A Life Cycle Assessment (LCA), using the end-point damage model (CEDM) of impact assessment, was conducted, to analyse the environmental impacts and pollutant payback times of photovoltaic ...production, including solar-grade silicon, silicon wafers, silicon solar cells and photovoltaic panels, in China. The inputs and outputs were obtained using site investigation, questionnaires, and field monitoring, and a method of aggregating the data into an industry-level database was established. The production yield of the studied samples accounted for an average 66% of the national yield in 2013. The results showed that the respiratory-inorganics and fossil-fuel categories contributed the most impact, because of the large electricity consumption required. Recent technological advances in raw material reduction and energy savings are the primary pathways to decreasing the environmental impacts. The environmental impact of a photovoltaic system is equivalent to 4.5% of that of the impact of the current coal-based electrical power system in China. The pollutant payback times of chemical oxygen demand, chloride, fluoride, ammonia gas, nitric oxide, sulfur dioxide, hydrogen chloride, hydrogen fluoride and carbon dioxide are 5.11, 1.02, 25.1, 8.01, 0.831, 0.784, 0.716, 1.12 and 0.884 years, respectively, indicating that most of the pollutants could be paid back within the expected lifetime of a photovoltaic system. Therefore, installing photovoltaic systems could reduce not only the consumption of non-renewable energy, but also the emitted pollutants, decreasing the environmental impacts of electricity generation.
•Integrate the product-level data into the industry-level database.•56% of the environmental impacts come from electricity consumption.•The environmental impact of PV system is equivalent to 4.5% of that of the current coal-based system in China.•And most of the pollutants could be paid back within the expected lifetime except for fluoride.
Fine particles can reduce the blast furnace’s gas and liquid permeability. The residual fine particle sampling and screening of the overhaul blast furnace were carried out to obtain particle size ...distribution. Chemical analysis, XRD, and SEM-EDS were used to analyze the chemical and phase composition, degree of graphitization, and microstructure to clarify the characteristics and evolution of fine particles. The results show a clear correlation between particle size and chemical composition. Although the phase components of different-size particles are similar in the same area, their chemical contents are quite different. The chemical and phase composition of particles with the same particle size significantly differ in the other regions. The fine particles in the S1 region mainly consist of coke powder, ZnO, and alkali metals. Significant amounts of slag iron minerals and C coexist in the fine particles of the S2 area. The slag iron minerals contents and the carbon graphitization degree of fine particles increase as the furnace burden descends.
Biomimetic mineralization of high-strength apatite structure essentially relies on mimicking the inorganic building blocks of naturally occurring bones. However, conventional routes still have ...substantial function gaps in providing precision control over the geometrical dimensions and crystalline morphology of biomineralized apatite. Herein, we conceived the concept of microwave-assisted biomineralization (MAB) to customize 1D hydroxyapatite nanowhiskers (HANWs) at graphene templates, rendering the formation of graphene-hydroxyapatite (Gr-HA) nanohybrids. The HANWs essentially resembled bone apatite in elemental composition (Ca/P = 1.74), diameter (~20 nm), crystallinity (63 %), and rodlike geometry (aspect ratio of ~6). The Gr-HA nanohybrids were uniformly incorporated into poly(lactic acid) (PLA) microfibers (~1 μm) by electrospinning, engendering fibrous membranes with a set of Gr-HA loadings (10, 20 and 30 wt%). Intimate interactions were generated between Gr-HA and PLA matrix, contributing to significant promotion of the mechanical properties for PLA composite membranes. For example, the yield strength and elastic modulus of the PLA composite membranes loaded with 30 wt% Gr-HA achieved 5.4 and 66.4 MPa, increasing nearly 182 % and over 94 % compared to those of pure PLA, respectively. Moreover, the bone-like HANWs endowed PLA membranes with excellent cytocompatibility and good bioactivity, as demonstrated by over 38 % increase in cell viability and rapid apatite formation in mineral solution. The impressive combination of mechanical properties and biological characteristics make the PLA/Gr-HA scaffolds promising for guided tissue/bone regeneration therapy.
The concept of microwave-assisted biomineralization was conceived to customize 20-nm-sized hydroxyapatite nanowhiskers with bone apatite-like structural features, conferring a combination of mechanical strength, osteogenesis and bioactivity for the poly(lactic acid) scaffolds. Display omitted
•A microwave-assisted biomineralization (MAB) approach was established.•MAB enabled rapid fabrication of hydroxyapatite nanowhiskers (HANWs) at graphene templates.•The HANWs (diameter of ~20 nm, crystallinity of 63 %) copied the structure of bone apatite.•The bone-like HANWs promoted the osteogenesis and bioactivity of poly(lactic acid) scaffolds.
The Olympics park in Beijing, 16 August 2019 (Picture by Kai Hu).
Display omitted
The relationship between environmental quality and economic growth has been a hot topic for decades. After years of ...rapid industrialization and urbanization, China’s environmental challenges are approaching a turning point. Following the principles of ecological civilization construction, China is on its way to maintaining high-quality and green economic development. On 10 June 2020, the Chinese Government reported the key findings of the Second National General Survey of Pollution Sources (fiscal year 2017), which provides strong quantitative evidence of progress toward ecological civilization. In terms of our comparison between the two National General Surveys in 2007 and 2017, it was found that environmental pollution, measured in terms of many wastewater and air emission pollutant discharges, is decreasing despite the steady growth in economic activities—and at a noticeably fast pace. Other national and local governments can adopt some of China’s ecological civilization practices, within their own individual contexts.
In recent years, concepts drawn from industrial ecology have been used to plan and develop eco-industrial parks (EIPs) in China. Attention for eco-industrial parks development projects has grown ...considerably among national and regional governments and also industries. Among of them, the National Demonstration Eco-industrial Parks program is the most significant program in China. The National Demonstration Eco-industrial Parks program in China has a clear set of indicators and performance targets, strong government support and direct involvement and strict structures and regulations to support it. This article provides an assessment of the progress of the National Demonstration Eco-industrial Parks Program in China by focusing on the key problems and dilemmas that arise in the course of developing EIPs in different economic regions. The paper draws upon both an extensive survey of EIPs and in-depth interviews conducted at 33 EIPs. It begins by introducing the experience of the National Demonstration Eco-industrial Parks Program, and then discusses the geographic distribution of EIPs and compares regional differences by analyzing data from 33 EIPs. The paper offers some brief suggestions for future development of EIPs in China and, finally, it explores factors that could affect the progress of EIPs drawing upon empirical work conducted in China.
Quantitative real-time polymerase chain reaction (qPT-PCR) is commonly used to analyze gene expression, however, the accuracy of the normalized results is affected by the expression stability of ...reference genes. Holotrichia oblita (Coleoptera: Scarabaeidae) causes serious damage to crops. Reliable reference genes in H. oblita are needed for qRT-PCR analysis. Therefore, we evaluated 13 reference genes under biotic and abiotic conditions. RefFinder provided a comprehensive stability ranking, and geNorm suggested the optimal number of reference genes for normalization. RPL13a and RPL18 were the most suitable reference genes for developmental stages, tissues, and temperature treatments; RPL13a and RPS3 were the most suitable for pesticide and photoperiod treatments; RPS18 and RPL18 were the most suitable for the two sexes. We validated the normalized results using odorant-binding protein genes as target genes in different tissues. Compared with the selected suitable reference genes, the expression of OBP1 in antennae, abdomen, and wings, and OBP2 in antennae and wings were overestimated due to the instability of ACTb. These results identified several reliable reference genes in H. oblita for normalization, and are valuable for future molecular studies.
Spermidine synthase (SPDS) is a key enzyme in the polyamine anabolic pathway.
genes help regulate plant response to environmental stresses, but their roles in pepper remain unclear. In this study, we ...identified and cloned a SPDS gene from pepper (
L.), named
(LOC107847831). Bioinformatics analysis indicated that
contains two highly conserved domains: an SPDS tetramerisation domain and a spermine/SPDS domain. Quantitative reverse-transcription polymerase chain reaction results showed that
was highly expressed in the stems, flowers, and mature fruits of pepper and was rapidly induced by cold stress. The function of
in cold stress response was studied by silencing and overexpressing it in pepper and
, respectively. Cold injury was more serious and reactive oxygen species levels were greater in the
-silenced seedlings than in the wild-type (WT) seedlings after cold treatment. Compared with the WT plants, the
-overexpression
plants were more tolerant to cold stress and showed higher antioxidant enzyme activities, spermidine content, and cold-responsive gene (
,
,
, and
) expression. These results indicate that
plays important roles in cold stress response and is valuable in molecular breeding to enhance the cold tolerance of pepper.
Abstract
Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is an important pest on maize, and it can cause large yield losses. As S. frugiperda has invaded many developing countries in ...Africa and Asia in recent years, it could impact food security. Pesticides remain the main method to control S. frugiperda in the field, and this pest has developed resistance to some pesticides. In this study, we used second-generation sequencing technology to detect the gene expression change of S. frugiperda after treatment by LC20 of three pesticides, lufenuron, spinetoram, and tetrachloroamide, which have different modes of actions. The sequence data were first assembled into a 60,236 unigenes database, and then the differential expression unigenes (DEUs) after pesticide treatment were identified. The DEU numbers, Gene Ontology catalog, and Kyoto Encyclopedia of Genes and Genomes pathway catalog were analyzed. Finally, 11 types of unigenes related to detoxification and DEUs after pesticide treatment were listed, and Cytochrome P450, Glutathione S-transferase, and ATP-binding cassette transporter were analyzed. This study provides a foundation for molecular research on S. frugiperda pesticide detoxification.
Due to its unique crystal structure and nano-properties, hydroxyapatite (HA) has become an important inorganic material with broad development prospects in electrical materials, for fire resistance ...and insulation, and in bone repair. However, its application is limited to some extent because of its low strength, brittleness and other shortcomings. Graphene (G) and its derivative graphene oxide (GO) are well known for their excellent mechanical properties, and are widely used to modify HA by domestic and foreign scholars, who expect to achieve better reinforcement and toughening effects. However, the enhancement mechanism has not been made clear. Accordingly, in this study, G and GO were selected to modify HA using the first-principles calculation method to explore the theory of interfacial bonding of composites and explain the microscopic mechanism of interfacial bonding. First-principles calculation is a powerful tool used to solve experimental and theoretical problems and predict the structure and properties of new materials with precise control at the atomic level. Therefore, the bonding behaviors of hydroxyapatite (100), (110) and (111) crystal planes with G or GO were comprehensively and systematically studied using first-principles calculation; this included analyses of the density of states and differential charge density, and calculations of interfacial adhesion work and elastic moduli. Compared to HA (100) and (111) crystal planes, HA (110) had the best bonding performance with G and with GO, as revealed by the calculation results. The composite material systems of HA (110)/G and HA (110)/GO had the smallest density of states at the Fermi level, the largest charge transfers of Ca atoms, the largest interfacial adhesion work and the most outstanding elastic moduli. These results provide a theoretical basis for the modification of HA to a certain extent, and are beneficial to the expansion of the scope of its application.
The mediator complex subunits (MED) constitutes a multiprotein complex, with each subunit intricately involved in crucial aspects of plant growth, development, and responses to stress. Nevertheless, ...scant reports pertain to the VunMED gene within the context of asparagus bean (Vigna unguiculata ssp. sesquipedialis). Establishing the identification and exploring the responsiveness of VunMED to cold stress forms a robust foundation for the cultivation of cold-tolerant asparagus bean cultivars.
Within this study, a comprehensive genome-wide identification of VunMED genes was executed in the asparagus bean cultivar 'Ningjiang3', resulting in the discovery of 36 distinct VunMED genes. A phylogenetic analysis encompassing 232 MED genes from diverse species, including Arabidopsis, tomatoes, soybeans, mung beans, cowpeas, and asparagus beans, underscored the highly conserved nature of MED gene sequences. Throughout evolutionary processes, each VunMED gene underwent purification and neutral selection, with the exception of VunMED19a. Notably, VunMED9/10b/12/13/17/23 exhibited structural variations discernible across four cowpea species. Divergent patterns of temporal and spatial expression were evident among VunMED genes, with a prominent role attributed to most genes during early fruit development. Additionally, an analysis of promoter cis-acting elements was performed, followed by qRT-PCR assessments on roots, stems, and leaves to gauge relative expression after exposure to cold stress and subsequent recovery. Both treatments induced transcriptional alterations in VunMED genes, with particularly pronounced effects observed in root-based genes following cold stress. Elucidating the interrelationships between subunits involved a preliminary understanding facilitated by correlation and principal component analyses.
This study elucidates the pivotal contribution of VunMED genes to the growth, development, and response to cold stress in asparagus beans. Furthermore, it offers a valuable point of reference regarding the individual roles of MED subunits.
PDF
