Compression, Shear and Bending Performance of X-type Lattice Truss Panel Structure by Theoretical Method and Simulation

Qian Zhang,Wenchun Jiang,Yanting Zhang,Shan-Tung Tu 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.1

X-type lattice truss panel structure (LTPS) with high strength-weight ratio has anisotropic mechanical properties. This paper proposes a theoretical mechanical model to give predictions of the compression, shear and bending performance of LTPS including the eff ective compressive/shearing modulus, eff ective compressive/shearing strength and failure loads under threepoint bending. These properties are expressed as analytical expressions involving all of the geometrical parameters. The numerical simulation is also performed, and the eff ects of the geometrical parameters are discussed. The results show that the predicted eff ective modulus and strength by the theoretical method agree well with the simulated results. The eff ective shear modulus in 23-direction is obviously higher than that in other directions. The geometrical parameters have signifi cant eff ects on the mechanical properties. The shear yielding strength increases with the increase of truss width and thickness, while it decreases with the increase of truss length and platform length. The truss thickness has the greatest eff ect on yielding strength, followed by the truss width and the truss length. The changes of the yielding strength with the increase of the angle from horizontal and defl ected angle are not monotonic. The failure loads of three-point bending by face sheets yielding and shear induced core collapse decrease, when the span increases. The proposed analytical expressions are available to the engineering application and more complicated calculations of structures made of X-type cores.

An Updated Meta-analysis and System Review:is Gemcitabine+Fluoropyrimidine in Combination a Better Therapy Versus Gemcitabine Alone for Advanced and Unresectable Pancreatic Cancer?

Tu, Chao,Zheng, Feng,Wang, Jin-Yu,Li, Yuan-Yuan,Qian, Ke-Qing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.14

Background: Pancreatic cancer ranks fourth in deaths caused by cancers throughout the world. Gemcitabine chemotherapy is the primary method of treatment of advanced pancreatic cancer, and in asco2014, it is still firstline chemotherapy. Howeve,r gemcitabine+fluorouracil regimens are also licensed and widely used worldwide. Clinical trials are the best way to evaluate drug efficacy. In this study, we performed a systematic review and a meta-analysis of randomized controlled trials (RCTs) to assess whether gemcitabine+fluoropyrimidine combination therapy improves the prognosis of unresectable pancreatic cancer compared with gemcitabine treatment alone. Materials and Methods: A quantitative up-to-date meta-analysis was undertaken to investigate the efficacy of gemcitabine-based combination treatment compared with gemcitabine monotherapy for locally advanced or metastatic pancreatic cancer. Inclusion was limited to high-quality randomized clinical trials. Results: A total of 12 studies were included in the present analysis, with a total of 3,038 patients recruited. The studies were divided into three subgroups including 5-FU / CAP / S-1 combined with gemcitabine. For the primary endpoint of overall survival (OS), gemcitabine-based combination therapy demonstrated significantly better outcome (HR, 0.88; 95% CI, 0.81-0.95) than gemcitabine monotherapy. The analysis of progression free survival (PFS) also provided a significant result for the combined therapy in a total of 8 trials (2,130 patients) (HR, 0.74; 95% CI, 0.63-0.86). With subgroup analysis according to the method of dosing delivery, we found that in the injection group with 3 trials (889 patients), a negative result was found (HR, 0.93; 95% CI, 0.77-1.12); while a positive result was observed in the oral group with 9 trials (2,149 patients) (HR, 0.87; 95% CI, 0.80-0.95). Conclusions: Gemcitabine combination therapy provides a modest improvement of survival, but is associated with more toxicity compared with gemcitabine monotherapy.

Multi-threshold remote sensing image segmentation with improved ant colony optimizer with salp foraging

Qian Yunlou,Tu Jiaqing,Luo Gang,Sha Ce,Heidari Ali Asghar,Chen Huiling 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.6

Remote sensing images can provide direct and accurate feedback on urban surface morphology and geographic conditions. They can be used as an auxiliary means to collect data for current geospatial information systems, which are also widely used in city public safety. Therefore, it is necessary to research remote sensing images. Therefore, we adopt the multi-threshold image segmentation method in this paper to segment the remote sensing images for research. We first introduce salp foraging behavior into the continuous ant colony optimization algorithm (ACOR) and construct a novel ACOR version based on salp foraging (SSACO). The original algorithm’s convergence and ability to avoid hitting local optima are enhanced by salp foraging behavior. In order to illustrate this key benefit, SSACO is first tested against 14 fundamental algorithms using 30 benchmark test functions in IEEE CEC2017. Then, SSACO is compared with 14 other algorithms. The experimental results are examined from various angles, and the findings convincingly demonstrate the main power of SSACO. We performed segmentation comparison studies based on 12 remote sensing images between SSACO segmentation techniques and several peer segmentation approaches to demonstrate the benefits of SSACO in remote sensing image segmentation. Peak signal-to-noise ratio, structural similarity index, and feature similarity index evaluation of the segmentation results demonstrated the benefits of the SSACO-based segmentation approach. SSACO is an excellent optimizer since it seeks to serve as a guide and a point of reference for using remote sensing image algorithms in urban public safety.

MiRNA-15a Mediates Cell Cycle Arrest and Potentiates Apoptosis in Breast Cancer Cells by Targeting Synuclein-γ

Li, Ping,Xie, Xiao-Bing,Chen, Qian,Pang, Guo-Lian,Luo, Wan,Tu, Jian-Cheng,Zheng, Fang,Liu, Song-Mei,Han, Lu,Zhang, Jian-Kun,Luo, Xian-Yong,Zhou, Xin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Background: Recent studies have indicated that microRNA-15a (miR-15a) is dysregulated in breast cancer (BC). We aimed to evaluate the expression of miR-15a in BC tissues and corresponding para-carcinoma tissues. We also focused on effects of miR-15a on cellular behavior of MDA-MB-231 and expression of its target gene synuclein-${\gamma}$ (SNCG). Materials and Methods: The expression levels of miR-15a were analysed in BC formalin fixed paraffin embedded (FFPE) tissues by microarray and quantitative real-time PCR. CCK-8 assays, cell cycle and apoptosis assays were used to explore the potential functions of miR-15a in MDA-MB-231 human BC cells. A luciferase reporter assay confirmed direct targets. Results: Downregulation of miR-15a was detected in most primary BCs. Ectopic expression of miR-15a promoted proliferation and suppressed apoptosis in vivo. Further studies indicated that miR-15a may directly interact with the 3'-untranslated region (3'-UTR) of SNCG mRNA, downregulating its mRNA and protein expression levels. SNCG expression was negatively correlated with miR-15a expression. Conclusions: MiR-15a has a critical role in mediating cell cycle arrest and promoting cell apoptosis of BC, probably by directly targeting SNCG. Thus, it may be involved in development and progression of BC.

Effect of notch position on creep damage for brazed joint

Luo, Yun,Jiang, Wenchun,Zhang, Qian,Zhang, Weiya,Woo, Wanchuck,Tu, Shan-Tung,Hao, Muming Elsevier Applied Science 2016 Advances in engineering software Vol.100 No.-

<P><B>Abstract</B></P> <P>In this paper, we investigated the effect of notch position on creep damage for Hastelloy C276-BNi2 brazed joint. Three different types of notches locate in edge of base metal (base notch), edge of filler metal (surface notch) and center of filler metal (inside notch) were compared, and the influence of notch geometric parameters on creep damage was also investigated. The results show that the different notch position and dimension generate different creep damage distributions and have a great influence on creep life. The creep failure is the easiest to occur in surface notch, then the base notch, and the last is inside notch. The brazed joint with higher maximum principal stress and von Mises stress generates creep failure easier. For the base notch, the failure time increases with the increase of base notch distance and the creep failure location moves gradually from the center of filler metal to notch tip. The notch locating away from filler metal is beneficial to reduce the creep damage in filler metal and enhance the creep life. For the inside notch, the failure time decreases with notch length increases and the maximum creep damage locates at notch tip. With the increase of inside notch width, the failure time increases first and then keep steadiness, and the failure location moves away from notch tip. The effects of notch position and dimension should be fully considered in creep failure analyses and life assessments of brazed joints.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The creep failure is easy generate in surface notch. </LI> <LI> The far away notch is helpful to reduce the creep damage of filler metal. </LI> <LI> As H increases, the failure location moves from filler metal to base metal. </LI> <LI> As H increases, the failure time increases first then keeps stable. </LI> <LI> The failure time decreases with L increases while it increases with W increases. </LI> </UL> </P>

Prediction of the remaining time and time interval of pebbles in pebble bed HTGRs aided by CNN via DEM datasets

Wu Mengqi,Liu Xu,Gui Nan,Yang Xingtuan,Tu Jiyuan,Jiang Shengyao,Qian Zhao 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.1

Prediction of the time-related traits of pebble flow inside pebble-bed HTGRs is of great significance for reactor operation and design. In this work, an image-driven approach with the aid of a convolutional neural network (CNN) is proposed to predict the remaining time of initially loaded pebbles and the time interval of paired flow images of the pebble bed. Two types of strategies are put forward: one is adding FC layers to the classic classification CNN models and using regression training, and the other is CNNbased deep expectation (DEX) by regarding the time prediction as a deep classification task followed by softmax expected value refinements. The current dataset is obtained from the discrete element method (DEM) simulations. Results show that the CNN-aided models generally make satisfactory predictions on the remaining time with the determination coefficient larger than 0.99. Among these models, the VGG19þDEX performs the best and its CumScore (proportion of test set with prediction error within 0.5s) can reach 0.939. Besides, the remaining time of additional test sets and new cases can also be well predicted, indicating good generalization ability of the model. In the task of predicting the time interval of image pairs, the VGG19þDEX model has also generated satisfactory results. Particularly, the trained model, with promising generalization ability, has demonstrated great potential in accurately and instantaneously predicting the traits of interest, without the need for additional computational intensive DEM simulations. Nevertheless, the issues of data diversity and model optimization need to be improved to achieve the full potential of the CNN-aided prediction tool

A Novel High Performance SOI LDMOS with Buried Stepped Gate Field Plate

Hongchao Hu,Hongli Dai,Luoxin Wang,Haitao Lyu,Yuming Xue,Tu Qian 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.6

With the continuous development of science and technology, the power semiconductor devices are becoming more and more extensive. A novel silicon-on-insulator (SOI) lateral double-diffused metal–oxide–semiconductor (LDMOS) has been proposed in this paper. The new device is mainly characterized by introducing a stepped gate field plate in the low-K dielectric buried layer (SGFP-LK). On the one hand, the stepped gate field plate introduces extra lateral electric field peaks, which makes the distribution of potential lines more uniform and improves the breakdown voltage (BV). Moreover, the stepped gate fi eld plate decreases the specific on-resistance ( R on,sp ) by a promoted depletion. On the other hand, different from the traditional buried oxygen layer, the low-K dielectric layer strengthens the vertical electric field and signifi cantly increases BV. Ultimately, compared with the conventional device (C-SOI LDMOS), the BV of the SGFP-LK LDMOS is dramatically enhanced by 107% and the R on,sp is reduced by 24.8%. Furthermore, the figure of merit is enhanced by 472%. In addition, the maximum lattice temperature of the SGFP-LK LDMOS is dropped by 23.1 K, which relieves self-heating effects to some extent.

Comparative Study on Anti-interference of Nondestructive Testing System with Annular Array Probes

Ru Bai,Zhiwei Li,Tengda Yang,Boyan Li,Aiyu Dou,Jiakun Tu,Jiaqi Li,Chuanjia Kou,Zhenghong Qian 한국자기학회 2024 Journal of Magnetics Vol.29 No.1

A pulsed eddy current nondestructive testing (PECT) system with annular array probes is designed for inner defect detection of metal pipelines. Tunneling magnetoresistance (TMR) array probes are applied to detect the magnetic signal generated by the inner surface defect of the metal pipelines. Compared to single probe structure, the annular array probes have advantages of high sensitivity, large scanning area and internal realtime detection. However, since many probes are densely arranged in the array, signal interference may occur between adjacent probes. Therefore, two methods of anti-interference, magnetic shielding and time-sharing excitation, are proposed in this work. By modeling and simulation, the working principles of the two antiinterference modes are analyzed and compared respectively. The experimental results show that both methods can reduce the interference between adjacent TMR probes. Compared with the time-sharing excitation method, the magnetic shielding method exhibits better performance with stronger differential signal peak and smaller error, and proves to be a more effective method for the defect detection of the metal pipelines.