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China's first Mars exploration mission, named Tianwen-1, landed on Mars on 15 May 2021. The Mars Surface Composition Detector (MarSCoDe) payload onboard the Zhurong rover applied the laser-induced breakdown spectroscopy (LIBS) technique to acquire chemical compositions of Martian rocks and soils. The quantitative interpretation of MarSCoDe-LIBS spectra needs to establish a LIBS spectral database that requires plenty of terrestrial geological standards. In this work, we selected 316 terrestrial standards including igneous rocks, sedimentary rocks, metamorphic rocks, and ores, whose chemical compositions, rock types, and chemical weathering characteristics were comparable to those of Martian materials from previous orbital and in situ detections. These rocks were crushed, ground, and sieved into powders less than <38 μm and pressed into pellets to minimize heterogeneity at the scale of laser spot. The chemical compositions of these standards were independently measured by X-ray fluorescence (XRF). Subsequently, the LIBS spectra of MAL standards were acquired using an established LIBS system at Shandong University (SDU-LIBS). In order to evaluate the performance of these standards in LIBS spectral interpretation, we established multivariate models using partial least squares (PLS) and least absolute shrinkage and selection (LASSO) algorithms to predict the abundance of major elements based on SDU-LIBS spectra. The root mean squared error (RMSE) values of these models are comparable to those of the published models for MarSCoDe, ChemCam, and SuperCam, suggesting these PLS and LASSO models work well. From our research, we can conclude that these 316 MAL targets are good candidates to acquire geochemistry information based on the LIBS technique. These targets could be regarded as geological standards to build a LIBS database using a prototype of MarSCoDe in the near future, which is critical to obtain accurate chemical compositions of Martian rocks and soils based on MarSCoDe-LIBS spectral data. [ABSTRACT FROM AUTHOR]

Toilet revolution has become one important part of a rural revitalization strategy in China, aiming to effectively reduce the incidence rate of fecal oral diseases, while to ensure the health-care level and quality of human beings. Since 2018, the Ministry of Agriculture and Rural Affairs, together with relevant departments, has taken active actions to vigorously promote the rural toilet revolution and achieved positive effects. However, some situation, like “poor construction, not working well and improper use” of rural toilets, still occurs in some rural areas. The main reason is a lack of a standard system for the toilet modernization and utilization of excrement, further to improve the hygiene of toilets facilities in rural areas. Therefore, this study first summarized the 22 national and industry standards system that were directly related to rural toilet construction and excrement disposal in China. It was found that the number of existing standards was seriously insufficient, indicating the standard system has not been well-established for the rural toilet construction and excrement disposal in China. As such, this study aims to establish a three-dimensional structure diagram of rural toilet construction and excrement disposal, using the system engineering technology method, including levels (basic standards, general standards, special standards), sequence (product equipment standards, engineering construction standards, technical method standards, operation management standards, safety and health standards), category (rural household toilet standards, fecal sewage centralized treatment center standards, other standards). An optimal level of special standard was further determined, according to the basic established principles of a standard system for rural toilet construction and excrement disposal. The key content of a standard system construction was proposed to fill the research gaps in the basic national standards, and the general standards system, as well as in the special standards. Four recommendations were also proposed during this time: 1) To organize a special standardization working group or professional committee as soon as possible to systematically implement the policy of the toilet revolution; 2) To strengthen the fundamental research on the various advanced international standards systems; 3) To speed up the preparation of urgently needed standards systems; 4) To encourage the local governments to actively prepare the local standards system, in order to provide for the rural toilet revolution in China. The standard system of toilet modernization and utilization of excrement in rural areas can provide an important means to guide the renovation of toilet and the utilization of excrement as resources, further to standardize development of the modern industry. [ABSTRACT FROM AUTHOR]

In analyses of urban environments, city-level sustainability assessments standards have received a lot of attention. Many countries, particularly in the developed world, have developed the standards to measure the performance of neighborhoods, districts, and cities in achieving sustainable development goals. In this study, four standards from China and the United States were selected and analyzed within the scope of green and sustainable development. China's new Assessment Standard for Green Eco-districts (ASGE) targets to support China's New-type Urbanization Plan from the conceptual stage to the concrete implementation. LEED® rating systems are one of the important references for the development of ASGE. By comparing ASGE with the advanced standards it draws from, this study aimed to evaluate ASGE's work in adapting to China's national conditions; pointing out the strengths and weaknesses and proposing improvements. The study results indicate that the rating systems of ASGE are in line with China's national conditions, and that some non-technical indicators are forward-looking, but that there is still room for improvement in terms of implementation paths, weight assignment, number of indicators, and index system. Based on these explorations, this study provides suggestions for aspects of principles and methods that could be used for the construction of similar standards in developing countries. [ABSTRACT FROM AUTHOR]