Tonal symmetry induces fluency and sense of well-formedness

Fluency influences grammaticality judgments of visually presented strings in artificial grammar learning (AGL). Of many potential sources that engender fluency, symmetry is considered to be an important factor. However, symmetry may function differently for visual and auditory stimuli, which present computationally different problems. Thus, the current study aimed to examine whether objectively manipulating fluency by speeding up perception (i.e. manipulating the inter-stimulus interval, ISI, between each syllable of a string) influenced judgments of tonal strings; and thus how symmetry-based fluency might influence judgments. In experiment 1, with only a test phase, participants were required to give their preference ratings of tonal strings as a measurement of fluency. In experiment 2, participants were instructed to make grammaticality judgments after being incidentally trained on tonal symmetry. Results of experiment 1 showed that tonal strings with shorter ISI were liked more than those with longer ISI while such difference was not found between symmetric and asymmetric strings without training. Additionally, experiment 2 found both main effects of symmetry and ISI as well as an interaction. In particular, only asymmetric strings were more likely to be judged as grammatical when they were presented at a shorter ISI. Taken together, participants were sensitive to the fluency induced by the manipulation of ISI and sensitive to symmetry only after training. In sum, we conclude that objective speed influenced grammaticality judgments, implicit learning of tonal symmetry resulted in enhanced fluency, and that fluency may serve as a basis for grammaticality judgments

Research on primary frequency regulation strategies for ancillary wind power inertia based on the rotor kinetic energy

The additional frequency control of wind turbines is an effective method to solve the problem of low inertia in power systems with high proportions of new energy. The primary frequency regulation of auxiliary wind power inertia systems based on rotor kinetic energy can not only make the wind turbine run at the maximum power point but also has the lowest cost and better economy of the auxiliary frequency regulation module. The wind power inertia output control scheme based on rotor kinetic energy control is constructed by considering the frequency response characteristics of synchronous generator sets and loads. The calculation model of the minimum inertia demand of the power system is established using the rate of change of frequency and the maximum frequency offset as constraints. Combined with the real-time operating conditions of the wind turbine, the speed regulation limit of the wind turbine rotor kinetic energy control is obtained to avoid wind turbine off-grid due to excessive frequency regulation. To prevent frequency secondary drop of the system during the speed recovery process, the steady speed recovery of the wind turbine is controlled by setting the rate of speed change. The feasibility of the strategy for the regulation of the auxiliary primary frequency proposed in this study was verified in an example based on a two-region, four-machine system. When a disturbance sets the sudden load power to 150 MW, under the kinetic energy control of the wind turbine rotor, the system frequency change rate and the maximum frequency offset are increased; in particular, the maximum frequency offset is reduced by 0.348 Hz, which further illustrates the flexibility and plasticity of the rotor kinetic energy control of the wind turbines. The results of this study provide a theoretical basis for adding additional frequency control to existing wind turbines

High speed laser surface modification of Ti-6Al-4V

Titanium and its alloys have been commonly used for biomedical implant applications for many years; however, associated high coefficient of friction, wear characteristics and low hardness have limited their long term performance. This article investigates the effects of the high speed laser surface modification of Ti–6Al–4V on the microstructure, surface roughness, meltpool depth, phase transformation, residual strain, microhardness, and chemical composition. Laser treatment was carried out using a 1.5 kW CO2 laser in an argon gas environment. Irradiance and residence time were varied between 15.7 to 26.7 kW/mm2 and 1.08 to 2.16 ms respectively. Laser treatment resulted in a 20 to 50 μm thick surface modified layer without cracks. An increase in residence time and irradiance resulted in higher depth of processing. Surface roughness was found to decrease with increase in both irradiance and residence time. Metallography showed that a martensite structure formed on the laser treated region producing acicular α-Ti nested within the aged β matrix. The laser treatment reduced volume percentage of β-Ti as compared to the non-treated surface. Lattice stains in the range of 0.81% to 0.91% were observed after laser surface modification. A significant increase in microhardness was recorded for all laser treated samples. Microhardness increased up to 760 HV0.05 which represented a 67% increase compared to the bulk material. Energy Dispersive X-ray Spectroscopy (EDS) analysis showed that laser surface modification produced a more homogenous chemical composition of the alloying elements compared to the untreated bulk metal

Studies of catalytic asymmetric transfer hydrogenation in batch and continuous reactors

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Assessment of Treatment Effect of Heavy Metal Pollution from Sewage Sludge in Wastewater Treatment Plant Discharge in China’s Nanjing MV Industrial Park

To explore methods for a comprehensive assessment of the treatment effect of heavy metal pollution in the sewage sludge from China’s industrial parks, we studied the wastewater treatment plant of the Nanjing MV Industrial Park as an example. Eight common heavy metals in sewage sludge – Zinc (Zn), Copper (Cu), Lead (Pb), Mercury (Hg), Chromium (Cr), Nickel (Ni), Arsenic (As), Cadmium (Cd) were studied. The treatment effect of these containments was comprehensively assessed using the absolute niche fitness model, the relative niche model and the spatial niche fitness model. All three models showed that Pb > Cu > Ni > Hg > Cd > Cr > Zn > As in the samples. However, they produced – different numerical values – the absolute niche suitability model < the spatial niche suitability model < and the relative niche suitability model. Therefore, we concluded that special attention should be paid to the carcinogenic risk of As and Cr heavy metals to the person exposed to the sewage sludge

Stripping of acetone from isopropanol solution with membrane and mesh gas-liquid contactors

Stripping of acetone from isopropanol utilizing nitrogen as a sweeping gas was conducted in gas/liquid contactors with slit type microchannels and containing flat sheet, metal and Teflon tortuous pore membranes or microfabricated metal meshes with straight pores. The contactor consisted of parallel metal plates, gaskets, and the membrane or the microstructured mesh so that passages for gas and liquid phases were formed. These slit type microchannels were 200 μm thick for both gas and liquid phases. All the membranes/meshes were wetted by the isopropanol solution. Breakthrough of one phase into the other was successfully described if contortion of the gas/liquid interface was considered at the pore ends. Various conditions during acetone stripping were investigated such as membrane type, gas and liquid flowrates and inlet acetone concentration. A contactor employing a Micro-Etch metal mesh with 76 μm openings and thickness of 50μm offered the lowest mass transfer resistance and resulted to the best acetone stripping performance. The separation efficiency increased by increasing the gas/liquid flowrate ratio, but was not affected when increasing the inlet acetone concentration. Good agreement between the experiments and an one-dimensional model with no adjustable parameters was observed

The Role of Geological Methods in the Prevention and Control of Urban Flood Disaster Risk: A Case Study of Zhengzhou

The frequent occurrence of urban flood disasters is a major and persistent problem threatening the safety of cities in China and elsewhere in the world. As this issue is so pervasive, exploring new methods for more effective risk prevention and urban flood disaster control is now being prioritized. Taking the case of the city of Zhengzhou as an example, this paper proposes using geological, hydrogeological, ecological, and environmental conditions together with appropriate engineering designs to address the problem of urban flooding. The strategy includes integrating urban sponge–hydrogeological conditions, ecological engineering, and the construction of deep underground water storage facilities. Field investigations, data collection and analysis, in situ observations, testing, and laboratory experiments, are analyzed to explain the formation mechanism and means to mitigate flood disasters in Zhengzhou. Our results suggest that the appropriate use of geological, ecological, and hydrogeological aspects, combined with effective engineering practices, can significantly improve the city’s flood control capacity. These measures can solve the problem of the “once-in-a-millennium” occurrence of torrential rain disasters such as the “720” torrential rainstorm that has affected the city of Zhengzhou

Analysis of Pathogen-Microbiota Indicator Responses in Surface Karst Springs under Various Conditions in a Rocky Desertification Area: A Case Study of the Xiaojiang Watershed in Yunnan

The Xiaojiang watershed in Luxi, Yunnan, is a typical rocky desertification area, in which karst groundwater pollution is severe and water resources are scarce. This article takes the watershed as an example and investigates the response mechanisms of surface karst spring water quality to agricultural pollution in rocky desertification areas. Specifically, the study was conducted as follows: (I) A total of 108 water samples from 54 sources were collected during the dry and wet seasons for analysis. (i) Principal component and correlation analyses identified the main pollution indicators in the soil surface karst zone of the area, including total bacterial count, total coliforms, COD, pH, and redox potential. (ii) It was also discovered that surface soil, impacted by agricultural activities, directly contributes to groundwater pollution in the soil surface karst zone. (II) Local soil was used to prepare soil columns under various conditions for simulation. The findings indicate: (i) Temperature significantly affects the surface karst springs, with higher temperatures leading to more pronounced water quality responses, increased enrichment of pathogen-microbiota indicators, and degraded water quality. (ii) Soil porosity substantially influences the water quality of surface karst springs. Increased porosity results in looser soil, more oxidizing conditions in the storage matrix, reduced pathogen-microbiota development, and consequently, less water pollution. This study offers theoretical and technical references for evaluating, monitoring, and issuing early warnings for pathogenic bacteria-microbiota pollution in groundwater in rocky desertification areas