The Important Role of Metaphor Theory in College English Education

This paper analyzes the main contents of modern conceptual metaphor theory of cognitive linguistics, discusses the use ofconceptual metaphor theory in college English teaching, teaching examples proved that the conceptual metaphor theory provides an analysis ofEnglish metaphor concept and means of language, and improved English teaching reform. We should make full use of new tools for the conceptof education in college English teaching. Metaphor is not only a linguistic phenomenon, but also a cognitive way. The study of metaphor has along history, and now it has become a hot topic in the academic field. The introduction of metaphor research into English teaching will producemore effective teaching methods. Conceptual metaphor theory is the core of cognitive linguistics, and its development has attracted the attentionof scholars.

Hybrid Active–Passive Prosthetic Knee:A Gait Kinematics and Muscle Activity Comparison with Mechanical and Microprocessor-Controlled Passive Prostheses

Existing microprocessor-controlled passive prosthetic knees(PaPKs)and active prosthetic knees(AcPKs)cannot truly simulate the muscle activity characteristics of the active–passive hybrid action of the knee during the normal gait.Differences in EMG between normal and different prosthetic gait for different phases were never separately analyzed.In this study,a novel hybrid active–passive prosthetic knee(HAPK)is proposed and if and how muscle activity and kinematics changes in different prosthetic gait are analyzed.The hybrid hydraulic-motor actuator is adopted to fully integrate the advantages of hydraulic compliance damping and motor efficiency,and the hierarchical control strategy is adopted to realize the adaptive predictive control of the HAPK.The kinematic data and EMG data of normal gait and different prosthetic gait were compared by experiments,so as to analyze the changes in the muscle activity and spatio-temporal data per phase compared to normal walking and the adaptations of amputees when walking with a different kind of prosthesis(the mechanical prosthesis(MePK),the PaPK and the HAPK).The results show that changes in prosthetic gait mainly consisted of decreased self-selected walking speed,gait symmetry and maximum knee flexion,increased first double support phase duration,muscle activation in both opposed and prosthetic limb and inter-subject variability.The differences between controls and MePK,PaPK and HAPK decreases sequentially.These results indicate that the hybrid active–passive actuating mode can have positive effects on improving the approximation of healthy gait characteristics.

Ordered Ultrathin Films of Perylene Anions and Layered Double Hydroxide Using Exfoliation-coassembly Method

Recently,the fabrication of ordered luminescent ultrathin film(UTF)materials based on layered double hydroxides(LDHs)has received much attention.However,how to obtain these UTFs assembled by small anions and LDHs nanosheets is still a challenge.Herein,perylene 3,4,9,10-tetracarboxylate(PTCB)was firstly chosen as the anion with the aim to obtain PTCB/LDH UTFs,which cannot be formed based on typical layer-by-layer(LBL)method.Then,the polymer anions(such as poly 4-styrene sulfonate(PSS)and poly vinyl sulfonate(PVS))were further chosen as the co-assembled units with PTCB,which can act as carriers to assemble with LDH nanosheets.The as-obtained PTCB@PSS/LDH and PTCB@PVS/LDH UTFs present long range ordered structures confirmed by powder X-ray diffraction(XRD),scanning electron microscopy(SEM)and atomic force microscopy(AFM).Moreover,these two UTF systems show polarized luminescence with the emissive anisotropy of ca.0.62 and 0.73.Therefore,this work presents an exfoliation-coassembly way to develop LDH-based ordered luminescent films,which may benefit their future optical display applications.

A new strategy for high-throughput identification of human gut microbiota containing specific monosaccharide

Dear Editor,The human gastrointestinal tract is colonized by trillions of microorganisms,the majority of which cannot be cultured (Wu et al.,2018).Numerous glycans are expressed on the surface of gut microbiota that are characteristic of different strains,and the diversity of these glycans is partially attributed to variations in their monosaccharides.