Nowadays, we face a series of global challenges, including the growing depletion of fossil energy, environmental pollution, and global warming. The replacement of coal, petroleum, and natural gas by secondary energy resources is vital for sustainable development. Hydrogen (H2) energy is considered the ultimate energy in the 21st century because of its diverse sources, cleanliness, low carbon emission, flexibility, and high efficiency. H2 fuel cell vehicles are commonly the end-point application of H2 energy. Owing to their zero carbon emission, they are gradually replacing traditional vehicles powered by fossil fuel. As the H2 fuel cell vehicle industry rapidly develops, H2 fuel supply, especially H2 quality, attracts increasing attention. Compared with H2 for industrial use, the H2 purity requirements for fuel cells are not high. Still, the impurity content is strictly controlled since even a low amount of some impurities may irreversibly damage fuel cells’ performance and running life. This paper reviews different versions of current standards concerning H2 for fuel cell vehicles in China and abroad. Furthermore, we analyze the causes and developing trends for the changes in these standards in detail. On the other hand, according to characteristics of H2 for fuel cell vehicles, standard H2 purification technologies, such as pressure swing adsorption (PSA), membrane separation and metal hydride separation, were analyzed, and the latest research progress was reviewed.
A novel
composite adsorbent, PTA@(Zn, Ni, Cu)-BTC, was prepared
by (Zn, Ni, Cu)-BTC doped with different amounts of phosphotungstic
acid (PTA) using an impregnation method. Apparatus like nitrogen adsorption–desorption,
X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier
transform infrared (FT-IR), inductively coupled plasma optical emission
spectroscopy (ICP-OES), and NH3-temperature programmed
desorption (NH3-TPD) are employed to characterize our obtained
adsorbents. The adsorption properties of as-prepared adsorbents for
the dibenzothiophene (DBT) were evaluated by means of fixed-bed breakthrough
experiments. Unlike conventional MOFs (metal–organic frameworks),
the PTA@(Zn, Ni, Cu)-BTC exhibited high DBT selectivity adsorption
performs with a superior uptake capacity compared with those previously
reported in the literatures. Additionally, PTA@(Zn, Ni, Cu)-BTC showed
a remarkable stability in the presence of benzene and acetone, maintaining
about 95% initial uptake capacity after eight regeneration procedures.
PTA@(Zn, Ni, Cu)-BTC is confirmed to be a hopeful material for DBT
capture toward deep desulfurization.
In this paper, we investigate the dynamical behaviors of a Morris-Lecar neuron model. By using bifurcation methods and numerical simulations, we examine the global structure of bifurcations of the model. Results are summarized in various two-parameter bifurcation diagrams with the stimulating current as the abscissa and the other parameter as the ordinate. We also give the one-parameter bifurcation diagrams and pay much attention to the emergence of periodic solutions and bistability. Different membrane excitability is obtained by bifurcation analysis and frequency-current curves. The alteration of the membrane properties of the Morris-Lecar neurons is discussed.
Circulating tumor cells (CTCs) are promising biomarkers for clinical application. Cancer screening with Low-Dose Computed Tomography (LDCT) and CTC detections in pulmonary nodule patients has never been reported. The aim of this study was to explore the effectiveness of the combined methods to screen lung cancer. Out of 8313 volunteers screened by LDCT, 32 ground-glass nodules (GGNs) patients and 19 healthy volunteers were randomly selected. Meanwhile, 15 lung cancer patients also enrolled. CellCollector, a new CTC capturing device, was applied for CTCs detection. In GGNs group, five CTC positive patients with six CTCs were identified, 15.6% were positive (range, 1–2). In lung cancer group, 73.3% of the analyzed CellCollector cells were positive (range, 1–7) and no “CTC-like” events were detected in healthy group. All CTCs detected from GGNs group were isolated from the CellCollector functional domain and determined by whole genomic amplification for next-generation sequencing(NGS) analysis. NGS data showed that three cancer-related genes contained mutations in five CTC positive patients, including KIT, SMARCB1 and TP53 genes. In four patients, 16 mutation genes existed. Therefore, LDCT combined with CTC analysis by an in vivo device in high-risk pulmonary nodule patients was a promising way to screen early stage lung cancer.
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