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1Analysis of the cylinder block tilting inertia moment and its effect on the performance of high-speed electro-hydrostatic actuator pumps of aircraft显示文摘Electro-hydrostatic actuator(EHA) pumps are usually characterized as high speed and small displacement.The tilting inertia moment on the cylinder block produced by the inertia forces of piston/slipper assemblies cannot be ignored when analyzing the cylinder block balance.A large tilting inertia moment will make the cylinder block tilt away from the valve plate, resulting in severe wear and significantly increased leakage.This paper presents an analytical expression for the tilting inertia moment on the cylinder block by means of vector analysis.In addition, a high-speed test rig was built up, and experiments on an EHA pump prototype were carried out at high speeds of up to 10,000 r/min.The predicted nature of the cylinder block tilt at high speeds corresponds closely to the witness marks on the dismantled EHA pump prototype.It is suggested that more attention should be given to the tilting inertia moment acting on the cylinder block of an EHA pump since both wear and leakage flow between the cylinder block and the valve plate are very much dependent on this tilting moment.Junhui ZHANG Qun CHAO Bing XU 2018Chinese Journal of Aeronautics2018,31,1:22
2Cardiotoxicity of 5-fluorouracil and capecitabine in Chinese patients: a prospective study显示文摘Background:5-Fluorouracil(5-FU)and capecitabine-associated cardiotoxicity ranging from asymptomatic electro-cardiography(ECG)abnormalities to severe myocardial infarction has been reported in a number of studies,but such cardiotoxicity in Chinese patients with malignant diseases has not been investigated to date.In the present study,we aimed to prospectively evaluate the incidence rates and clinical manifestations of 5-FU-and capecitabine-associated cardiotoxicity in cancer patients recruited from multiple centers in China.Methods:Among the 527 patients who completed the study,196 received 5-FU-based chemotherapy and 331 received capecitabine-based chemotherapy as either first-line or adjuvant therapy.Adverse events were reported during the treatment and up to 28 days of follow-up.Outcome measures included ECG,myocardial enzymes,cardiac troponin,brain natriuretic peptide and echocardiography.Univariate analysis and logistic regression were performed for subgroup analysis and identification of significant independent variables that are associated with cardiotoxicity of both agents.Results:In total,161 of 527 patients(30.6%)experienced cardiotoxicity.The incidence rate of cardiotoxicity was 33.8%(112/331)in the capecitabine group,which was significantly higher than the rate of 25%(49/196)in the 5-FU group(P=0.0042).110/527 patients(20.9%)suffered arrhythmia,105/527(19.9%)developed ischemic changes,while only 20/527 patients(3.8%)presented heart failure and 6/527 patients(1.1%)had myocardial infarction.Pre-existing cardiac disease,hypertension,capecitabine-based chemotherapy and duration of treatment were identified as sig-nificant risk factors associated with cardiotoxicity.The odds ratio were 15.7(prior history of cardiac disease versus no history),1.86(capecitabine versus 5-FU),1.06(5-8 versus 1-4 chemotherapy cycles)and 1.58(hypertension versus no hypertension),respectively.Conclusions:Cardiotoxicity induced by fluoropyrimidines in the Chinese population may be underestimated in clini-cal practice.Close monitoring of patients is recommended,especially for those patients at high risk for cardiotoxicity.Possible risk factors are duration of treatment,capecitabine-based chemotherapy,pre-existing cardiac diseases and hypertension.Trial registration This study was initiated on January 22,2014 and has been retrospectively registered with the registra-tion number ChiCTR1800015434 .Jianjun Peng Chao Dong Chang Wang Weihua Li Hao Yu Min Zhang Qun Zhao Bo Zhu Jun Zhang Wenliang Li Fenghua Wang Qiong Wu Wenhao Zhou Ying Yuan Meng Qiu Gong Chen 2018Cancer Communications2018,38,1:23
3Eleven COVID-19 Outbreaks with Local Transmissions Caused by the Imported SARS-CoV-2 Delta VOC-China,July-August,2021显示文摘Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Lei Zhou Kai Nie Hongting Zhao Xiang Zhao Bixiong Ye Ji Wang Cao Chen Hong Wang Jiangli Di Jinsong Li Chao Li Zhixiao Chen Ruiqi Ren Peihua Niu Hui Chen Tao Chen Yali Wang Lili Li Bingxue Han Ruhan A Si Chen Dan Li Dan Li Chunxia Jin Xin Zhang Jiangmei Liu Chunyu Xu Yecheng Yao Yenan Feng Zhili Li Bike Zhang Yang Song Peter Hao Yanping Zhang Hao Li Qun Li George F.Gao Guoqing Shi Wenbo Xu 2021China CDC weekly2021,3,41:13
4Three New Anthraquinones from Polygonum cillinerve显示文摘Three new anthraquinones, emodin-8-β-D-(2″-O-coumarate)glucoside 1, emodin-8-β- D-(6′-O-acetyl)glucoside 2 and physicon-8-β-D-(6′-O-acetyl)glucoside 3, were isolated from the roots of Polygonum cillinerve and their structures were established by spectroscopic methods. The biological activity indicated that compound 1 had the scavenging activity on 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals (the IC50 = 8.5 μmol/L), and compound 1-3 showed no activities against HL-60 and BGC-823 cells by MTT method in vitro.Huan Yang QI Chao Feng ZHANG Mian ZHANG Jian Qun LIU Zheng Tao WANG 2005Chinese Chemical Letters2005,16,8:10
5Soybean AP1 homologs control flowering time and plant height显示文摘Flowering time and plant height are key agronomic traits that directly affect soybean(Glycine max)yield.APETALA1(AP1)functions as a class A gene in the ABCE model for floral organ development,helping to specify carpel,stamen,petal,and sepal identities.There are four AP1 homologs in soybean,all of which are mainly expressed in the shoot apex.Here,we used clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein 9 technology to generate a homozygous quadruple mutant,gmap1,with loss-of-function mutations in all four GmAP1 genes.Under short-day(SD)conditions,the gmap1 quadruple mutant exhibited delayed flowering,changes in flower morphology,and increased node number and internode length,resulting in plants that were taller than the wild type.Conversely,overexpression of GmAP1a resulted in early flowering and reduced plant height compared to the wild type under SD conditions.The gmap1 mutant and the overexpression lines also exhibited altered expression of several genes related to flowering and gibberellic acid metabolism,thereby providing insight into the role of GmAP1 in the regulatory networks controlling flowering time and plant height in soybean.Increased node number is the trait with the most promise for enhancing soybean pod number and grain yield.Therefore,the mutant alleles of the four AP1 homologs described here will be invaluable for molecular breeding of improved soybean yield.Liyu Chen Haiyang Nan Lingping Kong Lin Yue Hui Yang Qingsong Zhao Chao Fang Haiyang Li Qun Cheng Sijia Lu Fanjiang Kong Baohui Liu Lidong Dong 2020Journal of Integrative Plant Biology2020,62,12:9
6Experimental study of an insert and its influence on churning losses in a high-speed electro-hydrostatic actuator pump of an aircraft显示文摘The speed of an Electro-Hydrostatic Actuator(EHA) pump can recently reach 20000 r/min, and its churning losses increase obviously with an increasing speed, which results in low efficiency and thus increasing heat in aircraft EHA systems. In order to reduce churning losses at high speeds, more attention should be given to the design of an insert. In this paper, the effect of an insert with different design parameters on churning losses is investigated through Computational Fluid Dynamics(CFD) simulation and experiments by calculating the difference between churning losses torques of the test pump with and without the insert based on a high-speed churning losses test rig.Analytical results show that the gap between the insert and the cylinder is critical for churning losses reduction. It is found that the churning losses of the test pump can be reduced with a decreasing gap between the cylinder block and the insert at high speeds. This is because the insert can decrease the turbulence occurrence at high speeds. The results can be used for flow field analysis and optimization of the high-speed EHA pump and provide a new method for improving efficiency of high-speed EHA pumps.Junhui ZHANG Ying LI Bing XU Min PAN Qun CHAO 2019Chinese Journal of Aeronautics2019,32,8:9
7CIVB flashback analysis of hydrogen flame based on azimuthal vorticity at mixing zone exit显示文摘Swirl-premixed combustion systems exhibit potential to meet future regulations on pollution emissions. However, combustion induced vortex breakdown(CIVB) flashback is frequently observed in these systems, especially for high hydrogen content fuel. In this study, a swirl-premixed burner with diverging centerbody was used to investigate CIVB flashback based on azimuthal vorticity at mixing zone exit. Through 2D axisymmetric model, it was found that there was a maximal azimuthal vorticity at mixing zone exit for each equivalence ratio. The physical meaning of these maximal azimuthal vorticity values was the minimally required azimuthal vorticity to trigger CIVB flashback. At the same time, the required azimuthal vorticity declined with the increase of equivalence ratio since turbulent burning velocity started to control flashback. Nevertheless, azimuthal vorticity offered by heat release increased with the increase of equivalence ratio, which promoted flame propagating upstream continually.TIAN Xiao Jing XING Shuang Xi CUI Yu Feng FANG Ai Bing NIE Chao Qun 2014Science China(Technological Sciences)2014,57,12:7
8Review of cylinder block/valve plate interface in axial piston pumps: Theoretical models,experimental investigations, and optimal design显示文摘Axial piston pumps have been widely used in aircraft hydraulic systems to supply the system with pressurized fluid. The continuous improvement of the aircraft performance has put forward the demand on aviation piston pumps for high power density, safety, and reliability. The lubricating interfaces in axial piston machines are the key design issue that greatly determines the pump performance and service life. The cylinder block/valve plate interface is one of these critical lubricating interfaces and has received considerable attention from many researchers in the last half century. This study aims to review the state-of-the-art literature on the cylinder block/valve plate interface comprehensively and systematically. First, we introduce various theoretical models developed to investigate the lubrication behaviors of the interface and compare them in terms of their assumptions and limitations. Second, the experimental studies on the cylinder block/valve plate interface are presented comprehensively, where the involved test rigs are divided into three types according to their fidelity levels and measurement functionality. Third, we summarize some typical approaches of structure optimization, surface shaping, and surface strengthening, which help improve the load-carrying and anti-wear capacities of the interface under severe operating conditions. Finally, the challenges and future trends of the cylinder block/valve plate interface research are discussed briefly.Jiang'ao ZHAO Yongling FU Jiming MA Jian FU Qun CHAO Yan WANG 2021Chinese Journal of Aeronautics2021,34,1:7
9Blocking of N-acetylglucosaminyltransferase V induces cellular endoplasmic reticulum stress in human hepatocarcinoma 7721 cells显示文摘N-acetylglucosaminyltransferase V (GnT-V ) 是重要 tumorigenesis 和联系转移的酶。为了学习它的简历,工作, GnT-V 稳定地压制了房间线(GnT-V-AS/7,721 ) 在以前的学习从 7,721 个 hepatocarcinoma 房间被构造。在这研究, cDNA 数组基因表示侧面在 GnT-V-AS/7,721 之间被比较并且父母 7,721 个房间。数据显示 GnT-V-AS/7,721 显示出与 ER 压力一致的一个典型表达式模式。ER 压力的分子的机制被分析在二展开的蛋白质回答(UPR ) 在关键分子上在 GnT-V-AS/7,721 探索小径。为 ATF6 和 Ire1/XBP-1 小径,它被 BIP 的起来规定在 mRNA 和蛋白质证实 XBP-1 的拼接的形式的水平,和外观。至于 PERK/eIF2alpha 小径,激活嗯 eIF2alpha kinase 津贴被观察。从 GnT-V-AS/7,721 房间证实结果,在 UPR 的关键分子在 7,721 个房间再被检验由特定的 RNAi 处理防碍 GnT-V。结果与从 GnT-V-AS/7721 的那些是类似的,显示那块 GnT-V 能明确地激活嗯在 7,721 个房间的应力。率(3 )H 人加入与率改正了(3 ) 在 GnT-V-AS/7,721 的 H 列伊加入与控制相比极大地是下面调整的,它表明了综合的酶的缺乏的功能在堵住的 GnT-V 以后的 N-glycans。而且,与 underglycosylation 联系的女伴 GRP94 的更快的移居形式,和细胞内部的 glycoproteins 的广泛地改变的 N-glycans 结构是也在 GnT-V-AS/7,721 检测了。这些结果支持了机制损害的那块 GnT-V 表达式女伴和 N-glycan-synthesizing 酶工作,它在 vivo 引起了 UPR。Huan Fang Wei Huang Ying Ying Xu Zong Hou Shen Chao Qun Wu Shou Yi Qiao Yan Xu Long Yu Hui Li Chen 2006Cell Research2006,16,1:7
10Response of macrophages in rat skeletal muscle after eccentric exercise显示文摘PurposeMacrophages 被知道众多的受伤纸巾取决于为愈合重要他们响应不同刺激的功能的显型。这研究的目的是揭示涉及导致锻练的骨胳的肌肉损害的巨噬细胞 phenotypic 变化, regeneration.MethodsAdult 男性 Sprague-Dawley 老鼠经历了下坡的跑的一个会议(有超过 0.95 的最低的记录的相对的腐殖的酸流动(HAF ) 的 16ouling 性质。在另一方面, PVA-ZnO 加入改进了腐殖的酸拒绝直到 96.03 吗?4 th 等级,他们在部分理解上被估计并且进一步分类就象对没有困难??Qun Zuo Shu-Chen Wang Xin-Kai Yu Wei-Wei Chao 2018Chinese Journal of Traumatology2018,21,2:6
11COVID-19 Cases Spread Through the K350 Train-Jilin and Heilongjiang Provinces,China,January 2021显示文摘As of 16∶00 on January 13,2021,95 positive cases of coronavirus disease 2019(COVID-19)were reported in Suihua City of Heilongjiang Province and an additional 35 cases have been linked across 7 cities in 3 provinces:Qiqihar City(7 cases),Mudanjiang City(4 cases),Harbin City(3 cases),and Yichun City(1 case)of Heilongjiang Province;Changchun City(9 cases)and Tonghua City(6 cases)of Jilin Province;and Weihai City of Shandong Province(1 case).Lei Zhou Laishun Yao Peter Hao Chao Li Qinglong Zhao Huiling Dong Jinhua Dou Shengnan Wang George F.Gao Qun Li Biao Huang 2021China CDC weekly2021,3,8:5
12Parallel selection of distinct Tof5 alleles drove the adaptation of cultivated and wild soybean to high latitudes显示文摘Photoperiod responsiveness is a key factor limiting the geographic distribution of cultivated soybean and its wild ancestor.In particular,the genetic basis of the adaptation in wild soybean remains poorly understood.In this study,by combining whole-genome resequencing and genome-wide association studies we identified a novel locus,Time of Flowering 5(Tof5),which promotes flowering and enhances adaptation to high latitudes in both wild and cultivated soybean.By genomic,genetic and transgenic analyses we showed that Tof5 en-codes a homolog of Arabidopsis thaliana FRUITFULL(FUL).Importantly,further analyses suggested that different alleles of Tof5 have undergone parallel selection.The Tof5H1 allele was strongly selected by humans after the early domestication of cultivated soybean,while Tof5H2 allele was naturally selected in wild soybean,and in each case facilitating adaptation to high latitudes.Moreover,we found that the key flowering repressor E1 suppresses the transcription of Tof5 by binding to its promoter.In turn,Tof5 physically associates with the promoters of two important FLOWERING LOCUS T(FT),FT2a and FT5a,to upregulate their transcription and promote flowering under long photoperiods.Collectively,ourfindings provide insights into how wild soybean adapted to high latitudes through natural selection and indicate that cultivated soybean underwent changes in the same gene but evolved a distinct allele that was artificially selected after domestication.Lidong Dong Qun Cheng Chao Fang Lingping Kong Hui Yang Zhihong Hou Yongli Li Haiyang Nan Yuhang Zhang Qingshan Chen Chunbao Zhang Kun Kou Tong Su Lingshuang Wang Shichen Li Haiyang Li Xiaoya Lin Yang Tang Xiaohui Zhao Sijia Lu Baohui Liu Fanjiang Kong 2022Molecular Plant2022,15,2:5
13Effects of splined shaft bending rigidity on cylinder tilt behaviour for high-speed electrohydrostatic actuator pumps显示文摘High-speed axial piston pumps are hydraulic power supplies for electro-hydrostatic actuators(EHAs). The efficiency of a pump directly affects the operating performance of an EHA, and an understanding of the physical phenomena occurring in the cylinder/valve plate interface is essential to investigate energy dissipation. The effects of the splined shaft bending rigidity on the cylinder tilt behaviour in an EHA pump need to be considered, because the deflection and radial expansion of a steel shaft rotating at a high speed cannot be ignored. This paper proposes a new mathematical model to predict the cylinder tilt behaviour by establishing a quantitative relationship between the splined shaft deflection, the cylinder tilt angle, and the tilt azimuth angle. The moments exerted by the splined shaft are included in the equilibrium equation of the cylinder. The effects of solid and hollow splined shafts equipped in an EHA pump prototype are compared at variable speeds of 5000–10,000 r/min. With a weight saving of 29.7%, the hollow shaft is experimentally found to have almost no influence on the volumetric efficiency, but to reduce the mechanical efficiency by 0.6–2.4%. The results agree with the trivial differences of the simulated central gap heights of the interface between the two shafts and the enlargement of the simulated tilt angles by the hollow shaft. The findings could guide designs of the cylinder/valve plate interface and the splined shaft to improve both the efficiency and power density of an EHA pump.Junhui ZHANG Yuan CHEN Bing XU Min PAN Qun CHAO 2019Chinese Journal of Aeronautics2019,32,2:4
14CDH13 Genetic Polymorphisms, Adiponectin and Ischemic Stroke: a Chinese Family-based Sib-pair Study显示文摘Objective To understand the relationships between CDH13(T-cadherin) genetic polymorphisms, adiponectin levels and ischemic stroke, and possible interactions between CDH13 polymorphisms and other risk factors. Methods We recruited 342 Chinese ischemic stroke sib pairs. We genotyped rs4783244 and rs7193788 on CDH13 using time-of-flight mass spectrometry genotyping technology and measured total and high-molecular weight(HMW) adiponectin levels. We investigated associations between SNPs and ischemic stroke, and interactions between SNPs and other risk factors using multi-level mixed-effects regression model. Results In individuals without ischemic stroke, CDH13 rs4783244 was associated with total adiponectin levels(per T: Coef =-0.257, P = 0.001). CDH13 rs7193788 was associated with total adiponectin levels(per A: Coef =-0.221, P = 0.001) and HMW adiponectin levels(per A: Coef =-0.163, P = 0.003). rs7193788 was significantly associated with ischemic stroke(GA/AA vs. GG: OR = 1.55, 95% CI: 1.07 to 2.24, P = 0.020) after Bonferroni correction(α = 0.025). There was an interaction between rs7193788 and diabetes(P = 0.036). Compared to diabetes-free individuals with rs7193788 GG genotype, diabetes patients with rs7193788 GA/AA genotypes had higher risks for ischemic stroke(OR = 2.64, 95% CI: 1.58-4.40, P < 0.001). Conclusion CDH13 genetic polymorphisms are associated with adiponectin levels and ischemic stroke. An interaction is found between CDH13 SNP and diabetes for ischemic stroke.CHEN Li SUN Ke Xin JUAN Juan FANG Kai LIU Kuo WANG Xue Yin WANG Ling YANG Chao LIU Xiao Qiang LI Jing TANG Xun WU Yi Qun QIN Xue Ying WU Tao CHEN Da Fang HU Yong Hua 2017Biomedical and Environmental Sciences2017,30,1:4
15Agronomical selection on loss-of-function of GIGANTEA simultaneously facilitates soybean salt tolerance and early maturity显示文摘Salt stress and flowering time are major factors limiting geographic adaptation and yield productivity in soybean(Glycine max).Although improving crop salt tolerance and latitude adaptation are essential for efficient agricultural production,whether and how these two traits are integrated remains largely unknown.Here,we used a genome-wide association study to identify a major salt-tolerance locus controlled by E2,an ortholog of Arabidopsis thaliana GIGANTEA(GI).Loss of E2 function not only shortened flowering time and maturity,but also enhanced salt-tolerance in soybean.E2 delayed soybean flowering by enhancing the transcription of the core flowering suppressor gene E1,thereby repressing Flowering Locus T(FT)expression.An E2 knockout mutant e2^(CR) displayed reduced accumulation of reactive oxygen species(ROS)during the response to salt stress by releasing peroxidase,which functions in ROS scavenging to avoid cytotoxicity.Evolutionary and population genetic analyses also suggested that loss-of-function e2 alleles have been artificially selected during breeding for soybean adaptation to high-latitude regions with greater salt stress.Our findings provide insights into the coupled selection for adaptation to both latitude and salt stress in soybean;and offer an ideal target for molecular breeding of early-maturing and salt-tolerant cultivars.Lidong Dong Zhihong Hou Haiyang Li Zhaobo Li Chao Fang Lingping Kong Yongli Li Hao Du Tai Li Lingshuang Wang Milan He Xiaohui Zhao Qun Cheng Fanjiang Kong Baohui Liu 2022Journal of Integrative Plant Biology2022,64,10:3
165-氟尿嘧啶和卡培他滨对中国患者的心脏毒性:一项前瞻性研究显示文摘背景与目的已有许多研究报道5-氟尿嘧啶(5-Fluorouracil,5-FU)和卡培他滨相关的心脏毒性,严重程度从无症状心电图(electrocardiography,ECG)异常到严重心肌梗塞而不同。目前为止,对中国恶性肿瘤患者的这种心脏毒性尚无研究。本研究旨在前瞻性地对多个中心招募的癌症患者进行5-FU和卡培他滨相关心脏毒性的发生率和临床表现进行评估。方法在完成研究的527例患者中,196例接受基于5-FU的化疗,331例接受基于卡培他滨的化疗并以其为一线或辅助治疗。在治疗期间和长达28 d的随访期间对所发生的不良反应进行记录。疗效测量指标包括心电图、心肌酶、心肌肌钙蛋白、脑钠肽和超声心动图。使用单因素分析和logistic回归方法进行亚组分析和鉴定与两种药物的心脏毒性相关的显著性独立变量。结果 527例患者中有161例(30.6%)出现心脏毒性。卡培他滨组的心脏毒性发生率为33.8%(112/331),显著高于5-FU组25%(49/196)的发生率(P=0.0042)。110/527患者(20.9%)发生心律失常,105/527(19.9%)发生缺血性改变,而只有20/527患者(3.8%)出现心力衰竭,6/527患者(1.1%)出现心肌梗塞。既往的心脏病、高血压、卡培他滨为基础的化疗和治疗时间被确定为与心脏毒性相关的显著风险因素。优势比分别为15.7(心脏病史vs.无病史)、1.86(卡培他滨vs. 5-FU)、1.06(5–8个化疗周期vs. 1–4个化疗周期)和1.58(高血压vs.无高血压)。结论氟嘧啶类药物在中国人群中引起的心脏毒性可能在临床实践中被低估。建议密切监测患者,尤其是对心脏毒性高风险的患者。可能的风险因素包括治疗持续时间、基于卡培他滨的化疗、既往心脏病史和高血压史。Jianjun Peng Chao Dong Chang Wang Weihua Li Hao Yu Min Zhang Qun Zhao Bo Zhu Jun Zhang Wenliang Li Fenghua Wang Qiong Wu Wenhao Zhou Ying Yuan Meng Qiu Gong Chen 2018癌症2018,37,10:3
17A New Anti-Collision Algorithm for Multi-Target Real Time Recognitionin RFID System显示文摘The problem of how to distinguish and recognize more than one target when they are entering the working area of the Radio Frequency Identification( RFID ) system should be considered in design of the system. To avoid signal interference with each other among all targets, an anti collision algorithm as well as the condition of working stability is proposed. The computer simulation shows that the new algorithm will be of advantages in the process of system design.SHEN Yu chao, WANG Hai bo, SHEN Shu qun, XU Da xiong (School of Electronic Engineering,Beijing University of Posts and Telecommunications,Beijing 100876,P.R.China) 2000The Journal of China Universities of Posts and Telecommunications2000,7,3:3
18Adaptive decision-level fusion strategy for the fault diagnosis of axial piston pumps using multiple channels of vibration signals显示文摘An axial piston pump is a key component that plays the role of the 'heart' in hydraulic systems. The pump failure will lead to an unexpected breakdown of the entire hydraulic system or even economic loss and catastrophic safety consequences. Several vibration-based machine learning methods have been developed to detect and diagnose faults of axial piston pumps. However,most of these intelligent diagnosis methods use single-sensor vibration data to monitor the pump health states. Additionally, the diagnostic accuracy is unacceptable in most situations due to the complex pump structure and limited sensor information.Therefore, this study proposes a multi-sensor fusion method to improve the fault diagnosis performance of axial piston pumps.The convolutional neural network receives three channels of vibration data and makes the final diagnosis through information fusion at the decision level. The proposed decision fusion method is evaluated on the classification task of leakage levels of an actual axial piston pump. The experimental results show that the proposed method improves the classification accuracy by adjusting the probability distribution of classification according to the learned weight matrix.CHAO Qun GAO HaoHan TAO JianFeng WANG YuanHang ZHOU Jian LIU ChengLiang 2022Science China(Technological Sciences)2022,65,2:2
19Effects of MoS_2 on mechanical and tribological properties of NiCr-based alloys显示文摘Ni Cr based alloys with a wide temperature range self lubrication were made by hot pressing the mixture powder of alloyed Ni Cr powder, elemental Mo, Al, Ti and B powders and MoS 2 powder. The mechanical and tribological properties of these alloys when rubbing with Al 2O 3 ceramics and W18Cr4V high speed steel were measured in the temperature range of 20~700 ℃, and the mechanisms of self lubrication and wear resistance were studied. The results showed that the alloy containing 10% MoS 2 has the best combination of mechanical properties, antifriction and wear resistance. Over a wide temperature range from 20 ℃ to 700 ℃, when rubbing with Al 2O 3, its friction coefficient and wear rate are 0.19~0.3 and (1.1~1.5)10 -14 m 3/(N·m), respectively; when rubbing with the high speed steel, those values are 0.18 ~ 0.26 and (0.6~3.2)×10 -15 m 3/(N·m), respectively.XIONG Dang sheng(熊党生) 1, PENG Chao qun(彭超群) 2, LIU Jin long(刘金龙) 1 1. College of Mechanical Engineering, China University of Mining and Technology, Xuzhou 221008, P.R.China 2. State Key Lab for Powder Metallurgy, Central South Unive 2000中国有色金属学会会刊:英文版2000,10,3:2
20A multiobjective evolutionary optimization method based critical rainfall thresholds for debris flows initiation显示文摘At present,most researches on the critical rainfall threshold of debris flow initiation use a linear model obtained through regression.With relatively weak fault tolerance,this method not only ignores nonlinear effects but also is susceptible to singular noise samples,which makes it difficult to characterize the true quantization relationship of the rainfall threshold.Besides,the early warning threshold determined by statistical parameters is susceptible to negative samples(samples where no debris flow has occurred),which leads to uncertainty in the reliability of the early warning results by the regression curve.To overcome the above limitations,this study develops a data-driven multiobjective evolutionary optimization method that combines an artificial neural network(ANN)and a multiobjective evolutionary optimization implemented by particle swarm optimization(PSO).Firstly,the Pareto optimality method is used to represent the nonlinear and conflicting critical thresholds for the rainfall intensity I and the rainfall duration D.An ANN is used to construct a dual-target(dual-task)predictive surrogate model,and then a PSO-based multiobjective evolutionary optimization algorithm is applied to train the ANN and stochastically search the trained ANN for obtaining the Pareto front of the I-D surrogate prediction model,which is intended to overcome the limitations of the existing linear regression-based threshold methods.Finally,a double early warning curve model that can effectively control the false alarm rate and negative alarm rate of hazard warnings are proposed based on the decision space and target space maps.This study provides theoretical guidance for the early warning and forecasting of debris flows and has strong applicability.YAN Yan ZHANG Yu HU Wang GUO Xiao-jun MA Chao WANG Zi-ang ZHANG Qun 2020Journal of Mountain Science2020,17,8:2
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