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文章速递Cyclomatic Complexity-Based Encapsulation, Data Hiding, and Separation of Concerns 认领
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作者 Charles W. Butler Thomas J. McCabe 《软件工程与应用(英文)》 2021年第1期44-66,共23页
<div style="text-align:justify;"> <span style="font-family:Verdana;">Three design principles are prominent in software development-encapsulation, data hiding, and separation of concerns... <div style="text-align:justify;"> <span style="font-family:Verdana;">Three design principles are prominent in software development-encapsulation, data hiding, and separation of concerns. These principles are used as subjective quality criteria for both procedural and object-oriented applications. The purpose of research is to quantify encapsulation, data hiding, and separation of concerns is quantified using cyclomatic-based metrics. As a result of this research, the derived design metrics, coefficient of encapsulation, coefficient of data hiding, and coefficient of separation of concerns, are defined and applied to production software indicating whether the software has low or high encapsulation, data hiding, and separation of concerns.</span> </div> 展开更多
关键词 Object-Oriented Design Methods Reliability Complexity Measures Software Design Encapsulation Information Hiding Separation of Concerns McCabe Metrics Coefficient of Encapsulation Coefficient of Data Hiding Coefficient of Separation of Concerns
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文章速递苯并咪唑聚合物树脂吸附分离Pd(Ⅱ) 认领
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作者 蒋绍松 陈慕涵 +2 位作者 金次 邵敏 黄章杰 《云南大学学报:自然科学版》 CAS CSCD 北大核心 2021年第1期125-131,共7页
将2-巯基苯并咪唑杂环化合物接枝到氯球聚合物基体上,制备了苯并咪唑聚合物树脂(PS-MBI)吸附剂,用于氯化介质中选择性回收Pd(Ⅱ);研究优化吸附分离参数,探讨了吸附分离机理.研究结果表明,在0.1 mol·L^−1的盐酸水溶液中,PS-MBI对Pd(... 将2-巯基苯并咪唑杂环化合物接枝到氯球聚合物基体上,制备了苯并咪唑聚合物树脂(PS-MBI)吸附剂,用于氯化介质中选择性回收Pd(Ⅱ);研究优化吸附分离参数,探讨了吸附分离机理.研究结果表明,在0.1 mol·L^−1的盐酸水溶液中,PS-MBI对Pd(Ⅱ)有较佳的吸附效果,最大吸附容量为138.8 mg·g^−1,PS-MBI可从Pd(Ⅱ),Pt(Ⅳ),Rh(Ⅲ),Cu^2+,Ni^2+,Fe^3+,和Zn^2+的混合溶液中分离Pd(Ⅱ),一步即可完成金属混合溶液中钯的分离,分离系数β(Pd/M)(M:Pt,Rh,Cu,Ni,Fe,Zn)均高于1.0×10^3;PS-MBI具有良好的重复使用性能,经3次吸附−洗脱循环,PS-MBI吸附Pd(Ⅱ)的回收率仍高于92.0%.FT-IR和XPS分析表明:PS-MBI吸附Pd(Ⅱ)为配位机理,Pd(Ⅱ)通过与咪唑环上N原子形成配位键,实现其与金属离子混合溶液的分离. 展开更多
关键词 杂环聚合物 吸附 分离 钯 机理
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文章速递氧化单元离心机分离效果工艺优化 认领
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作者 闫一伟 李宁辉 +1 位作者 徐军 王彦 《聚酯工业》 CAS 2021年第1期38-40,共3页
介绍离心机的工作原理,从离心机的进料量、喷嘴、转速、稀碱加入量、溶剂加入量、沉淀剂温度等方面,分析了氧化单元离心机分离效果的影响因素,并提出相应措施,进而对系统进行简单优化处理。
关键词 PTA 离心机 分离 优化
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气液旋流分离技术应用研究进展 认领
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作者 蔡禄 孙治谦 +2 位作者 朱丽云 王旱祥 王振波 《石油机械》 北大核心 2021年第1期102-109,共8页
气液旋流分离设备具有分离效率高、体积小及工作稳定等优点,在油田开发、天然气开采、油气输送和压缩空气净化处理等领域得到了广泛应用。油田开发中,常用的气驱技术能够提高采出率,但油井气液比会增大,油气分离技术要求日趋严苛。对气... 气液旋流分离设备具有分离效率高、体积小及工作稳定等优点,在油田开发、天然气开采、油气输送和压缩空气净化处理等领域得到了广泛应用。油田开发中,常用的气驱技术能够提高采出率,但油井气液比会增大,油气分离技术要求日趋严苛。对气液旋流分离设备的分离原理及国内外研究现状进行了简要介绍,阐述了分离性能的优化方法,分析了理论研究的不足。研究结果发现:气液旋流分离设备的分离性能受其结构参数、操作参数以及流体物性参数等因素的影响。国内外学者为提高分离效率采取了改进外部结构和内部流场的措施,为进一步提升工业生产效率提供了可能。随着气液旋流分离技术应用领域的不断拓宽,旋流器及内部流场的定量数值研究对工程应用具有重要意义。研究内容可为气液旋流分离器的设计与应用提供指导。 展开更多
关键词 气液两相流 分离 旋流器 优化 研究进展
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Molecular dispersion enhances photovoltaic efficiency and thermal stability in quasi-bilayer organic solar cells 认领
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作者 Xuning Zhang Yanxun Li +9 位作者 Dongyang Zhang Guangbao Wu Hong Zhang Jiyu Zhou Xing Li Saud-uz-Zafar Jianqi Zhang Zhixiang Wei Huiqiong Zhou Yuan Zhang 《中国科学:化学英文版》 SCIE EI CAS 2021年第1期116-126,共11页
In comparison to widely adopted bulk heterojunction(BHJ)structures for organic solar cells(OSC),exploiting the sequential deposition to form planar heterojunction(PHJ)structures enables to realize the favorable vertic... In comparison to widely adopted bulk heterojunction(BHJ)structures for organic solar cells(OSC),exploiting the sequential deposition to form planar heterojunction(PHJ)structures enables to realize the favorable vertical phase separation to facilitate charge extraction and reduce charge recombination in OSCs.However,effective tunings on the power conversion efficiency(PCE)in PHJ-OSCs are still restrained by the currently available methods.Based on a polymeric donor PBDBT-2 F(PBDBT=Poly[[4,8-bis[5-(2-ethylhexyl)-4-fluoro-2-thienyl]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4 H,8 H-benzo[1,2-c:4,5-c′]dithiophene-1,3-diyl]-2,5-thiophenediyl])and a non-fullerene(NF)acceptor Y6,we proposed a strategy to improve the properties of photovoltaic performances in PHJ-based OSCs through dilute dispersions of the PBDBT-2 F donor into the acceptor-dominant phase with the sequential film deposition.With the control of donor dispersions,the charge transport balance in the PHJ-OSCs is improved,leading to the expedited photocarrier sweep-out with reduced bimolecular charge recombination.As a result,a PCE of 15.4%is achieved in the PHJ-OSCs.Importantly,the PHJ solar cells with donor dispersions exhibit better thermal stability than corresponding BHJ devices,which is related to the better film morphology robustness and less affected charge sweep-out during the thermal aging. 展开更多
关键词 diluted donor dispersion sequential film deposition vertical phase separation thermal stability
一/二价离子分离膜材料研究进展 认领
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作者 黄清波 刘公平 金万勤 《化工学报》 EI CAS 北大核心 2021年第1期334-350,共17页
一/二价离子分离膜在能源存储和转换、污染监测和控制、清洁工业过程等领域发挥重要作用。本文旨在回顾近年来一/二价离子分离膜材料的研究进展,重点综述聚合物膜、混合基质膜及金属有机骨架和二维材料等新型膜用于一/二价离子分离的研... 一/二价离子分离膜在能源存储和转换、污染监测和控制、清洁工业过程等领域发挥重要作用。本文旨在回顾近年来一/二价离子分离膜材料的研究进展,重点综述聚合物膜、混合基质膜及金属有机骨架和二维材料等新型膜用于一/二价离子分离的研究现状,深入讨论界面聚合、层层组装、沉积、共混等不同制备方法对膜微结构和分离性能的影响,探讨一/二价离子分离膜面临的主要挑战和未来研究方向。 展开更多
关键词 膜 分离 选择性 一/二价离子 离子筛分
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恩施藤茶乙醇提取物对高温煮熟鱼肉腐败菌的抑制作用研究 认领
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作者 李宇 刘翠君 +3 位作者 赵仁君 罗建群 冉亚兰 何美军 《保鲜与加工》 CAS 北大核心 2021年第1期124-130,共7页
以生长菌落数为评价指标,研究恩施藤茶乙醇提取物对高温煮熟鱼肉的防腐效果;采用稀释平板法分离纯化和16S rDNA测序技术鉴定导致高温煮熟鱼肉腐败变质的细菌;运用滤纸片法测试恩施藤茶乙醇提取物对腐败变质细菌的抑菌活性;通过测定恩施... 以生长菌落数为评价指标,研究恩施藤茶乙醇提取物对高温煮熟鱼肉的防腐效果;采用稀释平板法分离纯化和16S rDNA测序技术鉴定导致高温煮熟鱼肉腐败变质的细菌;运用滤纸片法测试恩施藤茶乙醇提取物对腐败变质细菌的抑菌活性;通过测定恩施藤茶乙醇提取物对腐败变质细菌生长曲线、导电率及生物大分子含量的影响研究其抑菌机理。结果表明:在储藏15 d内,30 mg·mL-1恩施藤茶乙醇提取物能完全抑制高温煮熟鱼肉中细菌生长;分离、鉴定了2株导致高温煮熟鱼肉腐败变质的细菌Bacillus methylotrophicus T-10、Alcaligenes faecalis T-9;恩施藤茶乙醇提取物对这2株腐败菌具有中敏抑菌活性(抑菌圈直径:10~20 mm),其最小抑菌浓度(MIC)分别为16.0 mg·mL-1和20.0 mg·mL-1;恩施藤茶乙醇提取物通过破坏菌体细胞膜的完整性,致使生物大分子物质外溢而发挥抑菌作用。 展开更多
关键词 腐败细菌 藤茶乙醇提取物 分离 鉴定 抑菌活性 最小抑菌浓度
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ZIFs椭圆形孔窗的精细调控及糠醛/5-羟甲基糠醛吸附分离性能研究 认领
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作者 赵宇 石琪 董晋湘 《化工学报》 EI CAS 北大核心 2021年第1期555-568,F0003,共15页
在生物质催化炼制呋喃化合物的过程中,通常得到的是低浓度糠醛(Fur)和5-羟甲基糠醛(5-HMF)的混合物。基于Fur和5-HMF都是椭圆形分子,因此通过设计构筑和调控椭圆形孔窗的吸附剂可以实现Fur和5-HMF的筛分分离。选用二价钴盐和三种烷基取... 在生物质催化炼制呋喃化合物的过程中,通常得到的是低浓度糠醛(Fur)和5-羟甲基糠醛(5-HMF)的混合物。基于Fur和5-HMF都是椭圆形分子,因此通过设计构筑和调控椭圆形孔窗的吸附剂可以实现Fur和5-HMF的筛分分离。选用二价钴盐和三种烷基取代基团逐渐增大的咪唑配体(2-乙基咪唑/2-eIm、2-丙基咪唑/2-pIm和2-丁基咪唑/2-bIm)合成了三种椭圆形孔窗尺寸逐渐减小的ANA拓扑ZIFs材料:ANA-[Co(eIm)2]、ANA-[Co(pIm)2]和ANA-[Co(bIm)2]。首先解析了这三种ZIFs材料的晶体结构,并对其进行了PXRD、水蒸气吸附、N2吸脱附和SEM等基本表征,然后采用静态吸附和动态柱吸附研究了这三种材料对Fur和5-HMF的吸附分离性能。静态吸附、单组分动态柱吸附以及综合速率模型模拟计算结果显示:ANA-[Co(pIm)2]狭窄的椭圆形孔窗与Fur分子尺寸接近,但小于5-HMF,使得Fur分子可以吸附进入椭圆形孔窗,而5-HMF分子几乎不能通过。进一步在双组分Fur/5-HMF(5%/5%,质量分数)动态柱吸附中,ANA-[Co(pIm)2]对Fur的吸附量为91.7 mg·g^-1,不吸附5-HMF。因此,通过改变咪唑配体取代基团精细调控ZIFs椭圆形孔窗尺寸,并利用ZIFs椭圆形孔窗的位阻效应实现了Fur和5-HMF的筛分分离。 展开更多
关键词 沸石咪唑酯骨架材料 糠醛 5-羟甲基糠醛 吸附 分离 回收
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Role of relaxin in diastasis of the pubic symphysis peripartum 认领
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作者 Yan Wang Yong-Qiang Li +2 位作者 Mei-Rong Tian Nan Wang Zun-Cheng Zheng 《世界临床病例杂志》 SCIE 2021年第1期91-101,共11页
BACKGROUND Separation of the pubic symphysis can occur during the peripartum period.Relaxin(RLX)is a hormone primarily secreted by the corpus luteum that can mediate hemodynamic changes during pregnancy as well as loo... BACKGROUND Separation of the pubic symphysis can occur during the peripartum period.Relaxin(RLX)is a hormone primarily secreted by the corpus luteum that can mediate hemodynamic changes during pregnancy as well as loosen the pelvic ligaments.However,it is unknown whether RLX is associated with peripartum pubic symphysis separation and if the association is affected by other factors.AIM To study the association between RLX and peripartum pubic symphysis separation and evaluate other factors that might affect this association.METHODS We performed a cross-sectional study of pregnant women between April 2019 and January 2020.Baseline demographic characteristics,including gestational age,weight,neonatal weight,delivery mode and duration of the first and second stages of labor,were recorded.The clinical symptoms were used as a screening index during pregnancy,and the patients with pubic symphysis and inguinal pain were examined by color Doppler ultrasonography to determine whether there was pubic symphysis separation.Serum RLX concentrations were evaluated 1 d after delivery using an enzyme-linked immunosorbent assay,and pubic symphysis separation was diagnosed based on postpartum X-ray examination.We used an independent-sample t test to analyze the association between serum RLX levels and peripartum pubic symphysis separation.Multivariate regression analysis was used to evaluate whether the association between RLX and peripartum pubic symphysis separation was confounded by other factors,and the association between RLX and the severity of pubic symphysis separation was also assessed.We used Pearson correlation analysis to determine the factors related to RLX levels as well as the correlation between the degree of pubic symphysis separation and activities of daily living(ADL)and pain.RESULTS A total of 54 women were enrolled in the study,with 15 exhibiting(observational group)and 39 not exhibiting(control group)peripartum pubic symphysis separation.There were no statistically significant differences in terms of maternal 展开更多
关键词 PREGNANCY Pubic symphysis separation RELAXIN Neonatal weight Crosssectional study Activities of daily living
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废旧三元锂离子电池正极材料回收技术研究进展 认领
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作者 田庆华 邹艾玲 +3 位作者 童汇 喻万景 张佳峰 郭学益 《材料导报》 EI CAS 北大核心 2021年第1期11-22,共12页
三元锂离子电池因其性能优越,在国内外便携式电子设备和新能源汽车中得到广泛应用。随着对锂离子电池需求量的不断增大,大量的锂离子电池将迎来"退役"高峰期。为实现有价金属资源的循环利用,降低固体废物处理对环境的影响,废... 三元锂离子电池因其性能优越,在国内外便携式电子设备和新能源汽车中得到广泛应用。随着对锂离子电池需求量的不断增大,大量的锂离子电池将迎来"退役"高峰期。为实现有价金属资源的循环利用,降低固体废物处理对环境的影响,废旧锂离子电池的回收利用受到了广泛的关注。通过对三元锂离子电池进行资源化回收利用,可以获得有价金属或直接制备电池材料。为了提高物料的有效回收率,通常采用预处理的方法来分离集流体和正极活性材料,实现物料的有效分离及进一步的后处理。然后,采用冶金处理的方法从正极活性材料中提取金属和分离杂质,其包括高温冶金和湿法冶金处理工艺。最后,结合材料合成的方法进一步制备得到电池材料或化合物。在现阶段的研究中,高温冶金过程面临着物料损耗大、能耗高、环境不友好等问题;湿法冶金过程存在酸耗大、除杂效率低、工艺流程长等问题。正极材料的再生过程、回收成本以及再合成材料的性能是限制其应用的重要因素。本文主要介绍了废旧三元锂离子电池回收过程及方法,包括预处理、高温冶金、湿法冶金、正极材料再生等,分析比较了其存在的主要问题,为废旧三元锂离子电池的资源化技术发展提供参考。最后,提出了废旧三元锂离子电池正极材料的回收应向绿色环保、短流程和低能耗的方向发展。 展开更多
关键词 三元正极材料 预处理 高温冶金 浸出 分离 再合成
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微孔聚丙烯膜表面壳聚糖季铵盐的共价修饰及其抗菌性能 认领
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作者 郑细鸣 范荣玉 《化工进展》 EI CAS 北大核心 2021年第1期332-338,共7页
为了赋予微孔聚丙烯膜(MPPM)抗菌能力,增强其抗污染性能,本文通过丙烯酸的光引发接枝聚合、壳聚糖与聚丙烯酸的酰胺化反应、壳聚糖胺基与2,3-环氧丙基三甲基氯化铵的开环加成,成功地在MPPM膜表面通过共价修饰技术构建了壳聚糖季铵盐修... 为了赋予微孔聚丙烯膜(MPPM)抗菌能力,增强其抗污染性能,本文通过丙烯酸的光引发接枝聚合、壳聚糖与聚丙烯酸的酰胺化反应、壳聚糖胺基与2,3-环氧丙基三甲基氯化铵的开环加成,成功地在MPPM膜表面通过共价修饰技术构建了壳聚糖季铵盐修饰层。构建过程通过FTIR、XPS和荧光素二钠盐染色分析得到了证实。静态水接触角和吸水量实验结果表明,制得的修饰膜具有优异的表面润湿性和吸水性,吸水量可达11.23mg/cm^2,为未修饰MPPM的1123倍。以大肠杆菌和金黄色葡萄球菌为代表,采用平板活菌计数法考察了修饰膜的抗菌性能和抗菌稳定性。研究结果表明,修饰膜具有良好的抗菌活性,对大肠杆菌的抗菌率可达98%,对金黄色葡萄球菌的抗菌率可达100%,且抗菌效果稳定,在水处理领域具有潜在的应用前景。 展开更多
关键词 膜 表面修饰 分离 壳聚糖 抗菌性能
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分子筛材料在小分子吸附分离中的应用 认领
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作者 刘珊珊 柴玉超 +1 位作者 关乃佳 李兰冬 《高等学校化学学报》 SCIE EI CAS 北大核心 2021年第1期268-288,共21页
吸附分离技术与工艺在工业上具有重要意义.常见的吸附剂包括沸石分子筛、金属有机框架材料、活性炭等材料.分子筛具有比表面积大、稳定性高、生产成本低等优势,可以满足吸附分离技术中高效、节能和环保的需求,是一种非常有应用前景的小... 吸附分离技术与工艺在工业上具有重要意义.常见的吸附剂包括沸石分子筛、金属有机框架材料、活性炭等材料.分子筛具有比表面积大、稳定性高、生产成本低等优势,可以满足吸附分离技术中高效、节能和环保的需求,是一种非常有应用前景的小分子混合物分离吸附剂.本文综合评述了吸附分离领域中常用的吸附剂材料的特点和吸附分离机理与评价方法,总结了分子筛在空气分离、烃类分离、二氧化碳吸附、芳香硫化物脱除、一氧化碳吸附、氮氧化物吸附、氢气储存吸附及氢同位素分离等领域的应用,并对基于分子筛膜的小分子混合物分离现状进行了介绍.此外,本文还系统分析了分子筛对不同混合物的吸附分离性能与其拓扑结构、骨架组成及改性方法之间的关系,并对未来的研究前景进行了展望. 展开更多
关键词 沸石分子筛 吸附 分离
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Al2O3色层法从低浓铀靶件中分离^99Mo条件研究 认领
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作者 黄文博 梁积新 +2 位作者 吴宇轩 于宁文 向学琴 《同位素》 CAS 2021年第1期54-60,I0004,共8页
在裂变^99Mo的生产工艺中,常用Al2O3色层法分离纯化^99Mo。为建立Al2O3色层法从低浓铀(LEU)靶件中分离裂变^99Mo的工艺,考察吸附时间、温度、酸度、预处理方式等对Al2O3吸附Mo效果的影响。研究采用Al2O3色层法从不同浓度HNO 3溶液中分... 在裂变^99Mo的生产工艺中,常用Al2O3色层法分离纯化^99Mo。为建立Al2O3色层法从低浓铀(LEU)靶件中分离裂变^99Mo的工艺,考察吸附时间、温度、酸度、预处理方式等对Al2O3吸附Mo效果的影响。研究采用Al2O3色层法从不同浓度HNO 3溶液中分离Mo。测定Al2O3色层法对Al和主要杂质元素Sr、Ru、Zr、Te、Cs、I的去污系数。研究结果表明,在0.05~0.1 mol/L HNO 3介质中Al2O3对Mo有出色的吸附性能,Mo吸附率在99%以上,在NH 4OH溶液中Al2O3不吸附Mo。经500℃活化3 h预处理得到的Al2O3-C具有更大的比表面积,且在HNO 3浓度大于0.1 mol/L时相比于150℃活化3 h预处理得到的Al2O3-B以及未经高温预处理得到的Al2O3-A对于Mo有更好的吸附性能。采用该工艺,通过Al2O3色层法从模拟的LEU靶件溶液中提取Mo,Mo回收率大于90%,Al2O3色层法对裂变杂质元素Ru、Sr、Zr、Te、Cs等的去除率均大于99.99%,对131 I的去除率大于92%。由此可见,Al2O3在HNO 3介质中对Mo的吸附率高,能够有效地去除^99Mo产品中的杂质核素,适用于从低浓铀靶件中分离裂变^99Mo。 展开更多
关键词 Al2O3色层法 低浓铀 裂变^99Mo 分离 去污
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影响髂腰内固定治疗创伤性脊柱骨盆分离疗效的因素 认领
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作者 和利 田维 +3 位作者 徐嵩 赵晓宇 苗军 贾健 《中国组织工程研究》 CAS 北大核心 2021年第6期884-889,共6页
背景:创伤性脊柱骨盆分离严重破坏腰骶部稳定性,治疗并发症多、预后差,影响因素较多。目的:分析钉棒系统髂腰内固定治疗创伤性脊柱骨盆分离临床疗效的影响因素。方法:回顾性分析天津宁河医院2009年9月至2018年9月收治的资料完整的创伤... 背景:创伤性脊柱骨盆分离严重破坏腰骶部稳定性,治疗并发症多、预后差,影响因素较多。目的:分析钉棒系统髂腰内固定治疗创伤性脊柱骨盆分离临床疗效的影响因素。方法:回顾性分析天津宁河医院2009年9月至2018年9月收治的资料完整的创伤性脊柱骨盆分离患者16例,均行钉棒系统髂腰内固定治疗。伴神经损伤12例,其中10例行骶神经减压治疗,2例影像学未见责任骨折块,未予处理。术后疗效采用日本骨科协会评分、骨盆指数和英国医学研究会神经功能评分进行评价。将年龄、性别、手术时机、复位质量、合并伤、神经损伤程度与术后功能评分的相关性进行单因素统计分析,其中年龄与日本骨科协会评分进行线性相关分析;性别、手术时机、复位质量、合并伤、神经损伤程度与日本骨科协会评分进行卡方检验统计分析。结果与结论:①全组患者均获得随访,随访时间17-38个月;②术后末次随访日本骨科协会评价结果:优4例,良5例,可4例,差3例;③影像学测量结果显示:屈曲型骶骨骨折骨盆指数改善率为78%,中立型和伸展型无改善;④末次随访英国医学研究会评分评估神经功能恢复情况,优5例,良4例,无变化3例,神经损伤临床恢复率为75%;⑤统计分析显示:神经损伤程度与伴有骨盆前环损伤影响手术疗效;⑥提示手术治疗创伤性脊柱骨盆分离的疗效受多种因素影响。在处理合并损伤的基础上,早期行髂腰内固定治疗维持脊柱骨盆和骨盆环稳定性,对伴有神经损伤者进行确切减压,是取得满意疗效的关键。 展开更多
关键词 骨 脊柱 骨盆 分离 骶骨 骨折 内固定 钢板 影像
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取向晶种法制备沸石分子筛膜研究进展 认领
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作者 刘益 刘毅 《高等学校化学学报》 SCIE EI CAS 北大核心 2021年第1期117-132,共16页
近年来沸石分子筛膜因在分离、催化、传感和防腐等研究领域具有重要的应用价值而引起广泛关注.其中,具有优先取向微观结构的沸石分子筛膜由于能够显著降低客体分子在膜内的扩散路径并减少膜内的晶间界缺陷密度,成为膜分离学科的研究重点... 近年来沸石分子筛膜因在分离、催化、传感和防腐等研究领域具有重要的应用价值而引起广泛关注.其中,具有优先取向微观结构的沸石分子筛膜由于能够显著降低客体分子在膜内的扩散路径并减少膜内的晶间界缺陷密度,成为膜分离学科的研究重点.本文以b-轴取向MFI沸石分子筛膜为主线,综述了国内外制备取向沸石分子筛膜的最新研究进展;详细介绍了取向晶种法制膜工艺,侧重总结了MFI沸石纳米片合成、b-轴取向沸石晶种单层制备以及二次生长调控等方面的研究成果;在深入探讨各类取向沸石分子筛膜制备策略的基础上,分析探讨了其中存在的关键问题与解决措施,最后对取向沸石分子筛膜的发展方向进行了展望. 展开更多
关键词 沸石 取向 晶种层 膜 分离
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Necessary and Sufficient Conditions for the Separability and the R-Separability of the Irrotational Stokes Equation and Applications 认领
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作者 Eleftherios Protopapas Maria Hadjinicolaou 《应用数学与应用物理(英文)》 2020年第11期2379-2401,共23页
In the present manuscript, we formulate and prove rigorously, necessary and sufficient conditions for all kinds of separation of variables that a solution of the irrotational Stokes equation may exhibit, in any orthog... In the present manuscript, we formulate and prove rigorously, necessary and sufficient conditions for all kinds of separation of variables that a solution of the irrotational Stokes equation may exhibit, in any orthogonal axisymmetric system, namely: simple separation and R-separation. These conditions may serve as a road map for obtaining the corresponding solution space of the irrotational Stokes equation, in any orthogonal axisymmetric coordinate system. Additionally, we investigate how the inversion of the coordinate system, with respect to a sphere, affects the type of separation. Specifically, we prove that if the irrotational Stokes equation separates variables in an axisymmetric coordinate system, then it R-separates variables in the corresponding inverted coordinate system. This is a quite useful outcome since it allows the derivation of solutions for a problem, from the knowledge of the solution of the same problem in the inverted geometry and vice-versa. Furthermore, as an illustration, we derive the eigenfunctions of the irrotational Stokes equation governing the flow past oblate spheroid particles and inverted oblate spheroidal particles. 展开更多
关键词 Axisymmetric Flow Stokes Operator Analytical Solution Separation and R-Separation of Variables Axisymmetric Orthogonal Coordinate Systems
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Optimization and verification of free flight separation similarity law in high-speed wind tunnel 认领
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作者 Fei XUE Xin JIN +4 位作者 Peihua FENG Han QIN Zenghui JIANG Yuchao WANG Peng BAI 《中国航空学报:英文版》 SCIE EI CAS CSCD 2020年第2期501-507,共7页
Based on the similarity of separation time,a similarity law optimization method for high-speed weapon delivery test is derived.The typical separation state under wind load is simulated by the numerical method.The real... Based on the similarity of separation time,a similarity law optimization method for high-speed weapon delivery test is derived.The typical separation state under wind load is simulated by the numerical method.The real separation data of aircraft,separation data of previous test methods,separation data of ideal wind tunnel test of previous methods,and simulation data of the proposed optimization method are obtained.A comparison of the data shows that the method proposed can improve the performance of tracking.Similarity law optimization starts with the development of motion equations and dynamic equations in the windless state to address the problems of mismatching between vertical and horizontal displacement,and to address the problems of separation trajectory distortion caused by insufficient gravity acceleration of the scaling model of existing light model.The ejection velocity of the model is taken as a factor/vector,and is adjusted reasonably to compensate the linear displacement insufficiency caused by the insufficient vertical acceleration of the light model method,so as to ensure the matching of the vertical and horizontal displacement of the projectile,and to improve the consistency between the test results of high-speed projection and the actual separation trajectory.The optimized similarity law is applicable to many existing free-throwing modes of high-speed wind tunnels.The optimized similarity law is not affected by the ejection velocity and hanging mode of the projectile.The optimized similarity law is suitable not only for the launching of the buried ammunition compartment and external stores,but also for the test design of projectile launching and gravity separation. 展开更多
关键词 Carrier and MISSILE interference EJECTION SEPARATION Gravity SEPARATION High-speed WEAPON delivery Multi-body SEPARATION SIMILARITY law OPTIMIZATION
Developing a Novel Approach for Sludge Treatment Using Microwaves Technology 认领
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作者 David Yu Wendy Li 《地球科学和环境保护期刊(英文)》 2020年第5期195-203,共9页
The purpose of this research is to find a method that can improve the cost and efficiency of sludge treatment. Currently, large amounts of sludge are produced every day, but sludge treatment is neither efficient nor p... The purpose of this research is to find a method that can improve the cost and efficiency of sludge treatment. Currently, large amounts of sludge are produced every day, but sludge treatment is neither efficient nor profitable. To improve the sludge treatment process, we proposed the method of using microwave technology to treat sludge. We hypothesized that using microwave technology, we can reduce the volume of the sludge up to 90%, and can save more energy and time comparing to the traditional methods that we are currently using to treat the sludge. To prove our hypothesis, we designed an experiment to compare the solid-liquid boundary height and the solid-liquid mass ratio of the sludge treated by the conventional method and the microwave technology. Prime temperature and time found for dewatering sludge are 70 Celsius degrees and five minutes. The results were rather surprising, as microwave heating demonstrated no significant advantage over conventional heating. The solid-liquid boundary height of sludge heated by conventional and by microwave methods are 22.34 mL and 22.56 mL;the solid-liquid mass ratio of sludge using conventional heating and microwave heating at 70 Celsius degrees are 14.28% and 14.55% (by separation with filter press), or 9.82% and 9.89% (by centrifugation). In conclusion, the difference is negligible. 展开更多
关键词 MUNICIPAL SEWER SLUDGE SLUDGE DEWATERING Microwave Treatment INTRACELLULAR Water Thermal CONDITIONING Solid Liquid Separation
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Evaluation of Chromite Recovery from Shaking Table Tailings by Magnetic Separation Method 认领
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作者 Shayan Khakmardan Ramona Javadi Doodran +2 位作者 Adel Shirazy Aref Shirazi Ezatollah Mozaffari 《地质学期刊(英文)》 2020年第12期1153-1163,共11页
This study aimed to evaluate the chromite recovery from shaking table tailings of Forumad plant by a dry high-intensity magnetic separation. The average feed grade of chromium trioxide (Cr<sub>2</sub>O<... This study aimed to evaluate the chromite recovery from shaking table tailings of Forumad plant by a dry high-intensity magnetic separation. The average feed grade of chromium trioxide (Cr<sub>2</sub>O<sub>3</sub>) was 7.62% by XRF. Also, different mineral phases were determined by XRD, identifying the presence of Chrysotile, Augite, Albite, Chlorite and Chromite. Although the Forumad plant usually applies gravity methods utilizing the specific gravity difference between chromite and other gangue minerals, this study applied magnetic separation utilizing the paramagnetic nature of chromite crystals to recover chromite from tailings. 27 tests for 3 factors in 3 levels designed by the Taguchi method with design expert 12 software to determine the optimum conditions for the grade and recovery. Finally, the best condition was identified at 10,000 gauss (or 1 tesla) in the magnetic field intensity, 1 kg/min feeding rate, and 40 rpm drum rotating speed which produced a concentrate with 34.65% Cr<sub>2</sub>O<sub>3</sub> and 59.42% recovery. 展开更多
关键词 CHROMITE Magnetic Separation PARAMAGNETIC Tailing Recovery
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Separation of Molybdenum Isotopes at Supercritical Fluid Extraction with Carbon Dioxide in a Vertical Gradient Field of Temperatures 认领
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作者 Boris Viktorovich Borts Stella Fedorovna Skoromnaya Viktor Ivanovich Tkachenко 《金属学报(美国)》 2020年第1期1-15,共15页
Separation of molybdenum isotope complexes by supercritical fluid extraction (SFE) with carbon dioxide was studied experimentally. The extraction of molybdenum isotope complexes was carried out in the updated extracti... Separation of molybdenum isotope complexes by supercritical fluid extraction (SFE) with carbon dioxide was studied experimentally. The extraction of molybdenum isotope complexes was carried out in the updated extraction chamber (reactor) of the SFE-U installation, which provided an initial pressure of P ≤ 20 MPa at constant temperatures of the upper T1 = 35&deg;C and bottom T2 = 45&deg;C flanges. The device, through which the eluent was discharged, involved a set of four thin tubes of different lengths located inside the reactor. The axes of the tubes and the reactor are parallel and the tubes are equally spaced circumferentially inside the reactor. The extract was removed from each tube through channels isolated from each other and located in the bottom flange with cylindrical expansion, in which several layers of filter paper were placed. After passing through the filters the extract entered a restrictor designed to remove the eluent from the reactor. The initial pressure of carbon dioxide and the holding time of the extract were specified in the experiments. The level of the eluent sampling was set by the lengths of the tubes depending on the reactor height. A method of producing molybdenum complexes was described. It was experimentally shown that at an initial pressure of 20 MPa and a given holding time a difference from the natural content of Mo isotopes for given heights of extract sampling depending on the reactor height was observed in extracts removed through filters. The ranges of deviation of the content of molybdenum isotopes in extracts from natural one were determined. 展开更多
关键词 Carbon Dioxide SUPERCRITICAL Fluids Extraction MOLYBDENUM ISOTOPES SEPARATION
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