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Photoelectrochemical (PEC) water-splitting using solar energy holds great promise for the renewable energy future, and a key challenge in the development of industry viable PEC devices is the unavailability of high-efficient photoanodes. Herein, we designed a TiO2 model photocatalyst with nano-groove pattern and different surface orientation using low-energy Ar+ irradiation and photoetching of TiO2, and significantly improved the intrinsic activity for PEC water oxidation. High-resolution transmission electron microscopy directly manifests that the grooves consist of highly stepped surface with steps and well-crystallized. Transient absorption spectroscopy reveals the groove surface that allows for increased recovery lifetime, which ensures promoted electron-hole separation efficiency. Surface photovoltage directly shows the carrier separation and transportation behaviors, verified by selective photodeposition, demonstrating the groove surface on TiO2 contributes to electron-hole separation. This work proposes an efficient and scalable photoanode strategy, which potentially can open new opportunities for achieving efficient PEC water oxidation performance.

Quantum key distribution (QKD)1,2 offers a long-term solution to secure key exchange. Due to photon loss in transmission, it was believed that the repeaterless key rate is bounded by a linear function of the transmittance, O(η) (refs. 3,4), limiting the maximal secure transmission distance5,6. Recently, a novel type of QKD scheme has been shown to beat the linear bound and achieve a key rate performance of $$O(\sqrt{\eta })$$ (refs. 7–9). Here, by employing the laser injection technique and the phase post-compensation method, we match the modes of two independent lasers and overcome the phase fluctuation. As a result, the key rate surpasses the linear bound via 302 km and 402 km commercial-fibre channels, over four orders of magnitude higher than existing results5. Furthermore, our system yields a secret key rate of 0.118 bps with a 502 km ultralow-loss fibre. This new type of QKD pushes forward long-distance quantum communication for the future quantum internet. Phase-matching quantum key distribution is implemented with a 502 km ultralow-loss optical fibre. The fluctuations of the laser initial phases and frequencies are suppressed by the laser injection technique and the phase post-compensation method.

A novel and effective method to co-extrude metallic alloys is described which named Direct Extrusion and Bending-Shear Deformation. The compound extrusion plates have cracked at 290 °C and 3 mm/s. According to this phenomenon, a model was built to investigate the crack generation and development between the 6061 Al and AZ31 Mg alloy during the compound extrusion process by DEFORM-3D. The cracking behavior of the Mg/Al composite rod with a soft Mg AZ31 core and a hard Al 6061 sleeve were systematically studied to disclose the influence of microstructure on crack in the different regions. The simulation results show that the distribution of strain and velocity has significant differences due to the influence of dies structure and material properties at different locations in the same region. The experimental results show that in the same conditions, there are differences in recrystallization and texture weakening of AZ31 Mg alloys and 6061 Al alloy, which are important factors for the formation of crack. Both the Mg layer and the Al layer have a homogeneous microstructure in the region d. Keywords: AZ31 Mg alloy, 6061 Al alloy, Compound extrusion, Crack, EBSD

2,5-Diethyl-1,4-benzenedinitrile N-oxide was designed and synthesized to achieve room temperature curing of hydroxyl-terminated polybutadiene binders. The structures and properties of the four cured elastomers having different content of curing agent were investigated. The results showed that the isoxazoline rings from the reaction of nitrile N-oxide with cis-alkene are observed in the four cured elastomers. The results also revealed that the hydroxyl-terminated polybutadiene with the lowest content of curing agent showed the lowest cross-linking density and stress at break. The proper activity and steric hindrance of 2,5‑diethyl-1,4-benzenedinitrile N-oxide gave better mechanical properties and hydrophobic properties of the cured elastomers than nitrile N-oxide prepared by our previous work.

(±)-Eurotone A [(±)- 1 ], a pair of new enantiomeric polyketide dimers, as well as six known biogenetically related polyketides ( 2 – 7 ) were isolated from a marine-derived fungus Eurotium sp. SCSIO F452. Their structures were determined by comprehensive spectroscopic methods, X-ray diffraction and quantum chemical calculations. Compound 1 represented the first pair of spirodihydrobenzanthracene enantiomers isolated from marine fungi with their absolute configurations assigned. A plausible biosynthetic pathway involving a key acid-mediated dimerization was proposed for 1 . The antioxidative activities of the new enantiomers were evaluated.

A new butenolide derivative (±)-asperteretal F (1) and related congener (2) recently reported containing an unusual 2-benzyl-3-phenyl substituted lactone core, together with five known compounds (3–7) were isolated and characterized from the fungus Aspergillus terreus. SCSIO FZQ028 derived from a deep-sea sediment of South China Sea. Their chemical structures were established on the basis of 1D- and 2D-NMR spectroscopic data, and HR-ESI-MS analysis. Additionally, all the compounds were evaluated for the antioxidative activities against DPPH, cytotoxic activities against two tumor cell lines (SF-268 and HepG-2), and antimicrobial activities. Compounds 2-4, and 7 showed significant activities against DPPH with IC50 ranging from 5.89 to 10.07 μg/mL. Compounds 2 and 4 showed moderate antimicrobial activities against all four tested bacteria.

The AZ31 Mg alloys were processed by 6% pre-compression and frustum shearing extrusion at various temperatures, and the microstructure, texture and mechanical properties of the resulting alloys are systematically investigated. The results show that the grain size monotonically increases from 6.4 to 12.6 μm and the texture intensity increases from 6.7 to 9.6 with the increase in the extrusion temperature. The combining effect of the pre-twinning and the frustum shearing deformation is found to contribute to the development of the weak basal texture in Mg alloys. The Mg alloy sheet produced at the extrusion temperature of 563 K exhibits excellent mechanical properties. The yield strength, ultimate tensile strength and elongation for the extruded alloys are 189.6 MPa, 288.4 MPa and 24.9%, respectively. Such improved mechanical properties are comparable or even superior to those of the alloys subjected to other deformation techniques, rendering the pre-compression and frustum shearing extrusion a promising way for further tailoring properties of Mg alloys.

Chiral sulfinamides are increasingly recognizedfor their extensive potential applications in chemistry, medicine and material science, yet chromatographic study on these compounds is seldom. In this article, we describe the enantioseparation of twelve closely related chiral sulfinamide derivatives on polysaccharide-based chiral stationary phases (CSPs). We investigated the factors affecting separation, such as the types of chiral columns, the concentration of polar alcohol and the column temperature. The acyclic sulfinamide derivatives-with the exception of a cyclic sulfinamide compound-were effectively resolved with a Chiralcel OD-H column and a mixture of n-hexane:isopropyl alcohol (90:10) as the mobile phase. All compounds except N-benzylidene-2-methylpropane-2-sulfinamide are baseline resolved on the Chiralpak AD-H column, but only eight compounds are resolved on a Chiralpak AS-H column under the given chromatographic conditions. This study offers valuable guidance for future chiral HPLC studies related to chiral sulfinamides.

During the process of whole slide imaging, it is necessary to focus thousands of fields of view to obtain a high-quality image. To make the focusing procedure efficient and effective, we propose a novel autofocus algorithm for whole slide imaging. It is based on convolution and recurrent neural networks to predict the out-of-focus distance and subsequently update the focus location of the camera lens in an iterative manner. More specifically, we train a convolution neural network to extract focus information in the form of a focus feature vector. In order to make the prediction more accurate, we apply a recurrent neural network to combine focus information from previous search iteration and current search iteration to form a feature aggregation vector. This vector contains more focus information than the previous one and is subsequently used to predict the out-of-focus distance. Our experiments indicate that our proposed autofocus algorithm is able to rapidly determine the optimal in-focus image. The code is available at https://github.com/hezhujun/autofocus-rnn.

Objective. The purpose of this study was to evaluate the effect of genetic-environmental interaction on myopia in Chinese children aged 6 to 9 years. Methods. Students had the physical examination and were required to provide basic demographic information. Their families were asked to fill in a questionnaire concerning factors related to myopia. Multiple regression analysis was performed, and adjusted risk ratio values were calculated to assess the role between gene and environment. Value of the environmental and genetic index (EGI) was calculated to demonstrate the effect of genetic-environmental interaction on myopia. Results. The prevalence of myopia maintained at a high level. EGI was calculated as 0.125 suggesting that genetic factors may play the 12.5% role in the formation of myopia and environmental factors may play a role of 87.5% in the formation of myopia. Conclusions. For young pupils aged 6 to 9 years, myopia prevalence maintained at a high level, and duration of homework time and staring at electronic screen were the strongest factors associated with myopia. The calculated value of EGI was low, which suggests that environmental factors may play the leading role in the formation of myopia. A long-term follow-up research to improve the accuracy value of EGI is our next job.

A series of ZrN-Ag nano-composite films were deposited using the RF magnetron sputtering system. The microstructure, mechanical properties and tribological performances were investigated. The results showed that ZrN-Ag films were composed of face-centered cubic (fcc)-ZrN and face-centered cubic (fcc)-Ag. With the increase of Ag content, the hardness of ZrN-Ag composite film increased rapidly and then decreased rapidly. The maximum hardness value was 22.8 GPa at 6.1at.% Ag. At room temperature, the coefficient of friction (Cof.) of ZrN-Ag films were lower than the ZrN film. During 25-500°C, the Cof. of ZrN-Ag films at 29.16 at.% Ag were lower than ZrN film, while the wear rate were higher than the ZrN film. In summary, the addition of Ag improved the hardness, and decreased the Cof. of the ZrN-Ag during 25-500°C.

This study investigated the feasibility of using an invasive snail, Pomacea canaliculata, as a food source and water purifier for the commercial breeding of the loach Misgurnus anguillicaudatus. The predatory potential of M. anguillicaudatus (3.5–5.5 g) against hatchling snails was evaluated in aquaria and simulated paddy fields. Some hatchling snails left the water to avoid being preyed upon by the loaches, and approximately 10 hatchlings died per day in the presence of five loaches in aquaria, whereas a weaker snail control effect was observed in the simulated paddy fields. The growth of rice seedlings (Oryza sativa) was not reduced by the presence of hatchling snails alone, but the shoot biomass of seedlings coexisting with snails was promoted after introducing the loaches. Additionally, the presence of P. canaliculata adults improved the aquatic environment in the short term for loach breeding by decreasing the turbidity of the water. Importantly, M. anguillicaudatus (12–18 g) mortality decrea...

Chlorhexidine (CHX)/β-cyclodextrin (β-CD) inclusion and chitosan nanoparticles containing bovine serum albumin (CS/BSA) were blended into chitosan acetic acid solution respectively or simultaneously to prepare a novel thermosensitive hydrogel dual sustained-release system. Rheological properties, release, cytocompatibility, and antibacterial activity were investigated. The results confirmed that CHX/β-CD and CS/BSA were well dispersed in the solution, and the rheological property of hydrogel was not affected. The system exhibited promising dual sustained release and cytocompatibility. Antibacterial results showed that CHX-loaded hydrogel had a desirable therapeutic effect on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

A pair of stereoisomers of new 4,5-dihydroxypiperine was isolated from P. retrofractum and showed profound activity on AlCl3-induced dementia. In order to determine their absolute configurations and biological activities, all four possible stereoisomers of 4,5-dihydroxypiperine were synthesized from piperidine by Sharpless asymmetric dihydroxylation and Mitsunobu reaction. Their absolute configurations were established as (4R,5R) (1), (4S,5S) (2), (4S,5R) (3) and (4R,5S) (4) by NMR, optical rotation and CD spectra. It is note that only compound 4 improved behavioral disorder in AlCl3-induced dementia. Accordingly, the pair of stereoisomers isolated from P. retrofractum was determined to be (4S,5S) and (4R,5S)-isomers (2 and 4). The ratio of the epimers was present as 1:0.7 (4:2).

The CaO–B2O3–SiO2 (CBS) glasses with addition of xLa2O3 (0 ≤ x ≤ 20 wt%) were prepared by conventional quenching method, the glass structure, phase transformation and microware dielectric properties were studied. The glass structure analysis by magic angle spinning nuclear magnetic resonance (MAS-NMR) and infrared (IR) spectroscopy indicated that [BO4] transformed into [BO3] and the proportion of Si–O–Si bridge oxygen bond in [SiO4] tetrahedrons decreased obviously with the addition of La2O3. The differential thermal analysis (DTA) revealed that the CBS glass system kept better glass-forming ability and the transition temperature (T g) decreased from 743 to 724 °C after addition of La2O3. As the content of La2O3 increases, the crystallization tendency of CaB2O4 is suppressed, while that for Ca2SiO4 is promoted. With appropriate content of La2O3 (5 wt%), the sample possess excellent dielectric properties (e r ≈ 4.1, tanδ ≈ 1.7 × 10−3 at 15 GHz). The variations of dielectric properties are believed to be appreciably associated with the relative content of the phases present.

The aim of the present work is to investigate the effects of SiO2 content on the structure of CaO–B2O3–SiO2–Al2O3–ZnO glass using the MAS-NMR, the fourier transform infrared spectrometer and differential scanning calorimetry (DSC). The results showed that the majority of Al existed in fourfold coordination and Zn acted as glass modifier in glass structure. With the increasing of SiO2 content, the relative amount of BIII units decreased while the BIV units increased and the proportion of Si–O–Si bridge oxygen bond in [SiO4] tetrahedrons increased obviously. The DSC curves revealed that the glass transition temperature increased from 732 to 773 °C with the increasing of SiO2 content, indicating that SiO2 generating more bridge oxygen can increase the degree of polymerization of glass structure.

The aim of the present work is to investigate the effects of Al2O3 content on both the structure and crystallization behavior of CaO–B2O3–SiO2 (CBS) glass composition using NMR, FT-IR and DSC. The density experimental results showed that the density (ρ) of glasses decreased linearly with increasing Al2O3 content, while the molar volume (Vm) of the glasses increased linearly. The NMR revealed that the Al occurred in the forms of AlIV, AlV and AlVI units. With the increasing Al2O3 content, the amount of Al species show little change, the relative amount of BIIIa and BIIIs units increases while the BIV units decrease, and the Q4 structural units increases clearly but the Q3 decreases. Further, crystallization peaks of CBS glasses shift to higher temperatures, indicating that Al2O3 addition can suppress crystallization of CBS glasses.

Ce-based materials have gained considerable prominence in catalysis as a type of the most valuable material for various applications ranging from automotive emission control to CO2 and water splitting. We here report a novel type-II CeO2/CeF3 composite, composed of two paradigms of Ce-based binary compounds, prepared by a facile one-step in-situ hydrothermal method, and explore its potential as a photocatalyst for solar energy conversion. Primarily, the morphologies, particle size and microstructures of CeO2/CeF3 composite can be modulated by the volume ratio of ethanol to water in the precursor solution. The photocatalytic activities firstly increase to a maximum and then decrease with the increased amount of ethanol. The hybrid CeO2/CeF3 particles with large size and polyhedron morphology exhibit superior photocatalytic activity, having a high rate constant k of MB decomposition about 7.6 times faster than that of the lowest one. A multiple synergetic mechanism in CeO2/CeF3 composite, which is featured by obvious promoted separation of photogenerated electrons and holes at the type-II heterojunction interfaces and in particular between the different facets of microcrystals, and the highly reactive facets exposed, has been proposed to account for its distinguished photocatalytic activity. This work provides some new insights for the synthesis and optimization of novel rare earth Ce-based composite photocatalyst with high photocatalytic performance.

Pepper is one of the most popular spices over the world and is called the King of Spices. Its essential oils (EOs) could alleviate neuronal ailments due to the inhibitory effect against acetylcholinesterase (AChE). In this study, the chemical compositions of 26 EOs prepared from white and black pepper collecting from 6 different cultivars were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 133 compounds were identified in the white and black pepper EOs. Monoterpenes and sesquiterpenes were found to be riched in these EOs, of which α-pinene, β-pinene, sabinene, 3-carene, limonene, and ( E)- β-caryophyllene were the major constituents. Most of pepper EOs showed potential AChE inhibitory activity with half-maximal inhibitory concentration (IC50) values in the range of 0.5-182.5 µg/mL. Comparison of chemical constitutes of pepper EOs from different cultivars suggested that α-pinene, β-pinene, and 3-carene with an IC50 value of 3.2, 53.3, and 2.9 µg/mL, respectively, might be used as Quality-marker (Q-marker) of pepper oil in inhibiting AChE.

The Ba2+ doped ceramics of Ca1−xBaxCu3Ti4O12 (x = 0.005, 0.01, 0.03, 0.05 and 0.1) were sintered via conventional solid-state reaction at 1050 °C for 8 h in air. The microstructure and electric properties of Ba2+ doping ceramics were investigated. The lattice parameters of Ca1−xBaxCu3Ti4O12 (CBCTO) ceramics decreased with the Ba2+ doping, and Ba1.31Ti8O16 as secondary phase was confirmed at x = 0.1. The doping of Ba2+ resulted in uniformly distribution of small size grain (~4 μm). All the doped samples showed lower value of dielectric constant than CaCu3Ti4O12 (CCTO), due to low resistivity of the grain boundary with the Ba2+ doped samples. The nonlinear coefficient and breakdown field were significantly enhanced by Ba2+ doping.

Three pairs of spirocyclic diketopiperazine enantiomers, variecolortins A-C (1-3), were isolated from marine-derived fungus Eurotium sp. SCSIO F452. Compound 1 possesses an unprecedented highly functionalized seco-anthronopyranoid carbon skeleton featuring a 2-oxa-7-azabicyclo[3.2.1]octane core. Compounds 2 and 3 represent rare examples of a 6/6/6/6 tetracyclic cyclohexene-anthrone carbon scaffold. Their structures were determined by spectroscopic analyses, X-ray diffraction, and ECD calculations. Their enantiomers exhibited different antioxidative and cytotoxic activities, and their modes of action were investigated.

Three new prenylated indole 2,5-diketopiperazine alkaloids (1–3) with nine known ones (5–13), one new indole alkaloid (4), and one new bis-benzyl pyrimidine derivative (14) were isolated and characterized from the marine-derived fungus Eurotium sp. SCSIO F452. 1 and 2, occurring as a pair of diastereomers, both presented a hexahydropyrrolo[2,3-b]indole skeleton. Their chemical structures, including absolute configurations, were elucidated by 1D and 2D NMR, HRESIMS, quantum chemical calculations of electronic circular dichroism, and single crystal X-ray diffraction experiments. Most isolated compounds were screened for antioxidative potency. Compounds 3, 5, 6, 7, 9, 10, and 12 showed significant radical scavenging activities against DPPH with IC50 values of 13, 19, 4, 3, 24, 13, and 18 µM, respectively. Five new compounds were evaluated for cytotoxic activities.

Lead-free (1−x)(Ba 0.85 Ca 0.15 )(Ti 0.9 Zr 0.1 )O 3 -xBa(Mg 1/3 Nb 2/3 )O 3 (BCZT-BMN) (x=0.05, 0.10, 0.15, 0.20) ceramics were fabricated by conventional solid-state reaction. The effect of Ba(Mg 1/3 Nb 2/3 )O 3 (BMN) addition on structure and electrical properties of BCZT ceramics were studied. The results show that the BCZT-BMN ceramics possess rhombohedral phase at x=0.05, orthorhombic and rhombohedral phases coexist at x=0.10, 0.15, 0.20. High Curie temperature (T c ) maintained over 300 °C at the compositions x=0.05 and 0.10. The samples at x=0.05 exhibit good ferroelectric properties. This work offers an effective way to adjust the range of service temperature of BCZT by BMN addition.

With the advent of cloud computing, renewable energy is integrated into data center power supply systems increasingly. The power statistics collection may not be available due to the instability of renewable energy, which results in incomplete data. The incomplete energy data will significantly disturb the management of data centers. We further propose a filling algorithm based on complete tolerance class. The algorithm expands the traditional tolerance relation, and fills the missing values of the energy data, which ensures the data integrity. By taking good advantage of in-Memory Computing, We further parallelize and optimize our algorithm using Spark. The experiment results demonstrate that our algorithm outperforms other general filling algorithms in terms of filling accuracy. The proposed algorithm also shows good performance as the missing rate rises up.

One of the fundamental problems in crowdsourcing is the trade-off between the number of the workers needed for high-accuracy aggregation and the budget to pay. For saving budget, it is important to ensure high quality of the crowd-sourced labels, hence the total cost on label collection will be reduced. Since the self-confidence of the workers often has a close relationship with their abilities, a possible way for quality control is to request the workers to return the labels only when they feel confident, by means of providing unsure option to them. On the other hand, allowing workers to choose unsure option also leads to the potential danger of budget waste. In this work, we propose the analysis towards understanding when providing the unsure option indeed leads to significant cost reduction, as well as how the confidence threshold is set. We also propose an online mechanism, which is alternative for threshold selection when the estimation of the crowd ability distribution is difficult., Comment: 25 pages, 1 figures

Beijing is located on the North China Plain with five rivers, which belong to the Hai River Basin. Its continental monsoon climate with uneven precipitation distribution is extreme likely lead to serious urban flood disasters. According to the disaster results, urban storm flood in Beijing can be classified into four types. Here typical extreme storm flood events and their characteristics in Beijing were analyzed in detail. It showed that storm flood events in recently decades had a trend, which centered in a relatively small area with high intensity and short duration. The main reasons of urban storm flood disaster were urbanization and basic facilities with low flood and drainage standard. Urbanization means land utilization significantly altering hydraulic processes, and extreme storm can easily exceed those facilities capacity. In order to deal with urban storm flood, Beijing government have taken four measurements, which were upgrading and reconstruction of rainwater pumping stations, improving projects of small and medium rivers, building sponge city, and implementing the West Suburb Storm-water Regulation Project. In addition, the flood warning and emergency management system has been established. Furthermore, some measurements were pointed to be done in the future, including improvement of the flood control management system, improvement of flood control plans, strengthening flood warning system, and strengthening social management and public awareness of flood prevention. With these improvements of management and engineering measurements, it can be more secure under intensive storms in Beijing. These experiences of flood control in Beijing can provide references for other cities.

It was found previously by us that the compositions of industrial alloy specializations are related to the chemical short-range ordering in solid solution alloys, which is in accordance with the cluster-plus-glue-atom model. This model identifies short-range-ordered chemical building units in solid solutions, which the specific alloy compositions rely on. For instance, substitutional-type FCC solid solution alloys are described by cluster-based units formulated as [cluster](glue atom)16, where the bracketed cluster is the nearest-neighbor coordination polyhedral cluster, cuboctahedron in this case, and one-to-six glue atoms occupy the inter-cluster sites at the outer-shell of the cluster. In the present paper, we investigate the atomic configurations of these local units in substitutional-type FCC solid solutions by exhausting all possible cluster packing geometries and relevant cluster formulas. The structural model of stable FCC solid solutions is first reviewed. Then, solute distribution configurations in FCC lattice are analyzed by idealizing the measured chemical short-range orders within the first and second neighborhoods. Two key assumptions are made with regards to the cluster distribution in FCC lattice. First, the clusters are isolated to avoid the short-range orders from extending to longer range ones. Second, the clusters are at most separated by one glue atom to confine the inter-cluster distances. Accordingly, only a few structural unit packing modes are identified. Among them, the configurations with glue atoms 0, 1, 3, and 6 show good homogeneities which indicate special structural stabilities. Finally, compositions of FCC Cu-Zn (representative of negative enthalpy systems) and Cu-Ni (positive enthalpy ones) industrial alloys are explained by using the structure units of cluster packing and the cluster formulas, expressed as [Zn-Cu12]Zn1-6 and [Zn-Cu12](Cu, Zn)6, where the cluster is Zn-centered, shelled with Cu atoms, and glued with one to six Zn or with a mixture of six Cu and Zn. In particular, the formula [Zn-Cu12]Zn6, with the highest Zn content, corresponds to the solubility limit in Cu-Zn alpha phase zone, which is also the composition of the specification C27400. The Cu-rich Cu-Ni alloys are explained by cluster formulas [Cu-Cu12](Cu, Ni) 6, where the cluster is Cu centered and glued with a mixture of six Cu and Ni. The Ni-rich Monel alloy is explained by cluster formulas [Ni-Ni12](Cu5Ni)-[Ni-Ni12]Ni6. The present work provides a new approach to alloy composition explanation and eventually to alloy composition design from the perspective of short-range ordering in solid solutions.