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A three-dimensional MOOC analysis framework was developed, focusing on platform design, organizational mechanisms, and course construction. This framework aims to investigate the current situation of big data MOOCs in the intelligent era, particularly from the perspective of improving the mental health of college students; moreover, the framework summarizes the construction experience and areas for improvement. The construction of 525 big data courses on 16 MOOC platforms is compared and analyzed from three aspects: the platform (including platform construction, resource quantity, and resource quality), organizational mechanism (including the course opening unit, teacher team, and learning norms), and course construction (including course objectives, teaching design, course content, teaching organization, implementation, teaching management, and evaluation). Drawing from the successful practices of international big data MOOCs and excellent Chinese big data MOOCs, and considering the requirements of authoritative government documents, such as the no. 8 document (J.G. [2019]), no. 3 document (J.G. [2015]), no. 1 document (J.G. [2022]), as well as the "Educational Information Technology Standard CELTS-22—Online Course Evaluation Standard", recommendations about the platform, organizational mechanism, and course construction are provided for the future development of big data MOOCs in China. [ABSTRACT FROM AUTHOR]

Alternaria mycotoxins are a class of important, agriculture-related hazardous materials, and their contamination in ruminant feeds and products might bring severe toxic effects to animals and even human beings. To control these hazardous compounds, a reliable and sensitive LC-MS/MS (liquid chromatography–tandem mass spectrometry) method was established for simultaneous determination of six target Alternaria mycotoxins in ruminant feeds, including ALT (Altenuene), AME (Alternariol Monomethyl Ether), AOH (Alternariol), ATX-Ι (Altertoxins I), TeA (Tenuazonic Acid), and TEN (Tentoxin). This developed analytical method was used for the determination of the presence of these substances in cattle and sheep feeds in Xinjiang Province, China. The results revealed that Alternaria mycotoxins are ubiquitously detected in feed samples. Especially, AME, AOH, TeA, and TEN are the most frequently found mycotoxins with a positive rate over 40% and a concentration range of 4~551 µg/kg. The proposed method could be applied for exposure investigation of Alternaria mycotoxins in ruminant feeds and for the reduction in the health risk to animals and even consumers. [ABSTRACT FROM AUTHOR]

China faces a difficult choice of maintaining socioeconomic development and carbon emissions mitigation. Analyzing the decoupling relationship between economic development and carbon emissions and its driving factors from a regional perspective is the key for the Chinese government to achieve the 2030 emission reduction target. This study adopted the logarithmic mean Divisia index (LMDI) method and Tapio index, decomposed the driving forces of the decoupling, and measured the sector's decoupling states from carbon emissions in Xinjiang province, China. The results found that: (1) Xinjiang's carbon emissions increased from 93.34 Mt in 2000 to 468.12 Mt in 2017. Energy-intensive industries were the key body of carbon emissions in Xinjiang. (2) The economic activity effect played the decisive factor to carbon emissions increase, which account for 93.58%, 81.51%, and 58.62% in Xinjiang during 2000–2005, 2005–2010, and 2010–2017, respectively. The energy intensity effect proved the dominant influence for carbon emissions mitigation, which accounted for −22.39% of carbon emissions increase during 2000–2010. (3) Weak decoupling (WD), expansive coupling (EC), expansive negative decoupling (END) and strong negative decoupling (SND) were identified in Xinjiang during 2001 to 2017. Gross domestic product (GDP) per capita elasticity has a major inhibitory effect on the carbon emissions decoupling. Energy intensity elasticity played a major driver to the decoupling in Xinjiang. Most industries have not reached the decoupling state in Xinjiang. Fuel processing, power generation, chemicals, non-ferrous, iron and steel industries mainly shown states of END and EC. On this basis, it is suggested that local governments should adjust the industrial structure, optimize energy consumption structure, and promote energy conservation and emission reduction to tap the potential of carbon emissions mitigation in key sectors. [ABSTRACT FROM AUTHOR]

Purpose: To explore the feasibility of sacral-2-alar (S2-alar) screw placement by measuring the length, diameter, and angle of the screw trajectory on computed tomography (CT). Methods: This study selected 100 Han-nationality adults in northern China with a normal spine and pelvis. CT data were imported into PHILIPS software for reconstructing the 3D digital images. The optimal S2-alar screw trajectory was imitated on CT. Parameters including the length of the screw trajectory, sagittal angle, coronal angle, distance between the entry point and the spinous process, and minimum diameter of the screw trajectory were measured to evaluate the application of S2-alar screws. Results: In total, 48 males and 52 females were included. The average length of the left screw trajectory was 47.18 ± 3.91 mm. The sagittal angle was 29.06 ± 4.00°. The coronal angle was 13.31 ± 6.95°. The distance between the entry point and the spinous process was 21.0 (3.7) mm. The minimum diameter of the screw trajectory was 17.1 (2.3) mm. The average length of the right screw trajectory was 45.46 ± 4.37 mm. The sagittal angle was 23.33 ± 4.26°. The coronal angle was 14.88 ± 6.84°. The distance between the entry point and the spinous process was 22.8 (2.9) mm. The minimum diameter of the screw trajectory was 16.9 (3.1) mm. In women, the average length of the left screw trajectory was 44.80 ± 3.66 mm. The sagittal angle was 32.14 ± 5.48°. The coronal angle was 16.04 ± 7.74°. The distance between the entry point and the spinous process was 21.8 (2.8) mm. The minimum diameter of the screw trajectory was 17.1 (5) mm. The average length of the right screw trajectory was 44.01 ± 3.72 mm. The sagittal angle was 25.12 ± 5.19. The coronal angle was 16.67 ± 8.34°. The distance between the entry point and the spinous process was 21.6 (2.7) mm. The minimum diameter of the screw trajectory was 17 (4.5) mm. As seen from the data, there were significant differences in the minimum diameter of the screw trajectory in both males and females. In females, there were also significant differences between the left and right sides in the coronal angle. Between males and females, there were statistically significant differences in the length of the screw trajectory. There were no statistically significant differences in the other parameters between males and females. Conclusion: The optimal screw trajectory of the S2-alar screw can be found on CT. The length and deflection angle of the screw meet the clinical requirements. This method is easy to perform and feasible for clinical application. [ABSTRACT FROM AUTHOR]

The grain impurity rate is an important index for assessing the quality of mechanical maize harvesting. Therefore, it is of great significance to clarify the current situation of maize impurity rate and study the factors that affect the impurity rate in order to promote the development of mechanical maize harvesting technology. From 2012 to 2019, a total of 2504 maize impurity rate measurements were obtained. The results showed that the average impurity rate at maize harvest was 1.18% in China, in which the Huang-Huai-Hai summer maize area was 1.68%, which was significantly higher than the 0.65% in the Northwest spring maize area and 0.77% in the North China spring maize area. There was a significant positive correlation between the impurity rate and the moisture content of the maize harvest. The average moisture content of maize at harvest in Huang-Huai-Hai summer maize area was the highest at 27.55%, which was the main reason for the high impurity rate in this area. When harvesting different varieties with the same moisture content, there were significant differences in the impurity rate between different varieties. The cob hardness of the variety may also affect the impurity rate of maize. Different harvesters and weather conditions during harvesting are also important factors affecting the impurity rate. Therefore, by breeding fast dehydrated varieties and harvesting maize in time, the impurity rate of maize during mechanical harvesting can be effectively reduced. [ABSTRACT FROM AUTHOR]

The milk bar is an emerging style of retail business that mainly produces pasteurized milk (PM) and other dairy products on-site in many large cities of the People's Republic of China. To date, no data about veterinary drug residues in PM samples produced from milk bars have been reported. The objective of this study was to investigate the safety of PM from a total of 182 PM samples collected from milk bars from 10 provincial capital cities and to analyze the residues of seven classes of 61 veterinary drugs. First, the chemical components were screened with test kits, and then the positive samples were further confirmed by ultraperformance liquid chromatography–tandem mass spectrometry. The results showed that 15 (8.24%) samples were screened positive for veterinary drugs, and six drugs in 11 (6.04%) samples were confirmed. The veterinary drugs detected were penicillin G (2.20%), tetracycline (1.10%), tylosin (1.10%), amoxicillin (0.55%), oxytetracycline (0.55%), and gentamicin (0.55%), with maximum residue levels of 3.4, 11.9, 28.2, 3.0, 26.9, and 63.5 μg kg−1, respectively. Veterinary drug residues were detected as positive in 7 of 10 cities, with the highest detection rate as 14.29% in Urumqi. No positive samples were found in the cities of Nanjing, Tianjin, and Nanning. All detected drug levels were far below the maximum residue levels regulated by China, the European Union, and the Codex Alimentarius Commission. This suggests that the overall veterinary drug residues in PM in milk bars reached the safety code of the country. However, potential risks still exist, and continuous attention should be paid to guarantee the safety of this milk product in the future. Sixty-one drug residues in Chinese milk bars pasteurized milk were first reported. Test kits combined with mass spectrometry were used for drug residue analysis. Six drugs in 11 (6.04%) samples were confirmed with residue levels below MRLs. [ABSTRACT FROM AUTHOR]

Loss of pod dehiscence was a key step in soybean [Glycine max (L.) Merr.] domestication. Genome-wide association analysis for soybean shattering identified loci harboring Pdh1, NST1A and SHAT1-5. Pairwise epistatic interactions were observed, and the dehiscent Pdh1 overcomes resistance conferred by NST1A or SHAT1-5 locus. Further candidate gene association analysis identified a nonsense mutation in NST1A associated with pod dehiscence. Geographic analysis showed that in Northeast China (NEC), indehiscence at both Pdh1 and NST1A were required in cultivated soybean, while indehiscent Pdh1 alone is capable of preventing shattering in Huang-Huai-Hai (HHH) valleys. Indehiscent Pdh1 allele was only identified in wild soybean (Glycine soja L.) accession from HHH valleys suggesting that it may have originated in this region. No specific indehiscence was required in Southern China. Geo-climatic investigation revealed strong correlation between relative humidity and frequency of indehiscent Pdh1 across China. This study demonstrates that epistatic interaction between Pdh1 and NST1A fulfills a pivotal role in determining the level of resistance against pod dehiscence, and humidity shapes the distribution of indehiscent alleles. Our results give further evidence to the hypothesis that HHH valleys was at least one of the origin centers of cultivated soybean. [ABSTRACT FROM AUTHOR]

Specific to problems of the existing round bale wrapping machine in China, such as small application scope and failing to satisfy the wrapping demands of round bales of different specifications, a tumbler-type round bale wrapping machine based on wrapping silage with stretch film was designed. By theoretical analysis and preliminary experiments of the corresponding wrapping process, revolving speed of tumbler, speed ratio between tumbler and carrier rollers, and pre-load force of stretch film were determined as experimental factors, while wrapping time and consumption of stretch film per unit mass of round bale were determined as evaluation indexes. Furthermore, quadratic regression orthogonal rotational combination experimental design was adopted to carry out the wrapping experiment. The regression models were set up, and influencing rules of experimental factors on evaluation indexes were also analyzed. The optimal parameter combination scheme was revolving speed of tumbler of 31-32 r/min, speed ratio between tumbler and carrier rollers of 2.6, and pre-load force of stretch film of 20-22 N. Under such a circumstance, the corresponding wrapping time required was 37.7-38.9 s and consumption of stretch film per unit mass of round bale was 3.21-3.46 kg/t. The predicted values and the measured values of evaluation indexes basically coincided with each other and the relative error fell below 5%, which indicated that both the optimized regression models acquired through the wrapping experiment and the relevant parameter optimization results were reliable. To guarantee the quality of rice straw silage, the round bale should be wrapped by no less than five layers of stretch films through the utilization of the tumbler-type round bale wrapping machine. The study results could be used as references for research and development of the round bale wrapping machine. [ABSTRACT FROM AUTHOR]

• The update preliminary design of CN HCCB TBM was introduced, considering manufacturing feasibility, measurement system interface and ALARR principle. • Some engineering analyses results of CN HCCB TBM were provided, including neutronic analysis, hydraulic analysis, thermo-hydraulic analysis and structural analysis. Preliminary results showed that the design requirements of different materials' temperature, stress could be generally met. • The preliminary fabrication procedure of CN HCCB TBM was proposed, including the key components and main welding technologies. • A semi-prototype mockup of CN HCCB TBM have been fabricated, which has preliminarily verified the fabrication feasibility of the update design. According to the national fusion development strategy, China has determined to test the Helium-cooled Ceramic-Breeder Test Blanket Module (HCCB TBM) in one equatorial port of ITER specific for the TBM program. In the preliminary design (PD) phase, the design of CN HCCB TBM was updated based on the conceptual design (CD), but made a lot of changes and optimizations considering the manufacturing feasibility, the measurement system interface, etc. In this paper, the updated preliminary design of CN HCCB TBM was introduced, and some engineering analysis results were provided, including neutronic analysis, hydraulic analysis, thermo-hydraulic analysis and structural analysis. Preliminary results showed that the design requirements of different materials' temperature and stresses could be generally met. Meanwhile, a semi-prototype mock-up of CN HCCB TBM has been fabricated, and the main results were summarized. [ABSTRACT FROM AUTHOR]

This paper investigates the failure of three gravity walls due to the 1999 Chi-Chi earthquake. Characteristics of the damaged walls were carefully recorded and backfill materials behind the damaged walls were collected and tested in the laboratory. Both the simplified analysis based on the Mononobe–Okabe method and the simplified dynamic analysis based on the Richards–Elms method were adopted. For the first case, the sliding of concrete wall blocks along the construction joint was observed. It was found that, during the earthquake, the frictional resistance at the untreated construction joint was not sufficient to resist the dynamic lateral thrust. For the second case, the retaining wall settled significantly and tilted about its toe. Seismic analysis of the wall indicated that, under the same horizontal acceleration, the factor of safety against bearing capacity failure was lower than that against overturning and sliding. A stability check against bearing capacity failure for the retaining wall should never be neglected. For the third case, the retaining wall built on top of the Che-Lung-Pu fault was severely damaged by the fault rupture. During the earthquake, the vertical displacement of the hanging wall uplifted the backfill, causing the wall to overturn. Horizontal displacement of the hanging wall caused the wall to slide and the soil in front of the toe to heave. [ABSTRACT FROM AUTHOR]

Methamphetamine (MAMP) is one of the most commonly abused illicit drugs in Asian countries, which belongs to the amphetamine-type stimulant class of substances. To detect the chronic drug misuse, human hairs have often been used as analytical specimens due to their long detection windows and easy accessibility. However, there is no investigation regarding the cut-off value of MAMP detection used in black-hair Chinese populations. Based on the analytical data obtained from 563 MAMP users, the cut-off value was found to be 0.97 ng/mg for the simultaneous detection of MAMP and amphetamine (AMP) ≥0.004 ng/mg (LOD). Through the established HPLC-MS/MS analytical method, the limits of detection and quantification of MAMP were 0.004 and 0.01 ng/mg, respectively. The cut-off value was optimized by AMP detection rate and receiver operating characteristic analysis, and the results were consistent with the previously reported MAMP/AMP ratio. [ABSTRACT FROM AUTHOR]