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Chen, Xinyi

Publications and source records attributed to Chen, Xinyi.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Coordinated Self-Assembly of Networked Microgrids Using Irving’s Algorithm

Abstract— Microgrid installations have regained significant interest, driven by the increasing adoption of distributed energy resources, decentralized controls, and ongoing technological advancements. While the number of microgrids increases, there are opportunities to coordinate networks of microgrids. In this study, Irving’s algorithm is applied to a framework for the coordinated self-assembly of networked microgrids. Compared with the authors’ previous work, this new study relaxes the constraint on participated microgrids to have a single global objective. Thus, each microgrid can rank others according to its local preference. This reduces the amount of shared information, improves the privacy, and enhances the flexibility. The adaptability to that proposed framework is also maintained. Examples are presented to illustrate the networking processes and self-assembly operations.

Xie, Jing↗
DOE OSTI2023

Mitigating the noise of DESI mocks using analytic control variates

In order to address fundamental questions related to the expansion history of the Universe and its primordial nature with the next generation of galaxy experiments, we need to model reliably large-scale structure observables such as the correlation function and the power spectrum. Cosmological N-body simulations provide a reference through which we can test our models, but their output suffers from sample variance on large scales. Fortunately, this is the regime where accurate analytic approximations exist. To reduce the variance, which is key to making optimal use of these simulations, we can leverage the accuracy and precision of such analytic descriptions using Control Variates (CV). The power of control variates stems from utilizing inexpensive but highly correlated surrogates of the statistics one wishes to measure. The stronger the correlation between the surrogate and the statistic of interest, the larger the variance reduction delivered by the method. We apply two control variate formulations to mock catalogs generated in anticipation of upcoming data from the Dark Energy Spectroscopic Instrument (DESI) to test the robustness of its analysis pipeline. Our CV-reduced measurements offer a factor of 5-10 improvement in the measurement error compared with the raw measurements. We explore the relevant properties of the galaxy samples that dictate this reduction and comment on the improvements we find on some of the derived quantities relevant to Baryon Acoustic Oscillation (BAO) analysis.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2023

Impact Analysis of Future Electric Vehicles Using Model of Real Distribution Feeders

Globally, the number of electric vehicles (EVs) continues to increase. This on-going trend poses challenges for power distribution systems. The inclusion of electric vehicle supply equipment (EVSE) should be compatible with a changing energy system, whose structure is becoming increasingly distributed. The impact of future EVs should be analyzed and considered in the system planning and upgrades. In this study, impact analysis of future EVs is conducted for a utility company of U.S. West Coast. Real data of distribution feeders is converted into the GridLAB-D model for running power flow analysis. An estimation of the additional loading of EVs in 2050 is provided by the utility company. Simple mitigation methods are tested to improve voltage profiles and complete this case study.

Xie, Jing↗
DOE OSTI2022

Broad-spectrum CRISPR-mediated inhibition of SARS-CoV-2 variants and endemic coronaviruses in vitro

A major challenge in coronavirus vaccination and treatment is to counteract rapid viral evolution and mutations. Here we demonstrate that CRISPR-Cas13d offers a broad-spectrum antiviral (BSA) to inhibit many SARS-CoV-2 variants and diverse human coronavirus strains with >99% reduction of the viral titer. We show that Cas13d-mediated coronavirus inhibition is dependent on the crRNA cellular spatial colocalization with Cas13d and target viral RNA. Cas13d can significantly enhance the therapeutic effects of diverse small molecule drugs against coronaviruses for prophylaxis or treatment purposes, and the best combination reduced viral titer by over four orders of magnitude. Using lipid nanoparticle-mediated RNA delivery, we demonstrate that the Cas13d system can effectively treat infection from multiple variants of coronavirus, including Omicron SARS-CoV-2, in human primary airway epithelium air-liquid interface (ALI) cultures. Our study establishes CRISPR-Cas13 as a BSA which is highly complementary to existing vaccination and antiviral treatment strategies.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Effect of Support on Oxygen Reduction Reaction Activity of Supported Iron Porphyrins

In this work, we report the oxygen reduction reaction (ORR) activity in acid of an Fe porphyrin on different supports. While the activity is high (E 1/2 = 0.34 V vs RHE with n = 3.8) when the Fe porphyrin is adsorbed on XC72 (a graphitic carbon), this activity is much lower when the porphyrin is adsorbed on either MoS 2 (E 1/2 = -0.15 V vs RHE with n = 2.2) or g-C 3 N 4 (E 1/2 = -0.24 V vs RHE with n = 3.1). Electron paramagnetic resonance (EPR), X-ray absorption fine structure (XAFS), and magnetometry measurements show the electronic structure around the Fe center is the same for all three supports. Only the Fe porphyrin supported on XC72 exhibits a pH dependence in its ORR activity. This observation, coupled with the increased hydrophilicity of XC72 relative to the other supports, suggests that the support-electrolyte interaction controls the ORR activity. Modification of MoS 2 to increase its hydrophilicity results in a more active ORR catalyst.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Chandra Follow-up of the SDSS DR8 Redmapper Catalog Using the MATCha Pipeline

In order to place constraints on cosmology through optical surveys of galaxy clusters, one must first understand the properties of those clusters. To this end, we introduce the Mass Analysis Tool for Chandra (MATCha), a pipeline that uses a parallellized algorithm to analyze archival Chandra data. MATCha simultaneously calculates X-ray temperatures and luminosities and performs centering measurements for hundreds of potential galaxy clusters using archival X-ray exposures. We run MATCha on the redMaPPer SDSS DR8 cluster catalog and use MATCha's output X-ray temperatures and luminosities to analyze the galaxy cluster temperature–richness, luminosity–richness, luminosity–temperature, and temperature–luminosity scaling relations. We detect 447 clusters and determine 246 r 2500 temperatures across all redshifts. Within 0.1 < z < 0.35, we find that r 2500 T X scales with optical richness (λ) as $\mathrm{ln}\left(\tfrac{{k}_{B}{T}_{{\rm{X}}}}{1.0\,\mathrm{keV}}\right)=(0.52\pm 0.05)\mathrm{ln}\left(\tfrac{\lambda }{70}\right)+(1.85\pm 0.03)$ with an intrinsic scatter of $0.27\pm 0.02$ ($1\sigma $). We investigate the distribution of offsets between the X-ray center and redMaPPer center within 0.1 < z < 0.35, finding that 68%.3 ± 6.5% of clusters are well-centered. However, we find a broad tail of large offsets in this distribution, and we explore some of the causes of redMaPPer miscentering.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Understanding the influence of carbon addition on the corrosion behavior and mechanical properties of Al alloy “covetics”

The recent invention of a new processing method for metals and alloys involving the addition of carbon has led to several reports demonstrating an enhancement in the mechanical properties of the materials known as covetics. In this work the corrosion behavior and mechanical properties of a 6061 aluminum-carbon covetic are investigated and explained. Covetic samples with carbon added were found to exhibit a corrosion potential 40-70mV higher than samples processed without the addition of carbon. However, the corrosion current density of the covetic with carbon added relative to samples without carbon added was also increased. Surface characterization following the corrosion testing using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction revealed significant differences between the covetic with carbon added and the covetic parent material processed without carbon addition. After corrosion, the surface of the covetic with carbon added showed a alloying element rich surface morphology from the parent alloy and exhibited a smaller grain size than the material processed without carbon. Additionally, changes in the mechanical properties of the covetic were observed with both the hardness and the compressive strength of the covetic increasing as a result of carbon addition. Finally, the observed change in corrosion behavior and mechanical properties of the covetic with carbon added, along with the physical characterization, are consistent with the formation of a secondary phase in the alloy induced by carbon addition during the process used to make the covetic.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Site-Selective Catalysis of a Multifunctional Linear Molecule: The Steric Hindrance of Metal–Organic Framework Channels

The site-selective reaction of a multifunctional linear molecule requires a suitable catalyst possessing both uniform narrow channel to limit the molecule rotation and a designed active site in the channel. Recently, nanoparticles (NPs) were incorporated in metal–organic frameworks (MOFs) with the tailorable porosity and ordered nanochannel, which makes these materials (NPs/MOFs) highly promising candidates as catalytic nanoreactors in the field of heterogeneous catalysis. Inspired by a “Gondola” sailing in narrow “Venetian Canal” without sufficient space for a U-turn, a simple heterogeneous catalyst based on NPs/MOFs is developed here that exhibits site-selectivity for the oxidation of diols by restricting the random rotation of the molecule (the “Gondola”) in the limited space of the MOF channel (the narrow “Venetian Canal”), thereby protecting the middle functional group via steric hindrance. This strategy is not limited to the oxidation of diols, but can be extended to the site-selective reaction of many similar multifunctional linear molecules, such as the reduction of alkadienes.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Investigation of the Cathode–Catalyst–Electrolyte Interface in Aprotic Li–O 2 Batteries

Enabled by a unique integrated fabrication and characterization platform, X-ray photoelectron spectroscopy (XPS) studies reveal the formation of a thin solid electrolyte interphase (SEI) layer on a Li–O2 cathode after the first cycle. Subsequent cycling indicates that this SEI layer is very stable in terms of both chemistry and morphology, even after extensive cycling, preserving reversibility at the cathode/electrolyte interface. Remarkably, even after cell failure, replacement of the lithium anode resulted in recovery of the cycling behavior with the same cathode. These results demonstrate that chemical stabilization of the cathode/electrolyte interface promotes long-term operation of DMSO-based Li–O2 Ru-catalyzed batteries. Characterization of the Li anode surface reveals electrolyte decomposition, and a partial mechanism is proposed for the observed chemical composition of the cathode SEI. These studies are enabled by conformal deposition of a heterogeneous OER catalyst on a freestanding, binder-free, mesoporous, carbon-based Li–O2 cathode with high capacity and long-term cycling stability.

25 ENERGY STORAGE↗
DOE OSTI2015

The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway.

60 APPLIED LIFE SCIENCES↗