Design and theoretical analysis of a sliding valve distribution radial piston pump

Guo Tong,Zhao Shengdun,Yu Yanghuiwen,Shang Peng 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

A Sliding valve distribution radial piston pump (SVDRPP) is presented. In this pump, a new distribution method that uses slidingvalves to distribute oil for the piston chambers is developed. With this design, the disadvantages brought by the distribution shaft and thecheck valves (traditional distribution mechanisms), such as the poor stress state of the shaft and the energy waste for opening the checkvalves, are expected to be eliminated. In addition, a method of using pressure oil to accomplish the returning stroke of the piston is alsoproposed, which could be used to replace the usage of springs along with their shortcomings. A pump with five pistons is designed as anexample to elaborate the structure and the working principle of SVDRPP. Furthermore, the flow characteristics of SVDRPP are studied,and the formulas of the displacement, the average flow rate and the instantaneous flow rate are deduced.

Analysis of decimation techniques to improve computational efficiency of a frequency-domain evaluation approach for real-time hybrid simulation

Tong Guo,Chengcheng,Weijie Xu 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.6

Accurate actuator tracking is critical to achieve reliable real-time hybrid simulation results for earthquake engineering research. The frequency-domain evaluation approach provides an innovative way for more quantitative post-simulation evaluation of actuator tracking errors compared with existing time domain based techniques. Utilizing the Fast Fourier Transform the approach analyzes the actuator error in terms of amplitude and phrase errors. Existing application of the approach requires using the complete length of the experimental data. To improve the computational efficiency, two techniques including data decimation and frequency decimation are analyzed to reduce the amount of data involved in the frequency-domain evaluation. The presented study aims to enhance the computational efficiency of the approach in order to utilize it for future on-line actuator tracking evaluation. Both computational simulation and laboratory experimental results are analyzed and recommendations on the two decimation factors are provided based on the findings from this study.

Analysis of decimation techniques to improve computational efficiency of a frequency-domain evaluation approach for real-time hybrid simulation

Guo, Tong,Xu, Weijie,Chen, Cheng Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.14 No.6

Accurate actuator tracking is critical to achieve reliable real-time hybrid simulation results for earthquake engineering research. The frequency-domain evaluation approach provides an innovative way for more quantitative post-simulation evaluation of actuator tracking errors compared with existing time domain based techniques. Utilizing the Fast Fourier Transform the approach analyzes the actuator error in terms of amplitude and phrase errors. Existing application of the approach requires using the complete length of the experimental data. To improve the computational efficiency, two techniques including data decimation and frequency decimation are analyzed to reduce the amount of data involved in the frequency-domain evaluation. The presented study aims to enhance the computational efficiency of the approach in order to utilize it for future on-line actuator tracking evaluation. Both computational simulation and laboratory experimental results are analyzed and recommendations on the two decimation factors are provided based on the findings from this study.

Quantitative Assessment of the Effects of MMP-2 Polymorphisms on Lung Carcinoma Risk

Guo, Xiao-Tong,Wang, Jun-Feng,Zhang, Lin-You,Xu, Guang-Quan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Background: Previous studies assessing associations between matrix metalloproteinase 2 (MMP-2) polymorphisms and lung cancer risk reported conflicting results. A meta-analysis was therefore performed to derive a more precise estimation. Method: Case-control studies assessing associations between MMP-2 C735T and C1306T polymorphisms and lung cancer risk were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. Results: 7 studies with a total of 3,189 lung cancer cases and 3,013 controls were finally included into this meta-analysis. Overall, the MMP-2 C735T polymorphism was associated with lung cancer risk under the homozygote model (CC versus TT: OR =1.44, 95% CI = 1.03-2.02, $I^2$ = 0%), while the MMP-2 C1306T polymorphism also associated demonstrated links with all four models (all P values less than 0.05). Subgroup analyses by race suggested obvious associations between MMP-2 C735T and C1306T polymorphisms and lung cancer risk in Asians but not in Caucasians. There was no evidence for publication bias. Conclusion: Currently available evidence supports teh conclusion that MMP-2 C735T and C1306T polymorphisms influence susceptibility to lung cancer in Asians.

Vibration-based structural health monitoring using CAE-aided unsupervised deep learning

Tong Guo,Minte Zhang,Ruizhao Zhu,Yueran Zong,Zhihong Pan 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.30 No.6

Vibration-based structural health monitoring (SHM) is crucial for the dynamic maintenance of civil building structures to protect property security and the lives of the public. Analyzing these vibrations with modern artificial intelligence and deep learning (DL) methods is a new trend. This paper proposed an unsupervised deep learning method based on a convolutional autoencoder (CAE), which can overcome the limitations of conventional supervised deep learning. With the convolutional core applied to the DL network, the method can extract features self-adaptively and efficiently. The effectiveness of the method in detecting damage is then tested using a benchmark model. Thereafter, this method is used to detect damage and instant disaster events in a rubber bearing-isolated gymnasium structure. The results indicate that the method enables the CAE network to learn the intact vibrations, so as to distinguish between different damage states of the benchmark model, and the outcome meets the high-dimensional data distribution characteristics visualized by the t-SNE method. Besides, the CAE-based network trained with daily vibrations of the isolating layer in the gymnasium can precisely recover newly collected vibration and detect the occurrence of the ground motion. The proposed method is effective at identifying nonlinear variations in the dynamic responses and has the potential to be used for structural condition assessment and safety warning.

X-Ray crystal structure of [HSm{V^IVO(TPPS)}]_<i>n</i> and encapsulation of nitrogen molecules in 1-D channels

Chen, Wen-Tong,Yamada, Yusuke,Liu, Guang-Ning,Kubota, Akira,Ichikawa, Takayuki,Kojima, Yoshitsugu,Guo, Guo-Cong,Fukuzumi, Shunichi Royal Society of Chemistry 2011 Dalton transactions Vol.40 No.48

<P>The crystal structure of an N<SUB>2</SUB>-encapusulated MOF, which is stable under open-air conditions at ambient temperature, was determined by single-crystal X-ray diffraction at 123 K. The crystal MOF of [HSm{V<SUP>IV</SUP>O(TPPS)}]<SUB><I>n</I></SUB> designed to have 1-D channels periodically constricted by porphyrins planes adsorbed N<SUB>2</SUB> at 77 K. The adsorbed N<SUB>2</SUB> molecules remained in the 1-D channels even after warming to ambient temperature. The single-crystal structure of [HSm{V<SUP>IV</SUP>O(TPPS)}]<SUB><I>n</I></SUB>⊃N<SUB>2</SUB> determined by X-ray diffraction indicated that N<SUB>2</SUB> molecules trapped in the constricted parts block other N<SUB>2</SUB> molecules in 1-D channels from escaping from the MOF. Such a unique encapsulation mode provides a promising approach toward designing novel MOFs with high gas storage capacity at ambient temperature.</P> <P>Graphic Abstract</P><P>The shrinking of a channel window to fit the size of stopper molecules enables encapsulation of adsorbates in the 1-D channels. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1dt10956a'> </P>

Combination of Tumor Volume and Epstein-Barr Virus DNA Improved Prognostic Stratification of Stage II Nasopharyngeal Carcinoma in the Intensity Modulated Radiotherapy Era: A Large-Scale Cohort Study

Qiu-Yan Chen,Shao-Yan Guo,Lin-Quan Tang,Tong-Yu Lu,Bo-Lin Chen,Qi-Yu Zhong,Meng-Sha Zou,Qing-Nan Tang,Wen-Hui Chen,Shan-Shan Guo,Li-Ting Liu,Yang Li,Ling Guo,Hao-Yuan Mo,Rui Sun,Dong-Hua Luo,Chong Zha 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose Little is known about combination of the circulating Epstein-Barr viral (EBV) DNA and tumor volume in prognosis of stage II nasopharyngeal carcinoma (NPC) patients in the intensity modulated radiotherapy (IMRT) era. We conducted this cohort study to evaluate the prognostic values of combining these two factors. Materials and Methods By Kaplan-Meier, we compare the differences of survival curves between 385 patients with different EBV DNA or tumor volume levels, or with the combination of two biomarkers mentioned above. Results Gross tumor volume of cervical lymph nodes (GTVnd, p < 0.001) and total tumor volume (GTVtotal, p < 0.001) were both closely related to pretreatment EBV DNA, while gross tumor volume of nasopharynx (GTVnx, p=0.047) was weakly related to EBV DNA. EBV DNA was significantly correlated with progress-free survival (PFS, p=0.005), locoregional-free survival (LRFS, p=0.039), and distant metastasis-free survival (DMFS, p=0.017), while GTVtotal, regardless of GTVnx and GTVnd, had a significant correlation with PFS and LRFS. The p-values of GTVtotal for PFS and LRFS were 0.008 and 0.001, respectively. According to GTVtotal and pretreatment EBV DNA level, patients were divided into a low-risk group (EBV DNA 0 copy/mL, GTVtotal < 30 cm3; EBV DNA 0 copy/mL, GTVtotal  30 cm3; or EBV DNA > 0 copy/mL, GTVtotal < 30 cm3) and a high-risk group (EBV DNA > 0 copy/mL, GTVtotal  30 cm3). When patients in the low-risk group were compared with those in the high-risk group, 3-year PFS (p=0.003), LRFS (p=0.010), and DMFS (p=0.031) rates were statistically significant. Conclusion Pretreatment plasma EBV DNA and tumor volume were both closely correlated with prognosis of stage II NPC patients in the IMRT era. Combination of EBV DNA and tumor volume can refine prognosis and indicate for clinical therapy.

Mechanical behavior of rock-coal-rock specimens with different coal thicknesses

Guo, Wei-Yao,Tan, Yun-Liang,Yu, Feng-Hai,Zhao, Tong-Bin,Hu, Shan-Chao,Huang, Dong-Mei,Qin, Zhe Techno-Press 2018 Geomechanics & engineering Vol.15 No.4

To explore the influence of coal thickness on the mechanical behavior and the failure characteristics of rock-coal-rock (RCR) mass, the experimental investigation of uniaxial compressive tests was conducted first and then a systematic numerical simulation by particle flow code (PFC2D) was performed to deeply analyze the failure mechanical behavior of RCR specimens with different coal thicknesses in conventional compression tests. The overall elastic modulus and peak stress of RCR specimens lie between the rock and the coal. Inter-particle properties were calibrated to match the physical sample strength and the stiffness response. Numerical simulation results show that the deformation and strength behaviors of RCR specimens depend not only on the coal thickness, but also on the confining pressure. Under low confining pressures, the overall failure mechanism of RCR specimen is the serious damage of coal section when the coal thickness is smaller than 30 mm, but it is shear failure of coal section when the coal thickness is larger than 30 mm. Whereas under high confining pressures, obvious shear bands exist in both the coal section and the rock section when the coal thickness is larger than 30 mm, but when the coal thickness is smaller than 30mm, the failure mechanism is serious damage of coal section and shear failure of rock section.

Verruciform Xanthoma of the Penis

Tongli Xia,Guizhong Li,전인선,Yanqun,Na Yinglu Guo,정문기 대한비뇨의학회 2004 Investigative and Clinical Urology Vol.45 No.3

Verruciform xanthoma is an uncommon benign lesion. The most common presentation occurs in the oral cavity; however, it has also been described in other sites, especially the penis. Herein is reported the first case of verruciform xanthoma of the penis in China, the fourteenth case in the literature. Clinically, genital verruciform xanthoma is often confuses with papillomas, verrucous carcinomas and squamous cell carcinomas, and therefore a histopathological diagnosis is necessary. (Korean J Urol 2004;45: 297-298)

Effect of Sn Micro-Alloying on Recrystallization Nucleation and Growth Processes of Ferritic Stainless Steels

Tong He,Yang Bai,Xiuting Liu,Dan Guo,Yandong Liu 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.4

We investigated the Effect of Sn micro-alloying on recrystallization nucleation and growth processes of ferritic stainlesssteels. The as-received hot rolled sheets were cold rolled up to 80% reduction and then annealed at 740–880 °C for 5 min. The cold rolling and recrystallization microstructures and micro-textures of Sn-containing and Sn-free ferritic stainless steelswere all determined by electron backscatter diff raction. Our Results show that Sn micro-alloying has important Effects onrecrystallization nucleation and growth processes of ferritic stainless steels. Sn micro-alloying conduces to grain fragmentationin the deformation band, more fragmented grains are existed in Sn-containing cold rolled sheets, which provides moresites for recrystallization nucleation. Sn micro-alloying also promotes recrystallization process and inhibits the growth ofrecrystallized grains. The recrystallization nucleation and growth mechanism of Sn-containing and Sn-free ferritic stainlesssteels are both characterized by orientation nucleation and selective growth, but Sn micro-alloying promotes the formation ofγ-oriented grains. Furthermore, Sn micro-alloying contributes to the formation of Σ13b CSL boundaries and homogeneousγ-fi ber texture. Combining the results of microstructure and micro-texture, the formability of Sn-containing ferritic stainlesssteels will be improved to some extent.