Carbon emission reduction in China is of great significance to curb global warming. Based on the land use perspective, the spatial characteristics of carbon emissions and carbon sinks in 30 Chinese ...provinces were analyzed and the carbon balance was partitioned by combining the economic contribution coefficient (ECC) and ecological support coefficient (ESC). It was found that (1) the intensity of land use in China is strong, being high in the southeast and low in the northwest, divided by the Heihe–Tengchong Line, and carbon source and carbon sink lands show clear spatial heterogeneity. (2) Total carbon emissions show clear spatial heterogeneity. Carbon emissions from construction land are the main source of carbon emissions. The carbon emission intensity and per capita carbon emissions are both high in the north and low in the south. (3) The total carbon sink is high in the north–south and low in the middle of the country, and woodland and grassland are the main sites of terrestrial carbon absorption. The overall carbon sink intensity shows a continuous decrease from southeast to northwest. (4) Based on the ECC and ESC indicators, 30 provinces were divided into four carbon zones and differentiated low-carbon development suggestions are proposed.
In modern agriculture, light plays an important role in plant growth. Far red light controls the whole growth process of plants from germination to vegetative growth to flowering. Here, we report the ...preparation and photoluminescence (PL) performance of Cr,Bi co-doped SrGdAlO4 phosphors by solution combustion method. The SrGdAlO4:Cr3+,Bi3+ phosphors exhibit far red broadband PL of 660–780 nm excited at 458 nm, and the maximum emission peak position is at 713 nm. It was found Cr3+ and Bi3+ replaced the positions of Al3+ and Gd3+ in the host material, respectively. The PL performance of SrGdAlO4:Cr3+,Bi3+ phosphors mainly depends on the 2E2 → 4A2 transition of Cr3+, and the addition of Bi3+ can effectively enhance the PL intensity of the phosphors. Notably, the SrGdAlO4:Cr3+,Bi3+ phosphors also exhibit obvious far red PL when coated onto glass substrate or mixed with plastics without affecting their visible light transmission. We believe our work will excite interests in further exploring the practical application of SrGdAlO4:Cr3+,Bi3+ phosphors as plant growth regulator in greenhouse.
•SrGdAlO4:Cr3+,Bi3+ phosphors were prepared by solution combustion and annealing at 1100 °C.•SrGdAlO4:Cr3+,Bi3+ phosphors exhibit far red broadband photoluminescence.•Doping Bi3+ can enhance PL and PLE intensity of Cr-doped SGA phosphors.•SrGdAlO4:Cr3+,Bi3+ phosphor can be coated onto the glass or mixed with plastics.
•Study the toxic and protective effects of a CSPon PC12 cells.•The CSP increases viability and reduces apoptosis of cells.•The CSP protects cells in a dose- and time-dependent manner.
As a great deal ...of interest is developed to study novel bioactive components with health benefit effects from natural resources, in this paper, a rat pheochromocytoma line 12 (PC12) cell is built to observe the protective effect of a Cynomorium songaricum Rupr. polysaccharide (CSP) against H2O2-induced oxidative stress. Fluorescence microscope, flow cytometry and micro-plate reader are used to assess cell viability and apoptosis. And the levels of reactive oxygen species (ROS), 8-hydroxy-2′-deoxyguanosine (8-OH-dG), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and lactate dehydrogenase (LDH) are evaluated. The results show that, the CSP can significantly protect PC12 cells against H2O2-induced oxidative stress, increase the intracellular antioxidase system load and inhibit H2O2-induced apoptosis by scavenging of ROS, regulating cell cycle, preventing DNA damage and protecting the cell membrane. This research would be benefit for preventing and curing the oxidation-related diseases in polysaccharide study.
In the process of purchasing materials, small enterprises are often unable to meet the minimum availability of suppliers in the process of purchasing due to the lack of economic strength and storage ...capacity of goods. Therefore, they will encounter difficulties in the process of purchasing.To solve this problem, the group-led centralized procurement strategy for small enterprises has become a new craze. In this paper, we transform the problem of centralized procurement lot into a multi-objective optimization problem by establishing a multi-objective optimization model with cost, quality and logistics as sub-objectives, and use genetic algorithms to solve the multi-objective optimization problem in order to achieve Pareto optimality among each purchaser and supplier. Finally, an example of procurement by the China Energy Investment Corporation is used to verify that the multi-objective optimization model for the collection of lots constructed in this paper can effectively promote the cooperation between purchasers and suppliers, and stimulate the competitive vitality of enterprises in the market.
The youngest generation of students prefers a more active learning style. Sandwich teaching may suit their learning style by alternating between active individual learning and passive collective ...learning. Sandwich teaching has been rarely applied to the Community Nursing Course for nursing students, and its teaching effects on this course remain unclear. This study applied Sandwich teaching to the Community Nursing Course for Chinese nursing undergraduates and investigated its effects on students' critical thinking, self-learning ability, course experience, and academic performance. This is a quasi-experimental study with 72 Chinese nursing undergraduates. Students receiving traditional teaching were enrolled in the control group (n = 36), and those who received Sandwich teaching were recruited into the experimental group (n = 36). Both groups received the 12-week, 90-min Community Nursing Course. Our main outcome variable, including students' critical thinking, self-learning ability, and course experience, was assessed by specific questionnaire. The paired t-tests were applied to compare the differences of the same group in the pre-test and the post-test, and the independent-sample t-tests were used to compare the differences between the two groups. We observed that nursing students' critical thinking ability and self-learning ability were significantly improved after receiving Sandwich teaching. Students' course experience of Sandwich teaching was significantly better than that of traditional teaching. The final exam score in the experimental group was not significantly higher than that in the control group. These results suggest that Sandwich teaching in Community Nursing Course improved Chinese nursing undergraduates' critical thinking, self-learning ability, and course experience, but failed in improving academic performance.
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•Composite polymer microcapsules are obtained by a SFEPE strategy.•The Pickering emulsion formulas can be optimized upon emulsification kinetics.•The phase behaviors during extraction ...can reveal the diffusion process.•The operation conditions slightly above MCP are conducive to extraction.
Polyphenylene oxide (PPO)/cellulose nanocrystal (CNC)/carbon black (CB) microcapsules were fabricated by the supercritical extraction of Pickering emulsion (SFEPE) method. The effects of Pickering emulsion formulations on the emulsion properties, emulsification kinetics, and CPM properties were investigated. The phase behaviors in the supercritical extraction process were studied, and the mass transfer between the emulsion droplet and supercritical carbon dioxide (SCCO2) was also interpreted. The results indicate that CNC concentration, CB concentration, and NaCl concentration can decrease the droplet size and creaming index of emulsions, while the water–oil ratio can decrease the droplet size but enhance the creaming index. The emulsion formulations of water–oil > 3, CNC concentration > 0.25 mg/mL, CB concentration < 2.5 mg/mL, and NaCl concentration > 2.5 mg/mL are conducive to the emulsion formation and emulsification kinetics. For the supercritical extraction on Pickering emulsions, the operation conditions slightly above the mixture critical point (9 MPa at 313 K, for example) are proved to be conducive to the extraction.
Sodium hypochlorite (NaClO) is an important chlorine-based disinfectant that has been widely used for disinfection in public places and domestic environments. In the present work, we have designed a ...novel electrolyzer for NaCl electrolysis to produce high-quality NaClO. The cell was separated into two chambers by a bipolar membrane. Thus, NaCl electrooxidation can be conducted in a basic anolyte, and H2O electroreduction can be conducted in an acidic catholyte. Consequently, higher efficiency can be achieved than that of conventional methods. After 3 h of electrolysis, the available chlorine reached 531.8 mg/L with no deformation of the bipolar membrane. This electrolyzer provides a new avenue to produce high-quality NaClO from NaCl electrolysis.
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•Pickled kohlrabi texture showed typical twice “increase-decrease” during pickling.•Texture change mechanism were studied by in situ immunofluorescence, LF-NMR and TEM.•Water state ...contributed to texture increase–decrease at the early pickling stage.•The degradation of cellular structure and pectin led to the final texture decrease.
Pickled kohlrabi is a traditional and favored vegetable product in China. During pickling, the hardness, springiness, and chewiness of kohlrabi all experienced a typical change with twice “increase-decrease” trend. However, little is known about its mechanism. In this study, in situ analysis including immunofluorescence, low field nuclear magnetic, and transmission electron microscopy were used to explore the effects of cell wall pectin, water state, and cellular structure on kohlrabi texture changes during pickling. Results revealed that at the early stage, due to the rapid loss of water after three times salting, the cells shrank and the interstitial space reduced, resulting in the first increase on kohlrabi texture. Subsequently, the dehydration-rehydration caused by the first brine processing resulted in the first decrease on kohlrabi texture. Then under the action of PME enzyme, more low-esterified pectin was produced, and chelate-soluble pectin with more branched structure was further formed, leading to another elevation of the sample texture. As the pickling continued, under the combined action of PG and PME, the molecular weight of pectin was decreased and the rigidity of the cell tissue was destroyed, caused kohlrabi texture continued to decline. These researches could provide important information and guidance for better maintaining the texture of pickled vegetables during processing.
Rapid, accurate and high throughput measurement of infectious viruses is an urgent need to prevent viral transmission. Loop-mediated isothermal amplification (LAMP) is an attractive isothermal ...amplification method for nucleic acid detection, especially for point-of-care (POC) testing, but it needs at least four primers and its sensitivity is also limited when integrating with visual detection methods. Herein, by designing only two primers to precisely recognize the four regions of the target, we developed a multiple thermocycles-based LAMP method (MTC-LAMP) for sensitive and specific testing and tracking of viral RNA. We also introduced a novel SYBR Green I (SG)-assisted stable colorimetric assay induced by the amplification products through the charge neutralization effect of positively charged SG toward gold nanoparticles (AuNPs). The ultralow nonspecific background of the double exponential amplification improved the detection sensitivity to near single-molecule level (1 aM, 3 copies in 5 μL solution), which was higher than RT-PCR and RT-LAMP. After adding AuNPs, a significant color difference between target and blank was immediately observed by naked eye. By introducing a peptide nucleic acid (PNA) clamp into our colorimetric MTC-LAMP assay, the specific distinguish of virus variants at single-base resolution was observed without the requirement of any equipment. This assay shows great potential for large-scale screening and tracking of the threatening viruses with ultrahigh sensitivity and pronounced colorimetric output, which is of great importance for pandemic control.
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•A multiple thermocycles-based LAMP (MTC-LAMP) is developed using only two primers.•A novel SYBR Green I (SG)-assisted stable colorimetric assay is designed.•The sensitivity of MTC-LAMP is much higher than RT-PCR and RT-LAMP.•Single-base resolution is achieved by introducing a PNA clamp into MTC-LAMP.
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