Prediction and test of stable transmission time of spiral bevel gear during a loss-of-lubrication event in helicopter transmission system

Purpose This paper aims to establish a prediction model of stable transmission time of spiral bevel gear during a loss-of-lubrication event in helicopter transmission system. Design/methodology/approach To observe the temperature change of spiral bevel gear during working condition, a test rig of spiral bevel gear was developed according to the requirements of experiments and carried out verification experiments. Findings The prediction is verified by the test of detecting the temperature of oil pool. The main damage form of helicopter spiral bevel gears under starved lubrication is tooth surface burn. The stable running time under oil-free lubrication is mainly determined by the degree of tooth surface burn control. Originality/value The experimental data of the spiral bevel gear oil-free lubrication process are basically consistent with the simulation prediction results. The results lay a foundation for the working life design of spiral bevel gear in helicopter transmission system under starved lubrication.

Stable transmission characteristics of double-hump solitons for the coupled Manakov equations in fiber lasers

The fiber laser has become an ideal ultrashort pulse source because of its cheap structure, high integration, convenient and controllable output direction, which greatly promotes the development and application of ultrafast optics. This paper mainly focuses on the control and amplification of double-hump solitons in fiber lasers theoretically. The bilinear forms and soliton solutions of the coupled Manakov equations are presented, and the transmission of double-hump solitons is discussed. The factors affecting the stable transmission of double-hump solitons are analyzed. The relevant conclusions have important guiding significance for understanding the generation of stable double-hump solitons in fiber lasers.

The impact of large and small dams on malaria transmission in four basins in Africa

Expansion of various types of water infrastructure is critical to water security in Africa. To date, analysis of adverse disease impacts has focused mainly on large dams. The aim of this study was to examine the effect of both small and large dams on malaria in four river basins in sub-Saharan Africa (i.e., the Limpopo, Omo-Turkana, Volta and Zambezi river basins). The European Commission’s Joint Research Center (JRC) Yearly Water Classification History v1.0 data set was used to identify water bodies in each of the basins. Annual malaria incidence data were obtained from the Malaria Atlas Project (MAP) database for the years 2000, 2005, 2010 and 2015. A total of 4907 small dams and 258 large dams in the four basins, with 14.7million people living close (< 5 km) to their reservoirs in 2015, were analysed. The annual number of malaria cases attributable to dams of either size across the four basins was 0.9–1.7 million depending on the year, of which between 77 and 85% was due to small dams. The majority of these cases occur in areas of stable transmission. Malaria incidence per kilometre of reservoir shoreline varied between years but for small dams was typically 2–7 times greater than that for large dams in the same basin. Between 2000 and 2015, the annual malaria incidence showed a broadly declining trend for both large and small dam reservoirs in areas of stable transmission in all four basins. In conclusion, the malaria impact of dams is far greater than previously recognized. Small and large dams represent hotspots of malaria transmission and, as such, should be a critical focus of future disease control efforts.

Homozygous spinocerebellar ataxia type 3 in China: a case report

Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disease caused by a heterozygous CAG repeat expansion in the ataxin 3 gene ( ATXN3). However, patients with homozygous SCA3 carrying expanded CAG repeats in both alleles of ATXN3 are extremely rare. Herein, we present a case of a 50-year-old female who had homozygous SCA3 with expansion of 62/62 repeats. Segregation analysis of the patient’s family showed both a contraction pattern of CAG repeat length and stable transmission. The present case demonstrated an earlier onset and more severe clinical phenotype than that seen in heterozygous individuals, suggesting that the gene dosage enhances disease severity.

Generation of Doubled Haploid Wheat-Triticum urartu Introgression Lines and Their Characterisation Using Chromosome-Specific KASP Markers

Wheat is one of the most important food and protein sources in the world and although, in recent years wheat breeders have achieved yield gains, they are not sufficient to meet the demands of an ever-growing population. Development of high yielding wheat varieties, resilient to abiotic and biotic stress resulting from climate change, has been limited by wheat’s narrow genetic base. In contrast to wheat, the wild relatives of wheat provide a vast reservoir of genetic variation for most, if not all, agronomic traits. Previous studies by the authors have shown the transfer of genetic variation from T. urartu into bread wheat. However, before the introgression lines can be exploited for trait analysis, they are required to have stable transmission of the introgressions to the next generation. In this work, we describe the generation of 86 doubled haploid (DH) wheat-T. urartu introgression lines that carry homozygous introgressions which are stably inherited. The DH lines were characterised using the Axiom® Wheat Relative Genotyping Array and 151 KASP markers to identify 65 unique T. urartu introgressions in a bread wheat background. DH production has helped accelerate the breeding process and facilitated the early release of homozygous wheat-T. urartu introgression lines. Together with the KASP markers, this valuable resource could greatly advance identification of beneficial alleles that can be used in wheat improvement.

Building of online evaluation system based on socket protocol

As an important part of the evaluation reform, online evaluation system can effectively improve the efficiency of evaluation work, which has been paid attention by teaching institutions. The online evaluation system needs to support the safe and stable transmission of information between the client and the server, and socket protocol establishes the connection through the listening port, which can easily carry out the message transmission and process control. Because it can well meet the construction requirements of online evaluation system, it is applied in our study. The building of online evaluation system based on socket protocol includes the function design of students and teachers, data flow design, evaluation difficulty grading design and system implementation. The system uses Java language and MVC mode for development, which has good scalability and platform-independence. It realizes the paperless examination process and greatly reduces the workload of teachers. The contribution of this paper is mainly reflected in two aspects. One is to explore the construction of an online evaluation system based on the socket protocol, and it provide an Asynchronous IO technical solution for the network communication between the student and the server, which provides a reference for the development of similar systems. The second is to give the realization method of the difficulty classification of the evaluation, and classify the difficulty of the test questions, which lays the foundation for carrying out personalized testing and evaluation.