16 research outputs found

    Cyclic axial compressive performance of hybrid double-skin tubular square columns

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    This paper presents an experimental study on the cyclic axial compressive behavior of FRP-concrete-steel hybrid double-skin tubular columns. The square column specimens were cast with an external Fiber Reinforced Polymer jackets, inner steel tube and concrete in between. The height of the columns was 500 mm and the side dimension was 150 mm. The effects of loading scheme, void ratio and diameter-thickness ratio on axial compression behavior were investigated. A total of eight columns were tested under monotonic and cyclic axial compression. The experimental results show that the effect of loading scheme on axial stress-strain envelope curve and the peak load were not significant, and the ultimate state of the square columns subjected to cyclic axial compression was very similar to that of specimens subjected to monotonic axial compression. Besides, compared with void ratio, the diameter-thickness ratio of the inner steel tube has significant influence on the peak load of the columns when subjected to cyclic axial compression

    Phosphotungstic acid intercalated Zn,Al-layered double hydroxides/ nanocellulose based 3D lightweight foam thermal insulation materials

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    In this study, [PW _12 O _40 ] ^3− anions have been intercalated into Zn,Al-Layered Double Hydroxides(ZnAl-NO _3 -LDHs) to synthesize ZnAl-PW _12 O _40 -LDHs by ion-exchange reaction. The chemical composition and structure were analyzed by XRD, FT-IR, ICP, and SEM. Then, the nanocellulose based 3D lightweight foam thermal insulation materials was prepared by ZnAl-PW _12 O _40 -LDHs and CNF compound with H _3 BO _3 . The TG showed that ZnAl-PW _12 O _40 - LDHs significantly reduced the maximum decomposition rate and increased the carbon residual rate at 800 °C, which indicated that ZnAl-PW _12 O _40 -LDHs can improve the oxidation resistance of CNF composite materials at high temperature.The fire resistance of different samples were evaluated by back temperature test and alcohol lamp flame test, CNF/50%ZnAl-PW _12 O _40 -LDHs /2%H _3 BO _3 showed best thermal stability and flame-retardant properties, which can be contributed to the decomposition products of ZnAl-PW _12 O _40 -LDHs, acting both as phase flame retardant and condensed phase flame retardant

    A risk assessment method of the energy supply chain based on combination weights and Technique for Order Preference by Similarity to an Ideal Solution

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    Nowadays, the energy supply chain (ESC) with the coupling of multiple energy systems is able to promote the complementation between various energy types. However, due to a more complex structure, ESCs are facing more risks from the internal major links and external environment. Hence, an risk assessment method of the ESC based on combination weights and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is proposed. First, a multi-level risk index system with 4 main indices and 16 sub-level indices is established. Next, methods of Criteria Importance Though Intercriteria Correlation (CRITIC) and entropy weighting are presented for determining the initial weights of each sub-level index respectively, in which the CRITIC method considers the conflicts between the indices, and the entropy method focuses on the variation of the index values. After that, a combination weighting approach based on relative entropy is used to assign the final combination weight to each index. Then, considering the final combination weights, the TOPSIS method is adopted to assess the risk level of an ESC. Finally, case studies of 4 regional ESCs are carried out to verify the effectiveness of the proposed method, while the final risk level score of region B’s ESC is the lowest which indicates the best performance in predicting, controlling, and mitigating its internal and external risks

    Radiative Transfer Model Simulations for Ground-Based Microwave Radiometers in North China

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    Ground-based microwave radiometer profilers (MWRPs) are widely used to provide high-temporal resolution atmospheric temperature and humidity profiles. The quality of the observed brightness temperature (TB) from MWRPs is key for retrieving accurate atmospheric profiles. In this study, TB simulations derived from a radiative transfer model (RTM) were used to assess the quality of TB observations. Two types of atmospheric profile data (conventional radiosonde and ERA5 reanalysis) were combined with the RTM to obtain TB simulations, then compared with corresponding observations from three MWRPs located in different places in North China to investigate the influence of input atmospheric profiles on TB simulations and evaluate the quality of TB observations from the three MWRPs. The comparisons of the matching samples under clear-sky conditions showed that TB simulations derived from both radiosonde and ERA5 profiles were very close to the TB observations from most of the MWRP channels; however, the correlation was lower and the bias was obvious at 51.26 GHz and 52.28 GHz, which indicates that the oxygen absorption component in the RTM needs to be improved for lower-frequency temperature channels. The difference in location of the radiosonde and MWRP sites affected the TB simulations for the water vapor channels, but had little impact on temperature channels that are insensitive to humidity. Comparisons of both simulations (ERA5 and Radiosonde) and the corresponding TB observations from the three sites indicated that the water vapor channels observation quality for the MWRP located in southern Beijing needs improvement. For the two types of profile data, ERA5 profiles have a more positive effect on TB simulations in the water vapor channels, such as enhanced consistence, reduced bias and standard deviation between simulations and observations for those MWRPs located away from the radiosonde station. Therefore, hourly ERA5 data are an optimal option in terms of compensating for limited radiosonde measurements and enhancing the monitoring quality of MWRP observations within 24 h

    Two-stage blockchain-based transaction mechanism of demand response quota

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    The current price guided demand response mechanism is difficult to accurately achieve the expected load reduction goal for the grid company, while the direct control demand response mechanism cannot meet the requirements of users for autonomous power consumption. Therefore, it is necessary to formulate an incentive compatible demand response mechanism to take the needs of demand-side users and the grid company into account. Based on the current bidding demand response program, a two-stage transaction mechanism of demand response quota based on blockchain is proposed in this work. Firstly, a two-stage transaction mechanism for demand response quota considering day-ahead bidding transaction and intra-day double auction transaction is designed. Then, the smart contract is introduced to realize the proposed blockchain-based two-stage transaction mechanism of demand response quota, and all the smart contract functions involved in each business link are customized. Finally, the effectiveness of the proposed transaction mechanism of demand response quota is illustrated by the simulation results on the platform of Remix IDE

    Trends of mitochondrial changes in AD: a bibliometric study

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    BackgroundAlzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive progress and memory loss, which eventually develops into dementia. It can cause personality disorders and decreased quality of life of patients. Currently, AD patients account for 60–70% of global dementia patients and the incidence rate of AD is increasing annually. AD not only causes pain to patients but also brings a heavy burden to the entire family. Studies have found that there is a connection between mitochondrial dysfunction and other biochemical changes in AD like classical neuropathological hallmarks (β-amyloid and tau protein), inflammation pathways, oxidative stress, and so on. Evidence shows that early treatment targeted directly to mitochondria could extend the lifespan of model mice and decrease the relevant neuropathological markers. Therefore, research on the mitochondrial dysfunction of AD can be of potential significance for clinical treatment. To date, few bibliometric analysis articles related to mitochondrial dysfunction of AD have been published. Bibliometric analysis refers to quantitatively analyzing certain aspects of articles like publishers, authors, and countries by using statistical and mathematical methods. Combined with statistical software, a large number of papers can be converted to visualization figures and tables, which provide vital information such as keyword hotspots and the names of contributing authors. Through the bibliometric analysis method, our study aimed to provide study trends and keyword hotpots for researchers to conduct further relevant research in this field.MethodsWe used the Web of Science core collection database as a literature retrieval tool to obtain data related to mitochondrial changes in Alzheimer’s disease during the last 20 years. The retrieval type was [TS = (Alzheimer’s disease)] ND [TS = (mitochondrion)], ranging from January 1, 2000 to June 30, 2022. VOSviewer v1.6.18, Arcgis 10.8, and HistCite pro 2.1 were used to conduct data visualization analysis. VOSviewer v1.6.18 made relevant network visualization maps of the cooperative relationship between relevant countries, institutions, and authors (co-authorship), the frequency of different keywords appearing together (co-occurrence), and the frequency of different articles cited together (co-cited). Arcgis 10.8 created the world map of publications distribution in this field and Histcite pro 2.1 was used to count the local citation score (LCS) of references. In addition, Journal Citation Reports were used to consult the latest journal import factor and JCI quartile.ResultsAs of June 30, 2022, from the Web of Science core collection, we selected 2,474 original articles in English, excluding the document types of the news items, meeting abstracts, and some articles that had little relevance to our theme. The United States acted as the leader and enjoyed a high reputation in this field. The University of California System was the institution that made the greatest contribution (3.64% with 90 papers). Most articles were published in the Journal of Alzheimer’s Disease (8.21%, with 203 papers). The most frequently co-cited journal in Q1 was the Journal of Biological Chemistry (8,666 citations, TLS: 1039591). Russel H. Swerdlow (55 publications) was the most productive author and PH Reddy was the most co-cited author with 1,264 citations (TLS: 62971). The hotpots of mitochondrial dysfunction in AD were as follows: “oxidative stress,” “amyloid-beta-protein,” “tau,” “apoptosis,” “inflammation,” “autophagy,” “precursor protein,” “endoplasmic-reticulum,” “dynamics” and “mitochondrial unfolded protein response.”ConclusionThis bibliometric analysis research will help readers rapidly identify current hotpots and milestone studies related to directions of interest in AD research

    Low-Cost 400 Gbps DR4 Silicon Photonics Transmitter for Short-Reach Datacenter Application

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    Targeting high-speed, low-cost, short-reach intra-datacenter connections, we designed and tested an integrated silicon photonic circuit as a transmitter engine. This engine can be packaged into an optical transceiver module which meets the QSFP-DD Form Factor, together with other electrical/optical components. We first present the design and performance of a high-speed silicon modulator, which had a 3-dB EO bandwidth of >40 GHz and an ER of >5 dB. We then incorporated the engine onto a test board and injected a 53.125 Gbaud PAM4 signal. Clear eye patterns were observed at the receiver with TDECQ ~3 dB for all four lanes
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