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In order to find corrosion and other defects of downhole tubing as early as possible in oil and gas production，and to ensure safe and efficient production of oil and gas，the article gave an overview of existing downhole corrosion inspection techniques and monitoring techniques for oil and gas wells both domestically and internationally.The application of the above techniques in domestic oil and gas fields were analyzed，and the prospects for the development of related techniques were putted forward.Furthermore，it was considered that improving the reliability and adaptability of the technology and equipment and achieving online monitoring and real-time monitoring were very important directions of researches.

Objective: Exploring the effects of miR-155 regulation of SMAD2 expression in podocyte injury as well as macrophage inflammatory response in mouse lupus nephritis. Methods: The experimental mice were randomly divided into blank, model, AAV9-miR-NC, AAV9-miR-155, AAV9-miR-anti, and AAV9-miR-anti-NC groups, with 8 mice in each group, of which the blank group was C57BL/6 mice, and the rest of the groups were MRL/lpr mice, and the groups were treated and sampled accordingly. The presence or absence of a binding site for miR-155 and SMAD2 was predicted by target genes, an online target gene prediction website. Dual luciferase reporter gene analysis system to validate the targeting relationship between miR-155 and SMAD2. Determination of 24 h urinary protein content in each group of mice by Caumas Brilliant Blue method. Hematoxylin-Eosin staining was used to observe the kidney tissues of mice ; qRT-PCR to detect the expression level of miR-155 in kidney tissues of each group. Western blot was used to detect nephrin, P-cadherin and SMAD2 protein expression in renal tissues. Immunofluorescence assay to detect the expression of inflammatory factors (IL-6, TNF-α) in mice. Results: Compared with the blank group, mice in the model group had elevated urinary protein, severe renal pathological damage, and decreased expression levels of nephrin, P-cadherin, and SMAD2 while increased expression levels of IL-6 and TNF-α in renal tissues (P<0.05). Compared with the model group and AAV9-miR-NC group, mice in the model group of AAV9- miR-155 group showed elevated urinary protein, obvious renal pathological damage, and obvious elevation of miR-155 in renal tissues, whereas the expression levels of nephrin, P-cadherin, and SMAD2 were decreased (P<0.05) whereas the fluorescence intensity of IL-6 and TNF-α was enhanced significantly; Compared with the model and AAV9-miR-anti-NC groups, mice in the AAV9-miR-anti group showed decreased urinary protein, improved renal pathological injury, decreased miR-155 expression, and increased expression levels of nephrin, P-cadherin, and SMAD2 compared to the model group (P<0.05) whereas the fluorescence intensities of IL-6 and TNF-α decreased; In the model group, AAV9-miR-NC group, and AAV9-miR-anti-NC group mice, the differences in the above indexes were not statistically significant (P>0.05). Dual luciferase reporter gene assay showed that miR-155 inhibited the fluorescence activity of wild-type SMAD2 cells and targeted the regulation of SMAD2 expression. Conclusion: High expression of miR-155 exacerbated podocyte injury and inflammatory response in lupus nephritis in mice by regulating SMAD2, whereas inhibition of miR-155 expression attenuated podocyte injury and inflammatory response in mice. [ABSTRACT FROM AUTHOR]

In order to clarify the effects of varying steam dryness on cut tobacco quality in different processes of tobacco primary processing, experiments were conducted during the tobacco-steam direct contact process of a tunnel-type tobacco conditioner and the tobacco-steam non-direct contact process of a cylinder dryer. The results showed that: 1) In the direct contact process, with the increase of steam dryness, the tobacco temperature increased while the moisture content in cut tobacco decreased. When the steam dryness exceeded 85%, the mass fractions of total plant alkaloids, total water-soluble sugars, reducing sugar, potassium, and chlorine in cut tobacco gradually increased. There was no significant change in the quantities of chemical components in mainstream smoke of cigarettes under different steam dryness, and the sensory quality of cigarettes improved with the increase in steam dryness. Therefore, in the direct contact process, steam dryness should preferably be above 85%. 2) In the non-direct contact process, with the increase of steam dryness, the dehydration rate of cut tobacco increased, while the SD of moisture content in cut tobacco decreased. When the steam dryness exceeded 80%, the stability of moisture content in cut tobacco gradually increased. There was no significant change in the quantities of chemical components in mainstream smoke of cigarettes under different steam dryness, and the sensory quality of cigarettes improved significantly when the steam dryness exceeded 90%. Therefore, the steam dryness should preferably be above 90% for the non-direct contact process. [ABSTRACT FROM AUTHOR]

This paper investigated the influence of water-borne epoxy resin emulsion (WER) dosage on the properties of modified emulsified asphalt and analyzed the modification mechanism of WER on emulsified asphalt. Water-borne epoxy modified emulsified asphalt was used to prepare MS-2 micro-surfacing mixture, and dispersed demulsifier was introduced to improve the construction performance of the mixture. The best content of each component and the best asphalt -aggregate ratio were obtained through orthogonal test. The results show that 6% water-borne epoxy emulsion asphalt has the best compatibility and storage stability. With the increase of water-borne epoxy content, the low-temperature performance of water-borne epoxy emulsion asphalt becomes worse and the anti-aging performance increases. The optimum asphalt-aggregate ratio of MS-2 micro-surfacing is 7.5%. When the added water is 3%, the cement content is 1%, and the dispersed demulsifier content is 0.25%, the prepared micro-surfacing has good water damage resistance, rutting resistance, tensile strength and cohesiveness, which can meet the normal use requirements of pavement. [ABSTRACT FROM AUTHOR]

In order to promote the uniformity of tobacco flavoring and flavor absorption, and reduce the pollution to environment, EDEM simulation software was used to simulate the movement of tobacco in a flavoring cylinder based on discrete element method. The number and shape of paddles, the rotational speed of cylinder and atomizing device were optimized through analyzing the movement trajectory and separation ratio of cut tobacco at different numbers of paddles and different rotational speeds of cylinder. An SJ236B flavoring cylinder manufactured by Kunming Marine Equipment Group Limited Corporation was tested and the contents of characteristic aroma components in 1 g of flavored cut tobacco were determined before and after optimization. The results showed that: after optimization, the RSD of methyl β-orcinolcarboxylate in tobacco decreased from 19.81% to 5.68% and that of benzyl benzoate decreased from 16.14% to 6.06% ; the desorption rate of methyl β-orcinolcarboxylate increased from 46.49% to 62.78% and that of benzyl benzoate increased from 24.34% to 65.40% ; the concentration of total non-methane hydrocarbon in the air around the flavoring cylinder reduced by more than 70%. This technology provides a support for improving the uniformity of cut tobacco flavoring. [ABSTRACT FROM AUTHOR]

Monolithic alumina aerogels were prepared by epoxide-assisted sol-gel method and supercritical drying technique using AlCl3 ⋅ 6H2O as raw material and Sr(NO3)2 as additive. The effects of SrO addition on thermal stability of alumina aerogels was investigated. The samples were characterized by X-ray diffraction (XRD), N2 adsorption-desorption method and field emission scanning electron microscopy (FESEM). The results show that alumina aerogel doped with SrO consist of lamellar and needle-like particles which are overlapped with each other to form a three-dimensional porous network structure. The SrO can obviously inhibit the phase transition of alumina aerogels at high temperature. With the increase of SrO content, the specific surface area of alumina aerogels increase. After calcination at 1 200 °C, SrO ⋅ 6Al2O3 phase is found in the aerogel with SrO content of 5 wt%, which preventing the phase transition of alumina aerogel. The surface area of alumina aerogel with 5 wt% SrO is 122 m²/g, which is 113 m²/g higher than that of pure alumina aerogel. [ABSTRACT FROM AUTHOR]

In this paper, field studies were conducted to determine the potential of alterations in physiology, and the intraspecific differences in sensitivity of 10 wheat (Triticum aestivum) cultivars to enhanced UV-B radiation. The supplemental UV-B radiation was 5.00 kJ x m(-2), simulating a depletion of 20% stratospheric ozone in Kunming area. The results showed that six of 10 tested wheat cultivars showed significant changes in total chlorophyll content, among which, chlorophyll a was strongly reduced, but chlorophyll b was reduced to a lesser extent, leading to a decrease in chlorophyll a/b ratio. The effects of UV-B on MDA and flavonoid contents also showed intraspecific difference. The MDA content of 5 cultivars was significant increased, while that of 2 cultivars was decreased. Four cultivars had significantly increased flavonoid content, but the flavonoid content in 2 cultivars was significantly decreased. The changes of chlorophyll and flavonoid contents were significantly correlated with the content of MDA(r = -0.78, P < 0.01 and r = -0.75, P < 0.05 respectively). There was a correlation between flavonoid and anti-UV-B radiation of wheat.