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Based on the theoretical approaches to interlanguage and discourse cohesiveness, this study examines international students' growth in discourse awareness and discourse competence in the teaching of elementary Chinese reading and writing, and explores a set of assessment methods for teaching discourse. The learners' knowledge and production of Chinese conjunctive words were assessed with multiple test methods, including the sentence sequencing test for testing learners' cognitive understanding of discourse cohesiveness, the elicitation tasks for assessing learners' production of conjunctive words, the tests of picture-based sentence writing and essay writing for evaluating learners' discourse awareness of the cohesiveness in form and meaning. 13 students were recruited by us to participate in these tests. A comprehensive discussion of the data supports that appropriate reading and writing instruction can develop learners' discourse competence and enhance their discourse awareness to a certain extent.

This study investigates the capacity of elementary-level Chinese second language learners to memorize serial verb sentences based on the results of a questionnaire. Our findings show that adult second language learners employ the concept of temporal sequence in language learning, consciously or unconsciously, whether or not the chronological principle has been formally taught. Therefore, we propose that specific cognitive principles, such as the chronological principle, should be carefully applied or formally taught in language training to maximize teaching and learning effectiveness.

Due to its own structural characteristics, a harmonic drive system has a wide range of nonlinear factors, such as flexible deformation, friction and external uncertain interference. Most of the traditional controllers simplify the system to a certain extent, or do not consider the nonlinear external disturbance, resulting in that the performance of the designed controller cannot achieve the desired results. In order to improve the accuracy of the system, the dynamic model of the harmonic drive system is established considering the nonlinear stiffness and nonlinear friction of the system. Based on the test data, the parameters of the model are identified by the least square method. Radial basis function （RBF） neural network is used to approximate the nonlinear friction and external uncertain disturbance torque of the system on-line, and an adaptive inversion controller based on RBF neural network is proposed. Using Lyapunov stability theory, the convergence of the closed-loop system is proved. The simulation results show that, compared with the ordinary Back-stepping control, the proposed RBF neural network adaptive inversion control can effectively approach the system nonlinear friction and external unknown disturbance after being subjected to external unknown disturbance, and its peak value of tracking error can be quickly stabilized to 0.000 82 rad. The Back-stepping control is sensitive to external unknown interference, and the peak value of its tracking error increases to about 0.012 3 rad. The proposed RBF neural network adaptive inversion control can suppress the influence of parameter dynamic changes and external disturbances on the transmission accuracy of the system, and improve the transmission accuracy of the system.

In Supplementary Table 1 of this Article, 23 samples (B10K-DU-029-32, B10K-DU-029-33, B10K-DU-029-36 to B10K-DU-029-44, B10K-DU- 029-46, B10K-DU-029-47, B10K-DU-029-49 to B10K-DU-029-53, B10K-DU- 029-75 to B10K-DU-029-77, B10K-DU-029-80, and B10K-DU-030-03; styled in boldface in the revised table) were assigned to the incorrect institution. Supplementary Table 1 has been amended to reflect the correct source institution for these samples, and associated data (tissue, museum ID/source specimen ID, site, state/province, latitude, longitude, date collected and sex) have been updated accordingly. The original table is provided as Supplementary Information to this Amendment, and the original Article has been corrected online.

The traditional fermentation process of soy sauce employs a hyperhaline model and has a long fermentation period. A hyperhaline model can improve fermentation speed, but easily leads to the contamination of miscellaneous bacteria and fermentation failure. In this study, after the conventional koji and moromi fermentation, the fermentation broth was pasteurized and diluted, and then inoculated with three selected microorganisms including Corynebacterium glutamicum, Corynebacterium ammoniagenes, and Lactiplantibacillus plantarum for secondary fermentation. During this ten-day fermentation, the pH, free amino acids, organic acids, nucleotide acids, fatty acids, and volatile compounds were analyzed. The fermentation group inoculated with C. glutamicum accumulated the high content of amino acid nitrogen of 0.92 g/100 mL and glutamic acid of 509.4 mg/100 mL. The C. ammoniagenes group and L. plantarum group were rich in nucleotide and organic acid, respectively. The fermentation group inoculated with three microorganisms exhibited the best sensory attributes, showing the potential to develop a suitable fermentation method. The brewing speed of the proposed process in this study was faster than that of the traditional method, and the umami substances could be significantly accumulated in this low-salt fermented model (7% w/v NaCl). This study provides a reference for the low-salt and rapid fermentation of seasoning.

Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity1-4. Sparse taxon sampling has previously been proposed to confound phylogenetic inference5, and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species.

In order to ensure the safe operation and production of oilfield gathering pipelines and to provide corrosion protection in advance,a failed oil and gas gathering pipeline in Tahe Oilfield was analyzed.The macro morphology observation of the corrosion perforation of such pipeline,the material composition analysis by direct reading spectrometer,the micro morphology observation of the sample corrosion by scanning electron microscope,the corrosion products analysis by X-ray diffractometer and energy disperse spectrometer,and the electrochemical testing were carried out to determine the cause of the perforation of the oil and gas gathering pipeline.Results showed that the highly mineralized corrosion medium,the crude oil containing a lot of CO2 and H2S,and the injected water poured into the stratum led to an CO2 corrosion inside the pipe wall.There were a lot of soluble calcium salts in the medium,and the chemical reaction between calcium salts and CO2 resulted in calcium carbonate scaling.The scaling and corrosion products were deposited on the uphill section of the pipeline,which led to serious corrosion of the metal matrix under scaling.The high-chloride ion accelerated the corrosion,and finally caused the perforation failure at the bottom of the pipeline.

The working condition of medium in the Tahe Oilfield sewage treatment system is complicated and harsh, and the forced current cathodic protection technology can effectively control the station corrosion, prolong the service life and improve the oil removal efficiency. Based on the research method of combining theory with practice and taking into account the relevant domestic and foreign standards and codes, the calculation method of the forced current parameters, the selection of the auxiliary anode block and the selection of the potentiostat were put forward from the aspects of design, construction and evaluation. The installation position and form of the auxiliary anode block were introduced, the key points and requirements of the construction quality control were summarized, and the field application of the forced current cathodic protection technology was analyzed and discussed. Besides, its applicability in Tahe Oilfield was analyzed from three levels: pre - application necessity analysis, field parameter determination and effect evaluation. It was proved that after applying the above - mentioned technology, the corrosion problem of sewage treatment system was effectively controlled, the safe and stable operation of the oil and gas processing system was ensured.

Without adding any interlayers or coatings, the lap welding experiment of AZ31B magnesium alloy and DP980 high-strength steel was performed with the laser-induced tungsten inert gas welding (TIG) arc technology. Through optimizing the process parameters, a high-quality lap weld joint was obtained. The effect of TIG arc current on the forming and mechanical properties of the joint was studied significantly. The results indicate that the wetting and spreading ability of magnesium alloy in high-strength steel is improved with the increase of arc current, which increases the weld width and reduces the wetting angle. Additionally, the maximum tensile load of magnesium alloy/steel welded joints increases first and then decreases with the increase of arc current and the fracture mode of the joint is changed from fracture along the interface to fracture along the weld. When the TIG current is 80 A and the laser power is 350 W, the maximum average tensile load of the welded joint reaches 279 N/mm.The increase of weld width, thickness of interfacial layer and pinning of laser keyholes together enhance the performance of magnesium alloy/steel joints.