基于小波分析和RBF神经网络的轴承故障诊断研究

为了提高轴承故障信号的诊断性能,采用小波分析和RBF神经网络相结合的方法对轴承振动信号进行故障分类。首先对轴承振动信号进行小波变化,采用软阈值去噪方法滤除振动信号噪声,然后对振动信号矩阵化处理,接着构建RBF神经网络,输入轴承振动信号特征向量,初始化权重和阈值,最后通过不断反向迭代得到稳定的RBF神经网络故障判别模型。实验证明:通过差异化设置隐藏层神经元数量,确定合适的RBF神经网络规模,经过小波去噪可以有效提高轴承故障判别准确率,相比于常见轴承故障分类算法,算法具有更高的故障判别准确率。

Expression of AIF-1 and RANTES in Unexplained Spontaneous Abortion and Possible Association with Alloimmune Abortion

Objective To investigate the effects of allograft inflammatory factor-1 （AIF-1） and （RANTES） in sera and deciduas on unexplained early spontaneous abortion. Methods AIF-1 and RANTES were examined in sera and deciduas/endometria of 43 unexplained early spontaneous abortion women （group A）, 40 healthy women with early pregnancy（group B） and 20 healthy women with no pregnancy （group C）. Immunohistochemistry and enzyme linked immunosorbent assay （ELISA） were used in this study. Results AIF-1 protein was expressed both in deciduas of group A and in endometria of group C. In group A, H scores in the recurrent abortion deciduas specimens were significantly greater than those in the first abortion;in endometrium, expression of AIF-1 was greater in the secretory than in proliferative phase of group C. In group B, concentrations of RANTES in sera were higher in 7th-8th week of pregnancy than in 6th-7th and 〉8th week of pregnancy; expression of AIF-1 protein showed a negative correlation with RASNTES concentration; a significant increase of the RANTES levels in sera and tissue was observed in group B. Conclusion These results demonstrate, for the first time, that AIF-1 are expressed in deciduas of unexplained spontaneous abortion suggesting that AIF-1 involve in alloimmune abortion; RANTES might act as a novel blocking antibody;AIF-1 and RANTES might act as reliable markers for diagnosis of early alloimmune abortion.

A novel mutation in PRPF31,causative of autosomal dominant retinitis pigmentosa,using the BGISEQ-500 sequencer

AIM： To study the genes responsible for retinitis pigmentosa.METHODS： A total of 15 Chinese families with retinitis pigmentosa, containing 94 sporadically afflicted cases, were recruited. The targeted sequences were captured using the Target_Eye_365_V3 chip and sequenced using the BGISEQ-500 sequencer, according to the manufacturer＇s instructions. Data were aligned to UCSC Genome Browser build hg19, using the Burroughs Wheeler Aligner MEM algorithm. Local realignment was performed with the Genome Analysis Toolkit（GATK v.3.3.0） Indel Realigner, and variants were called with the Genome Analysis Toolkit Haplotypecaller, without any use of imputation. Variants were filtered against a panel derived from 1000 Genomes Project, 1000 G_ASN, ESP6500, Ex AC and db SNP138. In all members of Family ONE and Family TWO with available DNA samples, the genetic variant was validated using Sanger sequencing.RESULTS： A novel, pathogenic variant of retinitis pigmentosa, c.357_358 del AA（p.Ser119 Serfs X5） was identified in PRPF31 in 2 of 15 autosomal-dominant retinitis pigmentosa（ADRP） families, as well as in one, sporadic case. Sanger sequencing was performed uponprobands, as well as upon other family members. This novel, pathogenic genotype co-segregated with retinitis pigmentosa phenotype in these two families. CONCLUSION： ADRP is a subtype of retinitis pigmentosa, defined by its genotype, which accounts for 20%-40% of the retinitis pigmentosa patients. Our study thus expands the spectrum of PRPF31 mutations known to occur in ADRP, and provides further demonstration of the applicability of the BGISEQ500 sequencer for genomics research.

Comparison and analysis of mitigation ambitions of Parties’ updated Nationally Determined Contributions

Understanding mitigation ambitions of the Nationally Determined Contributions(NDCs)should include both the equity of supporting the Paris Agreement goals and the costs of achieving the proposed mitigation targets.This study presents a new framework that combines equity and economic costs to compare and analyze mitigation ambitions of Parties'updated NDCs.Under representative 2℃ and 1.5℃ pathways,this framework uses multiple equity-principled allocations to derive the alignment of the updated NDCs with the Paris Agreement goals,and further applies a computable general equilibrium model to assess the economic costs of implementing the updated NDCs.The results show that global 2030 emissions may meet the selected global 2℃ pathway if all Parties achieve their most ambitious mitigation efforts,but there is still an emissions gap of 10-15 GtCO_(2) to follow the selected 1.5℃ pathway.From the perspective of equity,the updated NDCs of the USA,the EU(including the UK in this study),and Japan lack ambition with respect to‘equal cumulative per capita emissions’under 2℃ and do not align with any equity principles under 1.5℃.The updated NDCs of China,India,Brazil and South Africa reflect their claims to‘equity’and‘common but differentiated responsibilities’.From the perspective of economic costs,the GDP and welfare losses of China,Brazil and South Africa incurred by achieving the updated NDCs are not lower than those of the three developed Parties.China's GDP loss is estimated at 0.43%-0.55%in 2030,which is higher than that of the USA(0.30%-0.38%)and the EU(0.25%-0.28%).This study suggests that developed Parties take the lead in further ratcheting up the NDCs and strengthen financial and technological support to developing countries so that the world could close the gap to 1.5℃.

Weakening behavior of waterproof performance in joints of shield tunnels under adjacent constructions

Groundwater leakage in shield tunnels poses a threat to the safety and durability of tunnel structures. Disturbance of adjacent constructions during the operation of shield tunnels frequently occurs in China, leading to deformation of tunnel lining and leakage in joints. Understanding the impact of adjacent constructions on the waterproofing performance of the lining is critical for the protection of shield tunnels. In this study, the weakening behavior of waterproof performance was investigated in the joints of shield tunnels under transverse deformation induced by adjacent construction. First, the relationship between the joint opening and transverse deformation under three typical adjacent constructions (upper loading, upper excavation, and side excavation) was investigated via elaborate numerical simulations. Subsequently, the evolution of the waterproof performance of a common gasket with a joint opening was examined by establishing a coupled Eulerian-Lagrangian model of joint seepage, and a formula describing the relationship between waterproof performance and joint opening was proposed. Finally, the weakening law of waterproofing performance was investigated based on the results of the aforementioned studies. It was determined that the joints with the greatest decline in waterproof performance were located at the tunnel shoulder in the upper loading case, tunnel crown in the upper excavation case, and tunnel shoulder in the side excavation case. When the waterproof performance of these joints decreased to 50% and 30%, the transverse deformations were 60 and 90 mm under upper loading, 90 and 140 mm under upper excavation, and 45 and 70 mm under side excavation, respectively. The results provide a straightforward reference for setting a controlled deformation standard considering the waterproof performance.

Understanding equityeefficiency interaction in the distribution of global carbon budgets

Equity and efficiency are two important factors guiding the mitigation of anthropogenic emissions to achieve the Paris climate goals.Previous studies have proposed a range of allocations of global carbon budgets,but few have quantified the equity-efficiency interaction.Based on an investigation of the existing allocation literature,this study conducts a novel analysis using a‘mixed’allocation‘big-data’framework to understand the equityeefficiency interaction in the distribution of global carbon budgets under 2℃ and 1.5℃ warming targets.At a global scale,a carbon Gini coefficient and aggregate abatement costs are used as quantitative metrics to reflect equity and efficiency,respectively.Results show an equity-efficiency frontier that reflects the opportunity for the international community to co-improve equity and efficiency on top of existing allocations.However,the frontier also features strong trade-offs to further improve equity and efficiency if national allocations are to be achieved individually.Our analysis verifies that such trade-offs are sensitively dependent on the level of global connection and integration.Linking national mitigation actions and potentials can help promote equity-efficiency synergies and contribute to the efficient achievement of the Paris Agreement's temperature and equity goals.