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Cementitious materials are the most widely used in the construction. However, cementitious materials have defects such as low tensile strength which is easy to cause the formation of cracks. In recent years, with the research and application of smart materials, intelligent cementitious materials with self-sensing, self-diagnosis and self-healing functions have received extensive researcher’s attention. In this paper, a polyacrylic hydrogel that could be utilized for self-healing of cementitious materials was designed, and the three-dimensional network structure of the hydrogel controlled the release rate of encapsulated repair agent. The phosphate-incorporated hydrogel was filled into cement slurry to prepare self-healing cementitious materials. After the cement sample cracked and water penetrated into the crack, the phosphate was released from hydrogel. Phosphate reacted with the calcium in the pore solution to form hydroxyapatite type minerals which healed the crack. The self-healing cementitious material is in a position to heal cracks of 300 μm in width. After healing for 28 days at 20oC and 95% of RH, the compressive strength of precracked specimens could reach 85% of that of intact ones.

Text representation, which converts text spans into real-valued vectors or matrices, is a crucial tool for machines to understand the semantics of text. Although most previous works employed classic methods based on statistics and neural networks, such methods might suffer from data sparsity and insensitivity to the text structure, respectively. To address the above drawbacks, we propose a general and structure-sensitive framework, i.e., the hierarchical architecture. Specifically, we incorporate the hierarchical architecture into three existing neural network models for document representation, thereby producing three new representation models for document classification, i.e., TextHFT, TextHRNN, and TextHCNN. Our comprehensive experimental results on two public datasets demonstrate the effectiveness of the hierarchical architecture. With a comparable (or substantially less) time expense, our proposals obtain significant improvements ranging from 4.65 to 35.08% in terms of accuracy against the baseline. We can conclude that the hierarchical architecture can enhance the classification performance. In addition, we find that the benefits provided by the hierarchical architecture can be strengthened as the document length increases.

Query suggestions help users refine their queries after they input an initial query. Previous work on query suggestion has mainly concentrated on approaches that are similarity-based or context-based, developing models that either focus on adapting to a specific user (personalization) or on diversifying query aspects in order to maximize the probability of the user being satisfied (diversification). We consider the task of generating query suggestions that are both personalized and diversified. We propose a personalized query suggestion diversification (PQSD) model, where a user’s long-term search behavior is injected into a basic greedy query suggestion diversification model that considers a user’s search context in their current session. Query aspects are identified through clicked documents based on the open directory project (ODP) with a latent dirichlet allocation (LDA) topic model. We quantify the improvement of our proposed PQSD model against a state-of-the-art baseline using the public america online (AOL) query log and show that it beats the baseline in terms of metrics used in query suggestion ranking and diversification. The experimental results show that PQSD achieves its best performance when only queries with clicked documents are taken as search context rather than all queries, especially when more query suggestions are returned in the list.

The effect of annealing on the self-organized morphology and component gradient distribution of films prepared from bimodal latexes blend containing 1:1 silicon-containing acrylate copolymer/silicon-free acrylate copolymer blend was studied using attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscopy with X-ray energy-dispersive (SEM-EDX) spectrometry, and atomic force microscopy (AFM). The distribution of silicon through the whole thickness of the film as a function of annealing was investigated using confocal Raman spectroscopy (CRS). AFM results show that poly(methyl methacrylate-co-n-butyl acrylate) latex fuses to form a continuous film at 25 °C. The wettability of the acrylate components and the heterogeneous composition of poly(3-[tris(trimethylsilyloxy)silyl] propyl methacrylate-co-methyl methacrylate) result in a graded block film. ATR-FTIR and SEM-EDX measurements reveal silicon-containing components segregate at the film–air interface upon annealing. CRS further shows that the nonlinear model gradient distribution of silicon is obtained, where the content of silicon component is enhanced and it gradually varies in the bulk. When the annealing temperature increases to 120 and 180 °C, blend latexes films demonstrate varying topography and phase images, indicating phase separation is induced by annealing. Furthermore, CRS implies that the destruction of the gradient structure is attributed to the phase separation of the two blend components.

Ionically cross-linked polyampholytic hydrogels were synthesized by redox copolymerization of acrylamide and an ionic complex of (N,N-diethylamino)ethyl methacrylate and acrylic acid (designated as PADA hydrogel). The swelling behavior of the hydrogels in water indicated that a minimal equilibrium swelling ratio is found when the molar ratio of anionic/cationic monomers was 1.55. In NaCl solution, the hydrogels exhibited the typical swelling behavior of conventional polyampholytic gels. Their equilibrium swelling ratios increased with an increase in the NaCl concentration. In solutions of multivalent ions (CaCl2 and trisodium citrate solutions), the equilibrium swelling ratios of the hydrogels increased first and were then followed by a decrease with an increase in salt concentration. Interestingly, an unexpected abrupt swelling phenomenon was observed when the fully swollen hydrogels in salt solution were transmitted to pure water. The unique swelling behavior of PADA hydrogels depends not only on the molar ratio of the anionic/cationic monomers but also on the valency of the ions.