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Sensing formic acid with a water-based chitosan lanthanide luminescence film
Xu Zheng,Xi Chen,Xudong Yu,Yifan Yang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-
A sensitive and selective formic acid sensor could be useful in detecting this corrosive acid in industrial,medical, and environmental settings. Herein, we present a film for detection of formic acid. We introducedchitosan as a film-forming factor to creatively overcome the problem that chitosan dissolves inacids. A carboxylic acid-carbon dot solution was used to replace the strong acid solution and prepare aluminescent film in which the color changed from green to blue when it was exposed to formic acid. Integrated data analysis of the film was used to distinguish vapor from formic acid/water solutions at differentconcentrations and with a detection limit of 0.01% v/v. The selectivity of the sensor was also investigated. After fumigation with ethanol and other common solvents, there was no response similar to thatfor formic acid. It is believed that films based on lanthanide complexes and chitosan could prevent corrosionand injury from formic acid.
Xudong Chen,Lingyu Xu,Jingwu Bu 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5
Due to the difficulties of testing concrete in direct uniaxial tension, only limited data are available. In this paper, the cyclic tensile test on the plain concrete was carried out. Based on the experimental data, the plasticity and damage evolution can be formulated with respect to elastic strain. A constitutive model for cyclic tensile behavior of concrete is proposed. The proposed model can describe the nonlinear post-peak performance of concrete in direct tension including hysteresis loops. Finally, a statistical damage model is derived to describe the microcrack growth of concrete under monotonic and cyclic tension loading. Results demonstrated that the microcracks growth of concrete under cyclic tension loading can be formulated by the Weibull cumulative distribution function.
Mechanical Behavior and Damage Evolution for Concrete Subjected to Multiple Impact Loading
Xudong Chen,Lingyu Xu,Qiao Zhu 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.6
In order to explore the dynamic mechanical properties and damage evolution for concrete under the repeated impact loading, the large-diameter (74 mm) Split Hopkinson Pressure Bar (SHPB) was used to conduct the dynamic compression test. The damage was calculated by the Weibull statistical damage model, and the stress-strain curves of concrete were analyzed to study the repeated impact loading effects on the damage of concrete. Meanwhile, the fracture process of the concrete was simulated with the finite element software (LS-DYNA) and Johnson Holmquist Concrete (*MAT_JOHNSON_HOLMQUIST_CONCRETE) constitutive model. The results showed that the dynamic elastic modulus and the peak stress of the specimens decreased with the increased number of repeated impacts, while the peak strain increased. The damage of concrete increased with the increased strain, and the damage increased sharply after the “inflection point”. In addition, the results obtained by finite element simulation agree with the experimental results.
Domain Adaption of Vehicle Detector based on Convolutional Neural Networks
Xudong Li,Mao Ye,Min Fu,Pei Xu,Tao Li 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.4
Generally the performance of a vehicle detector will decrease rapidly, when it is trained on a fixed training set but applied to a specific scene with view changes. The reason is that in the training set only a few samples are helpful for vehicle detection in the specific scene while other samples disturb the accurate detections. To solve this problem, we propose a novel transfer learning method to adapt the trained vehicle detector based on convolutional neural networks (ConvNets) to a specific scene with several new labeled samples. At first we reserve the share-filters and update the non-shared filters to improve the sensitivity of the vehicles in the specific scene. Then we combine the similar feature maps to accelerate the detection speed. At last for making the vehicle detector stable, we fine-tune it several times with the updated training set. Our contributions are an original research on transferring the vehicle detector based on ConvNets and an optimization approach about removing the redundant connections in the ConvNet vehicle detector. The extensive comparative experiments on three different datasets demonstrate that the transferred detectors achieve the improvements on both of the accuracy and speed.
Study of the Application of Fructooligosaccharides in Piglets
Chuanlai Xu,Xudong Chen,Cheng Ji,Qiugang Ma,Kai Hao 아세아·태평양축산학회 2005 Animal Bioscience Vol.18 No.7
In this study, 90 crossbred weaned pigs (Duroc횞Landrace횞Large White) weighing ~ 7.86짹0.06 kg each were randomly allotted to one of three dietary treatments. Control pigs were a fed corn-soybean meal diet with no additives. The two treatment groups were fed the basal diet supplemented either with 75 mg/kg Aureomycin or 0.4% fructooligosaccharides (FOS) in order to study the effects on performance, serological indices, and enteric morphology in addition to examining the content of volatile fatty acids in intestinal digesta. The results indicate that the diets containing FOS and antibiotics had a significant effect on feed conversion ratios (FCR) and diarrhea incidence, as well as increasing the concentrations of isobutyric and butyric acid and total VFAs in the caecum, and acetic acid, isovaleric acid, and total VFAs in feces. Supplementation with FOS also resulted in significantly longer mucosal villi height and a higher percentage of goblet cells compared with the control. No difference was found in crypt depth among the three treatments. While serum glucose levels were significantly higher following FOS supplement, differences in serum total protein, albumin, globulin, and urea nitrogen levels were not significant.
Yanfeng Wang,Xudong Guo,Zhigang Wang,Zhixin Guo,Mingtao Liu,Keyu Zhao,Xue Feng,Xu Zheng,Xiaojing Wang,Huifang Hao 한국통합생물학회 2017 Animal cells and systems Vol.21 No.5
PSMB1 (proteasome subunit beta type 1) is a core component of the 20S proteasome, and based on its structure, it might have a crucial function in the transcription of certain genes. Rheb (Ras homolog enriched in brain) is a Ras-like small GTPase that acts as an upstream positive regulator of the mechanistic target of rapamycin complex 1 (mTORC1) pathway. We cloned and characterized PSMB1 (KY310590.1) to determine its function in cell cycle progression and proliferation of goat fetal fibroblasts (GFbs). Further, by yeast two-hybrid screen and coimmunoprecipitation, we conformed that PSMB1 interacts directly with Rheb. An siRNA was designed and expressed targeting PSMB1 mRNA in GFbs and inducing cell cycle arrest. Rheb overexpression in GFbs significantly increased the number of S phase cells and growth efficiency compared with control cells. These data indicate that PSMB1 and Rheb have important functions in the cell cycle and proliferation of GFbs, indicating that their interaction governs many processes in GFbs.
Stress field interference of hydraulic fractures in layered formation
Zhu, Haiyan,Zhang, Xudong,Guo, Jianchun,Xu, Yaqin,Chen, Li,Yuan, Shuhang,Wang, Yonghui,Huang, Jingya Techno-Press 2015 Geomechanics & engineering Vol.9 No.5
Single treatment and staged treatments in vertical wells are widely applied in sandstone and mudstone thin interbedded (SMTI) reservoir to stimulate the reservoir. The keys and difficulties of stimulating this category of formations are to avoid hydraulic fracture propagating through the interface between shale and sand as well as control the fracture height. In this paper, the cohesive zone method was utilized to build the 3-dimensional fracture dynamic propagation model in shale and sand interbedded formation based on the cohesive damage element. Staged treatments and single treatment were simulated by single fracture propagation model and double fractures propagation model respectively. Study on the changes of fracture vicinity stress field during propagation is to compare and analyze the parameters which influence the interfacial induced stresses between two different fracturing methods. As a result, we can prejudge how difficult it is that the fracture propagates along its height direction. The induced stress increases as the pumping rate increasing and it changes as a parabolic function of the fluid viscosity. The optimized pump rate is $4.8m^3/min$ and fluid viscosity is $0.1Pa{\cdot}s$ to avoid the over extending of hydraulic fracture in height direction. The simulation outcomes were applied in the field to optimize the treatment parameters and the staged treatments was suggested to get a better production than single treatment.
Bing Sun,Xiaofei Xu,Xudong Wan 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.12
Based on the perspective of innovation ecosystem, the paper studies the relationships between openness and absorptive capacity of leading firms’, and how they make effects on innovation performance. Based on a survey of 126 high-tech firms’ in China, we found both the openness and absorptive capacity have a positive impact on innovation performance. A finding shows that the scope of openness is wider, the knowledge acquisition capability contributes more to the innovation performance; also, the depth of openness is deeper, the knowledge exploitation capability is more helpful to improve the innovation performance.