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91.
Amjad Rehman Muhammad A. Khan Zahid Mehmood Tanzila Saba Muhammad Sardaraz Muhammad Rashid 《Microscopy research and technique》2020,83(4):410-423
The numbers of diagnosed patients by melanoma are drastic and contribute more deaths annually among young peoples. An approximately 192,310 new cases of skin cancer are diagnosed in 2019, which shows the importance of automated systems for the diagnosis process. Accordingly, this article presents an automated method for skin lesions detection and recognition using pixel‐based seed segmented images fusion and multilevel features reduction. The proposed method involves four key steps: (a) mean‐based function is implemented and fed input to top‐hat and bottom‐hat filters which later fused for contrast stretching, (b) seed region growing and graph‐cut method‐based lesion segmentation and fused both segmented lesions through pixel‐based fusion, (c) multilevel features such as histogram oriented gradient (HOG), speeded up robust features (SURF), and color are extracted and simple concatenation is performed, and (d) finally variance precise entropy‐based features reduction and classification through SVM via cubic kernel function. Two different experiments are performed for the evaluation of this method. The segmentation performance is evaluated on PH2, ISBI2016, and ISIC2017 with an accuracy of 95.86, 94.79, and 94.92%, respectively. The classification performance is evaluated on PH2 and ISBI2016 dataset with an accuracy of 98.20 and 95.42%, respectively. The results of the proposed automated systems are outstanding as compared to the current techniques reported in state of art, which demonstrate the validity of the proposed method. 相似文献
92.
Polarized Optoelectronics of CsPbX3 (X = Cl,Br, I) Perovskite Nanoplates with Tunable Size and Thickness 下载免费PDF全文
Xuexi Sheng Gaoyu Chen Chong Wang Weiqi Wang Junfeng Hui Qi Zhang Kehan Yu Wei Wei Mingdong Yi Mian Zhang Yu Deng Peng Wang Xiangxing Xu Zhihui Dai Jianchun Bao Xun Wang 《Advanced functional materials》2018,28(19)
Low dimensional semiconductor nanomaterials have shown their tailorable properties for a variety of promising applications in decades. Here a general strategy to synthesize all‐inorganic CsPbX3 (X = Cl, Br, I or their mixture) perovskite 2D nanoplates by introducing additional metal halides MX'2 or MX'3 (M = Cu, Zn, Al or Pb, etc.; X' = Cl, Br or I) is reported. These CsPbX3 perovskite nanoplates have uniform thickness and tunable size, which can be feasibly controlled by the component and ratio of the metal halides, temperature, time, and ligands. The well‐defined morphology of the nanoplates makes them ideal building blocks for the self‐assembly in the face‐to‐face and column‐by‐column arrangement. Compared to the optically isotropic CsPbX3 nanocubes, the 2D CsPbX3 nanoplates exhibit remarkable polarized UV–vis absorption and photoluminescence not only in liquid solvent and solid resin matrix, but also in self‐assembled films. An optoelectronic photodetector sensitive for linear polarized light is fabricated to demonstrate the proof‐of‐concept. 相似文献
93.
94.
通过对埋设热电偶的不同类型混凝土分别加热到300℃、500℃、700℃后,对混凝土内部埋设热电偶处周边的石英砂提取试样,运用包裹体爆裂法检测试件内部经历的最高温度,并与热电偶测温法所测得的温度做比较,验证包裹体爆裂测温法的准确性,并检验包裹体的不可复现性。结果表明,包裹体爆裂法与热电偶测温法所得出的结论基本上还是一致的。 相似文献
95.
Tannin fraction from Ampelopsis grossedentata leaves tea (Tengcha) as an antioxidant and α‐glucosidase inhibitory nutraceutical 下载免费PDF全文
Sheng Geng Yongsheng Chen Arshad Mehmood Abbasi Hanjun Ma Haizhen Mo Benguo Liu 《International Journal of Food Science & Technology》2016,51(12):2692-2700
Leaf of Ampelopsis grossedentata is a new resource of functional foods with healthful properties. Antioxidant and α‐glucosidase inhibitory activities of water extract (made in the style of drinking), tannin fraction (TF) and dihydromyricetin (DMY) from A. grossedentata leaves were evaluated. The main component of TF was identified as gallotannins. DPPH and ABTS radical scavenging activities and reducing power of TF were superior to those of water extract, however, inferior to those of DMY. In no PBS wash protocol of cellular antioxidant activity assay, DMY and TF exhibited similarly, while in PBS wash protocol, the value of TF was higher than that of DMY. In addition, TF possessed the highest α‐glucosidase inhibitory activities (IC50 = 1.94 μg mL?1), followed by water extract (IC50 = 23.10 μg mL?1) and DMY (IC50 = 72.21 μg mL?1). The strong α‐glucosidase inhibitory activity of TF may attribute to the binding capacity to enzymes, as confirmed by fluorescence analysis. 相似文献
96.
环保型钻井液体系 总被引:9,自引:0,他引:9
在大量室内研究基础上,研发了环保型钻井液体系,其基础配方为:4%膨润土浆+0.3%IND-30+1.5%NAT-20+3%FXJS+2%NFT-25.该钻井液体系采用环保添加剂配制,抗温能力强,达150℃;抗污染性能佳,抗盐量可达30%,抗土侵量达8%;油层保护效果好,渗透率恢复率在81.5%以上;环保性能理想,废弃钻井液抛洒后,地表层0~20 cm厚度土壤的环境质量指标均保持在中国土壤环境质量标准二级水平以上,同时使沙地土壤的水分含量和肥力水平大大提高.该环保型钻井液体系已先后在塔里木、克拉玛依和江苏油田的15口井中获得成功应用,环保与油层保护效果理想.抛洒过废弃钻井液的井区周围土壤的有机质、速效氮、速效磷和速效钾含量明显提高.与常规钻井液相比,使用环保型钻井液体系单井平均可节约综合成本40.87×10<'4>元,15口井总计可节约综合成本613.05×10<'4>元. 相似文献
97.
Nasir Mehmood Khan Tai‐Hua Mu Miao Zhang Jing‐Wang Chen 《International Journal of Food Science & Technology》2013,48(6):1260-1268
The influence of high hydrostatic pressure (HHP) treatment on the physicochemical and emulsifying properties of sweet potato protein (SPP) at various concentrations, e.g. 2%, 4% and 6% (w/v, SPP‐2, SPP‐4 and SPP‐6), was investigated. Significant differences in hydrophobicity, enthalpy of denaturation and solubility were observed (P < 0.05). Emulsifying activity indexes (EAI) of SPP‐2 and SPP‐6 increased at 400 MPa, whereas EAI of all SPP significantly decreased at 600 MPa (P < 0.05). Emulsion stability (ESI) was significantly decreased for SPP‐2 and SPP‐6, while increase in ESI was observed for SPP‐4 above 200 MPa (P < 0.05). SPP‐2 emulsions showed sharp decrease in apparent viscosity with pressure increase, while pseudo plastic flow behaviour was not changed for all of emulsions. Sporamins A and B were well‐adsorbed in pressurised emulsion without displacement. These results suggest that HHP treatment could be used to modify the physicochemical and emulsifying properties of SPP. 相似文献
98.
Reactivity of partially reduced arylhydroxylamine and nitrosoarene metabolites of 2,4,6-trinitrotoluene (TNT) toward biomass and humic acids 总被引:1,自引:0,他引:1
Sequential anaerobic/aerobic treatment of 2,4,6-trinitrotoluene (TNT) generally results in the incorporation of residues into biomass and natural organic matter fractions of a system. To better understand the potential contribution of hydroxylamine and nitroso moieties in these reactions, studies were conducted using model systems taking advantage of the biocatalytic-activity of Clostridium acetobutylicum that does not produce aminated TNT derivatives. To evaluate binding to biomass only, systems containing cell-free extracts of C. acetobutylicum and molecular hydrogen as a reductant were employed. At the end of treatment, mass balance studies showed that 10% of the total 14C was associated with an insoluble protein-containing precipitate that could not be extracted with organic solvents. Model reactions were conducted between a mixture of 2,4-dihydroxylamino-6-nitrotoluene (DHA6NT) and 4-hydroxylamino-2,6-dinitrotoluene (4HADNT) and 1-thioglycerol to test the involvement of the nitroso-thiol reaction in binding to biomass. It was demonstrated that DHA6NT formed a new and relatively polar product with 1-thioglycerol only in the presence of oxygen. The oxygen requirement confirmed that the nitroso functionality was responsible for the binding reaction. The reactivity of arylhydroxylamino and nitrosoarene functionalities toward International Humic Substance Society (IHSS) peat humic acid was evaluated under anaerobic and aerobic conditions, respectively. 4HADNT showed no appreciable reactivity toward peat humic acid. Conversely, the nitrosoarene compound, nitrosobenzene, showed rapid reactivity with peat humic acid (50% removal in 48 h). When tested with two other humic acids (selected on the basis of their protein content), it became apparent that the proteinaceous fraction was responsible at least in part for the nitrosoarene's removal from solution. Furthermore, the pretreatment of the humic acids with a selective thiol derivatizing agent had a considerable effect on their ability to react with nitrosobenzene. Finally, molecular modeling tools were used to compare the electrophilic characteristics of potential nitroso intermediates forming from the oxidation of arylhydroxylamino metabolites of TNT. Molecular modeling analysis demonstrated that the more reduced TNT derivative containing nitroso groups were more likely to react with nucleophiles in humic substances than the less reduced nitroso intermediates. 相似文献
99.
The texture of a machined surface generated by a cutting tool, with geometrically well-defined cutting edges, carries essential information regarding the extent of tool wear. There is a strong relationship between the degree of wear of the cutting tool and the geometry imparted by the tool on to the workpiece surface. The monitoring of a tool’s condition in production environments can easily be accomplished by analyzing the surface texture and how it is altered by a cutting edge experiencing progressive wear and micro-fractures. This paper discusses our work which involves fractal analysis of the texture of surfaces that have been subjected to machining operations. Two characteristics of the texture, high directionality and self-affinity, are dealt with by extracting the fractal features from images of surfaces machined with tools with different levels of tool wear. The Hidden Markov Model is used to classify the various states of tool wear. In this paper, we show that fractal features are closely related to tool condition and HMM-based analysis provides reliable means of tool condition prediction. 相似文献
100.