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In order to effectively provide guidance for the selection of aircraft dissimilar metals from the perspective of corrosion protection, the corrosion behavior of typical aircraft lap structures was studied by finite element simulation and corrosion test for the specific service environment of aircraft. The aluminum alloy, composite material and lap joints were subjected to cyclic immersion corrosion test in the laboratory. Then the galvanic corrosion law between aluminum alloy and composite was revealed by polarization curve measurement test, macroscopic and microscopic morphology observation, fatigue test and XRD measurement. Taking the electrochemical parameters measured by polarization curve as boundary conditions, the corrosion simulation model of lap joint was established. After 0 cycle and 10 cycles of cyclic immersion corrosion test, the results show that the self-corrosion potential and self-corrosion current density of aluminum alloy are -802 mV and 2.357×10-7 A/cm2, -872 mV and 1.477×10-6 A/cm2. The self-corrosion potential and self-corrosion current density of composite material are -240 mV and 6.217×10-7 A/cm2, -98 mV and 2.286×10-7 A/cm2, respectively. With the extension of the corrosion cycle, 7B04 aluminum alloy shows a trend of increasing self-corrosion rate and negative shift of self-corrosion potential, while composite material shows a trend of positive shift of self-corrosion potential and slowly increasing self-corrosion rate. The corrosion products of lap joints gradually increase and the corrosion degree becomes more and more serious. With the extension of corrosion cycle, fatigue life decreases and the depth of corrosion pits increases. The corrosion products include Al(OH)3, Al2O3, AlCl3. The simulation results of lap joints are in good agreement with cyclic immersion corrosion test results. The corrosion prone parts of the typical lap structure of the aircraft were given, and the law of galvanic corrosion was revealed, which points out the direction for the corrosion protection of the aircraft structure.

Early Permian fusulinids from both northern and southern parts of the Baoshan Block (western Yunnan, Southwest China) are illustrated and compared with coeval fusulinid faunas from other northern peri-Gondwana areas to disclose paleogeographic information. Systematic study of collected fusulinid materials and examination of published data from the Dingjiazhai area, northern Baoshan Block, show that fusulinids there include Eoparafusulina pseudosimplex and Pseudofusulina macilenta. Fusulinids from the Aluotian Section, southern Baoshan Block, consist of P. minituinidiscula n. sp., P. inacilenta, P. turnidiscula, E. pseudosimplex, E. aff. E. laudoni, and E. sp. Early Permian fusulinids from both northern and southern Baoshan Blocks are dominated by Pseudofusulina and Eoparafusulina species and they are similar to those from Central Pamir, South Afghanistan, East-Central Iran, Central Oman, East Hindu Kush and northern Karakorum, revealing a Sakmarian to Artinskian age. Moreover, detailed comparison shows that the Early Permian fusulinid assemblage from the Baoshan Block is more similar to those from East-Central Iran, Central Pamir and South Afghanistan. This implies that the Baoshan Block may have been near those areas during the Early Permian. [ABSTRACT FROM AUTHOR]

Two Permian fusulinid faunas, including nine species belonging to six genera, from the northern Tengchong Block, Southwest China, are studied and compared with the coeval fusulinid faunas from other blocks with Gondwana-affinity and South China. In the Kongshuhe section, the fauna is dominated by Eoparafusulina in the lower part of the Dadongchang Formation and possibly suggests an age of Sakmarian, while in the Shanmutang section, the fauna from the middle of the Dadongchang Formation mainly consists of Chusenella mingguangensis n. sp. and Monodiexodina gigas n. sp., indicating a Wordian to Capitanian age. Study has also demonstrated that fusulinid faunas from the Tengchong Block shared similar features with the contemporary faunas from the Baoshan Block and Sibumasu Block in the low generic and specific diversities and the absence of the taxa commonly found in Cathaysia Tethys areas, such as the Pseudoschwagerinidae, Verbeekinidae, and Neoschwagerinidae. However, visible differences in species composition still exist between the faunas of the Tengchong Block and those of the other two blocks, revealing an apparent regional feature in the faunas of the Tengchong Block. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical features and therapeutic effects of sudden deafness after radiotherapy combined with chemotherapy in nasopharyngeal carcinoma patients., Method: Clinical data of 42 nasopharyngeal carcinoma patients suffered from sudden deafness after radiotherapy combined with chemotherapy were analyzed retrospectively. Among the 42 patients, 2 showed moderate deafness, 4 presented excessive deafness, 30 suffered from severe deafness, and 6 exhibited profound deafness. The audiogram pattern of 33 patients met with the type of high tone frequencies hearing loss, and that of the rest 9 cases showed hearing loss at all frequencies. All patients received medical therapy combined with hyperbaric oxygen therapy., Result: Of all the cases with hearing loss, 2 were cured, 2 showed excellent recovery, 9 came out partial recovery, and 29 showed no response to the treatment. The total effective rate was 30.95%. For the accompanied symptoms, none of the 30 cases of tinnitus were relieved, 3 out of 10 cases of aural fullness were cured, and the 5 cases of dizziness or vertigo were all improved., Conclusion: The sudden deafness after radiotherapy combined with chemotherapy in patients with nasopharyngeal carcinoma is closely related to radiotherapy. The hearing loss is serious, and the therapeutic effects are not satisfactory.