13 results on '"Hongqiang Chai"'
Search Results
2. Construction of Solid-Liquid Two-Phase Flow and Wear Rate Prediction Model in Multiphase Pump Based on Mixture Model-Discrete Phase Model Combination Method
- Author
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Xin Guo, Guangtai Shi, Yexiang Xiao, Hongqiang Chai, Wenjuan Lv, and Jie Fu
- Subjects
multiphase pump ,solid-liquid two-phase flow ,wear ,wear rate prediction model ,Naval architecture. Shipbuilding. Marine engineering ,VM1-989 ,Oceanography ,GC1-1581 - Abstract
Blade wear is the critical problem in the operation of multiphase pump. This paper presents a numerical study of the multiphase flow of multiphase pump. The trajectory of particles in the pump is calculated by the discrete phase model. Then, the simulation results are compared with the model test results of the pump to verify the correctness of the simulation method. The results show that the particles in the impeller domain are mainly near the hub, and the particles in the diffuser domain form a agglomerated area in the middle of the flow channel. The average wear rate of the impeller is more affected by the particle size than that of the diffuser. The maximum wear rate of blade surface increases first and then decreases with the increase of particle size. According to the wear data under different particle sizes, the regression model between particle size and wear rate is fitted to predict the wear of mixed transport pump in actual operation. The research results have important reference value for the prediction of the wear performance of the multiphase pump.
- Published
- 2024
- Full Text
- View/download PDF
3. The causal association between maternal smoking around birth on childhood asthma: A Mendelian randomization study
- Author
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Zijun Ding, Lei Pang, Hongqiang Chai, Fei Li, and Ming Wu
- Subjects
maternal smoking around birth ,childhood asthma ,maternal Alzheimer's disease ,maternal hypertension ,maternal heart disease ,Mendelian randomization ,Public aspects of medicine ,RA1-1270 - Abstract
To explore the causal relationship between maternal smoking around birth and childhood asthma using Mendelian randomization (MR). Using the data from large-scale genome-wide association studies, we selected independent genetic loci closely related to maternal smoking around birth and maternal diseases as instrumental variables and used MR methods. In this study, we considered the inverse variance weighted method (MR-IVW), weighted median method, and MR-Egger regression. We investigated the causal relationship between maternal smoking around birth and maternal diseases in childhood asthma using the odds ratio (OR) as an evaluation index. Multivariable MR (MVMR) included maternal history of Alzheimer's disease, illnesses of the mother: high blood pressure and illnesses of the mother: heart diseaseas covariates to address potential confounding. Sensitivity analyses were evaluated for weak instrument bias and pleiotropic effects. It was shown with the MR-IVW results that maternal smoking around birth increased the risk of childhood asthma by 1.5% (OR = 1.0150, 95% CI: 1.0018–1.0283). After the multivariable MR method was used to correct for relevant covariates, the association effect between maternal smoking around birth and childhood asthma was still statistically significant (P < 0.05). Maternal smoking around birth increases the risk of childhood asthma.
- Published
- 2022
- Full Text
- View/download PDF
4. Analysis of straight conjugate internal gear pump through numerical modeling and experimental validation.
- Author
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Hongqiang Chai, Guolai Yang, Guoguo Wu, Guixiang Bai, and Chuanchuan Cao
- Subjects
Medicine ,Science - Abstract
As a medium and low pressure gear machine without automatic compensation structure for axial and radial clearances, the friction pairs in the straight conjugate internal gear pumps (SCIGPs) depend on the fixed small clearances to seal, lubricate and transfer the force. The oil film design of the friction pairs has become an important part of gear pump design. However, there has never been a publicly published research on the oil film design of the SCIGP in past literature. This paper applies orthogonal test to the oil film design of the SCIGP for the first time to determine the best working clearances. With this goal, the paper first provides the mathematical models for analyzing the internal leakage flow and the viscous friction loss, which elucidate the relationships between the leakage and the friction loss with working conditions. After that, the orthogonal test scheme for numerical simulation was designed on the basis of determining the range of oil film thickness. The paper also propounds the viewpoints of using the range-method to estimate the primary and secondary relationship of factors and determining the optimal combination according to the test target. Based on this concept, the main factors affecting the target are procured and the optimal working clearances of the friction pairs are determined. For the purpose of verifying the model, the redesigned prototype was tested and compared with the simulation results. The results validate the applicability of the simulation model and the correctness of the simulation method. Finally, the paper summarizes the ways to improve the total efficiency and the working conditions at the highest efficiency.
- Published
- 2022
- Full Text
- View/download PDF
5. A Review on Rolling Bearing Fault Signal Detection Methods Based on Different Sensors
- Author
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Guoguo Wu, Tanyi Yan, Guolai Yang, Hongqiang Chai, and Chuanchuan Cao
- Subjects
rolling bearing ,fault detection ,type of fault signal ,diagnostic method ,sensor ,Chemical technology ,TP1-1185 - Abstract
As a precision mechanical component to reduce friction between components, the rolling bearing is widely used in many fields because of its slight friction loss, strong bearing capacity, high precision, low power consumption, and high mechanical efficiency. This paper reviews several excellent kinds of study and their relevance to the fault detection of rolling bearings. We summarize the fault location, sensor types, bearing fault types, and fault signal analysis of rolling bearings. The fault signal types are divided into one-dimensional and two-dimensional images, which account for 40.14% and 31.69%, respectively, and their classification is clarified and discussed. We counted the proportions of various methods in the references cited in this paper. Among them, the method of one-dimensional signal detection with external sensors accounted for 3.52%, the method of one-dimensional signal detection with internal sensors accounted for 36.62%, and the method of two-dimensional signal detection with external sensors accounted for 19.72%. The method of two-dimensional signal detection with internal sensors accounted for 11.97%. Among these methods, the highest detection rate is 100%, and the lowest detection rate is more than 70%. The similarities between the different methods are compared. The research results summarized in this paper show that with the progress of the times, a variety of new and better research methods have emerged, which have sped up the detection and diagnosis of rolling bearing faults. For example, the technology using artificial intelligence is still developing rapidly, such as artificial neural networks, convolutional neural networks, and machine learning. Although there are still defects, such methods can quickly discover a fault and its cause, enrich the database, and accumulate experience. More and more advanced techniques are applied in this field, and the detection method has better robustness and superiority.
- Published
- 2022
- Full Text
- View/download PDF
6. The safety and effectiveness of laparoscopic anterior sacral ligament suspension combined with dome suspension in the treatment of bladder prolapse after hysterectomy: a retrospective cohort study
- Author
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Lei Pang, Zijun Ding, Hongqiang Chai, Fei Li, Ming Wu, and Weibing Shuang
- Subjects
Reproductive Medicine ,Urology - Published
- 2023
7. Causal relationship between smoking status, smoking frequency and bladder cancer: a Mendelian randomization study
- Author
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Lei, Pang, Zijun, Ding, Hongqiang, Chai, Fei, Li, Ming, Wu, and Weibing, Shuang
- Subjects
Genetics ,Molecular Biology ,Biochemistry - Abstract
Smoking is a well-established risk factor for bladder cancer. However, it remained unclear that whether smoke status and smoke frequency increase bladder cancer.We aim to explore the causal relationship between smoking status, smoking frequency and the risk of bladder cancer by Mendelian randomization.Large sample size of the genome-wide association(GWAS) database of smoking status, smoking frequency and bladder cancer were obtained. Smoking status included never, previous and current whereas smoking frequency included cigarettes smoked per day, number of cigarettes currently smoked daily and pack years of smoking. Six sets of instrumental variables and 78 related single nucleotide polymorphic(SNP) loci were identified (P 5 × 10-8. Linkage disequilibrium R2 0.001). The causal relationship between smoking status and bladder tumor was studied by inverse variance weighted (IVW), weighted median and MR-Egger regression. Sensitivity analysis were also performed.There is no causal effect from smoke status on bladder cancer risk while significantly positive relationship between smoking frequency on bladder cancer risk were found. IVW results showed that cigarettes smoked per day, number of cigarettes currently smoked daily and pack years of smoking increase bladder cancer (OR 1.001, 95% CI 1.000-1.002, P = 0.047; OR 1.003, 95% CI 1.000-1.005, P = 0.028; OR 1.004, 95% CI 1.001-1.006, P = 0.003). Sensitivity analysis showed that genetic pleiotropy did not bias the results.The results of two sample Mendelian randomization analysis show that there is a positive causal relationship between smoking frequency and the risk of bladder cancer.
- Published
- 2022
8. Analysis of Flow Characteristics of Straight Conjugate Crescent Gear Pump at Variable Working Conditions
- Author
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Guoguo Wu, Guolai Yang, Chuanchuan Cao, and Hongqiang Chai
- Subjects
Article Subject ,General Mathematics ,General Engineering - Abstract
The working conditions (i.e., gas content, working pressure, and working temperature) of oil in the actual hydraulic system are always in a dynamic process, which will cause the basic properties of oil (i.e., density, absolute viscosity, and effective bulk modulus) to change and further generate changes of the flow characteristics in the straight conjugate crescent gear pump (SCCGP). However, no clear explanation has been given for the variation of the flow characteristics of the SCCGP with the working conditions in previous studies. This paper first expounds the gear pair profile equations used to draw the tooth profile curves and the equation applicable to the calculation of the geometric displacement at the given geometric parameters. Subsequently, the mathematical models of the oil’s basic properties are analyzed, and it is explained how the changing working conditions affect the changes in oil properties. After that, the paper designs an orthogonal test scheme and applies it to the study of the flow characteristics of the SCCGP for the first time to optimize its working conditions. Then, the paper performs simulations in commercial CFD numerical software, and the change laws of the internal flow field, flow pulsation, pressure pulsation, volumetric efficiency, and total efficiency of the SCCGP at different working conditions are analyzed in detail. The working conditions for decreasing pulse rate and improving total efficiency are summarized. Finally, for model validation purposes, the paper elucidates the construction process of a high-pressure positive displacement pump test system and carried out experimental research. The simulation and actual measurement results are compared under the same working conditions. The results validate the accuracy of the simulation model and the potential for future analytical studies.
- Published
- 2022
9. Causal relationships between DNA methylation、Golgi membrane proteins、endoplasmic reticulum aminopeptidase and abnormal spermatozoa: a two sample Mendelian randomization study
- Author
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Lei Pang, Zijun Ding, Hongqiang Chai, Fei Li, Ming Wu, and Weibing Shuang
- Abstract
To explore the causal relationship between DNA methylation, Golgi membrane protein, endoplasmic reticulum aminopeptidase, ADP-ribose pyrophosphatase, mitochondrialon abnormal spermatozoa by two-sample Mendelian randomization (TSMR) method.Genetic loci closely related to DNA methylation PhenoAge acceleration, Golgi membrane protein 1, endoplasmic reticulum aminopeptidase 1, endoplasmic reticulum aminopeptidase 2, ADP-ribose pyrophosphatase, mitochondrial were selected as instrumental variables, andTSMR was performed by the inverse variance weighted method, MREgger regression, and weighted median method respectively. Sensitivity analysis was conducted to evaluate the robustness of the MR results.IVW showed that the DNA methylation PhenoAge acceleration(OR = 1.12, 95% CI: 1.01–1.23), Golgi membrane protein 1(OR = 1.22, 95% CI: 1.04–1.44), and endoplasmic reticulum aminopeptidase 2(OR = 1.13, 95% CI: 1.04–1.24) were associated with an increased risk of abnormal spermatozoa. However, there was no evidence of the association between ADP-ribose pyrophosphatase, mitochondrial (IVW OR = 1.25, 95% CI: 0.95–1.63), endoplasmic reticulum aminopeptidase 1 (IVW OR = 1.01, 95% CI: 0.90–1.12) and abnormal spermatozoa. Sensitivity analysis detected little evidence of pleiotropy in the current study.There is a positive causal relationship between DNA methylation PhenoAge acceleration, Golgi membrane protein 1, and endoplasmic reticulum aminopeptidase 2 on abnormal spermatozoa.
- Published
- 2022
10. HPV-16 Expression and Loss of Cell Differentiation in Primary Bladder Tumors
- Author
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Lei Pang, Zijun Ding, Fei Li, Hongqiang Chai, Ming Wu, and Jinkai Shao
- Subjects
Human papillomavirus 16 ,Urinary Bladder Neoplasms ,General Immunology and Microbiology ,Article Subject ,Papillomavirus Infections ,Urinary Bladder ,DNA, Viral ,Humans ,Cell Differentiation ,General Medicine ,Papillomaviridae ,General Biochemistry, Genetics and Molecular Biology - Abstract
Objective. Primary bladder tumors have a high degree of malignancy. To investigate the expression of human papillomavirus type 16 (HPV-16) in primary bladder tumors and the loss of cell differentiation and to explore the significance of HPV-16 detection, it is expected to be a disease. Treatment provides a theoretical basis. Methods. Fifty-seven patients with primary bladder tumors admitted to our hospital from January 2019 to January 2022 were selected as the research subjects, and they were divided into HPV-related groups according to the human papillomavirus (HPV) infection status ( n = 28 ) and HPV unrelated group ( n = 29 ). The general data of patients were collected, the expression of HPV-16 in bladder tissue samples was detected, and the correlation between pathological parameters and HPV-16 expression was analyzed. Results. Among HPV subtypes, HPV 16 subtype accounted for the highest proportion, followed by HPV-18 and HPV-6 subtypes; there was no significant difference in tumor stage (stage 1, stage a, stage 2a) between the HPV-related group and the HPV-unrelated group (stage 1, stage a, and stage 2a). P > 0.05 ); there was no significant difference in postoperative pathological expression (high expression and low expression) of patients ( P > 0.05 ); there was no statistical difference in age and gender between HPV-related and HPV-unrelated groups ( P > 0.05 ), HPV-related group and HPV-unrelated group compared daily regular drinking and smoking status, the difference was statistically significant ( P < 0.05 ); HPV-16 expression was not correlated with tumor differentiation degree and age of patients ( P > 0.05 ); the area under the curve (AUC) of HPV-16 for judging primary bladder tumor expression and cellular molecular deletion was 0.891, with a sensitivity of 83.94% and a specificity of 88.57%. Conclusion. HPV-16 is an upper, expressed in primary bladder tumors and will participate in the differentiation and loss of cells, which can provide effective guidance and basis for the diagnosis of primary bladder tumors, which is an important factor for judging the pathological stage and prognosis of patients and can provide a theoretical reference for the formulation of therapeutic measures.
- Published
- 2022
- Full Text
- View/download PDF
11. Analysis of straight conjugate internal gear pump through numerical modeling and experimental validation
- Author
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Hongqiang Chai, Guolai Yang, Guoguo Wu, Guixiang Bai, and Chuanchuan Cao
- Subjects
Kinetics ,Multidisciplinary ,Friction ,Computer Simulation ,Equipment Design ,Mechanical Phenomena - Abstract
As a medium and low pressure gear machine without automatic compensation structure for axial and radial clearances, the friction pairs in the straight conjugate internal gear pumps (SCIGPs) depend on the fixed small clearances to seal, lubricate and transfer the force. The oil film design of the friction pairs has become an important part of gear pump design. However, there has never been a publicly published research on the oil film design of the SCIGP in past literature. This paper applies orthogonal test to the oil film design of the SCIGP for the first time to determine the best working clearances. With this goal, the paper first provides the mathematical models for analyzing the internal leakage flow and the viscous friction loss, which elucidate the relationships between the leakage and the friction loss with working conditions. After that, the orthogonal test scheme for numerical simulation was designed on the basis of determining the range of oil film thickness. The paper also propounds the viewpoints of using the range-method to estimate the primary and secondary relationship of factors and determining the optimal combination according to the test target. Based on this concept, the main factors affecting the target are procured and the optimal working clearances of the friction pairs are determined. For the purpose of verifying the model, the redesigned prototype was tested and compared with the simulation results. The results validate the applicability of the simulation model and the correctness of the simulation method. Finally, the paper summarizes the ways to improve the total efficiency and the working conditions at the highest efficiency.
- Published
- 2021
12. The causal relationship between immune cells and different kidney diseases: A Mendelian randomization study.
- Author
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Lei Pang, Zijun Ding, Hongqiang Chai, and Weibing Shuang
- Abstract
Studies have suggested that the progress of most kidney diseases from occurrence to course and subsequent related complications are closely related to inflammatory reaction. Increased common leukocytes count in the family (neutrophils, eosinophils, basophils, lymphocytes, etc.) are also involved in the tissue damage of kidney diseases. However, these studies are only traditional observational studies, which cannot prove whether there is a causal relationship between these four kinds of leukocytes count and kidney diseases. We aim to explore the causal relationship between these four kinds of leukocytes count and kidney diseases by Mendelian randomization (MR). Large sample size of the genome-wide association database of four cell traits (neutrophil, basophil, lymphocyte, and eosinophil cell counts) in the leukocyte family were used as exposure variables. The outcome variables were various renal diseases (including chronic renal failure, acute renal failure, hypertensive heart or/and kidney disease, hypertensive renal disease, disorders resulting from impaired renal tubular function, and type 1 diabetes with renal complications). The covariates used in multivariable MR are also four cell traits related to blood cells (neutrophil, basophil, lymphocyte, and eosinophil cell counts). Instrumental variables and single nucleotide polymorphic loci were identified (P < 5 × 10
−8 . Linkage disequilibrium R2 < 0.001). The causal relationships were studied by inverse variance weighted (IVW), weighted median, and MR-Egger regression. Sensitivity analysis was also performed. In our study, IVW analysis results showed that increased neutrophil cell count was a risk factor for chronic renal failure (OR = 2.0245861, 95% CI = 1.1231207–3.649606, P = 0.01896524), increased basophil cell count was a risk factor for chronic renal failure (OR = 3.975935, 95% CI = 1.4871198–10.62998, P = 0.005942755). Basophil cell count was not a risk factor for acute renal failure (OR = 1.160434, 95% CI = 0.9455132–1.424207, P = 0.15448828). Increased basophil cell count was a protective factor for hypertensive heart and/or renal disease (OR = 0.7716065, 95% CI = 0.6484979–0.9180856, P = 0.003458707). Increased basophil cell count was a risk factor for disorders resulting from impaired renal tubular function (OR = 1.648131, 95% CI = 1.010116–2.689133, P = 0.04546835). Increased lymphocyte cell count was a risk factor for hypertensive renal disease (OR = 1.372961, 95% CI = 1.0189772–1.849915, P = 0.03719874). Increased eosinophil cell count was a risk factor for type 1 diabetes with renal complications (OR = 1.516454, 95% CI = 1.1826453–1.944482, P = 0.001028964). Macrophage inflammatory protein 1b levels was a protective factor for renal failure (OR = 0.9381862, 95% CI = 0.8860402–0.9934013, P = 0.02874872). After multivariable MR was used to correct covariates (neutrophil, basophil, and lymphocyte cell counts), the correlation effect between increased eosinophil cell counts and type 1 diabetes with renal complications was still statistically significant (P = 0.02201152). After adjusting covariates (neutrophil, basophil, and eosinophil cell counts) with multivariable MR, the correlation effect between increased lymphocyte cell counts and hypertensive renal disease was still statistically significant (P = 0.02050226). This study shows that increased basophils can increase the relative risk of chronic renal failure and renal tubular dysfunction, and reduce the risk of hypertensive heart disease and/or hypertensive nephropathy, while increased basophil cell count will not increase the relative risk of acute renal failure, increased neutrophil cell count can increase the risk of chronic renal failure, increased lymphocyte cell count can increase the relative risk of hypertensive nephropathy, and increased eosinophil cell count can increase the relative risk of type 1 diabetes with renal complications. Macrophage inflammatory protein 1b levels was a protective factor for renal failure. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
13. Numerical Simulation of Flow Characteristics of H76 Type Double Disc Check Valve Under Different Open Angle
- Author
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Guolai Yang, Hongqiang Chai, Dongwu Chen, Wenqi Li, and Donghua He
- Subjects
business.product_category ,Materials science ,Check valve ,Computer simulation ,Open angle glaucoma ,Flow (mathematics) ,Mechanics ,Type (model theory) ,business - Published
- 2015
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