34 research outputs found
Consumption and Happiness
<p>We examine the relationship between (relative) consumption and happiness using panel data for China, an important developing country. We find that consumption has a positive effect on happiness. An increase in the average consumption of those of the same age, education and gender at the community level has a positive effect on happiness, consistent with a signalling effect, while an increase in the consumption of the highest spenders in this group engenders a jealousy effect. There is mixed evidence that conspicuous consumption and consumption that increases social connectedness increases happiness, while relative deprivation in visible consumption has strong negative effects on happiness. Our findings add to the literature on the effect of relativities in influencing individual happiness.</p
Ultrafast Dynamics of Defect-Assisted Electron–Hole Recombination in Monolayer MoS<sub>2</sub>
In
this Letter, we present nondegenerate ultrafast optical pump–probe
studies of the carrier recombination dynamics in MoS<sub>2</sub> monolayers.
By tuning the probe to wavelengths much longer than the exciton line,
we make the probe transmission sensitive to the total population of
photoexcited electrons and holes. Our measurement reveals two distinct
time scales over which the photoexcited electrons and holes recombine;
a fast time scale that lasts ∼2 ps and a slow time scale that
lasts longer than ∼100 ps. The temperature and the pump fluence
dependence of the observed carrier dynamics are consistent with defect-assisted
recombination as being the dominant mechanism for electron–hole
recombination in which the electrons and holes are captured by defects
via Auger processes. Strong Coulomb interactions in two-dimensional
atomic materials, together with strong electron and hole correlations
in two-dimensional metal dichalcogenides, make Auger processes particularly
effective for carrier capture by defects. We present a model for carrier
recombination dynamics that quantitatively explains all features of
our data for different temperatures and pump fluences. The theoretical
estimates for the rate constants for Auger carrier capture are in
good agreement with the experimentally determined values. Our results
underscore the important role played by Auger processes in two-dimensional
atomic materials
Surface Recombination Limited Lifetimes of Photoexcited Carriers in Few-Layer Transition Metal Dichalcogenide MoS<sub>2</sub>
We present results on photoexcited
carrier lifetimes in few-layer transition metal dichalcogenide MoS<sub>2</sub> using nondegenerate ultrafast optical pump–probe technique.
Our results show a sharp increase of the carrier lifetimes with the
number of layers in the sample. Carrier lifetimes increase from few
tens of picoseconds in monolayer samples to more than a nanosecond
in 10-layer samples. The inverse carrier lifetime was found to scale
according to the probability of the carriers being present at the
surface layers, as given by the carrier wave function in few layer
samples, which can be treated as quantum wells. The carrier lifetimes
were found to be largely independent of the temperature, and the inverse
carrier lifetimes scaled linearly with the photoexcited carrier density.
These observations are consistent with defect-assisted carrier recombination,
in which the capture of electrons and holes by defects occurs via
Auger scatterings. Our results suggest that carrier lifetimes in few-layer
samples are surface recombination limited due to the much larger defect
densities at surface layers compared with the inner layers
Your Remnant Tells Secret: Residual Resolution in DDoS Protection Services
<p>Used to identify the adoption of DDoS Protection Services offered by CDN platforms</p>
<p>Including AS numbers, CNAME strings, and IP ranges collected from each CDN vendor studied in the paper</p
Evaluation of hemoglobin A<sub>1c</sub> measurement from filter paper using high-performance liquid chromatography and immunoturbidimetric assay
<p>Glycated hemoglobin (HbA<sub>1c</sub>) measurement from whole blood (WB) samples is inconvenient for epidemic surveillance and self-monitoring of glycemic level. We evaluated HbA<sub>1c</sub> measurement from WB blotted on filter paper (FP), which can be easily transported to central laboratories, with high-performance liquid chromatography (HPLC) and immunoturbidimetric assay (ITA). WB was applied to Whatman filter paper. By using HPLC and WB samples as reference methods, these FP samples were evaluated on HPLC and ITA. Inter- and intra-assay variation, WB vs. FP agreement and sample stability at 20–25 °C and −70 °C were assessed by statistical analysis. Results showed that the coefficient of variation (CV, %) of FP samples for HPLC and ITA were 0.44–1.02% and 1.47–2.72%, respectively (intra-assay); 2.13–3.56% and 3.21–4.82%, respectively (inter-assay). The correlation of WB HPLC with FP analyzed using HPLC and ITA are both significant (<i>p</i> < 0.001). Sample stability showed that FP method up to 5 days at 20–25 °C and 5 weeks at −70 °C is accurate and reproducible. In conclusion, FP samples analyzed by HPLC and ITA can both provide an alternative to WB for HbA<sub>1c</sub> measurement, supporting the use of FP method in epidemic surveillance and healthcare units.</p
A Palladium-Catalyzed Regioselective Hydroesterification of Alkenylphenols to Lactones with Phenyl Formate as CO Source
An
effective PdÂ(OAc)<sub>2</sub>-PPh<sub>3</sub> catalyzed hydroesterification
of alkenylphenols with phenyl formate as CO surrogate is described.
A variety of lactones are obtained in generally high yields with high
regioselectivities. In one case, 76% ee is obtained with a chiral
ligand
Facile Palladium-Catalyzed Hydrocarboxylation of Olefins without External CO Gas
An
effective Pd-catalyzed hydrocarboxylation of olefins with phenyl
formate and formic acid is described. A variety of carboxylic acids
are obtained in good yields with high regioselectivities under operationally
simple conditions without the use of toxic CO gas
Subnanogram Mass Measurements on Plasmonic Nanoparticles for Temperature-Programmed Thermal Analysis
Ultrasensitive thermogravimetric analysis of adsorbed organic
molecules has been achieved on an ordered array of gold nanoparticles
used as a novel plasmonic nanobalance. The extinction peaks of the
resonating surface plasmon of nanoparticle arrays shift upon loading
molecules and return to the original position after a linear temperature
rise process. A good correlation exists between the film thickness
and magnitude of peak shifts. The detection range of plasmonic nanobalance
derived from our results can reach a subnanogram level (1.8 pg on
an active area of 100 μm<sup>2</sup>), which is much lower than
those of mechanical or electronic mass-measuring devices. Such high
mass sensitivity, combined with the remote detection capability and
high-temperature operation of plasmonic sensors, allows the in situ
detections of the masses of loaded material and thermally desorbed
molecules
Cancer incidence rate ratio for ADM users vs. non-users.
<p>Results from spline models A - with no adjustment, B - adjusted for age, gender, calendar time, BMI, and smoking status (including interactions of age and gender; age and BMI). For metformin and sulfonylurea, allocation of RR >1 at the initiation refers to the effect of being already treated with other anti-diabetic medicines. Thick dashed lines indicate 95% CIs, thin horizontal dotted line is a reference line for no effect, tick marks along the base of plot for cancers occurred among users.</p
Risk ratio of cancer incidence for users of ADM vs. non-users according to treatment.
<p>Model I: Adjusted for age, gender, calendar time.</p><p>Model II: Adjusted for age, gender, calendar time, BMI, smoking status, interaction of age and gender, age and BMI.</p><p>Abbreviations: ADM, anti-diabetic medication; N, number of incident cancer cases; IR, incidence rate; PY, person-years; RR, risk ratio; CI, confidence intervals.</p><p>Risk ratio of cancer incidence for users of ADM vs. non-users according to treatment.</p