•The advantages and classifications of S-CO2 cycles are presented.•Applications of cycles especially in nuclear and solar industries are summarized.•The theoretical and experimental analysis of ...system and component are investigated.•The comparison of working fluids and component designs are analyzed.•The challenges to improve the efficiency of S-CO2 cycle applications are concluded.
The development technology and applications of supercritical CO2 power cycle have recently been gaining a lot of attention for applications to different energy industries. The advantage of the S-CO2cycle is high-efficiency within an economic and convenient structure. The stable chemical properties make it be proper to a range of metal material applications. This study provides a detailed comprehensive study of the recent development trends of the S-CO2 power cycle and the different applications of S-CO2 power cycle in various energy industries, especially nuclear energy and solar energy. The theoretical analysis, experimental analysis and the classification of different approaches are summarized for energy sources. The comparison of working fluids, component designs are presented in the article as well. The challenges for improving the efficiency of S-CO2 power cycle applications are analyzed. The study will be a beneficial complement to understanding the recent progress.
Rapeseed (Brassica napus) is the second most important oilseed crop in the world but the genetic diversity underlying its massive phenotypic variations remains largely unexplored. Here, we report the ...sequencing, de novo assembly and annotation of eight B. napus accessions. Using pan-genome comparative analysis, millions of small variations and 77.2-149.6 megabase presence and absence variations (PAVs) were identified. More than 9.4% of the genes contained large-effect mutations or structural variations. PAV-based genome-wide association study (PAV-GWAS) directly identified causal structural variations for silique length, seed weight and flowering time in a nested association mapping population with ZS11 (reference line) as the donor, which were not detected by single-nucleotide polymorphisms-based GWAS (SNP-GWAS), demonstrating that PAV-GWAS was complementary to SNP-GWAS in identifying associations to traits. Further analysis showed that PAVs in three FLOWERING LOCUS C genes were closely related to flowering time and ecotype differentiation. This study provides resources to support a better understanding of the genome architecture and acceleration of the genetic improvement of B. napus.
In this perspective paper, the present status and development tendency of concentrating solar power (CSP) are analyzed from two aspects: (1) Potential pathways to efficient CSP through improving ...operation temperature to above 700 °C; (2) Technologies for efficient solar collection, thermal storage, and power generation at >700 °C. Based on the analyses, barriers on the way to the high-temperature CSP are summarized. They are: (1) the lack of methodology for heliostat design and field layout optimization, (2) significant performance degradations of solar-thermal conversion, heat storage and transfer in receiver and thermal energy storage due to high temperature, (3) the lack of suitable supercritical CO2(S–CO2) Brayton cycle for CSP and mature design methods for S–CO2 components. To overcome these issues, perspectives on following three aspects are proposed. Firstly, optimization approaches for optimal heliostat size and layout, and game-changing techniques for heliostat structure design should be brainstormed. Secondly, receivers and thermal storage devices designed through efficiency-improving approaches and fabricated by durable materials should be developed to maintain efficient and reliable operation. Thirdly, the developments of novel S–CO2 cycle and corresponding key components are eagerly desired to achieve efficient thermal-electric conversion. Perspectives from this paper would present possible approaches to efficient CSP.
•Present status and perspectives of concentrating solar power are analyzed.•Approaches to optimal heliostat size, structure, and layout shall be brainstormed.•Efficient high-temperature receivers and heat storage devices shall be developed.•Developments of novel S–CO2 cycle and its key components are eagerly desired.
The solid-liquid phase change energy storage system promoted the efficient and sustainable utilization of dispersive and intermittent renewable energy. Low energy storage rate and unbalanced ...thermophysical characteristics existed in the vertical shell-and-tube heat storage tubes. To improve thermal properties and melting uniformity, this paper proposed a non-uniform angled fin type considering the optimization by the non-uniform arrangement and angled fins with small angles. A visual experimental platform was designed and built, and the reliability of the numerical model was verified by the experimental results. Numerical simulations of a single shell-and-tube heat storage tube regarding maximizing phase change rate were carried out. The development of the phase change interface and transient temperature field during the charging process of the non-uniform angled fins with downward 10° were obtained. Results showed that, compared with the uniform straight fin tube, the non-uniform angled fin can effectively promote the melting process of the whole fin tube, especially in the bottom area, leading to a 69.59% reduction in complete melting time. This provided a reference for the performance optimization of the shell-and-tube finned phase change heat storage tube.
•Non-uniform angled fins are designed for improving energy storage.•A 69.59% reduction in full melting time is obtained compared with uniform straight finned tube.•Unbalance of thermophysical characteristics are effectively reduced by non-uniform design.•Non-uniform angled fins achieved heat flux improvement of TES unit as large as 29.19%.
•Compressed foam greatly reduces complete melting time by 13.9%, under the same mass of metals.•A proper compressive ratio leads to a synchronized in melting for the top and bottom region.•Compressed ...metal foam significantly improves thermal conductivity and bottom conduction.•Over compressing metal foam causes an increment more than 129.4% in full melting time.•Excessive compression leads to serious non-uniform features of different regions.
Metal foams have high thermal conductivity and can be used to markedly improve the low effective conductivity in phase change materials (PCMs) during the process of melting and solidification. Furthermore, natural convection as a main way to heat transfer should be achieved attention in thermal enhancement. To further accelerate the energy storage rate, porous metal foam was compressed and saturated with PCMs. The latent heat thermal energy storage tubes packed with compressed metal foams under various compression ratios were designed and analyzed compared with uncompressed tubes. Good agreement between experimental results and numerical simulations assessed the applicability of the established numerical model. The observations on the melting process including melting fraction, temperature response distribution and uniformity, velocity field, heat flux and energy storage were further discussed. Results showed that the compressed metal foam had a better performance on improving phase change, achieving a reduction of 13.9% for complete melting time. The enhancement of thermal conductivity and the strengthening of natural convection were synergized. However, over compressing metal foam will not help reduce the melting time, leading a prolonged melting time by 129.4% and serious non-uniformity in the melting process of different regions, as well.
•Effects of key parameters on SPT with various S-CO2 Brayton cycles are analyzed.•Multi-objective optimization of SPT with different S-CO2 cycles are performed.•Different S-CO2 cycles are compared ...for applications in SPT based on Pareto fronts.
Supercritical CO2 (S-CO2) Brayton cycles are recently proposed to be integrated into the solar power tower (SPT) due to their high efficiency and compactness. Comparison of different S-CO2 Brayton cycle layouts is of great significance for selecting a suitable one in the SPT plant. Both of the efficiency and specific work are important performance criteria for the SPT plant. However, previous studies compared only one individual criterion, or both of them just separately. This paper puts forward a systematic comparison of different S-CO2 Brayton cycle layouts based on multi-objective optimizations. The two performance criteria are compared simultaneously between different S-CO2 cycle layouts by comparing the Pareto optimal fronts obtained from multi-objective optimizations. The results suggest that the inter-cooling cycle layout and the partial-cooling cycle layout can generally yield the most excellent performances, and followed by the recompression cycle layout and the pre-compression cycle layout, while the simple recuperation cycle layout has the worst performances. The advantages of the partial-cooling cycle layout and the inter-cooling cycle layout are more prominent compared with the other cycle layouts in the case of high compressor inlet temperature. The provided systematic comparison can be helpful in selecting the most suitable cycle layout for the application in SPT when there are specified requirements for the efficiency and the specific work. In addition, novel salts with high upper limit temperature (higher than 650 °C) are recommended to be developed as the heat transfer fluid for improving system performances.
The first appeal of clinical assay is always accurate and rapid. For alkaline phosphatase (ALP) monitoring in medical treatment, a rapid, reliable surface-enhanced Raman scattering (SERS) test kit is ...designed based on a “hot spots” amplification strategy. Consisting of alkyne-tagged Au nanoparticles (NPs), Ag+, and enzyme substrate, the packaged test kit can achieve one-step clinical assay of ALP in human serum within several minutes, while the operation is simple as it directly inputs the sample into the test kit. Here, Ag+ ions are adsorbed onto the surface of Au core due to electrostatic interaction between Ag+ and the negatively charged donor surface, then enzymatic biocatalysis of ALP triggers the reduction of Ag+ and subsequently silver growth occurs on every Au core surface in a controllable manner, forming “hot spots” between the Au core and Ag shell, in which the SERS signal of alkyne Raman reporters would be highly amplified. Meanwhile, ALP mediates a redox reaction of Ag+ as well as the dynamic silver coating process so the increase of SERS intensity is well-controlled and can be recognized with increasing amounts of the targets. Instead of conventional NP aggregation, this leads to a more reproducible result. In particular, the distinct Raman emission from our self-synthesized alkyne reporter is narrow and stable with zero background in the Raman silent region, suffering no optical fluctuation from biosystem inputs and the detection results are therefore reliable with a limit of detection of 0.01 U/L (2.3 pg/mL). Along with ultrahigh stability, this SERS test kit therefore is an important point-of-care candidate for a reliable, efficacious, and highly sensitive detection method for ALP, which potentially decreases the need for time-consuming clinical trials.
Ficus carica is an Asian species of flowering plant belonging to the genus Ficus of the family Moraceae, native to Western Asia and the Middle East. Its fruits, usually known as common fig or fig, ...have been consumed as a very popular health-promoting fruit worldwide since ancient times. To investigate the potential health-promoting chemical constituents of the fruits of F. carica, a systematic phytochemical study on its fruits was therefore carried out. In our study, four new structurally diverse prenylated isoflavone derivatives, ficucaricones A–D (1–4), along with 12 known analogues (5–16) were separated from the fruits of F. carica. Their chemical structures were ambiguously elucidated based on extensive spectroscopic methods. The anti-inflammatory effects and antiproliferative activities of these isolated prenylated isoflavone derivatives were tested. Prenylated isoflavone derivatives (1–16) displayed remarkable inhibitory effects against nitric oxide (NO) production with the IC50 values ranging from 0.89 ± 0.05 to 8.49 ± 0.18 μM, comparable to that of the positive control (hydrocortisone). Furthermore, compounds 1–16 also exhibited pronounced antiproliferative activities against diverse human cancer cell lines in vitro, holding the IC50 values ranging from 0.18 ± 0.03 to 18.76 ± 0.09 μM. These findings indicate that regular consumption of the fruits of F. carica may help to prevent the occurrence of inflammatory diseases and tumors. Moreover, the isolation and characterization of these prenylated isoflavone derivatives possessing remarkable anti-inflammatory effects and antiproliferative activities could be meaningful to the discovery of new anti-inflammatory and antitumor agents.
•The energy-exergy-economic (3E) model is developed for S-CO2 coal-fired system.•The layout of water-cooling wall is optimized for large scale S-CO2 power plant.•The effect of inter-cooling process ...on performance of component is revealed.•Preliminarily conceptual design of the crucial components is proposed.
The conceptual design and systematic comparison of S-CO2 coal-fired power generation systems are performed in the viewpoint of the thermodynamic analysis and economic assessment to promote the practical application in the industry. First, the differences between the conventional steam boiler and S-CO2 boiler are pointed out. 3 layouts of the water-cooling wall are compared in the aspect of the hydrodynamic characteristic and structural parameters to select the suitable one coupled to the S-CO2 cycles. Based on the optimized water-cooling wall layout, the energy, exergy and economic analysis models of the integrated S-CO2 coal-fired power systems are further developed. Finally, the mechanism of the inter-cooling thermodynamic process to improve the system performance is investigated and the distribution of the individual irreversibility is given. The systematic comparison is performed among 3 configurations of S-CO2 coal-fired power plants with consideration of the thermo-economic performance. The conceptual design of key components is also provided. The results demonstrate that the S-CO2 boiler is fatter due to 8 times larger mass flow rate of working fluid than the conventional steam boiler. The layout of water-cooling wall with the split flow strategy and vertical tubes is helpful in compacting the scale of the boiler for its less diameter and number of tubes, and its thermal efficiency is higher than that of other layouts. Among the 3 S-CO2 cycle layouts studied, the S-CO2 coal-fired power system with the inter-cooling cycle yields highest efficiency and is the most economic configuration. The thermal efficiency of the S-CO2 coal-fired power plant composing the inter-cooling cycle is 47.69–49.09% with total thermal conductance of recuperators changed from 120 MW·K−1 to 180 MW·K−1 when the turbine inlet parameters are 620 °C/620 °C/30 MPa, and displays an advantage over the ultra-supercritical steam Rankine power plant. The system levelized cost of electricity is 0.0397 $·(kW·h)−1 and shows great commercial potential. The detailed discussion of this study is beneficial to a comprehensive understanding of various S-CO2 coal-fired power systems and provide a clue to establish a practical power plant for the application of coal-fired industry.
The potential to improve the performance of molten salt solar power tower system (SPT) is explored through the proposal of CO2-based binary mixture cycle in the present study. The feasibility of ...using xenon and butane as the additives to the S-CO2 cycle are discussed from the perspective of thermodynamic analysis. The detail parametric study is performed to reveal the effects of crucial parameters on the performance of 4 system configurations. Furthermore, the systematic comparison is conducted for 4 cycle layouts adopting CO2/xenon, CO2 and CO2/butane separately to illustrate the mechanism of performance improvement of SPT system coupled to CO2-based binary mixture cycle. The optimal performance of the SPT system is also demonstrated. Finally, the best performance system layout and suitable additives are recommended. The results indicate the following issues. Adding xenon into S-CO2 cycle can obviously improve the overall thermal efficiency and exergy efficiency. While the effects of butane as an additive are converse. The inter-cooling CO2/xenon cycle is recommended as the most suitable layout coupled to the SPT system, and the exergy efficiency is 1.18%∼1.32% higher than that of the SPT system with S-CO2 inter-cooling cycle. Detail exergy loss fraction distribution illustrates that the receiver is the highest exergy loss part and followed by the heliostat field, and butane as an additive is beneficial to reduce the receiver exergy loss for its smaller temperature difference. The study can provide a novel way to improve the SPT system performance and give a clue to the addition of CO2-based binary mixture in power cycles particularly for the application of SPT system.
•Improvement on SPT performance is explored via using CO2-based mixture cycle.•Effects of key parameters on SPT with various CO2-based mixture cycle are analyzed.•Systematic comparison of different system layouts is performed.•Optimal additive and cycle configuration are recommended for SPT.
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