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Carbon emission reduction in the construction industry is crucial for promoting low-carbon transformation of the industry and for realizing the carbon peaking and carbon neutrality goals. This study analyzes the current status of carbon emissions in Chinese construction industry. It identifies that the production of building materials and the operation of buildings are the primary sources of carbon emissions in the overall construction process. Moreover, the growth rate of carbon emissions from the construction industry in China is decelerating, and the spatial characteristics of carbon emissions demonstrate an increase from the south to the north and from the west to the east. We have identified six key challenges that must be addressed to achieve carbon peaking and carbon neutrality in the construction industry of China: policy and standards framework, energy-efficient and carbon-reducing technologies, reduction of carbon emissions from existing buildings, carbon emission data collection and monitoring systems, economic incentives, and increased awareness of carbon reduction. Staged goals for the low-carbon development of the construction industry are also proposed. Furthermore, we suggest improving related policies and standards system, optimizing the use of energy-saving technologies, reducing carbon emissions in existing buildings, developing green finance, improving the ability to monitor carbon emissions, and enhancing the awareness of energy conservation and carbon reduction, so as to provide references for the low-carbon transformation and high-quality development of China’s construction industry.

BackgroundIn the Shanghai High Repetition rate XFEL (X-ray free electron laser) and Extreme Light (SHINE) facility, the vertical linear polarization laser is generated by using 40 planar superconducting undulators (SCUs) with a period length of 16 mm, length of 4 m, and a gap of 4 mm. At present, the Hall probes are the most reliable method for measuring the undulator magnetic field whilst the positioning accuracy of the sensitive center of the Hall probe is one of the main factors affecting the accuracy of magnetic field measurement.PurposeThis study aims to calibrate the position of the Hall probes' sensitive region for magnetic field measurements of SCU with high-precision.MethodsThe experimental platform for magnetic field point measurement of SCUs was introduced in details, a sledge with three mounted Hall probes and a retro-reflector were applied for magnetic field measurement. By flipping the sledge, the lateral distance between the sensitive centers of the Hall probe and each other were obtained, so did the lateral distance between the sensitive centers of the Hall probe and the apex of the pyramid prism. Therefore, the position of the Hall probes' sensitive region and center of the retro-reflector were calibrated.Results & ConclusionsThe positional calibration of the Hall probes has an accuracy higher than ±10 μm, which meets the requirements for magnetic field measurement.

The recent expansion of shellfish mariculture could significantly impact the ocean carbon cycle and its associated biogeochemical processes. To understand the source and fate of particulate organic carbon (POC), a summer cruise was conducted from September 8 to 10, 2022, at a mussel farm on Gouqi Island and its adjacent areas located in the East China Sea. Parameters included in situ temperature and salinity, contents of dissolved oxygen (DO), suspended particulate matter (SPM), POC, and chlorophyll a (Chl a), as well as the stable carbon isotopic composition (δ13C) of organic matter in particle and sediment samples, which were analyzed to facilitate a comparative assessment of the areas inside and outside the mussel farm. The POM was much fresher (POC/Chl a < 150) inside the farm with little impact from sediment resuspension (lower SPM content, 11.6 ± 6.6 mg/L), while a significant influence of sediment resuspension was found outside the farm (SPM > 20 mg/L, POC/Chl a > 150). A two end-member mixing model showed that 82.0 ± 6.0% of POC originated from marine algae within the farm, much higher than that outside the farming area (66.1 ± 7.8%). Moreover, elevated DO saturation but relatively low Chl a concentration within the farm suggested continuous algae consumption following potential high productivity. The averaged δ13C values were similar among suspended POC, sinking POC, and sedimentary organic carbon within the farm, implying the fast export and burial of POC. This is likely due to the filter-feeding habits of mussels, who ingest fresh POC and then pack it as fecal pellets that rapidly settle into the sediment. This study sheds light on the distribution and sources of POM inside and outside the mussel farm on Gouqi Island, enhancing our understanding of the marine carbon cycle on shellfish farms and providing insights into the underlying biogeochemical processes. [ABSTRACT FROM AUTHOR]

Noise pollution is considered an important aspect of global environmental issues. The construction of urban rail transit is gradually increasing, leading to excessive noise pollution in rail transit projects. The noise during construction has negatively impacted both the construction workers and residents in the surrounding neighborhoods. Therefore, monitoring and managing the noise is very important. In this study, noise sensors and sound level meters were employed to monitor the noises produced in an urban rail transit project. Then, Cadna/A software was utilized to simulate the noise characteristics. Based on the results, it was found that daytime noise has a maximum of 89.5dB(A), which exceeds the standard. To alleviate the noise impacts, a noise reduction scheme was put forward. The implementation of the noise reduction scheme is predicted to have an effect, resulting in an approximate 10-20dB reduction in noise level. The implementation of the scheme will allow the construction noise of the case projects to meet the national standard. This study addresses the research gaps related to construction noise in urban rail transit projects and provides valuable references for the noise control of urban rail transit projects in China. [ABSTRACT FROM AUTHOR]