As a type of novel material, open-cell copper (Cu) foam has been widely applied in electrode production of batteries, due to its functional and structural properties. The use of ultrasonic welding technique to join Cu foam and aluminium (Al) plate has been proven to be feasible, but quality evaluation of the joints remains a blank to be filled in. In this study, orthogonal test design is used to investigate the effects of welding pressure, welding amplitude, welding energy and the interaction among the three parameters on the shear-tensile strength of ultrasonically welded joints of Cu foam/Al plate, and it is influenced by the three parameters in the following order: welding pressure > welding energy > welding amplitude. Based on the results of the orthogonal test, a Cu foam/Al plate ultrasonic welding joint evaluation system is established, based on which, qualitative and quantitative analysis on the quality of the joints classified the joints into three grades. The optimal parameter combination of the welding joint of Cu foam/Al plate is obtained as follows: 0.5 MPa, 65%, 130 J, under which the porous structure of the joint is complete while its tensile strength is equal to or even better than the base material.
This dataset is the supporting data and code for the article "Environmental conditions are the dominant factor to influence stability of terrestrial ecosystems on the Tibetan plateau". unprocessed data.xlsx is all the data supporting this study, provided in different sheets by type. Sheet1 has a description of the original dataset. stability.csv is the supporting data used to complete all analyses in the main text, which has been organized into a format that can be analyzed directly using the R code provided. analysis.R is the R code that completes the main analysis of the paper;
The leaf economics spectrum (LES) is the leading theory of plant ecological strategies based on functional traits, which explains the trade-off between dry matter investment in leaf structure and the potential rate of resource return, revealing general patterns of leaf economic traits investment for different plant growth types, functional types, or biomes. Prior work has revealed the moderating role of different environmental factors on the LES, but whether the leaf trait bivariate relationships are shifted across climate regions or across continental scales requires further verification. Here we use the Köppen–Geiger climate classification, a very widely used and robust criterion, as a basis for classifying climate regions to explore climatic differences in leaf trait relationships. We compiled five leaf economic traits from a global dataset, including leaf dry matter content (LDMC), specific leaf area (SLA), photosynthesis per unit of leaf dry mass (A mass ), leaf nitrogen concentration (N mass ), and leaf phosphorus concentration (P mass ). Moreover, we primarily used the standardized major axis (SMA) analysis to establish leaf trait bivariate relationships and to explore differences in trait relationships across climate regions as well as intercontinental differences within the same climate type. Leaf trait relationships were significantly correlated across almost all subgroups ( P < 0.001). However, there was no common slope among different climate zones or climate types and the slopes of the groups fluctuated sharply up and down from the global estimates. The range of variation in the SMA slope of each leaf relationship was as follows: LDMC–SLA relationships (from −0.84 to −0.41); A mass –SLA relationships (from 0.83 to 1.97); A mass –N mass relationships (from 1.33 to 2.25); N mass –P mass relationships (from 0.57 to 1.02). In addition, there was significant slope heterogeneity among continents within the Steppe climate (BS) or the Temperate humid climate (Cf). The shifts of leaf trait relationships in different climate regions provide evidence for environmentally driven differential plant investment in leaf economic traits. Understanding these differences helps to better calibrate various plant-climate models and reminds us that smaller-scale studies may need to be carefully compared with global studies.
Ultra-short term wind speed forecast for wind farm is of great significance to the real-time scheduling of wind power system. In this paper, NWP (Numerical Weather Prediction) wind speed time series and measured wind speed time series were decomposed into different bands by wavelet multi-resolution analysis. Pearson product-moment correlation coefficient was used to verify the correction premise. Then the linear correction method was used to correct the low frequency stationary NWP wind speed. To test the approach, the data from Yilan wind farm of Heilongjiang province were used. The results show that when a strong correlation exists in the system deviation of training periods and testing periods, the prediction accuracy of ultra-short term wind speed will be significantly improved.
A 'ggplot2' extension for visualizing China's map, offering customizable projections, boundary styles, and buffer zones for thematic maps. Suitable for spatial data analysis and enhancing map visualization with flexible styling options.
This Conference Presentation, “β-Sn-based plasmonic materials and their near-field enhancement performance” was recorded for Photonics Asia 2021, held in Nantong, China.
The bit error (BER) performance of CDMA in a frequency-selective fading channel can be significantly improved by the use of frequency-domain equalization (FDE). There are three methods can be used to implement FDE in CDMA uplink [I. Martoyo et al., 2003]: the cyclic prefix [K.L. Baum et al., 2002], the zero padding and the overlap-cut (OC). However, the first two methods not only yield lower bandwidth efficiency, but also create higher latency, so the OC is the better choice. In this case, we don't have to modify the structure of the frame. This is very important and useful for applications in which the frame structure is predefined. Thus, this paper proposes an approach to use the improved overlap-cut (IOC) method and parallel interference cancellation (PIC) architecture integrate with frequency domain decision feedback equalization (FD-DFE).
A series of numerical simulations have been carried out to investigate the ECC water injection in Hualong NO.1 with a Direct Vessel Injection (DVI) system during a Large Break Loss-of-Coolant Accident (LBLOCA) using RELAP5 code. Some parametric studies are performed to investigate the effect of the DVI nozzle elevation and the location of the broken cold leg. The results showed that the filling rate in the lower plenum is the highest at the elevation of 300 mm below the centerline of the cold leg. Comparing the result at the elevation of 200 mm below and above the centerline of the cold leg, it can be derived that the ECC water film is wider at a higher elevation resulting in a larger filling rate. And by considering the filling rate with different location of the broken cold leg at a given DVI nozzle elevation, the major findings show that a larger distance between the break and the DVI nozzle leads to a lower bypass fraction and a larger filling rate in the lower plenum. Also, the comparison of the ECC water injection mode and condensation effect are performed.
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