A Numerical Study On The Indoor Thermal Environment Served By A Novel Air Source Heat Pump Powered Bed-Based Space Heating (ASHP-BBSH) System

A numerical study on the indoor thermal environment served a novel air source heat pump powered bed-based space radiation heating (ASHP-BBSH) system is reported in this paper. This novel system combines the merits from a Chinese Kang, or a heated bed, widely used in northern rural China and a standard ASHP system, which can provide localized space heating via both convection and radiation to maintain a comfortable indoor thermal environment, at reduced energy use. In this novel bed-based system, a bed is heated and thus used as a radiator for providing space heating at both daytime and nighttime. In this paper, firstly, a numerical model for a bedroom with a heated bed was firstly built and a manikin with simplified dimensions and physiological shape sitting on the heated bed has been added to the numerical model. Secondly, using the model, the relationships between indoor thermal environment and a number of influencing factors, including the bed surface temperature and heating area were numerically studied. Thirdly, a comparison between the novel system and a standard ASHP system was numerically conducted to demonstrate the advantages of the novel bed-based space heating system. The numerical results show that compared with a standard ASHP system, a better thermal comfort level and higher energy saving potential can be achieved by applying the ASHP-BBSH system. Necessary parameters for the system design and operation in the follow-up experimental work were provided

Learning-based superresolution land cover mapping

Super-resolution mapping (SRM) is a technique for generating a fine spatial resolution land cover map from coarse spatial resolution fraction images estimated by soft classification. The prior model used to describe the fine spatial resolution land cover pattern is a key issue in SRM. Here, a novel learning based SRM algorithm, whose prior model is learned from other available fine spatial resolution land cover maps, is proposed. The approach is based on the assumption that the spatial arrangement of the land cover components for mixed pixel patches with similar fractions is often similar. The proposed SRM algorithm produces a learning database that includes a large number of patch pairs for which there is a fine and coarse spatial resolution representation for the same area. From the learning database, patch pairs that have similar coarse spatial resolution patches as those in input fraction images are selected. Fine spatial resolution patches in these selected patch pairs are then used to estimate the latent fine spatial resolution land cover map, by solving an optimization problem. The approach is illustrated by comparison against state-of-the-art SRM methods using land cover map subsets generated from the USA’s National Land Cover Database. Results show that the proposed SRM algorithm better maintains the spatial pattern of land covers for a range of different landscapes. The proposed SRM algorithm has the highest overall accuracy and Kappa values in all these SRM algorithms, by using the entire maps in the accuracy assessment

Permanent disappearance and seasonal fluctuation of urban lake area in Wuhan, China monitored with long time series remotely sensed images from 1987 to 2016

Lakes are important to the healthy functioning of the urban ecosystem. The urban lakes in Wuhan, China, which is known as ‘city of hundreds of lakes’, are facing substantial threats mainly due to rapid urbanization. This paper focused on detecting the spatial and temporal change of urban lakes in Wuhan, using a long time series of Landsat and HJ-1A remotely sensed data from 1987 to 2016. The permanent disappearance and seasonal fluctuation of 28 main urban lakes were analysed, and their relationships with climatic change and human activities were discussed. The results show that most lakes in Wuhan had shrunk over the past 30 years resulting in a permanent change from water to land. The shrinkage was also most apparent in the central region of the city. Seasonal fluctuations of lake area were evident for most lakes but the relative important driving variable of lake area change varied between sub-periods of time for different lakes. The explanatory power of impervious surface to five-year permanent water change is 91.75%, suggesting that urbanization – as increasing impervious surface – had led to the shrinkage of urban lakes in Wuhan. In all, 128.28 km2 five-year permanent water disappeared from 1987 to 2016

Experimental study on the mechanisms of flow and sediment transport in a vegetated channel

Laboratory experiments were conducted in a flume with 3 types of artificial flexible submerged and emergent vegetation. Detailed velocity and sediment concentration in the channel were measured. The results show that submerged and emergent vegetation generates a much greater resistance to flow, and significantly alters the vertical distributions of velocity, especially in the vegetated and downstream regions. In comparison with the non-vegetated case, the turbulence kinetic energy and Reynolds stresses in the vegetated and downstream regions are much higher, indicating strong flow turbulence and momentum exchange in these areas. The high turbulence also results in a nearly constant fine suspended sediment concentration in the water column for all cases, while the increased resistance causes the coarser suspended sediment concentration to decrease. In addition, the sediment retention by the vegetation with small height is insignificant, but for the canopy with large height, the significant sediment deposition is found at the upstream region of the vegetated region

Simultaneous extraction and determination of alkaloids and organic acids in Uncariae Ramulas Cum Unicis by vortex-assisted matrix solid phase dispersion extraction coupled with UHPLC-MS/MS

A simple and efficient vortex-assisted matrix solid phase dispersion with a ultra-high-performance liquid chromatography-triple quadrupole mass spectrometer (VA-MSPD-UHPLC-MS/MS) was applied for simultaneous extraction and determination of seven alkaloids and three organic acids from Uncariae Ramulas Cum Unicis. The optimal extraction conditions of the target components were obtained by Box-Behnken design (BBD) combined with response surface methodology (RSM). The results of the method validation showed that this analytical method displayed good linearity with a correlation coefficient (r) no lower than 0.9990. The recoveries of ten active ingredients from Uncariae Ramulas Cum Unicis ranged from 95.9% to 103% (RSD ≤ 2.77%). The RSDs of intra-day and inter-day precisions were all below 2.97%. The present method exhibited not only lower solvent and sample usage, but also shorter sample processing and analysis time. Consequently, the developed VA-MSPD-UHPLC-MS/MS method could be successfully and effectively used for the extraction and analysis of ten active components from Uncariae Ramulas Cum Unicis

Pharmacokinetics, Bioavailability, and Tissue Distribution Study of Angoroside C and Its Metabolite Ferulic Acid in Rat Using UPLC-MS/MS

Angoroside C is a phenylpropanoid glycoside compound isolated from the dried root of Scrophularia ningpoensis Hemsl., which possesses the effects of preventing ventricular remodeling, reducing pulmonary oedema, and reducing blood pressure, as well as having the properties of anti-platelet aggregation, hepatoprotection and anti-nephritis, etc. However, few investigations have been conducted on the absorption, distribution, metabolism, and excretion (ADME) study of angoroside C. Thus, a fast ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) method was established for the determination of angoroside C and its metabolite ferulic acid in rat plasma and tissue homogenate. The two analytes were extracted from the biosamples using a simple protein precipitation with acetonitrile. The developed method was validated and successfully applied to the pharmacokinetics, bioavailability and tissue distribution study after the intragastric administration of angoroside C (100 mg/kg) or the intravenous administration of angoroside C (5 mg/kg), respectively. The results showed that angoroside C can be absorbed extremely quickly (Tmax = 15 min), can be eliminated very rapidly (t1/2 = 1.26 h), and its oral bioavailability is only about 2.1%. Furthermore, angoroside C was extensively distributed in all main organs (liver, heart, spleen, lung, kidney, and brain), and the highest concentration was detected in the lung 15 min after oral administration. This paper also indicated that angoroside C could be converted to the active metabolite ferulic acid in vivo. The maximum concentrations of ferulic acid in the kidney occurred at 6 h after oral administration. In summary, this study explored some of the pharmacokinetic characteristics of angoroside C in vivo, and the data produced could provide a basis for the further investigation of angoroside C

Evidence for a Monolayer Excitonic Insulator

The interplay between topology and correlations can generate a variety of unusual quantum phases, many of which remain to be explored. Recent advances have identified monolayer WTe2 as a promising material for exploring such interplay in a highly tunable fashion. The ground state of this two-dimensional (2D) crystal can be electrostatically tuned from a quantum spin Hall insulator (QSHI) to a superconductor. However, much remains unknown about the nature of these ground states, including the gap-opening mechanism of the insulating state. Here we report systematic studies of the insulating phase in WTe2 monolayer and uncover evidence supporting that the QSHI is also an excitonic insulator (EI). An EI, arising from the spontaneous formation of electron-hole bound states (excitons), is a largely unexplored quantum phase to date, especially when it is topological. Our experiments on high-quality transport devices reveal the presence of an intrinsic insulating state at the charge neutrality point (CNP) in clean samples. The state exhibits both a strong sensitivity to the electric displacement field and a Hall anomaly that are consistent with the excitonic pairing. We further confirm the correlated nature of this charge-neutral insulator by tunneling spectroscopy. Our results support the existence of an EI phase in the clean limit and rule out alternative scenarios of a band insulator or a localized insulator. These observations lay the foundation for understanding a new class of correlated insulators with nontrivial topology and identify monolayer WTe2 as a promising candidate for exploring quantum phases of ground-state excitons.Comment: 37 pages, 4 Main Figures + 15 SI Figur