Text-video retrieval is a challenging task that aims to identify relevant videos given textual queries. Compared to conventional textual retrieval, the main obstacle for text-video retrieval is the semantic gap between the textual nature of queries and the visual richness of video content. Previous works primarily focus on aligning the query and the video by finely aggregating word-frame matching signals. Inspired by the human cognitive process of modularly judging the relevance between text and video, the judgment needs high-order matching signal due to the consecutive and complex nature of video contents. In this paper, we propose chunk-level text-video matching, where the query chunks are extracted to describe a specific retrieval unit, and the video chunks are segmented into distinct clips from videos. We formulate the chunk-level matching as n-ary correlations modeling between words of the query and frames of the video and introduce a multi-modal hypergraph for n-ary correlation modeling. By representing textual units and video frames as nodes and using hyperedges to depict their relationships, a multi-modal hypergraph is constructed. In this way, the query and the video can be aligned in a high-order semantic space. In addition, to enhance the model's generalization ability, the extracted features are fed into a variational inference component for computation, obtaining the variational representation under the Gaussian distribution. The incorporation of hypergraphs and variational inference allows our model to capture complex, n-ary interactions among textual and visual contents. Experimental results demonstrate that our proposed method achieves state-of-the-art performance on the text-video retrieval task.

Lightweight microwave-absorbing (MA) materials with broadband absorption in the C-band remain challenging to date. Recent studies have shown that promoting anisotropy in materials is expected to break the Snoek limit and enhance the absorption performance of magnetic materials in the C-band. In this paper, two-dimensional (2D) large-size coral-like iron-based composites (LCIC) were prepared using an NH4NO3-assisted blow molding separation strategy. The special structure with large shape anisotropy realizes a wide and strong natural magnetic resonance, leading to strong magnetic loss. The enhanced natural resonance effectively broadens the effective absorption bandwidth (EAB) of the LCIC in the C-band. The minimum reflection loss (RLmin) of LCIC is -41.64 dB, and the EAB is 5.42 GHz (3.83-9.25 GHz), covering the entire C-band. Strong natural resonance is necessary to improve the dissipation of magnetic losses in low-frequency electromagnetic waves. This work explores the important role of size effect in enhancing the C-band absorption properties of magnetic materials. It provides a feasible reference for the preparation of C-band broadband, strongly absorbing MA materials.

Modern recommender systems often utilize low-dimensional latent representations to embed users and items based on their observed interactions. However, many existing recommendation models are primarily designed for coarse-grained and homogeneous interactions, which limits their effectiveness in two key dimensions: i) They fail to exploit the relational dependencies across different types of user behaviors, such as page views, add-to-favorites, and purchases. ii) They struggle to encode the fine-grained latent factors that drive user interaction patterns. In this study, we introduce DHCF, an efficient and effective contrastive learning recommendation model that effectively disentangles users' multi-behavior interaction patterns and the latent intent factors behind each behavior. Our model achieves this through the integration of intent disentanglement and multi-behavior modeling using a parameterized heterogeneous hypergraph architecture. Additionally, we propose a novel contrastive learning paradigm that adaptively explores the benefits of multi-behavior contrastive self-supervised augmentation, thereby improving the model's robustness against data sparsity. Through extensive experiments conducted on three public datasets, we demonstrate the effectiveness of DHCF, which significantly outperforms various strong baselines with competitive efficiency.

Explicitly, effective dispersion configuration and hierarchical network construction are two practicable measures to develop the broadband and lightweight absorbers. Based on the newly developed sugar blowing art, 3D Luffa aerogels heterostructure have been successfully developed through metal ion assisted caramel blowing (MCB) strategy. The Luffa foam hierarchical configuration with those dielectric, magnetic, and porous interfaces can be all achieved. Such hierarchical 3D lightweight aerogels are facilitated to building effective impedance matching networks (2.4 wt%) and exhibit an optimized polarization relaxation. Thus, the effective absorbing bandwidth (EAB) of the Luffa aerogel can be broadened up to 8.0 GHz. Moreover, the MCB strategy can be applicable to a wide range of divalent metal ions (Co2+, Ni2+, Mn2+, Zn2+ et al.). This study provides a new method for efficient synthesis of aerogel network structures and opens a way to realize lightweight and broadband electromagnetic wave absorbing (EWA) materials.

The preparation of highly absorbing and high-performance electromagnetic wave-absorbing materials remains a significant challenge. In this paper, carbon matrix composites modified with sodium inorganic salts (CMS) have been successfully prepared by using the solvent evaporation method in combination with the hydrothermal treatment and high temperature carbonization processes. The composition of the product can be manipulated by varying the material ratios, which in turn affects the interface and dielectric properties of the material. Sodium carbonate (Na2CO3) was produced as a transition phase between sodium silicate and carbon matrix due to high temperature. According to differential charge density a significant charge accumulation found between the interfacial of Na2CO3 and carbon layer is helpful to polarization. The synergistic effect of polarization and conduction loss due to the formation of multiple heterogeneous interfaces and carbon matrix results in excellent electromagnetic wave absorption performance. The minimum reflection loss (RLmin) is -55.49 dB when the thickness is 3.1 mm. Furthermore, CMS composites exhibit notable flame retardancy and thermal insulation properties, rendering them suitable for a diverse range of applications. These remarkable achievements provide new ideas for the design and development of efficient electromagnetic wave absorption materials.

Benefiting from a particular ceramic/graphene interface anchored structure, SiBON/reduced graphene oxide nanoplatelets (RGNPs) composite was successfully designed. The electromagnetic wave is smoothly introduced into the composite from the outer layer composed of wave transmission ceramics and attenuated from the inner RGNPs layer, which solves the high impedance matching characteristic of RGNPs. With high-performance electromagnetic absorption, the composites are synthesized by an innovative chemical grafting method, and its absorbing mechanism is discussed. The SiO2 (110) lattice plane is oriented to the edge of RGNPs using the preferred orientation when forming SiBON ceramic. A composite structure is formed with SiBON as external antenna poles and RGNPs as internal signal processors. The interaction between different dielectric loss mechanism balances is achieved by adjusting the content of the ceramic. Results prove that the composite has the best electromagnetic wave absorption performance, when the mass ratio of SiBON ceramics to RGNPs is 1:10, and the filling amount is 20 wt%, forming a broad absorption band (4.80 GHz, 12.88 GHz-17.68 GHz). When the mass ratio of SiBON ceramics to RGNPs is 1:40, the maximum reflection loss is -50.43 dB (13.44 GHz) at a small thickness (1.7 mm).

In recent years, the research popularity to photocatalytic degradation of organic dyes has decreased. It's not that the research isn't important, but that it has hit a bottleneck. It is difficult to reduce the degradation time of organic pollution to less than 10 minutes. The synergetic hydrogen production by organic dye degradation has always been a goal, however, due to its uncontrollability, people have given up their attention to it in recent years. This study prepares the tremella-like ZnO/Bi-QDs/BiOBr photocatalyst which can completely degrade RhB in 8 min, it can reach to 2 min when pH is 5, it is faster than any dye degradation methods currently in use, and it can realize the complete degradation of RhB in 120 min under natural sunlight. More importantly, the žOH and h+ are distributed on porous ZnO by the action of Z-type heterojunctions, and the RhB is also mainly distributed on porous ZnO by porous adsorption, which made the žOH and h+ were used for photodegradation of RhB, but the e- is distributed on BiOBr to be used for photolysis of water to produce hydrogen, and the synergetic hydrogen production by organic dye degradation is controllably realized. The hydrogen production rate reaches to 1674.4 μmol·g-1·h-1 in RhB aqueous solution under visible light. The active groups of dye photodegradation can be regulated, and the synergetic hydrogen production by organic dye degradation is realized.

ZnO is the most common gas sensitive material, but it can only respond at high temperature for its extremely high initial resistance, and its recovery time is often longer. The construction of porous structure can improve the gas adsorption capacity, and electrolyte doping can reduce the initial resistance and recovery time. In this study, the Zn-5(OH)(6)(CO3)(2) precursor was prepared and then calcined to prepare the 3D hollow peony flower-like ZnCO3/ZnO nanocomposites with vertical and parallel bidirectional pores. The bidirectional porous structure increased the specific surface areas to 350.280 m(2)center dot g(-1). For 100 ppm NOx (NO2: NO=17:5) gas detection, the electrolyte (ZnCO3) doping decreased the recovery time to 15 s at room temperature (25 degrees C), and its gas response reached to 159 at room temperature and 233 at 45 degrees C. Due to electrolyte doping, the gas-sensitive property was sharply increased, and the recovery time was much shorter than the response time, both them were much very rare. The excellent and unique gas sensitivity could be attributed to the larger specific surface area, flower-like porous structure and the ionic lattice field interactions.

AgAlO2 is a p-type semiconductor with strong absorption capacity to visible light and ZnO is an n-type semi-conductor with strong absorption capacity to ultraviolet light, but they both possess strong recombination ability of electrons and holes. In this work, a kind of S-type heterojunction was constructed to realize the effective separation of photogenerated electrons and holes in a pumice stone morphology AgAlO2@ZnO composite. The prepared material had macroporous and ordered mesoporous dual porous structures; the pumice stone structure provided the macroporous structures, and the mesoporous structure was derived from the wrapped ZnO precursor in AgAlO2, which greatly improved the exposure rate of the active sites. The material showed excellent photocatalytic properties and showed photocatalytic degradation and photocatalytic hydrogen production performances under simulated solar light. More particularly, it showed photocatalytic hydrogen production performances in RhB or MO solution without the MeOH sacrificial agent. This study provided a new way for the construction of a new S-type heterojunction and a new idea for the further study of S-type heterojunction photocatalysts.

复合激发低碳水泥是最近几年兴起的一种可替代水泥的新型碱激发材料,具有微观结构致密、强度高且水化产物中几乎不存在Ca(OH)2等影响材料耐久性的产物等优良性能.文章通过在复合激发低碳水泥中掺入不同比例的脱硫石膏,研究脱硫石膏对复合激发低碳水泥性能的影响,结果表明,复合激发低碳水泥中掺加未煅烧的原状脱硫石膏最佳,最佳掺量为其胶凝材料的5％.

2D pitaya slice nano-LAS/carbon sheets prepared by ammonium nitrate-assisted self-polymerization andin situblown strategy achieved superior EMW absorbing performance with 8.21 GHz bandwidth.

The silicon coated Carbon nanotubes (CNTs) nanocomposite (CNTs@Si) with a shell structure was successfully synthesized by a simple chemical vapor deposition (CVD) method. In this work, the CNTs@Si is not only introduced as a structural material providing oxidation performance, but also as an extremely effective electromagnetic wave (EMW) absorption nanocomposite. Dielectric characteristics EMW absorption properties within the frequency range of 2-18 GHz of CNTs@Si were studied, and the oxidation resistance of CNTs@Si was characterized. Due to the dense space conductive network formed by CNTs, the EMW absorbing properties of CNTs@Si nanocomposite features excellent electromagnetic wave absorption capacity at a filling amount of 1%. The maximum reflection loss (RL) reaches-61.57 dB at the thickness of 1.8 mm, and a wide effective absorption bandwidth (EAB, RL <-10 dB) of 2.88 GHz is achieved. The obtained CNTs@Si core-shell nanocomposites exhibit excellent antioxidant performance and absorbing performance due to silicon bridging. Efficient electromagnetic wave absorption and excellent oxidation resistance of CNTs@Si can be regarded as a brand-new competitive candidate for EMW absorption materials in harsh environment. (c) 2021 Elsevier Inc. All rights reserved.

Electromagnetic absorbers(EMA)have driven the development of Electromagnetic(EM)technology and advanced EM devices.Utilizing the EM energy conversion of EM absorbers to design various devices is attractive and promising,especially in personal protection and healthcare.In this review article,the sim-ulation and numerical analysis of EM materials are reviewed,from numerical analysis of dielectric param-eters,simulation of wave absorbing performance,electromagnetic performance improvement,and struc-tural construction optimization.For the EM response mechanism,radiation-dependent relaxation and charge transport energy transitions are dissected.For the EM calculation section,two leading roles are highlighted,including the purposeful design of EM and the provision of theoretical guidance for optimiz-ing electromagnetic absorption performance.In addition,this work points out the current problems and potential opportunities in the numerical simulation of absorbing materials,points out the new develop-ment direction,and proposes prospects.

In this work, the hollow porous cauliflower shaped cobalt spheres/graphite nanosheets (hp-Co/GNs) composites with brilliant absorbing performance have been successfully fabricated through a simple solvothermal method and a subsequent hydrothermal reduction process. When the filling amount of absorbing agent is 30 wt%, the composite exhibits excellent absorbing properties in the range of 4-7.92 GHz in S band and 16.24-18 GHz in Ku band. The optimum reflection loss value (RLmin) can be up to -52.1 dB at a thickness of 4.5 mm. By changing the time of the second step hydrothermal reduction reaction, the morphology of the composite changes and its microwave absorption properties are regulated. Its excellent microwave absorption performance benefits from the special hollow porous cauliflower shaped structure and the synergism of magnetic loss and dielectric loss. This study demonstrated that cauliflower shaped hp-Co/GNs composites can be applied as a better electromagnetic wave absorbing material.

A new approach to improve the interfacial matching of carbon fiber-reinforced lithium-aluminum-silicon(Cf/ LAS) composites is proposed, which is achieved by Ni nanoparticles catalyzing the formation of a tunable graphite layer on the surface of Cf. The interfacial structure between the composites can be effectively improved by tuning parameters such as Ni2+ content and sintering holding time, and ultimately, the mechanical properties of the composites can be improved. Interestingly, due to the introduction of Ni2+, a yolk-shell type graphite layer is formed between the Cf and LAS, and the bridging effect of the graphite layer improves interfacial bonding. The highest flexural strength (515 +/- 30 MPa) and fracture toughness (14.7 +/- 1.6 MPa center dot m(1/2)) were obtained. Taking Cf/LAS as an example, the relationship between interfacial matching and mechanical properties of composites is systematically investigated and may provide a new idea for the improvement of mechanical properties of fiberreinforced composites.

ZnO/SnO2 often is used as the gas sensitive materials, but the gas sensors based on ZnO/SnO2 shows the gas sensing property at the higher temperature because of its much higher initial resistance. In this study, porous ZnO/SnO2 material with regular octahedral structure was successfully prepared, and the ZnO was wrapped into SnO2 to form the heterostructure which improved the separation efficiency of electron-hole to decrease the initial resistance in the prepared materials. The prepared material showed much better gas sensing property at the room and near-room temperatures (35 ?, NRT). The response of the octahedral ZnO/SnO2 to 100 ppm ethanol gas was 17.8, and the response time was only 1 s at NRT. Moreover, the prepared gas sensor had the much better gas selectivity to ethanol gas detection. The excellent gas sensing performance could be attributed to which the porous structure, the large specific surface area and the n-n heterojunctions could provide the more gas adsorption active sites and the electronic transmission channels to make the gas sensor with the better gas sensitive response to the target gas. (C) 2022 Elsevier B.V. All rights reserved.

Due to the seriousness of the electromagnetic pollution, it is urgent to develop high-efficiency broadband electromagnetic wave absorption (EMA) materials. As a traditional EMA material, the question of expanding absorption bandwidth for Fe3O4/C composite need to be addressed. Based on this consideration, rationally designed Fe3O4/C nano-composite with the regular mesoscopic (1-100 nm) arrangement structure has practical significance. Benefited from this unique structure, the obtained Fe3O4/C mesoscopic ordered nano-composite exhibits broadband absorbing characteristics in 2-12 GHz. The effective absorption bandwidth value of the material is 6.40 GHz at low frequency (covered C band) and the minimum reflection loss is-50.47 dB. The superior broadband is derived from the good whole-test-frequency impedance matching and the strong low-frequency magnetic loss, which is achieved by the regularly mesoscopic arrangement of the magnetic nano particles. This study will provide certain inspirations and guidance for the design of low frequency broadband EMA materials in the future.

With the fast development of E-communication technology, effective electromagnetic wave absorbing materials are highly needed to address the growing electromagnetic pollution. Herein, Indium doped tin microsphere/ reduced graphene oxide (In-Sn/rGO) composites with rich impurity defects were synthesized via the sol-gel and hydrothermal method. The excellent microwave absorption of In-Sn/rGO composites can be attributed to the modifications of electronics status and Fermi energy level after In doping. This can significantly increase the carrier mobility between In-Sn microspheres and rGO sheets to strike a superior interfacial polarization loss. As a result, the maximum absorptivity can reach -51.16 dB at 8.73 GHz (thickness: 3.5 mm) with a lower filler loading of 10 wt%. Meanwhile, the synthesized In-Sn/rGO composites also exhibit an ultra-wide absorbing frequency range of 13.84 GHz (within the X band, Ku band, and most of the C band). This research provides a new idea for the synthesis of effective microwave absorbing material by introducing impurity defects.

采用活性碳纤维转换法制备了壳核结构SiC/C纤维,采用拉曼光谱、SEM、XRD以及热重分析等测试方法对比研究了生成SiC的厚度对壳核结构SiC/C纤维样品的热重及吸波性能的影响.结果表明:包裹SiC壳层后样品吸波性能得到提高,样品厚度为3.0 mm时,保温4 h样品的最小反射损耗在8.24 GHz处达到-17.22 dB,低于-10 dB(90％的电磁波被吸收)的频宽在2.0 mm处达到4.8 GHz(11.12～15.92 GHz);保温3 h样品的最小反射损耗在8.23 GHz处达到-14.45 dB,低于-10 dB(90％的电磁波被吸收)的频宽在2.0 mm处达到4.56 GHz(10.88～15.44 GHz);且随着SiC含量的升高,试样微波吸收性能有所增强;制备的壳核结构SiC/C纤维样品起始氧化温度提高了150℃以上,并且最终残余质量在50％左右,即包裹SiC纤维后样品的抗氧化能力大大提高.

Inspired by the nostril structure of human, a multifunctional lithium aluminosilicate/CNT composite with nostril like structure has been developed for gas filtration and electromagnetic wave (EMW) absorption. The lithium aluminosilicate/CNT composites were fabricated by catalytic chemical vapor deposition (CCVD) method. Lithium aluminosilicate (LAS) ceramic with 3D pore structure work as the skeleton, in which carbon nanotubes (CNT) in situ grow evenly and form an electric conductive network. With the addition of CNT, the microwave absorption and gas filtration properties of the LAS/CNT composites have been improved remarkably compared with the LAS ceramic. The excellent multifunction benefits from the special nostril like structure. This work not only has an excellent application prospect in the field of EMW absorbing materials, but also has a great potential in the fields of gas filtration, catalyst carrier and so on. At the same time, it also proposes a new avenue for multifunctional microwave absorbing materials.