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Evolution process of rock mass engineering system using systems science 被引量:1
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作者 Laigui Wang Yanhui Xi +2 位作者 Xiangfeng Liu Na Zhao Ziling Song 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第6期724-726,共3页
The rock mass engineering system (RMES) basically consists ofrock mass engineering (RME), water system and surroundingecological environments, etc. The RMES is characterized by nonlinearity,occurrence of chaos and... The rock mass engineering system (RMES) basically consists ofrock mass engineering (RME), water system and surroundingecological environments, etc. The RMES is characterized by nonlinearity,occurrence of chaos and self-organization (Tazaka, 1998;Tsuda, 1998; Kishida, 2000). From construction to abandonmentof RME, the RMES will experience four stages, i.e. initial phase,development phase, declining phase and failure phase. In thiscircumstance, the RMES boundary conditions, structural safetyand surrounding environments are varied at each phase, so arethe evolution characteristics and disasters (Wang et al., 2014). 展开更多
关键词 ROCK Evolution process of rock mass engineering system using systems science
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Process intensification in vapor–liquid mass transfer: The state-of-the-art 被引量:1
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作者 Hong Li Chuanhui Wu +2 位作者 Zhiqiang Hao Xingang Li Xin Gao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第6期1236-1246,共11页
The concept of process intensification(PI) has absorbed diverse definitions and stays true to the mission—'do more with less', which is an approach purposed by chemical engineers to solve the global energy &a... The concept of process intensification(PI) has absorbed diverse definitions and stays true to the mission—'do more with less', which is an approach purposed by chemical engineers to solve the global energy & environment problems. To date, the focus of PI has been on processes mainly involving vapor/liquid systems. Based on the fundamental principles of vapor–liquid mass transfer process like distillation and absorption, there are three strategies to intensify interphase mass transfer: enhancing the overall driving force, improving the mass transfer coefficient and enlarging the vapor–liquid interfacial area. More specifically, this article herein provides an overview of various technologies to strengthen the vapor–liquid mass transfer, including application of external fields, addition of third substances, micro-chemical technology and usage of solid foam, with the objective to contribute to the future developments and potential applications of PI in scientific research and industrial sectors. 展开更多
关键词 mass TRANSFER Transport process TWO-PHASE flow process INTENSIFICATION MICROWAVE field Foam
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Determination of geological strength index of jointed rock mass based on image processing 被引量:7
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作者 Kunui Hong Eunchol Han Kwangsong Kang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第4期702-708,共7页
The geological strength index(GSI) system,widely used for the design and practice of mining process,is a unique rock mass classification system related to the rock mass strength and deformation parameters based on the... The geological strength index(GSI) system,widely used for the design and practice of mining process,is a unique rock mass classification system related to the rock mass strength and deformation parameters based on the generalized Hoek-Brown and Mohr-Coulomb failure criteria.The GSI can be estimated using standard chart and field observations of rock mass blockiness and discontinuity surface conditions.The GSI value gives a numerical representation of the overall geotechnical quality of the rock mass.In this study,we propose a method to determine the GSI quantitatively using photographic images of in situ jointed rock mass with image processing technology,fractal theory and artificial neural network(ANN).We employ the GSI system to characterize the jointed rock mass around the working in a coal mine.The relative error between the proposed value and the given value in the GSI chart is less than 3.6%. 展开更多
关键词 Jointed rock mass Geological strength index(GSI) Image processing Fractal dimension Artificial neural network(ANN)
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Prediction of Pitting Corrosion Mass Loss for 304 Stainless Steel by Image Processing and BP Neural Network
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作者 ZHANG Wei LIANG Cheng-hao 《Journal of Iron and Steel Research International》 SCIE CAS CSCD 2005年第6期59-62,共4页
Image processing technique was employed to analyze pitting corrosion morphologies of 304 stainless steel exposed to FeCl3 environments. BP neural network models were developed for the prediction of pitting corrosion m... Image processing technique was employed to analyze pitting corrosion morphologies of 304 stainless steel exposed to FeCl3 environments. BP neural network models were developed for the prediction of pitting corrosion mass loss using the obtained data of the total and the average pit areas which were extracted from pitting binary image. The results showed that the predicted results obtained by the 2-5-1 type BP neural network model are in good agreement with the experimental data of pitting corrosion mass loss. The maximum relative error of prediction is 6.78%. 展开更多
关键词 BP neural network image processing pitting corrosion mass loss PREDICTION
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MASS BALANCES OF MAJOR CHEMICAL CONSTITUENTS IN BOHAI SEA WATER Ⅱ.REMOVAL PROCESSES
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作者 李悦 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1994年第3期236-245,共10页
The removal processes of major seawater chemical constituents in the Bohai Sea include seawater ex-change between the Bohai Sea and the Northern Yellow Sea,cation exchange,interstitial water burialand spray,formation ... The removal processes of major seawater chemical constituents in the Bohai Sea include seawater ex-change between the Bohai Sea and the Northern Yellow Sea,cation exchange,interstitial water burialand spray,formation of illite,sepiolite,sulfate and sulfur,and carbonates.The mass balance calculationbased on these processes is very applicable to the Bohai Sea. 展开更多
关键词 mass BALANCE chemical CONSTITUENT Bohai SEA REMOVAL process
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Mineral Processing of Silica Sand in Hanout Area/South of Jordan
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作者 Jamal Alali 《Open Journal of Geology》 2023年第7期667-696,共30页
White sandstone samples from Hanout area of Late Cambrian-Early Ordovician sandstone in south of Jordan were studied and assessed as a source of glass sand. Upgrading the sand included removing or reducing the content... White sandstone samples from Hanout area of Late Cambrian-Early Ordovician sandstone in south of Jordan were studied and assessed as a source of glass sand. Upgrading the sand included removing or reducing the content of the contaminant oxides and the heavy minerals. The aim of this research was to achieve this upgrading by examining the best-suited and cost-effective processing method(s) with sufficient product recovery. Following the initial sample characterisation at “bench scale”, a pilot study was performed. A high-grade Glass Sand product of 500 - 125 μm size fraction was produced by wet screening, attrition scrubbing and the separation of heavy minerals using spirals. The high quality Glass Sand product compared well with Grade-A of the British Standard for glass sand. Due to the relatively low level of impurities in the raw material, a substantial silica sand recovery was produced with a high silica grade. The silica sand product was capable to be used in the high quality glass industry and in many other applications where pure silica is required. The mass flowrate of the feeds and the products in the spiral was calculated for the bulk sample as well as the amount of water required operating the process. 展开更多
关键词 Glass Sand Grade and Recovery mass Balance Mineral processing
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ANALYSIS OF THE THERMOPHYSICAL PARAMETERS OF MOIST WOOD PARTICLE MATERIAL IN A COUPLED HEAT AND MASS TRANSFER PROCESS OF FREEZING BY USING FINITE ELEMENT METHOD
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作者 Shang DekuNortheast Forestry University 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1991年第2期69-76,共8页
The coupled heat and moisture transfer in a freezing process of wood particle material was mathematically modeled in the paper. The models were interactively solved by using the numerical method(the finite element met... The coupled heat and moisture transfer in a freezing process of wood particle material was mathematically modeled in the paper. The models were interactively solved by using the numerical method(the finite element method and the finite difference method). By matching the theoretical calculation to an experiment, the nonlinear problem was analyzed and the variable thermophysical parameters concerned was evaluated. The analysis procedure and the evaluation of the parameters were presented in detail. The result of the study showed that by using the method as described in the paper, it was possible to determine the variable (with respect to temperature, moisture content and freezing state) thermophysical parameters which were unknown or difficult to measure as long as the governing equations for a considered process were available. The method can significantly reduces the experiment efforts for determining thermophysical parameters which arc very complicated to measure. The determined variable of the effective heat conductivity of wood particle material was given in the paper. The error of the numerical calculation was also estimated by the comparison with a matched experiment. 展开更多
关键词 Finite element method Freezing process Coupled heat and mass transfer Variable thermophysical parameters
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Study of a mass transfer-reaction model for SO_2 absorption process using LAS/H_2SO_4 solution
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作者 Yue Changtao Li Shuyuan +3 位作者 Chen Weihong Guo Shaohui Yang Yuhua Sha Yingxun 《Petroleum Science》 SCIE CAS CSCD 2010年第3期397-402,共6页
A regenerative absorption process for removal of SOx from FCC off-gas using LAS/ H2SO4 solution as absorbant was studied and pilot-plant experiments were carried out. A mass transfer- reaction model for the SO2 absorp... A regenerative absorption process for removal of SOx from FCC off-gas using LAS/ H2SO4 solution as absorbant was studied and pilot-plant experiments were carried out. A mass transfer- reaction model for the SO2 absorption process was established based on pilot-plant experiments, and the concentration distribution of components in the liquid film, and the partial pressure and mass transfer rate of SO2 along the height of the absorption tower, was calculated from this model. The numerical simulation results were compared with the experimental results and proved that the model can be used for describing the SO2 absorption process. 展开更多
关键词 Regenerative absorption process SOx cleanup LAS/H2SO4 solution mass transfer-reactionmodel
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恒温下相对湿度对果蔬热风干燥特性和品质的影响及调控 被引量:2
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作者 巨浩羽 张卫鹏 +3 位作者 于贤龙 王庆惠 高振江 肖红伟 《农业工程学报》 EI CAS CSCD 北大核心 2024年第2期29-40,共12页
相对湿度作为干燥介质的重要参数,对干燥热质传质过程和干燥品质具有显著影响。但由于相对湿度对干燥过程的影响机理及优化调控机制尚不明确,导致相对湿度的调控方式多依靠经验,造成干燥效率低、品质差、能耗高等问题。对于传质过程,降... 相对湿度作为干燥介质的重要参数,对干燥热质传质过程和干燥品质具有显著影响。但由于相对湿度对干燥过程的影响机理及优化调控机制尚不明确,导致相对湿度的调控方式多依靠经验,造成干燥效率低、品质差、能耗高等问题。对于传质过程,降低相对湿度能够增大对流传质系数,加快物料表面水分蒸发;而对于传热过程,升高相对湿度能够增大对流传热系数,加快物料升温速率。相对湿度较高时,物料升温速率快,内部水分迁移量增大,但表面水分蒸发量较小;而当相对湿度较低时,物料升温速率较慢,内部水分迁移量较小,但表面水分蒸发量较大。相对传热和传质过程的影响此消彼长,互相耦合。高相对湿度主要体现为对传热过程的影响,低相对湿度主要体现为对传质过程的影响。高相对湿度能够抑制物料表面的结壳,并能够提高复水性,降低收缩率。阶段降湿及多阶段降湿干燥方式下物料表面形成和保持了蜂窝状多孔结构,能够提高干燥效率和品质。基于监测物料温度的相对湿度调控方式被验证为较优的相对湿度控制方式。阶段降湿干燥方式适用性的实质为:干燥过程中所体现出的对流传热热阻和内部导热热阻的相对大小,及对流传质阻力和内部传质阻力的相对大小,不同干燥条件和物料种类、厚度会影响以上传热传质阻力的大小,从而呈现出不同适应性的结果。当阶段降湿干燥过程中传热毕渥数>1且传质毕渥数>0.1时,说明阶段降湿干燥过程适用于此物料的干燥。该文综合论述了相对湿度对果蔬热风干燥过程中热质传递及干燥品质的影响,优化调控策略及适用性范围4个方面内容,明确了果蔬热风干燥过程中相对湿度的影响机理,为相对湿度的优化调控提供理论依据和技术支持。 展开更多
关键词 干燥 相对湿度 传热过程 传质过程 调控策略 适用性
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水平对置撞击流反应器强化液-液萃取及传质特性
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作者 张建伟 张昊明 +1 位作者 董鑫 冯颖 《高校化学工程学报》 EI CAS CSCD 北大核心 2024年第5期724-734,共11页
为了研究撞击流技术强化水相从煤油相中萃取乙酸,考察操作条件和溶液性质对萃取效果和传质特性的影响,测定液滴分散程度,利用响应面法优化萃取工况。结果表明:随煤油相进口体积流量和相比(水相与煤油相的体积流量比)的增加,分散相液滴... 为了研究撞击流技术强化水相从煤油相中萃取乙酸,考察操作条件和溶液性质对萃取效果和传质特性的影响,测定液滴分散程度,利用响应面法优化萃取工况。结果表明:随煤油相进口体积流量和相比(水相与煤油相的体积流量比)的增加,分散相液滴粒径分布范围先缩小后扩大,Sauter平均直径d32先减小后增大。萃取率和总体积传质系数随煤油相进口体积流量的增加、水相黏度的增加和表面张力的减小而先增大后减小,随相比的增加呈先增后减再增加的趋势。各因素对萃取率的影响程度为:相比>煤油相进口体积流量>十六烷基三甲基溴化铵(CTAB)质量浓度,且交互作用显著。最佳工况下萃取率为93.11%,较传统萃取工艺提高了5.11%。 展开更多
关键词 撞击流反应器 过程强化 萃取 传质 响应面分析
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冠状动脉CTA成像技术中KV值与体质量的关系研究
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作者 邹才盛 梁萍 +6 位作者 陈更瑞 叶佳国 王贤坤 夏世豪 高官华 胡宗宇 陈小妹 《中国CT和MRI杂志》 2024年第7期93-95,共3页
目的本研究旨在探讨低管电压扫描在冠脉CTA成像技术中KV值与体质量的关系。方法选取疑似为冠状动脉疾病患者120例为研究对象,所有患者均行冠状动脉CTA检查。根据KV值不同分为三组:A组120 KV(45例);B组100 KV(45例);C组80 KV(30例)。并... 目的本研究旨在探讨低管电压扫描在冠脉CTA成像技术中KV值与体质量的关系。方法选取疑似为冠状动脉疾病患者120例为研究对象,所有患者均行冠状动脉CTA检查。根据KV值不同分为三组:A组120 KV(45例);B组100 KV(45例);C组80 KV(30例)。并将各组患者按体质量不同分为分为<70 kg、70~85kg、>85kg三个级别,C组不设>85kg级别。所有患者使用的对比剂为碘普罗胺(370 mgI/m1)。比较各组各个体质量级别的图像质量和有效辐射剂量。结果除80KV组70~85kg级别出现2分外,其余各组各级别患者图像质量主观评分均≥3分,A、B组中>85kg级别和C组70~85kg级别评分较低,与其他组评分差别明显。同样是≤70 kg体质量患者在不同KV组其血管CT值差异明显,均有统计学意义(均P<0.001)。同样是70~85kg体质量级别患者在不同KV组其血管CT值差异明显,差异均有统计学意义(均P<0.001)。同样是>85kg体质量级别患者在不同KV组其血管CT值差异明显,差异均有统计学意义(均P<0.001)。B组>85kg级别和C组70~85kg级别的SNR和CNR均较其他组降低,图像质量较差。同样<70 kg级别在100KV组比120KV组ED减少42.4%,80KV组比120KV组减少68.3%(P<0.001);同样是70~85kg级别在100KV组比在120KV组的ED减少40.4%,在80KV组比在120组ED减少68.3%(P<0.001);同样是>85kg级别在100KV组的ED比在120KV组减少40.8%(P<0.001)。结论在冠状动脉CTA成像,体质量≤70 kg的患者应用80 KV剂量、体质量70~85kg的患者应用100 KV剂量可获得与120 KV剂量相当的图像质量,而且可有效减少辐射剂量。 展开更多
关键词 CTA 冠状动脉CTA 人体质量指数 辐射剂量 图像处理 管电压
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考虑过程能力指数的参数和容差并行设计方法
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作者 伍建军 周敏 蔡伟 《机械科学与技术》 CSCD 北大核心 2024年第10期1747-1753,共7页
针对传统田口产品优化设计中先参数设计后容差设计试验次数多、制造成本高的问题,引入非对称质量损失和考虑过程能力指数的参数和容差并行设计,在保证产品质量的同时,有效的节约了制造成本。首先,进行中心复合试验设计,再由试验数据建... 针对传统田口产品优化设计中先参数设计后容差设计试验次数多、制造成本高的问题,引入非对称质量损失和考虑过程能力指数的参数和容差并行设计,在保证产品质量的同时,有效的节约了制造成本。首先,进行中心复合试验设计,再由试验数据建立均值和方差的响应曲面模型;随后提出非对称质量损失函数以及根据经验数据建立容差成本模型,之后再构建改进的过程能力指数;最后将非对称质量损失函数和容差成本模型代入过程能力指数函数中,并利用改进遗传算法(NSGA-Ⅱ)寻优同时得出参数及其容差组合。通过桥式放大机构试验的实例分析,说明该方法提高了产品的质量性能,并减少了生产运作成本。 展开更多
关键词 参数设计 容差设计 并行设计 过程能力指数 非对称质量损失
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7700型电感耦合等离子体质谱仪常见故障排除流程及方法
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作者 杨志群 《分析仪器》 CAS 2024年第1期80-84,共5页
电感耦合等离子体质谱仪具有快速、灵敏、多元素、动态范围宽、干扰容易控制等特点,作为常用微量及痕量多元素分析手段,已经广泛用于环境、食品、农业、半导体、临床和药物、地质、核工业、法医、化合物石化等领域。电感耦合等离子体质... 电感耦合等离子体质谱仪具有快速、灵敏、多元素、动态范围宽、干扰容易控制等特点,作为常用微量及痕量多元素分析手段,已经广泛用于环境、食品、农业、半导体、临床和药物、地质、核工业、法医、化合物石化等领域。电感耦合等离子体质谱仪的科学管理和正确使用,以及合理维护,是获得良好测试数据和延长仪器使用寿命的前提和基础。针对日常测试软件硬件问题,提出故障排除流程及解决办法,为设备操作人员和检测人员提供技术支持。 展开更多
关键词 电感耦合等离子体质谱仪 常见故障 排除流程
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相平衡关系在《化工原理》单元过程强化中的应用
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作者 葛明兰 曹睿 +1 位作者 彭梦甜 樊燕芳 《山东化工》 CAS 2024年第9期221-223,共3页
相平衡条件是传质过程的热力学极限,借此可以确定分离级数、液气比等操作参数,设计和优化分离工艺,探索体系极限。本文列举了蒸馏、吸收、萃取单元操作中相平衡的内容,说明通过改变温度、压力、浓度或增加促进剂可以改善相平衡,调整传... 相平衡条件是传质过程的热力学极限,借此可以确定分离级数、液气比等操作参数,设计和优化分离工艺,探索体系极限。本文列举了蒸馏、吸收、萃取单元操作中相平衡的内容,说明通过改变温度、压力、浓度或增加促进剂可以改善相平衡,调整传质过程的控制步骤,从而对化工过程实现精准设计和调控,是过程强化的重要手段。对于这些能源密集型单元过程,相平衡模型的准确预测或模拟是高效分离或纯化、减少能耗和原料损失的必要保障。 展开更多
关键词 相平衡 单元操作 过程强化 热力学条件 传质
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缩口T型微通道内纳米流体吸收CO_(2)的流动与传质研究
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作者 赵若晗 黄蒙蒙 +3 位作者 朱春英 付涛涛 高习群 马友光 《化工学报》 EI CSCD 北大核心 2024年第1期221-230,共10页
构建了一种气相缩口的T型微通道,研究了二氧化硅(SiO_(2))纳米流体吸收CO_(2)过程的气液两相流动与传质性能。在实验范围内,观察到了泡状流、串珠流、紧密弹状流和弹状-环状流。随着气相流速的增加,泡状流的气泡生成频率f和比表面积a快... 构建了一种气相缩口的T型微通道,研究了二氧化硅(SiO_(2))纳米流体吸收CO_(2)过程的气液两相流动与传质性能。在实验范围内,观察到了泡状流、串珠流、紧密弹状流和弹状-环状流。随着气相流速的增加,泡状流的气泡生成频率f和比表面积a快速增大,串珠流的f和a变化很小,紧密弹状流的f和a逐渐减小。随着连续相和分散相流速的增大以及纳米颗粒浓度的升高,液侧体积传质系数均表现出增大的趋势。与等宽T型通道相比,缩口T型微通道的最大比表面积增幅达29.6%。结果表明气相入口的缩径效应可有效提高气液两相流的传质面积,有利于气液传质性能的改善和提高。 展开更多
关键词 二氧化碳捕集 纳米流体 微通道 传质 过程强化
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A Physical Interpretation of Mass-Energy Equivalence Based on the Orthogonal Collision
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作者 Weihong Qian 《Journal of Modern Physics》 2023年第7期1067-1086,共20页
Einstein described the mass-energy equivalence as the most important result of special relativity. But more than a century after Einstein first derived the relationship between mass-energy equivalence (or mass-energy ... Einstein described the mass-energy equivalence as the most important result of special relativity. But more than a century after Einstein first derived the relationship between mass-energy equivalence (or mass-energy equation), questions left for people are how to understand that mass and energy are somehow equivalent, and how to give the dynamical process for the conversion from mass to energy (or vice versa). This paper first interprets the formula of mass-energy equivalence published by Einstein in 1905, and then gives the equivalence relationship of mass-energy transition based on the dynamics of particle orthogonal collision. As a result, the orthogonal collision of two high-energy mass particles can generate a huge mass-energy density, equivalent to the total energy of N new particles, which is a one-way dynamic process that generates new mass-energy density and new matter. This conversion of mass into energy has nothing to do with special relativity. 展开更多
关键词 mass-Energy Equivalence Orthogonal Collision Physical Interpretation Dynamical process Special Relativity
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加工方式对大豆油中挥发性物质的影响
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作者 程建军 王兆华 +3 位作者 于殿宇 张赫 尤美月 潘明喆 《中国食品学报》 EI CAS CSCD 北大核心 2024年第2期248-259,共12页
为探究加工方式对大豆油风味物质的影响,采用电子鼻与顶空固相微萃取-气相色谱-质谱联用相结合的方法分析浸提、热榨和冷榨3种方式加工的大豆油挥发性物质的差异。结果表明:在3种大豆油样品中共检出86种挥发性物质,其中浸提油53种,热榨... 为探究加工方式对大豆油风味物质的影响,采用电子鼻与顶空固相微萃取-气相色谱-质谱联用相结合的方法分析浸提、热榨和冷榨3种方式加工的大豆油挥发性物质的差异。结果表明:在3种大豆油样品中共检出86种挥发性物质,其中浸提油53种,热榨油54种,冷榨油45种,主要包括醛类、醇类、酮类、酸类、酯类、萜烯类、杂环类(呋喃和吡嗪)以及烃类等化合物。在3种大豆油中检出相同的挥发性物质有24种。主成分分析和层次聚类分析结果表明加工方式对大豆油风味的影响较大。采用气味活度值(OAV)判定3种大豆油样品的关键风味物质,浸提油中检出关键风味物质15种,以3-壬烯-2-酮等物质为主,使浸提油具有浆果风味。热榨油中检出关键风味物质16种,其中2,5-二甲基吡嗪等杂环类物质使热榨油具有独特的烘焙风味。冷榨油中检出12种关键风味物质,以(E,E)-2,4-庚二烯醛等醛类物质为主,使冷榨油具有天然油脂风味。偏最小二乘回归分析表明电子鼻与气相色谱-质谱联用的检测结果间存在较好相关性。 展开更多
关键词 气相色谱-质谱联用法(GC-MS) 电子鼻 大豆油 加工方式 风味物质
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基于代谢组学的绿茶热加工过程中化学成分变化规律解析 被引量:1
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作者 于帅 许继业 +5 位作者 胡争艳 高健健 陈丹 谭俊峰 林智 戴伟东 《食品科学》 EI CAS CSCD 北大核心 2024年第12期165-175,共11页
为探究高火功绿茶品质的形成机理,基于超高效液相色谱-四极杆轨道阱质谱代谢组学方法对绿茶加工过程样进行分析,重点关注杀青、干燥和焙火等热加工过程中化学成分差异及变化规律。在绿茶不同热加工过程样中共鉴定出125种化合物,包括10... 为探究高火功绿茶品质的形成机理,基于超高效液相色谱-四极杆轨道阱质谱代谢组学方法对绿茶加工过程样进行分析,重点关注杀青、干燥和焙火等热加工过程中化学成分差异及变化规律。在绿茶不同热加工过程样中共鉴定出125种化合物,包括10种黄烷醇类、14种二聚儿茶素类、19种黄酮醇-O-糖苷类、5种黄酮-C-糖苷类、8种N-乙基-2-吡咯烷酮取代的儿茶素(N-ethyl-2-pyrrolidinone-substituted flavan-3-ols,EPSF)类、16种氨基酸类、13种酚酸类、4种有机酸类、11种生物碱类、13种脂类、4种香气糖苷类和8种其他类化合物。偏最小二乘判别分析和热图分析结果表明,绿茶热加工过程中内含成分变化明显,筛选出114种具有显著差异的化合物(P<0.05)。在杀青、干燥、焙火等过程中,大部分儿茶素、二聚儿茶素类化合物含量下降,EPSF类、黄酮-C-糖苷类和脂类化合物含量明显上升;香气糖苷类化合物(苯乙醇樱草糖苷、芳樟醇樱草糖苷和芳樟醇氧化物樱草糖苷等)含量在杀青过程中增加了439%~2497%;N-1-脱氧-D-果糖酰茶氨酸含量在干燥过程中增加了820%~1290%;黄酮醇-O-糖苷类化合物(杨梅素-3-半乳糖苷、山柰酚-3-半乳糖苷、山柰酚-3-阿拉伯糖苷、杨梅素-3-葡萄糖苷和山柰酚-3-葡萄糖苷等)含量在焙火过程中明显下降。本研究可为后续进一步提升绿茶品质提供理论参考。 展开更多
关键词 绿茶 热加工过程 代谢组学 液相色谱-质谱联用 化学成分
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亚毫米气泡和常规尺寸气泡气液两相流流动与传质特性对比 被引量:1
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作者 崔怡洲 李成祥 +4 位作者 翟霖晓 刘束玉 石孝刚 高金森 蓝兴英 《化工学报》 EI CSCD 北大核心 2024年第1期197-210,F0004,共15页
通过实验和数值模拟系统研究了亚毫米气泡鼓泡塔与常规鼓泡塔在流动和传质特性上的区别,并建立了适用于亚毫米气泡气液两相流流动和传质过程的数值模拟方法。研究结果表明,相比常规鼓泡塔,相同操作条件下亚毫米气泡鼓泡塔的气泡尺寸分... 通过实验和数值模拟系统研究了亚毫米气泡鼓泡塔与常规鼓泡塔在流动和传质特性上的区别,并建立了适用于亚毫米气泡气液两相流流动和传质过程的数值模拟方法。研究结果表明,相比常规鼓泡塔,相同操作条件下亚毫米气泡鼓泡塔的气泡尺寸分布更窄,平均尺寸降至前者3%左右,气含率提高2倍以上,比表面积提高2个数量级。另外亚毫米气泡气液两相流中气液径向分布更均匀,轴向返混程度更小。亚毫米气泡鼓泡塔的相界面积是强化传质的关键控制因素,其液相传质系数虽低于常规鼓泡塔,但依靠巨大的相界面积,其体积传质系数是常规鼓泡塔的10倍左右。针对大规模鼓泡塔反应器的模拟结果也表明,亚毫米气泡可使反应器达到更均匀的气含率分布,受初始气液分布的影响小。 展开更多
关键词 亚毫米气泡 鼓泡塔 气液两相流 传质 数值模拟 过程强化
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基于HPLC法及UPLC-MS法测定芫花饮片炮制前后7种成分的含量变化
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作者 张萍 米宏英 +4 位作者 严华 魏锋 高慧媛 马双成 陆兔林 《中国药事》 CAS 2024年第5期575-587,共13页
目的:建立HPLC法及UPLC-MS法测定芫花中银椴苷、木犀草素、芹菜素、绿原酸、羟基芫花素、芫花素及芫花酯甲7种化学成分含量的方法,分析芫花炮制前后化学成分的变化。方法:采用HPLC法,测定银椴苷、木犀草素、芹菜素、绿原酸、羟基芫花素... 目的:建立HPLC法及UPLC-MS法测定芫花中银椴苷、木犀草素、芹菜素、绿原酸、羟基芫花素、芫花素及芫花酯甲7种化学成分含量的方法,分析芫花炮制前后化学成分的变化。方法:采用HPLC法,测定银椴苷、木犀草素、芹菜素、绿原酸、羟基芫花素和芫花素6种成分的含量,色谱柱为Agilent Eclipse Plus C18(250 mm×4.6 mm,5μm),流动相为乙腈(A)-0.1%甲酸(B)梯度洗脱,流速为1.0 mL·min^(-1),进样量10μL。同时采用UPLC-MS方法测定芫花酯甲的含量,色谱柱为ACQUITY UPLC HSS T3 C18色谱柱(2.1 mm×100 mm,1.8μm),流动相为乙腈(A)-0.1%甲酸(B)梯度洗脱,流速0.3 mL·min-1,柱温35℃,进样量1μL。结果:7种成分的含量由高到低依次为芫花素>绿原酸>银椴苷>芹菜素>羟基芫花素>木犀草素>芫花酯甲。芫花炮制后7种成分的含量均发生一定程度的变化,其中绿原酸成分在炮制后含量有升高有降低,变化不明显;对于银椴苷和芹菜素成分,炮制后含量降低;对于木犀草素、羟基芫花素和芫花素3个成分,炮制后含量升高;对于芫花酯甲成分,炮制后含量降低。结论:该方法简便、灵敏、高效,为考察芫花饮片炮制前后的质量变化提供了技术支持。 展开更多
关键词 芫花 炮制 化学成分 含量测定 液相色谱 液质联用色谱
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