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A 794-cm section was collected from Tengger Nuur in the Inner Mongolian Plateau. Accelerator mass spectrometry 14C data were determined to set an age-depth model after removing about 1920 years of the carbon reservoir effect. Based on the multi-proxies grain size, carbonate-content, total organic carbon-content, ratio of C/N, ratios of Mg/Ca and Sr/Ca, and carbonate carbon and oxygen isotopes, paleoenvironmental changes since the last deglaciation were reconstructed. Tengger Nuur was very shallow during the last deglaciation under a cool and wet climate, especially during the interval of the cold Younger Dryas event. Although, temperature and humidity increased from the early Holocene (∼10,450–8750 cal a BP), low lake levels indicated that the summer monsoon was not sufficiently strong to reach the modern monsoon boundary in Inner Mongolia. High monsoon precipitation caused lake expansion during 8750–5000 cal a BP, but the lake level oscillated in a shallow state under high evaporation. A low lake-level event occurred with the interval of a cold-wet climate during 5450–5100 cal a BP. The summer monsoon receded gradually to maintain a deep lake under high effective humidity during 5000–2000 cal a BP, punctuated by low lake-level events at intervals of 4300–3980 cal a BP and 3700–2750 cal a BP. With the arrival of the cold and dry westerly after 2000 cal a BP, lakes shrank gradually to become salinized or completely desiccated, but their levels oscillated at shallow depths during the four periods of 1900–1800 cal a BP, 1500–1050 cal a BP, 550–400 cal a BP (Little Ice Age), and 100 cal a BP–AD 1985. Therefore, the eastern summer monsoon was weak in the early Holocene, and lake-level oscillation was controlled by effective humidity in arid and semi-arid areas.

Digital droplet PCR (ddPCR) is a powerful amplification technique for absolute quantification of viral nucleic acids. Although commercial ddPCR devices are effective in the lab bench tests, they cannot meet current urgent requirements for on-site and rapid screening for patients. Here, we have developed a portable and fully integrated lab-on-a-disc (LOAD) device for quantitively screening infectious disease agents. Our designed LOAD device has integrated (i) microfluidics chips, (ii) a transparent circulating oil-based heat exchanger, and (iii) an on-disc transmitted-light fluorescent imaging system into one compact and portable box. Thus, droplet generation, PCR thermocycling, and analysis can be achieved in a single LOAD device. This feature is a significant attribute for the current clinical application of disease screening. For this custom-built ddPCR setup, we have first demonstrated the loading and ddPCR amplification ability by using influenza A virus-specific DNA fragments with different concentrations (diluted from the original concentration to 107 times), followed by analyzing the droplets with an external fluorescence microscope as a standard calibration test. The measured DNA concentration is linearly related to the gradient–dilution factor, which validated the precise quantification for the samples. In addition to the calibration tests using DNA fragments, we also employed this ddPCR-LOAD device for clinical samples with different viruses. Infectious samples containing five different viruses, including influenza A virus (IAV), respiratory syncytial virus (RSV), varicella zoster virus (VZV), Zika virus (ZIKV), and adenovirus (ADV), were injected into the device, followed by analyzing the droplets with an external fluorescence microscope with the lowest detected concentration of 20.24 copies/µL. Finally, we demonstrated the proof-of-concept detection of clinical samples of IAV using the on-disc fluorescence imaging system in our fully integrated device, which proves the capability of this device in clinical sample detection. We anticipate that this integrated ddPCR-LOAD device will become a flexible tool for on-site disease detection. [ABSTRACT FROM AUTHOR]

Understanding the shear mechanics mechanism of bolted joints is of great significance for predicting and preventing geological disasters. Most current studies seldom consider the rheological effects of bolted joints. In this paper, a comprehensive rheological constitutive model is proposed, accounting for initial damage and damage evolution across different rheological stages and bolt characteristics. The model incorporates an elastoplastic Hooke body for instantaneous deformation, parametric nonlinear Kelvin and viscous models for attenuation and steady creep stages, and a visco-plastic model based on time-dependent shear strength for accelerated creep stage. Additionally, a bolt-rock cooperative deformation model is introduced, considering the evolution of the bolt's elastic modulus. The resulting elasto-viscoplastic constitutive model effectively describes the shear rheological behavior of bolted joints, with its validity and superiority demonstrated through comparisons with shear creep tests and the Maxwell model. This research aims to provide valuable theoretical guidance for the construction and reinforcement of rock mass engineering projects. [ABSTRACT FROM AUTHOR]

In July 2019, a goaf collapse accident occurred in Luanping Huabing iron mine, the "Space-Sky-Ground-Depth" integrated exploration technology including remote sensing monitoring, transient electromagnetic detection, fretting exploration, TRT advance forecast, engineering geological drilling, and 3D laser scanning were used to detect the goaf accurately. Combining key techniques and methods of multi-scale monitoring, the model was built, confirming the location, shape, volume, and other 3D spatial data of the goaf, which provided a good foundation for stowing governance. This comprehensive survey method pioneered the integration of a variety of technical means, has the advantages of high efficiency, accurate data, and intuitive results, and has great promotional value for the survey of blind goaf areas. [ABSTRACT FROM AUTHOR]