107 research outputs found
Recent advances in multistep solution nanosynthesis of nanostructured three-dimensional complexes of semiconductive materials
AbstractConstructing simply nanostructured zero-, one-, and two-dimensional crystallites into three-dimensional multifunctional assemblies and systems at low-cost is essential and highly challenging in materials science and engineering. Compared to the simply nanostructured components, a three-dimensional (3D) complex made with a precisely controlled spatial organization of all structural nanocomponents can enable us to concert functionalities from all the nanocomponents. Methodologically, so doing in nm-scales via a solution chemistry route may be much easier and less expensive than via other mechanisms. Hence, we discuss herein some recent advances in multistep solution syntheses of nanostructured 3D complexes of semiconductors with a focus mainly on their synthetic strategies and detailed mechanisms
Knowledge-based Transfer Learning Explanation
Machine learning explanation can significantly boost machine learning's
application in decision making, but the usability of current methods is limited
in human-centric explanation, especially for transfer learning, an important
machine learning branch that aims at utilizing knowledge from one learning
domain (i.e., a pair of dataset and prediction task) to enhance prediction
model training in another learning domain. In this paper, we propose an
ontology-based approach for human-centric explanation of transfer learning.
Three kinds of knowledge-based explanatory evidence, with different
granularities, including general factors, particular narrators and core
contexts are first proposed and then inferred with both local ontologies and
external knowledge bases. The evaluation with US flight data and DBpedia has
presented their confidence and availability in explaining the transferability
of feature representation in flight departure delay forecasting.Comment: Accepted by International Conference on Principles of Knowledge
Representation and Reasoning, 201
Direct Determination of Electron-Phonon Coupling Matrix Element in a Correlated System
High-resolution electron energy loss spectroscopy measurements have been
carried out on an optimally doped cuprate Bi2Sr2CaCu2O8+{\delta}. The
momentum-dependent linewidth and the dispersion of an A1 optical phonon are
obtained. Based on these data as well as the detailed knowledge of the
electronic structure from angle-resolved photoemission spectroscopy, we develop
a scheme to determine the full structure of electron-phonon coupling for a
specific phonon mode, thus providing a general method for directly resolving
the EPC matrix element in systems with anisotropic electronic structures
Relational Message Passing for Fully Inductive Knowledge Graph Completion
In knowledge graph completion (KGC), predicting triples involving emerging
entities and/or relations, which are unseen when the KG embeddings are learned,
has become a critical challenge. Subgraph reasoning with message passing is a
promising and popular solution. Some recent methods have achieved good
performance, but they (i) usually can only predict triples involving unseen
entities alone, failing to address more realistic fully inductive situations
with both unseen entities and unseen relations, and (ii) often conduct message
passing over the entities with the relation patterns not fully utilized. In
this study, we propose a new method named RMPI which uses a novel Relational
Message Passing network for fully Inductive KGC. It passes messages directly
between relations to make full use of the relation patterns for subgraph
reasoning with new techniques on graph transformation, graph pruning,
relation-aware neighborhood attention, addressing empty subgraphs, etc., and
can utilize the relation semantics defined in the ontological schema of KG.
Extensive evaluation on multiple benchmarks has shown the effectiveness of
techniques involved in RMPI and its better performance compared with the
existing methods that support fully inductive KGC. RMPI is also comparable to
the state-of-the-art partially inductive KGC methods with very promising
results achieved. Our codes and data are available at
https://github.com/zjukg/RMPI.Comment: under revie
Simultaneous extraction and purification of alkaloids from Sophora flavescens Ait. by microwave-assisted aqueous two-phase extraction with ethanol/ammonia sulfate system
A rapid and effective method of integrating extraction and purification for alkaloids from Sophora flavescens
Ait. was developed by microwave-assisted aqueous two-phase extraction (MAATPE) based on the
high efficiency of microwave-assisted extraction (MAE) and the demixing effect of aqueous two-phase
extraction (ATPE). The aqueous two-phase system (ATPS), ethanol/ammonia sulfate was chosen from
seven combinations of ethanol/salt systems, and its extraction properties were investigated in detail.
Key factors, namely, the compositions of ATPS, solvent-to-materials ratio, and the extraction temperature
were selected for optimization of the experimental conditions using response surface methodology (RSM)
on the basis of the results of the single-factor experiment. The final optimized conditions were, the compositions
of ATPS: ethanol 28% (w/w) and (NH4)2SO4 18% (w/w), solvent-to-material ratio 60:1, temperature
90 C, extraction time 5 min, and microwave power 780 W. MAATPE was superior to MAE, the latter
using a single solvent, not only in extraction yield but also in impurity content. Moreover, compared with
the combination of MAE and ATPE in the two-step mode, MAATP demonstrated fewer impurities, a better
yield (63.78 ± 0.45 mg/g) and a higher recovery (92.09 ± 0.14%) in the extraction and purification of alkaloids.
A continuous multiphase-extraction model of MAATPE was proposed to explicate the extraction
mechanism. MAATPE revealed that the interaction between microwave and ATPS cannot only cause plant
cell rupture but also accelerate demixing, improving mass-transfer from solid–liquid extraction to liquid–
liquid purification. MAATPE simplified procedures also contributed to the lower loss occurrence, better
extraction efficiency, and reduced impurity to target constituents.The Science and Technology Project of Guangzhou (No. 2008Z1-E301) and Faculty Development fund Project of Guangdong Pharmaceutical University (No. 52104109
Benchmarking knowledge-driven zero-shot learning
External knowledge (a.k.a. side information) plays a critical role in
zero-shot learning (ZSL) which aims to predict with unseen classes that have
never appeared in training data. Several kinds of external knowledge, such as
text and attribute, have been widely investigated, but they alone are limited
with incomplete semantics. Some very recent studies thus propose to use
Knowledge Graph (KG) due to its high expressivity and compatibility for
representing kinds of knowledge. However, the ZSL community is still in short
of standard benchmarks for studying and comparing different external knowledge
settings and different KG-based ZSL methods. In this paper, we proposed six
resources covering three tasks, i.e., zero-shot image classification (ZS-IMGC),
zero-shot relation extraction (ZS-RE), and zero-shot KG completion (ZS-KGC).
Each resource has a normal ZSL benchmark and a KG containing semantics ranging
from text to attribute, from relational knowledge to logical expressions. We
have clearly presented these resources including their construction,
statistics, data formats and usage cases w.r.t. different ZSL methods. More
importantly, we have conducted a comprehensive benchmarking study, with two
general and state-of-the-art methods, two setting-specific methods and one
interpretable method. We discussed and compared different ZSL paradigms w.r.t.
different external knowledge settings, and found that our resources have great
potential for developing more advanced ZSL methods and more solutions for
applying KGs for augmenting machine learning. All the resources are available
at https://github.com/China-UK-ZSL/Resources_for_KZSL.Comment: Published in Journal of Web Semantics, 2022. Final version please
refer to our Github repository
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