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Drying is the key process through which the aroma of tencha forms. However, the effects of drying method on volatiles are unknown. We compared tencha-ro drying with regular drying. Volatiles in tencha infusions were extracted using headspace solid-phase microextraction and solvent-assisted flavor evaporation combined with gas chromatography-mass spectrometry. Partial least squares (PLS), odor activity value (OAV), and heat map analyses were performed to identify the optimal drying method for creating a seaweed-like aroma. Changes in the key volatile compounds of the samples were investigated. The tencha infusions contained 125 volatiles with nine chemical structures. According to the sensory evaluation, tencha-ro drying was the optimal method for producing high-quality tencha with an intense and consistent seaweed-like aroma. The PLS model accurately distinguished among the types of tencha. By combining OAVs with screening through multivariate statistical analysis, six volatile compounds were revealed to contribute substantially to tencha's seaweed-like aroma: 2-ethyl-3,5-dimethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-5-methylpyrazine, dimethyl sulfide, β-ionone, and 2-formyl-1-methylpyrrole. The findings provide a theoretical basis and technical guidance for the processing of high-quality tencha with a strong seaweed-like aroma. PRACTICAL APPLICATION: This study demonstrated that tencha-ro drying contributes to the formation of a seaweed-like aroma in tencha and provides theoretical guidance for tea factories to use the appropriate drying methods for high-quality tencha.

Fresh tea leaves (Camellia sinensis; Chuanxiaoye) used to make tencha tea are a combination of the stem and leaf. Tencha made from the leaf alone is considered a high-quality tencha beverage with a seaweed-like aroma, mellow taste, and a green appearance. However, no study has investigated the differences between these two variants. In this study, the effects of stem removal on physicochemical properties and sensory quality of tencha beverage were investigated. The appearance feature, taste, and aroma were evaluated, and the results indicated that stem removal improved the quality of tencha beverages. The water extract, total free amino acids, total catechin, epigallocatechin gallate, caffeine, and chlorophyll were higher in leaf-only tencha (LOT) than in leaf and stem tencha (LST), whereas the crude fiber and phenol ammonia ratios were lower in LOT than in LST. Principal component analysis and hierarchical clustering analysis further discriminated between the tencha beverages with different stem contents. This study provided a theoretical basis for quality control by adopting a stem-leaf separation process in tencha manufacturing. PRACTICAL APPLICATION: This research provides theoretical guidance for improving tencha quality during manufacturing.

A porous MoS2-polyhedral oligomeric silsesquioxane (POSS) nanohybrid was prepared from octavinyl-POSS nanoparticles and MoS2 nanosheets for the first time, the structure and composition of which were confirmed by X-ray powder diffraction (XRD), Fourier-transform infrared spectra (FTIR), scanning electron microscopy (SEM), energy dispersive spectra (EDS) and thermal gravimetric analysis (TGA). As a comparison, MoS2 nanosheets, octavinyl-POSS and MoS2-POSS nanohybrid were used as lubricating additives for liquid paraffin (LP), which decreased the friction coefficients of LP by 7.8% (MoS2), 14.1% (octavinyl-POSS), and 18.8% (MoS2-POSS). Compared with MoS2 and octavinyl-POSS, the MoS2-POSS nanohybrid can be dispersed in organic solvents more homogeneously without adscititious dispersants or surfactants due to its better organic compatibilities. SEM and EDS analyses indicate that a synergistic frictional effect is responsible for the improved friction-reduction and anti-wear behavior.

In the context of climate change, enhanced human activities and ecological changes, the danger level for mountain floods has increased significantly, posing direct or potential hazards to local residents. To determine the current status, focus and trends in mountain flood research, in this study, we visualize the number of publications and citations, the countries and institutions engaged in research, co-citations and key literature, keyword categories and research areas, using keyword timeline analysis and burst detection based on the bibliometric software CiteSpace and VOSviewer and the Web of Sciences core collection database. The results show that the total number of publications and citations in the mountain flood field has experienced rapid growth to date. The United States, China, Germany, the United Kingdom, and Switzerland are the main countries driving the development of the field. The field is of great interest within multiple disciplinary categories and is characterized by multiple research hotspots, multiple research objectives, and cross-fertilization of multiple disciplinary categories. Analysis of the keyword timeline network and highlighted words show that disaster risk evaluation based on remote-sensing technology, the alpine region of the Himalayas, the response mechanisms of heavy rainfall to mountain floods, and the construction of hydrological models, will be research hotspots in the future.

Intelligent construction is the inevitable choice for the traditional construction industry to transform into technology intensive, and the production mode of intelligent construction will inevitably form D (Date), M (Modeling), B (Blueprint), P (Precision). In western China, the production level is on the lower side, and the urban infrastructure construction needs to be optimized and improved urgently. Therefore, it is very important to update the city appearance and improve the building quality through intelligent construction. In this paper, the application of DMBP intelligent building technology is analyzed based on the case of prefabricated houses in western China, which provides reference for the optimization and transformation of the construction industry.

Liver is responsible for 90% of lipid synthesis in poultry, thus, it plays an important role in the growth of Muscovy ducks, which have a high fat deposition ability in a time-dependent manner. Therefore, male Muscovy ducks at 14, 28, 42, and 56 days were selected for body weight (BW), carcass weight (CW), subcutaneous fat thickness (SFT), abdominal fat weight (AFW), intramuscular fat content (IMF), and breast muscle fiber (BMF) diameter and density determination. Two-dimensional electrophoresis (2-DE) combining liquid chromatography linked to tandem mass spectrometry (LC-MS/MS) was used to analyze proteomic changes in liver at each stage. The BW, CW, AFW, SFT, and BMF diameter and density were significantly increased, while IMF content was significantly decreased at 28 to 42 days of age (p &lt, 0.05). There were 57 differentially abundant protein (DEP) spots representing 40 proteins identified among the ages, in which 17, 41 and 4 spots were differentially abundant at 14 vs. 28, 28 vs. 42, and 42 vs. 56, respectively. Gene Ontology enrichment analysis found that DEPs were mostly enriched in the oxidation-reduction process, carboxylic acid metabolism, etc. Protein–protein interaction showed that catalase (CAT), triosephosphate isomerase (TPI), and protein disulfide-isomerase (PDI) were the key proteins responsible for the growth of Muscovy duck. In conclusion, 28 to 42 days of age is the crucial period for Muscovy ducks, and the ability of metabolism and antioxidants were significantly enhanced in liver.

This study attempted to detect the total theaflavins content in black tea using a portable electronic tongue integrated with chemometric algorithms. Glassy carbon as a working electrode was used to collect the cyclic voltammetry current signals from the black tea samples. The synergy interval partial least square with competitive adaptive reweighted sampling (Si-CARS-PLS) was attempted to optimize and select the most informative current signal variables at special potentials for the prediction of the total theaflavins content in black tea. Models were optimized via cross validation. Compared with other characteristic variables selection methods, Si-CARS-PLS showed the best performance, employing only 13 variables (0.23% of the total variables), to achieve Rp = 0.8302 and RMSEP = 0.257 in the prediction set. The portable electronic tongue based on glassy carbon electrode and cyclic voltammetry combined with variable selection algorithm Si-CARS-PLS, proved a promising, rapid and cost-effective method to measure the total theaflavins content in black tea.

Crush-tear-curl (CTC) black tea is a popular beverage, owing to its unique taste characteristics and health benefits. However, differences in the taste quality and chemical profiles of CTC black tea from different geographical regions remain unclear. In this study, 28 CTC black tea samples were collected from six geographical regions and analyzed using electronic tongue and ultrahigh performance liquid chromatography-Orbitrap-mass spectroscopy. The e-tongue analysis indicated that each region's CTC black tea has its own relatively prominent taste characteristics: Sri Lanka (more umami and astringent), North India (more umami), China (more sweetness and astringent), South India (moderate umami and sweetness), and Kenya (moderate umami and astringent). Based on multivariate statistical analysis, 78 metabolites were tentatively identified and used as potential markers for CTC black tea of different origins, mainly including amino acids, flavone/flavonol glycosides, and pigments. Different metabolites, which contributed to the taste characteristics of CTC black tea, were clarified by partial least squares regression correlation analysis. Our findings may serve as useful references for future studies on origin traceability and quality characteristic determination of CTC black teas. PRACTICAL APPLICATION: This study provides useful references for future studies on the origin traceability and taste characteristic determination of CTC black teas from different geographical regions.

A porous MoS

Aroma is one of the most important quality attributes of black tea infusions. In this study, the aroma quality of 44 Dianhong black tea (DBT) infusions were investigated by rapid gas phase electronic nose (GC-E-Nose) combined with multivariate statistical analysis for the first time. Among 61 volatile compounds identified, the most abundant ones were aldehydes. Both partial least squares discriminant analysis (PLS-DA) and Fisher discriminant analysis (FDA) could effectively classify the aroma quality of DBT infusions. The prediction accuracy of FDA (95.2%) was higher than that of PLS-DA (78.6%). Moreover, stepwise multiple linear regression was shown to accurately predict the quality score of DBT infusions, and the Rp value of the sensory score of the predicted model was 0.94. Furan, methyl acetate, 2,3-pentanedione, limonene, and linalool were found positively correlated with the aroma quality of DBT infusions, while 3-ethylpentane, 1-pentene, (E)-2-hexene, and methyl eugenol were negatively correlated with the aroma quality of DBT infusions. These results contribute to understand that rapid GC-E-Nose technology is a supplement to the objective sensory evaluation, and provide a new technical method for the quality evaluation and control of tea infusions.

This study aimed to evaluate the effects of incorporation of aleurone‐rich fraction (ALF) on the hydration and rheological properties of wheat dough. Incorporation of ALF significantly increased water absorption (P

Perfluorooctanoic acid (PFOA) is widely distributed in various environmental media and is toxic to organisms. This study demonstrated that PFOA induces hepatotoxicity in the frog and evaluated the role of CYP3A and the Nrf2-ARE signaling pathway in regulating responses to PFOA-induced hepatotoxicity. Rana nigromaculata were exposed to 0, 0.01, 0.1, 0.5, or 1 mg/L PFOA solutions in a static-renewal system for 14 days. Liver tissue samples were collected 24 h after the last treatment. Hepatic histology was observed by HE staining and transmission electron microscopy. The oxidative stress levels in the liver were measured. The expression levels of CYP3A, Nrf2, NQO1, and HO-1 mRNA were measured by quantitative reverse transcription–polymerase chain reaction. PFOA-treated frog liver tissue exhibited diffuse cell borders, cytoplasmic vacuolization, broken nuclei, nuclear chromatin margination, and swollen mitochondria. In addition, the livers of PFOA-treated frogs showed a significantly elevated content of reactive oxygen species, malondialdehyde, glutathione and glutathione S-transferase activity compared to the livers of control frogs. However, the glutathione peroxidase activities concomitantly decreased in PFOA-treated frogs compared to those in the control group. Furthermore, compared with control frogs, the expression levels of CYP3A, Nrf2, and NQO1 mRNA significantly increased in PFOA-treated frogs. HO-1 mRNA expression remarkably increased only in groups treated with 0.5 or 1 mg/L PFOA. Our results indicate that PFOA induces hepatotoxicity in a dose-dependent manner. Furthermore, the results of the comparison analysis between different gender groups illustrated that PFOA is more toxic to female frogs than male frogs. Our results demonstrated that PFOA causes liver damage and that CYP3A enhances PFOA-induced female frogs hepatotoxicity are more virulent than male through biotransformation, and the activation of the Nrf2-ARE pathway is induced to protect against hepatotoxicity in Rana nigromaculata, all of which provide the scientific basis for the protection of amphibians against environmental contaminants.

In this paper, the effects of graphene content, water-to-binder ratio (w/b) and curing age on the conductivity of magnesium sulfate cement were evaluated. Besides, the enhancement and conductivity mechanism of graphene was analyzed by means of electrochemical impedance spectroscopy (EIS) technique and scanning electron microscopy (SEM). As a result, the conductivity of the composite was improved and percolation phenomenon was observed. The conductivity percolation interval of the specimens was about 0.6 wt%–1.4 wt%. The relationship between conductivity and graphene content was described. The conductivity of the composite was improved with the interaction of ionic conduction, graphene tunnel conduction and contact conduction.

The black tea could be stored for a long time, and subsequently affects the flavor characteristics. In the present study, the effects of storage years (1, 2, 3, 4, 5, 10, 17 and 20 years) on the chemical profiling and taste quality of keemun black tea (KBT) were compared by metabolomics and quantitative sensory evaluation. The main polyphenols were degraded during the storing, especially 10-year storage, but caffeine and theobromine were stable. The intensity of bitterness, astringency, umami was negatively correlated to storage years, with correlation coefficient at −0.95, −0.91 and −0.83 respectively, whereas sweetness had positive correlation coefficient at 0.74. Quinic acid, galloylated catechins, linolenic acid, linoleic acid, malic acid, palamitic acid, and theaflavin-3-gallate were marker compounds which were responsible for distinguishing short and long time preserved KBT. The contents of fatty acids were positively correlated to storage time and sweet intensity.

We introduce a new enhanced algorithm with a population entropy based population adaptation strategy under the framework of SHADE (PE-SHADE). The distribution state of the population is characterized, and then the population size is adapted with a population increasing strategy and a population reduction strategy. Experimental results on CEC2014 statistically support the effectiveness of the proposed algorithm.

A Fe-Mn bi-metallic oxide supported on granular activated carbon (Fe-Mn GAC) has been fabricated by an impregnation-desiccation method and tested in the catalytic ozonation of methyl orange (MO) degradation and mineralization. X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy characterizations revealed that Fe-Mn oxides were successfully loaded and uniformly distributed on the GAC, and nitrogen adsorption isotherms showed that the supported GAC retained a large surface area and a high pore volume compared with the pristine GAC. The catalytic activity was systematically assessed by monitoring the MO removal efficiencies at different operational parameters, such as catalyst dosage, initial solution pH, and ozone flow rate. The Fe-Mn GAC exhibited better catalytic activity relative to ozone alone and GAC alone, improving the TOC removal by 24.5 and 11.5 % and COD removal by 13.6 and 7.3 %, respectively. The reusability of the hybrid was examined over five consecutive cyclic treatments. The Fe-Mn GAC catalytic activity was only a slight loss in the cycles, showing good stability. The addition of Na2CO3 as hydroxyl radicals (•OH) scavengers proved that the catalytic ozonation mechanism was the enhanced generation of •OH by the Fe-Mn GAC. The above results render the Fe-Mn GAC an industrially promising candidate for catalytic ozonation of dye contaminant removal.

Monolayer or ultrathin transition metal dichalcogenides cover a wide range of atomically thin two-dimensional (2D) materials, whose fascinating properties have made them promising candidates for many applications. In this work, ultrathin MoS2 flakes were successfully exfoliated, induced by bovine serum albumin (BSA) or hemoglobin (HB), under vigorous ultra-sonication. They were used as additives for water-based lubricating systems and related investigations indicated that they could improve the friction performance and anti-wear abilities at a relatively low concentration: 0.10 wt% of additive contents can make the average friction coefficient stabilize in the range between 0.06 and 0.08, which results from the formation of a dynamic protective film on the friction surfaces. The protein-induced ultrathin MoS2 flakes are also expected to be useful for other hydrophilic lubrication systems, which possess great scientific value and promising application prospects compared with bulk or microscale lubricating additives.

Polyhedral oligomeric silsesquioxane (POSS) based nanohybrids were prepared via “thiol–ene click” reaction between vinylPOSS and alkyl mercaptan. The structure and composition of these hybrids were characterized by 1H nuclear magnetic resonance (1H NMR), thermo-gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The effects of carbon chains of mercaptan and concentration variations of POSS nanohybrids on the tribological performance improvements of liquid paraffin (LP) were investigated. According to our experimental results, the optimal concentration of POSS nanohybrids in LP was 0.40 wt%, corresponding to the lowest friction coefficients of 0.099 (for OS-POSS additive) and 0.101 (for OD-POSS additive) respectively. POSS nanohybrids can achieve homogeneous dispersion in LP, while a hard, stable Si–O cage in their molecular structure provided effective wear resistance. These nanohybrids were expected to be useful for more lubricating oil systems, which possess great scientific values and promising application prospects compared with pure solid or liquid lubricating additives.

The present study compared the microbial population in the samples of steamed green tea and its superfine green tea powder by determining and analyzing microbial changes during ball milling, which is the key step of producing superfine green tea powder. The results showed that after ball milling the microbial counts of superfine green tea powder were dramatically decreased than steam green teas in which the total aerobic count were more than 104 CFU/g in 14/19 samples. With the duration of ball milling, the microbial population of superfine green tea powder was correspondingly decreased till below 103 CFU/g. To study the mechanism of ball milling on microbial counts’ decreasing, a mold strain was isolated, purified and identified from the samples. Subsequently, the mold strain was cultured and individually ball-milled. The results indicated that fungal cell wall was disrupted and then microbial DNA was released during the process. Moreover, microbial populations in the tea samples were negatively correlated with cell wall breakage ratio. It was suggested that the ball milling was effective strategy for controlling the microbial contamination during the processing of superfine green tea powder.

The problem of optimally designing an interplanetary trajectory for a space mission is considered in this paper. To tackle the extreme non-linearity of the search space, a case learning-based differential evolution algorithm, named CLDE, is proposed. It stores successful control parameters (scaling factor and crossover possibility) and retrieve the available reference information according to a geographic similarity in each generation. To depart from the basin of attraction of a local optimum, CLDE will give up learning from the successful cases once no better offsprings have been obtained within a certain number of generations and generate new control parameters. Two versions of CLDE have been developed, for global optimization (G-CLDE) and local optimization (L-CLDE), respectively. Their performance has been tested on GTOP benchmarks and real mission design. Experimental results show that G-CLDE performs better than related algorithms, including PYGMO algorithms and recently published L-SHADE variants. L-CLDE can improve upon the best known solution for the Messenger benchmark (full version). By connecting G-CLDE and L-CLDE together, CLDE finds promising results in acceptable computational time on the GTOP benchmark.

In this work, a label-free fluorimetric method for sensitive and selective detection of Cr(III) was developed by utilizing NaY/GdF4:Yb,Er upconversion nanoparticles (UCNPs) and citrate-modified silver nanoparticles (Cit-AgNPs) mixed system. The photophysical and morphological properties of the prepared UCNPs were characterized by various spectroscopic and microscopic techniques. The fluorescence of amino-modified UCNPs can be quenched due to the Cr(III) induced aggregation of Cit-AgNPs by means of inner filter effect. The observed quenching in the fluorescence intensity of the UCNPs is found to be dependent on the concentration of Cr(III). The fluorescence decreases linearly within the investigated concentration of 0.5–40 μM Cr(III) with a limit of detection 34 nM. The practical applicability of the present sensing method is ascertained by detecting Cr(III) in spiked tap water and instant tea samples.

Microcystin-leucine-arginine (MCLR) is the most popular and toxic variant among microcystins, which can cause severe reproductive toxicity to animals. However, the mechanisms of reproductive toxicity induced by MCLR in amphibians are still not entirely clear. In the current study, toxicity mechanisms of MCLR on the reproductive system of male Rana nigromaculata followed by low concentration (0, 0.1, 1, and 10 μg/L) and short-term (0, 7, and 14 days) MCLR exposure were shown. It was observed that MCLR could be bioaccumulated in the testes of male frogs, and the theoretical bioaccumulation factor values were 0.24 and 0.19 exposed to 1 μg/L and 10 μg/L MCLR for 14 days, respectively. MCLR exposure significantly decreased testosterone (T) concentrations and increased estradiol (E2) concentrations exposed to 1 and 10 μg/L MCLR for 14 days. The mRNA levels of HSD17B3 were downregulated, and HSD17B1 and CYP19A1 mRNA expression levels were upregulated, respectively. Only 10 μg/L MCLR group showed significant induction of follicle-stimulating hormone (FSH) levels and cyclic adenosine monophosphate (cAMP) content. Moreover, AR and ESR1 mRNA expression levels were significantly upregulated exposed to 1 and 10 μg/L MCLR for 14 days, respectively. Our results suggested that low-concentration MCLR induced transcription changes of CYP19A1, HSD17B3, and HSD17B1 led to endocrine disorders, and caused interference of spermatogenesis by the decrease of T and abnormal gene expressions of AR and ESR1 in the testes of R. nigromaculata.

Uncertainty is wide-spreads in practical projects which can be solved by interval method. Regarding the temperature field prediction of structures with uncertain parameters, a vertex combination method is presented on the basis of the sampling according to the vertex combinations of interval parameters and monotonic relationship of objective function which can effectively reduce the number of boundary combined samples. A numerical example of heat transfer problems of a panel without thermal resource is used to verify the effectiveness of the proposed method.