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Tea plants, as essential health beverages, are widely recognized for their rich content of antioxidant metabolites. This study utilized metabolomics analysis techniques to compare the metabolic differences between Camellia tachangensis F. C. Zhang, Camellia gymnogyna Hung T. Chang, and Camellia sinensis (L.) O. Kunzte, aiming to reveal their potential antioxidant activities. By applying UPLC–MS/MS technology, we analyzed metabolites in the samples and identified 1056 metabolites. We utilized statistical methods such as orthogonal partial least squares discriminant analysis (OPLS‐DA) and principal component analysis to evaluate and compare the variations in the samples. An intersection analysis of metabolites from the three types of tea plants identified 29 major differential metabolites. Functional annotation and pathway analysis of these differential metabolites were conducted, ultimately discussing 24 antioxidant‐related metabolites, primarily belonging to flavonoids, phenolic acids, and other categories. Among the three types of tea, C. tachangensis has the highest content of procyanidin B4, which is the most abundant substance in this tea. In terms of the impact of this substance on tea, it is known to have antioxidant properties and contributes to the overall antioxidant capacity of tea. In both C. gymnogyna and C. sinensis, the top 5 antioxidant metabolites include substances such as apigenin‐6,8‐di‐C‐glucoside (vicenin‐2), epigallocatechin, and apigenin‐5‐O‐glucoside. These substances belong to the flavonoid class and contribute to the antioxidant properties of these teas. Beyond the flavonoids and phenolic acids, other classes of metabolites in tea plants also exhibited significant antioxidant properties. These different metabolites play a key role in the antioxidant function of tea, contributing to their potential health benefits. The metabolites provide crucial insights for exploring and developing high‐antioxidant products that occur naturally. [ABSTRACT FROM AUTHOR]

The petal blight disease of alpine Rhododendron severely impacts the ornamental and economic values of Rhododendron. Plant secondary metabolites play a crucial role in resisting pathogenic fungi, yet research on metabolites in alpine Rhododendron petals that confer resistance to pathogenic fungi is limited. In the present study, the secondary metabolites in Rhododendron delavayi, R. agastum, and R. irroratum petals with anti-pathogenic activity were screened through disease index analysis, metabolomic detection, the mycelial growth rate, and metabolite spraying experiments. Disease index analysis revealed that R. delavayi petals exhibited the strongest disease resistance, while R. agastum showed the weakest, both under natural and experimental conditions. UHPLC-QTOF-MS/MS analysis identified 355 and 274 putative metabolites in positive and negative ion modes, respectively. The further antifungal analysis of differentially accumulated baicalein, diosmetin, and naringenin showed their half-inhibitory concentrations (IC50) against Neopestalotiopsis clavispora to be 5000 mg/L, 5000 mg/L, and 1000 mg/L, respectively. Spraying exogenous baicalein, diosmetin, and naringenin significantly alleviated petal blight disease caused by N. clavispora infection in alpine Rhododendron petals, with the inhibition rates exceeding 64%. This study suggests that the screened baicalein, diosmetin, and naringenin, particularly naringenin, can be recommended as inhibitory agents for preventing and controlling petal blight disease in alpine Rhododendron. [ABSTRACT FROM AUTHOR]

Iron (Fe) deficiency chlorosis (FDC) in plant is associated with high bicarbonate concentration in calcareous soil and irrigation water, which leads to new leaf yellowing and lessens crop yield and quality. However, little is known about whether the chlorosis under bicarbonate stress resulted from blocking root–shoot Fe translocation or root Fe absorption. Moreover, the molecular response of chlorotic leaf under bicarbonate stress has been rarely reported on. The purpose of this study was to investigate the effect of bicarbonate on Fe acquisition, Fe translocation as well as Fe accumulation in roots, normal leaf (NL) and chlorotic leaf (CL) of Medicago lupulina. Seeds were grown with and without Fe and NaHCO3 (Fe and Bic) in the nutrient solution for 10 d. Fe content, gene expression and enzymatic activity in different tissues were determined. A factorial statistical design with two factors (Fe and Bic) and two levels of each factor was adopted: + Fe, −Fe, + Fe + Bic and −Fe + Bic. Results indicated that bicarbonate stress increased the expression of genes MlHA1, MlFRO1 and MlIRT1 related to Fe acquisition and promoted the Fe absorption from solution. Furthermore, the presence of bicarbonate stress inhibited the expression of MlMATE66 in roots, prevented the Fe translocation from roots to developing leaf, brought about Fe accumulation in roots and reduced the Fe content in new leaf. Generally, according to our results, bicarbonate could prevent Fe translocation from roots into developing leaf, decrease Fe bioavailability and induce chlorosis in M. lupulina. [ABSTRACT FROM AUTHOR]

Flower color is an important ornamental feature that is often modulated by the contents of flavonoids. Chalcone synthase is the first key enzyme in the biosynthesis of flavonoids, but little is known about the role of R. delavayi CHS in flavonoid biosynthesis. In this paper, three CHS genes (RdCHS1-3) were successfully cloned from R. delavayi flowers. According to multiple sequence alignment and a phylogenetic analysis, only RdCHS1 contained all the highly conserved and important residues, which was classified into the cluster of bona fide CHSs. RdCHS1 was then subjected to further functional analysis. Real-time PCR analysis revealed that the transcripts of RdCHS1 were the highest in the leaves and lowest in the roots; this did not match the anthocyanin accumulation patterns during flower development. Biochemical characterization displayed that RdCHS1 could catalyze p-coumaroyl-CoA and malonyl-CoA molecules to produce naringenin chalcone. The physiological function of RdCHS1 was checked in Arabidopsis mutants and tobacco, and the results showed that RdCHS1 transgenes could recover the color phenotypes of the tt4 mutant and caused the tobacco flower color to change from pink to dark pink through modulating the expressions of endogenous structural and regulatory genes in the tobacco. All these results demonstrate that RdCHS1 fulfills the function of a bona fide CHS and contributes to flavonoid biosynthesis in R. delavayi. [ABSTRACT FROM AUTHOR]

Among ornamental plants, the colour of the petals is an important feature. However, the reason for the colour differences of Rhododendron liliiflorum remains unclear. To reveal the differences in the colour of R. liliiflorum, high-efficiency liquid chromatographic collar (UPLC–MS/MS) technology was used to study the yellow and white parts of R. liliiflorum. A total of 1187 metabolites were identified in R. liliiflorum petals, including 339 flavonoid metabolites. Seventy-eight types of flavonoids in these metabolites were found in the yellow and white parts of R. liliiflorum petals, along with 11 other significantly enriched substances. Combining gene expression-related data with differential metabolite data demonstrated effects of enrichment in the flavanonols (fustin), flavonols (epiafzelechin and afzelechin), and flavanones (pinocembrin) of flavonoid biosynthesis; glyccitin, 6″-O-malonylgenistin, and 6-hydroxydaidzein of isoflavonoid biosynthesis; and anthocyanin biosynthesis of malvidin-3-O-galactoside (primulin), delphinidin-3-O-rutinoside, cyanidin-3-O-glucoside (kuromanin), and cyanidin-3-O-rutinoside (keracyanin), which are potentially the contributing factors responsible for the differences in petal colour in R. liliiflorum. This study establishes a connection between the differential metabolites underlying the color differences in the petals of R. liliiflorum and the gene expression in R. liliiflorum. This will provide a foundation for subsequent research on the regulation of flower color in R. liliiflorum and have profound implications for horticultural applications of R. liliiflorum. [ABSTRACT FROM AUTHOR]

Previous studies have indicated that amide proton transfer-weighted imaging (APTWI) could be utilized for differentiating benign and malignant tumors. The APTWI technology has increasingly being applied to breast tumor research in recent years. However, according to the latest literature retrieval, no relevant previous studies compared the value of APTWI and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in distinguishing benign lesions from malignant lesions. In the present study, the application of APTWI and DCE for differentiating the benign and malignant breast lesions was investigated. APTWI was performed on 40 patients (42 lesions) who were enrolled in this prospective study. The lesions were split into two groups, one with malignant breast lesions (n = 28) and the other with benign breast lesions (n = 14), based on the results of the histology. The measured image characteristics (APT value, apparent diffusion coefficient [ADC] value, and time-of-intensity-curve [TIC] type) were compared between the two groups, and the ROC curve was used to quantify the diagnostic performance on the basis of these factors. The correlation between the APT values and the estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), and Ki-67 expression levels and histological grades was examined using Spearman's correlation coefficient. The measured APT and ADC values showed a strong inter-observer agreement according to the intraclass correlation coefficients (0.954 and 0.825). Compared to benign lesions, malignant lesions had significantly higher APT values (3.18 ± 1.07 and 2.01 ± 0.51, p < 0.001). Based on APTWI, DCE, diffusion-weighted imaging (DWI), and ADC + APTWI, ADC + DCE, and DCE + APTWI, the area-under-the-curve values were 0.915, 0.815, 0.878, 0.921, 0.916, and 0.936, respectively. APTWI is a potentially promising method in differentiating benign and malignant breast lesions, and may it become a great substitute for DCE examination in the future. [ABSTRACT FROM AUTHOR]

Nickel‐copper‐zinc (NiCuZn) spinel ferrites have attracted intensive research owing to their unique magnetic properties and low co‐fire temperature. Combustion synthesis has been viewed as a promising protocol for the large‐scale fabrication of NiCuZn spinel ferrites. However, the spinel ferrites prepared by this method usually suffer from limited saturation magnetization and high coercivity due to their large size, which will impose detrimental harmonics on electrical equipment (e. g. transformer, motor, etc.). To address these issues, highly porous NiCuZn spinel ferrite hierarchies were prepared within several hours through a modified solution combustion method, using glucose and ammonium nitrate as the fuel and combustion enhancer, respectively. The as‐obtained NiCuZn spinel ferrite hierarchies show excellent magnetic properties with a high saturation magnetization up to 62.61 emu/g and a low coercivity of 9.6 Oe thanks to the rational distribution of cations and grain size. More importantly, this method also allows various modifications (heteroatom doping) and large‐scale applications, which may be promising for the fabrication of high‐performance soft magnets for electrical equipment. [ABSTRACT FROM AUTHOR]

The interface microzone characteristics determine the thermophysical properties of diamond/Cu composites, while the mechanisms of interface formation and heat transport still need to be revealed. Here, diamond/Cu-B composites with different boron content were prepared by vacuum pressure infiltration. Diamond/Cu-B composites up to 694 W/(mK) were obtained. The interfacial carbides formation process and the enhancement mechanisms of interfacial heat conduction in diamond/Cu-B composites were studied by HRTEM and first-principles calculations. It is demonstrated that boron can diffuse toward the interface region with an energy barrier of 0.87 eV, and these elements are energetically favorable to form the B4C phase. The calculation of the phonon spectrum proves that the B4C phonon spectrum is distributed in the range of the copper and diamond phonon spectrum. The overlapping of phonon spectra and the dentate structure together enhance the interface phononic transport efficiency, thereby improving the interface thermal conductance. [ABSTRACT FROM AUTHOR]

Existing Siamese trackers usually do not update templates or adopt single‐updating strategies. However, historical information cannot be effectively utilized when using these strategies, and model drift from complex tracking challenges cannot be addressed. To address this issue, a novel tracking framework that learns the model update with local trusted templates is proposed in this paper. The authors propose a complementary confidence evaluation method to select local trusted templates in a sliding window. This provides high‐confidence historical information. The authors also propose a method including linear learning and deep learning to learn to model updates. Different from traditional update strategies, the authors' method combines non‐linear and linear updates to obtain reliable templates with the most abundant historical information, which solves the complex tracking challenges to a certain extent. Finally, the adaptive fusion response maps of the two strategies determine the final tracking based on the confidence evaluation. Experimental results on NFS, UAVDT, UAV123, UAV20L and VOT2016 show that our method performs favourably when compared with current state‐of‐the‐art methods. [ABSTRACT FROM AUTHOR]

Spinel ferrites have been widely used in various fields, among which nickel‐zinc (NiZn) ferrites have drawn much attention due to their high electrical resistivity as well as low eddy current loss. To accommodate highly‐integrated modern electronic devices, the preparation methods for nano/micro‐sized NiZn ferrites have been widely discussed. Nevertheless, these current synthesis routes are usually cost/time‐consuming, which hinders their large‐scale production for practical applications. Herein, we present a facile, low‐cost synthesis strategy for NiZn ferrites (NixZn1−xFe2O4, x=0, 0.25, 0.5, 0.75 and 1) through a blowing‐combustion method. The effect of Ni/Zn molar concentration on the structure, morphology as well as magnetic properties has been thoroughly investigated through X‐ray diffraction, Raman spectroscopy, scanning electron microscopy and vibrating sample magnetometer. Thanks to the synergetic effect of the pure phase and moderate Ni molar concentration, the Ni0.75Zn0.25Fe2O4 shows an enhanced saturation magnetization of 44.98 emu/g. More importantly, this blowing‐combustion method may also be commonly applied to other spinel ferrites with different stoichiometric ratios and heteroatom doping. [ABSTRACT FROM AUTHOR]

Rhododendron liliiflorum H. Lév., with white outer edges and yellow inner edges of petals, is an ornamental flower that originated in China. In this study, we analysed the white (W) and yellow (Y) parts of R. liliiflorum flowers by RNA sequencing. Then, unigene assembly, unigene annotation, and classification of Eukaryotic Orthologous Groups (KOGs) were performed. Gene ontology (GO) classification and pathway enrichment analysis for unigenes were also conducted. A total of 219,221 transcripts and 180,677 unigenes of R. liliiflorum were obtained from 48.52 Gb of clean reads. Differentially expressed gene (DEG) analysis indicated that 2310 unigenes were upregulated and 3062 were downregulated in W vs. Y. Thirty-six of these DEGs were involved in the flavonoid biosynthesis pathway. Pathway enrichment analysis showed that DEGs were significantly enriched in phenylpropanoid, flavonoid, and isoflavone biosynthesis. The expression of dihydroflavonol-4-reductase (DFR) and chalcone synthase (CHS) may affect differences in R. liliiflorum flower colour. The findings on flavonoid biosynthesis and other related genes in this study will provide guidance for exploring the mechanism of flower colour formation in Rhododendron. [ABSTRACT FROM AUTHOR]

Floral development and senescence are a crucial determinant for economic and ornamental value. CircRNAs play an essential role in regulating plant growth and development; however, there is no systematic identification of circRNAs during the lifespan of flowers. This study aims to explore the expression profile and functional role of circRNAs in the full flowering stages of Rhododendron delavayi Franch. We carried out transcriptome sequencing of the six stages of Rhododendron delavayi Franch flowers to identify the circular RNA expression profile. In addition, using bioinformatics methods, we explored the functions of circRNAs, including analysis of the circRNA-miRNA-mRNA network, short time-series expression miner (STEM), and so on. We identified 146 circRNAs, of which 79 were differentially expressed from the budding to fading stages. Furthermore, using STEM analysis, one of the 42 circRNA expression model profiles was significantly upregulated during the senescence stage, including 16 circRNAs. Additionally, 7 circRNA-miRNA-mRNA networks were constructed with 10 differentially expressed circRNAs, in which some target mRNA may regulate the development and senescence of the Rhododendron flowers. Finally, by analyzing the correlation between circRNAs and mRNA, combined with existing reports, we proposed that circRNAs play a regulatory role during flower development and senescence by mediating the jasmonate signaling pathway. Overall, these results provide new clues to the potential mechanism of circRNAs acting as novel post-transcriptional regulators in the development and senescence process of flowers. [ABSTRACT FROM AUTHOR]

Ships sailing in the area of a bridge are vulnerable to the influence of complex water flow, due to the complex flow pattern around the bridge pier. Ships often crash into bridge piers, leading to serious economic losses and threating personal safety. Based on the common forms of piers of skew bridges, the hydrodynamic problems encountered during ship–bridge interactions in the area of a skew bridge were studied using particle image velocimetry-based flume testing, physical model testing, and numerical simulation. The influence of the flow angle of attack of a round-ended pier on the force and center of gravity of a ship moving on both sides of a pier is discussed under various ship–bridge transverse spacings. The results show that as a ship passes through the bridge area, the bow roll moment exhibits three peak values: 'positive', 'negative', and 'positive', and the curve of the center of gravity position forms the shape of a 'straw hat'. With an increase in the flow angle of attack of the pier, the negative peak value and the second positive peak value of the bow roll moment of the ship passing through the back flow side of the pier become greater than those on the upstream side. Moreover, the ship's navigation attitude is more unstable compared to that upstream, and the ship is at risk of colliding with the pier and sweeping. The width of the restricted water area, determined by the hydrodynamic action between the ship and bridge in the skew bridge area, is the same as that determined by the critical lateral velocity. For the ship class referred to in this study, the current code can also be used in channel design, to safeguard ship and personal safety with piers with a large flow angle of attack. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: With the rapid development of the wearable electronics, the flexible supercapacitor with high energy density has attracted more and more attentions. From the viewpoint of outdoor and underwater application, this research tried to impart the superhydrophobicity to the flexible supercapacitors. The polyvinyl alcohol/HNO3 hydrogel was utilized as the electrolyte, which could achieve self‐healing capability without the freezing/thawing process. Both microscale graphene and nanoscale carbon nanotubes were utilized as the electrode materials. After surface modification, the hydrophobic suspension composed of graphene and carbon nanotubes was sprayed onto the two sides of hydrogel electrolyte to construct superhydrophobic electrode. Hence, the superhydrophobicity endows the supercapacitor with outstanding self‐cleaning performance. The all‐in‐one structure endows the supercapacitor with improved capacitive ability, outstanding flexibility, good anti‐abrasion property, and reliable self‐healing capability. The combination of superhydrophobicity and flexible energy storage might have a broad application for the outdoor and underwater wearable electronics applications. [ABSTRACT FROM AUTHOR]

Bone mesenchymal stem cells (BMSCs) are the most commonly investigated progenitor cells in bone tissue engineering for treating severe bone defects. Strategies for regulating BMSC differentiation fate have received wide attention, in which redox homeostasis plays an important role due to the change in energy metabolism during stem cell differentiation. In the present study, it was observed that autophagic activity was induced along with BMSC osteogenic differentiation and subsequently regulated reactive oxygen species (ROS) generation and the level of osteogenesis. Furthermore, it was also observed that neuropeptide substance P (SP) administration could enhance the autophagic activity in rat BMSCs via the AMPK and mTOR pathways, as well as decreasing ROS generation and promoting osteogenic differentiation. Inhibition of autophagic activity by 3-MA reversed the effects of SP on ROS and osteogenic levels. The present results indicated that autophagic activity participated in the regulation of differentiation fate of BMSCs and SP could promote osteogenic differentiation by activating autophagy, providing a more precise biological mechanism for its application in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Karst topography is formed from the dissolution of soluble rocks, such as limestone and dolomite. In soils of such a landform, excessive contents of exchangeable calcium seriously limit the growth of vegetations. Researches have proved that rhizosphere microorganisms and endophytes help host plants to adapt to various adverse environments. The adaptive capacity of plants that grow in adverse environment with salt, drought, thermal and heavy metal stresses partially or completely comes from symbiotic microorganisms. By using the high-throughput amplicon sequencing, the bacterial community structures in soil with high calcium contents and roots and leaves of Cochlearia henryi that is commonly seen in karst area were analyzed. The bacteria community structures in these three compartments showed obvious differences. This indicates that C. henryi, which is adaptive to high calcium stress, selectively co-exists with specific bacteria. Although the bacteria community structures in these three compartments differed significantly, there were 73 operational taxonomic units (OTUs) shared by karst soils as well as roots and leaves of C. henryi. The phylogenetic diversity of these 73 OTUs differed significantly from that of overall OTUs detected. There were also obvious differences in KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways and abundance values between the 73 OTUs and overall bacterial communities. A large number of OTUs shared by the karst soils, roots and leaves of C. henryi had close genetic relationship with known stress-resistant bacterial strains. Our results showed that the functional bacteria can be predicted by exploring core bacteria, bacteria shared by soils, adaptable plant roots and leaves. This information will potentially accelerate studies on natural microbial communities which can promote the adaptive capacity of host plants to high calcium stress, and will be valuable for finding microbial strains for field application in karst topography. [ABSTRACT FROM AUTHOR]

Chinese liquor is one of the world’s oldest distilled alcoholic beverages and an important commercial fermented product in China. The Chinese liquor fermentation process has three stages: making Daqu (the starter), stacking fermentation on the ground, and liquor fermentation in pits. We investigated the bacterial diversity of Maotai and Guotai Daqu and liquor fermentation using high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene. A total of 70,297 sequences were obtained from the Daqu samples and clustered into 17 phyla. The composition of the bacterial communities in the Daqu from these two soy sauce aroma-style Chinese liquors was the same, although some bacterial species changed in abundance. Between the Daqu and liquor fermentation samples, 12 bacterial phyla increased. The abundance of Lactobacillus and Pseudomonas increased in the liquor fermentation. This study has used high-throughput sequencing to provide new insights into the bacterial composition of the Chinese liquor Daqu and fermentation. Similarities in the distribution of bacteria in the soy sauce aroma-style Chinese liquors Daqu suggest that the abundance of bacteria might be generally concerned to other liquor. [ABSTRACT FROM AUTHOR]

In this paper, a new point cloud compression method is proposed. The 3D color point cloud is firstly mean-shift clustered into many homogeneous blocks based on the similar spatial (XYZ) information of each point. Based on the RANdom SAmple Consensus (RANSAC) algorithm, those points being clustered in the same block are fitted by a 3D plane and all these points belonging to the same block are projected to this corresponding plane. For every plane an optimal rectangle bounding box is identified and is divided into n × n grids, the color (RGB) information associated with each grid point is replaced by the average of RGB values of all the projected points falling in this grid. Finally, a 2D DCT (Discrete Cosine Transform) transform is performed on these n × n grids points. The compressing ratio can reach 32 with negligible spatial and color distortion. [ABSTRACT FROM AUTHOR]

[Objective] To establish methods to determine the content of Aconitine, Yunaconitine, Crassicauline and Vilmorrianine in Aconitun sungpanense Hand-Mazz. and provide scientific basis for its reasonable and safe application. [Methods] Aconitine, Yunaconitine, Crassicauline and Vilmorrianine were used as references. Phenomenex Gemini C18 110A (250 mm ×4.6 mm, 5 [μm); mobile phase; acetonitrile -0.2% acetic acid (pH was regulated to by triethylamine); gradient elute; flow rate; 1 mL/min; UV wavelength 235/254 nm; column temperature; 30 CC. [Results] The content of the 4 Ester-series alkaloids in Aconitun sungpanense Hand. -Mazz. could be determined at the same time. The average recovery rate (n = 6) of Aconitine, Yunaconitine, Crassicauline and Vilmorrianine reached 99. 65% (RSD = 1. 46%), 99. 13% (RSD = 1.32%), 98.13% (RSD =0.98%) and 98.66% (RSD = 1.67%). [Conclusions] The method was simple, accurate and had good repeatability. It could determine the content of Aconitine, Yunaconitine, Crassicauline and Vilmorrianine in Aconitun sungpanense Hand.-Mazz. at the same time. It also provided scientific basis for standardizing the processing of Aconitun sungpanense Hand. -Mazz. and its reasonable and safe application. [ABSTRACT FROM AUTHOR]

3D visualization and real-time rendering of large-scale scenes is an important task of virtual reality. In this paper, different from local loading and roaming of the scenes, we focus on dynamic loading and real-time roaming, based on the remote servers and clients, to facilitate the efficient transmission and reduce the transmission time. More specifically, a novel dynamic scheduling algorithm in the client side is used to optimize the loading and real-time rendering performance, i.e., this method can dynamically load and unload the partitioned data blocks from the server side according to the roaming viewpoints so that we can realize the infinite roaming of a large scale scene. In order to accommodate different networking scenarios, we also design a multi-resolution scheme for those server-stored scene blocks according to different communication channel conditions, so that the most suitable resolution scheme can be automatically chosen. As shown in the experiments, our method only requires a small amount of memory overhead, while efficiently realizes infinite roaming of the large city scenes. [ABSTRACT FROM AUTHOR]

The thermal conductivity of diamond hybrid SiC/Cu, diamond/Cu and SiC/Cu composite were calculated by using the extended differential effective medium (DEM) theoretical model in this paper. The effects of the particle volume fraction, the particle size and the volume ratio of the diamond particles to the total particles on the thermal conductivity of the composite were studied. The DEM theoretical calculation results show that, for the diamond hybrid SiC/Cu composite, when the particle volume fraction is above 46% and the volume ratio of the diamond particles to the SiC particles is above 13:12, the thermal conductivity of the composite can reach 500 W·m·K. The thermal conductivity of the composite has little change when the particle size is above 200 μm. The experimental results show that Ti can improve the wettability of the SiC and Cu. The thermal conductivity of the diamond hybrid SiC/Cu is almost two times better than that of the diamond hybrid SiC/Cu. It is feasible to predict the thermal conductivity of the composite by DEM theoretical model. [ABSTRACT FROM AUTHOR]

The package and system level temperature and thermal stress distributions of 10 W light emitting diode (LED) with 4 chips and 100 W LED with 100 chips were investigated using finite element analysis. The chips were arranged on a Si sheet which is soldered on the copper/diamond composite slug with very high conductivity. The experimental results show that the maximal temperature appears in the chips of both two high power LEDs packages. Compared with the 10 W LEDs package with 4 chips array, the heat issue caused by stacking and coupling of the heat in 100 W LEDs package with 100 chips array is more serious. The chip temperature in the center of the array is much higher, and it decreases with the distance between the chip and the center of LEDs increases. Great thermal stress lies between the chips and the solder, which will reduce the reliability of the package. [ABSTRACT FROM AUTHOR]

Diamond reinforced copper (Cu/diamond) composites were prepared by a pressure infiltration technique. The composites show a super high conductivity of 713 W·m·K in combination with an extremely low coefficient of thermal expansion (CTE) of 7.72 × 10 K (25-100°C), which are achieved by modifying the copper matrix with adding 0.3 wt.% of boron to get a good thermal contact between the matrix and the diamond particles. By adopting a series of postmachining techniques the composites were made into near-net-shape parts, and an electroless silver coating was also successfully plated on the composites. Finally, their potential applications in the thermal management of light emitting diodes (LED) were illustrated via prototype examples. [ABSTRACT FROM AUTHOR]

Diamond/Cu- xCr composites were fabricated by pressure infiltration process. The thermal conductivities of diamond/Cu- xCr ( x = 0.1, 0.5, 0.8) composites were above 650 W/mK, higher than that of diamond/Cu composites. The tensile strengths ranged from 186 to 225 MPa, and the bonding strengths ranged from 400 to 525 MPa. Influences of Cr element on the thermo-physical properties and interface structures were analyzed. The intermediate layer was confirmed as CrC and the amount of CrC increased with the increase of Cr concentration in Cu- xCr alloys. When the Cr concentration was up to 0.5 wt.%, the content of the CrC layer was constant. As the thickness of the CrC layer became larger, the composites showed a lower thermal conductivity but higher mechanical properties. The coefficients of thermal expansion (CTE) of diamond/Cu- xCr ( x = 0.1, 0.5, 0.8) composites were in good agreement with the predictions of the Kerner' model. [ABSTRACT FROM AUTHOR]

Forced convection heat transfer of single-phase water in helical coils was experimentally studied. The testing section was constructed from a stainless steel round tube with an inner diameter of 10 mm, coil diameter of 300 mm, and pitch of 50 mm. The experiments were conducted over a wide Reynolds number range of 40000 to 500000. Both constant-property flows at normal pressure and variable-property flows at supercritical pressure were investigated. The contribution of secondary flow in the helical coil to heat transfer was gradually suppressed with increasing Reynolds number. Hence, heat transfer coefficients of the helical tube were close to those of the straight tube under the same flow conditions when the Reynolds number is large enough. Based on the experimental data, heat transfer correlations for both incompressible flows and supercritical fluid flows through helical coils were proposed. [ABSTRACT FROM AUTHOR]

Gasification of peanut shell, sawdust and straw in supercritical or subcritical water has been studied in a batch reactor with the presence of a series of Raney-Ni and its mixture with ZnCl2 or Ca(OH)2. The main gas products were hydrogen, methane, carbon dioxide, and a small amount of carbon monoxide. Different types of Raney-Ni, containing different metal components such as Fe, Mo or Cr, have different influences on the gasification yield and hydrogen selectivity. The catalysis effect can be improved obviously by adding ZnCl2 or Ca(OH)2. Increasing the reaction temperature or adding ZnCl2 and Ca(OH)2 could improve the mass of H2 in gas products and reduce the mass of CH4 and CO2 at the same time. The possible mechanism is that ZnCl2 can decompose the biomass particle by accelerating cellulose hydrolyzation in high-temperature water, increasing more specific surface to admit catalysts, while Ca(OH)2 can absorb CO2 to produce CaCO3 deposit, which can drop out from the reactant system, and which will drive the reaction to get more hydrogen. With respect to the biomass conversion to gas product and selectivity of H2 at low temperature, the series of Raney-Ni has shown many advantages over other catalysts; thus, this kind of catalyst has great potential to be utilized in the hydrogen industry for the gasification of biomass. [ABSTRACT FROM AUTHOR]

The key reasons that the present method cannot be used to solve the industrial multiphase flow pattern recognition are clarified firstly. The prerequisite to realize the online recognition is proposed and recognition rules for partial flow pattern are obtained based on the massive experimental data. The standard templates for every flow regime feature are calculated with self-organization cluster algorithm. The multi-sensor data fusion method is proposed to realize the online recognition of multiphase flow regime with the pressure and differential pressure signals, which overcomes the severe influence of fluid flow velocity and the oil fraction on the recognition. The online recognition method is tested in the practice, which has less than 10 percent measurement error. The method takes advantages of high confidence, good fault tolerance and less requirement of single sensor performance. [ABSTRACT FROM AUTHOR]

Hydrogen is a clean energy carrier. Converting abundant coal sources and green biomass energy into hydrogen effectively and without any pollution promotes environmental protection. The co-gasification performance of coal and a model compound of biomass, carboxymethylcellulose (CMC) in supercritical water (SCW), were investigated experimentally. The influences of temperature, pressure and concentration on hydrogen production from co-gasification of coal and CMC in SCW under the given conditions (20–25 MPa, 650°C, 15–30 s) are discussed in detail. The experimental results show that H2, CO2 and CH4 are the main gas products, and the molar fraction of hydrogen reaches in excess of 60%. The higher pressure and higher CMC content facilitate hydrogen production; production is decreased remarkably given a longer residence time. [ABSTRACT FROM AUTHOR]

Diamond particle-reinforced copper matrix composites (Diamond/Cu) are recognized as promising electronic packaging materials due to their excellent thermophysical properties. It is necessary to investigate the reliability of Diamond/Cu composites under extreme environmental conditions. The corrosion behavior of Diamond/Cu composites was studied in a 5 wt% NaCl neutral salt spray. Surface morphology, thermal conductivity, bending strength, corrosion rate, and corrosion depth resulting from corrosion were researched in this paper. The results showed that the corrosion phenomenon mainly occurs on the copper matrix, and the diamond and interface products do not corrode. The corrosion mechanism of Diamond/Cu composites was micro-galvanic corrosion. The corrosion product formed was Cu2Cl(OH)3. The salt spray environment had a great influence on the composite surface, but the composite properties were not significantly degenerated. After a 168-h test, the bending strength was unaltered and the thermal conductivity of gold-plated composites showed a slight decrease of 1–2%. Surface gold plating can effectively improve the surface state and thermal conductivity of Diamond/Cu composites in a salt spray environment. [ABSTRACT FROM AUTHOR]

The present study aimed at systematically investigating the endophytic communities of dominant plants in the karst ecosystem. Soil and plant materials were collected and after sequencing of the 16 s RNA, the diversity and abundance of the endophytic community structures in leaves were examined. Our results showed that abundant and diverse endogenous bacteria were associated with the leaves of common dominant plants living in the karst ecological environment. Notably, common traits and significant differences in the endophytic community structures were recorded among different plant species with different leaf grown in soils with different calcium contents. These observations implied that plants may adopt different strategies to adapt to the karst ecological environment. In addition, the endophytic bacteria associated with the leaves may be involved in different physiological strategies used by the plants to adapt to the karst ecological environment. These findings provide new avenues for developing microbial agents that could be suitable for the karst ecological environment and will provide sustainable solutions for improving the ability of plants to adapt to karst special adversities, and thus for karst geomorphological environmental protection and agricultural development. [ABSTRACT FROM AUTHOR]