Identification of Perilla Based on Three-Dimensional Fluorescence Spectra Using Wavelet Packet Decomposition, Fisher Discriminant Analysis and Support Vector Machine

In order to rapidly identify perilla species and avoid passing off, three-dimensional (3D) fluorescence spectral data of perilla from four regions in China were acquired. A feature selection strategy of fluorescence data based on wavelet packet decomposition fused with Fisher discriminant analysis (FDA) was proposed, and effective identification of the four species of perilla was implemented. First, the 3D fluorescence data were preprocessed by using Delaunay triangle interpolation to remove the adverse influence of Rayleigh scattering and Raman scattering; Savitzky-Golar (SG) convolutional smoothing was applied to smooth the data for the purpose of reducing the interference of noise. At the same time, the 3D fluorescence data were initially screened to remove emission wavelengths with fluorescence intensity less than 0.01. Second, the 3-layer sym4 wavelet packet decomposition of the emission spectrum corresponding to each excitation wavelength was performed, and the wavelet packet energy value of the lowest frequency band was calculated as the amount of spectral data characterization for each excitation wavelength. Third, FDA was used for discriminant analysis of these wavelet packet energy values, and the discrepancy information contained in them was fused to obtain the new variables generated by FDA; the first three FD variables with 99% cumulative discriminative power were selected as variables for the characterization of the discrepancy information of different species, and then a characterization strategy for the 3D fluorescence data was proposed. Finally, two pattern recognition algorithms, back propagation neural network (BPNN) and support vector machine (SVM), were used to analyze the characterization variables, and identification results were obtained with FDA + BPNN and FDA + SVM. A correct rate of 97.5% for the training set and 95% for the test set was observed with FDA + BPNN, and the correct rate obtained with FDA + SVM for both the training and test sets was 98.33%. These results showed that 3D fluorescence spectroscopy combined with wavelet packet decomposition, FDA and SVM algorithms could basically identify perilla from different regions, which will provide a basis for further research on perilla, such as quantitative detection of some active components

Synergy of slippery surface and pulse flow: An anti-scaling solution for direct contact membrane distillation

Recent progress on mitigating scaling on hydrophobic membrane distillation (MD) membrane focuses on the design of superhydrophobic/omniphobic surface and process optimization. However, the rationale for scaling resistance is not yet complete. We attempted in this work to unravel the correlation of scaling resistance based on the synergy of slippery surface (via chem-physical engineering) and pulse flow (process engineering). Superhydrophobic micro-pillared polyvinylidene fluoride (MP-PVDF) and CF4 plasma modified MP-PVDF (CF4-MP-PVDF) were utilized as the model membranes. We proposed rheometry as a simple quantitative measure for the wetting state in a hydrodynamic environment. Results showed that MP-PVDF possessed pinned wetting and prone to scaling (2000 mg/L CaSO4 solution) in both steady and pulse flow. In contrast, the CF4-MP-PVDF showed suspended wetting and excellent scaling resistance (at water recovery of 60%, the CF4-MP-PVDF surface was still clean without any crystals) under pulse flow, but not at steady flow. At steady flow, feed over-pressure changes the suspended wetting to pinned wetting by pushing the water-gas interface into the pillars, thereby resulting in scaling for CF4-MP-PVDF. At pulse flow, rhythmic fluctuation in the water-gas interface for CF4-MP-PVDF led to sustained scaling resistance. For the first time, we experimentally demonstrated a scaling resistance in DCMD via engineering surface wetting state and process. We envision that this rationale would pave the forward-looking strategy for a robust stable MD process in the near future

Slippery for scaling resistance in membrane distillation: a novel porous micropillared superhydrophobic surface

Scaling in membrane distillation (MD) is a key issue in desalination of concentrated saline water, where the interface property between the membrane and the feed become critical. In this paper, a slippery mechanism was explored as an innovative concept to understand the scaling behavior in membrane distillation for a soluble salt, NaCl. The investigation was based on a novel design of a superhydrophobic polyvinylidene fluoride (PVDF) membrane with micro-pillar arrays (MP-PVDF) using a micromolding phase separation (μPS) method. The membrane showed a contact angle of 166.0 ± 2.3° and the sliding angle of 15.8 ± 3.3°. After CF4 plasma treatment, the resultant membrane (CF4-MP-PVDF) showed a reduced sliding angle of 3.0o. In direct contact membrane distillation (DCMD), the CF4-MP-PVDF membrane illustrated excellent anti-scaling in concentrating saturated NaCl feed. Characterization of the used membranes showed that aggregation of NaCl crystals occurred on the control PVDF and MP-PVDF membranes, but not on the CF4-MP-PVDF membrane. To understand this phenomenon, a “slippery” theory was introduced and correlated the sliding angle to the slippery surface of CF4-MP-PVDF and its anti-scaling property. This work proposed a well-defined physical and theoretical platform for investigating scaling problems in membrane distillation and beyond

Unprecedented scaling/fouling resistance of omniphobic polyvinylidene fluoride membrane with silica nanoparticle coated micropillars in direct contact membrane distillation

Recent development of omniphobic membranes shows promise in scaling/fouling mitigation in membrane distillation (MD), however, the fundamental understanding is still under dispute. In this paper, we report a novel omniphobic micropillared membrane coated by silica nanoparticles (SiNPs) (SiNPs-MP-PVDF) with dual-scale roughness prepared by a micromolding phase separation (μPS) and electrostatic attraction. This membrane was used as a model for analysis of scaling behavior by calcium sulfate (CaSO4) scaling and fouling behavior by protein casein in comparison with commercial (C-PVDF) and micropillared (MP-PVDF) membranes. Unprecedented scaling/fouling resistance to CaSO4 and casein was observed in direct contact membrane distillation (DCMD) for SiNPs-MP-PVDF membrane. Similar scaling and fouling occurred for commercial PVDF and micropillared PVDF membranes. The observation corresponds well to the wetting state of all membranes as SiNPs-MP-PVDF shows suspended wetting, but MP-PVDF shows pinned wetting. From a hydrodynamic view, the suspended wetting attributes a slippery surface which reduces the direct contact of foulants to solid membrane part and leads to significantly reduced fouling and scaling. However, a pinned (or metastable) wetting state leads to a stagnant interfacial layer that is prone to severe fouling and scaling. This work highlights that both scaling and fouling resistance are indeed of suspended wetting state and slippage origin

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

Essential and unique roles of PIP5K-γ and -α in Fcγ receptor-mediated phagocytosis

The actin cytoskeleton is dynamically remodeled during Fcγ receptor (FcγR)-mediated phagocytosis in a phosphatidylinositol (4,5)-bisphosphate (PIP2)-dependent manner. We investigated the role of type I phosphatidylinositol 4-phosphate 5-kinase (PIP5K) γ and α isoforms, which synthesize PIP2, during phagocytosis. PIP5K-γ−/− bone marrow–derived macrophages (BMM) have a highly polymerized actin cytoskeleton and are defective in attachment to IgG-opsonized particles and FcγR clustering. Delivery of exogenous PIP2 rescued these defects. PIP5K-γ knockout BMM also have more RhoA and less Rac1 activation, and pharmacological manipulations establish that they contribute to the abnormal phenotype. Likewise, depletion of PIP5K-γ by RNA interference inhibits particle attachment. In contrast, PIP5K-α knockout or silencing has no effect on attachment but inhibits ingestion by decreasing Wiskott-Aldrich syndrome protein activation, and hence actin polymerization, in the nascent phagocytic cup. In addition, PIP5K-γ but not PIP5K-α is transiently activated by spleen tyrosine kinase–mediated phosphorylation. We propose that PIP5K-γ acts upstream of Rac/Rho and that the differential regulation of PIP5K-γ and -α allows them to work in tandem to modulate the actin cytoskeleton during the attachment and ingestion phases of phagocytosis

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve