基于关系自适应解码的实体关系联合抽取

基于编码器-解码器的实体关系联合抽取模型解决了流水线模型存在的误差传递问题,但是以往基于编码器-解码器的模型还是存在两点问题:一是在解码阶段同时生成实体和关系,而两者是不同的对象,使得同一语义空间的映射降低了抽取效果;二是没有考虑不同关系之间的交互信息.针对这两点问题,提出了关系自适应解码模型.所提模型将实体关系联合抽...     

Distributed electric power systems of the future: Institutional and technological drivers for near-optimal performance

Viewing electric power distribution systems as complex engineering systems whose states and inputs are defined by both technical and non-technical components of the system could help us understand challenges and lead to possible innovative solutions. In this setup, regulatory incentives, pricing, demand, and technological innovation are all endogenous feed-forward and/or feedback signals to the existing physical network and shape its evolution in both the short and long terms. We suggest that it is, indeed, possible to design technical, economic, and regulatory feed-forward and feedback signals keeping in mind the desired performance of the system. A particularly unique challenge is to enhance and operate the existing systems by incorporating distributed technologies (distributed generation or DG, active demand response, controllable wires) whose added value comes from just-in-time and right-location adjustments to the changing conditions. One way of interpreting the value of technologies of this type is to understand that they provide flexible and efficient responses by the end-user (DG and demand), therefore reducing the need for capacity reserve at the system level. Technical implementations and regulatory rules are not in place today to support systematic penetration of these technologies into the existing distribution systems. In this paper we stress the critical role of future load serving entities (LSEs) as aggregators and catalysts of customer choice at the value as one possible way forward. The LSEs would, through systematic protocols between themselves and the wholesale markets, on one side, and the customers whom they serve, on the other side, effectively implement incentives to induce near-optimal distribution system performance over long time horizons by investing in near-optimal technologies. These incentives must capture and compare both cumulative effects of real time decisions and the effects of longer-term investment decisions on near-optimal industry architecture. A non-traditional cost–benefit analysis which draws on temporal and spatial economies of scope is critical for ensuring penetration of what might be viewed as a rather costly disruptive technology. To illustrate the relevance of such analysis on incentives design, we provide numerical examples showing the objectives of the price-responsive demand and the objectives of the evolving distribution (local wire) companies under several regulatory rules.     

Transmission electron microscopy of nanocomposite CrB-N thin films

This paper reports on the preparation and characterization of Crentities/sbnd" class="glyphImg">Bentities/sbnd" class="glyphImg">N nanocomposite coatings for low friction, low wear and high thermostability applications. Sputtered Crentities/sbnd" class="glyphImg">Bentities/sbnd" class="glyphImg">N thin films were prepared in order to obtain a composite structure consisting of hard CrB₂ and CrN crystallites as well as hexagonal BN lubricant phase by unbalanced magnetron sputtering (UBM) of a CrB₂ target in an Ar/N₂ gas discharge. Coatings, with a total thickness of 4.5-5.5 μm, were deposited at 450 °C on silicon single-crystal substrates. A nanocomposite structure was obtained by increasing the nitrogen content of the sputtering gas. The coating microstructure was investigated on selected samples by high-resolution transmission electron microscopy. The films were generally found to consist of crystallites of a 1-4 nm size embedded in amorphous matrix. This crystalline phase was identified by electron diffraction as hexagonal CrB₂ for low nitrogen content and cubic CrN for high nitrogen content. In the medium composition range, the structure was amorphous, still keeping the two-phase morphology. The use of high-resolution imaging mode helped to reveal the composition of the amorphous phase which seems predominantly to consist of boron nitride.     

Degradation of cyanobacteria toxin by advanced oxidation processes

Advanced oxidation processes (AOPs) using O(3), H(2)O(2), O(3)/H(2)O(2), O(3)/Fe(II), and Fenton treatment were investigated for the degradation of aqueous solutions of cyanobacteria. The effects of concentration of reactants, temperature, and pH on toxins degradation were monitored and the reaction kinetics was assessed. O(3) alone or combined with either H(2)O(2) or Fe(II) were efficient treatment for toxins elimination. A higher toxin oxidation tendency was observed with Fenton reaction; total toxins degradation (MC-LR and MC-RR) was achieved in only 60s. The ozonation treatment was successfully described by second-order kinetics model, with a first-order with respect to the concentration of either ozone or toxin. At 20 degrees C, with initial concentration of MC-LR of 1mg/L, the overall second-order reaction rate constant ranged from 6.79 x 10(4) to 3.49 x 10(3)M(-1)s(-1) as the solution pH increased from 2 to 11. The reaction kinetics of the other AOPs (O(3)/H(2)O(2), O(3)/Fe(II), and Fenton), were fitted to pseudo first-order kinetics. A rapid reaction was observed to took place at higher initial concentrations of O(3), H(2)O(2) and Fe(II), and higher temperatures. At pH 3, initial concentration of toxin of 1mg/L, the pseudo first-order rate constant, achieved by Fenton process, was in order of 8.76+/-0.7s(-1).     

基于卷积神经网络的食品安全领域谣言检测方法

近年来,食品安全已经成为政府和社会最关心的问题之一。与此同时,大量食品安全领域的谣言也在社交媒体平台上疯狂传播。现有的研究大多针对通用领域的谣言进行检测,忽视了不同领域谣言之间存在的差异性。针对食品安全这一领域谣言的特点,提出一种基于卷积神经网络的食品安全领域谣言检测方法。用领域实体抽取策略得到的实体特征与文本卷积神经网络提取的深度文本特征做拼接融合,再进行谣言判断。实验结果表明,在食品安全领域谣言数据集上,采用该方法检测效果明显优于通用的谣言检测方法,在准确率、召回率和F1值等评价指标上都表现最优。     

描述CPS物理实体的时空Petri网模型

时间Petri网在经典Petri网的基础上引入了时间因素,不仅能分析逻辑层次的系统性能,还能分析时间层次的系统性能,然而包含空间因素的信息物理融合系统(cyber-physical system,CPS)的产生需要对时间Petri网进行拓展。CPS集成计算系统和物理系统,不仅能够实时感知物理环境信息,并且能够通过物理实体改变物理环境。对CPS的物理层面特点进行了深入分析,研究了CPS物理实体的属性及其位置变迁过程,提出了一种CPS物理实体的形式化建模方法。在时间Petri网的基础上引入了空间因素,构造了时空Petri网模型,使其不仅能够描述物理实体逻辑及时间层次的行为,并且能够描述物理实体位置变迁所引起的状态变化。最后以机器人控制系统为例,进一步阐述了时空Petri网模型的有效性。     

农村经营制度创新若干问题探讨

农村经营制度的创新,其实质就是如何推进农村的统一经营。要推进农村统一经营,必须要有相应的制度供给,包括村民自治制度、土地制度、经营主体制度。这些制度具体又该如何构建,则取决于对统一经营的性质、统一经营与政府干预、统一经营与土地制度的逻辑关系以及统一经营主体与农村中的相关组织之间的关系的认识。     

The observation of nanometer-sized entities in sulphided Mo-based catalysts on various supports

The progressive sulphidation of molybdenum-based hydrotreating model catalysts is studied using HRTEM and XPS. The catalysts are sulphided quasi in situ and prepared for TEM measurements in a glovebox. Subsequently, a specially developed vacuum-transfer specimen holder is used for transfer to the TEM. Using this procedure, a previously unknown feature is observed in the catalysts. Apart from the well-known slab-like structure of bulk molybdenum disulphide, nanometer-sized spherical entities of molybdenum sulphide or oxysulphide are observed. For a series of model CoMo/silica catalysts, these spots predominantly occur after mild sulphidation procedures. At higher sulphidation temperatures, these spots exist next to the slabs of MoS₂-like material. Comparison with practical molybdenum-based hydrotreating catalysts shows that these, too, can contain spots next to or instead of slabs, depending on precursor preparation and sulphidation procedures.