The injected grid current of the voltage-controlled grid-connected inverter has serious distortion due to the low frequency harmonic components in the output voltage, which is resulted by the dead ...time of the drive signals of the power switches, and the distortion cannot be eliminated even when an output voltage closed loop is incorporated. This paper introduces a virtual series impedance to increase the output impedance of the grid-connected inverter only at the dominated lower harmonic frequencies; thus, the injected grid current quality can be improved and the dynamic performance of the grid-connected inverter is not deteriorated. Experimental results from a 6-kW single-phase grid-connected inverter confirm the effectiveness of the proposed method.
Although high-throughput RNA sequencing (RNA-seq) has greatly advanced small non-coding RNA (sncRNA) discovery, the currently widely used complementary DNA library construction protocol generates ...biased sequencing results. This is partially due to RNA modifications that interfere with adapter ligation and reverse transcription processes, which prevent the detection of sncRNAs bearing these modifications. Here, we present PANDORA-seq (panoramic RNA display by overcoming RNA modification aborted sequencing), employing a combinatorial enzymatic treatment to remove key RNA modifications that block adapter ligation and reverse transcription. PANDORA-seq identified abundant modified sncRNAs-mostly transfer RNA-derived small RNAs (tsRNAs) and ribosomal RNA-derived small RNAs (rsRNAs)-that were previously undetected, exhibiting tissue-specific expression across mouse brain, liver, spleen and sperm, as well as cell-specific expression across embryonic stem cells (ESCs) and HeLa cells. Using PANDORA-seq, we revealed unprecedented landscapes of microRNA, tsRNA and rsRNA dynamics during the generation of induced pluripotent stem cells. Importantly, tsRNAs and rsRNAs that are downregulated during somatic cell reprogramming impact cellular translation in ESCs, suggesting a role in lineage differentiation.
An independently controlled neutral module (ICNM) can be adopted in a three-phase four-wire inverter to form the neutral line and provide the path for zero-sequence current when the loads are ...unbalanced. The original control objective of the ICNM is to stabilize the neutral point voltage. Since there is a -180° phase jump at the resonant frequency of the neutral inductor and split dc-link capacitors in the system loop gain, system instability may occur. In order to ensure system stability, the inductor current feedback scheme (ICFS) can be incorporated, which is equivalent to introducing a resistor in series with the inductor branch. However, it will lead to increased zero-sequence current flowing through the dc-link capacitors, thus increasing the neutral point voltage ripple. In this paper, three improved control schemes, namely, notch-filter-incorporated inductor current feedback scheme (NF-ICFS), proportional resonant cascaded regulator plus inductor current feedback scheme (PR+ICFS), and neutral current feed-forward plus inductor current feedback scheme (NCFF+ICFS), are proposed, which not only ensure system stability, but also maintain a small neutral point voltage ripple. A 10-kW prototype of the three-phase four-wire inverter with ICNM is built and tested in the laboratory, and the experimental results verify the effectiveness of the proposed control schemes.
Highlights
Three-dimensional ordered porous carbon foam with abundant hetero-atoms is successfully prepared through employing silica microspheres template.
The pore volume and specific surface area ...are effectively adjusted by an equivalent substitute strategy to investigate their influence on electromagnetic wave absorption performances.
The attenuation mechanism of electromagnetic wave is clarified according to the contribution of conduction loss and polarization loss on dielectric loss.
Three-dimensional (3D) ordered porous carbon is generally believed to be a promising electromagnetic wave (EMW) absorbing material. However, most research works targeted performance improvement of 3D ordered porous carbon, and the specific attenuation mechanism is still ambiguous. Therefore, in this work, a novel ultra-light egg-derived porous carbon foam (EDCF) structure has been successfully constructed by a simple carbonization combined with the silica microsphere template-etching process. Based on an equivalent substitute strategy, the influence of pore volume and specific surface area on the electromagnetic parameters and EMW absorption properties of the EDCF products was confirmed respectively by adjusting the addition content and diameter of silica microspheres. As a primary attenuation mode, the dielectric loss originates from the comprehensive effect of conduction loss and polarization loss in S-band and C band, and the value is dominated by polarization loss in X band and Ku band, which is obviously greater than that of conduction loss. Furthermore, in all samples, the largest effective absorption bandwidth of EDCF-3 is 7.12 GHz under the thickness of 2.13 mm with the filling content of approximately 5 wt%, covering the whole Ku band. Meanwhile, the EDCF-7 sample with optimized pore volume and specific surface area achieves minimum reflection loss (RL
min
) of − 58.08 dB at 16.86 GHz while the thickness is 1.27 mm. The outstanding research results not only provide a novel insight into enhancement of EMW absorption properties but also clarify the dominant dissipation mechanism for the porous carbon-based absorber from the perspective of objective experiments.
Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune disease that affects exocrine glands. To study the molecular mechanism and identify crucial genes/pathways in pSS pathogenesis, the ...microarray‐based whole‐genome gene expression profiles from salivary glands of patients with pSS and non‐sicca controls were retrieved. After normalization and subsequent batch effect adjustment, significance analysis of microarrays method was applied to five available datasets, and 379 differentially expressed genes (DEGs) were identified. The 300 upregulated DEGs were enriched in Gene Ontology terms of immune and inflammatory responses, including antigen processing and presentation, interferon‐mediated signaling pathway, and chemotaxis. Previously reported pSS‐associated genes, including HLA‐DRA, TAP2, PRDM1, and IFI16, were found to be significantly upregulated. The downregulated DEGs were enriched in pathways of salivary secretion, carbohydrate digestion and absorption, and starch and sucrose metabolism, implying dysfunction of salivary glands during pathogenesis. Next, a protein‐protein interaction network was constructed, and B2M, an upregulated DEG, was shown to be a hub, suggesting its potential involvement in pSS development. In summary, we found the activation of pSS‐associated genes in pathogenesis, and provide clues for salivary glands dysfunction. Experimental investigation on the identified DEGs in this study will deepen our understanding on pSS.
Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune disease that affects exocrine glands. We found the activation of pSS‐associated genes in pathogenesis, and provide clues for salivary glands dysfunction.
The potential predictive significance of atherogenic index of plasma (AIP) for cardiovascular outcomes in patients with acute coronary syndrome (ACS) and who have undergone percutaneous coronary ...intervention (PCI), with low-density lipoprotein-cholesterol (LDL-C) below 1.8mmol/L, has not been well explored.
The retrospective cohort analysis included 1,133 patients with ACS and LDL-C levels below 1.8mmol/L who underwent PCI. AIP is calculated as log (triglyceride/high-density lipoprotein-cholesterol). Patients were divided into two groups according to the median value of AIP. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCEs), a composite of all-cause death, nonfatal myocardial infarction, ischemic stroke or unplanned repeat revascularization. The association between AIP and the prevalence of MACCE was evaluated using multivariable Cox proportional hazard models.
Over a median follow-up of 26 months, the incidence of MACCE was higher in the high AIP group compared to the low AIP group (9.6% vs. 6.0%, P log-rank = 0.020), and the difference was mainly derived from an increased risk of unplanned repeat revascularization (7.6% vs. 4.6%, P log-rank = 0.028). After adjusting for multiple variables, elevated AIP was independently associated with an increased risk of MACCE, regardless of whether AIP was considered a nominal or continuous variable (hazard ratio HR 1.62, 95% confidence interval CI 1.04-2.53 or HR 2.01, 95% CI 1.09-3.73).
The present study demonstrates that AIP is a significant predictor of adverse outcomes in ACS patients undergoing PCI with LDL-C < 1.8mmol/L. These results suggest that AIP may offer supplementary prognostic information for ACS patients with optimally managed LDL-C levels.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Both subsoiling tillage (ST) and ridge and furrow rainfall harvesting (RF) are widely implemented and play an important role in boosting wheat productivity. However, information about the effects of ...ST coupled with RF during the summer fallow season on wheat productivity and environmental issues remains limited. This study aims to explore the effects of ST coupled with RF on water harvesting, wheat productivity–yield traits, water and nutrient use efficiency and quality, and soil nitrate-N residue in dryland winter wheat–summer fallow rotation at the intersection of southern Loess Plateau and western Huang–Huai–Hai Plain in China in 2018–2022. Three tillage practices—deep plowing with straw turnover (PTST), subsoiling with straw mulching (STSM), and STSM coupled with RF (SRFSM)—are conducted during the summer fallow season. The results indicated that tillage practices during the summer fallow season significantly impacted wheat productivity and soil nitrate-N residue. Compared to PTST, STSM significantly enhanced rainfall fallow efficiency and water use efficiency by 7.0% and 14.2%, respectively, as well as N, P, and K uptake efficiency by 16.9%, 16.2%, and 15.3%, and thus increased grain yield by 14.3% and improved most parameters of protein components and processing quality, albeit with an increase in nitrate-N residue in the 0- to 300-cm soil depth by 12.5%. SRFSM, in turn, led to a further increase in water storage at sowing, resulting in an increase of water use efficiency by 6.8%, as well as N, P, and K uptake efficiency and K internal efficiency by 11.8%, 10.4%, 8.8%, and 4.7%, thereby significantly promoting grain yield by 10.2%, and improving the contents of all the protein components and enhancing the processing quality in grain, and simultaneously reducing the nitrate-N residue in the 0- to 300-cm soil layer by 16.1%, compared to STSM. In essence, this study posits that employing subsoiling coupled with ridge–furrow rainfall harvesting (SRFSM) during the summer fallow season is a promising strategy for enhancing wheat yield, efficiency, and quality, and simultaneously reducing soil nitrate-N residue within the dryland summer fallow–winter wheat rotation system.
With the rapid development of urbanization and industrialization, the rural functions in China's mountainous regions have tended to diversify, and the use of sloping cultivated land has also evolved. ...Exploring the coupling relationship between rural functional diversification and the evolution of sloping cultivated land is of great significance to the protection of cultivated land in mountainous areas and the sustainable development of villages. We constructed a theoretical framework to analyze the interaction between rural functional diversification and the evolution of sloping cultivated land and then verified it with Fengjie County, China. Our research results show that: the overall agricultural production function, industrial production function, leisure and tourism function, social security function, and ecological conservation function of Fengjie County continue to develop, and the diversification level of rural functions has been enhanced. The high density value areas of sloping cultivated land were more dispersed, and the area of sloping cultivated land showed a decreasing trend. The coupling coordination degree between rural functional diversification and the evolution of gentle sloping cultivated land showed a downward trend, and the ecological economic level of gentle sloping cultivated land decreased. The coupling coordination value with steep sloping cultivated land and sharp steep sloping cultivated land showed a firstly decreasing and then increasing trend, and the ecological economic level of the two kinds of cultivated land increased. The study area can be summarized into four coupling modes and different development strategies should be adopted for different coupling modes. These research methods and findings can provide a reference value for the optimal utilization of sloping cultivated land resources in other mountainous areas.
•This paper has constructed a theoretical model to characterize how rural functional diversification drives the evolution of sloping cultivated land in mountainous areas.•This paper summarized four coupling models of rural function diversification and sloping cultivated land evolution.•Analyzed the driving mechanisms of the coupled relationship between rural functional diversification and sloping cultivated land.
The rational design of the heterogeneous interfaces enables precise adjustment of the electronic structure and optimization of the kinetics for electron/ion migration in energy storage materials. In ...this work, the built-in electric field is introduced to the iron-based anode material (Fe2O3@TiO2) through the well-designed heterostructure. This model serves as an ideal platform for comprehending the atomic-level optimization of electron transfer in advanced lithium-ion batteries (LIBs). As a result, the core-shell Fe2O3@TiO2 delivers a remarkable discharge capacity of 1342 mAh g−1 and an extraordinary capacity retention of 82.7% at 0.1 A g−1 after 300 cycles. Fe2O3@TiO2 shows an excellent rate performance from 0.1 A g−1 to 4.0 A g−1. Further, the discharge capacity of Fe2O3@TiO2 reached 736 mAh g−1 at 1.0 A g−1 after 2000 cycles, and the corresponding capacity retention is 83.62%. The heterostructure forms a conventional p-n junction, successfully constructing the built-in electric field and lithium-ion reservoir. The kinetic analysis demonstrates that Fe2O3@TiO2 displays high pseudocapacitance behavior (77.8%) and fast lithium-ion reaction kinetics. The capability of heterointerface engineering to optimize electrochemical reaction kinetics offers novel insights for constructing high-performance iron-based anodes for LIBs.
Objective In the context of a large number of rural labors migrating to cities and towns, clarifying the impact of labor transfer on the green production efficiency of grains for farming households ...has important policy implications in promoting the steady improvement of green production efficiency and promoting sustainable development of agricultural ecology.Methods Based on the survey data of 770 grain-producing farming households from Hubei and Henan Provinces, this study used the data envelopment analysis-slacks-based measure (DEA-SBM) model to calculate the green production efficiency of grains, and used the Tobit model to demonstrate the impact of labor transfer and technology extension on the green production efficiency of grains.Results The research showed that labor transfer had an inhibitory effect on the green production efficiency of grains for farming households in both the temporal and spatial dimensions. Government green technology extension measures could promote the improvement of green production efficiency of grains and effectively alleviate the negative impact of labor transfer on green production efficiency of grains. The mitigating effect of technology extension services on the green production efficiency of farming households was limited by the age and income of farmers. For young and high-income farmers, its mitigating effect is insignificant. Conclusion Therefore, we should improve the rural labor security mechanism, expand the promotion channels of green production technologies, and focus on the promotion of green production technology for older and low-income farming households, to promote the improvement of green production efficiency of grains and effectively speed up the process of high-quality agricultural development.
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