bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cost Analysis of Nuclear Hydrogen Production Using IAEA-HEEP 4 Software
Authors: Dewita E , Prassanti R , Widana K S , Susilo Y S B 
Published: October 2021

Abstract
Hydrogen is a commercially important element. Basically, there are several methods of hydrogen production that have been commercially used, such as Steam Methane Reforming (SMR), High Temperature Steam Electrolysis (HTSE), and thermochemical cycles, like Sulphur-Iodine (SI). Among these methods, SMR is the most widely used for large-scale hydrogen production, with conversion efficiency between 74–85% and it has commercially used in some fertilizer industries in Indonesia. Steam reforming is a method to convert alkane (natural gas) compounds to hydrogen and carbon dioxide (synthetic gas) by adding moisture at high pressure and temperature (35-40 bar; 800-900°C). These hydrogen production technologies can be coupled with different nuclear reactors based on the heat required in the process. The High Temperature Gas-cooled Reactor (HTGR) using helium as a coolant, has a high outlet temperature (900°C), so it can potentially be used to supply for process heat for hydrogen production, coal liquefaction/gasification or for other industrial processes requiring high temperature heat. Hydrogen production cost from SMR method is influenced by a range of technical and economic factors. The fuel component of natural gas needed in the SMR method can be replaced by nuclear heat from a nuclear power plant (NPP) operating in cogeneration mode (i.e. simultaneous producing electric power and heat), hence contributing to the reduction of carbon dioxide in the process.
In the SMR method, fuel costs are the largest cost component, accounting for between 45% and 75% of production costs. Therefore, there is opportune to assess the economics of hydrogen production by using nuclear heat. The economic evaluation is done by using IAEA HEEP-4 Software.
The results comprise cost break up for 2 cases, coupling SMR process for hydrogen production with: (1) 2 HTGRs of 170 MWth/unit; and (2) 1 HTGR of 600 MWth/unit. The cost of hydrogen production is highly depend on the scale of the NPP as energy source and results indicated that hydrogen production cost of the 1 HTGR Unit600 MWth (Case 2) has a lower value (1.72 US$/kgH2), than the cost obtained when 2 HTGR units of 170 MWth each (case 1) are considered (2.72 US$/kgH2). For comparison, the hydrogen production cost by using SMR with carbon capture and storage (CCS) with natural gas as fuel is 2.27 US$/kgH2.
Consecutive Heat Treatment of Pre-lathed Pebble Fuel Elements for HTGR
Authors: Zhou X , Wang L , Kang Y , Zhang S , Li J , Shi X , Liu B , Zhang J , Tang Y 
Published: October 2021

Abstract
In current manufacture process of pebble fuel elements for HTGR, the green pebbles were first carbonized, then lathed and purified at high temperature. The whole heat treatment process included two cycles of heating and cooling and corresponding two loading and unloading processes, which took approximately 90 hours in total. In order to reduce the time and energy consumed and improve the efficiency during the heat treatment process, a consecutive heat treatment process of pebble fuel elements for HTGR was established. In the newly established consecutive heat treatment process, the pebble fuel elements were carbonized and high temperature purified continuously in a specific furnace. The consecutive heat treatment process took less than 60 hours, which included only one cycle of heating and cooling and corresponding one loading and unloading process. Moreover, in order to recycle the matrix graphite powder after lathing, the green pebbles were machined to a certain size before suffering the heat treatment. However, in order to make the size of pebble fuel elements after the consecutive heat treatment meet the technical requirements, it is necessary to figure out their dimension changes during the heat treatment. As the pebbles were prepared by cold quasi-isostatic molding method, their dimension changes parallel and perpendicular to the molding direction were different. In order to better control the dimension changes of pebbles in the heat treatment process, the effects of physical properties such as apparent density, and particle size distribution of matrix graphite powder on the prepared pebbles were comparatively studied. Finally, the consecutive heat treatment of pre-lathed pebble fuel elements for HTGR was established. The comprehensive properties of pebbles prepared with the newly established consecutive heat treatment process satisfied all the technical requirements.
Hyphenated SEM-Raman Characterization for Matrix Graphite of HTGR Spherical Fuels
Authors: Jiao Z , Chen X , Zhang C , Xu G , Liu B , Yin Z 
Published: October 2021

Abstract
Matrix graphite (MG) is an important material for the spherical fuel elements of high temperature gas-cooled reactors (HTGR). After carbonization, the matrix material is composed of three isomers of natural graphite, artificial graphite, and carbon derived from phenolic resin (resin carbon) with the same element but different structure. According to previous study, the three components have different effect on the fission products diffusion and adhesion in the irradiated fuel. However, the characterizing methods to discriminate natural graphite, artificial graphite and resin carbon are rare. In this study, Raman Imaging and Scanning Electron (RISE) microscopy was used to study the structure and distribution of natural graphite, artificial graphite, resin carbon and graphite oxides produced from electrochemical deconsolidation of MG in post-irradiation examination (PIE). Natural graphite and artificial graphite have only a couple of Raman-active bands visible in the spectra between 1100-2400 cm-1, including the strong G band at ~1580 cm-1 and the weak D band at ~1350 cm-1. The D band is activated once the defects are introduced into sp2 hybridized carbon networks, and the intensity of D band is proportional to the defect concentration. Resin carbon has a strong D band, which can be easily distinguished from natural graphite and artificial graphite. The results show that the resin carbon is evenly coated on the surface of the natural and artificial graphite particles, and the network frame is formed during the pressing process to fix the graphite particles. This work also revealed that the changes of surface morphologies of MG after electrochemical deconsolidation by In-situ SEM analysis, of which a lot of cracks and holes on the surface of MG. Meanwhile, Raman spectra suggest that crystalline graphite and resin carbon have different oxidation behaviors. This work will provide a new method for MG components discriminating.
Ti3SiC2-TiC-Si Antioxidant Coating Prepared on SiC coated MG Spheres of HTR Fuel Element by Molten Salt Technique
Authors: Yang H , Zhao H , Liu X , Zhang K , Wang T , Li Z , Gao Y , Liu Bing 
Published: October 2021

Abstract
A Ti3SiC2-TiC-Si composite coating was prepared by molten salt technique on the surface of SiC coated matrix graphite (MG) spheres of HTR fuel element with different Ti content. The coating is composed of a transition layer, a SiC layer and an outer Ti- rich layer. When the content of Ti is 0.6g, the coating consists of Ti3SiC2, SiC, and TiC; when Ti content are 1.2g and 2.4g, the coating is composed of Ti3SiC2, SiC, TiC, and Si. Oxidation tests show that the kinetics of oxidation is parabolic at the beginning of oxidation; then it becomes linear after oxidation for 5h. The coating prepared with 0.6g Ti shows the best oxidation resistance, and the weight reduction of the coated MG spheres is only 0.33% after oxidation in static air at 1773K for 50h. These results show that Ti-based composites coating a kind of anti-oxidation coating system worth studying.
Drop analysis of Active Magnetic Bearing with rolling-sliding integrated auxiliary bearing
Authors: Wang Mingqi , Liu Xingnan , Zhao Yulan , Yang Guojun , Chen Jianqiang , Shi Zhengang 
Published: October 2021

Abstract
The Active Magnetic Bearing (AMB) technology is introduced in the High Temperature Reactor-Pebble-bed Modules (HTR-PM) demonstration nuclear power plant, which is being constructed in Shandong province, China. The auxiliary bearing is one of the most important components guaranteeing the reliability of the AMB. It also has an important impact on the reliability of the whole reactor system. Compared with the traditional auxiliary bearing, a novel one proposed by the authors has a smaller impact force and the rotor center orbit is much more concentrated during the rotor drop. This paper establishes an analytical model of drop of rolling-sliding integrated auxiliary bearing to analyze the above phenomena. Based on the Hertz contact theory, the complex structure inside the rolling bearing is simplified through a spring damping model. The overall impact model of the rolling-sliding integrated auxiliary bearing is established. Then, according to the structural characteristics of the rolling-sliding integrated auxiliary bearing, the tangential force inside the rolling- sliding integrated auxiliary bearing can be obtained by applying the angular momentum theorem. Finally, a four-degree-of-freedom horizontal rotor drop model is established to analyze and calculate the center orbit and motion state of the rotor. The analytical model is helpful in the selection and design of auxiliary bearing for AMB. In further research this contact model can be used to calculate the center orbit and contact forces in the application of the rolling-sliding integrated auxiliary bearing.
HTR-10 OTTO Cycle Depletion Simulation Using Discrete Element Method Coupled Monte Carlo
Authors: Putra F 
Published: October 2021

Abstract
Pebble bed reactor core contains 27,000 pebbles placed in a random position. Since the pebble insertion relies on gravity, the pebble placement pattern is irregular. Discrete Element Method used to simulate the pebble interaction and pebble movement during HTR-10 operation. Even though pebbles distributed randomly, the random generation of pebble positions used in most research does not mimic the actual pebble position and pebble surface contact. The Discrete Element Method provides a realistic interpretation of the pebble position by considering the pebble surface contact and gravity force. Each pebble coordinates from the Discrete Element Method obtained to construct Monte Carlo geometry of the HTR-10 core realistically. By coupling the DEM simulation with Monte Carlo simulation, it is possible to calculate the depletion while considering the core dynamic characteristic. The OTTO recirculation depletion calculation scheme with steady 10MW power for 368 days was constructed and demonstrated in this work. The DEM coupled Monte Carlo method allow one to track and predict each depleted fuel composition. Although the flux distribution change is slight in every timestep, the relation between flux and depleted U235 and Xe135 composition deserves to be taken into account. The calculation model in this work is comparable with the other calculation, but the timestep adjustment is needed to provide more accurate and representative results. Flux calculation and depletion simulation performed using the OpenMC program with ENDF/B-VIII.0 cross-section data. Please refer to digital version to view graph.
Preliminary Study on HTR-10 Operating in Higher Outlet Temperature
Authors: Zheng Yanhua , Xia Bing , Chen Zhipeng , Zhang Han , Sun Jun 
Published: October 2021

Abstract
High Temperature Gas-cooled Reactor (HTGR), which has well-known safety features and high temperature heat supply capability, is expected to be widely used for heat supply and technology heat utilization including the hydrogen production, and so contributing to the reduction of carbon dioxide emissions in various sectors. The 10 MW High Temperature gas-cooled test Reactor (HTR-10) had been constructed and operated in China as a pilot plant to demonstrate the inherent safety features of the modular HTGR. The first criticality of HTR-10 at air condition was realized on December 1, 2000, and the full power operation for 72 h on January 29, 2003. Supported by Chinese National S&T Major Project, HTGR for hydrogen production are now being studied. The physical and thermal hydraulic design to raise the outlet helium temperature of the HTR-10 reactor core from 700 °C to 850~1000 °C is carried out. In this paper, the preliminary thermal hydraulic design of the HTR- 10 with the outlet helium temperature of 950 °C (HTR-10H) is introduced. The power density distribution, the fuel temperature distribution and the reactor pressure vessel (RPV) temperature are studied to identify what need to be focused on next. Besides, the typical DLOFC accident has been studied to evaluate the safety feature of the HTR-10 operating under higher core temperature and outlet temperature. The preliminary results show that, operated at the higher outlet helium temperature, the original acceptance criteria for HTR-10 will be challenged. In the future, the design optimization, as well as the possible modification of these acceptance criteria, which were set more than two decades ago, should be studied based on the current knowledge of the fuel element properties and structure material properties.
Experimental Study on the Residual Heat Removal System in HTR-10
Authors: Li Jing , Wei Liqiang , Zheng Yanhua , Ma Tao , Chen Xiaoming , Xie Feng , Wang Haitao 
Published: October 2021

Abstract
The 10MW high temperature gas-cooled reactor (HTR-10) is a modular pebble-bed type reactor, of which the inlet and outlet helium temperature are 250 and 700 °C, respectively. It reached to its first criticality in December, 2000, and operated for nearly twenty years successfully. Currently, HTR-10 is the only pebble-bed type high temperature gas-cooled reactor that can operate in the world. To verify the natural circulation operating characteristics and safety features of the passive residual heat removal system, a series of experimental studies have been performed under different operation conditions of HTR-10, which include the performance tests of the passive residual heat removal system under various reactor operating power, different ambient temperature and single loop run mode. According to the data collation and result analysis, it shows that the performance of the residual heat removal system in HTR-10 meets the design and safety requirements.
MUF Calculation of Indonesian 10-MWt RDE Experimental HTGR Using Combined Uncertainty Approach
Authors: Adhi Arief S. , Husein Mohamad S.F. , Winastri Pertiwi D. 
Published: October 2021

Abstract
A safeguards assessment for the 10-MWt RDE Experimental HTGR needs to be established in order to fulfill the requirements needed to construct it. Methods and instruments used for the RDE’s nuclear material accounting and safeguards system are reviewed in this paper. Material unaccounted for (MUF) is calculated using the uncertainty of each method and instrument. The effectiveness of the safeguards system is examined by comparing the resulting MUF with the number of SQ ( = significant quantity, i.e. the approximate amount of nuclear material for which the possibility of manufacturing of a nuclear explosive device cannot be excluded). The total uncertainty from each KMP showed a number less than 10%. The number of MUF in each KMP according to total uncertainty showed a number below 1 kg of U-235 in one inventory period (~12 months). According to the number of MUF counted, it is impossible to reach 1 SQ if the diversion done is only by taking the advantage of MUF in the measurement. The result of total uncertainty and MUF calculation showed that the safeguards system and the material measurement designed for RDE is amendable. The sets of instruments and measurements designed will give a comprehensive data of each nuclear material in the RDE. The low number of MUF in comparison with the SQ showed that the RDE has a high proliferation resistance.
Chinese Math Word Problems Generation Network
Authors: Huang Junjian , Xu Ming , Zheng Hengyi , Shang Qian 
Published: October 2021

Abstract
Aiming at the feature vector bottleneck problem and the high time cost of the training process in the automatic generation of Chinese math word problems under the end-to-end architecture, we proposed an automatic generation method of Chinese math word problems based on the pre-training model combined with the integration of encoder and decoder. We used a deep neural network to model the mathematical equation sequence and Chinese keyword information, and used the stepped attention matrix to generate word problems. For training and testing on the Ape210K data set, compared with the end-to-end method, the Rouge-1 and Rouge-L evaluation indicators in our method was increased by 14.1% and 12.5%, as well as the training time cost was reduced by nearly 50%.
Intelligent Question Answering System Based on Machine Reading Comprehension
Authors: Shang Qian , Xu Ming , Qin Bin , Lei Pengbin , Huang Junjian 
Published: October 2021

Abstract
Question answering(Q&A) system is important for accelerating the landing of artificial intelligence. This paper makes an improvement on the Q&A system which uses the method of retrieval-machine reading comprehension (MRC). In the retrieval phase, we use BM25 to recall some documents and split these documents into paragraphs, then we reorder the paragraphs according to the correlation with the question, so as to reduce the number of recalled paragraphs and improve the speed of MRC. In the MRC stage, we design a multi-task MRC structure, which can judge whether the paragraph contains answer and locate answer accurately. Besides, we modify the loss function to fit the sparse labels during the training. The experiments are carried out on multiple data sets to verify the effectiveness of the improved system.
Self-Amplificated Network: Learning fine-grained learner with few samples
Authors: Dai Xili , Ma Chunmei , Sun Jingwei , Zhang Tao , Gong Haigang , Liu Ming 
Published: October 2021

Abstract
Training deep neural networks from only a few examples has been an interesting topic that motivated few shot learning. In this paper, we study the fine-grained image classification problem in a challenging few-shot learning setting, and propose the Self-Amplificated Network (SAN), a method based on meta-learning to tackle this problem. The SAN model consists of three parts, which are the Encoder, Amplification and Similarity Modules. The Encoder Module encodes a fine-grained image input into a feature vector. The Amplification Module is used to amplify subtle differences between fine-grained images based on the self attention mechanism which is composed of multi-head attention. The Similarity Module measures how similar the query image and the support set are in order to determine the classification result. In-depth experiments on three benchmark datasets have showcased that our network achieves superior performance over the competing baselines.
Deep Reinforcement Learning for Stock Recommendation
Authors: Shen Yifei , Liu Tian , Liu Wenke , Xu Ruiqing , Li Zhuo , Wang Jia 
Published: October 2021

Abstract
Recommending stocks is very important for investment companies and investors. However, without enough analysts, no stock selection strategy can capture the dynamics of all S&P 500 stocks. Nevertheless, most existing recommending strategies are based on predictive models to buy and hold stocks with high return potential. But these strategies fail to recommend stocks from different industrial sectors to reduce risks. In this article, we propose a novel solution that recommends a stock portfolio with reinforcement learning from the S&P 500 index. Our basic idea is to construct a stock relation graph (RG) which provide rich relations among stocks and industrial sectors, to generate diversified recommendation result. To this end, we design a new method to explore high-quality stocks from the constructed relation graph with reinforcement learning. Specifically, the reinforcement learning agent jumps from each industrial sector to select stock based on the feedback signals from the market. Finally, we apply portfolio allocation methods (i.e., mean-variance and minimum-variance) to test the validity of the recommendation. The empirical results show that the performance of portfolio allocation based on the selected stocks is better than the long-term strategy on the S&P 500 Index in terms of cumulative returns.
Research on Scheduling Problem of Manufacturing/remanufacturing Hybrid Systems
Authors: Huang Si , Liu Lin , Yang Yuting , Duan Yuli , Huang Linying 
Published: October 2021

Abstract
Remanufacturing plays a significant effect on saving social resources, developing green economy and reducing enterprise cost. Aiming at a production scheduling problem in manufacturing/remanufacturing hybrid systems we investigated, a multi-objective optimal scheduling model is built. The goals of optimization are to minimize total equipment idle time, total delivery delay and total setup time which are consistent with actual needs of the enterprise. An improved NSGA-II is adopted to increase the population diversity and improve the search performance. The similarity degree S is employed to evaluate the diversity of population in this paper. Crossover and mutation operations are adjusted adaptively based on S. This algorithm is applied to an engine manufacturing enterprise compared with the original genetic algorithm. The analysis of experimental results shows that the way in this paper has certain superiority.
Research on XBRL Continuous Internal Audit under the Big Data
Authors: Wen Yong 
Published: October 2021

Abstract
The development of digital industrialization has promoted the continuous emergence of new industries, new formats and new models, and has also promoted the transformation of the traditional internal audit model to digital and intelligent. Big data, cloud computing, XBRL, artificial intelligence and other digital technologies are important means to achieve full audit coverage, big data audit has become a hot topic in the current audit field, relevant literature mainly focuses on the impact of big data on traditional audit concepts and audit methods, the impact and risks of big data technology on informatization audits, and how the auditing community responds. However, the research on the integration of big data technology and XBRL technology into continuous internal auditing is relatively rare. Based on the introduction of three XBRL continuous internal audit models, this article analyzes the continuous internal audit process of the XBRL information system, and discusses the application of big data technology in XBRL continuous internal audit.
Workspace Analysis of Spray Painting Robot with Two Working Modes for Large Ship Blocks in Ship Manufacturing
Authors: Zeng Qingfei , Liu Xuemei , Yang Zhen , Hu Xiaocai 
Published: October 2021

Abstract
Spray painting is crucial in the process of shipbuilding and runs through the whole process of shipbuilding. In order to obtain the good coating quality during the painting process, gantry type painting robot could be used because of its resource-saving and environment-friendly characteristics. Based on the structural parameters of the spray painting manipulator with 3DOF (Degree of freedom) gantry, the kinematic model of the painting robot system can be established. From the perspective of the two commonly working modes, namely 3P3R robot structure and the 3P6R redundant robot structure, their spraying workspace are analyzed. The result shows that the workspace volume of the 3P6R robot is much larger than that of the 3P3R robot. However, the inverse kinematics solution of 3P3R robot has analytical solution, which makes the control accurate and easy to use, and through the simulation, we can give the theoretical basis for the engineering.