Experimental study of the influence of drainage conditions on sandstone mechanics and its deformation localization characteristics

In order to study the deformation localization failure characteristics of sandstone under the coupling action of seepage and stress, the triaxial compression tests of sandstone under different drainage conditions were carried out using the visualized triaxial servo control test system combined with three-dimensional digital image correlation (3D-DIC). The rock mechanics, seepage and deformation localization characteristics were analyzed, and the micro-morphology of fracture surface after sandstone failure was analyzed using electron microscope scanning. The results shown that the peak strength and elastic modulus of sandstone under drainage condition were higher than those under undrained condition, the peak strength, elastic modulus and Poisson’s ratio of sandstone increased with the increasing seepage water pressure, the time point of penetration crack and maximum permeability would be advanced. When the seepage water pressure was the same, the localized zone of deformation field cloud map of the sand surface was wider in the undrained condition than that in the drained condition, i.e., the macroscopic crack of rock was more obvious. Water flow under drained condition took away the mineral particles inside the rock and formed holes, the rupture surface of which was smoother than that under undrained condition, whereas flakes cuttings were obviously attached to the surface of the particles under undrained condition. The initiation point of radial deformation localization was consistently higher than that of axial deformation localization for all drainage conditions, with an average increase of 1.23%. The initiation stress levels of the radial and axial deformation localization increased with increasing seepage water pressure, i.e., the initiation time point was earlier. The radial and axial initiation stress level of sandstone under drainage condition were higher than those under undrained condition, with an average increase of 1.85% and 2.21% respectively. When the water pressure was the same, the initiation stress and stress level were more significantly affected by water pressure in the undrained condition than in the drained condition

Visual search for numbers in the patterned sequence

Explore the how attention select when items in search space correlated. Especially focus on guidance not directly to the target, but to the item which help most on narrowing search space

Can you see the wolf chasing the sheep? The relationship between free will related beliefs and intention perception

Previous research suggests that belief in free will is related to intention perception, one of the most fundamental processes in social perception and social cognition. However, this research has not been able to distinguish between differences in sensitivity and response bias. Here, we used a chasing detection task that allowed us to investigate whether individuals who believe more in free will are better at detecting intentionality cues (sensitivity) or are instead more prone to see such cues even when they are not there (bias). In addition, we measured three beliefs related to free will: belief in free will, belief in dualism, and belief in determinism. The results showed that belief in determinism was correlated negatively with perceptual sensitivity and positively with response bias. Follow-up analyses further indicated that the negative relationship with sensitivity was entirely explained by the positive relationship with response bias. In contrast, no correlations were observed for belief in free will or belief in dualism. This indicates that beliefs related to free will, but not belief in free will itself, are associated with an increased tendency to perceive intentional behavior, even when there is none

For the longer-term benefits: When non-target is preferentially selected in visual search.

Selective attention toward the target in visual search has been extensively studied, but little is known about the selection process and role of attention toward non-target. However, daily life scenes often contain a large number of interrelated items, and focusing on non-target is not only common but also helpful for locating the target. Here we explore this in three experiments in which participants searched for a target number among regularly or randomly arranged numbers. Results showed that human used the regularity of the search sequence to shorten the search time. Reaction time and eye movement data suggested that humans could narrow down the search space based on the selected non-target and the regularity, thereby increasing search speed. Further model simulations found that attention prioritized non-target location that was most helpful in narrowing the search space, rather than location where the target was most likely to present, especially when the search space contained a large number of items. Although the probability of finding the target immediately is reduced, the probability of locating the target next increases, thus the entire search process benefits. We generalize this attention selection mechanism as the informative searching hypothesis, which suggests that attention is guided to the item with the highest expected information gain. Such selection mechanism may be an important basis for resource-limited human beings to successfully interact with complex real-world

ShenSupplementalExperiments – Supplemental material for Object-Based Attention on Social Units: Visual Selection of Hands Performing a Social Interaction

<p>Supplemental material, ShenSupplementalExperiments for Object-Based Attention on Social Units: Visual Selection of Hands Performing a Social Interaction by Jun Yin, Haokui Xu, Jipeng Duan and Mowei Shen in Psychological Science</p

Jointly Perceiving Physics and Mind: Motion, force and intention

Physics and mind are two major causes of motion. In a leash-chasing display, a disc (“sheep") is being chased by another disc (“wolf"), which is physically constrained by a leash attached to a third disc (“master"). A number of interesting motions can emerge from this simple system, such as a wolf being dragged away from its target. Therefore, it is important for vision to jointly infer a physics-mind combination that can best explain the motions. Here we reported two discoveries from studying this display to support this theory. First, an intuitive physical system like a leash can greatly lessen the detrimental effects of spatial deviation and the diminishing objecthood on perceived chasing, strengthening its robustness. Second, a mutual dependency exists between physics and mind, where disrupting one will inevitably result in an impaired perception on the other. These results collectively support a joint perception of physics and mind

ShenOpenPracticesDisclosure – Supplemental material for Object-Based Attention on Social Units: Visual Selection of Hands Performing a Social Interaction

<p>Supplemental material, ShenOpenPracticesDisclosure for Object-Based Attention on Social Units: Visual Selection of Hands Performing a Social Interaction by Jun Yin, Haokui Xu, Jipeng Duan and Mowei Shen in Psychological Science</p

Polar firn properties in Greenland and Antarctica and related effects on microwave brightness temperatures

In studying the mass balance of polar ice sheets, fluctuations in firn density near the surface is a major uncertainty. In this paper, we explore these variations at locations on the Greenland Ice Sheet and at the Dome C location in Antarctica. Borehole in situ measurements, snow radar echoes, microwave brightness temperatures, and modeling results from the Community Firn Model (CFM) are used. It is shown that firn density profiles can be represented using three processes: "long-scale"and "short-scale"density variations and "refrozen layers". Consistency with this description is observed in the dynamic range of airborne 0.5-2GHz brightness temperatures and snow radar echo peaks in measurements performed in Greenland in 2017. Based on these insights, a new analytical partially coherent model is implemented to explain the microwave brightness temperatures using the three-scale description of the firn. Short- and long-scale firn processes are modeled as a 3D continuous random medium with finite vertical and horizontal correlation lengths as opposed to past 1D randomly layered medium descriptions. Refrozen layers are described as deterministic sheets with planar interfaces, with the number of refrozen-layer interfaces determined by radar observations. Firn density and correlation length parameters used in forward modeling to match measured 0.5-2GHz brightness temperatures in Greenland show consistency with similar parameters in CFM predictions. Model predictions also are in good agreement with multi-angle 1.4GHz vertically and horizontally polarized brightness temperature measured by the Soil Moisture and Ocean Salinity (SMOS) satellite at Dome C, Antarctica. This work shows that co-located active and passive microwave measurements can be used to infer polar firn properties that can be compared with predictions of the CFM. In particular, 0.5-2GHz brightness temperature measurements are shown to be sensitive to long-scale firn density fluctuations with density standard deviations in the range of 0.01-0.06gcm-3 and vertical correlation lengths of 6-20cm