Search

In recent years, the frequency and intensity of exposure to heat stress have increased gradually, seriously hampering the production of maize. This paper presents a study designed to analyze how the development, physiology and dispersal of pollen from the heat‐resistant maize variety Zhengdan958 and the heat‐sensitive maize variety Xianyu335 are affected by exposure to heat stress during the tasselling stage. Our results showed That exposure to heat stress significantly increased the antioxidant enzyme activity in pollen. Upon visual inspection of the pollen, we found that the lower water content had given rise to wrinkles in the pollen surface, sunken germination pores, and morphological deformations. In addition, the anther dehiscence process was hindered, resulting in a reduced amount of pollen being dispersed. We also found elevated levels of abscisic acid (ABA), jasmonic acid (JA) and its derivatives, indole acetic acid (IAA) and gibberellin‐3 (GA3) in heat‐pollens, as well as elevated ratios of IAA to ABA and ABA to GA3. Ultimately impaired pollen fertility. Summarizing, our experiment revealed that reduced pollen quantity and quality are significant contributors to fertility losses in summer maize exposed to heat stress at anthesis, and we hope that our analysis of the physiological mechanisms involved can contribute to the development of crop management measures aimed at countering the increasingly detrimental effects of heat stress on the production of summer maize. [ABSTRACT FROM AUTHOR]

Global climate changes have led to frequent and recurrent heat stress, which has seriously affected the world maize production. The experiment presented in this paper was carried out during the maize‐growing season in 2021 and 2022 at the Huang–Huai–Hai Region Maize Science and Technology Innovation Center (36°09′N, 117°09′E) in Tai'an, Shandong province, China. The test site is located in the semi‐humid warm temperate continental monsoon climate zone, soil is brown loam. We selected different heat‐sensitive maize varieties: heat‐tolerant variety Zhengdan 958 (ZD958) and heat‐sensitive variety Xianyu335 (XY335) to study the stress effects of high temperature on the development of tassel in the key stage of its differentiation (the 12‐leaf stage, V12). We found that exposure to heat stress during the V12 stage significantly reduced the tassel size and the anther dehiscence area, making it difficult to disperse pollen, thus effectively reducing pollen production. In addition, heat stress had significant negative effects on pollen development, resulting in deformed pollen and lower pollen viability and germination rate. Our results also showed that heat stress significantly increased the activities of key reactive oxygen species‐scavenging enzymes including superoxide dismutase, peroxidase and catalase, and that the malondialdehyde and H2O2 content in tassels exposed to heat stress were significantly higher than those control group, where it should be noted that for the XY335, these effects were more pronounced than for the ZD958. The endogenous hormone content of tassels exhibited a variety of responses. After heat stress, the zeatin and salicylic acid content in tassels of both maize varieties were significantly lower than those in the respective control groups, while the abscisic acid and gibberellin acid content were significantly higher. With respect to the jasmonic acid and 3‐indoleacetic acid content, the two maize varieties exhibited opposite responses: in tassels from ZD958 plants subjected to heat stress were higher than those in the respective control group, while in tassels from XY335 plants, they were lower. The observed changes in protective enzyme activities and endogenous hormone contents induced by heat stress significantly affected the development of maize tassels and significantly reduced the amount, activity and germination rate of pollen. [ABSTRACT FROM AUTHOR]

Grain crops are easily contaminated by fungi due to the existence of various microorganisms in the storage process, especially in humid and warm storage conditions. Compared with conventional methods, surface-enhanced Raman scattering (SERS) has paved the way for the detection of fungi in grain crops as it is a rapid, nondestructive, and sensitive analytical method. In this work, Aspergillus niger, Saccharomyces cerevisiae, Fusarium moniliforme and Trichoderma viride in grain crops were detected using colloidal Au nanoparticles and SERS. The results indicated that different fungi showed different Raman phenotypes, which could be easily characterized by SERS. Combined with multivariate statistical analysis, identification of a variety of fungi could be accomplished rapidly and accurately. This research can be applied for the rapid detection of fungi in the food and biomedical industries. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to analyze the clinical application value of shear wave elastography (SWE) technique for early diagnosis of diabetic peripheral neuropathy (DPN). Methods: Diabetic patients hospitalized in the Department of Endocrinology of the First Affiliated Hospital of Anhui Medical University from August 2021 to February 2022 were enrolled as DPN group (n=38) and non-DPN group (n=35) based on the neurophysiological examination results. 30 healthy subjects were recruited as the control group during the same period. Ultrasound examination of the tibial nerve and related laboratory tests were examined and collected for the total 103 study subjects. Statistical analysis of the collected data, and the receiver operating characteristic(ROC) curve for determination of the optimal cut-off values of mean stiffness of tibial nerve to detect DPN, with determination of area under curve (AUC), specificity, sensitivity, and Youden index.P value < 0.05 is considered statistically significant. Results: Gender, age and BMI differences among three groups were insignificant (P>0.05). The difference of serological indicators between DPN and non-DPN groups was also not found (P>0.05), whereas longer duration of diabetes was observed in DPN group as compared to non-DPN group. As to the ultra-sound relevant parameters, the cross-sectional area and elastic modulus of the tibial nerve in both lower extremities among these three groups were not significantly different (Oneway ANOVA analysis) although the differences were indeed observed if we compared DPN group exclusively with non-DPN group, or compared non-DPN group with healthy group, or compared DPN group with healthy group (t test). Additionally, the mean elasticity (Emean) cut-off value for the diagnosis of DPN was preferably taken as 67.55 kPa. Conclusion: SWE has unique advantages in early detection and diagnosis of DPN, which deserve further research. [ABSTRACT FROM AUTHOR]

Objectives: We investigated the effect and mechanism of miR-21-3p on the biological behavior of keratinocyte HaCaT cells. Methods: HaCaT cells were transfected with miR-21-3p mimics and miR-21-3p inhibitor, respectively. Cell proliferation was detected by CCK-8, and apoptosis and cell cycle were analyzed by flow cytometry. The expression changes of Bax and Bcl-2 were measured with immunohistochemistry. The mRNA expressions of IL-17A and STAT3 were detected by real-time fluorescence quantitative PCR. Cytokeratin 17 protein was detected by Western blot. The relationship between miR-21-3p and STAT3 was verified by dual luciferase reporter gene assay. Results: The miR-21-3p mimics significantly promoted the proliferation and cell cycle progression of HaCaT cells. However, miR-21-3p mimics significantly inhibited cell apoptosis, decreased Bax expression and increased Bcl-2 expression. Additionally, miR-21-3p mimics significantly increased the expressions of Cytokeratin 17 protein, IL-17A mRNA and STAT3 mRNA. Of note, the miR-21-3p inhibitor exhibited contrary effects to miR-21-3p mimics. Furthermore, STAT3 was a direct target of miR-21-3p. Conclusion: miR-21-3p may promote the abnormal proliferation and inhibit apoptosis of HaCaT cells, possibly through regulating JAK/STAT pathway and the expression of Cytokeratin 17. [ABSTRACT FROM AUTHOR]

Aspergillus flavus and Aflatoxins in grain crops give rise to a serious threat to food security and cause huge economic losses. In particular, aflatoxin B1 has been identified as a Class I carcinogen to humans by the International Agency for Research on Cancer (IARC). Compared with conventional methods, Surface-Enhanced Raman Scattering (SERS) has paved the way for the detection of Aspergillus flavus and Aflatoxins in grain crops as it is a rapid, nondestructive, and sensitive analytical method. In this work, the rapid detection of Aspergillus flavus and quantification of Aflatoxin B1 in grain crops were performed by using a portable Raman spectrometer combined with colloidal Au nanoparticles (AuNPs). With the increase of the concentration of Aspergillus flavus spore suspension in the range of 102–108 CFU/mL, the better the combination of Aspergillus flavus spores and AuNPs, the better the enhancement effect of AuNPs solution on the Aspergillus flavus. A series of different concentrations of aflatoxin B1 methanol solution combined with AuNPs were determined based on SERS and their spectra were similar to that of solid powder. Moreover, the characteristic peak increased gradually with the increase of concentration in the range of 0.0005–0.01 mg/L and the determination limit was 0.0005 mg/L, which was verified by HPLC in ppM concentration. This rapid detection method can greatly shorten the detection time from several hours or even tens of hours to a few minutes, which can help to take effective measures to avoid causing large economic losses. [ABSTRACT FROM AUTHOR]

• An intelligent inverse method is proposed, where MMA works with FEM and binary reconstruction. • The size of chip-integrated logic gates (OR, XOR, NOR, AND and NAND) are 2 μm × 2 μm. • The bandwidth of logic gates are nearly ten times more than the other reported conventional gates. The Si-based chip-integrated OR, XOR, NOR, AND and NAND all-optical logic gates (AO-LGs) with footprints of 2 μm × 2 μm are inversely designed based on an intelligent method, which combines the method of moving asymptotes (MMA) with the finite element method (FEM). In this method, the substrate is divided into many small units, and the refractive index of each unit will be perturbed according to design expectation. Therefore, the optimized refractive index will be gradient, which divorces from fabrication. Binary reconstruction is the process of changing the gradient media into binary media, by filtering out the gradient virtual media, smoothing the boundaries, and refilling Si or air on the substrate to form a new structure. Numerical simulations demonstrate that all the AO-LGs designed by this method work effectively. The contrast ratio (CR) of OR/XOR gate ranges from 23.50 dB to 25.50 dB, NOR gate ranges from 6.33 dB to 7.91 dB, AND gate ranges from 4.44 dB to 6.13 dB, and NAND gate ranges from 8.85 dB to 10.07 dB. And these designed AO-LGs achieve nearly ten times more broad bandwidth than the other reported conventional gates without suffering other performances too much. The OR/XOR, and NOR gate functions well in a broad band range from 800 nm to 1600 nm, and from 850 nm to 1350 nm. AND gate functions well from 1000 nm to 1240 nm and from 1310 nm to 1400 nm. NAND gate functions well from 1360 nm to 1530 nm. It is expected that such a robust method can serve extensive applications in designing photonic devices, and the compact logic gates may contribute to broad applications of future optical computing and signal processing. [ABSTRACT FROM AUTHOR]

Licorice was widely used in food and herbal medicine. In its extract industry, a substantial amount of licorice protein was produced and discarded as waste. Herein, we extracted Licorice Protein Isolate (LPI) and explored its potential as a curcumin nanocarrier. Using a pH-driven method, we fabricated LPI-curcumin nanoparticles with diameters ranging from 129.30 ± 3.21 nm to 75.03 ± 1.19 nm, depending on the LPI/curcumin molar ratio. The formation of LPI-curcumin nanoparticles was primarily driven by hydrophobic interactions, with curcumin entrapped in LPI being in an amorphous form. These nanoparticles significantly enhanced curcumin properties in terms of solubility, photochemical stability, and stability under varying pH, storage, and physiological conditions. Moreover, the loaded curcumin exhibited a 2.58-fold increase in cellular antioxidant activity on RAW 264.7 cells and a 1.86-fold increase in antitumor activity against HepG2 cells compared to its free form. These findings suggested that LPI could potentially serve as a promising novel delivery material. [ABSTRACT FROM AUTHOR]

Licorice was widely used in food and herbal medicine. In its extract industry, a substantial amount of licorice protein was produced and discarded as waste. Herein, we extracted Licorice Protein Isolate (LPI) and explored its potential as a curcumin nanocarrier. Using a pH-driven method, we fabricated LPI-curcumin nanoparticles with diameters ranging from 129.30 ± 3.21 nm to 75.03 ± 1.19 nm, depending on the LPI/curcumin molar ratio. The formation of LPI-curcumin nanoparticles was primarily driven by hydrophobic interactions, with curcumin entrapped in LPI being in an amorphous form. These nanoparticles significantly enhanced curcumin properties in terms of solubility, photochemical stability, and stability under varying pH, storage, and physiological conditions. Moreover, the loaded curcumin exhibited a 2.58-fold increase in cellular antioxidant activity on RAW 264.7 cells and a 1.86-fold increase in antitumor activity against HepG2 cells compared to its free form. These findings suggested that LPI could potentially serve as a promising novel delivery material. [ABSTRACT FROM AUTHOR]

Dielectric elastomers (DEs) have a great potential in applications as smart materials such as artificial muscles and flexible robotics, due to their advantages of large deformation, good flexibility and fast actuation response. However, the excellent electro-actuation performance of DE materials is always achieved under high electric fields, which limits their widespread application. Herein, the synthesized acrylate-based copolymer E 8 G 2 (the molar ratio between 2-ethylhexyl acrylate and glycidyl methacrylate is 8:2) was incorporated into the polydimethylsiloxane (PDMS) matrix by solution mixing and compression molding to prepared a series of bi-network DE composites. The design of the all-organic bi-network structure not only regulates the dielectric-flexibility of E 8 G 2 /PDMS composites synchronously but also relieves the problem of plasticizer exudation. The E 8 G 2 /PDMS composites achieved a remarkable electro-actuated strain of 43.86 % at 50 V/μm, which is improved by 431.08 % compared with pure PDMS (6.95 %). Consequently, this study provides a promising approach for the preparation of advanced DE composites with outstanding electro-actuated performance in low-field driving applications. [Display omitted] • The dielectric elastomer with all-organic bi-network structures were prepared. • The electro-actuated strain of DE composite reaches 43.86 % at low-field of 50 V/μm. • The synergistic regulation on ε r and Y leads to the improved electro-actuation. • The long-standing issue of plasticizer-exudation from DE composites is relieved. [ABSTRACT FROM AUTHOR]

The existing quality monitoring method of dynamic compaction construction is costly and inefficient, and the measurement results for the falling distance of the hammer and the number of tamping times may even become completely ineffective in abnormal situations during the construction process, such as empty hook rise and early release hammer. Therefore, this paper proposes an effective measurement method based on time series model. Simulate the regular periodic motion state transformation in strong ramming construction by motion state discrimination model, combined with the prediction interval of running time estimation model to assist state discrimination, realizes real-time monitoring of anomalies as well as effective measurement of important construction parameters such as the tamping times and the falling distance of the hammer. Experimental results demonstrate that the method achieves accuracy of 100% under normal tamping conditions, and accuracy of no less than 95% even in tamping conditions involving abnormal behavior. • Constructed DCC state discrimination model based on bi-objective parallel features. • Proposed a method measuring tamping times using combined temporal-spatial features. • Established a model for estimating the duration of states based on prior data. [ABSTRACT FROM AUTHOR]

Through one-step reaction, a robust hypercrosslinked pyrene-based porous organic polymer (HcPPy) with a high BET surface area was effectively achieved from pyrene. HcPPy was demonstrated as an excellent electrode material. When explored as an anode material for lithium ion batteries, HcPPy exhibited a high capacity even at high current densities (up to 683 mA h g−1 at 1000 mA g−1). When used as a cathode material, HcPPy exhibited good rate and cycling stability with a capacity of 110 mA h g−1 at 100 mA g−1 over 200 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • "Extra conjugation" method is developed for NIR TADF OLEDs with high radiance. • Intramolecular hydrogen bonds extend molecular conjugation for accurate modulation. • A high radiance of 95,894 m W Sr−1 m−2 with 744 nm peaked EL emission is realized. • Force and medicine induced SpO 2 variations are detected by 740 nm NIR TADF OLED. Real-time in-home monitoring oxygen saturation (SpO 2) is of great significance for early diagnosis and treatment of severe COVID-19, however, which should be based on multi-wavelength technology and complicated equipment. Herein, as a proof of concept, 740 nm is chosen as singlet light source for single-wavelength SpO 2 detection, since absorbance differences between oxyhemoglobin (HbO 2) and other interferences are the most rational. To controllably optimize excited-state characteristics of a near-infrared (NIR) thermally activated delayed fluorescence (TADF) emitters, an "extra conjugation" method is demonstrated by C NQP-TPA , whose 2,3-dicyanoquinoxaline phenanthroline (CNQP) acceptor forms strong intramolecular hydrogen bonds with two phenyls of triphenylamine (TPA) donors, which not only reduce excited-state relaxation-induced energy lose, but also provide more space for accurate modulation of intermolecular charge transfer (CT) interactions. As consequence, at the suitable doping concentration, CNQP-TPA endowed its device with a high radiance reaching ∼105 mW Sr−1 m−2 and desired electroluminescence peak at 744 nm. This device is further used as light source to detect SpO 2 variation under single-wavelength mode. These results indicate the potential of NIR TADF materials and devices for in-home SpO 2 monitoring and pre-diagnosis and prevention of severe COVID-19. [ABSTRACT FROM AUTHOR]

Hypericin is widely utilized for its precise antidepressant properties, but its exact antidepressant mechanism remains unclear. Gap junctions, which were predominantly expressed in astrocytes in the central nervous system, are concerned with the pathogenesis of depression. However, the role of hypericin in gap junctional dysfunction in depression has rarely been investigated. Here, we found that gap junctions were ultra-structurally broadened in the chronic unpredictable stress (CUS) rat model of depression, while hypericin repaired the dysfunction of gap junctions. Suppression of gap junctions by bilateral injection of carbenoxolone (CBX) in the prefrontal cortex of rats significantly inhibited the restoration of gap junctional dysfunction in depression by hypericin. Meanwhile, hypericin failed to show antidepressant benefits. Furthermore, in corticosterone (CORT)-stimulated primary astrocytes derived from neonatal rats, hypericin dramatically reversed the phosphorylation of connexin 43 (Cx43), normalizing the expression of Cx43 and thereby ameliorating gap junctional dysfunction. Comparatively, CBX inhibited the remission of hypericin on gap junctional intercellular communication function. Gap junctional function might be a novel therapeutic target for hypericin in the treatment of depression and provide potential novel insights into the antidepressant mechanism of other herbal ingredients. [Display omitted] • Hypericin has therapeutic efficacy in treating depression. • Hypericin repaired the dysfunction of gap junctions in depression. • Hypericin interacts with Cx43-gap junction channel by molecular docking. • Hypericin relieves depression by improving Cx43-based gap junctional function. [ABSTRACT FROM AUTHOR]

Device simplification is of practical significance for organic light emitting diodes (OLEDs), and remains the great challenge for deep‐red emitters. Herein, a deep‐red thermally activated delayed fluorescence molecule (pTPA‐DPPZ) is reported which features a T shaped structure containing two triphenylamine (TPA) donors, one either side of a planar dipyridophenazine (DPPZ) acceptor. The rational spatial arrangement of the functional groups leads to limited but sufficient molecular packing for effective carrier transport. The neat pTPA‐DPPZ film achieves an around 90‐fold improved radiation rate constant of 107 s−1 and the nearly unitary reverse intersystem crossing (RISC) efficiency, as well as accelerated emission decays for quenching suppression. The high radiation and RISC result in a photoluminescence quantum yield of 87 %. The bilayer OLED based on the pTPA‐DPPZ emissive layer achieved the record external quantum efficiencies of 12.3 % for maximum and 10.4 % at 1000 nits, accompanied by the deep‐red electroluminescence with the excellent color purity. [ABSTRACT FROM AUTHOR]

Device simplification is of practical significance for organic light emitting diodes (OLEDs), and remains the great challenge for deep‐red emitters. Herein, a deep‐red thermally activated delayed fluorescence molecule (pTPA‐DPPZ) is reported which features a T shaped structure containing two triphenylamine (TPA) donors, one either side of a planar dipyridophenazine (DPPZ) acceptor. The rational spatial arrangement of the functional groups leads to limited but sufficient molecular packing for effective carrier transport. The neat pTPA‐DPPZ film achieves an around 90‐fold improved radiation rate constant of 107 s−1 and the nearly unitary reverse intersystem crossing (RISC) efficiency, as well as accelerated emission decays for quenching suppression. The high radiation and RISC result in a photoluminescence quantum yield of 87 %. The bilayer OLED based on the pTPA‐DPPZ emissive layer achieved the record external quantum efficiencies of 12.3 % for maximum and 10.4 % at 1000 nits, accompanied by the deep‐red electroluminescence with the excellent color purity. [ABSTRACT FROM AUTHOR]

Si–Ge alloys are a new type of semiconductor material that are of great significance for the development of microelectronic technology, especially in the photoelectricity industry and for thermoelectric conversion in high temperature applications (>700 K). In the present work, a novel Ge allotrope in the C 2/ c phase with band gap of 1.102 eV was firstly proposed, which is suitable for the absorption of sunlight. C 2/ c -Ge are mechanically, dynamically and thermodynamically stable. A series of Si 24- x Ge x alloys (x = 0, 8, 16, 24) in the C 2/ c phase with band gaps of 1.10–1.50 eV are predicted by ab initio calculations at ambient conditions. The Si 24- x Ge x alloys (x = 0, 8, 16, 24) in C 2/ c phase have better absorption ability than that of the Si in diamond, hP12 and oC12 phases. The Si 24- x Ge x alloys in the C 2/ c phase have the strong absorption in the visible, which have a great impact on the new-generation photovoltaic applications. [ABSTRACT FROM AUTHOR]

Abstract In order to solve the low accuracy of the classic spectral matching algorithms in matching the spectral data of different pigment materials in the homochromatic similar system, this paper proposed a spectral matching algorithm based on adaptive threshold levenshtein distance. The levenshtein distance was researched to improve the matching accuracy by using its characteristics of to be sensitive to the spectral reflectance difference. At the same time, by adaptively setting the judgment condition of levenshtein distance, the error of this algorithm in matching the spectral data of the same pigment material under different conditions is reduced. And the identification accuracy of different pigment materials in the homochromatic similar system is improved. The experimental results show that compared with the traditional spectral matching algorithm, the matching accuracy of the adaptive levenshtein distance algorithm is higher, and the identification result for the pigment is better. [ABSTRACT FROM AUTHOR]

In order to solve the ill-posed problem in the process of reconstructing the spectral reflectance of the traditional matrix R method, a regularization matrix R method was proposed in this paper. Through analyzing the ill-posed equation of matrix R to reconstruct the spectral reflectance, the Tikhonov regularization method was researched to restrict the ill-posed problem to solve the Moore-Penrose pseudo inverse matrix. The L-curve method was used to obtain the optimal regularization parameter by training samples data in order to effectively restrict the ill-posed situation which was caused by the equation solving of spectral reconstruction. The experimental results verified that the proposed regularization matrix R method had higher spectral and chromatic accuracy of reconstructed spectrum than traditional matrix R method. At the same time, the proposed regularization matrix R method achieved good performance for color reproduction of real mural in practical application. [ABSTRACT FROM AUTHOR]

Poor qualities of ZnMgO thin films are likely to be obtained at higher Mg content, which can decrease the performance of ZnMgO-based devices. This study focuses on improving the qualities of ZnMgO thin films to increase the performance of CdTe solar cell. It is found that the rapid thermal annealing (RTA) treatment increases the crystallinity, eliminates defects and improves the conductivity of ZnMgO thin films. These are helpful to suppress the recombination caused by bulk and interface defects as well as to reduce the cell's series resistance. The Fermi level moves close to conduction band and both the conduction and valence band energy shift lower relative to band energy of CdSSeTe film after RTA, which could not only increase the built-in voltage but also enhance the electron transport and block the hole recombination. As a result, the efficiency of CdTe solar cells is enhanced when using the RTA-treated ZnMgO, with maxium power conversion efficiency reaching values of 15.7%, which are much higher than those of the cells with the as-grown ZnMgO (11.6%). RTA is proved to be one of the excellent methods to control the properties of ZnMgO for improving the performance of CdTe solar cell. [ABSTRACT FROM AUTHOR]

Polymer nanocomposites have been widely used in the preparation of coating agents in the leather industry. Considering the complex bio-effect and ecological risk of nanomaterial, research on the biodegradability and biocompatibility of polyacrylate/metal nanocomposites in activated sludge system is of specific significance. We investigated the change of the bacterial community and diversity of activated sludge fed with polyacrylate/ZnO nanocomposites in both low (500 mg COD /L) and high (1000 mg COD/L) doses. COD removal, dehydrogenase activity, and total protein of activated sludge system were monitored in all treatments over 30 days. The results demonstrated that the exposure to both polyacrylate/ ZnO nanocomposite and polyacrylate decreased the dehydrogenase activity at early stage comparing to the control, but had no significant influence on COD removal. Overall, the bacterial communities in activated sludge were resistant to polyacrylate/ZnO nanocomposites, and had higher levels of metabolic activity, protein accumulation and bioavailability when exposed to these chemicals comparing to the control especially at later stages of incubation (15–30 days), which indicated that these polyacrylate/ZnO nanocomposites of certain amount were biocompatible to activated sludge system. [ABSTRACT FROM AUTHOR]

• A comprehensive theoretical study of photophysical behaviors of 1,2-DHPs and 1,4-DHPs was carried out using the DFT and TDDFT methods. • The UV–Vis absorption and fluorescence emission spectra of a series of different substituent 1,2-DHPs and 1,4-DHPs were obtained. • The substituents at different positions on the 1,2-DHPs and 1,4-DHPs scaffolds play a different role in controlling the excitation energy and other photophysical properties. In this article, the photophysical properties of DHPs, including 1,2-DHPs and 1,4-DHPs, were studied experimentally and theoretically. Their structural differences bring about different photophysical properties, and also lead to different photochemical properties. Specifically, a series of different substituted 1,2-DHPs and 1,4-DHPs were synthesized to measure their UV–Vis absorption and fluorescence emission spectra in diluted solutions and theoretical calculations were performed at the density functional theory (DFT) level. To describe the reactivities of the DHPs, time-dependent density functional theory (TDDFT) was used to optimize their ground- and excited-state structures, and their electronic excitation energies were calculated at the B3LYP-D3/def2-TZVP level. Frontier molecular orbitals and electron-hole distribution analyses were used to illustrate the electron transition types. The differences between the ground- and excited-state structures of the different DHPs were characterized by carrying out a root-mean-square-deviation (RMSD) analysis. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The photophysical properties of heterocyclic analogs of 1,4-cyclohexadiene were studied by theoretical calculation and experiment. • Their photophysical and photochemical properties were found to be related to the incorporation of different heteroatoms on the 1,4-cyclohexadiene ring. • The photophysical properties of heterocyclic analogs of 1,4-cyclohexadiene are meaningful for explaining their photochemical reactivity. The photophysical and photochemical properties of a series of heterocyclic analogs of 1,4-cyclohexadiene were studied by theoretical calculation and experiment. With the incorporation of different heteroatoms, the analogs presented distinct photophysical and photochemical properties from 1,4-cyclohexadiene. Their ultraviolet–visible absorption spectra were measured and found to be related to the heteroatoms on the 1,4-cyclohexadiene ring. Calculation of the geometrical and electronic structures of the ground-states revealed that incorporation of the heteroatom affected the photophysical properties of the molecule. The de-excitation processes and electron transition modes were discussed according to the calculated values of the spin–orbit coupling matrix and the electron-hole distributions of the excited states. The reactive sites and geometrical structures showed that incorporation of a heteroatom into 1,4-cyclohexadiene changed the spin density distribution and thus influenced the photochemical properties. These findings are meaningful in explaining the photo-reactivities of these molecules, and provide foundations for further experimental/theoretical investigations and pharmacological applications based on established structure–property correlations. [ABSTRACT FROM AUTHOR]

In this article, the intermolecular [2+2] cycloaddition of 1,2-dihydropyridines was achieved for the first time by visible light-catalyzed. A series of novel and complex cyclobutane derivatives, the dimers of diethyl 1,2-diaryl-1,2-dihydropyridine-3,5-dicarboxylate, were synthesized efficiently with visible light catalysts under the irradiation of blue LED lamps. The density functional theory and time-dependent density functional theory were used to elucidate the detailed reaction processes, such as the reaction mechanism and the stereoselectivity of cycloaddition products. [Display omitted] • The intermolecular [2 + 2] cycloaddition of 1,2-dihydropyridines was achieved for the first time by visible light-catalyzed. • A series of novel and complex cyclobutane derivatives, the dimers of diethyl 1,2-diaryl-1,2-dihydropyridine-3,5-dicarboxylate, were synthesized efficiently with visible light catalysts under the irradiation of blue LED lamps. • The DFT and TDDFT theoretical calculations were carried out to reveal the reaction mechanism and the stereoselectivity of cycloaddition products. [ABSTRACT FROM AUTHOR]

The performance of multiple-input multiple-output wireless optical communication systems that adopt Q-ary pulse position modulation over spatial correlated log-normal fading channel is analyzed in terms of its un-coded bit error rate and ergodic channel capacity. The analysis is based on the Wilkinson’s method which approximates the distribution of a sum of correlated log-normal random variables to a log-normal random variable. The analytical and simulation results corroborate the increment of correlation coefficients among sub-channels lead to system performance degradation. Moreover, the receiver diversity has better performance in resistance of spatial correlation caused channel fading. [ABSTRACT FROM AUTHOR]

This study investigates the influence of climatic changes on the annual stream flow of the Nu (Salween) River, over the period from 1958 to 2004. While the flow of the Nu River is mainly influenced by precipitation, the role of temperature in governing stream flow appears to be increasing as the climate warms. The first principal component extracted from climatic data accounts for 52.5% of observed variance in stream flow over the period 1958–2004. A transition toward a warmer, more humid regional climate has been ongoing since the 1980s, as evidenced by increases in temperature, precipitation, and stream flow in the Nu River Basin. A continuing trend toward higher temperatures and more intense precipitation will likely lead to increased Nu River stream flow in the future. Synoptic climatology indicates a link between extremes in annual Nu River stream flow and anomalies in atmospheric circulation patterns such as the mid-latitude westerlies and the South Asian Summer Monsoon. [ABSTRACT FROM AUTHOR]

Purpose:To evaluate the effect of static magnetic fields (SMFs) on insulin secretion and explore the mechanisms underlying exposure to SMF-induced insulin secretion in rat insulinoma INS-1 cells. Materials and methods:INS-1 cells were exposed to a 400 mT SMF for 72 h, and the proliferation of INS-1 cells was detected by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The secretion of insulin was measured with an enzyme linked immunosorbent assays (ELISA), the expression of genes was detected by real-time PCR, and the expression of proteins was measured by Western blotting. Results:Exposure to an SMF increased the expression and secretion of insulin by INS-1 cells but did not affect cell proliferation. Moreover, SMF exposure up-regulated the expression of several pancreas-specific transcriptional factors. Specifically, the activity of the rat insulin promoter was enhanced in INS-1 cells exposed to an SMF, and the expression levels of synaptosomal-associated protein 25 (SNAP-25) and syntaxin-1A were up-regulated after exposure to an SMF. Conclusions:SMF exposure can promote insulin secretion in rat INS-1 cells by activating the transcription of the insulin gene and up-regulating the expression of vesicle-secreted proteins. [ABSTRACT FROM AUTHOR]

[Display omitted] • "Asymmetric D-A-wA" strategy is demonstrated for high-efficiency red TADF emitters. • Diphenylphosphine oxide as the second acceptor markedly improves TADF properties. • Strong red emission peaked at 645 nm with a high PLQY of 94.7 % is realized. • The maxima of 19360 cd m−2 for luminance and 11.4 % for EQE at 632 nm are achieved. A feasible strategy of asymmetric donor–acceptor-second acceptor (D-A-A) structure is proposed for improving the photoluminecense (PL) and electroluminescence (EL) performance of red thermally activated delayed fluorescence (TADF) emitters. As a concept, four newly TADF emitters are designed and synthesized, D-A-A structure o TPAPO-DTPZ and p TPAPO-DTPZ and D-A-D type o DTPA-DTPZ and p DTPA-DTPZ, by using triphenylamine (TPA), dithieno[2,3- a :3′,2′- c ]phenazine (DTPZ) and diphenylphosphine oxide (DPPO) groups as the donor, acceptor and second acceptor, respectively. It is demonstrated that abound intra- and inter-molecular C H···O hydrogen bonds are forming between TPA donor and DPPO acceptor for the asymmetric compounds, which effectively promote the intra- and inter-molecular charge transfer. Moreover, the steric hindrance of DPPO group availably suppresses the concentration quenching. As a consequence, the asymmetric D-A-A structured o TPAPO-DTPZ and p TPAPO-DTPZ exhibit relatively higher PL quantum yields and lower nonradiation rates, and thus better EL performance. In particular, device based on p TPAPO-DTPZ achieves the maximum luminance of 19360 cd m−2 and external quantum efficiency of 11.4 % at 632 nm, which are 2.3 and 1.5 times the values of p DTPA-DTPZ based device. [ABSTRACT FROM AUTHOR]

The Ag 2 O/Ag 2 CO 3 /multi-walled carbon nanotube (MWNTs) composite photocatalysts were prepared by calcination of the obtained precipitate. The structures and morphology of as-prepared composite photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS). The Ag 2 O/Ag 2 CO 3 /MWNTs composite photocatalysts exhibit higher degradation rate of ciprofloxacin (CIP) than the pure Ag 2 CO 3 , Ag 2 O/Ag 2 CO 3 and Ag 2 CO 3 /MWNTs under visible light irradiation. The amount of loaded Ag 2 CO 3 onto MWNTs and calcined time for Ag 2 CO 3 /MWNTs were systematically investigated, and the optimal amount of loaded Ag 2 CO 3 and calcined time of Ag 2 CO 3 /MWNTs are 150 wt% and 10 min, respectively. The highest photocatalytic degradation rate of CIP could reach 76% under optimal conditions. The active species trapping experiments were also analyzed, the results show that the holes are main contributor for the degradation processes of CIP, furthermore the electrons, O 2 − and OH are also crucially influenced the photocatalytic degradation processes of CIP. The possible photocatalytic processes of CIP with Ag 2 O/Ag 2 CO 3 /MWNTs composite photocatalyst are also proposed. [ABSTRACT FROM AUTHOR]

Ag/Ag 3 PO 4 /active carbon (AC) composite photocatalysts were successfully synthesized using the simple deposition and photoinduced methods. The structures, morphology and photocatalytic properties of as-prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS). The Ag/Ag 3 PO 4 /AC composite photocatalysts exhibited a conspicuously improved photocatalytic performance for tetracycline (TC) degradation. The optimal conditions of loaded dosage and photoinduced time were investigated, and the results showed that the photoinduced time played an important role in prepared processes, and also that for the loaded dosage of Ag 3 PO 4 . The DRS analysis showed that the composite photocatalysts exhibited strong absorption ability in the visible light range. The radicals trap experiments demonstrated that there were multiple active species during the degrading process of TC. The possible mechanism of improved photocatalytic activity of Ag–Ag 3 PO 4 /AC composite was also proposed. [ABSTRACT FROM AUTHOR]

The elongation factor Tu (EF-Tu) receptor (EFR) in cruciferous plants specifically recognizes the N-terminal acetylated elf18 region of bacterial EF-Tu and thereby activates plant immunity. It has been demonstrated that Arabidopsis EFR confers broad-spectrum bacterial resistance in the EFR transgenic solanaceous plants. Here, the transgenic rice plants (Oryza sativa L. ssp. japonica cv. Zhonghua 17) and cell cultures with constitutive expression of AtEFR were developed to investigate whether AtEFR senses EF-Tu and thus enhances bacterial resistance in the monocot plants. We demonstrated that the Xanthomonas oryzae-derived elf18 peptide induced oxidative burst and mitogen-activated protein kinase activation in the AtEFR transgenic rice cells and plants, respectively. Pathogenesis-related genes, such as OsPBZ1, were upregulated dramatically in transgenic rice plant and cell lines in response to elf18 stimulation. Importantly, pretreatment with elf18 triggered strong resistance to X. oryzae pv. oryzae in the transgenic plants, which was largely dependent on the AtEFR expression level. These plants also exhibited enhanced resistance to rice bacterial brown stripe, but not to rice fungal blast. Collectively, the results indicate that the rice plants with heterologous expression of AtEFR recognize bacterial EF-Tu and exhibit enhanced broad-spectrum bacterial disease resistance and that pattern recognition receptor-mediated immunity may be manipulated across the two plant classes, dicots and monocots. [ABSTRACT FROM AUTHOR]

[Display omitted] • Near-infrared TADF emission from phenanthroline based molecule is demonstrated. • NIR emission and radiation efficiency are balanced in CNPP-TPA. • Strong NIR emission peaked at 701 nm with PLQY of 96.5% is realized. • A maximum EQE (8.69%) of vacuum-evaporated device peaked at 684 nm is achieved. • A maximum EQE (2.02%) of spin-coated device peaked at 700 nm is achieved. Efficient thermally activated delayed fluorescence (TADF) emitters are of practical significance for realizing high-performance organic light emitting diodes (OLEDs), which remains the great challenge for near-infrared (NIR) emitters because of their narrow bandgap worsened non-radiative transition. Herein, a NIR TADF molecule (CNPP-TPA) is reported, composed of 2,3-dicyanopyrazino phenanthroline (CNPP) as acceptor and triphenylamine as donor. The strong electron-withdrawing effect of CNPP and intramolecular hydrogen bond endow CNPP-TPA with efficient NIR photoluminescence emission peaked at 701 nm with a high photoluminescence quantum yield of 96.5%, owing to rapid singlet radiation and effective reverse intersystem crossing. Vacuum -evaporated and spin-coated organic light-emitting diodes exhibit the NIR emissions respectively peaked at 684 nm and 700 nm, corresponding to Commission International de L'Eclairage (CIE) coordinates of (0.68, 0.31) and (0.69, 0.30), respectively. Significantly, these two devices achieved the state-of-the-art external quantum efficiencies of 8.69% and 2.02%. [ABSTRACT FROM AUTHOR]

ABSTRACT A July-May precipitation reconstruction for the period AD 1816-2010 was developed from a tree-ring width chronology of Picea wilsonii for the Xinglong Mountains area of Lanzhou. The reconstruction explains 55.8% of the actual precipitation variance during the calibration period from 1951 to 2010. Wet conditions prevailed during the periods 1822-1835, 1843-1858, 1870-1877, 1884-1891, 1911-1921, 1933-1938, 1944-1979 and 2009-2010. Dry episodes occurred during 1816-1821, 1836-1842, 1859-1869, 1878-1883, 1892-1910, 1922-1932, 1939-1943 and 1980-2008. Multi-taper method spectral analysis indicates the existence of some significant peaks at 2.8, 3.0 and 3.5 years. Spatial correlations with gridded land surface precipitation data revealed that our reconstruction represents regional precipitation signal for a large area of North China linked to the East Asian summer monsoon (EASM). Comparison with other tree-ring-based precipitation/drought reconstructions from surrounding areas implies a high degree of confidence for our reconstruction. Precipitation variations in the study area are significantly correlated with sea surface temperatures in eastern equatorial Pacific Ocean and tropical western Pacific Ocean, suggesting a possible connection of regional precipitation variations to the EASM and the El Niño-Southern Oscillation (ENSO). [ABSTRACT FROM AUTHOR]

The graphitic carbon nitride (g-C 3 N 4 ), as one photocatalyst which possess the suitable band gap, is better for modified TiO 2 and enhanced photocatalytic degradation of organic pollutants. In this work, the g-C 3 N 4 /TiO 2 were successfully prepared via directly calcined the mixture of melamine and P25. The as-prepared g-C 3 N 4 /TiO 2 photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and high resolution electron microscopy (HRTEM), Raman and Fourier transform-infrared spectroscopy (FT-IR). The photocatalytic performances of g-C 3 N 4 /TiO 2 composites were investigated by degradation of ciprofloxacin. The results showed that the g-C 3 N 4 and P25 were successfully composited, and the bond of C–N was well formed, the calcined temperature for as-prepared photocatalysts and the ratio of melamine and P25 were important to the degradation rate of ciprofloxacin. When the mixture of melamine and P25 with 1:2, and calcined temperature at 600 °C, the degradation rate of ciprofloxacin could reach 95% in 60 min. The enhanced photocatalytic performances could be mainly attributed to the suitable band gap structure with heterojunction of CN-P25. Finally, the possible transferred processes of photoelectrons and photoholes were proposed. [ABSTRACT FROM AUTHOR]

Tea infusion is a colloidal system. As a first attempt to systematically characterize tea micro-nanoparticles, the effect of pH on colloidal properties of Lapsang souchong black tea infusion was investigated in this study. At the native pH 5 of black tea infusion, micro/nanoparticles were revealed by Cryo-TEM (Cryo-transmission electron microscopy) to be of a structure consisting of dominantly spherical polyphenol oxidase (PPO)-polyphenols complexes and surrounding linear polysaccharide chains with an average hydrodynamic diameter (D h) of 128 nm and ζ-potential of −23.7 mV. It is the first time to demonstrate the black tea micelle consists of spherical and fibrous nanostructures, possibly responding to protein and polysaccharides. Increasing pH resulted in a decrease in polyphenols content and the disassembling of the micro/nanostructure. On the other hand, the decrease of pH through their respective isoelectric points led to the formation of PPO-polyphenols complexes, polysaccharide aggregation, and further aggregations among different molecules and their complexes and a drastic increase in the precipitation when pH was lower than pH 5. The predominant effect of pH on colloidal properties of black tea infusion reveals an electrostatic nature of intramolecular and intermolecular interactions among PPO, polysaccharides and polyphenols. Those results provide new clues to a practical and effective quality control of black tea products as well as an insight into health benefits of black tea. • The black tea contains negatively charged NPs (Dh = 128 nm) at its native pH of 5. • Increasing pH induced the disassembly of the micro/nanostructure. • pH < 5, formation of complexes and precipitates was promoted. • Electrostatic interaction primarily defines the nanostructure. [ABSTRACT FROM AUTHOR]

Ginsenoside Rg1, a traditional Chinese medicine monomer, has been shown to have antidepressant effects. We previously found that Rg1 exerts antidepressant effects by improving the gap junction channels (GJCs) dysfunction; however, the downstream mechanisms through which Rg1 ameliorates GJC dysfunction remain unclear. Since hemichannels directly release glutamate, GJC dysfunction decreases the expression levels of glutamate transporters in astrocytes, and glutamatergic system dysfunction plays an essential role in the pathogenesis of depression. The glutamatergic system may be a potential downstream target of Rg1 that exerts antidepressant effects. Therefore, in this study, we aimed to determine the downstream mechanisms by which Rg1 ameliorated GJC dysfunction and exerted its antidepressant effects. Corticosterone (CORT) is used to mimic high glucocorticoid levels in patients with depression in vitro. Primary cortical astrocytes were isolated and phosphorylation of connexin43 (Cx43) as well as the functions of hemichannels, GJCs, and the glutamatergic system were evaluated after drug treatment. Rg1 pretreatment reversed the anomalous activation of Cx43 phosphorylation as well as the dysfunction of hemichannels, GJCs, and the glutamatergic system induced by CORT. These results suggest that Rg1 can ameliorate CORT-induced dysfunction of the glutamatergic system in astrocytes by potentially reducing Cx43 phosphorylation and inhibiting opening of hemichannels, thereby improving GJC dysfunction. [ABSTRACT FROM AUTHOR]

An ultra-compact Si-based beam splitter (BS) with footprint of 1 μm × 2 μm has been reported. It can split beams fifty–fifty with a 180-deg separation angle, and it is suit for integrated on a chip. It achieves high efficiency of 94.6% and 93.1% at wavelengths 1310 and 1550 nm, respectively, and more than 91% from 950 to 1600 nm. If Si is replaced with GaN or SiC in this device, it also can split the beam with high efficiency. Based on this, by means of replacing substrate material, different kinds of BSs for suitable wavebands can be fabricated in the same pipeline without changing mask template. This device has been designed by an intelligent method, which combines the method of moving asymptotes and the finite-element method, and GaN-based and SiO2-based BSs have been designed by this method for near-infrared and visible light, respectively. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a fuzzy self-adaptive digital audio watermarking method based on a time-spread echo hiding algorithm is proposed. Echo spreading is performed in the impulse response domain using PN sequences to achieve good robustness of echo hiding and high secrecy of spread spectrum. Fuzzy theory is employed in the embedding process to control the power of the watermark. Since fuzzy set theory is capable of performing complex nonlinear mappings between input and output spaces, it can effectively estimate the strength of a frame for each subband and ensure that the embedded watermark in the original audio is self-adaptive. A listening test and simulation results show that the algorithm is robust for common digital audio processing methods as attacks and that the quality of the audio is retained. [Copyright &y& Elsevier]

The hydrazone ligand, methyl‐2‐pyridyl ketone benzoyl hydrazone (L), and its complexes with rare earth nitrates have been synthesized. These new complexes with the general formula of Ln(L) 2 (NO 3 ) 3 · nH 2 O (where Ln=La, n=5.5; Ce, Pr, n=5; Nd, Eu, n=4) were characterized by mass spectra, elemental analysis, IR spectra, thermal analysis, UV spectra, molar conductivity, and luminescent spectra. All the complexes are stable in air. The results show that the lanthanide ions in each complex are coordinated through oxygen and nitrogen atoms of the ligand, the oxygen atoms of the nitrate, and coordinated water molecules. The amide‐oxygen atoms of L coordinate to the Ln ions in its keto‐form. Tentative structures for the complexes have been proposed. [ABSTRACT FROM AUTHOR]

This study aims to develop a simple, sensitive, low-cost, environmentally friendly and flexible surface-enhanced Raman scattering (SERS) platform, combined with a portable Raman spectrometer, for the rapid and on-site SERS detection of bacteria. Commercial tobacco packaging paper (TPP) with little background interference was used as a loading medium that effectively adsorbed Au nanoparticles and provided sufficient "hot spots". This Au-tobacco packaging paper (Au-TPP) substrate used as a flexible SERS platform can maximize sample collection by wiping irregular surfaces, and was successfully applied to the on-site and rapid detection of pathogenic bacteria. Raman fingerprints of pathogenic bacteria can be obtained by SERS detection of spiked pork using wipeable Au-TPP, which verifies its value in practical applications. The results collected by SERS were further verified by polymerase chain reaction (PCR) results. It showed several advantages in on-site SERS detection, including accurate discrimination, simple preparation, easy operation, good sensitivity, accuracy and reproducibility. This study indicates that the established flexible SERS platform has good practical applications in pathogenic bacterial identification and other rapid detections. [ABSTRACT FROM AUTHOR]

Cloud and snow in remote sensing images typically block the underlying surface information and interfere with the extraction of available information, so detecting cloud and snow becomes a critical problem in remotely sensed image processing. The current methods for detecting clouds and snow are susceptible to interference from complex background, making it difficult to recover cloud edge details and causing missing and false detection phenomena. To address these issues, a cross-dimensional feature attention aggregation network is suggested to realize the segmentation of clouds and snow. To address the problem of interference induced by the similar spectral characteristics of clouds and snow, the context attention aggregation module is added to conflate feature maps of various dimensions and screen the information. Multi-scale strip convolution module (MSSCM) and its improved version MSSCMs are used to extract edge characteristics at different scales and improve the harsh segmentation border. Also, adding deep feature semantic information extraction module to deep features to guide the classification of the model to avoid the interference of complex background. Finally, a 'los beatles' module is used to replace the traditional linear combination in the decoding stage, and the feature information of different granularity is fused and extracted to enhance the model's detection efficiency. In this paper, experiments are carried out on the public datasets: CSWV, HRC _ WHU and L8 _ SPARCS. The MIOU scores on the three datasets are 89.507 % , 91.674 % and 80.722 % , respectively. Comparative experiment findings demonstrate that the network presented in this article can attain the highest detection accuracy and good detection efficiency with low parameters. [ABSTRACT FROM AUTHOR]

• Synthesis 2,3-dihydropyrroles by the photochemical ring contraction. • The chiralities of 2,3-dihydropyrroles and 1,4-dihydropyridines have stereoconvergence. • Readily available starting materials, metal-free and easy to handle procedures. Strategies by introducing chiral auxiliaries into the photoreactive substrate 1,4-dihydropyridines, an interesting diastereoselectivity of 2,3-dihydropyrroles in the process of photochemical ring contraction was observed. The diastereoselectivity of (2 R ,3 R) and (2 S ,3 S)-2,3-dihydropyrroles was related to the phenyl group and the chirality of C-4 in 1,4-dihydropyridines and similar to that of 1,4-dihydropyridines. The yields and diastereomeric excess of all obtained products supporting the experimental data were compared and discussed in theoretical calculations. A concise theoretical study was used to explain the diastereoselectivity observed in the photochemical ring contraction of 1,4-dihydropyridines to 2,3-dihydropyrroles. [ABSTRACT FROM AUTHOR]

• This study analyzed the spatiotemporal influence of drivers to vegetation variation. • Identify the effects of vegetation variation on different soil erosion types. • We provide a driver-pattern-effect connection of vegetation variation. Vegetation is at the nexus of water, soil, and the atmosphere, making it a significant indicator of climatic variability and shifts in human activity. The spatial attribution analysis of vegetation changes may help us to identify and estimate the relationship between variation in vegetation and different erosion types, and their correspondence may be in the antecedents and consequences of vegetation dynamics. Here, based on time series datasets for the Bashang Plateau and northern North China's mountainous region from 1998 to 2015, we used trend analysis, partial correlation analysis, and univariate linear regression to investigate the sustainability of vegetation variations and to determine the driving mechanisms of climatic and anthropogenic factors in vegetation dynamics at the regional scale. Further, we applied correlation analysis and models (i.e., USLE and RWEQ) to detect the spatial heterogeneity of soil erosion dynamics and the effects of vegetation coverage variation on the dynamics of water erosion, wind erosion, and wind-water erosion. Our results revealed a significant increasing trend in Normalized Difference Vegetation Index (NDVI) and the improved area accounted for more than 80% of the study area. The response of vegetation variation to climatic factors displayed a high correlation with precipitation for a 1-month lag in the semi-humid area, especially in forestland, and with temperature for a 0-month lag in the semi-arid area, particularly in farmland. These results suggest human activity has had a greater effect on vegetation variations than climatic factors during 2011–2015, and that human activity was the dominant factor controlling vegetation changes in terms of the spatial distribution of major drivers; notably, the implementation of the vegetation restoration projects affected the spatiotemporal patterns of vegetation cover. During 1998–2015, the increased vegetation coverage played a dominant role in reducing water erosion of the forestland, and it had a vital impact on lessening wind erosion in open land and sparsely vegetated areas, while the increased fractional vegetation coverage (FVC) may have been a contributing factor to aggravated soil erosion in the wind-water erosion zone of grassland and forestland. Hence, the importance of the implementation of revegetation projects on soil erosion reduction should not be underestimated. [ABSTRACT FROM AUTHOR]

• Four types of ZIF-8 polyhedral carbons were successfully synthesized. • ZIF-8/C-R2 exhibited high reversible capacity and excellent rate capability compared to other three ZIF-8/C polyhedrons. • Vertices and edges provide more lithium-ion storage sites. • ZIF-8/C-R2 with more vertices and edges has structural advantages to accelerate the transport of lithium-ions. Polyhedral carbons from zeolitic imidazolate frameworks (ZIFs) have been studied as anode materials for lithium-ion batteries, because their topological feature enabled ideal research objects. However, the similarities and differences of lithium-ion storage behavior between ZIFs polyhedral carbons have not been systematically studied. Here we synthesized four kinds of ZIF-8 polyhedral carbons, including cubes (ZIF-8/C-C), small rhombicuboctahedrons (ZIF-8/C-R1), large rhombicuboctahedrons (ZIF-8/C-R2) and dodecahedrons (ZIF-8/C-D), and well-studied their storage behavior. The as-made ZIF-8/C-R2 with 24 vertexes and 48 edges exhibited superior electrochemical performance (657 mAh g−1 at 0.1 A g−1) compared to other ZIF-8/C polyhedrons with less vertexes and edges. In situ TEM was employed to observe the lithiation process of various ZIF-8/C polyhedrons, showing that the solid electrolyte interface films were initiated to form at the vertex sites followed by the edges, which indicates that it is reasonable to design advanced polyhedral electrode materials with abundant vertexes and edges by applying Euler's formula. [ABSTRACT FROM AUTHOR]

Thermal comfort evaluations in the built environment are essential to occupant's satisfaction and also building energy consumption. Traditionally, thermal comfort has been assessed by Fanger's PMV model that was developed based on extensive laboratory tests. However, it's been found that PMV predictions are not good in field studies, especially in buildings with natural ventilation. In this paper, machine learning (ML) algorithms were used to predicted occupants' thermal comfort votes (TCV) and thermal sensation votes (TSV), using 5512 sets of thermal comfort data collected in naturally ventilated residential buildings in fourteen cities in China. Environmental parameters, personal parameters, climatic types, and adaptive control measures were considered and used as input parameters for the ML model. It was found that environmental parameters (both outdoors and indoors), personal parameters (metabolic rate and clothing insulation), and climatic types all significant affect both TCV and TSV, while adaptive control measures only affect TSV but not TCV. Comparing with established models (PMV, ePMV and aPMV), the ML models had smaller errors in predicting TSV and TCV. Based on these results, we suggest that the ML, especially ANNs model was reliable in predicting occupants' TCV and TSV in naturally ventilated residential buildings, and performed better than traditional thermal balance based models. Moreover, using the new model, we found that acceptable temperature ranges in naturally ventilated buildings were far wider than the ASHRAE adaptive comfort zone, suggesting that appropriate models should be established based on local data. [ABSTRACT FROM AUTHOR]

In this manuscript, is addressed the computational prediction of five new allotropes based on the Squaroglitter structure (t P8 carbon). DFT calculations of t P12, t P16, t P24, o P12 and o P18 allotropes attest their nanotube and cage type. It is determined that they display dynamical and mechanical stability. Regarding the mechanical stability, the calculated values of the shear modulo and Young's moduli of tP167 and oP12 structures are greater than value depicted by the Squaroglitter. Although in general the studied structures, have a smaller mechanical anisotropy in their Young's modulus when compared against the parent structure. In addition, the tP16 structure has a direct band gap of circa 1.61 eV. [ABSTRACT FROM AUTHOR]

• The g-C 3 N 4 /7Ag/m-CeO 2 composite photocatalyst was successfully synthesized. • The introduction of g-C 3 N 4 nanosheets alleviated the photocorrosion of Ag. • The g-C 3 N 4 /7Ag/m-CeO 2 exhibits higher activity for CO 2 photoconversion. In this work, the ordered mesoporous CeO 2 (m-CeO 2) was successfully fabricated via the nanocasting pathway, through using SBA-15 as a hard template. Besides, g-C 3 N 4 /Ag/m-CeO 2 composite was successfully constructed by calcination method. Meanwhile, the obtained samples were investigated by series of test techniques. The XRD, SEM and TEM results show that the m-CeO 2 and Ag/m-CeO 2 with the ordered mesoporous trait. Besides, the EPR, Raman and XPS results suggest that the oxygen vacancies (O v) and Ce3+ and Ce4+ are in g-C 3 N 4 /Ag/m-CeO 2. In addition, the ordered mesostructure is favorable for the CO 2 molecular movement and adsorption/desorption reaction. The g-C 3 N 4 nanosheets, a promising material possessing suitable conductor band, large specific area, non-toxicity, and outstanding chemical stability, is a candidate semiconductor for CO 2 conversion. The introduction of g-C 3 N 4 nanosheets to Ag/m-CeO 2 overcomes the photocorrosion of Ag nanoparticles and Ag facilitate the transfer of photogenerated electrons. The photocatalytic activity results show that when the loading of Ag is 7 wt%, the g-C 3 N 4 /7Ag/m-CeO 2 composite exhibits the superiority activity for CO 2 photoconversion to CO (13.94 μmol/g) and CH 4 (7.39 μmol/g) under UV-irradiation in 10 h. [ABSTRACT FROM AUTHOR]

• MgZnO:F films with high Mg content were synthesized by RF magnetron co-sputtering. • Structural, electrical and optical properties of the films were investigated. • F occupied O sites, decreased the resistivity without reducing optical loss. • Low resistivity and high carrier concentration were simultaneously realized. Fluorine-doped Mg 0.21 Zn 0.79 O (MZO:F) thin films were successfully deposited on glass substrates at room temperature by radio frequency (RF) magnetron co-sputtering method with Mg 0.21 Zn 0.79 O, MgF 2 , and ZnF 2 targets. Low resistivity (1.26 × 10-1 Ω⋅cm), high Hall mobility (3.55 cm2/Vs) and high carrier concentration (1.39 × 1019 cm−3) were simultaneously realized in the annealed MZO:F film. The effects of doping concentration and annealing temperature on the structural, morphological, electronic, electrical and optical properties of MZO:F films were systematically investigated in this study. XRD and XPS analysis confirmed that F atoms have entered into crystal lattices of MZO and acted as donors when they occupied O sites in the hexagonal lattice. Moreover, it was observed that both doping concentration and annealing temperature greatly affected the crystallinity, grain size, growth orientation and surface morphology of the MZO:F thin films. In addition, the optical gap changed dramatically with the F content and annealing temperature, which could be attribute to the Burstein-Moss effect accompanied by the effects of fluctuating potential arising from the randomly situated impurities. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2) modified g-C 3 N 4 for composite photocatalysts were fabricated by using ball-milling and calcination. The physicochemical properties of as-obtained photocatalysts were characterized by XRD, XPS, SEM, TEM, UV–vis DRS, PL and Photocurrents. The results show that the heterostructure successfully formed between TiO 2 and C 3 N 4 , and the heterostructure could effectively enhance the separation rate of the photogenerated electrons and holes. Also the positions of conduction band (CB) and valence band (VB) changed with improving the amount of TiO 2 in the as-prepared photocatalysts. The photocatalytic activities of as-prepared photocatalysts were investigated by photoreduction of CO 2 , the results exhibit that the composite photocatalysts clearly improve the photoreduction of CO 2 to CH 4 and CO. The highest yields of CH 4 and CO are of 72.2 and 56.2 μmol g−1 at an optimized modified amounts of TiO 2 under 4 h irradiation of 8 W UV lamp, respectively. The strategy of TiO 2 modified C 3 N 4 could successfully obtain effective photocatalyst for CO 2 conversion. Image 1056065 • TiO 2 modified g-C 3 N 4 composite photocatalysts were fabricated by using ball-milling method and calcination. • The positions of conduction band (CB) and valence band (VB) changed with improving the amount of TiO 2 in the composite photocatalysts. • The composite photocatalysts clearly improve the photoreduction of CO 2 to CH 4 and CO. [ABSTRACT FROM AUTHOR]