Effects Of Simultaneous CO2 Addition To The Fuel And Oxidizer Streams On Soot Formation In Co-flow Diffusion Ethylene Flame

Soot formation in a co-flow diffusion ethylene flame with the addition of CO2 to the fuel (the CO2-F), oxidizer (the CO2-O), and fuel/oxidizer (the CO2-F/O) streams was numerically and experimentally investigated in this study. The effects of different CO2 addition ways on soot inception, soot condensation, H-abstraction-C2H2-addition (HACA) and oxidation by O2/OH processes, were quantitatively analyzed by introducing the integrated reaction rates over the whole computational domain. The simulated and experimental results showed that the CO2-F/O was the most effective in inhibiting soot formation and flame temperature, followed by the CO2-O, and the CO2-F. Compared with the CO2-F, the suppression effect of the CO2-O on soot inception was weaker due to the higher concentration of benzo(ghi) fluoranthene (BGHIF). Since the rate of C4H2 formation via C2H4 → C2H3 → C2H2 → C4H2 was inhibited by the CO2-O, lowering the consumption rate of acenaphthalene (A2R5) via C4H2 + A2R5=\u3eA4, more A2R5 converted to BGHIF via A2R5 → A2- → A2 → BGHIF. The suppression effects of different ways of CO2 addition on HACA surface growth and soot condensation were identical: CO2-F \u3c CO2-O \u3c CO2-F/O. The decrease of benzo(a)pyrene (BAPYR) mole fraction accounted for the decline of soot condensation rate, and the decreases of H and OH mole fractions were responsible for the drop of HACA surface growth rate. Compared with the CO2-F, the CO2-O and the CO2-F/O had stronger suppression effects on the soot oxidation by O2 process due to the lower concentration of O2 in the oxidizer stream. Whichever CO2 addition ways were adopted, the soot oxidation by O2 process was more sensitive than the soot oxidation by OH process with the CO2 addition

Minimally-Supervised Speech Synthesis with Conditional Diffusion Model and Language Model: A Comparative Study of Semantic Coding

Recently, there has been a growing interest in text-to-speech (TTS) methods that can be trained with minimal supervision by combining two types of discrete speech representations and using two sequence-to-sequence tasks to decouple TTS. To address the challenges associated with high dimensionality and waveform distortion in discrete representations, we propose Diff-LM-Speech, which models semantic embeddings into mel-spectrogram based on diffusion models and introduces a prompt encoder structure based on variational autoencoders and prosody bottlenecks to improve prompt representation capabilities. Autoregressive language models often suffer from missing and repeated words, while non-autoregressive frameworks face expression averaging problems due to duration prediction models. To address these issues, we propose Tetra-Diff-Speech, which designs a duration diffusion model to achieve diverse prosodic expressions. While we expect the information content of semantic coding to be between that of text and acoustic coding, existing models extract semantic coding with a lot of redundant information and dimensionality explosion. To verify that semantic coding is not necessary, we propose Tri-Diff-Speech. Experimental results show that our proposed methods outperform baseline methods. We provide a website with audio samples

Non-Abelian Chiral Spin Liquid on the Kagome Lattice

We study $S=1$ spin liquid states on the kagome lattice constructed by Gutzwiller-projected $p_x+ip_y$ superconductors. We show that the obtained spin liquids are either non-Abelian or Abelian topological phases, depending on the topology of the fermionic mean-field state. By calculating the modular matrices $S$ and $T$, we confirm that projected topological superconductors are non-Abelian chiral spin liquid (NACSL). The chiral central charge and the spin Hall conductance we obtained agree very well with the $SO(3)_1$ (or, equivalently, $SU(2)_2$) field theory predictions. We propose a local Hamiltonian which may stabilize the NACSL. From a variational study we observe a topological phase transition from the NACSL to the $Z_2$ Abelian spin liquid.Comment: 12 pages, 7 figures, 1 tabl

Variability of size-fractionated phytoplankton standing stock in the Amundsen Sea during summer

The size-fractionated composition of phytoplankton greatly influences the transfer efficiency of biomass in pelagic food chains and the biological carbon flux from surface waters to the deep sea. To better understand phytoplankton abundance and composition in polynya, ice zone, and open ocean regions of the Amundsen Sea Sector of the Southern Ocean (110°W–150°W), its size-fractionated distribution and vertical structure are reported for January to February 2020. Vertical integrated (0–200 m) chlorophyll (Chl) a concentrations within Amundsen polynya regions are significantly higher than those within ice zone (t test, p 20 μm) contribute 60% of the total Chl in Amundsen polynya and sea ice areas, and form subsurface chlorophyll maxima (SCM) above the pycnocline in the upper water column, probably because of diatom blooms. Net-, nano-, and picoplankton comprise 39%, 32%, and 29% of total Chl in open ocean stations, respectively. The open-ocean SCM migrates deeper and is below the pycnocline. The Amundsen Sea SCM is moderately, positively correlated with the euphotic zone depth and moderately, negatively correlated with column-integrated net- and nanoplankton Chl

Arctigenin alleviates ER stress via activating AMPK

Aim: To investigate the protective effects of arctigenin (ATG), a phenylpropanoid dibenzylbutyrolactone lignan from Arctium lappa L (Compositae), against ER stress in vitro and the underlying mechanisms. Methods: A cell-based screening assay for ER stress regulators was established. Cell viability was measured using MTT assay. PCR and Western blotting were used to analyze gene and protein expression. Silencing of the CaMKKβ, LKB1, and AMPKα1 genes was achieved by RNA interference (RNAi). An ATP bioluminescent assay kit was employed to measure the intracellular ATP levels. Results: ATG (2.5, 5 and 10 μmol/L) inhibited cell death and unfolded protein response (UPR) in a concentration-dependent manner in cells treated with the ER stress inducer brefeldin A (100 nmol/L). ATG (1, 5 and 10 μmol/L) significantly attenuated protein synthesis in cells through inhibiting mTOR-p70S6K signaling and eEF2 activity, which were partially reversed by silencing AMPKα1 with RNAi. ATG (1-50 μmol/L) reduced intracellular ATP level and activated AMPK through inhibiting complex I-mediated respiration. Pretreatment of cells with the AMPK inhibitor compound C (25 μmol/L) rescued the inhibitory effects of ATG on ER stress. Furthermore, ATG (2.5 and 5 μmol/L) efficiently activated AMPK and reduced the ER stress and cell death induced by palmitate (2 mmol/L) in INS-1 β cells. Conclusion: ATG is an effective ER stress alleviator, which protects cells against ER stress through activating AMPK, thus attenuating protein translation and reducing ER load