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A condition-controlled strategy for selectively synthesis of 2-acylbenzothiazoles and bibenzo[b][1,4]thiazines from aryl methyl ketones and disulfanediyldianilines was realized using I2/DMSO or I2/MeCN systems, respectively. The desired products were synthesized in only 15 min with moderate to excellent yields (50%-90%) under microwave-assisted, metal-free conditions. The strategy provides a great advantage for selective synthetic applications in the efficient synthesis of benzothiazoles and bibenzothiazines heterocycle compounds.

It is established that ultrathin layered double hydroxide nanosheets (LDHNS) and zeolitic imidazole frameworks (ZIF) are desirable electrochemical sensing modifiers owing to their large surface area and abundant catalytic sites. Integration of them is thus an effective solution to maximize their electrocatalytic activity. Herein, a novel reaction–diffusion framework (RDF) technique is applied for the in situ growth of ZIF-67 on ultrathin CoAl-LDHNS (CoAl-LDHNS@ZIF-67). In a confined space of the agar gel matrix of RDF, the coordination reaction between organic ligands and CoAl-LDHNS without an additional Co2+ source achieves the controllable growth of ZIF-67 crystals through a long vertical diffusion. The prepared composite comprises both CoAl-LDHNS and ZIF-67 components with a certain ratio and provides a large surface area and amply catalytic sites, thus realizing a rapid transfer of electron and mass. The CoAl-LDHNS@ZIF-67 modified electrode is employed for the simultaneous detection of naphthol isomers by differential pulse voltammetry. Naphthol isomers display anodic reactions with a wide peak potential difference, allowing their simultaneous detection feasible. Voltammetric responses of α-naphthol and β-naphthol follow good linearity against the concentration in a wide range from 0.3 to 150 μM with limits of detection of 54 and 82 nM, respectively. The proposed sensor also demonstrates excellent selectivity, stability, reproducibility, and practicability for the simultaneous detection of naphthol isomers.

In ceramic/metal brazing, high residual stress usually causes fracture in the ceramic substrates. Therefore, composite fillers consisting of ductile matrix featuring low yield strength and elastic modulus, as well as reinforcements featuring low coefficient of thermal expansion (CTE), are employed. However, for AgCuTi-base composite fillers, the reinforcements are likely to weaken the deformability of brazing seams (BS), i.e. increase the elastic modulus and yield stress of BS. To address this issue, we developed a new AgCu-base composite filler with “hedgehog-like” reinforcement clusters. Herein, AgCu + NbB2 composite filler was used to braze ZrB2–SiC and TC4-TiBw, wherein ductile Ag(s,s) and Cu(s,s) dominated BS, thereby ensuring high deformability; in addition, a NbB layer along with limited TiB whiskers was formed at the NbB2/brazes interface with the orientation relationship of (-11-1)NbB//(0-1-1)TiB and [-314]NbB//[12-2]TiB, resulting in “hedgehog-like” reinforcement clusters. This structure exhibited the following advantages: (i) crystallographic misfit at the interface of reinforcement clusters/brazes and the controlled formation of TiB whiskers minimised the conventional fine grain strengthening and dispersion strengthening effects of BS; (ii) isolated reinforcement clusters decelerated the increase in the elastic property of BS; (iii) “hedgehog-like” structure absorbed fracture energy by deflecting cracks; and (iv) the formation of brittle compounds could be avoided. In other words, the designed reinforcement clusters reduced the deformability expense and compensated for the mechanical-resistance of BS. Therefore, the maximum joint strength was obtained with 2 wt% NbB2, which increased the shear strength of the joint six times compared to that with 0 wt% NbB2. For the joints failing inside ceramic substrates, (i) the key factor for limiting joint strength was the residual stress inside ceramics and (ii) the remission of the trade-off between thermal expansion mismatch and deformability expense contributed to relaxing residual stress, thereby confirming the reliability of our design.

Ti3C2Tx exhibits excellent electromagnetic (EM) shielding and electrochemical properties. However, the inherent re-stacking tendency and easy oxidation of Ti3C2Tx limit its further application. In this study, a multi-walled carbon nanotube/polyaniline composite (CNT/PANI, denoted as C–P) was introduced into Ti3C2Tx nanosheets to obtain a Ti3C2Tx–CNT/PANI composite (T@CP). Owing to the integrated effects of Ti3C2Tx and C–P, the contribution of absorption was significantly improved, which finally enhanced the EM shielding performance of T@CP. The highest total EM shielding effectiveness (SET) was close to 50 dB (49.8 dB), which was substantially higher than that of pure Ti3C2Tx (45.3 dB). Moreover, T@CP demonstrated outstanding supercapacitive performance. The specific capacitance of T@CP (2134.5 mF/cm2 at 2 mV/s) was considerably higher than that of pure Ti3C2Tx (414.3 mF/cm2 at 2 mV/s). These findings provide a new route for the development of high-efficiency Ti3C2Tx-based bifunctional EM shielding and electrochemical materials.

The erosion of soluble rock and transformation of groundwater result in the high geometrical irregularity of cavities in nature. The purpose of this paper is to quantitatively describe the shape of irregular cavities using Fourier transform analysis. Firstly, multi-level characterization indexes of the 2D section of cavities have been proposed, considering the high shape irregularity of cavities. The first level indexes include Shape Factor (SF), Aspect Ratio (AR) and Sphere Like (SL). The second level indexes consist of Angularity Factor (AF) and Convexity Factor (CF). The third level indexes are Roundness Factor (RF). Then, the geometric contour of cavity was transformed into a 2D waveform, with an equal-angle points sampling of the cavity boundary. The geometric boundary of irregular cavity was segmented and transformed from discrete time domain to frequency domain based on discrete Fourier transform (DFT). Furthermore, we proposed Fourier shape descriptor, which was found to control the cavity shape. The relationship between Fourier shape descriptors in different sequences and multi-level characterization indexes was determined using designed and irregular nature cavities as sample data. The results demonstrated that the Fourier shape descriptors​ D 2 , D 3 and D 8 mainly control multi-level characterization indexes including the overall shape, the irregularity and the roughness of the cavity boundary, respectively. Finally, the 3D characterization method of cavity shape was further proposed based on averaging the 2D sections, which hence offers a possible way to further quantitatively study the mechanical properties of surrounding rockmass effected by the irregular shape of cavities.

The SiCf/SiC composites/Ni-based superalloys dissimilar joining encountered the problem of huge thermal mismatch and uncontrollable interfacial reactions. Two novel composite fillers were designed for the dissimilar joining. An AuCuTi/Mo/AuCuTi filler enabled a complete hindrance on the atomic exchange by a 50 μm Mo interlayer and an effective stress relief by multiple layers of the ductile (Au, Cu) solid solution and rigid Mo insert. Furthermore, the addition of B introduced an extra dimensionality to control the diffusion of interstitial atoms (Ni, Cr, and Si) and some TiB whispers to add extra nucleation sites for the Ni-compounds, by which way an easier and more accurate method to control the distribution of metallic atoms were obtained. The load-carrying of joints increased by 17.7% when using an AuCuTiB/Mo/AuCuTiB filler, because of the distribution of intermetallic compounds was homogenized and fined, and the interfacial region changed from Ti3SiC2 to TiC + Ni-compounds.

Triple negative breast cancer (TNBC) is one of the most malignant subtypes of breast cancer. Here, we report the construction of graphene nanoribbon (GNR)-based supramolecular ensembles with dual-receptor (mannose and αvβ3 integrin receptors) targeting function, denoted as GNR-Man/PRGD, for targeted photothermal treatment (PTT) of TNBC. The GNR-Man/PRGD ensembles were constructed through the solution-based self-assembly of mannose-grafted GNRs (GNR-Man) with a pyrene-tagged αvβ3 integrin ligand (PRGD). Enhanced PTT efficacies were achieved both in vitro and in vivo compared to that of the non-targeting equivalents. Tumor-bearing live mice were administered (tail vein) with GNR-Man/PRGD and then each mice group was subjected to PTT. Remarkably, GNR-Man/PRGD induced complete ablation of the solid tumors, and no tumor regrowth was observed over a period of 15 days. This study demonstrates a new and promising platform for the development of photothermal nanomaterials for targeted tumor therapy., Dual receptor-targeting supramolecular glycomaterials are constructed based on graphene nanoribbons for the targeted photothermal therapy of triple-negative breast cancer in vivo.

Assimilating Sentinel-2 images with the CERES-Wheat model can improve the precision of winter wheat yield estimates at a regional scale. To verify this method, we applied the ensemble Kalman filter (EnKF) to assimilate the leaf area index (LAI) derived from Sentinel-2 data and simulated by the CERES-Wheat model. From this, we obtained the assimilated daily LAI during the growth stage of winter wheat across three counties located in the southeast of the Loess Plateau in China: Xiangfen, Xinjiang, and Wenxi. We assigned LAI weights at different growth stages by comparing the improved analytic hierarchy method, the entropy method, and the normalized combination weighting method, and constructed a yield estimation model with the measurements to accurately estimate the yield of winter wheat. We found that the changes of assimilated LAI during the growth stage of winter wheat strongly agreed with the simulated LAI. With the correction of the derived LAI from the Sentinel-2 images, the LAI from the green-up stage to the heading–filling stage was enhanced, while the LAI decrease from the milking stage was slowed down, which was more in line with the actual changes of LAI for winter wheat. We also compared the simulated and derived LAI and found the assimilated LAI had reduced the root mean square error (RMSE) by 0.43 and 0.29 m2 m−2, respectively, based on the measured LAI. The assimilation improved the estimation accuracy of the LAI time series. The highest determination coefficient (R2) was 0.8627 and the lowest RMSE was 472.92 kg ha−1 in the regression of the yields estimated by the normalized weighted assimilated LAI method and measurements. The relative error of the estimated yield of winter wheat in the study counties was less than 1%, suggesting that Sentinel-2 data with high spatial-temporal resolution can be assimilated with the CERES-Wheat model to obtain more accurate regional yield estimates.

Formic acid intercalated Mg-Al layered double hydroxide (Mg-Al Fo-LDH) was prepared by calcination reduction intercalation assembly technology. The structure of the deicing additive was characterized by fourier transform infrared (FTIR) and X-ray diffraction (XRD). The freezing point of aqueous solution with different quality of deicing additive and the surface freezing point and adhesion of asphalt mixture were tested. The results show that formic acid ion has been intercalated into the interlayer of Mg-Al layered double hydroxide by FTIR and XRD patterns. The freezing point of 5wt% Mg-Al Fo-LDH aqueous solution reaches -9.32 °C, while the surface freezing point of the asphalt mixture mixed with 5wt% Mg-Al Fo-LDH is -6.5°C. At -8 °C, the adhesion force of the surface ice layer is 78.4N, and after the asphalt mixture is soaked in water, the surface freezing point and adhesion force of the ice layer do not change.

Nowadays, there is much attention focusing on lead halide perovskite because of its admirable performances in optoelectronic applications. However, the notorious toxicity and long-term instability are two main factors limiting its widespread applications. The findings of this work demonstrate a facile synthesis process for novel lead-free CsAgCl2 perovskite microcrystals with no organic ligand involved. The fundamental properties of the CsAgCl2 microcrystals are revealed by applying temperature-dependent X-ray diffraction and photoluminescence measurements from 77 to 300 K. Furthermore, the CsAgCl2 microcrystals exhibit excellent air (60 days), thermal (100 °C), and light stability. Meanwhile, the CsAgCl2 microcrystals have shown exciting potential applications in the fields of photocatalysis and photoelectrochemistry.

Surface-enhanced Raman scattering (SERS) substrates based on graphene and its derivatives have recently attracted attention among those interested in the detection of trace molecules; however, these substrates generally show poor uniformity, an unsatisfactory enhancement factor, and require a complex fabrication process. Herein, we design and fabricate three-dimensional (3D) graphene/silicon (3D-Gr/Si) heterojunction SERS substrates to detect various types of molecules. Notably, the detection limit of 3D-Gr/Si can reach 10-10 M for rhodamine 6G (R6G) and rhodamine B (RB), 10-7 M for crystal violet (CRV), copper(II) phthalocyanine (CuPc), and methylene blue (MB), 10-8 M for dopamine (DA), 10-6 M for bovine serum albumin (BSA), and 10-5 M for melamine (Mel), which is superior to most reported graphene-based SERS substrates. Besides, the proposed 3D-Gr/Si heterojunction SERS substrates can achieve a high uniformity with relative standard deviations (RSDs) of less than 5%. Moreover, the 3D-Gr/Si SERS substrates are reusable after washing with ethyl alcohol to remove the adsorbed molecules. These excellent SERS performances are attributed to the novel 3D structure and abundantly exposed atomically thin edges, which facilitate charge transfer between 3D-Gr and probe molecules. We believe that the 3D-Gr/Si heterojunction SERS substrates offer potential for practical applications in biochemical molecule detection and provide insight into the design of high-performance SERS substrates.

The co-production of ethylene glycol and methanol via ethylene carbonate hydrogenation derived from CO2 has attracted great concerns because of the promising chemical utilization of CO2 in large-scale. Copper-based catalysts are widely concerned in hydrogenation of ester due to the high catalytic efficiency and low cost, but the stability of copper-based catalyst is poor and needs to be further improved. In this study, the modification Cu–C@SiO2-R catalyst with graphite oxide was prepared by using Cu3(BTC)2 as the precursor and ammonia evaporation method, and was applied in ethylene carbonate hydrogenation to synthesis ethylene glycol and methanol. Furthermore, the catalysts were characterized in detail. The results showed that the Cu–C@SiO2-R catalyst was modified with graphite oxide, the average size of Cu particles was 2.9 nm and Cu particles had good dispersion. In addition, both Cu–C@SiO2-R and Cu@SiO2-R catalysts had similar ratio of Cu+/(Cu0+Cu+). In a batch reactor, under 453 K, 5 MPa, 4 h, the catalytic efficiency was 80.0% EC conversion 92.2% EG and 70.8% MeOH selectivity showing excellent catalytic performance capability of Cu–C@SiO2-R catalyst. In long-term experiment, the Cu–C@SiO2-R catalyst showed excellent stability after using for 264 h. The activity was 0.63 gEC gcat−1 h−1, and 100.0% EC conversion 99.9% EG and 85.8% MeOH selectivity could be achieved in a fixed bed. After the long-term experiment, the Cu+/(Cu++Cu0) ratio in Cu–C@SiO2-R catalyst kept at around 0.48. In contrast, the Cu+/(Cu++Cu0) ratio in Cu@SiO2-R catalyst decreased sharply from 0.48 to 0.38. The stability of the structure and the balance of valence of Cu were considered to be responsible to the stability of Cu–C@SiO2-R catalyst, because the graphite oxide not only kept the Cu+/(Cu0+Cu+) ratio stability, but also restrained the aggregation of Cu particles and loss of copper. This work provides an in-depth understanding of the stabilization mechanism of Cu and can be a reference for the industrial application of ethylene carbonate hydrogenation.

Background Effective soybean seed phenotyping demands large-scale accurate quantities of morphological parameters. The traditional manual acquisition of soybean seed morphological phenotype information is error-prone, and time-consuming, which is not feasible for large-scale collection. The segmentation of individual soybean seed is the prerequisite step for obtaining phenotypic traits such as seed length and seed width. Nevertheless, traditional image-based methods for obtaining high-throughput soybean seed phenotype are not robust and practical. Although deep learning-based algorithms can achieve accurate training and strong generalization capabilities, it requires a large amount of ground truth data which is often the limitation step. Results We showed a novel synthetic image generation and augmentation method based on domain randomization. We synthesized a plenty of labeled image dataset automatedly by our method to train instance segmentation network for high throughput soybean seeds segmentation. It can pronouncedly decrease the cost of manual annotation and facilitate the preparation of training dataset. And the convolutional neural network can be purely trained by our synthetic image dataset to achieve a good performance. In the process of training Mask R-CNN, we proposed a transfer learning method which can reduce the computing costs significantly by finetuning the pre-trained model weights. We demonstrated the robustness and generalization ability of our method by analyzing the result of synthetic test datasets with different resolution and the real-world soybean seeds test dataset. Conclusion The experimental results show that the proposed method realized the effective segmentation of individual soybean seed and the efficient calculation of the morphological parameters of each seed and it is practical to use this approach for high-throughput objects instance segmentation and high-throughput seeds phenotyping.

Bismuth-borate glass, 40Bi2O3–60B2O3 (mol.%), was prepared and acted as a braze to join sapphire in air. Ahead of brazing, basic properties of glass were investigated, including structure and thermal parameters. The thermal expansion test showed that CTE of glass was 8.4 × 10−6/°C in period from 20 to 450 °C, suggesting a good thermal compatibility with sapphire. Bi45BO69 was the main crystalline phase in glass according to DSC analysis [BiO6], [BO3] and [BO4] were major units in 40Bi2O3–60B2O3 glass on the basis of FT-IR spectra analysis. In addition, the wetting behavior of the 40Bi2O3–60B2O3 glass on the sapphire substrate was favourable. Thereafter, sapphire plates were joined at 700 °C for 0 and 20 min, respectively. The results showed that Al4B2O9 whiskers grew in joint when holding for 20 min due to a reaction between 40Bi2O3–60B2O3 glass braze and sapphire. The shear strength was improved greatly as a result of Al4B2O9 whiskers’ appearance.

A new Au-Cu-Ti filler featuring superior mechanical properties was developed to enable the brazing of a SiCf/SiC composite (CMCs) to itself and a Ni-based superalloy (GH536). The progression of the interfacial reactions was studied using a combination of thermodynamic calculations and experimental observations. It was found that the interfacial reaction was Ti-dominant at the early brazing stage and then gradually transformed to Ni-dominant with the continuous dissolution of the GH536 substrate. Thus, the typical microstructure of GH536/Ti-Ni-Cr-Fe+(Au, Cu)ss + MoNiSi/Ni-Cr-Fe-Si-C (Ni2Si + Fe2Si + Cr3C2)+(Au, Cu)ss/Ni2Si + TiC+(Au, Cu)ss/ Cr3C2+Ni2Si + TiC + Fe2Si/CMCs could be described by the following three stages: a Ti-dominated stage, full interdiffusion stage, and Ni-dominated stage. A maximum shear strength of 36 MPa was obtained for joints brazed at 1050℃ for 10 min, at which a failure occurred at the CMCs/brazing seam interface. The control of the interfacial reactions and the stress relaxation of (Au, Cu)ss contributed to the superior mechanical performance of the composite.

Joining of Y3Al5O12 garnet single crystal (YAG) was achieved by using a bismuth-borate based glass filler. The thermal properties of glass filler were experimentally determined and the wettability of molten glass on YAG was investigated. The YAG reacted with glass to form ZnAl2O4 particles and Y2O3 nanowires successively as joining temperature is above 625℃. ZnAl2O4 preferentially nucleated and grew on Y2O3 nanowires. The cooperative growth of the two phases accelerated YAG decomposition, which in turn led to cluster growth of Y2O3 nanowires and aggregation of ZnAl2O4 particles at elevated temperature. The microstructure evolution and reaction mechanism were studied. The highest shear strength of 29.6 ± 5.2 MPa was obtained for the joint brazed at 650℃. The fracture morphology demonstrated that the dispersive strengthening of ZnAl2O4 and stress relief by Y2O3 nanowire network contributed to the superior mechanical performance.

Tree mortality models play an important role in predicting tree growth and yield, but existing mortality models for Larix gmelinii subsp. principis-rupprechtii, an important species used for regeneration and afforestation in northern China, have overlooked potential regional influences on tree mortality. This study used data acquired from 102 temporary sample plots (TSPs) in natural stands of Prince Rupprecht larch in the state-owned Guandi Mountain Forest (n = 67) and state-owned Boqiang Forest (n = 35) in northern China. To model stand-level tree mortality, we compared seven model forms of county data. Three continuous (dominant height, plot mean diameter, and basal area per hectare) and one dummy variable with two levels (region) were used as fixed effects variables. Tree morality variations caused by forest blocks were accounted for using forest blocks as a random effect in selected models. Results showed that tree mortality significantly positively correlated with stand basal area and dominant height, but negatively correlated with stand mean diameter. Incorporating both the dummy variables and random effects into the tree mortality models significantly increased the fitting improvements, and Hurdle Poisson mixed-effects model showed the most attractive fit statistics (largest R2 and smallest RMSE) when employing leave-one-out cross-validation. These mixed-effects dummy variable models will be useful for accurately predicting Larix tree mortality in different regions.

Basic Oxygen Furnace (BOF) dust is a secondary resource with high total iron (TFe) content produced in metallurgical steelmaking process. It is the most economical way to recycle BOF dust by adding binders to prepare cold-bonded pellets and returning to BOF for steelmaking. Nevertheless, the digestion reaction of dead-burned MgO and CaO contained in BOF dust causes expansion and cracking of the pellets. Based on the hydration mechanism of nonhydraulic cementitious materials, it was first proposed to use the dead-burned MgO contained in BOF dust as a binder raw material, mixed with MgCl2 or KH2PO4 to form magnesium oxychloride (MOC) or magnesium potassium phosphate (MKP) binder to prepare cold-bonded pellets, while simultaneously consuming MgO and reducing the expansion stress generated by digestion reaction. In this paper, a comparative analysis of strength and bonding mechanism of the two binders is carried out to lay the foundation theory for their rational application. The results show that MKP and MOC binders are beneficial to improve the early and later strength of pellets respectively. The acicular 5 phase crystals formed by MOC binder have strong surface polarity and high bonding strength. They are interlocked to generate a network structure, which forms a unified whole with high strength after the dust particles are wrapped; the prismatic K-Struvite crystals formed by MKP binder have strong intermolecular force and high binder self-strength. They are embedded in the gaps between the dust particles and form solid bridges to improve the pellet strength.

We disclose herein a Au(I)-catalyzed domino cyclization of 1,6-diynes incorporated with indole. This protocol enabled the diastereoselective buildup of indole-fused azabicyclo[3.3.1]nonanes from linear precursors. Density functional theory calculations showed that the reaction proceeded via an unprecedented cascade dearomatization/rearomatization/dearomatization process. Independent gradient model analysis revealed that a noncovalent attractive interaction between the distal alkyne and the Au/proximal complex was responsible for the chemoselectivity of the first spirocyclization step.

Aphids are infected by a series of bacteria that can help them survive on specific host plants. However, the associations between aphids and these bacteria are not clear, and the bacterial communities in many aphid species are poorly characterized. Here, we investigated the bacterial communities of cotton aphids (Aphis gossypii) on 2 representative winter host plants and transferred to 3 summer host plants by 16S rDNA sequencing using the Illumina MiSeq platform. Our results revealed that the bacterial communities varied among cotton aphids on hibiscus, cotton aphids on pomegranate, cotton aphids on cotton transferred from hibiscus, cotton aphids on muskmelon transferred from hibiscus, cotton aphids on cucumber transferred from hibiscus,. The diversity and richness of the bacterial communities were significantly higher in aphids on muskmelon and aphids on cucumber than in the other treatments. There were two main factors influencing the distribution of internal bacterial OTUs revealed by principal component analysis, including the differences among Punicaceae, Malvaceae and Cucurbitaceae. There were 28 bacterial communities with significant differences between two arbitrary treatments, which could be grouped into 6 main clusters depending on relative abundance. Moreover, our results indicated that in addition to the obligate endosymbiont Buchnera, with a dominant position (> 52%), A. gossypii also harbored 3 facultative endosymbiotic bacteria (Serratia, Arsenophonus, and Wolbachia) and 3 possibly symbiotic bacteria (Acinetobacter, Pantoea, and Flavobacterium). There were several correspondences between the symbiotic bacteria in cotton aphids and the specific host plants of the aphids. This study provides a better understanding of the interactions among symbiotic bacteria, aphids and host plants, suggesting that the selection pressure on aphid bacterial communities is likely to be exerted by the species of host plants.

Uniform and fine in-situ short-fiber/particle hybrid reinforcements were obtained in a SiCf/SiC composite/Ni-based superalloy joint by using a novel AuCuTiB/Mo/AuCuTiB composite filler. The growth of in-situ phases showed a strong dependence on the numbers of nucleation sites and metal atoms on the ceramic side. Inadequate brazing conditions adversely affected the formation of indirect TiB whiskers, and excessive brazing conditions induced an accumulation of metal atoms. As a result, the in-situ phases switched from Ti5Si3 + TiC to Ti5Si3 + Ni + TiB + TiC, and to (Ni, Ti)-(Si, C) + TiB with increasing brazing conditions. The size, type, and composition of the in-situ phases were effectively controlled by adjusting the brazing conditions (B content, brazing temperature, and holding time). In light of this, the shear strength of the joint was optimized at 124.9 MPa. The excellent mechanical performance was ascribed to (i) a suitable interfacial layer and (ii) the effective stress relief of in-situ phases and ductile/rigid/ductile multiple layers. Moreover, the joint exhibited mechanical stability at 973 K because the in-situ phases can serve as a high-temperature resistant second structure.

This work reports on uniformly mingled nanostructures of Co3O4 and MnO2 deposited on a well-aligned electrospun carbon nanofiber (WA-ECNF) mat for rapid glucose electrooxidation and sensing. The hy...

Bovine intestinal heparins are structurally distinct from porcine intestinal heparins and exhibit lower specific anticoagulant activity (units/mg). The reduced content of N-sulfo, 3-O-sulfo glucosamine, the central and critical residue in heparin's antithrombin III binding site, is responsible for bovine intestinal heparin's reduced activity. Previous studies demonstrate that treatment of bovine intestinal heparin with 3-O-sulfotransferase in the presence of 3'-phosphoadenosine-5'-phosphosulfate afforded remodeled bovine heparin with an enhanced activity reaching the United States Pharmacopeia's requirements. Starting from this remodeled bovine intestinal heparin, we report the preparation of a bovine intestinal low molecular weight heparin having the same structural properties and anti-factor IIa and anti-factor Xa activities of Enoxaparin. Moreover, this bovine intestinal heparin-derived "Enoxaparin" showed comparable platelet factor-4 binding affinity, suggesting that it should exhibit similarly low levels of heparin induced thrombocytopeneia, HIT.

The ester functionality is commonly seen in the areas of chemical biology and medicinal chemistry for the design of cell‐permeable active molecules. Ester‐based pro‐drug/pro‐sensor strategies are employed to mask polar functional groups (i. e. carboxylic acids) and improve the overall cell permeability of these functional molecules. However, their use as reactive units for sensing applications, including bacterial detection, has not been fully explored. Herein, we synthesised two TCF‐based fluorescent probes, TCF‐OAc and TCF‐OBu. As expected, both TCF‐OAc and TCF‐OBu demonstrated a significant fluorescence (22‐ and 43‐fold, respectively) and colorimetric response (yellow to purple) towards porcine liver esterase (PLE) with a limit of detection of 1.18 mU/mL and 0.45 mU/mL, respectively. With these results in hand, the ability of these probes to detect planktonic suspensions of gram‐positive Staphylococcus aureus (S. aureus) and gram‐negative Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli) were evaluated. Different fluorescence responses for gram‐positive and gram‐negative bacteria were observed between TCF‐OAc and TCF‐OBu. After 1 h incubation, TCF‐OAc proved more sensitive towards S. aureus, demonstrating a significant fluorescence “turn on” response (16‐fold); whereas, TCF‐OBu was more selective towards P. aeruginosa, with a 22‐fold increase in the fluorescence response observed. These results demonstrate the influence of the ester chain length on the selectivity for bacterial species.

Nanographenes (NGs) are exceptionally hydrophobic. They are insoluble in water, preventing the exploration and utilization of their photophysical properties under aqueous conditions. This work discloses an atomically precise water-soluble synthetic NG 1, featuring a 2 nm sp2 carbon skeleton appended with 12 branched triethylene glycol chains. It synergistically combines low critical solution temperature (LCST) behavior and a photothermal effect to create the first thermo- and photo-responsive atomically precise NG functioning in an aqueous solution. The LCST behavior can be attributed to a delicate balance of hydrophobic-hydrophilic interactions, providing a sensitive thermal response to changes over a temperature range of physiological interest (close to 37 °C). Moreover, 1 has considerable photothermal conversion capability, with irradiation of 1 in water by red or near infrared light increasing the solutions temperature to above the clouding point within seconds, leading to a reversible clear-to-turbid transition over many cycles without evident fatigue.

Today, a growing number of third-generation semiconductor-based power devices are used in products that can continuously operate at high temperatures for extended periods of time. Hence, traditional tin-lead and lead-free solders are no longer suitable for modern electronic packaging. A common method is to apply Ag paste for bare Cu–Cu joints under an inert or reductive atmosphere. In this study, the citrate-coated nanosized Ag paste was utilized to generate robust bare Cu–Cu joints under atmospheric conditions. The average size of citrate-coated Ag particles was approximately 4.76 ​nm after being cleaned by deionized water and acetone. The effects of process parameters, such as cleaning, joining temperature, holding time, and joining pressure, on the mechanical properties of the bare Cu–Cu joints were thoroughly investigated. Increasing washing and joining temperatures resulted in a shear strength increase of up to 28.2 ​MPa ​at a joining temperature of 260 ​°C after seven washes. In addition, a holding time of 30 ​min and a joining pressure of 1 ​MPa were selected as optimal process conditions for the application of citrate-coated nanosized Ag paste onto bare Cu–Cu joints. The newly developed Cu–Cu joints showed excellent thermal stability at 150 ​°C using the citrate-coated nanosized Ag paste. After long-term aging, the joints exhibited stability at 250 ​°C for 144 ​h, indicating a good high-temperature reliability for three-dimensional integrated circuits (3D ICs) fabricated under atmospheric conditions.

A novel design of a multi-layered joint architecture, characterized by the controllable spatial distribution of ceramic reinforcements, was obtained, when brazing ZrB2-SiC ceramics and Ti-6Al-4 V reinforced by TiB whiskers with AgCu filler. To induce SiC reinforcements to cluster together, within the center of the filler and especially away from the ZrB2-SiC, SiC was added into joint, in the form of a SiC interlayer featuring a 3D-bridged network structure with continuous micro-channels infiltrated by capillary force by liquid filler during brazing. Different SiC particles were connected together, by micro-bridges being not destroyed during brazing. The layer rich in SiC could reduce thermal expansion mismatch between different substrates, the AgCu next to the ZrB2-SiC could relax the strain energy by high plastic deformation. Compared to joint brazed with single AgCu, joint strain energy decreased from 10.8 × 10−6 J to 8.6 × 10−6 J, accordingly joint shear strength increased from ∼5.4 MPa to ∼41.2 MPa.

This study focused on joining high volume fraction SiC particles reinforced aluminum matrix composites (55 vol% SiCp/Al) with 50SnO–20ZnO–30P2O5 (SZP) glass directly in air. Prior to joining, various properties of the SZP glass and its wettability on the composites were investigated. The results showed that the coefficient of thermal expansion of the glass was 10.58 × 10-6/°C (20–369 °C), which closely match with 55 vol% SiCp/Al composites. The glass transition, crystallization, and softening temperature were identified to be 369, 397, and 486 °C, respectively. Subsequent wetting tests confirmed excellent wettability of the glass on the composites. The joint exhibited sound bonding that was free of defects when brazed at 550 °C for 10 min Zn2P2O7 was formed adjacent to the composites due to the crystallization of the glass. The mechanical properties of the joint were proven to be suitable, exhibiting an average shear strength of 55.3 MPa.

The separation of ethylene glycol (EG) and 1,2-butanediol (1,2-BDO) azeotrope in the synthesis process of EG via coal and biomass is becoming of increasing commercial and environmental importance. Selective adsorption is deemed as the most promising methods because of energy saving and environment favorable. In this paper, NaY zeolite was used to separate 1,2-BDO from EG, and its adsorption properties was then investigated. The isotherms of EG and 1,2-BDO in vapor and liquid phases from 298 to 328 K indicated that they fitted Langmuir model quite well, and the NaY zeolite absorbent favored EG more than 1,2-BDO. The grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulation techniques were conducted to investigate the competition adsorption and diffusion characteristics in different adsorption regions. It was observed that EG and 1,2-BDO molecules all have the most probable locations of the center of the 12-membered ring near the Na cations. The diffusivities of EG are lower than those of 1,2-BDO at the same adsorption concentration. At last, the breakthrough curves of the binary mixture regressed from the empirical Dose-Response model in fixed-bed column showed that the adsorption selectivity of EG could reach to as high as 2.43, verified that the NaY zeolite could effectively separate EG from 1,2-BDO. This work is also helpful for further separation of other dihydric alcohol mixtures from coal and biomass fermentation.

The 2-methoxyiminoacyl-mediated arylation of substituted phenylalanines has been examined. Selective monoarylation at the ortho position was achieved using pyridone ligands which decelerate the arylation process. Density functional theory (DFT) study of a continuous C-H arylation process that included the first and second arylation stage was performed. The computational result shows that the introduction of a pyridone ligand obviously disfavors the second arylation stage, which directly contributes to the selectivity between the mono/diarylated products. Furthermore, results of the kinetic isotope effect and a control experiment are agreed with DFT study.

Obtaining surface albedo of high accuracy and analyzing spatial and temporal characteristics are essential for detecting change mechanism and influencing factors of surface albedo in deserts. Surface albedo from the Operational Land Imager (OLI) was assimilated into black-sky short-wave albedo (BSA) with an ensemble Kalman filter (EnKF) algorithm, to retrieve the surface albedo of high accuracy in Badain Jaran Desert. The results show that the average relative error decreases from 14.813% to 8.530% when surface albedo based on OLI is assimilated into BSA with the EnKF, and assimilated value can accurately describe the spatial and temporal distribution of surface albedo. The surface albedo has an obvious seasonal difference and presents a U-shape curve in a year, with the highest albedo in winter and lowest in summer. Owing to snow cover in some high-altitude areas, surface albedo is the highest and the spatial difference reaches maximum (variation coefficient=0.14) in winter. The Structure Similarity in surface albedo increases from the hinterland of desert (0.40–0.70) to the outer areas (0.70–0.90), as dune number decreases and distance between dunes increases. Compared with mobile and semi-mobile dunes, the minimum surface albedo of semi-fixed and fixed dunes postpones one month due to lag effect of the vegetation response to precipitation.

Amphiphilic phospholipid-iodinated polymer conjugates were designed and synthesized as new macromolecular probes for a highly radiopaque and biocompatible imaging technology. Bioconjugation of PEG 2000-phospholipids and iodinated polyesters by click chemistry created amphiphilic moieties with hydrophobic polyesters and hydrophilic PEG units, which allowed their self-assemblies into vesicles or spiked vesicles. More importantly, the conjugates exhibited high radiopacity and biocompatibility in in vitro X-ray and cell viability measurements. This new type of bioimaging contrast agent with a Mn value of 11 289 g mol-1 was found to have a significant X-ray signal at 3.13 mg mL-1 of iodine equivalent than baseline and no cytotoxicity after 48 hours incubation of with HEK and 3T3 cells at 20 μM (20 picomoles) concentration of conjugates per well. The potential of adopting the described macromolecular probes for bioimaging was demonstrated, which could further promote the development of a field-friendly and highly sensitive bioimaging contrast agent for point-of-care diagnostic applications.

Borate based glass, 25Bi2O3–75B2O3 (mol.%), was employed as a braze to join sapphire in an atmospheric environment. The crystallization behaviour as well as the crystallization kinetics of the glass during the heating process were investigated in a variety of ways. Wetting tests were conducted to research the wetting and spreading performances of the glass on the surface of sapphire prior to joining. Furthermore, sapphire joints were reliably obtained under various joining parameters. The dependence of the microstructural evolution and mechanical performance of sapphire joints on temperature and dwell time were also explored. The research results indicate that 25Bi2O3–75B2O3 glass possesses outstanding glass-forming ability and excellent wettability on the surface of sapphire. Bi6B10O24 crystalline phases were produced in the seam. The width of the joint as well as the quantity of Bi6B10O24 crystals increased at first and then decreased with the extension of dwell time. Simultaneously, the shear strength of the joints had a tendency to improve gradually and then diminish with the rise in brazing temperature. The maximum strength of the joints (49.3 MPa) was obtained by brazing at 700 °C for 20 min.

The Bi2O3–B2O3–SiO2–ZnO glass braze was used to bond the Yttrium iron garnet (YIG) ferrite. The (i) microstructure evolution and (ii) mechanical and dielectric properties of YIG/YIG joints were investigated. The results show that the bonding of YIG ferrite with Bi2O3–B2O3–SiO2–ZnO glass braze was effective at brazing temperature. There were nearly free of defects. At the YIG/glass interface, gray YBO3 whiskers, gray layered YBO3, and black block Fe2O3 phases were observed due to the reaction of the glass braze and YIG ferrite. As the brazing temperature or holding time increased, the gray layered YBO3 phase turned into YBO3 whisker gradually. This is because the B–O bonds of [B3O9] ring in the unit cell of the layered YBO3 are broken and evaluated to [BO4] in the cell of YBO3 whisker. The shear strength reached a maximum of 65 MPa for the joint brazed at 725 °C because of the enhancement effect of YBO3 whisker and Fe2O3 phases. The relative dielectric constant of the joint brazed at 700 °C was about 16, which was close to that of YIG ferrite. Moreover, the dielectric loss of this joint was about 0.005.

Alkaline phosphatase (ALP) is an important enzyme-based biomarker present in several bacterial species; however, it is currently undervalued as a strategy to detect pathogenic bacteria. Here, we explore our ALP-responsive colorimetric and fluorescent probe (TCF-ALP) for such applications. TCF-ALP displayed a colorimetric and fluorescence response towards Staphylococcus aureus (S. aureus), with a limit of detection of 3.7 × 106 CFU mL−1 after 24 h incubation. To our surprise, TCF-ALP proved selective towards Staphylococcus bacteria when compared with Enterococcus faecalis (E. faecalis), and Gram-negative P. aeruginosa and E. coli. Selectivity was also seen in clinically relevant S. aureus biofilms. Owing to the high prevalence and surface location of S. aureus in chronic wounds, TCF-ALP was subsequently encapsulated in polyvinyl alcohol (PVA)-based hydrogels as a proof-of-concept “smart” wound dressing. TCF-ALP hydrogels were capable of detecting S. aureus in planktonic and biofilm assays, and displayed a clear colour change from yellow to purple after 24 h incubation using ex vivo porcine skin models. Overall, TCF-ALP is a simple tool that requires no prior knowledge, training, or specialist equipment, and has the potential to overcome issues related to invasive swabbing and tissue biopsy methods. Thus, TCF-ALP could be used as a tool to monitor the early development of infection in a wound and allow for the rapid provision of appropriate treatment for Staphylococcal bacterial infections.

The wetting and brazing of Y3Fe5O12 (YIG) ceramics with a Ag–8CuO–2TiO2 filler was investigated for the first time. For comparison, the wettability of a Ag–10CuO filler on YIG ceramics was similarly investigated. The Ag–8CuO–2TiO2 filler has an equilibrium contact angle of approximately 31 °C on the YIG substrate at 1000 °C; thus, its wettability is excellent. Moreover, its wettability exceeds that of Ag–10CuO. The microstructure and the interfacial structure between the filler and the substrate were determined using scanning electron microscopy, X-ray diffraction, EPMA and transmission electron microscopy. The liquid Ag–8CuO–2TiO2 filler can react with the YIG substrate by forming continuous Y2Ti2O7 layers with dotted CuFe2O4 and promote the wetting behavior and bonding performance. The average shear strength could exceed 30 MPa for the joints at a brazing temperature of 1000 °C. As rupture occurred adjacent to the seam at the ceramic side, the strengths of the interfaces were characterized via nanoindentation. The hardness of the interface with doped TiO2 exceeds that of Ag–10CuO, which is strengthened by the dotted CuFe2O4 among Y2Ti2O7.

The key challenge of the photocatalytic technology is to discover a low-cost photocatalyst with the functions of efficient sunlight utilization and high charge separation rate for application in the field of renewable energy generation. Graphitic carbon nitride (g-C3N4) has spurred worldwide attention due to its abundance of raw materials, superior visible-light response activity, facile synthetic strategy, chemical stability, and a unique layered structure. In the past decade, the combination of g-C3N4 and organic compounds became a research hotspot because of its low cost, adjustable solar light absorption band and stable crystal structures. In this review, (1) the latest developments in the morphology control of g-C3N4 as a photocatalyst including nanorods, nanotubes, nanosheets, nanospheres, porous structures and other different tunable nanostructures, are systematically studied. (2) The incorporation strategies of g-C3N4 with various organic compounds including recently reported organic molecules, polymers and metal–organic frameworks (MOFs) with the aim of improving the overall photocatalytic performance are discussed in detail. (3) We theoretically present applications in water splitting, CO2 reduction, pollutant degradation and environmental disinfection. Finally, the research challenges and prospects of organic compound composited g-C3N4 towards hydrogen evolution through water splitting are proposed.

TiO2 is not among the traditional electromagnetic (EM) absorbing material candidates owing to its poor response in the EM wave region. Although the EM wave absorption performance can be improved by hybrid and/or hydrogenated TiO2, the difficulty and risk of the experimental process are increased. Herein, rutile TiO2 nanorod was successfully prepared by two-step method. The analysis of dielectric properties exhibits that rutile TiO2 nanorod has excellent charge storage capacity. The results of EM wave absorbing performance show that impedance matching caused by anomalous resonance leads to frequency selective absorption. Such anomalous resonance is due to the resonant polarization of ionic clusters formed by oxygen ions and titanium ions. Moreover, metastructure design shows that the EM absorption frequency and the EM wave absorption bandwidth can be tuned through the design of metamaterial. Our founding will broaden the field of vision for the design of EM wave absorbing materials in the future.

Bismuth glasses with different Bi2O3 and ZnO contents (designated as Bi15, Bi25, Bi36) were designed to investigate the interfacial microstructure evolution of magnesium titanate ceramic (MTC) joints. The mechanical and dielectric properties of joints were also studied. (Zn,Mg)2TiO4 layer formed at the interface by the substitution reaction of Zn. Bi4Ti3O12 blocks generated at the interface of Bi15 glass seam due to low Bi2O3 content, while Bi4Ti3O12 whiskers formed at the interface of Bi25 glass seam owing to the concentration gradient of Ti. Small Bi4Ti3O12 plate-like phases formed with a high concentration of [BiO6] and Ti, dispersing in the Bi36 glass seam. Rod-like MgSiO3 were produced at the interfaces of all glass seams. Besides, MgO phases formed in the Bi36 glass seam, owning to the increase of O2− concentration. The shear strength of MTC/Bi36/MTC joints reached a maximum of 86.1 MPa under a combined effect of excellent matching and strengthening of small rod-like MgSiO3 and plate-like Bi4Ti3O12. The dielectric and microwave dielectric properties were evaluated by the impedance analyser and the vector network analyser. The dielectric characteristics of MTC joints were similar to those of MTC base material. The microwave dielectric loss tangent of MTC joints was less than 0.09.

Leaf color has been considered an important agronomic trait in rice (Oryza sativa L.) for a long time. The changes in leaf color affect the yield of rice. In this study, a green-revertible albino (graS) mutant was isolated from a 60Co-gamma-irradiated mutant pool of indica cultivar Guangzhan 63-4S. The fine mapping indicated that graS mutant was mapped to chromosome 1, and was located in a confined region between markers ab134 and InDel 8 with genetic distances of 0.11 and 0.06 cM, respectively. Based on the annotation results, four open reading frames (ORFs) were predicted in this region. Sequence analysis revealed that LOC_Os01g55974 had a 2-bp nucleotide insertion (AA) in the coding region that led to premature termination at the 324th base. Sequence analysis and expression analysis of related genes indicated that LOC_Os01g55974 is the candidate gene of GraS. We studied the genome and protein sequences of LOC_Os01g55974, and the data showed that GraS contains a deoxycytidine deaminase domain, which was expressed ubiquitously in all tissues. Further investigation indicated that GraS plays an essential role in the regulation of chloroplast biosynthesis, photosynthetic capacity and yield. Moreover, leaf color mutant can be used as an effective marker for the purity of breeding and hybridization.

In this paper, 0.5 wt% carbon nanotubes (CNTs) and 0.05 wt% graphene nanosheets (GNSs) were selected as additives to modify the properties of Sn–Cu–Ni solder joints for solar cell. The mechanical properties of Sn–Cu–Ni solder joints can be improved by 20–25%. The interface growth behavior of Cu–Sn intermetallic compounds at Sn–Cu–Ni/Cu and Sn–Cu–Ni–0.5CNTs–0.05GNSs/Cu couples after 250 °C and 260 °C soldering with 10 min and 20 min. The experimental results indicate that the growth rate of Cu6Sn5 IMC of Sn–Cu–Ni/Cu solder joints is higher than that of Sn–Cu–Ni–0.5CNTs–0.05GNSs/Cu solder joints. That is, adding 0.5 wt% CNTs and 0.05 wt% GNSs can reduce the growth rate of the Cu6Sn5 IMC layer, which can be attributed to the reduction of the element diffusion coefficient. In addition, the stress–strain of the two solder joints were calculated using finite element method, it is found that the Sn–Cu–Ni–0.5CNTs–0.05GNSs/Cu solder joints have significantly less stress–strain than Sn–Cu–Ni/Cu solder joints, due to the reduction of Cu6Sn5 layer thickness, fatigue life of solder joints can be enhanced by three times.

As the important data basis of surrounding rock classification, rock mass structural information obtained by traditional image processing and feature extraction algorithms could not be quantitatively analyzed because of the uncertainty and geometric randomness of structural planes. In this paper, based on straight line detection, intelligent scissors, and morphological edge detection algorithms, the multiple interpretation system of rock mass image including linear bunching extraction, magnetic tracking extraction, and multiparameter characterization was researched and developed, and the actual distribution information and the related probability distribution model of structural planes could be obtained directly. On the basis of this, plenty of corresponding random rating-values meeting the probability distribution models of these evaluation indices were gained by Monte Carlo Simulation. The distribution probability affiliated with different rock mass grade was attained by inductive statistics, and the robust evaluation of surrounding rock classification could be carried out. Taking the robust results as learning samples, the response model of surrounding rock grade based on Gaussian process classification was established, making the evaluation of surrounding rock subclassification more rapid and robust.

Summary The leaf is a crucial organ evolved with remarkable morphological diversity to maximize plant photosynthesis. The leaf shape is a key trait that affects photosynthesis, flowering rates, disease resistance and yield. Although many genes regulating leaf development have been identified in the past years, the precise regulatory architecture underlying the generation of diverse leaf shapes remains to be elucidated. We used cotton as a reference model to probe the genetic framework underlying divergent leaf forms. Comparative transcriptome analysis revealed that the GhARF16‐1 and GhKNOX2‐1 genes might be potential regulators of leaf shape. We functionally characterized the auxin‐responsive factor ARF16‐1 acting upstream of GhKNOX2‐1 to determine leaf morphology in cotton. The transcription of GhARF16‐1 was significantly higher in lobed‐leaved cotton than in smooth‐leaved cotton. Furthermore, the overexpression of GhARF16‐1 led to the up‐regulation of GhKNOX2‐1 and resulted in more and deeper serrations in cotton leaves, similar to the leaf shape of cotton plants overexpressing GhKNOX2‐1. We found that GhARF16‐1 specifically bound to the promoter of GhKNOX2‐1 to induce its expression. The heterologous expression of GhARF16‐1 and GhKNOX2‐1 in Arabidopsis led to lobed and curly leaves, and a genetic analysis revealed that GhKNOX2‐1 is epistatic to GhARF16‐1 in Arabidopsis, suggesting that the GhARF16‐1 and GhKNOX2‐1 interaction paradigm also functions to regulate leaf shape in Arabidopsis. To our knowledge, our results uncover a novel mechanism by which auxin, through the key component ARF16‐1 and its downstream‐activated gene KNOX2‐1, determines leaf morphology in eudicots.

Let D be a finite distributive lattice with n join-irreducible elements. It is well-known that D can be represented as the congruence lattice of a rectangular lattice L which is a special planer semimodular lattice. In this paper, we shall give a better upper bound for the size of L by a function of n, improving a 2009 result of G. Grätzer and E. Knapp.

The German cockroach Blattella germanica (L.) is an important pest in medical, veterinary, and public health. Studies on the olfaction mechanism of hemimetabolous insects have rarely been reported, especially in cockroaches. Pheromone-binding proteins (PBPs) play a vital role in insect sex pheromone recognition, which solubilize and carry the hydrophobic pheromonal compounds through the antennal lymph to receptors. In this study, two potential PBPs (BgerOBP26 and BgerOBP40) were identified on the basis of their biased expression in male antennae using tissue transcriptome data and verified by the quantitative real-time polymerase chain reaction approach. We then expressed and purified the two identified odorant-binding proteins (OBPs) using the Escherichia coli expression system and affinity purification. In vitro binding studies showed that the two OBPs display stronger binding affinities to the female volatile sex pheromone blattellaquinone than to its analogues and contact sex pheromone components. Finally, three-dimensional modeling of the two OBPs and dock conformation with sex pheromone molecules showed BgerOBP26 has a larger odorant cavity and more conservative active amino acid residues than BgerOBP40. These results illuminated the binding characteristics of potential PBPs of B. germanica, which could lay the groundwork for improved understanding of many aspects of the chemical ecology of B. germanica. Moreover, this information complements the understanding of the olfactory molecular mechanism in cockroaches and provides potential gene targets for B. germanica control.

Here, we report a β-galactosidase (β-Gal)-responsive photochromic fluorescent probe, NpG, that was designed to prebind to human serum albumin (HSA) to form the probe/protein hybrid, NpG@HSA. The formation of NpG@HSA led to an increase in fluorescence emission (520 nm) corresponding to the binding of the fluorescent naphthalimide unit with HSA. In addition, this enabled visualization of the spiropyran fluorescence emission in aqueous media. Our probe/protein hybrid approach afforded a unique imaging platform with enhanced cell permeability and solubility that was capable of visualizing the cellular uptake of NpG@HSA before its activation by β-Gal. The β-Gal-mediated cleavage of the galactose unit within the NpG@HSA hybrid resulted in the formation of NpM@HSA and an increase in red fluorescence emission (620 nm). The resultant merocyanine unit was then able to undergo photoisomerization (merocyanine ↔ spiropyran) to facilitate STORM (i.e., stochastic optical reconstruction microscopy) imaging with minimal phototoxicity and excellent photostability/reversibility. Using STORM, NpG@HSA was able to determine the subcellular distribution of β-Gal activity between cell lines with nanoscale precision. We believe that this system represents a versatile imaging platform for the design of photochromic fluorescent probes suitable for illuminating the precise location of disease-specific biomarkers in various cellular processes.

In consideration of its high electromechanical coupling coefficient, thinned piezoelectric thick film from the bulk materials by chemical and mechanical polishing (CMP) process is used for high-performance piezoelectric harvesters and flexible sensors. Here, the flexible strain sensor 3 × 3 array based on CMP fabrication method is presented for the first time, and the laser-patterned flexible stainless steel serpentine wires as interconnects signal. The testing results show that the output voltages of the strain sensor array exhibit good linearity towards the corresponding strains, and also increase with the applied frequency. The maximum sensitivity of strain sensor array is 1.88 mV/μe. Moreover, this sensor array is demonstrated to monitor the surface strain of a complex structure such as the contraction and expansion of irregular balloon, which indicates its great promising in monitoring vital signs for heart healthcare.

Basic Oxygen Furnace (BOF) dust can be mixed with binders to prepare cold-bonded pellets and return to BOF for recycling, because of its high total iron and alkaline oxide content. Nevertheless, the lengthy digestion reaction of dead-burned MgO and CaO contained in BOF dust causes expansion and cracking of the pellets, which seriously affect the pellet strength. In this study, it was first proposed to use a hydration reaction between dead-burned MgO and KH2PO4 to form bonding phases based on the hydration mechanism of magnesium potassium phosphate (MKP) cementitious material, to solidify MgO contained in BOF dust and improve the pellet strength. The key issue of using MKP cementitious material as a binder to improve the pellet strength is to choose appropriate magnesium-to-phosphate molar ratio M/P and water-to-binder mass ratio w/b. Based on this, cold-bonded pellets were prepared by using different ratios of MKP binder. The compressive strength, hydration products, microstructure and thermal properties of the pellets were analyzed, and the bonding mechanism of MKP binder in the pellets was proposed. The results show that the pellets have the highest mechanical strength and the most K-Struvite crystals under M/P molar ratio of 4 and w/b mass ratio of 0.5. At high temperatures, K-Struvite crystals will not evaporate harmful phosphorus-containing substances due to the decomposition of the binder components. MKP binder is unevenly distributed in the pellets: in the binder concentrated areas, the massive and dense K-Struvite crystals wrap BOF dust particles; in the binder decentralized areas, the fine K-Struvite crystals are filled between the dust particles or adhere to the surface of dust matrix, connecting the dust particles into a whole.

This paper reports new geochronological (U–Pb) and isotope (C, O, and S) data to investigate the timing of mineralization and mode of ore genesis for the recently discovered Changtuxili Mn–Ag–Pb–Zn deposit, located on the western slopes of the southern Great Hinggan Range in NE China. The mineralization is hosted by intermediate–acidic lavas and pyroclastic rocks of the Baiyingaolao Formation. Three stages of mineralization are identified: quartz–pyrite (Stage I), galena–sphalerite–tetrahedrite–rhodochrosite (Stage II), and quartz–pyrite (Stage III). δ13C and δ18O values for carbonate from the ore vary from −8.51‰ to −4.96‰ and 3.97‰ to 15.90‰, respectively, which are indicative of a low-temperature alteration environment. δ34SV-CDT values of sulfides range from −1.77‰ to 4.16‰ and show a trend of equilibrium fractionation (δ34SPy ​> ​δ34SSp ​> ​δ34SGn). These features indicate that pyrite, sphalerite, and galena precipitated during the period of mineralization. The alteration mineral assemblage and isotope data indicate that the weakly acidic to weakly alkaline ore-forming fluid was derived largely from meteoric water and the ore-forming elements C and S originated from magma. During the mineralization, a geochemical barrier was formed by changes in the pH of the ore-forming fluid, leading to the precipitation of rhodochrosite. On the basis of the mineralization characteristics, new isotope data, and comparison with adjacent deposits, we propose that the Changtuxili Mn–Ag–Pb–Zn deposit is an intermediate-to low-sulfidation epithermal deposit whose formation was controlled by fractures and variability in the pH of the ore-forming fluid. The surrounding volcanic rocks yield zircon U–Pb ages of 160−146 ​Ma (Late Jurassic), indicating that the mineralization is younger than 146 ​Ma.

A novel asymmetric synthesis of dihydropyridinones with vicinal quaternary stereocenters has been realized by asymmetric aza-Diels-Alder reactions of 3-amido allylic alcohols with oxazolones enabled by chiral phosphoric acid catalysis. A series of aryl/alkyl- and alkyl/alkyl-disubstituted 3-amido allylic tertiary alcohols and 4-substituted oxazolones could be well tolerated in these reactions, producing dihydropyridinones with excellent diastereoselectivities and high enantioselectivities. Mechanistic study and control experiments were performed to shed light on the reaction mechanism, in which a configurationally defined β,β-disubstituted α,β-unsaturated N-H ketimine was proposed as the key intermediate.