The creation of a road network can lead to the fragmentation and reduction of the connectivity of the ecological habitat. The study of urban ecological networks under threat from rapidly developing road networks is of great significance in understanding the changes in urban ecological processes and in constructing a reasonable ecological network. Spatial syntax is a linear space analysis method based on graph theory. Taking Wuhan city as an example and adopting spatial syntax to quantify road network threat factors, two resistance surfaces are established based on land use type assignment and overlapping road network threat factor assignment. The ecological environment under two scenarios is constructed by combining the MSPA (Morphological Spatial Pattern Analysis) method and MCR (Minimal Cumulative Resistance) model to comprehensively evaluate the network. Results demonstrate that spatial syntax can effectively describe the spatial characteristics of the road network. The average resistance value of the study area increases by 15.94%, the length of corridor increases by 37.9 km, the energy consumption of biological and material exchanges increases, and the resistance increases. To a certain extent, the model reflects the impact of road network threats on ecological processes. The results are useful in identifying the impact of human activities on ecological processes and provide a reference point for the construction of urban ecological security patterns.

A scientific carbon accounting system can help enterprises reduce carbon emissions. This study took an enterprise in the Yangtze River basin as a case study. The accounting classification of carbon emissions in the life cycle of lime production was assessed, and the composition of the sources of carbon emission was analyzed, covering mining explosives, fuel (diesel, coal), electricity and high-temperature limestone decomposition. Using the IPCC emission factor method, a carbon life cycle emission accounting model for lime production was established. We determined that the carbon dioxide equivalent from producing one ton of quicklime ranged from 1096.68 kg CO₂ equiv. to 1176.96 kg CO₂ equiv. from 2019 to 2021 in the studied case. The decomposition of limestone at a high temperature was the largest carbon emission source, accounting for 64% of the total carbon emission. Coal combustion was the second major source of carbon emissions, accounting for 31% of total carbon emissions. Based upon the main sources of carbon emission for lime production, carbon emission reduction should focus on CO₂ capture technology and fuel optimization. Based on the error transfer method, we calculated that the overall uncertainty of the life cycle carbon emissions of quicklime from 2019 to 2021 are 2.13%, 2.07% and 2.09%, respectively. Using our analysis of carbon emissions, the carbon emission factor of producing one unit of quicklime in the lime enterprise in the Yangtze River basin was determined. Furthermore, this research into carbon emission reduction for lime production can provide a point of reference for the promotion of carbon neutrality in the same industry.

Heavy metal pollution in cultivated land poses a serious threat to environmental health and farmers’ livelihoods. As the direct user of cultivated land, understanding farmers’ adaptive behavior to heavy metal pollution, and its influencing factors, can provide insight and information relevant for decision-making, so as to better manage the hazards and risks of heavy metal pollution. We proposed a conceptual framework of “farmers’ characteristics-perceptions-adaptive behaviors”. Factor analysis and mediation effect analysis were used to explore the influence of characteristics and perceptions on adaptive behaviors. The data of 278 farmers in a typical mining area in Daye, China, show that local farmers perceive the hazards of heavy metal pollution, but their adaptive behaviors are hindered to a certain extent. The results of the mediation effect analysis show that perceptions of health impact, self-efficacy, and adaptive cost play a partial mediating role in the impact of characteristics on adaptive behaviors. In addition, the influence of the “factor of dependence on farmland” and the “factor of obstacles to action” on adaptive behavior have no significant relationship with perception levels. By comparing the influencing factors, we found that although farmers’ perceptions have mediating effects between characteristics and adaptive behaviors, characteristics still play a decisive role in adaptive behaviors.

A scientific carbon accounting system can help enterprises reduce carbon emissions. This study took the enterprise in the Yangtze River basin as a case study. The accounting classification of carbon emissions in the life cycle of lime production was assessed, and the composition of the sources of carbon emission was analyzed, covering mining explosives, fuel (diesel, coal), electricity and high temperature limestone decomposition. Using the IPCC emission factor method, a carbon life cycle emission accounting model for lime production was established. We determined that a total of 354,200 tons of carbon emissions were generated from producing 321,000 tons of lime in a year. The decomposition of limestone at a high temperature was the largest carbon emission source, accounting for 62.34% of the total carbon emission. Coal combustion was also an important source of carbon emissions, accounting for 32.66% of total carbon emissions. The carbon emission for one ton of activated lime was 1.46kg, 1.49kg, 1100kg and 1102.95kg respectively for the open-pit, mining stage, crushing stage, and the calcination stage. Based upon the main sources of carbon emission for lime production, carbon emission reduction should focus on CO2 capture technology, fuel optimization and energy control. Using our analysis of carbon emissions, the carbon emission factor of producing unit quicklime of the lime enterprise in the Yangtze River basin was determined. Furthermore, the research into carbon emission reduction for lime production can provide a point of reference for the promotion of carbon neutrality in the same industry.

Many popular online social networks, such as Twitter, Tumblr, and Sina Weibo, adopt too simple privacy models to satisfy users’ diverse needs for privacy protection. In platforms with no (i.e., completely open) or binary (i.e., “public” and “friends-only”) access control, users cannot control the dissemination boundary of the content they share. For instance, on Twitter, tweets in “public” accounts are accessible to everyone including search engines, while tweets in “protected” accounts are visible to all the followers. In this work, we present Arcana to enable fine-grained access control for social network content sharing. In particular, we target the Twitter platform and introduce the “private tweet” function, which allows users to disseminate particular tweets to designated group(s) of followers. Arcana employs Ciphertext-Policy Attribute-based Encryption (CP-ABE) to implement social circle detection and private tweet encryption so that access-controlled tweets are only readable by designated recipients. To be stealthy, Arcana further embeds the protected content as digital watermarks in image tweets. We have implemented the Arcana prototype as a Chrome browser plug-in, and demonstrated its flexibility and effectiveness. Different from existing approaches that require trusted third-parties or additional server/broker/mediator, Arcana is light-weight and completely transparent to Twitter – all the communications, including key distribution and private tweet dissemination, are exchanged as Twitter messages. Therefore, with small API modifications, Arcana could be easily ported to other online social networking platforms to support fine-grained access control.

Knowledge payment products are becoming more and more popular among the public, among which audio-based knowledge payment products have a greater potential to develop as an emerging form. But they are still receiving less attention and recognition at present. Based on TPB theory, this study explores 15 factors that may influence Chinese college students' willingness to purchase audio-based knowledge payment products from three aspects: behavioral attitude, subjective norms, and perceived behavioral control, and through logistic regression analysis of 427 valid questionnaires, we conclude that behavioral attitude has a significant positive influence on college students' willingness to pay for audio-based knowledge, and propose suggestions for this study. The findings of this study suggest that the producers of paid audio knowledge products should pay more attention to the quality and connotation of the products themselves, and appropriately shorten the playing time of individual contents to meet the fragmented needs of college students. At the same time, universities can also try to cooperate with audio platforms to reduce the purchase cost of students and regulate the content of products.