401 research outputs found
What can we learn from China's health system reform?
Get PDFQingyue Meng and colleagues assess what China’s health system reform has achieved and what needs to be done over the next decad
Stable mode-locking in an Yb:YAG laser with a fast SESAM
No full textStable mode-locking in a diode-pumped Yb:YAG laser was obtained with a very fast semiconductor saturable absorber mirror (SESAM). The pulse width was measured to be 4 ps at the central wavelength of 1047 nm. The average power was 200 mW and the repetition rate was 200 MHz
Passive mode locking of an Yb:YAB laser with a low modulation depth SESAM
No full textA passive mode-locked diode-pumped self-frequency-doubling Yb:YAB laser with a low modulation depth semiconductor saturable absorber mirror operating at 374 MHz is demonstrated. The measured pulse duration is 1.98 ps at the wavelength of 1044 nm. The maximum average power reaches 45 mW
Patient Knowledge and Antibiotic Abuse: Evidence from an Audit Study in China
Get PDFWe ask how patient knowledge of appropriate antibiotic usage affects both physicians prescribing behavior and the physician-patient relationship. We conduct an audit study in which a pair of simulated patients with identical flu-like complaints visits the same physician. Simulated patient A is instructed to ask a question that showcases his/her knowledge of appropriate antibiotic use, whereas patient B is instructed to say nothing beyond describing his/her symptoms. We find that a patient’s knowledge of appropriate antibiotics use reduces both antibiotic prescription rates and drug expenditures. Such knowledge also increases physicians’ information provision about possible side effects, but has a negative impact on the quality of the physician-patient interactions.
Environmental catalysts for remediation of volatile organic compounds
No full textVolatile organic compounds (VOCs) are an important type of indoor air pollutant that threatens both environment and human health. Catalytic remediation is an attractive method to treat VOCs, but most catalysts are insufficiently active at low temperatures (< 200 °C) or in a humid environment. This work combines both experiments and studies of the catalytic mechanism to identify the candidate catalytic materials. Cerium oxide and titanium dioxide were employed as support materials. Vanadia and nano-gold/platinum/palladium catalysts were deposited on these materials to enhance the catalytic performance. Operando methodology was employed to study the relationship between catalytic performance and adsorption of VOCs at the active sites. Aerogel technology was introduced to improve the catalytic activity in wet condition. Ceria-silica aerogel with a large surface area (ca. 300-500 m2·g-1) and well-dispersed ceria clusters demonstrate stable activity in the presence of water vapor, overcoming the decline in catalytic activity caused by humidity. In addition, the transition metal oxides derived from metal organic frameworks (MOFs) were investigated systematically for remediation of VOCs. The light-off temperatures are all less than 200 °C for metal oxides such as MnOx, Co3O4, CuO, and CeO2 derived from MnBDC, ZIF-67, CuBDC, and CeBDC, respectively. The 2D rhombic binary metal oxides CeCuOx derived by pyrolysis of bimetallic CeCu-MOF exhibits extremely high activity and selectivity oxidizing toluene with T50 and T90 (temperatures for 50% and 90% conversion) at 150 °C and 185 °C respectively.</p
Fiber-optic detection of ultrashort laser pulses diffusely reflected from Intralipid skin phantom:Effect of numerical aperture and scattering anisotropy
No full textIn this paper, simulations by Monte Carlo method are applied to reveal the effect of numerical aperture (NA) of a detector (backward registration) and scattering anisotropy of a sample (g) on the probing depth of the sample. Correlation between temporal and depth-resolved detection is investigated as a function of the considered characteristics, NA and g. Decrease of the numerical aperture of the detector or increase of the scattering anisotropy of the sample lead to probing of deeper depths and larger region around. These depths correspond to the maximal numbers of the detected photons measured with time-resolved registration. The better correlation comes from the use of fibers with smaller apertures and media with strong forwards scattering (high value of anisotropy factor).</p
SURVEY OF INORGANIC COMPONENTS IN ATMOSPHERIC PARTICLES OF THREE URBAN AREAS CAUSED BY WINTER ENERGY CONSUMPTION IN CHINA AND JAPAN
No full textInvestigation of Pyrolysis/Gasification Process Conditions and Syngas Production with Metal Catalysts Using Waste Bamboo Biomass: Effects and Insights
No full textThe primary objective of this study was to examine the catalytic behaviors exhibited by diverse metal catalysts such as CaO, NiO, and K2CO3 for pyrolysis and gasification application with waste biomass. The investigation involved fine tuning the conditions of pyrolysis/gasification by optimizing the pyrolysis atmosphere, catalyst addition methods, and catalyst quantities. The behaviors were investigated using thermal analysis (TG-DTA), and the production gaseous contents were analyzed via GC-FID. The results showed that Ar gas proved to be well suited for the pyrolysis reaction. The incorporation of catalysts through mixing and impregnation techniques ensured the homogeneous dispersion of catalyst particles within the sample, offering a clear advantage over the two-stage approach. Among the various catalysts explored, K2CO3 demonstrated the most favorable catalytic impact, resulting in an enhancement of char yield from 20.2 to 26.8%, while the tar yield was reduced from 44.3 to 38.6%. Furthermore, the presence of K during gasification reactions was found to foster accelerated reaction rates and an increase in syngas production yield
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