Spatial Structure of Urban Residents’ Leisure Activities: A Case Study of Shenyang, China

The spatial characteristics of residents’ leisure activities not only reflect their demand for urban leisure space but also affect the urban spatial layout. This study takes Shenyang, China as an example and analyzes the characteristics of residents’ leisure activities through questionnaires. On this basis, it uses point of interest data and mobile phone signaling data to identify various types of residential and leisure functional relationships, and uses spatial analysis and community detection to assess the distance characteristics, flow patterns, and community structure of residents’ leisure activities, so as to discuss the spatial structure of residents’ leisure activities in Shenyang. The results showed that: (1) in addition to leisure at home, Shenyang residents mainly went to shopping malls, supermarkets,and parks for leisure activities, and the proportions of residents of the two types of leisure activities were approximately equal;(2) the average distances that residents traveled for shopping and park leisure were near in the middle and far in the periphery, and the travel costs of peripheral residents for centrally located leisure were higher than those for residents in central areas;(3) the flow patterns of the residential-shopping and residential-park functional relationships displayed clustering mode characteristics, and Shenyang presented a significant monocentric structure;and (4) residents’ shopping activities were concentrated in the southern community, and walking in the park activities were concentrated in the western community. Residents’ leisure activities were characterized by centripetal agglomeration,which was prone to problems such as traffic congestion and big city diseases. The spatial expansion process in the city was characterized by obvious directional inheritance and path dependence, and the construction of sub-cities is needed to improve the related service facilities.

Bruch's membrane opening-minimum rim width and visual field loss in glaucoma:a broken stick analysis

AIM:To determine the Bruch's membrane opening-minimum rim width(BMO-MRW) tipping point where corresponding visual field(VF) damages become detectable.METHODS:A total of 85 normal subjects and 83 glaucoma patients(one eye per participant) were recruited for the study.All of the patients had VF examinations and spectral-domain optical coherence tomography to measure the BMO-MRW.Total deviation values for 52 VF points were allocated to the corresponding sector according to the Garway-Heath distribution map.To evaluate the relationship between VF loss and BMOMRW measurements,a "broken-stick" statistical model was used.The tipping point where the VF values started to sharply decrease as a function of BMO-MRW measurements was estimated and the slopes above and below this tipping point were compared.RESULTS:A 25.9% global BMO-MRW loss from normative value was required for the VF loss to be detectable.Sectorally,substantial BMO-MRW thinning in inferotemporal sector(33.1%) and relatively less BMO-MRW thinning in the superotemporal sector(8.9%) were necessary for the detection of the VF loss.Beyond the tipping point,the slopes were close to zero throughout all of the sectors and the VF loss was unrelated to the BMO-MRW loss.The VF loss was related to the BMO-MRW loss below the tipping point.The difference between the two slopes was statistically significant(P≤0.002).CONCLUSION:Substantial BMO-MRW loss appears to be necessary for VF loss to be detectable in patients with open angle glaucoma with standard achromatic perimetry.

Atomically precise metal nanoclusters for(photo)electroreduction of CO_(2): Recent advances, challenges and opportunities

To alleviate the global warming by removing excess CO_(2) and converting them into value-added chemicals,(photo)electrochemical reduction has been recognized as a promising strategy.As the CO_(2) reduction reaction(CO_(2) RR) is involved with multiple electrons and multiple products,plus the complexity of the surface chemical environment of the catalyst,it is extremely challenging to establish the structure/function relationship.Atomically precise metal nanoclusters(NCs),with crystallographically resolved structure,molecule-like characters and strong quantum confinement effects,have been emerging as a new type of catalyst for CO_(2) RR,and more importantly,they can provide an ideal platform to unravel the comprehensive mechanistic insights and establish the structure/function relationship eventually.In this review,the recent advances regarding employing molecular metal NCs with well-defined structure including Au NCs,Au-based alloy NCs,Ag NCs,Cu NCs for CO_(2) RR and relevant mechanistic studies are discussed,and the opportunities and challenges are proposed at the end for paving the development of CO_(2) RR by using atomically precise metal NCs.