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The wheat aphid Schizaphis graminum (Rondani) displays wing dimorphism with both winged and wingless adult morphs. The winged morph is an adaptive microevolutionary response to undesirable environmental conditions, including undesirable population density, photoperiod, temperature, and host plant. Here we studied the integrative effects of population density, photoperiod, temperature, and host plant on the induction of alate aphids in S. graminum. The present results show that these four factors all play roles in inducing alate aphids in S. graminum but population density is the most important under almost all circumstances. In importance, population density is followed by photoperiod, host plant, and temperature, in that order. These results indicate that ambient environmental factors are highly important to stimulation of alate aphids in S. graminum, especially when population density reaches 64 individuals per leaf.

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Mode I crack propagation process of concrete under relatively low loading rates which cover four orders of magnitude (0.2 μm/s to 2.0 mm/s) is investigated with three‐point bending (TPB) beams. All measured material properties exhibit rate sensitivity and follow a log‐linear relationship with the loading rate. A rate‐sensitive softening curve is established. The complete load‐crack mouth opening displacement (P‐CMOD) curve, crack propagation length, and fracture process zone (FPZ) length are simulated based on crack growth criterion with the fitted material parameters under those loading rates. Results show that the simulated P‐CMOD curves agree well with those of experimental measurements. It is clear that the peak load increases with the loading rate and so is the critical crack mouth opening displacement. Moreover, under the same load level, the length of the FPZ and the cohesive stress at the initial crack tip also increase with the increasing loading rate.

IntroductionResearch on collocations has become an essential issue in L2 acquisition and cognitive psychology. Previous studies have mainly focused on phonographic languages such as English, Swedish, and German, and primarily discussed the effect of semantic transparency and translational congruency. However, these studies have lacked (1) an analysis of the interactions between presentation modalities (visual vs. auditory) and the semantic transparency and translational congruency, and (2) a discussion of an ideographic language, such as Chinese and Japanese.MethodsWe conducted an experiment with 36 Chinese Japanese-as-a-Foreign-Language learners to examine the processing of Japanese collocations. In the experiment, we manipulated the presentation modality, semantic transparency, and translational congruency during a lexical judgment task.ResultsData analysis using linear mixed-effects models revealed the following. (1) In both conditions of semantic transparency and translational congruency, the auditory presentation was associated with longer reaction times than the visual presentation. (2) In the visual presentation condition, neither semantic transparency nor translational congruency showed significant effects. (3) In the auditory presentation condition, the reaction time for collocations with high semantic transparency tended to be longer than that for collocations with medium semantic transparency and significantly longer than that for collocations with low semantic transparency. The reaction time for collocations with congruent translation was longer than that for collocations with incongruent translation.DiscussionThese results support the dual-route model of Japanese collocational processing by Chinese Japanese-as-a-Foreign-Language learners. Our findings suggest that whether the analytic or holistic processing dominates is closely related to the learners’ knowledge of Chinese and Japanese Kanji words and strongly influenced by the presentation modality, semantic transparency, and translational congruency.