294 research outputs found
R32 Compressor for Air conditioning and Refrigeration applications in China
No full textThis paper evaluates the compressor performance and reliability impact by using R32 refrigerant for air conditioning (residential and commercial system); Performance and reliability impacts are compared with different popular refrigerants used in China, for example, R410A & R22 for AC. The design improvement on the scroll compressor will be discussed in order to reach required efficiency and reliability; these improvements include lubrication, internal heat management, motor design, and vapor injection technologies, etc
An experimental study on the lateral pile–soil interaction of offshore tetrapod piled jacket foundations in sand
No full textRecently, tetrapod piled jacket (TPJ) foundations have shown considerable promise in offshore developments, due to the increases in power capacity and water depth for offshore wind turbines. This paper presents a set of centrifuge tests to look into the lateral loading behaviour of TPJ foundations in sand, with the overall load–displacement responses of the foundation as well as the soil resistance and internal forces on or within individual piles being examined carefully. Test results show that the back-row piles are more likely to be pulled out when the TPJ foundation is loaded laterally along the diagonal direction compared to when loaded along the orthogonal direction. The lateral soil resistance per unit length on the back-row pile(s) is approximately 60% of that on the front-row one(s) in the orthogonal loading case, and only about 40% in the diagonal loading case. Moreover, although the TPJ foundation is in its form a special case of pile groups, it is highlighted in the present study that the former case exhibits distinct loading behaviour from the latter case due to the typically large overturning moment encountered by the foundations for offshore wind turbines. Finally, the p-multipliers of the piles are demonstrated to be dependent on pile deflections, but independent on soil depths, and as a result, a modified pm model is proposed to provide guidance for the design of TPJ foundations in sand.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Nucleation-Mediated Aluminum Deposition/Stripping for Long-Life Molten Salt Aluminum Batteries
No full textMolten salt aluminum batteries (MSABs) hold significant promise for grid-scale energy storage due to the low cost and high capacity of the aluminum anode. However, an aluminum dendrite stemming from nonuniform electrodeposition leads to safety and stability issues. Here, we describe a membrane electrode with predeposited aluminum metal featuring surface-mediated nucleation and growth behavior for operation in alkali chloroaluminate melt electrolytes. The introduction of TiN, as aluminophilic sites, facilitates the initial growth of aluminum on TiN by forming Al-N bonding, thereby enabling uniform aluminum nucleation and mediated growth along the TiN/C fiber, resulting in reversible and dendrite-free aluminum plating/stripping. The TiN/C@Al electrode enables symmetric cells to maintain stable cycling for over 850 h (10.0 mA cm-2; 5.0 mA h cm-2) and shows high rate performance at up to 30.0 mA cm-2. The Al-graphite cell using a TiN/C@Al anode demonstrates long-term stability over 7000 cycles at 2.0 A g-1 and enhanced rate capability with 72.2 mA h g-1 even at 5.0 A g-1. To validate practical scalability, we designed an Ah-level TiN/C@Al-based molten salt Al-graphite pouch cell. This approach offers a scalable pathway for overcoming the limitations of state-of-the-art anodes in MSABs, enabling high-performance and cost-effective energy storage solutions.This work was supported by the National Natural Science Foundation of China (NSFC, 92372115) and the Beijing Natural Science Foundation (NoZ220020). We also acknowledge the support from the National Natural Science Foundation of China (NSFC, grant no. 22075002) and the China Postdoctoral Science Foundation (grant no. 8206300678). We also acknowledge the support from the China National Petroleum Corporation-Peking University Strategic Cooperation Project of Fundamental Research and the Red Avenue Postdoctoral Program in the School of Materials Science and Engineering of Peking University. We also acknowledge the Materials Processing and Analysis Center of Peking University for instrument use
Ductoagathoxylon Jimsarensis gen. nov. et sp. nov., A Gymnospermous Stem from the Wuchiapingian (Upper Permian) Wutonggou Formation in the Junggar Basin, Northern Bogda Mountains, Northwestern China
No full textA silicified stem, Ductoagathoxylon jimsarensis Wan, Yang, Liu et Wang gen. nov. et sp. nov., is described from the Wuchiapingian (late Permian) Wutonggou Formation from the Dalongkou section, Jimsar County, Xinjiang Uygur Autonomous Region, northwestern China. It is composed of a pith, and primary and secondary xylem. The stem is characterized by a solid, heterocelluar pith with grouped secretory ducts and cells, an end- to mesarch primary xylem, and an Agathoxylon-type secondary xylem. Based on the Agathoxylon-type secondary xylem and the occurrence of secretory ducts and cells in the pith, it is suggested that Ductoagathoxylon is of a coniferous affinity. It provides additional evidence for the biodiversity of the Wuchiapingian Subangaran flora in northwestern China. Growth rings and false rings in D. jimsarensis and other previously reported fossil woods from the Wutonggou Formation in the Junggar Basin indicate both seasonal and intra-seasonal growth variations caused by environmental stress and precipitation seasonality. The fossil stem records suggest varying climatic and environmental conditions between the Dalongkou section in the northern Bogda Mountains and the Tarlong-Taodonggou sections, about 70 km to the south, in the southern Bogda Mountains during the Wuchiapingian
Effectiveness of CT radiomic features combined with clinical factors in predicting prognosis in patients with limited-stage small cell lung cancer
No full textAbstract
Background
The prognosis of SCLC is poor and difficult to predict. The aim of this study was to explore whether a model based on radiomics and clinical features could predict the prognosis of patients with limited-stage small cell lung cancer (LS-SCLC).
Methods
Simulated positioning CT images and clinical features were retrospectively collected from 200 patients with histological diagnosis of LS-SCLC admitted between 2013 and 2021, which were randomly divided into the training (n = 140) and testing (n = 60) groups. Radiomics features were extracted from simulated positioning CT images, and the t-test and the least absolute shrinkage and selection operator (LASSO) were used to screen radiomics features. We then constructed radiomic score (RadScore) based on the filtered radiomics features. Clinical factors were analyzed using the Kaplan–Meier method. The Cox proportional hazards model was used for further analyses of possible prognostic features and clinical factors to build three models including a radiomic model, a clinical model, and a combined model including clinical factors and RadScore. When a model has prognostic predictive value (AUC > 0.7) in both train and test groups, a nomogram will be created. The performance of three models was evaluated using area under the receiver operating characteristic curve (AUC) and Kaplan–Meier analysis.
Results
A total of 1037 features were extracted from simulated positioning CT images which were contrast enhanced CT of the chest. The combined model showed the best prediction, with very poor AUC for the radiomic model and the clinical model. The combined model of OS included 4 clinical features and RadScore, with AUCs of 0.71 and 0.70 in the training and test groups. The combined model of PFS included 4 clinical features and RadScore, with AUCs of 0.72 and 0.71 in the training and test groups. T stages, ProGRP and smoke status were the independent variables for OS in the combined model, whereas T stages, ProGRP and prophylactic cranial irradiation (PCI) were the independent factors for PFS. There was a statistically significant difference between the low- and high-risk groups in the combined model of OS (training group, p‚Äâ<‚Äâ0.0001; testing group, p‚Äâ=‚Äâ0.0269) and PFS (training group, p‚Äâ<‚Äâ0.0001; testing group, p‚Äâ<‚Äâ0.0001).
Conclusion
Combined models involved RadScore and clinical factors can predict prognosis in LS-SCLC and show better performance than individual radiomics and clinical models.
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Part-Whole Relational Few-Shot 3D Point Cloud Semantic Segmentation
No full textThe author wishes to extend sincere appreciation to Professor Lin Shi for the generous provision of equipment support, which significantly aided in the successful completion of this research. Furthermore, the author expresses gratitude to Associate Professor Ning Li and Teacher Wei Guan for their invaluable academic guidance and unwavering support. Their expertise and advice played a crucial role in shaping the direction and quality of this research.Peer reviewe
Medulloprotaxodioxylon Triassicum gen. nov. et sp. nov., A Taxodiaceous Conifer Wood from the Norian (Triassic) of Northern Bogda Mountains, Northwestern China
No full textA permineralized coniferous wood, Medulloprotaxodioxylon triassicum Wan, Yang, Tang, Liu et Wang gen. et sp. nov., is described from the Norian (Late Triassic) Huangshanjie Formation in the Dalongkou Section, Jimsar County, Xinjiang Uygur Autonomous Region, northwestern China. The fossil wood is composed of the pith, primary and secondary xylem. The pith is solid, circular, heterocellular, with numerous isolated or clustered secretory cells, and parenchyma. Secretory cells commonly form a network in a radial view. The pith is surrounded by numerous primary xylem strands and about 22 distinctive leaf traces. The primary xylem is endarch. Tracheids of primary xylem have helical and scalariform thickenings. The secondary xylem is pycnoxylic, composed of tracheids, rays and axial parenchyma. The general aspect of the tracheids and rays, presence of taxodioid cross-field pits, and abundant axial parenchyma, indicate M. triassicum can be related to the taxodiaceous Cupressaceae sensu lato. By comparison with fossil and extant species of the Cupressaceae, M. triassicum is most comparable to Sequoiadendron giganteum (Lindley) Buchholz. It is hypothesized that M. triassicum represents an ancestral form of the Sequoioideae Saxton based on the anatomical characteristics of the pith and secondary xylem. The occurrence of M. triassicum would indicate that the taxodiaceous conifers had already individualized within the Cupressaceae during the Late Triassic
Study on the Influence of Downstream Slope Ratio on Seismic Response of Concrete Faced Rockfill Dam
No full textApplication of comprehensive water-saving irrigation development level model based on FCE in a regional area
No full textResearch of Controlled polarization light splitting technology based on the liquid crystal light modulator
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