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With the development of mobile Internet technology,social media has become the main approach for the public to share views and express their emotions.Sentiment analysis for social media texts in major social events can effectively monitor public opinion.In order to solve the problem of low accuracy and efficiency of existing Chinese social media sentiment analysis algorithms,an ensemble sentiment analysis big data method(S-FWS) based on Spark distributed system is proposed.Firstly,the new words are found by calculating the PMI association degree after pre-segmentation by Jieba library.Then,the text features are extracted by considering the importance of words and feature selection is realized by Lasso.Finally,in order to improve the traditional Stacking framework neglecting the feature importance,the accuracy information of the primary learners is used to weight the probabilistic features,and the polynomial features are constructed to train the secondary learner.A variety of algorithms are introduced in the stand-alone mode and the Spark platform receptively to carry out comparative experiments.Results show that the S-FWS method proposed in this paper has certain advantages in accuracy and time consumption;distributed system can greatly improve the operating efficiency of the algorithms,and with the increase of working nodes,the time consumption of the algorithms gradually decreases.

BACKGROUND Hydrogen and oxygen isotopes can be used to identify water sources and trace water cycles and have been used in hydrogeochemistry since the 1950s. Studies have been carried out on stable isotopes of atmospheric precipitation, rivers and lakes in Xinjiang.However, the research on hydrogen and oxygen isotopes of waters in Altay is scarce, except for atmospheric precipitation. Researchers found that the rainfall in the Altai Mountains during the warm season (April-October) increased significantly from 1959 to 2014. Due to this background of climate condition changes, it is meaningful to study the hydrogen and oxygen isotope compositions of various types of water bodies in the Altay region, at the southern foot of the Altai Mountains. OBJECTIVES To obtain the basic data of hydrogen and oxygen isotopic composition of water in Altay and reveal their spatial distribution characteristics. METHODS Hydrogen and oxygen isotope compositions of river water, lake water, spring water, snow water, and water from a mine pit in the Altay region of Xinjiang were determined by liquid water laser isotope analyzer (LGR DT100, America). The dissolved oxygen (DO), TDS, T, and pH of the water samples were measured using the German WTW3430 multi-parameter water quality analyzer. The concentrations of Na+, K+, Ca2+, and Mg2+ were analyzed by inductively coupled plasma-optical emission spectrometry (PE8300, PerkinElmer, USA). The concentrations of HCO3- and CO32- were determined by alkali titration method. Cl- and SO42- concentrations were analyzed by ion chromatography method. RESULTS The results showed that the ranges of δ18O and δD of the waters in the Altay area were from -15.4‰ to -5‰ and from -121‰ to -49‰, respectively. The hydrogen and oxygen isotope content of various types of water in the Altay region were significantly different. The δ18O and δD values of river waters varied from -15.4‰ to -11.5‰ and from -114‰ to -100‰, respectively, and the deuterium excess parameter varied from -12.4‰ to 12.4‰. The δ18O and δD of Ulungur Lake were much higher than those of surface rivers, with an average value of -5.95‰ and -78.5‰, respectively. The deuterium excess parameter of Ulungur Lake was much lower than those of surface rivers, with an average value of -30.9‰. The δ18O value (-14.9‰ and -11.8‰) of groundwater was similar to that of surface rivers, but δD (-114‰ and -121‰) was slightly higher than that of surface rivers, indicating that groundwater was supplied by surface rivers but may be affected by water-rock reactions. The δ18O and δD values of snow water and the water from a mine pit were -11.8‰ and -90‰, -11.6‰ and -106‰, respectively. The fitting lines for hydrogen and oxygen isotopes of the Irtysh River and Ulungur River were δD=1.7297δ18O-83.879 and δD=1.986δ18O-76.5, respectively. Surface rivers were remarkably different from the global and Urumqi atmospheric precipitation lines, indicating that apart from atmospheric precipitation, surface rivers were also recharged by glacier meltwater, and underwent evaporation and isotope fractionation during the water cycle.Due to the temperature and latitude effect of hydrogen and oxygen isotopes, the δD and δ18O showed significant positive correlation relationships with T, TDS, and the molar concentration of major ions such as Na+, K+, Ca2+, Cl-, and SO42-, also showing a significant negative correlation with the latitude of the sampling sites and DO (P < 0.05, n=32). CONCLUSIONS The hydrogen and oxygen isotope composition characteristics obtained in this study provide basic data for the stable isotope research of various types of water bodies in the Altay area.The precipitation in Altay has increased significantly in recent decades. Due to this background, it is indeed necessary to continue to conduct long-term and in-depth systematic research on the composition of hydrogen and oxygen isotopes in Altay's atmospheric precipitation and other types of water bodies.

Safe and efficient land-air communication is an important means to improve flight safety. It is necessary to comprehensively evaluate the functions, performance and system safety of the new intelligent system in order to use artificial intelligence(AI) technology to replace the function of flight crew. The detailed operation process of the artificial intelligence flight communication system and the interoperation interface of the avionics system are designed. The working principle and architecture of the artificial intelligence flight communication system, as well as the hardware implementation scheme and some pilot operational procedures are given. The advantages of AI technology instead of flight communicator function is conducted. Based on the analysis of system safety and communication performance, it is concluded that the scheme of the AI flight communicator system is feasible, and its performance is better than the original artificial air-ground communication system.

BACKGROUND When inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine the rare earth elements (REE) in the barite-associated light rare earth ores, Ba and light rare earth elements La, Ce, Pr, Nd, Sm, cause severe mass spectral overlap interference to the medium and heavy rare earths. Therefore, under the condition that complete digestion of oress, if the appropriate pretreatment method can be selected to achieve effective separation of the target elements from the matrix, it will be beneficial to reduce mass spectrum interferences. OBJECTIVES To reduce the mass spectrum interferences by establishing a simple and effective pretreatment method for separation of rare earth elements from barium and other coexisting elements in barite-associated rare earth ores. METHODS The barite-associated rare earth ores samples were fused with sodium peroxide and sodium carbonate. After dissolution of the fusion cake, the target REE and the undesired barium were precipitated in triethanolamine solution, but some matrix elements like Si, Fe, Mg, and Al in samples, and most fusion agents, were separated by filtration. The target REE were secondly precipitated in ammonium hydroxide after dissolution of the precipitates by acid, so that Ba, Sr and Ca could be separated from REE. The separation exceeds 96%, so the mass spectrum interferences caused by barium polyatomic ions were effectively reduced. In addition, the interference correction coefficients by measuring the interference concentration at m/z 138-175 of the high concentration lighter rare earths standard single element solution were adopted to account for the oxide and hydroxide overlap problem for the determination of middle and heavier rare earth elements. RESULTS The validity of the method was evaluated by analyses of rare earth ores certified reference materials and the results were in good agreement with certified values (|RE| < 10%). For the actual sample analysis of the barite-associated rare earth ores, the relative standard deviations (n=12) were from 0.5% to 4.6%, which proved that the method can be used to analyze rare earth elements in high-Ba ores. CONCLUSIONS The results demonstrate that this method is both practical and effective for rare earth elements analysis in barite-associated rare earth ores.

BACKGROUND The Sichuan Jiajika ore field is one of the most concentrated areas of lithium resources in China and even in the world. At present, the understanding of the spectroscopy of the Jiajika lithium deposit is still very poor. OBJECTIVES To better understand the spectra of lithium ore deposits and provide the basis for hyperspectral study of lithium ore deposits by spectrum measurement of typical rocks. METHODS Spectra of typical rocks and minerals collected in Jiajika area were measured by Analytical Spectral Devices (ASD) FieldSpec-4 Spectroradiometer and a spectral library of this area was built. The spectral characteristics of rocks and minerals including biotite schist, grenatiteschist, grenatite cordieriteschist, hornstone, granite, pegmatite containing spodumene, pegmatite without spodumene, quartz vein, feldspar, spodumenemono, biotite, aquamarine were analyzed. RESULTS The results indicate that there are differences in spectral characteristics between rock masses and surrounding rocks. The reflectance of surrounding rocks is less than 0.2, and absorption characteristics are not obvious, whereas the reflectance of rock masses is less than 0.5, and there are three absorption features at 1413 nm, 1911 nm, 2197 nm. In addition, granite, pegmatite containing spodumene, and pegmatite without spodumene can be discriminated by their unique spectra on 1413 nm and 2197 nm. The unique spectral characteristics of spodumene and aquamarine can be applied for ore exploration. CONCLUSIONS The research on the surface spectroscopy of the Jiajika type lithium ore deposit carried out in this paper has important guiding significance for hyperspectral remote sensing mapping and geological prospecting.

BACKGROUND A new deposit type with a scheelite-beryl-molybdenite assemblage was first discovered in the Zhen'an area of Shaanxi Province. BAOBJECTIVES The research on chromatic mechanism and genetic mechanism of emerald was carried out. METHODS Combined with the geological survey, Electron Microprobe and in-situ Micro X-ray Diffractomer were used to conduct mineral research. RESULTS The emerald mainly occurs in the quartz (calcite) veins as euhedral crystal and is associated with scheelite. Both the core and rim of the emerald with high V2O3 contents of 0.64%-0.98% and 1.04%-1.42%, respectively, show an increased V2O3 trend from core to rim. Diffraction data show that the emerald is normal beryl and has two kinds of isomorphous substitution mechanism, Al↔Me2+ and Be↔Li. Vanadium is the main coloring element of emerald and was mainly derived from carbonaceous slate, mica schist, and dolomitic marble, whereas Be, Si and Al were derived from deep acidic igneous rocks. CONCLUSIONS The discovery provides basic geological data for the comprehensive development and utilization of tungsten and antimony mineral resources in the deposit, and indicates new prospecting directions for continued searching for rare metal deposits in the region and deep areas of the South Qinling.

'Mung Bean Rock' or 'Green Bean Rock' is a type of clay-like rock formed by Paleomatization and diagenesis. These rocks are distributed mainly between early and middle Triassic strata in Southwestern China and are good regionally isochronal mark beds. Studying the diagenetic age of 'Mung Bean Rock' is of great significance for further understanding of its diagenetic mechanism and age background. The debris zircon of 'Mung Bean Rock' in Chongqing Tongliang was used for U-Pb dating by LA-ICP-MS in this study. The zircon crystals have almost complete shape and zoning textures with high U and Th content, typical of magma zircon. Weighted average ages of the zircon 206Pb/238U peak at 245.86±0.98 Ma and 277.6±3.8 Ma. 'Mung Bean Rock' is located in the base of the Leikoupo Formation, the age of 245.86 Ma represents the timing of the zircons entering the sedimentary basin with volcanic ash at the base of the Leikoupo Formation in Tongliang, Chongqing. The age is similar to that of the tuff in Guizhou and Guangxi, indicating that regional volcanic eruption occurred at around 246 Ma. The older zircon was brought into the sedimentary basin during weathering of early igneous rocks and deposited with 'Mung Bean Rock'. A peak age at 277 Ma may imply that there was magmatic activity in the middle Permian period.

For high density polyethylene pipe connection，welding technology is the key of the high density engineering plastic pressure pipe safety. And the temperature distribution in the welding process has a very important influence on the welding quality. Polyethylene pipe weld joints of one dimensional unsteady overall heat transfer model is established by MARC software and simulates temperature field and stress field distribution of the welding process，and the thermocouple temperature automatic acquisition system of welding temperature field changes were detected，and compared by simulation and experiment .The results show that，at the end of the heating，the temperature of the pipe does not reach the maximum，but reached the maximum at 300 s，which indicates that the latent heat of phase change in the process of pressure welding. In the process of pressure welding， the axial stress of the pipe is gradually changed from tensile stress to compressive stress.

In this paper, the nonlinear dynamic behavior of a long hollow cylinder consisting of temperature-dependent functionally graded material (FGM) subjected to thermal shocking is investigated. Material parameters of the FGM hollow cylinder, except the Poisson’s ratio, are assumed to be graded continuously through the thickness according to the power law expressions, and they are assumed to be temperature dependent. The governing equation of the motion of the FGM hollow cylinder is obtained based on the plane-stain theory and together with the governing equation of the transient heat transfer problem is solved by the finite difference method, Newmark method, and iterative method. Numerical examples are carried out in which the Si3N4-SUS304 FGM hollow cylinders are considered, and some valuable dynamic thermoelastic characteristics of the FGM hollow cylinder subjected to symmetric or asymmetric thermal shocking are revealed.

This study proposes a two-channel fiber optic cable television (CATV) transport system based on Fabry–Perot laser diodes (FP-LDs) with a split band technique. To reduce the interference between channels, we apply the split band technique to two channels with different frequencies by using two converters at each moment. In this two-channel transmission scheme, composite second-order (CSO) and composite triple-beat (CTB) distortions induced by the systems are possibly confined in unused channels and result in good transmission performances. Through a 40 km standard single-mode fiber transmission, excellent performances of carrier-to-noise ratio (≥50 dB), CSO (≥70 dB), and CTB (≥72 dB) are obtained using the proposed fiber optic CATV transport systems. The proposed systems employing FP-LDs with a split band technique are also simpler and more cost effective than conventional externally modulated systems.