Search

Background: This paper investigates the mechanical properties and failure behaviours of rivet-bonded hybrid joints composed of aluminium adherends and steel rivets under quasi-static tensile loading. Objective: The damage law of hybrid joints is studied to provide a reference for the design and manufacture of hybrid joints. Methods: Tensile tests were conducted on aluminium and steel specimens at various triaxial stress levels. The corresponding finite element model (FEM) was developed to verify the Johnson–Cook damage parameters of the studied metals. The hybrid joint considering the rivet forming process was constructed through FE modelling using the Johnson–Cook failure criterion and Cohesive Zone Model (CZM), which was then validated with the experimental results. Results: Experimental results of the hybrid joint showed that a typical two-stage failure: 1) the adhesive layer bears the majority of the load during the initial loading stage, and 2) the adhesive layer completely fails after reaching the peak load and the rivet solely bears the load subsequently. Conclusions: The riveting process did not cause damage to the adhesive layer, which ensured the reliability of the manufacturing techniques of the hybrid joint. And the yielding of rivets may buffer the immediate failure of hybrid joints. [ABSTRACT FROM AUTHOR]

A sodium lidar (light detection and range) network for the Earth's mesosphere and lower thermosphere (MLT) temperature, wind and sodium density measurements is designed and constructed in the second phase of the Chinese Meridional Project. Five narrowband sodium lidar systems are deployed across various regions in China, designed and developed based on similar principles and structures. They adhere to uniform data processing standards and operate under the same observational protocols. This allows them to form a network of lidar systems capable of detecting temperature and wind fields in the MLT. The preliminary observation results of the lidar near Tibetan plateau is demonstrated in this paper. This lidar network offers horizontal perspectives on large scale that a single‐station lidar system can't provide. Its future observations are expected to advance the understanding of atmospheric waves by studying wave propagation, chemical‐dynamical coupling processes and the horizonal structure of in the MLT region. Plain Language Summary: This paper describes a new lidar (light detection and range) network to observe the mesosphere and lower thermosphere (MLT) region, which is the coldest area in the earth. Five narrow band sodium lidars in this network measure the temperature, wind and sodium density. They adhere to uniform data processing standards and follow the same observational protocols, which define the temporal and range resolution of lidar data, as well as the world geodetic system. The preliminary results for wind, temperature and sodium density are obtained. The lidar network will provide effective means for MLT research. Key Points: Narrowband sodium lidar based on pulsed seeder laser is constructed to measure wind and temperature in the mesosphere and lower thermosphere regionFive lidars distributed in the region of China from 19.5°N to 53.5°N, and from 87.2°E to 122.4°E form a lidar networkPreliminary observation results are demonstrated the ability and potential of the lidar network to conduct more scientific research [ABSTRACT FROM AUTHOR]

Developing a stiffness-toughness balance, low-cost, and biodegradable PLA composite is an effective strategy for improving product market competitiveness, reducing dependence on petroleum-based resources and protecting the environment. Rice husk (RH) is extensively used as a filler in polymers, but the addition of too much rice husk into PLA has damaged the toughness of the composite. In this work, fully biodegradable composites with a stiffness-toughness balance and low cost are successfully fabricated through melt blending of PLA, RH and acetyl tributyl citrate (ATBC), named PLAC0, PLAC3, PLAC6, PLAC9, PLAC12, PLAC15, PLAC18, PLAC20 respectively according to amount of ATBC (0phr, 3phr, 6phr, 9phr, 12phr, 15phr, 18phr, 20phr). The results show that bio-based plasticizer ATBC can improve the flowability of PLA composites, further enhancing their processability, which promotes the dispersion of RH in PLA. The impact strength and elongation at break of PLAC20 reach the value of 100 J/m and 148%, achieving an increase of 4.3 and 60.1 times compared with PLAC0, respectively. The torque rheological test shows that the maximum torque and equilibrium torque of PLAC18 decrease by about 67.4% and 63.5% respectively compared to PLAC0. This suggests a decrease in friction between PLA molecular chains, thereby increasing the fluidity of PLA composites and indicating a significant improvement in processing performance. As the ATBC amount increases, the water absorption rate of the composite progressively rises, while the contact angle steadily diminishes, resulting in the improvement for hydrophilicity, thereby broadening its potential applications. [ABSTRACT FROM AUTHOR]

Polybutylene succinate (PBS) is an aliphatic linear polyester that is known for its excellent biodegradability and biocompatibility, making it one of the most promising application polymers. However, its disadvantages of poor toughness, low thermostability, and high crystallinity limit its large-scale commercial applications. In this article, a novel epoxy-functionalized core–shell starch particle (CSP-GMA) is successfully synthesized by virtue of soap-free emulsion polymerization, which consists of a "hard" starch (St) core and a "soft" ethyl acrylate (EA) shell grafted with glycidyl methacrylate (GMA). A binary blend of biodegradable polymers is prepared via a melt blend process with CSP-GMA as a core–shell particle modifier and PBS as a polymer matrix. The mechanical properties, thermal behavior, crystallization properties, stability and microscopic morphology of PBS/CSP-GMA blends are thoroughly studied. The incorporation of 20 wt% CSP-GMA into the PBS blend promotes an increase in the impact strength by 55% and the elongation at break by 173% higher than that of pure PBS respectively, which indicates that our work proposes an efficient strategy for fabricating PBS blends with good comprehensive properties and low cost. The DSC testing shows that the crystallinity of PBS blend is reduced in comparison to PBS, while the crystallization temperature is also decreased, confirming that CSP-GMA can facilitate the crystallization of PBS. The SEM observation reveals that owing to the compatibility arising between two phases interface due to the presence of epoxy group on core–shell starch particle surface, CSP-GMA is better dispersed in the PBS matrix, resulting in the improvement for performance of PBS blends. [ABSTRACT FROM AUTHOR]

In this article, a strategy is proposed to prepare highly toughened composites from polypropylene (PP), rice husk charcoal (RHC) and glycidyl methacrylate (GMA)-modified EPDM using melt blending and hot pressing. The structure of GMA-modified EPDM is confirmed by Fourier transform infrared spectroscopy (FTIR). The influences of the amounts of EPDM and GMA-modified EPDM on PP composites are investigated by virtue of mechanical properties testing, dimensional stability analysis, thermogravimetric analysis (TGA), X ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that the incorporation of GMA-modified EPDM significantly improves the toughness of PP composites and compared to PRHC the impact strength of PRKEG10 is up to the value of 537 J/m and increases by 555%, concurrently the tensile strength and modulus exhibit less decrease with the value of 8.22 MPa and 353 MPa, respectively. Shrinkage measurements show the dimensional change rates of length, width, and height decrease from 3.2%, 2.9%, and 3.3% to 1.73%, 1.46%, and 1.93%, respectively, improving the dimensional stability of PP composites. SEM reveals that shear yield and cavitation during the loading process lead to the excellent toughness of PP composites. This strategy provides a novel route to fabricate high ductility rice husk charcoal-based PP composites and expand certain industrial application. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides (TMDs) like MoSe2 exhibit remarkable optical properties such as intense photoluminescence (PL) in the monolayer form. To date, narrow-linewidth PL is only achieved in micrometer-sized exfoliated TMD flakes encapsulated in hexagonal boron nitride (hBN). In this work, we develop a growth strategy to prepare monolayer MoSe2 on hBN flakes by molecular beam epitaxy in the van der Waals regime. It constitutes the first step toward the development of large area single crystalline TMDs encapsulated in hBN for potential integration in electronic or optoelectronic devices. For this purpose, we define a two-step growth strategy to achieve monolayer-thick MoSe2 grains on hBN flakes. The high quality of MoSe2 allows us to detect very narrow PL linewidth down to 5.5 meV at 13 K, comparable to the one of encapsulated exfoliated MoSe2 flakes. Moreover, sizeable PL can be detected at room temperature as well as clear reflectivity signatures of A, B, and charged excitons. [ABSTRACT FROM AUTHOR]

Polypropylene has a wide range of applications in scientific research, industry, and production due to its excellent mechanical properties and chemical stability. However, owing to its low melt strength, inferior dimensional stability, and poor thermal stability, thus limiting its further application. Addressing this challenge, a series of polymer composites consisting of rice husk charcoal (RHC), modified using 3-glycidyloxypropyltrimethoxysilane (KH560) as the silane coupling agent, and polypropylene (PP) have been fabricated by virtue of a melt blending process by us. Thermal behaviour, crystallization properties, mechanical properties, dimensional stability and microscopic morphology of PP/RHC composites are studied in detail. The results show that, when 20% modified RHC was added to the composites, it increased the initial decomposition temperature of PP by 130℃, which represents that we manufactured PP composites with better thermal properties by simple processing. The rheological performance tests showed that the addition of RHC increased the stiffness and dimensional stability of the composites, which is more conducive to the processing and moulding of the material. SEM indicated that KH560 can increase the compatibility of RHC with PP substrate, thus improving the performance of conforming materials. [ABSTRACT FROM AUTHOR]

This study was designed to explore cryptanshinone (CPT) extract of Salvia miltiorrhiza stimulating pediatric acute myeloid leukemia (AML) stem cell (LSC) apoptosis and anti-inflammatory mechanism via accelerating microRNA (miR)-211-5p to restrain Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway activation. Obtaining blood samples from pediatric acute myeloid leukemia patients and healthy volunteers and detecting miR-211-5p and JAK2 were performed. Purchase of the human AML cell line KG1a was conducted, and sorting of KG1a cells was to gain LSC. Test of miR-211-5p and JAK2, the phosphorylation of JAK2/STAT3 was implemented. Pretreatment of LSCs was with CPT. Variation of miR-211-5p and JAK2 in LSCs was via plasmid transfection to explore their actions in cell advancement with apoptosis and inflammation. Identification of the targeting of miR-211-5p with JAK2 was implemented. In results: MiR-211-5p was declined in endometrial cancer, while JAK2 was elevated; CPT was available to boost LSC apoptosis and restrain the inflammation; elevated miR-211-5p or repressive JAK2 was available to strengthen the acceleration of CPT on LSCs apoptosis and the repression of inflammation; MiR-211-5p targeted JAK2; augmented JAK2 was available to turn around the action of elevated miR-211-5p. We conclude that CPT extract of Salvia miltiorrhiza stimulated pediatric LSC apoptosis and restrained the inflammation via accelerating microRNA (miR)-211-5p to suppress JAK2/STAT3 pathway activation. [ABSTRACT FROM AUTHOR]

Migration of conventional petrochemical plasticizers can negatively affect the performance of plasticized products, human health and the environment and result in the reduction of petroleum resources. Thus, the development of bio-based plasticizers with migration resistance is very critical. In this study, two novel bio-based plasticizers with different structures derived from ricinoleic acid, i.e., epoxy acetylated benzyl ricinoleate (EABR) and epoxy acetyl terephthalate ricinoleate (EATPR), with good plasticizing effect and migration resistance were synthesized and characterized. The structure of EABR and EATPR was confirmed using FTIR and 1H NMR spectroscopies. The mechanical, thermal, and migration properties of the PVC samples plasticized with EABR and EATPR were extensively investigated, and the commercial plasticizer dioctyl terephthalate (DOTP) was used for comparison. The plasticized PVC samples with EABR and EATPR showed similar impact strength, elongation at break, and glass transition temperature (Tg) to DOTP-plasticized samples, indicating a good plasticizing effect on PVC. Furthermore, EABR and EATPR demonstrated superior performance in migration and volatility tests compared to DOTP. Besides, the plasticizing properties of the plasticized PVC were very sensitive to the structure of the plasticizer; EATPR, with a symmetric structure, showed better plasticization and plasticizing efficiency than EABR, with an asymmetric structure. In conclusion, the two bio-based plasticizers derived from ricinoleic acid showed attractive potential as alternatives to phthalate plasticizers, especially EATPR, with a larger symmetric molecular structure and higher aliphatic content. [ABSTRACT FROM AUTHOR]

In this contribution, isosorbide dinonanoate (SDN), an environmentally sustainable plasticizer for polypropylene (PP), is successfully synthesized by virtue of esterification reaction using isosorbide and nonanoic acid with the reaction temperature of 120 °C, and the reaction time of 5 h. When the corporation of plasticizer SDN into PP matrix is the value of 15 phr, the impact strength of PP blends reaches 121 J/m, the dramatically increase of 384% compare to that of PP. DMA results shows that the glass transition temperature (Tg) of PP blends gradually decline with the increasing amount of SDN, indicating the efficient plasticization action of the SDN. It is suggested that SDN can be feasibly inserted into the non-polar matrix and then more evenly dispersed in matrix, herein, it will increase the distance between the polymer chains, improving the mobility of the molecular chains and the processing performance of the polymers. Furthermore, the plasticizing effect and environmental friendliness of SDN can be a potential replacement for o-phenyl plasticizers in the industry in the future. [ABSTRACT FROM AUTHOR]

Coal spontaneous combustion risk assessment is a global technical challenge for the sustainable development of deep mining technology, and C2H4 is a key indicator for early warning of coal spontaneous combustion. Tunable diode laser absorption spectroscopy (TDLAS) has the advantages of high selectivity, high sensitivity, high accuracy and real-time on-line measurement, and it can detect multiple gases simultaneously, so it has significant advantages in the accurate detection of coal spontaneous combustion indicator gases. To address the problem of cross-interference between the near-infrared absorption lines of CH4 and C2H4, which are the indicator gases of spontaneous combustion in coal, a multi-line fitting method was proposed in this study to calibrate the concentration of C2H4. The high-precision Environics2000 automatic standard gas dispenser from the United States, which has a built-in CPU computer control and data control and processing system, was used. Its gas concentration accuracy: ± 1.0%, gas flow accuracy: ± 1.0%, gas repeatability accuracy: ± 1.0%, flow linearity accuracy: ± 0.5%, and inlet operating pressure: minimum 10 psig (0.67 bar) ~ 75 psig (5.04 bar). The measured and simulated WMS-2f/1f signals were multilinearly fitted using a multilinear fitting algorithm and wavelength modulation spectroscopy (WMS), and the measurement of C2H4 concentration was achieved based on the extracted spectral line information. The results show that the maximum relative error of C2H4 concentration measurement is 2.40%, which is 54% lower than that of the conventional 2f peak measurement method, thus demonstrating the effectiveness of the multilinear fitting algorithm in the inversion of C2H4 concentration under the interference of absorption lines. In addition, this study has far-reaching implications for the application of TDLAS technology in the accurate detection of coal spontaneous combustion indicator gases. [ABSTRACT FROM AUTHOR]

Starting in the early 1990's, the Tropical Atmosphere Ocean (TAO)/TRIangle Trans Ocean buoy Network (TRITON) array has been the pervasive source for observing large‐scale equatorial wave propagation which is key for El Nino/Southern Oscillation (ENSO) predictions. However, removal of western TRITON moorings, the plan to reorganize the array (i.e., TPOS 2020), and availability of other sources of in situ data (e.g., Argo) have highlighted the need to rigorously assess the impact of TAO/TRITON data on ENSO predictions. Therefore, we evaluate TAO/TRITON array using data denial assimilation experiments and assess the impact on coupled atmosphere/ocean predictions of the big 2015 El Niño. Validation of the CONTROL (assimilates all available data) and NOTAO (withholds TAO/TRITON data) reanalyses shows that assimilating TAO/TRITON data generally improves comparisons versus gridded and pointwise in situ observations. This is especially true across the entire basin above and in the eastern half of the Pacific just below the thermocline for temperature. Even with relatively few observations, salinity is generally improved except near 120°W near the surface. To evaluate the impact of TAO/TRITON data on ENSO initialization, seasonal forecasts were initialized from the CONTROL and NOTAO experiments. For the 9‐month forecasts which were initialized in January, July, and October 2015, both the amplitude and the accuracy of the ensembles initialized with TAO/TRITON data were closer to observations. Through the analysis of Kelvin and Rossby waves, we show that the impact of TAO/TRITON is to generally shoal the mixed layer depth, leading to amplification of the El Niño downwelling signal, and improving the amplitude of the ENSO signal. Plain Language Summary: The Tropical Atmosphere Ocean (TAO)/TRIangle Trans Ocean buoy Network (TRITON) mooring array straddles the equator in the tropical Pacific and is designed to monitor the large‐scale, basin‐wide ocean waves that comprise the changes in the El Niño/Southern Oscillation (ENSO) strength. We isolate the impact of these moorings by contrasting two simulations. In one, we use the TAO/TRITON data (i.e., the CONTROL experiment) and in the other we withhold these data (NOTAO). Using these data in the CONTROL generally improves the temperature and salinity model reconstruction especially in the eastern tropical Pacific, where variations in upwelling of the cold tongue define the ENSO cycle. Next, seasonal ENSO forecasts initialized with the CONTROL more accurately represented the increase in sea surface temperature in the eastern equatorial Pacific due to El Niño than those initialized by the NOTAO experiment. The reason for this is that the layer at the ocean surface that is most strongly impacted by the wind is shallower in the case when assimilating TAO data and so any wind forcing has bigger impact on the ocean. These results suggest that it is important to continue to observe the ocean using these near‐equatorial moorings to assure the best possible ENSO forecasts. Key Points: Tropical Atmosphere Ocean improves the temperature and salinity especially above the thermocline and in the upwelling region of the tropical eastern PacificShoaled mixed layer depth serves to amplify the El Nino signal leading to improved El Nino/Southern Oscillation (ENSO) forecasts as validated by NINO3.4 SSTBoth Rossby (January 2015) and Kelvin (July, October 2015) waves contribute to overall upwelling and improved ENSO forecasts [ABSTRACT FROM AUTHOR]

Insight into the anisotropic fracture properties of shale under a high in situ stress is important for the design and optimization of hydraulic fracturing treatment for deep shale formations. In this work, a series of hydraulic fracturing tests were conducted on hollow double wing crack specimens of Longmaxi shale with three principal fracture orientations: arrester, divider, and short transverse orientations. To reveal the influence of in situ stress on shale fractures, various confining pressures, i.e., 0, 20, 40, 60, and 80 MPa, were applied. The 3D anisotropic fracture properties of shale under deep in situ stress conditions were then investigated and highlighted. The breakdown pressure, mode I fracture toughness, and fracture energy were found to increase significantly with the confining pressure, indicating that the fracture resistance of the studied shale increases remarkably under high in situ stresses. Furthermore, as expected, both the fracture toughness and fracture energy exhibited remarkable anisotropies under each confining pressure condition, and the minimum fracture toughness and fracture energy were always found in the short transverse orientation. Interestingly, the fracture toughness and fracture energy in the arrester orientation were found to be smaller than those in the divider orientation under confining pressures ranging from 0 to 60 MPa, while the opposite was true under a confining pressure of 80 MPa, demonstrating that shale fracture anisotropy is influenced by in situ stress that should be carefully considered in hydraulic fracturing design. For fracture morphology, a higher confining pressure leads to a smoother fracture surface and more transgranular cracking. Highlights: Slight crack deflection is observed only in the arrester orientation The increase rates of fracture resistances gradually reduce as confining pressure increases High in situ stress changes the anisotropy in fracture resistance Unexpected, a higher confining pressure leads to a smoother fracture surface [ABSTRACT FROM AUTHOR]

Coal spontaneous combustion risk assessment is a global technical challenge for the sustainable development of deep mining technology, and C2H4 is a key indicator for early warning of coal spontaneous combustion. Tunable diode laser absorption spectroscopy (TDLAS) has the advantages of high selectivity, high sensitivity, high accuracy and real-time on-line measurement, and it can detect multiple gases simultaneously, so it has significant advantages in the accurate detection of coal spontaneous combustion indicator gases. To address the problem of cross-interference between the near-infrared absorption lines of CH4 and C2H4, which are the indicator gases of spontaneous combustion in coal, a multi-line fitting method was proposed in this study to calibrate the concentration of C2H4. The high-precision Environics2000 automatic standard gas dispenser from the United States, which has a built-in CPU computer control and data control and processing system, was used. Its gas concentration accuracy: ± 1.0%, gas flow accuracy: ± 1.0%, gas repeatability accuracy: ± 1.0%, flow linearity accuracy: ± 0.5%, and inlet operating pressure: minimum 10 psig (0.67 bar) ~ 75 psig (5.04 bar). The measured and simulated WMS-2f/1f signals were multilinearly fitted using a multilinear fitting algorithm and wavelength modulation spectroscopy (WMS), and the measurement of C2H4 concentration was achieved based on the extracted spectral line information. The results show that the maximum relative error of C2H4 concentration measurement is 2.40%, which is 54% lower than that of the conventional 2f peak measurement method, thus demonstrating the effectiveness of the multilinear fitting algorithm in the inversion of C2H4 concentration under the interference of absorption lines. In addition, this study has far-reaching implications for the application of TDLAS technology in the accurate detection of coal spontaneous combustion indicator gases. [ABSTRACT FROM AUTHOR]

A field campaign (29 May to 14 June 2018) was conducted at a mountain site in central China. The chemical composition of non‐refractory submicron particulate matter (NR‐PM1) and the particle number size distribution (PNSD) were measured, respectively. The mean NR‐PM1 mass concentration was 20.94 ± 10.14 μg m−3, among which organics (47%) was the most abundant component, followed by sulfate (37%), ammonium (11%), nitrate (4%), and chloride (1%). Notably, sulfate accounted for more than 70% of the secondary inorganic aerosols. Positive matrix factorization (PMF) analysis of the composition data resulted in three organic aerosol (OA) factors: hydrocarbon‐like OA (HOA), oxygenated OA I (OOA‐I), and oxygenated OA II (OOA‐II). The secondary organic aerosol (SOA) composed of the latter two factors (SOA: OOA‐I + OOA‐II) was dominant in OA (80.7%). The PMF analysis of the PNSD data yielded three factors: new particle formation related mode, growth mode, and accumulation mode, among which the last factor dominated both number and volume ratios. The sulfate formation was characterized by the sulfur oxidation ratio (SOR), heterogeneous sulfate production rate (Phet), and gaseous sulfuric acid concentration, representing secondary sulfate transformation, heterogeneous reactions, and gas phase reactions, respectively. The results showed that Phet was well correlated with both sulfate concentrations and SOR, especially during the polluted periods. Our study demonstrates that photochemically‐driven heterogeneous reactions contribute dominantly to the sulfate formation and SOA is formed predominantly by photochemical oxidation of volatile organic compounds under high temperatures and ultraviolet (UV) intensities, and NOX concentrations on Mt. Wudang during the campaign period. Plain Language Summary: In this study, the chemical composition and size distribution of submicron aerosols were measured at a mountain site in central China (Mt. Wudang), and the sources as well as controlling factors were further investigated. Our results reveal that photochemical reactions play an important role in both sulfate and secondary organic aerosol formation. For sulfate, heterogeneous reactions were dominant during the polluted periods, whereas gas‐phase reactions are more pronounced during the clean periods. Key Points: Organics and sulfate account for more than 80% mass concentration of submicron aerosols on Mt. WudangHeterogenous reactions lead to sulfate formation on Mt. Wudang during the polluted periodsSecondary organic aerosol was mainly formed by photochemical reactions on Mt. Wudang [ABSTRACT FROM AUTHOR]

Schizochytrium sp. is a marine fungus, which usually lives in the salinity of 40–100% seawater and has unique salt tolerance characteristics. In this study, we explored the candidate mitogen-activated protein kinase (MAPK) related to the salt-tolerant regulatory network from Schizochytrium sp. Firstly, 6 potential MAPK genes from Schizochytrium sp. were identified based on the genome information and bioinformatics analysis. Then, the MAPK gene expression of Schizochytrium sp. under different cultivation conditions locked two genes encoding Mpk6315 and Mpk2022. Furthermore, overexpressing of Mpk6315 in S. cerevisiae enhanced cell growth by 62% while and Mpk2022 overexpression improved the membrane integrity under different stress conditions, indicating that Mpk6315 might play an important role for cell growth and Mpk2022 could help cells to encounter different environmental stressors. This study was the first time to identify the MAPK genes from Schizochytrium sp., which could enlarge the MAPK modules of salt stress tolerance and provide new elements for improving the stress resistance of other microorganisms. [ABSTRACT FROM AUTHOR]

This work proposed an efficient method to synthesize acrylonitrile-butadiene-styrene (ABS) copolymer and α-Methylstyrene (α-MSt)/N-phenylmaleimide (NPMI)/Acrylonitrile (AN) (MSAMI) random copolymer via emulsion polymerization, aiming to combine the excellent heat resistance of MSAMI and numerous advantages of ABS resin including mechanical properties, processing and recyclability. The effects of the MSAMI content and α-MSt/AN ratio on the thermal performance, mechanical properties and the morphology of heat-resistant ABS were investigated by FITR, dynamic mechanical analyses (DMA), Vicat Softening Temperature (VST), Thermogravimetric Analysis (TGA) and Scanning Electron Microscope (SEM). As a result, the heat-resistant of ABS resin was obviously enhanced by MSAMI, and its glass transition temperature (Tg) could be extended with the increase of NPMI content. The Tg could reach 173°C when NPMI content was 20% at the same trend as the VST. Synthetically, the contradiction between the heat resistance and mechanical properties of ABS resin reached a good balance when the NPMI content was 15% and α-MSt/AN ratio was 69/31. In SEM, the fracture morphology of the heat-resistant ABS resin was gradually tended to be smooth with the increase of the NPMI content. Therefore, the MSAMI random copolymer was successful prepared, which provided insight for the synthesis of heat-resistant modifiers and promoted the potential application of heat-resistant modifiers in automobiles and aircraft. [ABSTRACT FROM AUTHOR]

In the present study, we explored whether sirtuin-3 (SIRT3) regulates the proliferation and migration of esophageal squamous cell carcinoma (ESCC) and investigated the mechanisms underlying the oncogene role of SIRT3. siRNA was used to transfect Eca109 cells and downregulate SIRT3. The proliferation and migration of Eca109 cells were examined by the CCK-8 assay, colony formation assay, Transwell assay, and scratch test. Quantitative real-time PCR and Western blotting were used to detect SIRT3, hexokinase 2, AKT, and p-AKT in Eca109 cells. Functional assays showed that downregulation of SIRT3 could inhibit the proliferation and migration of ESCC cells. Reduced SIRT3 expression downregulated hexokinase 2 expression and inhibited AKT activation in ESCC. These results indicated that SIRT3 promote ESCC development and progression by regulating hexokinase 2 through the AKT signaling pathway. SIRT3 promote ESCC proliferation and migration by regulating HK-2 through the AKT signaling pathway. [ABSTRACT FROM AUTHOR]

MicroRNA (miRNA) was verified to display an important molecular regulatory role in the development of skeletal muscle. In this study, we identified the differentially expressed miRNAs from longissimus dorsi muscle of Dazu black goat at different stages (75 days embryonic stage [ET]) and 1 day after birth [DC]) to understand the regulatory role of miRNAs in the development of skeletal muscle. This work is expected to provide a theoretical basis for goat breeding in meat production. Results revealed a total of 218,161,800 clean tags from all the libraries; 546 significant differentially (p < 0.05) expressed miRNAs (DE_miRNAs) were identified, including 321 up-regulated and 225 down-regulated DE_miRNAs. Moreover, GO and KEGG analyses of the genes targeted by the DE_miRNAs revealed 59 and 345 significantly enriched GO terms and pathways associated with muscle development, respectively, such as the PI3K/Akt, Wnt. A total of 21 miRNAs from 546 DE_miRNAs were selected to estimate the agreement rate between miRNA-seq by RT-qPCR, and the results showed that the expressed pattern was completely unified from both. In brief, a series of miRNAs related to muscle development was identified in this study. This work provides valuable information to further understand the molecular regulatory mechanism of muscle development in goats. [ABSTRACT FROM AUTHOR]

A highly sensitive fluorescence-enhanced aptasensor was designed to detect silver ions (Ag+) using metal-enhanced fluorescence. Interaction of Ag+ with cytosine nucleobases was used to achieve a low detection limit. Aptamer-modified gold nanoparticles (Au NPs) were mixed with 6-carboxyfluorescein (FAM)-labeled DNA to prepare the sensor. In a solution without Ag+, aptamer and FAM-labeled DNA strands remained free because of repulsion between cytosine. In the presence of Ag+, pairs of aptamer and FAM-labeled DNA strands formed double helices through cytosine–Ag+– cytosine interactions. These interactions brought FAM close to the Au NPs. The number of adenines repeats in the aptamer was altered to adjust the distance between the Au NPs and FAM, and provide controllable localized surface plasmon resonance. With the optimum number of adenine repeats (n = 24), the linear range for detection of Ag+ was 0.694 to 6.94 nmol/L and the detection limit was 0.694 nmol/L. The aptasensor showed excellent specificity and gave a strong detection signal for Ag+ present at trace concentrations to overcome issues associated with the detection of weak signals. [ABSTRACT FROM AUTHOR]

Human temporal bone specimens are used in experiments measuring the sound transfer of the middle ear, which is the standard method used in the development of active and passive middle ear implants. Statistical analyses of these experiments usually require that the TB samples are representative of the population of non-pathological middle ears. Specifically, this means that the specimens must be mechanically well-characterized. We present an in-depth statistical analysis of 478 data sets of middle ear transfer functions (METFs) from different laboratories. The data sets are preprocessed and various contributions to the variance of the data are evaluated. We then derive a statistical range as a reference against which individual METF measurements may be validated. The range is calculated as the two-sided 95% tolerance interval at audiological frequencies. In addition, the mean and 95% confidence interval of the mean are given as references for assessing the validity of a sample group. Finally, we provide a suggested procedure for measuring METFs using the methods described herein. [ABSTRACT FROM AUTHOR]

The excavation-induced deterioration of rock mass quality and integrity may significantly affect the stability of deep underground spaces. However, the influence of the burial depth on excavation-induced rock mass structural deterioration remains unclear. To address this issue, in the Jinping II auxiliary tunnels, borehole acoustic wave and digital panoramic borehole imaging tests were conducted at five depths, and the surrounding rock mass structure deterioration was comprehensively quantified at these depths. The results show that the wave curve significantly varies with increasing depth, and the deeper the tunnel section is, the more severe the rock damage is, the larger the excavation damage zone is, and the more complex the generated fracture network is. An excavation-damaged zone and excavation-disturbed zone (EdZ) were found in the rock masses at shallow depths, while a highly damaged zone (HDZ) and EdZ were observed at greater depths. Further investigation demonstrates that the formation pattern of excavation-damaged zones (EDZs) at deep depths follows a stress-concentration-controlled mode, and at very shallow depths, horizontal unloading plays a dominant role in the EDZ formation process (yielding a pure unloading-controlled mode), while at intermediate depths, a mixed EDZ formation mode is observed. [ABSTRACT FROM AUTHOR]

Wave height attenuation in vegetation canopies is often all attributed to the drag force exerted by vegetation, whereas other potential dissipation process is often neglected. Previous studies without vegetation have found that opposing currents can induce wave breaking and greatly increase dissipation. It is not clear if similar process may also occur in vegetation canopies. We conducted systematic flume experiments to show that wave breaking in opposing currents can occur in vegetated flows, but only in submerged canopies with shear currents above vegetation top. Subsequently, we developed a new analytical model to understand and assess the contribution of both drag‐induced dissipation in the lower vegetation layer and current‐induced breaking in the upper free layer. A new generic drag coefficient relation was applied in the model to quantify drag‐induced dissipation with various current‐wave combinations. It shows that breaking induced by opposing currents constitutes an essential part (up to 87%) of the total dissipation, which leads to considerably higher dissipation than the cases with following currents. Breaking can occur with various submergence ratios and with small opposing currents in the submerged vegetation field. It indicates that similar breaking process is likely to occur in real vegetation fields. The present study reveals and quantifies the current‐induced wave breaking process that has not been reported before, which can improve our understanding of vegetation wave dissipation capacity in field conditions. Plain Language Summary: Nature‐based coastal protection has drawn much attention from coastal scientists, engineers, and managers. This measure conserves and (re)creates vegetated coastal wetlands, for example, saltmarshes, mangroves, and seagrasses as buffers to attenuate incident waves and reduce wave load on dikes. The mechanisms of wave dissipation in coastal wetlands have been extensively investigated. Existing studies generally attribute all the dissipation to the drag force exerted by vegetation, whereas indirect wave dissipation that may occur with accompanying tidal currents is generally neglected. By extensive flume experiments, we found that substantial indirect wave dissipation can be induced by triggered breaking. Such process takes place in submerged canopies with a suitable submergence ratio (e.g., 1< water depth/canopy height <4.5), where the currents above the submerged canopies is accelerated by the underneath vegetation drag. These insights highlight the importance of previously overlooked indirect wave dissipation in vegetation fields (not by vegetation drag but by breaking), which are likely to occur in shallowly submerged mangrove and saltmarsh canopies. Thus, the knowledge and the model developed in the present study provide a base for more precise predictions of coastal wetlands' protection values. Key Points: A generic CD‐Re relation for various current‐wave combinations has been proposedOpposing currents can trigger wave breaking in submerged canopies, leading to greater wave dissipation than following currentsAn analytical model is developed to assess the contribution of wave breaking as indirect wave dissipation by vegetation [ABSTRACT FROM AUTHOR]

To evaluate ultrasonic features of the major salivary glands in patients with immunoglobulin G4-related sialadenitis (IgG4-RS) and to explore the differences between IgG4-RS and Sjögren's syndrome (SS). We conducted the study in 150 patients with IgG4-RS and 100 patients with SS. Ultrasonographic variables of the static images of major salivary glands were analysed. An experienced radiologist scored the confidence rating regarding the presence of the characteristic imaging findings using a five-grade rating system. Ultrasonography scores between IgG4-RS and SS were compared. The major salivary glands were significantly larger in patients with IgG4-RS than in the SS group. The main features of ultrasonography of the salivary glands in IgG4-RS were various hypoechoic lesions and increased colour Doppler signalling. In contrast, the major salivary glands in SS exhibited hyperechoic lines and/or spots and obscuration of the gland configuration. The scores of the summarized sonographic characteristics also showed statistically significant differences between the IgG4-RS and SS groups. This study revealed different ultrasonic features of the major salivary glands in patients with IgG4-RS and SS. The scored sonographic features were helpful in differentiating IgG4-RS from SS. Consequently, we suggest that ultrasonography of major salivary glands could be a useful imaging procedure in the evaluation of patients suspected of having IgG4-RS. [ABSTRACT FROM AUTHOR]

Development of animal models that accurately recapitulate human cancer is an ongoing challenge. This is particularly relevant in the study of osteosarcoma (OS), a highly malignant bone tumor diagnosed in approximately 1000 pediatric/adolescent patients each year. Metastasis is the leading cause of patient death underscoring the need for relevant animal models of metastatic OS. In this study, we describe how existing OS mouse models can be interrogated in a time-course context to determine the kinetics of spontaneous metastasis from an orthotopically implanted primary tumor. We evaluated four highly metastatic OS cell lines (3 human, 1 mouse) to establish a timeline for metastatic progression in immune deficient NSG mice. To discern the effects of therapy on tumor development and metastasis in these models, we investigated cisplatin therapy and surgical limb amputation at early and late timepoints. These data help define the appropriate observational periods for studies of metastatic progression in OS and further our understanding of existing mouse models. Efforts to advance the study of metastatic OS are critical for facilitating the identification of novel therapeutics and for improving patient survival. [ABSTRACT FROM AUTHOR]

The photoelectron characteristics and nano-doping mechanism of Cu-doped ZnSe/ZnS/L-cys self-assembled core-shell quantum dots (QDs) are studied by surface photovoltaic (SPV) and photoacoustic (PA) techniques, XRD, HRTEM, FT-IR, UV-VIS adsorption, and Laser Raman spectra. The results suggest that the doped copper element prefers to locate at the Zn atomvacancy of the (111) face of the QDs in the Cu2+ ion form. The defect-state levels are referred to the shallow accepter levels, leading to an obvious quantum confinement effect and a weakened n-type surface photovoltaic characteristic in the Cu-doped QDs. The quantum confinement effect strongly depends on the depth of the quantum well that is buried in the space charge region located in the graded-band-gap and at the side of the core-ZnSe. These electron structures are responsible for the increased lifetime and diffusion length of photogenerated free charge carriers, which significantly enhance the intensity of SPV response, enlarge the range of SPV response, and weaken the PA signals that are closely related to non-radiation deexcitation processes. [ABSTRACT FROM AUTHOR]

In this article, glycidyl methacrylate (GMA) was grafted on poly(butylene succinate) (PBS) by virtue of reactive blending in the extrusion process and thermoplastic starch (TPS) was prepared via a melt blend process with anhydroxylitol tripelargonate (AXP) as a bio-based plasticizer and starch as a polymer matrix. A ternary blend of fully biodegradable polymers, namely PBS-g-GMA, thermoplastic starch and poly(butylene adipate-co-terephthalate) (PBAT), was successfully fabricated in an attempt to achieve novel entirely biodegradable composites with good comprehensive properties. The mechanical properties, rheological behavior, thermal behavior, crystallization properties and microscopic morphology of PBS-g-GMA/TPS/PBAT composites were investigated in detail. The incorporation of 30 wt% TPS into the PBS-g-GMA/TPS composite promoted a dramatic increase of 47% in the Izod impact strength of the PBS, which indicated that our work proposed an efficient route to fabricate PBS composites with good properties by a simple, eco-friendly, and low-cost processing methodology. DMA results showed that the loss factor of the composite was dependent on the TPS amount, meanwhile, with the increase of PBAT, the glass transition temperature (Tg) was more affected. The change in storage modulus indicates that the addition of TPS can improve the elasticity and the degradation of elastic properties due to the addition of PBAT. Analysis of the rheological results showed that the storage modulus (G′), loss modulus (G′′) and complex viscosity increased significantly with increasing PBAT and TPS amount which could enhance their processability. SEM indicated that PBAT was compatible with the system, and the appearance of particles at a high TPS amount confirmed the occurrence of phase separation. [ABSTRACT FROM AUTHOR]

Anhydroxylitol tripelargonate (AXP), a novel environmentally sustainable plasticizer for poly(lactic acid)/poly(butylene succinate) (PLA/PBS) blends, is successfully synthesized. The chemical structure of AXP is confirmed by FTIR and 1H-NMR. The influence of varying the addition of AXP on mechanical property, thermal property, crystallization, rheological behavior and micromorphology of PLA/PBS blends is investigated in detail. The results are shown that the toughness and elongation at break of the blends are improved gradually with the increase of plasticizer addition, which indicates that plasticizer play a good plasticizing role in toughening blends. Furthermore, the introduction of AXP reduces the glass transition temperature (Tg) of the blends and simultaneously enhances its crystallization and processability. Observing the impact section of blends by SEM, it can be found that plasticizer AXP could change the blend from brittle fracture to ductile fracture. Additionally, the plasticization of AXP rivalled those petro-based plasticizers, and could be potential substitute to supplant O-benzene plasticizer in the future industry. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the downtime is simply assumed to be constant and the limited resources are not considered in the current selective maintenance of the series-parallel system, a three-objective selective maintenance model for the series-parallel system is established to minimize the maintenance cost, maximize the probability of completing the next task and minimize the downtime. The maintenance decision-making model and personnel allocation model are combined to make decisions on the optimal length of each equipment's rest period, the equipment to be maintained during the rest period and the maintenance level. For the multi-objective model established, the NSGA-III algorithm is designed to solve the model. Comparing with the NSGA-II algorithm that only considers the first two objectives, it is verified that the designed multi-objective model can effectively reduce the downtime of the system. [ABSTRACT FROM AUTHOR]

Anomalous Hall effect (AHE) has been studied for ferrimagnetic antiperovskite Mn4-xDyxN films grown by molecular-beam epitaxy. The introduction of Dy changes the AHE dramatically, even changes its sign, while the variations in magnetization are negligible. Two sign reversals of the AHE (negative-positive-negative) are ascribed to the variation of charge carriers as a result of Fermi surface reconstruction. We further demonstrate that the AHE current JAH is dissipationless (independent of the scattering rate), by confirming that anomalous Hall conductivity, σAH, is proportional to the carrier density n at 5K. Our study may provide a route to further utilize antiperovskite manganese nitrides in spintronics. [ABSTRACT FROM AUTHOR]

A 1‐month field campaign (May 29–June 29, 2018) was conducted at a mountain site (862 m above sea level) on the Wudang Mountains in China. The particle number size distribution (3–400 nm), size‐resolved cloud condensation nuclei (CCN, at 0.2% and 0.8% SS), and nonrefractory PM1 chemical composition were measured, respectively. The occurrence of the three chosen new particle formation (NPF) events (June 4, 7, and 11) was facilitated by southwest or west winds with a speed of about 3–4 m s−1. The hygroscopicity parameter (κ) value of newly grown particles varied in a wide range (0.25–0.8) during the events, leading to large uncertainties (−98% to 38%) on the NCCN prediction compared to the campaign. During growth of the newly formed particles for the three events, condensation of sulfuric acid vapor accounts for 14%–42%, 2%–8%, and 3%–9%, respectively, indicating that organic vapors may play an important role in particle growth. For plume‐type events with rapid growth, the observed high CCN activity (i.e., June 7 event) may be explained by the contribution of amines and depression of surface tension in the presence of organic surfactants during particle growth. Our study demonstrates that the contribution of NPF to CCN concentration is modulated by many key factors including growth rate, hygroscopicity, concentrations of new particles and preexisting particles, and variation of those factors from one event to another leads to large uncertainties on the CCN prediction. Plain Language Summary: A 1‐month field experiment (May 29–June 29, 2018) was conducted at a mountain site (862 m above sea level) on the top of the Wudang Mountains in China. Several particle characteristics including particle sizes, chemical composition, and cloud condensation nuclei (CCN) were measured using advanced analytical instruments. During the campaign, events corresponding to a well‐known atmospheric phenomenon called new particle formation were observed and facilitated by southwest or west winds. New particles, once they are formed, can grow to CCN sizes to enhance cloud formation. Prediction of CCN concentration is subject to large uncertainties during particle formation events because of large variation of particle hygroscopicity. In the atmosphere, sulfuric acid, an important condensable gas, plays an important role in particle growth. However, in our study, sulfuric acid vapor contributes minor to particle growth compared to organic compounds. Our study concludes that contribution of new particles to CCN concentration was controlled by many factors and might vary substantially from one event to another. Key Points: Substantial variation of hygroscopicity leads to significant uncertainties in cloud condensation nuclei predictionContribution of new particle formation to cloud condensation nuclei concentration varies in a large range from one event to anotherThe growth rate, hygroscopicity, new particle concentration, and preexisting particles are the key factors of the cloud condensation nuclei contribution [ABSTRACT FROM AUTHOR]

In this study, we analyzed the ocean surface wind speed dependence of off‐nadir data from the Surface Waves Investigation and Monitoring (SWIM) aboard the Chinese‐French Oceanography Satellite (CFOSAT). When the data were analyzed, the SWIM normalized radar cross section (NRCS) at most incidence angles decreased along the NCEP Global Forecast System wind speed. This trend is consistent with that in a Ku‐band geophysical model function at low incidence angles (KuLMOD2S), although there was a systematic bias between the two. The consistency indicates that the SWIM data quality was normal in terms of wind speed dependence. The bias was recalibrated using a numerical weather prediction‐based ocean calibration method and the wind speeds were retrieved from the recalibrated NRCS data using the KuLMOD2S model. Finally, the retrievals at off‐nadir as well as the wind products at nadir were validated using collocated CFOSAT scatterometer (CSCAT) wind measurements. When the results were validated, the retrievals at 0.5° were consistent with the averaged wind products at nadir and both had a root mean square difference (RMSD) around 1.4 m/s compared to the CSCAT winds. Moreover, the winds retrieved from the SWIM data at most incidence angles were in good agreement with the CSCAT winds,and the RMSD values were within 2.0 m/s for incidence angles less than 7.5°, although the retrieval accuracy was poor at larger incidence angles. These results demonstrate that the SWIM data at incidence angles below 7.5° have an ability to retrieve the wind speed. Key Points: Chinese‐French Oceanography Satellite (CFOSAT) Surface Waves Investigation and Monitoring (SWIM) data quality is normal in terms of the ocean surface wind speed dependenceWind speeds are retrieved from recalibrated CFOSAT SWIM off‐nadir dataSWIM wind speed retrievals for incidence angles less than 7.5° are in good agreement with the CFOSAT scatterometer winds [ABSTRACT FROM AUTHOR]

Soil microorganisms are an important component of forest ecosystems and have an important role in maintaining ecosystem stability. High-throughput sequencing technology was used to analyze the microbial composition and diversity of three typical forest, including Larix gmelinii forest (LG), Pinus sylvestris forest (PS), and Betula platyphylla forest (BP) in the Greater Xing’an Mountains, China. The results showed that there were significant differences in soil physical and chemical properties (pH, total organic carbon, total nitrogen and total phosphorus) among the three forest types. Soil bacterial alpha diversity (Shannon and Simpson) was not significantly different between forest types, but principal co-ordinates analysis (PCoA) results showed that soil bacterial beta diversity varied significantly (PERMANOVA: R2 = 0.5014, P < 0.01). In the three forest types of soil, the composition of the dominant bacterial phyla was basically the same. The relative abundance of Acidobacteria in BP soil was 34.64%, Proteobacteria was 27.00%, Chloroflexi was 10.32%; the relative abundance of Proteobacteria in LG soil dominant bacteria was 30.62%, Acidobacteria was 18.31%, Actinobacteria was 16.01%; the relative abundance of Proteobacteria in PS soil was 25.54%, Acidobacteria was 24.59%, Actinobacteria was 16.46%. Redundancy analysis (RDA) results showed that pH, TP, TN and TOC were the main environmental factors affecting the soil bacterial community structure. The findings of this study are intended to provide a new perspective on microbial ecology for a deeper understanding of the biogeochemical cycle in forest soils in the Greater Xing’an Mountains, China. [ABSTRACT FROM AUTHOR]

Background: The combination of conventional transarterial chemoembolization (cTACE) and systemic therapy has the potential to treat chemotherapy-refractory unresectable colorectal liver metastases (CRLMs). This study aimed to compare survival after this combined treatment versus systemic chemotherapy alone. Methods: This single-centre RCT included patients with unresectable CRLMs that progressed after first-line treatment. Patients were randomized on a 1: 1 basis to either systemic chemotherapy with or without cTACE, without further stratification. The primary outcome was progression-free survival (PFS). Secondary outcomes were overall response rate, disease control rate, conversion rate to liver resection, overall survival, and adverse events. Results: Of 180 patients recruited, 168 were randomized. Eighty-five patients in arm A received systemic chemotherapy plus cTACE and 83 in arm B received systemic chemotherapy alone. Median PFS was longer in arm A than B (6.7 versus 3.8 months; hazard ratio (HR) 0.67, 95 per cent c.i. 0.49 to 0.91; P=0.009), but did not translate into prolonged median overall survival (18.4 versus 14.8 months; HR=0.92, 0.62 to 1.36; P=0.669). Overall response rates (20 versus 22 per cent; P=0.788) and conversion rate to liver resection (18 versus 16 per cent; P=0.730) were no different between arms A and B. The disease control rate was higher in arm A than arm B (67 versus 51 per cent; P=0.030). No adverse event higher than grade 3 according to the Common Terminology Criteria for Adverse Events was observed during treatment. Conclusion: Systemic chemotherapy plus cTACE is a safe option as second-line treatment for unresectable colorectal liver metastases, with a modest effect on PFS. Registration number: NCT03783559 (http://www.clinicaltrials.gov). [ABSTRACT FROM AUTHOR]

Single-phase and oxygen doped Mn2N0.86 thin films have been grown on MgO (111) by plasma-assisted molecular beam epitaxy. The films grow under tensile strain and, remarkably, they show ferromagnetic-like interactions at low temperature and ferromagnetic ordering agreed well with the Bloch-law T3/2 at room-temperature. We further demonstrate the enlarged Mn 3s splitting (6.46 eV) and its possible relation to the observed ferromagnetism. Our study not only provide a strategy for further theoretical work on oxygen doped manganese nitrides, but also shed promising light on utilizing its room-temperature FM property to fabricate spintronic devices. [ABSTRACT FROM AUTHOR]

The first concerned question on the fundamental physics of the resistive switching (RS) effect in metal/Nb-doped SrTiO3 junctions is whether the RS does take place at the whole interface or at some local regions of the interface. Even though several investigations provide the clues of the filamentary nature of the RS, direct evidences are still required. Moreover, there is obvious inconsistency between the possible filamentary feature and the observed capacitance-voltage (C-V) hysteresis loops. Here, we report direct evidences of a filamentary RS effect in Pt/Nb-doped SrTiO3 junctions. The virgin Pt/NSTO junctions show an initial RS effect. The current-voltage (I-V) characteristic of the initial RS and the C-V characteristic in the virgin junctions are interpreted by using the theory of metal/semiconductor contacts. The correspondence between the initial RS and the C-V hysteresis loops is also discussed. The most important is that an electroforming process is observed at a large forward voltage, which is a direct indication of the formation of conductive filaments across the Pt/NSTO interface. Following the electroforming, the Pt/NSTO junctions exhibit a filamentary RS effect. The I-V characteristic of the filamentary RS deviates from the theoretical prediction of metal/semiconductor interfaces. However, the C-V characteristic is almost the same as that of the virgin junctions. This demonstrates that the conductive filaments are formed at local regions of the Pt/NSTO interface and a majority of the interface remains invariant. The results clearly show that a filamentary RS effect occurs in the Pt/NSTO junctions and that the observed C-V hysteresis loops are not correlated to the filamentary RS. © 2014 AIP Publishing LLC. [ABSTRACT FROM AUTHOR]

Fracking is widely applied to enhance shale gas mining, and insight into the fracture behaviors of shale rocks is important. To characterize the fracture properties of Lower Silurian Longmaxi shale, a chevron-notched deep beam specimen, which inherits the advantages of notched deep beam and chevron-notched specimens, is introduced, and several three-point bend tests were conducted on the Longmaxi shale specimens in three principal fracture orientations: the divider, short-transverse, and arrester orientations; the anisotropy in the critical shape coefficient, fracture toughness and fracture energy were then examined and highlighted. The results demonstrate that the critical shape coefficient depends on the anisotropic elasticity of the investigated shale, and a maximum error in the calculated fracture toughness of 9.2% could occur if a critical shape coefficient for isotropic rock is adopted. For the tested shale, the mode I fracture toughness in the divider orientation is close to that in the arrester orientation, with both values being approximately 1.5 times that in the short-transverse orientation; in addition, a progressive decrease in fracture energy from the arrester orientation to the short-transverse orientation is apparent. The fracture surface morphology was observed by scanning electron microscopy, and obvious material deterioration was found near the fracture surfaces for the arrester and divider samples. [ABSTRACT FROM AUTHOR]

In 2014, 45 isolates of Colletotrichum spp. from Jinzhong City (Shanxi Province, China) that had never used Qo inhibitor (QoI)-type fungicides were characterised for sensitivity to picoxystrobin through growth inhibition tests with 100 μg/ml salicylhydroxamic acid. The isolates showed similar sensitivity, the EC50 values ranging from 0.021 to 0.197 μg/ml. Baseline sensitivity was distributed as unimodal curves with mean EC50 values of 0.108 ± 0.004 μg/ml for picoxystrobin. In field experiments in 2015 and 2016, 57 isolates of Colletotrichum spp. from four geographical regions of China revealed a mean EC50 value of 1.074 ± 3.287 μg/ml, which was 9.94-fold higher than the baseline sensitivity. In these four regions, Qo inhibitors provided control efficacy of about 85%. The isolates with low, moderate, and high resistance to the QoI fungicide picoxystrobin accounted for 3.5%, 7.0%, and 5.3% of all 57 isolates, respectively. However, during continuous asexual culturing of the resistant isolates on fungicide-free medium for ten generations, picoxystrobin sensitivity of low and moderate resistant isolates was restored. Moreover, spore production, mycelial growth rates, and spore germination rates of the resistant isolates did not differ significantly from those of the sensitive isolates. Genetic analysis for mutations showed that picoxystrobin resistance was associated with a point mutation from GGT to GCT at codon 143 in the CytB gene (G143A) in high resistant mutants of C. gloeosporioides, but no point mutation was detected in low and moderate resistant isolates. Positive cross-resistance between picoxystrobin and QoIs (azoxystrobin and kresoxim-methyl) was observed; no cross-resistance between picoxystrobin and other type fungicides (carbendazim and prochloraz) was detected. [ABSTRACT FROM AUTHOR]

Poly (vinyl alcohol)/sodium alginate hydrogels were prepared by freeze‐thaw followed by calcium ion crosslinking. Chloramphenicol release behavior from the poly (vinyl alcohol)/sodium alginate hydrogels in mimic conditions of gastrointestinal tract was examined. The effects of composition, number of freeze‐thaw cycles and calcium ion concentration on drug release process were investigated. The results showed that the cumulative release amount of chloramphenicol from the hydrogels (crosslinked through 4 freeze‐thaw cycles and immersed in 2 % calcium chloride solution) decreased from 84.3 % to 72.3 % as sodium alginate content increased from 0 % to 75 %. For the hydrogels containing 50 % sodium alginate and immersed in 2 % calcium chloride solution after the freeze‐thaw cycles, cumulative release amount of chloramphenicol decreased from 83.5 % to 76.6 % as the freeze‐thaw cycles increased from 2 to 6. Cumulative release amount of chloramphenicol from the hydrogels containing 50 % sodium alginate and with 4 freeze‐thaw cycles decreased from 79.8 % to 75.6 % when concentration of calcium chloride solution increased from 1 % to 4 %. [ABSTRACT FROM AUTHOR]

Anthropogenic heat (AH) is an important part of urban surface energy balance. Although AH affects regional climates through changing land-atmosphere interactions, the climate forcing from AH are not usually calculated in state-of-the-art regional climate simulations. In this paper, the spatial pattern of AH in 20 automatic weather station sites in the Beijing municipal administrative area is parameterized by employing nighttime light data. Two experiments were designed and performed to quantify the influence of AH on the surface balance of energy and water through running the Integrated urban Land Model (IUM). The results show that due to accounting for AH, the simulated LST increases; the net radiation decreases around noon; the absolute value of the ground heat flux increases around noon; the sensible heat flux increases in the daytime; the evapotranspiration decreases around noon and increases in the morning and evening; volumetric soil moisture and soil water storage decrease; aggregated evapotranspiration increases. [ABSTRACT FROM AUTHOR]

In order to solve the problem of non-uniform powder concentration in electrical discharge machining (EDM) working fluid, a mathematical model of powder particle movement in stirred tank was established, and the flow field and solid-liquid suspension uniformity were simulated in this paper. The factors of slot shape, depth-diameter ratio, blade angle, blade installation height, and solid particle volume fraction which affected flow field distribution, solid suspension particle uniformity, and power consumption were researched, and the stirred tank structure was optimized. When the ratio of spherical stirred tank depth to diameter is 0.8, the blade design angle is 45°, and the installation height of impeller blade is 120 mm, the suspension uniformity of solid particles is the best and the power consumption is the smallest. Under the conditions of Al powder concentration 4 g/L, pulse width 175 μs, and pulse interval 75 μs, the powder-mixed EDM experiment of SiC/Al functionally gradient material was carried out with this optimized stirring device. The results show that the material removal rate of powder-mixed EDM increased by 24.82% and the surface roughness decreased by 27.28% than that of the conventional EDM. [ABSTRACT FROM AUTHOR]

Illumina high-throughput sequencing was applied to study the microbial community structure and seasonal variations in the mudflat sediments of Sansha Bay, China. Significant seasonal differences of microbial communities were observed, and pH, total P, total N, and organic carbon concentration were important factors affecting the microbial communities. A total of 52 bacterial phyla were detected in the sediments, dominated by γ-Proteobacteria (27.78%), δ-Proteobacteria (20.16%) and Bacteroidetes (10.58%). A total of 717 bacterial genera were detected, and among the top 100 genera with the highest abundances, 48 genera changed significantly (p <0.05) with seasons. The microbial community structure in summer was significantly different from others, and the environmental factors driving the changes were mainly temperature, organic carbon and total N concentration. The bacteria with higher abundances in summer were mainly attached bacteria, thermophilic bacteria, anaerobic bacteria, and those involved in carbon and nitrogen cycling, while in other seasons, those with higher abundances were mainly aerobic bacteria, which could adapt to low temperatures and are involved in the degradation of cellulose and chitosan. However, the physicochemical indexes didn't change significantly, which indicated that the bacterial communities are more sensitive and can serve as a good sentinel for environmental changes. [ABSTRACT FROM AUTHOR]

In order to solve the problem of low efficiency and poor surface quality, the method of powder mixed electrical discharge machining (PMEDM) was proposed for machining SiC/Al functionally graded materials (FGM). The thermo-electrical coupling simulation model was established. Based on the results of single-pulse discharge simulation, PMEDM material removal mechanism was researched. At the same time, the continuous multi-pulse EDM discharge dynamic simulation was studied. The position and the size of discharge crater and material removal rate (MRR) researched were discussed. Using PMEDM SiC/Al FGM, the crater depth is shallower and the radius is larger than traditional EDM. Under the condition of 5-wt% SiC/Al FGM, peak current 14 A, powder concentration 4 g/L, pulse width 175 μs, and pulse interval 75 μs, the maximum MRR error between simulation and experiment is 5.81%, and the minimum error is 4.13%. Compared with the traditional EDM, the efficiency of PMEDM is improved by 16.34%, and the surface roughness is reduced by 29.42%. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to investigate whether isolated maternal hypothyroxinaemia (IMH) is associated with risks of small/large-for-gestational-age (SGA/LGA) infants.Design: Population-based prospective cohort study.Setting: Ma'anshan Maternal and Child Health (MCH) clinics, China.Population: Pregnant women with singleton births (n = 3178).Methods: Descriptive statistics were calculated for the demographic characteristics of the mothers and their newborns. Linear regression was applied to estimate the association between thyroid hormone levels and birthweight. Logistic regression was performed to calculate the association between IMH and SGA/LGA.Main Outcome Measures: Outcomes included SGA/LGA.Results: The prevalence of IMH, defined as a free thyroxine value (FT4) lower than the 2.5th percentile with normal thyroid stimulating hormone, was 2.5% (78/3080) and 2.5% (74/2999) in the first and second trimesters, respectively. Additionally, 306 (9.6%) and 524 (16.5%) infants were defined as SGA and LGA, respectively. No evidence supported the notion that IMH is associated with an increased risk for SGA in either the first [odds ratio (OR): 1.762, 95% confidence interval (CI): 0.759-4.089] or the second (OR: 0.763, 95% CI: 0.231-2.516) trimester. However, an increased risk of LGA was observed among IMH women in the second trimester (OR: 2.088, 95% CI: 1.193-3.654). Maternal TPO-Ab positivity in the second trimester increased the risk of SGA (OR: 2.094, 95% CI: 1.333-3.290).Conclusion: This study provides evidence that IMH is associated with LGA.Funding: This work was supported by the National Natural Science Foundation of China (No. 81330068).Tweetable Abstract: Isolated maternal hypothyroxinaemia may increase the risk of large-for-gestational-age infants. [ABSTRACT FROM AUTHOR]