For the ultimate strength model test evaluation of large ship structures, the distortion model with non-uniform ratio between the main size and the plate thickness size is usually adopted. It is the key to carry out s...For the ultimate strength model test evaluation of large ship structures, the distortion model with non-uniform ratio between the main size and the plate thickness size is usually adopted. It is the key to carry out scale model test to establish a distortion model similar to the real ship structure under combined load. A similarity criterion for ship distortion model under the combined action of bending moment and surface pressure was proposed, and the scale effect for the criterion was verified by a se ries of numerical analysis and model tests. The results show that the similarity criterion for ship distor tion model under combined loads has a certain scale effect. For the model tests of ship cabin struc tures, it is suggested that the scale range between the plate thickness scale and the main dimension scale should be controlled within 2:1, which can be used as a reference for distortion model design and ultimate strength test of large-scale ship structures.展开更多
A hull structure is prone to local deformation and damage due to the pressure load on the surface.How to simulate surface pressure is an important issue in ship structure test.The loading mode of hydraulic actuator co...A hull structure is prone to local deformation and damage due to the pressure load on the surface.How to simulate surface pressure is an important issue in ship structure test.The loading mode of hydraulic actuator combined with high-pressure flexible bladder was proposed,and the numerical model of the loading device based on flexible bladder was established.The design and analysis method of high-pressure flexible bladder based on aramid-fiber reinforced thermoplastic polyurethane was proposed to break through the surface pressure loading technology of ship structures.The surface pressure loading system based on flexible bladder was developed.The ultimate strength verification test of the box girder under the combined action of bending moment and pressure was carried out to systematically verify the feasibility and applicability of the loading system.The results show that the surface pressure loading technology can be used well for applying uniform pressure to ship structures.Compared with the traditional surface loading methods,the improved device can be applied with horizontal constant pressure load,with rapid response and safe process,and the pressure load is always stable with the increase of the bending moment load during the test.The requirement for uniform loading in the comprehensive strength test of large structural models is satisfied and the accuracy of the test results is improved by this system.展开更多
The repairing effect of poly(N-vinylpyrrolidone-co-methacrylic acid)on permed or bleached damaged hair was studied.The combing and tensile strength of permed and bleached hair before and after treatment with the copol...The repairing effect of poly(N-vinylpyrrolidone-co-methacrylic acid)on permed or bleached damaged hair was studied.The combing and tensile strength of permed and bleached hair before and after treatment with the copolymer solution were tested,and the effects of the mass fraction of copolymer solution and immerseing time on the combing and tensile strength for permed or bleached damaged hair were investigated.The repair mechanism of permed or bleached damaged hair was also explored.The results show that when the immersing time is 3 hours,the tensile strength of the permed hair increases with the mass fraction of the copolymer solution Tensile strength within 0%-0.3%,but no obvious change is observed when250 Yield strength the mass fraction is over 0.3%.Therefore,the optimal mass 200 fraction of the copolymer solution for repairing the permed hair(cN/dtex)is 0.3%.Similarly,the optimal mass fraction of the copolymer 150strength/solution for repairing the bleached hair is 0.5%.Furthermore,the effects of immersing time on the tensile strength of the100Tensile damaged hair fibers were compared between the permed and90 bleached hair before and after treatment with the copolymer500.40.30.500.10.2 solution.Coincidentally,the optimal immersion time for permedw(P(NVP-co-MAA))/%or bleached damaged hair is both 2 hours.The tensile strength of the permed and bleached hair soaked in 0.3%and 0.5%copolymer solutions for 2 hours increases by 15.55%and 18.12%,respectively,compared to untreated hair.Through infrared spectroscopy analysis,it is found that the amide II band in hair fibers shifted to the blue after repair,with the wave number shift of 11.12 and 11.09 cm^(-1),which confirm the formation of hydrogen bonds in the hair samples.Additionally,the urea hydrogen bond disruption experiment demonstrates that urea does not disrupt the hydrogen bonds in untreated hair fibers,but prevents the formation of new hydrogen bonds in damaged hair fibers.It further validates that the improvement of the tensile strength of the copolymer treated damaged hair fibers is mainly due to the formation of hydrogen bonds.After treatment with the copolymer,the dry and wet combing friction decrease by 30.73%and 28.55%for the permed hair,and decrease by 28.55%and 24.83%for the bleached hairs,respectively.The scanning electron microscope shows that the copolymer can flatten the cuticle and fill the space between the raised cuticles.展开更多
The existing multi-view subspace clustering algorithms based on tensor singular value decomposition(t-SVD)predominantly utilize tensor nuclear norm to explore the intra view correlation between views of the same sampl...The existing multi-view subspace clustering algorithms based on tensor singular value decomposition(t-SVD)predominantly utilize tensor nuclear norm to explore the intra view correlation between views of the same samples,while neglecting the correlation among the samples within different views.Moreover,the tensor nuclear norm is not fully considered as a convex approximation of the tensor rank function.Treating different singular values equally may result in suboptimal tensor representation.A hypergraph regularized multi-view subspace clustering algorithm with dual tensor log-determinant(HRMSC-DTL)was proposed.The algorithm used subspace learning in each view to learn a specific set of affinity matrices,and introduced a non-convex tensor log-determinant function to replace the tensor nuclear norm to better improve global low-rankness.It also introduced hyper-Laplacian regularization to preserve the local geometric structure embedded in the high-dimensional space.Furthermore,it rotated the original tensor and incorporated a dual tensor mechanism to fully exploit the intra view correlation of the original tensor and the inter view correlation of the rotated tensor.At the same time,an alternating direction of multipliers method(ADMM)was also designed to solve non-convex optimization model.Experimental evaluations on seven widely used datasets,along with comparisons to several state-of-the-art algorithms,demonstrated the superiority and effectiveness of the HRMSC-DTL algorithm in terms of clustering performance.展开更多
Instance segmentation plays an important role in image processing.The Deep Snake algorithm based on contour iteration deforms an initial bounding box to an instance contour end-to-end,which can improve the performance...Instance segmentation plays an important role in image processing.The Deep Snake algorithm based on contour iteration deforms an initial bounding box to an instance contour end-to-end,which can improve the performance of instance segmentation,but has defects such as slow segmentation speed and sub-optimal initial contour.To solve these problems,a real-time instance segmentation algorithm based on contour learning was proposed.Firstly,ShuffleNet V2 was used as backbone network,and the receptive field of the model was expanded by using a 5×5 convolution kernel.Secondly,a lightweight up-sampling module,multi-stage aggregation(MSA),performs residual fusion of multi-layer features,which not only improves segmentation speed,but also extracts effective features more comprehensively.Thirdly,a contour initialization method for network learning was designed,and a global contour feature aggregation mechanism was used to return a coarse contour,which solves the problem of excessive error between manually initialized contour and real contour.Finally,the Snake deformation module was used to iteratively optimize the coarse contour to obtain the final instance contour.The experimental results showed that the proposed method improved the instance segmentation accuracy on semantic boundaries dataset(SBD),Cityscapes and Kins datasets,and the average precision reached 55.8 on the SBD;Compared with Deep Snake,the model parameters were reduced by 87.2%,calculation amount was reduced by 78.3%,and segmentation speed reached 39.8 frame·s−1 when instance segmentation was performed on an image with a size of 512×512 pixels on a 2080Ti GPU.The proposed method can reduce resource consumption,realize instance segmentation tasks quickly and accurately,and therefore is more suitable for embedded platforms with limited resources.展开更多
Automatic splicing of interrupted yarns in ring spinning has always been a problem in the industry.Factors such as low yarn strengths and environmental influence on yarn tensions make it difficult to control the yarn ...Automatic splicing of interrupted yarns in ring spinning has always been a problem in the industry.Factors such as low yarn strengths and environmental influence on yarn tensions make it difficult to control the yarn tension during the robotic splicing process.The purpose of this research is to design active disturbance rejection control(ADRC)for a third-order nonlinear tension system subject to external disturbances.Firstly,a third-order extended state observer(ESO)is designed to achieve the suppression and the compensation of the internal modeling error and the external disturbances of the system.Secondly,the adaptive gain error feedback control and the filtering process are designed to reduce the influence of sensor noise on the disturbance observation.Finally,the tension control during the splicing process is simulated and experimented,and the experiments show that the method has good robustness in the tension tracking task under a dynamic environment,which verifies the effectiveness of the method.展开更多
The cicada genus Vietanna is reviewed based on the descriptions of two new species,V.perparva sp.nov.and V.longiloba sp.nov.,from China.The relationship of this genus to related taxa is discussed based on the phylogen...The cicada genus Vietanna is reviewed based on the descriptions of two new species,V.perparva sp.nov.and V.longiloba sp.nov.,from China.The relationship of this genus to related taxa is discussed based on the phylogeny of Vietanna and representative species from subtribes Puranina,Leptopsaltriina,Euterpnosiina and Leptosemiina based on the mitochondrial gene COI and nuclear genes EF-1αand ARD1.展开更多
The AGCU X Plus STR system is a newly developed multiplex PCR kit that detects 32 X-chromosomal STR loci simultaneously.These are DXS6807,DXS9895,linkage group 1(DXS10148,DXS10135,DXS8378),DXS9902,DXS6795,DXS6810,DXS1...The AGCU X Plus STR system is a newly developed multiplex PCR kit that detects 32 X-chromosomal STR loci simultaneously.These are DXS6807,DXS9895,linkage group 1(DXS10148,DXS10135,DXS8378),DXS9902,DXS6795,DXS6810,DXS10159,DXS10162,DXS10164,DXS7132,linkage group 2(DXS10079,DXS10074,DXS10075),DXS981,DXS6800,DXS6803,DXS6809,DXS6789,DXS7424,DXS101,DXS7133,GATA172D05,GATA165B12,linkage group 3(DXS10103,HPRTB,DXS10101),GATA31E08 and linkage group 4(DXS8377,DXS10134,DXS7423).A major advantage of this kit is that it takes into account linkage between loci,in addition to detecting more X-STR loci.In order to evaluate the forensic application of 32 X-STR fl uorescence amplifi cation system,PCR settings,sensitivity,species specifi city,stability,DNA mixtures,concordance,stutter,sizing precision,and population genetics investigation were evaluated according to the Scientific Working Group on DNA Analysis Methods(SWGDAM)developmental validation guidelines.The study showed that the genotyping results of each locus were signifi cantly accurate when the DNA template was at least 62.5 pg.Complete profi les were obtained for the 1∶1 and 1∶3 combinations.A total of 209 unrelated individuals from Southern Chinese Han community,consisting of 84 females and 125 males,were selected for population studies,and 285 allele profi les were detected from 32 X-STR loci.The polymorphism information content(PIC)ranged from 0.2721 in DXS6800,to 0.9105 in DXS10135,with an average of 0.6798.DXS10135(PIC=0.9105)was the most polymorphic locus,with discrimination power(DP)of 0.9164 and 0.9871 for the male and female.The cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) valu es were all greater than 0.999999999.There were 78 different DXS10103-HPRTB-DXS10101 haplotypes among the 125 males,and the haplotype diversity was 0.9810.There was no signifi cant difference in the cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) values whether considering linkage or not.In summary,the new X-STR multiplex typing system is effective and reliable,which can be useful in human genetic analysis and kinship testing as a potent complement to autosomal STR typing.展开更多
Oxidized nanoporous g-C3N4(PCNO)decorated with graphene oxide quantum dots(ox-GQDs)was successfully prepared by a facile self-assembly method.As co-catalysts,the ultrasmall zero-dimensional(0 D)ox-GQDs can achieve uni...Oxidized nanoporous g-C3N4(PCNO)decorated with graphene oxide quantum dots(ox-GQDs)was successfully prepared by a facile self-assembly method.As co-catalysts,the ultrasmall zero-dimensional(0 D)ox-GQDs can achieve uniform dispersion on the surface/inner channels of PCNO,as well as intimate contact with PCNO through hydrogen bonding,π-π,and chemical bonding interactions.In contrast with PCNO,the ox-GQDs/PCNO composite photocatalysts possessed improved light-harvesting ability,higher charge-transfer efficiency,enhanced photooxidation capacity,and increased amounts of reactive species due to the upconversion properties,strong electron capturing ability,and peroxidase-like activity of the ox-GQDs.Therefore,the visible-light photocatalytic degradation and disinfection performances of the ox-GQDs/PCNO composite were significantly enhanced.Remarkably,the composite with a 0.2 wt.% deposited amount of ox-GQDs(ox-GQDs-0.2%/PCNO)exhibited optimum amaranth photodegradation activity,with a corresponding rate about 3.1 times as high as that of PCNO.In addition,ox-GQDs-0.2%/PCNO could inactivate about 99.6%of Escherichia coli(E.coli)cells after 4 h of visible light irradiation,whereas only^31.9% of E.coli cells were killed by PCNO.Furthermore,h+,·O2-,and·OH were determined to be the reactive species generated in the photocatalytic process of the ox-GQDs/PCNO system;these species can thoroughly mineralize azo dyes and effectively inactivate pathogenic bacteria.展开更多
Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reactio...Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reaction is challenging.In this study,2D/2D step-schemeα-Fe2O3/Bi2WO6(FO/BWO)heterostructure photo-Fenton catalysts were successfully fabricated by a facile hydrothermal method.The as-prepared materials were characterized by XRD,FT-IR,TEM,XPS,UV-vis DRS,PL,I-t,EIS,and BET analyses.Under visible light irradiation,FO/BWO exhibited remarkably high and stable photo-Fenton catalytic activity for the degradation of methyl blue(MB)at low concentrations of H2O2.It was noted that FO/BWO(0.5)displayed a significantly enhanced photo-Fenton catalytic activity,which was 11.06 and 3.29 times those of FO nanosheets and BWO nanosheets,respectively.The notably improved photo-Fenton catalytic activity of FO/BWO was mainly due to the combination of H2O2 and FO under light illumination and the presence of the 2D/2D S-scheme heterostructure,with the large contact surface,abundant active sites,and efficient separation rate of photogenerated carriers playing contributory roles.Additionally,a possible catalytic mechanism for the FO/BWO composite was preliminarily proposed via active species trapping experiments.In summary,this study provided new insights into the synthesis of an effectively heterogeneous 2D/2D S-scheme photo-Fenton catalyst for degradation of organic pollutants in wastewater.展开更多
A piezoelectric sensor charge/voltage conversion circuit is designed based on the principle that piezoelectric sensor can convert the vibration or shock acceleration into the charge proportionally.Effect of temperatur...A piezoelectric sensor charge/voltage conversion circuit is designed based on the principle that piezoelectric sensor can convert the vibration or shock acceleration into the charge proportionally.Effect of temperature characteristic of feedback capacitor on the switching circuit output is analyzed based on the acquisition and measurement system in this paper.The characteristics of different filters are analyzed,and the corresponding filter circuit is configured according to the actual sensor bandwidth.Experiments show that the circuit can effectively filter out noises among the vibration signal and obtain vibration signal accurately.展开更多
The scarcity and weak durability of metal,especially precious metal catalysts are big obstacles for their large-scale application in many reactions.The state-of-the-art of the catalytic science prefers such type of ca...The scarcity and weak durability of metal,especially precious metal catalysts are big obstacles for their large-scale application in many reactions.The state-of-the-art of the catalytic science prefers such type of catalysts,which can replace metal-based catalysts to alleviate energy and environmental crises and exhibit catalytic performance comparable to or even exceeding these metal catalysts.Herein,we report that N-doped porous carbon(NKC)derived from cheap and abundant radish can be employed as versatile and efficient bifunctional catalysts in both the catalytic reduction of 4-nitrophenol(NRR)and oxidation of styrene(SOR).The series of NKC catalysts were prepared with a simple and facile one-pot strategy by coupling the N-doping,carbonization and KOH activation processes.These catalysts show hierarchical porosity,with the specific surface area,total pore volume and N-doping content ranging from 918.9-3062.7 m^2 g^-1,1.01-2.04 cm^3 g^-1 and 1.29-15.3 at%,respectively.Interestingly,our finding suggests that the catalytic performance is not directly related to these parameters but correlates positively with the content of graphitic N dopants,which is the dominant contributor for impelling both the NRR and SOR.Another intriguing finding is that for both reactions,the optimal catalyst was found to be the NKC-3-800 which possesses the highest graphitic N content of 3.13 at%.In addition,to gain insight into the catalytic behavior,analyses of kinetics and thermodynamics were performed,and the catalytic mechanisms were postulated.This work paves the way for the construction of biomass-derived N-doped carbon catalysts for bi-or even multi-functional applications in various organic reactions.展开更多
Loading of cocatalysts can effectively inhibit the recombination of photogenerated carriers in photocatalysts and greatly improve the photocatalytic hydrogen production rate. Cocatalysts can be deposited at the outlet...Loading of cocatalysts can effectively inhibit the recombination of photogenerated carriers in photocatalysts and greatly improve the photocatalytic hydrogen production rate. Cocatalysts can be deposited at the outlet points of electrons using a photochemical method, which is beneficial for the following photocatalytic hydrogen production reaction. H2PO2^– has been used in the photochemical reduction of transition metals because of its special properties. However, the particles formed in the presence of H2PO2^– are very large and highly crystalline, which may inhibit the activity of photocatalysts. In this study, we designed a new method for synthesizing photocatalysts by photodeposition using some other phosphates, aiming to prepare controllable weakly crystalline and small-size cocatalysts to improve the hydrogen production activity. The cocatalyst prepared using H2PO3^– as an inorganic sacrificial agent has an amorphous structure and an average size of about 10 nm. The optimal photocatalytic hydrogen production rate of the obtained Ni(OH)2/g-C3N4(4.36 wt%) is 13707.86 μmol·g^-1·h^-1, which is even higher than the activity of Pt-4.36 wt%/g-C3N4(11210.93 μmol·g^-1·h^-1). Mechanistic studies show that loading of Ni(OH)2 can efficiently accelerate the separation and transfer efficiency of photogenerated charge carriers.展开更多
In the practical measurement of signal to noise ratio(SNR)of analog-to-digital converters(ADCs)by using fast Fourier transformation(FFT)method,the non-coherent sampling is inevitable,leading to spectral leakage which ...In the practical measurement of signal to noise ratio(SNR)of analog-to-digital converters(ADCs)by using fast Fourier transformation(FFT)method,the non-coherent sampling is inevitable,leading to spectral leakage which in turn affects the calculation accuracy and final measurement results.In this paper,a new method based on the Blackman-Harris windowed triple-spectrum-line interpolation is presented for the measurement of ADCs SNR by FFT.The simulation platform is built based on MATLAB and the behavioral dynamic models of the high-speed ADC products of Analog Devices Inc.(ADI)are simulated.The simulation results show that,even in the case of the maximum non-coherent degree,the SNR error is less than0.23dB and reaches the testing standards provided by ADI,confirming that the proposed method is effective for suppressing the spectral leakage effects and improving the SNR test accuracy.展开更多
Photocatalytic water splitting based on semiconductor photocatalysts is a promising approach for producing carbon‐neutral,sustainable,and clean H_(2) fuel.Cocatalyst loading,which is an appealing strategy,has been ex...Photocatalytic water splitting based on semiconductor photocatalysts is a promising approach for producing carbon‐neutral,sustainable,and clean H_(2) fuel.Cocatalyst loading,which is an appealing strategy,has been extensively employed to improve the photocatalytic efficiency semiconductors.In view of the high cost and rare preservation of noble metal cocatalysts that significantly hinder their utilization for large‐scale energy production,various cocatalysts comprising earth‐abundant ele‐ments have been developed as noble‐metal‐free candidates using different methods to boost pho‐tocatalytic water splitting.Among these preparation strategies,photodeposition has attracted tre‐mendous attention in the deposition of earth‐abundant cocatalysts owing to its simplicity and mod‐erate availability,improved interfacial charge separation and transfer,and abundant active sites on the surface.In this review,we first summarize the deposition principles,deposition advantages,categories of cocatalysts,roles of cocatalysts,influencing factors,modification strategies,and design considerations in the photodeposition of earth‐abundant cocatalysts.The photodeposited earth‐abundant cocatalysts for the photocatalytic H_(2) evolution half reaction,photocatalytic O_(2) evo‐lution half reaction,and overall photocatalytic water splitting are discussed.Finally,some perspec‐tives on the challenges and possible future directions for the photodeposition of earth‐abundant cocatalysts in photocatalytic water splitting are presented.展开更多
In view of the problems of multi-scale changes of segmentation targets,noise interference,rough segmentation results and slow training process faced by medical image semantic segmentation,a multi-scale residual aggreg...In view of the problems of multi-scale changes of segmentation targets,noise interference,rough segmentation results and slow training process faced by medical image semantic segmentation,a multi-scale residual aggregation U-shaped attention network structure of MAAUNet(MultiRes aggregation attention UNet)is proposed based on MultiResUNet.Firstly,aggregate connection is introduced from the original feature aggregation at the same level.Skip connection is redesigned to aggregate features of different semantic scales at the decoder subnet,and the problem of semantic gaps is further solved that may exist between skip connections.Secondly,after the multi-scale convolution module,a convolution block attention module is added to focus and integrate features in the two attention directions of channel and space to adaptively optimize the intermediate feature map.Finally,the original convolution block is improved.The convolution channels are expanded with a series convolution structure to complement each other and extract richer spatial features.Residual connections are retained and the convolution block is turned into a multi-channel convolution block.The model is made to extract multi-scale spatial features.The experimental results show that MAAUNet has strong competitiveness in challenging datasets,and shows good segmentation performance and stability in dealing with multi-scale input and noise interference.展开更多
Power consumption in test mode is much higher than that in normal mode,which is prone to causing circuit damage and reducing the yield of chips.To reduce the power dissipation efficiently,a modified linear feedback sh...Power consumption in test mode is much higher than that in normal mode,which is prone to causing circuit damage and reducing the yield of chips.To reduce the power dissipation efficiently,a modified linear feedback shift register(LFSR)is designed to decrease switching activity dramatically during the generation of address sequences for memory built-in self-test(MBIST).The address models are generated by a blend of two address generators with an optimized address partition and two distinct controlled clock signals.An address generator circuit for MBIST of 64 k×32 static random access memory(SRAM)is designed to illustrate the proposed scheme.Experimental results show that when the address bus size is 16 bits,compared with the traditional LFSR,the proposed LFSR can reduce the switching activity and dynamic power by 71.1%and 68.2%,respectively,with low area overhead.展开更多
The self-attention networks and Transformer have dominated machine translation and natural language processing fields,and shown great potential in image vision tasks such as image classification and object detection.I...The self-attention networks and Transformer have dominated machine translation and natural language processing fields,and shown great potential in image vision tasks such as image classification and object detection.Inspired by the great progress of Transformer,we propose a novel general and robust voxel feature encoder for 3D object detection based on the traditional Transformer.We first investigate the permutation invariance of sequence data of the self-attention and apply it to point cloud processing.Then we construct a voxel feature layer based on the self-attention to adaptively learn local and robust context of a voxel according to the spatial relationship and context information exchanging between all points within the voxel.Lastly,we construct a general voxel feature learning framework with the voxel feature layer as the core for 3D object detection.The voxel feature with Transformer(VFT)can be plugged into any other voxel-based 3D object detection framework easily,and serves as the backbone for voxel feature extractor.Experiments results on the KITTI dataset demonstrate that our method achieves the state-of-the-art performance on 3D object detection.展开更多
The active sites of monodisperse transition metal Ni-clusters were anchored on carbon nitride(CN)by an in situ photoreduction deposition method to promote the efficient separation of photogenerated charges and achieve...The active sites of monodisperse transition metal Ni-clusters were anchored on carbon nitride(CN)by an in situ photoreduction deposition method to promote the efficient separation of photogenerated charges and achieve high-efficiency photocatalytic activity for hydrogen evolution.The Ni-cluster/CN exhibited a photocatalytic hydrogen production rate of 16.5 mmol·h^(-1)·g^(-1) and a total turnover frequency(TOF(H_(2)))value of 461.14 h^(-1).X-ray absorption spectroscopy based on synchrotron radiation indicated that CN had two reaction centers to form stable interface interactions with monodispersed Ni-clusters,in which carbon can act as an electron acceptor,while nitrogen can act as an electron donor.Meanwhile,the hybrid electronic structure of the Ni-cluster/CN system was constructed,which was favorable for photocatalytic activity for hydrogen production.An in-depth understanding of the interfacial interaction between CN and Ni-clusters will have important reference significance on the mechanistic study of development based on the cocatalyst.展开更多
Objective To screen forα-glucosidase inhibitor active compounds in the total saponins of Baibiandou(Lablab Semen Album)based on UHPLC-Q-Exactive Orbitrap MS technology and to evaluate its hypoglycemic activity in viv...Objective To screen forα-glucosidase inhibitor active compounds in the total saponins of Baibiandou(Lablab Semen Album)based on UHPLC-Q-Exactive Orbitrap MS technology and to evaluate its hypoglycemic activity in vivo.Methods Acarbose was used as the positive control,and the median inhibitory concentration(IC50)was used as the evaluation index ofα-glucosidase inhibitory activity to establish an in vitroα-glucosidase inhibition model.Further,UHPLC-Q-Exactive Orbitrap MS technology was used to screen and identify the active compounds ofα-glucosidase inhibitors in the total saponins of Baibiandou(Lablab Semen Album)in order to further verify the activity of the main active monomer and to perform homologous modeling and molecular docking of yeast-derivedα-glucosidase and human-derivedα-glucosidase,while the hypoglycemic activity was evaluated in diabetic mice.Results This study successfully identified 15 compounds with potentialα-glucosidase inhibitory activity,including Chikusetsusaponin IVa,from the total saponins of Baibiandou(Lablab Semen Album).Simultaneously,we verified the activity of the main active monomer Chikusetsusaponin IVa,and showed that it has strongα-glucosidase inhibitory activity.Theα-glucosidase inhibitory concentration IC50 was(565.2±1.026)μg/m L,and the IC50 of acarbose,which was lower than the positive control,was(706.6±1.058)μg/m L.The docking energies of Chikusetsusaponin IVa were–6.1 and–7.7 kcal/mol with yeast-derivedα-glucosidase and human-derivedα-glucosidase molecules,respectively.Both showed strong binding activity,and the levels of alanine aminotransaminase(ALT),aspartate aminotransaminase(AST),UREA,Creatinine(CREA),and cholesterol(CHO)were significantly decreased by Chikusetsusaponin IVa(P<0.05).In addition,it could repair damaged liver and pancreas cells of diabetic mice to some extent.Conclusion This study provides a basis for screeningα-glucosidase inhibitors and structural modifications of the total saponins of Baibiandou(Lablab Semen Album).展开更多
文摘For the ultimate strength model test evaluation of large ship structures, the distortion model with non-uniform ratio between the main size and the plate thickness size is usually adopted. It is the key to carry out scale model test to establish a distortion model similar to the real ship structure under combined load. A similarity criterion for ship distortion model under the combined action of bending moment and surface pressure was proposed, and the scale effect for the criterion was verified by a se ries of numerical analysis and model tests. The results show that the similarity criterion for ship distor tion model under combined loads has a certain scale effect. For the model tests of ship cabin struc tures, it is suggested that the scale range between the plate thickness scale and the main dimension scale should be controlled within 2:1, which can be used as a reference for distortion model design and ultimate strength test of large-scale ship structures.
文摘A hull structure is prone to local deformation and damage due to the pressure load on the surface.How to simulate surface pressure is an important issue in ship structure test.The loading mode of hydraulic actuator combined with high-pressure flexible bladder was proposed,and the numerical model of the loading device based on flexible bladder was established.The design and analysis method of high-pressure flexible bladder based on aramid-fiber reinforced thermoplastic polyurethane was proposed to break through the surface pressure loading technology of ship structures.The surface pressure loading system based on flexible bladder was developed.The ultimate strength verification test of the box girder under the combined action of bending moment and pressure was carried out to systematically verify the feasibility and applicability of the loading system.The results show that the surface pressure loading technology can be used well for applying uniform pressure to ship structures.Compared with the traditional surface loading methods,the improved device can be applied with horizontal constant pressure load,with rapid response and safe process,and the pressure load is always stable with the increase of the bending moment load during the test.The requirement for uniform loading in the comprehensive strength test of large structural models is satisfied and the accuracy of the test results is improved by this system.
文摘The repairing effect of poly(N-vinylpyrrolidone-co-methacrylic acid)on permed or bleached damaged hair was studied.The combing and tensile strength of permed and bleached hair before and after treatment with the copolymer solution were tested,and the effects of the mass fraction of copolymer solution and immerseing time on the combing and tensile strength for permed or bleached damaged hair were investigated.The repair mechanism of permed or bleached damaged hair was also explored.The results show that when the immersing time is 3 hours,the tensile strength of the permed hair increases with the mass fraction of the copolymer solution Tensile strength within 0%-0.3%,but no obvious change is observed when250 Yield strength the mass fraction is over 0.3%.Therefore,the optimal mass 200 fraction of the copolymer solution for repairing the permed hair(cN/dtex)is 0.3%.Similarly,the optimal mass fraction of the copolymer 150strength/solution for repairing the bleached hair is 0.5%.Furthermore,the effects of immersing time on the tensile strength of the100Tensile damaged hair fibers were compared between the permed and90 bleached hair before and after treatment with the copolymer500.40.30.500.10.2 solution.Coincidentally,the optimal immersion time for permedw(P(NVP-co-MAA))/%or bleached damaged hair is both 2 hours.The tensile strength of the permed and bleached hair soaked in 0.3%and 0.5%copolymer solutions for 2 hours increases by 15.55%and 18.12%,respectively,compared to untreated hair.Through infrared spectroscopy analysis,it is found that the amide II band in hair fibers shifted to the blue after repair,with the wave number shift of 11.12 and 11.09 cm^(-1),which confirm the formation of hydrogen bonds in the hair samples.Additionally,the urea hydrogen bond disruption experiment demonstrates that urea does not disrupt the hydrogen bonds in untreated hair fibers,but prevents the formation of new hydrogen bonds in damaged hair fibers.It further validates that the improvement of the tensile strength of the copolymer treated damaged hair fibers is mainly due to the formation of hydrogen bonds.After treatment with the copolymer,the dry and wet combing friction decrease by 30.73%and 28.55%for the permed hair,and decrease by 28.55%and 24.83%for the bleached hairs,respectively.The scanning electron microscope shows that the copolymer can flatten the cuticle and fill the space between the raised cuticles.
基金supported by National Natural Science Foundation of China(No.61806006)Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The existing multi-view subspace clustering algorithms based on tensor singular value decomposition(t-SVD)predominantly utilize tensor nuclear norm to explore the intra view correlation between views of the same samples,while neglecting the correlation among the samples within different views.Moreover,the tensor nuclear norm is not fully considered as a convex approximation of the tensor rank function.Treating different singular values equally may result in suboptimal tensor representation.A hypergraph regularized multi-view subspace clustering algorithm with dual tensor log-determinant(HRMSC-DTL)was proposed.The algorithm used subspace learning in each view to learn a specific set of affinity matrices,and introduced a non-convex tensor log-determinant function to replace the tensor nuclear norm to better improve global low-rankness.It also introduced hyper-Laplacian regularization to preserve the local geometric structure embedded in the high-dimensional space.Furthermore,it rotated the original tensor and incorporated a dual tensor mechanism to fully exploit the intra view correlation of the original tensor and the inter view correlation of the rotated tensor.At the same time,an alternating direction of multipliers method(ADMM)was also designed to solve non-convex optimization model.Experimental evaluations on seven widely used datasets,along with comparisons to several state-of-the-art algorithms,demonstrated the superiority and effectiveness of the HRMSC-DTL algorithm in terms of clustering performance.
基金supported by National Key Research and Development Program(No.2022YFE0112400)National Natural Science Foundation of China(No.21706096)Natural Science Foundation of Jiangsu Province(No.BK20160162).
文摘Instance segmentation plays an important role in image processing.The Deep Snake algorithm based on contour iteration deforms an initial bounding box to an instance contour end-to-end,which can improve the performance of instance segmentation,but has defects such as slow segmentation speed and sub-optimal initial contour.To solve these problems,a real-time instance segmentation algorithm based on contour learning was proposed.Firstly,ShuffleNet V2 was used as backbone network,and the receptive field of the model was expanded by using a 5×5 convolution kernel.Secondly,a lightweight up-sampling module,multi-stage aggregation(MSA),performs residual fusion of multi-layer features,which not only improves segmentation speed,but also extracts effective features more comprehensively.Thirdly,a contour initialization method for network learning was designed,and a global contour feature aggregation mechanism was used to return a coarse contour,which solves the problem of excessive error between manually initialized contour and real contour.Finally,the Snake deformation module was used to iteratively optimize the coarse contour to obtain the final instance contour.The experimental results showed that the proposed method improved the instance segmentation accuracy on semantic boundaries dataset(SBD),Cityscapes and Kins datasets,and the average precision reached 55.8 on the SBD;Compared with Deep Snake,the model parameters were reduced by 87.2%,calculation amount was reduced by 78.3%,and segmentation speed reached 39.8 frame·s−1 when instance segmentation was performed on an image with a size of 512×512 pixels on a 2080Ti GPU.The proposed method can reduce resource consumption,realize instance segmentation tasks quickly and accurately,and therefore is more suitable for embedded platforms with limited resources.
基金National Natural Science Foundation of China(No.52275478)Fundamental Research Funds for the Central Universities,China(No.2232024Y-01)DHU Distinguished Young Professor Program,China(No.LZB2023001)。
文摘Automatic splicing of interrupted yarns in ring spinning has always been a problem in the industry.Factors such as low yarn strengths and environmental influence on yarn tensions make it difficult to control the yarn tension during the robotic splicing process.The purpose of this research is to design active disturbance rejection control(ADRC)for a third-order nonlinear tension system subject to external disturbances.Firstly,a third-order extended state observer(ESO)is designed to achieve the suppression and the compensation of the internal modeling error and the external disturbances of the system.Secondly,the adaptive gain error feedback control and the filtering process are designed to reduce the influence of sensor noise on the disturbance observation.Finally,the tension control during the splicing process is simulated and experimented,and the experiments show that the method has good robustness in the tension tracking task under a dynamic environment,which verifies the effectiveness of the method.
基金supported by the National Natural Science Foundation of China(32070476,32270496)。
文摘The cicada genus Vietanna is reviewed based on the descriptions of two new species,V.perparva sp.nov.and V.longiloba sp.nov.,from China.The relationship of this genus to related taxa is discussed based on the phylogeny of Vietanna and representative species from subtribes Puranina,Leptopsaltriina,Euterpnosiina and Leptosemiina based on the mitochondrial gene COI and nuclear genes EF-1αand ARD1.
文摘The AGCU X Plus STR system is a newly developed multiplex PCR kit that detects 32 X-chromosomal STR loci simultaneously.These are DXS6807,DXS9895,linkage group 1(DXS10148,DXS10135,DXS8378),DXS9902,DXS6795,DXS6810,DXS10159,DXS10162,DXS10164,DXS7132,linkage group 2(DXS10079,DXS10074,DXS10075),DXS981,DXS6800,DXS6803,DXS6809,DXS6789,DXS7424,DXS101,DXS7133,GATA172D05,GATA165B12,linkage group 3(DXS10103,HPRTB,DXS10101),GATA31E08 and linkage group 4(DXS8377,DXS10134,DXS7423).A major advantage of this kit is that it takes into account linkage between loci,in addition to detecting more X-STR loci.In order to evaluate the forensic application of 32 X-STR fl uorescence amplifi cation system,PCR settings,sensitivity,species specifi city,stability,DNA mixtures,concordance,stutter,sizing precision,and population genetics investigation were evaluated according to the Scientific Working Group on DNA Analysis Methods(SWGDAM)developmental validation guidelines.The study showed that the genotyping results of each locus were signifi cantly accurate when the DNA template was at least 62.5 pg.Complete profi les were obtained for the 1∶1 and 1∶3 combinations.A total of 209 unrelated individuals from Southern Chinese Han community,consisting of 84 females and 125 males,were selected for population studies,and 285 allele profi les were detected from 32 X-STR loci.The polymorphism information content(PIC)ranged from 0.2721 in DXS6800,to 0.9105 in DXS10135,with an average of 0.6798.DXS10135(PIC=0.9105)was the most polymorphic locus,with discrimination power(DP)of 0.9164 and 0.9871 for the male and female.The cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) valu es were all greater than 0.999999999.There were 78 different DXS10103-HPRTB-DXS10101 haplotypes among the 125 males,and the haplotype diversity was 0.9810.There was no signifi cant difference in the cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) values whether considering linkage or not.In summary,the new X-STR multiplex typing system is effective and reliable,which can be useful in human genetic analysis and kinship testing as a potent complement to autosomal STR typing.
基金supported by the National Natural Science Foundation of China(21707052)Jiangsu Agriculture Science and Technology Innovation Fund(CX(18)2025)+1 种基金Fundamental Research Funds for the Central Universities(JUSRP11905 and JUSRP51714B)Key Research and Development Program of Jiangsu Province(BE2017623)~~
文摘Oxidized nanoporous g-C3N4(PCNO)decorated with graphene oxide quantum dots(ox-GQDs)was successfully prepared by a facile self-assembly method.As co-catalysts,the ultrasmall zero-dimensional(0 D)ox-GQDs can achieve uniform dispersion on the surface/inner channels of PCNO,as well as intimate contact with PCNO through hydrogen bonding,π-π,and chemical bonding interactions.In contrast with PCNO,the ox-GQDs/PCNO composite photocatalysts possessed improved light-harvesting ability,higher charge-transfer efficiency,enhanced photooxidation capacity,and increased amounts of reactive species due to the upconversion properties,strong electron capturing ability,and peroxidase-like activity of the ox-GQDs.Therefore,the visible-light photocatalytic degradation and disinfection performances of the ox-GQDs/PCNO composite were significantly enhanced.Remarkably,the composite with a 0.2 wt.% deposited amount of ox-GQDs(ox-GQDs-0.2%/PCNO)exhibited optimum amaranth photodegradation activity,with a corresponding rate about 3.1 times as high as that of PCNO.In addition,ox-GQDs-0.2%/PCNO could inactivate about 99.6%of Escherichia coli(E.coli)cells after 4 h of visible light irradiation,whereas only^31.9% of E.coli cells were killed by PCNO.Furthermore,h+,·O2-,and·OH were determined to be the reactive species generated in the photocatalytic process of the ox-GQDs/PCNO system;these species can thoroughly mineralize azo dyes and effectively inactivate pathogenic bacteria.
文摘Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reaction is challenging.In this study,2D/2D step-schemeα-Fe2O3/Bi2WO6(FO/BWO)heterostructure photo-Fenton catalysts were successfully fabricated by a facile hydrothermal method.The as-prepared materials were characterized by XRD,FT-IR,TEM,XPS,UV-vis DRS,PL,I-t,EIS,and BET analyses.Under visible light irradiation,FO/BWO exhibited remarkably high and stable photo-Fenton catalytic activity for the degradation of methyl blue(MB)at low concentrations of H2O2.It was noted that FO/BWO(0.5)displayed a significantly enhanced photo-Fenton catalytic activity,which was 11.06 and 3.29 times those of FO nanosheets and BWO nanosheets,respectively.The notably improved photo-Fenton catalytic activity of FO/BWO was mainly due to the combination of H2O2 and FO under light illumination and the presence of the 2D/2D S-scheme heterostructure,with the large contact surface,abundant active sites,and efficient separation rate of photogenerated carriers playing contributory roles.Additionally,a possible catalytic mechanism for the FO/BWO composite was preliminarily proposed via active species trapping experiments.In summary,this study provided new insights into the synthesis of an effectively heterogeneous 2D/2D S-scheme photo-Fenton catalyst for degradation of organic pollutants in wastewater.
文摘A piezoelectric sensor charge/voltage conversion circuit is designed based on the principle that piezoelectric sensor can convert the vibration or shock acceleration into the charge proportionally.Effect of temperature characteristic of feedback capacitor on the switching circuit output is analyzed based on the acquisition and measurement system in this paper.The characteristics of different filters are analyzed,and the corresponding filter circuit is configured according to the actual sensor bandwidth.Experiments show that the circuit can effectively filter out noises among the vibration signal and obtain vibration signal accurately.
文摘The scarcity and weak durability of metal,especially precious metal catalysts are big obstacles for their large-scale application in many reactions.The state-of-the-art of the catalytic science prefers such type of catalysts,which can replace metal-based catalysts to alleviate energy and environmental crises and exhibit catalytic performance comparable to or even exceeding these metal catalysts.Herein,we report that N-doped porous carbon(NKC)derived from cheap and abundant radish can be employed as versatile and efficient bifunctional catalysts in both the catalytic reduction of 4-nitrophenol(NRR)and oxidation of styrene(SOR).The series of NKC catalysts were prepared with a simple and facile one-pot strategy by coupling the N-doping,carbonization and KOH activation processes.These catalysts show hierarchical porosity,with the specific surface area,total pore volume and N-doping content ranging from 918.9-3062.7 m^2 g^-1,1.01-2.04 cm^3 g^-1 and 1.29-15.3 at%,respectively.Interestingly,our finding suggests that the catalytic performance is not directly related to these parameters but correlates positively with the content of graphitic N dopants,which is the dominant contributor for impelling both the NRR and SOR.Another intriguing finding is that for both reactions,the optimal catalyst was found to be the NKC-3-800 which possesses the highest graphitic N content of 3.13 at%.In addition,to gain insight into the catalytic behavior,analyses of kinetics and thermodynamics were performed,and the catalytic mechanisms were postulated.This work paves the way for the construction of biomass-derived N-doped carbon catalysts for bi-or even multi-functional applications in various organic reactions.
文摘Loading of cocatalysts can effectively inhibit the recombination of photogenerated carriers in photocatalysts and greatly improve the photocatalytic hydrogen production rate. Cocatalysts can be deposited at the outlet points of electrons using a photochemical method, which is beneficial for the following photocatalytic hydrogen production reaction. H2PO2^– has been used in the photochemical reduction of transition metals because of its special properties. However, the particles formed in the presence of H2PO2^– are very large and highly crystalline, which may inhibit the activity of photocatalysts. In this study, we designed a new method for synthesizing photocatalysts by photodeposition using some other phosphates, aiming to prepare controllable weakly crystalline and small-size cocatalysts to improve the hydrogen production activity. The cocatalyst prepared using H2PO3^– as an inorganic sacrificial agent has an amorphous structure and an average size of about 10 nm. The optimal photocatalytic hydrogen production rate of the obtained Ni(OH)2/g-C3N4(4.36 wt%) is 13707.86 μmol·g^-1·h^-1, which is even higher than the activity of Pt-4.36 wt%/g-C3N4(11210.93 μmol·g^-1·h^-1). Mechanistic studies show that loading of Ni(OH)2 can efficiently accelerate the separation and transfer efficiency of photogenerated charge carriers.
基金Summit of the Six Top Talents Program of Jiangsu Province(No.2013-DZXX-027)Fundamental Research Funds for the Central Universities(Nos.JUSRP51510,JUSRP51323B)Graduate Student Innovation Program for Universities of Jiangsu Province(Nos.SJLX16_0500,KYLX16_0776,SJCX17_0510)
文摘In the practical measurement of signal to noise ratio(SNR)of analog-to-digital converters(ADCs)by using fast Fourier transformation(FFT)method,the non-coherent sampling is inevitable,leading to spectral leakage which in turn affects the calculation accuracy and final measurement results.In this paper,a new method based on the Blackman-Harris windowed triple-spectrum-line interpolation is presented for the measurement of ADCs SNR by FFT.The simulation platform is built based on MATLAB and the behavioral dynamic models of the high-speed ADC products of Analog Devices Inc.(ADI)are simulated.The simulation results show that,even in the case of the maximum non-coherent degree,the SNR error is less than0.23dB and reaches the testing standards provided by ADI,confirming that the proposed method is effective for suppressing the spectral leakage effects and improving the SNR test accuracy.
文摘Photocatalytic water splitting based on semiconductor photocatalysts is a promising approach for producing carbon‐neutral,sustainable,and clean H_(2) fuel.Cocatalyst loading,which is an appealing strategy,has been extensively employed to improve the photocatalytic efficiency semiconductors.In view of the high cost and rare preservation of noble metal cocatalysts that significantly hinder their utilization for large‐scale energy production,various cocatalysts comprising earth‐abundant ele‐ments have been developed as noble‐metal‐free candidates using different methods to boost pho‐tocatalytic water splitting.Among these preparation strategies,photodeposition has attracted tre‐mendous attention in the deposition of earth‐abundant cocatalysts owing to its simplicity and mod‐erate availability,improved interfacial charge separation and transfer,and abundant active sites on the surface.In this review,we first summarize the deposition principles,deposition advantages,categories of cocatalysts,roles of cocatalysts,influencing factors,modification strategies,and design considerations in the photodeposition of earth‐abundant cocatalysts.The photodeposited earth‐abundant cocatalysts for the photocatalytic H_(2) evolution half reaction,photocatalytic O_(2) evo‐lution half reaction,and overall photocatalytic water splitting are discussed.Finally,some perspec‐tives on the challenges and possible future directions for the photodeposition of earth‐abundant cocatalysts in photocatalytic water splitting are presented.
基金National Natural Science Foundation of China(No.61806006)Jiangsu University Superior Discipline Construction Project。
文摘In view of the problems of multi-scale changes of segmentation targets,noise interference,rough segmentation results and slow training process faced by medical image semantic segmentation,a multi-scale residual aggregation U-shaped attention network structure of MAAUNet(MultiRes aggregation attention UNet)is proposed based on MultiResUNet.Firstly,aggregate connection is introduced from the original feature aggregation at the same level.Skip connection is redesigned to aggregate features of different semantic scales at the decoder subnet,and the problem of semantic gaps is further solved that may exist between skip connections.Secondly,after the multi-scale convolution module,a convolution block attention module is added to focus and integrate features in the two attention directions of channel and space to adaptively optimize the intermediate feature map.Finally,the original convolution block is improved.The convolution channels are expanded with a series convolution structure to complement each other and extract richer spatial features.Residual connections are retained and the convolution block is turned into a multi-channel convolution block.The model is made to extract multi-scale spatial features.The experimental results show that MAAUNet has strong competitiveness in challenging datasets,and shows good segmentation performance and stability in dealing with multi-scale input and noise interference.
基金Foundation items:Fundamental Research Funds for the Central Universities(No.JUSRP51510)Primary Research&Development Plan of Jiangsu Province(No.BE2019003-2)。
文摘Power consumption in test mode is much higher than that in normal mode,which is prone to causing circuit damage and reducing the yield of chips.To reduce the power dissipation efficiently,a modified linear feedback shift register(LFSR)is designed to decrease switching activity dramatically during the generation of address sequences for memory built-in self-test(MBIST).The address models are generated by a blend of two address generators with an optimized address partition and two distinct controlled clock signals.An address generator circuit for MBIST of 64 k×32 static random access memory(SRAM)is designed to illustrate the proposed scheme.Experimental results show that when the address bus size is 16 bits,compared with the traditional LFSR,the proposed LFSR can reduce the switching activity and dynamic power by 71.1%and 68.2%,respectively,with low area overhead.
基金National Natural Science Foundation of China(No.61806006)Innovation Program for Graduate of Jiangsu Province(No.KYLX160-781)University Superior Discipline Construction Project of Jiangsu Province。
文摘The self-attention networks and Transformer have dominated machine translation and natural language processing fields,and shown great potential in image vision tasks such as image classification and object detection.Inspired by the great progress of Transformer,we propose a novel general and robust voxel feature encoder for 3D object detection based on the traditional Transformer.We first investigate the permutation invariance of sequence data of the self-attention and apply it to point cloud processing.Then we construct a voxel feature layer based on the self-attention to adaptively learn local and robust context of a voxel according to the spatial relationship and context information exchanging between all points within the voxel.Lastly,we construct a general voxel feature learning framework with the voxel feature layer as the core for 3D object detection.The voxel feature with Transformer(VFT)can be plugged into any other voxel-based 3D object detection framework easily,and serves as the backbone for voxel feature extractor.Experiments results on the KITTI dataset demonstrate that our method achieves the state-of-the-art performance on 3D object detection.
文摘The active sites of monodisperse transition metal Ni-clusters were anchored on carbon nitride(CN)by an in situ photoreduction deposition method to promote the efficient separation of photogenerated charges and achieve high-efficiency photocatalytic activity for hydrogen evolution.The Ni-cluster/CN exhibited a photocatalytic hydrogen production rate of 16.5 mmol·h^(-1)·g^(-1) and a total turnover frequency(TOF(H_(2)))value of 461.14 h^(-1).X-ray absorption spectroscopy based on synchrotron radiation indicated that CN had two reaction centers to form stable interface interactions with monodispersed Ni-clusters,in which carbon can act as an electron acceptor,while nitrogen can act as an electron donor.Meanwhile,the hybrid electronic structure of the Ni-cluster/CN system was constructed,which was favorable for photocatalytic activity for hydrogen production.An in-depth understanding of the interfacial interaction between CN and Ni-clusters will have important reference significance on the mechanistic study of development based on the cocatalyst.
基金funding support from the Program of the Educational Commission of Hunan Province of China(No.20B418)。
文摘Objective To screen forα-glucosidase inhibitor active compounds in the total saponins of Baibiandou(Lablab Semen Album)based on UHPLC-Q-Exactive Orbitrap MS technology and to evaluate its hypoglycemic activity in vivo.Methods Acarbose was used as the positive control,and the median inhibitory concentration(IC50)was used as the evaluation index ofα-glucosidase inhibitory activity to establish an in vitroα-glucosidase inhibition model.Further,UHPLC-Q-Exactive Orbitrap MS technology was used to screen and identify the active compounds ofα-glucosidase inhibitors in the total saponins of Baibiandou(Lablab Semen Album)in order to further verify the activity of the main active monomer and to perform homologous modeling and molecular docking of yeast-derivedα-glucosidase and human-derivedα-glucosidase,while the hypoglycemic activity was evaluated in diabetic mice.Results This study successfully identified 15 compounds with potentialα-glucosidase inhibitory activity,including Chikusetsusaponin IVa,from the total saponins of Baibiandou(Lablab Semen Album).Simultaneously,we verified the activity of the main active monomer Chikusetsusaponin IVa,and showed that it has strongα-glucosidase inhibitory activity.Theα-glucosidase inhibitory concentration IC50 was(565.2±1.026)μg/m L,and the IC50 of acarbose,which was lower than the positive control,was(706.6±1.058)μg/m L.The docking energies of Chikusetsusaponin IVa were–6.1 and–7.7 kcal/mol with yeast-derivedα-glucosidase and human-derivedα-glucosidase molecules,respectively.Both showed strong binding activity,and the levels of alanine aminotransaminase(ALT),aspartate aminotransaminase(AST),UREA,Creatinine(CREA),and cholesterol(CHO)were significantly decreased by Chikusetsusaponin IVa(P<0.05).In addition,it could repair damaged liver and pancreas cells of diabetic mice to some extent.Conclusion This study provides a basis for screeningα-glucosidase inhibitors and structural modifications of the total saponins of Baibiandou(Lablab Semen Album).