摘要：Homogeneous redox mediation is efficient in alleviating the shuttling effect and slow redox kinetics of lithium polysulfides in lithium-sulfur ***,their perfect performance is not fulfilled owning to the fact that the multi-step transformation of lithium polysulfides requests the multifunctional active positions for the tandem *** on the redox comediation principles,a promoter of mixing organodiselenide and organoditelluride(mixed-Se/Te)was raised to induce tandem catalysis and boost the effective electrochemical conversion of lithium *** specifically,diphenyl diselenide facilitated the liquid-liquid and solid-liquid transformation between lithium polysulfides and sulfur,while diphenyl ditelluride improved the solid-liquid transformation concerning lithium sulfide ***,even under high sulfur loading of 6.5 mg cm^(−2) and low electrolyte/sulfur ratio of 5.88μL mg^(−1),the 10 mM low concentration mixed-Se/Te promoter offered a high discharge capacity of 6.6 mAh cm^(−2) and high rate performance of 4.1 mAh cm^(−2) at 0.5 ***,the assembled 1.5 Ah-level lithium-sulfur pouch cells provide an energy density of 332 Wh kg^(−1) at 0.05 C and good cycling *** research demonstrates the applicability of propelling continuous sulfur conversion reactions with detached active positions and is anticipated to stimulate deep molecular design of kinetic promoter to targeted energy-associated redox reactions.

摘要：Evapotranspiration(ET)is of great significance for the ecological environment and water resource utilization in arid and semi-arid *** Mongolian Plateau,owing to drought,low rainfall,and extremely uneven distribution of water resources,has a typical temperate continental climate.A refined understanding of the spatiotemporal distribution of ET in this region will help in establishing regulatory strategies for climate change responses,regional livestock regulation,and grassland degradation *** this study,meteorological station data,precipitation data,and the Penman-Monteith model were used to study the temporal and spatial distribution characteristics of actual ET over the Mongolian Plateau from 2011 to *** found that:(1)The spatial distribution of ET in the Mongolian Plateau showed a high trend in the north and east and a low trend in the middle and *** was a significant difference in the regional annual ET,with the highest ET reaching over 500 mm and the lowest being only approximately 70 mm.(2)The annual ET values in 2013,2018,and 2019 were relatively large,varying between 80 and 500 mm,and the overall ET of the Mongolian Plateau first decreased,then increased,and then decreased.(3)The temporal distribution exhibits a unimodal trend of increasing and then decreasing,with July being the turning ***-September was a period of high ET,with the highest ET exceeding 100 *** vegetation coverage was high,precipitation was abundant,and the vegetation ET effect was *** was a period of low ET,with a maximum ET of approximately 10 mm in January and december;the ET for the month with the lowest value was approximately *** quantitative inversion method proposed in this study can provide method and data support for north and central Asia,and other large arid and semi-arid areas.

摘要：We develop a data driven method(probability model) to construct a composite shape descriptor by combining a pair of scale-based shape descriptors. The selection of a pair of scale-based shape descriptors is modeled as the computation of the union of two events, i.e.,retrieving similar shapes by using a single scale-based shape descriptor. The pair of scale-based shape descriptors with the highest probability forms the composite shape descriptor. Given a shape database, the composite shape descriptors for the shapes constitute a planar point set.A Vor-Tree of the planar point set is then used as an indexing structure for efficient query operation. Experiments and comparisons show the effectiveness and efficiency of the proposed composite shape descriptor.

摘要：In order to investigate the effects of pockets in the porthole die on the metal flow,temperature at the die bearing exit and the extrusion load were contrasted with the traditional die design without the pockets in the lower *** different multi-hole porthole dies with and without pockets in lower die were *** the extrusion process was simulated based on the commercial software *** simulation results show that the pockets could be used to effectively adjust the metal flow and especially benefit to the metal flow under the *** addition,the maximum temperature at the die bearing and the peak extrusion load decrease,which indicates the possibility of increasing the extrusion speed and productivity.

摘要：An adjustable ejector expansion device for a CO2 heat pump water heater (HPWP) is proposed to improve the system performance. It has been designed to investigate experimentally the effects of the motive nozzle throat area of the ejector, entrained flow pressure, back pressure and primary flow pressure on the entrainment ratio. Experiments based on different motive nozzle throat areas were conducted and the results of the prototype ejector using CO2 as working fluid are presented. The results show that an adjustable ejector can achieve high performance and work well in a wide range of working conditions.

摘要：Background:It is not completely clear whether a very high pre-therapy viral load(≥500000 copies/ml)can impair the virological *** aim of this study was to examine the influence of very high baseline HIV-rNA levels on long-term virological responses under one type of ***:A retrospective study was performed based on data from two multicenter cohorts in China from January to November 2009,and from May 2013 to december *** HIV infected adults between 18 and 65 years old were recruited before receiving non-nucleoside reverse transcriptase inhibitor-based *** patients had baseline HIV-rNA levels over 500 copies/ml,good adherence,and were followed for at least 24 *** suppression was defined as the first HIV-rNA<50 copies/*** failure was defined as any of incomplete viral suppression(HIV-rNA≥200 copies/ml without virological suppression within 24 weeks of treatment)and viral rebound(confirmed HIV-rNA level≥50 copies/ml after virological suppression).Chi-square test,Kaplan–Meier analysis,Cox proportional hazards model and Logistic regression were used to compare virological response between each pretreated viral load ***:A total of 758 treatment-naïve HIV patients in China were *** follow-up time(IQr)was 144(108–276)*** week 48,rates of virological suppression in three groups(<100000,100000–500000 and≥500000 copies/ml)were 94.1,85.0,and 63.8%,respectively(P<0.001).Very high baseline HIV viremia over 500000 copies/ml were found to be associated with delayed virological suppression(≥500000 vs<100000,adjusted relative hazard=0.455,95%CI:0.32–0.65;P<0.001)as well as incomplete viral suppression(≥500000 vs<100000,adjusted odds ratio[aOr]=6.084,95%CI:2.761–13.407;P<0.001)and viral rebound(≥50000 vs<100000,aOr=3.671,95%CI:1.009–13.355,P=0.048).Conclusions:Very high levels of pre-treatment HIV-rNA were related with delayed efficacy of NNrTI-based ArT and increased risk of treatment failure.

摘要：To solve the problem of slow leaching speed of copper,surfactant was added into lixivium as leaching agent in the *** on physical chemistry and seepage flow mechanics,the leaching mechanics of surfactant was *** solution surface tension and surfactant adsorbing on the surface of ore have a significant impact on the surface wetting *** leaching rate for response,the study screened out three main factors by Plackett-Burman design method:the sulfuric acid concentration,surfactant concentration and *** these three factors,the surfactant concentration is the most important contributor to leaching *** obtaining the experiment center by the steepest ascent experiment,a continuous variable surface model was built by response surface *** solving quadratic polynomial equation,optimal conditions for leaching were finally obtained as follows:the sulfuric acid concentration was 60 g/L,the surfactant concentration was 0.00914 mol/L,and the temperature was 45 °*** leaching rate was 66.81% in the optimized leaching conditions,which was close to the predicted value,showing that regression result was good.

摘要：Heart diseases remain the top threat to human health,and the treatment of heart diseases changes with each passing *** evidence shows that three-dimensional(3d)printing allows for a more precise understanding of the complex anatomy associated with various heart *** addition,3d-printed models of cardiac diseases may serve as effective educational tools and for hands-on simulation of surgical *** introduce examples of the clinical applications of different types of 3d printing based on specific cases and clinical application scenarios of 3d printing in treating heart *** also discuss the limitations and clinically unmet needs of 3d printing in this context.

摘要：In recent years, solar desalination and water evaporation/purification with various artificial architectures have drawn significant attention. Herein, we introduce a rational design structure for efficient solar water evaporation and purification, focusing on the balance between water transportation and thermal *** wood after a simple flame treatment on the surface was utilized as the solar absorber, with a high solar absorbance(~90 %), good hydrophilicity, and excellent heat localization abilities. Besides,a thermal insulator(polystyrene foam) was used to further reduce the thermal loss, and the optimized ratio between the water path and thermal insulator was obtained. A set of floating foam-flamed-wood(F-F-wood) devices were fabricated with a high evaporation rate of 3.92 kgm-2 h-1, exhibiting photothermal purification abilities from seawater and wastewater containing organic dyes and heavy metals. This study sheds light on the rational design of scalable and low-cost devices for solar water evaporation and purification.

摘要：A new fabrication technology for three-dimensionally buried silica on silicon optical waveguide based on deep etching and thermal oxidation is presented. Using this method, a silicon layer is left at the side of waveguide. The stress distribution and effective refractive index are calculated by using finite element method and finite different beam propagation method, respectively. The results indicate that the stress of silica on silicon optical waveguide fabricated by this method can be matched in parallel and vertical directions and stress birefringence can be effectively reduced due to the side-silicon layer.