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101.
It is a crucial need for a clustering technique to produce high-quality clusters from biomedical and gene expression datasets without requiring any user inputs. Therefore, in this paper we present a clustering technique called KUVClust that produces high-quality clusters when applied on biomedical and gene expression datasets without requiring any user inputs. The KUVClust algorithm uses three concepts namely multivariate kernel density estimation, unique closest neighborhood set and vein-based clustering. Although these concepts are known in the literature, KUVClust combines the concepts in a novel manner to achieve high-quality clustering results. The performance of KUVClust is compared with established clustering techniques on real-world biomedical and gene expression datasets. The comparisons were evaluated in terms of three criteria (purity, entropy, and sum of squared error (SSE)). Experimental results demonstrated the superiority of the proposed technique over the existing techniques for clustering both the low dimensional biomedical and high dimensional gene expressions datasets used in the experiments. 相似文献
102.
Xiaojia Wang Mi Chen Wei Xia Keyu Zhu Shanshan Zhang Weiqun Xu Yuxiang Guan 《Expert Systems》2020,37(2):e12484
In China, Type 2 diabetes mellitus (T2DM) is increasingly affecting people's health. Although many risk factors related to T2DM have been researched, the association between social relationships and risk management of T2DM in China has not been fully researched. Therefore, we obtained 2,969 valid cases from the National Chinese Medicine Clinical Research Base-Key Disease of Diabetes Mellitus Study to evaluate the role of social relationships in the risk management of T2DM. We first establish an indicators system of social relationship factors and then propose a comprehensive method that integrates subjective (analytical network process) and objective (entropy weight method) evaluations to rank the importance of the 17 social relationship factors that were the most important and commonly used. The results suggest that different social relationship factors have different effects on the risk management of T2DM. Patients and health workers should pay more attention to the high-benefit factors and thus improve the efficiency of the risk management of T2DM. These findings provided theoretical support for patients and health workers by developing the positive effects of social relationships in improving the risk management of T2DM to the fullest degree. 相似文献
103.
针对宽带调制解调技术中广泛存在的IQ不平衡问题,在IQ不平衡模型及补偿原理的分析基础上提出了一种宽带数字接收机IQ不平衡估计与自适应补偿算法。首先利用解调数据对IQ不平衡参数进行实时估计,然后利用估计参数对接收信号进行自适应补偿。实验结果表明,所提算法可以有效解决宽带调制解调系统中普遍存在的IQ不平衡问题,提升系统误码性能。 相似文献
104.
铜-配体(L)-三肽组成的三元复合物[Cu(L)M]2+,其中,L表示4′-氯-2,2′:6′,2″-三联吡啶(缩写为4Cl-tpy);M表示酪氨酰-甘氨酰-色氨酸(YGW)及其修饰型三肽(CH3CO-YGW-OCH3,缩写 Ac-YGW-OMe)。使用该复合物,通过碰撞诱导解离 (collision-induced dissociation, CID)产生两种自由基离子 ([YGW]·+和[Ac-YGW-OMe]·+)。采用串联质谱结合密度泛函理论 (density functional theory, DFT)得到气相稳定结构,并研究其气相解离行为。研究结果表明,[YGW]·+和[Ac-YGW-OMe]·+的气相解离行为截然不同,[YGW]·+主要产生[M-CO2-116]+和[M-CO2]·+碎片离子;而[Ac-YGW-OMe]·+在气相中主要产生[M-CH3OH]·+碎片离子。推测这两种离子的气相裂解机理分别为:[YGW]·+羧基上的质子重排到多肽骨架中羰基氧上,经历 Cα-C键的断裂产生[M-CO2]·+、断裂色氨酸侧链 Cβ-Cγ键产生[M-CO2-116]+离子;[Ac-YGW-OMe]·+则先经历质子重排到酯基氧上,然后经过C-O酯键的断裂形成[M-CH3OH]·+离子。参与重排的质子可能有3个来源:Ac-YGW-OMe中甘氨酸的Cα-H、色氨酸的Cα-H 或Cβ-H,该机理有待进一步验证。本研究将为其他类型多肽及衍生物的结构及气相反应机理研究提供参考。 相似文献
105.
Roland E. Allen 《Journal of Modern Optics》2020,67(1):35-40
ABSTRACTRelatively simple but apparently novel ways are proposed for viewing three related subjects: black hole entropy, the black hole information paradox, and time travel paradoxes. (1) Gibbons and Hawking have completely explained the origin of the entropy of all black holes, including physical black holes – nonextremal and in 3-dimensional space – if one can identify their Euclidean path integral with a true thermodynamic partition function (ultimately based on microstates). An example is provided of a theory containing this feature. (2) There is unitary quantum evolution with no loss of information if the detection of Hawking radiation is regarded as a measurement process within the Everett interpretation of quantum mechanics. (3) The paradoxes of time travel evaporate when exposed to the light of quantum physics (again within the Everett interpretation), with quantum fields properly described by a path integral over a topologically nontrivial but smooth manifold. 相似文献
106.
Bo Wu Huiying Du Ping Hu Zhanyu Gao Ruikai Liu Chonghua Pei 《Journal of Energetic Materials》2021,39(1):10-22
ABSTRACT In recent years, the exploration of a practical strategy for novel energetic molecules with high energy and low sensitivity is very desirable but highly challenging. Novel ionic energetic molecules have attracted much attention in this area due to their prominent advantages including low sensitivities, high thermal stability, and excellent energy performances. Herein, five different ionic energetic molecules based on new monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties with enhanced oxygen balance have been synthesized, characterized and evaluated as potential high-energy materials. Thermal stability, sensitivities and energy output test were measured and studied in detail. The heats of formation and energetic parameters were calculated by using Gaussian 09 suite of programs and EXPLO 5 code. The results suggest that all as-prepared new molecules exhibit good thermal stability with high decomposition temperature (3, 231°C; 5, 160°C; 6, 185°C; 7, 180°C; 8, 213°C), and relative low sensitivity (IS > 20 J, FS = 324 N). Inheriting the significant oxygen content of monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties, they also possess good energy properties (v D = 8238 ~ 9208 m s?1, P = 26.8 ~ 36.7 GPa, V o = 481.8 ~ 959.4 L kg?1), which make them competitive high-energy materials. 相似文献
107.
108.
109.
Khalid Quertite Hanna Enriquez Nicolas Trcera Yongfeng Tong Azzedine Bendounan Andrew J. Mayne Gérald Dujardin Pierre Lagarde Abdallah El kenz Abdelilah Benyoussef Yannick J. Dappe Abdelkader Kara Hamid Oughaddou 《Advanced functional materials》2021,31(7):2007013
Silicene, a new 2D material has attracted intense research because of the ubiquitous use of silicon in modern technology. However, producing free-standing silicene has proved to be a huge challenge. Until now, silicene could be synthesized only on metal surfaces where it naturally forms strong interactions with the metal substrate that modify its electronic properties. Here, the authors report the first experimental evidence of silicene nanoribbons on an insulating NaCl thin film. This work represents a major breakthrough, for the study of the intrinsic properties of silicene, and by extension to other 2D materials that have so far only been grown on metal surfaces. 相似文献
110.
《Ceramics International》2021,47(19):27177-27187
BaZrO3-based materials doped with a trivalent cation have excellent chemical stability and relatively high proton conductivity which makes them potential proton conducting oxide materials for various electrochemical device applications such as hydrogen processing, high-temperature electrolysis, and solid electrolyte in fuel cells. However, BaZrO3 showed poor sinterability, requiring high sintering temperatures (1700–2100 °C) with longtime sintering (20–100 h) to achieve the desired microstructure and grain growth. This sintering problem can be solved by slightly doping BaZrO3 with a sintering aid element. Therefore, in this study, two different zirconate proton conductors: BaZr0·9Y0·1O3-α (BZY) and BaZr0·955Y0·03Co0·015O3-α (BZYC) were sintered in an air atmosphere and an oxygen atmosphere for 20 h in the temperature range of 1500–1640 °C. The sinterability was evaluated by analyzing the XRD diffraction patterns, lattice constant, lattice strain, crystallite size, relative density, open porosity, closed porosity, surface morphology, grain size, and grain boundary distribution, using the XRD, SEM, EDX, and Archimedes density measurement methods. It is concluded that in an oxygen atmosphere, sintering aid Co not only improves the relative density but also produces highly dense fine particles with clear grain boundaries which are promising for electrochemical hydrogen device applications. 相似文献