MATEC Web of Conferences最新文献

筛选
英文 中文
Investigation of the Optimum Shotcrete Mixing Ratio for Slope Protection using Fly Ash 粉煤灰护坡喷射混凝土最佳配合比研究
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338402004
Thang Kel Win, Nur Irfah Mohd Pauzi
{"title":"Investigation of the Optimum Shotcrete Mixing Ratio for Slope Protection using Fly Ash","authors":"Thang Kel Win, Nur Irfah Mohd Pauzi","doi":"10.1051/matecconf/202338402004","DOIUrl":"https://doi.org/10.1051/matecconf/202338402004","url":null,"abstract":"Shotcrete has now grown in popularity and can replace cast-in-place (CIP) concrete in applications such as retaining walls and slope stabilisation. However, due to the problems like cracking due to shrinkage and the durability concern, this practise is still limited. So, cementitious material such as fly ash is used in this situation to increase the strength of the concrete and also to make sure it is high durability and safe to use in construction. Fly ash can be known as a coal combustion residual which is commonly occur in thermal power plant and it had been widely used as an alternative material during the production of Portland cement concrete. Supplementary cementitious materials is widely used in the mixing of concrete due to its unique properties which can harden the concrete via its hydraulic and pozzolanic activity. A series of experiments will be conducted to make sure that the fly ash that had been mixed with Portland cement is safe to use and also can increase the compressive strength of the cement. Throughout the experiments, a series of data will be display with the addition of 5%,10%,15%,20%,25%,30%,35% of pozzolans in the cement mixing ratio. The addition of fly ash during the mixing of concrete will indirectly reduce the cost of construction and also the rate of pollution to the environment as it is being classified as a scheduled waste in Malaysia according to the Environmental Quality Act 1974.This research will mainly focus on the performance of shotcrete with the addition of cementitious material which is fly ash as an alternative product compare to the tradition concrete and compare the differences in the achievement of shotcrete with and without the addition of fly ash so that the comparison is more clearly and more understandable. Next, the utilization of the nominal aggregates will be 10-20mm.The amount of fly ash added to the mixing of concrete will be in the range of 5% to 35%.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135212091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Post-realization phase of an interior green wall: A case study 室内绿墙的后期实现阶段:一个案例研究
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338501005
Ivana Halaszova, Renata Baskova
{"title":"Post-realization phase of an interior green wall: A case study","authors":"Ivana Halaszova, Renata Baskova","doi":"10.1051/matecconf/202338501005","DOIUrl":"https://doi.org/10.1051/matecconf/202338501005","url":null,"abstract":"One of the popular modern ways to bring greenery back into interiors are interior green walls, which are also known as vertical gardens. Along with the increase in awareness of green walls, their technical solutions are also increasing and their innovation is progressing rapidly. In recent years, green walls have rapidly moved from the simplest walls with the need for mechanical service to maintenance-free walls connected to the digital environment using various sensors. The contribution is focused on the inputs of monitoring in the post-implementation phase of the interior green wall located on the premises of the Technical University in Košice. The goal of the monitoring is to define the inputs for the transition to digitized maintenance of the green wall. The article analyses of the inputs of 3-month monitoring of a green wall with simple manual maintenance. At the end of the paper, the requirements for setting up a digital device ensuring suitable conditions for the sustainability of green construction are specified.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135312899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Investigation of the interactions between tomatoes and handling devices in mechanized processes 机械化过程中番茄与处理装置相互作用的研究
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338706003
Ivan Mortev, Miho Mihov, Rumyana Kireva, Viktoriya Kancheva
{"title":"Investigation of the interactions between tomatoes and handling devices in mechanized processes","authors":"Ivan Mortev, Miho Mihov, Rumyana Kireva, Viktoriya Kancheva","doi":"10.1051/matecconf/202338706003","DOIUrl":"https://doi.org/10.1051/matecconf/202338706003","url":null,"abstract":"Tomatoes are a major vegetable crop worldwide. Production costs for large due to high harvesting costs and difficult mechanization. An increase in labour productivity, the profitability of production, the increase in production and the decrease in cost is possible through the introduction of mechanization of production processes, the most important of which is harvesting [19]. It absorbs over 50% of total costs [5, 10]. Mechanized harvesting reduces labour costs 10 times, and according to Bakulev [1], the profitability of production reaches 200%. Research by the University of California [18] indicates that the price of mechanically harvested tomatoes is $9.84/t, and for hand-harvested tomatoes - $17.19/t. Depending on the qualifications of the workers, mechanization saves from 70 to 440 man-hours per hectare. The mechanization of harvesting also has a biological side [6]. The short period of harvesting allows to control the ripening. Thus, the degree of de-esterification of the pectin content beyond the desired can be avoided. A lot of research has been done to create a robot that picks tomatoes but it is still only in the research field. A practically implemented mechanization of the process is achieved with a tomato harvester that harvests the entire crop at once. Due to the large losses due to damage to the fruit and leakage of juice, this method also needs improvement. In the present study, dependencies have been derived that make it possible to determine the parameters of the handling devices in the tomato harvester in order to obtain a better result from the mechanized harvesting of tomatoes.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135447943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of SAPs and polypropylene fibres on the freeze-thaw resistance of low carbon roller compacted concrete pavement sap和聚丙烯纤维对低碳碾压混凝土路面抗冻融性能的影响
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337808006
Vahid Afroughsabet, A. Al-Tabbaa
{"title":"Effect of SAPs and polypropylene fibres on the freeze-thaw resistance of low carbon roller compacted concrete pavement","authors":"Vahid Afroughsabet, A. Al-Tabbaa","doi":"10.1051/matecconf/202337808006","DOIUrl":"https://doi.org/10.1051/matecconf/202337808006","url":null,"abstract":"Most concrete currently used in pavement is based on Portland cement (PC), being responsible for 8-10% of total CO2 emission. Moreover, external pavements are subjected to exposure classes XF4 and XD3 which are related to corrosion and freeze-thaw. Freeze-thaw resistance is an important durability property of concrete, especially for concrete pavements that are subjected to the de-icing salts. This study was designed to explore the freeze-thaw resistance and mass scaling resistance of low carbon Roller Compacted Concrete (RCC) in the presence of water and de-icing salts. Four different RCC mixes were used with a water/binder ratio of 0.45. PC was replaced with 80% ground granulated blast-furnace slag (GGBS) in all mixes to develop low carbon concrete and move towards a more sustainable cementitious composite. To assess the effectiveness of smart engineered additives, superabsorbent polymers (SAPs) were used at 0.3% by weight of total binder, and Polypropylene (PP) fibre with 12-mm length at fibre volume fractions of 0.3% for the mitigation of freeze-thaw damage. The compressive strength, freeze-thaw resistance, and mass scaling resistance of concrete specimens were evaluated. The results indicate that both additives improved the compressive strength and freeze-thaw resistance of concrete with and without de-icing salts. The inclusion of PP fibre was more effective compared to the addition of SAPs to mitigate the extent of internal structural damage and mass scaling of self-healing concrete mixes with respect to the reference concrete after 56 freeze-thaw cycles.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73463814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Simulation of deformation behaviour of Aluminium 7075 during Equal Channel Angular Pressing (ECAP) 7075铝合金等径角挤压变形行为模拟
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337401002
H. Shagwira, J. Obiko, F. Mwema, T. Jen
{"title":"Simulation of deformation behaviour of Aluminium 7075 during Equal Channel Angular Pressing (ECAP)","authors":"H. Shagwira, J. Obiko, F. Mwema, T. Jen","doi":"10.1051/matecconf/202337401002","DOIUrl":"https://doi.org/10.1051/matecconf/202337401002","url":null,"abstract":"This paper presents a finite element simulation of equal channel angular pressing (ECAP) since it is one of the most common and successful severe plastic deformation techniques. This study reports the influence of the most significant factors influencing the ECAP technique. Through finite element simulation, the effect of the die geometry, workpiece geometry, and the pressing speed on the effective strain distributions, damage, and pressing loads, were investigated. The influence of the ECAP method on different material models is also presented. Additionally, the prospective expansion and future applications of ECAP are herein highlighted. From the results, the die geometry of a 90° channel imparts the highest strains during ECAP. Additionally, specimens of rectangular geometry are susceptible to cracking and damage as compared to circular samples. It was found that very high processing speeds (>7mm/sec) are undesirable during ECAP since they cause very high internal stresses to the structure of the workpieces. Besides, processing at room temperature can achieve homogeneous strain distribution with minimum sample damage.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"03 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86046878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Time of protection equivalence principle to allow design barrier layers for promoting the use of recycled materials for food contact 保护时间等效原理允许设计屏障层,促进使用可回收材料进行食品接触
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337906001
Natacha Daoud, C. Breysse, S. Domenek, O. Vitrac
{"title":"Time of protection equivalence principle to allow design barrier layers for promoting the use of recycled materials for food contact","authors":"Natacha Daoud, C. Breysse, S. Domenek, O. Vitrac","doi":"10.1051/matecconf/202337906001","DOIUrl":"https://doi.org/10.1051/matecconf/202337906001","url":null,"abstract":"European and national environmental protection policies have programmed the forthcoming end of single-use plastics, including food packaging. Because plastic materials account for 50% of plastic waste, closed-loop recycling seems imperative. Still, plastics other than PET (Polyethylene terephthalate) are not widely recycled for food contact due to safety concerns. Among them, postconsumer polyolefins are heavily formulated, degraded, and contaminated by the previously contacting product. Using recycled materials behind a functional barrier (FB) could resolve the issue under specific provisions, but neither the European regulation nor the US FDA offer guidance concerning functional barriers evaluation and use. Mathematical modeling is the only viable method recognized by European and American agencies to evaluate recycled material under usage conditions. This study numerically explores the possibility of combining two effects: decontamination of the recycled material and a functional barrier to allow safe use of the recycled material.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81471820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Feasibility study on construction of RCC gravity dam under special climatic conditions in Tibet 西藏特殊气候条件下碾压混凝土重力坝建设可行性研究
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338001029
Ni Pu, Jingyu Wang, Weibin Zhong, Nan Zheng, Jinming Ren
{"title":"Feasibility study on construction of RCC gravity dam under special climatic conditions in Tibet","authors":"Ni Pu, Jingyu Wang, Weibin Zhong, Nan Zheng, Jinming Ren","doi":"10.1051/matecconf/202338001029","DOIUrl":"https://doi.org/10.1051/matecconf/202338001029","url":null,"abstract":"According to the experience in the construction of water conservancy and hydropower projects in the Mainland, RCC dam construction has two main advantages: the rapid construction speed of roller compacted concrete can realize early power generation, and the price of fly ash is much lower than that of cement, which can reduce the project cost. Tibet has special geographical environment and climatic conditions, and generally has the characteristics of “high altitude, low pressure, low temperature, large temperature difference between day and night, and dry climate”. Taking the dam-building environment in central Tibet as an example, through investigation and research and analogy of similar projects, this paper analyzes the adaptability of construction of RCC gravity dams in Tibet from the aspects of geographical environment, climatic conditions, material properties, construction progress, and project cost. Adaptability to high altitudes. It provides a reference for choosing a safe, reliable, economical and reasonable dam type in the construction of water conservancy and hydropower projects. It provides reference for selecting safe, reliable, economical and reasonable dam types in water conservancy and hydropower engineering construction.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84445920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Development of bio-inspired multi-functional polymeric-based fibers (BioFiber) for advanced delivery of bacterial-based self-healing agent in concrete 用于在混凝土中先进输送细菌基自愈剂的仿生多功能聚合物基纤维(BioFiber)的开发
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202337802001
M. H. Khaneghahi, Divya Kamireddi, Seyed Ali Rahmaninezhad, C. Schauer, Christopher M. Sales, A. Najafi, Aidan Cotton, Amir Sadighi, Y. Farnam
{"title":"Development of bio-inspired multi-functional polymeric-based fibers (BioFiber) for advanced delivery of bacterial-based self-healing agent in concrete","authors":"M. H. Khaneghahi, Divya Kamireddi, Seyed Ali Rahmaninezhad, C. Schauer, Christopher M. Sales, A. Najafi, Aidan Cotton, Amir Sadighi, Y. Farnam","doi":"10.1051/matecconf/202337802001","DOIUrl":"https://doi.org/10.1051/matecconf/202337802001","url":null,"abstract":"The goal of this research is to develop innovative damage-responsive bacterial-based self-healing fibers (hereafter called BioFiber) that can be incorporated into concrete to enable two functionalities simultaneously: (1) crack bridging functionality to control crack growth and (2) crack healing functionality when a crack occurs. The BioFiber is comprised of a load-bearing core fiber, a sheath of bacteria-laden hydrogel, and an outer impermeable strain-responsive shell coating. An instant soaking manufacturing process was used with multiple reservoirs containing bacteria-laden, hydrophilic prepolymer and crosslinking reagents to develop BioFiber. Sodium-alginate was used as a prepolymer to produce calcium-alginate hydrogel via ionic crosslinking on the core fiber. The dormant bacteria (spore) of Lysinibacillus sphaericus was incorporated in hydrogel as a self-healing agent. Then, an impermeable polymeric coating was applied to the hydrogel-coated core fibers. The impermeable strain-responsive shell coating material was manufactured using the polymer blend of polystyrene and polylactic acid. The high swelling capacity of calcium-alginate provides the water required for the microbially induced calcium carbonate precipitation (MICP) chemical pathway, i.e., ureolysis in this study. The strain-responsive impermeable coating provides adequate flexibility during concrete casting to protect the spores and alginate before cracking and sufficient stress-strain behavior to grant damage-responsiveness upon crack occurrence to activate MICP. To evaluate the behavior of developed BioFiber, the swelling capacity of the hydrogel, the impermeability of shell coating, the spore casting survivability, and MICP activities were investigated.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86920352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Simulation analysis of internal and external faults in transformer area 变压器区内外故障的仿真分析
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338201041
Peixian Bai, Yixuan Jia
{"title":"Simulation analysis of internal and external faults in transformer area","authors":"Peixian Bai, Yixuan Jia","doi":"10.1051/matecconf/202338201041","DOIUrl":"https://doi.org/10.1051/matecconf/202338201041","url":null,"abstract":"Under different types of internal and external faults of transformers, electrical quantities such as voltage, differential current and transformer oil flow rate change accordingly. In this paper, the variation law is studied, and the variation law of differential current and other electrical quantities under different types of faults and abnormal conditions inside and outside the transformer area is verified by simulation. The characteristics of faults inside and outside the area are different, and the faults inside and outside the transformer area are judged. At the same time, ANSYS Maxwell 3D, ANSYS Fluent and other software are used to model and simulate the transformer, and the oil flow rate changes under different operating conditions such as normal operation, external fault and internal fault of the transformer are analyzed.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87028006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A hybrid sentiment based stock price prediction model using machine learning 基于混合情绪的机器学习股票价格预测模型
MATEC Web of Conferences Pub Date : 2023-01-01 DOI: 10.1051/matecconf/202338101017
Awais Mehmood, Muhammad Khurram Ali
{"title":"A hybrid sentiment based stock price prediction model using machine learning","authors":"Awais Mehmood, Muhammad Khurram Ali","doi":"10.1051/matecconf/202338101017","DOIUrl":"https://doi.org/10.1051/matecconf/202338101017","url":null,"abstract":"Accurate stock market prediction is highly desirable to corporations and investors. In this study a deep learning model based on LSTM, BiLSTM with attention mechanism used to predict stocks closing price for next 30 days of two banks listed in Pakistan Stock Exchange. For accurate stock price prediction, it is necessary to consider volatile factors such as news sentiments along with historical data. This study covers that aspect by incorporating news sentiments along with historical stock data that is distributed over a span of ten years from Jan 2011 to July 2021. Preprocessing and sentiment analysis of data was performed using python NLTK module. After that we built a univariate deep learning model based on four layers of LSTM and one dense layer to combine all layers and performed a prediction on train and test data followed by a multivariate deep learning model based on BiLSTM with self-attention mechanism and found out that incorporation of news sentiments really improved the prediction accuracy by reducing the values of mean squared error. Finally, we did the prediction for next 30 days of stock closing price of two banks and compared those predicted prices with actual prices and got quite accurate results.","PeriodicalId":18309,"journal":{"name":"MATEC Web of Conferences","volume":"58 9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86793735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信