The chemical composition and manufacturing technology of glass beads excavated from the Hetian Bizili site, Xinjiang

The Hetian Bizili site in Lop County, located on the southern route of the Silk Road in Xinjiang, China, was a trade and cultural hub between the East and the West in ancient times. In 2016, a large number of glass beads were unearthed from the 40 tombs excavated on this site. In this study we determined the chemical compositions and manufacturing technology of bodies and decorations of twelve glass beads from the M5 tomb of Bizili by using LA-ICP-AES, EDXRF, Raman Spectrometry, and SR-μCT. The chemical compositions of the beads were all Na2O–CaO–SiO2, with plant ash mainly used as a flux. Lead antimonate and lead stannate were used as the opacifying agents. We detected elevated levels of boron and high levels of phosphorus in some beads: this is discussed in the context of the type of flux used and the possible use of a P-rich opacifier. Some of the beads with high contents of aluminum may potentially come from Pakistan. In terms of manufacturing technology, the craftsmen made ‘eye’ beads in different ways and also trail decorated beads

A Multivariate Generalizability Theory Approach to College Students' Evaluation of Teaching

Teachers' teaching level evaluation is an important component in classroom teaching and professional promotion in the institutions of higher learning in China. Many self-made questionnaires are currently being administered to Chinese college students to evaluate teachers' classroom teaching performance. Quite often, due to the absence of strong educational, and psychological measurements and theoretical foundations for these questionnaires, their dependability remains open to doubt. Evaluation time points, the number of students, major type, and curriculum type were examined in relation to college students' perceptions on their teachers' classroom teaching performance, using Teachers' Teaching Level Evaluation Scale for Colleges (TTLES-C). Data were collected in a sample of 556 students at two time points from three Chinese universities and were analyzed using multivariate generalizability theory. Results showed that evaluations at the beginning of the spring semester produced better outcomes than did evaluations at the end of the fall semester, and 20 student evaluators were sufficient to ensure good dependability. Results also revealed that the evaluation dependability of science curriculum appeared higher than that of liberal arts curriculum. Recommendations were discussed on the evaluation criteria and mode

Dl-3-n-Butylphthalide Reduces Cognitive Deficits and Alleviates Neuropathology in P301S Tau Transgenic Mice

Alzheimer’s disease (AD) is a destructive and burdensome neurodegenerative disease, one of the most common characteristics of which are neurofibrillary tangles (NFTs) that are composed of abnormal tau protein. Animal studies have suggested that dl-3-n-butylphthalide (dl-NBP) alleviates cognitive impairment in mouse models of APP/PS1 and SAMP8. However, the underlying mechanisms related to this remain unclear. In this study, we examined the effects of dl-NBP on learning and memory in P301S transgenic mice, which carry the human tau gene with the P301S mutation. We found that dl-NBP supplementation effectively improved behavioral deficits and rescued synaptic loss in P301S tau transgenic mice, compared with vehicle-treated P301S mice. Furthermore, we also found that it markedly inhibited the hyperphosphorylated tau at the Ser262 site and decreased the activity of MARK4, which was associated with tau at the Ser262 site. Finally, dl-NBP treatment exerted anti-inflammatory effects and reduced inflammatory responses in P301S mice. In conclusion, our results provide evidence that dl-NBP has a promising potential for the therapy of tauopathies, including AD

Mechanical Coupling Error Suppression Technology for an Improved Decoupled Dual-Mass Micro-Gyroscope

This paper presents technology for the suppression of the mechanical coupling errors for an improved decoupled dual-mass micro-gyroscope (DDMG). The improved micro-gyroscope structure decreases the moment arm of the drive decoupled torque, which benefits the suppression of the non-ideal decoupled error. Quadrature correction electrodes are added to eliminate the residual quadrature error. The structure principle and the quadrature error suppression means of the DDMG are described in detail. ANSYS software is used to simulate the micro-gyroscope structure to verify the mechanical coupling error suppression effect. Compared with the former structure, simulation results demonstrate that the rotational displacements of the sense frame in the improved structure are substantially suppressed in the drive mode. The improved DDMG structure chip is fabricated by the deep dry silicon on glass (DDSOG) process. The feedback control circuits with quadrature control loops are designed to suppress the residual mechanical coupling error. Finally, the system performance of the DDMG prototype is tested. Compared with the former DDMG, the quadrature error in the improved dual-mass micro-gyroscope is decreased 9.66-fold, and the offset error is decreased 6.36-fold. Compared with the open loop sense, the feedback control circuits with quadrature control loop decrease the bias drift by 20.59-fold and the scale factor non-linearity by 2.81-fold in the ±400°/s range

Design of a Compliant Mechanism Based Four-Stage Amplification Piezoelectric-Driven Asymmetric Microgripper

The existing symmetrical microgrippers have larger output displacements compared with the asymmetrical counterparts. However, the two jaws of a symmetrical microgripper are less unlikely to offer the same forces on the two sides of a grasped micro-object due to the manufacture and assembly errors. Therefore, this paper proposes a new asymmetric microgripper to obtain stable output force of the gripper. Compared with symmetrical microgrippers, asymmetrical microgrippers usually have smaller output displacements. In order to increase the output displacement, a compliant mechanism with four stage amplification is employed to design the asymmetric microgripper. Consequently, the proposed asymmetrical microgripper possesses the advantages of both the stable output force of the gripper and large displacement amplification. To begin with, the mechanical model of the microgripper is established in this paper. The relationship between the driving force and the output displacement of the microgripper is then derived, followed by the static characteristics’ analysis of the microgripper. Furthermore, finite element analysis (FEA) of the microgripper is also performed, and the mechanical structure of the microgripper is optimized based on the FEA simulations. Lastly, experimental tests are carried out, with a 5.28% difference from the FEA results and an 8.8% difference from the theoretical results. The results from theoretical calculation, FEA simulations, and experimental tests verify that the displacement amplification ratio and the maximum gripping displacement of the microgripper are up to 31.6 and 632 μm, respectively

Quand la chaîne opératoire funéraire se dévoile : sépultures de l’âge du bronze dans le désert du Taklamakan (Chine du Nord-Ouest)

International audienceIn the Taklamakan Desert, in the province of Xinjiang (former Chinese Turkestan), an arid region in northwestern China, excavations and surveys by the French- Chinese archaeological mission in Xinjiang have been ongoing since the early 1990s. In particular, the mission has brought to light a number of spontaneous mummies in a sepulchral context (natural mummification with no human intervention). The burial zone known as the North cemetery, dated to ca. 1900-1500 cal. BC, is located in a fossil delta of the Keriya river, which flowed through the Taklamakan desert in the past. These graves are exceptionally wellpreserved, so that a direct reading can be made of each sequence in the funerary chaîne opératoire. This also makes it possible to investigate certain parameters that may have determined the treatment of the corpse, especially the existence of differential funeral sequences according to the sex or age of the deceased. Our results show that the treatment of the corpse according to its biological sex points to differentiation criteria that would undoubtedly have escaped direct observation in a temperate environment, where the remains could not have been preserved by natural mummification. The study also showed that this Bronze Age population applied a funerary chaîne opératoire in which the natural environment could have been used to promote mummification of the corpses.Le désert du Taklamakan, dans la province du Xinjiang (ancien Turkestan chinois), région aride de la Chine du Nord-Ouest, fait l’objet de fouilles et de prospections depuis le début des années 1990 par la Mission archéologique franco-chinoise au Xinjiang (dir. C. Debaine-Francfort et A. Idriss). Cette mission a notamment mis au jour des momies spontanées en contexte sépulcral (momification naturelle sans intervention anthropique). La zone funéraire dite du Cimetière nord, datée de ca. 1900-1500 cal. BC, se situe dans un delta fossile de la rivière Keriya qui traversait autrefois le désert de Taklamakan. L’état de conservation exceptionnel de ces sépultures offre l’opportunité d’une lecture directe de chaque séquence de la chaîne opératoire funéraire. Elle permet également de nous interroger sur certains paramètres dont dépend le traitement du cadavre, en particulier l’existence de séquences funéraires différentielles en fonction du sexe ou de l’âge du défunt. Nos résultats montrent que le traitement du cadavre selon son sexe biologique concerne des critères de différenciation qui auraient sans aucun doute échappé à l’observation en milieu tempéré–sans la conservation due à la momification naturelle. En outre, l’étude montre également que la population de l’âge du Bronze a appliqué une chaîne opératoire funéraire qui pourrait avoir utilisé le milieu naturel pour favoriser la momification des cadavres

Bronze Age Textiles of the North Cemetery: discoveries made by the Franco-Chinese Archaeological Mission in the Taklamakan Desert, Xinjiang, China

International audienceA cemetery dated Middle to Late Bronze Age (c. 1700 BC and earlier), excavated by the Franco-Chinese Archaeological Mission in Xinjiang (north-west China) in the Taklamakan desert, produced more than one hundred different textiles. The context of the excavation and its circumstances are presented by the directors of the Mission and the totality of the material from one of the only two burials left undisturbed by looters are published, giving a sampling of the range of textiles that were originally to be found in each tomb.Une nécropole de l'âge du bronze (environ 1700 av. J.-C.) fouillée par la Mission franco-chinoise au Xinjiang (nord-ouest de la Chine), dans le désertdu Taklamakan, a livré plus d'une centaine de vestiges textiles différents. Le contexte et les circonstances de cette découverte sont présentés par les directeurs de la Mission et la totalité du matériel textile d'une des rares tombes épargnées par les pilleurs est publié, fournissant un catalogue de la diversité des textiles originellement présents dans chaque tombe