20 research outputs found

    Electrodeposition of Neodymium_Iron Group Alloy Films in( p _CH 3C 6H 4SO 3) 3Nd+DMF System

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    本世纪30年代Audreith等人基于分离稀土元素的目的,在某些有机溶剂电解液中用汞阴极电沉积了个别的稀土汞齐[1].1954年Moeler等在乙二胺中电沉积了Y、La和Nd(稀土含量只有50%左右)[2].随着电子和信息技术的发展,稀土合金功能薄膜...Neodymium p _toluenesulfonate was prepared and applied to the electrodepositon of neodymium_iron group alloy films. This salt has high solubility in DMF and can be dehydrated easily. Cyclic voltammograms of Pt electrode in ( p _CH 3C 6H 4SO 3) 3Nd+MCl 2(M=Fe,Co,Ni)+DMF indicated that the neodymiun_iron group alloys can be elcetrodeposited from this medium, the Nd_Fe,Nd_Co and Nd_Ni films were obtained by electrolysis at constant potential. The Nd_Fe,Nd_Co and Nd_Ni films are amorphous in which the rare earth contents are in the range of 15 at%~60 at% as analyzed by XRD and EDS. The Nd content in the deposited film increases with the shift of cathode potential to the negative direction. The deposited Nd_Co film has good soft magnetic properites and its crystallization temperature was determined as 468.3 ℃.Author's Address: School of Chem. and Chem. Engin., Zhongshan University, Guangzhou 51027

    BiGA-YOLO: A Lightweight Object Detection Network Based on YOLOv5 for Autonomous Driving

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    Object detection in autonomous driving scenarios has become a popular task in recent years. Due to the high-speed movement of vehicles and the complex changes in the surrounding environment, objects of different scales need to be detected, which places high demands on the performance of the network model. Additionally, different driving devices have varying performance capabilities, and a lightweight model is needed to ensure the stable operation of devices with limited computing power. To address these challenges, we propose a lightweight network called BiGA-YOLO based on YOLOv5. We design the Ghost-Hardswish Conv module to simplify the convolution operations and incorporate spatial coordinate information into feature maps using Coordinate Attention. We also replace the PANet structure with the BiFPN structure to enhance the expression ability of features through different weights during the process of fusing multi-scale feature maps. Finally, we conducted extensive experiments on the KITTI dataset, and our BiGA-YOLO achieved a [email protected] of 92.2% and a [email protected]:0.95 of 68.3%. Compared to the baseline model YOLOv5, our proposed model achieved improvements of 1.9% and 4.7% in [email protected] and [email protected]:0.95, respectively, while reducing the model size by 15.7% and the computational cost by 16%. The detection speed was also increased by 6.3 FPS. Through analysis and discussion of the experimental results, we demonstrate that our proposed model is superior, achieving a balance between detection accuracy, model size, and detection speed

    Preparation and evaluation of a novel monolithic column containing double octadecyl chains for reverse-phase micro high performance liquid chromatography.

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    A novel reverse-phase monolithic stationary phase containing double long alkyl chains was prepared based on the thermally initiated co-polymerization of 3-methylacryloyl-3-oxapropyl-3-(N,N-dioctadecylcarbamoyl)-propionate (AOD) and ethylene glycol dimethacrylate (EDMA) in the presence of 2-methyl-1-propanol and 1,4-butanediol as the selected porogens. The polymerization was carefully optimized and good permeability, stability and column efficiency were observed for the final monolithic columns. The column also showed good long term stability and reproducibility. The methylene selectivity demonstrates typical reversed phase characteristics. The optimized poly (AOD-co-EDMA) monolith exhibited good selectivity for a range of non-polar test analytes such as PAHs, tocopherols and alkylphenones. A good separation of intact proteins was also observed

    Separation of deamidated peptides with mixed-mode chromatography using phospholipid-functionalized monolithic stationary phases

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    Deamidation of asparagine (Asn) residues of monoclonal antibodies (mAbs) plays a pivotal role in the in vivo/vitro degradation or efficacy loss of biopharmaceuticals. However, a major challenge for MS analysis of deamidation of Asn-containing peptides in mAbs, is due to the fact that there is only a 1 Da mass shift between the native form (Asn residues) and deamidated forms (n-aspartyl (n-Asp) and isoaspartyl (isoAsp) residues with identical mass). Therefore, a chromatographic separation of the deamidated proteins and/or the peptides derived therefrom is needed prior to MS analysis. In this study, the monolithic column with various stationary phases, including reverse phase (RP), single phospholipid-functionalized and mixed phospholipid-functionalized monoliths, were prepared for the separation of the deamidation-sensitive signature peptide (IYPTNGYTR) of trastuzumab and its two deamidated products, n-Asp55 residue IYPTDGYTR and isoAsp55 residue IYPTisoDGYTR. Compared to the RP monolith, the phospholipid-functionalized monoliths provided mixed-mode interactions and exhibited better peak shape and separation selectivity. The effect of the parameters, including the type and concentration of buffer, temperature and pH value on the separation performance were investigated. Under the optimal conditions, the three peptides were fully separated on a mixed phosphocholine (PC) / phosphatidic acid (PA) functionalized monolith (poly (MDPC60PA40-co-EDMA)) due to the joint contribution of hydrophobic and electrostatic interactions. Therefore, the novel method based on the mixed phospholipids-functionalized monolithic column exhibited good potential for the analysis of deamidated peptides, which will be useful for the in-depth study of post-translational modifications of mAbs

    Association between the Classification of the Genus of Batrachospermaceae (Rhodophyta) and the Environmental Factors Based on Machine Learning

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    Batrachospermaceae is the largest family of freshwater red algae, widely distributed around the world, and plays an important role in maintaining the balance of spring and creek ecosystems. The deterioration of the current global ecological environment has also destroyed the habitat of Batrachospermaceae. The research on the environmental factors of Batrachospermaceae and the accurate classification of the genus is necessary for the protection, restoration, excavation, and utilization of Batrachospermaceae resources. In this paper, the database of geographical distribution and environmental factors of Batrachospermaceae was sorted out, and the relationship between the classification of genus and environmental factors in Batrachospermaceae was analyzed based on two machine learning methods, random forest and XGBoost. The result shows: (1) The models constructed by the two machine learning methods can effectively distinguish the genus of Batrachospermaceae based on environmental factors; (2) The overall AUC score of the random forest model for the classification and prediction of the genus of Batrachospermaceae reached 90.41%, and the overall AUC score of the taxonomic prediction of each genus of Batrachospermaceae reached 85.85%; (3) Combining the two methods, it is believed that the environmental factors that affect the distinction of the genus of Batrachospermaceae are mainly altitude, average relative humidity, average temperature, and minimum temperature, among which altitude has the greatest influence. The results can further clarify the taxonomy of the genus in Batrachospermaceae and enrich the research on the differences in environmental factors of Batrachospermaceae

    Electroreduction of Holmium Ion on Iron Electrde in Molten Cholorides

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    用循环状安、恒电位断电、电位阶跃、X射线衍射和电子探针研究了Ho(Ⅲ)在氯化物熔体中铁电极上还原的电极过程及表面合金层的物相.Ho(Ⅲ)在铁电极上还原,首先形成多种钬和铁的金属间化合物,然后才析出金属钬,电荷转移是可逆的.测定了Ho-Fe体系四个金属间化合物的生成自由能、Ho在合金化阴极中的扩散系数及扩散活化能.The cyclic voltammetry,open circuit potential-time curve after poteritiostaticelectrolysis,current-time curve at potential step,x-ray diffraction and electron probe microanalysiswere used to investigate the electrode process of Ho(Ⅲ)reduced on iron electrode in molten chloridesand the phases of surface alloy layer.The Ho-Fe alloys are formed at first,and then the metallicholmium is deposited when Ho(Ⅲ)is reduced on iron electrede. The charge transfer is reversible. Thefree energies of formation for the four intermetallic compounds of Ho-Fe system,the diffusioncoefficients and diffusion activation energy of Ho in alloyed cathode are determined.作者联系地址:中山大学化学系,广州师范学院Author's Address: Department of Chemistry,Zhongshan University Guangzhou 51027

    Electrochemical Studies of ZnCl 2 Urea Melts

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    研究了温度、浓度对ZnCl2-尿素熔体电导的影响,ZnCl2-NaCl-尿素熔体的电导率(125℃)可达30ms·cm-1以上.用循环伏安曲线、恒电位电解及断电后的电位-时间曲线,研究尿素熔体中Zn2+的电还原和锌在钛、铜电极上的电沉积.Zn2+的电还原为一步可逆过程,锌沉积在铜电极上会形成CuZn5合金.Zn2+在熔体中扩散系数为1.3×10-6cm2·s-1(125℃)The electric conductivities of ZnCl 2 Urea melts were determined.The influences of temperature and concentration on the conductance have been studied.The cylic voltammetry,potentiostatic electrolysis and open circuit potential time curve after electrolysis,X ray diffraction were used to investigate the electroreduction of Zn 2+ , electrodeposition of zinc on some electrodes in urea metal chlorides melt. The conductivity of urea NaCl ZnCl 2 melt can reach to over 30 ms·cm -1 (125 ℃), and has a liner relationship with temperature from 108 to 140 ℃. The electroreduction of Zn 2+ to zinc is reversible at one step, and CuZn 5 alloy has been found on copper electrode. The diffusion coefficient of Zn 2+ in urea NaCl ZnCl 2 melt was determined as 1.3×10 -6 cm 2·s -1 (125 ℃).作者联系地址:中山大学化学系Author's Address: Department of Chemistry, Zhongshan Universit

    Infection and Colonization of Pathogenic Fungus Fusarium proliferatum in Rice Spikelet Rot Disease

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    Rice spikelet rot disease (RSRD), caused by Fusarium proliferatum, is an emerging disease. So far, the effects of diseased rice floral organs as well as the primary infection sites and stages of this pathogen are not determined. We investigated changes in the floral organs, along with the infection processes of the pathogen in plants inoculated with F. proliferatum and labelled with a green fluorescent protein during different growth stages of rice. The results showed that RSRD is not a systemic infectious disease, which has negative effects on the fertility of the infected rice. F. proliferatum caused brown colored anthers, crinkled pistils and ovaries, pollen grain deformities and anther indehiscence. The number of pollen grains on the stigmas decreased significantly in the infected spikelets, and the anther dehiscence and seed-setting rate successively declined by 69% and 73%, respectively, as a result of the infection. The initial infection stage occurred at the pollen cell maturity stage, and the primary invasion sites were determined to be the anthers of rice. It was noted that the pathogen mainly damaged the pollen cells, and with the exception of the filaments, proceeded to colonize the pistils and endosperm. Keywords: Fusarium proliferatum, rice spikelet rot disease, green fluorescent protein, infection process, infection stage, invasion sit

    Construction of a Novel Semiautomated Electrochemical Sensor Array Platform and Its Application in Multiplexed Monitoring of Antibiotic Therapy

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    At present, traditional analytical methods suffer from issues such as complex operation, expensive equipment, and a lengthy testing time. Electrochemical sensors have shown great advantages and application potential as an alternative solution. In this study, we proposed a novel semiautomated electrochemical sensor array (SAESA) platform. The sensor array was fabricated using screen-printed technology with a tubular design where all electrodes were printed on the inner wall. The integration of the tubular sensor array with a pipet allows for a semiautomated process including sampling and rinsing, which simplifies operation and reduces overall time. Each working electrode in the tubular sensor array underwent distinct decoration to get specific sensing responses toward the target analytes in a mixture environment (e.g., blood samples). To demonstrate the applicability of the developed sensing platform for simultaneous multianalyte detection, we chose antibiotic treatment for inflammatory infection as a model scenario and continuously measured three biomarkers, namely, tigecycline (TGC), procalcitonin (PCT), and alanine aminotransferase (ALT). The detection limits were 0.3 μM, 0.3 ng/L, and 2.76 U/L, respectively. The developed semiautomated electrochemical sensor array exhibits characteristics such as rapid and simple operation, portability, good selectivity, and excellent stability
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