Carbon Dots in Porous Materials: Host–Guest Synergy for Enhanced Performance

Carbon dots (CDs) are emerging as a new class of carbon nanomaterials, which have inspired growing interest for their widespread applications in anti-counterfeiting, sensing, bioimaging, optoelectronic and energy-related fields. In terms of the concept of host–guest assembly, immobilizing CDs into porous materials (PMs) has proven to be an effective strategy to avoid the aggregation of bare CDs in solid state, in particular, the host—guest synergy with both merits of CDs and PMs affords composites promising properties in afterglow and tunable emissions, as well as optimizes their performance in optics, catalysis, and energy storage. This Minireview summarizes the recent progress in the research of CDs@PMs, and highlights synthetic strategies of constructing composites and roles of porous matrices in boosting the applications of CDs in diverse areas. The prospect of future exploration and challenges are proposed for designing advanced CDs-based functional nanocomposite materials.     

Positive‐temperature‐coefficient/negative‐temperature‐coefficient effect of low‐density polyethylene filled with a mixture of carbon black and carbon fiber

Low‐density polyethylene (LDPE) filled with carbon black (CB) and carbon fiber (CF) composites were prepared by a conventional melt‐mixing method. The effects of a mixture of CB and CF on the positive‐temperature‐coefficient (PTC) effect and the negative‐temperature‐coefficient (NTC) effect, as well as the percolation threshold, were examined in detail. A synergy effect between CB and CF occurred, in that continuous conductive pathways formed within the CB/CF‐filled composite. The percolation threshold was moved to a reduced filler content with the addition of CF to an LDPE/CB composite. A model was proposed to explain the difference in the PTC behavior of composites containing CB and CF and composites containing only CB or CF. In addition, the NTC effect was weakened with a mixture of CB and CF, and a relatively small radiation dose was required to eliminate the NTC phenomenon in LDPE/CB/CF composites. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3094–3101, 2003     

正六边形板式换热器传热和流动特性研究

本文研究了一种具有球面肋的正六边形板式换热器,分别对其两流体和三流体换热的情况进行数值模拟,讨论了其在顺流和逆流状态下的性能.与60°的人字形板式换热器进行比较,正六边形板式换热器在单位压降下的综合传热性能较优.本文还拟合了传热准则方程式和摩擦系数方程式.结果表明,该种新型板式换热器结构紧凑,布置灵活,具有好的综合传热...     

Partial Information Decomposition and the Information Delta: A Geometric Unification Disentangling Non-Pairwise Information

Information theory provides robust measures of multivariable interdependence, but classically does little to characterize the multivariable relationships it detects. The Partial Information Decomposition (PID) characterizes the mutual information between variables by decomposing it into unique, redundant, and synergistic components. This has been usefully applied, particularly in neuroscience, but there is currently no generally accepted method for its computation. Independently, the Information Delta framework characterizes non-pairwise dependencies in genetic datasets. This framework has developed an intuitive geometric interpretation for how discrete functions encode information, but lacks some important generalizations. This paper shows that the PID and Delta frameworks are largely equivalent. We equate their key expressions, allowing for results in one framework to apply towards open questions in the other. For example, we find that the approach of Bertschinger et al. is useful for the open Information Delta question of how to deal with linkage disequilibrium. We also show how PID solutions can be mapped onto the space of delta measures. Using Bertschinger et al. as an example solution, we identify a specific plane in delta-space on which this approach’s optimization is constrained, and compute it for all possible three-variable discrete functions of a three-letter alphabet. This yields a clear geometric picture of how a given solution decomposes information.     

Generalised Measures of Multivariate Information Content

The entropy of a pair of random variables is commonly depicted using a Venn diagram. This representation is potentially misleading, however, since the multivariate mutual information can be negative. This paper presents new measures of multivariate information content that can be accurately depicted using Venn diagrams for any number of random variables. These measures complement the existing measures of multivariate mutual information and are constructed by considering the algebraic structure of information sharing. It is shown that the distinct ways in which a set of marginal observers can share their information with a non-observing third party corresponds to the elements of a free distributive lattice. The redundancy lattice from partial information decomposition is then subsequently and independently derived by combining the algebraic structures of joint and shared information content.     

Using mixture‐amount modeling to optimize the advertising media mix and quantify cross‐media synergy for specific target groups

One of the critical decisions in media planning is how to allocate advertising efforts across different media. While studies indicate that marketers can create positive synergy effects by spreading their effort across several media, there is little understanding of how much should be invested in each specific medium to optimize advertising results. In this study, we apply a novel methodology, mixture‐amount modeling, which allows advertisers to determine the optimal allocation of advertising effort across media as a function of the total advertising effort. Moreover, we test how the optimal allocation and the resulting response change for consumers with distinctive media usage patterns and varying degrees of product category experience. Based on these results, we quantify the potential synergy between media and calculate the synergistic capacity for specific target groups. We apply the model to data from 52 beauty care advertising campaigns that ran on TV and in magazines in the Netherlands and Belgium. We determine the optimal allocation of advertising investments (measured through Gross Rating Points) to maximize campaign recognition. Our findings support the existence of positive synergistic effects between magazine and TV advertising and illustrate that these effects depend on consumers' media usage and product category experience.     

Dual‐Functionalized Crescent Microgels for Selectively Capturing and Killing Cancer Cells

In cancer therapy, the selective targeting of cancer cells while avoiding side effects to normal cells is still full of challenges. Here, we developed dual‐functionalized crescent microgels, which selectively captured and killed lung cancer cells in situ without killing other cells. Crescent microgels with the inner surface of the cavity functionalized with antibody and containing glucose oxidase (GOX) in the gel matrix have been produced in a microfluidic device. These microgels presented high affinity and good selectivity to lung cancer cells and retained them inside the cavities for extended periods of time. Exposing the crescent hydrogels to physiological concentrations of glucose leads to the production of a locally high concentration of H₂O₂ inside the microgels’ cavities, due to the catalytic action by GOX inside the gel matrix, which selectively killed 90 % cancer cells entrapped in the microgel cavities without killing the cells outside. Our strategy to create synergy between different functions by incorporating them in a single microgel presents a novel approach to therapeutic systems, with potentially broad applications in smart materials, bioengineering and biomedical fields.     

基于LIBS技术的脐橙中铜含量联合区间偏最小二乘法定量分析

选用60个果形相当的脐橙样品进行激光诱导击穿光谱(LIBS)试验,引入联合区间偏最小二乘法(siPLS)的分析方法,实现水果脐橙中重金属铜元素的LIBS定量分析。先对脐橙在320~340nm波段内激光诱导击穿光谱进行九点平滑处理,并提取特征光谱CuI324.75nm为分析线。采用siPLS方法将光谱划分为25个子区间,当选择其中5、14、16、22 4个子区间建立的模型时效果最佳,其校正集相关系数和均方根误差分别为0.988 3和5.61,预测集相关系数和均方根误差分别为0.979 2和8.62。研究表明,与偏最小二乘法(PLS)相比,改进的siPLS模型更能有效利用光谱中的信息,减少模型计算量,提高预测能力。为进一步实现水果中痕量重金属元素的快速定量分析提供了方法。     

多纵向涡对管内湍流换热特性影响的数值分析

对多纵向涡对管内湍流换热和流阻特性进行了数值分析。结果表明,多纵向涡可明显强化管内湍流换热,其流阻增加与换热增强相当。在计算范围内管内湍流换热时纵向涡对越多强化效果越好,多纵向涡的尺度应与热边界层厚度相当。同时,管内多纵向涡沿轴向还具有不易衰减的特性,这为多纵向涡的应用提供了方便。