126 research outputs found
Land Acquisition, Labor Allocation, and Income Growth of Farm Households
This article investigates how land acquisition during urbanization affects labor allocation decisions of farm households in China. We develop an agricultural household model by including land acquisition to examine its impacts on nonfarm labor participation and income. Two data sets (self-designed household surveys at Xingwen County in 2012 and the China Household Finance Survey (CHFS) data covering 29 provinces in 2013) are adopted for empirical analysis. The results find that land reduction has significantly positive effects on the probability and the share of family nonfarm labor allocation from both data sets. We also find that land acquisition increases the household income of the land acquisition group in CHFS data
Revealing the photophysics of gold-nanobeacons via time-resolved fluorescence spectroscopy
We demonstrate that time-resolved fluorescence spectroscopy is a powerful tool to investigate the conformation states of hairpin DNA on the surface of gold nanoparticles (AuNPs) and energy transfer processes in Au-nanobeacons. Long-range fluorescence quenching of Cy5 by AuNPs has been found to be in good agreement with electrodynamics modelling. Moreover, time-correlated single-photon counting (TCSPC) is shown to be promising for real-time monitoring of the hybridization kinetics of Au-nanobeacons, with up to 60% increase in decay time component and 300% increase in component fluorescence fraction observed. Our results also indicate the importance of the stem and spacer designs for the performance of Au-nanobeacons
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Thermodynamics of interaction between <img src='http://www.niscair.res.in/jinfo/small.gif' border=0>-cystine and sodium/magnesium chloride in aqueous solution
1126-1130Interactions of -cystine
with sodium chloride and magnesium chloride have been studied by determining
the solubility of cystine in aqueous salt solutions of different concentration
at varying temperatures. The interaction thermodynamic parameters have been
estimated with the solubility data. The results show that both NaCl and MgCl2
in water is beneficial to dissolution of -cystine.
Enthalpy or entropy of interaction between -cystine and NaCl is negative while that between -cystine
and MgCl2 is positive. These interesting results are discussed in
the light of static electricity theory as well as hydration of ions
Cation-π interactions: Synthesis and crystal structure of complex [K(DB18C6)]I<sub>3</sub>
1202-1204A dibenzo-18-crown-6 (DB18C6) complex, [K(DB18C6)]I3
has been isolated and characterized by elemental analysis, IR and X-ray diffraction
analysis. The complex belongs to triclinic, space group P21/c with
cell dimensions, a = 0.97870(17), b = 1.6909(3), c = 1.5435(3)
nm, β= 98.435(3)·, V = 2.5266(7) nm3,
Z = 2, Dcalc. = 1.026 Mg/m3, F(000) = 740, RI =
0.0534 and wR2 = 0.1666. In the solid state, two [K(DB18C6)]+
complex cations form a dimeric structure bridged by K+-π
interactions
One-dimensional chain crown ether complexes: Synthesis and crystal structure of [Na(18-crown-6)]<sub>2</sub>[M(mnt)<sub>2</sub>](M = Zn, Cd)
327-330The reactions of IR-crown-6 with Na2[Zn(mnt)2]
and Na2[Cd(mnt)2] have been studied and the complexes
[Na(18-crown-6)]2[M(mnt)2](M = Zn, Cd), are characterized
by elemental
analysis, IR spectrum and X-ray
diffraction analysis. 1 and 2 belong to monoclinic, space group
c2/c with cell dimensions, 1: a = 2.2418(6), b = 1.1359(3), c =
1.9887(6) nm,
β= 120.391 (4)o, V = 4.368(2),
nm3, Z = 4, Dcalcd = 1.399 Mg/m3, F(000) = 1920, R1
= 0.0302, wR2 = 0.0560 and 2: a = 2.2547(6), b =
1.1412(3), c = 1.9938(6) nm, β=119.715(4)°, V = 4.455 nm3, Z
= 4, Dcalcd = 1.442 Mg/m3 , F(000)= 1992, R1 = 0.0384,
wR2 = 0.0575. Two complexes display a one-dimensional chain of [Na(18C6)]+(complex
cations and [M(mnt)2]2- (M = Zn, Cd) complex anion bridged
by Na-O interactions between adjacent [Na(18C6)]+
units respectively
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