30 research outputs found
Poly[octaaquadi-μ-phosphato-trinickel(II)]. Corrigendum
Corrigendum to Acta Cryst. (2008), E64, m259
Poly[octaaquadi-μ-phosphato-trinickel(II)]
In the title compound, [Ni3(PO4)2(H2O)8]n, which was synthesized hydrothermally, all the Ni atoms are located in slightly distorted octahedral coordination environments. Two phosphate groups and two Ni atoms share a centrosymmetric four-membered ring and an eight-membered ring such that the four-membered ring is inside the eight-membered ring. The eight-membered rings are connected with the other Ni atoms (lying on centres of symmetry) through phosphate anions, generating a one-dimensional chain structure. Adjacent chains are connected through hydrogen bonds, forming a three-dimensional network
Association of Diurnal Rainfall in Northeastern Tibetan Plateau with the Retreat of the South Asian High
The characteristics of intense diurnal precipitation occurring beneath the South Asian High (SAH) are diagnosed in the summer monsoon season from 2010 to 2015 using observational data. The diagnostics indicate that summer nighttime rainfall events in the northeastern Tibetan Plateau can intensify towards the end of the monsoon period. By defining a transition index to identify the transition day during which the episodes of diurnal convection start to decline, daily thermodynamic properties and precipitation from each year were composited before and after the transition date. The analysis reveals that warmer air, increased moisture, and stronger upward velocity are present in the atmosphere before the transition day, potentially elevating nighttime convective precipitation. Enhanced upward velocity that is present through the two months prior to transition date coincides with the timing of the peak SAH, while weakened upward velocity afterwards coincides with its subsequent retreat. The large-scale lift due to terrain-ambient air interaction underneath the SAH and the increased moisture content can enhance the potential for diurnal convection, which lends support to the nighttime peak of rainfall. This feature persists until the transition date, after which the SAH starts to retreat
Empagliflozin rescues pro-arrhythmic and Ca 2+ homeostatic effects of transverse aortic constriction in intact murine hearts
We explored physiological effects of the sodium-glucose co-transporter-2 inhibitor empagliflozin on intact experimentally hypertrophic murine hearts following transverse aortic constriction (TAC). Postoperative drug (2–6 weeks) challenge resulted in reduced late Na+ currents, and increased phosphorylated (p-)CaMK-II and Nav1.5 but not total (t)-CaMK-II, and Na+/Ca2+ exchanger expression, confirming previous cardiomyocyte-level reports. It rescued TAC-induced reductions in echocardiographic ejection fraction and fractional shortening, and diastolic anterior and posterior wall thickening. Dual voltage- and Ca2+-optical mapping of Langendorff-perfused hearts demonstrated that empagliflozin rescued TAC-induced increases in action potential durations at 80% recovery (APD80), Ca2+ transient peak signals and durations at 80% recovery (CaTD80), times to peak Ca2+ (TTP100) and Ca2+ decay constants (Decay30–90) during regular 10-Hz stimulation, and Ca2+ transient alternans with shortening cycle length. Isoproterenol shortened APD80 in sham-operated and TAC-only hearts, shortening CaTD80 and Decay30–90 but sparing TTP100 and Ca2+ transient alternans in all groups. All groups showed similar APD80, and TAC-only hearts showed greater CaTD80, heterogeneities following isoproterenol challenge. Empagliflozin abolished or reduced ventricular tachycardia and premature ventricular contractions and associated re-entrant conduction patterns, in isoproterenol-challenged TAC-operated hearts following successive burst pacing episodes. Empagliflozin thus rescues TAC-induced ventricular hypertrophy and systolic functional, Ca2+ homeostatic, and pro-arrhythmogenic changes in intact hearts
Development of Temperature Calibration Device for Microwave Digestion System in Biochemical Laboratory
As a sample pretreatment device, microwave digestion instrument is widely used in biochemical laboratories. The temperature parameters of the microwave digestion instrument directly decide the accuracy of the experimental results. At present, there is no relevant calibration specification,method or device for microwave digestion system in China. Due to the special working principle of the microwave digestion instrument, the calibration device must be used in the high temperature microwave environment, and the ordinary temperature measuring device will cause ignition, explosion and other phenomena, which will endanger the life and health of the calibration personnel. This article presents a set of calibration device for microwave digestion system, with measuring range of (0~200) °C, accuracy of no less than ± 0.1 °C, and resolution of 0.01 °C. The presented device also solves the potential problems of ignition and explosion, which commonly exist in ordinary temperature measuring devices
Development of Temperature Calibration Device for Microwave Digestion System in Biochemical Laboratory
As a sample pretreatment device, microwave digestion instrument is widely used in biochemical laboratories. The temperature parameters of the microwave digestion instrument directly decide the accuracy of the experimental results. At present, there is no relevant calibration specification,method or device for microwave digestion system in China. Due to the special working principle of the microwave digestion instrument, the calibration device must be used in the high temperature microwave environment, and the ordinary temperature measuring device will cause ignition, explosion and other phenomena, which will endanger the life and health of the calibration personnel. This article presents a set of calibration device for microwave digestion system, with measuring range of (0~200) °C, accuracy of no less than ± 0.1 °C, and resolution of 0.01 °C. The presented device also solves the potential problems of ignition and explosion, which commonly exist in ordinary temperature measuring devices
An Air-to-Soil Transition Model for Discrete Scattering-Emission Modelling at L-Band
Topsoil structures and inhomogeneous distribution of moisture in the soil volume will induce dielectric discontinuities from air to bulk soil, which in turn may induce multiple and volume scattering and affect the microwave surface emission. In situ ELBARA-III L-band radiometer observations of brightness temperature TBp (p =H or V polarization) at the Maqu site on the Eastern Tibetan Plateau are exploited to understand the effect of surface roughness on coherent and incoherent emission processes. Assisted with in situ soil moisture (SM) and temperature profile measurements, this study develops an air-to-soil transition (ATS) model that incorporates the dielectric roughness (i.e., resulted from fine-scale topsoil structures and the soil volume) characterized by SM and geometric roughness effects, and demonstrates the necessity of the ATS model for modelling L-band TBp. The Wilheit (1978) coherent and Lv et al. (2014) incoherent models are compared for determining the dielectric constant of bulk soil in the ATS zone and for calculating soil effective temperature Teff. The Tor Vergata discrete scattering model (TVG) integrated with the advanced integral equation model (AIEM) is used as the baseline model configuration for simulating L-band TBp. Whereafter, the ATS model is integrated with the foregoing model for assessing its performance. Results show the ATS-based models reduce the underestimation of TBp (≈20-50 K) by the baseline simulations. Being dynamic in nature, the proposed dielectric roughness parameterization in the ATS model significantly improves the ability in interpreting TBp dynamics, which is important for improving SM retrieval at the global scale
An Assessment of the Coupled Weather Research and Forecasting Hydrological Model on Streamflow Simulations over the Source Region of the Yellow River
The Source Region of the Yellow River (SRYR), renowned as the “Water Tower of the Yellow River”, serves as an important water conservation domain in the upper reaches of the Yellow River, significantly influencing water resources within the basin. Based on the Weather Research and Forecasting (WRF) Model Hydrological modeling system (WRF-Hydro), the key variables of the atmosphere–land–hydrology coupling processes over the SRYR during the 2013 rainy season are analyzed. The investigation involves a comparative analysis between the coupled WRF-Hydro and the standalone WRF simulations, focusing on the hydrological response to the atmosphere. The results reveal the WRF-Hydro model’s proficiency in depicting streamflow variations over the SRYR, yielding Nash Efficiency Coefficient (NSE) values of 0.44 and 0.61 during the calibration and validation periods, respectively. Compared to the standalone WRF simulations, the coupled WRF-Hydro model demonstrates enhanced performance in soil heat flux simulations, reducing the Root Mean Square Error (RMSE) of surface soil temperature by 0.96 K and of soil moisture by 0.01 m3/m3. Furthermore, the coupled model adeptly captures the streamflow variation characteristics with an NSE of 0.33. This underscores the significant potential of the coupled WRF-Hydro model for describing atmosphere–land–hydrology coupling processes in regions characterized by cold climates and intricate topography
Nanostructured conjugated ladder polymers for stable and fast lithium storage anodes with high-capacity
N anoparticles of n-type conjugated ladder polymer poly(benzobisimidazobenzophenanthroline) (BBL) and its analogue (SBBL) are prepared through a reprecipitation method. The ladder polymers are tested as anode materials for lithium-ion batteries for the first time. They exhibit high capacity, good rate performance, and excellent cycle life, especially at high temperature of 50 °C