摘要：
Developing novel photoelectric functional materials based on dithienylethenes (DTEs) building block has drawn increasing attention due to their excellent photochromic properties. In this contribution, two D-A type DTE derivatives 3 and 4 bearing triphenylamine (TPA) and anthraquinone (or anthracene) groups have been synthesized, and their structures have been characterized by means of NMR and MS. The UV-vis spectroscopy results show that compounds 3 and 4 exhibited reversible photochromism in toluene and THF solutions under UV/vis light irradiation, featuring good fatigue resistance and responsiveness. However, almost no photochromic properties for DTEs 3 and 4 were observed in larger polar DMSO. Interestingly, DTE 3 with obvious push-pull characteristics also displayed visible-light driven photochromic behavior in toluene. Meanwhile, fluorescence spectroscopy experiments have shown that DTE 4 with the anthracene fluorescent group showed fluorescent switching properties upon UV/vis light irradiation in toluene and THF solutions. The electrochemical results revealed a certain decrease in the half-wave potential of TPA-based 3 and 4 after UV irradiation, suggesting that the increasing conjugation degree of the ring-closed isomers results in the increase of HOMO orbital energy and the decrease of HOMO-LUMO gap and is beneficial for the occurrence of oxidation process, which are further proved by DFT calculations. TDDFT predicts that the transition absorption of the ring-closed isomers 3c and 4c respectively at 615 nm and 651 nm mainly come from pi-pi* mixed with TPA-*anthraquinone CT or TPA-*anthracene CT transition, which is consistent with the experimental results.
期刊：
Communications in Nonlinear Science and Numerical Simulation,2024年128:107602 ISSN：1007-5704
通讯作者：
Hu, LJ
作者机构：
[Hu, LJ; Hu, Lijun] Hengyang Normal Univ, Sch Math & Stat, Hengyang 421002, Hunan, Peoples R China.;[Wang, Xiaohui] Univ Texas Rio Grande Valley, Sch Math & Stat Sci, Edinburg, TX 78539 USA.
通讯机构：
[Hu, LJ ] H;Hengyang Normal Univ, Sch Math & Stat, Hengyang 421002, Hunan, Peoples R China.
关键词：
3D compressible flows;Roe scheme;Shock instability;Contact discontinuities;High accuracy
摘要：
The low-dissipation Roe scheme is a popular shock capturing scheme but the shock instability, such as the infamous carbuncle phenomenon, seriously affects its application in high Mach number flows. Although considerable research has been undertaken in two dimensions, mechanism analysis of the three-dimensional shock instability is relatively scarce. Numerical simulations of the Sedov blast wave indicate that the shock instability is more prominent in three dimensions, so it has theoretical and practical significance to analyze and heal the numerical instability. The mechanism for three-dimensional shock instability has been thoroughly studied by means of the linearized stability analysis and the dissipation-controlling approach which introduces the required transverse dissipation in the numerical shock layer and is adopted to enhance the Roe scheme's shock stability. Furthermore, the unphysical expansion shock resulting from the violation of entropy condition is eliminated by a simple modification of numerical signal speed. For the improvement of the resolution for contact discontinuities and shear waves, an algebraic method which combines the THINC reconstruction scheme and the BVD algorithm is employed to minimize the density difference in the numerical diffusion term. A series of benchmark numerical experiments fully demonstrate that the proposed scheme is endowed with excellent robustness against the shock instability and high accuracy for contact discontinuities and shear waves.
作者：
Kuang, Juanli*;Cao, Xiawei;Li, Songxiao;Li, Lang
期刊：
Journal of King Saud University - Computer and Information Sciences,2024年36(1) ISSN：1319-1578
通讯作者：
Kuang, Juanli;Li, L
作者机构：
[Kuang, Juanli] Macau Univ Sci & Technol, Fac Innovat Engn, Macau 999078, Peoples R China.;[Kuang, Juanli; Li, Lang] Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang 421002, Peoples R China.;[Cao, Xiawei; Kuang, Juanli; Li, Lang] Applicat Hengyang Normal Univ, Hunan Prov Key Lab Intelligent Informat Proc, Hengyang 421002, Peoples R China.;[Li, Songxiao] Univ Elect Sci & Technol China, Inst Fundamental & Frontier Sci, Chengdu 610054, Sichuan, Peoples R China.
通讯机构：
[Kuang, JL; Li, L ] H;Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang 421002, Peoples R China.
关键词：
Internet of Things;Block cipher;Lightweight cryptography;GFN;Pseudo -random;Negative feedback mechanism
摘要：
The Internet of Things (IoT) has gained popularity in various fields, including components such as embedded devices and wireless sensors. However, ensuring the security of data transmission from these devices is of critical importance. In light of these challenges, a novel lightweight encryption method called DRcipher is proposed in this paper for resource-constrained IoT devices. DRcipher has a 64-bit block size and supports either 96-bit or 128-bit key sizes. In order to improve the security, DRcipher employs a pseudo-random number of encryption rounds determined by the primary key. DRcipher adopts the structure of Generalized Feistel Network (GFN) with 4 branches, and its round functions consist of F-function, FF-function and RP permutation components. In particular, there is a negative feedback mechanism between the FF-function and the overall round of encryption functions. In addition, DRcipher is synthesised using Synopsys Design Compiler version A-2007.12-SP1 and the UMCL18G212T3 standard cell library. DRcipher-96 has an area footprint of 1546 Gate Equivalents (GE), while DRcipher-128 has a slightly larger area footprint of 1646 GE. Moreover, a comprehensive security analysis shows that the proposed DRcipher ensures high-level security redundancy against differential cryptanalysis, linear cryptanalysis, and so on.
作者机构：
[Li, Suxun] Changan Univ, Sch Earth Sci & Resources, Xian 710054, Peoples R China.;[Feng, Chang; Yang, Liu; Li, Suxun] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Feng, C] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
通讯机构：
[Feng, C ] ;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词：
driving factors;evapotranspiration;MODIS;spatiotemporal patterns;standard deviation ellipse;Xiangjiang River Basin
摘要：
Evapotranspiration (ET) is a crucial parameter in the process of the hydrological cycle. It is of great significance for water resource management and the improvement of ecological systems in the Xiangjiang River Basin (XRB) to explore the spatial and temporal dynamic characteristics of ET. Based on MOD16, this study revealed the characteristics of spatial and temporal patterns of ET in the XRB from 2000 to 2020. We first applied land use data and change rate for overall trend analysis on ET. Then, we obtained spatiotemporal migration routes of ET through standard deviation ellipse (SDE). Furthermore, we demonstrated the effects of monsoon and urban expansion on ET change. Accordingly, we observed the following novel spatiotemporal patterns of ET: (1) while the ET of artificial surfaces decreased from 2000 to 2020, the change rate in most regions of the XRB was 8.83%, indicating that the overall trend of ET in the XRB was increasing. (2) At 10-year intervals, the SDE center of ET all migrated in a clockwise direction. (3) The correlation between precipitation and ET is more obvious than that between temperature and ET. (4) With the direct effects of monsoon on precipitation in East Asia, we found that the changes in precipitation are consistent with the ET change.
摘要：
High-performance photodetectors hold promising potential in optical communication and imaging systems. However, conventional counterparts are suffering narrow detection range, high power consumption, and poor polarization sensitivity. Characteristics originating from switchable polarization in ferroelectrics can be used to optimize the photo-to-electric procedure and improve the photodetection performance. In this regard, we constructed a configuration by integrating 2-dimensional molybdenum disulfide (MoS(2)) with ferroelectric lithium niobate (LiNbO(3)), resulting in the MoS(2)/LiNbO(3) heterostructured photodetector. Benefiting from the pyroelectric effect of LiNbO(3), the limitation of bandgap on the detection range can be broken, thus broadening the response band of the detector to 365 to 1,064 nm, as well as enabling the self-powered characteristic. Meanwhile, high carrier mobility and decent light absorbance of MoS(2) introduce robust light-matter interactions with the underlying LiNbO(3), leading to ultrafast rise/fall times of ≈150 μs/250 μs and switching ratios of up to ≈190. Moreover, the highest responsivity, specific detectivity, and external quantum efficiency achieved were 17.3 A·W(-1), 4.3 × 10(11) Jones, and 4,645.78%, respectively. Furthermore, because of the anisotropy of the spontaneous-polarized LiNbO(3) substrate, the photocurrent of the device achieved a dichroic ratio of 7.42, comparing favorably to most MoS(2)-based photodetectors. This work demonstrates the integration potential between ferroelectric LiNbO(3) and 2-dimensional materials for high-performance photodetection.
通讯机构：
[Xiaohui Ling] L;Laboratory for Spin-Orbit Photonics, College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, People's Republic of China
关键词：
angular momentum;photonic orbital Hall effect;vortex phase;mode decomposition
摘要：
The photonic orbital Hall effect (POHE) refers to the vortex-dependent beam shifts, which is generally believed to result from the conversion of intrinsic orbital angular momentum (IOAM) to extrinsic orbital angular momentum (EOAM). However, the physical mechanism of the POHE, such as how the IOAM is converted to the EOAM, remains further elucidation. In this paper, we re-examine the POHE of a vortex beam with additional IOAM illuminating at an optically thin slab by means of vortex mode decomposition. By considering the competition and coupling between the radial and azimuthal vortex harmonics of the abnormal mode in the transmitted beam, it is found that the underlying mechanism of the POHE is in fact a spin-to-orbital angular momentum (OAM) conversion process. And the IOAM carried by the incident beam is directly superimposed on the OAM obtained during the conversion. Our findings not only offer an alternative perspective for understanding the POHE, but also exhibit application potential in orbit-orbit and spin-orbit optical components.
通讯机构：
[Yun-Wu Li; Jin-Sheng Zhao] S;[Yi-Jin Wu] K;Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, and School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, P. R. China<&wdkj&>Key Laboratory of Functional Metal-Organic Compounds of Hunan Province, Hunan Province Universities Key Laboratory of Functional Organometallic Materials, College of Chemistry and Material Science, Hengyang Normal University, Hengyang 421008, P. R. China
摘要：
The cathodic product Li(2)CO(3), due to its high decomposition potential, has hindered the practical application of rechargeable Li-CO(2)/O(2) batteries. To overcome this bottleneck, a Pt/FeNC cathodic catalyst is fabricated by dispersing Pt nanoparticles (NPs) with a uniform size of 2.4 nm and 8.3 wt % loading amount into a porous microcube FeNC support for high-performance rechargeable Li-CO(2)/O(2) batteries. The FeNC matrix is composed of numerous two-dimensional (2D) carbon nanosheets, which is derived from an Fe-doping zinc metal-organic framework (Zn-MOF). Importantly, using Pt/FeNC as the cathodic catalyst, the Li-CO(2)/O(2) (V(CO(2))/V(O(2)) = 4:1) battery displays the lowest overpotential of 0.54 V and a long-term stability of 142 cycles, which is superior to batteries with FeNC (1.67 V, 47 cycles) and NC (1.87 V, 23 cycles) catalysts. The FeNC matrix and Pt NPs can exert a synergetic effect to decrease the decomposition potential of Li(2)CO(3) and thus enhance the battery performance. In situ Fourier transform infrared (FTIR) spectroscopy further confirms that Li(2)CO(3) can be completely decomposed under a low potential of 3.3 V using the Pt/FeNC catalyst. Impressively, Li(2)CO(3) exhibits a film structure on the surface of the Pt/FeNC catalysts by scanning electron microscopy (SEM), and its size can be limited by the confined space between the carbon sheets in Pt/FeNC, which enlarges the better contacting interface. In addition, density functional theory (DFT) calculations reveal that the Pt and FeNC catalysts show a higher adsorption energy for Li(2)CO(3) and Li(2)CO(4) intermediates compared to the NC catalyst, and the possible discharge pathways are deeply investigated. The synergetic effect between the FeNC support and Pt active sites makes the Li-CO(2)/O(2) battery achieve optimal performance.
关键词：
long memory;regime switching;FIEGARCH;MRS-FIEGARCH
摘要：
Recent research suggests that long memory can be caused by regime switching and is easily confused with it. However, if the causes of confusion were properly controlled, they could be distinguished. Motivated by this idea, our study aims to distinguish between the long memory and regime switching of financial volatility. We firstly modeled the long memory and regime switching of volatility using the Fractionally Integrated Exponential GARCH (FIEGARCH) and Markov Regime-Switching EGARCH (MRS-EGARCH) frameworks, respectively, and performed a simulation study on their finite-sample properties when innovations followed a non-normal distribution. Subsequently, we demonstrated the confusion between the FIEGARCH and MRS-EGARCH processes using simulations. A recent study theoretically proved that the time-varying smoothing probability series can induce the presence of significant long memory in the regime-switching process. To control for its effect, the two-stage two-state FIEGARCH and MRS-FIEGARCH frameworks are proposed. The Monte Carlo studies showed that both frameworks can effectively distinguish between the pure FIEGARCH and pure MRS-EGARCH processes. When the MRS-FIEGARCH model was further employed to fit series generated with the MRS-FIEGARCH process, it outperformed the ordinary FIEGARCH model. Finally, an empirical study of NASDAQ index return was conducted to demonstrate that our MRS-FIEGARCH model can provide potentially more reliable long-memory estimates, identify the volatility states and outperform both the FIEGARCH and MRS-EGARCH models.
摘要：
Unmanned missions have become more and more popular in recent years. The related technologies of unmanned ground vehicles and unmanned aerial vehicles are growing rapidly, but research on unmanned surface vehicles (USVs) is rare. Water surface object detection algorithms play a crucial role in the field of USVs. However, achieving an object detection algorithm that balances speed and accuracy in the presence of interference is a difficult challenge. We proposed a network, DBCR-YOLO, that improved the detection accuracy while meeting real-time requirements. Based on YOLOv5, we added an additional detection head for detecting tiny objects. Then, we replaced the downsampling in YOLOv5's backbone network with the proposed double sampling mechanism to solve the problem that paying attention to the key features of objects cannot be done in the downsampling process of YOLOv5. Finally, we substituted the proposed BCR neck for YOLOv5's neck, thus improving the fusion of features between different scales based on fewer parameters and fewer calculations. We tested our network on the water surface object detection dataset. Compared with YOLOv5, DBCR-YOLO improved the detection accuracy by 3.4%. At the same time, DBCR-YOLO achieved the highest accuracy in comparison with other networks. (c) 2023 SPIE and IS&T
作者机构：
[Deng, Zhiwei; Quan, Bin] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Quan, Bin] Hengyang Base Int Ctr Space Technol Nat & Cultural, Hengyang 421002, Peoples R China.
通讯机构：
[Quan, B ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;Hengyang Base Int Ctr Space Technol Nat & Cultural, Hengyang 421002, Peoples R China.
关键词：
land use and land cover change;Intensity Analysis;change detection;Chang-Zhu-Tan Metropolitan Region
通讯机构：
[Yanliang Tan] C;College of Physics and Electronic Engineering , Hengyang Normal University, Hengyang, Hunan Province 421008, China
摘要：
Radon-222 (Rn-222) exhalation rate is vital for estimating radiation risk from many kinds of materials. AlphaGUARD measures the radon concentration based on the ionization chamber principle, which is currently recognized as a reference instrument to measure radon. In China, measurements of radon exhalation rate are performed by AlphaGUARD operated in flow-through mode on a reference device to verify measurement accuracy. These measurements are performed in both open and closed loop. AlphaGUARD can fast rapidly the variation of the radon concentration in the chamber, which is tightly pressed against the surface of the medium to accumulate the exhaled radon. When the model is used to obtain the radon exhalation rate, the radon exhalation rates obtained by nonlinear data fitting on the measured radon concentrations are similar to the reference value of the device. The difference of radon exhalation rate values of six measurements is small.
摘要：
According to the methodical examination of the physicochemical, sensory, and antioxidant properties of flavored yogurts which fortified with different amounts of Lentinula edodes stipe (LES), we found that the LES was beneficial to improve some physicochemical (pH, viable lactic acid bacteria density, and syneresis) and sensory properties (fermented odor and taste quality), and the antioxidant activity (ABTS and DPPH radical scavenging activity) of the plain yogurt, which has the potential to be used in functional yogurt. The results above were also helpful for the rational utilization of LES toward value‐added products. Abstract The Lentinula edodes stipe (LES), a by‐product of L. edodes fruiting body processing, is rich in dietary fiber, protein, and polysaccharides, which can be served as the functional ingredient in dairy products. In this study, stirred yogurts fortified with 1%, 2%, and 3% LES were prepared, and the effects of LES on the changes in color, pH, titratable acidity (TA), viable lactic acid bacteria (LAB) cells, syneresis, viscosity, texture, and antioxidant activity of the flavored yogurt were monitored at the beginning and the end of storage. The LES decreased the lightness, increased the red–green color values and yellow–blue color values, decreased the pH values, and increased the contents of TA, the viable LAB cells, and the antioxidant activity of yogurt samples in a dose‐dependent manner. The addition of LES showed double‐edged effects on the texture of yogurt, which significantly reduced firmness and viscosity but decreased the syneresis. Compared with plain yogurt, the 2% LES‐fortified yogurt exhibited similar index values of texture parameters and higher scores of the appearance, fermented odor, taste quality, and overall acceptance, suggesting that this might be the optimal dose for industrial production. After cold storage for 28 days, pH values of all yogurt samples further decreased with increasing of TA. Interestingly, syneresis of LES‐fortified yogurt decreased and the viable LAB cells and antioxidant activity of 3% LES‐fortified yogurt slightly decreased. Therefore, LES is beneficial to improve physicochemical, sensory, and antioxidant properties of yogurt, which has the potential to be used in functional dairy products.
作者机构：
[Chen, Shaolin; Chen, SL] Hengyang Normal Univ, Coll Math & Stat, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Chen, SL ] H;Hengyang Normal Univ, Coll Math & Stat, Hengyang 421008, Hunan, Peoples R China.
关键词：
Heinz type inequality;Lipschitz continuous;Polyharmonic mapping;Quasiconformal mapping
摘要：
Suppose that f satisfies the following: (1) the polyharmonic equation triangle(m) f = triangle(triangle(m-1) f ) = phi(m) (phi(m) is an element of C((B-n) over bar, R-n)), (2) the boundary conditions triangle(0) f = phi(0), triangle(1) f = phi 1, ..., triangle(m-1) f = phi(m-1 )on Sn-1 (phi (j) is an element of C(Sn-1, R-n) for j is an element of {0, 1, ... , m - 1} and Sn-1 denotes the boundary of the unit ball B-n), and (3) f (0) = 0, where n >= 3 and m >= 1 are integers. Initially, we prove a Schwarz type lemma and use it to obtain a Heinz type inequality of mappings satisfying the polyharmonic equation with the above Dirichlet boundary value conditions. Furthermore, we establish a Bloch type theorem of mappings satisfying the above polyharmonic equation, which gives an answer to an open problem in Chen and Ponnusamy, (2019). Additionally, we show that if f is a K-quasiconformal self-mapping of Bn satisfying the above polyharmonic equation, then f is Lipschitz continuous, and the Lipschitz constant is asymptotically sharp as K -> 1(+) and parallel to phi(j) parallel to infinity -> 0(+) for j is an element of {1, ... , m}.(c) 2023 Royal Dutch Mathematical Society (KWG). Published by Elsevier B.V. All rights reserved.
作者机构：
[Chen, Zhongwen] Hengyang Normal Univ, Coll Econ & Management, Hengyang 421002, Peoples R China.;[Shi, Yanlin] Macquarie Univ, Dept Actuarial Studies & Business Analyt, Sydney, NSW 2109, Australia.;[Shu, Ao] Hunan Univ, Business Sch, Changsha 410012, Peoples R China.
通讯机构：
[Ao Shu] B;Business School, Hunan University, Changsha 410012, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
mortality rates;Lee–Carter model;time-varying coefficients;rotated age pattern;life expectancy
摘要：
Influential existing research has suggested that rather than being static, mortality declines decelerate at young ages and accelerate at old ages. Without accounting for this feature, the forecast mortality rates of the popular Lee-Carter (LC) model are less reliable in the long run. To provide more accurate mortality forecasting, we introduce a time-varying coefficients extension of the LC model by adopting the effective kernel methods. With two frequently used kernel functions, Epanechnikov (LC-E) and Gaussian (LC-G), we demonstrate that the proposed extension is easy to implement, incorporates the rotating patterns of mortality decline and is straightforwardly extensible to multi-population cases. Using a large sample of 15 countries over 1950-2019, we show that LC-E and LC-G, as well as their multi-population counterparts, can consistently improve the forecasting accuracy of the competing LC and Li-Lee models in both single- and multi-population scenarios.
作者机构：
[Tan, L.; Wu, Y. -j.; Tan, L; Huang, Z. -x.; Liu, H.; Liu, Y. -x.; Wu, YJ] Hengyang Normal Univ, Coll Chem & Mat Sci, Hunan Engn Res Ctr Monitoring & Treatment Heavy Me, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421001, Peoples R China.
通讯机构：
[Tan, L; Wu, YJ ] H;Hengyang Normal Univ, Coll Chem & Mat Sci, Hunan Engn Res Ctr Monitoring & Treatment Heavy Me, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421001, Peoples R China.
关键词：
Ag coating;Surfactant;Zinc-metal battery;Zinc dendrite
摘要：
Rechargeable aqueous zinc (Zn) batteries are promising for large energy storage due to their low cost, high safety, and environmental compatibility, but their commercialization is hindered by the severe irreversibility of Zn metal anodes as exemplified by water-induced side reactions (H2 evolution and Zn corrosion) and dendrite growth. In this work, hierarchical layered silver-coated zinc anode under the assistance of anionic surfactant (trisodium citrate) was prepared for long-time cycle stabilities of zinc stripping and plating, where Ag coating has a strong affinity to Zn adatoms and hierarchical structure exhibits a positive role in inducing the (002) plane preferred-orientation growth of Zn phase. Benefiting from these features, hierarchical Ag-coated zinc anode was able to operate stability for more than 1200 cycles compared with the pure zinc anode at 2 mA/cm(2) for 1 mAh/cm(2), and an asymmetric cell shows superior Coulombic efficiency of similar to 99.6% over 800 cycles at a current density of 1 mA/cm(2) and 0.5 mAh/ cm(2), as well as a long cycling stability of 500 cycles with capacity of 115 mAh/g in MnO2||H-Zn@Ag full batteries. This work provides a new insight to improve the performance of Zn-metal batteries.(c) 2023 Elsevier Ltd. All rights reserved.
期刊：
Journal of Food Measurement and Characterization,2023年17(3):2386-2403 ISSN：2193-4126
通讯作者：
Zaixiang Lou
作者机构：
[Zheng, Xiaodan; Dai, Wenna; Bede, Dery; Lou, Zaixiang; Wang, Hongxin] Jiangnan Univ, Sch Food Sci & Technol, State Key Lab Food Sci & Technol, Wuxi 214122, Peoples R China.;[Zheng, Xiaodan; Dai, Wenna; Bede, Dery; Lou, Zaixiang; Wang, Hongxin] Jiangnan Univ, Natl Engn Res Ctr Funct Food, Wuxi 214122, Peoples R China.;[Wan, Chunpeng] Jiangxi Agr Univ, Coll Agron, Collaborat Innovat Ctr Post Harvest Key Technol &, Jiangxi Key Lab Post Harvest Technol & Nondestruct, Nanchang 330045, Peoples R China.;[Chen, Xiaohua] Hengyang Normal Univ, Hengyang 421001, Peoples R China.
通讯机构：
[Zaixiang Lou] S;State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, People’s Republic of China<&wdkj&>National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, People’s Republic of China
摘要：
Biofilm is a complex community of microorganisms with a more stable form compared to planktonic bacteria. Probiotic strains in biofilms have been found to have beneficial effects in numerous studies. The formation process and the regulatory mechanisms of biofilm were introduced. Strategies to promote biofilm growth were reviewed in categories. And the extraction and purification process of natural products in exogenous substances was also sorted out and summarized. The research found that different modes of action of the promoting biofilm molecules discussed were facilitated by interfering with the quorum sensing pathways, adhesion mechanisms, the two-component system, influencing extracellular polymers, and secondary messengers involved in various signaling pathways. The studies showed that the strength of the biofilm can be promoted by altering the adhesion surface material and nutrient sources. Probiotics and their secondary metabolites made critical impacts. Further studies found that the ingredients that can promote the formation of bacterial biofilms include hormones, inorganic ions (Mn2+, Cu2+, Fe3+), and natural extracts (inulin, fructooligosaccharides, malic acid, catechins, genistein, cranberry extract, resveratrol, propolis ethanolic extract, bioactive peptides, etc.). The method of extraction and purification prefers safe and low-harm solvents such as ethanol and water. Physical methods were also used to improve yields, such as microwaves, ultra-high pressure, column chromatography, etc. A multi-point, staggered, and all-round examination of the development of probiotic biofilms was directed. The exploration of probiotic biofilm will be a significant advancement heading in the field of probiotic research.
期刊：
Journal of Mathematics,2023年2023 ISSN：2314-4629
作者机构：
[Wang, Keyan; Hu, Boxia] Hengyang Normal Univ, Sch Math & Stat, Hengyang 421008, Hunan, Peoples R China.;[Hu, Boxia] Hunan Univ, Sch Math, Changsha 410082, Hunan, Peoples R China.
摘要：
In this paper, two efficient two-grid algorithms for the convection-diffusion problem with a modified characteristic finite element method are studied. We present an optimal error estimate in L-p-norm for the characteristic finite element method unconditionally, while all previous works require certain time-step restrictions. To linearize the characteristic method equations, two-grid algorithms based on the Newton iteration approach and the correction method are applied. The error estimate and the convergence result of the two-grid method are derived in detail. It is shown that the coarse space can be extremely coarse and achieve asymptotically optimal approximations as long as the mesh sizes H=Oh(1/3) in the first algorithm and H=Oh(1/4) in the second algorithm, respectively. Finally, two numerical examples are presented to demonstrate the theoretical analysis.
期刊：
Journal of Physical Chemistry Letters,2023年14(26):6099-6109 ISSN：1948-7185
通讯作者：
Qian, Dong;Liu, JL;Waterhouse, GIN
作者机构：
[Liu, Jinlong; Qian, Dong; Chen, Xiangxiong; Wang, Bowen; Luo, Ziyu; Li, Jie; Liu, JL; Zhang, Xinxin; Liu, Canhui] Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;[Chen, Xiangxiong] Yoening Tianci Min Changsha Technol Ctr, Changsha 410083, Peoples R China.;[Li, Junhua] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Waterhouse, Geoffrey I. N.; Waterhouse, GIN] Univ Auckland, Sch Chem Sci, Auckland 1142, New Zealand.
通讯机构：
[Qian, D; Liu, JL ] C;[Waterhouse, GIN ] U;Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;Univ Auckland, Sch Chem Sci, Auckland 1142, New Zealand.
摘要：
Herein, a simple two-step synthetic method was developed for the synthesis of NiFe(2)O(4) nano-microrods supported on Ketjenblack carbon (NiFe(2)O(4)/KB). A sodium tartrate-assisted hydrothermal method was employed for the synthesis of a NiFe-MOF/KB precursor, which was then pyrolyzed under N(2) at 500 °C to yield NiFe(2)O(4)/KB. Benefiting from the presence of high-valence Ni(3+) and Fe(3+), high conductivity, and a large electrochemically active surface area, NiFe(2)O(4)/KB delivered outstanding OER electrocatalytic performance under alkaline conditions, including a very low overpotential of 258 mV (vs RHE) at 10 mA cm(-2), a small Tafel slope of 43.01 mV dec(-1), and excellent durability in 1.0 M KOH. Density functional theory calculations verified the superior alkaline OER electrocatalytic activity of NiFe(2)O(4) to IrO(2). While both catalysts possessed a similar metallic ground state, NiFe(2)O(4) offered a lower energy barrier in the rate-determining OER step (*OOH → O(2)) compared to IrO(2), resulting in faster OER kinetics.
