Separation Technology, Thermodynamics : On the information and methods for calculation of Sanchez-Lacombe and group-contribution Lattice-fluid equations of state

( Cheng Yong Wang ),( Zhi Gang Lei ) 한국화학공학회 2006 Korean Journal of Chemical Engineering Vol.23 No.1

Study on the Real-Time Precise Orbit Biases Correction Technique for the GPS/VRS Network

LI Cheng-gang,HUANG Ding-fa,ZHOU Dong-wei,ZHOU Le-tao,XIONG Yong-liang,XU Rui 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.2 No.-

A precise real-time method of using the IGS ultra rapid products (IGU) and the GPS broadcast ephemeris to calculate the VRS orbit corrections was presented here which was suited for GPS/VRS reference station network based positioning. Test data acquired from both the SGRSN (Sichuan GPS Reference Station Network) and SCIGN (Southern California integrated GPS network) were used to evaluate the performance of the modeling techniques. The new method was proven to be more precise and reliable compared with the existing conventional network-based orbit error interpolation method. It was shown that 0.004ppm relative accuracy was reached, namely the influence from the orbit bias for the RTK positioning within 100km area can be of sub-millimeter level.

Fault identification method for planetary gear based on DT-CWT threshold denoising and LE

Xihui Chen,Gang Cheng,Hongyu Li,Yong Li 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.3

Planetary gear is widely used in large-scale complex mechanical systems. However, because of the particularity of planetary gear transmission, serious wear and fatigue crack failures often occur in the sun gear, planet gears, and inner gear ring. In addition, every type of fault will experience different degradation processes. Improving the operation reliability of mechanical equipment through fault diagnosis of planetary gears and monitoring their degradation process is beneficial. This paper proposes a planetary gear fault identification method based on Dual-tree Complex wavelet transform (DT-CWT) threshold denoising and Laplacian eigenmaps (LE). The noise reduction processing of the original signal is achieved by the DT-CWT threshold denoising method, which takes full advantage of DT-CWT and is combined with the wavelet threshold of rigrsure principle. The original high-dimensional feature set, including the time domain features, frequency domain features, permutation entropy, and fractal box dimension of the denoised signal, is constructed from multiangles. To solve the problems of excessively large feature dimension and the existence of redundant information, the LE algorithm is used to reduce the dimension of the original high-dimensional feature set, and the low-dimensional sensitive features are obtained. Through the above method, the effective identification of different fault states and different degradation states of the planetary gear are achieved.

A novel method for identifying rotor-stator rubbing positions using the cepstrum analysis technique

Guo Chen,Yong-Quan Liu,Guang-Yi Jiang,Cheng-Gang Li,Guo-Quan Feng,De-You Wang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9

A novel method of aero-engine rubbing positions identification based on cepstrum analysis is proposed, and the transfer path characteristicswhich reflect the transfer characteristics information from rubbing points to casing measuring points are separated from the vibrationacceleration signals of casing by means of cepstrum analysis. Therefore, there is different transfer characteristics information atdifferent rubbing positions, and in view of this, twenty rubbing positions identification features from the cepstrum are extracted. A largenumber of rubbing experiments of different positions are simulated with the rotor experiment rig of aero-engine, and the characteristicanalysis of experimental samples at different rubbing positions is carried out, and the results indicate the consistency of features to thesame rubbing position and the difference of the features to the different rubbing positions. Finally, the aero-engine rubbing positionsidentification is carried out using the nearest neighbor classification method, the recognition rate reaches 100%, and the effectiveness ofthe method is full verified.

Clinical Outcomes of Basaloid Squamous Cell Carcinoma of the Esophagus: A Retrospective Analysis of 142 Cases

Zhang, Bai-Hua,Cheng, Gui-Yu,Xue, Qi,Gao, Shu-Geng,Sun, Ke-Lin,Wang, Yong-Gang,Mu, Ju-Wei,He, Jie Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Background: Basaloid squamous cell carcinoma of the esophagus (BSCCE) is a rare and distinctive tumor with no standard treatment. This study aimed to explore treatment in relation to prognosis of the disease. Methods: A total of 142 patients with BSCCE that underwent treatment in our hospital from March 1999 to July 2010 were retrospectively analyzed. All patients received surgery, 42 postoperative radiotherapy and 28 patients chemotherapy. Results: There were 26 patients included in stage I, 60 in stage II, 53 in stage III and 3 in stage IV. The clinical symptoms and macroscopic performances of BSCCE did not differ from those of typical esophageal squamous cell carcinoma. Among 118 patients receiving endoscopic biopsy, only 12 were diagnosed with BSCCE. The median survival time (MST) of the entire group was 32 months, with 1-, 3- and 5-year overall survival (OS) of 81.4%, 46.8% and 31.0%, respectively. The 5-year OS of stage I and II patients was significantly longer than that of stages III/IV, at 60.3%, 36.1% and 10.9%, respectively (p<0.001, p=0.001). The MST and 5-year OS were 59.0 months and 47.4% in patients with tumors located in the lower thoracic esophagus, and 27.0 months and 18.1% in those with lesions in the upper/middle esophagus (p=0.002). However, the survival was not significantly improved in patients undegoing adjunctive therapy. Multivariate analysis showed TNM stage and tumor location to be independent prognostic factors. Furthermore, distant metastasis was the most frequent failure pattern, with a median recurrence time of 10 months. Conclusion: BSCCE is an aggressive disease with rapid progression and a propensity for distant metastasis. It is difficult to make a definitive diagnosis via preoperative biopsy. Multidisciplinary therapy including radical esophagectomy with extended lymphadenectomy should be recommended, while the effectiveness of radiochemotherapy requires further validation for BSCCE.

Identification of candidate odorant‐degrading enzyme genes in the antennal transcriptome of Aphidius gifuensis

Kang Zhi‐Wei,Liu Fang‐Hua,Xu Yong‐Yu,Cheng Jia‐Hui,Lin Xiao‐Li,Jing Xiang‐Feng,Tian Hong‐Gang,Liu Tong‐Xian 한국곤충학회 2021 Entomological Research Vol.51 No.1

Odorant‐degrading enzymes (ODEs) have been found in insect antennae and play a critical role in signal chemical degradation once the message is conveyed. Significant progress has been made in characterizing ODEs in a variety of pests but very little is known in their natural enemies. We have carried out an antennae‐ and sex‐specific transcriptome of Aphidius gifuensis, a natural enemy of aphid, to identify the candidate ODEs. Based on the antennae‐ and sex‐specific transcriptome, a total of 100 putative ODEs were identified including one aldehyde oxidase (AOX), four alcohol dehydrogenases (ADs), eight UDP‐glucuronosyltransferases (UGTs), 45 cytochrome P450 (P450s), nine glutathione S‐transferases (GSTs) and 40 carboxylesterases (CCEs or CXEs). Additionally, we used RT‐qPCR to determine the expression profiles of these genes in tissues of both sexes. Based on the phylogenic analysis and tissue‐expression patterns, AgifEstE4, AgifCXE3, AgifCCE4, AgifCCE7, and AgifCCE18 were suggested as key ODEs in A. gifuensis. In addition, the female or male specifically enriched genes, such as AgifCCE17, AgifEstB1, AgifCYP18a1, AgifUGT2C2, were also considered to involve in the chemosensory processing in A. gifuensis. This study not only identified the candidate ODEs in A. gifuensis but also provided source for further exploration of the molecular mechanisms of chemical signal transductions in A. gifuensis, as well as other hymenopteran species.

Assessment of the crest cracks of the Pubugou rockfill dam based on parameters back analysis

Zhou, Wei,Li, Shao-Lin,Ma, Gang,Chang, Xiao-Lin,Cheng, Yong-Gang,Ma, Xing Techno-Press 2016 Geomechanics & engineering Vol.11 No.4

The crest of the Pubugou central core rockfill dam (CCRD) cracked in the first and second impounding periods. To evaluate the safety of the Pubugou CCRD, an inversion analysis of the constitutive model parameters for rockfill materials is performed based on the in situ deformation monitoring data. The aim of this work is to truly reflect the deformation state of the Pubugou CCRD and determine the causes of the dam crest cracks. A novel real-coded genetic algorithm based upon the differences in gene fragments (DGFX) is proposed. It is used in combination with the radial based function neural network (RBFNN) to perform the parameters back analysis. The simulated settlements show good agreements with the monitoring data, illustrating that the back analysis is reasonable and accurate. Furthermore, the deformation gradient of the dam crest has been analysed. The dam crest has a great possibility of cracking due to the uncoordinated deformation, which agrees well with the field investigation. The deformation gradient decreases to the value lower than the critical one and reaches a stable state after the second full reservoir.

Microstructure evolution and effect on deuterium retention in oxide dispersion strengthened tungsten during He⁺ irradiation

Ding, Xiao-Yu,Xu, Qiu,Zhu, Xiao-yong,Luo, Lai-Ma,Huang, Jian-Jun,Yu, Bin,Gao, Xiang,Li, Jian-Gang,Wu, Yu-Cheng Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.12

Oxide dispersion-strengthened materials W-1wt%Pr₂O₃ and W-1wt%La₂O₃ were synthesized by wet chemical method and spark plasma sintering. The field emission scanning electron microscopy (FE-SEM) analysis, XRD and Vickers microhardness measurements were conducted to characterize the samples. The irradiations were carried out with a 5 keV helium ion beam to fluences up to 5.0 × 10²¹ ions/m² under 600 ℃ using the low-energy ion irradiation system. Transmission electron microscopy (TEM) study was performed to investigate the microstructural evolution in W-1wt%Pr₂O₃ and W-1wt%La₂O₃. At 1.0 × 10²⁰ He⁺/m², the average loops size of the W-1wt%Pr₂O₃ was 4.3 nm, much lower than W-1wt% La₂O₃ of 8.5 nm. However, helium bubbles were not observed throughout in both doped W materials. The effects of pre-irradiation with 1.0 × 10²¹ He⁺/m² on trapping of injected deuterium in doped W was studied by thermal desorption spectrometry (TDS) technique using quadrupole mass spectrometer. Compared with the samples without He⁺ pre-irradiation, deuterium (D) retention of doped W materials increased after He⁺ irradiation, whose retention was unsaturated at the damage level of 1.0 × 10²²D₂⁺/m². The present results implied that irradiation effect of He⁺ ions must be taken into account to evaluate the deuterium retention in fusion material applications.

A comparative study of three collocation point methods for odd order stochastic response surface method

Li, Dian-Qing,Jiang, Shui-Hua,Cheng, Yong-Gang,Zhou, Chuang-Bing Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.5

This paper aims to compare three collocation point methods associated with the odd order stochastic response surface method (SRSM) in a systematical and quantitative way. The SRSM with the Hermite polynomial chaos is briefly introduced first. Then, three collocation point methods, namely the point method, the root method and the without origin method underlying the odd order SRSMs are highlighted. Three examples are presented to demonstrate the accuracy and efficiency of the three methods. The results indicate that the condition that the Hermite polynomial information matrix evaluated at the collocation points has a full rank should be satisfied to yield reliability results with a sufficient accuracy. The point method and the without origin method are much more efficient than the root method, especially for the reliability problems involving a large number of random variables or requiring complex finite element analysis. The without origin method can also produce sufficiently accurate reliability results in comparison with the point and root methods. Therefore, the origin often used as a collocation point is not absolutely necessary. The odd order SRSMs with the point method and the without origin method are recommended for the reliability analysis due to their computational accuracy and efficiency. The order of SRSM has a significant influence on the results associated with the three collocation point methods. For normal random variables, the SRSM with an order equaling or exceeding the order of a performance function can produce reliability results with a sufficient accuracy. The order of SRSM should significantly exceed the order of the performance function involving strongly non-normal random variables.

A comparative study of three collocation point methods for odd order stochastic response surface method

Dian-Qing Li,Shui-Hua Jiang,Yong-Gang Cheng,Chuang-Bing Zhou 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.5

This paper aims to compare three collocation point methods associated with the odd order stochastic response surface method (SRSM) in a systematical and quantitative way. The SRSM with the Hermite polynomial chaos is briefly introduced first. Then, three collocation point methods, namely the point method, the root method and the without origin method underlying the odd order SRSMs are highlighted. Three examples are presented to demonstrate the accuracy and efficiency of the three methods. The results indicate that the condition that the Hermite polynomial information matrix evaluated at the collocation points has a full rank should be satisfied to yield reliability results with a sufficient accuracy. The point method and the without origin method are much more efficient than the root method, especially for the reliability problems involving a large number of random variables or requiring complex finite element analysis. The without origin method can also produce sufficiently accurate reliability results in comparison with the point and root methods. Therefore, the origin often used as a collocation point is not absolutely necessary. The odd order SRSMs with the point method and the without origin method are recommended for the reliability analysis due to their computational accuracy and efficiency. The order of SRSM has a significant influence on the results associated with the three collocation point methods. For normal random variables, the SRSM with an order equaling or exceeding the order of a performance function can produce reliability results with a sufficient accuracy. The order of SRSM should significantly exceed the order of the performance function involving strongly non-normal random variables.