Preparation and Properties of Bacterial Cellulose/Hyaluronic Acid Oral Disintegrating Films
WU Xiaoyan;SONG Wei;CHEN Shuang;XIAO Ru;The oral disintegrating film(ODF)offers significant advantages such as superior patient compliance and rapid action onset as a form of solid drug delivery.However,the drug loading efficiency and dosage of the ODF currently available in the market are limited. To enhance the drug loading efficiency,with bacterial cellulose(BC)and hyaluronic acid(HA)as film-forming agents,glycerol(GL)as a plasticizer,and diprophylline(Dilor)as the model drug,a Dilor-ODF was prepared by a solvent casting method for the treatment of acute asthma-related diseases.The BC nano-network structure was utilized to augment the drug loading efficiency of the Dilor-ODF,while HA and GL were used to improve the elongation at break. The disintegration time,drug loading efficiency and drug releasing rate,and tensile properties of the Dilor-ODF were mainly evaluated. The results indicated that the Dilor-ODF exhibited a smooth surface with a uniform thickness and a maximum drug loading efficiency of(51. 10±0. 08)%. The time for complete disintegration and that for drug release in simulated oral saliva were less than 30 and 90 s,respectively,indicating the effect of rapid release. The tensile strength and elongation at break of the Dilor-ODF were(46. 3 ± 2. 8)MPa and(1. 9 ± 0. 2)%,respectively. The thermal decomposition temperature of the Dilor-ODF was higher than 200 ℃,satisfying subsequent processing demand.
Development of Electrochemical Sensor for Cefadroxil Antibiotic Based on Conductive Carbon Black Decorated with Tetrabutylammonium Tetrafluoroborate
ZHU Zongxian;ZHANG Xuan;The development of analytical methods for antibiotic detection has become crucial for public health. In this research, a novel and simple electrochemical sensor for sensitive detection of cefadroxil(CFL) antibiotic was developed. The glassy carbon electrode(GCE) was coated with cheap conductive carbon black VXC-72R that was decorated with tetrabutylammonium tetrafluoroborate(TBABF4), to construct the electrochemical sensor TBABF4/VXC-72R/GCE. It was found that CFL exhibited a reduction peak at approximately 0.22 V on TBABF4/VXC-72R/GCE. TBABF4/VXC-72R/GCE showed a linear response to CFL in a concentration range of 0.3-10.0 μmol/L, with a detection limit of 0.2 μmol/L(a signal-to-noise ratio of 3). TBABF4/VXC-72R/GCE showed good reproducibility, high storage stability and anti-interference performance. Analytical applications for CFL detection in real lake water, pharmaceutical tablet and fetal bovine serum samples were achieved.
Interfacial Connection and Service Performance of CFRP-6061 Aluminum Alloy Enhanced by Laser-Plasma Co-Treatment
LIU Yang;CHENG Lele;LIU Yuhang;JIAO Zihe;ZHANG Jianxin;YU Muhuo;SUN Zeyu;Carbon fiber reinforced polymer(CFRP)-aluminum alloys have the advantages of both CFRP and aluminum alloys,but their different properties make the connection challenging. In this study,the response surface method(RSM)was used to optimize the laser and plasma processing parameters for treating the 6061 aluminum alloy(AA 6061)surface. The AA 6061 surface was subjected to laser-plasma co-treatment with the optimized parameters.The CFRP-AA 6061 were prepared by the co-curing method. The interface properties of the CFRP-AA 6061 were evaluated by using the climbing drum peel(CDP)test. The single lap layer shear(SLLS)strengths of different treatment procedures under different service aging conditions were investigated. The optimal laser processing parameters included a laser scanning line spacing of0. 115 mm,a laser scanning rate of 102. 719 mm/s and a laser frequency of 10. 763 kHz,resulting in an average peel strength of 103. 76(N·mm)/mm. The optimal plasma processing parameters included a gas flow rate of597. 383 L/h,a processing distance of 5. 821 mm and a processing time of 173. 132 s,resulting in an average peel strength of 66. 39(N·mm)/mm. Under the optimal laserplasma co-treatment condition,the average peel strength can reach 113. 02(N·mm)/mm,and the interfacial connection is better under different service aging conditions.This research can provide a reference for the interface treatment of composite-metal heterogeneous connections.
Preparation of Ultra-High Capacity Anode C/SnO2@NC@CC for Lithium-Ion Batteries
MOU Xina;ZHOU Xin;ASAD Khaleeq;WANG Chunrui;SnO_2-based anodes for lithium-ion batteries(LIBs)experience volume expansion,leading to rapid capacity decay and low conductivity. To address this problem,a composite consists of C/SnO2with a core-shell structure and a carbonized nitrogen-doped Co-metal organic framework(Co-MOF)(NC)supported on carbon cloth(CC)was designed and prepared,which was denoted as C/SnO2@NC@CC. C/SnO2@NC@CC could be used directly as a flexible anode for LIBs. The combination of core-shell structure centered on carbon spheres,carbonized nitrogendoped Co-MOF,and CC not only restricts the volume expansion but also functions as conductive networks to improve the electrical conductivity. C/SnO2@NC@CC exhibits excellent electrochemical performance with charge and discharge specific capacities of 2 066. 0 and2 077. 1 mAh/g,respectively,after 120 cycles at a current density of 0. 5 A/g.
All-Cellulose Composites Fabricated by Partially Dissolving Wood Pulp in Cryogenic Aqueous Phosphoric Acid
METASEBIA Gizaw;WANG Bijia;FENG Xueling;RONG Liduo;All-cellulose composites(ACCs) are composites that use non-derivatized cellulose as both the matrix and the reinforcement phase. ACC consists entirely of cellulose, and since the reinforcement phase and the matrix have exactly the same chemical properties, they can overcome the problem of poor fiber-matrix adhesion in biocomposites. In this study, ACC was prepared by partially dissolving wood pulp in a cryogenic aqueous phosphoric acid solution, and the effects of dissolution temperature, dissolution time and pressing load on the properties of ACC were investigated. The results showed that a dissolution time of 45 min achieved the optimal reinforcement-matrix ratio. The use of an aqueous ethanol solution at an ethanol mass fraction of 50% as a coagulation bath and a pressing load of 3 000 kg during the drying process achieved the best mechanical properties of ACC, with a tensile strength of 49.3 MPa(approximately 210% higher than that of the untreated wood pulp) and an elastic modulus of 1.6 GPa(approximately 122% higher than that of the untreated wood pulp). The composite's compactness affected ACC's mechanical properties. The air permeability analysis showed that the barrier performance of ACC was also significantly better than that of the untreated wood pulp. With a pressing load of 3 500 kg, the surface water contact angle(WCA) increased to 110.3°(approximately 94% higher than that of the untreated wood pulp), and the air permeability was significantly reduced to 1.1 mm/s, showing its good application prospects in the field of green packaging materials.
Antimicrobial and Preservative Effects of Codonopsis Pilosula Extract and Identification of its Active Ingredients
LIU Yao;ZHANG Shixuan;CAO Zhangjun;HUANG Zhiwei;Codonopsis pilosula(C. pilosula),Astragalus membranaceus(A. membranaceus)and Angelica sinensis(A. sinensis)are three common medicinal and dietary tonifying herbs. In this research,the antimicrobial effects of their aqueous and ethanol extracts were analyzed by using the filter paper diffusion method and microdilution method.The results showed that the aqueous extracts of these three medicinal herbs had no significant inhibitory effect on the growth of four common food-contaminated microorganisms:Escherichia coli(E. coli),Staphylococcus aureus(S.aureus),Candida albicans(C. albicans)and Saccharomyces cerevisiae(S.cerevisiae). Only the C.pilosula ethanol extract(denoted as CEE)could significantly inhibit the growth of S.aureus. The antimicrobial and preservative effects of CEE were investigated by using carrot juice as a model. It was found that CEE exhibited significant synergistic antimicrobial and preservative effects with the chemical preservative benzoic acid. When benzoic acid was reduced to half of its conventional food preservative dosage,the combined addition could completely inhibit the growth of S. aureus within 6 d. CEE was further analyzed by highperformance liquid chromatography(HPLC)and primary mass spectrometry(MS1),and lobetyolin was preliminarily identified as the main active ingredient. The minimum inhibitory concentration(MIC)of lobetyolin was determined to be 40 μg/mL when used alone. The cell counting kit-8(CCK-8)assay showed that both CEE and lobetyolin exhibited low cytotoxicity on human normal liver QSG-7701 cells at the preservative dosage,suggesting promising potential for developing safe and effective food preservatives from traditional Chinese medicinal herbs.
Dynamic Characteristic Analysis and Structural Optimization of Entire Double-Shaft-Driven Needle Punching Machine for C/C Crucible Preforms
SUN Zhihong;DENG Qicai;QU Zhiyang;WANG Zhenxi;WANG Bing;ZHANG Xi;ZHANG Jingzhang;Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms. Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms. The intense vibration during needle punching not only generates huge noise, but also substantially reduces the quality of the preform. It is imperative to perform a dynamic analysis and optimization of the entire needle punching machine. In this paper, the three-dimensional(3D) model of the entire double-shaft-driven needle punching machine for C/C crucible preforms is established. Based on the modal analysis theory, the modal characteristics of the needle punching machine under various operating conditions are analyzed and its natural frequencies and vibration modes are determined. The harmonic response analysis is then employed to obtain the amplitude of the needle plate at different frequencies, and the structural weak points of the needle punching machine are identified and improved. The feasibility of the optimized scheme is subsequently reevaluated and verified. The results indicate that the first six natural frequencies of the machine increase, and the maximum amplitude of the needle plate decreases by 70.3%. The enhanced dynamic characteristics of the machine significantly improve its performance, enabling more efficient needle punching of C/C crucible preforms.
Structural Reliability Analysis Method Based on Kriging and Spherical Cap Area Integral
ZHANG Jixiang;CHEN Zhenzhong;CHEN Ge;LI Xiaoke;ZHAO Pengcheng;PAN Qianghua;In the structural reliability analysis, the first-order reliability method(FORM) often yields significant errors when addressing nonlinear problems. Although the second-order reliability method(SORM) can provide higher accuracy, the additional computation of the Hessian matrix leads to lower computational efficiency. Additionally, when the dimensionality of the random variables is high, the approximation formula of SORM can result in larger errors. To address these issues, a structural reliability analysis method based on Kriging and spherical cap area integral is proposed. Firstly, this method integrates FORM with the quasi-Newton algorithm Broyden-Fletcher-Goldfarb-Shanno(BFGS), trains the Kriging model by using sample points from the algorithm's iteration process, and combines the Kriging model with gradient information to approximate the Hessian matrix. Then, the failure surface is approximated as a rotating paraboloid, utilizing the spherical cap to replace the complex surface. For the n-dimensional case, the hyperspherical cap area expression is combined with the integral method to calculate the failure probability. Finally, the method is validated through three examples, demonstrating improved computational accuracy and efficiency compared to traditional methods.
DrownACB-YOLO:an Improved YOLO for Drowning Detection in Swimming Pools
ZENG Xiaoya;XU Wujun;ZHANG Xiunian;With the rise in drowning accidents in swimming pools, the demand for the precision and speed in artificial intelligence(AI) drowning detection methods has become increasingly crucial. Here, an improved YOLO-based method, named DrownACB-YOLO, for drowning detection in swimming pools is proposed. Since existing methods focus on the drowned state, a transition label is added to the original dataset to provide timely alerts. Following this expanded dataset, two improvements are implemented in the original YOLOv5. Firstly, the spatial pyramid pooling(SPP) module and the default upsampling operator are replaced by the atrous spatial pyramid pooling(ASPP) module and the content-aware reassembly of feature(CARAFE) module, respectively. Secondly, the cross stage partial bottleneck with three convolutions(C3) module at the end of the backbone is replaced with the bottleneck transformer(BotNet) module. The results of comparison experiments demonstrate that DrownACB-YOLO performs better than other models.
A Hybrid Simulation-Experimental Method for Deriving Equivalent Dynamic Parameters of O-Ring Support Systems
LIU Yi;YE He;ZHANG Lingfeng;LI Shujia;CHEN Ge;WANG Yongxing;The high-speed winding spindle employs a flexible support system incorporating rubber O-rings. By precisely configuring the structural parameters and the number of the O-rings, the spindle can stably surpass its critical speed points and maintain operational stability across the entire working speed range. However, the support stiffness and damping of rubber O-rings exhibit significant nonlinear frequency dependence. Conventional experimental methods for deriving equivalent stiffness and damping, based on the principle of the forced non-resonance method, require fabricating custom setups for each O-ring specification and conducting vibration tests at varying frequencies, resulting in low efficiency and high costs. This study proposes a hybrid simulation-experimental method for dynamic parameter identification. Firstly, the frequency-dependent dynamic parameters of a specific O-ring support system are experimentally obtained. Subsequently, a corresponding parametric finite element model is established to simulate and solve the equivalent elastic modulus and equivalent stiffness-damping coefficient of this O-ring support system. Ultimately, after iterative simulation, the simulated and experimental results achieve a 99.7% agreement. The parametric finite element model developed herein can directly simulate and inversely estimate frequency-dependent dynamic parameters for O-rings of different specifications but identical elastic modulus.
Magnetic Resonance Image Super-Resolution Based on GAN and Multi-Scale Residual Dense Attention Network
GUAN Chunling;YU Suping;XU Wujun;FAN Hong;The application of image super-resolution(SR)has brought significant assistance in the medical field,aiding doctors to make more precise diagnoses. However,solely relying on a convolutional neural network(CNN)for image SR may lead to issues such as blurry details and excessive smoothness. To address the limitations,we proposed an algorithm based on the generative adversarial network(GAN)framework. In the generator network,three different sizes of convolutions connected by a residual dense structure were used to extract detailed features,and an attention mechanism combined with dual channel and spatial information was applied to concentrate the computing power on crucial areas. In the discriminator network,using InstanceNorm to normalize tensors sped up the training process while retaining feature information. The experimental results demonstrate that our algorithm achieves higher peak signal-to-noise ratio(PSNR)and structural similarity index measure(SSIM)compared to other methods,resulting in an improved visual quality.
Incomplete Physical Adversarial Attack on Face Recognition
HU Weitao;XU Wujun;In recent work, adversarial stickers are widely used to attack face recognition(FR) systems in the physical world. However, it is difficult to evaluate the performance of physical attacks because of the lack of volunteers in the experiment. In this paper, a simple attack method called incomplete physical adversarial attack(IPAA) is proposed to simulate physical attacks. Different from the process of physical attacks, when an IPAA is conducted, a photo of the adversarial sticker is embedded into a facial image as the input to attack FR systems, which can obtain results similar to those of physical attacks without inviting any volunteers. The results show that IPAA has a higher similarity with physical attacks than digital attacks, indicating that IPAA is able to evaluate the performance of physical attacks. IPAA is effective in quantitatively measuring the impact of the sticker location on the results of attacks.
Tracking the information about your manuscript
Communicate with the editorial office
Query manuscript payment status Peer ReviewOnline Review
Online Communication with the Editorial Department Editorial OfficeCollecting, editing, reviewing and other affairs offices
Managing manuscripts
Managing author information and external review Expert Information
Download Center
Call for Papers
News
OSID Open Science Program
JDHUE Selected for CAS 2024 “Bilingual Communication Project of Scientific Journals”
JDHUE Selected for Shanghai Scientific Journals' Most Beautiful Cover Case Library
JDHUE Editorial Department Presents Thesis Writing Lecture for Graduate Students in the College of Chemistry and Chemical Engineering at DHU
JDHUE Editorial Department Presents Scientific Paper Writing Standards Lecture for International Students at DHU
more..Links
Subscription
Journal information
Journal of Donghua University (English Edition)
Started: 1984
Supervised by: Ministry of Education, China
Administered by : Donghua University
Editor-in-Chief: Zhu Meifang
CN: 31-1920/TS
ISSN: 1672-5220