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1. chinaXiv:202005.00098 [pdf]

Stable oxygen-hydrogen isotopes reveal water use strategies of Tamarix taklamakanensis in the Taklimakan Desert, China

DONG Zhengwu; LI Shengyuo; ZHAO Ying; LEI Jiaqiang; WANG Yongdong; LI Congjuan
Subjects: Biology >> Botany >> Applied botany

Tamarix taklamakanensis, a dominant species in the Taklimakan Desert of China, plays a crucial role in stabilizing sand dunes and maintaining regional ecosystem stability. This study aimed to determine the water use strategies of T. taklamakanensis in the Taklimakan Desert under a falling groundwater depth. Four typical T. taklamakanensis nabkha habitats (sandy desert of Tazhong site, saline desert-alluvial plain of Qiemo site, desert-oasis ecotone of Qira site and desert-oasis ecotone of Aral site) were selected with different climate, soil, groundwater and plant cover conditions. Stable isotope values of hydrogen and oxygen were measured for plant xylem water, soil water (soil depths within 0–500 cm), snowmelt water and groundwater in the different habitats. Four potential water sources for T. taklamakanensis, defined as shallow, middle and deep soil water, as well as groundwater, were investigated using a Bayesian isotope mixing model. It was found that groundwater in the Taklimakan Desert was not completely recharged by precipitation, but through the river runoff from snowmelt water in the nearby mountain ranges. The surface soil water content was quickly depleted by strong evaporation, groundwater depth was relatively shallow and the height of T. taklamakanensis nabkha was relatively low, thus T. taklamakanensis primarily utilized the middle (23%±1%) and deep (31%±5%) soil water ?and groundwater (36%±2%) within the sandy desert habitat. T. taklamakanensis mainly used the deep soil water (55%±4%) and a small amount of groundwater (25%±2%) within the saline desert-alluvial plain habitat, where the soil water content was relatively high and the groundwater depth was shallow. In contrast, within the desert-oasis ecotone in the Qira and Aral sites, T. taklamakanensis primarily utilized the deep soil water (35%±1% and 38%±2%, respectively) and may also use groundwater because the height of T. taklamakanensis nabkha was relatively high in these habitats and the soil water content was relatively low, which is associated with the reduced groundwater depth due to excessive water resource exploitation and utilization by surrounding cities. Consequently, T. taklamakanensis showed distinct water use strategies among the different habitats and primarily depended on the relatively stable water sources (deep soil water and groundwater), reflecting its adaptations to the different habitats in the arid desert environment. These findings improve our understanding on determining the water sources and water use strategies of T. taklamakanensis in the Taklimakan Desert.

submitted time 2020-05-31 From cooperative journals:《Journal of Arid Land》 Hits4791Downloads1094 Comment 0

2. chinaXiv:202004.00042 [pdf]

Stable oxygen-hydrogen isotopes reveal water use strategies of Tamarix taklamakanensis in the Taklimakan Desert, China

DONG Zhengwu; LI Shengyu; ZHAO Ying; LEI Jiaqiang; WANG Yongdong; LI Congjuan
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology

Tamarix taklamakanensis, a dominant species in the Taklimakan Desert of China, plays a crucial role in stabilizing sand dunes and maintaining regional ecosystem stability. This study aimed to determine the water use strategies of T. taklamakanensis in the Taklimakan Desert under a falling groundwater depth. Four typical T. taklamakanensis nabkha habitats (sandy desert of Tazhong site, saline desert-alluvial plain of Qiemo site, desert-oasis ecotone of Qira site and desert-oasis ecotone of Aral site) were selected with different climate, soil, groundwater and plant cover conditions. Stable isotope values of hydrogen and oxygen were measured for plant xylem water, soil water (soil depths within 0–500 cm), snowmelt water and groundwater in the different habitats. Four potential water sources for T. taklamakanensis, defined as shallow, middle and deep soil water, as well as groundwater, were investigated using a Bayesian isotope mixing model. It was found that groundwater in the Taklimakan Desert was not completely recharged by precipitation, but through the river runoff from snowmelt water in the nearby mountain ranges. The surface soil water content was quickly depleted by strong evaporation, groundwater depth was relatively shallow and the height of T. taklamakanensis nabkha was relatively low, thus T. taklamakanensis primarily utilized the middle (23%±1%) and deep (31%±5%) soil water and groundwater (36%±2%) within the sandy desert habitat. T. taklamakanensis mainly used the deep soil water (55%±4%) and a small amount of groundwater (25%±2%) within the saline desert-alluvial plain habitat, where the soil water content was relatively high and the groundwater depth was shallow. In contrast, within the desert-oasis ecotone in the Qira and Aral sites, T. taklamakanensis primarily utilized the deep soil water (35%±1% and 38%±2%, respectively) and may also use groundwater because the height of T. taklamakanensis nabkha was relatively high in these habitats and the soil water content was relatively low, which is associated with the reduced groundwater depth due to excessive water resource exploitation and utilization by surrounding cities. Consequently, T. taklamakanensis showed distinct water use strategies among the different habitats and primarily depended on the relatively stable water sources (deep soil water and groundwater), reflecting its adaptations to the different habitats in the arid desert environment. These findings improve our understanding on determining the water sources and water use strategies of T. taklamakanensis in the Taklimakan Desert.

submitted time 2020-04-23 From cooperative journals:《Journal of Arid Land》 Hits1767Downloads964 Comment 0

3. chinaXiv:201711.02788 [pdf]

Analysis and mitigation of the carrier phase delay effect of the digital phase generated carrier algorithm

邵士勇
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

We present an improved digital phase generated carrier (PGC)algorithm based on the synchronous carrier restoration(SCR) method to mitigate the carrier phase delay effects. The most distinguishing feature of this method is that it picks up the carrier signal information (frequency and phase) from the interference signal directly and accomplishes the processing of carrier signal restoration synchronically. In comparison with the traditional one which adopts the initial carrier signal, the total-harmonic-distortions of the SCR method is only 0.091%, lower than the traditional one's 18.38%, and the signal-to-noise-ratio increases 29 dB. Further, we derive the analytic expression of distortion component and verify it by experiments. Thistechnique may be potentially applied in a long distance large-scale distributed fiber-optic interferometer sensors array.

submitted time 2017-11-29 Hits1523Downloads861 Comment 0

4. chinaXiv:201703.00611 [pdf]

Multiple solutions in extracting physics information from experimental data

C. Z. Yuan; X. H. Mo; P. Wang
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

Multiple solutions exist in many experimental situations when several interfering amplitudes are summed to fit experimentally measured distributions, such as cross sections, mass spectra, and/or the angular distributions. We show a few examples where multiple solutions are found, but only one solution is reported in the publications. Since there is no standard rule for choosing one among the solutions as the physics one, we propose a simple rule that agrees with what has been adopted in previous literatures: the solution corresponding to the minimal magnitudes of the amplitudes must be the physical solution. We suggest test this rule in the future analyses.

submitted time 2017-03-26 Hits14337Downloads1363 Comment 0

5. chinaXiv:201703.00598 [pdf]

Measuring ψ″ → K0SK0L as a test of the S- and D-wave mixing of charmonia

P. Wang; X. H. Mo; C. Z. Yuan
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

Adding to the long standing “ρπ puzzle” in ψ′and J/ψ decays, recently BEijing Spectrometer (BES) reported B(ψ′→ K0SK0L) which is enhanced relative to the pQCD “12% rule” expectation from B(J/ψ → K0SK0L). If the enhancement is due to the mixing of the S- and D-wave charmonium states as in the ρπ case, the newly measured B(ψ′ → K0SK0L) gives a constraint on B(ψ″ → K0SK0L).It erves as a good test for the scenario of the S- and D-wave mixing in the ψ′and ψ″.

submitted time 2017-03-26 Hits1345Downloads767 Comment 0

6. chinaXiv:201703.00597 [pdf]

Measuring ψ″→ρπ in e+e? experiment

P. Wanga; C. Z. Yuan; X. H. Mo
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

In S- and D-wave mixing scheme, the branching ratio of ψ″→ρπ is estimated. Together with the continuum cross section of ρπ estimated by form factor, the observed cross section of ρπ production at ψ″ in e+e? experiment is calculated taking into account the interference effect between the resonance and continuum amplitudes and the initial state radiative correction. The behavior of the cross section reveals that the disappearance of ρπ signal just indicates the existence of the corresponding branching ratio Bψ″→ρπ at the order of 10?4.

submitted time 2017-03-26 Hits1331Downloads695 Comment 0

7. chinaXiv:201612.00466 [pdf]

Realistic Flipped SU(5) from Orbifold SO(10)

Balazs,C; Kang,Z; Li,T; Wang,F; Yang,JM
Subjects:

We propose a realistic flipped SU(5) model derived from a five-dimensional orbifold SO(10) model. The Standard Model (SM) fermion masses and mixings are explained by combining the traditional Froggatt-Nielsen mechanism with the five-dimensional wave funct

submitted time 2016-12-28 Hits2946Downloads1829 Comment 0

8. chinaXiv:201612.00457 [pdf]

Light Dark Matter from the U(1)XU(1)XU(1)_X Sector in the NMSSM with Gauge Mediation

Kang,Z; Li,T; Liu,T; Tong,C; Yang,JM
Subjects:

Cosmic ray anomalies observed by PAMELA and Fermi-LAT experiments may be interpreted by heavy (TeV-scale) dark matter annihilation enhanced by Sommerfeld effects mediated by a very light (sub-GeV) U(1)_X gauge boson, while the recent direct searches from

submitted time 2016-12-28 Hits1972Downloads1164 Comment 0

9. chinaXiv:201612.00415 [pdf]

SUSY induced top quark FCNC decay t→cht→cht \rightarrow { ch} after Run I of LHC

Cao,J; Han,C; Wu,L; Yang,JM; Zhang,M
Subjects:

In light of the Higgs discovery and the nonobservation of sparticles at the LHC, we revisit the supersymmetric theory (SUSY) induced top quark flavor-changing decay into the Higgs boson. We perform a scan over the relevant SUSY parameter space by consider

submitted time 2016-12-28 Hits2065Downloads1206 Comment 0

10. chinaXiv:201612.00397 [pdf]

Closing up a light stop window in natural SUSY at LHC

Kobakhidze,A; Liu,N; Wu,L; Yang,JM; Zhang,M
Subjects:

Top squark (stop) plays a key role in the radiative stability of the Higgs boson mass in supersymmetry (SUSY). In this work, we use the LHC Run-1 data to determine the lower mass limit of the right-handed stop in a natural SUSY scenario, where the higgsin

submitted time 2016-12-28 Hits1633Downloads922 Comment 0

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