Developing an effective and reliable power flow (PF) tool is of great significance for the steady-state analysis of autonomous AC/DC hybrid microgrids (MGs). In this paper, a generalized PF model is ...constructed based on holomorphic embedding (HE). With a well-designed embedding technique, the nonlinear PF problem is modeled into an embedded system, which comprehensively accounts for the distinct features of islanded hybrid MGs (such as droop-regulated distributed generations (DGs) and AC/DC interlinking converters (ICs), the variation of system frequency and its effect on admittance matrix and loads in AC part). The embedded system has a generalized structure with a constant sparse matrix, which not only enables it to be solved recursively and efficiently, but also facilitates wide applicability and convenient operation. Moreover, the proposed HE-based model features a deterministic germ that relates to a physical state, which allows it to inherit the merit of the canonical embedding in converging to upper-branch solution reliably and unambiguously, without dependency on initial estimates of state variables. The feasibility and applicability of the proposed model are validated on 3 test systems of different sizes. Furthermore, the computational efficiency and convergence performance are also evaluated.
•Holomorphic embedding power flow modeling of islanded AC/DC hybrid microgrids.•Compatibility with droop regulation and distinct features of hybrid MGs.•Deriving reliable power flow solutions without dependency on initial guesses.•Generalized framework for wide applicability and efficient operation.•Experimental validation has been done on hybrid MGs of different sizes.
Power flow (PF) calculation plays a fundamental role in the steady-state analysis of isolated microgrids (MGs). In this paper, a novel analytical PF algorithm based on holomorphic embedding (HE) is ...proposed for isolated AC MGs considering hierarchical control (HC). With a deliberate design in embedding technique, the presented algorithm not only inherits the deterministic property of the canonical embedding that enables to derive the upper-branch (operable) solution explicitly, but also is compatible with the HC characteristic of isolated MGs. Furthermore, the embedded PF model features a general structure with a constant recursive matrix, which can accommodate various bus types and network re-configurations (including both radial and meshed networks), as well as non-nonlinearities of voltage-dependent load models. Case studies are carried out on 3 test systems: a 12-bus MG and modified IEEE 33-bus and 123-bus distribution systems. Numerical results reveal the applicability and efficacy of the proposed algorithm.
Linearization of nonlinear power flow equation is of great significance to power system analysis because it can reduce computational burden and guarantee theoretical convergence, the improvement of ...whose accuracy is a crucial research topic. The existing Taylor expansion based linear power flow models may not perform accurately when the system operating point is far from the expansion point. In this paper, we propose a linear power flow model with minimum mean square error in the approximation region from the perspective of function approximation theory, which is different from the local mathematical properties inherent in the Taylor expansion principle. The proposed model can consider the information of the AC power flow equation in the defined approximation region instead of just using a base point. Therefore, the overall accuracy of the model can be greatly improved. Numerical results verify the effectiveness of the proposed least-squares approximation based linear power flow model.
Lianhuaqingwen (LH) as traditional Chinese medicine (TCM) formula has been used to treat influenza and exerted broad-spectrum antiviral effects on a series of influenza viruses and immune regulatory ...effects Ding et al. (2017). The goal of this study is to demonstrate the antiviral activity of LH against the novel SARS-CoV-2 virus and its potential effect in regulating host immune response.
The antiviral activity of LH against SARS-CoV-2 was assessed in Vero E6 cells using CPE and plaque reduction assay. The effect of LH on virion morphology was visualized under transmission electron microscope. Pro-inflammatory cytokine expression levels upon SARS-CoV-2 infection in Huh-7 cells were measured by real-time quantitative PCR assays.
LH significantly inhibited SARS-CoV-2 replication in Vero E6 cells and markedly reduced pro-inflammatory cytokines (TNF-α, IL-6, CCL-2/MCP-1 and CXCL-10/IP-10) production at the mRNA levels. Furthermore, LH treatment resulted in abnormal particle morphology of virion in cells.
LH significantly inhibits the SARS-COV-2 replication, affects virus morphology and exerts anti-inflammatory activity in vitro. These findings indicate that LH protects against the virus attack, making its use a novel strategy for controlling the COVID-19 disease.
Background and Purpose
Severe influenza virus‐infected patients have high systemic levels of Th1 cytokines (including IFN‐γ). Intrapulmonary IFN‐γ increases pulmonary IFN‐γ‐producing T lymphocytes ...through the CXCR3 pathway. Virus‐infected mice lacking IP‐10/CXCR3 demonstrate lower pulmonary neutrophilic inflammation. AMG487, an IP‐10/CXCR3 antagonist, ameliorates virus‐induced lung injury in vivo through decreasing viral loads. This study examined whether AMG487 could treat H1N1 virus‐induced mouse illness through reducing viral loads or decreasing the number of lymphocytes or neutrophils.
Experimental Approach
Here, we studied the above‐mentioned effects and underlying mechanisms in vivo.
Key Results
H1N1 virus infection caused bad overall condition and pulmonary inflammation characterized by the infiltration of lymphocytes and neutrophils. From Day‐5 to Day‐10 post‐virus infection, bad overall condition, pulmonary lymphocytes, and IFN‐γ concentrations increased, while pulmonary H1N1 viral titres and neutrophils decreased. Both anti‐IFN‐γ and AMG487 alleviated virus infection‐induced bad overall condition and pulmonary lymphocytic inflammation. Pulmonary neutrophilic inflammation was mitigated by AMG487 on Day‐5 post‐infection, but was not mitigated by AMG487 on Day‐10 post‐infection. H1N1 virus induced increases of IFN‐γ, IP‐10, and IFN‐γ‐producing lymphocytes and activation of the Jak2‐Stat1 pathways in mouse lungs, which were inhibited by AMG487. Anti‐IFN‐γ decreased IFN‐γ and IFN‐γ‐producing lymphocytes on Day‐5 post‐infection. AMG487 but not anti‐IFN‐γ decreased viral titres in mouse lung homogenates or BALF. Higher virus load did not increase pulmonary inflammation and IFN‐γ concentrations when mice were treated with AMG487.
Conclusion and Implications
AMG487 may ameliorate H1N1 virus‐induced pulmonary inflammation through decreasing IFN‐γ‐producing lymphocytes rather than reducing viral loads or neutrophils.
•Carbon coating is achieved by chemical vapor deposition, and prelithiation is achieved by solid state reaction.•The combined effect of carbon layer and lithium silicate improves the initial ...Coulombic efficiency.•The full cell of prelithiation of carbon coated disproportionated SiO exhibits good cycling performance.
Silicon monoxide (SiO) is a common high-capacity anode material for lithium-ion batteries (LIBs). However, its low initial Coulombic efficiency (ICE) hinders its development as anode material for LIBs. Here, we report a composite material (d-SiO/C/LSO) prepared by prelithiation of carbon coated disproportionated SiO (d-SiO/C) with lithium hydride (LiH), which has an ICE of 90.3 % and initial discharge capacity of 1465 mAh/g. Compared with the ICE (76.7 %) of SiO materials obtained by a single carbon coating process or the ICE (81.0 %) of SiO materials obtained by a single pre-lithiation process, the ICE of SiO materials obtained by the combination of the two processes has been greatly improved. Meanwhile, the carbon layer, and the partial lithium silicate phase between the carbon layer and SiO also have a favourable effect on the cycling performance of the SiO anode for LIBs. The NMC811||d-SiO/C/LSO full cell shows the capacity retention of 86.5 % after 100 cycles.
Linear group 13 E&z.tbd;E triple bonds Cui, Zhong-hua; Liu, Yu-qian; Huang, Runfeng ...
Physical chemistry chemical physics : PCCP,
05/2021, Volume:
23, Issue:
2
Journal Article
Peer reviewed
The unexpected linear group 13 E
&z.tbd;
E triple bonds were herein uncovered with the
D
3h
-symmetry E
2
M
5
+
(M = Li, Na, and K) clusters, where the linear M-E
&z.tbd;
E-M form is perfectly ...surrounded by M
3
motifs. The increasing nonbonded electron density of the heavier main-group elements is the key issue for the
trans
-bent geometry, and yet it is strongly suppressed in E
2
M
5
+
, creating two degenerate π bonds and one multi-center σ bond.
The surrounding Na
5
motifs suppress the nonbonded electron density of E atoms, effectively resulting in two degenerate π bonds and one multicenter σ bond in the unprecedented linear heavier group 13 E&z.tbd;E triple bonds.
We report herein evidence of E&z.tbd;E triple bonds (E = Group 13) promoted by the perpendicularly surrounding M
4
(M = Li and Na) motifs. The global minimum of E
2
M
4
(E = B, Al, and Ga) is a
D
4h
...-symmetry structure where E-E is surrounded perpendicularly by square M
4
motifs, whereas the
C
s
-symmetry structure formed by E-E-M surrounded partially by M
3
motifs is the lowest-energy structure for E = In and Tl. Chemical bonding reveals that strong charge transfer from M
4
to E
2
dimer not only provides efficient electrons to form E&z.tbd;E triple bonds, but also the resulting electrostatic interactions between M
4
and E
2
play a driving force to stabilize these intriguing triply bonded species.
Chemical bonding analysis shows that strong charge transfer arises from M
4
(M = Li and Na) motifs to E
2
(E = Group 13), further making an E&z.tbd;E triple bond composed of two π bonds and one delocalized σ bond.
Development of type I photosensitizers (PSs) with strong hydroxyl radical (·OH) formation is particularly important in the anaerobic tumor treatment. On the other hand, it is challenging to obtain an ...efficient solid‐state intramolecular motion to promote the development of molecular machine and molecular motor. However, the relationship between them is never revealed. In this work, a pyrazine‐based near‐infrared type I PS with remarkable donor–acceptor effect is developed. Notably, the intramolecular motions are almost maximized by the combination of intramolecular and intermolecular engineering to simultaneously introduce the unlimited bond stretching vibration and boost the group rotation. The photothermal conversion caused by the intramolecular motions is realized with efficiency as high as 86.8%. The D–A conformation of PS can also induce a very small singlet‐triplet splitting of 0.07 eV, which is crucial to promote the intersystem crossing for the triplet sensitization. Interestingly, its photosensitization is closely related to the intramolecular motions, and a vigorous motion may give rise to a strong ·OH generation. In view of its excellent photosensitization and photothermal behavior, the biocompatible PS exhibits a superior imaging‐guided cancer synergistic therapy. This work stimulates the development of advanced PS for the biomedical application and solid‐state intramolecular motions.
In this work, the relationship between type I photosensitization with strong hydroxyl radical (∙OH) formation and intramolecular motions is established. The solid‐state intramolecular motions are almost maximized by the double engineering which may lead to a strong ∙OH generation. Combined with the high photothermal conversion efficiency, the synergistic phototherapy toward in vivo tumor can be well performed.
The unexpected linear group 13 Etriple bond, length as m-dashE triple bonds were herein uncovered with the D3h-symmetry E2M5+ (M = Li, Na, and K) clusters, where the linear M-Etriple bond, length as ...m-dashE-M form is perfectly surrounded by M3 motifs. The increasing nonbonded electron density of the heavier main-group elements is the key issue for the trans-bent geometry, and yet it is strongly suppressed in E2M5+, creating two degenerate π bonds and one multi-center σ bond.
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