Search

In this paper, polyamine-functionalized carbon dots (CDs) were synthesized by means of low temperature (<100°C) carbonization of citric acid at the presence of polyethylenimine (PEI), resulting spherical calcium carbonate micro-particles from inverse micro-emulsion system. Nanoscaled spherical silicas were prepared by Stöber method via deposition on the surface of micron calcium carbonate. Scanning- and transmission-electron microscopic analysis confirmed a micro-/nano-complex structure, enabling the composite material coating possessed coarser surface similar to those of 'lotus leaf'. After modification with 1 H, 1 H, 2 H, 2 H-perfluorodecanethiol, both good super hydrophobicity and good fluorescent performance were confirmed by the water contact angle of 154.1°±1.5°, their surface-free energy, and fluorescence quantum yield of 14.1%, which provides an inexpensive and easy way to fabricate superhydrophobic material with fluorescence characteristics and promotes high value application of inorganic materials. [ABSTRACT FROM AUTHOR]

In this paper, polyamine-functionalized carbon dots (CDs) were synthesized by means of low temperature (<100°C) carbonization of citric acid at the presence of polyethylenimine (PEI), resulting spherical calcium carbonate micro-particles from inverse micro-emulsion system. Nanoscaled spherical silicas were prepared by Stöber method via deposition on the surface of micron calcium carbonate. Scanning- and transmission-electron microscopic analysis confirmed a micro-/nano-complex structure, enabling the composite material coating possessed coarser surface similar to those of 'lotus leaf'. After modification with 1 H, 1 H, 2 H, 2 H-perfluorodecanethiol, both good super hydrophobicity and good fluorescent performance were confirmed by the water contact angle of 154.1°±1.5°, their surface-free energy, and fluorescence quantum yield of 14.1%, which provides an inexpensive and easy way to fabricate superhydrophobic material with fluorescence characteristics and promotes high value application of inorganic materials. [ABSTRACT FROM AUTHOR]

According to the Dual Circulation Strategy in China, financing leasing is an inevitable choice to enhance the competitiveness of the equipment manufacturing industry supply chain. Taking listed equipment manufacturing companies in China as the research objects, the article examines the impact of financial leasing on the supply chain competitiveness and its influence mechanism. The results show that the financial leasing can significantly improve the market competitiveness and capital competitiveness of equipment manufacturing enterprises in the supply chain. The heterogeneity analysis of the property rights shows that financial leasing mainly enhances the supply chain market competitiveness of state-owned equipment manufacturing enterprises. From the perspective of factor circulation, this study verifies the effectiveness of financial leasing in enhancing the supply chain competitiveness of equipment manufacturing enterprises. There are some policy enlightenment and experience significance for financial innovation promoting the factor recycling and improving the supply chain competitiveness. [ABSTRACT FROM AUTHOR]

The operation of a reservoir may change natural hydrological processes, thus affecting the habitat of aquatic organisms. However, the risks posed by reservoirs on aquatic organisms remain to be fully evaluated. In this study, a risk assessment model was established to assess the ecological risk of reservoir flow regulation based on the consequences of deviating from the environmental flow range of an aquatic habitat. We applied this model to the Three Gorges Reservoir by obtaining the risk time series of different aquatic habitats in the Yangtze River before and after the construction of the reservoir. The risk analysis results showed that when habitat discharge is above or below the appropriate range of environmental flows, the ecological risk increases. The Chinese sturgeon, four major Chinese carp species, and finless porpoise habitats were identified to be at low-flow risk, low-flow risk, and high-flow risk, respectively. We suggest that the habitat flows of Chinese sturgeon, four major Chinese carp species, and finless porpoise during the spawning period should not be less than 6,850, 7,000, and 13,500 m3/s, respectively. The results of this study could help river managers optimize reservoir operations to minimize risks and maximize ecological benefits. [ABSTRACT FROM AUTHOR]

Adipose tissue inflammation in obese patients can cause a series of metabolic diseases. There are a variety of immune cells in adipose tissue, and studies have shown that T cells are associated with adipose tissue inflammation. This review aims to describe the current understanding of the relationship between T cells and adipose tissue inflammation, with a focus on regulation by T cell subtypes. Studies have shown that Th1, Th17 and CD8+ T cells, which are important T cell subsets, can promote the development of adipose tissue inflammation, whereas Treg cells protect against inflammation, suggesting that targeting the mechanism by which T cell subtypes regulate adipose tissue inflammation is a potential therapeutic strategy for treating obesity. T cells play important roles in regulating obesity-associated adipose tissue inflammation, thus providing new research directions for the treatment of obesity. More studies are needed to clarify how T cell subtypes regulate adipose tissue inflammation to identify new treatments for obesity. [ABSTRACT FROM AUTHOR]

The present work investigates corrugation growth and mitigation associated with vibration interference between multiple moving wheels and resilient track. A discretely supported slab track is developed in the time domain. The tangential contact between the wheel and rail is described using an unsteady two-dimensional model. Combined these two models with long-term wear, the growth processes of corrugation under single and multiple wheel-rail interaction are simulated. The results show that low-frequency standing wave between wheels caused by vibratory interferences can lead to the drastic fluctuation of the contact force and thusly the standing wave-shaped profile of corrugation occur on railhead. It is also found that corrugation with multiple wavelengths successively appear and these wavelengths are always equivalent to unit fractions of the wheelbase, in which characteristic wavelengths predicted reach agreements with the observed results in situ. It is concluded that low-frequency standing wave between moving wheels are the dominant contributions to corrugation growth and the dependence of wavelengths on the wheelbase constitutes the wavelength-fixed nature of rail corrugation. Furthermore, the corrugation mitigation is investigated by installing rail damper. The results show that short pitch rail corrugation can be postponed by rail damper, but rail corrugation have the potential to reappear. [ABSTRACT FROM AUTHOR]

The traditional ghost imaging encryption system has high pressure in key transmission and management for involving a series of random phase-only masks (POMs) as keys. And conventional ghost imaging encoding is vulnerable to a chosen-plaintext attack owing to the linearity of the system. To address these problems, a plaintext-related ghost imaging encryption system which can reduce the key size and ensure the security of the system was proposed in this study. It uses parameter keys and plaintext information to generate all random POMs for encryption of plaintext. POMs used to encrypt images depend on both parameter keys and plain image, thus protecting information from cracking by the chosen-plaintext. At the same time, a multiple-image encryption method based on plaintext-related ghost imaging encryption was developed to improve the encryption efficiency of the system. The proposed method is the characteristic of strong multiple-image encryption ability, high security and enough simple structure. [ABSTRACT FROM AUTHOR]

Ghost imaging can capture a scene without directly catching sight of the target, but in the case of high compression ratio, high-quality imaging is challenging at present. Here a ghost imaging method using weight coefficient matching based on discrete cosine transform (DCT) is proposed, in which the high-quality target images can be retrieved by obtaining the larger weight value in one-dimensional (1D) DCT spectrum. In the case of low sampling, the proposed method can not only acquire the spectral coefficients with large weight, but also put them in the correct position; eventually it can obtain the desired image by inverse discrete cosine transform of the spectrum. At the same sampling ratio, both simulation results and optical experiments show that the reconstructed image quality of the proposed method exhibits better performance. In addition, even the sampling ratio is as low as about 3%, the outline of the target image can still be roughly recognized. [ABSTRACT FROM AUTHOR]

An optical image encryption method with multiple light paths is proposed based on compressive ghost imaging. In the encryption process, M random phase-only masks (POMs) are generated by means of logistic map algorithm, and these masks are then uploaded to the spatial light modulator (SLM). The collimated laser light is divided into several beams by beam splitters as it passes through the SLM, and the light beams illuminate the secret images, which are converted into sparse images by discrete wavelet transform beforehand. Thus, the secret images are simultaneously encrypted into intensity vectors by ghost imaging. The distances between the SLM and secret images vary and can be used as the main keys with original POM and the logistic map algorithm coefficient in the decryption process. In the proposed method, the storage space can be significantly decreased and the security of the system can be improved. The feasibility, security and robustness of the method are further analysed through computer simulations. [ABSTRACT FROM PUBLISHER]

A kind of multilevel authentication system for multiple-image based on modulated real part synthesis and iterative phase multiplexing in the Fresnel domain is proposed. In the design process of the low-level authentication system, a series of normalized real part information are iteratively generated by phase retrieval algorithm in the Fresnel domain, and the final private keys for different individual low-level certification images can be fabricated by binary amplitude modulation, superposition, synthesis, and sampling; while in the design process of the high-level authentication system, the final private keys for different individual high-level certification images can be generated by iterative phase information encoding and multiplexing. During the high-level authentication, the meaningful certification image can be reconstructed by the inverse Fresnel transform with the corresponding correct private keys, meanwhile, the correlation coefficient is utilized as judgment criterion; while in the low-level authentication, with the help of correct keys, the noise-like image with meaningless information can be recovered, but a remarkable peak output in the nonlinear correlation coefficient can be generated, which is adopted as the criterion to judge whether the low-level authentication is successful or not. Theoretical analysis and numerical simulations both verify the feasibility of the proposed method. [ABSTRACT FROM PUBLISHER]

In this study, douchi and soypaste, representative soy-fermented foods in China, were investigated as intact food materials on the stability of their angiotensin I-converting enzyme inhibitory activities during processing and simulated gastrointestinal digestion. Results showed that the angiotensin I-converting enzyme inhibitory activities of most samples tested, including active fractions by gel filtration from a potent soypaste sample, could be well-preserved or even enhanced after treating at 120°C, pH 2–10 or digesting with pepsin, trypsin, and chymotrypsin. The total angiotensin I-converting enzyme inhibitory activities of the products after processing and digestion considerably depended on the active inhibitors originally generated during their manufacturing. These findings indicated great potential of douchi and soypaste to exert hypotensive effect upon ingestion and provided support on developing antihypertensive functional soy-fermented foods or components by manufacturing products with good angiotensin I-converting enzyme inhibitory activity. [ABSTRACT FROM PUBLISHER]

A new kind of multilevel authentication system based on the (t,n) threshold secret sharing scheme and the iterative phase retrieval algorithm in Fresnel domain is proposed, in which, the first phase distribution iteratively generated is divided intonparts and delivered tondifferent participants, during high-level authentication, anyt(t???n) or more of them can be collected to reconstruct the original meaningful certification image; While in the case of low-level authentication, anyt???1 or fewer will gain no significant information of certification image, however, it can result in a remarkable peak output in the nonlinear correlation coefficient of the recovered image and the standard certification image, which can successfully provide an additional authentication layer for the high-level authentication. Theoretical analysis and numerical simulations both validate the feasibility of our proposed scheme. [ABSTRACT FROM AUTHOR]

Loop-mediated isothermal amplification (LAMP) performed with protein DNA polymeraseBstand DNA chains was influenced by nanoparticles in different ways. The effects of different concentrations of gold nanoparticles (AuNPs) with diameters 10 and 20 nm and silver nanoparticles (AgNPs) 1–10 nm in diameter on the amplification of the pR72H gene of Vibrio parahaemolyticus were investigated. AuNPs with a diameter of 10 nm in 0.6–60 nM concentration accelerated initiation of the LAMP reaction, 3 nM AuNPs reduced the reaction time by about 10 min, whereas 20 nm AuNPs did not, although neither size increased the yield after 60 min. AgNPs inhibited the LAMP reaction both in speed and yield at concentrations of 0.6–60 nM; the yield of amplification was reduced by 50% and 80% for 12 and 60 nM, respectively, after reaction for 1 h. This indicated that strong bactericidal effects of silver are also observed in its nanoparticles. The molecular mechanism of AuNPs and AgNPs in LAMP needs to be explored further, although their size-related electronic, magnetic and optical properties, as well as their ability to affect protein denaturation, or hydrophilic/hydrophobic effects may be involved. [ABSTRACT FROM AUTHOR]

In-chain multi-functionalized polybutadiene possessing definite geminal dimethylamino groups along polymer backbone, poly(butadiene-co-1,1-bis(4-dimethylaminophenyl)ethylene), has been designed and synthesized via anionic copolymerization of butadiene with 1,1-bis(4-dimethylanimophenyl)ethylene usingsec-butyllithium as initiator. Narrow molecular weight distribution copolymers withMn = 12–28 kg/mol (Mw/Mn < 1.10) were characterized by size exclusion chromatography,1H-NMR spectroscopy and DSC. The amine functionality was readily controlled by the amount of polar modifiers appropriately selected and the polymer molecular weight. The incorporation of 1,1-bis(4-dimethylanimophenyl)ethylene unit resulted in increases in glass transition temperatures of copolymers and had little effect on butadiene microstructure. [ABSTRACT FROM PUBLISHER]

A robust image watermarking scheme based on phase-shifting interferometry (PSI) and singular value decomposition (SVD) is proposed, in which, a grayscale image watermark is encrypted into multiple interferograms using the techniques of double random-phase encoding (DRPE) and PSI. By choosing the appropriate weighting factor, the interferograms are embedded in the singular values of the R, G, and B components of the host image. The scheme achieves a high level of security due to DRPE and at the same time preserves high imperceptibility and robustness due to SVD properties. Simulated results of the proposed scheme are provided to demonstrate the high robustness, not only against the geometric distortion attacks but also against general image processing attacks. [ABSTRACT FROM PUBLISHER]

Steps located in the non-aerated flow region of a chute are prone to cavitation damage. Two models operated with various Froude numbers and bottom slopes were employed to measure the pressure on the steps. The minimum and maximum pressures on the horizontal step surfaces occurred at the chute beginning and at the chute end, respectively. These characteristics were also found in the fully-developed flow region. The time-averaged pressure on the horizontal step surfaces is negative at the chute start, and then becomes positive along the flow direction in the non-uniform flow region. On the vertical step surfaces, the pressure is always negative at the top and remains negative along the entire vertical surface if the unit discharges are high enough in the non-uniform flow region. These results differ from the pressure characteristics in the uniform aerated flow region. [ABSTRACT FROM PUBLISHER]