A Novel Gearbox Strength Check Method by Finite Element Analysis

In order to meet the design requirements of gearbox for different gears, a novel method to verify bolts and gearbox housing is applied, which reduced the time and cost of experimental testing. The finite element analysis of this article is divided into two parts. Firstly, the axial force of the bolt is calculated by finite element method, and the bolts are verified according to VDI2230 standard. Secondly, the force of the gearbox housing is calculated and the strength of the gearbox housing in different gears is verified. Results show that the maximum axial force exerted on the bolt is 4761.8N at the hole 16. The maximum stress value of the gearbox is 234.2 MPa in the first gear state, which closes to the tensile strength 240 MPa. The maximum stress value of the improved gearbox housing is reduced to 133.9 MPa, meeting the usage requirements. In addition, this article established a finite element verification process for the gearbox housing. Although the grid size and boundary conditions apply only to this type of gearbox, the analysis process is applicable to the static strength verification of any gearbox housing

The effect of symmetrical and asymmetrical hearing impairment on the music quality perception

The purpose of this study was to investigate the effect of symmetrical, asymmetrical and unilateral hearing impairment on music quality perception. Six validated music pieces in the categories of classical music, folk music and pop music were used to assess music quality in terms of its ‘pleasantness’, ‘naturalness’, ‘fullness’, ‘roughness’ and ‘sharpness’. 58 participants with sensorineural hearing loss [20 with unilateral hearing loss (UHL), 20 with bilateral symmetrical hearing loss (BSHL) and 18 with bilateral asymmetrical hearing loss (BAHL)] and 29 normal hearing (NH) subjects participated in the present study. Hearing impaired (HI) participants had greater difficulty in overall music quality perception than NH participants. Participants with BSHL rated music pleasantness and naturalness to be higher than participants with BAHL. Moreover, the hearing thresholds of the better ears from BSHL and BAHL participants as well as the hearing thresholds of the worse ears from BSHL participants were negatively correlated to the pleasantness and naturalness perception. HI participants rated the familiar music pieces higher than unfamiliar music pieces in the three music categories. Music quality perception in participants with hearing impairment appeared to be affected by symmetry of hearing loss, degree of hearing loss and music familiarity when they were assessed using the music quality rating test (MQRT). This indicates that binaural symmetrical hearing is important to achieve a high level of music quality perception in HI listeners. This emphasizes the importance of provision of bilateral hearing assistive devices for people with asymmetrical hearing impairment

Event Related Potential Evidence of Enhanced Visual Processing in Auditory Associated Cortex in Adults with Hearing Loss

Objective: The present study investigated the characteristics of visual processing in the auditory-associated cortex in adults with hearing loss using event-related potentials. Methods: Ten subjects with bilateral postlingual hearing loss were recruited. Ten age- and sex-matched normal-hearing subjects were included as controls. Visual (“sound” and “non-sound” photos)-evoked potentials were performed. The P170 response in the occipital area as well as N1 and N2 responses in FC3 and FC4 were analyzed. Results: Adults with hearing loss had higher P170 amplitudes, significantly higher N2 amplitudes, and shorter N2 latency in response to “sound” and “non-sound” photo stimuli at both FC3 and FC4, with the exception of the N2 amplitude which responded to “sound” photo stimuli at FC3. Further topographic mapping analysis revealed that patients had a large difference in response to “sound” and “non-sound” photos in the right frontotemporal area, starting from approximately 200 to 400 ms. Localization of source showed the difference to be located in the middle frontal gyrus region (BA10) at around 266 ms. Conclusions: The significantly stronger responses to visual stimuli indicate enhanced visual processing in the auditory-associated cortex in adults with hearing loss, which may be attributed to cortical visual reorganization involving the right frontotemporal cortex

Massive seasonal high-altitude migrations of nocturnal insects above the agricultural plains of East China

High-altitude, windborne movements of insects occur on an enormous scale, and have significant impacts on ecosystem function, provision of beneficial services, disease spread, and agricultural productivity. We used a combination of insect monitoring radar, balloon-borne nets, and searchlight traps to characterize the intensity, taxonomic composition, direction, and geographical extent of nocturnal insect “bioflows” occurring at heights to ~1 km above the agricultural lands of East China during spring, summer, and fall. We demonstrate seasonal northward and southward flows and show that the transport of insect biomass is considerably greater above this globally important food-production region than above the United Kingdom (the only other region where it has been quantified to date) and is dominated by species that are agricultural pests. Long-distance migrations of insects contribute to ecosystem functioning but also have important economic impacts when the migrants are pests or provide ecosystem services. We combined radar monitoring, aerial sampling, and searchlight trapping, to quantify the annual pattern of nocturnal insect migration above the densely populated agricultural lands of East China. A total of ~9.3 trillion nocturnal insect migrants (15,000 t of biomass), predominantly Lepidoptera, Hemiptera, and Diptera, including many crop pests and disease vectors, fly at heights up to 1 km above this 600 km-wide region every year. Larger migrants (>10 mg) exhibited seasonal reversal of movement directions, comprising northward expansion during spring and summer, followed by southward movements during fall. This north–south transfer was not balanced, however, with southward movement in fall 0.66× that of northward movement in spring and summer. Spring and summer migrations were strongest when the wind had a northward component, while in fall, stronger movements occurred on winds that allowed movement with a southward component; heading directions of larger insects were generally close to the track direction. These findings indicate adaptations leading to movement in seasonally favorable directions. We compare our results from China with similar studies in Europe and North America and conclude that ecological patterns and behavioral adaptations are similar across the Northern Hemisphere. The predominance of pests among these nocturnal migrants has severe implications for food security and grower prosperity throughout this heavily populated region, and knowledge of their migrations is potentially valuable for forecasting pest impacts and planning timely management actions

Efficacy and safety of low-dose IL-2 in the treatment of systemic lupus erythematosus: A randomised, double-blind, placebo-controlled trial

Objectives Open-labelled clinical trials suggested that low-dose IL-2 might be effective in treatment of systemic lupus erythematosus (SLE). A double-blind and placebocontrolled trial is required to formally evaluate the safety and efficacy of low-dose IL-2 therapy. Methods A randomised, double-blind and placebocontrolled clinical trial was designed to treat 60 patients with active SLE. These patients received either IL-2 (n=30) or placebo (n=30) with standard treatment for 12 weeks, and were followed up for additional 12 weeks. IL-2 at a dose of 1 million IU or placebo was administered subcutaneously every other day for 2 weeks and followed by a 2-week break as one treatment cycle. The primary endpoint was the SLE Responder Index-4 (SRI-4) at week 12. The secondary endpoints were other clinical responses, safety and dynamics of immune cell subsets. Results At week 12, the SRI-4 response rates were 55.17% and 30.00% for IL-2 and placebo, respectively (p=0.052). At week 24, the SRI-4 response rate of IL-2 group was 65.52%, compared with 36.67% of the placebo group (p=0.027). The primary endpoint was not met at week 12. Low-dose IL-2 treatment resulted in 53.85% (7/13) complete remission in patients with lupus nephritis, compared with 16.67% (2/12) in the placebo group (p=0.036). No serious infection was observed in the IL-2 group, but two in placebo group. Besides expansion of regulatory T cells, low-dose IL-2 may also sustain cellular immunity with enhanced natural killer cells. Conclusions Low-dose IL-2 might be effective and tolerated in treatment of SThe work was supported by the National Natural Science Foundation of China (31530020,31570880,81471601,81601417 and 81701598), Peking-Tsinghua Center for Life Sciences to ZG LI, Beijing Sci-Tech Committee Z171100000417007,Clinical Medicine Plus X-Young Scholars Project of Peking University (PKU2019LCXQ013) supported by the Fundamental Research Funds for the Central Universities, Beijing Nova Program Z171100001117025, National Key Research and Development Program of China (2017YFC0909003 to DY), BellberryViertel Senior Medical Research Fellowship to DY and Beijing SL PHARM

Effect of Different References on Auditory-Evoked Potentials in Children with Cochlear Implants

Background: Nose reference (NR), mastoid reference (MR), and montage average reference (MAR) are usually used in auditory event-related potential (AEP) studies with a recently developed reference electrode standardization technique (REST), which may reduce the reference effect. For children with cochlear implants (CIs), auditory deprivation may hinder normal development of the auditory cortex, and the reference effect may be different between CIs and a normal developing group.Methods: Thirteen right-side-CI children were recruited, comprising 7 males and 6 females, ages 2–5 years, with CI usage of ~1 year. Eleven sex- and age-matched healthy children were recruited for normal controls; 1,000 Hz pure tone evoked AEPs were recorded, and the data were re-referenced to NR, left mastoid reference (LMR, which is the opposite side of the implanted cochlear), MAR, and REST. CI artifact and P1–N1 complex (latency, amplitudes) at Fz were analyzed.Results: Confirmed P1–N1 complex could be found in Fz using NR, LMR, MAR, and REST with a 128-electrode scalp. P1 amplitude was larger using LMR than MAR and NR, while no statistically significant difference was found between NR and MAR in the CI group; REST had no significant difference with the three other references. In the control group, no statistically significant difference was found with different references. Group difference of P1 amplitude could be found when using MR, MAR, and REST. For P1 latency, no significant difference among the four references was shown, whether in the CI or control group. Group difference in P1 latency could be found in MR and MAR. N1 amplitude in LMR was significantly lower than NR and MAR in the control group. LMR, MAR, and REST could distinguish the difference in the N1 amplitude between the CI and control group. Contralateral MR or MAR was found to be better in differentiating CI children versus controls. No group difference was found for the artifact component.Conclusions: Different references for AEP studies do not affect the CI artifact. In addition, contralateral MR is preferable for P1–N1 component studies involving CI children, as well as methodology-like studies

A Minimum-Entropy Based Residual Range Cell Migration Correction for Bistatic Forward-Looking SAR

For bistatic forward-looking synthetic aperture radar (BFSAR), motion errors induce two adverse effects on the echo, namely, azimuth phase error and residual range cell migration (RCM). Under the presumption that residual RCM is within a range resolution cell, residual RCM can be neglected, and azimuth phase error can be compensated utilizing autofocus methods. However, in the case that residual RCM exceeds the range resolution, two-dimensional defocus would emerge in the final image. Generally speaking, residual RCM is relatively small and can be neglected in monostatic SAR, while the unique characteristics of BFSAR makes the residual RCM exceeding range resolution cell inevitable. Furthermore, the excessive residual migration is increasingly encountered as resolutions become finer. To cope with such a problem, minimum-entropy based residual RCM correction method is developed in this paper. The proposed method eliminates the necessity of the parametric model when estimating the residual RCM. Moreover, it meets the practical needs of BFSAR owing to no requirement of exhaustive computation. Simulations validate the effectiveness of the proposed method

The Design of a Lean CRM Software Process Model

In this paper, the concept and development of CRM (customer relationship management) are discussed, we defined a customer “lead” concept which emphasized the inter-connection of downstream and upstream processes of our customers. It is pointed out that the key point in CRM is the customer lead management in the software design and implementation. Based on this perspective, the processes of lead processing, lead management, and inside lead management are further elaborated, analyzed and their models are proposed. The problem of analyzing customers’ behavior is also studied. Hence a simplified and lean integrated CRM software process is finally given, and this integrated model can be used to build CRM software for small and medium-sized manufacturing enterprises