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Recycling the arsenic-rich biomass of Pteris vittata is a critical problem during phytoremediation primarily because of the low value and high risk of arsenic-rich biomass. Nevertheless, extracts of P. vittata have been found to have a variety of bio-activities (e.g., anti-oxidation, anti-cancer, and anti-bacterial) and abundant valuable bio-active compositions (e.g., flavonoids), which might present a new solution for the recycling of P. vittata harvests. This work demonstrated a pilot-scale experiment to extract and purify the phenolic compounds from 1 t of arsenic-rich P. vittata biomass. Result showed that 47.9 kg of phenolic-rich extract with a potential value of US$908.66-8345.14 was obtained. This extract showed no acute oral toxicities (LD50 > 10 g/kg), no skin irritation, and no chronic risks in the long-term skin contact exposure pathways. All of the wastes from production have been recycled and safely disposed with low cost (US$28.44), and the cost may be further reduced. The calculated benefits from this method showed a potential to provide 995-53,050 US$/hm2 per year to a phytoremediation project. Therefore, this strategy could address the issue of expensive phytoremediation.

Ecosystem water use efficiency (EWUE) is a popular issue in the comprehensive study of climate change, ecology, and hydrology. Currently, views on the response of EWUE to temperature, precipitation, and drought remain controversial. Based on ecosystem net primary productivity (NPP) and evapotranspiration (ET) datasets, both of which were retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) using the Carnegie Ames Stanford approach (CASA) and surface energy balance algorithms for land (SEBAL) models, respectively, this study comprehensively examined the relationship between EWUE and temperature, precipitation, and drought in the Tianshan Mountains of Central Asia. The results showed that EWUE had an obvious temporal change trend in the Tianshan Mountains. The EWUEs of all vegetation types presented an increasing trend in spring and a decreasing trend in autumn. These results led to a phase shift in the annual cycle of EWUE over the years. Compared with 2000 to 2003, from 2012 to 2016, the annual EWUE cycle had advanced by 32 days. Precipitation generally had a negative effect on EWUE, while temperature had an obvious positive effect on EWUE. The EWUE responses to drought for the different vegetation types showed a variety of change trends. With the increase in drought stress, EWUE not only showed a simple upward or downward trend but also showed an upward trend followed by a downward trend or a downward trend followed by an upward trend. EWUE is more sensitive to changing environments than NPP or ET and is more suitable for analyzing ecosystem responses to global change.

Abstract Induction time and agglomeration of methane hydrate formation in dispersed systems play an important role in exploitation of natural gas hydrate, prevention of gas hydrate plug, and application of hydrate-based technologies. In this work, an autoclave with particle video microscope (PVM) probe was used to detect induction time of methane hydrate formation as a function of the water cut, dosage of sorbitan monolaurate (Span 20), and subcooling. Forty-one experiments and thirty-six experiments of induction time have been conducted for methane hydrate formation at constant pressure and at nonconstant pressure, respectively. The results showed subcooling was the major factor that affects induction time during methane hydrate formation process. Subcooling of 4 K can be seen as an inflection point because the average methane hydrate formation time was less than 200 min when the subcooling was greater than 4 K, while methane hydrate formation time exhibited more stochastic when the subcooling was less than 4 K. The results also suggested that there exists a transformation range of subcooling (TRS) during methane hydrate formation process. The agglomerated mechanism of methane gas hydrate may be changed when the subcooling is greater than TRS, and subcooling of 4 K is included in the TRS.

Understanding the responses of vegetation characteristics and soil properties to grazing disturbance is useful for grassland ecosystem restoration and management in semiarid areas. Here, we examined the effects of long-term grazing on vegetation characteristics, soil properties, and their relationships across four grassland types (meadow, Stipa steppe, scattered tree grassland, and sandy grassland) in the Horqin grassland, northern China. Our results showed that grazing greatly decreased vegetation cover, aboveground plant biomass, and root biomass in all four grassland types. Plant cover and aboveground biomass of perennials were decreased by grazing in all four grasslands, whereas grazing increased the cover and biomass of shrubs in Stipa steppe and of annuals in scattered tree grassland. Grazing decreased soil carbon and nitrogen content in Stipa steppe and scattered tree grassland, whereas soil bulk density showed the opposite trend. Long-term grazing significantly decreased soil pH and electrical conductivity (EC) in annual-dominated sandy grassland. Soil moisture in fenced and grazed grasslands decreased in the following order of meadow, Stipa steppe, scattered tree grassland, and sandy grassland. Correlation analyses showed that aboveground plant biomass was significantly positively associated with the soil carbon and nitrogen content in grazed and fenced grasslands. Species richness was significantly positively correlated with soil bulk density, moisture, EC, and pH in fenced grasslands, but no relationship was detected in grazed grasslands. These results suggest that the soil carbon and nitrogen content significantly maintains ecosystem function in both fenced and grazed grasslands. However, grazing may eliminate the association of species richness with soil properties in semiarid grasslands.

To meet the demand of talents in the rapid and sustainable development of the steel manufacturing industry and the needs of the local development of green and intelligent steel technology, this paper presented a reformed training program of intelligent manufacturing of universities for the steel industry. The training program explored the reform plan of talent training objectives, curriculum system, teaching mode, practical links, and operation mechanism of intelligent manufacturing engineering, and built a system with the goal of cultivating innovative ability covering green and intelligent concepts. A new mode of talent cultivation that covers the green and intelligent manufacturing concept and awareness, engineering knowledge, and innovation ability is built, to cultivate high-quality engineering talents who can adapt to the demand of green and intelligent development of steel and other industries. The innovative talent cultivation mode could reconstruct the steel intelligent manufacturing engineering education system and produce a demonstrative effect and good social benefits on the construction of intelligent manufacturing engineering specialty in the industry-featured colleges and universities.

ABSTRACTWith massive urbanization and infrastructure investments occurring in China, understanding GHG emissions from infrastructure use in small and large Chinese cities with different administrative levels is important for building future low-carbon cities. This paper identifies diverse data sources to assess GHG emission from community-wide infrastructure footprints (CIF) in four Chinese cities of varying population (1 to 20 million people) and administrative levels: Yixing, Qinhuangdao, Xiamen and Beijing. CIF addresses seven infrastructure sectors providing energy (fuels/coal), electricity, water supply and wastewater treatment, transportation, municipal waste management, construction materials, and food to support urban activities. Industrial energy use dominates the infrastructure GHG CIF in all four cities, ranging from 76% of total CIF in Yixing to 30% in Beijing, followed by residential energy use (6–13%), transportation (4–12%), commercial energy use (2–25%), food (6–11%), cement use (3–8%) and...

Abstract In order to assess the feasibility of utilizing renewable hydrogen as transport fuel for fuel cell vehicles, four possible low-carbon hydrogen supply routes for a hydrogen refueling station located in Shanghai are studied. Route Ⅰ and II are onsite hydrogen supply routes powered by a stand-alone or grid-connected photovoltaic (PV)-wind generation system separately. Route Ⅲ and IV are offsite hydrogen supply routes, in which hydrogen is produced by a stand-alone or grid-connected PV-wind generation system located in Qinghai Province respectively and delivered via liquid hydrogen truck to Shanghai. The microgrid system for hydrogen production is designed and optimized with the aid of HOMER Pro® software. The results show that in hydrogen production stage, Route Ⅳ shows the best economic performance, both in the total net present cost (NPC) cost and levelized cost of energy (LCOE) cost. As for the whole hydrogen supply chain, Route IV is also the most economic hydrogen supply way, the levelized cost of hydrogen (LCOH) of which is slightly lower than that of Route II. The sensitivity results show that the total LCOH cost of Route Ⅳ is feasible based on the current shorter electrolyzer's lifetime. Therefore, it indicates that nowadays, producing hydrogen from a grid connected PV-wind hybrid power system in renewable energy rich area (Qinghai Province) and delivering it via liquid hydrogen truck to a refueling station in east coast area (Shanghai) of China may be a feasible solution.

Historical grassland cover change is vital for global and regional environmental change modeling; however, in China, estimates of this are rare, and therefore, we propose a method to reconstruct grassland cover over the past 300 years. By synthesizing remote sensing-derived Chinese land use and land cover change (LULCC) data (1980–2015) and potential natural vegetation data simulated by the relationship between vegetation and environment, we first determined the potential extent of natural grassland vegetation (PENG) in the absence of human activities. Then we reconstructed grassland cover across western China between 1661 and 1996 at 10 km resolution by overlaying the Chinese historical cropland dataset (CHCD) over the PENG. As this land cover type has been significantly influenced by anthropogenic factors, the data show that the proportion of grassland in western China continuously decreased from 304.84 × 106 ha in 1661 to 277.69 × 106 ha in 1996. This reduction can be divided into four phases, comprising a rapid decrease between 1661 and 1724, a slow decrease between 1724 and 1873, a sharp decrease between 1873 and 1980, and a gradual increase since 1980. These reductions correspond to annual loss rates of 7.32 × 104 ha, 2.90 × 104 ha, 17.04 × 104 ha, and −2.37 × 104 ha, respectively. The data reconstructed here show that the decrease in grassland area between 1661 and 1724 was mainly limited to the Gan-Ning region (Gansu and Ningxia) and was driven by the early agricultural development policies of the Qing Dynasty. Grassland was extensively cultivated in northeastern China (Heilongjiang, Jilin, and Liaoning) and in the Xinjiang region between 1724 and 1980, a process which resulted from an exponential increase in immigrants to these provinces. The reconstruction results enable provide crucial data that can be used for modeling long-term climate change and carbon emissions.