搜索到341827篇“ EXTRACTION“的相关文章
Physical Determination and Extraction of Annona muricata Seed Oil
2025年
The physical examination of the fruit of soursop fruit (Annona muricata) selected from different parent trees was investigated. Three-stage modified Soxhlet method was used which includes a percolator (boiler and reflux) which circulates the solvent, a thimble (usually made of thick filter paper) which retains the seed to be extracted, and a siphon mechanism, which periodically empties the condensed solvent from the thimble back into the percolator. The extraction of oil from the seed and the percentage yield was examined. The oil samples were characterized for physico-chemical properties. The maximum values of physical parameters found were fruit weight 3.7 ± 7.09, fruit length 12.2 ± 28.3 cm, with 15.2 ± 20.81 cm and 0.12 ± 18.91 g for pulp weight. The percentage oil yield of 48.5% was obtained due to the environmental factors such as the soil type, planting season and optimal temperature of the region of seed cultivation. The result of chemical properties showed maximum acid value 0.46 mg KOH, FFA of 0.33 mg, saponification of 189.4 mg KOH mg and peroxide value of 4.33 mg/g. The oil physical properties as discovered have a melting point of 32˚C, smoke point of 198˚C and flash point of 280˚C. The results obtained in this study further reveal the potential of oil from seed of soursop as a substitute for conventional vegetable oil due to its high flash point which is an indication of its low flammability and can be used as a good source of food, industrially can be used as an anti-microbial agent and for pest control.
Chioma Don-LawsonReminus OkahAdele Ruth Chituru
关键词:EXTRACTION
A Review of Joint Extraction Techniques for Relational Triples Based on NYT and WebNLG Datasets
2025年
In recent years,with the rapid development of deep learning technology,relational triplet extraction techniques have also achieved groundbreaking progress.Traditional pipeline models have certain limitations due to error propagation.To overcome the limitations of traditional pipeline models,recent research has focused on jointly modeling the two key subtasks-named entity recognition and relation extraction-within a unified framework.To support future research,this paper provides a comprehensive review of recently published studies in the field of relational triplet extraction.The review examines commonly used public datasets for relational triplet extraction techniques and systematically reviews current mainstream joint extraction methods,including joint decoding methods and parameter sharing methods,with joint decoding methods further divided into table filling,tagging,and sequence-to-sequence approaches.In addition,this paper also conducts small-scale replication experiments on models that have performed well in recent years for each method to verify the reproducibility of the code and to compare the performance of different models under uniform conditions.Each method has its own advantages in terms of model design,task handling,and application scenarios,but also faces challenges such as processing complex sentence structures,cross-sentence relation extraction,and adaptability in low-resource environments.Finally,this paper systematically summarizes each method and discusses the future development prospects of joint extraction of relational triples.
Chenglong MiHuaibin QinQuan QiPengxiang Zuo
Construction of a Maritime Knowledge Graph Using GraphRAG for Entity and Relationship Extraction from Maritime Documents
2025年
In the international shipping industry, digital intelligence transformation has become essential, with both governments and enterprises actively working to integrate diverse datasets. The domain of maritime and shipping is characterized by a vast array of document types, filled with complex, large-scale, and often chaotic knowledge and relationships. Effectively managing these documents is crucial for developing a Large Language Model (LLM) in the maritime domain, enabling practitioners to access and leverage valuable information. A Knowledge Graph (KG) offers a state-of-the-art solution for enhancing knowledge retrieval, providing more accurate responses and enabling context-aware reasoning. This paper presents a framework for utilizing maritime and shipping documents to construct a knowledge graph using GraphRAG, a hybrid tool combining graph-based retrieval and generation capabilities. The extraction of entities and relationships from these documents and the KG construction process are detailed. Furthermore, the KG is integrated with an LLM to develop a Q&A system, demonstrating that the system significantly improves answer accuracy compared to traditional LLMs. Additionally, the KG construction process is up to 50% faster than conventional LLM-based approaches, underscoring the efficiency of our method. This study provides a promising approach to digital intelligence in shipping, advancing knowledge accessibility and decision-making.
Yi HanTao YangMeng YuanPinghua HuChen Li
溶剂萃取法回收锗资源研究进展
2025年
锗是一种稀散金属,广泛应用于红外技术、光纤、半导体等高科技领域,被认定为战略资源。由于锗资源稀少且分布分散,其提取技术受到原料来源限制,富集难度较大,因此,合理开发初级和二次锗资源以保障锗产业的稳定发展,成为全球紧迫的需求。溶剂萃取法以其高分离系数、高效率、良好选择性、简便流程以及可大规模连续生产等优点,在湿法领域回收锗有一定优势,并在理论和应用研究中取得了显著进展。综述了溶剂萃取法在锗回收中的应用进展,重点分析了不同萃取剂的萃取机理和性能,探讨了当前面临的主要问题,并展望了未来的发展趋势及应用前景。
许妍妍郭文欢张致远惠明洋刘璐李鹏滕道光
关键词:回收溶剂萃取萃取剂
关于某矿四采区钻孔有效抽采半径的研究
2025年
某矿隶属于全国瓦斯灾害严重矿区之一的韩城矿区,其四采区位于目前主采区三采区的北侧,为三采区的接续采区,其符合“东南低、西北高”的瓦斯赋存规律,瓦斯浓度高且压力大,为了达到瓦斯超前治理及绿色开采的目标,文中通过施工一定数量抽采钻孔,综合矿井可解吸瓦斯量W j和瓦斯预抽防突指标确定达标瓦斯含量W D;然后,对考察区段内测定孔抽采流量、抽采负压、抽采瓦斯浓度等相关抽采参数进行连续性、周期性的观测,最后,根据瓦斯抽采数据绘制抽采纯量随时间的变化图,拟合得到抽采衰减负指数公式,进而结合目标瓦斯含量推算出考察区段内达到预期抽采半径R需要的抽采时间t,为矿井的瓦斯灾害治理奠定了一定的理论基础。
高建中刘帅费军勃崔浩雷普
关键词:突出煤层瓦斯抽采抽采半径
快速溶剂-固相萃取法测定土壤中多溴联苯醚
2025年
为建立快速、简便地分析土壤中12种多溴联苯醚(polybrominated diphenyl ethers,PBDEs)质量分数的检测方法,对仪器的参数和样品净化过程进行了优化。通过对比不同仪器参数组合、固相萃取柱种类、活化和洗脱溶剂组合及溶剂洗脱量对样品中12种PBDEs回收率的影响,确定了最优条件。在最优条件下,对实际土样进行加标验证,12种PBDEs的平均加标回收率为90.36%~121.40%,回收率相对标准偏差为4.11%~8.76%,东营油田土壤中PBDEs的质量分数为6.68×10^(-9)~105.68×10^(-9)。本方法使用C18固相萃取柱替代传统复合硅胶柱,简化了样品处理过程,具备操作便捷、稳定性好的优点,适用于大规模土壤样品中PBDEs的检测。
龚飞杰齐安安李一凡张雄飞黄琦杨凌霄
关键词:快速溶剂萃取多溴联苯醚土壤气相色谱-质谱法固相萃取
综采工作面瓦斯抽采钻孔设计及抽采效果分析
2025年
为了减少综采工作面回采期间本煤层、采空区以及上覆裂隙带瓦斯涌出量,长沟煤矿对15112工作面回采期间提出了“顺层钻孔抽采+高位裂隙钻孔抽采+采空区埋管抽采”等联合抽采技术,并对瓦斯抽采钻孔进行合理设计,通过实际应用效果来看:采用顺层钻孔瓦斯抽采时抽采浓度高,高位钻孔瓦斯抽采时,钻孔终孔位置与回风巷水平距为30~50 m处时抽采效果好,采空区埋管瓦斯抽采时埋管合理位置位于上隅角往里15~20 m处,采取联合瓦斯抽采技术后,工作面在后期回采中平均瓦斯浓度控制在0.3%以下。
李宏清
关键词:综采工作面瓦斯抽采
以气质联用分析为基础的多溴二苯醚萃取方法探究
2025年
多溴二苯醚的定量测试多采用气相色谱质谱联用法,目前气质联用仪的设备参数优化程度较高,样品前处理方法成为影响测定结果准确性的关键因素。此次试验设计了三种不同的前处理方法提取RoHS用质控物中的十溴二苯醚,对比分析了索氏萃取、微波萃取、超声提取的不同特点及影响因素,为实验室内部质控、优化检验流程、提高工作效率提供了参考依据。
周铭
关键词:十溴二苯醚微波萃取超声萃取
顶空固相微萃取/气相色谱法快速萃取-解吸土壤中7种芳香族化合物
2025年
利用氧化石墨烯功能化修饰固相微萃取(GO@SPME)针,结合气相色谱(GC)-氢火焰离子化检测器(FID)建立了检测土壤中7种挥发性芳香烃及其衍生物(包括甲苯、氯苯、乙苯、对二甲苯、邻二甲苯、硝基苯和萘)的快速萃取和解吸策略。考察了萃取液体积、搅拌速率、萃取温度、加盐量、解吸温度、萃取时间和解吸时间对目标物萃取效果的影响,确定在土壤样品中加入内标物质(氘代甲苯),经甲醇提取,顶空固相微萃取快速富集,再结合GC-FID进行检测,基质匹配内标法定量分析。在优化的实验条件下,该方法在15 s内可实现对目标物的快速萃取与解吸(萃取时间12 s,解吸时间3 s)。土壤样品中7种挥发性芳香烃及其衍生物的线性关系良好,相关系数(r^(2))均不小于0.9989,方法检出限(LOD,S/N=3)为1.71~11.60μg/g,定量下限(LOQ,S/N=10)为5.70~38.67μg/g;在3个不同加标水平(60、120、180μg/g)下的平均回收率为87.3%~109%,相对标准偏差(RSD)不大于12%。该方法前处理简单快速,成本较低,数据稳定可靠,适用于土壤样品中芳香族类化合物的快速检测。
李丙阳王钊陈佳邱洪灯
关键词:顶空固相微萃取土壤
Synergistic solvent extraction system of bis(pyridin-2-ylmethyl)dodecan-1-amine and dinonylnaphthalene for enhanced selective extraction of nickel and cobalt
2025年
Simultaneous recovery of Ni and Co from Fe(Ⅲ)and Al is a critical challenge in hydrometallurgical processes.Recognized solvent extraction systems often struggle with selectivity and effective performance in mixed metal ion environments.Herein,a new synergistic solvent extraction(SSX)system comprised of a novel pyridine analog,N,N-bis(pyridin-2-ylmethyl)dodecan-1-amine(BPMDA),and dinonylnaphthalene sulfonic acid(DNNSA)with tributyl phosphate as phase modifier is introduced.The SSX system demonstrates high extraction performance achieving>90%for Ni and>97%for Co in a singlestage extraction process,with high selectivity.Under optimal conditions,the selectivity sequence is observed as Co^(2+)(>97%)>Ni^(2+)(>90%)>Mn^(2+)(<20%)>Fe^(3+)(<10%)>Mg^(2+)(<5%)>Al^(3+)(<2%)>Ca^(2+)(<1%).Spectroscopic analysis evidences the preferential binding of BPMDA with Ni and Co in the presence of DNNSA,concurrently achieving a significant reduction in the co-extraction of Fe(Ⅲ)and Al.The selective complexation of Ni and Co using the SSX system offers a highly efficient and selective approach for their extraction,with promising potential for applications in recovery-based processes.
Bharat Prasad SharmaTianzhang WangYufeng LiangJinping XiongLiangrong YangZheng Li
关键词:HYDROMETALLURGY

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曾伟民
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