deemed as an efficient strategy to boost the transport and separation of photoinduced charge pairs in semiconductor-based photocatalytic system. Herein, a novel dual-functional ZnIn2S4/Ta3N5 (ZIS/TN) nanocomposite with intimate contacts was fabricated with a one-pot eco-friendly hydrothermal method. This core/shell heterojunction consisting of ZnIn2S4 nanosheet shell and Ta3N5 nanoparticle core is observed to possess the enhanced visible light harvesting capacity, increased specific surface areas, more high-speed charge nanochannels and accelerated charge transfer and separation. Thus, as prepared ZIS/TN nanocomposite displayed dramatically strengthened dual-functional photocatalytic performances of hydrogen production and tetracycline hydrochloride (TCH) photodegradation. As a result, the improved H2-production activity of 834.86 μmol g−1 h−1 was obtained by sample ZIS/TN-2, which is 6.07 times higher than that of pure ZnIn2S4 nanosheet. Moreover, the highest TCH photodegradation efficiency of 89.95% is achieved by the sample ZIS/TN-3, which is 1.90 and 11.01 times more than those of bare ZnIn2S4 and Ta3N5. In addition, the core/shell heterojunction exhibits super photostability and reusability due to the protection of external ZnIn2S4 layer from the photocorrosion of Ta3N5 core. Furthermore, the possible reaction mechanisms and the degradation intermediate products of TCH were also put forwarded in depth based on transient photocurrent response, active species tapping experiment, electronspin response (ESR) technique and HPLC-MS method. This work could stimulate an innovative vision in constructing dual-functional Ta3N5-based core/shell heterostructure with wonderful photocatalytic H2 evolution and antibiotic pollutant photodegradation activities.

γ-Amide-e-caprolactones including 7-oxo-N-propyloxepane-4-carboxamide (NNCL), N-isopropyl-7-oxooxepane-4-carboxamide (NICL), N,N-diethyl-7-oxooxepane-4-carboxamide (DECL), and 5-(pyrrolidine-1-carb...

Frequency‐dependent amplitude variation with offset offers an effective method for hydrocarbon detections and analysis of fluid flow during production of oil and natural gas within a fractured reservoir. An appropriate representation for the frequency dependency of seismic amplitude variation with offset signatures should incorporate influences of dispersive and attenuating properties of a reservoir and the layered structure for either isotropic or anisotropic dispersion analysis. In this study, we use an equivalent medium permeated with aligned fractures that simulates frequency‐dependent anisotropy, which is sensitive to the filled fluid of fractures. The model, where pores and fractures are filled with two different fluids, considers velocity dispersion and attenuation due to mesoscopic wave‐induced fluid flow. We have introduced an improved scheme seamlessly linking rock physics modelling and calculations for frequency‐dependent reflection coefficients based on the propagator matrix technique. The modelling scheme is performed in the frequency‐slowness domain and can properly incorporate effects of both bedded structure of the reservoir and velocity dispersion quantified with frequency‐dependent stiffness. Therefore, for a dispersive and attenuated layered model, seismic signatures represent a combined contribution of impedance contrast, layer thickness, anisotropic dispersion of the fractured media and tuning and interference of thin layers, which has been avoided by current conventional methods. Frequency‐dependent amplitude variation with offset responses was studied via considering the influences of fracture fills, layer thicknesses and fracture weaknesses for three classes amplitude variation with offset reservoirs. Modelling results show the applicability of the introduced procedure for interpretations of frequency‐dependent seismic anomalies associated with both layered structure and velocity dispersion of an equivalent anisotropic medium. The implications indicate that anisotropic velocity dispersion should be incorporated accurately to obtain enhanced amplitude variation with offset interpretations. The presented frequency‐dependent amplitude variation with offset modelling procedure offers a useful tool for fracture fluid detections in an anisotropic dispersive reservoir with layered structures.

We investigated reflection dispersion characteristics of a poroelastic layer with patchy saturations in seismic low-frequency range. Frequency-dependent attenuation and dispersion of phase velocity...

A novel Co-WC composite coating was deposited on the surface of high speed steel (HSS) substrate by an energy-efficient method of electrodeposition. The effects of process parameters on friction and wear properties of the composite coatings were evaluated, and the worn morphologies of Co-WC composite coatings were investigated by scanning electron microscopy. Results revealed that the incorporation of WC particles can significantly improve the wear resistance of the coating. As the current density was increased to 6.5Adm-2 and the WC concentration was increased to 35g/L, the Co-WC composite coating had the lowest friction coefficient and wear loss.

Seismic wave propagation through a fluid‐saturated poroelastic layer might be strongly affected by media heterogeneities. Via incorporating controlled laboratory simulation experiments, we extend previous studies of time‐lapse seismic effects to evaluate the wave scattering influence of the heterogeneous nature of porous permeable media and the associated amplification effects on 4D seismic response characteristics of reservoir fluid substitution. A physical model consisted of stratified thin layers of shale and porous sandstone reservoir with rock heterogeneities was built based on the geological data of a real hydrocarbon‐saturated reservoir in Northeast China. Multi‐surveys data of good quality were acquired by filling poroelastic reservoir layers with gas, water and oil in sequence. Experimental observations show that reservoir heterogeneity effect causes significantly magnified abnormal responses to the fluid‐saturated media. Specifically, reflection signatures of the gas‐filled reservoir are dramatically deviated from those of the liquid fluid‐filled reservoir, compared with ones of the homogeneous media. By removing the influences unrelated to reservoir property alterations, 4D seismic estimates of travel‐time and frequency‐dependent characteristic are reasonably consistent with fluid variations. Nevertheless, strong 4D amplitude difference anomalies might not correspond to the regions where fluid variations occur. We also find that 4D seismic difference attributes are evident between oil‐ and water‐filled models, whereas significant between oil‐ and gas‐filled models. Meanwhile, rock physics modelling results reveal the predicted 4D seismic differences are obviously smaller than those calculated from seismic observations. The results in this paper, therefore, implicate that the effect of a reservoir's heterogeneous nature might be beneficial for hydrocarbons detection as well as monitoring small variations in pore fluids.

Biochar amendments have been considered to increase the competitive abilities of legumes in mixed cultures. However, little is known about how biochar affects the nutrient and Cd allocation within legume-grass mixtures. Therefore, we conducted a pot experiment to explore the effects of biochar addition rate (0, 1, 2.5, and 5%) on four monocultures, the legume Trifolium repens (Tr), Lolium perenne (Lp), Dactylis glomerata (Dg) and Festuca arundinacea (Fa), and three mixed cultures, i.e., Tr + Lp, Tr + Lp + Dg, and Tr + Lp + Dg + Fa. Regardless of biochar addition, Tr plants showed the lowest aboveground Cd concentration among the monoculture treatments. Compared with non-biochar addition treatment, the 1% biochar addition significantly promoted aboveground biomass accumulation and P, K, Ca, and Mg uptake in the aboveground parts of the Tr monoculture treatments by 39.32, 39.88, 88.27, 69.68, and 51.96%, respectively. Nevertheless, the aboveground biomass and P, K, Ca, and Mg uptake as well as the proportion of these parameters in Tr plants in all plant species mixture treatments decreased after biochar application. Maximum aboveground P and Mg uptake occurred in the four-species mixture treatments without biochar addition, whereas maximum values of these parameters occurred in the three-species mixture treatments with 5% biochar addition. Shoot Cd uptake was not decreased by biochar addition at all plant species treatments. Based on the results, it was suggested that biochar could not reduce Cd uptake by increasing the proportion of legumes in the legume-grass mixtures. The complementarity effects on nutrient uptake in the plant species mixtures depended on the amount of biochar added.

Satellites have shown free-space quantum-communication ability; however, they are orbit-limited from full-time all-location coverage. Meanwhile, practical quantum networks require satellite constellations, which are complicated and expensive, whereas the airborne mobile quantum communication may be a practical alternative to offering full-time all-location multi-weather coverage in a cost-effective way. Here, we demonstrate the first mobile entanglement distribution based on drones, realizing multi-weather operation including daytime and rainy nights, with a Clauser-Horne-Shimony-Holt S-parameter measured to be 2.41 ± 0.14 and 2.49 ± 0.06, respectively. Such a system shows unparalleled mobility, flexibility and reconfigurability compared to the existing satellite and fiber-based quantum communication, and reveals its potential to establish a multinode quantum network, with a scalable design using symmetrical lens diameter and single-mode-fiber coupling. All key technologies have been developed to pack quantum nodes into lightweight mobile platforms for local-area coverage, and arouse further technical improvements to establish wide-area quantum networks with high-altitude mobile communication., We demonstrate the first drone-based entanglement distribution under multi-weather conditions, which exhibits the third possible experimental strategy for quantum communication, in addition to fiber and satellite.

The main aim of this work was to evaluate the feasibility of microalgae-assisted aquaculture and explore the relevant mechanisms. In this regard, our work explored the pollution problems in traditional aquaculture and studied the contribution of microalgae to eutrophication control, oxygen gas production and feed replacement. Besides, potential protection mechanisms of microalgae-assisted aquaculture were studied by bacterial community profile analysis and microscope observation. The results showed that microalgae performed well in nutrient assimilation and oxygen production, thus slowing down the eutrophication and preventing oxygen depletion in aquaculture. Study of the mechanisms revealed that microalgae-assisted aquaculture contained much fewer pathogens and a microalgal biofilm was formed to prevent the eutrophication caused by sludge degradation. It is expected that the findings in this work can support the further development of microalgae-assisted aquaculture and promote the industry upgrade.

There has been an increasing interest in recent years in using clustering analysis for the identification of traffic patterns that are representative of traffic conditions in support of transportation system operations and management (TSMO); integrated corridor management; and analysis, modeling, and simulation (AMS). However, there has been limited information to support agencies in their selection of the most appropriate clustering technique(s), associated parameters, the optimal number of clusters, clustering result analysis, and selecting observations that are representative of each cluster. This paper investigates and compares the use of a number of existing clustering methods for traffic pattern identifications, considering the above. These methods include the K-means, K-prototypes, K-medoids, four variations of the Hierarchical method, and the combination of Principal Component Analysis for mixed data (PCAmix) with K-means. Among these methods, the K-prototypes and K-means with PCs produced the best results. The paper then provides recommendations regarding conducting and utilizing the results of clustering analysis.

Background In plants, ammonium metabolism is particularly important for converting absorbed nitrogen into amino acids. However, the molecular mechanism underlying this conversion remains largely unknown. Results Using wild type Arabidopsis thaliana (Col-0) and AtPDF2.1 mutants (pdf2.1–1 and pdf2.1–2), we found that the small cysteine-rich peptide AtPDF2.1, a plant defensin, is involved in regulating ammonium metabolism in the shoot. Ammonium significantly induced the expression of AtPDF2.1 in the shoot and root, particularly in root xylem vascular bundles, as demonstrated by histochemical analysis. Subcellular localization analysis revealed that AtPDF2.1 was localized to the cell wall. Ammonium concentration was higher in the shoot of mutants than in the shoot of Col-0, but no differences were found for total nitrogen content, root ammonium concentration, and the expression of the ammonium transporter gene AtAMT2.1. The activity of glutamine synthetase was significantly decreased in mutants, and the glutamine synthetase family genes GLN1.3 and GLN1.5 were significantly downregulated in mutants compared to Col-0. The activity of nitrate reductase showed no difference between mutants and Col-0. Conclusions Overall, these data suggest that AtPDF2.1 affects ammonium metabolism by regulating the expression of GLN1.3 and GLN1.5 through a yet unidentified mechanism.

In this paper, an efficient algorithm is developed to automatically detect and extract coronal loops. First of all, in the algorithm, three characteristics associated with coronal loops are used to construct a match filter able to enhance the loops. Secondly, the method combining a high-pass filter (unsharp-mask enhancement) with a global threshold is used to further enhance and segment the loops. Thirdly, to extract every individual coronal loop and obtain their parameters (the 2D projected space coordinates and lengths) from the segmented loops, a clustering method of the pixels with approximate local direction and connected domain is further used. Fourthly, to evaluate the performance of the developed algorithm, images observed by the Transition Region and Coronal Explorer (TRACE), the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) and the High-Resolution Coronal Imager (Hi-C) are used, and comparison experiments between the existing algorithms and the developed algorithm are performed. Finally, it is found that the developed algorithm is commensurate with the two most promising algorithms, oriented coronal curved loop tracing (OCCULT) and its improved version, OCCULT-2, in performance. Therefore, for scientific applications associated with coronal loops, the developed algorithm will be a powerful tool.

To characterize the degree of organic matter graphitization in the over mature lower Paleozoic marine shales from South China, a suite of kerogen samples covering different maturity (Ro% ranging from 1.2% to 4.2%) were analyzed by Laser Raman microprobe (LRM), Transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Chemical structures and related major changes caused by thermal evolution history were systematically discussed. The results indicate that with the thermal maturity increasing, the aliphatic side chains fall off gradually, and the aromatic rings increase continuously. The ordered structure of shales continues to enhance, leading to the increasing of graphitization degree. The parameters of LRM (i.e. position of G and D bands, peak position difference (RBS), full width at half maximum (FWHM) and intensity ratio (ID/IG)) highlight the “turning point” at maturity level around RmcRo% = 3.5%, which represents the chemical structure jump of the kerogen. This chemical structure jump can be characterized by the continuous decreasing of amorphous carbon before the RmcRo% exceeded 3.5% and the sharp increasing degree of aromatic conjugation after that point. TEM analysis indicates that the carbon layers of shale samples with RmcRo% exceeds 3.5% show better ordering and continuity than that of low maturity shale samples. The FTIR analysis suggests that there are relatively high aromatics C C chains and very few aromatic C-H chains in the high maturity samples. This critical chemical structure jump at RmcRo% = 3.5% could be interpreted as the structure of organic matter begins to transform from amorphous carbon to crystalline graphite in shales. Due to the increasing degree of graphitization, graphitized shale is characterized by stable chemical structure, condensed and orderly carbon layer constructure, and ultra-low resistivity.

The rational design and construction of p-n heterojunctions were deemed as an efficient strategy for promoting the separation and migration of photogenerated electron-hole pairs. Here, a facile in-situ deposition process was applied to develop a novel dual-functional Ag2O quantum dot/ZnIn2S4 nanosheet (AO/ZIS) composite photocatalyst, which assisted to the uniform distribution of Ag2O quantum dots on the surfaces of ZnIn2S4 nanosheets for the fabrication of the unique p-n heterostructure. The as-prepared AO/ZIS hybrids presented significantly enhanced photocatalytic performance for both hydrogen generation and tetracycline hydrochloride (TCH) decomposition. The results indicated that sample AO/ZIS-2 possessed the highest photocatalytic H2 production capacity (2334.19 μmol·g−1) and TCH photodegradation rate (1.62 × 10−2 min−1), which were 3.38 and 3.82 times as high as those of bare ZnIn2S4. Meanwhile, based on a series of characterization analysis, it could be determined that the increased surface area, enhanced spectral absorption and the fabrication of p-n heterojunction with the interface electric field were primarily responsible for the wonderful photocatalytic activities. Ultimately, the possible energy band transition after contact and photocatalytic mechanism were elucidated according to the ESR and Mott-Schottky results. It is predictable that our work will provide some inspiration for exploring other p-n heterojunctions with excellent performances.

Acridines and phenazines are common motifs in bioactive compounds and natural products. Many excellent works on the synthesis of these skeletons starting from diaryliodonium salts, benzaldehydes, anthranils, azobenzenes, and nitrosobenzenes have been reported. In this overview, we highlight several recent elegant works on the synthesis of acridines and phenazines.1 Introduction2 Synthesis of Acridines3 Synthesis of Phenazines4 Conclusion

Chromium isotope data were obtained from olivine, orthopyroxene and chromite separates of the Kizildag ophiolite, SE Turkey, to investigate the effects of high temperature magma processes on Cr isotope fractionation. Harzburgite in the Kizildag ophiolite has the δ53Cr values of −0.14 to −0.12‰ in chromite, and −0.08 to −0.01‰ in bulk rocks. These Cr isotope fractionations could be driven by partial melting and metasomatism. The dunite and chromitite samples from the mantle-crust transition zone of the Kizildag ophiolite are cumulates, and their chromite and olivine have δ53Cr values of −0.29 to −0.06‰ and −0.11 to 0.41‰, respectively. The δ53Cr values of chromite are negatively correlated with the chemical indices of fractional crystallization (e.g., Fe# of chromite), suggesting that Cr isotopes were fractionated during fractional crystallization. In the chromitite, the degree of Cr isotope fractionation increases with fractional crystallization, with 0.23‰ Cr isotope fractionation occurring at mineral scale. During fractional crystallization, solid phases preferentially incorporate Cr, particularly heavy Cr isotopes, driving the depletion of Cr and enrichment of light Cr isotopes in the evolved melts. The δ53Cr values of olivine are higher than the coexisting chromite, which could be explained by the fact that the olivine grains were probably formed earlier than the chromite. The Cr isotopic features of chromite in the podiform chromitite (−0.22 to −0.04‰) from the mantle sequence are consistent with the modelled fractional crystallization trend, confirming the magmatic origin of the podiform chromitite. Therefore, a significant Cr isotope fractionation at chromite from the Kizildag ophiolite could be induced by the high-temperature fractional crystallization.

Harzburgites with high modal orthopyroxene (generally >23 vol%) in Archean craton, mantle wedge and oceanic lithospheric mantle are considered to be produced by the interaction between Si-rich liquids and rocks. However, the absence of samples from continental margin hinders the recognition whether this process is prevalent. Mantle xenoliths entrained in Miocene basalts from the Thrace Basin, the margin of Eurasian continent, are dominated by harzburgites with anomalously high orthopyroxene modes. These orthopyroxene grains closely associate with spinel and occasionally with clinopyroxene. In these orthopyroxene-spinel associations, orthopyroxene grains can be up to 1 cm in diameter and display high Al2O3 contents (1.41–4.61 wt%) and Mg# values (89.6–92.4), while spinel crystals are anhedral and bud-shaped and are commonly foliated, with a wide variation in Cr# values ranging from 7.8 to 52.7. The Fe2+/Fe3+ vs. TiO2 diagram shows lots of these spinels are “magmatic” (i.e. spinel crystallized from melts). The orthopyroxene grains have LREE diverging from the modelled melting trends, indicating possible metasomatism following partial melting. They are present in elongated shape, cutting across olivine grains and also replacing olivine as surrounding rims. Fine-grained olivine is occasionally enclosed in the orthopyroxene-spinel association. We, therefore, propose that the association of orthopyroxene and spinel developed from the melt/fluid-rock interaction. These features indicate mineral phase transformation from olivine to orthopyroxene, which can be expressed by the equation: ‘Mg2SiO4 (Ol) + SiO2 = Mg2Si2O6 (Opx)’. The observed Al-rich rim of spinel and bud-shaped Al-spinel, suggest sufficient amount of Al in the Si-rich liquids. The mechanism involved here is the consumption of olivine to produce orthopyroxene and spinel as in the equation: ‘Mg2SiO4 (Ol) + Al2O3 = MgSiO3 (Opx) + MgAl2O4 (Sp)’. The Si and Al were enriched in the percolating liquids. Both the high-Cr# and low-Cr# spinels with ‘magmatic’ features imply the percolating liquids were multi-staged or inhomogeneous Cr contents in the liquids. This melt/fluid-rock interaction may account for the formation of abundant harzburgites with high orthopyroxene modes in the Eurasian continental margin. Thus, it indicates the reacting harzburgites are prevalent in the lithospheric mantle beneath oceanic crust, Archean craton and mantle wedge, as well as in the continental margin.

We report the generation of frequency-uncorrelated photon pairs from counter-propagating spontaneous parametric down-conversion in a periodically-poled KTP waveguide. The joint spectral intensity of photon pairs is characterized by measuring the corresponding stimulated process, namely, the difference frequency generation process. The experimental result shows a clear uncorrelated joint spectrum, where the backward-propagating photon has a narrow bandwidth of 7.46 GHz and the forward-propagating one has a bandwidth of 0.23 THz like the pump light. The heralded single-photon purity estimated through Schmidt decomposition is as high as 0.996, showing a perspective for ultra-purity and narrow-band single-photon generation. Such unique feature results from the backward-wave quasi-phase-matching condition and does not has a strict limitation on the material and working wavelength, thus fascinating its application in photonic quantum technologies.

The transfer function method is a common method for establishing a traveling wave field in a sound tube to measure the reflection and transmission coefficient of underwater material. The voltage applied to the secondary sound source can be calculated in accordance with the transfer matrix between the sound sources and hydrophones, then a traveling wave field can be established in the sound tube. However, the transfer function must be remeasured when the measurement frequency needs to be changed. A checking procedure of the traveling wave field in the sound tube is essential before measuring underwater acoustic material. If it is not an accurate traveling wave field, the secondary sound source signal should be corrected until the traveling wave field meets the requirements. To address these problems, an adaptive control method for generating plane traveling waves is proposed. The phase difference of sound pressures measured using the two hydrophones between the secondary sound source and the sample is used as the objective function in the adaptive algorithm, and the amplitude and phase of the secondary sound source can be obtained using the adaptive control system in the frequency domain. When a traveling wave field is formed, the reflection and transmission coefficient of the sample can be measured at the same time. With this method, the procedure of testing the traveling wave field is omitted. If the state of the primary sound source changes, the signal form of the secondary sound source can be changed immediately. Therefore, the efficiency of material measurement is improved. Theoretically, this method can obtain the most matching signal form of the secondary sound source, such that the accuracy of this method is remarkably high. Simulation and experimental results in this paper show that the measurement accuracy is reliable within the frequency range of 100–2500 Hz.

Arbuscular mycorrhizal fungi (AMF) are well known for their important physiological implications on diversified host plants, while the information on AMF diversity and its relationship with soil properties of Camellia oleifera is yet not fully understood. In the proposed study, high-throughput sequencing of small subunit ribosomal RNA was performed to analyze the AMF diversity of the rhizosphere and endosphere of 20-year-old C. oleifera Xianglin in the field at Wuhan (China) and their relationship with soil physico-chemical properties. As high as 30.73–41.68% of the roots of C. oleifera were colonized by indigenous AMF with a spore density of 66–111 spores/10 g soil. The surface soil (0–20 cm) showed significantly higher root fungal colonization, spore density, soil hyphal length, and easily extractable glomalin-related soil protein content than the sub-surface soil (20–40 cm). Soil pH value, available K, and NO3−-N content affected the root and soil mycorrhizal development, whilst soil pH proved to be the most influential soil property governing their variability. A total of 467 OTUs associated with AMF were detected from the endosphere and rhizosphere, representing 10 genera and 138 species, of which 295 OTUs and 9 genera were jointly observed. The genus Glomus displayed maximum relative abundance (&gt, 86%) in both endosphere and rhizosphere. Scutellospora was detected in the endosphere, but absent in the rhizosphere. The endosphere recorded a relatively higher number of OTUs and alpha diversity indices (Shannon, Simpson, and PD index) of AMF than rhizosphere. Our study, hence, revealed that C. oleifera in fields was mainly colonized by Glomus, coupled with comparatively greater AMF diversity in the endosphere than in the rhizosphere, governed predominantly by soil pH, NO3−-N content, and available K content.

In a fractured porous hydrocarbon reservoir, wave velocities and reflections depend on frequency and incident angle. A proper description of the frequency dependence of amplitude variations with offset (AVO) signatures should allow effects of fracture infills and attenuation and dispersion of fractured media. The novelty of this study lies in the introduction of an improved approach for the investigation of incident-angle and frequency variations-associated reflection responses. The improved AVO modeling method, using a frequency-domain propagator matrix method, is feasible to accurately consider velocity dispersion predicted from frequency-dependent elasticities from a rock physics modeling. And hence, the method is suitable for use in the case of an anisotropic medium with aligned fractures. Additionally, the proposed modeling approach allows the combined contributions of layer thickness, interbedded structure, impedance contrast and interferences to frequency-dependent reflection coefficients and, hence, yielding seismograms of a layered model with a dispersive and attenuative reservoir. Our numerical results show bulk modulus of fracture fluid significantly affects anisotropic attenuation, hence causing frequency-dependent reflection abnormalities. These implications indicate the study of amplitude versus angle and frequency (AVAF) variations provides insights for better interpretation of reflection anomalies and hydrocarbon identification in a layered reservoir with vertical transverse isotropy (VTI) dispersive media.

Wearable electronics, electronic skins, and human-machine interfaces demand flexible sensors with not only high sensitivity but also a wide linear working range. The latter remains a great challenge and has become a big hurdle for some of the key advancements imperative to these fields. Here, we present a flexible capacitive pressure sensor with ultrabroad linear working range and high sensitivity. The dielectric layer of the sensor is composed of multiple layers of double-sided microstructured ionic gel films. The multilayered structure and the gaps between adjacent films with random topography and size enhance the compressibility of the sensor and distribute the stress evenly to each layer, enabling a linear working range from 0.013 to 2063 kPa. Also, the densely distributed protrusive microstructures in the electric double layer contribute to a sensitivity of 9.17 kPa

Humidity sensors have broad applications in health monitoring, environmental protection and human-machine interface, and robotics. Here, we developed a humidity sensor using alkali oxidation method to grow in situ TiO2 nanowires on two-dimensional Ti3C2 MXene. With an order of magnitude larger surface area compared to pure Ti3C2 or TiO2 materials, the urchin-like Ti3C2/TiO2 composite demonstrates a record high sensitivity in a low relative humidity (RH) environment (∼280 pF/% RH from 7% RH to 33% RH). Complex impedance spectroscopy and Schottky junction theory were employed to understand the underlying sensing mechanisms of the Ti3C2/TiO2 composite under various humidity conditions. We demonstrate the application of humidity sensors made with the Ti3C2/TiO2 composite for noncontact detection of the presence of various liquids as well as human fingers.

The overall production of degraded grassland ecosystems can be improved by reseeding appropriate species, but the responses of soil microbes to reseeded grassland after a long-term growth, especially the mediation effects of soil chemical compounds on the soil microbial community composition, have rarely been reported. In this study, we reseeded a degraded grassland with Bromus inermis Leyss and investigated the changes in aboveground (grassland biomass) and belowground factors (soil properties, soil chemical compounds, soil microbial diversity, and community) under reseeded and non-reseeded treatments. The reseeding of B. inermis significantly (P

Thiadiazole moieties are present in many natural products and pharmaceutical compounds that possess a broad spectrum of biological activities, serving as antidepressant, anxiolytic, antimicrobial, antitubercular, antiinflammatory, antidiabetic, anticancer, antihypertensive, or antifungal drugs. Many excellent methods have been reported for accessing such frameworks. In this review, we summarize advances made within the past ten years in the synthesis of various types of thiadiazole.1 Introduction2 Synthesis of Thiadiazoles2.1 Synthesis of 1,2,3-Thiadiazoles2.1.1 Synthesis of 1,2,3-Thiadiazoles from Diazo/Azide Compounds2.1.2 Synthesis of 1,2,3-Thiadiazoles from Sulfonyl Hydrazines or N-Tosylhydrazones2.2 Synthesis of 1,2,4-Thiadiazoles2.2.1 Synthesis of 1,2,4-Thiadiazoles from Thioamides or their Derivatives2.2.2 Synthesis of 1,2,4-Thiadiazoles from Amidines or 2-Aminopyridines2.3 Synthesis of 1,3,4-Thiadiazoles2.4 Synthesis of 1,2,5-Thiadiazoles3 Conclusion

Efficient design and construction of core-shell heterojunction is regarded as a promising strategy to promote interface electronic transfer for achieving enhanced photocatalytic hydrogen evolution and pollutant degradation. Thus, in this study, a novel core-shell CdIn2S4/Ta3N5 (CIS/TN) nanocomposite photocatalyst was designed and successfully fabricated via the facile in-situ hydrothermal process, where the CdIn2S4 nano-octahedra densely anchored on the surface of Ta3N5 nanoparticles to form the core-shell heterostructure. The as-prepared CIS/TN heterostructures all showed high dual-functional photocatalytic performances for H2 generation and Methyl Orange (MO) decomposition. Compared with pristine CdIn2S4, the photocatalytic activities of CIS/TN heterostructures were obviously enhanced and the sample CIS/TN-3 with the 3 wt% of Ta3N5 possessed the highest H2 production of 122.6 μmol·h−1·g−1, which was about 2.43 times as high as that of CdIn2S4 nano-octahedra. Also, it presented the optimal MO photodegradation efficiency (92.2%) and its rate constant was 2.79 times higher than that of pure CdIn2S4. The wonderful dual-functional photocatalytic performance could be attributed to the broad spectral adsorption region and efficient transfer of photoinduced charge carriers between the intimate heterogeneous interface, which would lead to the higher quantum yield and efficiency. The detailed charge transfer path and possible reaction mechanism were also proposed based on the results of trapping experiments and ESR analysis. Our research may provide a direct guidance for developing other highly-efficient Ta3N5-based core/shell heterostructure for energy conversion and environmental governance.

The development of highly efficient and multifunctional composite photocatalysts for both energy conversion and environmental governance has obtained great concerns. Here, a novel CdIn2S4/TiO2 (CIS/THS) hollow composite photocatalyst was firstly designed and synthesized via a facile in-situ growth process, where the CdIn2S4 nano-octahedra densely attached on the surface of TiO2 hollow spheres to form the unique hybrid heterostructure. The as-synthesized CIS/THS heterojunctions exhibit much superior photocatalytic activities for hydrogen evolution and Methyl Orange (MO) decomposition in comparison to pure CdIn2S4 and TiO2 hollow spheres. The experimental results display that the CIS/THS-3 sample with the 30 wt% of TiO2 presents the optimal photocatalytic H2 production efficiency and its generation rate is 3.38 and 2.56 times as high as those of pure TiO2 and CdIn2S4. Besides, the as-synthesized CIS/THS-3 hybrid also possesses the best MO photodegradation performance and its rate constant is 11.43 and 8.34 times higher than those of pure TiO2 and CdIn2S4. The enhanced photocatalytic activities can be assigned to the synergistic effect, optimized light-harvesting capacity and the formation of hybrid heterostructure for boosting interfacial charge transfer and separation. Furthermore, based on the trapping experiments and ESR analysis, the possible type-Ⅱ interface charge transport mechanism was also proposed. Our study may provide the direct guidance for constructing other hollow TiO2-based composite photocatalysts with superior photocatalytic water splitting and degradation performances.

Carbonatite metasomatism plays an important role in modifying the composition of Earth's mantle, however, its effect on mantle Mg isotopic composition is poorly constrained. Here, we report high-precision mineral Mg isotope data for three suites of mantle peridotite xenoliths that experienced variable degrees of carbonatite metasomatism. The δ 26 Mg values of minerals in these xenoliths are variable and range from −0.32 to −0.11‰ in olivine, from −0.28 to −0.09‰ in orthopyroxene, from −0.27 to −0.05‰ in clinopyroxene, from 0.06 to 0.44‰ in spinel and from −0.61 to −0.37‰ in garnet. Calculated bulk-rock δ 26 Mg values of the peridotites vary from −0.27 to −0.10‰, falling within and slightly higher than the normal mantle range (−0.25 ± 0.07‰). The coexisting minerals are in isotopic equilibrium, with clinopyroxene δ 26 Mg values correlated with the carbonatite metasomatic indices such as MgO and Na2O in orthopyroxene. These results suggest that carbonatite metasomatism does not produce light Mg isotopic signature in mantle peridotites as previously suggested, instead it might slightly elevate their δ 26 Mg values. Therefore, carbonatite-metasomatized peridotites in the mantle cannot be the primary source rocks of low- δ 26 Mg mantle-derived magmas. Instead, fractional crystallization and accumulation of chromite during ascent of the basaltic magmas may explain the isotopically light basalts, as supported by the covariations of δ 26 Mg with chemical indices of chromite crystallization (e.g., Cr, V, Fe and Ti). Consequently, chromite crystallization may significantly influence the physiochemical processes on the genesis of basalts, which would require comprehensive evaluation in future studies.

As compared with Si as the substrate, ferroelectric (FE) HfZrO x with orthorhombic phase on Si0.56Ge0.44 substrate was found to demonstrate improved FE characteristics. Through the incorporation of Ge into the silicon substrate, remanent polarization ( ${P}_{r}$ ) can be further enhanced by 58% magnitude to $15~\mu \text{C}$ /cm2. Moreover, devices on Si0.56Ge0.44 show significant reliability enhancement in terms of negligible ${P}_{r}$ degradation up to 107 cycles under ±4 MV/cm with 10-kHz bipolar stress and desirable retention up to 104 s arising from smaller imprint effect against time at 85°C. The major role of Ge introduction into the substrate is to suppress the formation of the interfacial layer (IL) between HfZrO x /substrate and further reinforce the quality of the IL. The suboxide IL of the enhanced quality can be explained by the fact that it is too thin to trap charges while less vulnerable to defect generation due to stronger bonding with fewer oxygen vacancies. The results suggest that as the technology advances from Si into SiGe platform, HfZrO x -based devices possess more reliable ferroelectricity for metal–FE–semiconductor (MFS) gate-stack for the next-generation FeFET.

Reservoirs are essential for the wellbeing of human societies, but can also be subject to negative ecological impacts. The Three Gorges Reservoir (TGR) in the upper Yangtze River is remarkable for its size and engineering; however, its effects on water quality are poorly understood. To the best of our knowledge, this study is the first to describe long-term (1992–2016) monitoring. It showed that the chemical oxygen demand (COD, via the potassium permanganate index) and total phosphorus (TP) have decreased 40.9% ± 9.9% and 22.2% ± 9.7% respectively in the TGR mainstream between impoundment in June 2003 and 2016, while total nitrogen (TN) and ammonium (NH4-N) have increased 1.3% ± 2.4% and 8.2% ± 2.6%. In addition, phytoplankton biomass has increased by a factor of 2.7 (1.1–4.8) over pre-impoundment levels in the mainstream, and tributary algal blooms have increased in frequency since 2004. The reductions in COD and TP were caused primarily by decreases in water flow speed, which lead to sediment settlement. The anti-seasonal operation pattern and water volume increased TGR may also increases the dilution capacity. TN and ammonium are less affected by sediment deposition and have increased slightly under intensified human activities. Decreased water flow speeds and nutrient enrichment have promoted increases in algal biomass, leading to blooms in tributary backwater zones. In situ experiments indicate that phytoplankton growth in the TGR is phosphorus limited during all seasons. Therefore, controlling phosphorus will reduce the short-term eutrophication potential in the reservoir. However, concurrent control of nitrogen and phosphorus inputs are necessary in the long term.

Begonia yizhouensis, a new species in Begonia sect. Coelocentrum (Begoniaceae) from Guangxi of China, is described and illustrated. Morphologically, it is similar to the adjacently distributed B. luochengensis, but clearly separated by its waxy leaves with glabrous or sometimes sparsely puberulous surfaces, larger variation in leaf color and maculation along the main veins, white to pinkish-white flowers and late flowering. Furthermore, molecular phylogenetic analysis indicated B. yizhouensis was a monophyletic lineage and was sister with B. luochengensis. The relationship of the new species and other similar species is also discussed. This new species is endemic to limestone hills in Guangxi and is assessed as “Endangered” (EN) according to the IUCN Red List Categories and Criteria. Additionally, morphological and molecular evidence for B. yishanensis not being synonymous with B. porteri is presented.

Aquaponics is considered as a possible method to produce aquatic animals and plants in an environmentally‐friendly way, but its commercialization is seriously hindered owing to some technical and economic problems. Recently, the integration of microbial community with aquaponics is on the way to becoming the next‐generation technology for the sustainable development and commercialization of the aquaponics industry. This article provides an authoritative discussion on the novel microbial community‐assisted aquaponics, which will be emerging from the research environment to industrial application in the coming future. Principles and key technologies of this novel aquaponics, as well as the potential challenges to its commercialization, are discussed. It is expected that the emerging technologies discussed in this work could address the existed technical problems and further promote the commercialization of aquaponics. © 2019 Society of Chemical Industry

We have studied the reflection dispersion signatures of a heterogeneously patchy saturated reservoir exhibiting attenuation and velocity dispersion in a seismic range of frequency. A modifi...

Hydrodynamic conditions are closely related to the development and dissipation of cyanobacterial blooms. The morphological features of Dolichospermum under different hydrodynamic conditions were analysed during three blooms in Gaoyang Lake, which is part of the backwater area of the China Three Gorges Reservoir, from 2007 to 2010. The results showed that the length of filaments and the morphology of cells were different in relation to the turbulence caused by the difference in hydraulic retention times. Thus, it was hypothesized that turbulence could shape the morphology and physiology of cyanobacteria. To answer the question regarding what the morphological and physiological responses of cyanobacteria to turbulent mixing mean for these organisms, laboratory experiments in continuous cultivation under different dilution rates were conducted to analyse the effects of specific turbulence intensity on the growth, nutrient uptake and morphology of Dolichospermum flos-aquae. Increasing the turbulence intensity caused synchronous increases in the ratio of the cellular length to the width, in the specific surface area of the filament and the cell and in the nutrient uptake rate; at the same time, the average filament length decreased. These indicated that the turbulence, within the range of our experimental design, could stimulate the growth of Dolichospermum by increasing its nutrient uptake. Additionally, at a high specific growth rate, the nutrient uptake rate of Dolichospermum changed more noticeably with the increasing morphological indicators, indicating that the rapidly growing Dolichospermum was more sensitive to turbulence. These findings explain the role of morphological strategies in the dominance of Dolichospermum within a certain range of turbulence intensity, especially in the early growth stage of blooms. The results also facilitate a greater understanding of the hydrodynamic effects on cyanobacteria and will be instrumental in developing flow regulation to control cyanobacterial blooms in reservoirs.

In this paper we present a new type of combined solitary wave solution for the variable coefficients higher-order nonlinear Schrodinger (HNLS) equation with non-Kerr nonlinearity, which governs the propagation of optical pulses in the heterogeneous optical fiber system under certain parametric conditions. Unlike those previously-reported solitary wave solutions for the classes HNLS, the expression of this solution in this paper is a composition of the summation of a hyperbolic secant function and a hyperbolic tangent function, and the solution can show the properties of bright and dark soliton respectively. Furthermore, we investigate the stability of the combined solitary wave solution under the small perturbation of noise, amplitude and phase position by using numerical simulation method.

A novel protocol for the C–H methylthiolation of 2-phenyl pyridines using DMSO as the methylthio source and an amino acid ligand is described. This simple procedure requires neither an oxidant nor additional solvent. The developed protocol tolerates a wide range of functional groups including methyl, methoxy, fluoro, chloro, and in particular the formyl group. This new strategy is highly regioselective and provides aryl methyl sulfides from 2-phenyl pyridines in moderate to good yields.

Spherical crystallization is an effective way to increase particle size, raise bulk density, and improve flowability and compressibility of crystals with small sizes, especially needle-like and flake-like microcrystals. In this work, a reverse antisolvent crystallization method was used to obtain the spherical crystals of carnosine instead of commercially available needle-like carnosine material. Besides, the solubility of carnosine in a binary solvent mixture of water + ethanol was measured at temperatures ranging from 288.05 to 323.15 K by using a gravimetric method under atmospheric pressure to optimize this crystallization process and increase the yield of carnosine. On the basis of these thermodynamic data, single factor analysis in a reverse antisolvent crystallization process was performed, including carnosine aqueous solution concentration, feeding rate, volume ratio of solution to antisolvent, temperature, and stirring speed. Polarizing microscopy, particle size distributions, and in situ particl...