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1. Enhancing Complex Causality Extraction via Improved Subtask Interaction and Knowledge Fusion

Author

Gao, Jinglong, Lu, Chen, Ding, Xiao, Li, Zhongyang, Liu, Ting, and Qin, Bing

Subjects
Computer Science - Computation and Language, Computer Science - Artificial Intelligence
Abstract

Event Causality Extraction (ECE) aims at extracting causal event pairs from texts. Despite ChatGPT's recent success, fine-tuning small models remains the best approach for the ECE task. However, existing fine-tuning based ECE methods cannot address all three key challenges in ECE simultaneously: 1) Complex Causality Extraction, where multiple causal-effect pairs occur within a single sentence; 2) Subtask~ Interaction, which involves modeling the mutual dependence between the two subtasks of ECE, i.e., extracting events and identifying the causal relationship between extracted events; and 3) Knowledge Fusion, which requires effectively fusing the knowledge in two modalities, i.e., the expressive pretrained language models and the structured knowledge graphs. In this paper, we propose a unified ECE framework (UniCE to address all three issues in ECE simultaneously. Specifically, we design a subtask interaction mechanism to enable mutual interaction between the two ECE subtasks. Besides, we design a knowledge fusion mechanism to fuse knowledge in the two modalities. Furthermore, we employ separate decoders for each subtask to facilitate complex causality extraction. Experiments on three benchmark datasets demonstrate that our method achieves state-of-the-art performance and outperforms ChatGPT with a margin of at least 30% F1-score. More importantly, our model can also be used to effectively improve the ECE performance of ChatGPT via in-context learning., Comment: NLPCC 2024 Oral

Published
2024

2. Self-Evolving GPT: A Lifelong Autonomous Experiential Learner

Author

Gao, Jinglong, Ding, Xiao, Cui, Yiming, Zhao, Jianbai, Wang, Hepeng, Liu, Ting, and Qin, Bing

Subjects
Computer Science - Computation and Language, Computer Science - Artificial Intelligence
Abstract

To improve the performance of large language models (LLMs), researchers have explored providing LLMs with textual task-solving experience via prompts. However, they rely on manual efforts to acquire and apply such experience for each task, which is not feasible for the growing demand for LLMs and the variety of user questions. To address this issue, we design a lifelong autonomous experiential learning framework based on LLMs to explore whether LLMs can imitate human ability for learning and utilizing experience. It autonomously learns and accumulates experience through experience transfer and induction, categorizing the types of input questions to select which accumulated experience to employ for them. Experimental results on six widely used NLP datasets show that our framework performs reliably in each intermediate step and effectively improves the performance of GPT-3.5 and GPT-4. This validates the feasibility of using LLMs to mimic human experiential learning and application capabilities. Additionally, we provide a detailed analysis of the behavior of our framework at each step., Comment: Accepted by ACL 2024 MAIN

Published
2024

3. Towards Generalizable and Faithful Logic Reasoning over Natural Language via Resolution Refutation

Author

Sun, Zhouhao, Ding, Xiao, Du, Li, Cai, Bibo, Gao, Jinglong, Liu, Ting, and Bing, Qin

Subjects
Computer Science - Artificial Intelligence, Computer Science - Computation and Language
Abstract

Large language models (LLMs) have achieved significant performance in various natural language reasoning tasks. However, they still struggle with performing first-order logic reasoning over formal logical theories expressed in natural language. This is because the previous LLMs-based reasoning systems have the theoretical incompleteness issue. As a result, it can only address a limited set of simple reasoning problems, which significantly decreases their generalization ability. To address this issue, we propose a novel framework, named Generalizable and Faithful Reasoner (GFaiR), which introduces the paradigm of resolution refutation. Resolution refutation has the capability to solve all first-order logic reasoning problems by extending reasoning rules and employing the principle of proof by contradiction, so our system's completeness can be improved by introducing resolution refutation. Experimental results demonstrate that our system outperforms previous works by achieving state-of-the-art performances in complex scenarios while maintaining performances in simple scenarios. Besides, we observe that GFaiR is faithful to its reasoning process., Comment: LREC-Coling 2024

Published
2024

4. Is ChatGPT a Good Causal Reasoner? A Comprehensive Evaluation

Author

Gao, Jinglong, Ding, Xiao, Qin, Bing, and Liu, Ting

Subjects
Computer Science - Computation and Language, Computer Science - Artificial Intelligence
Abstract

Causal reasoning ability is crucial for numerous NLP applications. Despite the impressive emerging ability of ChatGPT in various NLP tasks, it is unclear how well ChatGPT performs in causal reasoning. In this paper, we conduct the first comprehensive evaluation of the ChatGPT's causal reasoning capabilities. Experiments show that ChatGPT is not a good causal reasoner, but a good causal explainer. Besides, ChatGPT has a serious hallucination on causal reasoning, possibly due to the reporting biases between causal and non-causal relationships in natural language, as well as ChatGPT's upgrading processes, such as RLHF. The In-Context Learning (ICL) and Chain-of-Thought (CoT) techniques can further exacerbate such causal hallucination. Additionally, the causal reasoning ability of ChatGPT is sensitive to the words used to express the causal concept in prompts, and close-ended prompts perform better than open-ended prompts. For events in sentences, ChatGPT excels at capturing explicit causality rather than implicit causality, and performs better in sentences with lower event density and smaller lexical distance between events. The code is available on https://github.com/ArrogantL/ChatGPT4CausalReasoning ., Comment: Accepted to Findings of EMNLP 2023

Published
2023

5. DiscrimLoss: A Universal Loss for Hard Samples and Incorrect Samples Discrimination

Author

Wu, Tingting, Ding, Xiao, Zhang, Hao, Gao, Jinglong, Du, Li, Qin, Bing, and Liu, Ting

Subjects
Computer Science - Machine Learning, Computer Science - Artificial Intelligence, Computer Science - Computer Vision and Pattern Recognition
Abstract

Given data with label noise (i.e., incorrect data), deep neural networks would gradually memorize the label noise and impair model performance. To relieve this issue, curriculum learning is proposed to improve model performance and generalization by ordering training samples in a meaningful (e.g., easy to hard) sequence. Previous work takes incorrect samples as generic hard ones without discriminating between hard samples (i.e., hard samples in correct data) and incorrect samples. Indeed, a model should learn from hard samples to promote generalization rather than overfit to incorrect ones. In this paper, we address this problem by appending a novel loss function DiscrimLoss, on top of the existing task loss. Its main effect is to automatically and stably estimate the importance of easy samples and difficult samples (including hard and incorrect samples) at the early stages of training to improve the model performance. Then, during the following stages, DiscrimLoss is dedicated to discriminating between hard and incorrect samples to improve the model generalization. Such a training strategy can be formulated dynamically in a self-supervised manner, effectively mimicking the main principle of curriculum learning. Experiments on image classification, image regression, text sequence regression, and event relation reasoning demonstrate the versatility and effectiveness of our method, particularly in the presence of diversified noise levels.

Published
2022

7. An Adaptive Spatial Network for UAV Image Real-Time Semantic Segmentation

Author

Wu, Qian, Song, JiaYu, Luo, YanBo, Li, Hao, Tian, Qin, Wang, Qi, Gao, Jinglong, Jia, Zhuoran, Rannenberg, Kai, Editor-in-Chief, Soares Barbosa, Luís, Editorial Board Member, Goedicke, Michael, Editorial Board Member, Tatnall, Arthur, Editorial Board Member, Neuhold, Erich J., Editorial Board Member, Stiller, Burkhard, Editorial Board Member, Tröltzsch, Fredi, Editorial Board Member, Pries-Heje, Jan, Editorial Board Member, Kreps, David, Editorial Board Member, Reis, Ricardo, Editorial Board Member, Furnell, Steven, Editorial Board Member, Mercier-Laurent, Eunika, Editorial Board Member, Winckler, Marco, Editorial Board Member, Malaka, Rainer, Editorial Board Member, Shi, Zhongzhi, editor, Jin, Yaochu, editor, and Zhang, Xiangrong, editor

Published
2022
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10. Studies on thickened tailings deposition in flume tests using the computational fluid dynamics (CFD) method

Author

Gao, Jinglong and Fourie, Andy

Subjects
Fluid dynamics -- Models -- Methods -- Analysis, Beaches -- Analysis -- Models, Flumes -- Models -- Analysis, Geophysical research, Slopes (Landforms) -- Models -- Analysis, Earth sciences
Abstract

Computational fluid dynamics (CFD) simulations of laboratory flume tests on thickened tailings were conducted to highlight the factors that may influence the slopes of final profiles achieved in such flumes. The numerical model was first validated against the analytical solution of a sheet of Bingham fluid on a flat plane at flow stoppage. It was then used to investigate the influence of several factors on the average slopes of the final profiles. The results show that an increase of volume, energy, flume width or base angle reduces the resulting slope angle. Moreover, the yield stress of the fluid generally has more influence on the final profiles than the viscosity. In addition, the viscosity tends to have less influence on the formation of the final profiles if the inertial effects are relatively weak. Finally, two dimensionless parameters are proposed to establish the relationship between the average slope, rheological properties, and geometrical parameters for planar deposition of thickened tailings in both sudden-release (S-R) and discharge flume tests. These results provide a better understanding of the deposition of thickened tailings in the field. The agreement between simulation results and laboratory observations in the literature gives confidence in the veracity of the computational results.Key words: thickened tailings, flume test, beach slope, computational fluid dynamics (CFD) modelling.Des simulations de la dynamique numerique des fluides (DNF) d'essais en canal de laboratoire sur des residus epaissis ont ete menees afin de mettre en evidence les facteurs susceptibles d'influencer les pentes des profils finaux obtenus dans ces canaux. Le modele numerique a d'abord ete valide contre la solution analytique d'une feuille de fluide de Bingham sur un plan plat a l'arret de l'ecoulement. Il a ensuite ete utilise pour etudier l'influence de plusieurs facteurs sur les pentes moyennes des profils finaux. Les resultats montrent qu'une augmentation du volume, de l'energie, de la largeur du canal ou de l'angle de base reduit l'angle de pente resultant. De plus, la limite elastique du fluide a generalement plus d'influence sur les profils finaux que la viscosite. De plus, la viscosite tend a avoir moins d'influence sur la formation des profils finaux si les effets inertiels sont relativement faibles. Enfin, deux parametres adimensionnels sont proposes pour etablir la relation entre la pente moyenne, les proprietes rheologiques et les parametres geometriques pour le depot planaire de residus epaissis dans les essais a deversement soudain (<< S-R >>) et dans les canaux de decharge. Ces resultats permettent de mieux comprendre le depot de residus epaissis sur le terrain. L'accord entre les resultats de la simulation et les observations de laboratoire dans la litterature donne confiance dans la veracite des resultats de calcul. [Traduit par la Redaction]Mots-cles : residus epaissis, essais en canal, pente de la plage, modelisation de la dynamique numerique des fluides (DNF)., 1. IntroductionThe beach slope developed by tailings slurry after it is discharged into a tailings storage facility (TSF) is of great importance for the design and operation of a TSF [...]

Published
2019
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13. Artificial intelligence-based medical image segmentation for 3D printing and naked eye 3D visualization

Author

Huang Xunan, Jie He, Guang Jia, Hao Jiaxue, Xiaoling Zhang, Liu Bo, Hongcai Wang, Zhao Yue, Sen Tao, Jiejing Zhou, Zhang Xianghuai, Gao Jinglong, and Tanping Li

Subjects
Clinical Practice, 3d printed, genetic structures, Computer science, business.industry, Image registration, 3D printing, Lumbar spine, Segmentation, Image segmentation, Artificial intelligence, business, Visualization
Abstract

Image segmentation for 3D printing and 3D visualization has become an essential component in many fields of medical research, teaching, and clinical practice. Medical image segmentation requires sophisticated computerized quantifications and visualization tools. Recently, with the development of artificial intelligence (AI) technology, tumors or organs can be quickly and accurately detected and automatically contoured from medical images. This paper introduces a platform-independent, multi-modality image registration, segmentation, and 3D visualization program, named artificial intelligence-based medical image segmentation for 3D printing and naked eye 3D visualization (AIMIS3D). YOLOV3 algorithm was used to recognize prostate organ from T2-weighted MRI images with proper training. Prostate cancer and bladder cancer were segmented based on U-net from MRI images. CT images of osteosarcoma were loaded into the platform for the segmentation of lumbar spine, osteosarcoma, vessels, and local nerves for 3D printing. Breast displacement during each radiation therapy was quantitatively evaluated by automatically identifying the position of the 3D printed plastic breast bra. Brain vessel from multi-modality MRI images was segmented by using model-based transfer learning for 3D printing and naked eye 3D visualization in AIMIS3D platform.

Published
2022

18. Chinese expert consensus on prevention and intervention for the elderly with malnutrition (2022).

Author

Mao, Yongjun, Wu, Jianqing, Liu, Gongxiang, Yu, Yao, Chen, Bo, Liu, Jia, Wang, Jianye, Yu, Pulin, Zhang, Cuntai, Wu, Jinhui, Cao, Jiumei, Chen, Zheng, Cui, Hua, Dai, Shuiping, Deng, Linzi, Gao, Jinglong, Gao, Xuewen, He, Ping, Jin, Zhe, and Kang, Lin

Subjects
PREVENTION of malnutrition, CONSENSUS (Social sciences), NUTRITIONAL assessment, CHRONIC diseases, NUTRITION education, QUALITY of life, OLD age
Abstract

Malnutrition is a state of altered body composition and body cell mass due to inadequate intake or utilization of energy or nutrients, leading to physical and mental dysfunction and impaired clinical outcomes. As one of the most common geriatric syndromes, malnutrition in the elderly is a significant risk factor for poor clinical outcomes, causing a massive burden on medical resources and society. The risk factors for malnutrition in the elderly are diverse and include demographics, chronic diseases, and psychosocial factors. Presently, recommendations for the prevention and intervention of malnutrition in the elderly are not clear or consistent in China. This consensus is based on the latest global evidence and multiregional clinical experience in China, which aims to standardize the prevention and intervention of malnutrition in the elderly in China and improve the efficacy of clinical practice and the prognosis of elderly patients. [ABSTRACT FROM AUTHOR]

Published
2022
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22. Evaluating intracranial artery dissection by using three-dimensional simultaneous non-contrast angiography and intra-plaque hemorrhage high-resolution magnetic resonance imaging: a retrospective study.

Author

Tang, Min, Gao, Jinglong, Gao, Jie, Yan, Xuejiao, Zhang, Xin, Li, Longchao, Xia, Zhe, Lei, Xiaoyan, and Zhang, Xiaoling

Subjects
*MAGNETIC resonance imaging, *SPONTANEOUS coronary artery dissection, *DIAGNOSTIC imaging, *ATHEROSCLEROTIC plaque, *VERTEBRAL artery dissections, *ANGIOGRAPHY, *HEMORRHAGE, *MAGNETIC resonance angiography, *DISSECTING aneurysms, *THREE-dimensional imaging, *CEREBRAL hemorrhage, *HEMATOMA, *STENOSIS, *INTRACRANIAL arterial diseases, *AMYLOID plaque, *RETROSPECTIVE studies, *DESCRIPTIVE statistics, *SENSITIVITY & specificity (Statistics), *RECEIVER operating characteristic curves, *DISEASE risk factors
Abstract

Background: There was no previous report on the three-dimensional simultaneous non-contrast angiography and intra-plaque hemorrhage (3D-SNAP) magnetic resonance imaging (MRI) sequence to diagnose intracranial artery dissection (IAD). Purpose: To improve the diagnostic accuracy and guide the clinical treatment for IAD by elucidating its pathological features using 3D-SNAP MRI. Material and Methods: From January 2015 to September 2018, 113 patients with suspected IAD were analyzed. They were divided into IAD and non-IAD groups according to the spontaneous coronary artery dissection (SCAD) criteria. All patients underwent 3D-SNAP, 3D-TOF, T2W imaging, 3D-PD, 3D-T1W-VISTA, and 3D-T1WCE) using 3.0-T MRI; clinical data were collected. The IAD imaging findings (intramural hematoma, double lumen, intimal flap, aneurysmal dilatation, stenosis, or occlusion) in every sequence were analyzed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic efficiency of each sequence. Results: There was a significant difference in the probability of intramural hematoma, relative signal intensity of intramural hematoma, double lumen, stenosis, or occlusion signs on 3D-TOF, T2W, 3D-PD, 3D-T1W-VISTA, 3D-SNAP, and 3D-T1WCE sequences (P <0.05). The 3D-SNAP and 3D-T1WCE sequences were most sensitive for diagnosing intramural hematoma and displaying double-lumen signs, respectively. The diagnostic efficiency of the 3D-SNAP sequence combined with 3D-T1WCE was the highest (area under the curve [AUC] 0.966). The AUC value of the 3D-SNAP sequence (AUC 0.897) was slightly inferior to that of 3D-T1W enhancement (AUC 0.903). Conclusion: 3D-SNAP MRI is a non-invasive and effective method and had the greatest potential among those methods tested for improving the diagnostic accuracy for IAD. [ABSTRACT FROM AUTHOR]

Published
2022
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24. Preparation and Adsorption Performance for La3+ of Polyionic Liquid Solid Phase Adsorbent.

Author

LI Zhixuan, GAO Jinglong, and ZUO Jicheng

Abstract

Three kinds of polyionic liquid solid phase adsorbent (P[BVIM]Br-MNPs), P[HVIM]Br-MNPs and P[OVIM]Br-MNPs) were prepared. The effects of P204 doping ratio, solid phase adsorbent amount, adsorption time and temperature, aqueous phase pH and initial mass concentration of La3+ in aqueous phase on adsorption of La3+ by polyionic liquid solid phase adsorbent were examined. Langmuir and Freundlich isotherm equations were used to fit test data. The results show that the saturated adsorption capacity of the solid phase adsorbent for La3+ is 57.80 mg/g at 70 °C and 1 g P[OVIM]Br-MnPs doped with 1 mL P204, and the adsorption process is mainly monollayer adsorption. [ABSTRACT FROM AUTHOR]

Published
2021
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25. Ablation and mechanical investigation of heat vulcanizing silicone rubber (HVSR) composite containing carbon fibers

Author

Yong Li, Gao Jinglong, Jingyu Su, Zhi Ye, Yin Zhengshuai, and Yanhui Liu

Subjects
Materials science, Polymers and Plastics, General Chemical Engineering, medicine.medical_treatment, Composite number, Vulcanization, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Ablation, Silicone rubber, 01 natural sciences, 0104 chemical sciences, law.invention, chemistry.chemical_compound, chemistry, law, Materials Chemistry, medicine, Composite material, 0210 nano-technology
Abstract

In this study, heat vulcanizing silicone rubber (HVSR) composites were prepared and the impact of the addition of carbon fibers (CFs) on the mechanical and ablation properties of the composite was demonstrated. It was found that with increasing content of CFs, the tensile property and the hardness of the composite increased significantly. The back-face temperature, the ablation rate and the ablation mechanism of the composite were discussed based on the data derived from several characterization methods, including oxygen-acetylene ablation device, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). Along with the increasing of the content of CFs, the mass and linear ablation rates both decreased, but the back-face temperature increased. The interaction between ablation layer and the composite became intense due to the addition of the CFs, which led to the difficult peel-off of the ablation layer. Four layers can be formed after the oxygen-acetylene ablation of the composite including the surface layer, the carbonization layer, the pyrolysis layer and the matrix layer. The ablation mechanism was also proposed. It mainly involves the carbonization of the composite, the ceramization of SiC and the shielding effect of the ablated layer.

Published
2016

26. The investigation of the structural change and the wetting behavior of electron beam irradiated PTFE film

Author

Ni Zaochun, Liu Yan-hui, and Gao Jinglong

Subjects
Polytetrafluoroethylene, Materials science, Polymers and Plastics, General Chemical Engineering, 02 engineering and technology, 021001 nanoscience & nanotechnology, Electron beam irradiation, chemistry.chemical_compound, 020303 mechanical engineering & transports, 0203 mechanical engineering, Structural change, chemistry, Cathode ray, Wetting, Irradiation, Physical and Theoretical Chemistry, Composite material, 0210 nano-technology
Abstract

The effect of electron beam (EB) irradiation on polytetrafluoroethylene (PTFE) film was studied in air at room temperature. The structural changes of the PTFE film irradiated by EB were determined by Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The morphological changes on the film surface were described using scanning electron microscopy (SEM). The surface hydrophilicity of the modified film was characterized through water contact angle measurement. The results show that scission of the chain on the surface of PTFE film was induced by EB irradiation. The atomic ratio of F/C decreased and the atomic ratio of O/C increased. The surface roughness of the irradiated sample increased. In the case of irradiation in the presence of residual air, carboxylic acid fluoride groups appear and can hydrolyze to carboxylic groups in the surface-near regions. These polar groups significantly reduced the hydrophobicity and oleophobicity of the PTFE film and consequently cause the decline of the water contact angle of the film surface. XRD analysis reveals an increase of the crystallite size of PTFE along with the increasing time of the irradiate.

Published
2016

27. Surface modification of YW2 cemented carbide cutting tool by high current pulsed electron beam

Author

Gao Jinglong, Changsheng Lou, Xiao Lyu, Yao Zhang, and Qiang Wang

Subjects
lcsh:TN1-997, Materials science, Cutting tool, YW2 Cemented Carbide tool, Alloy, Metallurgy, engineering.material, Indentation hardness, Surface modification, Machining, engineering, Cemented carbide, Cutting performance, General Materials Science, Irradiation, Mechanical property, Beam (structure), lcsh:Mining engineering. Metallurgy
Abstract

Surface modification of YW2 cemented carbide cutting tool was carried out through high current pulsed electron beam with different pulsed times, and the microstructural, mechanical properties and cutting performance is also investigate in this work. The evolution of phase composition and morphology of tool were tested by means of XRD and SEM, and the microhardness was measured. The results showed that, metastable new phase (Co3W3C) is presented in tool surface after beam irradiation. The metastable phase and residual compressive stress induced by HCPEB treatment modified the microhardness of YW2 turning insert dramatically. The cutting performance of YW2 turning insert with 40times irradiation was examined and compared with original one by machining Ti-6Al-4V alloy bar. It is found that the irradiated YW2 tool increased cutting speed than that of un-irradiated one along with serious wear.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.6748

Published
2015

34. PIK3CA and TP53 Gene Mutations in Human Breast Cancer Tumors Frequently Detected by Ion Torrent DNA Sequencing

Author

Bai, Xusheng, primary, Zhang, Enke, additional, Ye, Hua, additional, Nandakumar, Vijayalakshmi, additional, Wang, Zhuo, additional, Chen, Lihong, additional, Tang, Chuanning, additional, Li, Jianhui, additional, Li, Huijin, additional, Zhang, Wei, additional, Han, Wei, additional, Lou, Feng, additional, Zhang, Dandan, additional, Sun, Hong, additional, Dong, Haichao, additional, Zhang, Guangchun, additional, Liu, Zhiyuan, additional, Dong, Zhishou, additional, Guo, Baishuai, additional, Yan, He, additional, Yan, Chaowei, additional, Wang, Lu, additional, Su, Ziyi, additional, Li, Yangyang, additional, Jones, Lindsey, additional, Huang, Xue F., additional, Chen, Si-Yi, additional, and Gao, Jinglong, additional

Published
2014
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37. Ablation and mechanical investigation of heat vulcanizing silicone rubber (HVSR) composite containing carbon fibers

Author

Liu, Yanhui, Su, Jingyu, Yin, Zhengshuai, Li, Yong, Zhi, Ye, and Gao, Jinglong

Abstract

In this study, heat vulcanizing silicone rubber (HVSR) composites were prepared and the impact of the addition of carbon fibers (CFs) on the mechanical and ablation properties of the composite was demonstrated. It was found that with increasing content of CFs, the tensile property and the hardness of the composite increased significantly. The back-face temperature, the ablation rate and the ablation mechanism of the composite were discussed based on the data derived from several characterization methods, including oxygen-acetylene ablation device, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). Along with the increasing of the content of CFs, the mass and linear ablation rates both decreased, but the back-face temperature increased. The interaction between ablation layer and the composite became intense due to the addition of the CFs, which led to the difficult peel-off of the ablation layer. Four layers can be formed after the oxygen-acetylene ablation of the composite including the surface layer, the carbonization layer, the pyrolysis layer and the matrix layer. The ablation mechanism was also proposed. It mainly involves the carbonization of the composite, the ceramization of SiC and the shielding effect of the ablated layer.

Published
2017
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38. Ablation Behavior of Silicone Rubber-Benzoxazine-Based Composites for Ultra-High Temperature Applications.

Author

Gao, Jinglong, Li, Zhixuan, Li, Jiayi, and Liu, Yanhui

Subjects
*TEMPERATURE, *SILICONES, *THERMAL stability, *CARBONIZATION
Abstract

A novel type of silicon rubber composite with benzoxazine resins (BZs) and ZrO2 was prepared. The ablative response of the composites was investigated. The results showed that the composites with BZs had superior thermal stability and higher resides compared to the pristine composites. The linear ablation rate of the composites decreased significantly with the increase in ZrO2 content. The maximum back-face temperature of the burnt samples was no more than 100 °C for the obtained composites. Three major ablation processes were carried out simultaneously during the ablation processing. These mainly involved the carbonization of the composite, and the formation of ceramic compounds such as SiC and ZrC, as well as the shielding effect of the ablated layer, which subsequently enhanced the ablation resistance of the composites. [ABSTRACT FROM AUTHOR]

Published
2019
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39. Spread is better: an investigation of the mini-slump test.

Author

Gao Jinglong, Fourie A., Gao Jinglong, and Fourie A.

Abstract

A key design parameter for high-density, thickened tailings (paste) is the yield stress, widely measured by the quick and easy slump test. The paper investigates current techniques for interpreting the cylindrical slump (or mini-slump) test, taking into account the lifting of the cylindrical mould in numerical simulations using a computational fluid dynamics approach. Simulations with different mould lifting velocities were carried out. The influence of plastic viscosity and yield stress on mini-slump test results was first studied using a mould lifting velocity of 0.01 m/s, representative of rates used in laboratory tests. To understand the influence of mould lifting velocity, the predicted slump and spread from mini-slump test simulations for three different scenarios (v(lifting) 0.002 m/s, v(lifting) 0.01 m/s and no lifting i.e. mould disappears instantaneously) were compared with those from vane viscometer experiments on the rheological properties of kaolin. The results suggest that the lifting speed of the mould has a significant influence on the mini-slump test result, which must therefore be taken into account in both numerical simulations and laboratory tests. It was found that the variation of mould lifting velocity had a greater influence on slump than spread, indicating that spread is a more appropriate measurement for determining the yield stress in a mini-slump test. This was particularly true for relatively low yield stresses of 60 Pa or less, which are values typical of most thickened tailings deposits currently operating internationally., A key design parameter for high-density, thickened tailings (paste) is the yield stress, widely measured by the quick and easy slump test. The paper investigates current techniques for interpreting the cylindrical slump (or mini-slump) test, taking into account the lifting of the cylindrical mould in numerical simulations using a computational fluid dynamics approach. Simulations with different mould lifting velocities were carried out. The influence of plastic viscosity and yield stress on mini-slump test results was first studied using a mould lifting velocity of 0.01 m/s, representative of rates used in laboratory tests. To understand the influence of mould lifting velocity, the predicted slump and spread from mini-slump test simulations for three different scenarios (v(lifting) 0.002 m/s, v(lifting) 0.01 m/s and no lifting i.e. mould disappears instantaneously) were compared with those from vane viscometer experiments on the rheological properties of kaolin. The results suggest that the lifting speed of the mould has a significant influence on the mini-slump test result, which must therefore be taken into account in both numerical simulations and laboratory tests. It was found that the variation of mould lifting velocity had a greater influence on slump than spread, indicating that spread is a more appropriate measurement for determining the yield stress in a mini-slump test. This was particularly true for relatively low yield stresses of 60 Pa or less, which are values typical of most thickened tailings deposits currently operating internationally.

40. The supercapacitive performances of Co(OH)2/Ni(OH)2 composites in lithium hydroxide solution: Selection of electrolyte and effect of weight ratio

Author

Su, Linghao, Gong, Liangyu, and Gao, Jinglong

Subjects
*COBALT compounds, *SUPERCAPACITORS, *LITHIUM hydroxide, *SOLUTION (Chemistry), *ELECTROLYTES, *COMPOSITE materials, *CYCLIC voltammetry
Abstract

Abstract: The supercapacitive performances of Co(OH)2/Ni(OH)2 composites in lithium hydroxide solution are investigated in detail. Cyclic voltammetries and galvanostatic charge/discharge measurements reveal that LiOH is the most suitable electrolyte for the composite electrodes among MOH (M=Li, Na and K). The redox behavior of the Co(OH)2/Ni(OH)2 composites different to that of the pure components shows that weight ratio of Co(OH)2/Ni(OH)2 exerts a great influence on the capacitive performances. After 1000 continuous charge/discharge cycles, the capacitance retention ratio for the composite electrode with the weight ratio of 2/3 is elevated from 41.6% to 88.2% compared with pure Ni(OH)2 electrode, exhibiting improved long-life cyclability. [Copyright &y& Elsevier]

Published
2012
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