Students' Intention of Visiting Urban Green Spaces after the COVID-19 Lockdown in China.

This study addresses students' perceptions of using urban green spaces (UGSs) after the easing of COVID-19 lockdown in China. We questioned whether they are still mindful of the risks from the outdoor gathering, or conversely, starting to learn the restoration benefits from the green spaces. Online self-reported surveys were distributed to the Chinese students aging from 14 to 30 who study in Hunan and Jiangsu Provinces, China. We finally obtained 608 complete and valid questionnaire forms from all participants. Their intentions of visiting UGSs were investigated based on the extended theory of planned behavior model. Structural equation modeling was employed to test the hypothesized psychological model. The results have shown good estimation performance on risk perception and perceived knowledge to explain the variances in their attitudes, social norms, and perceived behavior control. Among these three endogenous variables, the perceived behavior control owns the greatest and positive influence on the behavioral intention, inferring that controllability is crucial for students to make decisions of visiting green spaces in a post-pandemic context

The concentrations of bone calcium, phosphorus and trace metal elements in elderly patients with intertrochanteric hip fractures

IntroductionTrace metal elements may play a crucial role in bone mineralization and metabolism. However, the quantification of trace element concentrations in human bone tissue has received little attention.Materials and methodsBone tissue samples were collected from 55 elderly patients (15 males and 40 females) with intertrochanteric hip fractures. The calcium, phosphorus, manganese, iron, copper, and zinc concentrations in the cortical bone zone, cancellous bone zone, and junction zone between cortical and cancellous bone were determined by energy-dispersive X-ray fluorescence (EDX). The differences in trace element concentrations in the three regions were compared, and the correlation between gender and bone trace element contents of the bones was analyzed using the Kruskal-Wallis’s test. The correlation between age, body mass index (BMI), and bone calcium, phosphorus concentrations, and trace elements in three bone zones was determined using Spearman correlation analysis.ResultsThe Kruskal-Wallis test showed no difference in bone phosphorus concentration among the three regions. In contrast, the difference in the concentrations of bone calcium and four metal elements was statistically significant (P<0.01). In addition, no statistical differences were observed in the concentrations of trace elements among the three regions in elderly male and female patients. Spearman correlation analysis showed a strong negative correlation between bone calcium and phosphorus in three bone regions (r=-0.999, -0.95, -0.998, P < 0.01) and a significant positive correlation between trace metal elements in the cancellous bone zone. In the junction zone, the BMI showed a strong positive correlation with bone calcium content (r=0.347, P=0.009) and a significant negative correlation with phosphorus content (r=-0.349, P=0.009).ConclusionBone calcium and phosphorus were the main components of hydroxyapatite, and these two elements accounted for the majority of bone mineral salts. Trace metal elements are essential for bone metabolism and specific synergistic interactions. BMI may be associated with bone calcium and phosphorus contents in elderly patients with osteoporosis

Extremely strong tubular stacking of aromatic oligoamide macrocycles

As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of Kdimer \u3e 1013 M–1 in CHCl3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (–49.77 kcal mol–1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. The persistent tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3. Includes supplemental material

Extremely strong tubular stacking of aromatic oligoamide macrocycles

As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of Kdimer \u3e 1013 M–1 in CHCl3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (–49.77 kcal mol–1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. The persistent tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3. Includes supplemental material

Self-assembling subnanometer pores with unusual mass-transport properties

A long-standing aim in molecular self-assembly is the development of synthetic nanopores capable of mimicking the mass-transport characteristics of biological channels and pores. Here we report a strategy for enforcing the nanotubular assembly of rigid macrocycles in both the solid state and solution based on the interplay of multiple hydrogen-bonding and aromatic π − π stacking interactions. The resultant nanotubes have modifiable surfaces and inner pores of a uniform diameter defined by the constituent macrocycles. The self-assembling hydrophobic nanopores can mediate not only highly selective transmembrane ion transport, unprecedented for a synthetic nanopore, but also highly efficient transmembrane water permeability. These results establish a solid foundation for developing synthetically accessible, robust nanostructured systems with broad applications such as reconstituted mimicry of defined functions solely achieved by biological nanostructures, molecular sensing, and the fabrication of porous materials required for water purification and molecular separations

Identification Method of Main Road Traffic Congestion Situation in Cold-Climate Cities Based on Potential Energy Theory and GPS Data

Traffic congestion is a global problem. Affected by climate, the issue of congestion in cold-climate cities is more serious. To comprehensively and accurately identify the traffic congestion situation on the main roads of cold-climate cities and to provide a reference for city managers for congestion treatment, this study applies the theory of potential energy to the problem of traffic congestion, draws on the symmetry of potential energy and the function mechanism of artificial potential fields, and establishes a traffic congestion potential energy model for the main roads in cold-climate cities. Taking Global Positioning System (GPS) data as the primary data, the model parameters are calibrated using a combination of subjective and objective empowerment methods, and the investigation into the congestion perception level determines the division threshold of the congestion potential energy level. Test results are encouraging, and the method considers the state and the trends and can avoid problems such as lagging road condition information

The effects of life course events on car ownership and sustainable mobility tools adoption decisions: Results of an error component random parameter logit model

Life course events can change household travel demand dramatically. Recent studies of car ownership have examined the impacts of life course events on the purchasing, replacing, and disposing of cars. However, with the increasing diversification of mobility tools, changing the fleet size is not the only option to adapt to the change caused by life course events. People have various options with the development of sustainable mobility tools including electric car, electric bike, and car sharing. In order to determine the impacts of life course events on car ownership and the decision of mobility tool type, a stated choice experiment was conducted. The experiment also investigated how the attributes of mobility tools related to the acceptance of them. Based on existing literature, we identified the attributes of mobility tools and several life course events which are considered to be influential in car ownership decision and new types of mobility tools choice. The error component random parameter logit model was estimated. The heterogeneity across people on current car and specific mobility tools are considered. The results indicate people incline not to sell their current car when they choose an electric bike or shared car. Regarding the life course events, baby birth increases the probability to purchase an additional car, while it decreases the probability to purchase an electric bike or joining a car sharing scheme. Moreover, the estimation of error components implies that there is unobserved heterogeneity across respondents on the sustainable mobility tools choice and the decision on household’s current car

Identification Method of Main Road Traffic Congestion Situation in Cold-Climate Cities Based on Potential Energy Theory and GPS Data

Traffic congestion is a global problem. Affected by climate, the issue of congestion in cold-climate cities is more serious. To comprehensively and accurately identify the traffic congestion situation on the main roads of cold-climate cities and to provide a reference for city managers for congestion treatment, this study applies the theory of potential energy to the problem of traffic congestion, draws on the symmetry of potential energy and the function mechanism of artificial potential fields, and establishes a traffic congestion potential energy model for the main roads in cold-climate cities. Taking Global Positioning System (GPS) data as the primary data, the model parameters are calibrated using a combination of subjective and objective empowerment methods, and the investigation into the congestion perception level determines the division threshold of the congestion potential energy level. Test results are encouraging, and the method considers the state and the trends and can avoid problems such as lagging road condition information

A Reversible Multimedia Representation Method and Its Applications in Multimedia Processing

The single type of multimedia data, such as text, image, video, and audio, has been extensively studied in the past decades. With the advances in multimedia applications and services, the exponential growth of multimedia data has emerged. Therefore, it is crucial to effectively represent multimedia data and capture the relationships among them in the study of multimedia applications. In the paper, we propose a novel reversible multimedia representation method based on a complex base. In the proposed multimedia representation method, we first process different modalities of data, such as text, image, and audio separately and convert them into different Gaussian integers, then place them on the same representation plane and resulting in a joint multimedia representation model. Therefore, the relationships of multimedia data are established by using the geometric operations on the same representation plane. Experimental results show that the proposed multimedia representation method is lossless and reversible. In addition, we explore the potential applications of the proposed representation method in multimedia camouflage and multimedia secret sharing, and verify that the proposed representation method has good practical applicability in multimedia security