Black carbon and organic carbon dataset over the Third Pole

The Tibetan Plateau and its surroundings, also known as the Third Pole, play an important role in the global and regional climate and hydrological cycle. Carbonaceous aerosols (CAs), including black carbon (BC) and organic carbon (OC), can directly or indirectly absorb and scatter solar radiation and change the energy balance on the Earth. CAs, along with the other atmospheric pollutants (e.g., mercury), can be frequently transported over long distances into the inland Tibetan Plateau. During the last decades, a coordinated monitoring network and research program named “Atmospheric Pollution and Cryospheric Changes” (APCC) has been gradually set up and continuously operated within the Third Pole regions to investigate the linkage between atmospheric pollutants and cryospheric changes. This paper presents a systematic dataset of BC, OC, water-soluble organic carbon (WSOC), and water-insoluble organic carbon (WIOC) from aerosols (20 stations), glaciers (17 glaciers, including samples from surface snow and ice, snow pits, and 2 ice cores), snow cover (2 stations continuously observed and 138 locations surveyed once), precipitation (6 stations), and lake sediment cores (7 lakes) collected across the Third Pole, based on the APCC program. These data were created based on online (in situ) and laboratory measurements. High-resolution (daily scale) atmospheric-equivalent BC concentrations were obtained by using an Aethalometer (AE-33) in the Mt. Everest (Qomolangma) region, which can provide new insight into the mechanism of BC transportation over the Himalayas. Spatial distributions of BC, OC, WSOC, and WIOC from aerosols, glaciers, snow cover, and precipitation indicated different features among the different regions of the Third Pole, which were mostly influenced by emission sources, transport pathways, and deposition processes. Historical records of BC from ice cores and lake sediment cores revealed the strength of the impacts of human activity since the Industrial Revolution. BC isotopes from glaciers and aerosols identified the relative contributions of biomass and fossil fuel combustion to BC deposition on the Third Pole. Mass absorption cross sections of BC and WSOC from aerosol, glaciers, snow cover, and precipitation samples were also provided. This updated dataset is released to the scientific communities focusing on atmospheric science, cryospheric science, hydrology, climatology, and environmental science. The related datasets are presented in the form of excel files. BC and OC datasets over the Third Pole are available to download from the National Cryosphere Desert Data Center (10.12072/ncdc.NIEER.db0114.2021; Kang and Zhang, 2021)

Clustering Algorithm Based on the Ground-Air Cooperative Architecture in Border Patrol Scenarios

The border security situation is complex and severe, and the border patrol system relying on the ground-air cooperative architecture has been paid attention to by all countries as an important means of protecting national security. In the flying ad-hoc network (FANET), under the ground-air cooperative architecture, an unmanned aerial vehicle (UAV) uses a patrol mobility model to improve patrol efficiency. Since the patrol mobility model leads to frequent changes in UAV movement direction to improve patrol efficiency, selecting some clustering utility factors and calculating utility factors in previous clustering algorithms do not apply to this scenario. To solve the above problems, in this paper, we propose a border patrol clustering algorithm (BPCA) based on the ground-air cooperative architecture, which is based on the existing weighted clustering algorithm and improved in terms of the selection of utility factors and calculations of utility factors in cluster head selection. This algorithm comprehensively considers the effects of relative speed, relative distance, and the movement model of the UAV on the network topology. Extensive simulation results show that this algorithm can extend the duration time of cluster heads and cluster members and improve the stability of clusters and the reliability of links

Optimisation on the microwave drying of ammonium polyvanadate (APV):based on a kinetic study

Abstract Vanadium pentoxide (V₂O₅) is one of the fundamental materials applied in the productions of batteries, vanadium-aluminium alloys, biomedicine, catalysis, etc. High purity V₂O₅ can be prepared from an intermediate product, namely ammonium polyvanadate (APV), using roasting after a drying process. In this paper, microwave heating was used as an alternative drying option for APV, which has advantages including selective heating, high heating efficiency, energy-saving, and environmental protection. The authors investigated the microwave heating characteristics of APV and discussed the effects of microwave power, the mass of APV, and initial water content on the efficiency of microwave drying. The dynamic analysis of the APV microwave drying process was also carried out. Four groups of thin-layer drying dynamic models, namely Modified-Page model, Verma model, Sickmplified-Fick’s-diffusion model, and Two-term-exponential model, were fitted with the experimental data. Through comparison, the Modified Page model could better describe the microwave drying process of APV

Resection of high-grade glioma involving language areas assisted by multimodal techniques under general anesthesia: a retrospective study

Abstract Background Multimodal techniques-assisted resection of glioma under general anesthesia (GA) has been shown to achieve similar clinical outcomes as awake craniotomy (AC) in some studies. In this study, we aim to validate the use of multimodal techniques can achieve the maximal safe resection of high-grade glioma involving language areas (HGILAs) under GA. Methods HGILAs cases were reviewed and collected between January 2009 and December 2020 in our center. Patients were separated into multimodal group (using neuronavigation, intraoperative MRI combined with direct electrical stimulation [DES] and neuromonitoring [IONM]) and conventional group (neuronavigation alone) and clinical outcomes were compared between groups. Studies of HGILAs were reviewed systematically and the meta-analysis results of previous (GA or AC) studies were compared with our results. Results Finally, there were 263 patients in multimodal group and 137 patients in conventional group. Compared to the conventional group, the multimodal group achieved the higher median EOR (100% versus 94.32%, P < 0.001) and rate of gross total resection (GTR) (73.8% versus 36.5%, P < 0.001) and the lower incidence of permanent language deficit (PLD) (9.5% versus 19.7%, P = 0.004). The multimodal group achieved the longer median PFS (16.8 versus 10.3 months, P < 0.001) and OS (23.7 versus 15.7 months, P < 0.001) than the conventional group. The multimodal group achieved a higher rate of GTR than the cohorts in previous multimodal studies under GA and AC (73.8% versus 55.7% [95%CI 32.0–79.3%] versus 53.4% [35.5–71.2%]). The multimodal group had a lower incidence of PLD than the cohorts in previous multimodal studies under GA (9.5% versus 14.0% [5.8–22.1%]) and our incidence of PLD was a little higher than that of previous multimodal studies under AC (9.5% versus 7.5% [3.7–11.2%]). Our multimodal group also achieved a relative longer survival than previous studies. Conclusions Surgery assisted by multimodal techniques can achieve maximal safe resection for HGILAs under GA. Further prospective studies are needed to compare GA with AC for HGILAs

Optimisation on the stability of CaO-doped partially stabilised zirconia by microwave heating

Abstract Partially stabilised zirconia has advantages for the applications in the metallurgical processes which have special requirements in corrosion resistance and high-temperature performance. In the present work, controllable microwave heating was used for the uniform thermal field and consequent microstructure improvement to further improve the stability of partially stabilised zirconia, which was 88.14% prepared by electric arc melting. Analyses including X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy (Raman) were used to study the effect of temperature change on the phase composition and structure of the samples. After heating at temperatures of 900 °C, 1000 °C, 1100 °C, 1200 °C and 1300 °C for 1h, the stabilities of the heated product were 88.51%, 95.02%, 95.17%, 96.31% and 97.64%, respectively. From the phase transformations based on the experimental results, the discussion indicates that the martensitic transformation temperature of zirconia from m-ZrO₂ to t-ZrO₂ during the heating stage was reduced under the radiation of microwave energy

Research on microwave drying technology in the procedure of preparation of V₂O₅ from ammonium polyvanadate (APV)

Abstract High-quality vanadium pentoxide powder is an important product of the vanadium industry and was usually prepared from ammonium polyvanadate (APV) using a roasting process combined with a drying pretreatment. Conventional hot air drying is usually used for the drying of APV, the heat transfer of which is from outside to inside thus limited the efficiency of the drying pretreatment. In the present paper, microwave heating was applied as an alternative heating method for the drying of APV because of its advantages including selective heating, high heating efficiency, low energy consumption, and green environmental protection. An experimental comparison between hot air drying and microwave drying is provided, and the results show that microwave drying is more energy-saving and faster. The drying characteristics of APV under the irradiation of microwave energy were investigated. The influences of factors including microwave power, material quality, and initial moisture content on microwave drying were studied. The results show that the microwave power, initial moisture content, and initial mass are positively proportional to the microwave drying efficiency of APV. Additionally, the Page model was robust in describing the kinetics of microwave drying and hot air drying of APV. This study provides fundamental knowledge on the microwave drying process and provides the trial for the industrial applications of microwave heating on the preparation of V₂O₅

Drying kinetics and microstructure evolution of nano-zirconia under microwave pretreatment

Abstract The effects of microwave power and sample quality on microwave drying kinetics and characteristics of zirconia were studied. It is found that by increasing the microwave power and decreasing the sample mass, the surface diffusion coefficient (Deff) appears to an upward tendency. The corresponding value Deff at a sample mass of 10, 20, 30, and 40g are 1.849E-14, 2.443E-14, 3.210E-14, and 3.278E-14 m²/s, respectively. The corresponding value Deff at a microwave power of 300, 400, 500, 600, and 700W are 1.270E-14, 1.784E-14, 2.619E-14, 3.392E-14, and 4.497E-14 m²/s, respectively. Besides, the materials were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR) to evaluate the changes of materials before and after drying. The results show that microwave accelerates the drying of zirconia and increases its dispersibility. The heat conduction direction of microwave drying is the same as that of moisture diffusion, which avoids being affected by heat inertia and heat transfer loss. The drying process is fast and efficient, and the microwave directly penetrates the product, avoiding the disadvantage of slow evaporation caused by the temperature gradient

Effect of microwave heating duration on the stability of the partially stabilised zirconia doped with CaO

Abstract In this paper, the stability of CaO doped partially stabilised zirconia (CaO-PSZ) prepared by electrofusion method was improved from 88.14% to 95% within one hour using the microwave heating method. The increase of the stability rate was because of the microwave heating method’s advantages, including selective heating and fast heating. Analysis techniques, namely X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Raman spectroscopy, and scanning electron microscopy (SEM), were used to analysis the influences of the holding time (1–4 h) on the CaO doped PSZ samples at a heating temperature of 1100 °C to understand the fundamental mechanism of the optimisation process. The Raman and XRD spectra were fitted by the Gaussian method to further analysis the effect of holding time on the microstructure evolution of the samples. The fitting results indicated that the sample’s crystal quality and stability were improved after microwave heating, and the optimised holding time is 2h