•Fe-based MILs were prepared via the facile solvothermal method.•MILs showed efficient removal rate through adsorption and degradation processes.•A possible catalytic degradation mechanism is ...proposed.
Fe-based metal–organic frameworks (MOFs) including MIL-101(Fe), MIL-100(Fe), MIL-53(Fe), and MIL-88B(Fe) prepared via a facile solvothermal process were introduced as both adsorbents and catalysts to generate powerful radicals from persulfate for acid orange 7 (AO7) removal in aqueous solution. Various catalysts were described and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray photoelectron spectra. Because of the high specific surface area of the materials, we studied the adsorption isotherms of the four MILs by the fitting of Langmuir adsorption isotherm. Meanwhile, the catalytic activities in persulfate oxidation system were investigated. The results showed that the sequence of the materials ability in the combination of adsorption and degradation was MIL-101(Fe)>MIL-100(Fe)>MIL-53(Fe)>MIL-88B(Fe), which had a close connection with the activity of metal ion in active site of the catalysts and their different cages in size. Moreover, the reactive species in MILs/persulfate system were identified as sulfate radicals and hydroxyl radicals. The reaction mechanism for persulfate activation over MILs was also studied.
The quality of urban public spaces affects the emotional response of users; therefore, the emotional data of users can be used as indices to evaluate the quality of a space. Emotional response can be ...evaluated to effectively measure public space quality through affective computing and obtain evidence-based support for urban space renewal. We proposed a feasible evaluation method for multi-type urban public spaces based on multiple physiological signals and ensemble learning. We built binary, ternary, and quinary classification models based on participants' physiological signals and self-reported emotional responses through experiments in eight public spaces of five types. Furthermore, we verified the effectiveness of the model by inputting data collected from two other public spaces. Three observations were made based on the results. First, the highest accuracies of the binary and ternary classification models were 92.59% and 91.07%, respectively. After external validation, the highest accuracies were 80.90% and 65.30%, respectively, which satisfied the preliminary requirements for evaluating the quality of actual urban spaces. However, the quinary classification model could not satisfy the preliminary requirements. Second, the average accuracy of ensemble learning was 7.59% higher than that of single classifiers. Third, reducing the number of physiological signal features and applying the synthetic minority oversampling technique to solve unbalanced data improved the evaluation ability.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
3.
Automatic Welding Seam Tracking and Identification Xinde Li; Xianghui Li; Shuzhi Sam Ge ...
IEEE transactions on industrial electronics (1982),
2017-Sept., 2017-9-00, 20170901, Letnik:
64, Številka:
9
Journal Article
Recenzirano
In the automatic welding process on mid/thick plates, the precision of the welding position has an important effect on welding quality, which mainly relies on the identification of the welding seam. ...However, due to some possible disturbances in complex unstructured welding environments, e.g., strong arc lights, welding splashes, thermal-induced deformations, etc., it is a great challenge to identify the welding seam. In this paper, we propose a robust automatic welding seam identification and tracking method by utilizing structured-light vision. First, after the preprocessing of the welding image, the gray distribution of the laser stripe is tracked and the profile of the welding seam is searched in a small area by using the Kalman filter, with the aim to avoid some disturbances. Second, in order to extract the welding seam profile, a series of centroids obtained by scanning the columns in the rectangular window are fitted using the least-squares method. Third, a character string method is proposed to qualitatively describe the welding seam profile, which might consist of different segment and junction relationship elements. And then, these character strings acquired from the object image are matched with those from the model, so that the position of the welding seam can be determined. Finally, the advantages of the new algorithm are testified and compared through several experiments.
Objective
Based on the assumption that the cultural image at the level of experience is the collective and individual psychological reality expressed by cultural narrative and individual narrative, ...to study the timeless Tales of Nezha (“Natch”) in China as an experiential cultural image of child development and parent-child relationship.
Method
We adopted the narrative analysis method which focused on qualitative content analysis, covering religion, folklore, literature, entertainment, education and other fields.
Result
Our exposition articulates a cultural narrative framework of diachronic and contemporary cultural image of “Nezha”, the iconic child deity. This framework refers to our academic research discipline of describing the image characteristics, plots and interpersonal relationship, and conceptualizing the theme as psychological meaning units of personal identity and parent-child relationship. By analogizing and comparing this framework with the “Nezha” of personal narratives in consultation, we found the interactive clues of the case’s identity and parent-child relationship. We then combined these with specific elements unique and particular to each individual case in order to achieve a meaningful case conceptualization. This process enabled us to apply psychotherapeutic intervention at opportune moments during a counselling session.
Conclusions
The cultural image emerging from the counseling is not only a personal narrative of resource and a tool for the client to externalize the problem and identity representation, but also a cultural narrative reference point for the counselor to understand the case and to engage in further in-depth work. The personal narrative qualitative data can be obtained by referring to four dimensions: external—internal, event—image, narrative—interpretation, and experience—reflection. With the narrative identity of client, the “Nezha” of personal narrative led to the theme that parent-child relationship impedes the development of personal identity. The counselor was thereby enabled to construct a new meaning and new identity with the client by providing appropriate information and knowledge of the cultural narrative.
It is generally assumed that any set of players can form a feasible coalition for classical cooperative games. But, in fact, some players may withdraw from the current game and form a union, if this ...makes them better paid than proposed. Based on the principle of coalition split, this paper presents an endogenous procedure of coalition formation by levels and bargaining for payoffs simultaneously, where the unions formed in the previous step continue to negotiate with others in the next step as “individuals,” looking for maximum share of surplus by organizing themselves as a partition. The structural stability of the induced payoff configuration is discussed, using two stability criteria of core notion for cooperative games and strong equilibrium notion for noncooperative games.
The incidence of non-alcoholic fatty liver disease (NAFLD) is rising annually, and emerging evidence suggests that the gut bacteria plays a causal role in NAFLD. Naringin, a natural flavanone ...enriched in citrus fruits, is reported to reduce hepatic lipid accumulation, but to date, no investigations have examined whether the benefits of naringin are associated with the gut bacteria. Thus, we investigated whether the antilipidemic effects of naringin are related to modulating the gut bacteria and metabolic functions. In this study, C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks, then fed an HFD with or without naringin administration for another 8 weeks. Naringin intervention reduced the body weight gain, liver lipid accumulation, and lipogenesis and attenuated plasma biochemical parameters in HFD-fed mice. Gut bacteria analysis showed that naringin altered the community compositional structure of the gut bacteria characterized by increased benefits and fewer harmful bacteria. Additionally, Spearman’s correlation analysis showed that at the genus level,
Allobaculum
,
Alloprevotella
,
Butyricicoccus
,
Lachnospiraceae_NK4A136_group
,
Parasutterella
and
uncultured_bacterium_f_Muribaculaceae
were negatively correlated and
Campylobacter
,
Coriobacteriaceae_UCG-002
,
Faecalibaculum
and
Fusobacterium
were positively correlated with serum lipid levels. These results strongly suggest that naringin may be used as a potential agent to prevent gut dysbiosis and alleviate NAFLD.
In this study, lanthanum hexaboride (LaB
) particle-reinforced titanium matrix composites (PRTMCs, TC4/LaB
) were successfully manufactured using the laser powder bed fusion (LPBF) process. ...Thereafter, the effect of the mass fraction of LaB
on the microstructure and the dynamic compressive properties was investigated. The results show that the addition of LaB
leads to significant grain refinement. Moreover, the general trend of grain size reveals a concave bend as the fraction increases from 0.2% to 1.0%. Furthermore, the texture intensity of prior β grains and α grains was found to be weakened in the composites. It was also observed that the TC4/LaB
have higher quasi-static and dynamic compressive strengths but lower fracture strain when compared with the as-built TC4. The sample with 0.5 wt.% LaB
was found to have the best strength-toughness synergy among the three groups of composites due to having the smallest grain size. Furthermore, the fracture mode of TC4/LaB
was found to change from the fracture under the combined action of brittle and ductility to the cleavage fracture. This study was able to provide a theoretical basis for an in-depth understanding of the compressive properties of additive manufacturing of PRTMCs under high-speed loading conditions.
In the process of automatic welding based on structured light vision, the precise localization of the welding seam in an image has an important influence on the quality of the welding. However, in ...practice, there is much interference, such as spatter and arc, which introduces great challenges for accurate welding seam localization. In this paper, we considered welding seam localization problem as visual target tracking and based on that, we proposed a robust welding seam tracking algorithm. Prior to the start of welding, the seam is separated using a cumulative gray frequency, which is utilized to adaptively determine the initial position and size of the search window. During the welding process, large seam motion range may result in only a portion of the welding seam exists in the search window. To prevent that, a tracking-by-detection method is used to calculate the location of the search window. Usually, the intersection of seam and noise, e.g., spatter, has a severe influence on the accuracy of feature points localization. In order to solve this problem, a sequence gravity method (SGM) for extracting a smoother center line of welding seam is proposed, which is able to reduce the impact of interference. The double-threshold recursive least square method is used to fit the curve obtained by SGM with the aim of improving the real-time performance and accuracy of the system. Finally, the superiority of the proposed algorithm is well demonstrated by comparison with other solutions for seam tracking and recognition through extensive experiments.
Flexural toppling is one of the main failure modes of natural and manmade anti-dip layered rock slopes. Based on cantilever slab tensile theory, the failure mechanism of flexural toppling was ...analyzed. A toppling slope is divided into three parts: the stability, tensile and shear zones. By considering this failure mechanism, a new stability analysis method for slopes against flexural toppling failure is proposed using equilibrium theory. In addition, a sensitivity analysis is performed to investigate the locations of possible failure surfaces and zones as well as changes in the stability of anti-dip rock slopes under different conditions. The results show that the positions of the inter-column forces have almost no effect on the stability factor but affect the areas of the tensile zone and the shear zone. The angle of the most dangerous potential failure surface increases with increasing dip angle and slope height, whereas the stability factor is negatively correlated with the dip angle and slope height but is positively correlated with the layer thickness. The failure mode is essentially flexural toppling when the layer thickness is small, but the failure mode gradually transitions to shear-sliding with increasing layer thickness. Finally, a real case study is analyzed using this method, and the calculated results are consistent with the actual conditions.
The slurry shield tunneling method has been widely used in the construction of underwater tunnels. However, during the construction of submarine tunnels, seawater can influence the engineering ...properties of bentonite slurry, which can cause excavation instability and other problems. This study aims to investigate the effect of seawater on the properties of bentonite slurry for shield tunneling, including the basic slurry and filter cake properties. Additionally, the infiltration behavior of the slurry after filter cake formation was also studied, the following results being obtained: (1) With an increase in seawater content, the bleeding rate and filtration volume of the slurry increased, and the rheological parameters decreased. (2) With an increase in seawater content, the permeability coefficient of the filter cake increased considerably. Microstructure analysis showed that the agglomeration of particles in the filter cake caused by seawater contamination increased the permeability of the filter cake. (3) The slurry infiltration tests indicated that the infiltration distance increased with increasing seawater content. Additionally, the infiltration of slurries with seawater could not effectively reduce the permeability coefficient of the tunnel face, which could lead to instability of the tunnel face. The findings of this study provide a reference for slurry preparation and stability analyses of submarine tunnel excavations.
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