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"Xiong, Wei"
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Comprehensive review on zinc‐ion battery anode: Challenges and strategies
Zinc‐ion batteries (ZIBs) have been extensively investigated and discussed as promising energy storage devices in recent years owing to their low cost, high energy density, inherent safety, and low environmental impact. Nevertheless, several challenges remain that need to be prioritized before realizing the widespread application of ZIBs. In particular, the development of zinc anodes has been hindered by many challenges, such as inevitable zinc dendrites, corrosion passivation, and the hydrogen evolution reaction (HER), which have severely limited the practical application of high‐performance ZIBs. This review starts with a systematic discussion of the origins of zinc dendrites, corrosion passivation, and the HER, as well as their effects on battery performance. Subsequently, we discuss solutions to the above problems to protect the zinc anode, including the improvement of zinc anode materials, modification of the anode–electrolyte interface, and optimization of the electrolyte. In particular, this review emphasizes design strategies to protect zinc anodes from an integrated perspective with broad interest rather than a view with limited focus. In the final section, comments and perspectives are provided for the future design of high‐performance zinc anodes. A systematic and detailed summary of the research progress on zinc ion battery anodes is presented, including the causes of zinc dendrites, corrosion passivation and hydrogen evolution reaction on zinc anodes along with the existing strategies. Perspectives are provided for the future design of high‐performance zinc anodes.
Journal Article
Current status of treatment of cancer-associated venous thromboembolism
Patients with cancer are prone to develop venous thromboembolism (VTE) that is the second leading cause of mortality among them. Cancer patients with VTE may encounter higher rates of VTE recurrence and bleeding complications than patients without cancer. Treatment of established VTE is often complex in patients with cancer. Treatment of cancer-associated VTE basically comprises initial treatment, long-term treatment, treatment within 6 months, treatment beyond 6 months, treatment of recurrent VTE, and treatment in special situations. Decision of antithrombotic therapy, selection of anticoagulants, duration of anticoagulation, decision of adjuvant therapy, and adjustment of regimen in special situations are the major problems in the treatment of cancer-associated VTE. Therapeutic anticoagulation is the key of the key in the treatment of cancer-associated VTE. In addition to the efficacy and safety of low-molecular-weight heparin (LMWH) that has been fully demonstrated, direct oral anticoagulants (DOACs) are increasingly showing its advantages along with the accompanying concern in the treatment of cancer-associated VTE. The latest ASCO, ITAC and NCCN guidelines agree with each other on most aspects with respect to the treatment of cancer-associated VTE, whereas differ on a few issues. Encompassing recent randomized controlled trials, clinical trials, and meta-analyses, as well as the comparison of the latest authoritative guidelines including the NCCN, ASCO, and ITAC guidelines in this field, the objective of this review is to present current overview and recommendations for the treatment of cancer-associated VTE.
Journal Article
TCN-attention-HAR: human activity recognition based on attention mechanism time convolutional network
Wearable sensors are widely used in medical applications and human–computer interaction because of their portability and powerful privacy. Human activity identification based on sensor data plays a vital role in these fields. Therefore, it is important to improve the recognition performance of different types of actions. Aiming at the problems of insufficient time-varying feature extraction and gradient explosion caused by too many network layers, a time convolution network recognition model with attention mechanism (TCN-Attention-HAR) was proposed. The model effectively recognizes and emphasizes the key feature information. The ability of extracting temporal features from TCN (temporal convolution network) is improved by using the appropriate size of the receiver domain. In addition, attention mechanisms are used to assign higher weights to important information, enabling models to learn and identify human activities more effectively. The performance of the Open Data Set (WISDM, PAMAP2 and USC-HAD) is improved by 1.13%, 1.83% and 0.51%, respectively, compared with other advanced models, these results clearly show that the network model presented in this paper has excellent recognition performance. In the knowledge distillation experiment, the parameters of student model are only about 0.1% of those of teacher model, and the accuracy of the model has been greatly improved, and in the WISDM data set, compared with the teacher's model, the accuracy is 0.14% higher.
Journal Article
Informational Frictions and Commodity Markets
This paper develops a model with a tractable log-linear equilibrium to analyze the effects of informational frictions in commodity markets. By aggregating dispersed information about the strength of the global economy among goods producers whose production has complementarity, commodity prices serve as price signals to guide producers' production decisions and commodity demand. Our model highlights important feedback effects of informational noise originating from supply shocks and futures market trading on commodity demand and spot prices. Our analysis illustrates the weakness common in empirical studies on commodity markets of assuming that different types of shocks are publicly observable to market participants.
Journal Article
Layered oxide cathodes for sodium‐ion batteries: From air stability, interface chemistry to phase transition
Sodium‐ion batteries (SIBs) are considered as a low‐cost complementary or alternative system to prestigious lithium‐ion batteries (LIBs) because of their similar working principle to LIBs, cost‐effectiveness, and sustainable availability of sodium resources, especially in large‐scale energy storage systems (EESs). Among various cathode candidates for SIBs, Na‐based layered transition metal oxides have received extensive attention for their relatively large specific capacity, high operating potential, facile synthesis, and environmental benignity. However, there are a series of fatal issues in terms of poor air stability, unstable cathode/electrolyte interphase, and irreversible phase transition that lead to unsatisfactory battery performance from the perspective of preparation to application, outside to inside of layered oxide cathodes, which severely limit their practical application. This work is meant to review these critical problems associated with layered oxide cathodes to understand their fundamental roots and degradation mechanisms, and to provide a comprehensive summary of mainstream modification strategies including chemical substitution, surface modification, structure modulation, and so forth, concentrating on how to improve air stability, reduce interfacial side reaction, and suppress phase transition for realizing high structural reversibility, fast Na+ kinetics, and superior comprehensive electrochemical performance. The advantages and disadvantages of different strategies are discussed, and insights into future challenges and opportunities for layered oxide cathodes are also presented. Recent progress in layered oxide cathodes for sodium‐ion batteries (SIBs) from air stability, interface chemistry, and phase transition are comprehensively summarized. The intrinsic degradation mechanisms behind electrochemical performance and mainstream modification strategies are systematically sorted out and analyzed. The remaining challenges, promising optimization strategies as well as endeavor directions to break current limitations are also presented for the future design of high‐performance layered oxide cathodes for SIBs.
Journal Article
Index Investment and the Financialization of Commodities
The authors found that, concurrent with the rapidly growing index investment in commodity markets since the early 2000s, prices of non-energy commodity futures in the United States have become increasingly correlated with oil prices; this trend has been significantly more pronounced for commodities in two popular commodity indices. This finding refiects the financialization of the commodity markets and helps explain the large increase in the price volatility of non-energy commodities around 2008.
Journal Article
Efficient purification of ethene by an ethane-trapping metal-organic framework
Separating ethene (C
2
H
4
) from ethane (C
2
H
6
) is of paramount importance and difficulty. Here we show that C
2
H
4
can be efficiently purified by trapping the inert C
2
H
6
in a judiciously designed metal-organic framework. Under ambient conditions, passing a typical cracked gas mixture (15:1 C
2
H
4
/C
2
H
6
) through 1 litre of this C
2
H
6
selective adsorbent directly produces 56 litres of C
2
H
4
with 99.95%+ purity (required by the C
2
H
4
polymerization reactor) at the outlet, with a single breakthrough operation, while other C
2
H
6
selective materials can only produce
ca
. ⩽ litre, and conventional C
2
H
4
selective adsorbents require at least four adsorption–desorption cycles to achieve the same C
2
H
4
purity. Single-crystal X-ray diffraction and computational simulation studies showed that the exceptional C
2
H
6
selectivity arises from the proper positioning of multiple electronegative and electropositive functional groups on the ultramicroporous pore surface, which form multiple C–H···N hydrogen bonds with C
2
H
6
instead of the more polar competitor C
2
H
4
.
The separation of high purity ethene from the mixed gaseous products of cracking poses significant obstacles. Here, the authors present a metal-organic framework which, in contrast to most absorbents, selectively binds the less polar ethane thus allowing the efficient collection of the target product.
Journal Article
Controlling guest conformation for efficient purification of butadiene
Conventional adsorbents preferentially adsorb the small, high-polarity, and unsaturated 1,3-butadiene molecule over the other C₄ hydrocarbons from which it must be separated. We show from single-crystal x-ray diffraction and computational simulation that a hydrophilic metal-organic framework, [Zn₂(btm)₂], where H₂btm is bis(5-methyl-1H-1,2,4-triazol-3-yl)methane, has quasi-discrete pores that can induce conformational changes in the flexible guest molecules, weakening 1,3-butadiene adsorption through a large bending energy penalty. In a breakthrough operation at ambient temperature and pressure, this guest conformation–controlling adsorbent eluted 1,3-butadiene first, then butane, butene, and isobutene. Thus, 1,3-butadiene can be efficiently purified (≥99.5%) while avoiding high-temperature conditions that can lead to its undesirable polymerization.
Journal Article