•The AdaBoost algorithm is adopted to predict the compressive strength of concrete.•1030 sets of data is collected to train the model and reaches an accuracy of 98%.•Different algorithms are compared ...to show the superior of the proposed model.•Key factors and in the AdaBoost and influence of input variables are investigated.
In this paper, an intelligent approach based on the machine learning technique is proposed for predicting the compressive strength of concrete. This approach employs the adaptive boosting algorithm to construct a strong learner by integrating several weak learners, which can find the mapping between the input data and output data. The weak learner whose predicting error is small will have a larger weight in the entire system, thus the overall accuracy of the strong learner will be enhanced. A total of 1030 sets of concrete compressive strength tests is collected to train and test the learners, in which the concrete mixture components (e.g., coarse/fine aggregates, cement, water, additive, etc.) and the curing time are set as the input data while the compressive strength value is set as the output data. The proposed approach is validated through a 10-fold cross validation method, and reaches an average accuracy of over 95% in sense of determination coefficient. In addition, a new dataset of 103 samples for concrete compressive strength is also adopted to demonstrate the generalization power of the proposed mode. The proposed approach is also compared to some other individual machine learning techniques that are already applied in this field, e.g., artificial neural network (ANN) and support vector machine (SVM), and shows superior advantages over these methods. Finally, the influence of some key factors in the adaptive boosting approach is also investigated, e.g., the amount of training data, the choice of weak learner, and the influence of the sensitivity and number of the input parameters. It is shown that using 80% of the total data for training can obtain acceptable prediction results and decision tree is the best choice for the weak learner in the boosting framework. Also, the importances of different input variables are obtained based on the sensitivity analysis results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Metallic lithium affords the highest theoretical capacity and lowest electrochemical potential and is viewed as a leading contender as an anode for high-energy-density rechargeable batteries. ...However, the poor wettability of molten lithium does not allow it to spread across the surface of lithiophobic substrates, hindering the production and application of this anode. Here we report a general chemical strategy to overcome this dilemma by reacting molten lithium with functional organic coatings or elemental additives. The Gibbs formation energy and newly formed chemical bonds are found to be the governing factor for the wetting behavior. As a result of the improved wettability, a series of ultrathin lithium of 10-20 μm thick is obtained together with impressive electrochemical performance in lithium metal batteries. These findings provide an overall guide for tuning the wettability of molten lithium and offer an affordable strategy for the large-scale production of ultrathin lithium, and could be further extended to other alkali metals, such as sodium and potassium.
Peripheral nerve injury (PNI) is a severe clinical disease leading to the loss of sensory and motor function and even lifelong disability of patients. Nerve scaffolds with conductive materials are ...beneficial to PNI repair and regeneration through the recovery of electrical signals transmission and regulation of nerve cell membrane function. In this study, composite poly(lactide‐co‐glycolide) (PLGA)/Ti3C2Tx (MXene) membranes with different content of MXene were fabricated by electrospinning, and these fibrous membranes showed favorable mechanical property for supporting nerve regeneration. With loaded MXene, the electrospun membranes exhibited good antibacterial property that the antimicrobial rate was as high as 80%, which is conducive to the prevention of wound inflammation after stent implantation. The loaded MXene also improved the hydrophilicity and conductivity of the electrospun composite membranes, which provided good biocompatibility for cell growth. Interestingly, treating in 75% ethanol solution made fabricated PLGA/MXene membranes rapidly crimp into stable nerve conduits for implanted application. These fabricated PLGA/MXene membranes showed good potential for nerve repair and have a good prospect for nerve conduit application.
Schematic of PLGA/MXene membranes preparation and application.
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A chestnut-like aroma is widely considered an important indicator of an excellent-quality green tea; however, the key odorants responsible for chestnut-like aroma have never been systematically ...studied and remain unknown. In this study, the aroma components of green teas and Chinese chestnuts were analyzed using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS), and 58 compounds were identified as common aroma components among green teas, boiled Chinese chestnuts, roasted Chinese chestnuts and raw Chinese chestnuts. Subsequently, 17 volatiles, including 3-methylbutanal, (E)-3-penten-2-one, ethylbenzene, heptanal, benzaldehyde, 2-pentylfuran, octanal, benzeneacetaldehyde, (E)-2-octenal, (E,E)-3,5-octadien-2-one, linalool, nonanal, (E)-2-nonenal, decanal, (Z)-hex-3-en-1-yl hexanoate, trans-β-ionone and (E)-nerolidol, were identified as the key odorants responsible for chestnut-like aroma based on the odor activity value (OAV) calculation method. Besides, the comparison of OAVs of key odorants between fresh tea leaves and finished teas indicated that all key odorants were present in fresh tea leaves and that their contents increased or decreased during tea processing. Moreover, the comparison between results of OAV and gas chromatography-olfactometry (GC-O) methods showed that ethylbenzene, heptanal, benzaldehyde, 2-pentylfuran, (E,E)-3,5-octadien-2-one, linalool, (Z)-hex-3-en-1-yl hexanoate and trans-β-ionone were the common identified compounds between the two methods. The identification of chestnut-like aroma in green teas will provide a theoretical basis for further research on the directional adjustment and control of tea aroma quality.
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•Volatiles of green teas and Chinese chestnuts were analyzed by GC × GC-TOFMS.•58 Compounds were identified as potential key odorants by statistical comparison.•17 Key odorants were determined by OAV calculation and validation analysis.•Key odorants showed different variation trends of contents during processing.•The GC-O analysis of green tea with chestnut-like aroma was performed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK, ZRSKP
Costly data movement in terms of time and energy in traditional von Neumann systems is exacerbated by emerging information technologies related to artificial intelligence. In‐memory computing (IMC) ...architecture aims to address this problem. Although the IMC hardware prototype represented by a memristor is developed rapidly and performs well, the sneak path issue is a critical and unavoidable challenge prevalent in large‐scale and high‐density crossbar arrays, particularly in three‐dimensional (3D) integration. As a perfect solution to the sneak‐path issue, a self‐rectifying memristor (SRM) is proposed for 3D integration because of its superior integration density. To date, SRMs have performed well in terms of power consumption (aJ level) and scalability (>102 Mbit). Moreover, SRM‐configured 3D integration is considered an ideal hardware platform for 3D IMC. This review focuses on the progress in SRMs and their applications in 3D memory, IMC, neuromorphic computing, and hardware security. The advantages, disadvantages, and optimization strategies of SRMs in diverse application scenarios are illustrated. Challenges posed by physical mechanisms, fabrication processes, and peripheral circuits, as well as potential solutions at the device and system levels, are also discussed.
This review summarizes the research progress in self‐rectifying memristors (SRM) and SRM‐based applications including 3D memory, in‐memory computing, neuromorphic computing, and hardware security. Through a comprehensive analysis of the advantages and disadvantages of SRMs in different application scenarios, as well as challenges at the device, 3D integration, and peripheral circuit levels, corresponding research ideas and potential solutions are proposed.
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•A water-soluble galactoglucan (PCP-1C) was purified from Poria cocos.•The chemical composition and structural features of PCP-1C were characterized.•PCP-1C can effectively inhibit the metabolism of ...toxicant and reduce liver damage.
To find the polysaccharide with hepatoprotective activity from Poria cocos and clarify its structure, a galactoglucan (PCP-1C) with a molecular weight of 17 kDa was purified from the Poria cocos sclerotium by column chromatography and activity evaluation in the present work. It was composed of galactose, glucose, mannose, and fucose in a molar percentage of 43.5: 24.4: 17.4: 14.6. Structural characterization showed that PCP-1C has a backbone consisted of 1,6-α-D-Galp, which branches composed of 1,3-β-D-Glcp, 1,4-β-D-Glcp, 1,6-β-D-Glcp, T-β-D-Glcp, T-α-D-Manp, T-α-L-Fucp and 1,3-α-L-Fucp. In vivo experiments found that PCP-1C can apparently improve the damage of liver tissue in CCl4-treated mice and relieve oxidative stress and inflammation. PCP-1C also reduced the expression of CAR and CYP2E1 in the liver. These findings indicated strong hepatoprotective effect of PCP-1C, which was attributed to the reduction of CCl4 metabolism via inhibiting the CAR/CYP2E1 signal pathway.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Nonalcoholic fatty liver disease (NAFLD) is one of the major health concerns worldwide. Farnesoid X receptor (FXR) is considered a therapeutic target for treatment of NAFLD. However, the mechanism by ...which activation of FXR lowers hepatic triglyceride (TG) levels remains unknown. Here we investigated the role of hepatic carboxylesterase 1 (CES1) in regulating both normal and FXR‐controlled lipid homeostasis. Overexpression of hepatic CES1 lowered hepatic TG and plasma glucose levels in both wild‐type and diabetic mice. In contrast, knockdown of hepatic CES1 increased hepatic TG and plasma cholesterol levels. These effects likely resulted from the TG hydrolase activity of CES1, with subsequent changes in fatty acid oxidation and/or de novo lipogenesis. Activation of FXR induced hepatic CES1, and reduced the levels of hepatic and plasma TG as well as plasma cholesterol in a CES1‐dependent manner. Conclusion: Hepatic CES1 plays a critical role in regulating both lipid and carbohydrate metabolism and FXR‐controlled lipid homeostasis. (Hepatology 2014;59:1761–1771)
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Li anodes have been rapidly developed in recent years owing to the rising demand for higher‐energy‐density batteries. However, the safety issues induced by dendrites hinder the practical applications ...of Li anodes. Here, Li metal anodes stabilized by regulating lithium plating/stripping in vertically aligned microchannels are reported. The current density distribution and morphology evolution of the Li deposits on porous Cu current collectors are systematically analyzed. Based on simulations in COMSOL Multiphysics, the tip effect leads to preferential deposition on the microchannel walls, thus taking full advantage of the lightening rod theory of classical electromagnetism for restraining growth of Li dendrites. The Li anode with a porous Cu current collector achieves an enhanced cycle stability and a higher average Coulombic efficiency of 98.5% within 200 cycles. In addition, the resultant LiFePO4/Li full battery demonstrates excellent rate capability and stable cycling performance, thus demonstrating promise as a current collector for high‐energy‐density, safe rechargeable Li batteries.
A new strategy to restrain lithium dendrite growth is proposed and demonstrated using vertically aligned microchannel Cu current collectors for Li metal anodes. Most of the lithium is preferentially deposited into the microchannels. The current‐density distribution, deposition behavior, and electrochemical performance are simulated and investigated experimentally to understand the effectiveness of the microchannel structure.
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Sulfide-based all-solid-state lithium-ion batteries (ASSLIBs) are promising candidates in the next generation of energy storage technology; the voltage mismatch and the resulting side reactions at ...the interface between the cathode and the solid electrolyte, however, dramatically deteriorate their cycling performance. Herein, for the first time, we report that the chemical interaction between LiCoO2 (LCO) and TiO2 can be regulated by two additives, carbon and Li2CO3, which in situ form a continuous ultrathin pure-phase Li2CoTi3O8 (LCTO) layer with a stable 3D network of spinel structures, relatively low electronic conductivity (2.5 × 10−8 S cm−1) and high lithium diffusion coefficient (DLi+ = 8.22 × 10−7 cm2 s−1) on the surface of LCO. When assembled in ASSLIBs, such an LCTO layer functions as an interlayer between the LCO and the Li10GeP2S12 solid electrolyte (LGPS). As a consequence, the original interface LCO/LGPS is substituted by two new interfaces LCO/LCTO and LCTO/LGPS. DFT calculations indicate that, compared with the LCO/LGPS, the new interfaces are not only thermodynamically and electrochemically more compatible, but also have higher interfacial affinity. Therefore, the relevant ASSLIB exhibits evidently reduced interfacial impedance, and it also displays a high initial capacity of 140 mA h g−1 and a reversible discharge specific capacity of 116 mA h g−1 after 200 cycles at room temperature (0.1C). In comparison, the ASSLIB assembled without the LCTO interlayer delivers an initial capacity of 98 mA h g−1 and only retains 22.4% capacity after 100 cycles (0.1C). Even at a high cutoff voltage (4.5 V vs. Li/Li+), the ASSLIB with the LCTO interlayer could also exhibit a high initial capacity of 180 mA h g−1 and a remarkable retention of 132 mA h g−1 after 100 cycles.
The electrochemical carbon dioxide reduction reaction (E‐CO2RR) to formate is a promising strategy for mitigating greenhouse gas emissions and addressing the global energy crisis. Developing low‐cost ...and environmentally friendly electrocatalysts with high selectivity and industrial current densities for formate production is an ideal but challenging goal in the field of electrocatalysis. Herein, novel titanium‐doped bismuth nanosheets (TiBi NSs) with enhanced E‐CO2RR performance are synthesized through one‐step electrochemical reduction of bismuth titanate (Bi4Ti3O12). We comprehensively evaluated TiBi NSs using in situ Raman spectra, finite element method, and density functional theory. The results indicate that the ultrathin nanosheet structure of TiBi NSs can accelerate mass transfer, while the electron‐rich properties can accelerate the production of *CO2− and enhance the adsorption strength of *OCHO intermediate. The TiBi NSs deliver a high formate Faradaic efficiency (FEformate) of 96.3% and a formate production rate of 4032 µmol h−1 cm−2 at −1.01 V versus RHE. An ultra‐high current density of −338.3 mA cm−2 is achieved at −1.25 versus RHE, and simultaneously FEformate still reaches more than 90%. Furthermore, the rechargeable Zn–CO2 battery using TiBi NSs as a cathode catalyst achieves a maximum power density of 1.05 mW cm−2 and excellent charging/discharging stability of 27 h.
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