Nuclear Modification to Parton Distribution Functions and Parton Saturation

We introduce a generalized definition of parton distribution functions (PDFs) for a more consistent all-order treatment of power corrections. We present a new set of modified DGLAP evolution equations for nuclear PDFs, and show that the resummed $\alpha_s A^{1/3}/Q^2$-type of leading nuclear size enhanced power corrections significantly slow down the growth of gluon density at small-$x$. We discuss the relation between the calculated power corrections and the saturation phenomena.Comment: 4 pages, to appear in the proceedings of QM200

Analysis of traffic noise distribution and influence factors in Chinese urban residential blocks.

To improve the acoustic environment of residential blocks, noise mapping is employed in this study to analyze traffic noise distribution and the influence factors of four types of residential blocks in China. The study shows that high-rise small blocks have the highest average noise level (Lavg) for ground and building facades, followed by small low-rise blocks while modern residential blocks yield the lowest value. An analysis of the standard deviation (STD) of spatial statistical noise level (Ln) shows that the STD of the ground and building façade of two types of small blocks is higher than that of other blocks. The analysis of influence factors indicates that the lot area of residential block has significant negative correlation with ground and building facade average noise level (Lavg), and street coverage ratio (SCR) has significant positive correlation with ground and building facade average noise level (Lavg). In low-rise and high-rise small blocks, ground space index (GSI) has significant negative correlation with ground and building facade average noise level (Lavg); street interface density (SID) has significant positive correlation with the STDs of ground and building facade noise. Floor space index (FSI) shows significant positive correlation with the STDs of ground and building facade noise in low-rise small block

Origins of the Isospin Violation of Dark Matter Interactions

Light dark matter (DM) with a large DM-nucleon spin-independent cross section and furthermore proper isospin violation (ISV) $f_n/f_p\approx-0.7$ may provide a way to understand the confusing DM direct detection results. Combing with the stringent astrophysical and collider constraints, we systematically investigate the origin of ISV first via general operator analyses and further via specifying three kinds of (single) mediators: A light $Z'$ from chiral $U(1)_X$, an approximate spectator Higgs doublet (It can explain the $W+jj$ anomaly simultaneously) and color triplets. In addition, although $Z'$ from an exotic $U(1)_X$ mixing with $U(1)_Y$ generating $f_n=0$, we can combine it with the conventional Higgs to achieve proper ISV. As a concrete example, we propose the $U(1)_X$ model where the $U(1)_X$ charged light sneutrino is the inelastic DM, which dominantly annihilates to light dark states such as $Z'$ with sub-GeV mass. This model can address the recent GoGeNT annual modulation consistent with other DM direct detection results and free of exclusions.Comment: References added and English greatly improve

The effects of sounds and food odour on crowd behaviours in urban public open spaces

Few studies have investigated the integrated effects of sound and odour on people with the purpose of improving the use of urban spaces. Therefore, this study aimed to provide further insight into such effects from the perspective of crowd behaviour. A covert behavioural observation experiment was conducted in a typical urban commercial pedestrian street, using the smell of a bakery as the odour source, while reproducing typical urban sound sources of music and fan sound (along with a condition where no sound was played) with and without odour. The present results show that for crowd path, in the no-odour condition, playing music significantly attracted the crowd, while fan sound tended to make the crowd path farther away from the sensory sources. With the bakery odour, individuals approached the sensory sources closer when playing the sound, whether it was music or fan sound. With regard to crowd speed, music significantly reduced it and the greater the proximity to the sound source, the slower the crowd speed. Fan sound increased the crowd speed, which was significantly higher in the presence rather than absence of bakery odour, and the average speed decreased gradually as proximity to the sensory sources increased. Finally, with regard to the duration time of the crowd, it increased with music and decreased with fan sound. The bakery odour also significantly increased the duration time. However, the interaction effect between sound and odour on crowd speed and duration time was not significant

The effect of foreground and background of soundscape sequence on emotion in urban open spaces

This paper discusses the influence of the soundscape sequence of different urban open spaces on emotion. Thirty participants with normal hearing were selected to listen to forty-two different acoustic sequences and report their emotional changes during the process. The data were analysed in four stages, and the results are as follows: First, emotional response highly correlates with background type. Only when the foreground is negative does it relate to the foreground type. Second, the positive foreground in the early part of a sequence, or the neutral (or negative) foreground in the later part of a sequence, induces a better emotional experience. Third, in an acoustic sequence, emotion changes along with a change in the foreground. The appearance of the foreground triggers emotional fluctuations, and the end of the foreground is followed by emotional recovery. Finally, combining foregrounds can aid in regulating negative emotions. This effect is related to the position of the positive foreground and background type. We offer suggestions on the design of urban soundscape from the perspective of emotion based on the findings

Influence of distance from traffic sounds on physiological indicators and subjective evaluation

This study examined the influence of different distances of traffic noise and sea sounds on physiological indicators and subjective evaluation. Scene re-creations employed three types of distance: actual close sounds (close to the sound source recorded on site), actual distant sounds (distance attenuation recorded on site) and artificial distant sounds (reduction of the same decibel level across frequencies). Participants displayed higher heart rate, amplitude of the R-wave (ΔR), heart rate variability, respiration rate, and skin conductance level (SCL) when close to the sound source. Actual distance attenuation affected most subjective evaluation factors (except for Familiarity and Excitement). The ΔR, electroencephalography alpha reactivity, and electroencephalography beta reactivity with actual distant sounds were lower and SCL was higher, relative to those with artificial distant sounds. These findings provide a reference for governments and urban planners when working to improve quality of life in urban areas

The multisensory environmental evaluations of sound and odour in urban public open spaces

Few studies have focused on the multisensory perception of audio–olfactory interaction with the purpose of improving the use of urban spaces. This study conducted multisensory environmental evaluations in three urban open spaces in China with the aim of verifying the existence of audio–olfactory interaction in the urban environments and providing different perspectives for the improvement of urban environmental quality. A sensewalk approach was adopted in the study, and the main research contents were: the odour’s effects on sound source and sound environment evaluations, and the sound’s effects on odour source and odour environment evaluations. The results indicated that food odour improved acoustic comfort and sound congruency and reduced subjective loudness. Pollution odour worsened the assessment of traffic and lowered subjective loudness. Sound decreased the subjective intensity of odour and exacerbated its evaluation. Additionally, food odour enhanced the sound environment assessment of pedestrian streets, while pollution odour worsened it. Sound had a weak impact on odour environment evaluations. The masking effect between sound and odour showed that the presence of the latter decreased subjective loudness while increased sound diminished the subjective intensity of odour. Furthermore, odour’s influence on sound evaluations was greater than the influence of sound on odour evaluations. These findings have implications for the planning and design of a livable and comfortable urban environment through the perspective of sensory interaction

Physiological indicators and subjective restorativeness with audio-visual interactions in urban soundscapes

The present study aimed to identify the trends of changes in physiological indicators and subjective restorativeness in response to audio-visual interactions in the environment. Four scenarios types were presented using four different modalities (video-sound, image-sound, sound-only, and video-only; each modality was evaluated by independent groups of subjects). The physiological responses and subjective restoration of subjects were measured to assess the interactions between the audio-visual modalities. These data were also analysed to determine the physiological and subjective differences between dynamic and static visual presentations. We found that with visual modalities, the heart rate (HR), heart rate variability (HRV) calculated using the standard deviation of the NN intervals (SDNN[sbnd]HRV), high-frequency band in the HRV power spectrum (HF[sbnd]HRV), alpha reactivity on electroencephalography, and skin temperature (ST) decreased; however, the beta reactivity on EEG and skin conductance level (SCL) increased. With auditory modalities, the SDNN[sbnd]HRV, HF-HRV, ST, and respiration depth decreased; however, the respiration rate and SCL increased. Use of static images and sound to reproduce the natural environment evoked more physiological comfort and subjective restorativeness. These findings could provide physiological insights for the theory of the restorative environment

Effect of the Visual Landscape and Soundscape Factors on Attention Restoration in the Public Space of Old Residential Areas by VR

The purpose of this study is to analyze the relationship between the visual landscape and soundscape factors of the public spaces in old residential areas and their attention restoration benefits for residents and to determine the main influencing factors. In this paper, the public spaces of six typical old residential areas in Tianjin were selected as the research object, and the restorative benefits of the respondents were analyzed through virtual reality environment, subjective evaluation, and attention testing methods. The results showed that the attention restoration benefits of the central square in the old residential area were better than those of the public space along the street. Second, greenery satisfaction, environmental cleanliness, architectural aesthetics, sky visibility, and soundscape evaluation are all significantly positively correlated with the attention restoration level. Finally, a “visual landscape and soundscape perception evaluation-attention restoration level” structural equation model was constructed. According to the model, both the visual landscape factors and soundscape evaluation factors in old residential areas had a direct positive impact on the attention restoration level, with a greater impact exerted by visual landscape factors than by soundscape evaluation factors. The findings from this study can provide significant information for the renewal of old residential areas

Overall effects of temperature steps in hot summer on students' subjective perception, physiological response and learning performance

University students are very likely to experience temperature steps before class in hot summer. This study aims to investigate the overall effects of step changes on students' subjective perception, physiological response and learning performance, so as to explore an optimal thermal condition for classrooms in hot summer. Four typical temperature step conditions (S6: 34 °C-28 °C, S8: 34 °C-26 °C, S10: 34 °C-24 °C, S12: 34 °C–22 °C) were developed to conduct experiments on sixteen participants. It has been found that after temperature steps, no more than 62.5% of students consistently found thermally acceptable at 22 °C; students felt the most acceptable and comfortable at 26 °C; the effect of thermal environment on workload was not significant in most cases, especially for memory-related tasks; students' negative mood was less at 26 °C than at 28 °C and 22 °C. When the temperature step was less than S12, blood pressure and blood oxygen saturation were insensitive to temperature steps; core temperature continued to rise during the first 5 min and then decreased significantly when the temperature step exceeded S8. No significant difference in learning performance was found among the four conditions; the differences in relative performance between thermal conditions were <2%, and are not likely to have practical meaning in building management practice. Overall, the optimal thermal condition is 26 °C, and it is recommended to set the indoor temperature between 24 and 28 °C