229 research outputs found
INFLUENCE OF EMERGENCY MANAGEMENT MECHANISM OF PUBLIC SECURITY EMERGENCIES ON PSYCHOLOGICAL COUNSELING AND INTERVENTION OF COLLEGE STUDENTS
A Case of Combining Coronary Angiography and CT Angiography to Diagnose an Acute ST Segment Elevation Myocardial Infarction and a Single Coronary Artery
Coronary artery anomalies encompass a wide spectrum of clinical presentations and pathophysiological mechanisms, exhibiting signifcant heterogeneity. The majority of coronary artery anomalies exhibit negligible clinical manifestations.. Among these anomalies, the occurrence of a single left coronary artery with congenital right coronary artery agenesis represents an exceedingly rare manifestation. This case report presents the clinical profle of a 37-year-old male patient who underwent intervention and coronary CT to confrm his acute myocardial infarction and a solitary left coronary artery. Athorough understanding of coronary variations and the identifcation of coronary lesions can enable cardiovascular physicians to adopt more personalized treatment strategies for their patients
Properties of Composite Oleogels Based on Soybean Isolate Protein Reinforced with Sodium Carboxymethylcellulose
The indirect preparation of oleogels by the aerogel template method has received widespread attention due to its advantages such as simple operation and excellent performance. In this study, composite aerogels of carboxy methyl cellulose-Na (CMC-Na) and soybean protein isolate (SPI) were prepared by the electrostatic interaction between them. The effects of different protein contents on the average particle size, microstructure, Fourier transform infrared (FTIR) spectrum, oil absorption kinetics, oil absorption capacity and oil holding capacity of aerogels were investigated. The oleogels prepared based on aerogel templates were characterized for their textural properties, antibacterial properties, and storage stability. The results showed that SPI and CMC-Na formed stable complexes through electrostatic interactions, and the average particle size of the complexes increased with protein content. The composite aerogel displayed a denser porous network structure along with improved oil-holding capacity, but had unfavorable effects on oil absorption performance. Moreover, the addition of protein improved the strength and Young’s modulus, and enhanced the antibacterial effect and storage stability of the oleogel. Therefore, the aerogel template method is good for preparing oleogels and a stable oleogel system can be prepared by electrostatic adsorption between polysaccharides and proteins
Effect of Ammonium Chloride Solution on the Growth of Phosphorus Gypsum Whisker and Its Modification
Cascade degradation and upcycling of polystyrene waste to high-value chemicals
Plastic waste represents one of the most urgent environmental challenges facing humankind. Upcycling has been proposed to solve the low profitability and high market sensitivity of known recycling methods. Existing upcycling methods operate under energy-intense conditions and use precious-metal catalysts, but produce low-value oligomers, monomers, and common aromatics. Herein, we report a tandem degradation-upcycling strategy to exploit high-value chemicals from polystyrene (PS) waste with high selectivity. We first degrade PS waste to aromatics using ultraviolet (UV) light and then valorize the intermediate to diphenylmethane. Low-cost AlCl3 catalyzes both the reactions of degradation and upcycling at ambient temperatures under atmospheric pressure. The degraded intermediates can advantageously serve as solvents for processing the solid plastic wastes, forming a self-sustainable circuitry. The low-value-input and high-value-output approach is thus substantially more sustainable and economically viable than conventional thermal processes, which operate at high-temperature, high-pressure conditions and use precious-metal catalysts, but produce low-value oligomers, monomers, and common aromatics. The cascade strategy is resilient to impurities from plastic waste streams and is generalizable to other high-value chemicals (e.g., benzophenone, 1,2-diphenylethane, and 4-phenyl-4-oxo butyric acid). The upcycling to diphenylmethane was tested at 1-kg laboratory scale and attested by industrial-scale techno-economic analysis, demonstrating sustainability and economic viability without government subsidies or tax credits
Summer extreme consecutive dry days over Northeast China in the changing climate: Observed features and projected future changes based on CESM-LE
Northeast China (NEC) is a major crop base in East Asia, and summer drought is one of the climate extremes that significantly influences NEC agricultural production. Therefore, understanding the response of NEC summer drought to global warming is of significance. In this study, based on observation and large-ensemble simulations of the Community Earth System Model (CESM-LE), the variabilities in summer extreme consecutive dry days (CDDs) over NEC are investigated in the present and future climate. In the observation, the NEC summer extreme CDDs showed an increasing trend during the past half century and experienced a significant interdecadal change around the middle 1990s, which is mainly due to the change in the anticyclone over Lake Baikal-Northeast Asia. The anticyclone-related anomalous downward motion and moisture divergence provided favorable conditions for increased summer CDDs over NEC. The CESM-LE multimember ensemble (MME) simulation could reproduce the change in NEC summer extreme CDDs and its related atmospheric circulations, indicating that the observed change in NEC summer extreme CDDs could be largely contributed by anthropogenic forcing. In the future warmer climate, the NEC summer extreme CDDs are projected to show interdecadal variability, which increase by approximately 6.7% in the early 21st century (2020–2030), then decrease by approximately 0.3% in the middle to late 21st century (2040–2080), and further increase by approximately 2.1% in the late 21st century (2085–2100). In addition, the projected changes in the anticyclone over Lake Baikal-Northeast Asia show a similar feature to that of the NEC summer extreme CDDs, which might further provide some confidence in the projection of the NEC summer extreme CDDs due to the physical connection between CDDs and anticyclone in the future
Excited-state spectroscopy of spin defects in hexagonal boron nitride
We used optically detected magnetic resonance (ODMR) technique to directly
probe electron-spin resonance transitions in the excited state of
negatively-charged boron vacancy (VB-) defects in hexagonal boron nitride (hBN)
at room temperature. The data showed that the excited state has a zero-field
splitting of ~ 2.1 GHz, a g factor similar to the ground state and two types of
hyperfine splitting ~ 90 MHz and ~ 18.8 MHz respectively. Pulsed ODMR
experiments were conducted to further verify observed resonant peaks
corresponding to spin transitions in the excited state. In addition, negative
peaks in photoluminescence and ODMR contrast as a function of magnetic field
magnitude and angle at level anti-crossing were observed and explained by
coherent spin precession and anisotropic relaxation. This work provided
significant insights for studying the structure of VB- excited states, which
might be used for quantum information processing and nanoscale quantum sensing
Revealing intrinsic domains and fluctuations of moir\'e magnetism by a wide-field quantum microscope
Moir\'e magnetism featured by stacking engineered atomic registry and lattice
interactions has recently emerged as an appealing quantum state of matter at
the forefront condensed matter physics research. Nanoscale imaging of moir\'e
magnets is highly desirable and serves as a prerequisite to investigate a broad
range of intriguing physics underlying the interplay between topology,
electronic correlations, and unconventional nanomagnetism. Here we report spin
defect-based wide-field imaging of magnetic domains and spin fluctuations in
twisted double trilayer (tDT) chromium triiodide CrI3. We explicitly show that
intrinsic moir\'e domains of opposite magnetizations appear over arrays of
moir\'e supercells in low-twist-angle tDT CrI3. In contrast, spin fluctuations
measured in tDT CrI3 manifest little spatial variations on the same mesoscopic
length scale due to the dominant driving force of intralayer exchange
interaction. Our results enrich the current understanding of exotic magnetic
phases sustained by moir\'e magnetism and highlight the opportunities provided
by quantum spin sensors in probing microscopic spin related phenomena on
two-dimensional flatland
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