203 research outputs found
Complex relationships between water discharge and sediment concentration across the Loess Plateau, China
Understanding of the relationship between water discharge (Q) and suspended sediment concentration (SSC) across the Loess Plateau is a prerequisite for evaluating different soil and water conservation measures. Using daily Q and SSC datasets, this study jointly analyzes changes in Q and SSC on the central Loess Plateau, a major sediment-producing area of China, during the periods 1971-1987 (P1) and 2008-2016 (P2). The results show that during both P1 and P2, the contributions of maximum-3-day-per-year sediment load (SSL) to the total SSL are almost invariably over 50% (dominant), with the majority increasing further between P1 and P2. The contribution of extreme high SSL events plays an overwhelming role in watersheds of area \u3c 10,000 km2, and appears almost independent of change in land cover condition. In the Helong section of the Yellow River, there is more evident reduction in SSC than Q between these two periods (streamflow becomes clearer), while the opposite occurred in the Jing River (streamflow lowers). In addition, the range of variation in SSC is large for small Q values, whereas the SSC for flood events tends to be relatively stable in gullied-hilly and flat-surfaced (Yuan) loess areas, which are major sediment producers. Based on scatter plots of SSC against Q after logarithmic transformation, we find that the lower boundary of the mapped data points for an individual station fits a straight line. This boundary relates to riverbed erosion. Given that soil erosion weakened on slopes over time and there is generally reduced streamflow in channels during P2, the boundary tends to move downward between P1 and P2 for most watersheds, reflecting the reduction in SSC for the same value of Q in P2 compared to P1
Bank Efficiency and Regional Economic Growth: Evidence from China
This paper examines for the first time the relationship between bank efficiency and regional economic growth in China with provincial data over 1995 - 2014. We find consistent and strong evidence that bank efficiency positively affects regional economic growth. Further, bank efficiency exerts a more pronounced impact on economic growth in inland provinces than coastal regions. The insignificant effect of the quantity of credit in our regressions suggests that a mere expansion of financial volume is not effective in promoting regional economic growth, whereas the improvement in the quality of financial intermediation plays an important role fostering provincial economic growth
[1,2-Bis(diphenylphosphino)ethane-κ2 P,P′](2-carboxylatothiophenolato-κ2 O,S)nickel(II) methanol solvate
In the title complex, [Ni(C7H4O2S)(C26H24P2)]·CH3OH, the nickel(II) centre adopts an approximately square-planar geometry, with the Ni atom coordinating to the S and O atoms of the bidentate thiosalicylate ligand and the two P atoms of the chelating Ph2PCH2CH2PPh2 ligand. There is hydrogen bonding between the methanol solvent molecule and the carbonyl O atom of the thiosalicylate ligand
Prevention of injury by resveratrol in a rat model of adenine-induced chronic kidney disease
Purpose: To investigate the preventive effect of resveratrol against renal pathological changes in a rat model of chronic kidney disease (CKD).Methods: CKD was induced by daily intragastric administration of adenine (200 mg/kg) for 1 month. The effect of 10, 15, and 20 mg/kg doses of resveratrol on the levels of parathyroid hormone, phosphorous, and fibroblast growth factor-23 (FGF-23) in rat urine samples after 2 months of adenine administration were analyzed using an auto-analyzer.Results: Resveratrol treatment significantly inhibited the adenine-mediated increase in serum parathyroid hormone, phosphorous and FGF-23 levels (p < 0.002). In rats treated with 10, 15 and 20 mg/kg doses of resveratrol after adenine, urine protein/creatinine ratio was reduced to 5, 675.6 ± 2453.7, 4, 789.8 ± 1,534.9, and 1, 965 ± 576.8 mg/g, respectively. In the untreated and normal control groups, the respective values were 7, 004 ± 1, 653.3 and 1, 627.5 ± 568.7 mg/g. Treatment with resveratrol after administration of adenine inhibited increases in creatinine, blood urea nitrogen, and uric acid levels in a dose-dependent manner (p < 0.002). Resveratrol treatment also inhibited adeninemediated increases in monocytes and inflammatory cells. Furthermore, resveratrol prevented renal tubule swelling and expansion induced by adenine administration.Conclusion: Resveratrol treatment prevent the renal pathological changes induced by adenine administration in a rat model of CKD by inhibiting FGF-23, parathyroid hormone, and phosphate. Thus, resveratrol may be of therapeutic importance for the treatment of CKD.Keyword: Parathyroid hormone, Phosphate, Creatinine, Monocytes, Chronic kidney disease, Fibroblast growth factor-2
Strong Photoluminescence Enhancement of MoS2 through Defect Engineering and Oxygen Bonding
We report on a strong photoluminescence (PL) enhancement of monolayer MoS2
through defect engineering and oxygen bonding. Micro- PL and Raman images
clearly reveal that the PL enhancement occurs at cracks/defects formed during
high temperature vacuum annealing. The PL enhancement at crack/defect sites
could be as high as thousands of times after considering the laser spot size.
The main reasons of such huge PL enhancement include: (1) the oxygen chemical
adsorption induced heavy p doping and the conversion from trion to exciton; (2)
the suppression of non-radiative recombination of excitons at defect sites as
verified by low temperature PL measurements. First principle calculations
reveal a strong binding energy of ~2.395 eV for oxygen molecule adsorbed on an
S vacancy of MoS2. The chemical adsorbed oxygen also provides a much more
effective charge transfer (0.997 electrons per O2) compared to physical
adsorbed oxygen on ideal MoS2 surface. We also demonstrate that the defect
engineering and oxygen bonding could be easily realized by oxygen plasma
irradiation. X-ray photoelectron spectroscopy further confirms the formation of
Mo-O bonding. Our results provide a new route for modulating the optical
properties of two dimensional semiconductors. The strong and stable PL from
defects sites of MoS2 may have promising applications in optoelectronic
devices.Comment: 23 pages, 9 figures, to appear in ACS Nan
1,3-Bis(carboxymethyl)imidazolium triiodide 1-carboxylatomethyl-3-carboxymethylimidazolium
In the title compound, C7H9N2O4
+·I3
−·C7H8N2O4, the two imidazolium units are hydrogen bonded through the carboxyl groups. The units are further linked via intermolecular O—H⋯O hydrogen bonding, resulting in a one-dimensional ladder-type structure. As a result, the two carboxy groups of each imidazolium unit adopt a cis configuration with respect to the imidazolium ring
Normal Red Blood Cell Count Reference Values in Chinese Presenile Women Given by Geographical Area
Background/PurposeWe aimed to standardize the normal reference value of red blood cell (RBC) counts in Chinese presenile women using an underlying scientific basis.MethodsThis research was conducted to study the relationship between the normal reference value of 31,405 RBC samples from presenile women in eight different geographical areas in China. RBC counts were determined using a microscopic counting method.ResultsThere was a significant correlation between geographical factors and the normal reference RBC value in presenile women (F = 187.82, p = 0.000). Using stepwise regression analysis, one regression equation was obtained.ConclusionIf geographical values are obtained in a certain area, the normal RBC reference value in presenile women in this area can be obtained using the regression equation
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