检索结果-南通市图书馆

Electrocatalytic Oxidation and Simultaneous Determination of Uric Acid,Xanthine,Hypoxanthine and Dopamine Based on β-Cyclodextrin Modified Glassy Carbon Electrode

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2012年第6期28卷 1047-1053页

作者： GONG Wei DOU Zhi-yu CUI Li-li liu da-jun he Xing-quan Department of Chemistry and Chemical Engineering Changchun University of Science and Technology Changchun 130022 P. R. China

A novel covalently modified glassy carbon electrode with β-cyclodextrin was prepared via electropolymerization technique for the simultaneous determination of uric acid（UA）,xanthine（XA）,hypoxanthine（HX） and dopamine（da）.This new electrode presented an excellent electrocatalytic activity towards the oxidation of UA,XA,HX and da by cyclic voltammetry（CV） *** oxidation peaks of the four compounds were well defined and had the enhanced peak *** separation potentials of the oxidation peaks for da-UA,UA-XA and XA-HX were 150,390 and 360 mV in CV,*** means of differential pulse voltammetry（DPV） method,the calibration curves in the ranges of 10―225,5―105,10―170 and 5―150 μmol/L were obtained for UA,XA,HX and da,*** lowest detection limits（S/N=3） were 5,1.25,5 and 1.5 μmol/L for UA,XA,HX and da,*** practical application of the modified electrode was demonstrated by the determination of da in hydrochloride injection and UA,XA,HX in human urine samples.

关键词： β-Cyclodextrin Uric acid Xanthine Hypoxanthine Dopamine

Deep learning methods for roping defect analysis in aluminum alloy sheets: prediction and grading

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第3期12卷 576-590页

作者： Yuan-Zhe Hu Ru-Xue liu Jia-Peng he Guo-Wei Zhou da-Yong Li State Key Laboratory of Mechanical Systems and Vibration Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240People’s Republic of China

Roping is a severe band-like surface defect that occurs in deformed aluminum alloy *** roping prediction and rating are essential for industrial ***,the authors introduced an artificial neural network(ANN)model to efficiently forecast roping behavior across the thickness of large regions with texture *** this study,the previously proposed ANN model for roping prediction is briefly reviewed,and a few-shot learning(FSL)-based method is developed for roping grading with limited *** consider the directionality of the roping patterns,the roping dataset constructed from experimental observations is transformed into the frequency domain for more compact characterization.A transfer-based FSL method is further presented for grade roping with manifold mixup regularization and the Sinkhorn mapping algorithm.A new component-focused representation is also implemented for data-processing,exploiting the close correlation between roping and power distribution in the frequency *** ultimate FSL method achieved an optimal accuracy of 95.65%in roping classification with only five training samples per class,outperforming four typical FSL *** FSL approach can be applied to grade the roping morphologies predicted by the ANN ***,the combination of prediction and grading using deep learning provides a new paradigm for roping analysis and control.

关键词： Roping Artificial neural network(ANN) Aluminum alloys Few-shot classification Surface morphology

Wavelength Variation of a Random Laser with Concentration of a Gain Material

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第10期28卷 91-94页

作者： CheN Shu-Jing SHI Jin-Wei ZHAI Tian-Rui WANG Zhao-Na liu da-he CheN Xiao Applied Optics Beijing Area Major Laboratory Department of PhysicsBeijing Normal UniversityBeijing 100875 Key Laboratory of Nondestructive Test(Ministry of Education) Nanchang Hang Kong UniversityNanchang 330063 College of Science Minzu University of ChinaBeijing 100081

The wavelength variation of a laser-dye-type random laser is observed *** is found that the emitting wavelength of a random laser changes with the change of concentration of the gain ***,the actual radiation wavelengt... 详细信息

关键词： material pumping laser

Honeycomb-like biochar framework coupled with Fe_(3)O_(4)/FeS nanoparticles as efficient heterogeneous Fenton catalyst for phenol degradation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 390-399页

作者： Aihua Cheng Yi he Xiaohe liu Chi he Department of Environmental Engineering College of Geology and EnvironmentXi’an University of Science and TechnologyXi’an 710054China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China National Engineering Laboratory for VOCs Pollution Control Material and Technology University of Chinese Academy of SciencesBeijing 101408China

Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater ***,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by *** prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the ***,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation ***,biochar can effectively promote cycling stability by limiting Fe *** work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.

关键词： Biomass Biochar Fenton reaction Fe_(3)O_(4)/FeS(Fe/S) Phenol degradation

Study on a semi-resolved CFD-DEM method for rod-like particles in a gas-solid fluidized bed

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第4期87卷 20-36页

作者： Liping he Zhengxian liu Yongzhi Zhao Department of Mechanics School of Mechanical EngineeringTianjin UniversityTianjin300350China Insttute of Process quipment College of Energy EngineeringZhejiang UniversityHangzhou30027China

Based on a semi-resolved CFD-DEM coupling method,this study proposed a method that uses the minimum distance between the fluid grid and the particle boundary as a reference value to determine the degree of influence of the target fluid grid on the particle's drag force.A fluidized bed of rod-like particles was chosen as a typical case to investigate the effect of different fluid grid scales on various fluidized bed characteristic *** calculation performance of the semi-resolved and unre-solved CFD-DEM coupling algorithm on key fluidized bed characteristic parameters such as average pressure drop,particle frequency distribution with bed height,and particle orientation distribution were *** was found that the semi-resolved CFD-DEM coupling algorithm gradually obtained results with higher consistency with decreasing fluid grid scale for key parameters such as particle frequency distribution with bed height,particle orientation distribution,and time-history mixing index,exhibiting a phenomenon similar to grid independence in fluid *** comparing with experimental results,it was verified that the semi-resolved CFD-DEM coupling algorithm can be applied to simulate multi-granular gas-solid systems with fluid grid scales equivalent to particle *** algorithm solves the limitation of fluid grid scale in the unresolved CFD-DEM coupling framework and improves the grid adaptability of the CFD-DEM coupling simulation algorithm.

关键词： CFD-DEM Semi-resolved method Fluid-solid flow Non-spherical particle Fluidized bed

Posterior Reduction and Monosegmental Fusion with Intraoperative Three-dimensional Navigation System in the Treatment of High-grade Developmental Spondylolisthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2015年第7期128卷 865-870页

作者： Wei Tian Xiao-Guang Han Bo liu Ya-Jun liu da he Qiang Yuan Yun-Feng Xu Department of Spine Surgery Beijing Jishuitan Hospital Beijing 100035 China

Background： The treatment of high-grade developmental spondylolisthesis （HGDS） is still challenging and controversial. In this study, we investigated the efficacy of the posterior reduction and monosegmental fusion assisted by intraoperative three-dimensional （3D） navigation system in managing the HGDS. Methods： Thirteen consecutive HGDS patients were treated with posterior decompression, reduction and monosegmental fusion ofL5/S1, assisted by intraoperative 3D navigation system. The clinical and radiographic outcomes were evaluated, with a minimum follow-up of 2 years. The differences between the pre- and post-operative measures were statistically analyzed using a two-tailed, paired t-test. Results： At most recent follow-up, 12 patients were pain-free. Only l patient had moderate pain, There were no permanent neurological complications or pseudarthrosis. The magnetic resonance imaging showed that there was no obvious disc degeneration in the adjacent segment. All radiographic parameters were improved. Mean slippage improved from 63.2% before surgery to 12.2% after surgery and 11.0% at latest follow-up. Lumbar lordosis changed from preoperative 34.9 ± 13.3° to postoperative 50.4 ±9.9°, and 49.3 ± 7.8° at last follow-up. L5 incidence improved from 71.0 ± 11.3° to 54.0 ± 1 1.9° and did not change significantly at the last follow-up 53.±1 15.4°. While pelvic incidence remained unchanged, sacral slip significantly decreased from preoperative 32.7± 12.5° to postoperative 42.6 ± 9.8°and remained constant to the last follow-up 44.4 ± 6.9°. Pelvic tilt significantly decreased from 38.4±12.5° to 30.9± 8.1° and remained unchanged at the last fbllow-up 28.1± 11.2°. Conclusions： Posterior reduction and monosegmental fusion of L5/S1 assisted by intraoperative 3D navigation are an effective technique for managing high-grade dysplastic spondylolisthesis. A complete reduction of local deformity and excellent correction of overall sagittal balance can be achieved.

关键词： High-grade Developmental Spondylolisthesis Intraoperative Three-dimensional Navigation Neurological Complication Reduction: Spondylolisthesis

Toxicity mechanisms of photodegraded polyvinyl chloride nanoplastics on pea seedlings

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2024年第4期18卷 111-124页

作者： Hao Wu Beibei he Bocheng Chen An liu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Nanoplasctics(NPs),which are very small in particle size,exert toxic effect to ***,compared to original NPs,photodegraded NPs would pose higher *** is because their relatively higher specific surface areas and the presence of additives which can more easily *** original NPs and aged NPs affect plant growth has not been widely *** work chose polyvinyl chloride NPs(PVC-NPs)that were subjected to up to 1000 h UV light radiation to explore the impact of PVC-NPs on the growth of pea seedlings(Pisum Sativum L.).The results indicated the existence of PVC-NPs with longer UV light radiation time and higher concentrations had more negative influences on pea seedlings’growth such as germination rate(decreased by 10.6%–22.5%),stem length(decreased by 2.8%–8.1%),dry weight(decreased by 6.3%–7.1%)and fresh weight(decreased by 6.7%–14.8%).It was also noted that photodegraded PVC-NPs resulted in damage to leaf stomata and roots,hindering photosynthesis and absorption of nutrients and hence the decrease in chlorophyll and soluble sugar *** to transcriptomic investigation results,the presence of aged PVC-NPs primarily influenced protein processing in endoplasmic reticulum(upregulated metabolic pathway)and phenylpropanoid biosynthesis(downregulated metabolic pathway)of pea *** results provide an in-depth understanding of how NPs influence the growth of plants.

关键词： Nanoplasctics Polyvinyl chloride Toxicity mechanisms Plant growth

Effects of vibration conditions,spatial confinement and friction on mixing and segregation characteristics of mixed pebble beds for CFETR WCCB blanket

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第2期85卷 268-279页

作者： Yong liu Chongyang he Cong Wang Lei Chen Songlin liu Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230027China Chengdu University Chengdu610106China Zhejiang Lab Hangzhou310000China

This paper presents the study of the dynamic characteristics of confined mixed pebble beds with different friction under different vibration conditions using the discrete element ***λsegre-gation index is used to quantify the degree of particle mixing or *** percolation,convection and diffusion mechanisms are responsible for the segregation patterns of the mixed *** results show the degree of segregation can be suppressed by decreasing the vibration acceleration or free space height below a *** simulation reveals the threshold of vibration acceleration or free space height both are related to the bed height increment which determines the strength of the percolation *** addition,the strength of percolation and convection becomes weaker by decreasing the friction of particles and walls,which makes the pebbled bed remains in a mixed state under *** findings are significant to clarify the main factors behind the three segregation mechanisms and hence provide solutions to retaining the mixed state of the Li2TiO3&Be12Ti mixed pebble bed.

关键词： Vibration Segregation Binary pebble bed Discrete element method

Identification of the optimal doping position of hetero-atoms in chalcogen-doped Fe-N-C catalysts for oxygen reduction reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 99-108页

作者： Weihao liu Huanhuan he Qingtao liu Xin Wan Jianglan Shui School of Materials Science and Engineering Beihang UniversityBeijing100191China School of Space and Environment Beihang UniversityBeijing102206China Tianmushan Laboratory Hangzhou310023China

The excellent oxygen reduction reaction(ORR)activity of Fe–N–C catalysts in acidic media makes them potential for low-cost proton exchange membrane fuel *** recent years,it has been shown that heteroatoms(B,O,S,P,Cl,F,etc.)can be used as electron-withdrawing groups to modulate the planar structure and electron distribution of the Fe–Nx active sites to achieve simultaneous improvement of catalytic activity and ***,the optimal location of the heteroatoms remains ***,taking chalcogen heteroatoms(S and Se)as an example,we control the doping positions and investigate their effect on the ORR performance of the Fe–N–C *** first coordination shell of the iron single atom is identified as the optimal doping *** optimized catalysts Fe–N_(3)Se_(1)/NC and Fe–N_(3)Se_(1)/NC demonstrate improved activity and stability in both half cells and fuel *** work provides insights into the enhancement mechanism of heteroatom doping in single-atom catalysts.

关键词： Oxygen reduction reaction Fe-N-C catalysts hetero-atom doping Doping position Enhancement mechanism