Micro-Fracture Toughness in a Nanoceramic Composite

Micro-fracture toughness in one nanoceramic composite, Al_2O_3/SiC_{nano}, is measured by Nanoindentation tests. Microscopy is adopted to probe that all nanoindentations are local at Al_2O_3, matrix component of the current composite and measure length of radial micro-cracks at corriers of nanoindentation. The measured fracture toughness at the shallow indentation is higher than those at deeper ones. Relations between micro-toughness and peak loads as well as peak depths are discussed. And an analysis to the energy consumed during the indentation and fracture toughness explained that, the lower fracture toughness measured in the deeper impression probably resulted from its fracture modes yielded by higher load and larger depth.

Reconstructing the evolutionary history of China: A caveat about inferences drawn from ancient DNA

The decipherment of the meager information provided by short fragments of ancient mitochondrial DNA (mtDNA) is notoriously difficult but is regarded as a most promising way toward reconstructing the past from the genetic perspective. By haplogroup-specific hypervariable segment (HVS) motif search and matching or near-matching with available modem data sets, most of the ancient mtDNAs can be tentatively assigned to haplogroups, which are often subcontinent specific. Further typing for mtDNA haplogroup-diagnostic coding region polymorphisms, however, is indispensable for establishing the geographic/genetic affinities of ancient samples with less ambiguity. In the present study, we sequenced a fragment (similar to 982 bp) of the mtDNA control region in 76 Han individuals from Taian, Shandong, China, and we combined these data with previously reported samples from Zibo and Qingdao, Shandong. The reanalysis of two previously published ancient mtDNA population data sets from Linzi (same province) then indicates that the ancient populations had features in common with the modem populations from south China rather than any specific affinity to the European mtDNA pool. Our results highlight that ancient mtDNA data obtained under different sampling schemes and subject to potential contamination can easily create the impression of drastic spatiotemporal changes in the genetic structure of a regional population during the past few thousand years if inappropriate methods of data analysis are employed.

Reconstructing temperature change in Central East China during 601-920 AD

Chinese Academy of Sciences [KZCX2-YW-Q1-01, KZCX2-YW-315]; National Natural Science Foundation of China [40625002]

印象形成中同化和对比效应研究

Impression formation is an important aspect of person perception and has important interpersonal consequences. There are assimilation and contrast effects in impression formation and is still considerable debate regarding the best way to account for them. This present research used trait-implying sentences as priming materials, trait inferences sever as self-generated primes, examined the effect of different trait knowledge in assimilation and contrast effects. Experiment 1 determined the priming and target stimuli of this research by pretest. In experiment 2, participants read trait-implying sentences and resulted in trait inference as self-generated primes, examined the influence of trait activation on impression formation. The results indicated that participants instructed to memorize trait-implying sentences showed assimilation effect, whereas participants instructed to form impression from trait-implying sentences showed contrast effect. Difference to previous studies that emphasized the impact of awareness of the prime in impression formation, this research paid attention to the impact of different trait knowledge that resulted from trait inference. Experiment 3 studied the influence of actor salience on impression formation. The results indicated that when trait-implying sentences that described actors with names and were accompanied with photos of the actors, participants showed contrast under both memorization and impression instructions. Experiment 4 studied the influence of attribution context on assimilation and contrasts. The results showed that contrast ensued when trait-implying sentences were accompanied with the information that suggested a person attribution, whereas assimilation ensued when that information suggested a situation attribution, independent of processing goals. Experiment 5 made a direct test of the effect of different trait knowledge in impression formation. The results discovered that when abstract trait concepts were activated they act as a general interpretation frame in encoding stage, whereas when specific actor-trait links were activated, the activated information is likely to be used as a comparative standard in judgment stage. All studied indicated that there are two types of activated trait knowledge in trait inference: abstract trait concepts versus specific actor-trait links. When trait inference activated abstract trait concepts, the activated information serves as interpretation frame and lead to assimilation effect during impression formation, when trait inference activated specific actor-trait links, the activated information is more likely to be used as a comparative standards and resulted in contrast effects. These findings have important implications for understanding the mechanism of impression formation and practical values for interpersonal communication.