Sensitivity analysis and parameter interval optimization for residual stress in polishing process of GH4169 blisk blade

Xiaojun Lin,Xiaopeng Xin,Rui Yang,Zhaozhao Lei,Luzhou Sun,Bao Yang,Changyou Bai,Yangwei Yan 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.2

Surface integrity has a significant impact on the performance and life cycle of the blisk blade. Residual stress, as one of the important characterization parameters of surface integrity, is closely related to the performance of the aeroengine blisk blade. A certain interval of residual compressive stress can significantly inhibit the generation of microcracks. This paper proposes an optimization method of polishing process parameter interval based on sensitivity analysis. This research studied the effect of polishing parameters of the alumina ACW (abrasive cloth wheel) on the surface residual stress of the GH4169 superalloy blisk blade. Firstly, the experiment was designed by four factors and three levels response surface method, the multiple regression of the experimental data based on Minitab software was used to get a prediction model of polished surface residual stress. And an analysis of variance was performed on the model. Subsequently, the model of relative sensitivity was got based on this model. The sensitivity order of polishing surface residual stress to each polishing parameter was obtained. And the judging method of stable interval and instable interval was put forward. Then, a parameter interval optimization method was proposed, and the optimal interval of process parameters was obtained. Finally, a polishing verification experiment was performed. The results show that: for the polishing of GH4169 superalloy blades, the surface residual stress is most sensitive to the feed rate vf of the ACW, followed by the granularity p and the rotation rate ω, and the compression depth ap is the least sensitive. The optimal interval of polishing process parameters is: the rotation rate ω is [11000 r/min, 11500 r/min], the feed rate vf is [100 mm/min, 200 mm/min], the compression depth ap is [0.6 mm, 1.0 mm], and the granularity p is [400 #, 600 #]. The optimized polishing process parameters can obtain a large and stable surface residual compressive stress, which is helpful to increase fatigue strength of the blisk blade.

Macro-/micro-environment-sensitive chemosensing and biological imaging

Yang, Zhigang,Cao, Jianfang,He, Yanxia,Yang, Jung Ho,Kim, Taeyoung,Peng, Xiaojun,Kim, Jong Seung The Royal Society of Chemistry 2014 Chemical Society reviews Vol.43 No.13

<P>Environment-related parameters, including viscosity, polarity, temperature, hypoxia, and pH, play pivotal roles in controlling the physical or chemical behaviors of local molecules. In particular, in a biological environment, such factors predominantly determine the biological properties of the local environment or reflect corresponding status alterations. Abnormal changes in these factors would cause cellular malfunction or become a hallmark of the occurrence of severe diseases. Therefore, in recent years, they have increasingly attracted research interest from the fields of chemistry and biological chemistry. With the emergence of fluorescence sensing and imaging technology, several fluorescent chemosensors have been designed to respond to such parameters and to further map their distributions and variations <I>in vitro</I>/<I>in vivo</I>. In this work, we have reviewed a number of various environment-responsive chemosensors related to fluorescent recognition of viscosity, polarity, temperature, hypoxia, and pH that have been reported thus far.</P> <P>Graphic Abstract</P><P>We have summarized the research progress on fluorescent sensors responsive to environmental factors, including local viscosity, polarity, temperature, hypoxia and pH. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4cs00051j'> </P>

Seismic performance and damage evaluation of concrete-encased CFST composite columns subjected to different loading systems

Xiaojun Ke,Haibin Wei,Linjie Yang,Jin An 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.1

This paper tested 11 concrete-encased concrete-filled steel tube (CFST) composite columns and one reinforced concrete column under combined axial compression and lateral loads. The primary parameters, including the loading system, axial compression ratio, volume stirrup ratio, diameter-to-thickness ratio of the steel tube, and stirrup form, were varied. The influence of the parameters on the failure mode, strength, ductility, energy dissipation, strength degradation, and damage evolution of the composite columns were revealed. Moreover, a two-parameter nonlinear seismic damage model for composite columns was established, which can reflect the degree and development process of the seismic damage. In addition, the relationships among the inter-story drift ratio, damage index and seismic performance level of composite columns were established to provide a theoretical basis for seismic performance design and damage assessments.

Impact of Size on Humidity Sensing Property of Copper Oxide Nanoparticles

Yang Gu,Huina Jiang,Zi Ye,Ning Sun,Xuliang Kuang,Weijing Liu,Gaofang Li,Xiaojun Song,Lei Zhang,Wei Bai,Xiaodong Tang 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.1

Three sizes of CuO nanosheets were synthesized by hydrothermal method. The structure and morphology of CuO nanosheets were characterized by X-ray difraction and scanning electron microscopy. Dielectrophoresis nano-manipulation technique was employed to arrange the materials on pre-designed Ti/Au electrodes to fabricate the three humidity sensors, and the sensing properties were then tested. The experimental results show that the sensitivity greatly increases with the decreasing size of CuO nanosheets, the sensitivity of sensor a, b, c are 369%, 3278%, 22,611% in 97.3% RH, respectively. The smaller sized CuO nanomaterials have better response characteristic, the response time of sensor a, b, c under 11.3–97.3% RH are 53 s, 49 s, 32 s, respectively. And correspondingly, hysteresis properties and the repeatability are also a little infuenced. In addition, based on complex impedance spectroscopy and multilayer adsorption theory, the impact of size on humidity sensing property was discussed. The results indicated the feasibility to obtain higher performance of humidity sensor, especially the higher sensitivity, via employment the smaller size sensing nanomaterials.

Are Chinese Edible Oils Safe? A Survey of Trans Fatty Acid Contents in Chinese Edible Oils

Xiaojun Huang,Shaoping Nie,Meiyan Yang,Jianhua Xie,Chang Li,Mingyong Xie 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.2

Nine different edible oil types from 7 cities in China were analyzed. Trans fatty acid (TFA) contents in edible oils were determined, TFA distribution characteristics were analyzed, and a risk assessment was performed. Total TFA contents varied from 0.075±0.011 to 2.243±0.770 g/100 g of oil, with a mean content of 0.66 g/100 g of oil. TFA contents differed among different oil types and among different cities. Generally speaking, oil samples from northern areas of China contained more TFA, and lard usually had higher levels of TFA than other oils. An exposure assessment showed that the estimated daily intake of TFA from Chinese edible oils was low, and a risk assessment indicated that there was a low risk for TFA consumption in Chinese edible oils.

Compound heterozygous mutations of NDUFV1 identified in a child with mitochondrial complex I deficiency

Tang Xiaojun,Xu Wuhen,Song Xiaozhen,Ye Haiyun,Ren Xiang,Yang Yongchen,Zhang Hong,Wu Shengnan,Lan Xiaoping 한국유전학회 2022 Genes & Genomics Vol.44 No.6

Background: Mitochondrial complex I deficiency (MCID) is the most common biochemical defect identified in childhood with mitochondrial diseases, mainly including Leigh syndrome, encephalopathy, macrocephaly with progressive leukodystrophy, hypertrophic cardiomyopathy and myopathy. Objective: To identify genetic cause in a patient with early onset autosomal recessive MCID. Methods: Trio whole-exome sequencing was performed and phenotype-related data analyses were conducted. All candidate mutations were confirmed by Sanger sequencing. Results: Here we report a child of Leigh syndrome presented with global developmental delay, progressive muscular hypotonia and myocardial damage. A missense mutation c.118C > T (p.Arg40Trp) and a previously reported mutation c.1157G > A (p.Arg386His) in NDUFV1 have been identified as compound heterozygous in the patient. The mutation p.Arg386His is closely associated with the impairment of 4Fe-4S domain and this mutation has been reported pathogenic. The c.118C > T mutation has not been reported in ClinVar and HGMD database. In silico protein analyses showed that p.Arg40 is highly conserved in a wide range of species, and the amino acid substitution p.Trp40 largely decreases the stability of NDUFV1. In addition, the mutation has not been detected in the Asian populations and it was predicted to be deleterious by numerous prediction tools. Conclusion: This research expands the mutation spectrum of NDUFV1 and substantially provides an early and accurate diagnosis basis of MCID, which would benefit subsequently effective genetic counseling and prenatal diagnosis for future reproduction of the family.

An Efficient Markov Chain Based Channel Model for 6G Enabled Massive Internet of Things

( Wei Yang ),( Xiaojun Jing ),( Hai Huang ),( Chunsheng Zhu ),( Qiaojie Jiang ),( Dongliang Xie ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.11

Accelerated by the Internet of Things (IoT), the need for further technical innovations and developments within wireless communications beyond the fifth generation (B5G) networks is up-and-coming in the past few years. High altitude platform station (HAPS) communication is expected to achieve such high levels that, with high data transfer rates and low latency, millions of devices and applications can work seamlessly. The HAPS has emerged as an indispensable component of next-generations of wireless networks, which will therefore play an important role in promoting massive IoT interconnectivity with 6G. The performance of communication and key technology mainly depend on the characteristic of channel, thus we propose an efficient Markov chain based channel model, then analyze the HAPS communication system's uplink capability and swing effect through experiments. According to the simulation results, the efficacy of the proposed scheme is proven to meet the requirements of ubiquitous connectivity in future IoT enabled by 6G.

Insulin resistance and overweight prolonged fertility-sparing treatment duration in endometrial atypical hyperplasia patients

Bingyi Yang,Liying Xie,Hongwei Zhang,Qin Zhu,Yan Du,Xuezhen Luo,Xiaojun Chen 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.3

Objective: Our previous study showed that insulin resistance (IR) was related to endometrial hyperplasia as well as endometrial cancer. But the exact impact of IR on fertility-sparing treatment in endometrial hyperplasic disease is unclear. This study investigated how IR affects fertility-sparing treatment in endometrial atypical hyperplasia (EAH) patients. METHODS: The 151 EAH patients received fertility-sparing treatment were retrospectively investigated. All patients received high-dose progestin combined with hysteroscopy. Therapeutic effects were evaluated by hysteroscopy every 3 months during the treatment. RESULTS: The median age was 33.0 years old (range, 21-54 years old). Sixty-one patients (40.4%) were insulin resistant. Three patients were excluded from the analysis because they chose hysterectomy within 3 months after initiation of progestin treatment. The 141 out of 148 (95.3%) patients achieved complete response (CR). No difference was found in cumulative CR rate between those with or without IR (90.2% vs. 95.6%, p=0.320). IR significantly affected therapeutic duration to achieve CR (8.1±0.5 months with IR vs. 6.1±0.4 months without IR, p=0.004). Overweight (body mass index [BMI]≥25 kg/m²) was associated with higher risk of treatment failure (odds ratio=5.61; 95% confidence interval=1.11-28.35; p=0.040) and longer therapeutic duration to achieve CR (7.6±0.5 months vs. 6.3±0.4 months, p=0.019). EAH patients with both IR and overweight (IR+BMI+) had the longest therapeutic time compared with other patients (8.8±0.6 months vs. 5.6±0.7, 6.3±0.4, and 6.4±0.8 months for IR-BMI+, IR-BMI-, and IR+BMI-, respectively, p=0.006). CONCLUSION: IR and overweight were associated with longer therapeutic duration in EAH patients receiving progestin-based fertility-sparing treatment.

Spectrum Usage Forecasting Model for Cognitive Radio Networks

( Wei Yang ),( Xiaojun Jing ),( Hai Huang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.4

Spectrum reuse has attracted much concern of researchers and scientists, however, the dynamic spectrum access is challenging, since an individual secondary user usually just has limited sensing abilities. One key insight is that spectrum usage forecasting among secondary users, this inspiration enables users to obtain more informed spectrum opportunities. Therefore, spectrum usage forecasting is vital to cognitive radio networks (CRNs). With this insight, a spectrum usage forecasting model for the occurrence of primary users prediction is derived in this paper. The proposed model is based on auto regressive enhanced primary user emergence reasoning (AR-PUER), which combines linear prediction and primary user emergence reasoning. Historical samples are selected to train the spectrum usage forecasting model in order to capture the current distinction pattern of primary users. The proposed scheme does not require the knowledge of signal or of noise power. To verify the performance of proposed spectrum usage forecasting model, we apply it to the data during the past two months, and then compare it with some other sensing techniques. The simulation results demonstrate that the spectrum usage forecasting model is effective and generates the most accurate prediction of primary users occasion in several cases.

In-pile tritium release behavior and the post-irradiation experiments of Li4SiO4 fabricated by melting process

Zhao Linjie,Yang Mao,Xiao Chengjian,Gong Yu,Ran Guangming,Chen Xiaojun,Li Jiamao,Yue Lei,Chen Chao,Hou Jingwei,Wang Heyi,Long Xinggui,Peng Shuming 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li4SiO4 pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li4SiO4 made by melt spraying method at 467 ◦C is approximately 23.34 h. High-density Li4SiO4 pebbles exhibit tritium release at relatively low temperatures (<600 ◦C) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ◦C and 550 ◦C is 1.19 × 10 11 cm2/s and 5.34 × 10 11 cm2/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.