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碘转移本体聚合制备PS-b-PBA-b-PS共聚物:聚合动力学、结构和性能

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高校化学工程学报 2024年第3期38卷 432-439页

作者：章璐鑫常兆恒余大洋包永忠浙江大学化学工程与生物工程学院化学工程国家重点实验室(浙江大学)浙江杭州310058 浙江大学衢州研究院浙江衢州324000

以碘仿为链转移剂、偶氮类化合物为引发剂,通过碘转移本体聚合合成碘封端聚丙烯酸丁酯(I-PBA-I),并以其调节苯乙烯扩链聚合,制得聚苯乙烯-b-聚丙烯酸丁酯-b-聚苯乙烯(PS-b-PBA-b-PS)共聚物,研究了聚合动力学、共聚物结构和性能。发现丙... 详细信息

以碘仿为链转移剂、偶氮类化合物为引发剂,通过碘转移本体聚合合成碘封端聚丙烯酸丁酯(I-PBA-I),并以其调节苯乙烯扩链聚合,制得聚苯乙烯-b-聚丙烯酸丁酯-b-聚苯乙烯(PS-b-PBA-b-PS)共聚物,研究了聚合动力学、共聚物结构和性能。发现丙烯酸丁酯均聚和苯乙烯扩链聚合均符合活性自由基聚合特征,反应初始BA与CHI3物质的量比n_(BA,0)/n_(CHI3,0)从100/1增至1 000/1时,I-PBA-I数均分子量由15 000增大到134 500;以数均分子量为28 400的I-PBA-I为大分子链转移剂,反应初始BA与St物质的量比n_(BA,0)/n_(St,0)为1/1、1/2、1/3和1/4时扩链得到数均分子量分别为46 000、69 000、97 500、127 000的PS-b-PBA-b-PS共聚物;嵌段共聚物微相分离,在增韧的同时保持一定的透光率,PS与PBA物质的量比n_(PS)/n_(PBA)为3.85/1的嵌段共聚物抗冲强度与商品化阴离子活性聚合苯乙烯-丁二烯嵌段共聚树脂相当。

关键词：聚苯乙烯聚丙烯酸丁酯碘转移聚合聚合动力学嵌段共聚物

危险化学品生产企业安全生产风险管理路径探索

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山西化工 2024年第6期44卷 219-221页

作者：张鲁新山东省农药科学研究院山东济南250100

某石化企业的硫回收装置存在易燃易爆性气体和毒性气体,为了提高安全风险控制水平,研究过程分析了硫回收工艺的危险性,介绍了反应气体的潜在风险及反应过程的腐蚀性,开展重大危险源等级评价;运用HAZOP分析法开展安全风险评价,根据评价... 详细信息

某石化企业的硫回收装置存在易燃易爆性气体和毒性气体,为了提高安全风险控制水平,研究过程分析了硫回收工艺的危险性,介绍了反应气体的潜在风险及反应过程的腐蚀性,开展重大危险源等级评价;运用HAZOP分析法开展安全风险评价,根据评价结果制定相应的安全对策。结果显示,该装置的主要风险点为反应酸性气体夹带液态甲醇、设备轻度腐蚀、风量与酸性气体积分数不佳,针对以上问题提出了应对措施,包括增加缓冲罐、控制酸性气分液罐内部温度等。

关键词：危险化学品生产企业硫回收装置重大危险源辨识安全风险管理路径

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长期照护人员分级评价指标体系的构建

军事护理 2024年第4期41卷 56-60页

作者：张露心傅卓凡张涛梅文稀李惠玲苏州大学苏州医学院护理学院江苏苏州215006

目的构建长期照护人员分级评价指标体系,为不同层级照护人员的准入、考核与培训提供参考。方法通过文献回顾和半结构访谈初拟长期照护人员分级评价指标,采用德尔菲法进行2轮函询,采用层次分析法计算指标权重。结果长期照护员评价指标体... 详细信息

目的构建长期照护人员分级评价指标体系,为不同层级照护人员的准入、考核与培训提供参考。方法通过文献回顾和半结构访谈初拟长期照护人员分级评价指标,采用德尔菲法进行2轮函询,采用层次分析法计算指标权重。结果长期照护员评价指标体系包括5个一级指标,17个二级指标,85个三级指标;照护师评价指标体系包括5个一级指标,19个二级指标,73个三级指标;照护督导评价指标体系包括5个一级指标,17个二级指标,59个三级指标。2轮专家积极系数为100%、95%,专家权威系数为0.863、0.862,肯德尔和谐系数为0.064,0.171(均P<0.001)。结论构建的长期照护人员分级评价体系具有科学性和可靠性,可为长期照护人员的分级考核与培训提供参考。

关键词：长期照护人员分级评价指标德尔菲法层次分析法

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丙烯酸丁酯碘转移细乳液聚合动力学

化学反应工程与工艺 2024年第2期40卷 160-167页

作者：常兆恒章璐鑫包永忠浙江大学化学工程联合国家重点实验室化学工程与生物工程学院浙江杭州310058 浙江大学衢州研究院衢州324000

碘转移聚合(ITP)是一种链调控剂易得的可逆失活自由基聚合法,细乳液ITP具有高的链调控剂使用效率和乳液稳定性。以碘仿为链转移剂、2,2’-偶氮二异丁基脒二盐酸盐(AIBA)为引发剂,进行丙烯酸丁酯(BA)细乳液ITP,研究AIBA浓度、碘仿浓度和... 详细信息

碘转移聚合(ITP)是一种链调控剂易得的可逆失活自由基聚合法,细乳液ITP具有高的链调控剂使用效率和乳液稳定性。以碘仿为链转移剂、2,2’-偶氮二异丁基脒二盐酸盐(AIBA)为引发剂,进行丙烯酸丁酯(BA)细乳液ITP,研究AIBA浓度、碘仿浓度和聚合温度对BA聚合转化率、反应速率、聚丙烯酸丁酯(PBA)平均分子量和分子量分布的影响。结果表明:BA细乳液ITP反应快,前期符合一级反应特征,表观反应速率常数随AIBA浓度增大和聚合温度升高而增大;碘仿浓度对反应速率影响不大,但影响PBA的分子量,当碘仿相对单体的摩尔浓度由1‰降低到0.25‰时,转化率大于90%的PBA的数均分子量由1.2×10^(5)增大到5.0×10^(5)左右。以PBA为大分子调节剂种子乳液进行甲基丙烯酸甲酯(MMA)扩链(其中BA与MMA物质的量比为1:1),成功制备了分子量和乳胶粒子粒径均增大的PMMA-b-PBA-b-PMMA共聚物乳液。聚合动力学研究和聚合物结构表征证实了BA和MMA细乳液聚合的“活性”特征。

关键词：丙烯酸丁酯碘转移聚合细乳液聚合聚合反应速率分子量

Poroelastic finite-difference modeling for ultrasonic waves in digital porous cores

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Earthquake Science 2014年第3期27卷 285-299页

作者： Li-Yun Fu Yan zhang Zhenglin Pei Wei Wei luxin zhang Key Laboratory of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of Sciences Beijing North NewTech PetroTech Ltd Schlumberger WesternGeco HoustonTXUSA

Scattering attenuation in short wavelengths has long been interesting to geophysicists. Ultrasonic coda waves, observed as the tail portion of ultrasonic wavetrains in laboratory ultrasonic measurements, are important for such studies where ultrasonic waves interact with smallscale random heterogeneities on a scale of micrometers, but often ignored as noises because of the contamination of boundary reflections from the side ends of a sample core. Numerical simulations with accurate absorbing boundary can provide insight into the effect of boundary reflections on coda waves in laboratory experiments. The simulation of wave propagation in digital and heterogeneous porous cores really challenges numerical techniques by digital image of poroelastic properties, numerical dispersion at high frequency and strong heterogeneity, and accurate absorbing boundary schemes at grazing incidence. To overcome these difficulties, we present a staggered-grid high-order finite-difference （FD） method of Biot＇s poroelastic equations, with an arbitrary even-order （2L） accuracy to simulate ultrasonic wave propagation in digital porous cores with strong heterogeneity. An unsplit convolutional perfectly matched layer （CPML） absorbing boundary, which improves conventional PML methods at grazing incidence with less memory and better computational efficiency, is employed in the simulation to investigate the influence of boundary reflections on ultra- sonic coda waves. Numerical experiments with saturated poroelastic media demonstrate that the 2L FD scheme with the CPML for ultrasonic wave propagation significantly improves stability conditions at strong heterogeneity and absorbing performance at grazing incidence. The boundary reflections from the artificial boundary surrounding the digital core decay fast with the increase of CPML thick- nesses, almost disappearing at the CPML thickness of 15 grids. Comparisons of the resulting ultrasonic coda Qsc values between the numerical and experimental

关键词： Digital porous cores Ultrasonic coda Poroelastic finite-difference modeling Unsplitconvolutional PML absorbing boundary

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精细控制智能化光伏大棚的设计

太阳能 2024年第5期 83-88页

作者：张露心颜加龙何秋喜郑皓文赵恒利楚雄师范学院物理与电子科学学院楚雄675000

温室大棚技术发展迅速,但其存在电力供给短缺、工作效率较低、管理精细化程度弱等问题,严重制约了中国设施农业的发展水平。设计了一种精细控制智能化光伏大棚,将光伏发电技术与精细化控制技术融入农业生产中,基于环境要素和农作物生长... 详细信息

温室大棚技术发展迅速,但其存在电力供给短缺、工作效率较低、管理精细化程度弱等问题,严重制约了中国设施农业的发展水平。设计了一种精细控制智能化光伏大棚,将光伏发电技术与精细化控制技术融入农业生产中,基于环境要素和农作物生长规律,通过传感技术,多维度精细化与智能化控制来协调和平衡参数,使光伏大棚中各参数都达到理想状态,保障对农作物生长过程中外界条件的稳定调节,建立满足农作物生长的最适宜环境,以此提高农作物的质量及产量。通过建立实物模型进行测试后发现,光伏发电系统能实现光伏大棚所需电能的正常供应,同时精细控制智能化系统可以实现农作物生长过程中重要参数数值的自动调节,且可以随时随地检测和监控,具备一定的推广价值。

关键词：光伏大棚精细控制智能化光伏发电农作物生长传感技术

维普期刊数据库博看期刊

Variable Structure Control for Uncertain System with Partial Actuator Faults

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Variable Structure Control for Uncertain System with Partial...

Poroelastic finite-difference modeling for ultrasonic waves in digital porous cores

第37届中国控制会议

作者： Heli Hu luxin zhang Dan Zhao College of Information Engineering Shenyang University College of Mechanical Engineering Shenyang University Department of Fundamental Teaching Shenyang Institute of Engineering

This paper is devoted to the variable structure control problems for a class of the uncertain systems with partial actuator *** actuator mode takes a more general form of actuator faults,which covers the non-faulty case and the partial degradation ***,the considered system is made equivalent transformation to design a simple sliding surface,which can ensure the behavior of system in the sliding mode exhibit desired ***,it is concentrating on optimizing the bounds of unmatched nonlinearity and designed gains to obtain the *** function mincx is utilized to solve the convex problem and guarantee the quadratic stability of the sliding *** the process of deriving theoretical results,some good techniques are developed for the less ***,the variable structure control with partial actuator faults is designed for the considered system to derive the state to the sliding surface and guarantee to maintain a sliding motion on it ***,based on of a numerical example,it is illustrated that the proposed variable structure control with partial actuator faults is effective.

关键词： Variable structure control Partial actuator faults Bound of unmatched nonlinearity and designed gain

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Poroelastic finite-difference modeling for ultrasonic waves ...

中国科学院地质与地球物理研究所2014年度（第14届）学术年会

Scattering attenuation in short wavelengths has long been interesting to *** coda waves,observed as the tail portion of ultrasonic wavetrains in laboratory ultrasonic measurements,are important for such studies where ultrasonic waves interact with smallscale random heterogeneities on a scale of micrometers,but often ignored as noises because of the contamination of boundary reflections from the side ends of a sample *** simulations with accurate absorbing boundary can provide insight into the effect of boundary reflections on coda waves in laboratory *** simulation of wave propagation in digital and heterogeneous porous cores really challenges numerical techniques by digital image of poroelastic properties,numerical dispersion at high frequency and strong heterogeneity,and accurate absorbing boundary schemes at grazing *** overcome these difficulties,we present a staggered-grid high-order finite-difference(FD)method of Biot’s poroelastic equations,with an arbitrary even-order(2L)accuracy to simulate ultrasonic wave propagation in digital porous cores with strong *** unsplit convolutional perfectly matched layer(CPML)absorbing boundary,which improves conventional PML methods at grazing incidence with less memory and bettercomputational efficiency,is employed in the simulation to investigate the influence of boundary reflections on ultrasonic coda *** experiments with saturated poroelastic media demonstrate that the 2L FD scheme with the CPML for ultrasonic wave propagation significantly improves stability conditions at strong heterogeneity and absorbing performance at grazing *** boundary reflections from the artificial boundary surrounding the digital core decay fast with the increase of CPML thicknesses,almost disappearing at the CPML thickness of *** of the resulting ultrasonic coda Qsc values between the numerical and experimental ultrasonic S waveforms for a c

关键词： Digital porous cores Ultrasonic coda Poroelastic finite-difference modeling Unsplit convolutional PML absorbing boundary

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蠕动滑坡成因及隧道变形机理的分析

岩石力学与工程学报 1999年第2期18卷 217-221页

作者：张鲁新周德培铁道科学研究院西北分院西南交通大学

以东荣河滑坡为例，利用现场勘测、滑坡监测及室内试验结果，分析了蠕动型滑坡成因，以及酿成隧道变形开裂的机理。得出的成果对蠕动滑坡体中隧道病害的有效防治提供了依据。

关键词：蠕动滑坡隧道蠕变变形机理